Office of Public Health

Ansgar Furst, Ph.D.Director of Neuroimaging Laboratory, WRIISC

VA Palo Alto, CAClinical Assistant Professor (Affiliated) of Psychiatry

and Behavioral Sciences and of Neurology and Neurological Sciences

Stanford University School of Medicine, CA

DTI as a promising tool for a deeper understanding of white matter pathology

Office of Public Health

Neuroimaging- What else?

Diffusion Tensor Imaging (DTI) F-MRI Diffusion-Weighted Imaging Diffusion-Spectrum Imaging Magnetic Resonance Spectroscopy Magnetization Transfer Imaging Magnetic Source Imaging

Office of Public Health

Neuroimaging- What else?

Diffusion Tensor Imaging (DTI) F-MRI Diffusion-Weighted Imaging Diffusion-Spectrum Imaging Magnetic Resonance Spectroscopy Magnetization Transfer Imaging Magnetic Source Imaging

Too many imaging sequences ?

Office of Public Health

Broad classification scheme

T1-weighted

T2-weightedT2-FLAIRT2*-GRE

SWI

DTIfMRIPET

Structure Function

Office of Public Health

Broad classification schemeStructure Function

Mass effects Volume changesMidline shifts

Altered synaptic/

metabolic activity, network

connectivity

Office of Public Health

Broad classification schemeStructure

Mass effects Volume changesMidline shifts

Office of Public Health

Broad classification schemeFunction

Stay tuned …

Altered synaptic/

metabolic activity, network

connectivity

Office of Public Health

Diffusion Tensor Imaging (DTI) MR sequence (available since the 90s)

relatively simple to implement and time efficient

Measures microscopic motion of water molecules in brain tissue

Gives an indirect account of integrity & connectivity of white matter fiber tracts

Office of Public Health

How does it work ?

Office of Public Health

How does it work ?

Office of Public Health

Office of Public Health

Soaker hose analogy

Office of Public Health

Soaker hose analogy

Office of Public Health

FA maps – no sense of direction

Office of Public Health

Tensors code direction of movement

Office of Public Health

(Directionally) colored FA maps

Anterior

Posterior

Left Right

Superior

Inferior

Office of Public Health

Patient 014 32-year old OIF veteran Blow to the head with LOC ~ 2 min,

additional LOC in bar fight and motor cycle accident < 1 min

Was in vicinity of numerous mortar blasts – no LOC but confused about circumstances afterwards

Patient complains about severe headache

Was diagnosed with TBI during WRIISC visit

Patient 014

Patient 014

Patient 014

Patient 014

Patient 014

Patient 014

Office of Public Health

DTI – just pretty pictures ? DTI imaging (particularly fiber tracking)

can be a very powerful tool in identifying otherwise unnoticed white matter compromises

However, customized fiber tracking is very time consuming and difficult to automatize as each patient’s fiber tract architecture is unique

In order to be useful to clinicians more easily interpretable, reliable quantification of white matter damage is needed

Office of Public Health

Please come and visit us at our poster!

DTI – towards a diagnostic tool

Office of Public Health

Suggested reading

If you want to learnmore about DTI

Recent data showingsuperior sensitivity ofDTI in detecting TBI

Office of Public Health

THANK YOU!