磁共振灌注成像评价兔后肢缺血模型肌肉灌注的实验研究

Application of MR perfusion imaging in assessment of muscle perfusion in hind-limb ischemia model of rabbit

目的:初步探讨磁共振灌注成像(MRPWI)在评估兔后肢缺血模型肌肉组织灌注中的应用价值.方法:对16只新西兰大白兔建立右后肢缺血模型,分别于术前、术后1,3,7,14,21,28,42,56,70d行MR灌注成像检查,原始灌注图像资料经MeanCurve软件处理,将感兴趣区(ROI)信号强度变化绘制成时间-信号增强百分比曲线,分析该灌注曲线特征并观察灌注参数(注药后开始强化时间、强化峰值、强化斜率)变化趋势.结果:术后右后肢血流灌注较对侧急剧减低,术后7d内灌注恢复非常缓慢,从14d起灌注恢复逐渐加快,但直至术后70d仍未恢复至正常灌注水平.结论:磁共振灌注成像能够安全、无创、半定量地且较准确地评估动物后肢缺血模型随时间推移发生的肌肉组织灌注变化.

AIM： To evaluate the application of magnetic resonance （MR） perfusion weighted imaging in the assessment of muscle perfusion in hind-limb isehemia model of rabbit. METHODS： Ischemia was induced in right hind limbs of 16 New Zealand white rabbits by complete excision of femoral artery. Before and 1,3, 7, 14, 21, 28, 42, 56, 70 d after the model establishment, MR perfusion scan was performed on models respectively and the pewent MR signal enhancement of the region of interest was plotted to draw a time-enhancement curve. The perfusion curve and parameters （enhancement onset time, peak value and slope rate ） were analyzed. RESULTS： Following femoral artery excision, a rapid reduction of muscle perfusion in right hind-limb was observed. Perfusion recovered very slowly during the first 7 d post-excision and faster perfusion recovery was observed within 14 to 70 d, but at last perfusion didn＇t reach the normal level. CONCLUSION： MR perfusion imaging is a safe, noninvasive, seml-quantitative and relatively accurate technique to assess time-dependent changes of muscle perfusion in hind-limb ischemia model of rabbit.