# Presentation: 877645

## Peter A. Bandettini, Ph.D

Unit on Functional Imaging Methods
Laboratory of Brain and Cognition, NIMH
&
Functional MRI Facility
National Institutes of Health

- Unit on Functional Imaging Methods
- Laboratory of Brain and Cognition, NIMH
- &
- Functional MRI Facility
- National Institutes of Health

**Limits of BOLD and Beyond:**
**Hemodynamics to Neuronal Currents**

## FIM Unit & FMRI Core Facility 	

**Peter Bandettini**
**Staff Scientists:**
**Sean Marrett**
**Jerzy Bodurka**
**Frank Ye**
**Wen-Ming Luh**
**Computer Specialist:**
**Adam Thomas**
**Post Docs:**
**Rasmus Birn**
**Hauke Heekeren**
**David Knight**
**Patrick Bellgowan**
**Ziad Saad**

**FIM Unit & FMRI Core Facility **

**Graduate Student:**
**Natalia Petridou**
**Post-Back. IRTA Students:**
**Elisa Kapler**
**August Tuan**
**Dan Kelley**
**Visiting Fellows:**
**Sergio Casciaro**
**Marta Maieron**
**Guosheng Ding**
**Clinical Fellow:**
**James Patterson**
**Psychologist:**
**Julie Frost**

**Summer Students:**
**Hannah Chang**
**Courtney Kemps**
**Douglass Ruff**
**Carla Wettig**
**Kang-Xing Jin**** **
**Program Assistant:**
**Kay Kuhns**
**Scanning Technologists:**
**Karen Bove-Bettis**
**Paula Rowser**

## The people who did all the work...

- Rasmus Birn

- Ziad Saad

- Patrick Bellgowan

- Natalia Petridou

- Jerzy Bodurka

## Hemodynamics

- Neuronal Currents

- -quick overview
- -linearity (steady state)
- -linearity (dynamic)
- -baseline signal
- -latency
- -width

- -model
- -approaches
*current phantom*
*cell cultures*
*human studies*
*-*why there is hope

## Hemodynamics

- Neuronal Currents

- -quick overview
- -linearity (steady state)
- -linearity (dynamic)
- -baseline signal
- -latency
- -width

- -model
- -approaches
*current phantom*
*cell cultures*
*human studies*
- -why there is hope

## Alternating Left and Right Finger Tapping 

**Alternating Left and Right Finger Tapping **

**~**** ****1992**

## ?

**?**

**?**

**?**

##  Neuronal Activity

- Number of Neurons

- Spiking Rate

- Local Field Potential

- Metabolism

- Hemodynamics

- Blood
- Volume

- Flow Velocity

- Aerobic Metabolism

- Anaerobic Metabolism

- BOLD Contrast

**-**

**-**

- Spiking Coherence

- Deoxy-Hb

- Oxygenated
- Blood

- Deoxygenated
- Blood

**+**

- MRI Pulse
- Sequence

- Perfusion

- Perfusion Contrast

- Inflow Contrast

## BOLD Contrast:

**BOLD Contrast:**
**A Few Strategies for Better Interpretation **

**Pulse sequence modulation**
**Neuronal activation modulation**
**Alternative measurement comparison**

## Pulse Sequence

*Venous inflow*
*(for ASL, w/ no VN***)**

*Arterial inflow*
*(BOLD TR < 500 ms)*

- Sensitivity

- Spatial
- Heterogeneity

## Hemodynamics

- Neuronal Currents

- -quick overview
- -linearity (steady state)
- -linearity (dynamic)
- -baseline signal
- -latency
- -width

- -model
- -approaches
*current phantom*
*cell cultures*
*human studies*
*-*why there is hope

## Logothetis et al. (2001) “Neurophysiological investigation of the basis of the fMRI signal” Nature, 412, 150-157

**S. M. Rao et al, (1996) “Relationship between finger movement rate and functional magnetic resonance signal change in human primary motor cortex.” *****J. Cereb. Blood Flow and Met.***** 16, 1250-1254.**

