Intellispace portal version 9

Three-dimensional (3D) coronary model segmentation and coronary centreline extraction were performed semi-automatically using a commercially available cardiac application (Comprehensive Cardiac Analysis, IntelliSpace Portal Version 9.0, Philips Medical Systems). The coronary lumen segmentation was reviewed in all patients and corrections were made if needed. The effective luminal diameter stenosis was measured on the coronary model images by identifying the minimum diameter compared to the reference diameter for all stenoses. The segmented coronary model was used as input for the on-site CT-FFR lumped-parameter simulation algorithm prototype (Philips Medical Systems). The lumped-parameter model enables fast individual CFD simulations of blood flow in extended vessel networks [25 ]. FFR values were computed by simulating the pressures in the aorta and in the coronary arteries during simulated hyperaemia and shown as colour gradients superimposed on the 3D coronary tree [13 (link), 25 ]. A point estimate of the computed FFR was taken at the lesion of interest, e.g. the most severe stenosis on CCTA proximal to the FFR pressure wire position.

3-dimensional (3D) coronary model segmentation and the extraction of the coronary centerlines was performed automatically using a commercially available cardiac application (Comprehensive Cardiac Analysis, IntelliSpace Portal Version 9.0, Philips Medical Systems Nederland B.V., Best, The Netherlands). The coronary lumen segmentation was reviewed in all patients and corrections were made if needed. The effective luminal diameter stenosis (EDS) was measured on the coronary model images by identifying the minimum diameter compared to a reference for all stenosis. The segmented coronary model was used as input for the on-site CT-FFR simulation algorithm prototype (Philips Medical Systems Nederland B.V., Best, The Netherlands)¹² . FFR values were computed by simulating flow in the aorta and in the coronary arteries during simulated hyperemia and pressure ratios were shown as color gradients onto the 3D coronary tree^{12 ,23 (link)}. Point estimates of the computed FFR were taken at the lesion of interest, the most severe stenosis at CCTA. A CT-FFR ≤ 0.80 in at least one of the vessels was regarded as an abnormal test.