Debatin J F, Strong J A, Sostman H D, Negro-Vilar R, Paine S S, Douglas J M, Pelc N J
Department of Radiology, Stanford University Medical Center, CA 94305.
J Magn Reson Imaging. 1993 May-Jun;3(3):443-50. doi: 10.1002/jmri.1880030303.
In the postoperative patient with anginal symptoms, differentiation between bypass graft compromise and nonischemic causes has until now been accomplished only by means of x-ray angiography. A non-invasive test is clearly desirable. The authors used a cine phase-contrast (PC) magnetic resonance (MR) imaging technique to characterize blood flow in native and grafted internal mammary arteries (IMAs). Ten volunteers and 15 patients who had recently undergone IMA coronary artery bypass grafting were imaged. Cine PC MR imaging was performed in the transaxial plane at the level of the pulmonary artery bifurcation. Flow in both IMAs was quantified and expressed as a percentage of cardiac output measured in the ascending aorta. In the 15 patients, flow analysis was performed in both the native and grafted IMAs. In the volunteers, IMA blood flow ranged from 2.1% to 4.3% of cardiac output on the left (mean, 3.5%) and 2.1% to 5.1% (mean, 3.5%) on the right. There was considerable intersubject variability, with coefficients of variation of 10.7% for the left and 12.3% for the right IMA. Intrasubject variability was limited, with estimated common standard deviations of 0.45% of cardiac output (range, 0.2%-1.1%) for the left and 0.39% (range, 0.1%-0.6%) for the right IMA. Flow in grafted IMAs was identified in 13 of 15 patients. In one of two patients without demonstrable IMA graft flow, cardiac catheterization confirmed lack of flow. IMA graft flow varied from 28 to 164 mL/min (mean, 80.3 mL/min). This study shows the feasibility of using cine PC MR imaging as a quantitative method of evaluating blood flow in IMA coronary artery bypass grafts.
对于有心绞痛症状的术后患者，迄今为止，旁路移植血管受损与非缺血性病因之间的鉴别仅通过X线血管造影来完成。显然需要一种非侵入性检查。作者使用电影相位对比（PC）磁共振（MR）成像技术来描述自体和移植的内乳动脉（IMA）中的血流情况。对10名志愿者和15名近期接受IMA冠状动脉旁路移植术的患者进行了成像。在肺动脉分叉水平的横断面进行电影PC MR成像。对双侧IMA的血流进行定量，并表示为升主动脉测量的心输出量的百分比。在15名患者中，对自体和移植的IMA均进行了血流分析。在志愿者中，左侧IMA血流占心输出量的2.1%至4.3%（平均3.5%），右侧为2.1%至5.1%（平均3.5%）。个体间存在相当大的变异性，左侧IMA的变异系数为10.7%，右侧为12.3%。个体内变异性有限，左侧IMA的心输出量估计共同标准差为0.45%（范围0.2% - 1.1%），右侧为0.39%（范围0.1% - 0.6%）。15名患者中有13名检测到移植IMA的血流。在两名未显示IMA移植血流的患者中，有一名经心导管检查证实无血流。IMA移植血流为28至164 mL/分钟（平均80.3 mL/分钟）。本研究表明，使用电影PC MR成像作为评估IMA冠状动脉旁路移植血管血流的定量方法是可行的。
