Library

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 2010-2014
  • 2000-2004  (4)
  • 1995-1999  (14)
  • 1985-1989  (10)
  • Tomography
  • 1
    Book
    Book
    Boston :Birkhäuser,
    Title: Sampling, wavelets, and tomography /
    Contributer: Benedetto, John , Zayed, Ahmed I.
    Publisher: Boston :Birkhäuser,
    Year of publication: 2003
    Pages: p. cm
    Series Statement: Applied and computational harmonic analysis
    ISBN: 0-8176-4304-4 , 3-7643-4304-4
    Type of Medium: Book
    Language: English
    Keywords: Hamonic analysis ; Wavelets (Mathematics) ; Fourier analysis ; Sampling (Statistics) ; Tomography
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Skeletal radiology 29 (2000), S. 409-412 
    ISSN: 1432-2161
    Keywords: Key words Tarsal bones ; abnormalities ; Tomography ; X-ray computed
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Objective. To determine the findings of calcaneonavicular coalition on coronal CT. Design. We retrospectively reviewed the CT scans of 14 calcaneonavicular coalitions in eight patients. All coalitions were visible on the axial scans, and the diagnosis was confirmed by surgery in five patients. These CT scans were compared with scans of ten normal feet. Results. We identified two features of calcaneonavicular coalition on coronal CT: lateral bridging (an abnormal bony mass lateral to the head of the talus) and rounding of the talus. All eight patients demonstrated at least one of these two findings. Conclusion. Although calcaneonavicular coalition is best seen on axial CT scans of the feet, there are two abnormalities, lateral bridging and rounding of the head of the talus, which should suggest the diagnosis on coronal CT scans.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1619-7089
    Keywords: Key words: Behçet’s disease ; Tomography ; emission computed ; Acetazolamide ; Diaschisis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. The purpose of this study was to characterise the nature of the baseline perfusion defects found in patients with Behçet’s disease using hexamethylpropylene amine oxime single-photon emission tomography in conjunction with acetazolamide test (Acz SPET). Eleven patients underwent both baseline and Acz SPET. Regions of interest (ROIs) were drawn on the areas with decreased perfusion (D-ROI) and, in the same section, on areas with normal perfusion (N-ROI). The ROIs were then repositioned on the corresponding section on Acz SPET. The mean ROI counts were then transformed into a perfusion index value (PIV) with reference to the global brain counts. In total we found 24 D-ROIs (17 in the cortical and 7 in subcortical grey matter). The influence of Acz infusion was selectively registered in the D-ROIs, where PIVs changed from 1.23±0.17 (baseline SPET) to 1.63±0.23 (Acz SPET) (P〈0.001). No significant difference was seen in the N-ROIs (1.46±0.21 and 1.40±0.17, respectively, on baseline SPET and Acz SPET). Our results demonstrate that Acz infusion increases the regional cerebral blood flow within baseline grey matter perfusion defects. This finding suggests that baseline perfusion abnormalities could reflect a disconnection rather than local vasculitic involvement.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1619-7089
    Keywords: Key words: Arrhythmias ; Imaging ; Tomography ; Infarct size ; Defibrillator
