Radt1

Front 1

What are x-rays?

Back 1

X- rays are a form of electromagnetic radiation with greater energy and shorter wavelength than visible light

Front 2

What is electromagnetic radiation?

Back 2

A method of transporting energy through space; can be described as particles or waves; has wavelength, frequency, and energy

Front 3

What is the relationship between wave length and energy?

Back 3

As wave length is decreased, energy is increased

Front 4

How are x-rays produced?

Back 4

When charged particles (electrons) are emitted from a cathode and strike the atoms of a target area (metal)

Front 5

What is excitation?

Back 5

When an atom receives a photon (bundle of energy) causing an electron to temporarily move up an energy level

Front 6

What is bremsstrahlung?

Back 6

Braking radiation; when the electron emitted from the cathode hits or approaches the nuclei of the metal target and becomes deviated due to the electromagnetic interaction, causing energy to be emitted in the form of a photon

Front 7

What are the physical properties of x-ray electromagnetic radiation?

Back 7

1. Wavelength; variable and energy-related

2. Direction; straight, can change directions

3. Penetration; varying degrees through objects

4. Fluorescence; causes on certain material

5. Latent image; invisible image, pre-processing

6. Excitation; causes

7. Mutogenic; causes changes in tissue

Front 8

What does the x-ray tube consist of? What occurs in the x-ray tube?

Back 8

A cathode and an anode; negatively charged electrons are emitted from the cathode towards the anode, where the electrons collide with positively charged molecules

Front 9

What kinds of energy are produced by the x-ray machine and what percentage of each?

Back 9

Heat, x-ray; 99%, 1%

Front 10

What is ionization?

Back 10

The process of removing electrons from an atom to create a positive charge

Front 11

When are x-rays most dangerous to living organisms?

Back 11

During fetal life (in humans, first trimester)

Front 12

What are the regulations on x-ray safety as according to OSHA, RRO 1990, Regulation 861?

Back 12

1. X-ray machines must be licensed, regulated, and inspected every 5 years

2. Employers have the responsibility of ensuring proper training and following of procedures is followed

Front 13

What is a dosimeter?

Back 13

A tool that measures accumulated radiation exposure

Front 14

How often do dosimeters have to be sent to a radiation protection bureau?

Back 14

Quarterly

Front 15

What PPE must be worn when taking x-rays while restraining?

Back 15

Gloves, apron, and thyroid shield with at least 0.5 mm of lead

Front 16

What is scatter radiation?

Back 16

Radiation produced when x-ray primary beams strike an object and reflect off, causing the scatter

Front 17

What three things should you think about in consideration to x-ray safety?

Back 17

1. Time (exposures)

2. Distance

3. Shielding

Front 18

What are the factors of exposure?

Back 18

1. mA and time

2. mA and kVp

3. Distance

Front 19

What is kVp?

Back 19

The penetrating power of the x-ray; the speed of which the electrons emitted by the cathode travel

Front 20

What effect does higher kVp have on an x-ray film?

Back 20

Higher kVp creates a darker/blacker image

Front 21

What is the quantity as it relates to x-rays?

Back 21

The number of electrons that will be converted to x-rays, produced by the mAs at the filament

Front 22

How are electrons produced?

Back 22

By heating the filament (at the cathode)

Front 23

What is thermionic emission?

Back 23

Electrons produced by the heating of the filament and the formation of an electron cloud around the filament

Front 24

What heats the filament?

Back 24

Milliamperes

Front 25

What is mA equivalent to?

Back 25

Quantity, or number, of x-rays produced

Front 26

What is total quantity dependent on?

Back 26

Length of exposure (time) as well as mA; mAs

Front 27

What would be preferable to change in x-ray quantity factors and why?

Back 27

Time; limits chance of patient moving and exposure to personnel

Front 28

What does kVp stand for and what does kVp affect?

Back 28

Kilovoltage potential or peak; quality

Front 29

What is kilovoltage?

Back 29

The kinetic energy of the electron

Front 30

What occurs to the average x-ray wave as kVp is increased?

Back 30

The average energy increases and exists at the same level than at lower kVp values

Front 31

What is the relationship between penetration and wavelength?

Back 31

The higher the penetration, the smaller the wavelength

Front 32

What is Sante's rule?

Back 32

kVp = thickness in cm x 20 + 40 (inches of SID)

Front 33

What is the inverse square law?

