Magnetic Resonance Imaging
white matter hyperintensities
WHITE MATTER HYPERINTENSITIES
In the course of the study protocol of the ICSS MRI substudy, patients underwent MRI scans at field strengths of 1.5 or 3 Tesla 1 to 7 days before treatment (pretreatment scan) and 1 to 3 days after treatment (posttreatment scan) using DWI and FLAIR sequences. MRI scans were assessed by an experienced neurologist and neuroradiologist, both masked to treatment. If disagreement could not be resolved by consensus, a third reviewer made the final decision. The presence of new periprocedural ischemic brain lesions was defined as hyperintense DWI lesions on the post-treatment MRI that were not present on the pretreatment MRI. Also, the number (lesion count) of new DWI lesions was assessed in each patient. Baseline white matter hyperintensities were quantified on pretreatment FLAIR sequences with the age-related-white matter changes (ARWMC) score.