Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    ISSN: 1432-1084
    Keywords: Brain, electrode position ; Epilepsy ; Three-dimensional MRI ; Three-dimensional reconstructions, MRI
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Subdural strip electrodes or intracerebral electrodes are used to localise epileptic foci, which is imperative in epilepsy surgery. The precise positioning of the subdural electrodes, which is performed via a bore-hole, is difficult. Therefore their location in relation to the gyri and sulci has to be determined by radiological techniques. In this study, a three-dimensional (3D) MRI technique was used for the localisation of intracranial EEG electrodes in 17 patients suffering from severe epilepsy. A 3D gradient echo sequence with slices of 1 mm thickness was required for the assessment of the gyral anatomy of the brain surface. A short repetition time of 30 ms leads to diagnostic image quality and to an acceptable measurment time of about 15 min. Postprocessing with 3D surface reconstruction was performed using a Sun workstation. Three-dimensional reconstruction allows a more precise registration of the localisation of the EEG elctrodes and the simultaneous display of the adjacent brain structures. The incorrect placement of intracranial electrodes was readily detected in 3 patients. Three-dimensional MRI with 3D surface reconstruction proved superior for the assessment of electrocorticogram electrode localisation compared with two-dimensional imaging and CT.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 42 (2000), S. 738-741 
    ISSN: 1432-1920
    Keywords: Key words Lymphoma ; Central nervous system ; Immunocytoma, cerebral ; Magnetic resonance imaging ; Magnetic resonance spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report on a young woman with a primary cerebral immunocytoma. Most primary cerebral nervous system lymphomas (PCNSL) are highly malignant undifferentiated B-cell tumours, there are few data on the clinical course, MRI and spectroscopy findings of this rare PCNSL subtype. MRI revealed a radially enhancing tumour with mild perifocal oedema. MR spectroscopy indicated low cell turnover. Slow clinical progression, no significant changes with treatment, and imaging findings were consistent with a low-grade malignant tumour.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-2102
    Keywords: Schlüsselwörter Magnetresonanz (MR) ; MR-Tomographie ; MR-Spektroskopie ; Relaxometrie ; Fett-/Wasser-Analyse ; Knochenmarkmetastasen ; Knochenmarkinfiltration ; Granulozytenkoloniestimulierender Faktor (G-CSF) ; Keywords Magnetic resonance (MR) ; MR-tomography ; MR-spectroscopy ; Relaxometry ; Fat-/water-analysis ; Bone marrow metastasis ; Bone marrow infiltration ; Granulocyte colony stimulating factor (G-CSF)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Abstract Aim. To study the effect of G-CSF therapy directly by MRI and 1H MRS in the lumbar and femoral bone marrow and differentiate between malignant bone marrow infiltration (MBMI) and reconversion of red marrow Methods. Thirteen patients could be examined twice, before and during G-CSF medicatio and another six only during treatment. T1 weighted spin-echo and opposed-phase gradient-echo images as well as the spectroscopic data (T2 values, water content) were analysed. Results. After G-CSF a pathologic bone marrow signal intensity was seen in 8/13 (lumbar) and 11/13 (femoral) patients respectively. The majority of the signal alterations were diffuse (6 and 8), the minority focal (2 and 3). If a patient was successfully stimulated, a significant increase in water content occured (21% lumbar, 34% femoral). T2 values did not change significantly, nor did they correlate with the stimulation success. Conclusions. MR tomography and -spectroscopy are suitable to detect lumbar and femoral bone marrow stimulation by G-CSF quantitatively and qualitatively. The changes may simulate MBMI. The adequate judgement of G-CSF treated bone marrow without pretherapeutic images is not possible.