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Infarct size as determined by perfusion imaging is an independent predictor of mortality after implantable cardioverter defibrillator (ICD) implantation in patients with coronary artery disease (CAD) and life-threatening ventricular arrhythmias (VA). However, its value as a predictor of VA recurrence and hospitalisation after ICD implantation is unknown. Therefore, the objective of this study was to evaluate whether infarct size as determined by perfusion imaging can help to identify patients who are at high risk for recurrence of VA and hospitalisation after ICD implantation.We studied 56 patients with CAD and life-threatening VA. Before ICD implantation, all patients underwent a uniform study protocol including a thallium-201 stress-redistribution perfusion study. A defect score as a measurement of infarct size was calculated using a 17-segment 5-point scoring system. Study endpoints during follow-up were documented episodes of appropriate anti-tachycardia pacing and/or shocks for VA and cardiac hospitalisation for electrical storm (defined as three or more appropriate ICD interventions within 24 h), heart failure or angina. After a mean follow-up of 470±308 days, 22 patients (39%) had recurrences of VA. In univariate analysis, predictors for recurrence were: (a) ventricular tachycardia (VT) as the initial presenting arrhythmia (86% vs 59% for patients without ICD therapy, P=0.04), (b) treatment with β-blockers (36% vs 68%, P=0.03) and (c) a defect score (DS) ≥20 (64% vs 32%, P=0.03). In multivariate analysis, VT as the presenting arrhythmia (χ2=5.51, P=0.02) and a DS ≥20 (χ2=4.22, P=0.04) remained independent predictors. Cardiac hospitalisation was more frequent in patients with a DS ≥20 (44% vs 13% for patients with DS 〈20, P=0.015) and this was particularly due to more frequent hospitalisations for electrical storm (24% vs 3% for patients with DS〈20, P=0.037). The extent of scarring determined by perfusion imaging can separate patients with CAD into high- and low-risk groups for recurrence of VA and cardiac hospitalisation after ICD implantation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European radiology 9 (1999), S. 1203-1204 
    ISSN: 1432-1084
    Keywords: Key words: Cellulosis ; Interstitial ; Tomography ; X-ray computed
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Chest radiographs and high-resolution chest CT scans were performed in a 30-year-old man with a history of intravenous drug abuse and diffuse micronodular infiltrates. Transbronchial biopsy gave a diagnosis of cellulose granulomatosis of the lung. Cellulose granulomatosis should be considered in the differential diagnosis of pulmonary interstitial disease, especially in the setting of intravenous drug abuse.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1279-8517
    Keywords: Shoulder ; Magnetic Resonance imaging ; Tomography ; X Ray computed ; Arthrography ; Labrum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé La possibilité de détecter et de classer les lésions du bourrelet supérieur de la cavité glénoïdale de la scapula (SLAP lesions: Superior Bourrelet Anterior to Posterior) est une nécessité pour le radiologue et l'orthopédiste confrontés à des patients présentant des douleurs de l'épaule. Le but de cette étude réalisée sur des épaules cadavériques, était de déterminer les valeurs respectives de l'arthro-scanner et de l'arthro-IRM dans la détection des variations anatomiques normales et des anomalies pathologiques du bourrelet glénoïdal supérieur. Un arthro-scanner, une arthro-IRM, puis une dissection anatomique ont été réalisées sur 23 épaules fraîches et les résultats de ces examens ont été analysés par un radiologue et deux chirurgiens orthopédistes. L'injection intra-articulaire de gadolinium n'étant actuellement pas autorisée en France, un produit de contraste iodé à été utilisé pour l'arthro-scanner et l'arthro-IRM. Dans cette étude, la sensibilité de l'arthro-IRM semblait meilleure que celle de l'arthro-scanner (respectivement 4 et 3 lésions diagnostiquées sur 5), bien que ce résultat ne soit pas statistiquement significatif compte tenu du petit nombre de cas. En conclusion, dans les conditions spécifiques de notre étude, l'arthro-IRM semble être la méthode de choix pour la détection et la classification des lésions du bourrelet glénoïdal supérieur.
