Use of contrast-enhanced ultrasound to monitor rabbit renal ischemia-reperfusion injury and correlations between time-intensity curve parameters and renal ICAM-1 expression.

BACKGROUND: Renal ischemia-reperfusion injury (IRI) is common in renal transplantation, shock, and nephrolithotomy. OBJECTIVE: To quantitatively assess rabbit renal IRI with contrast-enhanced ultrasound (CEUS) and investigate associations between renal cortical time-intensity curve (TIC) parameters and intracellular adhesion molecule-1 (ICAM-1) expression. METHODS: Eighteen white rabbits were randomly assigned into control and IRI groups (n = 9 each), and CEUS examination was performed 24 h after modeling. TIC parameters including arrival time (AT), time to peak intensity (TTP), changes in peak intensity, area under the curve (AUC), and slope of the ascending TIC, and correlations between these parameters and ICAM-1 expression were evaluated with linear correlation analyses. RESULTS: AT, TTP, and AUC were significantly increased in the IRI group (P < 0.05), and the slope of the ascending TIC was significantly lower than that in the control group (P < 0.05). ICAM-1 content in the renal cortex was significantly increased in the IRI group (P < 0.05). In addition, the slope of the ascending TIC negatively correlated with renal ICAM-1 expression (r =-0.923, P < 0.01), whereas AT and TTP positively correlated with ICAM-1 expression (r = 0.697 and 0.892, both P < 0.01). CONCLUSIONS: TIC parameters including the slope of the ascending TIC, AT, and TTP closely correlated with ICAM-1 in the renal cortex, and it is considered that the TIC can be used to quantitatively monitoring renal cortex blood perfusion and CEUS can be used to indirectly evaluate the degree of inflammatory reaction associated with renal IRI. CEUS may be a useful non-invasive method to identify inflammation caused by renal IRI-associated diseases.