- Poster presentation
- Open Access
Accuracy of flow measurement with phase contrast MRI in a stenotic phantom: where should flow be measured?
© Khodarahmi et al; licensee BioMed Central Ltd. 2012
- Published: 1 February 2012
- Pulsatile Flow
- Common Iliac Artery
- Laser Light Sheet
- Stereoscopic Particle Image Velocimetry
- Electromagnetic Flowmeter
Phase-contrast magnetic resonance imaging (PC-MRI) provides a powerful method for the quantification of blood velocity. Accuracy of flow measurement with PC-MRI has been validated with several techniques such as Doppler ultrasound and electromagnetic flowmeters. However, these methods suffer from low accuracy, especially in pulsating flows where short response times are required.
Herein, a series of detailed experiments are reported for validation of MR measurements of steady and pulsatile flows with stereoscopic particle image velocimetry (SPIV) on three different stenotic models with 50%, 74%, and 87% area occlusions. Mean inlet Reynolds number was 190 for both steady and pulsatile cases, mimicking the flow of the human common iliac artery.
Axial PC-MRI images were acquired at three sites: inlet (two diameters proximal to the stenosis), throat, and outlet (two diameters distal to the stenosis) using a 3T TX Achieva Philips MRI scanner with slice thickness = 4 mm, resolution = 1 × 1 mm, TE/TR = 3.0/4.0 ms, field of view = 64 × 64 mm, and velocity encoding (Venc) = 30-200 cm/s depending on the imaging section.
Agreement between PC-MRI and SPIV was demonstrated for both steady and pulsatile flow measurements at the inlet by evaluating the linear regression between the two methods, which showed a correlation coefficient of >0.99 and >0.96 for steady and pulsatile flows, respectively.
Our experiments revealed that the most accurate measures of flow by PC-MRI are found at the throat of the stenosis. This study also illustrates that SPIV provides an excellent approach to in-vitro validation of new or existing PC-MRI flow measurement techniques.
This work was supported in part by the National Science Foundation under Grant 0730467 and by an innovative grant from the Clinical and Translational Research Program of the University of Louisville.
This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.