## Hemodynamics

- Neuronal Currents

- -quick overview
- -linearity (steady state)
- -linearity (dynamic)
- -baseline signal
- -latency
- -width

- -model
- -approaches
*current phantom*
*cell cultures*
*human studies*
*-*why there is hope

## R. L. Savoy, et al., Pushing the temporal resolution of fMRI: studies of very brief visual stimuli, onset variability and asynchrony, and stimulus-correlated changes in noise [oral], 3'rd Proc. Soc. Magn. Reson., Nice, p. 450. (1995). 

- R. L. Savoy, et al., Pushing the temporal resolution of fMRI: studies of very brief visual stimuli, onset variability and asynchrony, and stimulus-correlated changes in noise [oral], 3'rd Proc. Soc. Magn. Reson., Nice, p. 450. (1995).

## Slide 15

**Bandettini, et al., The functional dynamics of blood oxygenation level contrast in the motor cortex, 12'th Proc. Soc. Magn. Reson. Med., New York, p. 1382. (1993). **

## Slide 17

## Different stimulus “ON” periods

- measured

- linear

- Signal

- 0.25 s

- 0.5 s

- 1 s

- 2 s

- 20 s

- Stimulus
- timing

- BOLD
- Response

*Brief stimuli produce larger responses than expected*

**Dynamic Nonlinearity Assessment**

**R. M. Birn, Z. Saad, P. A. Bandettini, (2001) “Spatial heterogeneity of the nonlinear dynamics in the fMRI BOLD response.” *****NeuroImage*****, 14: 817-826.**

## Spatial Heterogeneity of BOLD Nonlinearity

**R. M. Birn, Z. Saad, P. A. Bandettini, (2001) “Spatial heterogeneity of the nonlinear dynamics in the fMRI BOLD response.” *****NeuroImage*****, 14: 817-826.**

**Spatial Heterogeneity of BOLD Nonlinearity**

## Results – visual task

- Nonlinearity

- Magnitude

- Latency

**R. M. Birn, Z. Saad, P. A. Bandettini, (2001) “Spatial heterogeneity of the nonlinear dynamics in the fMRI BOLD response.” *****NeuroImage*****, 14: 817-826.**

## Sources of this Nonlinearity

- Neuronal
- Hemodynamic
- Oxygen extraction
- Blood volume dynamics

- Volume

- Flow In

- Flow Out

- Oxygen Extraction

## BOLD Correlation with Neuronal Activity

**Logothetis et al. (2001) “****Neurophysiological investigation of the basis of the fMRI signal” ****Nature, 412, 150-157.**

**P. A. Bandettini and L. G. Ungerleider, (2001) “From neuron to BOLD: new connections.” Nature Neuroscience, 4:  864-866.**

## Slide 23

## Results – constant gratings

- Results – constant gratings

- 0

- 1000

- 2000

- 3000

- 0

- 1

- 2

- 3

- Measured Amplitudes

- Stimulus Duration (ms)

- Amplitude (%)

- Estimated
- Neuronal
- activity

**a** = initial slope

**b** = final slope

- 200

*Simulation*

**Notes:**
Averaged over ROI (entire activated region) and across 5 subjects.  (Each subject showed a similar response, but noisier.)

