Abstract #4082

Normalization of Magnetization Transfer Ratio MRI for Multicentre Clinical Trials

Robert Allan Brown¹, Sridar Narayanan¹, Harold Atkins², Mark S. Freedman³, Douglas L. Arnold¹

¹Montreal Neurological Institute, McGill University, Montreal, QC, Canada; ²Division of Hematology, Ottawa Hospital Regional Cancer Centre, Ottawa, ON, Canada; ³Department of Medicine (Neurology), the Ottawa Hospital, Ottawa, ON, Canada

Magnetization transfer ratio MRI is a promising technique for measuring in vivo demyelination and remyelination. However, MTR values are scanner and sequence dependent. We propose a normalization technique, based on imaging of a normal control, that maps MTR values to a semi-quantitative scale that is comparable across sites in multicentre trials and between studies. The performance of this technique is compared to an alternative, statistically based technique proposed in the literature.