title: 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.
authors.affiliation: Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, Great Ormond Street Hospital for Children, NHS Foundation Trust , London , UK.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Biglino
authors.affiliation: Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, Great Ormond Street Hospital for Children, NHS Foundation Trust , London , UK.
authors.forename: Daria
authors.initials: D
authors.lastname: Cosentino
authors.affiliation: Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, Great Ormond Street Hospital for Children, NHS Foundation Trust , London , UK.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Steeden
authors.affiliation: Laboratory of Biological Structures Mechanics (LAbS), Politecnico di Milano , Milan , Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: De Nova
authors.affiliation: Laboratory of Biological Structures Mechanics (LAbS), Politecnico di Milano , Milan , Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Castelli
authors.affiliation: Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, Great Ormond Street Hospital for Children, NHS Foundation Trust , London , UK.
authors.forename: Hopewell
authors.initials: H
authors.lastname: Ntsinjana
authors.affiliation: Laboratory of Biological Structures Mechanics (LAbS), Politecnico di Milano , Milan , Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Pennati
authors.affiliation: Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, Great Ormond Street Hospital for Children, NHS Foundation Trust , London , UK.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Taylor
authors.affiliation: Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, Great Ormond Street Hospital for Children, NHS Foundation Trust , London , UK.
authors.forename: Silvia
authors.initials: S
authors.lastname: Schievano
keywords: cardiovascular magnetic resonance imaging; congenital heart disease; mock circulatory loop; rapid prototyping; validation