A .2 copper filter reduces exposure by approx. ______%.
Correct Answers 50%
A 2.0mm copper filter reduces the dose by ___%. Correct
Answers 70%
A fluoro operator standing 3ft from the source of the x-ray beam
receives _______% of patient's entrance skin exposure. Correct
Answers .1%
A nurse worker is exposed to 230mR/hr from a radiation source.
If the nurse remains at that position for 37 minutes, what will be
the total occupational exposure? Correct Answers 230mR/hr
divided by 60 minutes =
3.83mR X 37 minutes = 141.83 = 142mR
A typical CXR delivers a dose of .1 mSv how many mrem is
that? Correct Answers 10 mrem
1mSv = .001sievert
1sievert = 100rem
1rem = 1000millirem
According to National Council on Radiation Protection &
Measurements (NCRP), it requires certain workers to be
monitored for occupational
,radiation exposure. Who are included in the requirement?
Correct Answers Any worker likely to receive a whole body
dose in excess of25mR in a given week.
A person who potentially could receive 10% of the maximum
annual dose limit.
Any person who routinely enters a designated high radiation
area.
Any person who operates fluoroscopic equipment.
Operators of mobile x-ray equipment.
People who service x-ray equipment.
According to the FDA what is the approximate time it would
take to receive an equivalent effective dose from natural
background radiation as compared to a routine BE fluoroscopic
study? Correct Answers FDA indicates that the approximate
time to receive an equivalent effective dose form natural
background radiation compared to a routine BE study is 2.7
years
According to the International Commission on Radiological
Protection (ICRP) the reported threshold dose for early onset of
erythema is said to be_____rads. Correct Answers 200 rads
According to Tile 21, Code of Federal Regulations Part 1020
(21 CFR 1020) x-ray equipment problems must be documented
,& corrected within how many days? Correct Answers 60 day
window
Acute radiation dermatitis results from an exposure of ___rads.
Correct Answers 200-800 rads
All the following are fundamental principles of radiation
protection, except:
1) 15% Rule
2) Time
3) Distance
4) Shielding Correct Answers 15% Rule is not a fundamental
principle of radiation.
Time, distance & shielding are.
Angiography & Interventional fluoro exams routinely use wedge
filters. What is its main purpose? Correct Answers Reduce the
glare from the unattenuated radiation near the edge of the patient
& improve the ABC (Automatic Brightness Control)
At what 2 angles from the table does the most scatter occur?
Correct Answers 135 & 120 degrees.
Minimum Scatter occurs at 45, 60 & 90 degrees
Beam limiting devices such as light field radiation should be
assessed how often? Correct Answers Every 6 months
, Beam limiting devices include light field radiation, field
congruence, image receptor-radiation field alignment, accuracy
of the x-y scales and illuminator bulb brightness should have
quality control tests performed every 6 months or semiannually.
Common materials used as filters in fluoro include? Correct
Answers Copper and Aluminum
Cones are used primarily for daylight vision. This type of vision
is referred to as? Correct Answers Photopic vision
Consideration should be given when positioning the patient to
reduce patient dose. Which of the following methods may
reduce patient dose?
1. Position the patient so that the radiosensitive areas
receive the exit dose
2. Place the patient on the table, slightly off center
3. Rotate the patient so that the gonads are away from primary
beam Correct Answers 1. Position the patient so that the
radiosensitive areas receive the exit dose
3. Rotate the patient so that the gonads are away from primary
beam
During pulsed fluoro for cineangiography the tube current
ranges from ___ to ___. Correct Answers 100 to 1000 mA