Dataset Information

Quantification correction for free-breathing myocardial T_1ρ mapping in mice using a recursively derived description of a T_1ρ* relaxation pathway.

ABSTRACT:

Background

Fast and accurate T_1ρ mapping in myocardium is still a major challenge, particularly in small animal models. The complex sequence design owing to electrocardiogram and respiratory gating leads to quantification errors in in vivo experiments, due to variations of the T_1ρ relaxation pathway. In this study, we present an improved quantification method for T_1ρ using a newly derived formalism of a T_1ρ* relaxation pathway.

Methods

The new signal equation was derived by solving a recursion problem for spin-lock prepared fast gradient echo readouts. Based on Bloch simulations, we compared quantification errors using the common monoexponential model and our corrected model. The method was validated in phantom experiments and tested in vivo for myocardial T_1ρ mapping in mice. Here, the impact of the breath dependent spin recovery time T_rec on the quantification results was examined in detail.

Results

Simulations indicate that a correction is necessary, since systematically underestimated values are measured under in vivo conditions. In the phantom study, the mean quantification error could be reduced from - 7.4% to - 0.97%. In vivo, a correlation of uncorrected T_1ρ with the respiratory cycle was observed. Using the newly derived correction method, this correlation was significantly reduced from r = 0.708 (p < 0.001) to r = 0.204 and the standard deviation of left ventricular T_1ρ values in different animals was reduced by at least 39%.

Conclusion

The suggested quantification formalism enables fast and precise myocardial T_1ρ quantification for small animals during free breathing and can improve the comparability of study results. Our new technique offers a reasonable tool for assessing myocardial diseases, since pathologies that cause a change in heart or breathing rates do not lead to systematic misinterpretations. Besides, the derived signal equation can be used for sequence optimization or for subsequent correction of prior study results.

SUBMITTER: Gram M

PROVIDER: S-EPMC9082875 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Quantification correction for free-breathing myocardial T<sub>1ρ</sub> mapping in mice using a recursively derived description of a T<sub>1ρ</sub>* relaxation pathway.

Gram Maximilian M Gensler Daniel D Albertova Petra P Gutjahr Fabian Tobias FT Lau Kolja K Arias-Loza Paula-Anahi PA Jakob Peter Michael PM Nordbeck Peter P

Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance 20220509 1

<h4>Background</h4>Fast and accurate T<sub>1ρ</sub> mapping in myocardium is still a major challenge, particularly in small animal models. The complex sequence design owing to electrocardiogram and respiratory gating leads to quantification errors in in vivo experiments, due to variations of the T<sub>1ρ</sub> relaxation pathway. In this study, we present an improved quantification method for T<sub>1ρ</sub> using a newly derived formalism of a T<sub>1ρ</sub>* relaxation pathway.<h4>Methods</h4>T ...[more]

PMID: 35534901

Similar Datasets

Project description:PurposeT1ρ dispersion quantification can potentially be used as a cardiac magnetic resonance index for sensitive detection of myocardial fibrosis without the need of contrast agents. However, dispersion quantification is still a major challenge, because T1ρ mapping for different spin lock amplitudes is a very time consuming process. This study aims to develop a fast and accurate T1ρ mapping sequence, which paves the way to cardiac T1ρ dispersion quantification within the limited measurement time of an in vivo study in small animals.MethodsA radial spin lock sequence was developed using a Bloch simulation-optimized sampling pattern and a view-sharing method for image reconstruction. For validation, phantom measurements with a conventional sampling pattern and a gold standard sequence were compared to examine T1ρ quantification accuracy. The in vivo validation of T1ρ mapping was performed in N = 10 mice and in a reproduction study in a single animal, in which ten maps were acquired in direct succession. Finally, the feasibility of myocardial dispersion quantification was tested in one animal.ResultsThe Bloch simulation-based sampling shows considerably higher image quality as well as improved T1ρ quantification accuracy (+ 56%) and precision (+ 49%) compared to conventional sampling. Compared to the gold standard sequence, a mean deviation of - 0.46 ± 1.84% was observed. The in vivo measurements proved high reproducibility of myocardial T1ρ mapping. The mean T1ρ in the left ventricle was 39.5 ± 1.2 ms for different animals and the maximum deviation was 2.1% in the successive measurements. The myocardial T1ρ dispersion slope, which was measured for the first time in one animal, could be determined to be 4.76 ± 0.23 ms/kHz.ConclusionThis new and fast T1ρ quantification technique enables high-resolution myocardial T1ρ mapping and even dispersion quantification within the limited time of an in vivo study and could, therefore, be a reliable tool for improved tissue characterization.

Dataset Information

Quantification correction for free-breathing myocardial T_1ρ mapping in mice using a recursively derived description of a T_1ρ* relaxation pathway.

Background

Methods

Results

Conclusion

Publications

Quantification correction for free-breathing myocardial T<sub>1ρ</sub> mapping in mice using a recursively derived description of a T<sub>1ρ</sub>* relaxation pathway.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Dataset Information

Quantification correction for free-breathing myocardial T1ρ mapping in mice using a recursively derived description of a T1ρ* relaxation pathway.

Background

Methods

Results

Conclusion

Publications

Quantification correction for free-breathing myocardial T<sub>1ρ</sub> mapping in mice using a recursively derived description of a T<sub>1ρ</sub>* relaxation pathway.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Quantification correction for free-breathing myocardial T_1ρ mapping in mice using a recursively derived description of a T_1ρ* relaxation pathway.