What can be seen: 

## Varying “ON” and “OFF” periods

*Rapid event-related design with varying ISI*

- 25% ON

- 50% ON

- 75% ON

-  8% ON

## Varying “ON” and “OFF” periods

*Estimated *
*Impulse Response*

*Predicted Responses *
*to 20 s stimulation *

## Hemodynamics

- Neuronal Currents

- -quick overview
- -linearity (steady state)
- -linearity (dynamic)
- -baseline signal
- -latency
- -width

- -model
- -approaches
*current phantom*
*cell cultures*
*human studies*
*-*why there is hope

## Continuously Growing

- Ziad Saad, Z. S. Saad, K. M. Ropella, E. A. DeYoe, P. A. Bandettini,
- The spatial extent of the BOLD response.  *NeuroImage, *(*in press).*

- Activation Area

- Inflection Point

- CC Histogram

**Notes:**
(perhaps show only six and keep going up till 22).
This is a plot of the number of activated voxels detected versus the number of averaged scans.
This data is from the 3T.
The red data represents positive responses and the green data represents negative responses. 
Different dots at any one number of average scans represents the estimates from the different permutations.
The curves represent linear fits to the average number of activated voxels versus Navg.
Note the dramatic increase in the number of activated voxels with Navg. This function fits a linear curve with a correlation of ~92-97%. 
Note also the very large scatter of the number of activated voxels for voxels in a single rep. (perhaps put the subject performance and the number of voxels versus repno here ...)

## The Skin Conductance Response (SCR)

- Sympathetic Nervous System

- _Ventromedial PFC_

- Hypothalamus

- Resistance change across
- two electrodes induced
- by changes in sweating.

- Sweat Gland

- Orbitofrontal Cortex

- J. C. Patterson II, L. G. Ungerleider, and P. A Bandettini, Task - independent functional brain activity correlation with skin conductance changes: an fMRI study. *NeuroImage* 17:1787-1806, (2002).

## Brain activity correlated with SCR during “Rest”

- J. C. Patterson II, L. G. Ungerleider, and P. A Bandettini, Task - independent functional brain activity correlation with skin conductance changes: an fMRI study. *NeuroImage* 17:1787-1806, (2002).

## Hemodynamics

- Neuronal Currents

- -quick overview
- -linearity (steady state)
- -linearity (dynamic)
- -baseline signal
- -latency
- -width

- -model
- -approaches
*current phantom*
*cell cultures*
*human studies*
*-*why there is hope

## Slide 32

## Latency

**Latency**

**Magnitude**

**+ 2 sec**

**- 2 sec**

## Venograms (3T)

**Venograms (3T)**

## Slide 35

## Hemi-Field Experiment

**Right Hemisphere**

**Left Hemisphere**

## =

**+ 2.5 s**

**- 2.5 s**

**0 s**

**500 ms**

**500 ms**

**Right**** ****Hemifield**

**Left Hemifield**

**-**

## 0

- 5

- 10

- 15

- 20

- 25

- 30

- 100

- 200

- 300

- 400

- 500

- Number of runs

- 8 sec on/off

- 16 sec on/off

- Smallest latency
- Variation Detectable
- (ms) (p < 0.001)

- t

- 1 run:

- -1000

- -500

- 500

- 1000

- Number

- delay estimate (ms)

- delay = 107ms

**11**

- 1% Noise
- 4% BOLD
- 256 time pts /run
- 1 second TR

## Optimal Detection of Hemodynamic Latency

**Optimal Detection of Hemodynamic Latency**

## Hemodynamics

- Neuronal Currents

- -quick overview
- -linearity (steady state)
- -linearity (dynamic)
- -baseline signal
- -latency
- -width

- -model
- -approaches
*current phantom*
*cell cultures*
*human studies*
- -why there is hope

## Hemodynamic Response Modulation

**Bottleneck**
**In Processing**
**(upstream)**

**Delayed**
**Processing**
**(downstream)**

**Hemodynamic Response Modulation**

## P.S.F. Bellgowan, Z. S. Saad, P. A. Bandettini, Understanding neural system dynamics through task modulation and measurement of BOLD amplitude, latency, and width. Proc. Nat'l. Acad. Sci. USA  (in press). 

*Our first attempt to apply this strategy..*

## Use of Task Timing Modulation to Extract Processing Streams  

- Use of Task Timing Modulation to Extract Processing Streams

- Stimuli – Six-letter English words and pronounceable non-words.
- 	   Each word or non-word was rotated either 0, 60,or 120 degrees
- Task – Lexical Decision (word / non-word).
- Dependent Measures – Percent Correct and Reaction Time.

