Part 2 X-Ray Physics

Front 1

What is another name for a photon in the air?

Back 1

Roentgen

Front 2

Diagnostic ability of Xray comes from ____________

Back 2

Ionization

Front 3

Roentgens produce ____% heat and ___% diagnostic ability

Back 3

99%, 1%

Front 4

What is a REM?

Back 4

Roentgen equivalent in man. This is the dose to a technician. A badge is worn to determine mAs (how many photons have hit them)

Front 5

What is MPD?

Back 5

Maximal Permissible Dose. Doseometry uses badges to determine the does a technician has been exposed to. A tech is only allowed to be exposed to 5 REMs per year. Formula for calculation is 5(N-18) 5 being max per year and N being current age. 18 comes from the youngest age you can be to work in xray. A 20 year old would calculate as follows: 5(20-18)= 10 REMS

Front 6

What is a RAD?

Back 6

Roentgen Absorbed Dose in anything. This includes the patient being exposed, and also anything that may make it through the walls and expose items or people outside the xray facility.

Front 7

Name 4 things used to reduce Anode heat.

Back 7

1. Rotate Anode (rotor)
2. Drop of oil
3. Long filament
4. Line focus principle

Front 8

What metal is found inside the xray machine to bounce electrons off?

Back 8

Tungsten

Front 9

What metal surrounds the x ray machine?

Back 9

Aluminum

Front 10

What metal is used in the grid?

Back 10

Lead

Front 11

What creates scatter?

Back 11

The patient. Big muscular people create the most scatter, therefore you have to increase the kVp

Front 12

With regards to screen crystals, what is the result of using small sized crystals?

Back 12

Great quality film, but high radiation to the patient

Front 13

With regards to screen crystals, what is the result of using large sized crystals?

Back 13

Low radiation to the patient, but produces a poor quality film

Front 14

With regards to screen crystals, what is the result of using no crystals?

Back 14

Best image available; however WAY too much radiation to the patient

Front 15

What size crystals do Rare Earth films use?

Back 15

Medium sized, good film, some radiation

Front 16

Are Chiropractic films shot with the cathode up or down?

Back 16

Cathode down due to Anode Heel Effect.

Front 17

In Primary Radiation, what produces the most photons (nucleus interaction)?

Back 17

Bremsstrahlung (Braking)

Front 18

In Primary Radiation, what produces the most energy (inner shell collision)?

Back 18

Characteristic (Collision)

Front 19

In Secondary Radiation, what produces outer shell electron collision, and as a result, energy loss?

Back 19

Compton (scatter)

Front 20

In Secondary Radiation, what produces an equal energy exchange and low energy photons?

Back 20

Thompson (Classical)

Front 21

With regards to kVp, what produces high contrast (few shades and short scale)?

Back 21

Low kVp

Front 22

With regards to kVp, what produces low contrast (lots of shade and long scale)?

Back 22

High kVp

Front 23

On xray, what is responsible for contrast?

Back 23

kVp

Front 24

On xray, what is responsible for density?

Back 24

mAs

Front 25

If you increase mAs, what will happen to the density?

Back 25

It will increase

Front 26

If you decrease kVp, what will happen to the contrast?

Back 26

It will increase (inverse relationship)

Front 27

What rule is used to alter contrast while maintaining the current density?

Back 27

15/50 rule 15 (kVp) / 50 (mAs)

Front 28

What does the inverse square law apply to?

Back 28

Focal film distance and mAs (density). If you double the distance, you have to 1/4th the mAs. If you half the distance, you need to 4X the mAs

Front 29

How do you increase detail on a film? (This WILL be on exam, know it!)

Back 29

Distance: Increased, FFD (film focal distance), decreased OFD (object film distance)
Shadow: Umbra
Screen: small crystals (Rare Earth blue green crystals are the exception- medium sized)
Focal spot: small (but hot spot on anode!)

Front 30

How do you decrease detail on a film? (This WILL be on exam, know it!)

Back 30

Distance: Decreased FFD (film focal distance), increased OFD (object film distance)
Shadow: Penumbra
Screen: Large crystals
Focal Spot: Large

Front 31

Water droplets between two films creates what?

Back 31

Kissing defect

Front 32

Static on a film is due to what?

Back 32

Lack of humidity

Front 33

Added filtration is what measurement?

Back 33

Usually aluminum and added (plus) inherent = total 2.5mm

Front 34

What is the line focus principle?

Back 34

Increase the angle of the target, which allows you to use a large filament which produces a larger focal spot (therefore no hot spot), and produces a smaller effective beam (greater detail)

Front 35

What is the grid ratio?

Back 35

It is the height to distance between lead strips

Front 36

What is the grid frequency?

Back 36

Number of strips per inch

Front 37

Film ____ supports the emulsion with the silver bromide and halide crystals.

Back 37

base

Front 38

In what order does the film development process occur?

Back 38

Develop--fix--wash--dry

Front 39

What color and wattage is preferred for a safe light?

Back 39

Red light, 7 watts (10 watts is 2nd best answer if 7 isn't listed)

Front 40

What is the purpose of a recumbent film?

Back 40

It compresses tissue. Used especially when the patient has excess weight.

Front 41

What makes up Quantum mottle?

Back 41

Screen crystal & packets of photons

Front 42

What does the law of Bergonie and Tribondeau state?

Back 42

X-rays are more effective on cells which have a greater reproductive activity.

Front 43

Which cells are the most radiosensitive (mutate)?

Back 43

Blood (WBC) and sperm

Front 44

Which cells are the least radiosensitive (death)?

Back 44

nerve, thyroid, ovaries

Front 45

What does a notch on the side of film indicate?

