The Value Of Single Photon Hypoxia Imaging In Assessing Viable Myocardium

Objective:Through the comparative study of single photon ^99mTc-HL91(^99mTc-4,9-diaza-3,3,10,10-tetramethyldodecane-2,11-dione dioxime)SPECT/CT hypoxic imaging and positron ¹⁸F-FDG(¹⁸F-fluorodeoxyglucose)PET/CT myocardial metabolism imaging in the evaluation of viable myocardium in myocardial ischemia/infarction,systematic analysis of single-photon^99mTc-HL91 SPECT/CT hypoxia from qualitative and semi-quantitative levels Value of imaging to assess viable myocardium.Methods:From July 2020 to February 15,2022,patients who were diagnosed with coronary heart disease by clinical or imaging examination in the Affiliated Hospital of Guilin Medical College and went to the Department of nuclear medicine for ^99mTc-TF(^99mTc-tetrofosmin)SPECT/CT resting gated myocardial perfusion imaging（G-MPI）with obvious radioactive distribution defect area,voluntarily participated in the follow-up study and signed the informed consent after knowing the examination,so they were given^99mTc-HL91 SPECT/CT hypoxic imaging on the same day,¹⁸F-FDG PET myocardial metabolism imaging was performed on the next day or another day.A total of 31 subjects volunteered to participate in the study,including 24 males and 7 females.The results of clinical blood sampling,coronary angiography or coronary CTA and ECG,G-MPI,PET myocardial metabolism imaging and related parameters SRS（total score of resting perfusion defect）were collected,and the collected ^99mTc-TF,^99mTc-HL91 and ¹⁸F-FDG imaging original inspection sequences were simultaneously imported into the Corridor-4DM v2016 myocardial perfusion imaging quantitative analysis software of the University of Michigan.Taking ¹⁸F-FDG PET/CT myocardial metabolism imaging as the gold standard for evaluating myocardial survival,the radioactive filling of ^99mTc-HL91 and ¹⁸F-FDG in the same myocardial segment with^99mTc-TF SPECT/CT resting G-MPI radioactive distribution defect were compared,To evaluate the value of single photon ^99mTc-HL91 SPECT/CT hypoxic imaging in detecting viable myocardium in myocardial ischemia/infarction area.The data were analyzed by t-test and diagnostic test.Results:In 31 subjects,^99mTc-TF resting G-MPI showed that 273（51.80%,273/527）myocardial segments had obvious perfusion defects（ischemia/infarction）,of which 266 ischemic/infarcted myocardial segments combined with ¹⁸F-FDG metabolic imaging showed myocardial survival（97.43%）,and 7ischemic/infarcted myocardial segments were myocardial death（2.56%）.In266 ischemic/infarcted segments with viable myocardium:（1）223 myocardial segments had different degrees of ^99mTc-HL91 radioactive uptake（positive segments）.The coincidence rate of ^99mTc-HL91 hypoxic imaging was 83.83%（223/266）;（2）According to the degree of radioactive defect indicated by^99mTc-TF resting G-MPI,the 266 myocardial segments（ischemic/infarcted but with viable myocardium）were divided into four subgroups.In each subgroup,the detection of viable myocardium by ¹⁸F-FDG PET myocardial metabolic imaging was taken as the gold standard.The efficiency of ^99mTc-HL91 SPECT/CT hypoxic imaging in detecting viable myocardium in myocardial ischemia/infarction was 75.25%（P=0.765>0.05）,61.66%（P<0.001）and 48.69%（P<0.001）in severe defect group and 24.09%（P=0.539>0.05）in complete defect group;（3）266 ischemic/infarcted segments with viable myocardium were divided into three subgroups according to the main coronary blood supply area of 17 segment bull’s-eye map.The diagnostic efficacy of ^99mTc-HL91 SPECT/CT hypoxic imaging in detecting viable myocardium was 40.09%in LAD group,46.90%in LCX group and 52.81%in RCA group,there were statistically significant differences among the three groups（P<0.001）.Conclusions:Single-photon ^99mTc-HL91 SPECT/CT hypoxia imaging has better diagnostic performance in detecting viable myocardium in myocardial ischemia/infarct area;Imaging has better diagnostic performance in the detection of viable myocardium in areas with mild radioactive distribution defects,but is less effective in the diagnosis of viable myocardium in areas with moderate and severe myocardial ischemia and in areas with different coronary blood supply.