Amann M, Papadopoulou A, Andelova M, Magon S, Mueller-Lenke N, Naegelin Y, Stippich C, Radue EW, Bieri O, Kappos L, Sprenger T. Magnetization transfer ratio in lesions rather than normal-appearing brain relates to disability in patients with multiple sclerosis.J Neurol. 2015 Jun. [Epub ahead of print]
Magnetization transfer ratio (MTR) is a semi-quantitative measure that seems to correlate with the degree of myelin loss and generally tissue destruction in multiple sclerosis (MS). Our objective was to comprehensively assess the MTR of lesions and normal appearing (NA) tissue separately in the white matter (WM), the cortex, the thalamus and the basal ganglia (BG) and determine their relative contribution to disability. In this cross-sectional study 71 patients were included (59 with relapsing-remitting MS, 12 with secondary progressive MS). We used a three-dimensional MTR sequence with high spatial resolution, based on balanced steady-state free precession. Mean MTR was calculated for lesions and NA tissue separately for each tissue type. Lesional MTR was lower than normal-appearing MTR in WM, cortex and thalamus. In the regression analysis, MTR of cortical lesions (β = -0.23, p = 0.05) and MTR of WML (β = -0.21, p = 0.08) were related by trend to the expanded disability status scale. MTR of WML significantly predicted the paced auditory serial-addition test (β = 0.35, p = 0.004). MTR of normal-appearing tissue did not relate to any outcome. Our results suggest that MTR of lesions in the white matter and cortex rather than of normal-appearing tissue relates to disability in patients with MS.
We want to measure progression but at present the gold standard is the clinical deterioration or lack of it if the drug works, a cases has been made for neurofilament in biological fluids, but one imaging outcome has been suggested to be MTR and if you have signal in lesions this is may correlate with accumulation to disability, but we have had these claims with other imaging outcomes. We will see how this outcome fares in clinical trials