final ch. 10 & 11

Question 1

Which of the following terms involves a random effect of ionizing radiation?

Answer 1

Stochastic event

Question 2

The responsibility for maintaining radiation monitoring records for all personnel and for providing counseling for individuals who receive monitor readings in excess of allowable limits belongs to the

Answer 2

designated radiation safety officer of a health care facility.

Question 3

Which of the following is not an x-ray beam limitation device?

Answer 3

Filter

Question 4

The protective tube housing serves as a shield against _____________________ entering the x-ray tube, thereby preventing electric shock while also facilitating cooling of the x-ray tube.

Answer 4

the high voltage

Question 5

When using digital fluoroscopy systems, making use of the last image hold feature can

Answer 5

be an effective dose reduction technique

Question 6

Which of the following agencies is responsible for enforcing radiation safety standards?
ICRP
NRC
NCRP
UNSCEAR

Answer 6

NRC

Question 7

Determine the cumulative effective dose (CumEfD) to the whole body of an occupationally exposed person who is 27 years old.

Answer 7

270 mSv

Question 8

Biologic effects such as cataracts that result from exposure to ionizing radiation appear to have which of the following?

Answer 8

Sigmoid threshold dose–response curve

Question 9

For radiation workers, such as medical imaging personnel, occupational risk may be equated with occupational risk in which of the following?
A. Other industries that are generally considered reasonably safe
B. Somewhat hazardous industries
C. hazardous industries
D. extremely hazardous industries

Answer 9

Other industries that are generally considered reasonably safe

Question 10

Revised estimates derived from more recent reevaluations of dosimetric studies on the atomic bomb survivors of Hiroshima and Nagasaki indicate which of the following?

Answer 10

An increase in the number of solid tumors in the survivor population

Question 11

When exposed to radiation as part of their educational experience, 18-year-old students should not exceed an effective dose limit of _________ annually.

Answer 11

1 mSv

Question 12

Which of the following groups has provided sufficient evidence of the induction of stochastic effects in humans resulting from high radiation absorbed doses?

Answer 12

Japanese atomic bomb survivors

Question 13

8. Responsibilities of a medical facility’s radiation safety officer (RSO) include which of the following?
9. Developing an appropriate radiation safety program
10. Maintaining radiation-monitoring records for all personnel
11. Repairing all broken or defective imaging equipment

Answer 13

1 and 2 only
1. Developing an appropriate radiation safety program

2. Maintaining radiation-monitoring records for all personnel

Question 14

To reduce exposure for pregnant imaging professionals and to control the exposure of the unborn during potentially sensitive periods of gestation, the NCRP now recommends a monthly equivalent dose limit not exceeding ______ per month to the embryo-fetus and a limit during the entire pregnancy not to exceed ________ after declaration of a pregnancy.

Answer 14

0.5 mSv, 5.0 mSv

Question 15

Which of the following is the annual occupational effective dose that applies to radiographers during routine operations?

Answer 15

50 mSv

Question 16

The radiographic beam should be collimated so that it is which of the following?

Answer 16

No larger than the image receptor

Question 17

Both alignment and length and width dimensions of the radiographic and light beams must correspond to within:

Answer 17

2% of the SID

Question 18

What is the function of a filter in diagnostic radiology?

Answer 18

To decrease the x-radiation dose to the patient’s skin and superficial tissue

Question 19

HVL may be defined as the thickness of a designated absorber required to do which of the following?

Answer 19

Decrease the intensity of the primary beam by 50% of its initial value

Question 20

The photostimulable phosphor in the computed radiography imaging plate is more sensitive to scatter radiation before and after it is sensitized through exposure to a radiographic beam. Because of this increased sensitivity, which of the following is true?

1. Five millimeters of added aluminum equivalent filtration must always be used during routine CR imaging.
2. A radiographic grid may be used more frequently during CR imaging.
3. Any source-to-image receptor distance can be used during CR imaging without adjustment in technical exposure factors.

Answer 20

2 only

2. A radiographic grid may be used more frequently during CR imaging.

Question 21

To minimize skin exposure to electrons produced by photon interaction with the collimator, how far below the collimator should the patient’s skin surface be?

Answer 21

At least 15 cm below

Question 22

Which of the following aluminum equivalents for total permanent filtration meets the minimum requirement for mobile diagnostic and fluoroscopic equipment?

Answer 22

2.5 mm aluminum equivalent

Question 23

The trough, or bilateral wedge, filter, which is used in some dedicated chest radiographic units, is an example of which of the following?

Answer 23

Compensating filter

Question 24

To decrease patient exposure during fluoroscopic procedures, the fluoroscopist can:

1. Limit the size of the fluoroscopic field to include only the area of anatomy that is of clinical interest
2. Employ the practice of pulsed fluoroscopy to reduce the overall length of exposure
3. Choose to use a conventional fluoroscope instead of an image intensification fluoroscope

Answer 24

1 and 2 only
1. Limit the size of the fluoroscopic field to include only the area of anatomy that is of clinical interest

2. Employ the practice of pulsed fluoroscopy to reduce the overall length of exposure

Question 25

A diagnostic-type protective tube housing must be constructed so that leakage radiation measured at a distance of 1 m from the x-ray source does not exceed ______ when the tube is operated at its highest voltage at the highest current that allows continuous operation.

Answer 25

1 Gya/hr