Radiology

Question 1

X rays discovered by

Answer 1

Roentgen, Nov 8th 1895

Question 2

Rollins

Answer 2

developed guidelines for protection of patients; lab rats

Question 3

Roentgenology

Answer 3

study or science of radiation as used in medicine and dentistry

Question 4

Radiolucent

Answer 4

e- pass, so not dense, shows black

Question 5

Radiopaque

Answer 5

e- do not pass, so dense, appears white

Question 6

Direct sensor

Answer 6

to computer

Question 7

attenuate

Answer 7

stop the electrons; shows up radiopaque (enamel) whereas dentin is less dense

Question 8

Indirect Sensor

Answer 8

simple film which goes into a processor-optime; photostimulable phosphor (PSP) is used which are thin imaging plates w/ no wires and is read by a laser

Question 9

How x-rays are produced

Answer 9

e- are produced at the tungsten filament (cathode) and propelled towards the anode at a speed dependent on the electrode potential between the anode and cathode.

bombarding a tungsten target (anode) with high V e- – go to the anode at high speeds

Question 10

Thermionic emmision

Answer 10

term used to describe boiling off of electrons

Question 11

Filament

Answer 11

coil of tungsten which emits electrons when heated

Question 12

Focussing cup

Answer 12

negatively charged molybdenum

Question 13

tungsten target

Answer 13

anode

Question 14

Focal Spot

Answer 14

area within target where e- are directed; smaller gives sharper image

Question 15

smaller focal spot

Answer 15

sharper image

Question 16

Bermsstrahlung (braking radiation)

Answer 16

higher energy, e- is slowed by protons in nucleus

Question 17

Characteristic radiation

Answer 17

e- knocks out inner shell electrons (K shell) –> unstable vacancy –> electrons fall down and emit photons

Question 18

controls speed of e- from cathode to anode

Answer 18

kV (kilovoltage) and mA

Question 19

controls quality of x ray beam

Answer 19

kV

Question 20

controls quanity of electrons

Answer 20

mA and time (1 impulse = 1/60)

Question 21

mA

Answer 21

controls numbrer of electrons and thus quanity of e-; higher = darker

Question 22

higher mA

Answer 22

darker (b/c greater quantity of e-)

Question 23

Radiographic contrast

Answer 23

related to quality of x-radiation; controlled by kV (high and low) related to number of shades of gray

Question 24

High contrast

Answer 24

short scale and less shades of gray (black and white is high contrast)

Question 25

low contrast

Answer 25

long scale (more colors), more shades of gray

Question 26

how image is produced

Answer 26

e- emitted from cone –> tissue –> attenuated –> some e- pass and hit sensor

Question 27

contrast controlled by

Answer 27

Kv

Question 28

Examples of radiolucencies

Answer 28

caries, fossa, sinus, pathology, PDL space, periapical pathology

Question 29

radiopaque examples

Answer 29

dentin, enamels, calculus, almalgam restoration (most), calculus,

Question 30

Most radiopaque

Answer 30

almalgman restoration

Question 31

DEJ visible on radiograph how

Answer 31

grey to white enamel

Question 32

lamina dura appearance on radiograph

Answer 32

radiopaque covering between root and bone (white to grey)

Question 33

Exposure

Answer 33

act of making or exposing a radiograph

Question 34

Higher kV

Answer 34

more penetrating power because kV controls the speed and quality of the beam

Question 35

Radiographic Density

Answer 35

degree of blackness on the radiograph, controlled by mA and time-related to quantity of x-radiation

Question 36

fogged areas

Answer 36

e- were bent