18F-FDG PET/CT分子显像评价缺血性心脏病患者心功能受损与脑葡萄糖代谢的相关性研究

目的从细胞能量代谢的角度评价缺血性心脏病(IHD)患者左心室功能受损与脑葡萄糖代谢水平之间的关系,探索心功能受损患者脑葡萄糖代谢减低的功能区。方法入选于2016年4月至2017年10月在北京安贞医院行99Tcm-甲氧基异丁基异腈(MIBI)门控单光子发射计算机断层扫描/CT(SPECT/CT)心肌灌注显像、18F-脱氧葡萄糖(FDG)门控正电子发射计算机断层成像/CT(PET/CT)心肌葡萄糖代谢显像和脑葡萄糖代谢显像(于3 d内完成所有检查)的IHD患者110例。采用QGS软件分析门控SPECT/CT心肌灌注显像和门控PET/CT心肌葡萄糖代谢显像数据,获取左心室功能参数,包括舒张末期容积(EDV)、收缩末期容积参数(ESV)和左心室射血分数(LVEF)。采用17段-5分法判断心肌存活和心肌梗死,并计算心肌存活范围及心肌梗死范围。根据心肌存活范围将患者分为存活心肌<10%组(44例)、存活心肌10%~<20%组(36例)和存活心肌≥20%组(30例)。采用Pearson相关系数分析心肌存活范围及心肌梗死范围等影像参数与脑葡萄糖代谢水平之间的相关性。采用脑代谢定量分析软件SPM评估全脑葡萄糖代谢标准摄取值的平均值(SUVmean)与小脑葡萄糖代谢SUVmean,并计算靶本比值全脑/小脑(TBR全脑/小脑),即全脑葡萄糖代谢SUVmean与小脑葡萄糖代谢SUVmean的比值。采用SPM软件评估3组之间不同脑功能区脑葡萄糖代谢水平的差异。结果男性101例,年龄(57±10)岁。TBR全脑/小脑与存活心肌范围、梗死心肌范围、门控SPECT/CT及门控PET/CT测得的LVEF有相关性(r值分别为0.280、-0.329、0.188、0.215,P均<0.05)。存活心肌<10%组患者的TBR全脑/小脑为(1.25±0.97),明显低于存活心肌10%~<20%组的1.32±0.17(P<0.05)和存活心肌≥20%组的1.34±0.16(P<0.05)。SPM分析发现,与存活心肌≥20%组比较,存活心肌<10%组患者的楔前叶、额叶、中央后回、顶叶、颞叶等脑功能区的脑葡萄糖代谢水平明显减低。结论IHD患者的左心室功能受损与脑葡萄糖代谢水平存在相关性。心肌存活量少的IHD患者,全脑葡萄糖代谢水平减低,且主要集中在与认知功能相关的脑功能区。

Association between brain glucose metabolism and cardiac dysfunction in patients with ischemic heart disease undergoing 18F-FDG PET/CT imaging

Objective To evaluate the relationship between the brain glucose metabolism and left ventricular function parameters,and to explore the cerebral glucose metabolism reduction regions in patients with ischemic heart disease(IHD).Methods A total of 110 consecutive IHD patients who underwent gated 99Tcm-sestamibi(MIBI)SPECT/CT myocardial perfusion imaging,gated 18F-fluorodeoxyglucose(FDG)PET/CT myocardial and brain glucose metabolic imaging within three days in Beijing Anzhen Hospital from April 2016 to October 2017,were enrolled in this study.Left ventricular functional parameters of SPECT/CT and PET/CT including end-diastolic volume(EDV),end-systolic volume(ESV)and left ventricular ejection fraction(LVEF)were analyzed by QGS software.Viable myocardium and myocardial infarction region were determined by 17-segment and 5 score system,and the ratio of viable myocardium and scar myocardium was calculated.According to the range of viable myocardium,the patients were divided into viable myocardium<10%group(n=44),viable myocardium 10%-<20%group(n=36)and viable myocardium≥20%group(n=30).Pearson correlation analysis was used to analyze the correlation between the range of viable myocardium and scar myocardium and the level of cerebral glucose metabolism.Brain glucose metabolism determined by the mean of standardized uptake value(SUVmean)was analyzed by SPM.The ratio of SUVmean in whole brain and SUVmean in cerebellum were calculated,namely taget/background ratio(TBR).Differences in cerebral glucose metabolism among various groups were analyzed by SPM.Results There were 101 males,and age was(57±10)years in this cohort.The extent of viable myocardium and the extent of scar,LVEF evaluated by SPECT/CT and PET/CT were significantly correlated with TBR(r=0.280,r=-0.329,r=0.188,r=0.215 respectively,all P<0.05).TBR value was significantly lower in viable myocardium<10%group,compared with viable myocardium 10%-<20%group(1.25±0.97 vs.1.32±0.17,P<0.05)and viable myocardium≥20%group(1.25±0.97 vs.1.34±0.16,P<0.05).Furthermore,in comparison with viable myocardium≥20%group,the hypo-metabolic regions of viable myocardium<10%group were located in the precuneus,frontal lobe,postcentral gyrus,parietal lobe,temporal lobe,and so on.Conclusions There is a correlation between impaired left ventricular function and brain glucose metabolism in IHD patients.In IHD patients with low myocardial viability,the level of glucose metabolism in the whole brain is decreased,especially in the brain functional areas related to cognitive function.