心率及心律对128层MSCT冠状动脉成像的影响

目的探讨心率及心律对螺旋CT冠状动脉CTA图像质量的影响。方法收集临床拟诊为冠状动脉疾患的614例患者，行128层螺旋CT回顾性心电门控增强扫描，根据心率将心律整齐者分为I～Ⅳ组，依照采集周期内心律变化幅度将心率≤80次／分者分为A～C组，评估各组图像质量。80例患者接受CAG检查，对其CTA与CAG检查结果进行统计学分析。结果614例中，CTA显示RCA优良者占90．88％（558／614），显示LAD优良者占90．55％（556／614），显示LCX优良者占90．07％（553／614）。80例CAG共显示618个冠状动脉节段；以CAG为金标准，CTA检测冠状动脉明显狭窄的敏感度为81．82％（108／132），特异度为96．91％（471／486），阳性预测值为87．80％（108／123），阴性预测值为95．15％（471／495），准确率为93．69％（579／618）；心率及心律变化幅度越低，CTA诊断的敏感度、准确率越高；心率≤80次／分或心律变化幅度≤10次时，阳性预测值较高。结论128层螺旋CT对于心律整齐、注射对比剂后心率≤80次／分者一般可以获得较高图像质量的CTA图像，且诊断准确率较高。

Impact of heart rate and rhythm on 128-MSCT coronary imaging

Objective To observe the impact of heart rate and rhythm on 128-MSCT coronary imaging. Methods Totally 614 patients with suspected coronary artery disease underwent enhanced retrospective ECG-gated scanning with a 128- MSCT scanner. The patients with regular heart rhythm were divided into group I --IV, and patients whose heart rate 480bpm were divided into group A--C, according to the range ability of heart rhythm in the collection period. All the images were evaluated. Eighty patients underwent CAG examination, and their CTA and CAG examination results were analyzed statistically. Results In CTA imaging of 614 patients, 90. 88% （558/614） right coronary artery, 90. 55% （556/ 614） left anterior descending artery and 90.07% （553/614） L-branch showed good. All of 618 coronary segments were displayed in 80 patients underwent CAG. Taking the results of CAG as gold standards, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CTA in coronary artery narrow was 81.82% （108/132）, 96.91% （471/486）, 87.80% （108/123）, 95.15% （471/495） and 93.69% （579/618）, respectively. For patients with slight change of heart rate and rhythm, the sensitivity and accuracy of CTA were high, and when heart rate 480 bpm or range ability of heart rhythm 410, the positive predictive value was high. Conclusion High quality CTA imaging and accuracy can be obtained in patient with tidy heart rhythm and heart rate 480 beat/min after contrast injection.