双能量CT心肌灌注碘图图像质量与重组时相的关系

Correlation between myocardial perfusion imaging quality and reconstruction time of dual-energy CT

目的探讨第2代双源CT(DSCT)心肌灌注图像质量与重组时相的关系。方法收集接受DSCT双能量成像方法扫描的患者,选取其中冠状动脉正常者28例。采用回顾性心电门控间隔5%重建出30%~80%R-R时相的图像,采用280ms全期相时间窗,定量测量各R-R间期的每段心肌灌注碘图图像的伪影面积,计算心底部、中部、心尖部、心尖层面平均各段的伪影面积,并进行统计学分析。结果心底部、中部、心尖部、心脏整体平均各段伪影面积差异有统计学意义(P均<0.01),均以60%R-R间期时相最小[(0.31±0.28)cm^2、(0.18±0.23)cm^2、(0.13±0.13)cm^2)、(0.22±0.18)cm^2]。心尖伪影面积不同R-R间期时相差异无统计学意义(P=0.634)。60%R-R间期心底部、中部、心尖部、心尖各层面平均各段碘图伪影面积差异有统计学意义(F=3.701,P=0.014),心尖部伪影面积最小,与中部差异无统计学意义(P>0.05),但明显低于其他部位的伪影面积(P<0.05)。结论第2代DSCT采用280ms全期相时间窗可提供优良的心肌灌注碘图,其中以60%左右R-R间期图像质量最佳。

Objective To evaluate the relationship between myocardial perfusion imaging quality and reconstruction time of dual-souce CT（DSCT）.Methods Myocardial perfusion imaging was performed in 28 subjects using second-generation DSCT.The coronary arteries of all selected subjects were normal.280 ms temporal resolution was used,and the image of 30%—80% R-R phase was reconstructed by retrospective ECG gating interval 5%.The artifact area of myocardial perfusion iodine map image of each R-R interval were obtained.Average segment artifacts of the heart bottom,central,apical,apical level of heart level were calculated and statistical analyzed.Results The artifact area of myocardial perfusion iodine map of the heart bottom,central,apical,and the whole heart had statistically significant differences（all P〈0.01）,and the minimum artifact area was in 60% R-R phase（[0.31±0.28]cm^2,[0.18±0.23]cm^2,[0.13±0.13]cm^2,[0.22±0.18]cm^2）.There was no difference between different phases of the heart apical level（P=0.634）.The minimum artifact area of myocardial perfusion iodine map of the heart bottom,central,apical,apical level in 60% R-R phase at the heart apical,the difference had statistically significant（F=3.701,P=0.014）,there was no difference between the heart apical and central（P〉0.05）,but the difference between the heart apical and other parts had statistically significant（P〈0.05）.Conclusion Using 280 ms temporal resolution,second-generation DSCT can achieve the optimal myocardial perfusion imaging quality using 60% R-R phase reconstruction.