Quantitative Abdominal Aortic Calcification Morphology Is Associated With Lumen Geometry

BACKGROUND: Calcification morphology is increasingly studied in coronary arteries but remains poorly characterized in the abdominal aorta. Whether morphology provides information beyond total calcium burden is unclear. We used micro-computed tomography (micro-CT) with near-histologic resolution to characterize abdominal aortic calcification morphology and evaluate its relationship with local lumen geometry. METHODS: Abdominal aortic specimens from 19 cadavers were imaged using micro-CT, yielding 26 lesions and 201 cross-sectional slices. Calcification was classified as concentric or eccentric based on circumferential arc. Measurements included calcium thickness, area, and arc, along with lumen area. Associations were assessed using linear mixed-effects models to account for clustering within lesions and specimens (effect estimates reported as β). RESULTS: Lumen area did not differ by morphologic classification. Greater calcium thickness (β [95% CI] = -10.076 [-16.539, -3.613]; p = 0.002), area (β = -0.403 [-0.803, -0.003]; p = 0.049), and arc (β = -0.080 [-0.138, -0.022]; p = 0.007) were each associated with smaller lumen area. In sensitivity analyses, associations for thickness and arc remained significant, whereas the association for area was attenuated. CONCLUSION: Quantitative morphologic features were inversely associated with lumen area, suggesting that calcification morphology may provide structural information beyond total calcium burden.