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Biomedical subjects

L J Wolansky

Publications and source records attributed to L J Wolansky.

24 records · Page 2Linked to original sources
PubMed1994

Triple-dose versus single-dose gadoteridol in multiple sclerosis patients.

Nine patients with multiple sclerosis underwent brain magnetic resonance imaging (MRI) to evaluate the contrast enhancement of individual lesions after a single dose and a triple dose of gadolinium. A single dose (0.1 mmol/kg) of gadoteridol was administered and after a delay, axial T1-weighted images were obtained. After an additional 0.2-mmol/kg dose, the same T1-weighted sequence was repeated. An unblinded reader simultaneously viewed the images from both doses, and utilizing a computer console to rule out flow artifacts, created a gold standard of "definite" enhancing lesions. Using this system, he determined that there was a total of 12 definite enhancing lesions among the patients. This reader also evaluated lesion conspicuity. The contrast-noise ratio was calculated for each lesion. A second reader, blinded to the dose used, then evaluated the number of enhancing lesions at both doses. The unblinded reader noted increased lesions at both doses. The unblinded reader noted increased lesion conspicuity after the triple dose. Contrast-noise ratios were significantly (p < 0.001) higher after the triple dose (mean, 9.19) than after the single dose (mean, 2.97). The blinded reader detected 11 of the 12 definite lesions on MRIs after the triple dose (sensitivity, 92%) but saw only 6 on MRIs after the single dose (sensitivity, 50%). The difference was significant (p < 0.001). Subjective analysis of the films revealed an increase in "ghosting artifacts" at the high dose. Administration of triple-dose gadolinium provides increased lesion conspicuity and an improved lesion detection rate when compared to single-dose gadolinium in patients with multiple sclerosis.

Brain↗
PubMedDate not supplied

Fast inversion recovery for myelin suppression (FIRMS). A new MRI pulse sequence for highlighting cerebral gray matter.

The purpose of this study is to test a new pulse sequence, fast inversion recovery for myelin suppression (FIRMS) for its ability to improve the conspicuity of gray matter. Twenty-six seizure patients were scanned with FIRMS as well as standard sequences. Gray matter conspicuity was evaluated objectively using region-of-interest calculations, including image contrast, contrast ratios, and contrast:noise (C/N). In evaluation of the hippocampus and cortex, all objective measurements of conspicuity were highest for FIRMS. In five clinical cases of suspected cortical dysplasia, FIRMS improved delineation of pathology in positive cases and ruled out the diagnosis in negative cases. In a case of hippocampal sclerosis, FIRMS was able to demonstrate atrophy of the alveus. Fast inversion recovery for myelin suppression holds promise for its ability to highlight the cerebral cortex and hippocampus.

Cerebral Cortex↗
PubMedDate not supplied

Gadoteridol in multiple sclerosis patients. A comparison of single and triple dose with immediate vs. delayed imaging.

Enhancement of lesions in multiple sclerosis (MS) has been investigated using standard and high doses of gadolinium. The purposes of this study are to compare the relative merits of single and triple dose as well as examine the merits of delayed triple-dose images in a large group of patients. Thirty-seven patients with multiple sclerosis underwent contrast enhanced brain magnetic resonance imaging (MRI). After noncontrast images, a single dose (0.1 mmol/kg) of gadoteridol was administered. Subsequently, axial T1-weighted images were obtained immediately after administration, and again after a delay of approximately 20 minutes. After an additional 0.2-mmol/kg dose was administered, to provide a total cumulative dose of 0.3 mmol/kg of gadoteridol, immediate and delayed axial T1-weighted image sequences were repeated. The contrast-noise ratio (C/N) was calculated for each identified, enhancing lesion in each series. Furthermore, blinded readings were performed to determine the lesion detection rate. Of the forty definite lesions that underwent all four sequences, triple-dose delayed images exhibited the highest contrast-noise ratio in a significantly larger number of lesions (p < 0.0001). Triple-dose immediate and delayed scans resulted in significantly higher contrast-noise ratios (6.47 and 9.99, respectively) when compared with those of the single dose scans (3.4 for immediate scans and 5.24 for delayed) (p < 0.01). The lesion detection rate was highest for triple dose delayed (95%), followed by triple-dose immediate (83%), single-dose delayed (68%) and finally, single-dose immediate scans (43%). Triple-dose immediate was noted to have a significantly increased (p < 0.0002) lesion detection rate with respect to the standard-dose immediate scans and standard-dose delayed scans (p < 0.02). In four lesions (10% of the total number of lesions), detection occurred only with the triple-dose delayed image sequence. Triple-dose 0.3 mmol/kg gadolinium with delayed imaging resulted in the highest lesion conspicuity and the highest lesion identification rate. There was a trend of progressively increasing detection rates from single-dose immediate scans to triple-dose delayed scans. Triple-dose delayed scans resulted in significantly higher (p < 2 x 10(-8) contrast noise ratios than all other sequences of this study.

Brain↗
PubMedDate not supplied

Water-suppression MRI: role in the evaluation of osseous lesions.

The efficacy of chemical shift based water-suppression MRI in the evaluation of bone marrow lesions has not been previously reported. T1-weighted images without and with water suppression were compared in five patients with 16 lesions. There was a significant improvement in the contrast-to-noise ratio (from 4.32 to 5.95, P < 0.01) and contrast ratio (from 1.71 to 5.69, P < 0.004) with water suppression. Water suppression may be useful clinically by increasing the conspicuity of bone marrow lesions.

Adult↗