C15: Review Questions

Question 1

When performing a mobile radiographic examination, if the protective factors of distance and shielding are equal, the radiographer should stand at a _____ to the scattering object (the patient) line.

Answer 1

90-degree angle

Question 2

Diagnostic imaging personnel may receive an annual occupational effective dose of _____ for whole-body exposure during routine operations.

Answer 2

50 mSv

Question 3

At a 90-degree angle to the primary x-ray beam, at a distance of 1 m, the scattered radiation is what fraction of the intensity of the primary beam?

Answer 3

1/1000

Question 4

If a radiographer stands 6 m away from an x-ray tube and receives an exposure rate dose of 4.0 mGya/hr, what will the exposure rate dose be if the same radiographer moves to stand at a position located 12 m from the x-ray tube?

Answer 4

1 mGya/hr

Question 5

Which of the following are methods that can be used by a C-arm operator to reduce their own occupational exposure and that of other personnel?
1. collimate the x-ray beam to include only the anatomy of interest
2. use the foot pedal or the handheld exposure switch with their cables extended away from the machine as far as possible whenever making an exposure
3. use magnification whenever possible to visualize body parts better

Answer 5

1 and 2 only

Question 6

If the Bucky slot shield and protective curtain or sliding panel were not in the correct position during a routine fluoroscopic examination, what exposure dose rate would the fluoroscopist experience?

Answer 6

exceed 1 mGya/hr at a distance of 0.6 m from the side of the x-ray table

Question 7

Units of either mAs/wk or mA-min/wk are used to determine the _____ for a specific x-ray room.

Answer 7

workload

Question 8

A Bucky slot shielding device of at least _____ must automatically cover the Bucky slot opening in the side of the x-ray table during a fluoroscopic examination when the Bucky tray is positioned at the foot end of the table.

Answer 8

0.25-mm lead equivalent

Question 9

For mobile radiographic units, which are not equipped with remote control exposure devices, the cord leading to the exposure switch must be long enough to permit the radiographer to stand at least _____ from the patient, the x-ray tube, and the useful beam to reduce occupational exposure.

Answer 9

2 m

Question 10

Of the following factors, which are specifically considered when determining thickness requirements for protective barriers?
1. occupancy factor (T)
2. workload (W)
3. use factor (U)
4. kVp

Answer 10

1, 2, 3 and 4