Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • 2010-2014  (24)
  • 2000-2004  (501)
  • 1890-1899  (2.322)
  • General Chemistry  (2.700)
  • MRI  (121)
  • ddc:510
Datenquelle
Materialart
Erscheinungszeitraum
Jahr
Schlagwörter
Sprache
  • 1
    facet.materialart.
    Unbekannt
    Supporting Global Numerical Optimization of Rational Functions by Generic Symbolic Convexity Tests (2010)
    Details
    Publikationsdatum: 2020-12-11
    Beschreibung: Convexity is an important property in nonlinear optimization since it allows to apply efficient local methods for finding global solutions. We propose to apply symbolic methods to prove or disprove convexity of rational functions over a polyhedral domain. Our algorithms reduce convexity questions to real quantifier elimination problems. Our methods are implemented and publicly available in the open source computer algebra system REDUCE. Our long term goal is to integrate REDUCE as a workhorse'' for symbolic computations into a numerical solver.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Format: application/postscript
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 2
    facet.materialart.
    Unbekannt
    Fault-Tolerant and Decentralized Lease Coordination in Distributed Systems (2010)
    Details
    Publikationsdatum: 2016-06-30
    Beschreibung: Applications which need exclusive access to a shared resource in distributed systems require a fault-tolerant and scalable mechanism to coordinate this exclusive access. Examples of such applications include distributed file systems and master/slave data replication. We present Flease, an algorithm for decentralized and fault-tolerant lease coordination in distributed systems. Our algorithm allows the processes competing for a resource to coordinate exclusive access through leases among themselves without a central component. The resulting system easily scales with an increasing number of nodes and resources. We prove that Flease ensures exclusive access, i.e. guarantees that there is at most one valid lease at any time.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 3
    facet.materialart.
    Unbekannt
    Robust Tail Assignment (2010)
    Details
    Publikationsdatum: 2020-08-05
    Beschreibung: We propose an efficient column generation method to minimize the probability of delay propagations along aircraft rotations. In this way, delay resistant schedules can be constructed. Computational results for large-scale real-world problems demonstrate substantial punctuality improvements. The method can be generalized to crew and integrated scheduling problems.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 4
    facet.materialart.
    Unbekannt
    State Trajectory Compression for Optimal Control with Parabolic PDEs (2010)
    Details
    Publikationsdatum: 2022-01-07
    Beschreibung: In optimal control problems with nonlinear time-dependent 3D PDEs, full 4D discretizations are usually prohibitive due to the storage requirement. For this reason gradient and quasi-Newton methods working on the reduced functional are often employed. The computation of the reduced gradient requires one solve of the state equation forward in time, and one backward solve of the adjoint equation. The state enters into the adjoint equation, again requiring the storage of a full 4D data set. We propose a lossy compression algorithm using an inexact but cheap predictor for the state data, with additional entropy coding of prediction errors. As the data is used inside a discretized, iterative algorithm, lossy coding maintaining an error bound is sufficient.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 5
    facet.materialart.
    Unbekannt
    A simple mathematical model of the bovine estrous cycle: follicle development and endocrine interactions (2010)
    Details
    Publikationsdatum: 2020-03-11
    Beschreibung: Bovine fertility is the subject of extensive research in animal sciences, especially because fertility of dairy cows has declined during the last decades. The regulation of estrus is controlled by the complex interplay of various organs and hormones. Mathematical modeling of the bovine estrous cycle could help in understanding the dynamics of this complex biological system. In this paper we present a mathematical model of the bovine estrous cycle that includes the processes of follicle and corpus luteum development and the key hormones that interact to control these processes. Focus in this paper is on development of the model, but also some simulation results are presented, showing that a set of equations and parameters is obtained that describes the system consistent with empirical knowledge. Even though the majority of the mechanisms that are included are only known qualitatively as stimulatory or inhibitory effects, the model surprisingly well features quantitative observations made in reality. This model of the bovine estrous cycle could be used as a basis for more elaborate models with the ability to study effects of external manipulations and genetic differences.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 6
    facet.materialart.
    Unbekannt
    Rapid Learning for Binary Programs (2010)
    Details
    Publikationsdatum: 2022-03-14
    Beschreibung: Learning during search allows solvers for discrete optimization problems to remember parts of the search that they have already performed and avoid revisiting redundant parts. Learning approaches pioneered by the SAT and CP communities have been successfully incorporated into the SCIP constraint integer programming platform. In this paper we show that performing a heuristic constraint programming search during root node processing of a binary program can rapidly learn useful nogoods, bound changes, primal solutions, and branching statistics that improve the remaining IP search.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Format: application/postscript
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 7
    facet.materialart.
    Unbekannt
    Models for Line Planning with Transfers (2010)
    Details
    Publikationsdatum: 2020-08-05
    Beschreibung: We propose a novel integer programming approach to transfer minimization for line planning problems in public transit. The idea is to incorporate penalties for transfers that are induced by “connection capacities” into the construction of the passenger paths. We show that such penalties can be dealt with by a combination of shortest and constrained shortest path algorithms such that the pricing problem for passenger paths can be solved efficiently. Connection capacity penalties (under)estimate the true transfer times. This error is, however, not a problem in practice. We show in a computational comparison with two standard models on a real-world scenario that our approach can be used to minimize passenger travel and transfer times for large-scale line planning problems with accurate results.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 8
    facet.materialart.
    Unbekannt
    Adaptive Timestep Control for the Contact-Stabilized Newmark Method (2010)
    Details
    Publikationsdatum: 2016-06-09
    Beschreibung: The aim of this paper is to devise an adaptive timestep control in the contact--stabilized Newmark method (CONTACX) for dynamical contact problems between two viscoelastic bodies in the framework of Signorini's condition. In order to construct a comparative scheme of higher order accuracy, we extend extrapolation techniques. This approach demands a subtle theoretical investigation of an asymptotic error expansion of the contact--stabilized Newmark scheme. On the basis of theoretical insight and numerical observations, we suggest an error estimator and a timestep selection which also cover the presence of contact. Finally, we give a numerical example.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 9
    facet.materialart.
    Unbekannt
    Railway capacity auctions with dual prices (2010)
    Details
    Publikationsdatum: 2020-08-05
    Beschreibung: Railway scheduling is based on the principle of the construction of a conflict-free timetable. This leads to a strict definition of capacity: in contrast with road transportation, it can be said in advance whether a given railway infrastructure can accommodate - at least in theory - a certain set of train requests. Consequently, auctions for railway capacity are modeled as auctions of discrete goods -- the train slots. We present estimates for the efficiency gain that may be generated by slot auctioning in comparison with list price allocation. We introduce a new class of allocation and auction problems, the feasible assignment problem, that is a proper generalization of the well-known combinatorial auction problem. The feasible assignment class was designed to cover the needs for an auction mechanism for railway slot auctions, but is of interest in its own right. As a practical instance to state and solve the railway slot allocation problem, we present an integer programming formulation, briefly the ACP, which turns out to be an instance of the feasible assignment problem and whose dual problem yields prices that can be applied to define a useful activity rule for the linearized version of the Ausubel Milgrom Proxy auction. We perform a simulation aiming to measure the impact on efficiency and convergence rate.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 10
    facet.materialart.
    Unbekannt
    Solving Optimal Control Problems with the Kaskade 7 Finite Element Toolbox (2010)
    Details
    Publikationsdatum: 2022-01-07
    Beschreibung: This paper presents concepts and implementation of the finite element toolbox Kaskade 7, a flexible C++ code for solving elliptic and parabolic PDE systems. Issues such as problem formulation, assembly and adaptivity are discussed at the example of optimal control problems. Trajectory compression for parabolic optimization problems is considered as a case study.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 11
    facet.materialart.
    Unbekannt
    Aggregation Methods for Railway Networks (2010)
    Details
    Publikationsdatum: 2020-08-05
    Beschreibung: In this paper a bottom-up approach of automatic simplification of a railway network is presented. Starting from a very detailed, microscopic level, as it is used in railway simulation, the network is transformed by an algorithm to a less detailed level (macroscopic network), that is sufficient for long-term planning and optimization. In addition running and headway times are rounded to a pre-chosen time discretization by a special cumulative method, which we will present and analyse in this paper. After the transformation we fill the network with given train requests to compute an optimal slot allocation. Then the optimized schedule is re-transformed into the microscopic level and can be simulated without any conflicts occuring between the slots. The algorithm is used to transform the network of the very dense Simplon corridor between Swiss and Italy. With our aggregation it is possible for the first time to generate a profit maximal and conflict free timetable for the corridor across a day by a simultaneously optimization run.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 12
    facet.materialart.
    Unbekannt
    Merging solutions of non-linear algebraic systems (2010)
    Details
    Publikationsdatum: 2020-12-11
    Beschreibung: In solving large polynomial algebraic systems that are too big for standard Gröbner basis techniques one way to make progress is to introduce case distinctions. This divide and conquer technique can be beneficial if the algorithms and computer programs know how to take advantage of inequalities. A further hurdle is the form of the resulting general solutions which often have unnecessarily many branches. In this paper we discuss a procedure to merge solutions by dropping inequalities which are associated with them and, if necessary, by re-parametrizing solutions. In the appendix the usefulness of the procedure is demonstrated in the classification of quadratic Hamiltonians with a Lie-Poisson bracket $e(3)$. This application required the solution of algebraic systems with over 200 unknowns, 450 equations and between 5000 and 9000 terms.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 13
    facet.materialart.
    Unbekannt
    A Dynamical Systems Approach for Static Evaluation in Go (2010)
    Details
    Publikationsdatum: 2020-12-11
    Beschreibung: In the paper arguments are given why the concept of static evaluation (SE) has the potential to be a useful extension to Monte Carlo tree search. A new concept of modeling SE through a dynamical system is introduced and strengths and weaknesses are discussed. The general suitability of this approach is demonstrated. A Remark: Among users of the Internet Go server KGS the abbreviation SE is used for 'Score Estimator'. Although different from 'Static Evaluation' a score estimator is easily obtained from static evaluation by adding up probabilities of chains to be alive at the end of the game or points to be owned by White or Black
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Format: application/postscript
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 14
    facet.materialart.
    Unbekannt
    Classification of integrable quadratic Hamiltonians on e(3) (2010)
    Details
    Publikationsdatum: 2020-12-11
    Beschreibung: Linear Poisson brackets on e(3) typical of rigid body dynamics are considered. All quadratic Hamiltonians of Kowalevski type having additional first integral of fourth degree are found. Quantum analogs of these Hamiltonians are listed.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Format: application/postscript
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 15
    facet.materialart.
    Unbekannt
    Classification of integrable super-systems using the SsTools environment (2010)
    Details
    Publikationsdatum: 2020-12-11
    Beschreibung: A classification problem is proposed for supersymmetric %scaling\/-\/in\-va\-ri\-ant evolutionary PDE that satisfy the assumptions of nonlinearity, nondegeneracy, and homogeneity. Four classes of nonlinear coupled boson\/-\/fermion systems are discovered under the weighting assumption $|f|=|b|=|D_t|=\oh$. The syntax of the \Reduce\ package \SsTools, which was used for intermediate computations, and the applicability of its procedures to the calculus of super\/-\/PDE are described.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Format: application/postscript
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 16
    facet.materialart.
    Unbekannt
    N=2 supersymmetric a=4-KdV hierarchy derived via Gardner's deformation of Kaup-Boussinesq equation (2010)
    Details
    Publikationsdatum: 2020-12-11
    Beschreibung: We consider the problem of constructing Gardner's deformations for the $N{=}2$ supersymmetric $a{=}4$--\/Korteweg\/--\/de Vries equation; such deformations yield recurrence relations between the super\/-\/Hamiltonians of the hierarchy. We prove the non\/-\/existence %P.~Mathieu's Open problem on constructing for of supersymmetry\/-\/invariant %Gardner's deformations that %solutions, retract to Gardner's formulas for the KdV equation %whenever it is assumed that, under the %respective component reduction. % in the $N{=}2$ super\/-\/field. the solutions . At the same time, we propose a two\/-\/step scheme for the recursive production of the integrals of motion for the $N{=}2$,\ $a{=}4$--\/SKdV. First, we find a new Gardner's deformation of the Kaup\/--\/Boussinesq equation, which is contained in the bosonic limit of the super\/-\/%$N{=}2$,\ $a{=}4$--\/SKdV hierarchy. This yields the recurrence relation between the Hamiltonians of the limit, whence we determine the bosonic super\/- /Hamiltonians of the full $N{=}2$, $a{=}4$--\/SKdV hierarchy.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Format: application/postscript
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 17
    facet.materialart.
    Unbekannt
    The Quickest Path to the Goal (2010)
    Details
    Publikationsdatum: 2020-08-05
    Beschreibung: We provide an introduction into the mathematics of and with paths. Not on the shortest, but hopefully on an entertaining path!
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 18
    facet.materialart.
    Unbekannt
    Linienoptimierung - reif für die Praxis? (2010)
    Details
    Publikationsdatum: 2020-08-05
    Beschreibung: Wir stellen in dieser Arbeit ein mathematisches Optimierungsmodell zur Bestimmung eines optimalen Linienplans vor, das sowohl die Fahrzeiten und die Anzahl der Umstiege berücksichtigt als auch die Kosten des Liniennetzes. Dieses Modell deckt wichtige praktische Anforderungen ab, die in einem gemeinsamen Projekt mit den Verkehrsbetrieben in Potsdam (ViP) formuliert wurden. In diesem Projekt wurde der Linienplan 2010 für Potsdam entwickelt. Unsere Berechnungen zeigen, dass die mathematische Optimierung in nichts einer "Handplanung" des Liniennetzes nachsteht. Im Gegenteil, mit Hilfe des Optimierungsprogramms ist es möglich, durch Veränderung der Parameter mehrere verschiedene Szenarien zu berechnen, miteinander zu vergleichen und Aussagen über minimale Kosten und Fahrzeiten zu machen.
    Schlagwort(e): ddc:510
    Sprache: Deutsch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Format: application/postscript
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 19
    facet.materialart.
    Unbekannt
    Positions in the Game of Go as Complex Systems (2010)
    Details
    Publikationsdatum: 2020-12-11
    Beschreibung: The paper gathers evidence showing different dimensions of the game of Go: the continuous and discrete nature of the game and different types of relations between state variables happening on ultra local, local, regional, and global scales. Based on these observations a new continuous local model for describing a board position is introduced. This includes the identification of the basic variables describing a board position and the formulation and solution of a dynamical system for their computation. To be usable as a static evaluation function for a game playing program at least group-wide (regional)aspects will have to be incorporated.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Format: application/postscript
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 20
    facet.materialart.
    Unbekannt
    Railway Track Allocation by Rapid Branching (2010)
    Details
    Publikationsdatum: 2020-08-05
    Beschreibung: The track allocation problem, also known as train routing problem or train timetabling problem, is to find a conflict-free set of train routes of maximum value in a railway network. Although it can be modeled as a standard path packing problem, instances of sizes relevant for real-world railway applications could not be solved up to now. We propose a rapid branching column generation approach that integrates the solution of the LP relaxation of a path coupling formulation of the problem with a special rounding heuristic. The approach is based on and exploits special properties of the bundle method for the approximate solution of convex piecewise linear functions. Computational results for difficult instances of the benchmark library TTPLIB are reported.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 21
    facet.materialart.
