Background and aims: Contrast harmonic imaging significantly increases the detectability of liver lesions which are invisible on conventional B-mode sonography. With the introduction of contrast agents, which can be visualized at low mechanical index (low-MI), continuous real time observation of liver lesions under contrast conditions is possible. We addressed the question whether contrast-enhanced sonography allows for intervention of hepatic lesions impossible to detect on conventional B-mode imaging.
Patients and methods: We evaluated twelve patients with hepatic tumors or abscesses, which could not be analyzed and punctured under fundamental B-mode guidance. The ultrasound contrast agent BRI was used for detection of the hepatic lesions under contrast harmonic imaging (CHI) conditions with phase inversion at low-MI.
Results: In eleven out of twelve patients interventions under CHI conditions were successful, as proven by histological, microbiological or tumor marker analysis. The puncture needles were visible in all cases. With an algorithm for optimizing the puncture conditions at low-MI CHI the biopsies can be performed in two steps.
Conclusions: Our results show that biopsies of liver lesions under real-time continuous CHI at low-MI are feasible.