Radiology, Vol 196, 511-515, Copyright © 1995 by Radiological Society of North America
Microscopic disease in normal-appearing white matter on conventional MR images in patients with multiple sclerosis: assessment with magnetization-transfer measurements
LA Loevner, RI Grossman, JA Cohen, FJ Lexa, D Kessler and DL Kolson
Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia 19104-4283, USA.
PURPOSE: To assess for the presence of microscopic abnormalities in
otherwise normal-appearing white matter on T2-weighted images in patients
with multiple sclerosis (MS) by using magnetization-transfer (MT)
measurements. MATERIALS AND METHODS: Twenty-three patients with MS and nine
healthy control subjects underwent magnetic resonance (MR) imaging with a
1.5-T system. MT ratios (MTRs) were measured in 16 areas of
normal-appearing white matter identified on conventional T2-weighted images
in patients with MS. MTRs in the same white-matter locations in control
subjects were determined. The two groups were compared. RESULTS: The mean
whole-brain MTR of normal-appearing white matter in patients was 40.13% +/-
1.37 (standard deviation; range, 36.31%- 42.09%); in control subjects,
42.93% +/- 0.95 (range, 41.62%-44.50%). The difference was statistically
significant (P < or = .001). Except for the internal capsules, the
difference in mean MTRs in each sublocation of the brain between patients
and control subjects was statistically significant (P < or = .05).
CONCLUSION: MT measurements are more sensitive than conventional MR imaging
in the detection of abnormalities beyond the resolution of T2-weighted
imaging.
