Area stenosis associated with non-invasive fractional flow reserve obtained from coronary CT images

Fractional flow reserve (FFR) determined by invasive angiography is the gold standard to assess the severity of coronary artery disease (CAD). FFRCT can be obtained non-invasively by combining computed tomography (CT) images and Computational Fluid Dynamics (CFD) method. In this study, FFR_CT was computed for 6 models of patient-specific left coronary artery trees reconstructed from CT images. A total of 12 stenoses were observed. FFR values obtained for 7 of the 12 stenoses during invasive angiography were used as the gold standard for comparison. On a per-stenosis basis, the sensitivity, specificity, positive predictive value and negative predictive value were 50%, 100%, 100% and 83.3% respectively for FFR_CT. A weak correlation was found between percent lumen diameter stenosis and FFR_CT (r=0.431; p>0.05). However, the correlation between percent lumen area stenosis and FFR_CT was significant (r=0.853; p<;0.05). Therefore, non-invasive FFR_CT appears to be a promising index to assess the severity of CAD and lumen area has distinct advantages over diameter measurement in terms of anatomy assessment.