Related Experiment Video
Updated: Apr 21, 2026
Contrast Imaging in Mouse Embryos Using High-frequency Ultrasound
Published on: March 4, 2015
In amnio MRI of mouse embryos
Thomas A Roberts1, Francesca C Norris1, Helen Carnaghan2
1UCL 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.
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.
Insights
This study introduces in amnio MRI for mouse embryos, preserving the amniotic sac for better visualization. This novel method accurately identifies external abnormalities missed by conventional techniques.
Area of Science:
- Developmental Biology
- Medical Imaging
- Genetics
Background:
- Conventional mouse embryo imaging excises the embryo from the amniotic sac, missing external structures.
- Existing methods like stereo microscopy and ex vivo MRI struggle to identify certain external embryonic abnormalities.
Purpose of the Study:
- To develop and validate an in amnio Magnetic Resonance (MR) imaging technique for mouse embryos.
- To demonstrate the capability of in amnio MRI in visualizing intact embryonic structures and external defects with high resolution.
- To compare the efficacy of in amnio MRI against conventional methods for identifying abdominal wall defects.
Main Methods:
- Developed an in amnio MR imaging methodology retaining the mouse embryo within the intact amniotic sac.
- Utilized high-resolution 3D MRI on a 9.4T scanner for imaging E17.5 mouse embryos.
- Compared in amnio MRI findings with stereo microscopy and conventional ex vivo MRI for normal and abnormal embryos.
Main Results:
- In amnio MRI achieved high spatial resolution (100 µm/px), enabling detailed 3D visualization of embryonic structures.
- Abnormal embryo phenotypes, including exomphalos and suspected gastroschisis, were not identifiable with stereo microscopy or conventional ex vivo MRI.
- In amnio MRI successfully identified exomphalos phenotypes in abnormal embryos with varying severity.
Conclusions:
- In amnio MRI offers a significant advancement for mouse embryo imaging by preserving the natural in utero environment.
- This technique is crucial for investigating the embryo-amnion relationship and detecting external abnormalities.
- In amnio MRI serves as a valuable complementary tool to histology and existing imaging modalities in the phenotyping community.
