Assessment of stenosis introduced flow resistance in CCTA-reconstructed coronary arteries

This paper introduces a universal approach for computation of vascular flow resistance of a 3D patient-specific coronary artery tree reconstructed from CCTA with the general aim of assessment of stenosis impact on blood flow. Next, the reconstructed vascular tree is represented through the network of resistance elements further used in lumped-parameter blood flow modelling. Also known as 0D modelling, this blood flow modelling approach is based on the analogy between hydraulic and electrical systems for solution of flow propagation. The steps of the proposed methodology include: (i) reconstruction of 3D coronary artery tree from CCTA; (ii) computation of flow resistances of all branches; (iii) construction of 0D tree model and its incorporation into the 0D CVS (Cardiovascular System) model; (iv) 0D blood flow simulations under various physiological conditions such as rest, exercise or hyperaemia. Simulation results indicated close correlation with the results of the corresponding 3D simulations in computed blood flow rate and pressure fields. It was concluded that flow resistance can be potentially used as a supplementary index for stenosis severity assessment. Its further application in 0D blood flow simulations provide information on blood flow haemodynamics with respect to the complete coronary artery tree, which can be particularly useful in the case of multiple intermediate stenoses.