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Question 1

what is medical imaging (3)

Answer 1

• Branch of medicine
• concerned with the development/use of imaging devices and techniques to obtain internal anatomic images
• provide biochemical and physiological analysis of tissues and organs.

Question 2

uses of medical imaging in healthcare (5)

Answer 2

• Assist diagnosis/ treatment of different medical conditions
• Body does not have to be opened up surgically to look at internal structures of body
• used by surgeons as an aid in surgical procedures
• preventative care (Mammography for breast cancer)
• study neurology and human behaviours (Brain imaging for effects of Alzheimer’s disease)

Question 3

modalities of medical imaging (5)

Answer 3

• radiography (xray)
• CT scan
• ultrasound
• MRI
• PET scan

Question 4

what is radiography

Answer 4

• Form of electromagnetic radiation of higher frequency than visible light

o stream of mass-less photons,
o each traveling in a wave-like
pattern at the speed of light.

Question 5

how do the following items show up in xrays
Calcium in bones
Soft tissue
Full of air

Answer 5

Calcium in bones (dense) ➔ absorbs more, so it shows up white in x-rays

Soft tissue ➔ absorbs fewer rays;

Full of air (eg lungs) ➔ absorbs no rays- appears black

Question 6

steps to radiography (5)

Answer 6

1. Increased filament voltage = large increase in tube current
2. Heated filament (cathode) emits electrons
3. Electrons travel to anode, hits metal target (tungsten) & produces X-rays (radiation)
4. X-ray produced directed towards the patient during medical scan
5. X-ray not absorbed by body transferred to xray plate

Question 7

dangers of radiation (3)

Answer 7

• Damages the cell to some extent (mutation / death to cells)
• damage depends on quality & quantity of exposure
• harmful effects of x-rays are cumulative.

With each dose, cell damage increases. the cumulative effect decreases over a period of time if patient has not had further exposure

Question 8

how to protect yourself from radiation (3)

Answer 8

distance, shield, time

Question 9

what is CT (computed tomography) (3)

Answer 9

• Medical imaging technique generates cross sectional images in the axial planes
• CT image is a display of the anatomy of a thin slices of a body
• Developed from multiple X-ray absorption measurements made around the body’s periphery

Question 10

uses of CT (4)

Answer 10

• muscle and bone disorders (tumors and fractures)
• diseases (cancer, heart disease)
• tumors, infections, or blood clots
• internal injuries