Аннотация:Introduction: We aimed to classify different degrees of cerebrovascular insufficiency (CVI) in patients with moya-moya disease (MMD) by measuring cerebral blood flow (CBF) and distinguishing arterial transit artefact (ATA) on arterial spin labeling (ASL) MRI. Methods: The study included 121 images of patients with MMD who underwent ASL MRI at 1,5 T before and after the surgical treatment (242 hemispheres). On ASL CBF maps, regions of interest (ROI) were manually drawn in each hemisphere in 7 zones on the axial view: 5 cortical areas (ACA, MCA, PCA and corresponding border zone territories), area in the white matter and in the basal ganglia. Quantitative and qualitative patterns of arterial transit artifacts (ATA) were studied. One-way analysis of variance (ANOVA) was used for group comparisons.Results: For classification of CVI distinguished patterns were divided into 4 statistically significant degrees based on CBF values and the presence of ATA in evaluated ROIs. Degree 0 with normal CBF values and without ATA (59 hemispheres) (CBF 60,37-68,64 ml/100gxmin, CI 95%). Degree 1 with moderate decreased CBF and the presence of ATA (97 hemispheres) (CBF 55,82-62,16 ml/100gxmin, CI 95%). Degree 2 with significantly decreased CBF and the presence of ATA (64 hemispheres) (CBF 25,64-28,96 ml/100gxmin, CI 95%). Degree 3 with very low CBF without ATA (22 hemispheres) (CBF 15,58-19,97 ml/100gxmin, CI 95%). All groups had significant differences between value of CBF in all cortical territories (ANOVA, F3,238=142,944, p<0,01 for MCA) and white matter areas (ANOVA, F3,238=3,157, p=0,025). Distinguished patterns had high correlation between Suzuki stage (ANOVA, F3,238=16,654, p<0,01) the severity of ischemic disease (assessed by mRS – ANOVA, F3,238=3,096, p=0,02) and the severity of neurologic deficit (assessed by NIHSS score – ANOVA, F3,238=3,060, p=0,029). Conclusion: The revealed ASL-MRI patterns correspond to the degree of CVI, stage of the disease, the clinical symptoms and can be used for the assessment in the patients with moya-moya disease.