Studying the Brain/Scans

Question 1

How does the EEG work?

Answer 1

It measures the overall electrical activity of the brain using electrodes on the scalp. (Lydia)

Question 2

What kind of picture does an EEG make?

Answer 2

Wavelike patterns on paper (Lydia).

Question 3

What is an EEG used for?

Answer 3

Diagnosing epilepsy, sleep disorders, strokes, brain tumours, brain infections, CNS disorders.

Question 4

Advantages of EEG

Answer 4

Non-invasive, painless, inexpensive, safe, provides a general measure of brain activity and has high temporal resolution.

Question 4

Disadvantages of EEG

Answer 4

Time-consuming, can’t establish precise activity in a particular localised region, only maps the surface of the cerebral cortex, not an imaging technique.

Question 5

How does a CT or CAT work?

Answer 5

X-ray that makes low resolution images which are computer produced.

Question 6

What kind of picture does the CAT make?

Answer 6

Tomographic images which are virtual ‘slices’ of specific areas of a scanned object. It is a still-image.

Question 7

What is the CAT used for?

Answer 7

Diagnosing tumours, blood clots, degenerative diseases (Parkinsons and dementia)

Question 8

Advantages of using the CAT

Answer 8

Used to determine whether surgery is necessary without needing exploratory surgery, very detailed structural imaging, abnormal neuroanatomy can be detected (tumours), adjacent slices can be combined to create a 3D representation.

Question 9

Disadvantages of using the CAT

Answer 9

No information regarding brain function, poor localisation, expensive, involves radiation (1 scan = 12 months of exposure to radiation), can’t be used on pregnant women.

Question 10

What does MRI stand for?

Answer 10

Magnetic Resonance Imaging

Question 11

What does CAT stand for?

Answer 11

Computed Axial Tomography

Question 12

How does an MRI work?

Answer 12

Uses strong magnetic fields, radio frequency pulses and computers to produce 3D images from which 2D slices can be displayed.

Question 13

What is an MRI like for a patient?

Answer 13

The patient is surrounded by a large electromagnet and is exposed to short powerful blasts of strong magnetic fields.

Question 14

What kind of picture does an MRI make?

Answer 14

3D images from which 2D ‘slice’ can be displayed.

Question 15

What does an MRI do?

Answer 15

Diagnoses tumours and neurological abnormalities as well as studies the spinal cord.

Question 16

Advantages of an MRI

Answer 16

Very detailed knowledge regarding structures, 3D imagery, safe, painless, non-invasive, no x-rays or radioactive material, no special preparations required.

Question 17

Disadvantages of an MRI

Answer 17

Can’t be used with claustrophobic or uncooperative patients. No ferromagnetic materials allowed (Metallic devices like pacemakers or metal in body, jewellery), very expensive.

Question 18

What does fMRI stand for?

Answer 18

Functional Magnetic Resonance Imaging

Question 19

How does an fMRI work?

Answer 19

Uses MRI technology to measure brain activity by detecting changes in blood flow.
Relies on cerebral blood flow and neuronal activation being coupled.
STILES

Question 20

What kind of picture does an fMRI make?

Answer 20

A clear image with the blood flow lit up.
- When an area of the brain is used, blood flow in that area should increase.
STILES

Question 21

What is an fMRI used for?

Answer 21

Examining brain anatomy.
Observing which part of the brain is handling critical functions.
Monitors growth and function of brain tumours.
Guides the planning of surgery or radiotherapy.
Assesses effects of strokes.

Question 22

Advantages of fMRI

Answer 22

Dynamic images, doesn’t use radiation, you can see the brain functions safely, non-invasive, high spatial resolution of neural activity, can detect abnormalities that might be obscured by bone tissue.

Question 23

Disadvantages of fMRI

Answer 23

Time delay (5-8 seconds behind real-time changes), claustrophobic, loud, ferromagnetic material is prohibited and it’s very expensive.