Test 2

Question 1

T/F: energy does not vanish, it changes - transits from one state to another

Answer 1

TRUE

Question 2

xrays are a type of _____ energy

Answer 2

electromagnetic energy

along with radiowaves, microwaves, UV, infrared

Question 3

the imaging system creates electromagnetic energy by converting ______ to ______

Answer 3

electrical energy to xray photons

Question 4

_____ is energy in transit

Answer 4

radiation

in the form of waves or particles

Question 5

what intercepts/absorbs with radiation then the radiation is said to be exposed

Answer 5

matter

Question 6

radiation when an electron is removed from its orbital

Answer 6

ionization

Question 7

reduced with negative charge electron and positively charged atom

Answer 7

ion pair

Question 8

what 3 rays/lights are capable ionizing matter

Answer 8

xray

gamma ray

UV light

Question 9

what 6 waves/light are not capable of ionizing matter

Answer 9

microwave

radiowave

UV

radar

cell phone

ultrasound

Question 10

radiation:

short freq vs long freq

Answer 10

short freq - greater energy

long freq - less energy

Question 11

natural sources of radiation

Answer 11

radon and cosmic

Question 12

man made radiation

Answer 12

medical imaging

Question 13

____ rays are particulate radiation

Answer 13

cosmic

Question 14

what is the largest natural radiation

Answer 14

radon gas

Question 15

who created the xray and when did he do it

Answer 15

willhelm roentgen

Nov 8, 1895

Question 16

x ray properties

Answer 16

no charge

penetrate most matter dependent on atomic number

ionization and biological effect

make compound fluoresce and emit light

travel at speed of light

Question 17

what are the 3 major components of the imaging system

Answer 17

xray tube

operating console

high voltage generator

Question 18

xrays are emitted ______ or in all directions

Answer 18

isotropically

Question 19

negative end of the xray tube composed of heat resistant filament made of thoriated tungsten

Answer 19

cathode

Question 20

______ : initially low electrical current heats the filament - when the temp becomes high enough the electrons boil off and are ejected from the filament - ______

Answer 20

filament current

thermionic emission

Question 21

most electrons emitted by the cathode are driven back by repulsion of the cloud of electrons

Answer 21

space charge effect

Question 22

cathodes filaments are embedded in _____, accelerates electron beam towards the anode target known as the focal spot

Answer 22

metal focusing cup

Question 23

focusing cup is ____ charged

Answer 23

negatively

Question 24

area of anode surface which receives the beam of electrons from the cathode

Answer 24

focal spot

Question 25

all electrons accelerated from ___ to ___ are negatively chargd

Answer 25

cathode to anode

Question 26

2 focal spots on anode corresponding to large or small filament of cathode

Answer 26

dual focus

Question 27

\_\_\_\_\_mA or more is used for large body part

Answer 27

400

Question 28

\_\_\_\_\_mA or less is used for smaller body parts

Answer 28

400

Question 29

\_\_\_\_\_ is the positive charged end of the xray tube

Answer 29

anode

Question 30

target for xray photons, rotates and dissipates heat during xray

Answer 30

anode function

Question 31

small focal spot allows for greater resolution of image, small focal spots are unable to dissipate heat - if you angle focal spot 5-15\* it will allow for larger area of heat dissipation whiole maintaining small focal spot

Answer 31

line focus principle

Question 32

reduces potential heat damage to the tube by rotating and dissipating heat

Answer 32

anode

Question 33

anode side must always face the thinner body part in order to maintain uniform tissue exposure

Answer 33

anode heel effect

Question 34

electrons that have bounced off and landed outside the focal spot - may contribute to increase in patients dose

Answer 34

extrafocal or off focus radiation

Question 35

will NOT reduce extrafocal radiation because it is not scatter radiation

Answer 35

grid

Question 36

modifies incoming voltage and to provide xray tube with power needed to produce an xray beam - converts voltage to kilovoltage

Answer 36

xray generator

Question 37

permits selection of technical factors and initiates the radiograph - allows you to select a given mA, kV, and time

Answer 37

control panel or operators console

Question 38

modifies the voltage incoming alternating current electrical signals to increase or decrease voltage in a circuit

Answer 38

transformer

Question 39

supplies the high voltage to xray tube - voltage increases and current decreases - creates higher voltage potential to ensure greater xray beam energry

Answer 39

step up transformer

Question 40

supplies power to heat filament of the xray tube - voltage decreases and current increases - creates lower voltage with increased cathode filament current and greater heat - responsible for high number of electrons emitted from cathode

Answer 40

step down transformer

Question 41

converts alternating current into direct current required by xray tube

Answer 41

rectifier

Question 42

restricts current flow in xray tube to one direct from cathode to anode only - prevents damage to xray filament

Answer 42

rectifier

Question 43

what are the two types of rectifiers

Answer 43

half wave full wave

Question 44

closed core transformer, autotransformer, shell type transformer

Answer 44

electromagnetic induction

Question 45

converts alternating current to direct current to ensure sustained flow of electrons to minimize ripple and flunctuation in current

Answer 45

voltage rectification

Question 46

provides constant potential voltage waveform, which doubles the radiation improving the image quality - also minimizes patient dose

Answer 46

high frequency power generator

Question 47

special highly insulated cables - affects the average value of voltage and current across the xray tube - increase power delivered to xray tube

Answer 47

high tension voltage cables

Question 48

beam restrictive lead lined device - used to reduce patients dose by restricting the xray beam

Answer 48

collimator

Question 49

aluminum filters placed at the exit port of the xray tube - primary role is to harden the beam - also removes or absorbs the xrays of lower energy

Answer 49

filtration

Question 50

aims at patient - helps identify the central ray position and bounded exposure area - cross hair of collimator light = central ray of xray beam - aimed at midpoint of anatomic area

Answer 50

collimator light

Question 51

control panel which allows the operator to select appropriate factors such as mA, kvp, and time

Answer 51

operators console

Question 52

adjustable and floatable - allows for better positioning

Answer 52

xray table

Question 53

contains grid which removes scatter radiation and improves image quality - contains cassette holder with film and cassette

Answer 53

bucky system

Question 54

composed of plastic exterior with inserted double sided intensifying screens

Answer 54

casettes

Question 55

made of rare earth elements such as gadolinium oxysulfate - screens emit light photons when interacting with xrays in order to reduce the patients dose - minimizes the number of xray photons during film exposure

Answer 55

intensifying screens

Question 56

composed of polyester and coated with emulsion containing silver halide crystals

Answer 56

radiographic film

Question 57

when exposed to xrays the crystals turn into metallic silver which blackens the film in contrast to the white or unexposed areas corresponding to body parts that have absorbed xrays

Answer 57

silver halide crystals

Question 58

image plate is used made up of photostimulable phosphor located inside cassette

Answer 58

computed radiography

Question 59

NUHS used ______ radiography

Answer 59

computed

Question 60

no cassettes requires - time efficient and lower radiation

Answer 60

digital radiography

Question 61

\_\_\_\_\_\_\_ manual processing takes an hour to process \_\_\_\_\_\_ takes 3 min \_\_\_\_\_\_ processing takes less than a min

Answer 61

radiographic processor - hour automatic processing - 3 min computed tomography - 1min