- Hypotheses :
- 	**1) Stimulus rotation of 120 degrees will result in:**
- 		a) Longer Reaction Times
- 		b) Stimulus rotation demands a change in perceptual
- 		perspective prior to linguistic processing, resulting in a
- 		delayed IRF onset in areas involved in Lexical and Pre-Lexical
- 		processing.
- 	 2**) Lexical discrimination will result in :**
- 		a) Longer Reaction Times for non-words due to
- 		increased Pre-Lexical processing demands.
- 		b) Wider IRF in Inferior Frontal cortex for non-words
- 		c) Delayed IRF onset in Left Middle Frontal Cortex

## Lexical Delay

- smudge

- slouch

- dierts

- cuhlos

- gedmus

**Lexical Delay**

- Words

- Non-Words

**Rotational Delay**

- 00

- 600

- 1200

- Mean
- Reaction Time

- 823 ms

- 891 ms

- 1446 ms

- 986 ms

- 1219 ms

- Mean
- Reaction Time

## Slide 45

## Regions of Interest

- Word vs. Non-word

- 0o, 60o, 120o Rotation

- Inferior Frontal Gyrus

- Precentral Gyrus

- Middle Temporal Gyrus

## Estimation of Delay, Width & Amplitude

**time (s)**

**Conv.**

**Adjust ********** to improve fit ****(Nelder-Mead simplex method)**

**5**

**10**

**15**

**0**

**0**

**20**

**Magnitude**

**Delay**

**Width**

- Warm colors are areas where Words > Non-words.  Cool colors (blues) are areas
- Where Non-words > words. The Left hemisphere is toward the left margin.
- The green arrows highlight the inferior frontal gyrus.

## Slide 49

## Distribution of Delay Estimates for Subject BP

## =

- minus

**=**

**Delay Maps**

**Delay Difference Map**

- minus

**=**

**Width Maps**

**Width Difference Map**

**Rotated 120****o**

**Not Rotated**

## Hemodynamics

- Neuronal Currents

- -quick overview
- -linearity (steady state)
- -linearity (dynamic)
- -baseline signal
- -latency
- -width

- -model
- -approaches
*current phantom*
*cell cultures*
*human studies*
- -why there is hope

## Toward direct mapping of neuronal activity:

** ****MRI detection of ultra weak and transient **
**magnetic field changes. **

**Jerzy Bodurka**
**Natalia Petridou**
**Peter A. Bandettini**

## Introduction

- These bio-currents induce **spatially distributed and transient** magnetic flux density (Bc) changes and magnetic field gradients (dBc/dr).
- In the context of MRI, these currents therefore alter **the magnetic phase** () of surrounding water protons.

## Introduction

- These bio-currents induce **spatially distributed and transient** magnetic flux density (Bc) changes and magnetic field gradients (dBc/dr).
- In the context of MRI, these currents therefore alter **the magnetic phase** () of surrounding water protons.

## J.P. Wikswo Jr et al.  J Clin Neuronphy 8(2): 170-188, 1991

**J.P. Wikswo Jr et al.*****  J Clin Neuronphy *****8(2): 170-188, 1991**

## The post synaptic potential lasts for 10ms or more, allowing integration of individual fields to create

- Schematic representation of (a) a postsynaptic potential and (b) an action potential as a function of time.

- MEG detectable > 100 fT field on surface of skull**  **

- Synchronous activity among large neuronal populations produce **small transient** magnetic field changes which are typically detected on the scalp with Magnetoencephalography (MEG).

## Introduction

- These bio-currents induce **spatially distributed and transient** magnetic flux density (Bc) changes and magnetic field gradients (dBc/dr).
- In the context of MRI, these currents therefore alter **the magnetic phase** () of surrounding water protons.