    Notes: Summary The ability to detect and categorize SLAP (Superior Labrum Anterior to Posterior) lesions of the scapular labrum is of practical importance to the orthopedic surgeon and the radiologist. The aim of this study, performed on cadaveric shoulders, was to determine whether CT arthrography or MR arthrography is able to show normal anatomical variation of the glenoid labrum and detect labral abnormalities. CT arthrography, MR arthrography followed by anatomical dissection were performed on twenty three fresh frozen cadaveric shoulders and analysed by a radiologist and two orthopaedic surgeons. As Gadolinium intra-articular injection is not allowed in France, we used an iodinated contrast media for both MR arthrography and CT arthrography. In this study, the sensitivity of MR arthrography seemed higher than CT arthrography (respectively 4 and 3 labral lesions diagnosed out of five), although no significant statistical conclusions can be made due to the small number of cases. In conclusion, under such specific conditions, MR arthrography seems to be the method of choice for the detection and classification of labral lesions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-0789
    Keywords: Key words Earthworm burrow system ; Seasonal variation ; 3D skeleton ; Tomography ; Image analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Four soil cores (length, 20 cm; diameter, 16 cm) were sampled in a Swiss pre-Alpine meadow with high earthworm abundance (〉400 individuals/m2); two cores were taken in October 1993 and the other two cores in April 1994. The cores were described using computer assisted tomography which gives a series of section images every 3 mm. A method for reconstructing the three-dimensional (3D) skeleton of the earthworm burrow system is presented and discussed. This method provides an image of the structural organisation of the burrow system and was found to be adequately sensitive for use in ecological and functional studies. The seasonal variation of these 3D skeletons was investigated using two approaches, i.e. the analysis of: (1) global burrow system characteristics, and (2) individual burrow characteristics. At the scale of the global burrow system no difference was found between seasons (same number of burrows and same total burrow length) except for the vertical segment distribution, which was homogeneous in spring and decreased with depth in the fall. The study of individual burrow characteristics revealed that burrows tended to be more vertical in spring and that their branching intensity was higher in this season.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1279-8517
    Keywords: Shoulder ; Magnetic Resonance imaging ; Tomography ; X Ray computed ; Arthrography ; Labrum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The ability to detect and categorize SLAP (Superior Labrum Anterior to Posterior) lesions of the scapular labrum is of practical importance to the orthopedic surgeon and the radiologist. The aim of this study, performed on cadaveric shoulders, was to determine whether CT arthrography or MR arthrography is able to show normal anatomical variation of the glenoid labrum and detect labral abnormalities. CT arthrography, MR arthrography followed by anatomical dissection were performed on twenty three fresh frozen cadaveric shoulders and analysed by a radiologist and two orthopaedic surgeons. As Gadolinium intra-articular injection is not allowed in France, we used an iodinated contrast media for both MR arthrography and CT arthrography. In this study, the sensitivity of MR arthrography seemed higher than CT arthrography (respectively 4 and 3 labral lesions diagnosed out of five), although no significant statistical conclusions can be made due to the small number of cases. In conclusion, under such specific conditions, MR arthrography seems to be the method of choice for the detection and classification of labral lesions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Annales geophysicae 16 (1998), S. 1180-1189 
    ISSN: 0992-7689
    Keywords: Tomography ; Airglow ; Mesopause ; Gravity waves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract It is pointed out that observations of periodic nightglow structures give excellent information on atmospheric gravity waves in the mesosphere and lower thermosphere. The periods, the horizontal wavelengths and the phase speeds of the waves can be determined from airglow images and, using several cameras, the approximate altitude of the luminous layer can also be determined by triangulation. In this paper the possibility of applying tomographic methods for reconstructing the airglow structures is investigated using numerical simulations. A ground-based chain of cameras is assumed, two-dimensional airglow models in the vertical plane above the chain are constructed, and simulated data are calculated by integrating the models along a great number of rays with different elevation angles for each camera. After addition of random noise, these data are then inverted to obtain reconstructions of the models. A tomographic analysis package originally designed for satellite radiotomography is used in the inversion. The package is based on a formulation of stochastic inversion which allows the input of a priori information to the solver in terms of regularization variances. The reconstruction is carried out in two stages. In the first inversion, constant regularization variances are used within a wide altitude range. The results are used in determining the approximate altitude range of the airglow structures. Then, in the second inversion, constant non-zero regularization variances are used inside this region and zero variances outside it. With this method reliable reconstructions of the models are obtained. The number of cameras as well as their separations are varied in order to find out the limitations of the method.