    Unbekannt
    Optimizing the Simplon Railway Corridor (2010)
    Details
    Publikationsdatum: 2020-08-05
    Beschreibung: This paper presents a case study on a railway timetable optimization for the very dense Simplon corridor, a major railway connection in the Alps between Switzerland and Italy. Starting from a detailed microscopic network as it is used in railway simulation, the data is transformed by an automatic procedure to a less detailed macroscopic network, that is sufficient for the purpose of capacity planning and amenable to state-of-the-art integer programming optimization methods. In this way, the macroscopic railway network is saturated with trains. Finally, the corresponding timetable is re-transformed to the microscopic level in such a way that it can be operated without any conflicts among the slots. Using this integer programming based micro-macro aggregation-disaggregation approach, it becomes for the first time possible to generate a profit maximal and conflict free timetable for the complete Simplon corridor over an entire day by a simultaneous optimization of all trains requests. This also allows to to undertake a sensitivity analysis of various problem parameters.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 22
    facet.materialart.
    Unbekannt
    Analysis of a multi-scale asymptotic model for internal gravity waves in a moist atmosphere (2010)
    Details
    Publikationsdatum: 2016-06-09
    Beschreibung: The thesis presents the analysis of a reduced model for modulation of internal gravity waves by deep convective clouds. The starting point for the derivation are conservation laws for mass, momentum and energy coupled with a bulk micro-physics model describing the evolution of mixing ratios of water vapor, cloud water and rain water. A reduced model for the identified scales of the regime is derived, using multi-scale asymptotics. The closure of the model employs conditional averaging over the horizontal scale of the convective clouds. The resulting reduced model is an extension of the anelastic equations, linearized around a constant background state, which are well-known from meteorology. The closure of the model is achieved purely by analytical means and involves no additional physically motivated assumptions. The essential new parameter arising from the coupling to a micro-physics model is the area fraction of saturated regions on the horizontal scale of the convective clouds. It turns out that this parameter is constant on the employed short timescale. Hence the clouds constitute a constant background, modulating the characteristics of propagation of internal waves. The model is then investigated by analytical as well as numerical means. Important results are, among others, that in the model moisture (i) inhibits propagation of internal waves by reducing the modulus of the group velocity, (ii) reduces the angle between the propagation direction of a wave-packet and the horizontal, (iii) causes critical layers and (iv) introduces a maximum horizontal wavelength beyond which waves are no longer propagating but become evanescent. The investigated examples of orographically generated gravity waves also feature a significant reduction of vertical momentum flux by moisture. The model is extended by assuming systematically small under-saturation, that is saturation at leading order. The closure is similar to the original case but requires additional assumptions. The saturated area fraction in the obtained model is no longer constant but now depends nonlinearly on vertical displacement and thus on vertical velocity.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: doctoralthesis , doc-type:doctoralThesis
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 23
    facet.materialart.
    Unbekannt
    A Constraint Integer Programming Approach for Resource-Constrained Project Scheduling (2010)
    Details
    Publikationsdatum: 2022-03-14
    Beschreibung: We propose a hybrid approach for solving the resource-constrained project scheduling problem which is an extremely hard to solve combinatorial optimization problem of practical relevance. Jobs have to be scheduled on (renewable) resources subject to precedence constraints such that the resource capacities are never exceeded and the latest completion time of all jobs is minimized. The problem has challenged researchers from different communities, such as integer programming (IP), constraint programming (CP), and satisfiability testing (SAT). Still, there are instances with 60 jobs which have not been solved for many years. The currently best known approach, lazyFD, is a hybrid between CP and SAT techniques. In this paper we propose an even stronger hybridization by integrating all the three areas, IP, CP, and SAT, into a single branch-and-bound scheme. We show that lower bounds from the linear relaxation of the IP formulation and conflict analysis are key ingredients for pruning the search tree. First computational experiments show very promising results. For five instances of the well-known PSPLIB we report an improvement of lower bounds. Our implementation is generic, thus it can be potentially applied to similar problems as well.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Format: application/postscript
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 24
    facet.materialart.
    Unbekannt
    Coupling Meshbased and Meshfree Methods by a Transfer Operator Approach (2010)
    Details
    Publikationsdatum: 2023-11-03
    Beschreibung: In contrast to the well known meshbased methods like the finite element method, meshfree methods do not rely on a mesh. However besides their great applicability, meshfree methods are rather time consuming. Thus, it seems favorable to combine both methods, by using meshfree methods only in a small part of the domain, where a mesh is disadvantageous, and a meshbased method for the rest of the domain. We motivate, that this coupling between the two simulation techniques can be considered as saddle point problem and show the stability of this coupling. Thereby a novel transfer operator is introduced, which interacts in the transition zone, where both methods coexist.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: reportzib , doc-type:preprint
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 25
    facet.materialart.
    Unbekannt
    Bad Guys are Rare: Probabilistic Analysis of an Elementary Dial-a-Ride Problem (2004)
    Details
    Publikationsdatum: 2020-08-05
    Beschreibung: This thesis deals with a Dial-a-Ride problem on trees and considers both offline and online versions of this problem. We study the behavior of certain algorithms on random instances, i.e. we do probabilistic analysis. The focus is on results describing the typical behavior of the algorithms, i.e. results holding with (asymptotically) high probability. For the offline version, we present a simplified proof of a result of Coja-Oghlan, Krumke und Nierhoff. The results states that some heuristic using a minimum spanning tree to approximate a Steiner tree gives optimal results with high probability. This explains why this heuristic produces optimal solutions quite often. In the second part, probabilistic online versions of the problem are introduced. We study the online strategies REPLAN and IGNORE. Regarding the IGNORE strategy we can show that it works almost optimal under high load with high probability.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: masterthesis , doc-type:masterThesis
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 26
    facet.materialart.
    Unbekannt
    Dynamical Configuration of Transparent Optical Telecommunication Networks (2003)
    Details
    Publikationsdatum: 2020-08-05
    Beschreibung: All-optical telecommunication networks allow for switching connections by lightpaths which can pass several network links without any opto-electronic conversion. Upon arrival of a connection request, it must be decided online, i.e., without knowledge of future requests, if it is accepted and in that case on which lightpaths the connection is routed. This online problem with the goal of maximizing the total profit gained by accepted requests is called Dynamic Singleclass Call Admission Problem (DSCA). We present existing and new algorithms for the DSCA as well as their theoretical and practical evaluation.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: masterthesis , doc-type:masterThesis
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 27
    facet.materialart.
    Unbekannt
    Adaptive Multilevel Cluster Analysis by Self-Organizing Box Maps (2002)
    Details
    Publikationsdatum: 2016-06-09
    Beschreibung: Als Cluster Analyse bezeichnet man den Prozess der Suche und Beschreibung von Gruppen (Clustern) von Objekten, so daß die Objekte innerhalb eines Clusters bezüglich eines gegebenen Maßes maximal homogen sind. Die Homogenität der Objekte hängt dabei direkt oder indirekt von den Ausprägungen ab, die sie für eine Anzahl festgelegter Attribute besitzen. Die Suche nach Clustern läßt sich somit als Optimierungsproblem auffassen, wobei die Anzahl der Cluster vorher bekannt sein muß. Wenn die Anzahl der Objekte und der Attribute groß ist, spricht man von komplexen, hoch-dimensionalen Cluster Problemen. In diesem Fall ist eine direkte Optimierung zu aufwendig, und man benötigt entweder heuristische Optimierungsverfahren oder Methoden zur Reduktion der Komplexität. In der Vergangenheit wurden in der Forschung fast ausschließlich Verfahren für geometrisch basierte Clusterprobleme entwickelt. Bei diesen Problemen lassen sich die Objekte als Punkte in einem von den Attributen aufgespannten metrischen Raum modellieren; das verwendete Homogenitätsmaß basiert auf der geometrischen Distanz der den Objekten zugeordneten Punkte. Insbesondere zur Bestimmung sogenannter metastabiler Cluster sind solche Verfahren aber offensichtlich nicht geeignet, da metastabile Cluster, die z.B. in der Konformationsanalyse von Biomolekülen von zentraler Bedeutung sind, nicht auf einer geometrischen, sondern einer dynamischen Ähnlichkeit beruhen. In der vorliegenden Arbeit wird ein allgemeines Clustermodell vorgeschlagen, das zur Modellierung geometrischer, wie auch dynamischer Clusterprobleme geeignet ist. Es wird eine Methode zur Komplexitätsreduktion von Clusterproblemen vorgestellt, die auf einer zuvor generierten Komprimierung der Objekte innerhalb des Datenraumes basiert. Dabei wird bewiesen, daß eine solche Reduktion die Clusterstruktur nicht zerstört, wenn die Komprimierung fein genug ist. Mittels selbstorganisierter neuronaler Netze lassen sich geeignete Komprimierungen berechnen. Um eine signifikante Komplexitätsreduktion ohne Zerstörung der Clusterstruktur zu erzielen, werden die genannten Methoden in ein mehrstufiges Verfahren eingebettet. Da neben der Identifizierung der Cluster auch deren effiziente Beschreibung notwendig ist, wird ferner eine spezielle Art der Komprimierung vorgestellt, der eine Boxdiskretisierung des Datenraumes zugrunde liegt. Diese ermöglicht die einfache Generierung von regelbasierten Clusterbeschreibungen. Für einen speziellen Typ von Homogenitätsfunktionen, die eine stochastische Eigenschaft besitzen, wird das mehrstufige Clusterverfahren um eine Perroncluster Analyse erweitert. Dadurch wird die Anzahl der Cluster, im Gegensatz zu herkömmlichen Verfahren, nicht mehr als Eingabeparameter benötigt. Mit dem entwickelten Clusterverfahren kann erstmalig eine computergestützte Konformationsanalyse großer, für die Praxis relevanter Biomoleküle durchgeführt werden. Am Beispiel des HIV Protease Inhibitors VX-478 wird dies detailliert beschrieben.
    Schlagwort(e): ddc:510
    Sprache: Englisch
    Materialart: doctoralthesis , doc-type:doctoralThesis
    Format: application/pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 28
    Digitale Medien
    Digitale Medien
    Bone marrow response in treated patients with Gaucher disease: evaluation by T1-weighted magnetic resonance images and correlation with reduction in liver and spleen volume (2000)
    Springer
    Skeletal radiology 29 (2000), S. 563-571 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Keywords Gaucher disease ; MRI ; Enzyme replacement therapy ; Liver ; Spleen ; Bone marrow
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Purpose. To determine whether T1-weighted magnetic resonance (MR) images can demonstrate response in the marrow of patients with type 1 Gaucher disease treated with enzyme replacement therapy (ERT) and to determine whether a relationship exists between liver and spleen volume reductions and visible marrow changes. Patients. Forty-two patients with type 1 Gaucher disease were evaluated on at least two occasions. Thirty-two patients received ERT. Of these patients, 15 had a baseline examination prior to the initiation of ERT. The remaining 10 patients did not receive ERT. Design. T1-weighted and gradient recalled echo (GRE) coronal images of the femurs and hips were obtained. Concurrently, liver and spleen volumes were determined using contiguous breath-hold axial gradient-echo images. T1-weighted images of the hips and femurs were evaluated to determine change or lack of change in the yellow marrow. Results. Of the 32 patients receiving ERT, 14 (44%) demonstrated increased signal on T1-weighted images suggesting an increase in the amount of yellow marrow. If only the 15 patients with a baseline examination were considered, the response rate to ERT was 67%. Using Student’s t-test a highly significant correlation (P〈0.005) was found between marrow response and reduction in liver and spleen volume. Conclusions. Marrow changes in patients receiving ERT can be detected by T1-weighted images. This response correlated with reductions in visceral volumes (P〈0.0005).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000276
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 29
    Digitale Medien
    Digitale Medien
    MR arthrography of the shoulder and hip after fluoroscopic landmarking (2000)
    Springer
    Skeletal radiology 29 (2000), S. 81-84 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Arthrography ; MRI ; Fluoroscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Purpose. To describe a technique for intra-articular injection in the MR suite after conventional fluoroscopic landmarking in order to streamline MR arthrography. Design and patients. This technique was performed on 33 consecutive patients referred for MR arthrography of the shoulder to evaluate the glenoid labrum and on 15 consecutive patients referred for MR arthrography of the hip to evaluate the acetabular labrum. The patients were landmarked in the fluoroscopy suite, followed by a conventional MR examination. The intra-articular injection was then performed on the MR table and the MR arthrographic sequences obtained. Results. One of the 48 injections was extra-articular, requiring a second injection. The other injections were performed without incident, and the average total procedure time for all injections was 10 min. Conclusions. This technique is a reliable method of streamlining intra-articular injections when performing conventional MR imaging prior to the MR arthrographic portion of the examination. It shortens the total MR examination time by eliminating a visit to the fluoroscopy suite in the middle of the MR study, and its use of a straight anterior approach for both the shoulder and hip joints should be familiar to most people who perform conventional arthrography.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050014
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 30
    Digitale Medien
    Digitale Medien
    Elastofibroma of the neck (2000)
    Springer
    Skeletal radiology 29 (2000), S. 109-111 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Fat ; Elastofibroma ; Neck ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Elastofibromas are benign lesions of the chest wall. We describe the first reported case of elastofibroma in the neck. Imaging features as well as location of the lesion were atypical. On computed tomography and magnetic resonance imaging the lesion contained a marked preponderance of fat, because the lesion arose within fat.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050021
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 31
    Digitale Medien
    Digitale Medien
    Oncogenic osteomalacia (2000)
    Springer
    Skeletal radiology 29 (2000), S. 117-124 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Osteomalacia ; Metabolic disease ; Hemangiopericytoma ; Fibrohistiocytic tumors ; Radiography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The clinical, imaging, metabolic, histologic and biochemical aspects of oncogenic osteomalacia are reviewed. The bone and soft tissue tumor and tumor-like lesions associated with this paraneoplastic syndrome are discussed. The radiologist’s role in the diagnosis and evaluation of this entity is presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050581
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 32
    Digitale Medien
    Digitale Medien
    Giant distal humeral geode (2000)
    Springer
    Skeletal radiology 29 (2000), S. 165-167 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Rheumatoid arthritis ; Geode ; Pathological fracture ; Humerus ; X-ray ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We describe the imaging features of a giant geode of the distal humerus in a patient with rheumatoid arthritis, which presented initially as a pathological fracture. The value of magnetic resonance imaging in establishing this diagnosis is emphasized.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050587
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 33
    Digitale Medien
    Digitale Medien
    Retroisthmic cleft: a stress fracture of the lamina (2000)
    Springer
    Skeletal radiology 29 (2000), S. 162-164 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Retroisthmic cleft ; Stress fracture ; Laminar fracture ; Xray ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The retroisthmic cleft is a rarely diagnosed defect in the lamina of the lumbar spine. It has always been considered a congenital anomaly. This is the first report we are aware of showing radiological changes in a retroisthmic cleft over a period of time. The follow-up of this patient over a period of 6 years, the radiological and scintigraphic appearances and a review of the literature suggests that the retroisthmic cleft is a stress fracture of the lamina.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050586
