An analytical phantom for the evaluation of medical flow imaging algorithms

Blood flow characteristics (e.g. velocity, pressure, shear stress, streamline and volumetric flow rate) are effective tools in diagnosis of cardiovascular diseases such as atherosclerotic plaque, aneurism and cardiac muscle failure. Noninvasive estimation of cardiovascular blood flow characteristics is mostly limited to the measurement of velocity components by medical imaging modalities. Once the velocity field is obtained from the images, other flow characteristics within the cardiovascular system can be determined using algorithms relating them to the velocity components. In this work, we propose an analytical flow phantom to evaluate these algorithms accurately. The Navier-Stokes equations are used to derive this flow phantom. The exact solution of these equations obtains analytical expression for the flow characteristics inside the domain. Features such as pulsatility, incompressibility and viscosity of flow are included in a three-dimensional domain. The velocity domain of the resulted system is presented as reference images. These images could be employed to evaluate the performance of different flow characteristic algorithms. In this study, we also present some applications of the obtained phantom. The calculation of pressure domain from velocity data, volumetric flow rate, wall shear stress and particle trace are the characteristics whose algorithms are evaluated here. We also present the application of this phantom in the analysis of noisy and low-resolution images. The presented phantom can be considered as a benchmark test to compare the accuracy of different flow characteristic algorithms.