Accuracy of computational hemodynamics in complex arterial geometries reconstructed from magnetic resonance imaging

Purpose: Combining computational blood flow modeling with three-dimensional medical imaging provides a new approach for studying links between hemodyn amic factors and arterial disease. Although this provides patient-specific hemodynamic information, it is subject to several potential errors. This st udy quantifies some of these errors and identifies optimal reconstruction m ethodologies. Methods: A carotid artery bifurcation phantom of known geomet ry was imaged using a commercial magnetic resonance (MR) imager. Three-dime nsional models were reconstructed from the images using several reconstruct ion techniques, and steady and unsteady blood flow simulations were perform ed. The carotid bifurcation from a healthy, human volunteer was then imaged in vivo, and geometric models were reconstructed. Results: Reconstructed m odels of the phantom showed good agreement with the gold standard geometry, with a mean error of approximately 15% between the computed wall shear str ess fields. Reconstructed models of the in vivo carotid bifurcation were un acceptably noisy, unless lumenal profile smoothing and approximating surfac e splines were used. Conclusions: All reconstruction methods gave acceptabl e results for the phantom model, but in vivo models appear to require smoot hing. If proper attention is paid to smoothing and geometric fidelity issue s, models reconstructed from MR images appear to be suitable for use in com putational studies of in vivo hemodynamics. (C) 1999 Biomedical Engineering Society. [S0090-6964(99)01401-0].