    Notes: Zusammenfassung Ziel. Ziel dieser Studie war die Beschreibung der Auswirkungen einer G-CSF-Medikation auf Magnetresonanztomographie (MRT) und -spektroskopie (MRS) des lumbalen und femoralen Knochenmarks unter besonderer Berücksichtigung potenzieller Probleme in der Differenzialdiagnose zwischen malignen Knochenmarkinfiltrationen (KMI) und Rekonversionsphänomenen im Rahmen der Knochenmarkstimulation. Methode. Vor und während der G-CSF-Therapie wurden 13 Patienten untersucht, nur während der Therapie 6 weitere. Die Ergebnisse der Bildanalyse T1-gewichteter und fettunterdrückter gegenphasierter Aufnahmen und der spektroskopischen Daten (T2-Zeiten, Wasseranteil) wurden vor und während der Therapie verglichen und im Vergleich zu Patienten mit bekannter Knochenmarkinfiltration im Rahmen maligner Grunderkrankungen analysiert. Ergebnisse. Nach G-CSF-Medikation wurde bei 8/13 (lumbal) bzw. 11/13 (femoral) Patienten in T1w- und opGE-Bildgebung ein pathologischer Knochenmarkbefund erhoben. Die Veränderung waren in der Mehrzahl diffus (6 bzw. 8), seltener fokal (2 bzw. 3). Bei den erfolgreich stimulierten Patienten wurde ein signifikanter Anstieg der Wasserfraktion nachgewiesen (+17 bzw. +24%). Die T2-Zeiten änderten sich nicht signifikant und korrelierten nicht mit dem Stimulationserfolg. Diskussion. Die MRT und MRS der LWS sind geeignet, die zentrale Knochenmarkstimulation nach G-CSF-Medikation qualitativ und (semi)quantitativ zu erfassen. Der G-CSF-Effekt kann das Bild einer malignen KMI simulieren. Die Beurteilung einer möglichen malignen KMI ist daher ohne Ausgangsbefund nach G-CSF-Therapie nicht möglich.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 302 (1981), S. 281-290 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The hyperfine structure of the atomic levels 5d 5 6s 2 6 S 5/2 and4 P 5/2 in185Re and187Re has been studied with high precision by atomic-beam magnetic-resonance. Additional measurements were performed in the 5d 5 6s 2 4 G 5/2 and 5d 6 6s 6 D 9/2 states of187Re. For the interpretation of the results eigenvectors in intermediate coupling have been derived by a least squares fit of all known levels of the configurations (5d+6s)7. The ratioB(185Re)/B(187Re) is the same for the6 S 5/2 and the4 P 5/2 state within the error limits of 6 parts in 105. Combining the present results with the known hyperfine structure data of186Re and188Re we find the magnetic-dipole hyperfine anomalies for the isotopic series185−188Re.
    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
    The European physical journal 307 (1982), S. 193-200 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The hyperfine structure constants and the electronic g J factor of the state 4f 11 6s 2 4 I 11/2 belonging to the holmium ground multiplet have been measured using the atomic beam magnetic resonance technique combined with a state-selective laser-induced detection of the resonant atoms. By the same method the g J factor of the level 4f 116s 24 I 9/2 was determined, while the hyperfine structures of this metastable state and of two high-lying even parity states have been investigated by high resolution laser spectroscopy. The results for the experimentalA andB factors of all four members of the ground multiplet allow a least-squares evaluation of the three magnetic dipole and the three electric quadrupole effective radial parameters for the configuration 4f 11 6s 2 of holmium, yielding an accurate value for the spectroscopic nuclear electric quadrupole moment:Q hfs(165Ho)=2.716(9)b (uncorrected for quadrupole shielding). From a comparison to the quadrupole moments measured in mesic holmium atoms the shielding factor could be estimated.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 283 (1977), S. 303-308 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The magnetic-dipole hyperfine interaction constantsA of low-lying metastable atomic levels in91Zr,181Ta,183W, and191Ir determined from atomic-beam magnetic-resonance investigations are analyzed with respect to the effective-operator formalism. Similar results for other 4d- and 5d-shell atoms are also tabulated. The experimental results for the effective 〈r −3〉 values are compared with relativistic predictions for the 4d N 5s and 5d N 6s 2 series.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 316 (1984), S. 247-248 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The hyperfine structure constants of95Mo and97Mo and the gJ-factors have been measured in the metastable multiplets 4d45s2 a5D, 4d55s a5S, a5P, and 4d6 c5D by atomic beam magnetic resonance combined with state-selective laser-induced detection of the rf-resonant atoms. Line isotope shifts and the A- and B-factors of further metastable levels and of high-lying odd-parity states were obtained from high-resolution Doppler-free laser spectroscopy.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 317 (1984), S. 237-240 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The magnetic dipole hyperfine interaction constantsA of the atomic ground state3 D 3 and of the first excited state3 D 3 in195Pt have been measured by atomic beam magnetic resonance. The electronicg J factors of these states were determined from the Zeeman splitting in194Pt. Using intermediate coupling wave functions derived for the configurations (5d+6s)10 effective hyperfine radial integrals are evaluated.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The hyperfine interaction constantsA andB of six low-lying metastable fine structure states of the two iridium isotopes191Ir and193Ir and the electronicg-factors of these levels have been measured using the atomic-beam magnetic-resonance method. From the values of the magnetic-dipole interaction constantsA, corrected for off-diagonal perturbations, we extracted the hyperfine anomaly of a pure 6s-electron state:191 Δ s 193 =0.64(7)%. Using nonrelativistic approximations for the effective radial parameters the nuclear electric-quadrupole moments were obtained:Q(191Ir) = 0.81(21)b,Q(193Ir)=0.73(19)b
    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
    The European physical journal 302 (1981), S. 369-370 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Relativistic self-consistent-field calculations of the radial hyperfine integrals have been performed for neutral atoms from Z=39 to Z=47. The comparison with experimental results gives an estimate of configuration interaction effects on the hyperfine interaction of these atoms.
    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...