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Coil profile estimation strategies for parallel imaging with hyperpolarized 13 C MRI
Author(s) -
Hansen Rie B.,
SánchezHeredia Juan Diego,
Bøgh Nikolaj,
Hansen Esben Søvsø Szocska,
Laustsen Christoffer,
Hanson Lars G.,
ArdenkjærLarsen Jan H.
Publication year - 2019
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.27892
Subject(s) - imaging phantom , undersampling , electromagnetic coil , calibration , image quality , computer science , scanner , iterative reconstruction , sensitivity (control systems) , image resolution , nuclear magnetic resonance , biomedical engineering , physics , materials science , artificial intelligence , nuclear medicine , optics , image (mathematics) , electronic engineering , medicine , quantum mechanics , engineering
Purpose To investigate auto‐ and pre‐calibration coil profile estimation for parallel imaging reconstruction of hyperpolarized 13 C MRI volumetric data. Methods Parallel imaging reconstruction was studied with 3 different approaches for coil profile estimation: auto‐calibration, phantom calibration, and theoretic calibration. Acquisition was performed with a 3D stack‐of‐spirals sequence with spectral–spatial excitation and Cartesian undersampling. Parallel imaging reconstructions were done with conjugate gradient SENSE and 3D gridding with inhomogeneity correction. The approaches were compared in simulations with different SNR, through phantom experiments, and in an in vivo pig study focused on the kidneys. All imaging was done with a rigid home‐built 12‐channel 13 C receive coil at 3T. Results The phantom calibrated and theoretic approaches resulted in the best structural similarities in simulations and demonstrated higher image quality in the phantom experiments compared to the auto‐calibrated approach. In vivo mapping of pyruvate uptake and lactate conversion improved for accelerated acquisitions because of a better temporal resolution. From a practical and image quality point of view, use of theoretic coil profiles led to improved results compared to the other approaches. Conclusion The success of the theoretic coil profile estimation demonstrates a negligible effect of load on sensitivity profiles at the carbon frequency at 3T. Through theoretic or phantom calibrated parallel imaging, accelerated 3D volumes could be reconstructed with sufficient sensitivity, temporal, and spatial resolution to map the metabolism of kidneys exemplifying abdominal organs. This approach overcomes a critical step in the clinical translation of parallel imaging in hyperpolarized 13 C MR.