Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation
<p>Abstract</p> <p>Background</p> <p>The study of myofiber reorganization in the remote zone after myocardial infarction has been performed in 2D. Microstructural reorganization in remodeled hearts, however, can only be fully appreciated by considering myofibers as cont...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2012-10-01
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| Series: | Journal of Cardiovascular Magnetic Resonance |
| Subjects: | |
| Online Access: | http://jcmr-online.com/content/14/1/70 |
| _version_ | 1797204397439057920 |
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| author | Mekkaoui Choukri Huang Shuning Chen Howard H Dai Guangping Reese Timothy G Kostis William J Thiagalingam Aravinda Maurovich-Horvat Pal Ruskin Jeremy N Hoffmann Udo Jackowski Marcel P Sosnovik David E |
| author_facet | Mekkaoui Choukri Huang Shuning Chen Howard H Dai Guangping Reese Timothy G Kostis William J Thiagalingam Aravinda Maurovich-Horvat Pal Ruskin Jeremy N Hoffmann Udo Jackowski Marcel P Sosnovik David E |
| author_sort | Mekkaoui Choukri |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>The study of myofiber reorganization in the remote zone after myocardial infarction has been performed in 2D. Microstructural reorganization in remodeled hearts, however, can only be fully appreciated by considering myofibers as continuous 3D entities. The aim of this study was therefore to develop a technique for quantitative 3D diffusion CMR tractography of the heart, and to apply this method to quantify fiber architecture in the remote zone of remodeled hearts.</p> <p>Methods</p> <p>Diffusion Tensor CMR of normal human, sheep, and rat hearts, as well as infarcted sheep hearts was performed <it>ex vivo</it>. Fiber tracts were generated with a fourth-order Runge-Kutta integration technique and classified statistically by the median, mean, maximum, or minimum helix angle (HA) along the tract. An index of tract coherence was derived from the relationship between these HA statistics. Histological validation was performed using phase-contrast microscopy.</p> <p>Results</p> <p>In normal hearts, the subendocardial and subepicardial myofibers had a positive and negative HA, respectively, forming a symmetric distribution around the midmyocardium. However, in the remote zone of the infarcted hearts, a significant positive shift in HA was observed. The ratio between negative and positive HA variance was reduced from 0.96 ± 0.16 in normal hearts to 0.22 ± 0.08 in the remote zone of the remodeled hearts (p<0.05). This was confirmed histologically by the reduction of HA in the subepicardium from −52.03° ± 2.94° in normal hearts to −37.48° ± 4.05° in the remote zone of the remodeled hearts (p < 0.05).</p> <p>Conclusions</p> <p>A significant reorganization of the 3D fiber continuum is observed in the remote zone of remodeled hearts. The positive (rightward) shift in HA in the remote zone is greatest in the subepicardium, but involves all layers of the myocardium. Tractography-based quantification, performed here for the first time in remodeled hearts, may provide a framework for assessing regional changes in the left ventricle following infarction.</p> |
| first_indexed | 2024-04-13T00:20:15Z |
| format | Article |
| id | doaj.art-7cab4cba00df4c11bfa43e3fce0a294e |
| institution | Directory Open Access Journal |
| issn | 1097-6647 1532-429X |
| language | English |
| last_indexed | 2024-04-24T08:34:35Z |
| publishDate | 2012-10-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Cardiovascular Magnetic Resonance |
| spelling | doaj.art-7cab4cba00df4c11bfa43e3fce0a294e2024-04-16T17:38:26ZengElsevierJournal of Cardiovascular Magnetic Resonance1097-66471532-429X2012-10-011417010.1186/1532-429X-14-70Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validationMekkaoui ChoukriHuang ShuningChen Howard HDai GuangpingReese Timothy GKostis William JThiagalingam AravindaMaurovich-Horvat PalRuskin Jeremy NHoffmann UdoJackowski Marcel PSosnovik David E<p>Abstract</p> <p>Background</p> <p>The study of myofiber reorganization in the remote zone after myocardial infarction has been performed in 2D. Microstructural reorganization in remodeled hearts, however, can only be fully appreciated by considering myofibers as continuous 3D entities. The aim of this study was therefore to develop a technique for quantitative 3D diffusion CMR tractography of the heart, and to apply this method to quantify fiber architecture in the remote zone of remodeled hearts.</p> <p>Methods</p> <p>Diffusion Tensor CMR of normal human, sheep, and rat hearts, as well as infarcted sheep hearts was performed <it>ex vivo</it>. Fiber tracts were generated with a fourth-order Runge-Kutta integration technique and classified statistically by the median, mean, maximum, or minimum helix angle (HA) along the tract. An index of tract coherence was derived from the relationship between these HA statistics. Histological validation was performed using phase-contrast microscopy.</p> <p>Results</p> <p>In normal hearts, the subendocardial and subepicardial myofibers had a positive and negative HA, respectively, forming a symmetric distribution around the midmyocardium. However, in the remote zone of the infarcted hearts, a significant positive shift in HA was observed. The ratio between negative and positive HA variance was reduced from 0.96 ± 0.16 in normal hearts to 0.22 ± 0.08 in the remote zone of the remodeled hearts (p<0.05). This was confirmed histologically by the reduction of HA in the subepicardium from −52.03° ± 2.94° in normal hearts to −37.48° ± 4.05° in the remote zone of the remodeled hearts (p < 0.05).</p> <p>Conclusions</p> <p>A significant reorganization of the 3D fiber continuum is observed in the remote zone of remodeled hearts. The positive (rightward) shift in HA in the remote zone is greatest in the subepicardium, but involves all layers of the myocardium. Tractography-based quantification, performed here for the first time in remodeled hearts, may provide a framework for assessing regional changes in the left ventricle following infarction.</p>http://jcmr-online.com/content/14/1/70Diffusion tensor imagingTractographyMyocardiumRemodelingHeart |
| spellingShingle | Mekkaoui Choukri Huang Shuning Chen Howard H Dai Guangping Reese Timothy G Kostis William J Thiagalingam Aravinda Maurovich-Horvat Pal Ruskin Jeremy N Hoffmann Udo Jackowski Marcel P Sosnovik David E Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation Journal of Cardiovascular Magnetic Resonance Diffusion tensor imaging Tractography Myocardium Remodeling Heart |
| title | Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation |
| title_full | Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation |
| title_fullStr | Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation |
| title_full_unstemmed | Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation |
| title_short | Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation |
| title_sort | fiber architecture in remodeled myocardium revealed with a quantitative diffusion cmr tractography framework and histological validation |
| topic | Diffusion tensor imaging Tractography Myocardium Remodeling Heart |
| url | http://jcmr-online.com/content/14/1/70 |
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