- Poster presentation
- Open Access
Second order motion compensated spin echo cardiac diffusion tensor imaging on clinical MR systems
© Stoeck et al. 2016
- Published: 27 January 2016
- Diffusion Tensor Imaging
- Spin Echo
- Helix Angle
- Free Breathing
- Order Motion
Recently second order motion compensated spin echo (SE) sequences in conjunction with high performance gradient systems have been proposed for diffusion weighted (DWI)  and diffusion tensor imaging (DTI) [2, 3] of the human in vivo heart. The method allows for free breathing acquisition without requiring dedicated patient feedback systems or other provisions , facilitating the transition of cardiac DTI into a clinical environment.
In this preliminary study we investigate the limits of SE based cardiac DTI relative to available gradient strengths to explore the required gradient specifications of clinical MR equipment.
Cardiac DTI was acquired on three healthy volunteers (28 ± 4 years/67 ± 11 kg) on a 1.5T clinical system (Philips Healthcare, Best, The Netherlands) equipped with a 5-channel cardiac receiver coil and a high performance gradient system (Gmax 80 mT/m, slew rate 100 mT/m/ms). The imaging sequence consists of a second order motion compensated SE imaging module with a single shot EPI readout . The sequence parameters are: FOV 230 × 100 mm2, resolution 2.5 × 2.5 mm2, slice thickness 6 mm, 10 averages, TR 3R-R. Three slices (apex/mid/base) were acquired triggered to 50% systole during free breathing and navigator gating (gating window 7 mm). Gmax per channel was set to 30, 40, 60 and 80 mT/m resulting in a TE of 96, 85, 73 and 66 ms. Three orthogonal diffusion encoding directions with b = 100 s/mm2 and 9 directions with b = 450 s/mm2 were acquired. The orientation of the directions was optimized to generate effective gradient strengths of 43, 56, 84 and 105 mT/m.
The LV was manually segmented and helix as well as transverse angles  were estimated. For a sector wise comparison the LV was segmented according to the AHA sectors with 5 transmural layers. To estimate the influence of low SNR due to prolonged TE, angulation was estimated additionally using only 4 out of 10 averages acquired at Gmax = 80 mT/m.
This study indicates that second order motion compensated spin echo diffusion tensor imaging is feasible on clinical MR systems without dedicated high performance gradients.
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.