Fundamentals of Radiologic Theory

Question 1

What year were x-rays discovered, and by whom? What was the first this he x-ray’d?

Answer 1

Discovered by Wilhelm Conrad Roentgen in 1895. Took x-ray of wifes hand

Question 2

Who produced the first dental radiograph and in what year?

Answer 2

Dr. Otto Walkhoff in 1895

Question 3

Who produced the first intra oral radiograph?

Answer 3

Dr. Edmund Kells

Question 4

Who created the first dental x-ray unit? What mistakes did he make?

Answer 4

William Rollins. Burnt his hand which led to interest in radiation protection

Question 5

Who developed the first hot cathode x-ray tube which was the prototype for all modern x-ray units?

Answer 5

William Coolidge

Question 6

What advancement was made in 1933 to x-ray units?

Answer 6

Oil was added to the tube to control heat

Question 7

What year did Kodak develop pre-wrapped film?

Answer 7

1913

Question 8

Who developed the bisecting technique?

Answer 8

Weston Price

Question 9

Who else worked on bisecting and also developed the bitewing technique?

Answer 9

Riley Raper

Question 10

Who were the three men who developed and worked on PT?

Answer 10

Dr. Edmund Kells, Franklin McCormack, Dr. Fitzgerald

Question 11

Who did the first pano?

Answer 11

Hisatugu Numata in 1933

Question 12

What happens when photons interact with material?

Answer 12

Ionization

Question 13

What kind of charge do photons have?

Answer 13

No charge

Question 14

What speed to rays move at?

Answer 14

186,000 miles per second

Question 15

What is wavelength?

Answer 15

Distance from the crest of one wave to the crest of the next wave

Question 16

What units are wavelengths measured in?

Answer 16

Angstrom units

1/1000,000,000cm

Question 17

What is the range of length of x-ray wavelengths used in diagnostic radiography?

Answer 17

0.1 to 0.5 Angstrom

Question 18

What does longer wavelength mean

Answer 18

Lower frequency, less energy, less ability to penetrate matter

Weaker- not for dental

Question 19

What does shorter wavelength mean?

Answer 19

Higher frequency, more energy, greater ability to penetrate matter

More ideal for dental

Question 20

What does frequency mean?

Answer 20

The number of crest passing a fixed point per second

Question 21

When are x-rays produced?

Answer 21

When subatomic particles interact with atoms

Question 22

2 Major parts of atoms

Answer 22

Centrally located nucleus

Electrons orbiting around the nucleus

Question 23

Which atom has the simplest arrangement?

Answer 23

Hydrogen Atom

Question 24

WHat does the nucleus consist of?

Answer 24

Positively charged protons

Neutrons

Question 25

How many protons and electrons are in a neutral atom?

Answer 25

Same number of protons and electrons

Question 26

What is ionization?

Answer 26

The production of ion pairs by the removal of an electron from an atom of the matter which is struck by the x-rays One or more electrons are removed from their orbit/shell

Question 27

WHat happens to an atom when it becomes ionized?

Answer 27

It loses its electrical neutrality and becomes positively charged Called a positive ion

Question 28

Why do we need to understand ionization?

Answer 28

We need to understand the therapeutic and harmful effects x-radiation can have on tissues. They can alter or destroy cells If too many cells are destroyed, normal function of tissue can be altered

Question 29

What happens when H2O in the body's tissues becomes ionized?

Answer 29

Causes the atomic structure to be altered to H2O2 (hydrogen peroxide) Causes local tissue damage

Question 30

What are the two types of ionizing radiation?

Answer 30

Particulate and Electromagnetic

Question 31

WHat is the major difference in the way x-rays and light affect photo-magnetic plates?

Answer 31

Radiation can penetrate opaque objects

Question 32

What are the three sets of terms used for units of radiation that are being phased out?

Answer 32

Roentgen, RAD and REM

Question 33

Which terms used for units of radiation are gaining greater acceptance?

Answer 33

The INternational System: - Coulombs per KG replaces Roentgen - Gray replaces RAD - Sievert replaces REM

Question 34

What are the 3 quantities used for x-ray protection measurement?

Answer 34

Exposure Absorbed dose Dose equivalent

Question 35

What is exposure? What units are used?

Answer 35

Measurement of ionization in air produced by x-rays or gamma rays Coulomb/Kg/Roentgen

Question 36

What is absorbed dose? What units are used?

Answer 36

Amount of energy deposited in any form of matter by any type of radiation gray (Gy) & RAD are used

Question 37

What is dose equivalent? What units are used?

Answer 37

Term used for radiation protection purpose to compare biological effects of various types of radiation Sievert (Sv)/ REM

Question 38

What units are used to measure all radiation?

Answer 38

Grays/RADs and Sieverts/REMs