## Derivation of B field generated in an MRI 

- voxel by a current dipole

- Single dendritic tree having a diameter d, and length L behaves like a conductor with conductivity . Resistance is R=V/I, where R=4L/(d2 ). From Biot-Savart:

**r****2**

- by substituting d = 4m,   0.25 -1 m-1, V = 10mV and
- r = 4cm ( measurement distance when using MEG) the resulting value is:  **B********0.002 fT**

- Because **B****MEG****=100fT** (or more) is measured by MEG on the scalp, a large number of neurons**, **(0.002 fT x 50,000 = 100 fT), must coherently act to generate such field. These bundles of neurons produce, within a typical voxel, 1 mm x 1 mm x 1 mm, a field of order:

**B****MRI** ******0.2nT**

## Can MRI Detect transient B0 changes

**On the order of 0.2 nT?**

## Introduction

- These bio-currents induce **spatially distributed and transient** magnetic flux density (Bc) changes and magnetic field gradients (dBc/dr).
- In the context of MRI, these currents therefore alter **the magnetic phase** () of surrounding water protons.

- Frequency shift associated with 0.2 nT field shift = 0.01 Hz.
- At TE = 30 ms,  = 0.09 deg.

## Hemodynamics

- Neuronal Currents

- -quick overview
- -linearity (steady state)
- -linearity (dynamic)
- -baseline signal
- -latency
- -width

- -model
- -approaches
*current phantom*
*cell cultures*
*human studies*
- -why there is hope

## wire

**wire**

**wire**

- X

- Z

- Current Phantom Experiment

## 

**calculated |*********B******c*****|  ||** ***B******0***

**Measurement**

**Correlation image**

**Spectral image**

**Simulation**

**Single shot GE EPI**

- ****

- 70 A current

****** ****20****0**

## B0 || Z

********* ******B = ************ / (************  TE)***

***SD of phase noise was ******=0.016 rad ***
*********B****** = 2.2 nT***

***Sensitivity:***
*** ************ ******B = (1.7 ± 0.3) nT***

- X

- Y

- Z

- B0 || Z

- X

- Z

**time ( s )**

**100 s**

- 10 A current

- **** (t)

**Single shot GE EPI, TR=54ms, TE=27ms, FOV=12cm, 64x64**

## J. Bodurka, P. A. Bandettini. Toward direct mapping of neuronal activity: MRI detection of ultra weak transient magnetic field changes, Magn. Reson. Med. 47: 1052-1058, (2002). 

**J. Bodurka, P. A. Bandettini. Toward direct mapping of neuronal activity: MRI detection of ultra weak transient magnetic field changes, Magn. Reson. Med. ****47: 1052-1058, (2002****). **

## Conclusions of phantom studies:

- magnitudes and spatial scales remain, the combination
- of a SE EPI sequence with precisely synchronized
- stimulation protocol optimizes the ability to detect small
- and transient magnetic field changes.

- Transient or periodic flux density changes as small as 200 pT can be detected using MRI.

## Optimization of Phase Detection

- Increase image S/N
- Reduce Temporal Phase Noise
- Selectively tune sequence to frequency
- 	of NMR phase change

## Sources of Phase Noise

- - cardiac pulsation
- - eye movement
- system instabilities (including eddy currents)

## Experiment (human respiration)

- 00

- 400

- 200

**B****0**

- 00

- 400

- 200

**B****0**

**.**

- 00

- 400

- 200

**B****0**

- BR10 nT

- BR5 nT

- BR7 nT

## GE

**Slice selection**

**Spatial encoding**

**Slice selection**

**Spatial encoding**

**GE**

**SE**

**90****0**

**90****0**

**180****0**

## 

**GE**
**spoiled**

- Spectral images

**   ****TR =1.0 sec**

**    ****GE**

**   ****SE**

** ****GE**
**TE=55ms**

** ****SE**
**TE=55ms**

- ****

- M

## TR

- SE sequence improve sensitivity to small and transient  B(t) changes and simultaneously reduces unwanted low-frequency field shift.