Back 45

That it is duplicating film

Front 46

_________ reduces exposed silver crystals

Back 46

Developer

Front 47

_______ removes unexposed crystals (clears, hardens) and has the most silver in it.

Back 47

Fixer

Front 48

______ discoloration is caused from poor washing

Back 48

Brown

Front 49

Old developer causes ______ film

Back 49

yellow

Front 50

If film is not exposed and developed, it will be what color?

Back 50

translucent / clear

Front 51

If film is exposed and developed, it will be what color?

Back 51

black

Front 52

Geometric unsharpness, image blur around the edges of the image

Back 52

Penumbra

Front 53

Which line is drawn from the hard palate to the foramen magnum to look for basilar invagination?

Back 53

Chamberlain's line

Front 54

Which line is drawn from the hard palate to the occiput to look for basilar invagination?

Back 54

McGregor's Line

Front 55

Which line is drawn from the nasion to the sella, then to the foramen magnum to check for Platybasia (Arnold Chiari malformation)?

Back 55

Martin's Basilar Angle

Front 56

Which line is drawn from anterior foramen magnum to posterior foramen magnum?

Back 56

McRae's Line

Front 57

Which line is drawn on a neutral lateral cervical film from the posterior body of C2 to the posterior body of C7 to look for kyphosis?

Back 57

Jackson's Stress Line

Front 58

Which line is drawn on the anterior aspect of spinouses in the cervicals (posterior spinal canal)?

Back 58

Spinolaminar Line

Front 59

Which line is drawn on the posterior aspect of the bodies (anterior spinal canal)?

Back 59

George's Line

Front 60

What does Eisenstein's canal to body ratio state?

Back 60

Body size to spinal canal should be 2:1 (good) 4:1 would be bad!

| BODY | canal |

Front 61

Which line is drawn from the inferior endplate of the superior vertebra to the superior facet of the inferior vertebra and is taken to check facet imbrication? (Only used when film is taken recumbent)

Back 61

McNab's Line

Front 62

Which line is drawn on a hyper extension film to predict facet degeneration?

Back 62

Van Akkerveeken's

Front 63

Which line is looked for on an A-P or Oblique film to check for alignment?

Back 63

Hadley's "S" Curve

Front 64

Which line is also known as the Lumbar Gravity Line, looks at sacral base relative to the floor and has an angle of less than 35-45 degrees in a normal patient?

Back 64

Ferguson's Line

Front 65

Which line indicates Hyperlordosis, increased shear and anterior weight bearing?

Back 65

Anterior Sacrum Line

Front 66

Which line indicates Hypolordosis, increased weight on sacrum and posterior weight bearing?

Back 66

Posterior Sacrum Line

Front 67

Which line looks at L5 relative to the sacral base, and should be less than 10-15 degrees in a normal patient?

Back 67

Lumbosacral Disc Line

Front 68

Where is a Salter Harris Type I fracture?

Back 68

At the growth plate (slipped Capital Epiphysis)

Front 69

Where is a Salter Harris Type II fracture?

Back 69

Growth plate and through Metaphysis

Front 70

Where is a Salter Harris Type III fracture?

Back 70

Growth plate, and through Epiphysis

Front 71

Where is a Salter Harris Type IV fracture?

Back 71

Obliquely through Epiphysis, growth plate and metaphysis

Front 72

Where is a Salter Harris Type V fracture?

Back 72

Compression fracture at growth plate (scoliosis)

Front 73

Which scoliosis is most common?

Back 73

Right lateral deviation of the spine

Front 74

Who generally has scoliosis most often, and where is it found?

Back 74

It is most commonly seen in the right Thoracolumbar region of adolescent girls.

Front 75

Which test is used to determine if a scoliosis is structural (progresses until maturation) or functional?

Back 75

Adam's Test

Front 76

What is the protocol for the care of scoliosis?

Back 76

0-20 degrees - Adjust
20-40 degrees - Bracing
> 40 degrees - Surgery
> 50 degrees causes cardiopulmonary compromise

Front 77

What does Kohler's teardrop (Walstrum's teardrop) indicate?

Back 77

Acetabular protrusion:
- bilateral (Paget's & RA)
- unilateral (Infection & OA)

Front 78

What does Klein's line indicate?

Back 78

Slipped capital epiphysis

Front 79

What does Skinner's line indicate?

Back 79

Paget's (Horizontal line where if bone slips below it =Bone softening)

"Skin head gets pushed below the line"

Front 80

Which line is curvi-linear, goes from the superior obturator to the inferior femoral and checks for general pathology?

Back 80

Shenton's

Front 81

What does the Femoral Angle (aka Mikulicz's) indicate?

Back 81

Coxa Vara = < 120 degree

Coxa Valgus = > 130 degree

Normal = 120-130 degrees

Front 82

What does Boehler's Angle indicate?

Back 82

If < 28 degrees indicates a calcaneal fracture. >28 degrees normal

Front 83

Rectifier

Back 83

changes AC to DC

Front 84

Transformer

Back 84

Steps up or down the power

Front 85

Transducer

Back 85

one form of energy to another

Front 86

Attenuation

Back 86

beam of radiation loses energy as it passes thru matter

Front 87

Low KVP =

Back 87

Black and White film

Front 88

High KVP =

Back 88

A lot of grey on the film

Front 89

1 RAD = ? REM

Back 89

1 REM

Front 90

Safe limit of RADs / year

Back 90

5 RADs (REM) per year

Front 91

Air-Gap Technique

Back 91

6-10" between the patient and the fim. Reduces patient does, but can magnify or distort the image