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 34
    Digitale Medien
    Digitale Medien
    Unsuspected metastases presenting as solitary soft tissue lesions: a fourteen-year review (2000)
    Springer
    Skeletal radiology 29 (2000), S. 270-274 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Soft tissue neoplasm ; Metastasis ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. To describe a series of patients with no known primary malignancy who presented with a solitary unsuspected soft tissue metastasis masquerading as a soft tissue sarcoma, and secondarily to describe the imaging appearance of these lesions. Design. Records of two academic hospitals with active orthopedic oncology services were reviewed for patients meeting the above criteria. Clinical charts were examined, and the imaging appearance of the soft tissue lesions retrospectively reviewed. Patients. Of 1421 patients examined for soft tissue lesions, 11 were found who met the above criteria. Results. Of the 11 patients whose initial presentation was a solitary soft tissue metastasis, eight were found to have a primary lung cancer, two were diagnosed with adenocarcinoma of unknown primary, and adenocarcinoma of the colon was discovered in the remaining patient. Conclusions. The clinical presentation of a solitary soft tissue metastasis without a known primary malignancy is a rare occurrence, with an incidence of approximately 0.8%. Lung cancer is the primary neoplasm in a high percentage of these cases.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050606
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 35
    Digitale Medien
    Digitale Medien
    MR imaging of clear cell sarcoma (malignant melanoma of the soft parts): a multicenter correlative MRI-pathology study of 21 cases and literature review (2000)
    Springer
    Skeletal radiology 29 (2000), S. 187-195 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Clear cell sarcoma ; Malignant melanoma of soft parts ; MRI ; Magnetic resonance ; Neoplasm
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. To evaluate MR imaging and pathology findings in order to define the characteristic features of clear cell sarcoma of the soft tissues (malignant melanoma of the soft parts). Design and patients. MR examinations of 21 patients with histologically proven clear cell sarcoma of the musculoskeletal system were retrospectively reviewed and assessed for shape, homogeneity, delineation, signal intensities on T1- and T2-weighted images, contrast enhancement, relationship with adjacent fascia or tendon, secondary bone involvement, and intratumoral necrosis. In 19 cases the pathology findings were available for review and for a comparative MR-pathology study. Results. On T1-weighted images, lesions were isointense (n=3), hypointense (n=7) or slightly hyperintense to muscle (n=11). Immunohistochemical examination was performed in 17 patients. All 17 specimens showed positivity for HMB-45 antibody. In nine of 11 lesions with slightly increased signal intensity on T1-weighted images, a correlative MR imaging-pathology study was possible. All nine were positive to HMB-45 antibody. Conclusions. Clear cell sarcoma of the musculoskeletal system often has a benign-looking appearance on MR images. In up to 52% of patients, this lesion with melanocytic differentiation has slightly increased signal intensity on T1-weighted images compared with muscle. As the presence of this relative higher signal intensity on T1-weighted images is rather specific for tumors displaying melanocytic differentiation, radiologists should familiarize themselves with this rare entity and include it in their differential diagnosis when confronted with a well-defined, homogeneous, strongly enhancing mass with slightly higher signal intensity compared with muscle on native T1-weighted images.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050592
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 36
    Digitale Medien
    Digitale Medien
    Erdheim-Chester disease with intramuscular lipogranuloma (2000)
    Springer
    Skeletal radiology 29 (2000), S. 227-230 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Erdheim-Chester Disease ; Lipogranuloma ; MRI ; Muscle ; Rectus femoris
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report on a rare manifestation of Erdheim-Chester disease with intramuscular lipogranuloma. The patient was a 66-year-old man who noted a soft tissue mass in the right quadriceps femoris muscle. Radiographs revealed symmetrical osteosclerosis in the diametaphysis of both femora and tibiae. An open biopsy revealed a proliferation of lipid-laden histiocytes in the femoral bone marrow and the quadriceps femoris muscle. To our knowledge, this is the second case of Erdheim-Chester disease involving muscle.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050598
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 37
    Digitale Medien
    Digitale Medien
    MR appearances in a case of femoral ecchinococcosis (2000)
    Springer
    Skeletal radiology 29 (2000), S. 235-238 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Femur echinococcosis ; MRI ; echinococcosis ; Hydatid cyst surgery ; Hydatid cyst ; anticestodal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Magnetic resonance (MR) findings of a rare case of osseous echinococcosis with involvement of the femur are described. Attention is drawn to the typical MR appearances and therapeutic management.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050600
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 38
    Digitale Medien
    Digitale Medien
    Congenital transverse deficiency of the tibia and fibula: a report of two cases (2000)
    Springer
    Skeletal radiology 29 (2000), S. 243-246 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Tibial deficiency ; Fibular deficiency ; Congenital hip dislocation ; Transverse limb deficiency ; X-ray ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report two similar, but unrelated, patients with congenital bilateral partial deficiencies of the tibia and fibula associated with intact feet. In both patients, the tibia and fibula were absent on initial radiographs, while the femur and the tarsal bones were well developed and there was bilateral teratologic dislocation of the hips. Ultrasound and magnetic resonance imaging (MRI) studies suggested the presence of cartilaginous remnants of the tibia and fibula. There were multidirectional instabilities in the knees and ankles. The clinical and radiological features of these cases are distinct from those of congenital longitudinal deficiency of the tibia, in which the fibula is always preserved, and from longitudinal deficiency of the fibula, in which the tibia is present and the foot is usually involved. We suggest that the bilateral partial deficiencies of the tibia and fibula associated with the intact foot and teratologic dislocation of the hips is a single-entity disorder, possibly categorized as an intercalary transverse deficiency of the lower limb.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050602
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 39
    Digitale Medien
    Digitale Medien
    The magnetic resonance imaging of musculoskeletal hemorrhage (2000)
    Springer
    Skeletal radiology 29 (2000), S. 1-9 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Soft tissue masses ; Hemorrhage ; MRI ; Iron ; Contrast enhancement, MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Hematomas in the extremities can present clinically as a soft tissue mass. Hematomas can usually be distinguished from neoplasia on MR by the signal patterns of hemoglobin breakdown products, which are dependent on the chemical bonding and oxidation state of hemoglobin iron. Beginning with a discussion of relevant atomic electronic structure, this review will examine how oxyhemoglobin, deoxyhemoglobin, methemoglobin, and hemosiderin, the principal iron compounds occurring in the various stages of a hematoma, affect its appearance on MRI.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050001
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 40
    Digitale Medien
    Digitale Medien
    Indirect wrist MR arthrography: the effects of passive motion versus active exercise (2000)
    Springer
    Skeletal radiology 29 (2000), S. 10-14 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Wrist ; MR arthrography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Purpose.In the wrist, to determine whether passive motion or active exercise yields a better indirect MR arthrographic effect following intravenous gadolinium administration. Design and patients. Twenty-six consecutive patients were studied by indirect wrist MR arthrography. In half active exercise and in half passive motion was performed. Four regions of interest were studied including the distal radioulnar joint, the radiocarpal joint, the midcarpal joint, and the triangular fibrocartilage. Ranges and means of signal intensity were calculated. Surgical follow-up was performed in 22 patients. Results. The joint fluid intensity was greatest in the distal radioulnar joint. Fluid signal intensity was greater and more consistent in the passive motion group although the results did not achieve statistical significance. Imaging accuracy appeared similar in the two groups and was excellent for the triangular fibrocartilage (100%) and scapholunate ligaments (96%). Conclusion. Active exercise and passive motion yield similar degrees of wrist arthrographic effect, but the effect of passive motion is somewhat more consistent. Preliminary data show good accuracy for internal derangements.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050002
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 41
    Digitale Medien
    Digitale Medien
    Type I Gaucher disease: extraosseous extension of skeletal disease (2000)
    Springer
    Skeletal radiology 29 (2000), S. 15-21 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Gaucher disease ; Bone disease ; Extraosseous Gaucher disease ; Bone marrow imaging ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. To investigate the frequency and morphology of extraosseous extension in patients with Gaucher disease type I. Design and patients. MRI examinations of the lower extremities were analyzed in 70 patients with Gaucher disease type I. Additionally, the thoracic spine and the midface were investigated on MRI in two patients. Results. Four cases are presented in which patients with Gaucher disease type I and severe skeletal involvement developed destruction or protrusion of the cortex with extraosseous extension into soft tissues. In one patient, Gaucher cell deposits destroyed the cortex of the mandible and extended into the masseter muscle. In the second patient, multiple paravertebral masses with localized destruction of the cortex were apparent in the thoracic spine. In the third and fourth patient, cortical destruction with extraosseous tissue extending into soft tissues was seen in the lower limbs. Conclusions. Extraosseous extension is a rare manifestation of Gaucher bone disease. While an increased risk of cancer, especially hematopoietic in origin, is known in patients with Gaucher disease, these extraosseous benign manifestations that may mimic malignant processes should be considered in the differential diagnosis of extraosseous extension into soft tissues. A narrow neck of tissue was apparent in all cases connecting bone and extraosseous extensions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050003
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 42
    Digitale Medien
    Digitale Medien
    Subchondral insufficiency fracture of the femoral head and medial femoral condyle (2000)
    Springer
    Skeletal radiology 29 (2000), S. 40-44 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Subchondral insufficiency fracture ; Femoral head ; Medial femoral condyle ; Osteonecrosis ; MRI ; X-ray
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  This case report documents the clinical, radiographic, and histologic findings in a 69-year-old obese man, who had subchondral insufficiency fracture both in the femoral head and medial femoral condyle. On plain radiographs, both lesions underwent subchondral collapse. Magnetic resonance images of the left hip showed a bone marrow edema pattern with associated low-intensity band on T1-weighted images, which was convex to the articular surface. The histopathologic findings in the hip and knee were characterized by the presence of a subchondral fracture with associated callus and granulation tissue along both sides of a fracture line. There was no evidence of antecedent osteonecrosis. To our knowledge, this is the first case report to describe the multiple occurrence of collapsed subchondral insufficiency fracture.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050007
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 43
    Digitale Medien
    Digitale Medien
    Cystic fibrous dysplasia mimicking giant cell tumor: MRI appearance (2000)
    Springer
    Skeletal radiology 29 (2000), S. 45-48 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Cystic fibrous dysplasia ; Giant cell tumor ; Femur ; X-ray ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report the case of a 43-year-old man who presented with an osteolytic and expansive lesion in the left distal femur mimicking a giant cell tumor. Magnetic resonance imaging (MRI) showed that most of the lesion was cystic, and histological examination revealed fibrous dysplasia with marked cystic degeneration. Radiographic findings of cystic fibrous dysplasia in the end of a long bone may be similar to those of a giant cell tumor, and a biopsy is essential for the final diagnosis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050008
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 44
    Digitale Medien
    Digitale Medien
    Primary hemangiopericytoma of the tibia: MR and angiographic correlation (2000)
    Springer
    Skeletal radiology 29 (2000), S. 49-53 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Hemangiopericytoma ; Tibia ; MRI ; Angiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The Magnetic Resonance Imaging (MRI) appearances of primary osseous hemangiopericytoma (HPC) have been rarely described. We report on a 46-year-old Chinese man with primary osseous HPC of the right tibia. The characteristic vascular distribution of this tumor, presenting with a ”spoke-wheel” appearance on MR images and with angiographic correlation, is described. Although not pathognomonic, this MR appearance may be an important finding in suggesting the diagnosis of osseous HPC.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050009
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 45
    Digitale Medien
    Digitale Medien
    Diffusion-weighted imaging of the musculoskeletal system in humans (2000)
    Springer
    Skeletal radiology 29 (2000), S. 555-562 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Keywords Diffusion ; MRI ; Skeletal system ; Spine ; neoplasms
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  This article reviews the principles of diffusion-weighted imaging (DWI) and recent results in DWI of the musculoskeletal system. The potential of DWI in the diagnosis of pathology of the musculoskeletal system is discussed. DWI is a relatively new MR imaging technique that has already been established in neuroradiology, especially in the early detection of brain ischemia. The random motion of water protons on a molecular basis can be measured with DWI. To date DWI of the abdomen and of the musculoskeletal system has only been employed in scientific studies, but first results indicate that it may also be beneficial in these fields. Different diffusion characteristics have been found in normal tissues such as muscle, fat and bone marrow. Also, pathologic entities such as neoplasms, post-therapeutic soft tissue changes and inflammatory processes can be differentiated. Normal muscle shows significantly higher diffusion values than subcutaneous fat and bone marrow, due to a higher mobility of water protons within muscle. Soft tissue tumors exhibit a significantly lower diffusion value compared with post-therapeutic soft tissue changes and inflammatory processes. Necrotic tumor tissue can be distinguished from viable tumor due to significantly higher diffusion of water protons within necrotic tissue.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000243
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 46
    Digitale Medien
    Digitale Medien
    Telangiectatic dedifferentiation of a parosteal osteosarcoma (2000)
    Springer
    Skeletal radiology 29 (2000), S. 597-600 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Keywords Parosteal osteosarcoma ; Telangiectatic osteosarcoma ; Dedifferentiation ; Femur ; Radiography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A unique case of parosteal osteosarcoma (POS) of the proximal femur, with areas of telangiectatic dedifferentiation, in a 28-year-old woman is reported. The patient had a 7-week history of pain and swelling in her right thigh. A biopsy diagnosis of POS was established. The patient was treated with two cycles of intra-arterial chemotherapy, followed by limb salvage surgery. Histological examination of the resected specimen showed POS with areas of dedifferentiation composed of high-grade telangiectatic osteosarcoma with associated secondary aneurysmal bone cyst change.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000247
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 47
    Digitale Medien
    Digitale Medien
    Malignant round cell tumours of bone: atypical clinical and imaging features (2000)
    Springer
