Exam 1 - 6. Radiation Safety and Protection

Question 1

5

What is the most significant and naturally occuring radioactive elements in the earth’s crust?

Question 2

5

Uranium-238 decays to form many by-products, one of them being _____.

Question 3

5

Radon is responsible for approximately ___% of the total background radiation.

Question 4

6

This type of radiation makes up _____% of the total background radiation.

Question 5

7

____ radiation makes up ___% of the total background radiation.

Question 6

7

___ and ____ are naturally occuring radioactive elements in the soil. They decay to form other elements, one of which is _____. They release ____ radiation.

Question 7

8

_____ make up ____% of the total background radiation.

Question 8

8

Internal radionuclides are ingested, mainly from ____, which contains uranium and thorium and their decay products.

Question 9

9

Approximately ____ x-ray and nuclear examinations are performed annually worldwide.

Question 10

9

The biggest source of medical radiation exposure are from ______, mostly of the chest and abdomen regions.

Question 11

10

Out of the 3.6 billion x-ray/nuclear examinations performed annually worldwide, approximately ___% of these are DENTAL RADIOGRAPHIC EXAMINATIONS. However, dental radiographic examinations only account for approximately ____% of the total exposure from medical sources

Question 12

13

Radiation is _____.

Question 13

15

The risk of radiation-induced cancer from dentomaxillofacial radiography is _____.

Question 14

16

What is the linear no-threshold hypothesis?

Question 15

18

_____ are set by policymakers to stay within a certain low dose range.

Question 16

26

____ offer equal of greater dose savings than the film sensors with comparable diagnostic quality.

Question 17

26

When utilizing film sensors, use the _____ film speed type. Speeds __, __, and ___ are available, with _____ being the slowest and __ being the fastest.

Question 18

27

These are a part of the image receptor system in extraoral radiographs (such as panoramic radiographs), which convert x-rays to light. They consist of materials that, when exposed to x-rays, fluoresce and give off light. The light then exposes the film to create an image

Question 19

27

The ADA recommends that _______intensifying screens be utilized, combined with high-speed films

Question 20

28

What source-to-skin distance should be used? What is the name of this technique?

Question 21

28

What does the inverse square law say about the distance of the x-ray beam and the beam’s intensity?

Question 22

29

Field of radiation at the patient’s skin surface should be no more than _____ in diameter.

Question 23

29

What shape of collimator is recommended? How much reduction in radiation does this shape have compared to the other shape?

Question 24

30

____ photons add no diagnostic value in imaging and only expose patients and personnel to unncessary radiation. To minimize them, ____ is used that is set by a manufacturer.

Question 25

30

Federal regulations in the US state that the total filtration in the path of an x-ray beam be equal to ____ mm of aluminum in machines that operate below 70 kV, and ____ mm of aluminum at higher kVp ranges

Question 26

The ____ gland is more susceptible to radiation exposure during dental radiographic exams given its anatomic position, particularly in children.

Question 27

31

Are lead aprons and thyroid collars currently recommended by the ADA?

Question 28

31

• The use of these holders improves the alignment of the film/sensor with the teeth and x- ray machine
• As a result, the x-ray beam is properly directed toward the receptors; this greatly reduces the chance of the beam partially missing the image receptor (a “cone-cut”) and reduces image distortion

Question 29

33

What is the optimal operating potential of dental x-ray units?

Question 30

33

f you were to take an anterior periapical image of the maxillary teeth, the alveolar bone and the teeth are less in terms of thickness when compared to the posterior maxillary teeth. So, to achieve an optimal image, you would need to ______. That is why exposure times vary from region to region.

Question 31

36

Radiographs are best viewed in a _____ room with light transmitted through films; all extraneous light should be eliminated.

Question 32

In the absence of a barrier in an existing facility, the operator shall remain at least ___ m, but preferably ____ m, from the x-ray tube head during the exposure. If the 2 m distance cannot be maintained, then a barrier shall be provided. This recommendation does not apply to ____.

Question 33

41

For handheld radiographic devices, the _____provides a zone where backscatter is negligible.

Question 34

41

The best position to use a handheld radiographic device is ___ to the operator.

Question 35

43

*Device worn by occupational professionals who may be at risk of getting exposed to radiation doses greater than one mSv/per year.
* Ensures that the professionals follow radiation rules and limit themselves to occupational exposure.
*The dosimeters consist of materials that are stimulated by radiation. These devices are then sent to a service (monthly or quarterly basis) that measures the total accumulated dose and send back a report which may contain recommendations on minimizing exposure, if a certain limit is exceeded.