Quantification of perivascular spaces at 7T: A potential MRI biomarker for epilepsy.
PURPOSE
7T (7T) magnetic resonance imaging (MRI) facilitates the visualization of the brain with resolution and contrast beyond what is available at conventional clinical field strengths, enabling improved detection and quantification of small structural features such as perivascular spaces (PVSs). The distribution of PVSs, detected in vivo at 7T, may act as a biomarker for the effects of epilepsy. In this work, we systematically quantify the PVSs in the brains of epilepsy patients and compare them to healthy controls.


METHODS
T2-weighted turbo spin echo images were obtained at 7T on 21 epilepsy patients and 17 healthy controls. For all subjects, PVSs were manually marked on Osirix image analysis software. Marked PVSs with diameter≥0.5mm were then mapped by hemisphere and lobe. The asymmetry index (AI) was calculated for each region and the maximum asymmetry index (|AImax|) was reported for each subject. The asymmetry in epilepsy subjects was compared to that of controls, and the region with highest asymmetry was compared to the suspected seizure onset zone.


RESULTS
There was a significant difference between the |AImax| in epilepsy subjects and in controls (p=0.016). In 72% of patients, the region or lobe of the brain showing maximum PVS asymmetry was the same as the region containing the suspected seizure onset zone.


CONCLUSION
These findings suggest that epilepsy may be associated with significantly asymmetric distribution of PVSs in the brain. Furthermore, the region of maximal asymmetry of the PVSs may help provide localization or confirmation of the seizure onset zone.
['Feldman|Rebecca Emily|RE|', 'Rutland|John Watson|JW|', 'Fields|Madeline Cara|MC|', 'Marcuse|Lara Vanessa|LV|', 'Pawha|Puneet S|PS|', 'Delman|Bradley Neil|BN|', 'Balchandani|Priti|P|']
D000293:Adolescent D000328:Adult D000368:Aged D001921:Brain D002552:Cerebral Ventricles D004827:Epilepsy D005260:Female D006801:Humans D007091:Image Processing, Computer-Assisted D008279:Magnetic Resonance Imaging D008297:Male D008875:Middle Aged D010841:Pia Mater D055815:Young Adult
Perivascular space MRI Magnetic resonance imaging 7 Tesla Focal epilepsy T2TSE Ultra-high field Virchow Robin space