A referenceless Nyquist ghost correction workflow for echo planar imaging of hyperpolarized [1 ‐13C]pyruvate and [1‐13C]lactate

We describe here a workflow for hyperpolarized 13C EPI that requires no reference scan. This involves the selection of a ghost‐containing background from a 13C image of a single metabolite at a single time point, the identification of phase correction coefficients that minimize signal in the selected area, and the application of these coefficients to images acquired at all time points and from all metabolites. The workflow was compared in phantom experiments with phase correction using a 13C reference scan, and yielded similar results in situations with a regular field of view (FOV), a restricted FOV and where there were multiple signal sources. When compared with alternative phase correction methods, the workflow showed an SNR benefit relative to integrated 13C reference echoes (>15%) or better ghost removal relative to a 1H reference scan. The residual ghosting in a slightly de‐shimmed B0 field was 1.6% using the proposed workflow and 3.8% using a 1H reference scan. The workflow was implemented with a series of dynamically acquired hyperpolarized [1‐13C]pyruvate and [1‐13C]lactate images in vivo, resulting in images with no observable ghosting and which were quantitatively similar to images corrected using a 13C reference scan.

We describe a workflow for hyperpolarized 13C echo planar imaging (EPI) that requires no reference scan. The workflow involves the selection of a ghost‐containing background from a 13C image of a single metabolite at a single time point...

Source: NMR in Biomedicine - December 1, 2017 Category: Radiology Authors: Jiazheng Wang, Alan J. Wright, Richard L. Hesketh, De ‐en Hu, Kevin M. Brindle Tags: RESEARCH ARTICLE Source Type: research