Claudon M, Barnewolt C E, Taylor G A, Dunning P S, Gobet R, Badawy A B
Department of Radiology, Children's Hospital, Boston, MA, USA.
Radiology. 1999 Sep;212(3):725-31. doi: 10.1148/radiology.212.3.r99se14725.
To evaluate contrast agent-enhanced harmonic ultrasonographic (US) imaging and Doppler hemodynamics during acute urinary obstruction.
In 12 piglets, the distal ureter was obstructed for 60 minutes, followed by intravenous injection of furosemide. In six piglets, ureteral pressure was further elevated to mean arterial pressure, and in six other piglets ureteral obstruction was released. Contrast-enhanced harmonic imaging was performed, and interlobar resistive index (RI) and renal blood flow were determined at baseline and during each experimental condition. A bolus injection curve was constructed by plotting mean pixel intensity versus time, and the area under this normalized curve was compared with renal blood flow values.
Ureteral obstruction and high ureteral pressure reduced cortical renal blood flow to 88% and 66%, respectively, of baseline values. Administration of contrast agent resulted in marked homogeneous enhancement of the renal cortex. The area under the curve diminished during ureteral obstruction and correlated well with mean cortical blood flow. RI correlated well with renal perfusion pressure but poorly with changes in renal blood flow.
Contrast-enhanced harmonic US imaging depicts changes in renal blood flow during acute obstruction. Interlobar RI is a good predictor of renal perfusion pressure but not of changes in renal blood flow.
评估急性尿路梗阻期间造影剂增强谐波超声（US）成像及多普勒血流动力学情况。
对12只仔猪，将输尿管远端梗阻60分钟，随后静脉注射速尿。6只仔猪中，输尿管压力进一步升高至平均动脉压，另外6只仔猪解除输尿管梗阻。进行造影剂增强谐波成像，在基线及各实验条件下测定叶间电阻抗指数（RI）及肾血流量。通过绘制平均像素强度与时间的关系构建团注注射曲线，并将该标准化曲线下的面积与肾血流量值进行比较。
输尿管梗阻及输尿管高压分别使肾皮质血流量降至基线值的88%和66%。注射造影剂后肾皮质出现明显均匀强化。输尿管梗阻期间曲线下面积减小，且与平均皮质血流量密切相关。RI与肾灌注压密切相关，但与肾血流量变化的相关性较差。
造影剂增强谐波超声成像可描绘急性梗阻期间肾血流量的变化。叶间RI是肾灌注压的良好预测指标，但不是肾血流量变化的良好预测指标。
