Optimization Selection Of Time-Window For Evaluation Of Coronary Microcirculation Dysfunction By Dual-energy CT Myocardial Blood-pool Imaging

Objective: 1.To verify the feasibility of noninvasive imaging myocardial infarction coronary microcirculation disorder by optimizing the different time windows.quantitatively analyze the correlation between the time of the interval of gender,age,height,weight,waist-hip ratio,and related medical history,calculate the scanning formula of the best scan time window and related factors;2.Complete the evaluation of coronary artery and one-stop myocardial perfusion and cardiac function.Methods: A total of 536 patients with typical myocardial infarction from June 2020 to December 2022 were collected,including 309 males and 227 females.Apply dual-energy CT myocardial blood-pool imaging(DECT-MBPI)to first-arterial-pass scan and delayed-scan.The images were post-processed by the workstation,and the low perfusion area in the first-pass scan was selected,and compared with the iodine value of the delayed enhancement area in each stage of delayed-scan.2.0mg I / ml was used as the cut-off value,and the area>2.0mg I / ml was judged as infarcted myocardium.The correlation between the baseline data and DEA was determined by Spearman correlation analysis,and the combined index of DEA was obtained by ordinal regression and multivariate regression analysis.Results: A total of 536 patients with acute myocardial infarction were collected,including22 with DEA at 2 minutes,386 with DEA at 4 minutes,and 128 with DEA at 6 minutes.Significant positive relationship between DEA time and age(r> 0,P <0.05),and significant negative relationship with heart rate,BMI,and hypertension(r <0,P <0.05);DEA time had no significant association between gender,hyperlipidemia,and diabetes(P> 0.05).The calculation formula of the joint index is: the joint index Y=0.051 age-0.049 heart rate-0.269BMI-0.500 hypertension.In patients with DEA at 4 minutes,the area under the combined index curve was 0.776,standard error 0.057,P=0.000,95% confidence interval(0.665-0.888),indicating that the combined index was more effective in diagnosing the disease.The maximum diagnostic index was chosen as the diagnostic cut-off,which was 0.465 when the sensitivity was 0.920 and the specificity was 0.545,corresponding to a diagnostic cut-off of-8.764.In patients with DEA at 6 minutes,the area under the combined index curve was0.705,standard error 0.027,P=0.000,95% confidence interval(0.651-0.758),indicating that the diagnostic effect of the combined index disease was general.The maximum diagnostic index was chosen as the diagnostic cut-off,at 0.336 when the sensitivity was 0.484 and the specificity was 0.852,and the corresponding diagnostic cut-off was-6.963.Conclusion: This study showed that the time of DEA onset was positively associated with age and heart rate,BMI and hypertension,but no significant association with gender,history of hyperlipidemia and diabetes.In the time window of predicting the onset of DEA in patients with acute myocardial infarction CMD,the combined index Y was effective at 4min and at6 min,providing a feasible scanning scheme for the DECT-MBPI time window for subsequent acute myocardial infarction CMD.