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Dynamically scaled phantom phase contrast MRI compared to true‐scale computational modeling of coronary artery flow
Author(s) -
Beier Susann,
Ormiston John A.,
Webster Mark W.,
Cater John E.,
Norris Stuart E.,
MedranoGracia Pau,
Young Alistair A.,
Cowan Brett R.
Publication year - 2016
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.25240
Subject(s) - imaging phantom , computational fluid dynamics , magnetic resonance imaging , flow (mathematics) , reynolds number , scanner , physics , mechanics , biomedical engineering , turbulence , medicine , radiology , optics
Purpose To examine the feasibility of combining computational fluid dynamics (CFD) and dynamically scaled phantom phase‐contrast magnetic resonance imaging (PC‐MRI) for coronary flow assessment. Materials and Methods Left main coronary bifurcations segmented from computed tomography with bifurcation angles of 33°, 68°, and 117° were scaled‐up ∼7× and 3D printed. Steady coronary flow was reproduced in these phantoms using the principle of dynamic similarity to preserve the true‐scale Reynolds number, using blood analog fluid and a pump circuit in a 3T MRI scanner. After PC‐MRI acquisition, the data were segmented and coregistered to CFD simulations of identical, but true‐scale geometries. Velocities at the inlet region were extracted from the PC‐MRI to define the CFD inlet boundary condition. Results The PC‐MRI and CFD flow data agreed well, and comparison showed: 1) small velocity magnitude discrepancies (2–8%); 2) with a Spearman's rank correlation ≥0.72; and 3) a velocity vector correlation (including direction) of r 2 ≥ 0.82. The highest agreement was achieved for high velocity regions with discrepancies being located in slow or recirculating zones with low MRI signal‐to‐noise ratio (SNR v ) in tortuous segments and large bifurcating vessels. Conclusion Characterization of coronary flow using a dynamically scaled PC‐MRI phantom flow is feasible and provides higher resolution than current in vivo or true‐scale in vitro methods, and may be used to provide boundary conditions for true‐scale CFD simulations. J. MAGN. RESON. IMAGING 2016;44:983–992.