Show simple item record

dc.contributor.author
Çavuşoğlu, Mustafa
dc.contributor.author
Mooiweer, Ronald
dc.contributor.author
Prüssmann, Klaas P.
dc.contributor.author
Malik, Shaihan J.
dc.date.accessioned
2017-07-25T12:47:31Z
dc.date.available
2017-06-12T20:11:18Z
dc.date.available
2017-07-25T12:47:31Z
dc.date.issued
2017-06
dc.identifier.issn
0952-3480
dc.identifier.issn
1099-1492
dc.identifier.other
10.1002/nbm.3697
en_US
dc.identifier.uri
http://hdl.handle.net/20.500.11850/129169
dc.identifier.doi
10.3929/ethz-b-000129169
dc.description.abstract
In parallel RF pulse design, peak RF magnitudes and specific absorption rate levels are critical concerns in the hardware and safety limits. The variable rate selective excitation (VERSE) method is an efficient technique to limit the peak RF power by applying a local-only RF and gradient waveform reshaping while retaining the on-resonance profile. The accuracy of the excitation performed by the VERSEd RF and gradient waveforms strictly depends on the performance of the employed hardware. Any deviation from the nominal gradient fields as a result of frequency dependent system imperfections violates the VERSE condition similarly to off-resonance effects, leading to significant excitation errors and the RF pulse not converging to the targeted peak RF power. Moreover, for iterative VERSE-guided RF pulse design (i.e. reVERSE), the k-space trajectory actually changes at every iteration, which is assumed to be constant. In this work, we show both theoretically and experimentally the effect of gradient system imperfections on iteratively VERSEd parallel RF excitations. In order to improve the excitation accuracy besides limiting the RF power below certain thresholds, we propose to integrate gradient field monitoring or gradient impulse response function (GIRF) estimations of the actual gradient fields into the RF pulse design problem. A third-order dynamic field camera comprising a set of NMR field sensors and GIRFs was used to measure or estimate the actual gradient waveforms that are involved in the VERSE algorithm respectively. The deviating and variable k-space is counteracted at each iteration of the VERSE-guided iterative RF pulse design. The proposed approaches are demonstrated for accelerated multiple-channel spatially selective RF pulses, and highly improved experimental performance was achieved at both 3 T and 7 T.
en_US
dc.language.iso
en
en_US
dc.publisher
Wiley
en_US
dc.rights.uri
http://creativecommons.org/licenses/by/4.0/
dc.subject
Excitation accuracy
en_US
dc.subject
Field monitoring
en_US
dc.subject
Gradient impulse response
en_US
dc.subject
Parallel transmit
en_US
dc.subject
RF power
en_US
dc.subject
VERSE
en_US
dc.title
VERSE-guided parallel RF excitations using dynamic field correction
en_US
dc.type
Journal Article
dc.rights.license
Creative Commons Attribution 4.0 International
dc.date.published
2017-02-17
ethz.journal.title
NMR in Biomedicine
ethz.journal.volume
30
en_US
ethz.journal.issue
6
en_US
ethz.journal.abbreviated
NMR Biomed
ethz.pages.start
e3697
en_US
ethz.size
13 p.
en_US
ethz.version.deposit
publishedVersion
en_US
ethz.identifier.wos
ethz.identifier.scopus
ethz.identifier.nebis
010842077
ethz.publication.place
Chichester
en_US
ethz.publication.status
published
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02140 - Dep. Inf.technologie und Elektrotechnik / Dep. of Inform.Technol. Electrical Eng.::02631 - Institut für Biomedizinische Technik / Institute for Biomedical Engineering::03628 - Prüssmann, Klaas P. / Prüssmann, Klaas P.
ethz.leitzahl.certified
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02140 - Dep. Inf.technologie und Elektrotechnik / Dep. of Inform.Technol. Electrical Eng.::02631 - Institut für Biomedizinische Technik / Institute for Biomedical Engineering::03628 - Prüssmann, Klaas P. / Prüssmann, Klaas P.
ethz.date.deposited
2017-06-12T20:12:19Z
ethz.source
ECIT
ethz.identifier.importid
imp593655505f0ab11483
ethz.ecitpid
pub:192128
ethz.eth
yes
en_US
ethz.availability
Open access
en_US
ethz.rosetta.installDate
2017-07-25T12:47:49Z
ethz.rosetta.lastUpdated
2018-11-05T15:17:04Z
ethz.rosetta.exportRequired
true
ethz.rosetta.versionExported
true
ethz.COinS
ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.atitle=VERSE-guided%20parallel%20RF%20excitations%20using%20dynamic%20field%20correction&rft.jtitle=NMR%20in%20Biomedicine&rft.date=2017-06&rft.volume=30&rft.issue=6&rft.spage=e3697&rft.issn=0952-3480&1099-1492&rft.au=%C3%87avu%C5%9Fo%C4%9Flu,%20Mustafa&Mooiweer,%20Ronald&Pr%C3%BCssmann,%20Klaas%20P.&Malik,%20Shaihan%20J.&rft.genre=article&
 Search via SFX

Files in this item

Thumbnail

Publication type

Show simple item record