Leptomeningeal Enhancement at 7T in Multiple Sclerosis: Frequency, Morphology, and Relationship to Cortical Volume.
BACKGROUND AND PURPOSE
Perform an investigation of the frequency and distribution of leptomeningeal enhancement on postgadolinium magnetization-prepared FLAIR (MPFLAIR) in multiple sclerosis (MS) on 7 Tesla (7T) MRI and to relate this finding to measures of brain structure and lesion volumes.


METHODS
Twenty-nine participants with MS underwent 7T MRI of the brain. Three healthy volunteers (HVs) were scanned for comparison. Areas of postcontrast leptomeningeal enhancement were identified. Images were segmented for brain structure and lesion volumes. The relationship between leptomeningeal enhancement and clinical and volumetric data was explored.


RESULTS
Two patterns of enhancement were found: "nodular" (discrete, spherical nodules at the pial surface or subarachnoid space) and "spread/fill" (appearance of contrast spread through the local subarachnoid space). Twenty-six of 29 (90%) MS participants had at least one focus of leptomeningeal enhancement. Nodular foci were present in 15 of 29 (51%) MS participants. Spread/fill foci were present in 22 of 29 (76%) MS participants. Two HVs had examples of nodular foci, but none had spread/fill enhancement. MS participants with spread/fill foci were older (48.9 years [SD 8.3]) than those without (33.3 years [SD 11.5], P = .005). MS participants with spread/fill foci had reduced cortical gray matter volume compared to those without (P = .020).


CONCLUSIONS
Leptomeningeal enhancement on postcontrast 7T MPFLAIR is more prevalent than prior reports at 3T-occurring at frequencies closer to histopathologic data. Spread/fill foci are associated with reduced cortical gray matter volumes and may represent blood-meningeal barrier breakdown near sites of meningeal inflammation, whereas nodular foci may be a normal variant.
['Harrison|Daniel M|DM|', 'Wang|Kevin Y|KY|', 'Fiol|Julie|J|', 'Naunton|Kerry|K|', 'Royal|Walter|W|', 'Hua|Jun|J|', 'Izbudak|Izlem|I|']
D000328:Adult D001921:Brain D005260:Female D066128:Gray Matter D006801:Humans D008279:Magnetic Resonance Imaging D008297:Male D008578:Meninges D008875:Middle Aged D009103:Multiple Sclerosis D009929:Organ Size D055815:Young Adult
Multiple sclerosis 7 Tesla meningeal meningeal inflammation meningeal enhancement ultra-high field MRI