FLAIR* to visualize veins in white matter lesions: A new tool for the diagnosis of multiple sclerosis?

OBJECTIVE

To explore the potential of a post-processing technique combining FLAIR and T* (FLAIR*) to distinguish between lesions caused by multiple sclerosis (MS) from cerebral small vessel disease (SVD) in a clinical setting.

METHODS

FLAIR and T* head datasets acquired at 3T of 25 people with relapsing MS (pwRMS) and ten with pwSVD were used. After post-processing, FLAIR* maps were used to determine the proportion of white matter lesions (WML) showing the 'vein in lesion' sign (VIL), a characteristic histopathological feature of MS plaques. Sensitivity and specificity of MS diagnosis were examined on the basis of >45% VIL and >60% VIL WML, and compared with current dissemination in space (DIS) MRI criteria.

RESULTS

All pwRMS had >45% VIL WML (range 58-100%) whilst in pwSVD the proportion of VIL WML was significantly lower (0-64%; mean 32±20%). Sensitivity based on >45% VIL was 100% and specificity 80% whilst with >60% VIL as the criterion, sensitivity was 96% and specificity 90%. DIS criteria had 96% sensitivity and 40% specificity.

CONCLUSION

FLAIR* enables VIL WML detection in a clinical setting, facilitating differentiation of MS from SVD based on brain MRI.

KEY POINTS

• FLAIR* in a clinical setting allows visualization of veins in white matter lesions. • Significant proportions of MS lesions demonstrate a vein in lesion on MRI. • Microangiopathic lesions demonstrate a lower proportion of intralesional veins than MS lesions. • Intralesional vein-based criteria may complement current MRI criteria for MS diagnosis.