T2: Radiography Flashcards Preview

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Flashcards in T2: Radiography Deck (49):
1

What is a radiograph?

photographic image caused by x-rays on sensitive film

2

What is radiology?

interpretation of radiographs (x-rays)

3

List some of the radiography licensing requirements

-Compliance w/ code of practice for radiation protection in vet. medicine (2009)

-Info on ventilation, drainage, surfaces

-Assessment of minimum amount of shielding req.

-Name of the personal radiation monitoring device

4

List the PPE required for radiography

-Lead apron, gloves, sleeves

-mobile shields

-personal radiation monitors

-thyroid shields

-goggles

5

What is ALARA and what are the 3 major principles it entails?

As Low As Reasonably Achievable

-TIME

-DISTANCE

-SHIELDING

6

Describe the process of assessing x-ray machine position

-check tube housing parallel to table w/ spirit level -check collimator & tube head are not crooked/

rotated

-Use protractor to measure correct angle of machine if head has angulation indicator

-Machine must be stabled & have means to prevent movement

-Never physically hold x-ray tube housing

7

What is focal film distance and how much should this distance be?

Distance b/w x-ray tube & x-ray film. 75 - 100cm

8

Does a digital radiograph require a darkroom?

No.

9

When should an x-ray grid be used?

for thoraxes deeper than 14cm and other body parts thicker than 10cm

10

What equipment is required for producing radiographs?

-X-ray machine, cassettes, intensifying screens, film & grids

-Table

-Technique charts & correction factors

-Measures

-PPE

-Positioning equip. & labels

-Contrast media

-ID equip.

-Dark room, viewing box & hot light

-Film processing equip.

-Records & storage/filing

11

Veterinarians are legally obliged to permanently mark radiograph. What are/are not acceptable ways of marking radiographs?

NOT acceptable to use pen or sticky label Acceptable:

-collimator marks,

-marker (L or R, Fore or Hind, view)

-ID label: name of practice, owner, date record no# -image

12

Describe the daylight and darkroom systems of ID radiographs

DL: using x-rite tape, or lead letters

DR: light box marker

13

Describe the chemical process (equipment) of creating radiographs, based on a manual system

Developing fluids: film placed in diff. fluids, kept in 3 chamber tank

-Developer: changes silver bromide & film to black metallic silver & is first solution film placed in

-Fixer: renders film light insensitive, also combined w/ hardener which hardens film emulsion to prevent scratching

-Water heater: developing fluid needs to be kept at 20˚C, use thermometer

-Developing tank: 3 chambers for developer - rinsing water

- fixer

-Stirring rods: stirs developing fluid prior to use. Evens temp & homogenises solution

14

What does the developer do?

  • Affected crystals become black (silver precipitates)
  • Unaffected crystals remain clear and wash off

15

What does the fixer do?

  • Makes visible image permanent
  • emulsion hardened

16

When should darkroom chemicals be renewed?

What are some tests that can be done to check this?

Before processing

  • Developer pH test. Should be above 10-11.5 pH
  • Fixer silver test. should be 3-6g/L

17

How much developer replenisher should you add if developer becomes exhausted?

Also how much for fixer?

  • 400ml developer replenisher /sq m film
  • 600ml fixer / sq m

18

Describe manual V auto processing

  • rapid processing solution used in emergencies or surgeries
  • film is developed and fixed for 15 - 20 seconds
  • Does not have same amount of contrast as normal and will discolour w/ time
  • no dark room req

19

What are contrast media in radiography?

Name two examples

 

  • Used to give more detail of a particular organ or body system by admin. compounds that outline interior lining or body cavity
  • Barium
  • Iodine

20

Describe positive contrast media

  • Show up as WHITE
  • Barium suplahte used in GIT
  • Iodine formulated in compounds used IV

21

Describe negative contrast media

  • Show up as BLACK
  • Gas used to outline organ

22

What should be carefully monitoring while a patient is under anaesthesia?

What can happen at deep levels of anaesthesia?

 

  • Monitoring should be continuous; VS every 5 mins
  • PR (rhythm and strength)
  • HR
  • MM colour
  • CRT
  • RR
  • Tidal volume (size of breath; approx 10 -15ml/kg body weight)
  • Temp
  • At deep levels tissue perfusion and oxygenation can become impaired, leading to cell death

23

Monitoring equipment:

What is an oesophageal stethoscope?

  • Used to continuously monitor heart and respiratory sounds
  • signal may be heard through earpieces or speaker

24

Monitoring equipment:

What is an ap-alert respiratory monitor?

  • sounds alarm of patient suffers apnoea (has not taken breath after specified time)
  • Beeping sound emitted w/ each breath
  • No info given on adequacy of breath

25

Monitoring equipment:

What is a pulse oximeter?

  • Measures PR and degree of oxygen saturation in arterial blood
  • Does this by measuring wavelengths of of red and infer-red light

26

Monitoring equipment:

What is an ECG?

  • electrocardiography
  • info on electrical activity of heart
  • no info on cardiac output (how well heart is pumping)
  • Does allow ID of arrythmias and other changes associated w/ physiological abnormalities

27

An anaesthetic record is an important legal document. What sort of things should be recorded?

