- Poster presentation
- Open Access
Direct comparison of in-vivo and post-mortem spin-echo based diffusion tensor imaging in the porcine heart
Journal of Cardiovascular Magnetic Resonance volume 17, Article number: P76 (2015)
Spin-echo based cardiac diffusion tensor imaging (DTI) is highly sensitive to myocardial strain . Imaging during systolic contraction requires precise planning of the sequence timing . Second order motion compensated diffusion encoding has recently been proposed for small animal imaging  to reduce the impact of myocardial strain on the diffusion tensor.
It is the objective of the present work to compare second order motion compensated spin-echo DTI of the in-vivo and post-mortem porcine heart on a clinical MR system.
Second order motion compensated diffusion encoding gradients were incorporated into a cardiac triggered single-shot spin-echo sequence (Figure 1). A pig (55kg) was imaged on a 1.5T clinical system (Philips Healthcare, Best, The Netherlands) equipped with a gradient system delivering 80mT/m@100mT/m/ms. Eight slices (Figure 2a) were acquired during free breathing with the following parameters: resolution: 2.2×2.2mm2, slice thickness: 6mm, reduced FOV : 230×98mm2, TR/TE: 2R-R/83ms, 10 averages. Fat suppression was established by spectral-spatial excitation. Ten diffusion-encoding directions  with a b-value of 450s/mm2 were applied during early systole. The pig was euthanized by a potassium injection inside the MR scanner and the imaging protocol was repeated. Helix angle maps were calculated upon tensor reconstruction . The myocardium was segmented in 4 angular and 4 radial segments per slice similar to the procedure proposed in  (Figure 2b).
Example helix angle maps are shown in Figure 2a). Sectors were spatially matched and the corresponding correlation analysis for in-vivo vs. post-mortem data are presented in Figure 2c). Root mean squared differences between sectors in-vivo and post-mortem were 10.0°, 8.9° and 11.7° for basal, mid and apical levels, respectively. Despite significant deformation of the post-mortem heart due to the loss in blood pressure, good agreement between in-vivo and post-mortem data is revealed.
Good correlation between in-vivo and post-mortem imaging was found proving that bulk motion and strain effects are well suppressed if second order motion compensated diffusion gradients are employed.
EU FP7 Marie-Curie fellowship to MG.
Gamper : MRM. 2007
Stoeck : ISMRM. 2011
Welsh : ISMRM. 2014
Feinberg : Radiology. 1985
Jones : MRM. 1999
Stoeck : PLoS ONE. 2014
Nielles-Vallespin : MRM. 2013
About this article
Cite this article
Stoeck, C.T., von Deuster, C., Cesarovic, N. et al. Direct comparison of in-vivo and post-mortem spin-echo based diffusion tensor imaging in the porcine heart. J Cardiovasc Magn Reson 17 (Suppl 1), P76 (2015). https://doi.org/10.1186/1532-429X-17-S1-P76
- Diffusion Tensor Imaging
- Myocardial Strain
- Porcine Heart
- Small Animal Imaging
- Early Systole