    Skeletal radiology 29 (2000), S. 646-651 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Keywords Ewing sarcoma ; Primitive neuroectodermal tumour ; Radiography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective.To describe the clinical, radiological and MRI features of six atypical cases of histologically proven appendicular Ewing sarcoma/ primitive neuroectodermal tumour (PNET). Design. Retrospective review of case notes and available imaging was carried out. Patients. Six patients (4 male, 2 female; mean age 27years, range 19–44 years), presenting over a 77-month period, were identified from the Bone Tumour Register. All had unusual clinical and imaging features for Ewing sarcoma/PNET. Results and conclusions. Four tumours were centred on the distal femoral metaphysis, one in the proximal tibial metaphysis and one in the distal tibial metaphysis. Plain radiographs were available in four cases and showed minor cortical changes. MRI demonstrated a relatively small, eccentrically located intraosseous component with a large, eccentric extraosseous component. Extension into the epiphysis was seen in three cases and into the adjacent joint in two cases. Intraosseous ”skip” metastases were present in three cases. The clinical and imaging features were atypical for conventional intraosseous Ewing sarcoma/PNET and the exact site of origin (intraosseous, periosteal or soft-tissue) was unclear.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000277
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 48
    Digitale Medien
    Digitale Medien
    Osteoblastoma-like osteosarcoma (2000)
    Springer
    Skeletal radiology 29 (2000), S. 656-659 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Keywords Osteoblastoma-like osteosarcoma ; Osteosarcoma ; Aggressive osteoblastoma ; Fibula ; Radiography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report an osteoblastoma-like osteosarcoma in the right proximal fibula in a 22-year-old woman. Radiographs showed an irregular osteolytic lesion from the metaphysis to the epiphysis in the proximal fibula with partial destruction of cortical bone. Tissue from a biopsy indicated a typical osteoblastoma. Curettage and bone graft was performed. One year after the surgery, local recurrence occurred, and a wide excision was performed. Histological examination of the en-bloc surgical specimen revealed the tumor had permeated through the host bony trabeculae, although the nuclear atypia was not marked. Immunohistochemical expression of MIB-1 was detected in 9.0% of cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000271
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 49
    Digitale Medien
    Digitale Medien
    Tunneling Schmorl’s nodes in an elderly woman treated for acute lymphoblastic leukemia (2000)
    Springer
    Skeletal radiology 29 (2000), S. 660-663 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Keywords Acute lymphoblastic leukemia ; Chemotherapy ; Spine ; Tunneling Schmorl’s nodes ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We present a 70-year-old woman with pre-B acute lymphoblastic leukemia in whom serial imaging studies showed the development of multiple vertebral collapse, and communicating superior and inferior Schmorl’s nodes creating a longitudinal channel (”tunneling” Schmorl’s nodes) through the anterior aspect of T12 to L3 vertebral bodies of her osteoporotic thoracolumbar spine. This was observed after achieving complete remission of the disease and during maintenance therapy. The finding is felt to be secondary to iatrogenic exacerbation of osteoporosis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000272
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 50
    Digitale Medien
    Digitale Medien
    Mid-foot reconstruction following involvement of five bones by giant cell tumor (2000)
    Springer
    Skeletal radiology 29 (2000), S. 664-667 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Keywords Giant cell tumor ; Multiple mid-foot bones ; Reconstructive surgery ; Radiography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report on a patient who had giant cell tumor involving multiple bones of the mid-foot. The tumor originated from the navicular bone, but also destroyed the cuboid, and all cuneiform bones. This unusual presentation of giant cell tumor presented a therapeutic challenge for the surgeons. The patient was treated with en bloc resection and the bony defect replaced with a massive iliac crest graft which united within 9 months and has remained stable for 7 years without local recurrence, and with excellent function of the foot.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000274
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 51
    Digitale Medien
    Digitale Medien
    Popliteal amyloidoma presenting with leg ischemia in a chronic dialysis patient (2000)
    Springer
    Skeletal radiology 29 (2000), S. 717-720 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Keywords Amyloidoma ; Bilateral ; Knee ; Popliteal fossa ; Claudication ; MRI ; MR angiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The authors report a case of bilateral popliteal amyloidoma causing stenosis of the popliteal artery and vein. This patient had been treated with hemodialysis for 26 years. The diagnosis was made with MR angiography. A popliteal tumor of the right knee was resected surgically and the histologic examination showed deposition of amyloid. After resecting the popliteal tumor, the severe leg pain and intermittent claudication improved. This report suggests that popliteal amyloid tumors should be considered in a patient undergoing long-term hemodialysis who complains of leg pain and intermittent claudication.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000282
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 52
    Digitale Medien
    Digitale Medien
    Sarcomatoid chordoma: chordoma with a massive malignant spindle-cell component (2000)
    Springer
    Skeletal radiology 29 (2000), S. 721-725 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Chordoma ; Sarcomatoid chordoma ; Transitional feature ; Sacrum ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report a case of chordoma containing a spindle cell sarcomatoid component with a gradual transition from conventional chordoma. Immunohistochemically, many tumor cells in both conventional chordoma and sarcomatoid components were positive for cytokeratins (AE1/AE3, CAM5.2) and epithelial membrane antigen as well as vimentin. This report provides a rare example of sarcomatoid chordoma. Familiarity with this type of bone tumor should help to avoid confusion with dedifferentiated chordoma and other spindle cell sarcomas or carcinomas.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000264
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 53
    Digitale Medien
    Digitale Medien
    Intra-articular regional migratory osteoporosis of the knee (2000)
    Springer
    Skeletal radiology 29 (2000), S. 97-100 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Transient osteoporosis ; Transient bone marrow edema ; Intra-articular regional migratory osteoporosis ; Knee ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report a case of lntra-articular regional migratory osteoporosis of the knee in a 53-year-old man. The case demonstrates an unusual pattern of migration of the marrow edema within the knee joint. This phenomenon has received scant attention in the radiological literature.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050018
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 54
    Digitale Medien
    Digitale Medien
    Desmoplastic fibroma of bone: MRI features (2000)
    Springer
    Skeletal radiology 29 (2000), S. 171-175 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Desmoplastic fibroma ; Bone tumor ; Femur ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Desmoplastic fibroma of bone is a very rare benign tumor, which may be locally aggressive. In contrast to the well-documented radiological appearance, the literature on MR imaging features of this tumor is scarce. The MR imaging characteristics in our case are compared to those previously reported. Although there is a considerable overlap in the MR imaging features with other bone tumors, an interesting MR feature of desmoplastic fibroma is the presence of low to intermediate signal intensity foci on T2-weighted images, which radiographically does not correspond to calcifications. This feature may help narrow the differential diagnosis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050589
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 55
    Digitale Medien
    Digitale Medien
    Chondromyxoid fibroma of the acromium with soft tissue extension (2000)
    Springer
    Skeletal radiology 29 (2000), S. 168-170 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Chondromyxoid fibroma ; Acromium ; Soft tissue extension ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Chondromyxoid fibroma is an unusual, benign tumor of cartilaginous origin and represents less than 1% of all primary bone tumors. It usually involves the long bones around the knee joint or the flat bones of the pelvis or ribs. Soft tissue extension is also thought to be rare in these lesions. They are usually eccentrically located in the metaphyses of the long bones and centrally in the flat bones. The radiographic appearances are characteristically those of a single, lytic lesion with lobulated margins, septations, cortical expansion and a sclerotic rim. Histologically, they display a lobulated pattern with spindle-shaped cells lying within a myxoid matrix with areas of hyaline cartilage. The differential diagnosis includes giant cell tumor, chondroblastoma or enchondroma as well as chondrosarcoma. The rarity of these lesions may render the diagnosis difficult to make, especially when the lesion involves an unusual site such as the acromium.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050588
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 56
    Digitale Medien
    Digitale Medien
    Intraosseous schwannoma of the metacarpal (2000)
    Springer
    Skeletal radiology 29 (2000), S. 224-226 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Intraosseous neurilemmoma (schwannoma) ; Primary bone neoplasm ; Metacarpal ; X-ray ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Intraosseous schwannoma (neurilemmoma) is an extremely rare, benign neoplasm, constituting less than 0.2% of primary bone tumors. It infrequently involves the bones of the hand. We present a case of intraosseous neurilemmoma of the metacarpal.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050597
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 57
    Digitale Medien
    Digitale Medien
    Hemangioma of bone arising in the ulna: imaging findings with emphasis on MR (2000)
    Springer
    Skeletal radiology 29 (2000), S. 231-234 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Hemangioma ; Ulna ; CT ; MRI ; X-ray
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  An 18-year-old woman presented with left elbow joint pain. Radiographs and computed tomographic scan showed a well-defined osteolytic lesion of the left ulna associated with a honeycomb appearance on the radiographs. Magnetic resonance images showed intermediate signal intensity on T1-weighted images and mixed intermediate and high signal intensities on T2-weighted images. Only the periphery of the lesion enhanced with intravenously injected gadolinium-diethylenetriamine pentaacetic acid. The lesion was curetted to avoid pathologic fracture, and a histologic diagnosis of cavernous hemangioma of bone was made. Hemangioma involving the ulna is rare, but should be included in the differential diagnosis of a radiographic osteolytic lesion with a honeycomb appearance.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050599
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 58
    Digitale Medien
    Digitale Medien
    Angiomyolipoma arising in the thigh (2000)
    Springer
    Skeletal radiology 29 (2000), S. 293-297 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Angiomyolipoma (AML) ; Soft tissue ; Thigh ; MRI ; CT ; Angiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A 41-year-old man presented with an asymptomatic mass in the right medial thigh. Magnetic resonance imaging (MRI) revealed a well-demarcated, 10-cm mass in the right adductor muscles. The margins of the mass exhibited high signal intensity and the rest showed low or iso signal intensity on T1-weighted MR images. However, the high signal intensity was decreased on T2-weighted images with fat suppression. The central part of the tumor was of inhomogeneous high signal intensity on T2-weighted images; after Gd-DTPA injection it enhanced inhomogeneously on T1-weighted images with fat suppression. On dynamic computed tomography (CT) in the arterial phase, there were strongly enhancing spotty areas in the tumor. At surgery, a yellow-whitish tumor was resected and a pathological diagnosis of angiomyolipoma (AML) in the thigh was made.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050612
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 59
    Digitale Medien
    Digitale Medien
    Bilateral metachronous periosteal tibial amyloid tumors (2000)
    Springer
    Skeletal radiology 29 (2000), S. 346-348 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Amyloid tumor ; Tibia ; Periosteum ; Bilateral ; MRI ; Bilateral metachronous periosteal tibial amyloid tumors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Localized primary periosteal amyloid tumors are extremely rare. A case of bilateral tibial amyloid tumor is presented. A 62-year-old woman initially presented with a painful mass in the anterior aspect of the right leg. There was no evidence of underlying systemic disease, including chronic infection or malignancy. Based on the results of resistance with Congo red staining to treatment with potassium permanganate and positivity for kappa light chain, we classified this particular case as AL-type amyloidosis. The patient noticed a swelling in the opposite leg 2 years later. The second tumor was also an AL-type amyloidoma. Amyloid tumors are generally solitary. This is the first case of bilateral periosteal amyloid tumors of the AL-type occurring in the tibiae.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000215
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 60
    Digitale Medien
    Digitale Medien
    Sonographic evaluation of digital annular pulley tears (2000)
    Springer
    Skeletal radiology 29 (2000), S. 387-391 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Trauma ; Hand ; Sonography ; Ultrasound ; Annular pulleys ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. To evaluate the sonographic (US) appearance of digital annular pulley (DAP) tears in high-level rock climbers. Design and patients. We performed a retrospective analysis of the US examinations of 16 high-level rock climbers with clinical signs of DAP lesions. MRI and surgical evaluation were performed in five and three patients respectively. The normal US and MRI appearances of DAP were evaluated in 40 and three normal fingers respectively. Results. Nine of 16 patients presented a DAP tear. In eight subjects (seven with complete tears involving the fourth finger and one the fifth finger), US diagnosis was based on the indirect sign of volar bowstringing of the flexor tendons. Injured pulleys were not appreciated by US. Tears concerned the A2 and A3 in six patients and the A3 and A4 in two patients. A2 pulley thickening and hypoechogenicity compatible with a partial tear was demonstrated in one patient. MRI and surgical data correlated well with the US findings. Four patients had tenosynovitis of the flexor tendons but no evidence of pulley disruption. US examinations of three patients were normal. In the healthy subjects US demonstrated DAP in 16 of 40 digits. Conclusion. US can diagnose DAP tears and correlates with the MRI and surgical data. Because of its low cost and non-invasiveness we suggest US as the first imaging modality in the evaluation of injuries of the digital pulley.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000226
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 61
    Digitale Medien
    Digitale Medien
    Chronic post-traumatic osteomyelitis of the lower extremity: comparison of magnetic resonance imaging and combined bone scintigraphy/immunoscintigraphy with radiolabelled monoclonal antigranulocyte antibodies (2000)
    Springer
    Skeletal radiology 29 (2000), S. 378-386 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Bones ; infection ; Bones ; radionuclide studies ; MRI ; comparative studies ; Bones ; MRI studies ; MRI ; extremities ; Bones ; immunoscintigraphy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. A retrospective study of the validity of combined bone scintigraphy (BS) and immunoscintigraphy (IS) using 99mTc-labelled murine antigranulocyte antibodies (MAB) and magnetic resonance imaging (MRI) in chronic post- traumatic osteomyelitis. Design and patients. The results of MRI and combined BS/IS of 19 lesions in 18 patients (13 men, 5 women; mean age 45 years, range 27–65 years) were independently evaluated by two radiologists and one nuclear medicine physician with regard to bone infection activity and extent. The patient group was a highly selective collection of clinical cases: the average number of operations conducted because of relapsing infection was eight (range 2–27), the average time interval between the last surgical intervention and the present study was 6.5 years (range 3 months to 39 years), and from the first operation was 14 years (range 1.5–42 years). Interobserver agreement on MRI was measured by kappa statistics. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated for MRI and the nuclear medicine studies. Results. For MRI/nuclear medicine, a sensitivity of 100%/77%, a specificity of 60%/50%, an accuracy of 79%/61%, a PPV of 69%/58% and a NPV of 100%/71% were calculated. Four MR examinations were false positives because of postsurgical granulation tissue. A high degree of interobserver agreement was found on MRI (κ=0.88). A low-grade infection was missed on two scintigrams, while four were false positive because of ectopic haematopoietic bone marrow, and in one examination the anatomical distortion resulted in an inaccurate assignment of the uptake leading to false positive findings. Image analysis was frequently hindered by susceptibility artefacts due to residual abrasions of metallic implants after removal of orthopaedic devices (15/18 patients); this led to limited assessment in 17% (3/18 patients). Conclusion. Acute activity in a chronic osteomyelitis can be excluded with high probability if the MRI findings are negative. In the first postoperative year fibrovascular scar cannot be distinguished accurately from reactivated infection on MRI and scintigraphy may improve the accuracy of diagnosis. MRI is more sensitive in low-grade infection during the later course than combined BS/IS. Scintigraphic errors due to ectopic, peripheral, haematopoietic bone marrow can be corrected by MRI.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000228
