Objective To explore the differences of coronary computed tomography-derived fractional flow reserve(CT-FFR)and dynamic stress computed tomography myocardial perfusion imaging(CT-MPI)parameters in obstructive coronary artery disease(CAD),and their correlation with coronary computed tomography angiography(CCTA)vessel stenosis.Methods A retrospective analysis was conducted on 37 patients with obstructive CAD who underwent combined CCTA and dynamic stress CT-MPI scans.Based on the CCTA results,the patients were divided into moderate CAD group(22 cases)and severe CAD group(15 cases).The lowest CT-FFR value and perfusion parameter values between the two groups were analyzed.A total of 111 vessels including the left anterior descending branch(LAD),left circumflex branch(LCX),and right coronary artery(RCA)were classified into the mild vessel stenosis group(＜25％)with 42 vessels,moderate vessel stenosis group(25％-69％)with 49 vessels,and severe vessel stenosis group(≥70％)with 20 vessels.The lowest CT-FFR value and lowest perfusion parameter value among these three groups were analyzed.The correlation between CT-FFR value and CT-MPI perfusion parameter values and their diagnostic efficacy were analyzed.Results At the patient level,the relative myocardial blood flow(rMBF),myocardial blood flow(MBF),myocardial blood volume(MBV),flow extraction product(FEP)in the severe CAD group were significantly lower than those in the moderate CAD group(P＜0.05),while there was no significance in CT-FFR and perfusion capillary blood volume(PCBV)between these two groups(P=0.061,0.098).At the vascular level,there were significant differences in rMBF and MBV among mild,moderate,and severe vessel stenosis groups(P＜0.05).CT-FFR showed significant difference between mild vs moderate vessel stenosis groups and mild vs severe vessel stenosis groups(P＜0.001),and no significant difference between moderate and severe vessel stenosis groups(P=0.355).rMBF had the highest correlation with the degree of vessel stenosis(r=-0.674).CT-MPI combined with CT-FFR had a high efficacy in diagnosing CCTA vessel stenosis,area under the curve(AUC)≥0.90.Conclusion rMBF is more effective than CT-FFR in evaluating the degree of vessel stenosis in CCTA.CT-FFR combined with CT-MPI is helpful to evaluate functional vascular stenosis.

Objective To explore the differences of coronary computed tomography-derived fractional flow reserve(CT-FFR)and dynamic stress computed tomography myocardial perfusion imaging(CT-MPI)parameters in obstructive coronary artery disease(CAD),and their correlation with coronary computed tomography angiography(CCTA)vessel stenosis.Methods A retrospective analysis was conducted on 37 patients with obstructive CAD who underwent combined CCTA and dynamic stress CT-MPI scans.Based on the CCTA results,the patients were divided into moderate CAD group(22 cases)and severe CAD group(15 cases).The lowest CT-FFR value and perfusion parameter values between the two groups were analyzed.A total of 111 vessels including the left anterior descending branch(LAD),left circumflex branch(LCX),and right coronary artery(RCA)were classified into the mild vessel stenosis group(＜25％)with 42 vessels,moderate vessel stenosis group(25％-69％)with 49 vessels,and severe vessel stenosis group(≥70％)with 20 vessels.The lowest CT-FFR value and lowest perfusion parameter value among these three groups were analyzed.The correlation between CT-FFR value and CT-MPI perfusion parameter values and their diagnostic efficacy were analyzed.Results At the patient level,the relative myocardial blood flow(rMBF),myocardial blood flow(MBF),myocardial blood volume(MBV),flow extraction product(FEP)in the severe CAD group were significantly lower than those in the moderate CAD group(P＜0.05),while there was no significance in CT-FFR and perfusion capillary blood volume(PCBV)between these two groups(P=0.061,0.098).At the vascular level,there were significant differences in rMBF and MBV among mild,moderate,and severe vessel stenosis groups(P＜0.05).CT-FFR showed significant difference between mild vs moderate vessel stenosis groups and mild vs severe vessel stenosis groups(P＜0.001),and no significant difference between moderate and severe vessel stenosis groups(P=0.355).rMBF had the highest correlation with the degree of vessel stenosis(r=-0.674).CT-MPI combined with CT-FFR had a high efficacy in diagnosing CCTA vessel stenosis,area under the curve(AUC)≥0.90.Conclusion rMBF is more effective than CT-FFR in evaluating the degree of vessel stenosis in CCTA.CT-FFR combined with CT-MPI is helpful to evaluate functional vascular stenosis.