ABSTRACT
Objective To explore the value of the ultrasound contrast agent in conjunction with advanced contrast imaging techniques in the evaluation of the renal cortical perfusion. Methods The animal model was established with ligating renal artery to cause the renal cortical perfusion decrease of rabbits. Real-time harmonic gray scale imaging was performed to visualize the contrast enhancement of the renal cortex. After bolus injection of contrast agent SonoVue, dynamic image was observed and recorded during the first three minutes. According to the time-intensity curve (TIC), accelerating time (AT),Peak intensity (A), time to half of peak intensity (T), difference between peak and base (PBD), slope rate of the curve (β) and the product of A and β (A·β) were obtained before and after the renal artery operation. The t test and correlation analysis was used to examine the above parameters. Results Before the renal artery operation, renal cortex enhanced rapidly and obviously, the way of the enhancement was renal artery-cortex-pyramids. After ligation of renal artery, AT prolonged evidently (P<0.001), A decreased obviously (P<0.001), T obviously shortened (P<0.001), PBD decreased markedly (P<0.001), while the decline of βinduced (P<0.002) and A·βobvious dropped(P<0.001). AT, BPD and A·βcorrelated with stenosis level of renal artery. Compared with 31%－69% group, AT prolonged evidently (P<0.001). A decreased obviously (P<0.029), PBD decreased obviously (P<0.001), A·β was dropped markedly (P<0.02) in 70%-93% stenosis group. Conclusions Contrast agent combining with developed contrast specific imaging is able to detect changes of renal cortical microcirculation sensitively with the help of analysis of TIC.