Clinical Application of Computer-Aided Diagnosis for Breast Ultrasonography: Factors That Lead to Discordant Results in Radial and Antiradial Planes

Objective: To investigate factors that may lead to discordant results in radial and antiradial planes when applying a computer-aided diagnostic system (S-DetectTM) for breast ultrasound (US). Methods: From May 2019 to September 2019, a total of 288 breast lesions from 286 consecutive women were analyzed. Diagnostic performance and diagnostic agreement of the CAD system between the radial and antiradial planes were calculated. Based on the CAD results in the radial and antiradial planes, the lesions were classified into two groups: the agreement group and the discordant group. Ultrasound imaging and clinicopathologic factors in the two groups were compared. Results: Of the 288 breast lesions, 187 (64.7%) were benign, and 101 (35.3%) were malignant. There was no difference in diagnostic performance of the CAD system between the radial and antiradial planes. The diagnostic agreement of the CAD system between these two orthogonal planes was good (kappa = 0.645). Compared to category 3, 4C and 5 lesions, category 4A and 4B lesions were more likely to have discordant CAD results. In the subgroup of malignant tumors, lesions diagnosed as carcinoma in situ (P = 0.014), staged as T1 (P = 0.013) and with low Ki-67 status (P = 0.024) were significantly associated with discordant CAD results. Conclusion: The CAD system for breast ultrasound has a favorable diagnostic performance, and discordant CAD results between the radial and antiradial planes were more frequent for BI-RADS category 4A-4B lesions and less invasive malignant lesions.