Preliminary evaluation of coronary fractional flow reserve derived from CT based on tracer-kinetics principle / 中华放射学杂志

ABSTRACT

Objective:To evaluate the feasibility and diagnostic efficacy of the coronary fractional flow reserve derived from CT (CT-FFR) measurement method based on tracer pharmacokinetic principle.Methods:A total of 130 patients (159 coronary artery vessels) who were admitted to Beijing Anzhen Hospital from January 2015 to March 2019 were included in this study retrospectively. All patients had completed coronary CT angiography (CCTA) and invasive coronary angiography with invasive FFR. Subjective assessment of stenosis degree was performed on CCTA images and non-invasive FFR measurement was performed by using a tracer-kinetics based on CT-FFR measurement method. The Bland-Altman method was used to evaluate the diagnostic consistency of the two methods. Compared with the invasive FFR results, the sensitivity, specificity, positive predictive value, negative predictive value, and area under the ROC curve (AUC) of tracer-kinetics based on CT-FFR results for the diagnosis of coronary ischemic lesions were evaluated. All cases were divided into two heart rate groups>65 bpm and ≤65 bpm. The diagnostic efficacy of tracer-kinetics based on CT-FFR in different heart rate groups was evaluated. χ 2 test and DeLong test were used to compare diagnostic performance in different evaluation methods and heart rate groups. Logistic regression analysis was used to evaluate the impact of factors such as heart rate, image thickness, image enhancement, and noise on the accuracy of diagnosis. Results:Bland-Altman analysis showed that the average difference between the two methods was -0.01. (-0.11-0.10). Compared with invasive FFR results, the tracer-kinetics based on CT-FFR method had a diagnostic sensitivity of 92.4%, specificity of 82.1%, positive predictive value of 87.6%, negative predictive value of 88.7%, and the area under ROC curve (AUC) value was 0.94. Compared with the diagnostic efficacy of luminal stenosis evaluated based on CCTA images, the difference was significantly statistical ( P<0.05). The diagnostic performance of CT-FFR had no statistically significant difference between the two heart rate groups. Factors such as heart rate, image thickness, image enhancement, and noise had no significant effect on the diagnostic accuracy of the tracer-kinetics based on CT-FFR method. Conclusions:The tracer-kinetics based on CT-FFR method may quickly complete the non-invasive FFR measurement on CCTA images with image quality that meets the needs of clinical diagnosis. It has a good diagnostic performance in the diagnosis of coronary ischemic lesions even for those cases with a faster heart rate. The diagnostic accuracy of tracer-kinetics based on CT-FFR method is not significantly affected by factors such as heart rate, image thickness, image enhancement, and image noise.