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Annales geophysicae 16 (1998), S. 1332-1342 
    ISSN: 0992-7689
    Keywords: Tomography ; Aurora ; EISCAT ; Ionosphere ; Conductivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Tomographic reconstruction of the three-dimensional auroral are emission is used to obtain vertical and horizontal distributions of the optical auroral emission. Under the given experimental conditions with a very limited angular range and a small number of observers, algebraic reconstruction methods generally yield better results than transform techniques. Different algebraic reconstruction methods are tested with an auroral are model and the best results are obtained with an iterative least-square method adapted from emission-computed tomography. The observation geometry used during a campaign in Norway in 1995 is tested with the are model and root-mean-square errors, to be expected under the given geometrical conditions, are calculated. Although optimum geometry was not used, root-mean-square errors of less than 2% for the images and of the order of 30% for the distribution could be obtained. The method is applied to images from real observations. The correspondence of original pictures and projections of the reconstructed volume is discussed, and emission profiles along magnetic field lines through the three-dimensionally reconstructed arc are calibrated into electron density profiles with additional EISCAT measurements. Including a background profile and the temporal changes of the electron density due to recombination, good agreement can be obtained between measured profiles and the time-sequence of calculated profiles. These profiles are used to estimate the conductivity distribution in the vicinity of the EISCAT site. While the radar can only probe the ionosphere along the radar beam, the three-dimensional tomography enables conductivity estimates in a large area around the radar site.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Geometriae dedicata 66 (1997), S. 357-368 
    ISSN: 1572-9168
    Keywords: Tomography ; convex sets ; X-ray ; chord function.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract A method for the reconstruction of boundary points of convex sets is provided starting from three X-ray pictures in two orthogonal directions and from a point.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 12
    ISSN: 1432-2161
    Keywords: Key words Tomography ; X-ray computed ; Fractures ; MRI ; Pelvis ; fractures ; Pelvis ; radionuclide studies ; Radiation ; injurious effects ; complications of ; Therapeutic radiology ; Tomography ; positron emission
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Pelvic bone injuries are infrequent complications of radiotherapy. However, insufficiency fractures in irradiated pelvic bones may be underdetected, particularly in postmenopausal women. We describe the clinical presentation, radiologic evaluation, and course of disease in three patients with postradiation pelvic insufficiency fractures. Differential diagnosis included metastatic disease, tumor recurrence, and second malignancy. Recognition of radiographic features may prevent unnecessary, possibly morbid treatments.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Skeletal radiology 26 (1997), S. 386-397 
    ISSN: 1432-2161
    Keywords: Key words Hip dislocation ; congenital ; Diagnostic imaging ; Tomography ; X-ray computed ; Magnetic resonance imaging ; Radiography ; Arthrography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Developmental dysplasia of the hip (DDH) has a broad spectrum of presentation with the minor findings resolving spontaneously and the most severe ones resulting in disability, if not diagnosed early in life. Diagnosis in the first few months of life allows conservative treatment with complete resolution in most cases. Suspicion of DDH is based on ethnic, family, and pregnancy history, and on physical examination of the newborn. Imaging assists in the diagnosis and follows the treatment. Different modalities have their own advantages and disadvantages. This article deals with the description of the disease, risk factors, statistics, the physical examination as applied to real-time sonography, and imaging (plain radiography, arthrography, computed tomography, and magnetic resonance imaging).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Urological research 24 (1996), S. 149-160 
