CORRELATION OF SPECTROSCOPY AND MAGNETIZATION-TRANSFER IMAGING IN THEEVALUATION OF DEMYELINATING LESIONS AND NORMAL APPEARING WHITE-MATTERIN MULTIPLE-SCLEROSIS

Magnetization transfer imaging (MT) and localized proton spectroscopy (H-1-MRS) were utilized in the evaluation of lesions (high signal abno rmalities on T-2-weighted images) and normal-appearing white matter (N AWM) in multiple sclerosis (MS). Eleven patients with a clinical diagn osis of MS were independently evaluated with both H-1-MRS and MT. The magnetization transfer ratio (MTR) of lesions was compared with the re lative concentration of N-acetyl-aspartate (NAA) and a composite peak at 2.1 to 2.6 ppm termed ''marker peaks.'' The MTR of white matter les ions in the MS patients was markedly decreased (6-34%; normal approxim ate to 42%), and correlated well with increase in the marker peaks reg ion (0.94-3.89). There was no correlation between the relative concent ration of NAA and MTR. Increased resonance peaks in the 2.1 to 2.6 ppm range and marked decreases in MTR may be a relatively specific indica tors of demyelination.