Journal of X-Ray Science and Technology 25 (2017) 213–232 DOI 10.3233/XST-17255 IOS Press 213 Computational evaluation of smoothed particle hydrodynamics for implementing blood flow modelling through CT reconstructed arteries Yi Qin a , Jianhuang Wu a,∗ , Qingmao Hu a , Dhanjoo N. Ghista a and Kelvin K.L. Wong a,b,∗ a Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Xili Nanshan, Shenzhen, China b School of Medicine, University of Western Sydney, NSW, Australia Received 26 August 2016 Revised 10 October 2016 Accepted 9 December 2016 Abstract. Simulation of blood flow in a stenosed artery using Smoothed Particle Hydrodynamics (SPH) is a new research field, which is a particle-based method and different from the traditional continuum modelling technique such as Computational Fluid Dynamics (CFD). Both techniques harness parallel computing to process hemodynamics of cardiovascular structures. The objective of this study is to develop and test a new robust method for comparison of arterial flow velocity contours by SPH with the well-established CFD technique, and the implementation of SPH in computed tomography (CT) reconstructed arteries. The new method was developed based on three-dimensional (3D) straight and curved arterial models of millimeter range with a 25% stenosis in the middle section. In this study, we employed 1,000 to 13,000 particles to study how the number of particles influences SPH versus CFD deviation for blood-flow velocity distribution. Because further increasing the particle density has a diminishing effect on this deviation, we have determined a critical particle density of 1.45 particles/mm 2 based on Reynolds number (Re = 200) at the inlet for an arterial flow simulation. Using this critical value of particle density can avoid unnecessarily big computational expenses that have no further effect on simulation accuracy. We have particularly shown that the SPH method has a big potential to be used in the virtual surgery system, such as to simulate the interaction between blood flow and the CT reconstructed vessels, especially those with stenosis or plaque when encountering vasculopathy, and for employing the simulation results output in clinical surgical procedures. Keywords: Blood flow simulation, smoothed particle hydrodynamics, stenosed artery, critical density, computed tomography, parallel computing 1. Introduction Stenosis in arteries is the result of atherosclerosis, and is one of the most common cardiovascular problem that can lead to the malfunction of the vascular system [1, 2]. The progression of plaque can result in the redistribution of wall shear stress inside the blood vessel wall, resulting in plaque growth and ∗ Corresponding authors: Kelvin K.L. Wong, School of Medicine, Western Sydney University, Locked Bag 1797 Penrith, NSW 2751, Australia. Tel.: +61 2 4620 3620; Fax: +61 2 9678 7160; E-mail: Kelvin.Wong@westernsydney.edu.au and Jianhuang Wu, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Boulevard, Xili Nanshan, Shenzhen 518055, China. Tel.: +86 0755 86392214; Fax: +86 0755 86392115; E-mail: jh.wu@siat.ac.cn. 0895-3996/17/$35.00 © 2017 – IOS Press and the authors. All rights reserved