Automated Evaluation of Intracranial Vessel Morphology in Normal Versus Pediatric Moyamoya Disease

Abstract

Abstract INTRODUCTION Evaluation of intracranial artery morphology plays an important role in diagnosing a variety of neurovascular diseases. In addition to clinical symptoms, diagnosis currently relies on qualitative rather than quantitative evaluation of vascular imaging sequences such as magnetic resonance angiography (MRA). However, previously described statistical cerebroarterial atlases have focused primarily on healthy adults and little information exists about what constitutes normal artery morphology in the pediatric population and across brain development. We aimed to quantitatively assess normal, age-related changes in artery morphology and compare normal morphology to that of children with Moyamoya disease (MMD). METHODS MRAs from 98 children (49 M/49F) aged .6 to 20 yr (median = 11.5 yr) with normal MRAs and and 18 children with radiographically confirmed MMD (10 M/8 F, median age = 7.1 yr) were retrospectively collected. All arteries were automatically segmented in both MRA datasets. Using an atlas-based approach, the radiuses of the main arteries of the anterior circulation (internal carotid artery (ICA), anterior cerebral artery (ACA), and middle cerebral artery (MCA)) and posterior circulation (PCA, BA) were measured at corresponding locations. Artery radii were compared between the 2 groups using MANCOVA with age and sex as covariates. RESULTS The artery radius was relatively consistent across age for all main arteries in normal patients. MANCOVA revealed that children with MMD exhibit significantly smaller ICA, MCA-M1, MCA-M2, and ACA radii (P < .001) compared to normal controls (mean vessel radii: ICA 1.27 vs 1.64 mm, MCA M1 0.92 vs 1.14 mm, MCA M2 0.66 vs 0.82 mm, ACA 0.72 vs 0.83 mm). There were no significant differences in the posterior circulation radii. CONCLUSION We present normal artery morphology data for children based on automatic segmentation of MRAs, and demonstrate that artery caliber is smaller in children with MMD. This resource will allow neurosurgeons to quantitatively assess MMD and the impact of bypass surgery on disease progression.