The “central vein sign” (CVS) in white matter lesions (WMLs) is a current radiological biomarker of multiple sclerosis (MS). Using magnetic susceptibility-based sequences, the CVS was observed in 80-100% of lesions at 7.0 tesla Magnetic Resonance Imaging (MRI) in the research setting. Recently, similar detection rate was reported at 3.0 Tesla (3T) MRI in the clinical setting using susceptibility-weighted angiography (SWAN)-venule sequence. Some data suggest that using 3D T2*EPI/ FLAIR*, the CVS may be useful to differentiate MS from other neurological diseases with focal WMLs.
The objective of our study was to determine if the CVS detected in SWAN-venule at 3T MRI discriminates MS from its radiological mimics.
Subjects were scanned on a 3T MRI system (Discovery MR750, GE, Milwaukee, USA) using a 32-channel head coil. We performed post-contrast 3D-FLAIR and SWAN-venule sequences [FOV = 22 cm x 16 cm; number of slices= 126; voxel resolution, 0.4 mm x 0.4 mm x 0.8 mm; TR = 47 msec; TE = 28 msec; flip angle = 8° ; ETL = 9; AT = 7.38 min]. MRIs with focal supratentorial WMLs visible in FLAIR, larger than 3 mm and smaller than 15 mm, were included. The CVS, defined as a thin hypointense line or a hypointense small dot centering a WML, was recorded blinded to the diagnosis on SWAN-venule by one junior neuroradiologist and two trained MS raters.
Twenty people with MS and 24 subjects with non-MS WMLs: 9 migraine, 6 Neuromyelitis Optica spectrum disease (NMOs), 5 Susac Syndrome (SS), and 4 with other vascular diseases (2 primary angiitis of the central nervous system, 1 small vessels disease, and 1 Lupus), were included. A total of 380 WMLs were detected in the MS group, and 427 WMLs in the non-MS group (215 migraine, 52 NMOs, 83 SS, and 77 in other vascular diseases). The CVS was detected in 86% of MS WMLs compared to 23% of WMLs of other diseases (25% of migraine, 21% of NMOs, 22% of other vascular diseases).
The use of SWAN-venule sequence for the identification of CVS on 3T MRI helps differentiate MS WMLs from other WMLs that mimic MS.