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@PHDTHESIS{Baier:1003824,
author = {Baier, Jasmin},
othercontributors = {Kiessling, Fabian and Djudjaj, Sonja},
title = {{I}nfluence of repeated imaging on animal welfare and study
results in healthy and tumor-bearing mice},
school = {Rheinisch-Westfälische Technische Hochschule Aachen},
type = {Dissertation},
address = {Aachen},
reportid = {RWTH-2025-01220},
pages = {Seite 507-514, 10 Seiten : Illustrationen},
year = {2024},
note = {Dissertation, Rheinisch-Westfälische Technische Hochschule
Aachen, 2024, Kumulative Dissertation},
abstract = {Non-invasive imaging is considered harmless for laboratory
animals and is often used in preclinical research to study
physiological processes. However, interventions such as
anesthesia, animal handling, contrast agent application, as
well as magnetic field or radiation exposure can cause
stress and potentially affect animal welfare and
physiological parameters. These effects might be
particularly relevant in longitudinal studies with repeated
examinations. Despite these potential risks, no systematic
study has been conducted yet to investigate the potential
impact of imaging modalities on animal welfare or study
outcomes. Therefore, this thesis aimed to investigate the
possible effects of repeated native and contrast-enhanced
(CE) magnetic resonance imaging (MRI) and computed
tomography (CT) examinations on the animal welfare, tumor
physiology and therapy response. In this regard, healthy and
4T1-tumor-bearing mice were investigated with longitudinal
MRI using 1T and 7T MRI devices under isoflurane anesthesia.
Observational score sheets, rotarod performance, heart rate,
and fecal corticosterone metabolites were assessed as
indicators of animal welfare. Tumor growth, tumor perfusion,
immune cell infiltration, and response to the multikinase
inhibitor regorafenib were evaluated to investigate tumor
physiology. The results demonstrated that repeated MRI
examinations did not lead to any observable changes in the
assessed parameters, indicating that the welfare of mice was
not compromised. Furthermore, tumor growth and therapy
response were not affected by the MRI procedures. However,
the anesthesia administration led to a reduction of spleen
weights in healthy mice. In the CT study, 4T1-tumor-bearing
mice were exposed to repeated native and contrast-enhanced
CT scans under isoflurane anesthesia. Similar to the MRI
experiment, behavioral assessments and tumor evaluations
were conducted. The findings indicated that repeated CT
examinations did not significantly affect animal welfare
according to the observational score sheet. However, motor
coordination was impaired after contrast-enhanced CT in
combination with tumor therapy. In terms of tumor
physiology, CT scans induced alterations such as increased
tumor perfusion and decreased cell proliferation,
particularly in the contrast-enhanced CT group. In
conclusion, repeated MRI examinations did not have adverse
effects on animal welfare or tumor physiology. However,
caution should be exercised regarding the potential
immunological effects of isoflurane anesthesia. Repeated CT
imaging impaired motor coordination and had notable effects
on tumor physiology. These findings emphasize the importance
of considering the potential impacts of the applied imaging
protocols on animal welfare and tumor physiology in
preclinical oncological research.},
cin = {811003-3 ; 924210},
ddc = {610},
cid = {$I:(DE-82)811003-3_20140620$},
pnm = {DFG project G:(GEPRIS)329693114 - Bildgebung im Kontext der
3R: Chancen und Herausforderungen (329693114) / FOR 2591:
Severity assessment in animal-based research (321137804)},
pid = {G:(GEPRIS)329693114 / G:(GEPRIS)321137804},
typ = {PUB:(DE-HGF)11},
url = {https://publications.rwth-aachen.de/record/1003824},
}
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