Interobserver agreement for sonograms of breast lesions obtained by an automated breast volume scanner

Objective: To evaluate the interobserver agreement of radiologists in the description and final assessment of breast sonograms obtained using an automated breast volume scanner (ABVS) using a unique descriptor of three-dimensional ultrasound (3D US) and the Breast Imaging Reporting and Data System (BI-RADS) US lexicon. Methods: From October to December 2010, 208 patients were subjected to an ABVS examination in the supine position, and data were automatically sent to the ABVS workstation. Two radiologists independently evaluated 234 breast masses (148 benign and 86 malignant masses) using a unique descriptor from the 3D US and the BI-RADS US lexicon. The reviewers were blinded to the patient's mammographic images, medical history, and pathologic findings. The interobserver agreement was measured using kappa statistics. Results: Substantial agreement was obtained for lesion shape, orientation, margin, echo pattern, posterior acoustic features, calcification and final assessment (κ = 0.79, 0.74, 0.76, 0.69, 0.68, 0.71 and 0.70, respectively). Fair agreement was obtained for retraction phenomenon and lesion boundary (κ = 0.54 and 0.42, respectively). Conclusions: The interobserver agreement for breast sonograms obtained by ABVS is good, especially for lesion shape and margin; however, the interobserver agreement for the retraction phenomenon, which is a unique descriptor of coronal-plane 3D US, needs to be improved