Oral Radio (Mental Dental)

Question 1

What dissipates heat in tubehead of xray machine?

Answer 1

Copper

Question 2

How xray beam weakens as it travels through matter

Answer 2

Attenuation

Question 3

Atomic nuclei or subatomic particles moving at high velocity
Alpha and beta particles from radioactive decay are examples

Answer 3

Particulate radiation

Question 4

Movement of energy as a combination of electrical and magnetic fields
SHorter wavelength= higher energy

Answer 4

Electromagnetic radiation

Question 5

_____ xray production
Primary source of x-ray photons
Electron stikes a target and brakes giving off energy
Generates continuous specturm of energy

Answer 5

Bremsstrahlung radiation

Question 6

____ xray production
Secondary source of xray photons
Electron accidentally knock into another electron and drops into a lower energy orbital
Emits a photon of specific energy

Answer 6

Characteristic xray production

Question 7

_______
-tungsten filament that produces electrons
Molybdenum focusing cp focuses beam onto small focal spot

Answer 7

Cathode (negative)

Question 8

_____
-Tungsten target that converts electrons to xray photons
Copper stem dissipates heat

Answer 8

Anode

Question 9

Does x radiation begin at cathode or anode?

Answer 9

Cathode to anode

Question 10

What does the glass in the xray tube do?

Answer 10

Insulation

Question 11

What does aluminum do in the xray tube?

Answer 11

Filtration

Question 12

What does lead in the xray tube do?

Answer 12

Collimation

Question 13

_____
-Quality of electrons
Number of photons
Density: darkness of image

Answer 13

Intensity

Question 14

______
-Quality of electrons
Energy of photons
Contrast: difference among gray values

Answer 14

Energy

Question 15

DOes exposure time affect intensity or energy?

Answer 15

INtensity

Question 16

What setting of xrays is most frequently changed?

Answer 16

Exposure time

Question 17

Does tube current affect intesnity or energy?

Answer 17

INtensity

Question 18

Does tube potential (kVp) affect intensity or energy?

Answer 18

Both

Question 19

Involves aluminum
Removes lower energy photons from the beam to reduce exposure
Conceptually similar to beam hardening

Answer 19

Filtration

Question 20

Involves lead
Reduces beam size to reduce pt exposure
Rectangular collimation is best method to reduce radiation dose

Answer 20

Collimation

Question 21

What is the best method to reduce radiation dose to pt?

Answer 21

Rectangular collimation

Question 22

To get a sharper image and less magnification, how do you position source and receptor?

Answer 22

Longer PID, close receptor

Question 23

_____ is the shadow behind an image
-Clear portion of the xray

Answer 23

Umbra

Question 24

_____ is the side shadow
-More blurry image

Answer 24

Penumbra

Question 25

Do you want focal spot size to be larger or smaller to create a sharper image

Answer 25

Smaller

Question 26

Do you want source to object distance to be longer or shorter to create a sharper image?

Answer 26

Longer

Question 27

Do you want object to image distance to be longer or shorter for a sharper image?

Answer 27

Shorter

Question 28

IF you increase exposure time, how is density and energy affected?

Answer 28

INcreased density (darkness)

Question 29

If you increase mA, how are density and energy affected?

Answer 29

Density increased

Question 30

If you increase kVp, how are density and contrast affected?

Answer 30

INcreased density; decreased contraact

Question 31

If you increase filter, how are density and contrast affected?

Answer 31

Decreased density(lighter); increased contrast

Question 32

If you increase distance, how are density and energy affected?

Answer 32

decreased density (lighter)

Question 33

Incident photon contacts an outer electron Decreases energy About 8% of interactions in a dental x-ray beam

Answer 33

Coherent scattering

Question 34

INcident photon contacts an inner electron and forms an ion pair Increases contrast About 30% of interactions in a dental x-ray beam

Answer 34

Photoelectric absorption

Question 35

Incident photon contacts an outer electron and forms ion pair Decreases contrast About 62% of interactions in a dental xray beam

Answer 35

Compton scattering

Question 36

______ Energy procduced by xray tuve Measured in Roentgen

Answer 36

Exposure

Question 37

Energy abosrbed in tissue MEasrued in Gray

Answer 37

Absorbed dose

Question 38

Energy absorbed in tissue multiplied by radiation weighting factor Measured in Sieverts

Answer 38

Equivalent dose

Question 39

Energy absorbed in tissue multiplied by tissue weighting factor Measured in Sievert

Answer 39

Effective dose

Question 40

___ effects Threshold dose must be achieved before any effects will be seen -Hair loss, cataracts, skin damage, oral mucosisits Not seen in dental xrays

Answer 40

Deterministic effects

Question 41

____ effects Linear no threshold model: there is no threshold dose

Answer 41

Stochastic effects

Question 42

DIrect or indirect radiation: accounts for 1/3 of biologic effects

Answer 42

Direct

Question 43

DIrect or indirect radiation: accounts for 2/3 of biologic effects

Answer 43

Indirect

Question 44

T/F: Cells that are mitotically active are more radiosensitive

Answer 44

Tru

Question 45

What is the occupational exposure limit of radiaition?

Answer 45

50 mSv / yr

Question 46

Is there more or less radiation with digital radiographs?

Answer 46

Less radiation

Question 47

_____ is in developer solution and is first electron donor that reduces silver ions to metallic silver at latent image site

Answer 47

Phenidone

Question 48

_____ in delveloper solution provides an electron to reduce oxidized phenidone to original active state

Answer 48

Hydroquinone

Question 49

____ is part of xray film with silver halide crystals in a gelatin material

Answer 49

Film emulsion

Question 50

____ is the main portion of the fixer solution that acts as a cleaning agent, removes undeveloped silver halide crystals

Answer 50

Ammonium thiosulfate

Question 51

Barium fluorohalide plates capture and store x-ray energy from dental exposure

Answer 51

PSP

Question 52

SIlicon sensor chips captures xray and rapidly displays image on monitor

Answer 52

CCD/ CMOS

Question 53

Angled PA ceph of skull Best film of paranasal sciences

Answer 53

Water's view

Question 54

Angled PA ceph of skull Best film to visualize condyles

Answer 54

Towne's view

Question 55

Base projection of skull Best film to visualize basilar skull and zygomatic fractures

Answer 55

Submentovertex view

Question 56

Central rsy of xray beam aimed perpendicular to the imaginary bisector between long axis of tooth and long axis of receptor

Answer 56

Bisecting angle technique

Question 57

REceptor is placed parallel to long axis of tooth Central ray of xray beam aimed perpendicular to long axis of both tooth and receptor

Answer 57

Paralleling technique

Question 58

What is the most common error in radiology?

Answer 58

Elongation

Question 59

INcreased radiographic density is caused by which of the following? Decreased kVp Decreased mA Decreased targetobject distance Increased object-image distance

Answer 59

Decreased target-object distance

Question 60

If an unwrapped xray film is exposed to ambient light for a second and then processed it _____ Will be darker than normal Will be lighter than normal Completely black completely clear

Answer 60

Completely black

Question 61

Which dental tissue is most likely to interact with xrays via photoelectric absorption?

Answer 61

Enamel: densest tissue

Question 62

Which of the following is the most radiosensitive type of cell? Skeletal muscle fiber Endothelial cell Neuron Macrophage Basal epithelial cell

Answer 62

Basal epithelial cells (stem cells constantly dividing)

Question 63

Which of the following influences the mean energy of xray beam? mA Exposure time Amount of filtration Collimation

Answer 63

Amount of filtration