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2022-11-13Zeitschriftenartikel
B+1 -correction of magnetization transfer saturation maps optimized for 7T postmortem MRI of the brain
dc.contributor.authorLipp, Ilona
dc.contributor.authorKirilina, Evgeniya
dc.contributor.authorEdwards, Luke J.
dc.contributor.authorPine, Kerrin J.
dc.contributor.authorJäger, Carsten
dc.contributor.authorGräßle, Tobias
dc.contributor.authorEBC Consortium
dc.contributor.authorWeiskopf, Nikolaus
dc.contributor.authorHelms, Gunther
dc.date.accessioned2024-09-10T13:45:37Z
dc.date.available2024-09-10T13:45:37Z
dc.date.issued2022-11-13none
dc.identifier.other10.1002/mrm.29524
dc.identifier.urihttp://edoc.rki.de/176904/12141
dc.description.abstractMagnetization transfer saturation (MTsat) is a useful marker to probe tissue macromolecular content and myelination in the brain. The increasedB+1-inhomogeneity at  ≥7 T and significantly larger saturation pulse flip angles which are often used for postmortem studies exceed the limits where previous MTsat B+1 correction methods are applicable. Here, we develop a calibration-based correction model and procedure, and validate and evaluate it in postmortem 7T data of whole chimpanzee brains. Theory The B+1 dependence of MTsat was investigated by varying the off-resonance saturation pulse flip angle. For the range of saturation pulse flip angles applied in typical experiments on postmortem tissue, the dependence was close to linear. A linear model with a single calibration constant C is proposed to correct bias in MTsat by mapping it to the reference value of the saturation pulse flip angle. Methods C was estimated voxel-wise in five postmortem chimpanzee brains. “Individual-based global parameters” were obtained by calculating the mean C within individual specimen brains and “group-based global parameters” by calculating the means of the individual-based global parameters across the five brains. Results The linear calibration model described the data well, though C was not entirely independent of the underlying tissue and B+1. Individual-based correction parameters and a group-based global correction parameter (C=1.2) led to visible, quantifiable reductions of B+1-biases in high-resolution MTsat maps. Conclusion The presented model and calibration approach effectively corrects for B+1 inhomogeneities in postmortem 7T data.eng
dc.language.isoengnone
dc.publisherRobert Koch-Institut
dc.rights(CC BY 3.0 DE) Namensnennung 3.0 Deutschlandger
dc.rights.urihttp://creativecommons.org/licenses/by/3.0/de/
dc.subjectcallibrationeng
dc.subjectchimpanzeeeng
dc.subjectmagnetization transfereng
dc.subjectMRIeng
dc.subjectpostmortemeng
dc.subjecttransmit fieldeng
dc.subjectultra high-fieldeng
dc.subject.ddc610 Medizin und Gesundheitnone
dc.titleB+1 -correction of magnetization transfer saturation maps optimized for 7T postmortem MRI of the brainnone
dc.typearticle
dc.identifier.urnurn:nbn:de:0257-176904/12141-2
dc.type.versionpublishedVersionnone
local.edoc.container-titleMagnetic Resonance in Medicinenone
local.edoc.container-issn1522-2594none
local.edoc.pages16none
local.edoc.type-nameZeitschriftenartikel
local.edoc.container-typeperiodical
local.edoc.container-type-nameZeitschrift
local.edoc.container-urlhttps://onlinelibrary.wiley.com/journal/15222594none
local.edoc.container-publisher-nameJohn Wiley & Sons, Incnone
local.edoc.container-volume89none
local.edoc.container-issue4none
local.edoc.container-reportyear2022none
local.edoc.container-firstpage1385none
local.edoc.container-lastpage1400none
dc.description.versionPeer Reviewednone

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