| Objectives:To explore the value of a new dark blood late gadolinium enhancement(DB-LGE)in the assessment of myocardial infarction(MI).And compared with the Conv-LGE(Conventional late gadolinium enhancemen,Conv-LGE)technology,to explore the differences in the assessment of myocardial infarction,and preliminary explore its application in infarcted patients with or without pathological Q wave.Methods:64 patients with myocardial infarction were selected from the Department of Cardiology,Beijing Anzhen Hospital,Capital Medical University from February 2017 to September 2017.After the patient confirmed that there was no MR contraindication,a 3.0T cardiac magnetic resonance(CMR)examination(Discovery MR 750W,GE,WI)was performed using a 32-channel heart-specific coil.CMR included cardiac films,Conv-LGE and DB-LGE.And 12-lead ECGs were performed on the same day.The study is divided into two parts:The first part:? The short-axis images of DB-LGE and Conv-LGE technology were divided into DB-LGE group and Conv-LGE group.The relevant signal parameters(SI,SIR,CNR)of the normal myocardium,infarcted myocardium and blood pool were measured and calculated on image analysis software.The differences in SI,SIR,and CNR between the tissues in the DB-LGE group and Conv-LGE group were compared.?According to the 17th segment of the heart of the American Heart Association(AHA),the infarcted myocardium of the DB-LGE group and Conv-LGE group was evaluated,including the number of infarcted segments and the transmural grade of infarcted myocardium.The difference in number of myocardial infarction segments and the transmural grade between DB-LGE group and Conv-LGE group were compared.?The ratio of MI volume to whole myocardial volume(MI%)was automatically calculated in the image analysis software,MI%between DB-LGE group and Conv-LGE groupwere compared.?Infarcted papillary muscles between DB-LGE group and Conv-LGE group were compared.The second part:According to the 12-lead ECG,the patients were divided into Q-Wave(QW)group and Non-Q-Wave(NQW)group.?The transmural grade of infarcted myocardium with QW or NQW between DB-LGE group and Conv-LGE group were compared.? The difference of MI%images between the QW group and NQW group on the DB-LGE were measured.?The efficacy of the DB-LGE technique for the infarcted myocardium in the QW and NQW groups was compared.Results:The image information of 56 patients was included in this study.The first part:?Compared with Conv-LGE technique,DB-LGE technique can provide higher CNR and SIR between infarcted myocardium and blood pool(6.3±2.6 vs.2.1 ± 1.3;5.4 ±1.9 vs.1.3 ±0.2).The difference was statistically significant(P<0.001**).DB-LGE images provide better visual contrast between the infarcted myocardium and the blood pool.?Conv-LGE found a total of 401 MI segments(about 42.1%),DB-LGE found a total of 450 MI segments(about 47.3%),the difference between the two techniques was statistically significant(P<0.001**).Conv-LGE:551(GradeO),64(Gradel),38(Grade2),53(Grade3),246(Grade4);DB-LGE:502(GradeO),113(Gradel),,38(Grade2),53(Grade3),246(Grade4),the difference between the two groups was statistically significant(P<0.001**).?The MI%of the DB-LGE group was greater than the MI%of the Conv-LGE group(19.3 ± 10.7 vs.18.9 ± 10.6).The difference between the two groups was statistically significant(P<0.001**).?9 patients had infarcted papillary muscles in the Conv-LGE images and 32 patients had infarcted papillary muscles in the DB-LGE images.Combined with echocardiography,7 of the 9 patients with infarcted papillary muscles detected in Conv-LGE images had severe mitral regurgitation and 2 had moderate mitral regurgitation;32 patients with infarcted papillary muscles were found in DB-LGE images,7 patients had severe mitral regurgitation,13 patients had moderate mitral regurgitation,and 12 patients had mild mitral regurgitation.The second part:?QW group,Conv-LGE:189(GradeO),18(Gradel),22(Grade2),19(Grade3),143(Grade4);DB-LGE:171(GradeO),36(Gradel),22(Grade2),19(Grade3),143(Grade4).NQW group,Conv-LGE:362(GradeO),46(Gradel),16(Grade2),34(Grade3),103(Grade4);DB-LGE:331(GradeO),77(Gradel),16(Grade2),34(Grade3),103(Grade4).The difference of transmural grade of MI between Conv-LGE and DB-LGE in the QWgroup orNQW group(Z=-4.24,P<0.001;Z=-5.57,P<0.001**).?On DB-LGE images,the MI%of QW group was larger than that of NQW group(24.2± 10.3 vs.15.9 ±9.8).There was a significant difference between the two groups(P<0.001**).?Compared with the QW group,the DB-LGE technique had better test efficacy in the NQW group(Z=-5.859 P<0.001**).Conclusions:?Compared with Conv-LGE technology,DB-LGE technology can provide better visual contrast between the infarcted myocardium and the blood pool.?Compared with Conv-LGE technology,DB-LGE technology can find more subendocardial infarcted myocardial segments.?Compared with Conv-LGE images,the measured MI%is larger on DB-LGE images.?Compared with Conv-LGE technology,DB-LGE technology in the identification of infarcted papillary muscles has more advantages;Size of infarced tpapillary muscles may be closely related with the degree of mitral regurgitation.?Whether in the QW group or the NQW group,DB-LGE technology can discover more subendocardial infarcted myocardial segments than Conv-LGE technology.?On DB-LGE images,the QW group had larger MI%than the NQW group.The DB-LGE technique can provide a more accurate assessment of the correlation between pathologic Q waves and size of infarcted myocardium.?Compared with the QW group,the DB-LGE technique has better test efficacy in the NQW group.The DB-LGE technique can provide a more accurate assessment of the correlation with non-pathological Q waves. |
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