Fabrication and Testing of a Microchannel Network Phantom for MRI Velocimetry

Abstract

The MRI velocity maps scale with the Reynolds number of the flow. The theoretical average velocity distribution in a single channel is compared to the experimental distribution, with a consistent over-prediction of velocity near the channel edges. Slice thickness, order of image acquisition, partial volume effects, and acceleration effects are investigated, and show little effect on the measured flow rates. Examination of anatomical MR images show that the channels decreased in height during fabrication, which explains some of the over-prediction in flow rates. The remainder of the discrepancy is attributed to random error caused by a combination of a high value of the maximum encoded velocity and a low signal to noise ratio of the images.