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dc.contributor.authorWang, Jiazhengen
dc.contributor.authorWright, Alanen
dc.contributor.authorHesketh, Richarden
dc.contributor.authorHu, De-Enen
dc.contributor.authorBrindle, Kevinen
dc.description.abstractSingle-shot EPI, which allows an image to be acquired using a single excitation pulse, is used widely for imaging the metabolism of hyperpolarized 13C-labeled metabolites in vivo as the technique is rapid and minimizes depletion of the hyperpolarized signal. However, EPI suffers from Nyquist ghosting, which normally is corrected for by acquiring a reference scan. In a dynamic acquisition of a series of images this results in sacrifice of a time point if the reference scan involves a full readout train with no phase encoding. This time penalty is negligible if an integrated navigator echo is used but at the cost of a lower signal-to-noise ratio (SNR) due to prolonged T2* decay. We describe here a workflow for hyperpolarized 13C EPI that requires no reference scan. This involves selecting a ghost-containing background from a 13C image of a single metabolite at a single time point, searching for phase correction coefficients that minimize signal in the selected area, and then applying 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 to alternative phase correction methods the workflow showed a SNR benefit when compared to integrated 13C reference echoes (>15%) or better ghost removal when compared 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.
dc.rightsAttribution 4.0 International*
dc.subjectMice, Inbred C57BLen
dc.subjectCarbon Isotopesen
dc.subjectLactic Aciden
dc.subjectPyruvic Aciden
dc.subjectEcho-Planar Imagingen
dc.subjectPhantoms, Imagingen
dc.subjectReference Standardsen
dc.subjectImage Processing, Computer-Assisteden
dc.subjectSignal Processing, Computer-Assisteden
dc.subjectSignal-To-Noise Ratioen
dc.titleA referenceless Nyquist ghost correction workflow for echo planar imaging of hyperpolarized [1-13 C]pyruvate and [1-13 C]lactate.en
prism.publicationNameNMR in biomedicineen
dc.contributor.orcidWang, Jiazheng [0000-0003-1182-442X]
dc.contributor.orcidWright, Alan [0000-0002-4577-5681]
dc.contributor.orcidHesketh, Richard [0000-0002-8109-0815]
dc.contributor.orcidBrindle, Kevin [0000-0003-3883-6287]
rioxxterms.typeJournal Article/Reviewen
pubs.funder-project-idCancer Research UK (unknown)
pubs.funder-project-idCancer Research UK (CB4100)
pubs.funder-project-idCancer Research UK (C14303_do not transfer)
pubs.funder-project-idAarhus University (Source: Data Science Research Centre (DSRC)) (15952)
pubs.funder-project-idCancer Research UK (16465)

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Attribution 4.0 International
Except where otherwise noted, this item's licence is described as Attribution 4.0 International