NA-MICNational Alliance for Medical Image Computing http://na-mic.org

Measuring Alcohol and Stress Interactions with Structural and Perfusion MRI

Chris Wyatt

External Collaboration

National Alliance for Medical Image Computing http://na-mic.org

Size comparison of human,

rhesus, and cynomolgus brain.

Introduction

• Our goal is to use MRI to examine the effects of chronic alcohol self-administration on brain structure and function in a group of monkeys that have been mother-reared or nursery-reared.– Jim Daunais (WFUHS PI)– Bob Kraft (WFUHS MR Physicist)– Chris Wyatt (VT Engineering)– Killian Pohl (NA-MIC Core 1)

Macaca mulatta (rhesus) 1:1 1:2.3 1:3

National Alliance for Medical Image Computing http://na-mic.org

NA-MIC Related Goal• Implement and validate

algorithms for:– brain extraction – white-gray matter

segmentation– subcortical structure

segmentation

Size comparison of human, rhesus, and cynomolgus brain.

National Alliance for Medical Image Computing http://na-mic.org

Methods

ApproximateBrain

Extraction

Initial GM/WM/CSFSegmentation

BiasCorrection

DeformableRegistrationof Priors *

EMSin Slicer 2.6

* Rhesus template and atlas graciously provided by Martin Styner and collaborators

National Alliance for Medical Image Computing http://na-mic.org

Results: Tutorial• Slicer 2.6 EMS tutorial similar to the existing one• Uses template/atlas created from our data (N=17)• Subject image has been bias corrected and the priors

registered• http://bsl.ece.vt.edu/download/NHP-EMSTut.zip

National Alliance for Medical Image Computing http://na-mic.org

Results: pre-post induction• Comparison of alcohol naive and post-

drinking induction (7 animals)

No significant change in GM/WM ratio

National Alliance for Medical Image Computing http://na-mic.org

Results: Other ages/species• Using data from similar projects we have

also developed atlases for– young rhesus macaque – cynomolgus macaque

• Have applied EMS in Slicer 2.6 as well.

Macaca fascicularis (cynomolgus)

National Alliance for Medical Image Computing http://na-mic.org

Future: Vervet model• The animals for this project

were divided into multiple serial cohorts from a separate project.

• That project has switched to a vervet animal model.

• So we will begin again with a vervet model in March.

Chlorocebus aethiops (vervet)

National Alliance for Medical Image Computing http://na-mic.org

Future: Improved Imaging• This gives us a chance to address some

of the imaging issues.– new custom coil

• much better uniformity

– optimized GM/WM contrast • (CNR ~ 7.5)

National Alliance for Medical Image Computing http://na-mic.org

Planned Products

• Acquisition of baseline vervet images for atlas development - March 08

• Vervet atlas completed - June 08

• Training and Induction 3-4 months• ad-lib access for 12 months• Final structural scans ~August 2009