    ISSN: 1434-0879
    Keywords: Regional renal blood flow ; Microsphere technique ; Tomography ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Variations in regional renal blood flow have been implicated in a variety of disease states. Many techniques have been developed in an attempt to accurately assess these changes. The microsphere technique is the most widely used method at the present time. This technique allows focal measurements to be performed, but there is a conflict between the resolution of the method and the number of microspheres necessary in each sample. New imaging techniques such as tomography and autoradiography enable visual assessment of renal blood flow. Though there is no ideal method, these techniques have opended up new possibilities in the quantification of regional renal blood flow.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Surveys in geophysics 17 (1996), S. 517-556 
    ISSN: 1573-0956
    Keywords: Borehole ; Logging ; Resistivity ; Electrical ; Electromagnetic ; Spontaneous Potential ; Radar ; Tomography ; History
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Electrical and electromagnetic geophysical techniques have reached a high level of technological sophistication since they were first used in boreholes less than one hundred years ago. Borehole logging-the detailed determination of rock and fluid properties adjacent to the borehole, and borehole geophysics-extending the range of geophysical investigation large distances away from the borehole, are essential for exploration, assessment and production of earth resources, as well as for fundamental studies of the earth. Borehole electrical and electromagnetic methods incorporate 17 decades of the electromagnetic spectrum, from 1000-s geomagnetic studies, through resistivity and permittivity measurements, to high-resolution resistivity imaging, NMR and optical spectroscopy.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Der Radiologe 36 (1996), S. 175-180 
    ISSN: 1432-2102
    Keywords: Schlüsselwörter Geschichte ; HNO-Radiologie ; Tomographie ; Computertomographie ; Magnetresonanztomographie ; Key words History ; Head and neck radiology ; Tomography ; Computer tomography ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The head and neck region is a limited anatomical area in radiological diagnostics. Nevertheless, head and neck radiology has a long and interesting history with excellent scientists involved in its development. Before the discovery of X-rays, no information about the head and neck could be obtained without surgery or even autopsy. Therefore, conventional radiograms and special projections were an important step forward. During the 1950s, a second diagnostic breakthrough was achieved by the introduction of tomographic techniques. Film tomography was the first step in this important development. Computed tomography and magnetic resonance imaging yielded astonishing and unforeseen results. Especially in the field of magnetic resonance imaging, the techniqual development has not yet come to an end. Scientific research and continuing education are required in order to achieve further advances in head and neck radiology, and European cooperation is on the way.
    Notes: Zusammenfassung Der Kopf-Hals-Bereich ist im Vergleich zu den anderen Regionen der radiologischen Diagnostik ein begrenztes Gebiet. Trotzdem hat die Kopf-Hals-Radiologie eine lange, interessante und von hervorragenden medizinischen Persönlichkeiten geprägte Geschichte. Wenn man berücksichtigt, daß vor der Entdeckung der Röntgenstrahlen Einblicke in das Schädelinnere und die Halsstrukturen ohne Sektion oder Operation überhaupt nicht möglich waren, bedeutete bereits die Einführung der Summationsaufnahmen und die Erarbeitung von Spezialprojektionen ein entscheidender Schritt. Ein zweiter diagnostischer Durchbruch erfolgte in den 50er Jahren dieses Jahrhunderts durch die Entwicklung der Schnittbildverfahren. Diese führten zunächst als konventionelle Tomographie, dann als Computertomographie und Magnetresonanztomographie zu erstaunlichen und unerwarteten Ergebnissen. Im MRT-Bereich ist diese Entwicklung noch nicht abgeschlossen. Intensivere medizinisch-wissenschaftliche Arbeit und gezieltere Fortbildung, auch in europäischem Rahmen, erscheinen erforderlich, um dieser Entwicklung gerade im Spezialbereich Kopf und Hals gerecht zu werden.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 17
    ISSN: 1432-1084
