q-Space Myelin Map: A new myelin-specific imaging technique for treatment monitoring of multiple sclerosis

Background: The hallmark of multiple sclerosis (MS) is demyelination of the central nervous system. In the McDonald diagnostic criteria, hyperintense signals on T2-weighted image (so-called “T2-lesions”) by magnetic resonance imaging (MRI) can substitute for clinical findings as evidence of disease activities; however, T2 signals are theoretically non-specific for demyelination and its over-reliance may lead not only to misdiagnosis but also to the failure of accurately monitoring disease activities, hence potentially causing over or under-treatment. In order to provide a more myelin-specific modality, we have recently developed q-space Myelin Map (qMM) and preliminary reported its utility in MS patients, particularly for depicting remyelination. This current study aimed to analyze clinical factors associated with qMM-supported remyelination in a series of consecutive MS patients initiating different disease-modifying drugs (DMDs), and to examine the utility and the feasibility of qMM in daily clinical practice. Methods Data from sequential patients with relapsing-remitting MS (RRMS) initiating one of the following DMDs at our center were collected: interferon β (IFN β), glatiramer acetate (GA), fingolimod (FTY), dimethyl fumarate (DMF), or natalizumab (NTZ). After treatment initiation, qMM was performed at 6-month intervals and the resulting images analysed for evidence of remyelination. Results 48 patients with RRMS were included: 22 with DMF, 14 with FTY, 4 with GA, 8 with NTZ, and 0 with IFN β. qMM revealed qMM-remyelination in 22 patients (45.8%), including 10 receiving DMF, 6 receiving FTY, 1 receiving GA, and 5 receiving NTZ. qMM-remyelination was significantly associated with younger age in the NTZ group(p = 0.036), and associated with female sex in the DMF group(p = 0.015). Conclusions This study demonstrated the potential clinical utility of qMM for visualizing remyelination in MS patients and fine-tuning their pharmacotherapy. Two potential clinical factors promoting qMM-remyelination were identified: female sex with DMF and younger baseline age with NTZ; a larger prospective study is warranted to confirm these results.