Using 4D Cardiovascular Magnetic Resonance Imaging to Validate Computational Fluid Dynamics: A Case Study

Abstract

Computational fluid dynamics (CFD) can have a complementary predictive role alongside the exquisite visualization capabilities of 4D cardiovascular magnetic resonance (CMR) imaging. In order to exploit these capabilities (e.g., for decision-making), it is necessary to validate computational models against real world data. In this study, we sought to acquire 4D CMR flow data in a controllable, experimental setup and use these data to validate a corresponding computational model. We applied this paradigm to a case of congenital heart disease, namely, transposition of the great arteries (TGA) repaired with arterial switch operation. For this purpose, a mock circulatory loop compatible with the CMR environment was constructed and two detailed aortic 3D models (i.e., one TGA case and one normal aortic anatomy) were tested under realistic hemodynamic conditions, acquiring 4D CMR flow. The same 3D domains were used for multi-scale CFD simulations, whereby the remainder of the mock circulatory system was appropriately summarized with a lumped parameter network. Boundary conditions of the simulations mirrored those measured in vitro. Results showed a very good quantitative agreement between experimental and computational models in terms of pressure (overall maximum % error = 4.4% aortic pressure in the control anatomy) and flow distribution data (overall maximum % error = 3.6% at the subclavian artery outlet of the TGA model). Very good qualitative agreement could also be appreciated in terms of streamlines, throughout the cardiac cycle. Additionally, velocity vectors in the ascending aorta revealed less symmetrical flow in the TGA model, which also exhibited higher wall shear stress in the anterior ascending aorta.

Aorta Ascending Aneurysm Analysis Using CFD Models towards Possible Anomalies

“…relatively long (15 min). Additionally, with limited spatial resolution compared to CT, despite the efforts in accelerating 4D sequences [12], not all clinical centres are proficient in using this technique [8]. Thus, CFD analysis reveals to be a relevant potential clinical tool to predict mal functions or future anomalies.…”

“…Eventually, the elastic membranes and smooth muscle within the aortic wall deteriorate and the vessel diameter increases [7]. Understanding the physiology of patients with aorta disease is crucial not only for understanding local hemodynamics in complex anatomies, but also refining the assessment of individual patients [8]. Cardiovascular magnetic resonance (CMR) and computed tomography (CT) imaging have been very useful in evaluating blood flow characteristics [9][10][11].…”

“…Cardiovascular magnetic resonance (CMR) and computed tomography (CT) imaging have been very useful in evaluating blood flow characteristics [9][10][11]. Although this imaging technique (i.e., CMR) provides a 3D flow map of the blood circulation and can be used to explain complex hemodynamic scenarios, simulating multiple conditions for the same patient is still Understanding the physiology of patients with aorta disease is crucial not only for understanding local hemodynamics in complex anatomies, but also refining the assessment of individual patients [8]. Cardiovascular magnetic resonance (CMR) and computed tomography (CT) imaging have been very useful in evaluating blood flow characteristics [9][10][11].…”

“…Although this imaging technique (i.e., CMR) provides a 3D flow map of the blood circulation and can be used to explain complex hemodynamic scenarios, simulating multiple conditions for the same patient is still relatively long (15 min). Additionally, with limited spatial resolution compared to CT, despite the efforts in accelerating 4D sequences [12], not all clinical centres are proficient in using this technique [8]. Thus, CFD analysis reveals to be a relevant potential clinical tool to predict mal functions or future anomalies.…”

3D Printing Cardiovascular Anatomy: A Single-Centre Experience

“…particle image velocimetry [23] or magnetic resonance imaging, thereby generating detailed visualisation data. A case study of CHD, namely transposition of the great arteries (TGA) repaired with the arterial switch procedure (ASO), was modelled for both purposes [26]. In this study, an MCL was built in order to be compatible with CMR image acquisition, and a 3D patient-specific model was inserted in the MCL for visualisation purposes.…”