Table 3

Summary of imaging outcomes for remyelination and repair in multiple sclerosis

Modality	Myelin sensitivity	Myelin specificity	Clinical correlation	Acquisition time	Comments
T₂ lesion evolution	Excellent	Poor	Poor	Short	Confounded by inflammation, axonal loss and oedema
T₁ lesion evolution	Good	Poor	Poor	Short	T1 hypointense lesion evolution may be useful in neuroprotection trials
MTR	Excellent	Good	Good	Short	Semiquantitative
qMT	Excellent	Good	Good	Moderate/long	Modelling the MT effect in tissue is complex
MWF	Excellent	Good	Good	Long	Limited brain coverage
▸ mcDESPOT	Excellent	Good	Unknown	Moderate	Accuracy questioned
▸ T2prep 3D SPIRAL	Excellent	Unknown	Unknown	Moderate	Limited evidence in patient groups
▸ 3D-GRASE	Excellent	Unknown	Unknown	Short	Limited evidence in patient groups
DTI	Excellent	Good	Good	Moderate	Low resolution and SNR, motion artefact susceptibility
PET	Excellent	Excellent	Unknown	Moderate/long	Further in vivo studies required
OCT	Poor	Poor	Excellent	Moderate	Useful to detect secondary neuroprotective effects

Ratings of ‘Excellent’, ‘Good’ and ‘Poor’ are qualitative and, although based on best currently available data, are inherently subjective in nature. Clinical correlation: refers to associations that have been observed between the imaging measure and a relevant clinical function measure. Acquisition times: Short <15 min, Moderate=15–30 min and Long >30 min.
DTI, diffusion tensor imaging; MT, magnetisation transfer; MTR, magnetisation transfer ratio; MWF, myelin water fraction; OCT, optical coherence tomography; PET, positron emission tomography; qMT, quantitative MT.