**TR**

**Slice selection**

**Spatial encoding**

**TE**

**Scaner**
**SE:**

**90****0**

**180****0**

**tau****EMF**

**Stimulus **
**onset:**

**delay**

******B****EMF****(t)**

## BEMF(t)

**P1 (70ms)**

**200fT**

******20ms**

******B****EMF****(t)**

## Tissue Cultures 

**detection of neuronal currents in vitro**

***Tissue Cultures***** **
**  ****Coronal sections of newborn-**
**    ****rat brains (in-plane:0.3-1mm****2**** **
**    ****thickness:~60********m) **

**Cx**

**CPu**

**GPe**

**STN**

**25 mV**
**10 s**

**physiological model**

**D. Plenz***** NNP, NIMH, NIH***

**Notes:**
To test our hypothesis (based on theoretical modeling and phantom experiments previously presented at hbm plus publications, etc) that the effects of neuronal currents can be imaged with MRI we performed in vitro experiments on rat brain slices. The cultures contain cortical, and basal ganglia tissue and exhibit spontaneous synchronous activity at <2Hz. The activity initiates at roughly every 10 sec and occurs in a cascade from cortex to basal ganglia. This property combined with the fact that we can avoid physiological fluctuations, makes this physiological model ideal to examine the possibility of imaging neuronal current effects, and thus further develop acquisition and analysis methods specific to this contrast mechanism
Trace was obtained with a single-channel recording

## detection of neuronal currents in vitro

**detection of neuronal currents in vitro**

**methods**

***Setup***
**  ****10cm diameter CSF-filled glass container**
**  ****3T GE scanner (Milwaukee, WI)**
**  ****10’’ surface coil (Nova Medical Inc)**
***Imaging***
***  *****FSE structural images (256x256)**
**  ****SE EPI single shot, TE: 60ms, TR:1s, flip angle: 90****0****,  **
**   ****FOV: 18cm, 64x64, 4 slices (3mm). Image**_**s**_**: 1200 (20 min)**
** **_**Active**_**:    10 min activity**
** **_**Inactive**_**: 10 min after TTX administration**

**Notes:**
The cultures were placed on a cover slip and lowered in a 10cm diameter CSF filled glass container. The cover slip was secured in place via a hallow tube which also served to inject TTX (tetrodotoxin – sodium channel blocker that kills activity). 
We acquired a total of 1200 images under two conditions. 600 images for Active: where neurons were spontaneously active; and 600 images for Inactive: after TTX administration

## results

**results**

- A: activity, on-off frequency (appx. 7 sec)
- B: activity
- C: scanner noise (cooling-pump)

- _Active_ state: black line, _Inactive_ state: red line

- A

- B

- C

- A

- B

- C

*1: *_*culture*_

*2: *_*CSF*_

- FSE image

**Hz**

**Hz**

**CSF**

**detection of neuronal currents in vitro**

**Culture**

**Notes:**
Note: each culture has a different on-off frequency (some of the cultures we had were epileptic, like this one, and I assume they had different activity patterns than non-epileptic ones). This spectrum was calculated with a sliding window fft of 150sec.

## Preliminary Human Studies

## Power spectra

- 0.5 Hz

- 0.5 Hz

**Eyes closed**

**Eyes open**

- Phase v=0.12Hz

- Closed

- Open

## Phase v=0.12Hz

- Closed

- Open

## Magnitude v=0.12Hz

- Closed

- Open

## Hemodynamics

- Neuronal Currents

- -quick overview
- -linearity (steady state)
- -linearity (dynamic)
- -baseline signal
- -latency
- -width

- -model
- -approaches
*current phantom*
*cell cultures*
*human studies*
- -why there is hope

## J.P. Wikswo Jr et al.  J Clin Neuronphy 8(2): 170-188, 1991

**J.P. Wikswo Jr et al.*****  J Clin Neuronphy *****8(2): 170-188, 1991**

## The post synaptic potential lasts for 10ms or more, allowing integration of individual fields to create

- Schematic representation of (a) a postsynaptic potential and (b) an action potential as a function of time.