Back 33

The intensity of the x-ray varies inversely with the distance squared from the source of the radiation (SID)

Front 34

What is intensity roughly equivalent to?

Back 34

1/SID^2

Front 35

What does SID affect on an x-ray image?

Back 35

The detail or image sharpness

Front 36

What does radiographic quality depend on?

Back 36

1. Density

2. Contrast

3. Detail and definition

Front 37

What is density?

Back 37

The degree of blackness or darkness on a radiograph

Front 38

What does density depend on?

Back 38

1. Quality (kVp)

2. Quantity (mAs)

3. Distance (SID)

4. Type/thickness of tissue

5. Processing

Front 39

What can you change during radiograph development/processing that will increase quality?

Back 39

1. Developing time

2. Developing temperature

Front 40

What is contrast? What can it be separated into?

Back 40

The visible difference between two adjacent radiographic densities; can be separated into radiographic contrast (contrast of adjacent areas on radiograph) and subject contrast (contrast of adjacent anatomical structures)

Front 41

What is a secondary way in which kVp affects contrast?

Back 41

The higher the kVp, the more scatter radiation, thus producing lower contrast as more grayness is created

Front 42

Why is scatter radiation undesirable?

Back 42

1. Exposes undesirable areas of film, causing poor contrast

2. Can be dangerous to patient and restrainer

Front 43

What affects scatter radiation?

Back 43

1. Greater patient thickness and density

2. High kVp

3. Increased field size

Front 44

When are grids used?

Back 44

To radiograph thicker body parts (more than 10 cm)

Front 45

What are the requirements for the safe light in a dark room?

Back 45

1. A maximum wattage of 15

2. Minimum distance of 4 feet from radiographs

Front 46

How do you test a safe light?

Back 46

By exposing the film in 1/4 increments for 1 minute intervals; film should be white/light, not dark

Front 47

What are the five steps of manual processing?

Back 47

1. Developing

2. Rinsing

3. Fixing

4. Washing

5. Drying

Front 48

Why should lids be kept on the fixer and developer chemicals?

Back 48

Chemicals will oxidize and darken

Front 49

What is the purpose of the developer?

Back 49

To convert a latent image to a visible image; to convert exposed silver halide crystals to black metallic silver

Front 50

What are the components of a developer?

Back 50

1. Developing or reducing agent

2. Accelerator or activator

3. Preservative

4. Restrainer

5. Solvent

Front 51

What are the components of the rinse bath?

Back 51

Water or acetic acid (vinegar)

Front 52

What are the purposes of the fixer?

Back 52

1. To clear away unexposed, undeveloped silver halide crystals; changes colour from milky white to clear white

2. To harden the emulsion

Front 53

What are the components of the fixer?

Back 53

1. Clearing or fixing agent

2. Preservative

3. Hardener

4. Acidifier

5. Buffer

6. Solvent

Front 54

What is the purpose of the wash bath?

Back 54

To remove the processing chemicals from the film

Front 55

What occurs in the silver halide crystals after exposure and during development?

Back 55

1. Exposed silver halide crystals are converted to black metallic silver by the developer

2. Unexposed silver halide crystals are removed by fixer

Front 56

Why can't fixer be poured down the drain?

Back 56

The fixer contains unexposed silver halide crystals washed away from film

Front 57

What are the advantages of automatic radiograph processing?

Back 57

1. Standardized consistent quality

2. Fast processing

3. Dries quickly

4. Saves labour

Front 58

What are the steps for the automatic processor?

Back 58

1. Close wash drain valve

2. Open water supply tap

3. Close processor cover and feed tray cover

4. Turn on power breaker

5. Press run button

6. Wait for ready lamp to light in 20 minutes

Front 59

Why should the feed tray cover of the automatic processor be left open?

Back 59

To prevent condensation of the chemicals when not processing

Front 60

How should the automatic processor be shut off?

Back 60

1. Turn off power breaker

2. Close water supply tap

3. Open wash drain valve only

4. Open feed tray cover and processor

Front 61

What temperature is the automatic processor water at?

Back 61

39 degrees celsius

Front 62

Why must film be identified in emulsion?

Back 62

1. Later identification

2. Determination of progressive evaluation

3. Legally required

Front 63

What must be on the film label?

Back 63

1. Name and address of hospital, practice, or veterinarian

2. Date

3. Patient information (can be substituted with file or radiography number)

Front 64

What types of film labels are there?

