Rating method for dilated Virchow-Robin spaces on magnetic resonance imaging.

BACKGROUND AND PURPOSE Dilated Virchow-Robin spaces are an emerging neuroimaging biomarker, but their assessment on MRI needs standardization. METHODS We developed a rating method for dilated Virchow-Robin spaces in 4 brain regions (centrum semiovale, basal ganglia, hippocampus, and mesencephalon) and tested its reliability in a total of 125 MRI scans from 2 population-based studies. Six investigators with varying levels of experience performed the ratings. Intraclass correlation coefficients were calculated to determine intra- and interrater reliability. RESULTS Intrarater reliability was excellent for all 4 regions (intraclass correlation coefficient, >0.8). Interrater reliability was excellent for the centrum semiovale and hippocampus (intraclass correlation coefficient, >0.8) and good for the basal ganglia and mesencephalon (intraclass correlation coefficient, 0.6-0.8). This did not differ between the cohorts or experience levels. CONCLUSIONS We describe a reliable rating method that can facilitate pathogenic and prognostic research on dilated Virchow-Robin spaces using MRI.