    Keywords: Digital radiography ; Image processing ; Subtraction ; Thorax ; Tomography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Digital tomosynthesis makes it possible to reconstruct multiple tomographs from digital data obtained during a single tomographic motion and permits digital processing, which adds a number of special advantages to the well-known advantages of conventional tomography. We performed digital tomosynthesis with a fluororadiographic TV unit with tomographic function which was capable of producing pulsed low-and high-energy X-rays alternately, and we studied digital image processing to improve the image clarity of the reconstructed tomographs. To identify the optimal parameters for processing image data by means of spatial frequency filtration we evaluated the spatial frequency distribution of image data in linear tomographs of the lung, and on the basis of the results of this study we developed several types of digital image processing to reduce tomographic blur and system noise, to improve visualisation of faint opacities, to reduce resistant tomographic blur as well as overall blur, and to generate low-noise bone images based on dual-energy subtraction tomosynthesis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Clinical rheumatology 14 (1995), S. 633-640 
    ISSN: 1434-9949
    Keywords: Scleroderma ; Lung Fibrosis ; High Resolution Computed ; Tomography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The aim of the study was to investigate the pulmonary parenchymal abnormalities by high resolution computed tomography (HRCT) in patients with various forms of scleroderma. Three scans were performed sequentially in all cases: one at the level of aortic arch, one at the tracheal carina and one 1–2 cm above the diaphragm. Seventy cases with limited, 21 patients with diffuse cutaneous systemic sclerosis and 10 cases with circumscribed scleroderma were investigated. The 21 patients with diffuse scleroderma included three normal HRCT scan (14%), three with ground glass attenuation (14%), one with ground glass attenuation with fibrosis, three with fibrosis (14%), six with subpleural and five with diffuse honeycombing. The majority of cases with extensive honeycombing of the lungs had anti-Scl 70 autoantibody which was the characteristic antibody of the diffuse scleroderma subset. The 70 cases with limited cutaneous systemic sclerosis were characterized by normal HRCT (43%), ground glass opacity with or without fibrosis (18.6%), whereas fibrosis was detected in 22.9%, subpleural or diffuse honeycombing in 15.7% of the patients. Six of the ten cases with circumscribed scleroderma also showed a fibrosis. Cases with diffuse scleroderma are characterized by the presence of advanced fibrosis, whereas the extent of fibrosis is far less pronounced in limited scleroderma. Mild fibrosis may also be present in circumscribed scleroderma forms.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 19
    ISSN: 1432-1106
    Keywords: Tomography ; Dopamine ; Striatum ; MPTP ; Monkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Positron emission tomography following intravenous administration of 6-[18F]-L-fluorodopa was used to investigate the usefulness of PET for the assessment of normal and abnormal dopaminergic function. For this purpose, the incracerebral distribution of 6-[18F]-L-fluorodopa and its metabolites was evaluated in normal control and asymptomatic MPTP-treated rhesus monkeys. MPTP is a neurotoxic compound which destroys selectively the dopaminergic neurons of the nigrostriatal pathways in primates. The 18F accumulation was found to be significantly reduced in the striatum, putamen more than caudate, of the MPTP-treated animals compared to the normal controls. The 18F accumulation in dopamine-poor areas did not differ between the two groups. The ratios of striatum to dopamine-poor brain area were highly correlated to the concentrations of the dopamine metabolite, homovanillic acid, in the cerebrospinal fluid of the same animals. The findings are consistent with the hypothesis that “silent damage” to the dopaminergic nigral neurons may precede the onset of parkinsonism by many years and that PET scanner examination using 6-[18F]-L-fluorodopa may be useful in the detection of subtle dopaminergic dysfunctions as may exist in DA-related motor syndromes and neuropsychiatric disorders.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Springer
    European journal of nuclear medicine 15 (1989), S. 189-193 
    ISSN: 1619-7089
    Keywords: SPECT ; Computers ; Tomography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A new method is described to allow interactive selection of the reconstruction filter at the time of interpretation of images from single-photon tomography. In the filtered back projection algorithm, the only part of the reconstruction process requiring user interaction is the selection of the window function. Since the ramp and window filters have different purposes, they can be separated, placing the window at the end of the reconstruction process as a three-dimensional filter. All stages of reconstruction except the window filtering are performed before the physician begins to interpret the study. The three-dimensional filtering is performed very rapidly with use of the Chebyshev convolution algorithm. A 64×64×64 pixel cube of data is filtered in 13–33 s using filters of 3–11 lengths. Smaller volumes of image data can be filtered in less than 1 s; thus, the user can interactively choose any desired filter for a given tomographic study at the time of interpretation of the images.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Oral radiology 5 (1989), S. 11-22 
    ISSN: 1613-9674
    Keywords: Temporomandibular joint ; Tomography ; Blurred image