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 62
    Digitale Medien
    Digitale Medien
    Tuberculosis of the sternum and clavicle: imaging findings in 15 patients (2000)
    Springer
    Skeletal radiology 29 (2000), S. 447-453 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Tuberculosis ; Sternum ; Clavicle ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. To describe the imaging findings in sterno-clavicular tubercular involvement. Design and patients. Fifteen patients with pathologically proven tuberculosis of the sternum and clavicle were retrospectively evaluated. Routine radiography, computed tomography (CT) and magnetic resonance imaging (MRI) were used in some or all of the patients. Clinical information and imaging features were evaluated in each case. Results. Eight patients had sterno-clavicular joint (SCJ) involvement, five had isolated sternal involvement and two had isolated clavicular involvement. Seven patients were evaluated with only CT, six with only MRI and two with both. There were eight male and seven female patients, varying in age between 16 and 78 years. Fever, swelling and pain were common presenting symptoms. Two patients were HIV positive. Radiographs were positive in only eight patients. Destruction and signal intensity (SI) changes of the sternum and clavicle, destruction of the cartilage, soft tissue changes representing granulation tissue/abscess, displacement of the adjacent structures (vessels, trachea, etc.) and inflammatory changes in the adjacent structures in the form of cellulitis and myositis were common imaging features. Conclusions. All imaging methods can provide complementary information regarding sterno-clavicular tubercular involvement that is helpful for determination of the therapy. MRI is useful in determining the extent of the lesion, particularly marrow involvement and soft tissue extent.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000207
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 63
    Digitale Medien
    Digitale Medien
    Diabetic muscle infarction: atypical MR appearance (2000)
    Springer
    Skeletal radiology 29 (2000), S. 477-480 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Diabetes mellitus ; Muscle, infarction ; Short T1 ; Hemorrhage ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We describe a case of diabetic muscle infarction which had atypical features of hyperintensity of the affected muscle on T1-weighted images. Biopsy was performed which revealed diffuse extensive hemorrhage within the infarcted muscle. We believe increased signal intensity on T1-weighted images should suggest hemorrhage within the infarcted muscle.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000246
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 64
    Digitale Medien
    Digitale Medien
    Multimodality imaging assessment of meniscal ossicle (2000)
    Springer
    Skeletal radiology 29 (2000), S. 481-484 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Meniscal ossicles ; Ultrasound ; CT-arthrography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A case of meniscal ossicles occurring in the left knee of a 23-year-old woman is presented. Radiographs showed two calcified lesions at the posteromedial aspect of the knee which were interpreted as loose bodies. Sonography, computed tomography arthrography and magnetic resonance imaging showed the fragments within the posterior horn of the medial meniscus permitting a diagnosis of meniscal ossicles. These techniques can detect meniscal ossicles and exclude intra-articular loose bodies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000235
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 65
    Digitale Medien
    Digitale Medien
    Metastatic bone tumor mimicking spontaneous osteonecrosis of the medial condyle of the femur: misleading appearance on MR imaging (2000)
    Springer
    Skeletal radiology 29 (2000), S. 286-288 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Metastatic bone tumor ; Knee ; Spontaneous osteonecrosis ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report a case of a metastatic bone tumor that mimicked spontaneous osteonecrosis of the medial condyle of the femur on magnetic resonance imaging.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050610
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 66
    Digitale Medien
    Digitale Medien
    Chronic ulceration of the leg following extensive scarring due to a snake bite complicated by squamous cell carcinoma (2000)
    Springer
    Skeletal radiology 29 (2000), S. 298-301 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Chronic leg ulcers ; Squamous cell carcinoma ; Malignancy ; Snake bite ; X-rays ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Chronic ulcers of the leg are common in Brazil, perhaps more common than in the developed world. We report a case of a chronic ulcer of the leg following extensive scarring due to a bite by a venomous snake, which eventually led to a squamous cell carcinoma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050613
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 67
    Digitale Medien
    Digitale Medien
    Intraosseous microcystic meningioma (2000)
    Springer
    Skeletal radiology 29 (2000), S. 354-357 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Intraosseous meningioma ; Microcystic meningioma ; Parietal bone ; X ray ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Extradural ectopic meningioma is a rare tumor. We report on an example of microcystic meningioma arising in the skull of an elderly woman. Radiological examination revealed a localized osteolytic lesion in the left parietal bone. At surgery, it was discovered that the tumor was located within the skull without any evidence of extraosseous extension. The light microscopic, immunohistochemical and ultrastructural features were consistent with a microcystic variant of meningioma. To our knowledge, this is the first case of an intraosseous microcystic meningioma, and we believe that this type of meningioma should be considered in the differential diagnoses of myxoid bone tumors of the calvarium.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000217
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 68
    Digitale Medien
    Digitale Medien
    Collagenous fibroma of the arm: a report of two cases (2000)
    Springer
    Skeletal radiology 29 (2000), S. 417-420 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Arm ; Collagenous fibroma ; Desmoplastic fibroblastoma ; Short T2 ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A recently proposed addition to fibrous tumors in soft tissue was first described as desmoplastic fibroblastoma and later renamed collagenous fibroma. This tumor is clinically and morphologically distinct and benign. However, only a few series have been reported, and the clinicopathologic features are not widely recognized. We present two cases of collagenous fibroma of the arm. Both patients presented with an enlarging, well-circumscribed and mobile soft tissue mass. Magnetic resonance imaging showed areas of low signal intensity on both T1- and T2-weighted sequences. Needle aspiration cytology revealed nondiagnostic samples because of the low cellularity of the tumors. Each of the resected tumors was composed of low-cellular spindle- to stellate-shaped cells in a fibrous matrix with clear margination. After the marginal excisions, no recurrences were observed. Clinicians should be aware of this entity to prevent overtreatment, because imaging findings and cytologic features are similar to those of desmoid tumor.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000223
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 69
    Digitale Medien
    Digitale Medien
    MRI in inflammatory myopathies (2000)
    Springer
    Skeletal radiology 29 (2000), S. 425-438 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Muscles ; MRI ; Myositis ; Muscles ; Abscess ; Dermatomyositis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Inflammatory myopathies encompass a group of acquired muscle disorders caused by infectious agents (bacteria, viruses, fungi and parasitic agents) or autoimmune processes (polymyositis, dermatomyositis and other types). In suspected infection sonography, CT and MRI are all able to show edema and fluid collections in soft tissues and muscles; sonography and CT may help guidance of a needle aspiration to establish a correct diagnosis. By offering better tissue differentiation, MRI appears to be more efficient than sonography and CT in diagnosing and managing autoimmune myopathies. MRI is indeed very sensitive to the presence of water and edema, and appears to be a very good indicator for an early diagnosis of diseases. MRI may also help to evaluate the extent and number of lesions, to guide a biopsy in an area of active disease and finally to follow the evolution under therapy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000238
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 70
    Digitale Medien
    Digitale Medien
    Chondro-osseous differentiation in fat tissue tumors: magnetic resonance imaging with pathological correlation (2000)
    Springer
    Skeletal radiology 29 (2000), S. 459-465 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Chondrolipoma ; Liposarcoma ; Mesenchymoma ; Cartilage ; Metaplasia ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Chondro-osseous differentiation of three benign or malignant fat tissue tumors – two chondrolipomas and a liposarcoma with cartilaginous metaplasia – was studied with magnetic resonance (MR) imaging and compared with their pathological findings. The results suggest that demarcation of cartilage tisssue can be clearly defined on MR imaging when the size of the cartilaginous area is large. Myxoid matrix, degenerative fat tissue and lipodystrophic change may decrease the delineation of the cartilage tissue.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000241
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 71
    Digitale Medien
    Digitale Medien
    Magnetresonanztomographie (MRT) des Gelenkknorpels Aktueller Wissensstand und neue Entwicklungen (2000)
    Springer
    Der Radiologe 40 (2000), S. 1141-1148 
    Details
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Gelenkknorpel ; MRT ; Arthrose ; Keywords Hyaline cartilage ; MRI ; Osteoarthritis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract MRI is the most accurate noninvasive technique available for assessment of normal articular cartilage and cartilage lesions. MRI cannot only provide morphologic information about the area of damage, but can also provide unique insight into the biochemical composition of the articular cartilage. New image processing techniques such as three-dimensional mapping of cartilage thickness will help to establish automated analysis of cartilage loss. Theses techniques are ideally suited for monitoring patients who undergo treatment with new chondroregenerative drugs.
    Notizen: Zusammenfassung Die MRT ist die beste verfügbare Untersuchungsmethode zur Darstellung des normalen und geschädigten Gelenkknorpels. Sie gibt nicht nur Aufschluss über die Morphologie des geschädigten Areals, sondern auch über die biochemische Zusammensetzung des Gelenkknorpels. Neue Bildverarbeitungstechniken wie die dreidimensionale Erfassung/Darstellung der Knorpeldicke werden bei der Entwicklung einer automatisierten Analyse des Knorpelverlustes helfen. Diese Techniken sind auch ideal zur Verlaufsbeobachtung von Patienten, die sich einer Behandlung mit knorpelregenerierenden Substanzen unterziehen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s001170050898
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 72
    Digitale Medien
    Digitale Medien
    Nutritialgefäßkanäle (2000)
    Springer
    Der Radiologe 40 (2000), S. 469-472 
    Details
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Nutritialgefäßkanäle ; Os lunatum ; Lunatummalazie ; Ganglion ; Ulnaimpaktionssyndrom ; Key words Nutrient vessel canals ; Lunate bone ; MRI ; Kienböcks disease ; Ulna impaction syndrome ; Carpal ganglia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Purpose: To find and describe potential MRI criteria of nutrient vessel canals of carpal bones. Methods and Material: 16 wrists of 13 patients with pain and radiographic depiction of cystic changes within the lunate were examined. The MRI protocol included coronal and sagittal T1- and T2-weighted SE sequences (4 mm slices, 120 FOV, 256×256 matrix) as well as coronal STIR images. Final diagnosis was confirmed by surgery (n=5) and follow up. 10 cadaveric ossa lunata were studied to describe size, number, location and shape of nutrient vessel canals. Results: Ganglion cysts (n=6) showed characteristic signs. In ulnar impaction syndrome (n=1) small cystic lesions in the lunate were surrounded by a sclerotic rim and located near the proximal ulnar surface. In Kienböck’s disease (n=3) cystic components were irregular and surrounded by bone marrow edema. Nutrient vessel canals (n=7) imaged as 1 to 3 small cystic lesions within the palmar or dorsal subchondral region. Conclusion: MRI can aid in differential diagnosis of cystic carpal lesions. Nutrient vessel canals may not be mistaken for pathologic cystic lesions. Carpal ganglion cysts show distinct diagnostic pattern.
    Notizen: Zusammenfassung Fragestellung: Sind karpale Nutritialgefäßkanäle auf MRI Bildern sichtbar und welche differentialdiagnostischen Kriterien lassen sich finden. Material und Methode: In 16 Fällen lagen bei 13 Patienten röntgenologisch wenige mm bis 2 cm große zystische Läsionen im Os lunatum vor. Das MRT-Protokoll umfaßte koronare und sagittale T1- und T2-gewichtete SE-Sequenzen mit 4 mm Schichtdicke, 120 mm Meßfeld und 2562 Matrix sowie koronare STIR-Sequenzen. Die Diagnosesicherung erfolgte durch Operation in 5 Fällen sowie Verlaufskontrollen. 10 mazerierte Ossa lunata wurden auf Form, Lokalisation, Anzahl und Größe der Nutritialgefäßkanäle untersucht. Ergebnisse: Ganglien (n=6) wiesen typische Zeichen auf. Im Falle eines Ulnaimpaktionssyndroms bei Ulna-Nullvariante wurden mehrere kleine zystische Läsionen im Os lunatum gefunden, umgeben von einem Sklerosesaum. Bei 3 Fällen einer frühen Lunatummalazie waren unregelmäßige zystische Komponenten von einem diffusen Ödem umgeben. In 7 Fällen mit sehr kleinen zystischen Defekten waren diese subchondral, palmar und dorsal gelegen und entsprachen aufgrund des klinischen Verlaufs und der Lokalisation Nutritialgefäßkanälen. Schlußfolgerung: Nutritialgefäßkanäle dürfen nicht mit pathologischen zystischen Prozessen des Os lunatums verwechselt werden. Mittels MRT können zystische Läsionen im und am Os lunatum weiter spezifiziert werden. Handgelenksganglien weisen typische MR-Zeichen auf.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s001170050698
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 73
    Digitale Medien
    Digitale Medien
    Plasmazelluläre Osteomyelitis der Brustwirbelsäule – ein Fallbericht (2000)
    Springer
    Der Radiologe 40 (2000), S. 557-560 
    Details
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Plasmazell-Osteomyelitis ; Magnetresonanztomografie ; Wirbelsäule ; Key words Plasmacellular osteomyelitis ; MRI ; Spine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract The authors report the case of a young patient suffering from plasmacellular osteomyelitis of the thoracic spine, a unusual localisation of this type of chronic osteomyelitis. They discuss the role of imaging diagnostic modalities in this disease, focussing on MRI.
    Notizen: Zusammenfassung Wir berichten über den Fall einer jungen Patientin mit Plasmazell-Osteomyelitis an der Brustwirbelsäule als ungewöhnliche Lokalisation dieser chronischen Osteomyelitis-Form. Dabei wird die Rolle der bildgebenden Diagnostik, insbesondere der Magnetresonanztomografie diskutiert.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s001170050753
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 74
    Digitale Medien
    Digitale Medien
    Septisch-embolischer und septisch-metastatischer Hirnabszess (2000)
    Springer
    Der Radiologe 40 (2000), S. 1017-1029 
    Details
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Hirnabszess ; Zerebritis ; Metastatische Herdenzephalitis ; Endokarditis ; MRT ; Gd-DTPA ; Keywords Brain abscess ; Cerebritis ; Metastatic focal encephalitis ; Endocarditis ; MRI ; Gd-DTPA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract The hematogenous spread of bacteria, fungi and protozoa may also reach the brain vessels, which happens mostly through septic emboli. From such an embolus a metastatic focal encephalitis and later a septic-embolic brain abscess may arise. The most frequently underlying infections that may cause septic emboli are bacterial endocarditis as well as bacterial infections of artificial heart valve prostheses. Congenital heart malformations with a right-to-left shunt also play here a certain role. Basically, however, all septic conditions and bacteriemias may cause septic-embolic brain abscesses. They occur frequently as multiple lesions. MRI is superior to CT in depicting the different stages of evolution from focal encephalitis, through the hardly encapsulated early abscess, to the formation of a membrane and later a dense fibrous capsule. The medical treatment of a brain abscess requires properly performed CT or MRI follow-up examinations in order to realize early enough a possible growing of such a lesion.
