Artificial intelligence assists identifying malignant versus benign liver lesions using contrast-enhanced ultrasound.

BACKGROUND AND AIM To construct a strategy that uses assistance from artificial intelligence (AI) to assist radiologists in the identification of malignant versus benign focal liver lesions (FLLs) using contrast-enhanced ultrasound's (CEUS). METHODS A training set (patients=363) and a testing set (patients=211) were collected from our institute. On four-phase CEUS images in the training set, a composite deep learning architecture was trained and tuned for differentiating malignant and benign FLLs. In the test dataset, AI performance was evaluated by comparison with radiologists with varied levels of experience. Based on the comparison, an AI assistance strategy was constructed, and its usefulness in reducing CEUS interobserver heterogeneity was further tested. RESULTS In the test set, to identify malignant versus benign FLLs, AI achieved an area under the curve of 0.934 (95%CI 0.890-0.978) with an accuracy of 91.0%. Comparing with radiologists reviewing videos along with complementary patient information, AI outperformed residents (82.9%-84.4%, P=0.038) and matched the performance of experts (87.2%-88.2%, P=0.438). Due to the higher positive predictive value (PPV) (AI: 95.6% vs. residents: 88.6%-89.7%, P=0.056), an AI strategy was defined to improve the malignant diagnosis. With the assistance of AI, radiologists exhibited a sensitivity improvement of 97.0%-99.4% (P<0.05) and an accuracy of 91.0%-92.9% (P=0.008-0.189), which was comparable to that of the experts (P=0.904). CONCLUSIONS The CEUS-based AI strategy improved the performance of residents and reduced CEUS's interobserver heterogeneity in the differentiation of benign and malignant FLLs.