Show simple item record

dc.contributor.authorSomai, Vencel
dc.contributor.authorKreis, Felix
dc.contributor.authorGaunt, Adam
dc.contributor.authorTsyben, Anastasia
dc.contributor.authorChia, Ming Li
dc.contributor.authorHesse, Friederike
dc.contributor.authorWright, Alan J
dc.contributor.authorBrindle, Kevin M
dc.date.accessioned2021-12-24T13:34:45Z
dc.date.available2021-12-24T13:34:45Z
dc.date.issued2022-05
dc.date.submitted2021-06-15
dc.identifier.issn0740-3194
dc.identifier.othermrm29110
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/331779
dc.descriptionFunder: Cambridge Commonwealth, European and International Trust; Id: http://dx.doi.org/10.13039/501100003343
dc.description.abstractPURPOSE: The performance of pulse sequences in vivo can be limited by fast relaxation rates, magnetic field inhomogeneity, and nonuniform spin excitation. We describe here a method for pulse sequence optimization that uses a stochastic numerical solver that in principle is capable of finding a global optimum. The method provides a simple framework for incorporating any constraint and implementing arbitrarily complex cost functions. Efficient methods for simulating spin dynamics and incorporating frequency selectivity are also described. METHODS: Optimized pulse sequences for polarization transfer between protons and X-nuclei and excitation pulses that eliminate J-coupling modulation were evaluated experimentally using a surface coil on phantoms, and also the detection of hyperpolarized [2-13 C]lactate in vivo in the case of J-coupling modulation-free excitation. RESULTS: The optimized polarization transfer pulses improved the SNR by ~50% with a more than twofold reduction in the B1 field, and J-coupling modulation-free excitation was achieved with a more than threefold reduction in pulse length. CONCLUSION: This process could be used to optimize any pulse when there is a need to improve the uniformity and frequency selectivity of excitation as well as to design new pulses to steer the spin system to any desired achievable state.
dc.languageen
dc.publisherWiley
dc.subjectRESEARCH ARTICLE
dc.subjectRESEARCH ARTICLES
dc.subjecthyperpolarized
dc.subjectmetabolism
dc.subjectMRI
dc.subjectnumerical optimization
dc.subjectpulse sequence
dc.titleGenetic algorithm-based optimization of pulse sequences.
dc.typeArticle
dc.date.updated2021-12-24T13:34:44Z
prism.publicationNameMagn Reson Med
dc.identifier.doi10.17863/CAM.79228
dcterms.dateAccepted2021-11-15
rioxxterms.versionofrecord10.1002/mrm.29110
rioxxterms.versionAO
rioxxterms.versionVoR
rioxxterms.licenseref.urihttp://creativecommons.org/licenses/by/4.0/
dc.contributor.orcidSomai, Vencel [0000-0001-9874-526X]
dc.contributor.orcidWright, Alan J [0000-0002-4577-5681]
dc.contributor.orcidBrindle, Kevin M [0000-0003-3883-6287]
dc.identifier.eissn1522-2594
pubs.funder-project-idCancer Research UK (C96/A25177)
pubs.funder-project-idCancer Research UK (C55296/A26605)
pubs.funder-project-idEuropean Commission Horizon 2020 (H2020) Future and Emerging Technologies (FET) (858149)
cam.issuedOnline2021-12-06


Files in this item

Thumbnail
Thumbnail

This item appears in the following Collection(s)

Show simple item record