    Notizen: Zusammenfassung Die hämatogene Ausbreitung von Bakterien, Pilzen oder Protozoen bis in die Hirngefäße erfolgt meist durch eine septische Embolie. Es entstehen eine metastatische Herdenzephalitis und im weiteren Verlauf daraus ein septisch-embolischer Hirnabszess. Die häufigste Grunderkrankung die zu septischen Embolien führt ist die bakterielle Endokarditis sowie die bakterielle Infektion von Herzklappenprothesen. Eine besondere Bedeutung kommt hier den angeborenen kardialen Fehlbildungen mit Rechts-Links-Shunt zu. Grundsätzlich können jedoch alle Bakteriämien zu septisch-embolischen Hirnabszessen führen. Septisch-embolische Hirnabszesse treten aufgrund ihres Entstehungsmechanismus häufig multipel auf. Die CT und besser noch die MRT erlauben die Darstellung aller Entwicklungsstadien von der Herdenzephalitis über den kaum abgegrenzten Abszess, die Membranbildung bis zur Entstehung einer dicken, die eitergefüllte Höhle allseits umgebenden Abszesskapsel. Die medikamentöse Therapie von Hirnabszessen erfordert Verlaufsuntersuchungen, um einer eventuellen Größenzunahme der Läsion(en) frühzeitig durch Umstellung der antibiotischen Medikation oder durch operative Abszessentfernung zu begegnen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s001170050874
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 75
    Digitale Medien
    Digitale Medien
    MRT bei Neugeborenen mit Verdacht auf zerebrale Störung (2000)
    Springer
    Der Radiologe 40 (2000), S. 18-27 
    Details
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter ; MRT ; Neugeborene ; Cerebrum ; Fetus ; Key words ; MRI ; Neonatal ; Brain ; Fetal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Magnetic resonance tomography (MRT) has become the most important method in the workup of infantile cerebral complications after primary sonography. Cerebral MR examination and image interpretation during the infantile period require extensive knowledge of morphological manifestations, their pathophysiological background, and frequency. The choice of imaging parameters and image interpretation is demonstrated in infarctions and hemorrhages of the mature and immature brain. A review of the main differential diagnoses is also given. The relevance of MR spectroscopy and fetal MRI is discussed.
    Notizen: Zusammenfassung Zur Abklärung zerebraler Veränderungen bei Neugeborenen hat sich die Magnetresonanztomographie (MRT) als wichtigste weiterführende Methode nach der Sonographie entwickelt. Die Durchführung und Auswertung der MR-Untersuchungen erfordern jedoch eine genaue Kenntnis der morphologischen Manifestationen, des pathophysiologischen Hintergrunds und der Häufigkeit bestimmter zerebraler Komplikationen in diesem Lebensalter. Resümee: Ausgehend von zerebrovaskulären Erkrankungen werden diese Fragen behandelt, wobei sowohl auf die Auswahl der adäquaten Untersuchungsparameter als auch auf die Bildinterpretation und die wichtigsten Differentialdiagnosen eingegangen wird. Die Bedeutung von MR-Spektroskopie und fetaler MRT wird diskutiert.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s001170050004
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 76
    Digitale Medien
    Digitale Medien
    Präoperative Markierung und Biopsie nicht palpabler Mammaläsionen mit einer Zieleinrichtung am Magnetom Open (2000)
    Springer
    Der Radiologe 40 (2000), S. 1098-1105 
    Details
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Mammatumor ; MRT ; Markierung ; Biopsie ; Keywords Breast lesion ; MRI ; Localization ; Biopsy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract Purpose. MRI-guided interventional maneuvers in the breast, when closed MRI scanners are employed are relatively complex and time consuming. The purpose of our investigations was to develop a special device for the localization and biopsy of breast lesions using an open low-field MRI Scanner (Magnetom Open, Siemens, Erlangen, Germany) permitting free access to the patient. Materials and Methods. Due to its particular material and construction characteristics, a newly developed device for localization and biopsy of breast lesions is appropriate to remain within the magnetic field during the examination without degrading image quality. We performed 125 tests in a phantom and 31 investigations in patients including 26 wire-localizations and 5 biopsies. Results. The interventional maneuvers in the phantom could be performed very precisely. In all 125 phantom studies, the needle (14G coaxial biopsy cannula, Bard) was positioned close to the simulated lesion. In 25 out of 26 patients the needle was positioned within a distance less than 5 mm from the lesion. When using the 14G coaxial biopsy cannula (Bard, Karlsruhe, Germany) the needle tip was found adjacent next to the lesion in all 12 cases (7 wire-localizations, 5 biopsies). Conclusions. Our results indicate that our device allows very precise preoperative localization of breast lesions within the Magnetom Open. Using MRI-compatible, large-core needles, biopsy under direct MRI control resulted in good results.
    Notizen: Zusammenfassung Zielsetzung. Am geschlossenen MRT-Gerät sind Interventionen an der Mamma relativ aufwendig und zeitintensiv. Ziel unserer Untersuchungen war es, eine Lokalisations- und Biopsieeinrichtung für das offene MRT-Gerät (Magnetom Open, Siemens) zu entwickeln und zu erproben, das Patienten und Methode. Es wurde eine Lokalisations- und Biopsieeinrichtung entwickelt, die aufgrund ihrer Bauart während der Intervention im Magnetfeld des MRT-Gerätes verbleiben kann und die Bildgebung nicht nachteilig beeinflusst. Um die Tauglichkeit dieses Gerätes zu überprüfen wurden 125 Untersuchungen am Phantom und 31 Patientenuntersuchungen (26 Drahtlokalisationen, 5 Biopsien) durchgeführt. Ergebnisse. Die Interventionen am Phantom konnten sehr genau gesteuert werden. In allen 125 Fällen lag die Interventionsnadel (14 G-Coaxial-Biopsiekanüle, Bard) direkt der Läsion an. Bei den Patientenuntersuchungen lag die Interventionsnadel in 25 von 26 Fällen weniger als 5 mm von der Läsion entfernt. Bei Verwendung der 14 G-Coaxial-Biopsie-Kannüle (Bard, Karlsruhe, Germany) lag die Interventionsnadel in allen 12 Fällen direkt der Läsion an (7 Drahtlokalisationen, 5 Hochgeschwindigkeitsbiopsien). Schlussfolgerung. Die Untersuchungen zeigen, dass mit der von uns entwickelten Zieleinrichtung sehr genaue präoperative Lokalisationen am Magnetom Open durchführbar sind. Durch die stabile Nadelführung sind bei Verwendung lumenstarker Materialien (14G) zudem exakte MRT-kontrollierte Biopsien möglich.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s001170050882
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 77
    Digitale Medien
    Digitale Medien
    Ossäre Manifestationen beim Non-Hodgkin-Lymphom im Kindes- und Jugendalter (2000)
    Springer
    Der Radiologe 40 (2000), S. 737-744 
    Details
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Lymphom ; MRI ; Keywords Lymphoma ; Bone neoplasms ; Diffusion coefficient ; ADC
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract Purpose. Skeletal manifestation of Non-Hodgkin's lymphoma is rare in pediatric patients. Objective of the study was to determine imaging features, before and after treatment, and to correlate these features with clinical outcome. Methods. A retrospective analysis of 1246 patients from two therapy studies (NHL-BMF-90 and 95) was performed. Imaging studies of 63 patients with bone involvement of lymphoma were reevaluated. Results. Incidence of initial bone involvement in Non-Hodgkin's lymphoma was 6.8%. Distribution was best assessed by bone scan, MRI revealed larger areas of marrow involvement and detected additional lesions. Sites of prediliction were long bones of the lower extremities with epiphyseal involvement in 39%. Residual signal alterations in MRI after succussful therapy remained in 71%. Osteonecrosis after therapy was a common finding. Clinical outcome war not correlated to the presence of bone involvement. Conclusions. Since clinical outcome is not effected by bone involvement in childhood NHL, value of screening may be limited. Knowledge of imaging characteristics is mandatory for inital evaluation of primary osseous lymphomas and symptomatic lesions as well as for therapy controlls.
    Notizen: Zusammenfassung Fragestellung. Skelettale Manifestationen des Non-Hodgkin-Lymphoms sind selten. Ziel der Studie waren die Analyse charakteristischer Veränderungen in der Bildgebung vor und nach Therapie sowie die Korrelation mit dem Therapieerfolg. Methode. Die retrospektive Analyse von 2 Therapiestudien (NHL-BMF-90 und 95) schloss 1246 Patienten ein. Die bildgebenden Untersuchungen von 63 Patienten mit skelettalem Lymphombefall wurden reevaluiert. Ergebnisse. Die Inzidenz des initialen Skelettbefalls beim Non-Hodgkin-Lymphom lag bei 6,8%. Die Verteilung der Skelettherde wurde durch die Szintigraphie am sichersten erfasst, die MRT detektierte im Vergleich größere Markraumbeteiligungen sowie zusätzliche Herdbildungen im Skelett. Prädilektionsorte waren die langen Röhrenknochen der unteren Extremitäten mit epiphysärer Beteiligung in 39% der Fälle. Residuale Signalveränderungen im MRT verblieben trotz kompletter Remission in 71% der Fälle. Osteonekrosen nach Chemotherapie waren häufig. Die therapeutische Ergebnisse wurden durch das Vorhandensein eines Skelettbefalls nicht beeinflusst. Schlussfolgerungen. Aufgrund der Beobachtung, dass die Therapieergebnisse vom Nachweis eines Skelettbefalls nicht wesentlich beeinflusst werden, erscheint der Wert der Screeninguntersuchung begrenzt. Die Kenntnis des Erscheinungsbilds vom NHL in der Bildgebung ist aber für die Beurteilung der primär ossären Lymphome und symptomatischer Herdbildungen sowie in der Therapiekontrolle notwendig.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s001170050804
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 78
    Digitale Medien
    Digitale Medien
    Blake's pouch cyst: an entity within the Dandy-Walker continuum (2000)
    Springer
    Neuroradiology 42 (2000), S. 290-295 
    Details
    ISSN: 1432-1920
    Schlagwort(e): Key words Blake's pouch cyst ; Dandy-Walker complex ; Dandy-Walker malformation ; Posterior fossa malformation ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Abnormal cerebrospinal fluid (CSF) collections within the posterior fossa are defined by the Dandy-Walker complex (DWC) and by arachnoid cysts (AC). The DWC includes the Dandy-Walker malformation (DWM), the Dandy-Walker variant (DWV) and the mega-cisterna magna (MCM). In addition, Tortori-Donati et al. added persistent Blake's pouch cyst (BPC) as an independent entity within the DWC. BPC represents a posterior ballooning of the superior medullary velum into the cisterna magna. All of these malformations are overlapping developmental anomalies characterized by varying degrees of malformation of the medullary vela, the cerebellar vermis and hemispheres, the fourth ventricle choroid plexus, the posterior fossa subarachnoid cisterns and the enveloping meningeal structures. We present two cases of persistent BPC detected in two adult women without history of gestational or subsequent growth problems. They underwent neuroradiological investigation because of headache and because of recurrent episodes of loss of consciousness, respectively. The MRI findings included tetraventricular hydrocephalus, wide communication of the fourth ventricle and the cystic posterior fossa (i. e. BPC), inferior posterior fossa mass effect with or without hypoplasia of both the cerebellar vermis and the medial aspects of the cerebellar hemispheres, and absence of communication between fourth ventricle and the basal subarachnoid space in the midline posteriorly. Persistent BPC is defined by a failure of embryonic assimilation of the area membranacea anterior within the tela choroidea associated with imperforation of the foramen of Magendie. Typically this condition becomes symptomatic early in life. In the current cases the normal function of the laterally positioned foramina of Luschka probably helped to maintain some CSF flow between intraventricular and subarachnoid spaces, with the establishment of a precarious equilibrium characterized by a compensatory enlargement of the cerebral ventricular system (i. e. hydrocephalus).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002340050888
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 79
    Digitale Medien
    Digitale Medien
    A pilot assessment of whether external coil MRI is useful to assess evacuatory disorders (2000)
    Springer
    International journal of colorectal disease 15 (2000), S. 91-95 
    Details
    ISSN: 1432-1262
    Schlagwort(e): Keywords Fecal incontinence ; Constipation ; MRI ; Ultrasound
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  This study assessed the value of common surface coil mag-netic resonance imaging (MRI) in patients with evacuatory disorders including fecal incontinence and constipation. These findings were then compared with those from other standard physiological examinations and/or surgical findings. From July 1996 to June 1997, 14 consecutive patients underwent surface coil MRI for evaluation of either fecal incontinence (n=5) or constipation (n=9). In patients with incontinence we compared the findings from endoanal ultrasound (EAUS), anal MRI, and surgery regarding morphopathological findings of the internal and external anal sphincter components. In constipated patients the findings of videoprography and dynamic pelvic MRI were compared regarding the presence of rectocele, rectoanal intussusception, and sigmoidocele as well as the measurements of anorectal angle and perineal descent. The five incontinent patients were all women, with a median age of 67 years (range 43–77). EAUS revealed an anterior sphincter defect in two patients, a posterior defect in one, and normal anal sphincter images in two. Surgical findings confirmed an anterior external anal sphincter scar in two patients, an internal anal sphincter defect in one, and an anatomically normal anal sphincter in two. In one patient, although anal MRI showed posterior external anal sphincter defect, EAUS and surgery revealed normal external anal sphincter appearance. The accuracy rate between EAUS and anal MRI was only 20%, that between surgery and anal MRI 40%, and that between surgery and EAUS 80%. Thus EAUS was more accurate than anal MRI in incontinent patients. The nine constipated patients were all women, with a mean age of 59 years (range 40–78). Videoproctography revealed an anterior rectocele in six patients, rectoanal intussusception in three, and sigmoidocele in five; no abnormalities were identified in two patients. On dynamic pelvic MRI anterior rectocele was seen in three patients and sigmoidocele in two, and five studies were interpreted as normal. One of the patients underwent sigmoidectomy for sigmoidocele, and five patients were treated by biofeedback. Thus the accuracy rate of dynamic pelvic MRI against videoproctography was 60% for anterior rectocele, 40% for sigmoidocele, and zero for rectoanal intussusception. In conclusion, neither MRI for the evaluation of patients with fecal incontinence nor for the evaluation of patients with constipation added any significant information that would warrant its continued use in these patient groups. Perhaps the more widespread availability of an endoanal coil will alter this conclusion; however, at the present time we cannot routinely endorse the expense, time, or inconvenience of these MRI investigations in patients with these diagnoses. Larger prospective comparative studies are required prior to endorsing the technique.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003840050239
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 80
    Digitale Medien
    Digitale Medien
    Noninvasive diagnosis of brain tumours in children (2000)
    Springer
    Child's nervous system 16 (2000), S. 731-734 
    Details
    ISSN: 1433-0350
    Schlagwort(e): Keywords Children ; Brain ; Tumour ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The author reviews the progress made during the last 25 years in noninvasive diagnosis of brain tumours in children. MRI has replaced all other modalities available at that time. The diagnosis is still based on a precise anatomical analysis of the lesion rather than on other specific findings. New techniques, such as spectroscopy and diffusion, may help to characterise further brain tumours in children preoperatively.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003810000333
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 81
    Digitale Medien
    Digitale Medien
    Die Kufs-Erkrankung Seltene Ursache einer früh beginnenden Demenz (2000)
    Springer
    Der Nervenarzt 71 (2000), S. 411-415 
    Details
    ISSN: 1433-0407
    Schlagwort(e): Schlüsselwörter Kufs ; Neuronale Zeroidlipofuszinose ; Demenz ; PET ; MRT ; Key words Kufs disease ; Neuronal ceroid lipofuscinosis ; Dementia ; PET ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary The case of a 35-year-old man with progressive dementia from the age of 17 is presented. Clinical examination showed mild extrapyramidal and cerebellar signs and rare myoclonus. Neuropsychological evaluation disclosed severe cognitive deficits. Magnetic resonance imaging (MRI) revealed moderate generalized atrophy with abnormal iron deposition in the basal ganglia. Positron emission tomography (PET) with 18-fluorodeoxyglucose (18-FDG) demonstrated clear temporoparietal hypermetabolism. The clinical symptoms and course are typical for the rare adult type of neuronal ceroid lipofusconoses (Kufs' disease). The diagnosis is supported by the electron microscope detection of an abnormal accumulation of lipid vacuoles and lipofuscin in the eccrine sweat glands and the rectal ganglia cells.
