In vivo cardiovascular magnetic resonance diffusion tensor imaging shows evidence of abnormal myocardial laminar orientations and mobility in hypertrophic cardiomyopathy

Journal of Cardiovascular Magnetic Resonance

Research

David N Firmin¹  Philip J Kilner¹  Dudley J Pennell¹  Tevfik F Ismail¹  Karen P McCarthy¹  Sanjay K Prasad¹  Andrew D Scott¹  Alexander R Lyon¹  Siew Y Ho¹  Laura-Ann McGill¹  Ranil de Silva¹  Pedro F Ferreira¹  Peter D Gatehouse¹  Margarita M Haba¹  Sonia Nielles-Vallespin² 

[1] National Institute of Health Research Cardiovascular Biomedical Research Unit, Royal Brompton Hospital and Imperial College, London, UK;National Institute of Health Research Cardiovascular Biomedical Research Unit, Royal Brompton Hospital and Imperial College, London, UK;National Institutes of Health, Bethesda, USA;

关键词: Diffusion tensor imaging;    Hypertrophic cardiomyopathy;    Cardiovascular magnetic resonance;    Myocardial architecture;    Laminar structure;    Sheet and shear layers;    Diastolic dysfunction;   

DOI  :  10.1186/s12968-014-0087-8

 received in 2014-03-03, accepted in 2014-09-24,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundCardiac 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).MethodsWe 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.ResultsVoxel-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°).ConclusionsIn 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.

【 授权许可】

Unknown   
© Ferreira et al.; licensee BioMed Central Ltd. 2014. 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 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.