Microstructural Infarct Border Zone Remodeling in the Post-infarct Swine Heart Measured by Diffusion Tensor MRI
Introduction: Computational models of the heart increasingly require detailed microstructural information to capture the impact of tissue remodeling on cardiac electromechanics in, for example, hearts with myocardial infarctions. Myocardial infarctions are surrounded by the infarct border zone (BZ),...
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Frontiers Media S.A.
2018-08-01
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| Series: | Frontiers in Physiology |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fphys.2018.00826/full |
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Article |
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DOAJ |
| language |
English |
| format |
Article |
| sources |
DOAJ |
| author |
Geoffrey L. Kung Geoffrey L. Kung Marmar Vaseghi Marmar Vaseghi Jin K. Gahm Jin K. Gahm Jane Shevtsov Alan Garfinkel Kalyanam Shivkumar Kalyanam Shivkumar Daniel B. Ennis Daniel B. Ennis Daniel B. Ennis |
| spellingShingle |
Geoffrey L. Kung Geoffrey L. Kung Marmar Vaseghi Marmar Vaseghi Jin K. Gahm Jin K. Gahm Jane Shevtsov Alan Garfinkel Kalyanam Shivkumar Kalyanam Shivkumar Daniel B. Ennis Daniel B. Ennis Daniel B. Ennis Microstructural Infarct Border Zone Remodeling in the Post-infarct Swine Heart Measured by Diffusion Tensor MRI Frontiers in Physiology cardiac computational models diffusion tensor MRI border zone cardiac remodeling cardiac electromechanics |
| author_facet |
Geoffrey L. Kung Geoffrey L. Kung Marmar Vaseghi Marmar Vaseghi Jin K. Gahm Jin K. Gahm Jane Shevtsov Alan Garfinkel Kalyanam Shivkumar Kalyanam Shivkumar Daniel B. Ennis Daniel B. Ennis Daniel B. Ennis |
| author_sort |
Geoffrey L. Kung |
| title |
Microstructural Infarct Border Zone Remodeling in the Post-infarct Swine Heart Measured by Diffusion Tensor MRI |
| title_short |
Microstructural Infarct Border Zone Remodeling in the Post-infarct Swine Heart Measured by Diffusion Tensor MRI |
| title_full |
Microstructural Infarct Border Zone Remodeling in the Post-infarct Swine Heart Measured by Diffusion Tensor MRI |
| title_fullStr |
Microstructural Infarct Border Zone Remodeling in the Post-infarct Swine Heart Measured by Diffusion Tensor MRI |
| title_full_unstemmed |
Microstructural Infarct Border Zone Remodeling in the Post-infarct Swine Heart Measured by Diffusion Tensor MRI |
| title_sort |
microstructural infarct border zone remodeling in the post-infarct swine heart measured by diffusion tensor mri |
| publisher |
Frontiers Media S.A. |
| series |
Frontiers in Physiology |
| issn |
1664-042X |
| publishDate |
2018-08-01 |
| description |
Introduction: Computational models of the heart increasingly require detailed microstructural information to capture the impact of tissue remodeling on cardiac electromechanics in, for example, hearts with myocardial infarctions. Myocardial infarctions are surrounded by the infarct border zone (BZ), which is a site of electromechanical property transition. Magnetic resonance imaging (MRI) is an emerging method for characterizing microstructural remodeling and focal myocardial infarcts and the BZ can be identified with late gadolinium enhanced (LGE) MRI. Microstructural remodeling within the BZ, however, remains poorly characterized by MRI due, in part, to the fact that LGE and DT-MRI are not always available for the same heart. Diffusion tensor MRI (DT-MRI) can evaluate microstructural remodeling by quantifying the DT apparent diffusion coefficient (ADC, increased with decreased cellularity), fractional anisotropy (FA, decreased with increased fibrosis), and tissue mode (decreased with increased fiber disarray). The purpose of this work was to use LGE MRI in post-infarct porcine hearts (N = 7) to segment remote, BZ, and infarcted myocardium, thereby providing a basis to quantify microstructural remodeling in the BZ and infarcted regions using co-registered DT-MRI.Methods: Chronic porcine infarcts were created by balloon occlusion of the LCx. 6–8 weeks post-infarction, MRI contrast was administered, and the heart was potassium arrested, excised, and imaged with LGE MRI (0.33 × 0.33 × 0.33 mm) and co-registered DT-MRI (1 × 1 × 3 mm). Myocardium was segmented as remote, BZ, or infarct by LGE signal intensity thresholds. DT invariants were used to evaluate microstructural remodeling by quantifying ADC, FA, and tissue mode.Results: The BZ significantly remodeled compared to both infarct and remote myocardium. BZ demonstrated a significant decrease in cellularity (increased ADC), significant decrease in tissue organization (decreased FA), and a significant increase in fiber disarray (decreased tissue mode) relative to remote myocardium (all p < 0.05). Microstructural remodeling in the infarct was similar, but significantly larger in magnitude (all p < 0.05).Conclusion: DT-MRI can identify regions of significant microstructural remodeling in the BZ that are distinct from both remote and infarcted myocardium. |
