# Presentation: 707787

## NEUROIMAGING(...at the NIH)

- Peter A. Bandettini, Ph.D.
- bandettini@nih.gov
- Functional MRI Facility
- Unit on Functional Imaging Methods
- Laboratory of Brain and Cognition

## Two Types of Neuroimaging

- Structural/Anatomical Imaging
- Functional Imaging

**Notes:**
There are two broad categories of medical brain imaging: Structural and Functional. Structural imaging reveals anatomy and is the most common form of brain imaging found in the clinic today. Functional imaging is an emerging field that is still rapidly developing. Clinical uses for functional imaging are still being tested, though it has already contributed significantly to basic neuroscience research.

## Structural Brain Imaging

- Reveals the anatomy of the brain and the physical structure of brain pathology.

- Primarily associated with Computerized Axial Tomography (CAT or CT) and Magnetic Resonance Imaging (MRI).

## Structural/Anatomical Imaging

- X-ray
- Computerized Tomography (CT)
- Magnetic Resonance Imaging (MRI)
- Angiography
- Venography
- Perfusion
- Diffusion Tensor Imaging

## Computerized Tomography (CT) 

- Source

- Detector

- X-ray Dense Tumor

## CT Images

## Magnetic Resonance Imaging

- Magnetic Resonance Imaging

## Magnetic Resonance Imaging

**N**

**S**

**Magnet**

## Magnetic Resonance Imaging

**N**

**S**

**Magnet**

## Magnetic Resonance Imaging

**N**

**S**

**Magnet**

## MRI Images with Different Contrast Weighting

- T1 Weighted

- T2 Weighted

## 3D Rendering

## Venograms (3T)

**Venograms (3T)**

## Perfusion Imaging with MRI

## Diffusion Tensor Imaging

- S. Mori - JHU

## Diffusion Tensor Imaging

**corpus callosum**

**corticospinal tract**

**optic radiation**

**anterior **
**thalamic radiation**

**cingulum**

**inferior occipitofrontal**
**fasculus**

**uncinate fasculus**

**inferior **
**longtudinal**
**fasculus**

**superior **
**longitudinal**
**fasculus**

- S. Mori - JHU

## Anatomical guidance with DTI:

- Example: Anatomical deformation due to tumor growth

- S. Mori - JHU

## Functional Imaging

- Unlike structural imaging, functional imaging provides pictures of brain physiology or chemistry.
- By targeting factors that are related to brain activity (eg. blood flow and oxygenation), images of brain activation can be obtained.
- Functional imaging has been used for pre-surgical mapping of function and, eventually, may replace or augment more traditional tests.
- Functional imaging is now a major new research paradigm in neuroscience.

**Notes:**
Characteristics of functional imaging:
Unlike structural imaging, functional imaging provides pictures of brain physiology or chemistry.
By targeting factors that are related to brain activity (eg. blood flow and oxygenation), images of brain activation can be obtained.
Functional imaging has been used for pre-surgical mapping of function and, eventually, may replace or augment more traditional tests.
Functional imaging is now a major new research paradigm in neuroscience.

## Functional Imaging

- Xenon Computerized Tomography (Xe CT)
- Positron Emission Tomography (PET)
- Single Photon Computed Tomography (SPECT)
- Functional MRI (fMRI)
- Electroencephalography (EEG)
- Magnetoencphalography (MEG)
- Transcranial Magnetic Stimulation (TMS)

## Functional Neuroimaging Techniques

- Log Time (sec)

- Log Size (mm)

- Non-invasive

- Invasive

## Positron Emission Tomography (PET)

- Positron emission tomography (PET) is a technique for studying functional processes  *in vivo* by measuring the concentrations of positron-emitting radioisotopes within the subject.
- PET is primarily used to study _biochemical and physiological processes_ within living organs with 3-dimensional spatial resolution.

## PET mechanism

- B

- Coincidence
- Detector

- Coincidence of
- A&B Detection

- Detectors

- Detectors

## Positron Emission Tomography

## Slide 24

## Blood Volume
Blood Oxyenation
Perfusion
Metabolism

**Blood Volume**
**Blood Oxyenation**
**Perfusion**
**Metabolism**

**Contrast in Functional MRI**

## Anatomic

- time

- _Anatomic_

- _Functional_

## Slide 27

## Local gradients solved the problem

**August, 1991**

## 1991-1992

**1991-1992**

**1992-1999**

## General Electric 3 Tesla Scanner

**General Electric 3 Tesla Scanner**

## fMRI instrumentation

## Slide 32

## Resting		   Active

**Resting****	****	****   ****Active**

- Blood Volume Changes with Brain Activation

## Slide 34

## BOLD Contrast in the Detection of Neuronal Activity

**BOLD Contrast in the Detection of Neuronal Activity**

**Cerebral Tissue Activation**

**Local Vasodilation**

**Increase in Cerebral Blood**
**Flow and Volume**

**Oxygen Delivery Exceeds**
**Metabolic Need**

**Increase in Capillary and Venous Blood Oxygenation**

**Decrease in Deoxy-hemoglobin**

***Deoxy-hemoglobin: paramagnetic***
***Oxy-hemoglobin: ******	******diamagnetic***

**Decrease in susceptibility-related**
**intravoxel dephasing**

**Increase in T2 and T2***

**Local Signal Increase in T2 and T2* - weighted sequences**

## Slide 36

## BOLD  

- (_b_lood _o_xygenation _l_evel _d_ependence)

