Imaging/Scans

Question 1

X-ray imaging

Answer 1

• dense structures appear as light areas
• cons = radiation exposure; 2D images

Question 2

CT scans

Answer 2

• detailed cross-sectional pictures of scanned body regions
• used for: images of bone, soft tissue, blood vessels
• cons: more radiation exposure than X-rays (may be of concern if used repeatedly)

Question 3

Digital Subtraction Angiography

Answer 3

• visualising blood vessels by X-ray or CT scan
• inject X-ray absorbing contrast agent, so imaged before and after can be compared
• cons: time-consuming, expensive, can have adverse reaction to contrast medium

Question 4

PET scans

Answer 4

• gamma rays emitted by radioactively tagged tracer molecule that’s been injected into the body
• can be used to detect cancer spread/ monitor response to cancer treatment; diagnose Alzheimer’s; explore brain for research
• cons: radiation exposure, poor image resolution

Question 5

MRI

Answer 5

• powerful magnets and radio waves used to image the location of hydrogen atoms in the body (doesn’t show bones)
• cons: more expensive, slower than CT scans, can’t be used with patients who have a metal implant

Question 6

fMRI

Answer 6

• tracks blood flow into various parts of the brain

Question 7

Ultrasound imaging

Answer 7

• pulses of sound waves produce ‘echoes’ when reflected by body tissues and analysed by a computer into body organs outlines
• cons: lower resolution (but sharpness is being improved)