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AuthorBracher, Anna-Katinkadc.contributor.author
Date of accession2016-03-15T10:43:07Zdc.date.accessioned
Available in OPARU since2016-03-15T10:43:07Zdc.date.available
Year of creation2015dc.date.created
AbstractThe clinical application of MRI in the field of dentistry is up to now limited to tumors and displacement of the TMJ because of the restricted delineation of the mineralized tissues of the teeth. Due to their fast signal decay and related limited SNR conventional MRI techniques are not able to assess those tissues. In this thesis dedicated imaging sequences using ultra-short echo times (UTE) were applied to detect the signal of mineralised tissues and enable the direct visualization of dental tissues and initial caries lesions. In UTE imaging the FID signal is sampled from central to outer part of the k-space during gradient ramp up. To ensure sufficient image quality, accurate knowledge of the system performance is mandatory to rebuild the waveform and timing of the gradient amplifier output. The system response of the gradient amplifier could be obtained by applying a commonly used trajectory mapping approach and was used to correct for waveform distortions. To automatically correct for timing inconsistencies a dedicated sequence was developed which enables k-space center-acquisition at partial ramp imaging (CAPRI). UTE/CAPRI have the potential for an earlier diagnosis of initial caries lesions and provide a more accurate assessment of the lesion dimension compared to x-ray imaging and enable new applications such as monitoring of re-mineralization therapy. The process of caries lesion can be assessed using MRI as a quantitative tool to observe tissue specific signal behaviour over time. The ability of UTE/CAPRI to visualize the anatomy in three dimensions facilitates the localization of the lesion and the detection of caries lesions located under fillings and crowns (secondary/hidden caries) which are often superimposed in conventional radiography projection images. Therefore the introduced imaging sequences can serve as an alternative technique to the used ionizing radiation based imaging techniques, which are the gold standard in nowadays dental investigations.dc.description.abstract
Languageendc.language.iso
PublisherUniversität Ulmdc.publisher
LicenseStandarddc.rights
Link to license texthttps://oparu.uni-ulm.de/xmlui/license_v3dc.rights.uri
KeywordDental MRIdc.subject
KeywordEarly detection of caries lesionsdc.subject
KeywordTrajectory mappingdc.subject
KeywordUltrashort echo timedc.subject
Dewey Decimal GroupDDC 610 / Medicine & healthdc.subject.ddc
LCSHMedical physicsdc.subject.lcsh
MeSHDental caries; Radiographydc.subject.mesh
MeSHMagnetic resonance imaging; Methodsdc.subject.mesh
MeSHRadiography, dentaldc.subject.mesh
MeSHTooth; Radiographydc.subject.mesh
TitleDental MRI for identification and quantification of initial caries lesionsdc.title
Resource typeDissertationdc.type
DOIhttp://dx.doi.org/10.18725/OPARU-3811dc.identifier.doi
PPN848913809dc.identifier.ppn
URNhttp://nbn-resolving.de/urn:nbn:de:bsz:289-vts-99667dc.identifier.urn
GNDKariesdc.subject.gnd
GNDKernspintomografiedc.subject.gnd
FacultyMedizinische Fakultätuulm.affiliationGeneral
Date of activation2016-02-29T17:00:52Zuulm.freischaltungVTS
Peer reviewneinuulm.peerReview
Shelfmark print versionW: W-H 14.610uulm.shelfmark
DCMI TypeTextuulm.typeDCMI
VTS ID9966uulm.vtsID
CategoryPublikationenuulm.category
Bibliographyuulmuulm.bibliographie


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