Low–mechanical-index B-mode phase-inversion harmonic imaging significantly improves hepatic lesion conspicuity during Sonazoid Kupffer phase: a prospective comparative study

PURPOSE: This study compared the imaging performance of low-mechanical-index phase-inversion harmonic imaging (low-MI PIHI) with conventional contrast-enhanced ultrasonography (CEUS) during the Kupffer phase (KP) of Sonazoid-enhanced imaging for visualizing hepatic lesions, focusing on lesion conspicuity and overall image quality. METHODS: This prospective study was approved by the Institutional Review Board and included 71 patients with 72 focal liver lesions examined between February 2023 and January 2024. All patients underwent Sonazoid-enhanced CEUS. Three image sets were acquired for each lesion: baseline B-mode imaging, conventional KP imaging, and low-MI PIHI KP imaging. Two independent radiologists, blinded to clinical information, independently evaluated lesion conspicuity, border delineation, and overall image quality using a 5-point Likert scale. RESULTS: Baseline B-mode imaging demonstrated the lowest lesion conspicuity scores, which improved with conventional KP imaging and were highest with low-MI PIHI KP imaging (all P