Comparison of 99Tcm-MIBI SPECT/18F-FDG PET imaging and cardiac MRI in assessment of myocardial injury cases with idiopathic dilated cardiomyopathy / 中华核医学与分子影像杂志

ABSTRACT

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 (normal2.1％ (12/582) ; mismatch18.1％ (15/83) ; mild-to-moderate match13.6％ (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.