Radiology

Question 1

Who discovered x-rays?

Answer 1

Willhelm Conrad Roentgen in 1895

Question 2

What is energy?

Answer 2

the ability to do work; energy cannot be created or destroyed, it can change form

Question 3

What are the 2 parts of an atom?

Answer 3

a central nucleus
orbiting electrons

Question 4

What is the primary kind of radiation produced in the dental x-ray tubehead?

Answer 4

bremsstrahlung radiation

Question 5

What is ionization?

Answer 5

electrons are removed from orbital shells of stable atoms through collision with x-raWy photons

Question 6

What is a photon?

Answer 6

a tiny bundle of pure energy that has no weight or rmass

Question 7

What is the lead collimator

Answer 7

a metal disc with a small opening in the center that limits the x-ray beam to a circular 2-inch opening
located in the position indicator device

Question 8

What does the position indicator device (PID) do?

Answer 8

used to aim the x-ray beam at the film in the patient’s mouth

Question 9

What is the selector button used for?

Answer 9

select the exposure time, milliamperage, and kilovoltage

Question 10

What is exposure time measured in? Examples?

Answer 10

fractions of a second called impulses
60 impulses = 1 second

Question 11

What does the mA amount control?

Answer 11

the number of electrons produced

Question 12

What does the kilovoltage (kVo) control? What is the general amount?

Answer 12

control the penetrating power
70/90 kVp

Question 13

What is a thermionic emission?

Answer 13

the release of electrons from the tungsten filament when the electrical current passes through and heats up

Question 14

What is primary radiation?

Answer 14

made of x-rays that come from the target of the x-ray tube

Question 15

What is secondary radiation?

Answer 15

x-radiation that is created when primary radiation interacts with matter

Question 16

What is scatter radiation?

Answer 16

a form of secondary radiation that occurs when an z-ray beam has been deflected from its path

DANGEROUS

Question 17

What does “density” mean in x-rays?

Answer 17

the overall blackness or darkness of a film

Question 18

What is Penumbra?

Answer 18

the fuzzy/blurred area that surrounds and image

Question 19

What is distortion?

Answer 19

the disproportionate change in size of images that is caused by too much or too little vertical angulation

Question 20

“exposure to radiation doesn’t become evident for many years after the time the rays were absorbed” this time lag is known as?

Answer 20

the latent period

Question 21

What are examples of critical organs?

Answer 21

skin
thyroid
lens of eye
bone marrow

Question 22

How much radiation do occupationally exposed persons experience?

Answer 22

5000 millirem

Question 23

How much radiation do non-occupationally exposed persons experience?

Answer 23

0.1 rem/year

Question 24

What is a dosimeter?

Answer 24

used to measure the amount of occupational exposure to ionizing radiation

Question 25

What concept states all exposure to radiation must be kept to a minimum?

Answer 25

ALARA

Question 26

In direct imaging, what is the image receptor?

Answer 26

a solid state sensor

Question 27

In indirect imaging, what is the image receptor?

Answer 27

a thin, flexible plate, the size of a conventional x-ray film that has been coated in phosphor crystals

Question 28

What is intraoral film?

Answer 28

a semiflexible acetate film that is coated on both side with an emulsion of silver bromide, silver halide, and silver iodide

Question 29

When an image is not visible before processing it is called the?

Answer 29

latent image

Question 30

What does film speed refer to? What classifications?

Answer 30

the amount of radiation required to produce a radiograph of standard density Classified from letters A through F

Question 31

What is the tube side of the outer packet?

Answer 31

solid white and when placed in mouth it faces towards the teeth

Question 32

What is the label side of the outer packet?

Answer 32

has a flap used to open the packet before processing

Question 33

What are the five basic sizes of intraoral film packets?

Answer 33

Child (#0) Narrow anterior 9#1) Adult (#2) Performed bitewing (#3) Occlusal (#4)

Question 34

What extraoral film is used to show a panoramic view of the upper and lower jaws on a single radiograph?

Answer 34

panoramic film

Question 35

What extraoral film is used to show the bony and soft tissue areas of the facial profile?

Answer 35

Cephalometric

Question 36

What is a cassette?

Answer 36

a plastic/metal case that is used to hold the film a protect it from light exposure

Question 37

What a re the two types of screen film used in extraoral radiography?

Answer 37

green-sensitive film - rare earth intensifying screen blue-sensitive film - calcium tungstate

Question 38

When an expired film is used it may produce a foggy image, this is known as?

Answer 38

age fog

Question 39

What is a stepwedge?

Answer 39

a device constructed of layered aluminum steps