Abstract #1152

High Field T1 Predicts Neuronal Loss in Multiple Sclerosis Cortical Grey Matter

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.