- Poster presentation
- Open Access
Quantification and comparison of 4D Flow MRI derived wall shear stress and MRE derived wall shear stiffness of abdominal aorta
© Illapani et al. 2016
- Published: 27 January 2016
- Wall Shear Stress
- Abdominal Aorta
- Pulse Wave Velocity
- Peak Flow
- Aortic Disease
Aortic wall shear stiffness (AWS) and wall shear stress (WSS) are important indicators of pathological changes in the abdominal aorta. Previous studies have shown that AWS increases with diseases such as hypertension and atherosclerosis while WSS decreases1,2 with these diseases. Therefore, early detection of AWS and WSS could significantly impact timely treatment of these pathological conditions. Non-invasive estimation of AWS and WSS became feasible after the recent advent of phase contrast MRI based magnetic resonance elastography (MRE)3 and 4D flow MRI4 respectively. We hypothesize that investigating the relationship between AWS and WSS may provide additional information to assist in diagnosis of aortic diseases. Therefore, in this study, we use both MRE and 4D flow MRI to estimate and establish the correlation between AWS and WSS in normal human subjects.
MRI was performed on 20 volunteers in a 3T Siemens scanner (Tim-Trio, Siemens Healthcare, Germany). Imaging parameters included: MRE : TE/TR = 9.52/14.28 ms; slice thickness = 6 mm; number of slices = 3; acquisition matrix = 128 × 64; α = 25o; Field of view (FOV) = 40 cm2; number of segments = 6 to 8 and a motion encoding gradient (MEG) = 120 Hz; 4D PC MRI: TE/TR = 2.1/5.1 ms; velocity encoding = 150cm/s; flip angle = 7o, acquisition matrix = 192 × 120 × 26; temporal resolution = 40.8 ms, spatial resolution = 1.7 × 2 × 2.2 mm3. Images were processed in MRElab (Mayo Clinic, Rochester, MN) to estimate end-systolic (ES) AWS while Ensight (CEI, Apex, NC) and custom built tool programmed in Matlab5 was used to measure WSS. Pulse wave velocity (PWV) was also estimated in Matlab (Mathworks, Natick, MA) to investigate the correlation with ES AWS.
From our results we can conclude that there is no correlation between ES AWS and WSS, however more studies are warranted.
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.