对比超声定量大鼠后肢骨骼肌绝对血流量的研究

Quantitative study of absolute blood flow of skeletal muscle in rats hind limb by contrast-enhanced ultrasound

目的评估超声造影定量大鼠骨骼肌绝对血流灌注的稳定性和可重复性。方法雄性Wistar大鼠12只,经尾静脉匀速输注超声造影剂,分别行心腔和骨骼肌声学造影。记录全部造影图像,脱机分析造影剂再填充曲线,测定心腔和骨骼肌的声学造影平台强度(A)、造影剂的再填充速率(β)。利用心腔声学强度进行骨骼肌造影的标化,计算骨骼肌绝对血流量;7d后再次行声学造影重复定量骨骼肌血流;比较两次造影定量骨骼肌血流结果的稳定性及造影曲线的拟合优度。结果所有大鼠后肢骨骼肌均获得满意的图像,同一只大鼠两次造影的骨骼肌血管密度、血流速度和骨骼肌绝对血流量比较,差异无统计学意义(P>0.05);全部造影曲线的拟合良好,决定系数为0.944±0.046(P<0.01)。结论以左室腔声学造影强度为参照定量骨骼肌绝对血流量具有良好的重复性,可视为一种在活体定量肌肉组织绝对血流量的新方法。

Objective To assess the stability and repeatability of quantification of absolute blood flow perfusion of skeletal muscle in rats hind limb by contrast - enhanced ultrasound. Methods The ultrasound imaging of heart and skeletal muscle was performed respectively on 12 male Wistar rats following continuous injection of contrast media. All the data were recorded and analyzed offline. The plateau video intensity （A） and the refilling velocity of contrast （[3） were measured, the absolute blood flow of rats hind limb was calculated. The stability of quantitative absolute blood flow and the goodness of curve fit were compared. Results Satisfactory images were obtained in all the rats. There was no significant difference between the vascular density, flow velocity and the absolute blood flow of the skeletal muscle of hind limb in the same rat at different time （P 〉 0.05 ）. The coefficient of determination of curve fit was 0. 944 ＋ 0. 046 （P 〈 0.01 ）. Conclusion Quantitative absolute blood flow of skeletal muscle has good repeatability and can be regarded as a new method to quantify absolute blood flow in vivo.