    Notizen: Zusammenfassung Berichtet wird der Fall eines 35-jährigen Patienten mit langsam progredienter Demenz seit dem 18. Lebensjahr. Zum Zeitpunkt der Untersuchung fielen klinisch eine leichtgradige extrapyramidale und zerebelläre Symptomatik sowie seltene Myoklonien auf, während die neuropsychologische Testung ausgeprägte kognitive Defizite ergab. Die kraniale Magnetresonanztomographie zeigte eine mäßige globale Atrophie und eine abnorme Eisenablagerung in den Basalganglien. In der Positronenemissionstomographie mit 18-FDG war ein deutlicher temporoparietaler Hypometabolismus erkennbar. Klinik und Verlauf sind typisch für die seltene adulte Variante der neuronalen Zeroidlipofuszinosen (Kufs-Typ). Diese Diagnose wird gestützt durch den elektronenmiroskopischen Nachweis abnormer Akkumulationen von Fettvakuolen und Lipofuszinablagerungen in den ekkrinen Schweißdrüsen der Haut und in den rektalen Ganglienzellen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s001150050577
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 82
    Digitale Medien
    Digitale Medien
    Qualitätssicherung nach der Behandlung von Gelenkknorpeldefekten (2000)
    Springer
    Arthroskopie 13 (2000), S. 132-137 
    Details
    ISSN: 1434-3924
    Schlagwort(e): Schlüsselwörter Qualitätssicherung ; Knorpeldefekte ; MRT ; Scores ; Keywords Quality control ; Cartilage repair ; MRI ; Clinical scores
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Most procedures currently in use for the treatment of full thickness cartilage defects lack solid data as a proof of quality. Various techniques for quality control are advisable. Meticulous documentation of adverse events and treatment failures is crucial. Patient self-assessment and clinical scores are often biased but focussed on the basis of medical efforts: the well-being of the patient. Second-look arthroscopies produce fewer facts for quality control than expected but enable therapeutical intervention. Magnetic resonance imaging will be essential for cartilage assessment in the future. To date, the evaluation of tissue quality is experimental. Histology and immunohistochemistry are widely accepted as precise tools to characterize cartilaginous tissue. Ethical reasons prohibit daily use. Quality control following the repair of cartilage defects is complicated, expensive, and of variable outcome, but dangerous if neglected. Multiple insignificant results can lead to a sharp image of the postoperative condition and may enable quality control of treatment and surgery.
    Notizen: Die meisten Verfahren zur Behandlung von Gelenkknorpeldefekten werden angewendet, ohne dass ihre Qualität zweifelsfrei nachgewiesen ist. Verschiedene Möglichkeiten der Qualitätssicherung können derzeit mit vertretbarem Aufwand routinemäßig eingesetzt werden. Die Beurteilung der Sicherheit einer Behandlung hinsichtlich Komplikationen und Therapieversagern ist von eminenter Bedeutung. Patientenfragebögen und klinische Scores sind subjektiv, orientieren sich aber am eigentlichen Ziel einer Therapie: der Wiederherstellung des Wohlbefindens des Patienten. Noch in den Anfängen, aber mit hervorragenden Perspektiven für die Zukunft steht die Magnetresonanztomographie. Knorpelqualität und -aktivität können heute noch nicht beurteilt werden. Die Kontrollarthroskopie nach der Behandlung von Gelenkknorpeldefekten liefert weniger harte Daten für die Qualitätssicherung als erwünscht, ermöglicht aber therapeutische Maßnahmen. Histologische Untersuchungen stehen im Ruf der unbestechlichen Präzision. Dem breiten Einsatz stehen jedoch fehlende Standards und berechtigte ethische Bedenken entgegen. Qualitätssicherung nach der operativen Behandlung von Gelenkknorpeldefekten ist schwierig, teuer und häufig ungenau – keine Qualitätssicherung ist oft gefährlich. Aus vielen, isoliert gesehen ungenauen Befunden werden die Bewertung eines Zustands immer sicherer und die Beurteilung der Qualität einer Behandlung möglich.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s001420050147
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 83
    Digitale Medien
    Digitale Medien
    Vergleichende Untersuchung sagittaler und koronaler MRT mit histologischen Diskus- und Kiefergelenkpräparaten zur Prüfung einer Identität von anteriorer Diskusdislokation und anterioren Kapselbindegeweben (2000)
    Springer
    Mund-, Kiefer- und Gesichtschirurgie 4 (2000), S. 285-291 
    Details
    ISSN: 1434-3940
    Schlagwort(e): Schlüsselwörter Kiefergelenk-MRT ; Diskusdislokation ; Kiefergelenkhistologie ; Keywords Temporomandibular joint (TMJ) ; MRI ; Anterior disk dislocation ; TMJ histology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract Problem. Anterior dislocation of the articular disk of the temporomandibular joint (TMJ) found by MRI tomography often presents a problem. It may persist in MRI despite improvement of articular symptoms and even be found in healthy persons free of any symptoms. Can this be explained by the similarity in structure of the anterior connective tissue of the disk and capsule and their pathological changes? Is a second coronal plane required for MRI investigation? Material and methods. The preauricular regions of 72 patients of the TMJ clinic were examined by oblique-sagittal and oblique-coronal MRI. A Siemens-Vision MRI was used. It was also possible to prepare 10 articular disks of the TMJ with anterior capsular tissue as well as 20 complete TMJs of adults from autopsy material. Sagittal, transversal, and horizontal serial sections were examined histologically. Results. In 49 of the 72 cases examined, an anterior dislocation without reduction found in the sagittal MRI was not confirmed in the oblique-coronal MRI. In the sagittal MRI it was possible to differentiate three, in the coronal MRI six typical forms of magnetic resonance signals, which are represented in figures. They are compared with anatomical and histological connective tissue findings adjacent to the TMJ. The structural similarity of the disk and anterior capsular tissue of the TMJ is demonstrated. The close connection of the disk and connective tissue surrounding the TMJ makes differentiation of MRI findings difficult especially following regressive and adaptive reactions. Conclusions. In MRI, anterior capsular tissue is able to simulate dislocation of the disk. Pathological tissue reactions may alter the MRI signal and lead to the wrong diagnosis of dislocation of the disk. Diagnosis of an anterior disk dislocation cannot be established solely on the basis of oblique-sagittal MRI findings.
    Notizen: Zusammenfassung Fragestellung. Der Befund anteriore Diskusdislokation im sagittalen MRT beinhaltet 2 ungeklärte Probleme. Trotz Rückbildung einer Gelenksymptomatik können anteriore Diskusdislokationen im MRT unverändert bestehen, sie wurden sogar bei gesunden Probanden beschrieben. Ist die Ursache in der feingeweblichen Ähnlichkeit der anterioren Diskus- und Kapselbindegewebe und in deren pathologischen Strukturänderungen zu suchen? Kann auf die Befundung in der 2. koronalen Ebene verzichtet werden? Material und Methode. Die präartikulären Regionen im schräg-sagittalen und im schräg-koronalen MRT von 72 Patienten aus der Kiefergelenkspezialsprechstunde wurden befundet. Die Untersuchungen erfolgten mit dem Siemens-Vision-MRT. Bei unselektierten Sektionen konnten 10 Disci articulares mit dem anterioren Kapselgewebe sowie 20 Kiefergelenkpräparate Erwachsener präpariert werden. Sagittale, transversale und horizontale Serienschnitte wurden histologisch untersucht. Ergebnisse. Bei 49 von 72 ausgewählten Fällen gab es für eine anteriore Diskusdislokation ohne Reduktion im sagittalen MRT keine Bestätigung im schräg-koronalen MRT. Es konnten in den sagittalen MRT 3, in den koronalen MRT 6 sich wiederholende Signalformen differenziert werden. Sie sind skizziert. Ihre Zuordnung zu gelenkumgebenden Bindegeweben erfolgte mittels Vergleich dieser Signalformen mit den anatomischen und histologischen Kiefergelenkpräparaten. Die feingewebliche Ähnlichkeit des Discus articularis mit dem anterioren Kapselbindegewebe wird aufgezeigt. Seine enge Verbindung mit den gelenkumgebenden Bindegeweben erschwert die Differenzierung im MRT insbesondere beim Vorliegen regressiver und adaptiver Reaktionen. Schlussfolgerung. Das anteriore Kapselgewebe kann eine Diskusdislokation im MRT vortäuschen. Pathologische Gewebereaktionen ändern das MRT-Signal und tragen dazu bei, falsch-positive Befunde zur Diskusdislokation entstehen zu lassen. Schräg-sagittale MRT sind für die Diagnosefindung „anteriore Diskusdislokation mit und ohne Reposition“ nicht ausreichend.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/PL00010789
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 84
    Digitale Medien
    Digitale Medien
    Osteoid osteoma of the cervical spine depicted as dumbbell tumor by MRI (2000)
    Springer
    European spine journal 9 (2000), S. 426-429 
    Details
    ISSN: 1432-0932
    Schlagwort(e): Key words Osteoid osteoma ; MRI ; Inflammatory reaction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We report a case of 14-year-old male patient with osteoid osteoma of the cervical spine. Magnetic resonance imaging (MRI) revealed a large dumbbell-shaped paravertebral tumor in the region of the exiting left C6 nerve. A computed tomographic (CT) scan after myelography showed a much smaller bony defect in the medial aspect of the left C6 pedicle with central calcification and extensive bone sclerosis around the defect, typical of osteoid osteoma. The diagnosis was confirmed postoperatively. The resected specimen exhibited extensive vascularization of the osteoid tissue. The case is presented because MRI did not allow a specific diagnosis of osteoid osteoma, and suggested the tumor was larger than in reality it was, by also depicting the reactive inflammation around the tumor as if it were part of the tumor.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s005860000148
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 85
    Digitale Medien
    Digitale Medien
    Cervical spondylotic myelopathy associated with syringomyelia: A case report (2000)
    Springer
    European journal of orthopaedic surgery & traumatology 10 (2000), S. 203-205 
    Details
    ISSN: 1432-1068
    Schlagwort(e): Cervical spondylotic myelopathy ; Syringomyelia ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case of syringomyelia associated with cervical spondylotic myelopathy is presented. A decompressive cervical laminectomy was performed. The patient improved gradually after operation. It is concluded that the choice of surgical treatment in cases with syringomyelia associated with cervical spondylotic myelopathy requires a careful neurological and radiological examination based on the findings of magnetic resonance imaging (MRI) and cine-MRI.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01682320
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 86
    Digitale Medien
    Digitale Medien
    Ovarian thecoma with ascites and high serum levels of CA125 (2000)
    Springer
    Archives of gynecology and obstetrics 264 (2000), S. 42-44 
    Details
    ISSN: 1432-0711
    Schlagwort(e): Key words Thecoma ; Ascites ; CA125 ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report a 34-year-old woman with an ovarian thecoma and ascites who exhibited high serum levels of CA125. Measuring serum tumor markers and imaging are two important diagnostic tools for malignant ovarian tumors. In the present case, a preoperative diagnosis of benign ovarian tumor could not be made due to the elevation of CA125 (895 U/ml) and nonspecific MRI findings.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/PL00007485
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 87
    Digitale Medien
    Digitale Medien
    Influence of age and duration of symptoms on fibre type distribution and size of the back muscles in chronic low back pain patients (2000)
    Springer
    European spine journal 9 (2000), S. 273-281 
    Details
    ISSN: 1432-0932
    Schlagwort(e): Key words Chronic low back pain ; Erector spinae muscle ; MRI ; Muscle biopsy ; Fibre type ; distribution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Many studies have documented an association between chronic low back pain (LBP) and deficits in back muscle strength and endurance. The sub-optimal performance is believed to be the result of alterations in the size and structure of the muscle, although the long-standing issue of whether the observed changes precede or are a consequence of the pain remains unresolved. If consequent to the problem, and predominantly related to disuse of the muscles, then it may be expected that a relationship between muscle structure and symptom duration would exist. Lumbar paraspinal muscle samples were obtained from 59 chronic LBP patients using the percutaneous biopsy technique. The samples were subject to routine histochemical analysis for the examination of muscle fibre type characteristics and cytochemical architectural changes. In 55 of the patients, the gross cross-sectional areas of magnetic resonance images of the trunk muscles were also measured. Multivariate analysis showed that symptom duration was the strongest predictor of the individual proportions of the fast-fatigable type IIX fibres; with age and gender included in the model, nearly 30% of the variance in fibre type distribution could be accounted for. Duration of pain had no influence on fibre size. Gross muscle cross-sectional area correlated directly with lean body mass and inversely with age, but showed no relationship with symptom duration. Pathological changes in the internal fibre structure were more frequently encountered in older patients, and were independent of symptom duration. The results suggest that, over the long term, fibre type transformations rather than alterations in fibre size are the predominant changes to be found in the muscles of chronic LBP patients. The direction of change supports the results of many previous studies that have demonstrated corresponding differences in the fatigability of the muscles. There is a strong case for the early implementation of active measures to attempt to offset the development of these changes in back pain patients.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s005860000189
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 88
    Digitale Medien
    Digitale Medien
    Progressive pseudorheumatoid dysplasia (2000)
    Springer
    European radiology 10 (2000), S. 1832-1835 
    Details
    ISSN: 1432-1084
    Schlagwort(e): Key words: Platyspondyly ; MRI ; Progressive pseudorheumatoid dysplasia ; Bone ; Osteochondrodysplasia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. A rare case of progressive pseudorheumatoid dysplasia (PPD) in a 9-year-old girl is presented. Clinically, chronic painless swollen joints, accompanied by progressive motion restriction and progressive walking difficulties, were found. Radiologically, there was enlargement of the epimetaphyseal portions of the large joints, metacarpal heads, and phalanges, and generalized platyspondyly with irregular delineation of the endplates of the vertebral bodies. The radioclinical features at the peripheral joints were originally misdiagnosed as juvenile rheumatoid arthritis (JRA), and the structural spinal abnormalities were neglected and interpreted as Scheuermann's disease. However, the absence of active inflammatory parameters argues against JRA, whereas the low age of onset of the irregularities at the vertebral endplates is an argument against the diagnosis of Scheuermann's disease. The combination of the dysplastic abnormalities of the spine, with platyspondyly and Scheuermann-like lesions at an unusually low age of onset, and radiological features mimicking JRA of the peripheral joints, is the clue to the diagnosis of this rare autosomal-recessive disease. This case is the first to document the MRI features of PPD of the spine.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003300000518
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 89
    Digitale Medien
    Digitale Medien
    Uterine endometrial stromal sarcoma located in uterine myometrium: MRI appearance (2000)
    Springer
    European radiology 10 (2000), S. 780-782 
    Details
    ISSN: 1432-1084
    Schlagwort(e): Key words: Uterus ; Endometrial stromal sarcoma ; Uterine myometrium ; Uterine leiomyoma ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Two cases of uterine endometrial stromal sarcoma whose main mass was located in uterine myometrium are reported. They mimicked uterine leiomyoma with cystic degeneration or uterine leiomyosarcoma. Endometrial stromal sarcoma should be suggested in the differential diagnosis of mass lesion in uterine myometrium.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003300051004
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 90
    Digitale Medien
    Digitale Medien
    Osteochondroma: MR imaging of tumor-related complications (2000)
    Springer
    European radiology 10 (2000), S. 832-840 
    Details
    ISSN: 1432-1084
