daily fmri practice john li md 9/27/2012. when you preparing a fmri study, you need to read and...

Daily fMRI PracticeJohn Li MD

9/27/2012

When you preparing a fMRI study, you need to

Read and understand the fMRI requirements.

Design and choose proper paradigms.

Choose the right coil, right gradient and sequences to acquire fMRI data.

Choose proper methods to minimize motion.

Daily fMRI Practice Mainly Involve Follow Modules

Data Acquisition

Paradigm

Post Processing

Result Interpretatio

n

Experiment Design

Designs for fMRI Data Acquisition

Block Design

Event Related Design

Resting State

Paradigms

Good Design

Careful Selection

Proper Delivery

Good Paradigm Performance Needs

Good instruction, correct understanding of paradigm, good performance of paradigm.

Close observation of subject performing paradigm.

Properly reminding the subjects about the coming steps

Checkerboard is one Well-Known Paradigm

Visual Stimulus Block Design

Baboon’s Visual and Motor Activation Results

Wey HY, Li J, Szabo CA, Fox PT, Leland MM, Jones L, Duong TQ. Neuroimage. 2010 Oct 1;52(4):1420-7

Different Frequency Will Stimulate Visual Cortex Differently

Different Frequency Will Stimulate Visual Cortex Differently

The Visual Cortex Activation Area will be Different with Different Designs of Checkerboards

Targeting Different Parts of Visual Field

Full Visual Field

Human Bilateral Finger Tapping Sequence fMRI Result

Thanks to Crystal Franklin for the picture.

Flashing Light and Tactile Stimulator

On

Vibration

Off

Example:Multi-surface Wooden Ball and Multi-grades Sand Paper Stimulus and Design

Example Results

Gao JH, Parsons LM, Bower JM, Xiong JH, Li JQ, Fox PT (1996): Cerebellum implicated in sensory acquisition and discrimination rather than motor control. Science 272:545-547

Psychological Paradigms

N-back, Gambling, Shape-Matching, Face-Matching, Stroop…

Visual Cue for Subject to Adjust the Squeeze Force

Rest RestSqueeze

3 min 3 min 3 min

Adjustable Weight LoadPressured Air for Removing

Weight Load Stopper

20°

Eccentric vs. Concentric Muscle Contraction in First Dorsal Interosseus

Coil SelectionAny coil can be used in fMRI studies. When using

GRAPPA or mSENSE, phased array coils are required.

T/R Head Coil

12 Channel Phased Array Coil

With Insert Gradient,

High Resolution fMRI

And Shorter TE

Will be Possible

TSE

Segmented EPI

Conventional GRE

Single Shot EPI

Comparison of Different Pulse Sequences Used in fMRI

Reducing Motion is One of the Keys for a Successful fMRI

Reducing Motion is One of the Keys to fMRI Success

Reducing Motion is One of the Keys to fMRI Success

Reducing Motion is One of the Keys to fMRI Success

Baboon Head Holder

Activation pattern in ASL with 2x2x5

300ml TRUTOL 75 (Glucose Tolerance Beverage)

300ml Water

HypothalamusMotion related areas

Motion artifact shares similar activation pattern

Thanks Claudia Huerta for Data Analysis

Adjusting Scan Parameters

TR, TE & flip angle Field of view, resolution & matrix sizeSlice thickness & gap between slicesNumber of slices & slice acquisition orderReceiver bandwidth & echo train space

GRAPPA and mSENSEWhen you choose parallel imaging technique GRAPPA or

mSENSE, you can get more slices for a given TR.

Auto Generation of fMRI Results

5% MVC

30% MVC

Interpretation of fMRI ResultsHypothalamus shows decreased activation after glucose ingestion.

Using Data Base to Track MRI Scans

Using Data Base to Track MRI Scans

Using Data Base to Track MRI Scans

Supplementing MRA with fMRI

MR Angiography Demonstrates an AVM (Arteriovenous Malformation)

Yellow Arrow: Supply Artery

Blue Arrow: AVM

Red Arrow: Drain Vein

Interpretation of fMRI ResultsT2 Axial Images T1 Axial ImagesAVM

Interpretation of fMRI Results

Verb Generation from Noun

Verb Generation from Picture

Language Center Is Dominant in the Left Hemisphere

Thank to Crystal Franklin for the pictures.

Thanks!