measuring alcohol and stress interactions with structural and perfusion mri

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 *

EM Segmenterin Slicer 2.x

* 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.x EM Segmenter 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 EM Segmenter in Slicer 2.x 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

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

Acknowledgements• NIH/NIAAA R01AA016748-01

– PI Jim Daunais WFUHS• NIH/NIDA R01DA020648

– PI Linda Porrino WFUHS

• The lobar parcellation atlas was provided by the UNC Neuro Image Analysis Laboratory and the UWisc Harlow Primate Laboratory. The following grants are acknowledge for support UNC NDDRC HD 03110, NIH AI067518, National Alliance for Medical Image Computing U54 EB005149-01.