P5.2.3

Question 1

How are infrared waves used in medical imaging?

Answer 1

Thermal imaging camera produces a thermogram to show different temperatures. They show blood flow issues in vessels

Pixels inside a CCD (e.g. phone camera), absorb infrared and produce an image with colour

Your skin emits more IR, due to hotness from injury or friction

Question 2

How can x-rays show broken bones?

Answer 2

Bones absorb x rays, soft tissue (muscles and skin) don’t.
Photographic film darkens when x-rays are absorbed and show the detailed internal structure of a person.

Photographic film is placed behind a person, the x rays are fired at the person and the bones absorb it, leaving that section white on the film

Question 3

What is a CCD?

Answer 3

Charged coupled device - made of pixels and detects EM radiation.

Question 4

What happens when a CCD detects x-rays?

Answer 4

Colours show different intensities of x rays that have travelled through
Higher density - more x rays absorbed

Dentists use x rays to diagnose teeth issues

Question 5

What is computerised tomography?

Answer 5

CT scan, uses x rays to make an image of a cross section of your body in 3D showing organs.

Question 6

How are gamma rays used in medical imaging?

Answer 6

Used as tracers to treat organ issues

Doctor injects patient with radioactive substance, the kidney then absorbs the tracer and produces a CCD image

Or in a thyroid gland, depending on how much absorption there is, it shows the issue