    Schlagwort(e): Key words: Osteochondroma ; Complications ; Chondrosarcoma ; Bone tumors ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Osteochondromas can be complicated by mechanical irritation, compression or injury of adjacent structures, fracture, malignant transformation, and postoperative recurrence. Magnetic resonance imaging represents the most valuable imaging modality in symptomatic cases, because it can demonstrate typical features of associated soft tissue pathology, which can be differentiated from malignant transformation. Reactive bursae formation presents as an overlying fluid collection with peripheral contrast enhancement. Dislocation, deformation, and signal alterations of adjacent soft tissue structures can be observed in different impingement syndromes caused by osteochondromas. Magnetic resonance imaging provides excellent demonstration of arterial and venous compromise and represents the method of choice in cases with compression of spinal cord, nerve roots, or peripheral nerves, depicting changes in size, position, and signal intensity of the affected neural structures. Malignant transformation as the most worrisome complication occurs in approximately 1 % of solitary and 5–25 % of multiple osteochondromas. Magnetic resonance imaging is the most accurate method in measuring cartilage cap thickness, which represents an important criterion for differentiation of osteochondromas and exostotic (low-grade) chondrosarcomas. Cartilage cap thickness exceeding 2 cm in adults and 3 cm in children should raise the suspicion for malignant transformation. Finally, MR imaging can detect postoperative recurrence by depiction of a recurrent mass presenting typical morphological features of a cartilage-forming lesion.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003300051014
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 91
    Digitale Medien
    Digitale Medien
    MR imaging following herniography in patients with unclear groin pain (2000)
    Springer
    European radiology 10 (2000), S. 1691-1696 
    Details
    ISSN: 1432-1084
    Schlagwort(e): Key words: Herniography ; MRI ; Hernia ; Groin pain
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. The aims of the present study were to assess if MRI gives the same diagnostic information as herniography concerning the presence of hernias and reveals other causes of groin pain. The prospective study enrolled 20 patients referred for herniography, 6 women and 14 men, mean age 48 years. After herniography the patients underwent MRI using T1-weighted, fat-suppressed inversion recovery (STIR), and magnetic resonance cholangiopancreaticography (MRCP) pulse sequences. No contrast medium was administered at MRI. Herniography revealed 11 hernias and MRI depicted 8 of these. Magnetic resonance imaging depicted well the anatomy in the groins. In 3 patients where hernias were not revealed, MRI revealed inflammatory changes in the symphysis region as a possible cause of groin pain. The primary diagnostic tool for diagnosing hernias is herniography. If the herniogram is normal, MRI may reveal other causes of groin pain and may also better visualize related structures in the groin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003300000555
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 92
    Digitale Medien
    Digitale Medien
    L5 radicular pain related to a cystic lesion of the posterior longitudinal ligament (2000)
    Springer
    European radiology 10 (2000), S. 1812-1814 
    Details
    ISSN: 1432-1084
    Schlagwort(e): Key words: Lumbar spine ; Ganglion cyst ; Posterior longitudinal ligament ; Radiculopathy ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. A 35-year-old man with a long history of left L5 radicular pain was found to have an intraspinal cystic lesion causing radicular compression. Magnetic resonance imaging demonstrated a round lesion situated in the anterior epidural space, with uniform high signal intensity on T2-weighted sequences characteristic of a cystic lesion. During surgery a liquid-containing cyst originating from the posterior longitudinal ligament was punctured and resected. The histologic aspect was that of a ganglion cyst without synovial layers. The radiologic differential diagnoses are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003300000445
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 93
    Digitale Medien
    Digitale Medien
    CT colonography and MR colonography: current status, research directions and comparison (2000)
    Springer
    European radiology 10 (2000), S. 786-801 
    Details
    ISSN: 1432-1084
    Schlagwort(e): Key words: CT ; MRI ; Colon ; Colonography ; Virtual colonoscopy ; Colorectal polyp ; Screening
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. With the introduction of multidetector technology in CT and the moveable table with integrated coil modules in MRI, the concept of multiorgan screening has become realistic. CT colonography and MR colonography are new radiologic techniques that promise to be highly sensitive colorectal screening examinations. This article reviews the current status and research directions in CT colonography and MR colonography, and compares these methods.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003300051006
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 94
    Digitale Medien
    Digitale Medien
    Chronic osteomyelitis of the femur: value of PET imaging (2000)
    Springer
    European radiology 10 (2000), S. 855-858 
    Details
    ISSN: 1432-1084
    Schlagwort(e): Key words:18FDG-PET ; Osteomyelitis ; Antigranulocyte antibody scintigraphy ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. The purpose of this report is to discuss FDG-PET as a potentially new imaging tool in the diagnosis of infections of osteosynthetic material. We present a patient with a poly-trauma who developed a chronic osteomyelitis and ostitis after repeated osteosynthesis in a fibular transplant to the left femur. Work up included MRI, antigranulocyte antibody scintigraphy and positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG). Infection of the fibular transplant was demonstrated clearly by PET but not by the other methods. Positron emission tomography may become an important indication in the diagnosis and follow-up of bone infection.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003300051019
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 95
    Digitale Medien
    Digitale Medien
    Diffusion-weighted echo-planar MR imaging in differential diagnosis of brain tumors and tumor-like conditions (2000)
    Springer
    European radiology 10 (2000), S. 1342-1350 
    Details
    ISSN: 1432-1084
    Schlagwort(e): Key words: Brain ; MRI ; Neoplasms ; Diffusion image ; Echo-planar MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. We assess diffusion-weighted MR images in the differential diagnosis of intracranial brain tumors and tumor-like conditions. Heavily diffusion-weighted (b = 1100 or 1200 s/mm2) axial images were obtained with single-shot echo-planar technique in 93 patients with pathologically confirmed various intracranial tumors and tumor-like conditions with diffusion gradient perpendicular to the images. We compared signal intensity of the lesions with those of gray and white matter, and cerebrospinal fluid (CSF). In 29 cases (31.1 %) the lesions were isointense to gray and/or white matter. However, 5 cases (5.4 %) showed extremely increased signal intensity: two epidermoid cysts; two chordomas; and one brain abscess. The entire portion of a tumor was markedly hyperintense in 10 cases (10.8 %): four malignant lymphomas; four medulloblastomas; one germinoma; and one pineoblastoma. A CSF-like hypointense signal was seen in many cystic tumors, and cystic or necrotic portions of tumors. A neurosarcoid granulation was the only solid lesion showing characteristically a hypointense signal like CSF. The combination of markedly hyperintense and hypointense signals was seen generally in hemorrhagic tumors. Diffusion-weighted echo-planar MR imaging is useful in the differential diagnosis of brain tumors and tumor-like conditions, and suggests specific histological diagnosis in some cases.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003309900310
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 96
    Digitale Medien
    Digitale Medien
    Value of (18F)-FDG positron emission tomography, computed tomography, and magnetic resonance imaging in diagnosing primary and recurrent ovarian carcinoma (2000)
    Springer
    European radiology 10 (2000), S. 761-767 
    Details
    ISSN: 1432-1084
    Schlagwort(e): Key words: Ovarian cancer ; Lesion characterization ; Recurrence ; PET ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. The aim of this study was to compare prospectively the accuracy of whole-body positron emission tomography (PET), CT and MRI in diagnosing primary and recurrent ovarian cancer. Nineteen patients (age range 23–76 years) were recruited with suspicious ovarian lesions at presentation (n = 8) or follow-up for recurrence (n = 11). All patients were scheduled for laparotomy and histological confirmation. Whole-body PET with FDG, contrast-enhanced spiral CT of the abdomen, including the pelvis, and MRI of the entire abdomen were performed. Each imaging study was evaluated separately. Imaging findings were correlated with histopathological diagnosis. The sensitivity, specificity and accuracy for lesion characterization in patients with suspicious ovarian lesions (n = 7) were, respectively: 100, 67 and 86 % for PET; 100, 67 and 86 % for CT; and 100, 100 and 100 % for MRI. For the diagnosis of recurrent disease (n = 10), PET had a sensitivity of 100 %, specificity of 50 % and accuracy of 90 %. The PET technique was the only technique which correctly identified a single transverse colon metastasis. Results for CT were 40, 50 and 43 %, and for MRI 86, 100 and 89 %, respectively. No statistically significant difference was seen. Neither FDG PET nor CT nor MRI can replace surgery in the detection of microscopic peritoneal disease. No statistically significant difference was observed for the investigated imaging modalities with regard to lesion characterization or detection of recurrent disease; thus, the methods are permissible alternatives. The PET technique, however, has the drawback of less accurate spatial assignment of small lesions compared with CT and MRI.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003300051000
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 97
    Digitale Medien
    Digitale Medien
    Plain film, CT and MRI sensibility in the evaluation of intraorbital foreign bodies in an in vitro model of the orbit and in pig eyes (2000)
    Springer
    European radiology 10 (2000), S. 1338-1341 
    Details
    ISSN: 1432-1084
    Schlagwort(e): Key words: Eye injuries ; CT ; MRI ; Eye foreign body
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Detection and characterization of intraorbital foreign bodies (IFB) is fundamental in acute trauma setting, preventing inflammatory sequelae or complications related to IFB movements when a MRI study is planned. Papers concerning plain film and CT sensibility in IFB detection show controversial results. For this reason we investigated plain film, CT and MRI sensibility in the evaluation of IFB. For an in vitro model, specimens of dry and fresh wood, glass, iron, plastic and graphite were immersed in animal lard and in a 0.9 % sodium chloride plus 3.5 g/dl human serum albumin solution. Specimens of different size and nature where also implanted into enucleated pig eyes. Air bubbles were introduced also. Plain film, CT and MRI investigation were performed. Plain films underestimated intraocular IFB as plastic, fresh or dry wooden IFB were not demonstrated. The CT study was always able to depict and differentiate IFB according to the attenuation values. Severe artefacts prevented demonstration of iron, glass and graphite IFB on MRI, whereas plastic or wooden IFB were always detected. Despite radiographs have been suggested as a prerequisite for MR imaging, because our results showed plain film to underestimate radiolucent IFB, we suggest CT as the modality of choice when IFB has to be ruled out.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003309900306
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 98
    Digitale Medien
    Digitale Medien
    Reversed palmaris longus muscle on MRI: report of four cases (2000)
    Springer
    European radiology 10 (2000), S. 1242-1244 
    Details
    ISSN: 1432-1084
    Schlagwort(e): Key words: Muscle anomalies ; Median nerve compression ; Wrist ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Muscle anomalies around the wrist, in particular the palmaris longus muscle, may cause effort-related median nerve compression. A search of the medical records at our university hospital between 1994 and 1999 revealed four patients with an effort-related median nerve compression due to a reversed palmaris longus muscle. Magnetic resonance imaging was used in the patient work-up and showed an anomalous muscle in each case that had been missed initially. All four patients were free of pain after simple excision of the anomalous muscle. Awareness of muscle anomalies at the wrist on MR imaging is essential in evaluating patients with nerve compressions at the wrist. The purpose of this article is to heighten this awareness in radiologists.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003300000314
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 99
    Digitale Medien
    Digitale Medien
    Mediastinal lymphangioma in adults: CT and MR imaging features (2000)
    Springer
    European radiology 10 (2000), S. 1310-1314 
    Details
    ISSN: 1432-1084
    Schlagwort(e): Key words: Thorax ; Mediastinum ; Lymphangioma ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Adult mediastinal lymphangiomas are rare lesions the diagnosis of which is difficult based on imaging studies. A retrospective study of CT, MR, and pathologic findings of mediastinal lymphangioma was performed in order to correlate pathological and imaging findings. Nine cases of adult lymphangiomas were identified in the records of our institution over a 12-year period. The CT, MR, and pathologic findings were reviewed. Lesions were classified pathologically as unilocular, cavernous, and intermediate types. Pathologic examination identified six cases of unilocular lesion, two cases of cavernous type, and one intermediate type. The CT features (n = 9) included a smoothly marginated non-enhancing mass of water attenuation (n = 7), a non-enhancing mass of soft tissue attenuation (n = 1), and an enhancing multiseptated mass (n = 1). Lesions were located in the anterior mediastinum (n = 2), right paratracheal (n = 4), subcarinal (n = 1), aortopulmonic window (n = 1) areas, and below the left hilum extending into the posterior mediastinum (n = 1). The MR features (n = 3) were characterized by an enhancing multicystic and multiseptated appearance, evocative of a cavernous type in two cases. The CT appearance of mediastinal thoracic lymphangioma is variable depending on the pathologic type. The most common unilocular type is a non-enhancing thin-walled mass on CT. A less frequent cavernous type can be suggested based on a multiseptated and loculated mass on CT and/or MR examination.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003300000380
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 100
    Digitale Medien
    Digitale Medien
    Study of the variations in length of the anterior cruciate ligament during flexion of the knee: use of a 3D model reconstructed from MRI sections (2000)
    Springer
    Surgical and radiologic anatomy 21 (2000), S. 313-317 
    Details
    ISSN: 1279-8517
    Schlagwort(e): Anterior cruciate ligament ; Kinematics ; Knee ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The aim of this study is to suggest an anatomic study of the modifications of the length of the anterior cruciate ligament (ACL) and its bundles during flexion with the aid of a 3D computerized model of the knee in a living subject. The method of evaluation suggested is a 3D computerized reconstruction based on MRI sections, reproducing the movement of flexion of the knee from 0 to 75°. Twenty-one sections were made for each of the 13 positions of flexion. The reconstruction of Delaunay and the realignment of each position provided a 3D model which allowed monitoring of a bony point during the movement. By knowing the relative displacement of the ligamentous attachments it was possible to define the biometry of the ligament by calculating the length of the bundles of the ACL in each position and to demonstrate the variations in length during the movement. The mean length of the ligament was 3.4 mm. The anteromedial bundle was longer by 30% compared with the other two bundles. During flexion the anteromedial bundle was not much modified (this feature seems to provide a reference position for a ligamentoplasty), the posterolateral bundle became taut after 30°, and the intermediate bundle relaxed from the beginning of movement. Based on the data from the literature, this method allows an anatomic approach to the ACL, bundle by bundle, during flexion movement.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s00276-999-0313-5
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...