摘要：
Objective To evaluate the relationship of myocardial MR contrast delay-enhancement and nuclear perfusion-metabolism pattern in patients with idiopathic dilated cardiomyopathy (IDCM).Methods Forty-two consecutive patients (29 men and 13 women,age:(53 ±12) years) diagnosed clinically with IDCM were enrolled.All patients underwent 99Tcm-MIBI SPECT,18F-FDG PET imaging and MR contrast delay-enhancement imaging within 3-7 d.The myocardial perfusion-metabolism segment analysis was performed using a 17-segment model.Segmental 99Tcm-MIBI and 18F-FDG uptakes were scored visually using a 4-grade scoring system (0 =normal uptake,1 =mildly reduced uptake,2 =moderately reduced uptake,3 =severely reduced uptake).Patterns of perfusiorn/metabolism were classified as normal,mismatch,mild-to-moderate match and severe match.Myocardial MR contrast delay-enhancement was classified into 3 categories (non,mid-wall and transmural delay-enhancement).x2 test was used to analyze the differences of perfusion/metabolism patterns among non,mid-wall and transmural delay-enhancement groups and the myocardial MR contrast delay-enhancement incidence among four perfusion/metabolism groups.Resuits Among the 42 patients,myocardial delay-enhancement was present in 18 patients,of which 94.4％ (17/18) showed abnormal myocardial perfusion/metabolism patterns and only 33.3 ％ (8/24) patients without abnormal myocardial delay-enhancement had abnormal myocardial perfusion/metabolism patterns (x2 =15.944,P ＜ 0.001).Perfusion/metabolism patterns varied in three different categories of non,mid-wall and transmural delay-enhancement (x2 =14.276,P ＜ 0.001).The normal peffusion/metabolism pattern proportions in the non,mid-wall and transmural delay-enhancement groups were 86.2％ (526/610),71.0％ (44/62) and 28.6％ (12/42),respectively.The incidence of transmural delay-enhancement (44.4％ (12/27)) was significantly higher in segments with severe match than that in the other 3 groups (normal:2.1％ (12/582) ; mismatch:18.1％ (15/83) ; mild-to-moderate match:13.6％ (3/22) ; x2 =112.530,P ＜ 0.001).Conclusions MR contrast delay-enhancement is much more sensitive in detecting moderate fibrosis,while nuclear perfusion-metabolism imaging can detect more impaired but viable myocardium.Combining the two imaging modalities is useful for providing comprehensive evaluations of myocardial injury in patients with IDCM.%目的 比较99Tcm-MIBI SPECT/18F-FDG PET心肌灌注/代谢显像与心脏MRI延迟增强成像2种影像学方法评价特发性扩张型心肌病(IDCM)心肌损伤的特点.方法 对42例明确诊断为IDCM的连续患者[其中男29例,女13例,年龄(53±12)岁],行99Tcm-MIBI SPECT、18F-FDG心肌灌注/代谢显像和心脏MRI延迟成像,间隔时间为3～7d.利用17节段模型分别为各节段心肌灌注和代谢图像的放射性摄取评分,共分为4个等级:0=摄取正常,1=摄取轻度降低,2=摄取中度降低,3=摄取严重降低.根据心肌灌注/代谢匹配情况分为正常、不匹配、轻中度匹配、完全匹配4组；根据心脏MRI延迟成像结果分为无延迟强化、壁间强化、透壁强化3组,采用x2检验比较不同强化组间的灌注/代谢异常率差异和不同灌注/代谢匹配组间的延迟强化发生率.结果 全部42例患者中,18例心脏MRI延迟成像出现延迟强化,其中94.4％ (17/18)患者心肌灌注/代谢异常；而另外24例心脏MRI延迟成像无延迟强化患者中,仅有33.3％ (8/24)患者心肌灌注/代谢异常(x2=15.944,P＜0.001).心肌节段分析中,无延迟强化、壁间强化、透壁强化3组相应的心肌灌注/代谢情况有差异,灌注/代谢正常率分别为86.2％ (526/610)、71.0％ (44/62)和28.6％ (12/42)(x2=14.276,P＜0.001).灌注/代谢不匹配组中75.9％ (63/83)的心肌节段无延迟强化,而灌注/代谢完全匹配组透壁强化的发生率(44.4％,12/27)明显高于其他3组[正常组2.1％(12/582)、不匹配组18.1％(15/83)、轻中度匹配组13.6％(3/22),x2=112.530,P＜0.001].结论 心脏MRI延迟成像检测轻度纤维化更敏感,而心肌灌注/代谢显像能够检测更多受损但存活的心肌.结合2种影像学方法评价IDCM患者心肌损伤可以提供更加全面的信息.
