Review

Question 1

Exists a threshold dose; deterministic radiation

Answer 1

Non-stochastic

Question 2

Occurs randomly; probabilistic radiation

Answer 2

Stochastic

Question 3

Divergence of x-ray as it travels

Answer 3

Attenuation

-Effected by SAD (Scatter, Absorption, Distance)

Question 4

Used to describe the amount of energy deposited in tissue (absorbed dose)

Answer 4

RAD (Radiation Absorbed Dose)

Question 5

Dose equivalence; unit of reporting occupational exposure

Answer 5

REM (Radiation Equivalent Man)

Question 6

Inverse Square Law

Answer 6

I1/I2 = D2^2/D1^2

Question 7

Site of x-ray production

Answer 7

Anode

Question 8

Source of electrons

Answer 8

Cathode

Question 9

If image is too dark (excess density)

Answer 9

Overexposure

Question 10

If image is too light (insufficient density)

Answer 10

Underexposure

Question 11

Short scale contrast

Answer 11

Overall image: very black and white
Number of grays: few
Contrast: high

Question 12

Long scale contrast

Answer 12

Overall image: very gray
Number of grays: many
Contrast: low

Question 13

Majority of the beam formation

Answer 13

Bremsstrahlung (Brems): < 69.5 kV –> 100% Brems

Question 14

Leads to development of characteristic radiation

Answer 14

Photoelectric effect: > 69.5 kV –> 10-15%

Question 15

Decides the energy/quality of the beam

Answer 15

kVp; controls the radiographic density

e.g. high kVp means less photon absorption and more shades of gray

Question 16

Decides beam quantity

Answer 16

mA

Question 17

Casting effects on mAs

Answer 17

Plaster: 2x (dry); 3x (wet)
Fiberglass: 40% (dry); 60% (wet)

Question 18

Radiosensitive cells

Answer 18

Skin basal cells, blood cells, intestinal crypt cells, reproductive cells

Question 19

Radioresistant cells

Answer 19

Brain cells, muscle cells, nerve cells

Question 20

5 Steps of Radiographic Interpretation

Answer 20

1. Quality
2. Soft Tissue
3. Bone & Bone Density
4. Joints & Joint Spaces
5. Biomechanical Evaluation

Question 21

Types of accessory naviculars

Answer 21

Type 1: Os Tibiale Externum; sesamoid within tibialis posterior tendon
Type 2: Pre-hallux; articulates with the navicular
Type 3: Cornuate/Gorilloid navicular; fused with the navicular

Question 22

Teardrop sign of ankle

Answer 22

Due to traumatic hemarthrosis of ankle joint; see outpocketing of ankle capsule on lateral projection

Question 23

Sullivan’s Sign

Answer 23

Splaying of digits due to neuroma formation