OBJECTIVETo study the sensitivity and feasibility of detecting microvascular inflammation in renal ischemia- reperfusion injury using microbubbles (MB) targeted to the intercellular adhesion molecule ICAM-1 and ultrasound radiation force (USRF).

METHODSMouse models of kidney ischemia-reperfusion were randomized into 5 groups with reperfusion time of 1, 3, 6, 12, and 24 h (IRlh, IR3h, IR6h, IR12h, and IR24h group, respectively). Each group was subdivided into targeted MB group (MBgroup) and targeted MB +USRF group (MBgroup). Kidney enhancement and the video intensity (VI) of the kidneys were compared among the groups.

RESULTSIn normal mice in either Mor MBgroup, no obvious enhancement of the kidney or significant increase in VI of the kidneys was observed (P=0.923). The kidneys were enhanced in all the mice with renal ischemia-reperfusion injury, and with the passage of time, the enhancement increased progressively. VI in the kidneys of mice with renal ischemia-reperfusion injury in MBgroup increased more significantly compared with the MBgroup. Significant difference in the VI was noted among the groups with different perfusion time but not between IR12h and IR24h groups.

CONCLUSIONMicrobubbles targeted to ICAM-1 combined with USRF can effectively evaluate renal ischemia-reperfusion injury in mice and can be used for early evaluation of microvascular inflammation and other endothelial responses.