Brain Scans

Question 1

What are the types of Brain Scans?

Answer 1

• Computed Axial Tomography (CAT)
• Magnetic Resonance Imaging (MRI)
• Positron Emission Tomography (PET)

Question 2

What is a Computed Axial Tomography (CAT) Scan?

Answer 2

• Series of x-rays that combine to form a 2D/3D picture
• Dye is injected into patient as a contrast material
• Patient placed in cylindrical CAT scan machine

Question 3

What are the Strengths of CAT Scans?

Answer 3

• Useful for revealing abnormal structures in brain such as tumors/structural damage
• Quality of image is higher than a traditional X-Ray

Question 4

What are the Weaknesses of CAT Scans?

Answer 4

• Requires more radiation than traditional X-Rays - more exposure to radiation
• Pregnant women are unable to be scanned in this way

Question 5

What are Magnetic Resonance Imaging (MRI) Scans?

Answer 5

• Involves use of magnetic field that cause atoms of brain to change their alignment when magnet is turned off
• A detector reads signals and uses them to map out the structure

Question 6

What are the Strengths of MRI Scans?

Answer 6

• Give a more detailed image of soft tissue in brain that CAT scans
• Best suited for cases when patient is to undergo examination several times successively in a short period of time - not exposing patient to radiation

Question 7

What are the Weaknesses of MRI Scans?

Answer 7

• Takes a long time

- Uncomfortable for patients

Question 8

What is a Functional MRI (FMRI)?

Answer 8

• Provides both anatomic + functional information by taking repeated images of the brain in action

Question 9

What are Positron Emission Tomography (PET) Scans?

Answer 9

• Involves administrating slightly radioactive glucose to patients
• Most active areas of brain use glucose + radiation detectors can see the radioactive areas - building up a picture of activity in brain
• Scans take 10-40 minutes to complete + are painless

Question 10

What are the Strengths of PET Scans?

Answer 10

• Reveal chemical information that is not available with other imaging - can distinguish between benign (not harmful) and malignant (harmful) tumors
• Can show brain in action

Question 11

What are the Weaknesses of PET Scans?

Answer 11

• Extremely costly - therefore not easily available for research
• Patient has to be injected with a radioactive substance
• only be used a few times
• Less precise than MRI scans