Meaghan Piretti Study Guide Questions With Complete
Solutions
Define OER
Oxygen enhancement ratio
The ratio of the radiation dose required to cause biological effect
in hypoxic (low oxygen) conditions to the dose required to cause
the same effect in oxygenated (normal oxygen) conditions
Formula for OER
OER = without oxygen/oxygenated tissues
X-ray OER
3
Whole body, yearly dose for technologist
50 mSv
Yearly dose to the lens of the eye
150 mSv
Yearly dose to skin
500 mSv
Yearly dose to extremities
500 mSv
Entire pregnancy fetal dose
5 mSv
,Monthly fetal dose
0.5 mSv
Public annual dose
5 mSv
Can also be referred to 10% of a technologist's dose
Yearly student radiographer dose
1 mSv
Formula for cumulative occupational exposure
Age x 10 mSv
Which dosimeter uses Lithium Fluoride
TLD
Which dosimeter uses Aluminum Oxide
OSL
Which dosimeter uses heat
TLD
Which dosimeter uses a laser
OSL
Which dosimeter provides a permanent record of dose
OSL
Where are dosimeters worn for a normal employee
At the collar above lead apron
,Where should the fetal dosimeter be worn
At waist level below the lead apron
What does "M" stand for on a dosimeter report
Minimal
How often are the dosimeter reports available for occupation
workers
Quarterly
How can a technologist protect themselves from radiation
exposure
Cardinal rules
Time, distance, shieldin
What does ALARA stand for
As Low As Reasonably Achievable
Define half value layer
The thickness of a material required to reduce the intensity of an
x-ray beam by 50%
Shielding requirements for apron & thyroid shield
0.5 mm Pb
Shielding requirements for lead gloves
0.25 mm Pb
Shielding requirements for protective curtain
0.25 mm Pb
, Shielding requirements for Bucky slot cover
0.25 mm Pb
What is a primary barrier
Any wall that may come in contact with the primary beam
Much be 1/16th inch thick and 7 ft high
What is a secondary barrier
Any part of the room not exposed to the primary beam but may
be exposed to leakage and scatter
Must be 1/32nd inch thick and go all the way to the ceiling
Formula for inverse square law
I1/I2 = D2^2/D1^2
Inverse square law
The intensity of radiation is inversely proportional to the square
of the distance from the source
If you double the distance the intensity is reduced to 1/4th
Where are the ionization chambers for the AEC
In the Bucky
What does AEC do
Stops exposure time when appropriate amount of radiation is
detected by ionization chambers
How does using AEC protect the pt from overexposure
Solutions
Define OER
Oxygen enhancement ratio
The ratio of the radiation dose required to cause biological effect
in hypoxic (low oxygen) conditions to the dose required to cause
the same effect in oxygenated (normal oxygen) conditions
Formula for OER
OER = without oxygen/oxygenated tissues
X-ray OER
3
Whole body, yearly dose for technologist
50 mSv
Yearly dose to the lens of the eye
150 mSv
Yearly dose to skin
500 mSv
Yearly dose to extremities
500 mSv
Entire pregnancy fetal dose
5 mSv
,Monthly fetal dose
0.5 mSv
Public annual dose
5 mSv
Can also be referred to 10% of a technologist's dose
Yearly student radiographer dose
1 mSv
Formula for cumulative occupational exposure
Age x 10 mSv
Which dosimeter uses Lithium Fluoride
TLD
Which dosimeter uses Aluminum Oxide
OSL
Which dosimeter uses heat
TLD
Which dosimeter uses a laser
OSL
Which dosimeter provides a permanent record of dose
OSL
Where are dosimeters worn for a normal employee
At the collar above lead apron
,Where should the fetal dosimeter be worn
At waist level below the lead apron
What does "M" stand for on a dosimeter report
Minimal
How often are the dosimeter reports available for occupation
workers
Quarterly
How can a technologist protect themselves from radiation
exposure
Cardinal rules
Time, distance, shieldin
What does ALARA stand for
As Low As Reasonably Achievable
Define half value layer
The thickness of a material required to reduce the intensity of an
x-ray beam by 50%
Shielding requirements for apron & thyroid shield
0.5 mm Pb
Shielding requirements for lead gloves
0.25 mm Pb
Shielding requirements for protective curtain
0.25 mm Pb
, Shielding requirements for Bucky slot cover
0.25 mm Pb
What is a primary barrier
Any wall that may come in contact with the primary beam
Much be 1/16th inch thick and 7 ft high
What is a secondary barrier
Any part of the room not exposed to the primary beam but may
be exposed to leakage and scatter
Must be 1/32nd inch thick and go all the way to the ceiling
Formula for inverse square law
I1/I2 = D2^2/D1^2
Inverse square law
The intensity of radiation is inversely proportional to the square
of the distance from the source
If you double the distance the intensity is reduced to 1/4th
Where are the ionization chambers for the AEC
In the Bucky
What does AEC do
Stops exposure time when appropriate amount of radiation is
detected by ionization chambers
How does using AEC protect the pt from overexposure
