1 / 17

Brain Structure Alterations Revealed Using MRI in an Ethanol Mouse Model

Brain Structure Alterations Revealed Using MRI in an Ethanol Mouse Model. Mark Shewfelt April 4, 2012. I ntroduction. Why a mouse model? Ethically acceptable Abundant with relatively low costs Approximately 99% of mice have genes that have a homologue in the human genome.

trixie
Download Presentation

Brain Structure Alterations Revealed Using MRI in an Ethanol Mouse Model

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Brain Structure Alterations Revealed Using MRI in an Ethanol Mouse Model Mark Shewfelt April 4, 2012

  2. Introduction Why a mouse model? • Ethically acceptable • Abundant with relatively low costs • Approximately 99% of mice have genes that have a homologue in the human genome

  3. Theory Magnetic Resonance Imaging (MRI) • 9.4T Magnet used • Based on the detection of oscillating magnetic field produced by a set of hydrogen nuclei • Tool for non-invasive detection of abnormal morphological patterns • 20 Mice were scanned for approximately an hour each • MICe Software used to manipulate MR images

  4. Image Registration • Process of determining the optimal spatial transformation that best aligns a given source image to a given target image • Objective is to achieve the maximum similarity between all of the MR images, in order to construct an unbiased average image • Feature-based and intensity-based approaches • Registration is very complex, it uses an algorithm that considers a transformation model, a similarity measure and optimization

  5. Group-wise Registration • Each individual image is associated with a deformation field that aligns it with the consensus average

  6. Importance of Averaging

  7. Average Image 124 Slices 84 Slices Side view Front view 55 Slices Top view

  8. Brain Atlas

  9. Methods Hippocampus Ventricles

  10. Results

  11. Results

  12. Results Hippocampus Ventricles

  13. Discussion Why does alcohol affect the ventricles more than the hippocampus? • Alcohol known to kill brain cells and decrease brain volume • Ventricles are fluid-filled sacs and therefore much more susceptible to change in volume compared to the more rigid hippocampus region • Function of hippocampus lies in long-term memory, which is not usually associated with the effects of alcohol

  14. Discussion However, • While it has been agreed that alcohol decreases brain volume in general, it has been shown to increase ventricular volume in humans • Perhaps long term alcoholism has dramatic effects on the ventricles • Mouse brain model is not always reliable for predicting similar physiological effects in humans!

  15. Conclusion • Brain atlases are exceptionally useful in determining abnormal morphological patterns • Brain ventricles in mice significantly decreased in size when introduced to alcohol, while the hippocampus did not

  16. Acknowledgements Many Thanks to: • Supervisor: Dr. Ravi Menon • Technical Support and Guidance: Dr. Alex Li • Site: Robarts Research Institute

  17. Thank you for listening, any questions?

More Related