Exam, neuroimaging 1

Question 1

when is x-ray imaging used?

Answer 1

• x-ray imaging is commonly used today to perform angiography, particularly in interventional radiology
• non-invasive

Question 2

name some facts about fMRI!

Answer 2

1. can be used to obtain a multitude of different tissue contrasts
2. involves risk?

Question 3

what is neurovuscular coupling?

Answer 3

neurovascular coupling describes the increase in local cerebral blood flow in response to increased neuronal activity

Question 4

What is PET short for?

Answer 4

Positron emission tomograohy

Question 5

How can PET imaging be used?

Answer 5

PET can be used to perform molecular imaging targeting different different neuroreceptor/neurotransmittrer systems

Question 6

what is neurovuscular coupling?

Answer 6

• Neurovascular coupling describes the increase in local cerebral blood flow in response to increased neuronal activity
• leads to an increase in cerebral blood flow peaking at approximately 5 s following the onset of neuronal activity

Question 7

What is PET short for?

Answer 7

Positron emission tomograohy
—> is a nuclear medicine functional imaging technique that is used to observe metabolic processes in the brain

—> non-invasive
—> CONS: involve exposure to ionizing radiation
—> expensive operating cost
—> areas with high radioactivity is associated with brain activity

Question 8

in which imaging method are the ultra sensitive sensors SQUID used?

Answer 8

?

Question 9

what is EEG short for?

Answer 9

Electroencephalogram

—> Electrophysiological method to record electrical activity of the brain
—> Electrodes plaid along the scalp
—> Typically Non-invasive (there is invasive electrodes as well)
—> exhibits brain rythms at specific frequency bands, which are associated with different cognitive states

Question 10

in which imaging method are the ultra sensitive sensors SQUID used?

Answer 10

MEG

—> SQUID is a very sensitive magnetometer

Question 11

what is BOLD short for?

Answer 11

Blood Oxygen Level Dependent contrast

Question 12

what is BOLD?

Answer 12

1. BOLD is commonly used in functional MRI

2. BOLD is based on the magnetic susceptibility difference between oxygenated and deoxygenated hemoglobin

Question 13

what is BOLD?

Answer 13

1. BOLD is commonly used in fMRI
2. BOLD is based on the magnetic susceptibility difference between oxygenated and deoxygenated hemoglobin
3. The BOLD contrast is based on changes in the T2 or T2* relaxation constants of the MR signal
4. BOLD-fMRI studies of task-based brain activation are usually performed at high field strengths, mainly 3 Tesla but also 7 Tesla
5. BOLD-fMRI studies of task-based brain activation usually employ general linear modeling approach, whereby the task time course is fit to the data time course in each voxel
6. BOLD-fMRI studies of task-based brain activation identify cluster of voxels exhibiting BOLD signal changes significantly associated with the task

Question 14

Who invented BOLD?

Answer 14

Seiji Ogawa, 1990

Question 15

WHO invented MRI?

Answer 15

MRI
—> Dr.Bennett and Dr. Weisman
—>1971.

Question 16

Who invented EEG?

Answer 16

Hans Berger, 1924

Question 17

who invented x-ray imaging for the brain?

Answer 17

Walter Dandy, 1918

Question 18

what is the typical spatial and temporal resolution of whole brain BOLD-fMRI studies at 3 Tesla?

Answer 18

4mm^3 and 1-3 seconds

Question 19

what is fMRI short for?

Answer 19

functional magnetic resonance imaging

Question 20

what is fMRI short for?

Answer 20

functional magnetic resonance imaging

Question 21

Name the different euro imaging methods in chronological order!

Answer 21

1. x-ray imaging,
   —>Walter Dandy
   —> 1918
2. EEG
   —> Hans Berger
   —> 1924
3. PET
   —> Kuhl, Chapman, Edwards
   —> 1950s
4. MEG
   —> David Cohen
   —> 1968
5. MRI
   —> Dr.Bennett and Dr. Weisman
   —>1971.
6. BOLD (fMRI)
   —> Seiji Ogawa
   —>1990

Question 22

What is resting-state fMRI studies?

Answer 22

• Resting-state fMRI studies have shown networks of brain regions with coherent BOLD signal fluctuation
• can be used to evaluate regional interactions that occur when a subject is not performing an explicit task (resting brain)
• changes observed through changes in blood flow creating a BOLD signal that can be measured in fMRI

Question 23

what is the difference between structural images and functional images?

Answer 23

• Structural images reflect brain morphology (structure)

- Functional images reflect some aspect of brain function

Question 24

what is CT scan?

Answer 24

• Computional tomography

- several x-ray in different angles (integrated some way)

Question 25

Name some functional neuroimaging techniques that can be used in awake humans!

Answer 25

EEG and MEG are the ones that most directly measure neuronal activity

Question 26

what is NIRS?

Answer 26

near infrared spectroscopy
—> non-invasive optical imaging technique
—> using low level of light to measure blood flow changes in the brain associated with brain activity

Question 27

What is MEG short for?

Answer 27

Magnetoencephalography
—> a functional neuroimaging technique for mapping brain activity by recording magnetic fields produced by electrical currents occurring naturally in the brain, using very sensitive magnetometers.
—> non-invasive
—> no ionizing radiation (vs PET)
—> high temporal resolution (vs fMRI)
—> originates from same neurophysiological process as EEG

Question 28

Who invented MEG?

Answer 28

David Cohen in 1968

Question 29

Who invented NIRS?

Answer 29

William Herschel
—> 19th century
—> industrial application 1950

Question 30

Why is it desirable to use EEG and fMRI simultaneously?

Answer 30

due to the high complementary spatiotemporal properties of the two types of signal

Question 31

What is a voxel?

Answer 31

“Voxel” is a term of art used in MRI scanning to describe a 3-dimensional extension of a pixel