Back 64

1. Lead markers

2. Lead impregnated tape

3. Photoimprinting system

Front 65

What must Seneca film labels include?

Back 65

1. Radiography log number

2. VAS number

3. Group identification

4. Settings of x-ray machine

5. Date

6. Anatomy and view

Front 66

How long must radiography logs be kept? How are radiography file numbers determined?

Back 66

5 years; current year followed by the x-ray number in three digits

Front 67

By what percentage should kVp or mAs be changed if modifications are needed?

Back 67

10%-15%; 2x or 1/2 (or 30%-50%)

Front 68

How much change is required to see a difference in density at lower kVp compared to higher kVp?

Back 68

Less change is required to see a change at low kVp, while more change is required at high kVp

Front 69

What does the first word or letter of positioning refer to? What does the second?

Back 69

The first area of the body at which the x-ray beam first penetrates

Front 70

What are the basic criteria for patient positioning?

Back 70

1. Welfare of the patient

2. Restraint and immobilization of the patient

3. Minimal trauma to area of interest

4. Least exposure to assistants

Front 71

What is the difference between radiopaque and radiolucent?

Back 71

Radiopaque objects do not allow penetration of the x-ray beam and thus show up white; radiolucent objects allow penetration of the x-ray beam and do not show up on x-rays

Front 72

What should you keep in mind while positioning for a radiograph?

Back 72

1. Where the area is measured

2. Where the area is centered

3. Peripheral boundaries

4. Parallel/perpendicular maintenance

Front 73

Where should an animal be measured for thoracic positioning?

Back 73

At level of the caudal border of scapula

Front 74

Where is the central beam for a lateral, DV, and VD x-ray?

Back 74

Lateral: Right 5-6th rib or caudal border of scapula

DV and VD: Caudal border of scapula

Front 75

When lungs are examined, where should the peripheral borders be?

Back 75

The scapulohumeral articulation/joint to L1

Front 76

How can inspiration be observed and why is it useful?

Back 76

Inspiration can be seen by observing the distance between the diaphragm and the heart; thoracic x-rays are best seen in inspiration (abdomen in expiration)

Front 77

What are concerns to keep in mind when taking DV x-rays?

Back 77

1. Motion

2. Hip dysplasia

3. Deep-chest

4. Trauma

Front 78

What are concerns to keep in mind when taking VD x-rays?

Back 78

1. Respiratory distress

2. Trauma

3. Motion

Front 79

When are thorax x-rays typically used?

Back 79

Breathing concerns and thoracic trauma

Front 80

How can you differentiate between VD and DV on a radiograph?

Back 80

The heart will appear longer and more oval in VD; the heart will appear shorter and displaced more in the left hemithorax in DV

Front 81

How can you differentiate between right lateral and left lateral on a radiograph?

Back 81

In a right lateral radiograph, the heart will appear oval in shape; in a left lateral radiograph, the heart will appear rectangular in shape

Front 82

Where should an animal be measured for an abdominal x-ray? Where should the beam be centered for a VD abdominal x-ray? What are the peripheral borders for a VD abdominal x-ray?

Back 82

At the thoracolumbar junction (the caudal aspect of the 13th rib); centered at 13th rib for canines and two fingerbreadths caudal for felines; T9 to femoral head

Front 83

What are the concerns to keep in mind when taking a VD abdominal x-ray?

Back 83

1. Trauma

2. Bloat

3. Emaciated

4. Obese

Front 84

What are the concerns to keep in mind when taking a lateral x-ray?

Back 84

Fluid, free air, or dyspnea

Front 85

What is barium used for and when should it not be used?

Back 85

Barium used for viewing obstructions and outline of intestinal tract; should not be used if tears or perforations of the digestive tract is suspected as it can cause peritonitis

Front 86

Why is the right lateral view preferable to the left?

Back 86

Stomach gas will move to the fundus and body, allowing for better visualization of the stomach as air moves upwards but fluid remains

Front 87

What should be changed when considering obese or emaciated animals?

Back 87

In obese animals, exposure should be increased; in emaciated animals, exposure should be decreased

Front 88

What size are the kidneys and where are they located in canines and felines on a radiograph?

Back 88

3x the size of L2

Canine: L kidney, L2-L4; R kidney, T12-L2

Feline: L kidney, L3-L5; R kidney, L1-L3