Integrated B0 and B1 mapping and image correction for hyperpolarized Carbon-13 metabolic imaging in the human brain
Yeung K., McGing J., Axford A., Birkhoelzer S., Shinozaki A., Lewis A., Rayner J., Rider O., Schulte R., Gleeson F., Tyler D., Grist J.
Motivation: B0 and B1 inhomogeneities affect signal quantification and kinetic modelling but are challenging to map and correct for in hyperpolarized MRI due to the signal being exogenous and non-renewable. Goal(s): Develop a fully-integrated B0 and B1 mapping method that does not require specialized pulse sequence programming, additional hardware, nor any additional carbon-13 dose. Approach: Varying echo times and flip angles in the imaging sequence. Results: The in-vivo field maps agreed well with independently acquired maps and could correct for B0 off-resonance blurring and B1 inhomogeneity. Impact: A fully-integrated B0 and B1 mapping and correction method for hyperpolarized carbon-13 MRI is presented and validated in vivo. This method is readily implemented and can improve image quality, helping 13C metabolic imaging become more robust for clinical studies.