  • Animal and procedure deets
  • baseline vital signs (b4 procedure)
  • drugs given, before, during, in recovery period
  • anaesthetic regime or equipment used
  • vital signs
  • any relevant comments

28

Once an animals temp falls to ............ cardiac arrest is likely to occur (from hypothermia).
These animals are prone to developing hypoxia.

  • 28 - 30˚C

29

How should you remove an endotracheal tube post anaesthesia in:

dogs?
cats?

  • dogs:
    - remove tube once swallow reflex is regained
  • cats:
    - as soon as show signs of wakening
  • Make sure cuff is deflated before removal

30

What does film density mean?

  • blackening of the film

31

What does film contrast mean?

  • difference b/w shades or densities on the RDG

32

Radiographic faults may occur due to?
(broad over view; 3 major points)

  • Inappropriate restraint or movement of patient
  • Failure to adequately maintain machine or equipment
  • Problems w/ exposure settings or development process

33

What are the many possible reasons as to why a film may be TOO DARK/INCREASED DENISTY?

This includes manual errors, technical errors and automatic processing errors.

  • mAs too high
  • kV too high
  • focal-film distance too short
  • surge in incoming line voltage
  • double exposure
  • forgot to use grid
  • overdeveloped
  • developer temp too high
  • over replenishing
  • light leak in dark room/processor cover
  • speed too slow/malfunctioning rollers

34

What is the kV(p) in relation to x-ray settings?

  • KiloVolt Peak
  • high = stronger x-ray
  • controls quality (grey)

35

What is the mA in relation to x-ray settings?

  • MilliAmps (x seconds)
  • Controls quantity (black)

36

What are the many possible reasons as to why a film may be TOO LIGHT/DECREASED DENISTY?

This includes manual errors, technical errors and automatic processing errors.

  • mAs too low
  • kV too low
  • focal-film distance too long
  • drop in incoming line voltage
  • no exposure
  • thickness wrong (technique chart incorrect)
  • underdeveloped
  • too cold
  • developer exhausted, too dilute, not mixed or contaminated
  • developer temp too low
  • under replenishing
  • exhausted developer

37

What are the many possible reasons as to why a film may be GREY/FOGGED?

This includes manual errors, technical errors and automatic processing errors.

  • accidental exposure to radiation (scatter, direct, secondary)
  • no grid used w/ thick objects
  • old film
  • incorrect storage
  • light leaking in
  • wrong safelight intensity
  • overdeveloping
  • contaminated developer
  • accidental x-ray exposure
  • light leaking
  • developer hot, contaminated, exhausted
  • incomplete fixing

38

What are the many possible reasons as to why a film may have BLACK MARKS/SPOTS?

This includes manual errors, technical errors and automatic processing errors.

  • scratches on film
  • rough handling
  • cassette not closed properly
  • film exposed to light
  • developer on unprocessed film
  • films stuck together in fixer

39

What are the many possible reasons as to why a film may have WHITE MARKS/SPOTS?

This includes manual errors, technical errors and automatic processing errors.

  • dirt/hair b/w film and screen
  • crack or defect in screen
  • damaged screens
  • grit/dust on film surface
  • air bubbles on film
  • film touching sides of tank

40

What are the many possible reasons as to why a film may have LINES?

This includes manual errors, technical errors and automatic processing errors.

  • grid out of focal range, upside-down, damaged
  • primary beam not centred

41

What are the many possible reasons as to why a film may be BLURRED?

This includes manual errors, technical errors and automatic processing errors.

  • grid out of focal range, upside-down, damaged
  • primary beam not centred
  • dirty rollers, wash water, air tubes
  • jammed films

42

Poor image quality:

What may cause low contrast?

  • Too high kV
  • Slow speed screen/film
  • No grid
  • Under filtration
  • Double exposure

43

Poor image quality:

Why may the image have poor detail?

  • blurring due to motion
  • machine focal spot too large or damaged
  • unsharpness: double exposure, object too thick, FF distance too short
  • Distortion/magnification: area of interest not close enough to film, primary beam not centred

44

How to improve image quality:

What shoulds you do if film intensity too dark?

  • decrease mAs by 30 – 50%
  • decrease kV by 10 – 15%

45

How to improve image quality:

What shoulds you do if film intensity too light?

  • Increase mAs by 30 – 50%
  • Increase kV by 10 – 15%

46

How to improve image quality:

When should you increase the factors?

  • object has increased fluid
  • obesity
  • plaster cast
  • positive contrast rdg (barium, iodine)

47

Evaluating the improperly exposed radiograph
(view pic in answer)

A image thumb
48

What details should you put in the radiographic record?

  • date
  • patient name/ID number
  • client name
  • type of animal
  • area viewed
  • positioning
  • tissue depth
  • exposure factors used
  • use of grid
  • developing time
  • comment on film quality

49

How should you clean and maintain equipment?
(simple, brief, not step by step).

  • Follow manufacturers instructions.
  • Do not bump tube
  • Keep tube free from dust, dirt and safely retracted out of the way
  • Never hold x-ray machines or tubes during exposure
  • Avoid prolonged use of ready modes and lighting of collimator
  • Clean surfaces w/ metho