Show simple item record

dc.contributor.author
Hennel, Franciszek
dc.contributor.author
Michael, Eric Seth
dc.contributor.author
Prüssmann, Klaas P.
dc.date.accessioned
2021-01-08T16:53:05Z
dc.date.available
2020-11-18T12:35:39Z
dc.date.available
2020-11-19T15:06:24Z
dc.date.available
2021-01-08T16:53:05Z
dc.date.issued
2021-02
dc.identifier.issn
0952-3480
dc.identifier.issn
1099-1492
dc.identifier.other
10.1002/nbm.4434
en_US
dc.identifier.uri
http://hdl.handle.net/20.500.11850/451856
dc.description.abstract
The dependence of the diffusion tensor on frequency is of great interest in studies of tissue microstructure because it reveals restrictions to the Brownian motion of water molecules caused by cell membranes. Oscillating gradient spin‐echo (OGSE) sequences can sample this dependence with gradient shapes for which the power spectrum of the zeroth moment is focused at a target frequency. In order to maintain the total spectral power (ie the b‐value), oscillating gradient amplitudes must grow with the frequency squared. For this reason, OGSE applications on clinical MRI scanners are limited to low frequencies, for which it is difficult to obtain a narrow frequency bandwidth of the gradient moment in a useful echo time. In particular, the commonly used pair of single‐period trapezoidal‐cosine pulses separated by a half‐period produces significant side lobes away from the target frequency. To mitigate this effect, improved OGSE waveforms are proposed, which reduce the gap between the two gradient pulses to the minimum duration required for the refocusing RF pulse. Additionally, a slight deviation from the periodicity of the waveforms is proposed in order to permit using the maximum slew rate of the gradient system for all lobes of trapezoidal waveforms while maintaining advantageous spectral properties, which is not the case for the currently used OGSE sequences. Numerical calculations validate these changes, showing that both modifications significantly narrow the gradient moment power spectrum and increase the contribution of its main lobe to the b‐value, thus improving the specificity of the measurement. The utility of the new shapes is demonstrated by diffusion tensor measurements of human white matter in vivo over the range of 30‐75 Hz with a b‐value of nearly 1000 s/mm2, using a high‐performance gradient insert. However, the improvement should increase the sampling precision of OGSE experiments for all gradient systems. © 2020 John Wiley & Sons, Ltd.
en_US
dc.language.iso
en
en_US
dc.publisher
Wiley
en_US
dc.subject
Diffusion MRI
en_US
dc.subject
Diffusion tensor
en_US
dc.subject
Microstructure
en_US
dc.subject
MRI pulse sequence design
en_US
dc.subject
OGSE
en_US
dc.subject
Restricted diffusion
en_US
dc.title
Improved gradient waveforms for oscillating gradient spin‐echo (OGSE) diffusion tensor imaging
en_US
dc.type
Journal Article
dc.date.published
2020-10-29
ethz.journal.title
NMR in Biomedicine
ethz.journal.volume
34
en_US
ethz.journal.issue
2
en_US
ethz.journal.abbreviated
NMR Biomed
ethz.pages.start
e4434
en_US
ethz.size
11 p.
en_US
ethz.identifier.wos
ethz.identifier.scopus
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
2020-11-18T12:35:44Z
ethz.source
WOS
ethz.eth
yes
en_US
ethz.availability
Metadata only
en_US
ethz.rosetta.installDate
2021-01-08T16:53:14Z
ethz.rosetta.lastUpdated
2021-02-15T23:02:52Z
ethz.rosetta.versionExported
true
ethz.COinS
ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.atitle=Improved%20gradient%20waveforms%20for%20oscillating%20gradient%20spin%E2%80%90echo%20(OGSE)%20diffusion%20tensor%20imaging&rft.jtitle=NMR%20in%20Biomedicine&rft.date=2021-02&rft.volume=34&rft.issue=2&rft.spage=e4434&rft.issn=0952-3480&1099-1492&rft.au=Hennel,%20Franciszek&Michael,%20Eric%20Seth&Pr%C3%BCssmann,%20Klaas%20P.&rft.genre=article&rft_id=info:doi/10.1002/nbm.4434&
 Search print copy at ETH Library

Files in this item

FilesSizeFormatOpen in viewer

There are no files associated with this item.

Publication type

Show simple item record