Deck 36: Designing for Radiation Protection

Question 1

A quantity that reflects both dose and volume of tissue irradiated is the ___________.

A) estimated skin exposure
B) dose area product
C) proportional region
D) rem

Answer 1

dose area product

Question 2

The source-to-skin distance must be no less than _____ cm on stationary fluoroscopes.

A) 30
B) 38
C) 42
D) 48

Answer 2

38

Question 3

Primary radiation is ______________________.

A) leakage radiation
B) the scattered beam
C) the useful beam
D) All of the above

Answer 3

the useful beam

Question 4

The collimator light must be accurate to within _____% of the SID.

A) 10
B) 5
C) 2
D) 1

Question 5

The ______________ is the primary protective barrier for the fluoroscopic x-ray tube.

A) ceiling
B) floor
C) image receptor
D) top

Question 6

The output intensities of reproduced exposures should not vary more than _____% from each other.

A) 5
B) 10
C) 15
D) 20

Question 7

Measuring the relationship between the output intensities of adjacent mA stations is a test of _________________.

A) HVL
B) beam limitation
C) reproducibility
D) linearity

Question 8

The design of an uncontrolled area in radiology is based on the NCRP recommended limit of _____ mGy/yr for the public.

A) 50
B) 10
C) 1
D) 0.5

Question 9

A cumulative timer is designed to _________________ of fluoroscopy beam-on time.

A) make the radiologist aware
B) turn off the radiation every 5 minutes
C) prevent more than 10 minutes
D) shut down the system after 15 minutes

Question 10

What is the minimum requirement for filtration on x-ray equipment operating above 70 kVp?

A) 1.5 mm Al equivalent
B) 2.0 mm Al equivalent
C) 2.5 mm Al equivalent
D) 3.5 mm Al equivalent

Question 11

The x-ray control panel must show ____________.

A) beam on time
B) mAs used
C) positive beam limitation
D) automatic exposure controls

Question 12

The leakage radiation limit for x-ray tubes is less than _____ mGy/hr at 1 meter from the tube housing.

A) 0.50
B) 1
C) 2
D) 3

Question 13

A secondary barrier is designed to absorb ______________ radiation.

A) leakage
B) scattered
C) primary
D) Both A and B

Question 14

The intensity of scatter radiation 1 m from the patient is approximately _____ of the intensity of the incident beam at the patient.

A) 0.01%
B) 0.1%
C) 10%
D) 50%

Question 15

The fluoroscopic exposure control switch is always a(n) ___________ type.

A) rheostat
B) automatic
C) deadman
D) on-off

Question 16

At the level of the tabletop, the intensity of the fluoroscopic beam should not exceed _______________ for each mA of operation at 80 kVp.

A) 2 mGy/hr
B) 0.2 mGy/hr
C) 21 mGy/min
D) 0.21 mGy/min

Question 17

A fluoroscopy system with automatic collimation must provide an unexposed border around the image at ____________ above the tabletop.

A) all heights
B) 35 cm
C) 25 cm
D) 18 cm

Question 18

Positive beam limitation must be accurate to within _____% of the SID.

A) 10
B) 5
C) 2
D) 1

Question 19

The Bucky slot opening in the side of the table must be automatically covered with _____ mm Pb during fluoroscopy.

A) 1.25
B) 1.0
C) 0.5
D) 0.25

Question 20

A controlled area is one occupied primarily by ____________________.

A) radiology personnel
B) patients
C) the general public
D) Both A and B

Question 21

Devices designed to measure total accumulated radiation intensity are called ______.

A) dosimeters
B) integrators
C) scintillation detectors
D) photo cathodes

Question 22

The advantage(s) of using thermoluminescent dosimeters is/are: I. small size.
II) immediate results.
III) tissue equivalent response.

A) I and II
B) II only
C) II and III
D) I and III

Question 23

The _____________ is used for precise calibration of the output intensity of diagnostic x-ray tubes.

A) G-M counter
B) ion chamber
C) scintillation detector
D) proportional counter

Question 24

Gas-filled radiation detectors are based on the ________________________.

A) thermoluminescence of crystals
B) photoemission of electrons
C) ionization of gas
D) scintillation of phosphors

Question 25

A Geiger-Muller counter is a(n) ________________________.

A) scintillation detector
B) optically stimulated dosimeter
C) gas-filled detector
D) thermoluminescent dosimeter