对比超声定量评价肾脏血流量的实验研究

目的 为评价对比超声(contrast-enhancedultrasound,CEU)定量肾脏血流量的准确性。方法 10只实验犬均分别在3种剂量(3、8和16mg·min^-1·kg^-1)多巴胺作用下,同步进行多普勒肾动脉血流量测定和对比超声肾皮质血流定量。标准化的肾动脉血流量(ml·min^-1·g^-1)等于肾动脉血流量除以肾脏质量。结果 与静息状态相比,在3种剂量多巴胺作用下肾动脉血流量均增加(P<0.05),且在低中剂量时肾动脉血流量随剂量的增加而增加(P<0.05),而在高剂量时肾动脉血流量的增加较低中剂量时减少(P<0.05)。对比超声测得的肾皮质血流量具有以上相似的血流变化特征,而且对比超声定量的肾皮质血流量与标准化的肾动脉血流量之间有良好的正相关(r=0.88,P<0.001)。结论 对比超声能准确地定量评价肾脏血流量。

Quantitative evaluation of canine renal blood flow with contrast-enhanced ultrasound

Objective To evaluate the accuracy of contrast-enhanced ultrasound (CEU) in renal blood flow quantification. Methods Regional renal perfusion was quantified with CEU in 10 dogs at the baseline level and after treatment with 3 doses of dopamine (3, 8 and 16 mg·kg^-1·min^-1), and renal arterial flow (RAF) was measured with ultrasonic flow probes deployed directly on the renal artery simultaneously. Normalized RAF was calculated as RAF divided by renal weight (ml·min^-1·g^-1). Results Compared with the baseline level, a progressive increase in RAF was induced by dopamine treatment at the doses of 3 and 8 mg·kg^-1·min^-1 (P<0.05), but at a higher dose of 16 mg·kg^-1·min^-1, the increment in RAF was reduced in comparison with that with the two lower doses (P<0.05). The same changes in cortical nutrient blood flow derived from CEU were observed. Significant positive correlation was found between normalized RAF and CEU-derived cortical nutrient blood flow (y=39.8x +44.3, r=0.88, P<0.001). Conclusion CEU can be used to accurately quantify renal blood flow in dogs.