Medical Imaging - The body

Question 1

Ultrasound

Answer 1

No radiation
Real-time imaging
Cost effective
Versatile

Question 2

X-rays

Answer 2

• Based on DENSITY differences because x-rays are attenuated as they pass through tissues

Question 3

Characteristic radiation

Answer 3

Emitted when an electron knocks out an
inner-shell electron, and another electron fills the vacancy.

Most radiolucent (barium/iodine used to show)
1) air/lung
2) fat
3) soft tissue
4) bone
Most radiopaque

Question 4

Bremsstrahlung radiation

Answer 4

Produced when high-speed electrons are
decelerated upon interacting with the target material.

Question 5

X-ray rule of thumb

Answer 5

AP (most common)
-1 meter from patient
- back to detector

PA
- clearer lung images as close to chest

Left lateral
- left side contact with cassete

Question 6

Contrast Radiography

Answer 6

Contrast agents on structures that dont absorb x-rays
- blood vessels usually iodine

e.g barium enema + gas

Question 7

Subtraction Angiography

Answer 7

Subtracting overlapping bone structures

Take post contrast - pre contrast = just the contrast no bone
- vascular abnormalities
- high-contast blood vessels no need for invasive surgical exploration

Question 8

CT Computed tomography

Answer 8

• Multiple x-rays in the axial plane(3d)
• higher radiation
• higher resolution & detects abnormalities in X-rays
• no film / ct scanner / xray tube
• anterior part (top)
  viewed from below

Question 9

MRI Magnetic resonance imagine