Volume 18 Supplement 1
4D Flow and 2D PC MRI: impact of volumetric coverage and three-directional velocity encoding on quantification of aortic hemodynamics
© Bollache et al. 2016
Published: 27 January 2016
The accurate assessment of arterial blood flow is crucial for the diagnosis and management of patients with cardiovascular disease. Our aim was to systematically compare three phase-contrast (PC) MRI sequences for the quantification of aortic hemodynamics, including: 1) 2D time-resolved (CINE) PC MRI with one-directional through-plane (2D-1dir) velocity encoding; 2) 2D CINE PC MRI with three-directional (2D-3dir) velocity encoding; 3) 4D flow MRI with full volumetric coverage of the aorta and three-directional velocity encoding.
All 2D-1dir CINE PC MRI indices in both the AA and DA were significantly lower than 2D-3dir indices, while a better agreement was found between 4D flow and 2D-3dir measurements (Figure 2). Differences between 2D-1dir and 2D-3dir indices, in percentage of the mean value, were lower in the DA than in the AA (Table), suggesting that flow is more complex in the AA and three-directional encoding is required to fully capture flow dynamics.
Our results suggest the importance of three-directional encoding of velocity for estimation of hemodynamic indices, especially when considering volume and peak velocity measured in the AA. Differences between the clinically used 2D-1dir and 2D-3dir CINE PC MRI sequences could also be attributed to changes in aortic hemodynamics between breath-hold and free-breathing acquisitions, highlighting the importance of technique-specific reference values for aortic flow and velocity indices.
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/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.