Radiography: Radiation Protection

Question 1

Measurement of radiation exposure from X-rays, gamma rays, or other types of radiation used in the treatment or detection of diseases, including cancer, is called _____________________ .

Answer 1

dosimetry

Question 2

Increasing the kVp of an X-ray beam will result in the photons having shorter or longer wavelengths?

Answer 2

Shorter

Question 3

An optically stimulated luminescence dosimetry measuring device uses what substance as a detector?

Answer 3

Aluminum oxide (Al₂O₃)

Question 4

What are the 3 classic acute radiation syndromes?

Answer 4

Hematopoietic syndrome (also called bone marrow syndrome), gastrointestinal syndrome, and cerebrovascular syndrome

Question 5

What are the 4 stages of acute radiation syndromes?

Answer 5

The prodromal stage (N-V-D stage), the latent stage, the manifest illness stage, and the recovery or death stage

Question 6

What term denotes the shedding of the outer-most layer of skin due to high radiation exposure?

Answer 6

Desquamation

Question 7

During which gestational trimester of development is a fetus most radiosensitive?

Answer 7

The first trimester

Question 8

_________________ is the restriction of the useful X-ray beam to the anatomy being imaged, thereby sparing adjacent tissue from unnecessary radiation exposure.

Answer 8

Collimation

Question 9

What does ALARA stand for?

Answer 9

As Low As Reasonably Achievable

Question 10

The effective dose to biologic material is expressed using what unit of measure?

Answer 10

Sievert (Sv)

Question 11

The absorbed dose is expressed using what unit of measure?

Answer 11

Gray (Gy)

Question 12

Does bone, muscle, or fat have the highest effective atomic number?

Answer 12

Bone

Question 13

What are the 3 cardinal principles of radiation protection?

Answer 13

Time, distance, and shielding

Question 14

Federal law requires at least __________________ total filtration for general-purpose X-ray tubes that operate above 70 kVp.

Answer 14

2.5 mm of aluminum equivalent

Question 15

The percentage of time when an X-ray beam is on and directed toward a protective barrier is called the _________________.

Answer 15

use factor

Question 16

Thermoluminescence dosimeters use what substance for radiation detection?

Answer 16

Lithium fluoride

Question 17

What type of secondary radiation protection is not always included as part of a typical lead apron and can decrease the amount of effective dose by 2.5-fold, with almost a 50% reduction in total exposure?

Answer 17

The thyroid shield

Question 18

_____________________ measures radiation exposure from natural background radiation sources during the monitoring period and any incidental exposure that may occur during shipment or storage.

Answer 18

A control dosimeter

Question 19

In fluoroscopy, what feature is used to maintain a consistent overall appearance of the image by automatically adjusting the kVp and/or mAs?

Answer 19

Automatic brightness control

Question 20

What are the main goals for using magnification mode in fluoroscopy?

Answer 20

To provide better spatial resolution and contrast resolution

Question 21

What components of a fluoroscopic imaging system serve as the primary protective barrier?

Answer 21

The image receptor assembly

Question 22

What type of radiation detectors are gas-filled?

Answer 22

Ion chambers and Geiger-Muller counters

Question 23

Substances or anatomy with higher atomic numbers have higher or lower attenuation values?

Answer 23

Higher

Question 24

Structures or anatomy with a low attenuation value that appear dark or black on a radiograph are considered to be _________________________ .

Answer 24

Radiolucent

Question 25

What is the equivalent dose of most diagnostic radiographic procedures?

Answer 25

**Less than 0.01 Sv**

Question 26

For occupational radiation dose exposure, equivalent annual dose limits for the lens of the eye are ______________ .

Answer 26

**150 mSv**

Question 27

What is the annual occupational effective dose limit?

Answer 27

**50 mSv**

Question 28

What is typically used to line the X-ray image intensifier/tube housing that protects RTs and patients from radiation leakage?

Answer 28

**Lead**

Question 29

Why must RTs using mobile radiographic equipment wear protective aprons?

Answer 29

**Because there is no protective barrier included in the construction of mobile radiography equipment**

Question 30

In situations where an RT must hold a patient upright for mobile radiography, the RT should stand in what position?

Answer 30

**At right angles or 90° to the scattering object**

Question 31

Fluoroscopic mAs must not exceed ___________________

Answer 31

**5 mAs**

Question 32

What is the dose limit for RTs who have formally declared their pregnancy to their employer?

Answer 32

**0.5 mSv per month**

Question 33

Protective lead aprons, gloves, and other protective equipment should be inspected how frequently for cracks and other defects?

Answer 33

**Yearly**

Question 34

Where is a dose area product meter generally located in imaging equipment?

Answer 34

**In the collimator assembly**

Question 35

Which type of shielding is suspended in the area of the collimator positioning light?

Answer 35

**The shadow shield**

Question 36

The disease with the shortest latent period as a result of radiation exposure is ____________

Answer 36

**leukemia**

Question 37

What are the 2 time periods associated with acute radiation lethality?

Answer 37

**The prodromal period and the latent period**

Question 38

What dose-reduction feature allows fluoroscopic imaging to be paused or stopped in order to retain a snapshot of the image displayed on the monitor?

Answer 38

**The last image hold/save grab feature**

Question 39

What type of radiation barriers are the imaging control booth walls and windows considered to be?

Answer 39

**Secondary barriers**

Question 40

The minimum source-to-skin distance for a stationary fluoroscopy unit is ____________ .

Answer 40

**38 cm or 15 inches**

Question 41

What thicknesses of lead barriers must be used for primary and secondary radiation barriers?

Answer 41

**Primary barriers must have 1/16th inch of lead protection and secondary barriers must have 1/32nd inch of lead protection**

Question 42

A fluoroscopic Bucky slot cover/shielding device protects what general area of the body?

Answer 42

**The gonad level/area**