Ishida N, Sakuma H, Cruz B P, Shimono T, Tokui T, Yada I, Takeda K, Higgins C B
Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507, Japan.
Radiology. 2001 Aug;220(2):441-7. doi: 10.1148/radiology.220.2.r01au16441.
To evaluate the sensitivity and specificity of breath-hold magnetic resonance (MR) flow measurement for detection of significant stenosis in internal mammary artery bypass grafts.
Twenty-six consecutive patients who had undergone coronary artery bypass surgery were examined. Breath-hold velocity-encoded cine MR images were obtained at the midpoint of the internal mammary artery between its origin from the subclavian artery and the distal anastomosis to the left anterior descending artery.
MR images were obtained successfully in 24 patients. At conventional angiography, no significant stenosis was observed in 17 patients (group A), and significant stenosis (diameter > 70%) was observed in seven patients (group B). The mean diastolic-to-systolic peak velocity ratio in group B (0.61 +/- 0.44 [SD]) was significantly lower than that in group A (1.88 +/- 0.96; P <.01). Evaluation of graft stenosis with the diastolic-to-systolic peak velocity ratio revealed a sensitivity of 86% and a specificity of 88%. The mean blood flow rate at baseline in group B (16.9 mL/min +/- 5.5) was significantly lower than that in group A (79.8 mL/min +/- 38.2; P <.01). The sensitivity and specificity of MR blood flow measurement in predicting significant stenosis were 86% and 94%, respectively. The mean pharmacologic flow reserve ratios were 2.00 +/- 1.43 in group A and 1.39 +/- 1.46 in group B (P >.05).
Fast MR blood flow measurement at baseline is highly useful for predicting significant stenosis in internal mammary arterial grafts.
评估屏气磁共振（MR）血流测量对内乳动脉搭桥移植血管严重狭窄检测的敏感性和特异性。
对26例连续接受冠状动脉搭桥手术的患者进行检查。在乳内动脉自锁骨下动脉起源至与左前降支远端吻合口之间的中点处，获取屏气速度编码电影MR图像。
24例患者成功获得MR图像。在传统血管造影中，17例患者（A组）未观察到明显狭窄，7例患者（B组）观察到明显狭窄（直径＞70%）。B组平均舒张期与收缩期峰值速度比（0.61±0.44[标准差]）显著低于A组（1.88±0.96；P＜0.01）。用舒张期与收缩期峰值速度比评估移植血管狭窄，敏感性为86%，特异性为88%。B组基线平均血流率（16.9 mL/min±5.5）显著低于A组（79.8 mL/min±38.2；P＜0.01）。MR血流测量预测严重狭窄的敏感性和特异性分别为86%和94%。A组平均药物血流储备比为2.00±1.43，B组为1.39±1.46（P＞0.05）。
基线快速MR血流测量对预测乳内动脉移植血管严重狭窄非常有用。