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary For this study, seven different types of phantom were made simulating the condyle. The phantoms attached to a human dry skull were tomographed using the Polytome-U, under identical conditions to those of tomography for patients. There was no significant difference of the images between tube side and film side of the mandible. The images of the medial part of the TMJ were clearer than that of the lateral part. A discrepancy of contours on the focal plane between the phantom and the tomographic image occurred when the inclination of the phantom surface was larger than the maximum exposure angle. Concerning the influence of focal movements to image quality, the images obtained from hypocycloidal movements were superior with minimum superimposition, although the contrast of the image varied when the phase of the hypocycloidal movements were altered. Any sectional images were not manifested with the phantoms when the inclination of the phantom surface was larger than 23 degrees. Furthermore, 106 condyles from human dry skull were examined on the area of which the inclination of the condylar surface was less than 23 degrees. The mean latero-medial distance of the area was 14.1mm, which corresponded to 75% of whole latero-medial distance of the condyle.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Oral radiology 5 (1989), S. 31-38 
    ISSN: 1613-9674
    Keywords: Panoramic radiography ; Tomography ; Scanography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In this report, basic principles of panoramic tomography are suggested. According to this principle, the effective rotation center doesn't have the importance as was considered before, the tomographic factor of panoramic tomography and the scanographic factor of panoramic tomography are clearly separated, and the relationship between these two factors are mentioned. Exposure angle and section thickness are related to the tomographc factor, and projection angles and image distortion and characteristics of formation of superimposed blurred structures are related to the scanographic factor. There are no machines satisfying the new principle, but the new panoramic tomograph can be designed according to and as an extension of this new principle.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 11 (1989), S. 33-40 
    ISSN: 0741-0581
    Keywords: High-voltage electron microscopy ; Thick specimens ; Tomography ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Optimal imaging of complex structures requires proper alignment relative to the optic axis of the electron microscope. This is especially important for high-voltage and intermediatevoltage microscopes, which form an in-focus image throughout the entire thickness of the object. As a result, structures at different specimen heights form overlapping and confused images that severely curtail the usefulness of these instruments.The work described here provides a generalized, flexible method for optimizing specimen orientation and eliminating or limiting image overlap by means of a commonly used double-tilt stage. Analysis of the motion about the two axes provides accurate tilting for any azimuthal direction whether or not it corresponds to a mechanical axis of the stage. An object can be positioned to minimize image overlap, to record stereopairs for any parallax axis, and to record three-dimensional data sets by the conical collection geometry.Images of muscle paracrystals are shown after tilting about an axis perpendicular to a symmetry direction. The tilted image displays higher-order symmetry, which is altered by changes of one degree. Precision double-tilting for optimizing stereopairs is shown for a desmosome recorded using different parallax axes and pretilts. A tomographic conical data-collection scheme is demonstrated by imaging a microtubule axoneme for a specific cone half-angle and arbitrary azimuthal angles.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 24
    ISSN: 1613-9674
    Keywords: Tomography ; Adaptive changes ; Temporomandibular joint
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary It is important for planning the treatment of patients with TMJ dysfunctions to know the location and the distribution of remodeling on the articular surfaces so that the direction of the load may be assessed. The aim of this study is to radiologically clarify the location and the distribution of articular remodeling, in order to investigate the correlation between joint morphology and oral function. The material used in this study was selective lateral tomograms of 110 arthritic patients ranging in age from 12 to 78 years. Three tomograms indicating the lateral, medial and central portion of the condylar heads were selected from 10 simultaneous serial tomograms. The incidence of flattening, concavity and irregularity of articular surfaces was examined on each anterior and posterior surfaces of both condylar heads and articular eminences. Articular remodeling occurred most frequently on the central portion of the condylar heads on the lateral tomograms. A number of flattened surfaces with or without concavity were unexpectedly found on the posterior surfaces of the condylar heads.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    European journal of nuclear medicine 12 (1987), S. 578-579 
