Impact of cardiac phase selection on computational fluid dynamics analysis

Jin Zheng; Xinxin Yu; Quanlin Sun; Yuan Huang; Yang Chen; Lin Gao; Ao Zhou; Jinhua Shen; Wenshan Ma; Jonathan R Weir-McCall; Umar Sadat; Longjiang Zhang; Zhongzhao Teng; Ximing Wang

doi:10.1016/j.jcct.2025.06.001

Impact of cardiac phase selection on computational fluid dynamics analysis

J Cardiovasc Comput Tomogr. 2025 Jun 16:S1934-5925(25)00346-6. doi: 10.1016/j.jcct.2025.06.001. Online ahead of print.

Authors

Jin Zheng¹, Xinxin Yu², Quanlin Sun³, Yuan Huang⁴, Yang Chen⁵, Lin Gao², Ao Zhou⁵, Jinhua Shen⁵, Wenshan Ma², Jonathan R Weir-McCall⁶, Umar Sadat⁷, Longjiang Zhang⁸, Zhongzhao Teng⁹, Ximing Wang¹⁰

Affiliations

¹ Department of Radiology, University of Cambridge, Cambridge, UK; MRC Laboratory of Medical Sciences, Imperial College London, Hammersmith Hospital Campus, London, UK.
² Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China.
³ Department of Radiology, University of Cambridge, Cambridge, UK.
⁴ EPSRC Cambridge Mathematics of Information in Healthcare Hub, University of Cambridge, Cambridge, UK.
⁵ Nanjing Jingsan Medical Science and Technology, Ltd., Jiangsu, China.
⁶ Department of Radiology, University of Cambridge, Cambridge, UK; Royal Papworth Hospital, Cambridge, UK; Department of Radiology, Royal Brompton Hospital, London, UK; School of Biomedical Engineering and Imaging Sciences, King's College, London, UK.
⁷ Lister Hospital, East and North Hertfordshire NHS Trust, Stevenage, UK.
⁸ Department of Radiology, Jinling Hospital, Nanjing, China.
⁹ Department of Radiology, University of Cambridge, Cambridge, UK; Nanjing Jingsan Medical Science and Technology, Ltd., Jiangsu, China; School of Life and Health Sciences, Fujian Fuyao University of Science and Technology, Fujian, China. Electronic address: zt@tenoke.com.
¹⁰ Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China. Electronic address: wxming369@163.com.

PMID: 40527642
DOI: 10.1016/j.jcct.2025.06.001

Abstract

Background: The selection of cardiac phase in coronary computed tomography angiography (CCTA) may affect computational fluid dynamics (CFD)-derived hemodynamic metrics; however, this influence is not well-quantified, particularly in anomalous coronary anatomies. This study aims to evaluate how cardiac phase selection impacts CFD outcomes in normal and anomalous coronary arteries.

Methods: Multiphase CCTA datasets were analyzed from 40 patients: 30 with systolic and diastolic reconstructions (10 inter-arterial anomalous right coronary artery [ARCA], 10 myocardial bridging [MB], 10 normal) and 10 additional normals with mid-diastolic and diastolic reconstructions. Geometric differences among phases were measured. CFD-derived parameters, including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT), and CCTA-derived fractional flow reserve (CT-FFR), were calculated. Phase-dependency was assessed by (i) comparing proximal right coronary artery (pRCA) and proximal left anterior descending artery (pLAD) measurements in normal systole vs. diastole and mid-diastole vs. diastole; (ii) comparing pRCA measurements in ARCA vs. normal, and pLAD measurements in MB vs. normal, for systole and diastole.

Results: Luminal area differences among phases in pRCA and pLAD segments demonstrated group-distance interactions (p < 0.05). Absolute relative differences in OSI were significantly smaller in pLAD for MB group (median 5.31% [IQR 2.61%-7.46%]) versus normal group (15.99% [6.23%-31.98%]; p = 0.0125). While TAWSS, OSI, and RRT exhibited phase-dependency, this was neither specific to patient cohorts nor coronary artery territories. The variation of relative differences in CT-FFR (maximum 2.4%) was generally lower than that in TAWSS (21.3%), OSI (63.9%), and RRT (28.1%), with all relative differences of the four parameters showing no significant variation from zero.

Conclusion: The coronary geometry showed clear phase-dependency. The phase dependency should not be ignored when CCTA is used to quantify TAWSS, OSI and RRT. Standardizing cardiac phase selection in CCTA-based CFD analyses is crucial for improving accuracy and clinical consistency.

Keywords: Computed tomography angiography; Coronary artery; Fractional flow reserve; Phase; Wall shear stress.