Klaus Schmierer1, Po-Wah So2, Shu F. An3, Sebastian Brandner3, David H. Miller1, Tarek A. Yousry4, Harold G. Parkes1
1Neuroinflammation, Institute of
Neurology, UCL, London, England, UK; 2Imaging Sciences Department,
Imperial College London, Hammersmith Hospital Campus, London, England, UK; 3Neurodegenerative
Disease, Institute of Neurology, UCL, London, England, UK; 4Brain
Repair & Rehabilitation, Institute of Neurology, UCL, London, England, UK
In multiple sclerosis (MS) brain white matter (WM) magnetisation transfer ratio (MTR) and T1 are associated with myelin and to a lesser degree axons. Substrate of these MR indices in MS cortical grey matter (CGM) is less clear. We investigated the association of myelin and neuronal density (ND) with T1, T2, and MTR in MS CGM using high-field (9.4T) MRI and histology. In CGM T1 was the strongest predictor of ND, whereas MTR was the main predictor of myelin. Fixation time is an important confounder that needs to be taken into account in studies using fixed post mortem samples.