Reliability and Reviewer Acceptance of Angioscore: A Quantitative Measure for Lower Limb Peripheral Arterial Disease Severity

Background: The arterial disease of the lower extremity is a major cause of patient morbidity. Treatment planning requires a precise diagnosis of lesion locationseverity, and length with accurate differentiation betweenhigh-grade stenosis (including occlusion) and lesser grade stenosis. Aim of Study: To assess the inter-reader of the reliability of angio-score for CT angiography in patients with peripheral arterial disease of the lower limbs as a quantitative method for assessment of disease severity. Subjects and Methods: Prospective study was done upon 162 patients with lower limb peripheral arterial disease (PAD) that underwent CTA of the lower limb. The image analysis was performed by both reviewers according to angio-score. Results: The overall inter-observer agreement for CTA of CT-angio-score by both reviewers was excellent (k=0.827, p=<0.001). The inter-observer agreement for CTA was excel-lent for aorto-iliac region (k=0.75, p=<0.001), femoro-popliteal region (K=0.92, p=<0.001) and infra-popliteal region (k=0.81, p=<0.001). There was excellent inter-observer agreement for TASC score (k=0.82, p=<0.001) and collateral score (k=0.91, p=<0.001). The angio-score well correlated with TASC score (k=0.81, p=<0.001), collateral score (k=0.84, p=<0.001) and clinical scores (K=0.89, p=0.001). Conclusion: We concluded that angio-score of lower limb arteries is a valid and reliable quantitative method for the evalu-ation of the lower limb arterial systems and can help guide the type of management in patients with arterial diseases and is well correlated with TASC, collateral, and clinical scores.