Imaging in the Courtroom:Alchemy is Back in Vogue

University of Denver Sturm College of Law 3/4/2011

Jonathan D. Brodie, Ph.D., M.D.

Dept. of Psychiatry

© 2011 Jonathon D. Brodie

What is an Image?

the vivid representation of anatomy or physiology

the pictorial or graphic display of data Images are sexy, can convey an

enormous amount of information AND can be used in a courtroom

© 2011 Jonathon D. Brodie

Anonymous Defense Attorney:

Images are sexy

Anonymous Defense Attorney:

Images are sexy

© 2011 Jonathon D. Brodie

Normal Control

Methamphetamine Abuser

© 2011 Jonathon D. Brodie

PET Imaging of Amyloid Deposits in Alzheimer’s Disease vs Normal Controls

Source: Klunk, et al. Ann Neurol 2004: 55:306-319.

PET imaging with a novel tracer, Pittsburgh Compound-B (PIB), can provide quantitative information on amyloid deposits in living subjects.

© 2011 Jonathon D. Brodie

Principles of Neuroimaging (I)

Objective is to detect some property of the brain (as measured by attenuation of x-rays, magnetic moments or dipoles, electrical signals, radioactive events) without invading it

Recognize that each imaging technique has a characteristic sensitivity, precision, accuracy and fidelity with respect to a physical and/or physiological process and generally in an artificial environment divorced from the very circumstances and behaviors that engendered the test.

© 2011 Jonathon D. Brodie

Structural ImagingCAT

X-Ray

MRI

Anatomy

CAT

X-Ray

MRI

© 2011 Jonathon D. Brodie

Computerized Tomography (CT) Imaging

(Similar image reconstruction, but based on absorption of x-rays)

© 2011 Jonathon D. Brodie

Proton density, recovery (T1) and decay (T2 and T2*) times.

• By ‘weighting’ the pulse sequence (and point at which data is collected) different images of the brain are obtained

• Weighting is achieved by manipulating TE (time to echo) and TR (time to repetition of the pulse sequence)

T1 weighted Density weighted T2 weighted

© 2011 Jonathon D. Brodie

Functional Imaging

PET

f MRI

EEGFunction

© 2011 Jonathon D. Brodie

f MRI Paradigms (VF & Pharm)

© 2011 Jonathon D. Brodie

fMRI Setup

© 2011 Jonathon D. Brodie

Statistical Mapsuperimposed on

anatomical MRI image

~2s

Functional images

Time

Condition 1

Condition 2 ...

~ 5 min

Time

fMRISignal

(% change)

ROI Time Course

Condition

Activation Statistics

Region of interest (ROI)

© 2011 Jonathon D. Brodie

f MRI from Stimulus to Publication

Courtesy SPM-Website © 2011 Jonathon D. Brodie

K-Space – an MRI literature name for Fourier

space

Source: Traveler’s Guide to K-space (C.A. Mistretta)http://www.cis.rit.edu/htbooks/mri/ © 2011 Jonathon D. Brodie

PET Function

© 2011 Jonathon D. Brodie

Imaging Alcohol’s Effects on the Human Brain

FDG/PET scan demonstrates acute reductions of brain metabolism with alcohol intoxication. ( Volkow et al)

sober

intoxicated

Same subjectO

HOHO OH

OH

18F

© 2011 Jonathon D. Brodie

Principles of Neuroimaging (II)

Applying a model to interpret the signal

Interpreting the reconstructed data in an experimental context or design

Statistical analysis and comparisons

Experimental conclusions or clinical inferences

© 2011 Jonathon D. Brodie

PET Analysis by within subject Subtraction:

Individual Variance and Mean Difference

Stimulation: flickering checkerboardControl: blank screen

© 2011 Jonathon D. Brodie

Even Identical twins are not the same

© 2011 Jonathon D. Brodie