Motion compensated spin echo cardiac diffusion tensor imaging in multiple cardiac phases using an ultrahigh gradient strength scanner
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Background
Cardiac diffusion tensor imaging (cDTI) has traditionally relied on inefficient stimulated echo techniques to robustly assess microstructural changes over the cardiac cycle. Ultrahigh gradient strength systems (>80mT/m) allow shorter motion compensated diffusion encoding. This study compares the ability of high and ultrahigh strength gradient systems to provide systolic and diastolic motion compensated spin echo (MCSE) cDTI.
Methods
Second order MCSE sequences were developed for a research-only Siemens 3T Connectom (300mT/m maximum gradient amplitude per axis) and breath hold cDTI was acquired at peak systole and end diastole. Acquisitions used the maximum achievable gradient strength (GUH, 116mT/m) and also limited to typical high gradient strengths (GH, 66mT/m based on 80mT/m maximum allowable), giving TE=48ms and 58ms respectively. Data were acquired at 2.8x2.8x8mm3, b=500s/mm2 (8 averages) and b=150s/mm2 (2 averages) in 6 encoding directions.
Results
22 healthy subjects were recruited. 20/21 and 21/22 systolic acquisitions at GUH and GH respectively met the >50% criteria of the circumferential myocardium showing the expected transmural variation in helix angle. For GUH and GH (16/20) 80% and (16/22) 73% of diastolic acquisitions were successful respectively. SNR was increased using GUH compared to GH (median [IQR]: 112.9 [3.8] vs. 9.6 [2.9], p=0.0002 diastole, 15.6 [5.9] vs. 12.5 [6.7], p=0.006 systole). Using GUH fractional anisotropy was lower in systole (0.349 [0.040] vs. 0.373 [0.019], p=0.002) and GUH transmural helix angle gradient (HAG) was steeper in diastole (-0.70 [0.17] vs. -0.55 [0.12] ˚/%, p=0.04). At both GUH and GH, sheetlet angle (|E2A|) was higher in systole than in diastole (30.7 [7.3] vs. 21.3 [6.7]˚ p=10-4 and 32.6 [10.9] vs. 26.0 [7.4]˚, p=0.03 respectively). Differences in HAG between phases were only apparent with GH (-0.88 [0.23] vs. -0.55 [0.15], p=10-4) and differences in the mean diffusivity only with GUH (1.64 [0.11] vs. 1.52 [0.24] x10-3mm2/s, p=0.002).
Conclusion
Ultrahigh strength gradient systems deliver higher SNR for MCSE and more robust imaging in diastole. While further work is required to further improve the reliability in diastole, at ultrahigh gradient strengths, cDTI using MCSE can identify dynamic changes in the cardiac microstructure. These findings will lead to more widespread use of multiphase MCSE in cDTI clinical research.
Cardiac diffusion tensor imaging (cDTI) has traditionally relied on inefficient stimulated echo techniques to robustly assess microstructural changes over the cardiac cycle. Ultrahigh gradient strength systems (>80mT/m) allow shorter motion compensated diffusion encoding. This study compares the ability of high and ultrahigh strength gradient systems to provide systolic and diastolic motion compensated spin echo (MCSE) cDTI.
Methods
Second order MCSE sequences were developed for a research-only Siemens 3T Connectom (300mT/m maximum gradient amplitude per axis) and breath hold cDTI was acquired at peak systole and end diastole. Acquisitions used the maximum achievable gradient strength (GUH, 116mT/m) and also limited to typical high gradient strengths (GH, 66mT/m based on 80mT/m maximum allowable), giving TE=48ms and 58ms respectively. Data were acquired at 2.8x2.8x8mm3, b=500s/mm2 (8 averages) and b=150s/mm2 (2 averages) in 6 encoding directions.
Results
22 healthy subjects were recruited. 20/21 and 21/22 systolic acquisitions at GUH and GH respectively met the >50% criteria of the circumferential myocardium showing the expected transmural variation in helix angle. For GUH and GH (16/20) 80% and (16/22) 73% of diastolic acquisitions were successful respectively. SNR was increased using GUH compared to GH (median [IQR]: 112.9 [3.8] vs. 9.6 [2.9], p=0.0002 diastole, 15.6 [5.9] vs. 12.5 [6.7], p=0.006 systole). Using GUH fractional anisotropy was lower in systole (0.349 [0.040] vs. 0.373 [0.019], p=0.002) and GUH transmural helix angle gradient (HAG) was steeper in diastole (-0.70 [0.17] vs. -0.55 [0.12] ˚/%, p=0.04). At both GUH and GH, sheetlet angle (|E2A|) was higher in systole than in diastole (30.7 [7.3] vs. 21.3 [6.7]˚ p=10-4 and 32.6 [10.9] vs. 26.0 [7.4]˚, p=0.03 respectively). Differences in HAG between phases were only apparent with GH (-0.88 [0.23] vs. -0.55 [0.15], p=10-4) and differences in the mean diffusivity only with GUH (1.64 [0.11] vs. 1.52 [0.24] x10-3mm2/s, p=0.002).
Conclusion
Ultrahigh strength gradient systems deliver higher SNR for MCSE and more robust imaging in diastole. While further work is required to further improve the reliability in diastole, at ultrahigh gradient strengths, cDTI using MCSE can identify dynamic changes in the cardiac microstructure. These findings will lead to more widespread use of multiphase MCSE in cDTI clinical research.
Date Issued
2026-05-19
Date Acceptance
2026-01-23
Citation
Journal of Cardiovascular Magnetic Resonance, 2026, 28 (1)
ISSN
1097-6647
Publisher
Elsevier
Journal / Book Title
Journal of Cardiovascular Magnetic Resonance
Volume
28
Issue
1
Copyright Statement
© 2026 The Authors. Published by Elsevier Inc. on behalf of Society for Cardiovascular Magnetic Resonance. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
10.1016/j.jocmr.2026.102699
Subjects
Cardiac diffusion tensor High gradient strength Motion-compensated diffusion encoding cDTI, Cardiac diffusion tensor imaging
MCSE, Motion compensated spin echo
G H , High strength gradients
G UH , Ultrahigh strength gradients
E2A, Absolute angle of second eigenvector
STEAM, Stimulated echo acquisition mode
SNR, Signal to noise ratio
TE, Echo time
G max , Maximum gradient strength for diffusion encoding
bSSFP, Balanced steady state free precession
ECG, Electrocardiogram
TR, Repetition time
GRAPPA, Generalised autocalibrating partially parallel acquisition
EPI, Echo planar imaging
MD, Mean diffusivity
FA, Fractional anisotropy
HA, Helix angle
LV, left ventricle
CMR, Cardiovascular magnetic resonance
SD, Standard deviation
BMI, Body mass index
IQR, Interquartile range
TA, Transverse angle
Publication Status
Published
Article Number
102699
Date Publish Online
2026-01-29