Inter-observer variability of Breast Imaging Reporting and Data System(BI-RADS) ultrasound final assessment

Abstract

Objective To evaluate the inter-observer variability of static breast sonogram final assessment among observers with different breast imaging experience, using the first edition of the Breast Imaging Reporting and Data System(BI-RADS) for ultrasound. Methods Thirty patients with 30 breast lesions were included who underwent beast lesions resection operation. A pathological diagnosis was available for all 30 lesions:16 (53%) malignant and 14 (47%) benign. Twelve radiologists independently reviewed two sonograms of each lesion, and assigned a final BI-RADS assessment category. Inter-observer variability was measured using kappa statistic. Positive predictive value(PPV) and negative predictive value (NPV) for final assessment were also calculated. Results As for the experienced observers,kappa values of categories 3,4 and 5 were 0.72,0.28 and 0.60,NPV of category 3 was 93% ,PPV of category 5 was 97% ,all of which decreased as the breast imaging experience reduced. PPVs of categories 4a,4b and 4c were 56 % ,88% and 69%, respectively. Conclusions Using BI-RADS final assessment, radiologists with sufficient breast imaging experience can provide accurate and consistent assessment for breast ultrasonography,but the agreement of diagnosis decreased as the breast imaging experience reduced. The clinical feasibility of 4a,4b and 4c subcategories is uncertain. Key words: Ultrasonography; Breast diseases