How Safe is that Imaging Test

Question 1

what is a sievert? SV unit?

Answer 1

Equivalent dose of radiation = absorbed + intensity

Question 2

which is worse?

Alpha or beta

Answer 2

alpha particles

Question 3

What are the particles what cause more damage?

Answer 3

Neutrons
Protons
alpha

Question 4

What are the particles what cause less damage?

Answer 4

beta

gamma

Question 5

what is effective dose?

Answer 5

amount and type of radiation + radiosensitivities of tisses/organs

Question 6

effective and equivalent dose measured in?

Answer 6

SV sievert or mSV millisievert

Question 7

example of a deterministic effect?

Answer 7

skin damage from sun exposure above threshold

Question 8

what is probabilistic or stochastic effect?

Answer 8

no threshold for effect, eg. cancer

Question 9

7 hour flight equivalent to?

Answer 9

CXR 0.04 or 0.05 mSV

Question 10

what is natural background radiation exposure?

Answer 10

2mSV per year

Question 11

each CT scan of abdomen is equivalent to?

Answer 11

1 year of smoking cancer risk (population basis)

Question 12

one brain CT equivalent to how many background years?

Answer 12

1

Question 13

one abdo and pelvis CT equivalent to how many background years?

Answer 13

12-15 yr

Question 14

one L-spine CT equivalent to how many background years?

Answer 14

2

Question 15

one chest CT equivalent to how many background years?

Answer 15

3-5 years

Question 16

one abdo CT equivalent to how many background years?

Answer 16

8-10 or 4-10

Question 17

what has replaced fluoroscopy?

Answer 17

endoscopy

Question 18

2 kinds of oral contrast for CT?

Answer 18

Barium

gastrografin (iodine)

Question 19

3 risks of intravascular contrast?

Answer 19

allergy
nephropathy
nephrogenic systemic fibrosis (MRI gadolinium)

Question 20

why less allergies with CT contrasts these days?

Answer 20

now use non-ionic agents

Question 21

contrast wil cause renal problems with people with eGFRs lower than? what to do?

Answer 21

40
prehydrate
another modality
scan without contrast

Question 22

what happens if someone’s eGFR is below 40 and you give them gadolinium?

Answer 22

nephrogenic systemic fibrosis

hardened fibrous skin nodules and plaques

Question 23

Contrast and Metformin?

Answer 23

stop metformin: risk of lactic acidosis

Question 24

contract may cause thyrotoxicosis in someone with?

Answer 24

Graves or hyperthyroidism

Question 25

what is you need a scan but they are getting treated for thyroid cancer?

Answer 25

don’t use the iodine contrast, will prevent the radioiodine from treatment

Question 26

who can’t have MRI?

Answer 26

Aneurysm clips
pacemaker
neuro stims, implanted electrodes
cochlear implants
grindings/shrapnel