Radiation in treatment and medicine

Question 1

what does radiation do

Answer 1

radiation transfers energy from place to place

Question 2

what does radiation include

Answer 2

all em waves, sound waves, and energy transferred by particles

Question 3

how do CAT scans work

Answer 3

use X-rays to scan body

Question 4

give advantages and disadvantages of CAT scans

Answer 4

A:
> detailed images
> 3D images can be built up on a computer from sectional scans
D:
> expensive equipment
> relatively high radiation dose

Question 5

how do ultrasound scans work

Answer 5

high frequency sound waves are reflected by features inside a patients body

Question 6

give advantages and disadvantages of ultrasound scans

Answer 6

A:
> very low risk - allows a real-time image to be viewed
D:
> none - widely used in prenatal monitoring

Question 7

how do endocopes work

Answer 7

uses fibre optics to provide live view of the internal structures in a patient

Question 8

give advantages and disadvantages of using endoscopes

Answer 8

A:
> provided direct, real-time view of internal body tissue
> allows keyhole surgery, without the need for major surgery
D:
> cannot see through tissues

Question 9

what is the intensity of radiation

Answer 9

it is the amount of energy arriving per second over an area of 1m^2. energy spreads out from a source in all directions.

Question 10

explain the link between intensity and distance

Answer 10

the intensity decreases with distance because the radiation is spread over an increasing area

Question 11

Use the equation:

intensity = power of incident radiation / area

Answer 11

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