Revealing hidden vascular patterns: a modified CEUS LI-RADS framework for HCC using super-resolution ultrasound

To investigate the incremental value of super-resolution ultrasound (SRUS) microvascular imaging in optimizing the contrast-enhanced ultrasound (CEUS) liver imaging reporting and data system (LI-RADS) for the hepatocellular carcinoma (HCC) diagnosis. This prospective study enrolled high-risk patients for HCC from January 2024 to April 2025. Each patient underwent B-mode US, color Doppler flow imaging (CDFI), micro-flow imaging (MFI), conventional CEUS, and SRUS microvascular imaging examinations. Based on the two additional vascular features (capsular vessels and chaotic vessels) displayed by SRUS microvascular imaging, three novel criteria were developed for modified CEUS LI-RADS (LR). The LR-4 or LR-M lesions were reclassified to LR-5 using the following three criteria: (I) the presence of capsular vessels; (II) the presence of chaotic vessels; (III) the presence of capsular vessels or chaotic vessels. The diagnostic performance of modified CEUS LI-RADS using three HCC criteria was evaluated and compared with that of the original CEUS LI-RADS. The reference standard was pathologic confirmation or composite criteria. Overall, 593 patients with 593 lesions were enrolled. The visualization rate of the capsular and chaotic vessel features by SRUS is higher than that of CDFI, MFI, and the arterial phase of CEUS (all P < 0.05). The inter-observer agreement was substantial for capsular vessels (kappa = 0.742) and chaotic vessels (kappa = 0.631). Compared with the original CEUS LI-RADS, three novel criteria for modified CEUS LI-RADS demonstrated higher sensitivity, accuracy, and area under the curve (AUC) (all P < 0.05). Particularly, criterion III achieved the best sensitivity (89.80%), accuracy (89.38%), and AUC (0.891), without a significant decrease in specificity (88.48%). SRUS microvascular imaging is able to reveal hidden vascular patterns in refining CEUS LI-RADS for HCC diagnosis.