What is the most common form of protection from radiation?
Lead shielding
100
Name three important functions of cassettes?
1) protect film from light
2) protect from damage (wrinkled, bent, scratched)
3) keep the intensifying screen in close contact to the film during exposure.
100
What is found in the mediastinum?
heart, trachea and esophagus
100
Name the four classifications of bones and an example of each.
1) long = femur
2) short = tarsals
3) flat = scapula
4) irregular = vertebra
100
What is fog?
Unwanted exposure to film, that will cause an overall increase in density.
200
Name the effective dose limit for a year for 1)occupationally exposed personnel 2)cumulative dose limit 3)general public.
1) 5 rem/year
2) age= rem/year
3).1 rem
200
Name thee three systems in the automatic processor?
1) transport- moves film
2) replenishment- adds fresh developer and fixer
3) recirculation
200
What structure separates the thoracic cavity from the abdominal cavity?
diaphragm
200
Name the heel bone?
Calcaneous
200
What are the two systems used to measure radiation and dose?
*also name the units
Conventional (British) System International (SI)
Roentgen --------------------------> Colombs
Rad --------------------------> Gray
Rem --------------------------> Siervert
300
What is RBE (relative biologic effectiveness)?
The ability of radiation to provide biologic damage
300
What type of filter must be on the light found in the darkroom and why?
GBX. Safe for use because it does not penetrate blue, green, or x-ray sensitive film.
300
What is the proper patient breathing instruction for a CXR?
1) effective communication-explain in laymens terms
2) positioning- position pts in comfortable position
3) immobilization
4) short exposure time
400
What two types of interaction can cause injury to living cells?
Indirect hit and direct hit
Indirect hit-Chemical reaction occurs in the cells water causing the formation of free radicals
Direct hit-Breakage of DNA molecule as a result of being struck by x-ray photons
400
What metal is found in the processor fixer fluid that must be recycled?
Silver
400
What is the desirable CXR technique?
High kVp, high mA, short time
400
Name the cassette and view for hand, wrist, and forearm.
BODY PART CASSETTE VIEWS
Hand (2) 10x12 PA,Oblique
1 8x10 Lateral
Wrist 10 x 12 PA,Oblique,Lateral
Forearm 14x17 AP, Lateral
400
State the Bergonie-Tribodeau law
Cell sensitivity to radiation exposure depends on 4 characteristics.
AGE-younger cells > older cells
DIFFERENTIATION- simple cells > older cells
METABOLIC RATE- faster metabolism > slower metabolism
MITOTIC- cells that divide and multiply rapidly > those that duplicate slowly
500
List the classifications of radiologic effects.
non-stochastic, stochastic, somatic
non-stochastic-occur at high doses. They are predictable and the effects are directly proportional to the dose.
stochastic-occur at low doses and the effects are random and unpredictable. This usually occurs in diagnostic procedures.
somatic-affects the body of the individual being irridated. Occurs in high doses of radiation
500
Name some film handling artifacts, automatic processor artifacts,and manual processor artifacts?
Film handling artifacts
-crescent marks
-abrasions
Automatic processor artifacts
-chemical stains
-roller marks
Manual processing artifacts
-"air bells"
-kiss marks
500
What is atelectasis?
Lung collapse
500
Name the cassette, views, and angle for foot, tib/fib, and knee.
BODY PART VIEWS CASSETTE ANGLE
Foot AP Axial, Oblique (2) 10x12 10*
Lateral
Tib/Fib AP, Lateral (2) 14x17 -
Knee AP, Lateral (2) 10 x12 5*
500
What is the inverse square law?
Anytime distance is halved, the exposure will increase by four times.