磁共振心肌灌注延迟增强与核素心肌灌注/代谢显像识别存活心肌对比研究

目的应用磁共振成像心肌灌注延迟显像(DE-MRI)所显示的高信号识别存活心肌和瘢痕组织,通过与99Tcm-甲氧基异丁基异腈(MIBI)单光子发射型计算机断层(SPECT)和18F-脱氧葡萄糖(FDG)SPECT进行对比研究,评估其诊断的敏感性和特异性,并分析两种方法的一致性。方法34例临床确诊的心肌梗死患者,拟行再血管化手术治疗。男性29例,女性5例,年龄(58.0±9.8)岁,接受心脏MRI及SPECT灌注/代谢显像检查。两种方法各划分5个等级,依据17节段分析法,分析34例患者共578个节段,并对两种评价心肌存活的方法行一致性分析。结果DE-MRI判断存活心肌431段(74.6%),坏死心肌147段(25.4%)。SPECT灌注/代谢显像诊断正常心肌336段(58.1%),坏死心肌212段(36.7%),缺血心肌30段(5.2%)。两种方法半定量分析显示一致性较好,Kappa值为0.51(>0.4)。以节段为单位,DE-MRI的敏感性为61.3%,特异性为95.4%。结论DE-MRI能够有效地识别存活心肌和瘢痕组织,并与18F-FDGSPECT一致性较好。

Identification of viable myocardium delayed enhancement magnetic resonance imaging and 99Tcm-sestamibi or 18F-fluorodeoxyglucose single photon emission computed tomography

OBJECTIVE: The aim of this study was to investigate the feasibility and accuracy of delayed enhancement magnetic resonance imaging (DE-MRI) for the assessment of myocardial viability in patients with myocardial infarction in comparison with (99)Tc(m)-sestamibi (MIBI) single photon emission computed tomography (SPECT) and (18)F-fluorodeoxyglucose (FDG) SPECT. Scar was defined as regionally increased MRI signal intensity 15 minutes after injection of 0.2 mmol/kg gadolinium-diethylenetriamine pentoacetic acid or reduced perfusion and glucose metabolism defined by SPECT. METHODS: A total of 34 patients with myocardial infarction (29 males, 58.0 +/- 9.8 years) were imaged with MRI and SPECT. RESULTS: A total of 578 segments were analyzed. DE-MRI and SPECT identified 431 and 336 viable segments respectively and SPECT also identified 30 ischemic segments. Necrotic segments identified by DE-MRI and SPECT were 147 and 212 respectively. Sensitivity and specificity of DE-MRI in identifying segments with matched flow/metabolism defects (scar tissues) was 61.3% and 95.4%, respectively. Quantitatively assessed relative MRI infarct area correlated well with SPECT infarct size. The value of Kappa was 0.51. CONCLUSION: DE-MRI provides a good tool for differentiating viable myocardium from scar tissues and the detection accuracy is comparable between DE-MRI and SPECT.