| topic |
cardiac computational models diffusion tensor MRI border zone cardiac remodeling cardiac electromechanics |
| url |
https://www.frontiersin.org/article/10.3389/fphys.2018.00826/full |
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doaj-be70808497504a67baa0bcb391f981752020-11-25T02:45:13ZengFrontiers Media S.A.Frontiers in Physiology1664-042X2018-08-01910.3389/fphys.2018.00826327452Microstructural Infarct Border Zone Remodeling in the Post-infarct Swine Heart Measured by Diffusion Tensor MRIGeoffrey L. Kung0Geoffrey L. Kung1Marmar Vaseghi2Marmar Vaseghi3Jin K. Gahm4Jin K. Gahm5Jane Shevtsov6Alan Garfinkel7Kalyanam Shivkumar8Kalyanam Shivkumar9Daniel B. Ennis10Daniel B. Ennis11Daniel B. Ennis12Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United StatesDepartment of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United StatesCardiac Arrhythmia Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United StatesDepartment of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United StatesDepartment of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United StatesDepartment of Computer Science, University of California, Los Angeles, Los Angeles, CA, United StatesDepartment of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United StatesDepartment of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United StatesCardiac Arrhythmia Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United StatesDepartment of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United StatesDepartment of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United StatesDepartment of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United StatesBiomedical Physics Interdepartmental Program, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United StatesIntroduction: Computational models of the heart increasingly require detailed microstructural information to capture the impact of tissue remodeling on cardiac electromechanics in, for example, hearts with myocardial infarctions. Myocardial infarctions are surrounded by the infarct border zone (BZ), which is a site of electromechanical property transition. Magnetic resonance imaging (MRI) is an emerging method for characterizing microstructural remodeling and focal myocardial infarcts and the BZ can be identified with late gadolinium enhanced (LGE) MRI. Microstructural remodeling within the BZ, however, remains poorly characterized by MRI due, in part, to the fact that LGE and DT-MRI are not always available for the same heart. Diffusion tensor MRI (DT-MRI) can evaluate microstructural remodeling by quantifying the DT apparent diffusion coefficient (ADC, increased with decreased cellularity), fractional anisotropy (FA, decreased with increased fibrosis), and tissue mode (decreased with increased fiber disarray). The purpose of this work was to use LGE MRI in post-infarct porcine hearts (N = 7) to segment remote, BZ, and infarcted myocardium, thereby providing a basis to quantify microstructural remodeling in the BZ and infarcted regions using co-registered DT-MRI.Methods: Chronic porcine infarcts were created by balloon occlusion of the LCx. 6–8 weeks post-infarction, MRI contrast was administered, and the heart was potassium arrested, excised, and imaged with LGE MRI (0.33 × 0.33 × 0.33 mm) and co-registered DT-MRI (1 × 1 × 3 mm). Myocardium was segmented as remote, BZ, or infarct by LGE signal intensity thresholds. DT invariants were used to evaluate microstructural remodeling by quantifying ADC, FA, and tissue mode.Results: The BZ significantly remodeled compared to both infarct and remote myocardium. BZ demonstrated a significant decrease in cellularity (increased ADC), significant decrease in tissue organization (decreased FA), and a significant increase in fiber disarray (decreased tissue mode) relative to remote myocardium (all p < 0.05). Microstructural remodeling in the infarct was similar, but significantly larger in magnitude (all p < 0.05).Conclusion: DT-MRI can identify regions of significant microstructural remodeling in the BZ that are distinct from both remote and infarcted myocardium.https://www.frontiersin.org/article/10.3389/fphys.2018.00826/fullcardiac computational modelsdiffusion tensor MRIborder zonecardiac remodelingcardiac electromechanics |