Contrast-Enhanced Ultrasound: A Useful Tool to Study and Monitor Hepatic Tumors Treated With Histotripsy.

Histotripsy is a novel noninvasive nonthermal, nonionizing, and precise treatment technique for tissue destruction. Contrast-enhanced ultrasound (CEUS) improves the detection, characterization, and follow-up of hepatic lesions because it depicts accurately the vascular perfusion of both normal hepatic tissue and hepatic tumors. We present the spectrum of imaging findings of CEUS after histotripsy treatment of hepatic tumors. CEUS provides real-time information, a close approximation to the dimension of the lesion, and a clear definition of its margins. Hepatic tumors detected by ultrasound can be potentially treated using B-mode ultrasound-guided histotripsy and characterized and monitored with CEUS. CEUS has shown to be very useful after tissue treatment to monitor and assess the evolution of the treated zone. Histotripsy treated zones are practically isoechogenic and slightly heterogeneous, and their limits are difficult to establish using standard B-mode ultrasound. The use of CEUS after histotripsy showing uptake of contrast protruding into the treated zone is clinically relevant to identify residual tumors and establish the most appropriate management strategy avoiding unnecessary treatments. We here describe CEUS findings after histotripsy for hepatic tumors.