Protection radiation ( intro to mdi)

Question 1

What is the unit and Sl unit Exposure in air ?

Answer 1

Unit Roentgen and SL unit C/Kg

Question 2

What is absorbed dose ? and the unit ?

Answer 2

Is the amount of energy absorbed in any medium ( it is for patient)
SL unit : Gray / unit : absorbed dose (rad)
1gy = 100 rad

Question 3

Dose equivalent ?

Answer 3

For the worker and population
Traditional unit : beta, gamma and alpha ( Rem)
Sl unit : Seivert
Sv = 100 rem

Question 4

Radiation activity

Answer 4

Traditional unit : Curie
Unit : Bq
1ci = 3.7 x 10^10 Bq

Question 5

what is AlARA ?

Answer 5

As low As Reasonably Achievable
Has principles : Time / distance and shielding

Question 6

Time ?

Answer 6

Reduces the time of an exposure which reduces the dose
minimize the time that you are contact with radioactive materials

Question 7

Distance ?

Answer 7

increasing distance reduces dose due inverse square law

increases the distance decreases the dose

the closer you are the source the greater your exposure will be

Question 8

Shielding ?

Answer 8

Are made of lead which absorbs x ray
gonads over reproductive organ ( lead aprons)

Question 9

what is the purpose of protective apparel ?

Answer 9

It must used when the x ray beam is turned on
Min = 0.5 mm pb when beam energy is100kvp

Question 10

Radiation effect ?

Answer 10

direct effect : Deposited directly to ( DNA)
results in cell death

Indirect effect : Deposited cytoplasmic ( water)
May exist long enough to affect DNA

Question 11

what are stem cells and mature cells ?

Answer 11

Stem cells are radiosensitive ( organs)
Mature cells are radioresistant

Question 12

Biological factors of radiosensitivity ?

Answer 12

Age , gender , metabolic rate and oxygen effect

Question 13

Principle’s of radiosensitivity ?

Answer 13

Growth rate
Immature cells
Rapidly dividing cells

Question 14

Others factors affect radiosensitivity ?

Answer 14

LET : ( linear energy transfer )
RBE : ( Relative biological effectiveness)

Question 15

what is LET and RBE ?

Answer 15

How ionizing energy is deposited in tissue

Is the ratio of the dose required by 2 radiations to cause the same level of biologic effect

Question 16

The highest factor affect radiosensitivity in the graph ?

Answer 16

Heavy nuclei
then alpha particles

Question 17

What are the biological effects of radiation ?

Answer 17

1) How the responses ( symptoms)
2) Relate to dose ( amount of dose received )

2 types : Stochastic Effects
Deterministic Effects

Question 18

what is stochastic effect ?

Answer 18

Have an increased probability of occurrence with increased dose
Non- threshold response , linear dose response

ex : sunlight , skin cancer
Depends on radiation dose
long period

Question 19

what is deterministic effects ?

Answer 19

Are those responses which increase in severity with increased dose
Threshold dose response , non linear dose response
high doses , depend on dose

It can cause fetal damage , skin injury

Question 20

Acute radiation syndrome ?

Answer 20

Is the high dose of radiation effects
syndromes : Hematologic / Gastrointestinal / CNS

Question 21

Stages of acute radiation ?

Answer 21

Prodromal : It shows the signs and symptoms resulting from radiation exposure to the whole body within hours ( last up day or two)

Latent : If there is no visible symptoms, there may be ongoing cell damage

Manifest : Effects are evident

Death : The survival depends on complex factors (amount and distribution of the radiation)

Question 22

What are the Doses of Hemopoietic , Intestinal and brain ?

Answer 22

The dose = 300 , Latency = 2 weeks and death = 3 weeks
The dose = 1000 , Latency = 3 days and death = 2 weeks
The dose = 2000 , Latency= 1 hour and death = 1 day

Question 23

What are the somatic effects ?

Answer 23

Gonadal effects : Sterility
Erythema : Skin reddening ( 6Gy)
Epilation : temporary hair loss ( 3 Gy)
Cataracts : Opacity ( 2Gy)

Question 24

Effects of Carcinogenesis ?

Answer 24

Fetal effects ( prenatal and neonatal death)
Genetic effects : Doubling dose / Significant dose