Experimental And Clinical Study On Evaluation Of Coronary Microcirculation By CT Myocardial Perfusion

Part Ⅰ Experimental study on evaluation of coronary microcirculation disorder by CT myocardial perfusion imaging Objective: Computed Computed Myocardial Perfusion Imaging(CT-MPI)was used to evaluate the feasibility and accuracy of Myocardial ischemia in the model of coronary microcirculation disorder and quantitatively obtain the changes of Myocardial Perfusion parameters.Methods: Experimental Chinese miniature pig only 10,USES the means of intervention by godet anterior descending microsphere injection using the same concentration of cosco,coronary microcirculation model is set up,respectively in the 60 min before modeling and modeling line 10 min after CTP resting state and load state scanning,will scan image data storage to PACS system through image post-processing software measured left ventricular Myocardial perfusion of the section 17 quantitative indicators,including Myocardial Blood Flow(Myocardial Blood Flow,MBF),Myocardial Blood Volume(Myocardial Blood Volume,MBV),etc.With the change of myocardial perfusion indexes before and after experimental pigs modeling for their reference,resting state after heart sarcomere section can be divided into modeling myocardial perfusion group after modeling,load state of myocardial perfusion,paired sample t test to compare MBF,MBV differences between groups,P < 0.05 statistically difference,and finally put to death animals parallel pathologic examination.Results: Two pigs died during modeling,and eight completed the experiment.The resting states of MBF and MBV in the myocardial ischemia zone were 98.61±50.91ml/(100ml·min)and 9.01±2.82 ml/100 ml,respectively.The load state MBF and MBV were 87.6±54.57 ml/(100ml·min)and 7.99±3.75 ml/100 ml,respectively.The resting states of MBF and MBV in the non-ischemic zone were 214.21±72.14 ml/(100ml·min)and 16.48±6.53 ml/100 ml,respectively.The load state MBF and MBV were287.13±133.62 ml/(100ml·min)and 21.62±8.37 ml/100 ml,respectively.Both resting and loaded MBF and MBV in the ischemic region were reduced compared with those in the non-ischemic region.Conclusion: Dynamic CTP can detect myocardial ischemia with coronary microcirculation disorder and quantitatively measure myocardial perfusion parameters for clinical reference.Part Ⅱ Evaluation of coronary microcirculation disorder based on dual-energy CT myocardial blood pool imagingObjective: The aim of this study was to assess the potential of dual-energy computed tomography(DECT)resting first-pass and delayed iodine mapping in detecting myocardial reperfusion injury in patients with acute myocardial infarction after coronary intervention.Methods: Fifty-nine patients with acute coronary syndrome with myocardial ischemia-reperfusion injury after coronary revascularization resting first-pass and delayed dual-energy myocardial blood pool imaging(DE-MBPI),which were retrospectively included in the prospective study cohort.Single-photon emission computed tomography(SPECT/CT)and positron emission computed tomography(PET/CT)were performed within one week to identify injury myocardium.Perfusion imaging(SPECT/CT rest MPI),positron emission computed tomography myocardial metabolism imaging(PET/CT MMI),analysis of 1003 myocardial segments in the left ventricle,the iodine content in the myocardial blood pool is expressed by the iodine map and iodine concentration value,and the nuclear Medical myocardial combined imaging(SPECT/CT rest MPI and PET/CT MMI)as reference standards,using visual analysis and visual/iodine concentration value analysis,comparing DE-MBPI first-pass scan with SPECT rest MPI,comparing DE-MBPI delayed scan and PET/CT MMI,use iodine diagram to qualitatively evaluate the reliability of DE-MBPI for judging myocardial activity,measure the quantitative analysis of iodine concentration in normal,ischemic and infarcted myocardium and obtain the threshold value,perform ROC curve analysis,calculate sensitivity,Specificity,positive predictive value,negative predictive value,and accuracy.Results: A total of 1003 myocardial segments were analyzed in 59 patients.The ROC curve analysis showed that DE-MBPI first-pass and delayed can accurately identify normal,ischemic and infarcted myocardium [the area under the curve(AUC)of the visual analysis were 0.954,0.863 and 0.855,respectively,(P<0.001);the area under the curve(AUC)of the iodine quantification value analysis were 0.957,0.900 and 0.906,respectively,(P<0.001)].The study obtained DE-MBPI first-pass and delayed the iodine quantification value in normal myocardium was 3.9 mg/ml and 1.8 mg/ml,respectively,(P<0.001).The iodine quantification value of the damaged myocardium(including ischemic and infarcted myocardium)at the DE-MBPI first-pass was 0.4mg/ml(P=0.776).The iodine quantification value in ischemic and infarcted myocardium at the DE-MBPI delayed were 0.3 mg/ml and 2.3 mg/ml,respectively.The cut-off value of the DE-MBPI first-pass to distinguish lesions from normal myocardium is 0.7 mg/ml.The cut-off value between DE-MBPI delayed to distinguish ischemia from normal myocardium is 0.8 mg/ml,and the cutoff value to distinguish between infarction and normal myocardium is 2.0 mg/ml.Conclusion: Myocardial iodine map and iodine quantification value obtained based on DE-MBPI first pass and delayed.Using nuclear medicine combined myocardial imaging as a reference,iodine maps and iodine quantification value analysis can identify normal,ischemic,and infarcted myocardium in patients with myocardial ischemia reperfusion injury.