Describe how AEC works
What is radiation is transmitted through the patient and converted into an electrical signal, terminating the exposure time
The purpose of the mAs readout
What is reports the actual mAs used for an exposure, can make exposure adjustments by switching to manual technique
Difference between additive and destructive pathological conditions
What is additive has increased thickness, mass, density and atomic number
Destructive has more air, reduced tissue mass, decreased density and decreased attenuation
If backup time is controlled automatically, at or above 50 kVp, backup timers terminate at a maximum of _______ mAs.
What is 600 mAs?
The quality control test of the AEC device to see that exposures for a given set of factors and selected detector result in mR readings within 5% is called:
reproducibility
The two types of radiation detectors used in AEC systems
What are phototimers and ionization chambers
Two types of exposure technique charts
What are:
Variable kVp - Fixed mAs
Fixed kVp - Variable mAs
AEC can also be called this
What is phototiming?
What is a caliper?
The level at which the backup timer should be set
What is 150-200% of the expected exposure time
Four major types of body habitus
Define MRT
What is minimal response time?
The common increment of density control listed on the control panel (-1, +1, +2), according to the textbook
What is 25%
The baseline kVp is increased by 2 for every 1-cm increase in part thickness is what type of chart?
What is Variable kVp - Fixed mAs chart?
APR
What is anatomically programmed technique
Factors that can affect IR exposure
What are patient thickness, pathologic conditions, contrast media, foreign objects, pockets of gas, tissue composition
Refers to the shortest exposure time the system can produce
What is MRT? (minimum response time)
AEC controls the amount of radiation reaching the IR by controlling the_________.
What is time of exposure?
AEC device that is an entrance-type device because the detectors are positioned in front of the IR
What is ionization chamber?
The function of an APR system
What is a system of preprogrammed exposure technique settings that is organized by position and examination and set through the control panel of the radiographic unit
The difference between positive and negative contrast media
negative is more radiolucent than surrounding tissue
positive is more opaque than surrounding tissue
What is incorrect detector selection or incorrect centering of body part on appropriate detector
Device(s) that convert(s) light energy to an electrical signal
What are photodiode and photomultiplier tube?
TRUE or FALSE. A high kVp decreases the exposure and reduces the overall radiation exposure to the patient.