lec 2- radiation safety

Question 1

name 5 types of cells in the body that are sensitive to radiation

Answer 1

Embryonic cells
Lymphocytes (WBC)
Erythrocytes (RBC)
Sperm
Epithelial cells 
Endothelial cells 
Connective tissue cells
Bone cells 
Nerve cells 
Brain cells 
Muscle cells

Question 2

name 5 body parts that are sensitive to radiation

Answer 2

Ovaries/Foetus/Female reproductive 
Marrow/Thymus/Spleen/Lymph nodes 
Marrow/blood 
Male reproductive 
Skin/Throat/intestines/organs
Blood vessels/Lymph vessels/heart 
Tendons/Ligaments 
Bones
Nerve system 
Brain 
Muscle

Question 3

list 4 forms of radiation protection

Answer 3

• Thyroid collar
• Lead apron
• Eye protection glasses
• Leg guards

Question 4

where is the ‘safest’ place to stand when there is radiation?

Answer 4

90 degrees to the patient

Question 5

where does the main scatter radiation come from?

Answer 5

primary beam
back scatter (30% strength of primary beam)

Question 6

what are the functions of cones in theatre?

Answer 6

• Improves image quality
• Reduces exposure to the patient if the cones are on the X-ray tube
• Reduces scatter radiation if cones are on the II

Question 7

what are 3 effects of contrast?

Answer 7

higher attenuation
increases contrast on the image
increases radiation to the surrounding tissues
risk/reward (need a good reason to use it)
possible allergic reaction
complications can occur
radiology departments have protocols for when to use contrast and when not to

Question 8

what are 5 things to be aware of when using radiation

Answer 8

• Protection devices/clothing available (lead/mobile barriers)
• Principles of safety: Distance/time/exposure level
• Direction of scatter radiation
• Personnel entering the room
• Regions of staff body areas in most danger
• Position of the X-ray equipment to minimise doses (I.I. or image receptor)
• Filters to reduce dose
• Exposure parameters to reduce dose
• Use of soft and hard cones
• Protection of nearby patients: even in the rooms next door

Question 9

in relation to the x-ray radiation spectrum, what affect does mAs, kV and filtration have on it

Answer 9

mAs: increases/decrease the spectral curve
kV: changes the shape of the spectral curve
filtration: hardens the x-ray beam

Question 10

how is ALARA applied?

Answer 10

increase kV
decrease mAs
use a filter
This decreases soft x-rays and surface dose, increases hard x-rays, decreases scatter and internal dose

Question 11

what are 4 general principles when in theatre

Answer 11

• I.I close to the patient: without touching sterile drapes
• Backscatter matters: wear lead protection in areas of back scatter
• Cones reduce the width of the primary beam
• Be aware of the different scatter patterns for each machine in use
• Have available proper lead protection clothing during the procedure
• Protect all staff and patients within the are the procedure is being done
• Distance matters