双源双能量CT成像评估猪急性心肌缺血再灌注损伤的实验研究

目的 评价双源双能量CT(DECT)成像诊断猪急性心肌缺血再灌注损伤的可行性和准确性.方法 8只猪通过开胸结扎冠状动脉左前降支(LAD)或第一对角支(D1)建立再灌注损伤模型,术后行DECT心肌灌注成像扫描.检查结束后立即处死动物,取出心脏,进行氯化三苯基四氮唑(TTC)染色,分析心肌缺血再灌注损伤范围.以病理结果为参照,测量损伤区、非损伤区的CT值以及损伤区面积.将左心室壁分为17个节段,确定DECT心肌灌注碘图、DECT(140、100和平均加权120 kV)3组图像和大体病理上心肌损伤的节段数.以病理结果为金标准分别评价DECT心肌灌注碘图、3组图像显示心肌损伤的敏感性、特异性和一致性.利用方差检验分析损伤区和非损伤心肌不同管电压条件的CT值、大体病理和DECT 3组图像所测量损伤区重量的差异.结果 8只猪DECT心肌灌注碘图见心尖前壁、心尖间隔灌注稀疏甚至缺损,DECT 3组图像中再灌注损伤区CT值均较正常心肌明显降低.与病理金标准对照,DECT心肌灌注碘图诊断再灌注损伤的敏感性、特异性分别为85.2％ (23/27)、86.2％ (94/109),Kappa值为0.62；DECT3组图像的敏感性、特异性和Kappa值:140 kV组分别为88.9％ (24/27)、92.7％ (101/109),0.76；100 kV组分别为85.2％ (23/27)、89.0％(97/109),0.67；平均加权120 kV组分别为88.9％ (24/27)、91.7％ (100/109),0.74.DECT 3组图像测量损伤心肌重量与大体病理所测值之间差异无统计学意义(F=0.419,P=0.741).结论 DECT心肌灌注成像可用于检测猪急性心肌缺血再灌注损伤,与病理诊断一致性较好.

Dual source dual energy CT of acute myocardial ischemic reperfusion injury: an experimental study in swine

Objective To investigate the feasibility and accuracy of dual energy CT (DECT) in detecting acute myocardial ischemic reperfusion injury in a swine model.Methods Acute myocardial ischemic reperfusion injury model was made by ligaturing the left anterior descending coronary artery (LAD)or the first diagonal artery ( D1 ) of swine heart,the first-pass contrast enhanced DECT was performed.And then pigs were sacrificed,and the hearts were removed,triphenyhetrazolium chloride staining was performed.The CT numbers of non-ischemic and ischemic regions were measured.In the short axis of the left ventricle,the ventricular wall was divided into 17 segments for analysis,segments with myocardial perfusion defect in DECT myocardial iodine maps,DECT ( 140,100 kV,weighted average 120 kV) were determined and compared with histopathology.The sensitivity,specificity and inter-modality agreement of DECT in detecting myocardial injury were calculated.One-way ANOVA test was used to analyze the differences between the CT number and weight of infracted myocardium measured on DECT at 140,100 kV,weighted average 120 kV in ischemic and normal regions.Results Partial sparse or defective perfusion in the apical anterior and septal wall were demonstrated in DECT myocardial iodine maps.The CT number of injured myocardium was significantly lower than that of normal myocardium at 140,100 kV,weighted average 120 kV.The sensitivity,specificity of DECT myocardial iodine maps were 85.2％ (23/27),86.2％ (94/109),and Kappa value was 0.62,the sensitivity,specificity at 140 kV were 88.9％ (24/27),92.7％ (101/109),and Kappa value was 0.76,the sensitivity,specificity at 100 kV were 85.2％(23/27),89.0％ (97/109),and Kappa value was 0.67,the sensitivity,specificity at weighted average 120 kV were 88.9％ (24/27),91.7％ ( 100/109),and Kappa value was 0.74.There were no significant differences between the weight of infracted myocardium measured on DECT at 140,100 kV,weighted average 120 kV and histopathological results ( F =0.419,P =0.741 ).Conclusion DECT myocardial iodine maps can detect acute myocardial ischemic reperfusion injury in a swine model and have a good correlation with histopathology.