- MEG detectable > 100 fT field on surface of skull**  **

## Technology

**Interpretation**

**Methodology**

**Applications**

## Methodology

**Interpretation**

**Applications**

**Technology**

**Physicists**

**Statisticians**

**Mathematicians**

**Physiologists**

**Neuroscientists**

**Clinicians**

**Engineers**

## Methodology

- 02

- 01

- 00

- 99

- 98

- 97

- 96

- 95

- 94

- 93

- 92

- 91

- 90

- 89

- 88

- 82

**Methodology**

- Hemoglobin

- Blood T2

- IVIM

- Baseline Volume

**Interpretation**

**Applications**

- Volume-V1

- BOLD

- Correlation Analysis

- Linear Regression

- Event-related

- BOLD -V1, M1, A1

- TE dep

- Veins

- IV vs EV

- BOLD models

- ASL

- Deconvolution

- Phase Mapping

- V1, V2..mapping

- Language

- Memory

- Presurgical

- Attention

- PSF of BOLD

- Pre-undershoot

- Ocular Dominance

- Mental Chronometry

- Electrophys. correlation

- 1.5T,3T, 4T

- 7T

- SE vs. GE

- Performance prediction

- Emotion

- Real time fMRI

- Balloon Model

- Post-undershoot

- Inflow

- PET correlation

- CO2 effect

-  CO2 Calibration

- Drug effects

- Optical Im. Correlation

- Imagery

- Clinical Populations

- Plasticity

- Complex motor

- Motor learning

- Venography

- Face recognition

- Children

- Simultaneous ASL and BOLD

- Surface Mapping

- Linearity

- Mg+

- Dynamic IV volume

- Bo dep.

- Diff. tensor

- Volume - Stroke

- Z-shim

- Free-behavior Designs

- Extended Stim.

- Local Human Head Gradient Coils

- NIRS Correlation

- SENSE

- Baseline Susceptibility

- Metab. Correlation

- Fluctuations

- Priming/Learning

- Resolution Dep.

- Tumor vasc.

**Technology**

- EPI on Clin. Syst.

- EPI

- Quant. ASL

- Multi-shot fMRI

- Parametric Design

- Current Imaging?

- Multi-Modal Mapping

- Nav. pulses

- Motion Correction

- MRI

- Spiral EPI

- ASL vs. BOLD

- >8 channels

- Multi-variate Mapping

- ICA

- Fuzzy Clustering

- Mixed ER and Blocked

- Linearity mapping

## FIM Unit & FMRI Core Facility 	

**Peter Bandettini**
**Staff Scientists:**
**Sean Marrett**
**Jerzy Bodurka**
**Frank Ye**
**Wen-Ming Luh**
**Computer Specialist:**
**Adam Thomas**
**Post Docs:**
**Rasmus Birn**
**Hauke Heekeren**
**David Knight**
**Patrick Bellgowan**
**Ziad Saad**

**FIM Unit & FMRI Core Facility **

**Graduate Student:**
**Natalia Petridou**
**Post-Back. IRTA Students:**
**Elisa Kapler**
**August Tuan**
**Dan Kelley**
**Visiting Fellows:**
**Sergio Casciaro**
**Marta Maieron**
**Guosheng Ding**
**Clinical Fellow:**
**James Patterson**
**Psychologist:**
**Julie Frost**

**Summer Students:**
**Hannah Chang**
**Courtney Kemps**
**Douglass Ruff**
**Carla Wettig**
**Kang-Xing Jin**** **
**Program Assistant:**
**Kay Kuhns**
**Scanning Technologists:**
**Karen Bove-Bettis**
**Paula Rowser**