PMID- 28122618 OWN - NLM STAT- MEDLINE DCOM- 20171212 LR - 20240117 IS - 1532-429X (Electronic) IS - 1097-6647 (Print) IS - 1097-6647 (Linking) VI - 19 IP - 1 DP - 2017 Jan 11 TI - Submillimeter diffusion tensor imaging and late gadolinium enhancement cardiovascular magnetic resonance of chronic myocardial infarction. PG - 9 LID - 10.1186/s12968-016-0317-3 [doi] LID - 9 AB - BACKGROUND: Knowledge of the three-dimensional (3D) infarct structure and fiber orientation remodeling is essential for complete understanding of infarct pathophysiology and post-infarction electromechanical functioning of the heart. Accurate imaging of infarct microstructure necessitates imaging techniques that produce high image spatial resolution and high signal-to-noise ratio (SNR). The aim of this study is to provide detailed reconstruction of 3D chronic infarcts in order to characterize the infarct microstructural remodeling in porcine and human hearts. METHODS: We employed a customized diffusion tensor imaging (DTI) technique in conjunction with late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) on a 3T clinical scanner to image, at submillimeter resolution, myofiber orientation and scar structure in eight chronically infarcted porcine hearts ex vivo. Systematic quantification of local microstructure was performed and the chronic infarct remodeling was characterized at different levels of wall thickness and scar transmurality. Further, a human heart with myocardial infarction was imaged using the same DTI sequence. RESULTS: The SNR of non-diffusion-weighted images was >100 in the infarcted and control hearts. Mean diffusivity and fractional anisotropy (FA) demonstrated a 43% increase, and a 35% decrease respectively, inside the scar tissue. Despite this, the majority of the scar showed anisotropic structure with FA higher than an isotropic liquid. The analysis revealed that the primary eigenvector orientation at the infarcted wall on average followed the pattern of original fiber orientation (imbrication angle mean: 1.96 +/- 11.03 degrees vs. 0.84 +/- 1.47 degrees , p = 0.61, and inclination angle range: 111.0 +/- 10.7 degrees vs. 112.5 +/- 6.8 degrees , p = 0.61, infarcted/control wall), but at a higher transmural gradient of inclination angle that increased with scar transmurality (r = 0.36) and the inverse of wall thickness (r = 0.59). Further, the infarcted wall exhibited a significant increase in both the proportion of left-handed epicardial eigenvectors, and in the angle incoherency. The infarcted human heart demonstrated preservation of primary eigenvector orientation at the thinned region of infarct, consistent with the findings in the porcine hearts. CONCLUSIONS: The application of high-resolution DTI and LGE-CMR revealed the detailed organization of anisotropic infarct structure at a chronic state. This information enhances our understanding of chronic post-infarction remodeling in large animal and human hearts. FAU - Pashakhanloo, Farhad AU - Pashakhanloo F AD - Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA. FAU - Herzka, Daniel A AU - Herzka DA AD - Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA. FAU - Mori, Susumu AU - Mori S AD - Department of Radiology, Johns Hopkins University, Baltimore, MD, USA. FAU - Zviman, Muz AU - Zviman M AD - Department of Medicine, Johns Hopkins University, Baltimore, MD, USA. FAU - Halperin, Henry AU - Halperin H AD - Department of Medicine, Johns Hopkins University, Baltimore, MD, USA. FAU - Gai, Neville AU - Gai N AD - Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD, USA. FAU - Bluemke, David A AU - Bluemke DA AD - Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD, USA. FAU - Trayanova, Natalia A AU - Trayanova NA AD - Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA. FAU - McVeigh, Elliot R AU - McVeigh ER AD - Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA. emcveigh@ucsd.edu. AD - Department of Medicine, Johns Hopkins University, Baltimore, MD, USA. emcveigh@ucsd.edu. AD - Departments of Bioengineering, Medicine, Radiology, University of California, 9500 Gilman Drive-MC0412,La Jolla, San Diego, 92093-0412, CA, USA. emcveigh@ucsd.edu. LA - eng GR - DP1 HL123271/HL/NHLBI NIH HHS/United States GR - R01 HL094610/HL/NHLBI NIH HHS/United States GR - R01 HL126802/HL/NHLBI NIH HHS/United States PT - Journal Article DEP - 20170111 PL - England TA - J Cardiovasc Magn Reson JT - Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance JID - 9815616 RN - 0 (Contrast Media) RN - K2I13DR72L (Gadolinium DTPA) SB - IM MH - Aged, 80 and over MH - Animals MH - Anisotropy MH - Chronic Disease MH - Contrast Media/*administration & dosage MH - *Diffusion Tensor Imaging MH - Disease Models, Animal MH - Female MH - Fibrosis MH - Gadolinium DTPA/*administration & dosage MH - Humans MH - Image Interpretation, Computer-Assisted MH - Imaging, Three-Dimensional MH - Magnetic Resonance Imaging/*methods MH - Myocardial Infarction/*diagnostic imaging/pathology/physiopathology MH - Myocardium/pathology MH - Predictive Value of Tests MH - Sus scrofa MH - Ventricular Remodeling PMC - PMC5264305 OTO - NOTNLM OT - Diffusion tensor imaging OT - Fiber structure OT - Late gadolinium enhancement OT - Microstructural remodeling OT - Myocardial infarction EDAT- 2017/01/27 06:00 MHDA- 2017/12/13 06:00 PMCR- 2017/01/11 CRDT- 2017/01/27 06:00 PHST- 2016/08/19 00:00 [received] PHST- 2016/12/20 00:00 [accepted] PHST- 2017/01/27 06:00 [entrez] PHST- 2017/01/27 06:00 [pubmed] PHST- 2017/12/13 06:00 [medline] PHST- 2017/01/11 00:00 [pmc-release] AID - S1097-6647(23)01043-8 [pii] AID - 317 [pii] AID - 10.1186/s12968-016-0317-3 [doi] PST - epublish SO - J Cardiovasc Magn Reson. 2017 Jan 11;19(1):9. doi: 10.1186/s12968-016-0317-3.