## BOLD:  Motor Cortex Activation

**BOLD:  **_**Motor Cortex Activation**_

## Cross Correlation Image

- _Cross Correlation Image_
- Anatomical Image

## Slide 40

## The BOLD Signal

- _B_lood _O_xygenation _L_evel _D_ependent (BOLD)  signal changes

*task*

*task*

## Alternating Left and Right Finger Tapping 

**Alternating Left and Right Finger Tapping **

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

## Slide 43

**Finger Movement**

**Left**

**Right**

**Toe Movement**

**Left**

**Right**

**Wrist**

**Fingers**

## Tactile Stimulation

**Tactile Stimulation**

**Finger Movement**

**1**

**2**

**3**

**4**

**5**

**6**

**7**

**8**

**9**

**10**

***Left***

***Right***

**Simple Finger Movement on the Left Hand**

**1**

**2**

**3**

**4**

**5**

**6**

**7**

**8**

**9**

**10**

***Left***

***Right***

**Simple Finger Movement on the RIght Hand**

**Complex Finger Movement on the Right Hand**

**1**

**2**

**3**

**4**

**5**

**6**

**7**

**8**

**9**

**10**

***Left***

***Right***

**1**

**3**

**2**

**4**

**5**

**6**

**7**

**8**

**9**

**10**

***Left***

***Right***

**Complex Finger Movement on the Left Hand**

**1**

**1**

**3**

**2**

**4**

**5**

**6**

**7**

**8**

**9**

**10**

***Left***

***Right***

**Imagined Complex Finger Movement on the Left Hand**

**1**

**1**

**3**

**2**

**4**

**5**

**6**

**7**

**8**

**9**

**10**

***Left***

***Right***

**Imagined Complex Finger Movement on the Right Hand**

**1**

## Word stem completion

## Slide 56

## FMRI of Leg Motor Topography - Medial Wall

*Macaque*

*Human*

**FMRI of Leg Motor Topography - Medial Wall**

- Thanks to S. Rao

## Reading

**Reading**

## Listening to Spoken Words

**Listening to Spoken Words**

## Slide 60

## ODC Maps using fMRI

**calcarine**

**1 cm**

- 1Malonek D, Grinvald A. *Science* 272, 551-4 (1996).
- 3Horton JC, Hocking DR. *J Neurosci* 16, 7228-39 (1996).
- 4Horton JC, et al. *Arch Ophthalmol* 108, 1025-31 (1990).

-  Identical in size, orientation, and appearance to those obtained by optical imaging1 and histology3,4.

- Menon et al.

## Slide 62

## Regions of Interest Used for Hemi-Field Experiment

- <date/time>

- Regions of Interest Used for Hemi-Field Experiment

**Right Hemisphere**

**Left Hemisphere**

## Slide 64

## Hemi-field with 500 msec asynchrony

- <date/time>

**Percent**

**MR**

**Signal**

**Strength**

**Time (seconds)**

**Average of 6 runs     Standard Deviations Shown**

## =

**+ 2.5 s**

**- 2.5 s**

**0 s**

**500 ms**

**500 ms**

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

**Left Hemifield**

**-**

## Word stem completion

## Presurgical Mapping

- O-15 PET

- Right Hand

- Right Foot

- Tumor

- Left Foot

- fMRI

## The

**The**
**End**

**< 1 s to render**

**Blocked trials:**
**  ****20 s on/20 s off**
**  ****8 blocks**

**Color shows**
**  ****through brain**

**Correlation > 0.45**

**Blocks**: _1_

- _2_

- _3_

- _4_

- _5_

- _6_

- _7_

- _8_

## Activation in the brain correlated with skin conductance changes

## Slide 71

## Slide 72

## Slide 73

## Slide 74

## Slide 75

## Magnetoencephalography (MEG)

- Figure 9-1, 9-2, 9-3
- pp 370, Orrison

- SQUID:
- _S_uperconducting _Q_uantum
- _I_nterference _D_evice

## Combined MEG and EEG

## MEG Mapping

## Alpha Wave Activity Mapped with MEG

## Transcranial Magnetic Stimulation

## Transcranial Magnetic Stimulation (TMS)

## Acknowledgements

- Ted Deyoe, Medical College of Wisconsin
- Kathleen Schmainda, Medical College of Wisconsin
- Steven Rao, Medical College of Wisconsin
- Robert Savoy, Massachusetts General Hospital
- Roger Tootell, Massachusetts General Hospital
- Bradley Bookbinder, Massachusetts General Hospital
- Randy Buckner, Washington University, St. Louis
- Robert Innis, National Institute of Mental Health
- Richard Coppola, National Institute of Mental Health
- Sosumu Mori, Johns Hopkins University
- Robert Cox, National Institute of Mental Health
- Ziad Saad, National Institute of Mental Health
- Eric Wong, University of California, San Diego
- Ravi Menon, University of Western Ontario
- Nikos Logothedis, Max Plank Institute, Germany

## 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**