Magnetization transfer imaging in patients with clinically isolated syndromes suggestive of multiple sclerosis

BACKGROUND AND PURPOSE: In patients with multiple sclerosis (MS), reduced m agnetization transfer ratios (MTRs) have been reported in white matter that appears normal on studies obtained with conventional imaging techniques. T he stage in the disease when this first becomes detectable is unclear. The purpose of this study was to measure the MTR of normal-appearing white matt er (NAWM) and lesions in patients with clinically isolated syndromes (CIS), many of whom are at the earliest stages of MS, and to determine the progno stic value of any observed changes. METHODS: Twenty-seven CIS patients and 13 matched control subjects were stu died, The mean MTR was measured from 10 regions of NAWN and, when present, from lesions. The patients were followed-up clinically for a median of 12 m onths. RESULTS: There was no significant difference in the mean MTR between NAWM i n control subjects (35.5% units) and that in CIS patients (38.4% units). Af ter 12 months' follow-up, MS developed in 26% of the patients, The MTR of N AWM in these patients did not differ from that of the other patients or the control subjects. CONCLUSION The reduced MTR in NAWM, described in established MS, was not de tectable in patients with CIS, MTR did not provide prognostic information f or this short period of follow-up.