Abdominal vascular calcification at CT: opportunistic quantification and imaging-based risk stratification.

Abdominal vascular calcification is increasingly recognized as a clinically relevant marker of systemic atherosclerotic burden and regional vascular disease. Because the abdominal aorta and its major branches are frequently captured on routine abdominal, oncologic, vascular, and preoperative CT examinations, CT provides a practical opportunity for opportunistic assessment of vascular calcium beyond the coronary circulation. This review summarizes current approaches to CT-based evaluation of abdominal vascular calcification, with a focus on abdominal aortic, renal artery, mesenteric and celiac artery, and aortoiliac calcification. We discuss imaging sources, acquisition protocols, anatomic coverage, and quantitative and semiquantitative scoring methods, including Agatston-based, volume-based, and length-adjusted metrics. We also review the clinical implications of calcification across abdominal vascular territories, including its associations with cardiovascular events, renal dysfunction, mesenteric ischemia, peripheral arterial disease, perioperative complications, and mortality. Finally, we highlight the emerging role of automated and artificial intelligence-based quantification in scalable risk stratification. Standardized definitions, harmonized scoring methods, validated thresholds, and prospective outcome-based studies are needed before abdominal vascular calcification can be fully integrated into routine clinical reporting. For AI-enabled opportunistic screening to be widely adopted, future multicenter validation studies should establish standardized anatomical definitions and scoring frameworks, assess algorithm performance in independent external datasets spanning diverse CT acquisition protocols and scanner platforms, and prioritize clinically meaningful outcome-based endpoints with sufficient follow-up rather than relying solely on segmentation accuracy.