Cervical cord magnetization transfer ratio and clinical changes over 18 months in patients with relapsing-remitting multiple sclerosis: a preliminary study

BACKGROUND: Magnetization transfer ratio (MTR) permits the quantitative estimation of cervical cord tissue damage in patients with multiple sclerosis (MS). OBJECTIVE: To determine whether a single time-point MTR scan of the cervical cord is associated with short-term disease evolution in patients with relapsing-remitting (RR) MS. METHODS: Using a 1.5-T magnetic resonance imaging (MRI) system with a tailored cervical cord phased array coil, fast short-tau inversion recovery (fast-STIR) and MTR scans were obtained from 14 untreated patients with RRMS at baseline. Cervical cord MTR histograms were derived. Over the 18-month follow-up period, relapse rate was measured and disability assessed by the Expanded Disability Status Scale (EDSS) score. RESULTS: Average cervical cord MTR was correlated with relapse rate (r= -0.56, P=0.037). A moderate correlation (r values ranging from -0.33 to -0.36) between baseline cervical cord MTR metrics and EDSS changes over 18 months was also noted, albeit statistical significance was not reached (P = 0.26 and 0.21, respectively) perhaps because of the relatively small sample size. CONCLUSIONS: This study suggests that a 'snapshot' MT MRI assessment of the cervical cord may detect cervical cord tissue changes associated with short-term disease evolution in RRMS.