Study Guide Exam 3 Flashcards
Cathode
Negative
Anode
Positive
What is diagnostic yield?
Diagnostic Yield is the amount of clinically useful information on a certain diagnostic image
What is diagnostic efficacy?
Diagnostic Efficacy is the accuracy of the amount of information on a medical image.
What is automatic exposure control?
the x-ray machine terminates an x-ray exposure when it detects enough radiation in the AEC cells, which has improved the consistency of image quality.
What is manual collimation?
manually set the imaging field around the part of interest
What is automatic collimation?
when the machine automatically detects the size of the image receptor and collimates to a size not larger than the image receptor AKA positive beam limitation
What are the 2 types of X-ray tube support systems?
overhead and floor mounted
Features of a radiographic table
Radiographic tables usually have a 4-way floating table top and is highly radiolucent, there is also tilting radiograph tables that do not have variable height capabilities
what is x-ray production?
: As you “rotor”/prep/boost the tube (press the exposure switch half way down), you are prepping the x-ray tube to make an exposure. What happens is the anode (positive side) starts to spin at a high rate while the cathode (negative side) heats up to the selected milliamperage (mA) and electrons boil off. When the exposure switch is pressed all the way down, a large potential difference (kVp) is applied across both poles of the x-ray tube, causing the electrons to travel from cathode to anode at high speed, producing an x-ray when the electrons hit the target on the anode. Don’t “rotor” too much/too long it can damage the X-ray tube
Fluoroscopic tables
capable of static radiographic imaging as well as live, real time imaging. Complete system consists of an R/F table, image receptor, x-ray generator and control, ceiling mounted x-ray tube and video display monitor.
LIH
Last Image Hold: The radiologist can save the picture on the screen as an image
instead of re-radiating a patient (like a screenshot on your phone)
An X-ray tube that has positive and negative sides are called what?
a diode
The elastic of a girl’s sock shows on the image, if you submit the image anyways what would happen?
it detracts from diagnostic effect
To improve the flexibility of a radiographic system, engineers designed a system that do what?
they move independently of one another
Chest x-rays are conveniently performed with what?
An upright cassette holder or bucky
What is another term for a collimator?
Positive beam limitations
What can damage do the x-ray tube effect?
Repeat boosting on the table
What is the barrier on a radiographic/fluoroscopic system?
A flat panel detector/ input intensifier
Fluoroscopy of a fractured hip is accomplished with what?
A C-arm
mages done by a CT scanner is what plane of the body?
The axial plane
Nuclear medicine is unique in its ability to detect what?
Tissue profusion and metabolic activities
In sonography, as sound frequency increases what happens to the depth?
It decreases
What zone is the actual MRI room in?
Zone 4
Sources of radiation
natural/background and human-made/artificial
What is ALARA?
AS LOW AS REASONABLY POSSIBLE
WB effective dose
annual: 50 mSv (5 rem)
cumulative: age x 1 mSv
Pregnancy dose limits
monthly: 0.5 mSv (0.05 rem)
total: 5 mSv
How do we monitor occupational dose?
OSL dosimeter
Radiosensitivity of cells
cells are more sensitive during active division, when they are more primitive in structure and/or have a high rate of mitosis
What is indirect action?
Because cells are approximately 80% water, indirect action occurs when water molecules are ionized. This action produces chemical changes (free radicals) within the cell that alter the internal environment, injuring the cell, and can result in eventual cell death. With x-radiation and gamma radiation, the vast majority of cellular damage results from indirect hits.
Acute Radiation Syndrome stages
- Prodromal stage
- Latent Stage
- Manifest Illness
- Recovery
OSL dosimeters
Optically Stimulated Luminescence to determine an individual’s exposure, the aluminum oxide material inside the badge is stimulated by a laser light, the material will become luminescent (emit a light, get it? Optically stimulated luminescence?) proportional to the exposure level
X-ray Beam Filter
Remember that the x-ray beam from the tube is heterogeneous (different energy levels).
An aluminum filter is used to block/absorb low-energy photons from reaching the patient. Low energy photons would not penetrate the patient so the patient would just absorb those photons, thereby increasing the patient’s entrance skin dose)
Which radiation monitor can provide a near-immediate reading of occupational doses?
pocket dosimiter
Radiation from the sun is what?
Natural background radiation
Base limits of radiation workers is what?
Occupational dose
Nausea is associated with what?
Prenominal period
What is the Geiger Muller counter?
A Geiger counter, also known as the Geiger-Muller tube, is an inexpensive and useful instrument used to quickly detect and measure radiation.
What are the different interactions of radiations? (Compton, etc.)
Classic Coherent Scattering, Photoelectric Interactions, Compton Scattering, Pair Production, Photodisintegration
what is pharmacology
Science concerned with the origin, nature, effects and uses of drugs.
What is Pharmacokinetics?
- Absorption
- Distribution
- Metabolism
- Excretion
Generic Name
Name given to a drug when it becomes commercially available
Chemical Name
identifies the chemical structure of a drug
Trade Name:
Name given by a particular manufacturer to a drug
What is a contraindication?
A contraindication is a reason or circumstance in which a drug or procedure should not be used because it could be harmful
what are analgesics?
relieve pain and inflammation
What is a laxative?
Laxatives treat constipation by softening hard stools or stimulating your bowels to get moving