Dataset Information

Addressing concomitant gradient phase errors in time-interleaved chemical shift-encoded MRI fat fraction and R₂ * mapping with a pass-specific phase fitting method.

ABSTRACT:

Purpose

Concomitant gradients induce phase errors that increase quadratically with distance from isocenter. This work proposes a complex-based fitting method that addresses concomitant gradient phase errors in chemical shift encoded (CSE) MRI estimation of proton density fat fraction (PDFF) and R₂ ^* through joint estimation of pass-specific phase terms. This method is applicable to time-interleaved multi-echo gradient-echo acquisitions (i.e., multi-pass acquisitions) and does not require prior knowledge of gradient waveforms typically needed to address concomitant gradient phase errors.

Theory and methods

A CSE-MRI spoiled gradient echo signal model, with pass-specific phase terms, is introduced for non-linear least squares estimation of PDFF and R₂ ^* in the presence of concomitant gradient phase errors. Cramér-Rao lower bound analysis was used to determine noise performance tradeoffs of the proposed fitting method, which was then validated in both phantom and in vivo experiments.

Results

The proposed fitting method removed PDFF and R₂ ^* estimation errors up to 12% and 10 s^-1 , respectively, at ±12 cm off isocenter (S/I) in a water phantom. In healthy volunteers, PDFF and R₂ ^* bias was reduced by ~10% (12 cm off-isocenter) and ~30 s^-1 (16 cm off-isocenter), respectively. An evaluation in 29 clinical liver datasets demonstrated reduced PDFF bias and variability (8.4% improvement in the coefficient of variation), even with the imaging volume centered at isocenter.

Conclusion

Concomitant gradient induced phase errors in multi-pass CSE-MRI acquisitions can result in PDFF and R₂ ^* estimation biases away from isocenter. The proposed fitting method enables accurate PDFF and R₂ ^* quantification in the presence of concomitant gradient phase errors without knowledge of imaging gradient waveforms.

SUBMITTER: Roberts NT

PROVIDER: S-EPMC8957492 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature

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Publications

Addressing concomitant gradient phase errors in time-interleaved chemical shift-encoded MRI fat fraction and R<sub>2</sub> * mapping with a pass-specific phase fitting method.

Roberts Nathan T NT Hernando Diego D Panagiotopoulos Nikolaos N Reeder Scott B SB

Magnetic resonance in medicine 20220204 6

<h4>Purpose</h4>Concomitant gradients induce phase errors that increase quadratically with distance from isocenter. This work proposes a complex-based fitting method that addresses concomitant gradient phase errors in chemical shift encoded (CSE) MRI estimation of proton density fat fraction (PDFF) and R<sub>2</sub> <sup>*</sup> through joint estimation of pass-specific phase terms. This method is applicable to time-interleaved multi-echo gradient-echo acquisitions (i.e., multi-pass acquisitions ...[more]

PMID: 35122450

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Dataset Information

Addressing concomitant gradient phase errors in time-interleaved chemical shift-encoded MRI fat fraction and R₂ * mapping with a pass-specific phase fitting method.

Purpose

Theory and methods

Results

Conclusion

Publications

Addressing concomitant gradient phase errors in time-interleaved chemical shift-encoded MRI fat fraction and R<sub>2</sub> * mapping with a pass-specific phase fitting method.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Dataset Information

Addressing concomitant gradient phase errors in time-interleaved chemical shift-encoded MRI fat fraction and R2 * mapping with a pass-specific phase fitting method.

Purpose

Theory and methods

Results

Conclusion

Publications

Addressing concomitant gradient phase errors in time-interleaved chemical shift-encoded MRI fat fraction and R<sub>2</sub> * mapping with a pass-specific phase fitting method.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Addressing concomitant gradient phase errors in time-interleaved chemical shift-encoded MRI fat fraction and R₂ * mapping with a pass-specific phase fitting method.