Contrast-enhanced ultrasound detects perfusion defects in an ex vivo porcine liver model: a useful tool for the study of hepatic reperfusion.

Following transplantation, areas of hypoperfusion can be associated with metabolic changes and poor organ recovery. Our study evaluated contrast-enhanced ultrasound (CEUS) agents for the detection of such areas. Livers were collected from ten pigs, connected to extracorporeal circuits and perfused using autologous blood. After 1 and 4 h livers were scanned with an ultrasound machine following the administration of CEUS agents. Biopsies from perfused and non-perfused areas were collected. The entire parenchyma enhanced strongly on non-contrast ultrasound at 1 h with no perfusion defects. Four hours later multiple perfusion defects manifested not evident with non-contrast ultrasound. Histology confirmed non-perfused areas corresponded to ischemic zones. In our model the addition of CEUS revealed perfusion defects after 4 h. This might facilitate detection and characterization of perfusion defects in transplanted livers.