Numerical analysis of the effect of trabeculae carneae models on blood flow in a left ventricle model constructed from magnetic resonance images

Although the blood flow velocity in a left ventricle (LV) has been considered to be sufficiently fast to prevent thrombus formation, internal wall structures, such as trabeculae carneae (TC) and papillary muscle, recently received attention as possible causes of reduced near-wall blood flow. As a fundamental consideration of this problem, this study established a method for constructing an unsteady LV model from magnetic resonance (MR) images and investigated the effect of a few simplified TC structures on the blood flow in the model. The LV model at arbitrary time steps was constructed by deforming a computational mesh generated from MR images at a reference time step. The validity of the proposed construction scheme was confirmed by comparison with the configuration of an LV model extracted from MR images. Numerical analysis was performed for the unsteady blood flow in LV models with and without two simplified TC structures. The flow field in the model with the internal structure differed from that in the model without the internal structure near the wall, and flow separation caused by the internal structure decreased wall shear stress on the rear of the internal structure. The computational results provide fundamental information for the complex interaction between the internal structures and the blood flow in an LV.