The novel criterion of Reynolds resolution to assess the wall shear stress accuracy estimated by magnetic resonance velocimetry*

Magnetic resonance velocimetry (MRV) is a versatile tool to obtain hemodynamic information related to cardiovascular disease. The wall shear stress (WSS) is one of important hemodynamic parameters available with MRV for clinical applications, and is considered to play an important role in assessing the development of atherosclerosis or plague rupture. Nevertheless, the accuracy of WSS estimated by MRV is rarely evaluated or reported in literature, especially in in vivo studies. We propose a novel and facile criterion to assess the accuracy of WSS estimation in MRV studies based on dimensional analysis. To ensure the inclusion of diverse and extensive cases, we evaluated the accuracy of WSS obtained by various MRV setups such as different radio frequency coils, strengths of magnetic field, even numerical results simulating MR measurements in addition to various Reynolds numbers and spatial resolutions. As a result, we propose a novel and simple criterion of Reynolds resolution which is found to be related to closely to the WSS accuracy.