Chapter 6

Question 1

Does high mA increase or decrease the amount of radiation to the
patient?

Answer 1

Increases the amount of radiation to the patient by increasing the number of x-rays produced.

Question 2

Discuss why pointed PIDs are prohibited. What type of PIDs should be
used?

Answer 2

They increase scatter radiation; use open-ended, lead-lined rectangular or
cylindrical PIDs instead.

Question 3

What must be used when using rectangular collimation with the paralleling technique.

Answer 3

Must use a receptor holder to maintain alignment and reduce radiation exposure.

Question 4

List recommended selection criteria for radiographic exposure.

Answer 4

Based on the patient’s medical and dental history, clinical examination,
and risk factors.

Question 5

What is ALARA?

Answer 5

“As Low As Reasonably Achievable” minimizing radiation exposure to
patients and operators.

Question 6

What happens if the dental tubehead drifts?

Answer 6

Can lead to improper positioning and exposure, increasing radiation risk.

Question 7

What removes long wavelength, low energy x-ray photons from the
beam?

Answer 7

Accomplished by using aluminum filtration.

Question 8

The collimator limits the size and shape of the x-ray beam to no more than
_____.

Answer 8

To no more than 2.75 inches (7 cm) in diameter at the skin surface.

Question 9

Compare D, E, and F speed film. How much radiation exposure is
reduced with each?

Answer 9

D-speed: Slowest, more radiation.
E-speed: Faster than D, about 40-50% less radiation.
F-speed: Fastest, about 20% less radiation than E-speed.

Question 10

What radiographic technique provides less radiation exposure to the thyroid gland and eyes?

Answer 10

Paralleling technique provides less exposure to the thyroid gland and
eyes.

Question 11

List optimum film viewing requirements.

Answer 11

low lighting, a viewbox with uniform light, magnification.

Question 12

What does film speed and FFD determine?

Answer 12

Film speed determines the amount of radiation required; focal film
distance (FFD) affects image sharpness and patient exposure.

Question 13

What does the choice of kV affect?

Answer 13

The contrast and quality of the radiographic image; higher kV results in lower contrast.

Question 14

Why is an increased target-receptor distance recommended?

Answer 14

Reduces image magnification and increases sharpness.

Question 15

Where should the operator be positioned during x-ray exposure?

Answer 15

Stand at least 6 feet away and at an angle of 90 to 135 degrees to the
primary beam.

Question 16

Where should the operator be positioned during x-ray exposure?

Answer 16

The operator should never hold the receptor or tubehead during
exposure.

Question 17

Who makes the final decision for selection criteria of xrays?

Answer 17

Made by the dentist based on clinical judgment and patient needs.