Image Production Flashcards
True or False The back up timer determines the maximum length of exposure time for an AEC exposure.
True
What is the time it takes for a system to respond and send the signal to terminate the exposure.
Minimum Response Time
_______ diseases will _________ subject contrast resulting in an increase in radiographic contrast.
Additive, increase
This is the direct controlling factor of radiographic receptor exposure.
mAs
Filtration changes the qualities of the beam, making the beam more _________.
Homogeneous
Radiographic contrast is defined as the _________ in densities.
Difference
A ______% increase or decrease in kVp, keeping all other factors constant will result in doubling or halving of radiographic receptor exposure.
15
An increase in kVp will _________ receptor exposure until 100% of the beam is successful in reaching the image receptor.
Increase
_____ are beam attenuators that decrease skin exposure to the patient.
Filters
What are the three factors that contribute to the absorbing ability of a given body part?
Thickness, Atomic number, specific gravity
(Specific gravity- a measure of the density of a substance in comparison to the density of water).
AS thickness _________ beam attenuation increases and receptor exposure _________.
Increase, decrease
This is defined as a variation in x-ray beam intensity with an increase in beam intensity toward the cathode end of the beam and a decrease in intensity toward the anode end of the beam.
Anode heel effect
This is defined as the variation or difference in opacity recorded on the radiograph.
Contrast
What type of contrast do you have when there is a large difference in measured opacity between two points on the image receptor.
High
What type of contrast media is used int he alimentary tract? Looking for two answers.
Barium sulfate and gastrografin
As OID increases, recorded detail ________.
Decreases
There are two types of patient motion. What are they?
Voluntary (respirations)
Involuntary (Peristalsis)
What type of patients are most sensitive to radiation exposure.
Pediatric
As a general rule parts measuring greater than ____cm require the use of a _______ to offset the production of secondary and scattered radiation in the volume of tissue as the x-ray beam passes through.
10, grid
_________ ___________ is the ability of the system to record adjacent small structures, equipment related. Hint: It is measured in line pairs per mm.
Spatial resolution
The glass envelope is comprised of what type of glass.
Pyrex
What is the negative end of the tube?
Cathode
What is the material of choice for the x-ray tube? Hint: It has a high melting point and atomic number.
Tungsten
Copper, molybdenum or graphite are the materials of choice for the _______ and base of the anode.
Neck, these are used due to light in weight.
The ________ is designed to reduce the number of repeated radiographs taken on a mixed population of patients due to over and under exposure.
AEC , Automatic Exposure Control
What is the most common type of beam restriction?
Collimation
Attaches to the bottom of the collimator housing. They create a circular shaped collimated field.
Cylinders and cones
In the United State, electrical energy is supplied in a _______ cycle alternating current.
60 cycle
________ are devices that convert alternating current into direct current.
Rectifiers
The ________ provides a vacuum environment for the operation of the image intensifier.
Glass envelope
What is the purpose of fluoroscopic viewing?
Allows for real time or dynamic motion viewing within the body.
______________ takes place in the computer which is where algorithms determine the histogram of the image.
Pre-processing
______ is the processing of mapping a large set of input values into a smaller set.
Quantization
Digital values provide a ________ (graph) of the exposure information
Histogram
______ is a histogram of the luminance values derived during image acquisition. Each pixel is changed into a new gray value the resultant image will have the appropriate brightness and contrast.
Look up table
_______ occurs by averaging all pixels frequency with surrounding pixel values to remove image noise. Also known as low-pass filtering.
Spatial frequency filtering (Smoothing)
___________ is an accepted standard for networked medical devices to exchange images and information.
DICOM, Digital Imaging and Communication in Medicine
__________ consist of digital acquisition equipment, workstations for display and manipulation of images and interconnected storage, devices that communicate over a network in the same language using the DICOM standard.
PACS, Picture Archiving and Communication System
A task completed step by step is known as a ______.
Workflow
_________ process of remote transmission and viewing of images.
Teleradiology
The ability to adjust the brightness and/or contrast of a digital image through _________.
Windowing
A wavy artifact in digital imaging caused when grid lines are projected onto the imaging plate and are parallel with the scanning laser.
Moire Effect or Aliasing
______ exposure time will help minimize the effects of voluntary and involuntary patient motion.
Short
This artifact appears as a black spider-like artifact on the image.
Static
______ image is caused when there is insufficient erasure of an image and a _______ image is seen on the new image.
Ghost, ghost
__________ ________ is defined as a set of comprehensive activities that are designed to maintain and monitor systems that produce a product.
Quality control
True or False The central ray should be directed to the center of the image receptor.
True
How often should the following QC be done:
Clean and inspect receptors
Clean CR reader air intakes
Inspect and clean keyboard and mouse
Weekly
How often should the following QC be done:
Inspect and clean cassettes
inspect laser printer for ink and pater
Daily
The majority of hospitals are voluntarily accredited by the __________. Accreditation is necessary for reimbursement from Medicare and insurance companies.
The Joint Commission
________ is the heating of the filament to the point that electron boil off its surface.
Thermionic Emission
______ is the central part of the atom containing positively charged protons and electrically neutral neutrons.
Nucleus
