64层螺旋CT评价冠状动脉支架内再狭窄的价值

Evaluation of coronary artery in-stent restenosis using 64-slice CT

目的评价64层螺旋CT诊断冠状动脉支架内再狭窄(ISR)的临床价值。方法采用64层螺旋CT对14例冠状动脉支架置入术后的患者(共37个支架)进行CT冠状动脉成像(CTA)。在CTA上,通过肉眼观察和测量支架内CT值两种方法诊断ISR。以冠状动脉造影(ISR≥50%)为标准,计算并比较两种方法诊断ISR的准确性。结果37个支架中,CCA检出ISR(≥50%)11个,正常(包括ISR＜50%)26个。与CCA对照,CTA肉眼观察法正确诊断ISR 2个,正常18个,CT值测量法则分别正确诊断ISR 3个,正常21个。两种方法诊断ISR的敏感性、特异性、阳性预测值和阴性预测值分别为18%、69%、20%、67%和27%、81%、38%、72%。两种方法各项准确性指标之间差异均无统计学意义(P＞0．05)。结论64层螺旋CT诊断ISR十分困难,但对排除ISR有一定的作用。

Objective To evaluate the accuracy of 64-slice CT in the diagnosis of coronary in-stent restenosis （ISR）. Methods Fourteen patients with 37 implanted coronary stents were examined by both 64-slice CT angiography （CTA） and conventional coronary angiography （CCA）. The diagnosis of ISR was evaluated by two methods （ visual inspection and the measurement of the in-stent contrast attenuation ） on CTA. The accuracy of the two methods in the diagnosis of ISR was compared with reference to CCA. Results ISR （ 〉 50% ） was found on CCA in 11 stents. CTA with visual inspection and with measurement of in-stent CT attenuation correctly detected ISR in 2 and 3 stents respectively with reference to CCA. The sensitivity, specificity, positive predictive value and negative predicitive value of the two methods were 18%, 69%, 20%, 67% and 27%, 81%, 38%, 72%, respectively. There was no significant difference （P 〉0. 05） between the accuracy of two methods. Conclusion The ISR was very difficult to diagnose by 64 slice CT, but the high specificity of 64-slice CT study implied an important role in excluding ISR.