SUMMARY 2

Question 1

What does position indicating device provide?

Answer 1

collimation

Question 2

what do electrons contact that produces x-rays?

Answer 2

tungsten target

Question 3

what dissipates heat?

Answer 3

copper rod

Question 4

where do x-rays lie on the electromagnetic spectrum?

Answer 4

between ultraviolet radiation and gamma rays

Question 5

what are electromagnetic waves packaged in to?

Answer 5

photons

Question 6

what happens to photons?

Answer 6

produced by x-ray tube, scattered and absorbed by tissue.

Question 7

what is attenuation?

Answer 7

how the x-ray beam weakens as it travels through matter

Question 8

what are receptors?

Answer 8

digital sensors that produce image

Question 9

what is a form of energy that acts by removing electrons from atoms and molecules to create ions?

Answer 9

ionising radiation

Question 10

in the x-ray tube, what is the cathode?

Answer 10

tungsten filament that produces electrons

Question 11

in the x-ray tube, what is the anode?

Answer 11

tungsten target that converts electrons to photons

99% heat
1% photons

Question 12

what is the glass for in an x-ray tube?

Answer 12

insultation

Question 13

what is aluminium for in an x-ray tube?

Answer 13

filtration

Question 14

what is lead for in an x-ray tube?

Answer 14

collimation - maintains a singular beam

Question 15

what does exposure time impact?

Answer 15

beam intensity

Question 16

what is mA?

Answer 16

tube current - flow of electrons through tube from filament to anode and then back

Question 17

what is kVp?

Answer 17

tube potential - electrons from cathode to anode (generate photons)

Question 18

what does aluminium do to act as a filter?

Answer 18

filters out low energy photons, reducing beam intensity - reduces dose, increasing image quality

Question 19

how does collimation work?

Answer 19

lead barrier that reduces scatter by limiting the size of the beam to either circle or rectangle

Question 20

what does a SOD increase result in?

Answer 20

intensity decrease

Question 21

what does an IOD decrease result in?

Answer 21

sharper image, less magnification

Question 22

what is it called when incident photon contacts outer shell electron and becomes shattered photon, changing direction?

Answer 22

coherent scattering

Question 23

what is the result of coherent scattering?

Answer 23

decrease contrast

Question 24

what is it called when incident photon contacts inner electron and forms an ion pair?

Answer 24

photoelectric absorption

Question 25

what is the result of photoelectric absorption?

Answer 25

increase contrast

Question 26

what is it called when incident photon contacts an outer electron and forms an ion pair?

Answer 26

compton scattering

Question 27

what is the result of compton scattering?

Answer 27

decrease contrast

Question 28

explain the bisecting angle technique?

Answer 28

x-ray aimed perpendicular to bisector between long axis of tooth and long axis of receptor

Question 29

explain the paralleling technique

Answer 29

receptor placed parallel to long axis of tooth x-ray perpendicular to long axis of tooth

Question 30

what intra oral technique is a bit more magnified?

Answer 30

paralleling

Question 31

what are the layers of an x-ray film?

Answer 31

base - flex plastic film emulsion - silver halide crystals in gelatine intensifying screen (in DPT) - coated with fluorescent phosphor

Question 32

what reaction results in a latent image?

Answer 32

silver halide crystals to reduced to neutral silver atoms

Question 33

what is a latent image?

Answer 33

invisible image

Question 34

what is converted into a visible image through chemical processing?

Answer 34

metallic silver

Question 35

what is radiolucency?

Answer 35

dark - photons pass through tissue to reach the film

Question 36

what is radioopacity?

Answer 36

light - photons attenuated and dont reach the film

Question 37

what is developing?

Answer 37

turning latent image to visible image

Question 38

what does the developing solution do?

Answer 38

converts crystals into metallic silver grains that are seen as dark on the image

Question 39

what does developing solution contain?

Answer 39

phenidone and hydroquinone

Question 40

what does phenidone do?

Answer 40

first electron donor that reduces silver ions to metallic silver at latent image

Question 41

what does hydroquinone do?

Answer 41

provides an electron to reduce oxidised phenidone to its original active state

Question 42

what is fixing?

Answer 42

washing away unexposed/ undeveloped silver grains

Question 43

what does fixer solution do?

Answer 43

removes unexposed silver halide crystals from emulsion, keeping the black metallic silver

Question 44

what does fixer solution contain?

Answer 44

ammonium thiosulphate - cleaning aluminium salts - hardener acetic acid - neutraliser sodium sulphite - preservative water - solvent

Question 45

what does washing do?

Answer 45

washes away residual chemicals

Question 46

what part of CCD/CMOS captures x-rays and displays image?

Answer 46

silicon sensor chip

Question 47

what part of the PSP plate captures x-rays?

Answer 47

barium fluorohalide