    ISSN: 1619-7089
    Keywords: Liver ; Radionuclide imaging ; Tomography ; Emission computed ; Hepatic veins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An area of photon deficiency in both planar and single photon emission computed tomography (SPECT) images of the liver using 99mTc-Sulfur Colloid was found to be due to a dilated hepatic vein.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Plasma chemistry and plasma processing 6 (1986), S. 127-141 
    ISSN: 1572-8986
    Keywords: Tomography ; emission coefficients ; nonsymmetric plasmas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract The technique of reconstructive tomography (RT) is a powerful method of obtaining local, spatially resolved volumetric emission coefficients from line integral data. The applicability of this technique as a diagnostic for nonuniform sources is studied using simulated data with and without noise. The major advantage of RT techniques is that they may be applied, without restriction, to highly asymmetric data as well as symmetric data. When applied to symmetric data, the technique appears to be less susceptible to noise than Abel inversion techniques. Also examined is a method of accounting for self-absorption under certain circumstances.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    European journal of nuclear medicine 12 (1986), S. S36 
    ISSN: 1619-7089
    Keywords: Myocardial metabolism ; Fatty acid ; Positron emission ; Tomography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Positron emission tomography with 11C-palmitate and single photon imaging with terminally radioiodinated fatty acid analogues (123I-FFA) were evaluated for the non-invasive assessment of regional myocardial fatty acid metabolism during ischaemia. Decreased uptake of tracer and delayed clearance of activity in the ischaemic myocardium were reported for both 11C-and 123I-labelled compounds. However, since during ischaemia both myocardial blood flow and oxidative metabolism are reduced concomitantly, either factor can be responsible for the changes observed. Experimental preparations in which fatty acid metabolism can be modified independently of flow are helpful for the characterization of the relationship between metabolism and myocardial kinetics of labelled fatty acids. Results obtained during flow-independent inhibition of fatty acid oxidation include the following observations: - In dogs with controlled coronary perfusion the rate of clearance of 11 C-palmitate activity is decreased during diminished delivery of oxygen, regardless of whether myocardial perfusion is concomitantly reduced or not. - In isolated rabbit hearts perfused at normal flow, the extraction of 123 I-FFA is decreased during hypoxia. - During pharmacological inhibition of fatty acid oxidation the deiodination of 123 I_FFA is markedly reduced in rat hearts in vivo and in vitro.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 28
    ISSN: 1573-9686
    Keywords: Renal cortex ; Perfusion ; X-ray ; Tomography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract The three-dimensional image data generated by the Dynamic Spatial Reconstructor (DSR) enables measurement of the three-dimensional distribution of blood supply in organs. We have applied this imaging technique to evaluate renal cortical blood flow distribution and compare it with distribution of radiolabeled microspheres. The DSR, a high temporal resolution volumetric roentgenographic computed tomographic scanner, was used to scan the volume containing a kidney in 0.13–0.26 s and repeating this scan 8–4 times per s for six s during a renal arteriogram. Five anesthetized dogs were studied in the prone position with the left kidney exteriorized through a flank incision. An electromagnetic flowmeter was placed around the renal artery and a needle placed retrograde into the artery for injection of a 2 cc bolus of contrast agent. During the scan the contrast agent was injected over a four s period during which radioactively labelled microspheres were injected into the left atrium. The tomographic images of approximately 10 parallel, 5 mm thick sagittal slices corresponding to the slices of the kidney used for counting microspheres in the cortical layers were displayed and analyzed. The time point chosen for analysis was the one in which peak brightness (i.e., concentration of contrast agent) was detected in the cortex. The spatial distribution of peak brightness values was compared to the number of microspheres at the same sampling locations. The microsphere-based value of regional cortical blood flow fell below the regression line for the juxtamedullary cortex and above for the outer cortex. This result is consistent with the preferential distribution of microspheres to the outer cortex whereas the contrast agent distributed more uniformly throughout the cortex.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...