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Characterization of diffuse fibrosis in the failing human heart via diffusion tensor imaging and quantitative histological validation
Author(s) -
Abdullah Osama M.,
Drakos Stavros G.,
Diakos Nikolaos A.,
WeverPinzon Omar,
Kfoury Abdallah G.,
Stehlik Josef,
Selzman Craig H.,
Reid Bruce B.,
Brunisholz Kim,
Verma Divya Ratan,
Myrick Craig,
Sachse Frank B.,
Li Dean Y.,
Hsu Edward W.
Publication year - 2014
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/nbm.3200
Subject(s) - diffusion mri , fractional anisotropy , heart failure , fibrosis , medicine , myocardial fibrosis , stage (stratigraphy) , biopsy , cardiomyopathy , cardiac imaging , biomarker , pathology , cardiology , nuclear medicine , magnetic resonance imaging , chemistry , radiology , biology , paleontology , biochemistry
Non‐invasive imaging techniques are highly desirable as an alternative to conventional biopsy for the characterization of the remodeling of tissues associated with disease progression, including end‐stage heart failure. Cardiac diffusion tensor imaging (DTI) has become an established method for the characterization of myocardial microstructure. However, the relationships between diffuse myocardial fibrosis, which is a key biomarker for staging and treatment planning of the failing heart, and measured DTI parameters have yet to be investigated systematically. In this study, DTI was performed on left ventricular specimens collected from patients with chronic end‐stage heart failure as a result of idiopathic dilated cardiomyopathy ( n = 14) and from normal donors ( n = 5). Scalar DTI parameters, including fractional anisotropy (FA) and mean (MD), primary ( D 1 ), secondary ( D 2 ) and tertiary ( D 3 ) diffusivities, were correlated with collagen content measured by digital microscopy. Compared with hearts from normal subjects, the FA in failing hearts decreased by 22%, whereas the MD, D 2 and D 3 increased by 12%, 14% and 24%, respectively ( P < 0.01). No significant change was detected for D 1 between the two groups. Furthermore, significant correlation was observed between the DTI scalar indices and quantitative histological measurements of collagen (i.e. fibrosis). Pearson's correlation coefficients ( r ) between collagen content and FA, MD, D 2 and D 3 were –0.51, 0.59, 0.56 and 0.62 ( P < 0.05), respectively. The correlation between D 1 and collagen content was not significant ( r = 0.46, P = 0.05). Computational modeling analysis indicated that the behaviors of the DTI parameters as a function of the degree of fibrosis were well explained by compartmental exchange between myocardial and collagenous tissues. Combined, these findings suggest that scalar DTI parameters can be used as metrics for the non‐invasive assessment of diffuse fibrosis in failing hearts. Copyright © 2014 John Wiley & Sons, Ltd.