brain scanning techniques

Question 1

what will the patient experience in a CAT scan

Answer 1

lies still on a moving platform
scanner passes around them
lasts from a few minutes to 30 minutes

Question 2

is CAT scans structure or activity based

Answer 2

structure

Question 3

give 3 strengths of CAT scans

Answer 3

detailed image of the structure of the brains for detecting brain damage from accidents

less risky than exploratory surgery

used to plan surgeries as it is quicker and more efficient

Question 4

give 3 weaknesses of CAT scans

Answer 4

uses radiation (1-3 years worth)

doesn’t look at activity

pregnant women or newborn babies can’t use it

Question 5

what will patients experience in PET scan

Answer 5

restrictions on diet before scans
injected with a FDG tracer
given a task to stimulate brain (CPT)

Question 6

in PET scans what is the colour of high activity

Answer 6

red

Question 7

in PET scans what is the colour of low activity

Answer 7

blue

Question 8

give 3 strengths of PET scans

Answer 8

indicating tumours from areas not functioning properly

low levels of substance used, so low risk

look at illnesses such as schizophrenia and depression

Question 9

give 3 weaknesses of PET scans

Answer 9

tracer injected- invasive

no long term effects researched yet

no pregnant women and children

Question 10

what is the validity of CAT scans (high and low)

Answer 10

accurately detect abnormalities
there may be a misdiagnosis due to quality of the scan

Question 11

what is the validity of PET scans (high and low)

Answer 11

74%-85% accurate

may be objective when analysing brains scans of tracer

Question 12

what is the validity of fMRI scans

Answer 12

most modern= most accurate (1990)

Question 13

how is the reliability of CAT scans high

Answer 13

shows slices of the brain/imaging in sections

Question 14

how is the reliability of PET scans high

Answer 14

shows brain activity (e.g. red is high and blue is low) producing the same comparable images

Question 15

how is the reliability of fMRI scans high

Answer 15

map of neutral activity shown in different brain areas

Question 16

what happens in PET scans (biologically)

Answer 16

glucose is used up
radioactive atoms break down positrons
gamma rays are produced
scanner picks up gamma rays and shows the activity

Question 17

what happens in fMRI scans (biologically)

Answer 17

the nuclei within water molecules align themselves with the direction of the magnetic field, as neutral activity occurs in the brain, blood flow increases in the active areas to keep up with the demand for oxygen

haemoglobin repels a magnetic field but once it becomes de-oxygenated it will follow the direction of the magnetic field, these changes are detected by the scanner and will create an image

Question 18

what will a patient experience in a fMRI scan

Answer 18

involves having your head placed in a very large, very powerful electromagnet
noisy process

Question 19

give 3 strengths of an fMRI scan

Answer 19

no radiation needed

non-invasive

structure and activity

Question 20

give 3 disadvantages of an fMRI scan

Answer 20

scan can be altered by movement

claustrophobic

people with metal implants cannot have it