['To evaluate a safe, non-invasive MRI method to measure regional blood brain barrier (BBB) integrity and investigate its relationship with neurocognitive function and regional gray matter volume (GMV) in childhood-onset SLE (cSLE).', 'In this cross-sectional, case-control study, capillary permeability was measured as a marker of BBB integrity in cSLE patients and matched healthy controls, using a combination of arterial spin labeling and diffusion-weighted brain MRI. Regional GMV was measured by voxel-based morphometry. Correlation analysis was done to investigate the relationship between regional capillary permeability and regional GMV. Formal neurocognitive testing was completed (attention, visuoconstructional ability, working memory and psychomotor speed), and scores were regressed against regional BBB integrity among cSLE patients.', 'Formal cognitive testing confirmed normal cognitive ability in all cSLE subjects (n=11) included in the analysis. Regional capillary permeability was negatively associated (p = 0.026) with neurocognitive performance concerning psychomotor speed in the cSLE cohort. Compared with controls (n=11), cSLE patients had significantly greater capillary permeability involving Brodmann areas (BA) 19, 28, 36 and 37, and caudate structures (all p\u2009<\u20090.05).'] Is blood Brain Barrier Permeability altered in patients with Systemic Lupus Erythematosus : A Novel Imaging Approach?