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The aim of this study was to evaluate microvascular perfusion after liver ischemia-reperfusion injury (IRI) in rabbits using the "flash-replenishment" method of contrast-enhanced ultrasound (CEUS) perfusion imaging. Twenty-eight rabbits underwent either 30, 60 or 90 min of ischemia and 120 min of reperfusion. CEUS perfusion imaging was performed using the "flash-replenishment" model, and hepatic microvascular perfusion parameters, including peak intensity (PI), area under the curve (AUC), and hepatic artery-to-vein transit time (HA-HVTT), were calculated. Prolonged ischemia upregulated intracellular adhesion molecule-1 (ICAM-1), alanine transaminase (ALT) and aspartate transaminase (AST) levels. Longer ischemia decreased PI and AUC, but increased HA-HVTT. The perfusion parameters were significantly correlated with Suzuki's pathology scores and ALT and AST levels. The "flash-replenishment" method of CEUS perfusion imaging is an accurate and non-invasive method for evaluating hepatic microvascular perfusion and provides a valuable experimental basis for early prediction of liver IRI damage after liver transplantation or liver resection., (Copyright © 2018 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.)

This study was designed to investigate whether hepatic arterial pressure and portal pressure have an effect on liver stiffness during the development of liver fibrosis. Liver fibrosis was induced in 50 healthy New Zealand white rabbits. Laparotomy was performed to measure liver stiffness, and the portal vein and hepatic artery were successively ligated to repeat the measurements. A significant difference was observed among liver stiffness values measured at different time points (F = 22.82, p < 0.001). Differences between original liver stiffness and liver stiffness measured after portal ligation were positively correlated with portal pressure (r = 0.801, p < 0.001). In animals with grade 4 liver fibrosis, the increase in liver stiffness caused by pressure was greater than that caused by extracellular matrix accumulation (p = 0.002). In conclusion, hepatic arterial pressure and portal pressure have a significant effect on liver stiffness during the development of liver fibrosis., (Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.)

This work investigated the influence of some factors on the property in vitro of a self-made lipid ultrasound (US) contrast agent (LCA) and evaluated the relationship of acoustic pressure and enhancement effect in normal rabbit kidney parenchyma. In the in vitro studies, filling gas, solvent and concentration of LCA solution were investigated. Morphologic characteristics, concentration and mean diameter of microbubbles were considered as indices. In the in vivo studies, contrast-tuned imaging (CnTi) technique was used to investigate the enhancement effects in kidney parenchyma under nine acoustic pressure levels. Among the samples saturated with different filling gases, perfluoropropane (C(3)F(8)) resulted in the highest concentration of microbubbles and air, the lowest. Microbubbles filled with C(3)F(8) or sulfur hexafluoride (SF(6)) were quite stable and remained at a high level of concentration (above 2 x 10(9) microbubbles per mL) much longer than did air-filled microbubbles. Among the four solutions tested, 5% glucose solution and 0.9% saline solution showed higher initial concentrations and greater longevity than dextran 40 glucose solution (6%) or distilled water. The concentration of LCA solution had a positive correlation with the microbubble concentration. All microbubble samples under different test conditions remained shape-complete and no aggregation or fusion was observed. The mean diameter of microbubble samples was about 3.4 microm. Contrast intensity and longevity of CnTi enhancement in vivo showed an acoustic-pressure-dependent decrease. At 1 kPa, contrast intensity increased 224-fold (4.47/0.02) and the longevity of CnTi enhancement in the kidney parenchyma remained longer.