RAD 111 Test 4 Study Guide
Amount of clinically useful information on a diagnostic image. Must outweigh the input factors of the procedure ordered.
(Is the correct test being ordered?)
Each imaging modality has its own __________ of information.
Accuracy of diagnostic information on a medical image.
(Did the test provide the information that was needed?)
Tilting radiographic tables will tilt from __________ to __________ to __________.
- Vertical upright
The interface between the radiographer and electronics of the x-ray machine.
Three key factors for exposure technique.
Overhead Tubecrane (OTC) motions.
Image Receptor technology is classified as __________ or __________.
- Cassette-based (CR)
- Cassette-less (DR)
Cassette-based receptor systems.
- Computed radiography (CR)
Systems that use thin-film technology (TFTs).
(Referred to as flat panel technology)
Only radiation that is of any clinical value.
- Radiation absorbed by detector
- Radiation able to be converted to an image
Converts x-ray to light before converting it to an electrical signal.
Indirect digital detector technology
The ionizing radiation that is most prevalent and most harmful to the human body.
Technology that converts an x-ray into an electrical signal.
Direct digital detector technology
Commonly referenced as computed radiography (CR).
Photostimulable Phosphor (PSP) technology
(Also known as storage-phosphor tech.)
After having been exposed, CR plates are extra sensitive to __________.
Fluoroscopy performed in surgery is typically accomplished with __________.
Portable C-arm system
Results in ionization of atoms.
Loss of electrons
Can have biologic effects.
Two sources of ionizing radiation.
- Natural (sun)
- Manmade (Nuclear power plants)
Three sources of human-made radiation.
- Medical x-rays
- Dental x-rays
- Nuclear power
Conditions necessary for x-ray production.
- Source of electrons (Cathode filament)
- Means of accelerating electrons/high-speed motion (Voltage)
- Mechanism stopping electrons abruptly/deceleration (Target/Anode)
Energy of beam is expressed in __________.
Kiloelectron volts (keV)
Three possible paths an x-ray beam can undergo.
- Total absorption
- Pass through with no energy loss
- Scattering/secondary interaction with loss of energy
Five types of x-ray interactions with matter.
- Classic coherent scattering
- Photoelectric interactions
- Compton scattering
- Pair production
Who does photoelectric interactions expose?
Who does compton scattering expose?
Reaction with matter that no ionization occurs.
Classic Coherent Scatter
Reaction with matter that involves very low energy x-rays.
Classic Coherent Scattering
SI units of measurement?
Radiation exposure in air.
Radiation absorbed dose.
Unit of dose equivalence.
Measures amount of energy absorbed in any medium.
New term for RAD.
1 Gray = __________ rad.
Accounts for different types of radiation and their biologic effects.
New term for REM.
1 Sv = __________ rem.
REM (Sv) is expressed as:
Product of absorbed dose in rad and radiation quality factor
(rem = rad X QF)
Measures activity of a radioactive material (radionuclide). It is used in medicine and radiation therapy.
New term for curie (Ci).
Becquerel (Bq) is defined as:
1 disintegration per second (1dps)
Units of energy equal to 1000 electron volts.
KeV (Kiloelectron volts)
Annual whole-body effective dose limit for the occupational worker.
5 rem (50 mSv)
Two major parts of a cell.
Percentage of water contained in the nucleus.
Two classes of human cells.
- Somatic (any cell that is not a genetic cell)
- Genetic (will affect future generations)
The cells that perform all the bodies functions.
Reproductive cells of an organism. Very radiosensitive.
According to the law of Bergonie and Tribondeau, cells are more radiosensitive if they are __________.
- Highly mitotic
- Primitive in structure
Cells are most sensitive to radiation during __________.
(More immature/rapidly dividing)
Acute radiation syndrome stages.
- Prodromal stage
- Latent period
- Manifest stage
- Recovery or death
Cardinal rules of protection of patient.
- Time (lowest possible)
Two effects that occur within the diagnostic range.
- Photoelectric effect
- Compton scattering
Reaction with matter where the incoming photon interacts with an inner-shell (k-shell) electron and is completely absorbed.
Radiation interaction responsible for most hazard to patients.
Because there is complete absorption in the patient
What type of exposure constitutes the greatest amount of man-made exposure?
Positive side of the x-ray tube.
Negative side of the x-ray tube.
What part of the x-ray tube provides the source of electrons?
Which type of reaction with matter occurs when x-rays possess energy levels below 10 keV?
In the Photoelectric effect, which electron produces an x-ray with energy high enough to impact your image?
The electron that drops in to the hole in the k-shell
Reaction with matter where an incoming photon interacts with an outer-shell electron and gives just enough energy to knock out the electron it collides with and continues on in a different direction.
How many chromosomes does a germ cell posses?
How many chromosomes does a somatic cell posses?
46 (23 pairs)
Reaction with matter where the incoming photon interacts with the force field around the nucleus then disappears.
Occurs above diagnostic range.
- Pair Production (radiation therapy)
- Photodisintegration (Nuclear industry)
Reaction with matter that requires very high energy photons.
For the pair production to occur, the energy of the incoming x-ray photon must be at least:
Reaction with matter that requires the energy of the photon to be extremely high.
Reaction with matter where the incoming photon interacts with the nucleus of the atom directly and creates nuclear instability.
Monthly equivalent dose to a fetus should not exceed __________
0.5 Sv (0.05 rem)
Personal radiation monitor that will provide a near immediate reading of radiation exposure.
Dose equivalent for radiation workers is based on radiation received from what source?
In radiographic/Fluoroscopic (R/F) system, the primary barrier is __________.
Image intensifier (flat panel detector)
A principle of the "ALARA" concept.
Occupational exposure should be kept as low as reasonably achievable