- Poster presentation
- Open Access
A new method for objective myocardial scar characterization using MR late gadolinium enhancement and post-contrast look-locker sequences
© Tao et al; licensee BioMed Central Ltd. 2013
- Published: 30 January 2013
- Relaxation Rate
- Late Gadolinium Enhancement
- Myocardial Scar
- Late Gadolinium Enhance
- Scar Region
Accurate characterization of myocardial scar has important diagnostic and prognostic implications for post-infarct patients. Previous studies have used late gadolinium enhanced (LGE) MR to characterize myocardial scar, by dividing the scar region into core and gray zones based on signal intensity in LGE. The characterization is however subjective to manual annotations, dependent on image acquisition parameters, contrast dose and timing, and has limited reproducibility. The purpose of this study is to objectively and reproducibly characterize infarcted myocardial tissue combining information from the LGE and post-contrast Look-Locker (LL) sequences.
Eighty-four post-infarct patients underwent magnetic resonance imaging at 1.5 T. Prior to the LGE acquisition, a LL sequence was acquired at one short-axis level to determine the optimal inversion time for LGE, and to estimate the T1 values of blood and myocardium. In the training group of 52 patients, the blood pool, viable myocardium, and fibrotic tissue were manually annotated and their relaxation rates were derived from the T1 map. The relationship between the relaxation rates of the viable/fibrotic tissue and the blood was modeled by linear regression. In the testing group of 32 patients, the linear models were applied to estimate the relaxation rates of viable and fibrotic myocardial tissue. The T1-identified viable and fibrotic regions were projected from the T1 map to the corresponding LGE slice, and their signal intensity was used to estimate the percentage of infarction within the complete LV. The T1-based scar identification was compared to manual scar identification results from two independent observers. Reproducibility of our method was evaluated by comparing the T1-based scar identification results obtained by the two observers.
By combining information from LL and LGE sequences, myocardial scar can be characterized in an objective and highly reproducible manner for post-infarct patients. Since the method does not require additional scanning it can be readily applied with standard cardiac CMR protocols.
European MEDIATE project (ITEA 09039)
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/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.