Three-Dimensional Ultrasound for Abdominal Aortic Aneurysm Surveillance: Diagnostic Accuracy, Reproducibility, and...

Accurate and reproducible imaging is essential for abdominal aortic aneurysm (AAA) surveillance. Conventional ultrasound (US) is operator-dependent, while computed tomography (CT) is unsuitable for repeated follow-up due to radiation and contrast exposure. Three-dimensional ultrasound (3D-US) has emerged as a potential alternative, but evidence remains fragmented. This study aimed to systematically evaluate the diagnostic accuracy, reproducibility, and agreement of 3D-US compared with CT for AAA surveillance.

A systematic review and meta-analysis were conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. MEDLINE, Embase, and the Cochrane Library were searched for studies evaluating 3D-US for AAA assessment. Outcomes included intra- and interobserver reproducibility, agreement with CT for maximum diameter measurement, and diagnostic accuracy. Random-effects models were used to pool estimates.

Twenty studies were included in the qualitative synthesis, and nine contributed to at least one quantitative meta-analysis. Interobserver reproducibility was excellent, with a pooled intraclass correlation coefficient (ICC) of 0.952 (95% confidence interval [CI], 0.941-0.962), while intraobserver reproducibility was even higher (ICC, 0.977; 95% CI, 0.968-0.985). Agreement between 3D-US and CT showed a pooled mean difference of 0.45 mm (95% CI, 0.02-0.88), well below clinically relevant thresholds. Diagnostic accuracy was high, with pooled sensitivity of 0.92 (95% CI, 0.89-0.94) and specificity of 0.90 (95% CI, 0.88-0.93). Moderate heterogeneity was observed for sensitivity, while specificity showed low-to-moderate heterogeneity.

3D-US provides highly reproducible measurements, close agreement with CT, and high diagnostic accuracy for AAA assessment. These findings support its role as a reliable, radiation-free modality for routine AAA surveillance.