MRI流体計測データ同化における部分体積効果の影響

抄録

Phase-contrast magnetic resonance imaging (PC-MRI) is a powerful tool for flow measurements in vivo and provides a volume-averaged velocity vector in each voxel of the MRI images (partial volume effect: PVE). Several flow data assimilation approaches between MRI and computational fluid dynamics (CFD) simulations have been proposed, while the observation model of the MRI velocity fields is not well established and the PVEs of the MRI images have been not fully considered. Therefore, this study evaluates the impacts of the PVE on MRI flow data assimilation. The flow data assimilation was formulated by minimizing the error between MRI and CFD flow velocity fields with respect to the inlet boundary following the adjoint variable method. Here, we considered two types of error functions with and without PVE and conducted numerical examples of the two-dimensional steady flow fields with three cases of MRI resolutions. Numerical examples successfully demonstrated that the effects of PVE are non-negligible in the case of low-resolution MRI images.