title: In-vivo 23Na-Magnetresonanztomographie am Herzen bei 7 Tesla
creator: Lott, Johanna
subject: ddc-530
subject: 530 Physics
description: This work presents a non-invasive determination of the total tissue sodium concentration (TSC, [Na+]) within the heart muscle using 23Na MRI at B0 = 7T in a clinically feasible measurement time. In a first study the influence of cardiac and respiratory motion and physical effects such as static, receive and transmit field inhomogeneities and partial volume effects, were evaluated and corrected. Relaxation times and TSC of ex-vivo blood samples and in-vivo calf muscle were determined and used to estimate myocardial data. For an acquisition time of 35 min, the measured myocardial TSC could be corrected by -(48 ± 5)% and determined to (31 ± 3)mm. The partial volume correction had the largest effect (-(34 ± 1)%), followed by respiratory and cardiac motion gating (-(11 ± 1)%). With the applied setup, correction for field inhomogeneities had negligible influences on TSC values (-(3 ± 2)%). The resulting myocardial TSC was 1.6-fold higher than the measured TSC of calf muscle ((20 ± 3)mm). In a second study, a new method to compensate for respiratory motion was developed, which increases the signal-to-noise ratio by a factor of p2 or decreases the acquisition time by a factor of two. Myocardial TSC can hence be quantified in a measurement time <20 min, facilitating future translation into clinical cardiac 23Na MRI studies.
date: 2020
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/28382/1/JL_Dissertation_final.pdf
identifier: DOI:10.11588/heidok.00028382
identifier: urn:nbn:de:bsz:16-heidok-283825
identifier:   Lott, Johanna  (2020) In-vivo 23Na-Magnetresonanztomographie am Herzen bei 7 Tesla.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/28382/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: ger