64层螺旋CT血管成像与心肌灌注显像探测功能相关冠状动脉病变

目的 比较64层螺旋CT血管成像(CTA)和心肌灌注显像(MPI)对功能相关冠状动脉狭窄性病变的诊断价值.方法 回顾性分析20例确诊和11例拟诊冠状动脉病变(CAD)患者的64层CTA和MPI图像.按照目测直径法判断CTA图像上冠状动脉狭窄程度:≥50%或＜50%;相应MPI图像上的心肌缺血分为可逆性和固定性灌注异常区.结果 31例患者的124条冠状动脉中,23条CTA图像上狭窄≥50% ,其中7条(30.43%)狭窄血管的供血心肌在MPI上呈现灌注异常区;101条狭窄＜50%及正常,其中10条(9.90%)血管的供血心肌在MPI图像上呈现灌注异常区.冠状动脉狭窄程度与其供应心肌节段发生缺血的风险概率之间差异有统计学意义(χ2=6.667,P=0.01),而冠状动脉不同狭窄部位与其供应心肌节段发生缺血的风险概率之间差异无统计学意义(χ2=6.839,P=0.065).64层螺旋CTA在探测MPI图像上缺血心肌节段所对应的狭窄≥50%冠状动脉的敏感度、特异性、阴性预测值、阳性预测值分别为41.18%、85.05%、90.01%和30.43%.结论 64层螺旋CTA能清晰显示冠状动脉的重要形态学信息,但其探测功能相关狭窄≥50%冠状动脉的阳性预测值较低,而MPI则是评价CAD导致心脏功能改变的重要检查方法.

Comparison of 64-slice spiral CTA and MPI in detection of functionally relevant coronary artery lesions

Objective To compare the accuracy of 64-slice spiral coronary angiography (CTA) and myocardial perfusion imaging (MPI) in the detection of functionally relevant coronary artery disease (CAD). Methods Twenty patients diagnosed as CAD and 11 suspected CAD were studied. Both 64-slice spiral CTA and MPI images were analyzed. For the evaluation of CTA,luminal narrowing ≥50% and ＜50% were visually assessed. Perfusion defects on MPI were detected and allocated to their corresponding coronary vessels.Results Among total 124 coronary vessels, CTA detected stenoses ≥50% in 23 arteries, and 7 showed perfusion defects in the corresponding myocardial areas on MPI. Ten of 101 vessels had stenoses＜50%,and no perfusion defects in the corresponding myocardial areas was found on MPI. There was difference between the degree of coronary artery stenoses and the risk probabilities of myocardial ischemia (χ~2=6.667, P=0.01). No statistical difference was detected between the coronary artery stenoses site and the risk probabilities of myocardial ischemia (χ~2=6.839, P=0.065). The sensitivity, specificity, negative and positive predictive values of 64-slice spiral CTA in detecting perfusion defects on MPI was 41.18%, 85.05%, 90.01% and 30.43%, respectively.Conclusion 64-slice spiral CTA can display important morphologic information of coronary arteries, but with a low positive predictive value. MPI can be used as an important method to evaluate the change of heart function resulted from CAD.