Radiology E1

Question 0

Which of the magnetic radiations have greater energy levels than X-rays?

Answer 0

Gamma

Question 1

What type of force carrier particles make up the X-ray beam?

Answer 1

Photons

Question 2

The quantum theory of radiation has been successful in correlating experimental data on ______________.

Answer 2

The production of X-Rays

Question 3

Within the X-ray tube, electrons stream from the filament of the ________ to __________.

Answer 3

Cathode (-) to Anode (+)

Question 4

What percentage of the kinetic energy of electrons that hit the anode are converted to heat?

Answer 4

99%

Question 5

What is the primary source of radiation from the X-ray tube?

Answer 5

Bremsstrahlung

Question 6

What happens if the kVP is increased?

Answer 6

An increase in kVP will….

INCREASE Maximal energy
INCREASE Photons generated
INCREASE Mean energy

Question 7

What type of photon scattering is most common in an X-Ray beam?

Answer 7

The highest percentage is Compton Scattering at 57%

Question 8

Lower energy photons are removed by aluminum filtration, so what happens to the beam?

Answer 8

X-Ray beams Mean Energy INCREASES and the Beam Intensity DECREASES.

Question 9

In Deterministic effects, related to a certain threshold, above which you will see this effect and below this threshold you will not is known as _________.

Answer 9

Stochastic threshold –> no threshold –> smallest amount can lead to carcinogenic effects.

Expl. of this is Sunburn from prolonged exposure to sunlight.

Question 10

What types of tissues are more susceptible to radio sensitivity?

Answer 10

Rapidly dividing cells such as Basal cells in the oral mucosa.

Fibroblast, neurons, kidney, striated muscle are not as easily affected because they do not divide

Question 11

Which is true about radiation therapy in the jaw of children?

Answer 11

If radiation precedes dental calcification it may destroy the tooth, especially if the child is undergoing chemotherapy.

Question 12

How soon after a patient completes head and neck radiation therapy should you wait before taking x-rays?

Answer 12

Avoid intraoral radiographs for the first 6 months

Question 13

Which organs have the lowest susceptibility to radiation?

Answer 13

Salivary glands

Question 14

What type of radiation from natural sources is the most common in the world’s population?

Answer 14

Radon

Question 15

Dental X-Rays are responsible for what percentage of human exposure to radiation?

Answer 15

<1%

Question 16

The average dose of an individual to occupation exposure from operation of equipment is what percentage of the allowable exposure?

Answer 16

Less than 1%

Question 17

According to the Linear Non-threshold hypothesis, is there any risk of cancer from exposure?

Answer 17

Yes, there is some risk.

Question 18

According to the principle of Justification, which does more good than harm?

Answer 18

Justification-slight increase in risk for cancer is worth irradiating patients

Question 19

Which is better for the patient in intraoral film speed?

Answer 19

E and F speed has the same useful contrast as D speed with much less radiation

Question 20

State regulations require collimated distance from the patient of how much distance?

Answer 20

Round= 7 cm or 2 3/4 "
Rectangle= 1/5 of that distance

Question 21

Lead is located in which layer of x-ray film?

Answer 21

Lead is positioned behind the black paper and film layers.

Question 22

What size of dental films are used for adult bite wings?

Answer 22

Size 2

Question 23

When you use a dark room with a Safe Light, how long can the light stay on before it will negatively affect the films?

Answer 23

5 minutes

Question 24

Change in which variables will result in decrease in film density?

Answer 24

Increasing focal spot to film distance.