Diffusion imaging of the in vivo heart using spin echoes–considerations on bulk motion sensitivity

Magnetic Resonance in Medicine - Tập 57 Số 2 - Trang 331-337 - 2007
Urs Gamper1, Peter Boesiger1, Sebastian Kozerke2
1Institute for Biomedical Engineering, University of Zurich and Swiss Federal Institute of Technology, Zurich, Switzerland#TAB#
2Institute for Biomedical Engineering, University of Zurich and Swiss Federal Institute of Technology Zurich, Switzerland

Tóm tắt

AbstractCardiac diffusion MRI based on stimulated‐echo acquisition mode (STEAM) techniques is hampered by its inherent low signal‐to‐noise ratio (SNR) efficiency. Diffusion imaging using standard spin‐echo (SE) techniques, on the other hand, offers higher SNRs but has been considered impractical for the beating heart due to excessive signal attenuation from cardiac bulk motion. In this work the effect of systolic cardiac motion on different diffusion‐encoding schemes was studied in detail. Numerical simulations based on in vivo motion data (acquired by MRI tagging techniques) demonstrate an up to 10‐fold decrease in bulk motion sensitivity of the diffusion encoding if the first‐order moment of the diffusion‐encoding gradients is nullified. It is shown that the remaining systolic phase pattern on the myocardium does not influence the magnitude images if the spatial resolution is chosen to be higher than 4 mm. Given these relatively low resolution requirements, we obtained in vivo diffusion‐weighted (DW) short‐axis images from four healthy volunteers using an SE‐based diffusion‐encoding sequence with excitation and refocusing in orthogonal planes for field of view (FOV) reduction. The results showed no significant signal loss due to cardiac motion, and the direction of the principal eigenvalues was found to be in good agreement with known myocardial fiber orientation. Magn Reson Med 57:331–337, 2007. © 2007 Wiley‐Liss, Inc.

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Tài liệu tham khảo

10.1016/S0006-3495(94)80775-1

10.1148/radiology.201.3.8939209

Mori S, 2005, MRI atlas of human white matter, 276

10.1002/ana.10137

10.1097/00004728-200407000-00019

10.1152/ajpheart.1998.274.5.H1627

10.1016/j.ejcts.2004.11.036

10.1152/ajpheart.1998.275.2.H697

10.1152/ajpheart.00889.2002

10.1016/0022-2364(85)90033-2

10.1002/mrm.1910320320

10.1002/mrm.1910340113

10.1002/mrm.1910340603

10.1006/jmrb.1996.0139

10.1002/(SICI)1522-2594(199908)42:2<393::AID-MRM22>3.0.CO;2-F

10.1002/mrm.10188

10.1063/1.1695690

10.3109/10976640009148678

10.1002/mrm.1910320116

StuberM.Quantification of the human heart wall motion by ultra‐fast magnetic resonance myocardial tagging techniques. Ph.D. dissertation ETH Zurich Zurich Switzerland 1997.

10.1148/radiology.156.3.4023236

10.1016/0022-2364(88)90131-X

10.1002/mrm.20024

10.1002/jmri.10250

10.1002/(SICI)1522-2594(199911)42:5<952::AID-MRM16>3.0.CO;2-S

10.1002/mrm.1910380414

10.1002/mrm.20183

10.1039/dc9786600199

10.1161/01.RES.74.5.789

10.1002/mrm.1138

Scollan DF, 1998, Histological validation of myocardial microstructure obtained from diffusion tensor magnetic resonance imaging, Am J Physiol, 275, 2308

10.1152/ajpheart.2001.281.3.H1280

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Magnetic Resonance in Medicine

Tập 57 Số 2

331-337

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