title: In amnio MRI of mouse embryos.
abstract: Mouse embryo imaging is conventionally carried out on ex vivo embryos excised from the amniotic sac, omitting vital structures and abnormalities external to the body. Here, we present an in amnio MR imaging methodology in which the mouse embryo is retained in the amniotic sac and demonstrate how important embryonic structures can be visualised in 3D with high spatial resolution (100 µm/px). To illustrate the utility of in amnio imaging, we subsequently apply the technique to examine abnormal mouse embryos with abdominal wall defects. Mouse embryos at E17.5 were imaged and compared, including three normal phenotype embryos, an abnormal embryo with a clear exomphalos defect, and one with a suspected gastroschisis phenotype. Embryos were excised from the mother ensuring the amnion remained intact and stereo microscopy was performed. Embryos were next embedded in agarose for 3D, high resolution MRI on a 9.4T scanner. Identification of the abnormal embryo phenotypes was not possible using stereo microscopy or conventional ex vivo MRI. Using in amnio MRI, we determined that the abnormal embryos had an exomphalos phenotype with varying severities. In amnio MRI is ideally suited to investigate the complex relationship between embryo and amnion, together with screening for other abnormalities located outside of the mouse embryo, providing a valuable complement to histology and existing imaging methods available to the phenotyping community.
authors.affiliation: UCL Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, United Kingdom; UCL Centre for Mathematics and Physics in the Life Sciences and Experimental Biology, University College London, London, United Kingdom.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Roberts
authors.affiliation: UCL Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, United Kingdom; UCL Centre for Mathematics and Physics in the Life Sciences and Experimental Biology, University College London, London, United Kingdom.
authors.forename: Francesca C
authors.initials: FC
authors.lastname: Norris
authors.affiliation: UCL Institute of Child Health, University College London, London, United Kingdom.
authors.forename: Helen
authors.initials: H
authors.lastname: Carnaghan
authors.affiliation: UCL Institute of Child Health, University College London, London, United Kingdom.
authors.forename: Dawn
authors.initials: D
authors.lastname: Savery
authors.affiliation: UCL Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, United Kingdom.
authors.forename: Jack A
authors.initials: JA
authors.lastname: Wells
authors.affiliation: UCL Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, United Kingdom.
authors.forename: Bernard
authors.initials: B
authors.lastname: Siow
authors.affiliation: UCL Institute of Child Health, University College London, London, United Kingdom.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Scambler
authors.affiliation: UCL Institute of Child Health, University College London, London, United Kingdom.
authors.forename: Agostino
authors.initials: A
authors.lastname: Pierro
authors.affiliation: UCL Institute of Child Health, University College London, London, United Kingdom.
authors.forename: Paolo
authors.initials: P
authors.lastname: De Coppi
authors.affiliation: UCL Institute of Child Health, University College London, London, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Eaton
authors.affiliation: UCL Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, United Kingdom.
authors.forename: Mark F
authors.initials: MF
authors.lastname: Lythgoe
mesh_terms: D000650:Amnion / Q000000981:diagnostic imaging*; D000653:Amniotic Fluid / Q000000981:diagnostic imaging*; D000818:Animals; D004622:Embryo, Mammalian / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D051379:Mice; D010920:Placenta / Q000000981:diagnostic imaging; D011247:Pregnancy; D011859:Radiography; D014470:Umbilical Cord / Q000000981:diagnostic imaging