Test #1 Flashcards
The biological effect of radiation is measured in what units?
Rem
The amount of x-rays received in the course of employment by an individual over 18years old is called what?
Occupational dose
Chronic exposure to xray radiation will most likely cause which of the following
^ rates of neoplasia
^ in rates of sqam cell carcinoma
^ risk of temp or perm infertility
ALL OF THE ABOVE
What causes a clear border around developed xray film?
collimation
Repeated exposure of an individual to small amounts of radiation can have which of the following effects?
cataract development in the eyes of the operator
What describes the purpose of collimation
it reduces the amount of scatter
where should a radiation monitoring device be worn for routine radiography?
outside the apron at thyroid level
Why are individuals under the age of 18 excluded from performing or assisting in radiography?
because their cells are reproducing more rapidly
What is the purpose of wearing leaded gloves when performing veterinary radiography
protect the wearer from scatter radiation
Which of the following statements describes a female radiographer’s special risks?
the embryo/fetus is most sensitive to radiation during the first three months of pregnancy
Define X-ray
a form of electromagnetic radiation similar to visible light, but much shorter in wavelength
Who credited with the discovery of medical use of x-rays
Wilhelm Conrad Roentgn
Xray absorption is determined by which 3 factors
atomic #
density
energy
List 2 concerns if exposed to radiation
cancer
infertility
The means of measuring the dose of radiation received by the radiographer
Maximum Permissible Dose
How is MPD measured?
Measures maximum amount of radiation over a given time
What device is used to measure MPD
Dosimeter Badge
Universal rules for positioning animals when taking a radiograph
bones/extremities: place on effected side
body cavity: taken V/D
Name the 5 directional terms for body cavities
Ventral Dorsal Cranial Caudal Lateral
What are 2 views used when performing a body cavity radiograph?
V/D
LAT
What are 2 views you could perform on an extremity radiograph
CR/CD
LAT
Directional terms for the extremities
Cranial Caudal Palmar Plantar Dorsal Extension Flexion
What must be included on the permanent label of a radiograph?
Patient
Hospital
Date
What is always included in the view when performing a long bone radiograph
joint above and below the bone
What is always included when doing a joint radiograph
1/4 to 1/3 of the bone above and below the joint
Name the 2 electrodes involved in generating xrays
Cathode -
Anode +
What 2 items are produced from the generation of xrays
heat
radiation
what are xray beams composed of and how do they travel
photons in the form of a wave
List the 5 different object densities from the least to most dense
air fat muscles & organs bone metal & enamel
List 5 areas that particularly sensitive to the effects of radiation
Skin & intestinal epithelium gonads thyroid lens of the eye blood forming organs
____ is the amount of energy transmitted by ionizing xrays to matter and is measured in ____
absorbed dose
gray
___ is the amount of radiation equal to the absorbed dose in tissue and is measured in ____
dose equivalent
Sv
List 3 different items of protective equipment that contain lead
gown
gloves
thyroid shield
list 3 safety precautions you should take when taking xrays (other than wearing protective equip)
look away collimate restrain devices avoid retakes least time possible
5 steps to processing radiographic film
developing rinsing fixing washing drying
The acid chemical that removes unexposed crystals
the fixer
___ is the alkaline chemical that converts the ____ on the film to a ____
developer
latent image
visible image
What is the minimum & maximum developing time?
2-5 min
What are the 2 types of water baths?
Circulation & Stationary
What are 2 types of film processing
manual
automatic
Instrument used to measure the area to be radiographed
calliper
Thorax Limits
Cranial- Thoracic inlet
Caudal- Diaphragm
Dorsal- Thoracic spine
Ventral- Sternum
Thorax Landmarks
Cranial- Manubrium
Caudal- Xiphoid Process
Dorsal- Dorsal Spinus Processes
Ventral- Sternum
Abdomen Limits
Cranial- Diaphragm
Caudal- Pelvic Inlet
Dorsal- Lumbar spine
Ventral- Linea alba
Abdomen Landmarks
Cranial- Xiphoid process
Caudal- Iliac Crest
Dorsal- Dorsal spinus processes
Ventral- Belly wall
Whole Body Limits
Cranial- Thoracic Inlet
Caudal- Pelvic Inlet
Dorsal- Spine
Ventral- Sternum
Whole Body Landmarks
Cranial- Manubrium
Caudal- Iliac Crest
Dorsal- Dorsal spinus processes
Ventral- Sternum
Pelvis Limits
Cranial- Pelvic inlet
Caudal- Tuberichii
Pelvis Landmarks
Cranial- Iliac crest
Caudal- Tuberichii
Cervical Spine Limits
Cranial- C1
Caudal- C7
Cervical Spine Landmarks
Cranial- wings of atlas
Caudal- dorsal tips of scapula
Thoracic Spine Limits
Cranial- T1
Caudal- T13
Thoracic Spine Landmarks
Cranial- Dorsal tips of scapula
Caudal- last rib
Lumbar spine limits
Cranial- L1
Caudal- L7
Lumbar spine landmarks
Cranial- last rib
Caudal- iliac crest
T/L Junction Limits
Cranial- T11
Caudal- L2
T/L junction Landmarks
Cranial- 9th rib
Caudal- iliac crest
2 Electromagnetic Radiation behaviors
- wavelength & frequency
2. protons, neutrons, & electrons
3 types of radiation
- primary
- secondary (scatter)
- background
2 types of primary radiation
- general (70% of beam)
2. characteristic (30% of beam)
Occupational exposure limits
whole body- 0.05sv
organs & tissue- 0.5sv
lens of eye- 0.15sv
How are extremity radiographs hung?
Proximal bones to the top & head to the left
Hanging a V/D body cavity?
Head at top, and patients left to your right
Hanging lateral body cavity?
Head to the left, and dorsal aspect at the top
4 types of xray units
Conventional
Mobile
Mounted
Small portable
5 Elements needed for xray production
Electron source- cathode Acceleration of electrons- kvp Free path- glass envelope Target area- focal spots Vacuum containment- glass envelope
Acceleration of cathodes is called
Kilovoltage KvP
The amount of energy in the circuit is called
Milliamperage mA
Most common anode
Rotating
Anode Heel Effect
if the anode target angle is decreased, the intensity on the anode side of the xray beam is decreased, more xrays leave the xray tube on the cathode side than on the anode side causing a variation in exposure to the xray film
Penumbra Effect
If focal spot is too big the image is blurred
5 possible areas of failure in the xray tube
Cathode/Filament Rotor Anode Anode Target Glass envelope
Low voltage circuit
Pre-heats filament
provides more electrons to the anode
amount produced
High voltage circuit
Speeds up electrons
sends to target
and measured in KVP
power behind electrons
