title: Computational fluid dynamics simulations of contrast agent bolus dispersion in a coronary bifurcation: impact on MRI-based quantification of myocardial perfusion.
abstract: Contrast-enhanced first-pass magnetic resonance imaging (MRI) in combination with a tracer kinetic model, for example, MMID4, can be used to determine myocardial blood flow (MBF) and myocardial perfusion reserve (MPR). Typically, the arterial input function (AIF) required for this methodology is estimated from the left ventricle (LV). Dispersion of the contrast agent bolus might occur between the LV and the myocardial tissue. Negligence of bolus dispersion could cause an error in MBF determination. The aim of this study was to investigate the influence of bolus dispersion in a simplified coronary bifurcation geometry including one healthy and one stenotic branch on the quantification of MBF and MPR. Computational fluid dynamics (CFD) simulations were combined with MMID4. Different inlet boundary conditions describing pulsatile and constant flows for rest and hyperemia and differing outflow conditions have been investigated. In the bifurcation region, the increase of the dispersion was smaller than inside the straight vessels. A systematic underestimation of MBF values up to -16.1% for pulsatile flow and an overestimation of MPR up to 7.5% were found. It was shown that, under the conditions considered in this study, bolus dispersion can significantly influence the results of quantitative myocardial MR-perfusion measurements.
authors.affiliation: Section of Medical Physics, Department of Radiology, University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany.
authors.forename: Regine
authors.initials: R
authors.lastname: Schmidt
authors.forename: Dirk
authors.initials: D
authors.lastname: Graafen
authors.forename: Stefan
authors.initials: S
authors.lastname: Weber
authors.forename: Laura M
authors.initials: LM
authors.lastname: Schreiber
mesh_terms: D000465:Algorithms; D001783:Blood Flow Velocity; D003198:Computer Simulation; D003251:Constriction, Pathologic / Q000473:pathology*; D003287:Contrast Media / Q000494:pharmacology*; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000033:anatomy & histology*; D003952:Diagnostic Imaging / Q000379:methods; D006321:Heart / Q000502:physiology*; D006801:Humans; D057446:Hydrodynamics; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008958:Models, Molecular; D009206:Myocardium / Q000473:pathology; D010477:Perfusion; D011673:Pulsatile Flow; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D003287:Contrast Media