In vivo cardiovascular magnetic resonance diffusion tensor imaging shows evidence of abnormal myocardial laminar orientations and mobility in hypertrophic cardiomyopathy
Author(s)
Type
Journal Article
Abstract
Background
Cardiac diffusion tensor imaging (cDTI) measures the magnitudes and directions of intramyocardial water diffusion. Assuming the cross-myocyte components to be constrained by the laminar microstructures of myocardium, we hypothesized that cDTI at two cardiac phases might identify any abnormalities of laminar orientation and mobility in hypertrophic cardiomyopathy (HCM).
Methods
We performed cDTI in vivo at 3 Tesla at end-systole and late diastole in 11 healthy controls and 11 patients with HCM, as well as late gadolinium enhancement (LGE) for detection of regional fibrosis.
Results
Voxel-wise analysis of diffusion tensors relative to left ventricular coordinates showed expected transmural changes of myocardial helix-angle, with no significant differences between phases or between HCM and control groups. In controls, the angle of the second eigenvector of diffusion (E2A) relative to the local wall tangent plane was larger in systole than diastole, in accord with previously reported changes of laminar orientation. HCM hearts showed higher than normal global E2A in systole (63.9° vs 56.4° controls, p =0.026) and markedly raised E2A in diastole (46.8° vs 24.0° controls, p < 0.001). In hypertrophic regions, E2A retained a high, systole-like angulation even in diastole, independent of LGE, while regions of normal wall thickness did not (LGE present 57.8°, p =0.0028, LGE absent 54.8°, p =0.0022 vs normal thickness 38.1°).
Conclusions
In healthy controls, the angles of cross-myocyte components of diffusion were consistent with previously reported transmural orientations of laminar microstructures and their changes with contraction. In HCM, especially in hypertrophic regions, they were consistent with hypercontraction in systole and failure of relaxation in diastole. Further investigation of this finding is required as previously postulated effects of strain might be a confounding factor.
Cardiac diffusion tensor imaging (cDTI) measures the magnitudes and directions of intramyocardial water diffusion. Assuming the cross-myocyte components to be constrained by the laminar microstructures of myocardium, we hypothesized that cDTI at two cardiac phases might identify any abnormalities of laminar orientation and mobility in hypertrophic cardiomyopathy (HCM).
Methods
We performed cDTI in vivo at 3 Tesla at end-systole and late diastole in 11 healthy controls and 11 patients with HCM, as well as late gadolinium enhancement (LGE) for detection of regional fibrosis.
Results
Voxel-wise analysis of diffusion tensors relative to left ventricular coordinates showed expected transmural changes of myocardial helix-angle, with no significant differences between phases or between HCM and control groups. In controls, the angle of the second eigenvector of diffusion (E2A) relative to the local wall tangent plane was larger in systole than diastole, in accord with previously reported changes of laminar orientation. HCM hearts showed higher than normal global E2A in systole (63.9° vs 56.4° controls, p =0.026) and markedly raised E2A in diastole (46.8° vs 24.0° controls, p < 0.001). In hypertrophic regions, E2A retained a high, systole-like angulation even in diastole, independent of LGE, while regions of normal wall thickness did not (LGE present 57.8°, p =0.0028, LGE absent 54.8°, p =0.0022 vs normal thickness 38.1°).
Conclusions
In healthy controls, the angles of cross-myocyte components of diffusion were consistent with previously reported transmural orientations of laminar microstructures and their changes with contraction. In HCM, especially in hypertrophic regions, they were consistent with hypercontraction in systole and failure of relaxation in diastole. Further investigation of this finding is required as previously postulated effects of strain might be a confounding factor.
Date Issued
2014-11-12
Date Acceptance
2014-09-24
Citation
Journal of Cardiovascular Magnetic Resonance, 2014, 16 (87), pp.1-16
ISSN
1097-6647
Publisher
BioMed Central
Start Page
1
End Page
16
Journal / Book Title
Journal of Cardiovascular Magnetic Resonance
Volume
16
Issue
87
Copyright Statement
© 2014 Ferreira et al.; licensee 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 credited. 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.
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 credited. 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.
Sponsor
British Heart Foundation
Identifier
https://jcmr-online.biomedcentral.com/articles/10.1186/s12968-014-0087-8
Grant Number
FS/11/67/28954
Subjects
Science & Technology
Life Sciences & Biomedicine
Cardiac & Cardiovascular Systems
Radiology, Nuclear Medicine & Medical Imaging
Cardiovascular System & Cardiology
Diffusion tensor imaging
Hypertrophic cardiomyopathy
Cardiovascular magnetic resonance
Myocardial architecture
Laminar structure
Sheet and shear layers
Diastolic dysfunction
LATE GADOLINIUM ENHANCEMENT
SPATIAL-RESOLUTION
DIASTOLIC FUNCTION
RAT-HEART
MRI
WALL
QUANTIFICATION
TROPONIN
TISSUE
FIBER
Aged
Cardiomyopathy, Hypertrophic
Case-Control Studies
Diffusion Magnetic Resonance Imaging
Diffusion Tensor Imaging
Female
Fibrosis
Humans
Image Interpretation, Computer-Assisted
Magnetic Resonance Imaging, Cine
Male
Middle Aged
Myocardial Contraction
Myocardium
Predictive Value of Tests
Ventricular Function, Left
Myocardium
Humans
Cardiomyopathy, Hypertrophic
Fibrosis
Image Interpretation, Computer-Assisted
Diffusion Magnetic Resonance Imaging
Magnetic Resonance Imaging, Cine
Case-Control Studies
Predictive Value of Tests
Myocardial Contraction
Ventricular Function, Left
Aged
Middle Aged
Female
Male
Diffusion Tensor Imaging
1102 Cardiorespiratory Medicine and Haematology
Nuclear Medicine & Medical Imaging
Publication Status
Published
Article Number
1
Date Publish Online
2014-11-12