Chapter 3 Test Review Flashcards
Identify two acts of legislation that includes radiographic procedures and equipment?
Radiation Control and Safety Act
Safe Medical Device Act
What government agency is CDRH apart of?
FDA ( Food and Drug Administration )
What 4 standards were established by HIPPA?
- record security
- electronic formats/ recording keeping
- Electronic identifiers and codes
- Confidentiality and Privacy Rules
What are the two routine checks of all equipment?
Processing system
External Beam Evaluation
What is the difference between Quality Assurance and Quality control?
Quality Assurance- provides consistency of high quality images.
Quality Control- keeps equipment updated to maintain quality standards.
Quality Control will reduce what?
Equipment Downtime
Number of repeats
What 4 test need to be done to provide Focal Spot Size Estimation?
- Line pair resolution tool
-Star test pattern - Pinhole camera
-Slit camera
What is the percentage for external beam evaluation acceptable limit?
+ or - 1%
What is the measuring tool used for Kilovoltage Accuracy? And the Acceptable Limit?
Dosimeters
+ or - 5%
What is the measuring tool used for mAs and milliamperage linearity? And the acceptable limit?
Same mAs at different mA and time settings
+ or - 10%
What is the measuring tool used for Exposure Reproducibility? And its acceptable limits?
mR/ mAs after several exposures at the same technical factors.
+ or - 5%
What is the half value layer and its acceptable limits?
The total filtration in the primary beam. Reduces the intensity of the beam to 1/2 of its original intensity.
No acceptable limits however, above 70kVp requires a minimum of 2.1mm but no more than a total of 2.5mm.
What percent is the angulator or protractor accuracy?
+ or - 1%
What are two kinds of Artifact Identifications?
Dead pixels
Dropped detector
What is the exposure rate for Fluoroscopic systems?
Maximum of 5R/min
What is the distance limits for stationary and mobile units?
Stationary- min 15”
Mobile- min 12”
What are the main causes for unacceptable radiographic images?
Patient Position
Equipment malfunction
Technical Factor problems
Patient Preperation
What indicator is used to identify appropriate IR exposure?
Exposure index
shape distortion is caused by misalignment of what?
Part to IR
Tube to IR
Part to Tube
Generators in most mobile equipment produce an output of what?
High Frequency
What is the correct order for the intensification tube?
Input Screen
Photocathode
Electrostatic Focusing lenses
Anode
Output screen
What are the x ray photons converted to in the input screen?
Light photons
What does the photocathode do?
Changes light photons into electrons
T/F: TFT’s are incorporated in digital Fluoroscopic Units?
True
What does the image intensifier do?
Brightens fluoroscopic images so it can be of diagnostic value.
What types of x ray beams are used in Fluoroscopy?
Continuous or pulsed
If there is an increased exposure time what technical factor decreases?
mA
What technical factor helps to reduce patient dose?
Increased exposure time
What two components sit above the output screen in the image intensifier?
CCD
Analong- to- Digital Converter
Explain how the image intensifier works?
- X ray beam passes through the patient and hits the anti scatter grid
- Incident X rays strike the input screen (phosphor) converts X-ray photons into light photons.
- When light photons are emitted from the input phosphor and stimulate the photocathode photo electrons are emitted through photo emission.
- Photo electrons are then formed into a concentrated stream by the electrostatic focusing lenses.
- Electostatic lenses helps the photo electrons pass through a hole in the anode and hit the output screen
- Output screen converts photo electrons back to light photons.
What is Flux Gain?
A measurement of the increased light photons
What can the video camera or CCD do?
Converts light photons into electrical signal and collect the electrical signal
What does the analog to digital converter do?
Converts electrical signal into a digital signal
What is the role of the anti scatter grid in the image intensifier?
Increase image contrast
What does Recordings of fluoroscopic images allow us to do?
Review
Analyze
Communicate findings
In the fluoroscopy recording system what does the vidicon Tube (video camera) do?
Takes light from the output phosphor and converts it into an electrical signal.
What does the CCD do an image?
Improves image quality
What is the difference between CCD and Vidicon tube?
CCD- higher spatial resolution and less image blooming or lag
Vidicon tube- lower spatial resolution but more image blooming or lag.
What is the recording system process with a flat panel detector?
- X ray photons convert into light photons at the Scintillation layer.
2.At the photodiode light photons are converted to electrical signals. - Electrical signals are stored and released by TFT and converted into a digital signal at the ADC.
What 3 things are true when it comes to fluoroscopy monitors?
They display images in black and white
They can be suspended from the ceiling
They can be found on wheeled carts or attached to a C-arm
What is the main difference between image recording process of an image intensifier and recording process of a flat panel detector?
Flat panel detectors use a TFT
In Fluoroscopic systems how is the CCD connected to the output phosphor?
Fiber- optically
What is the correct order of the imaging recording components in a fluoroscopy system that uses a Flat Panel Detector?
TFT—-> ADC —-> CCD—> Computer—-> viewing monitor
What component of the image intensifier contributes to the image quality? And Why?
Input phosphor layer - due to the curve
List the image quality issues with the image intensifier?
Vignetting
Pincushioning
S-Shaped distortion
Blooming
Veiling glare
Lag
Noise
What does Vignetting do to an image?
Decreases the image brightness around the edges of the image
What causes Vignetting? And what is the effect?
The curve of the input phosphor layer or object to image distance.
Image contrast and detail on the edges of the image.
How can Vignetting be corrected?
-Image processing
-Adjust image intensifier
-Reducing OID
What does Pincushioning due to an image?
Parts of the image appear curved or bent inward towards the center of the image.
What is the cause of Pincushioning? And what can it effect?
Curved input phosphor and external magnetic fields.
Inaccuracy of measurements
How can Pincushioning be corrected?
Image processing
What does S-Shape do to an image?
Parts of the image appear curved or bent Inward toward the center.
What causes the S-Shape to appear on an image? What can it effect?
External magnetic fields and misangulation of X ray beam.
Inaccuracy of measurements
How can S-Shape be corrected?
Image processing
What does Blooming do to an image?
Parts of the image has white out and loses visual sharpness
What causes Blooming? And what does it effect?
High energy x ray photons hitting the input phosphor.
Loss of acuity
How can Blooming be corrected?
Proper patient positioning
Centering anatomy of interest
Appropriate collimation
What is Veiling Glare and what does it do to an image?
It’s a type of blooming. Causes contrast reducing haze on the fluoroscopic image.
What is the cause of Veiling Glare? And what does it effect?
Scattering of x-ray, light, and electron energies.
Contrast- impacts image clarity
How can Veiling Glare be corrected?
Grids
Appropriate collimation
What does Lag do?
Delays response time of the image intensifier to changes in beam intensity
How can lag be corrected?
Frame averaging
High speed image intensifier
What is Noise?
Grainy or mottled image
What is the cause of noise? And what does it effect?
IR does not get enough radiation.
Impacts the image clarity
How can Noise be corrected?
Increase mA and or kVp
Decrease SID
List a few patient considerations in Fluoroscopy?
Explain the procedure to the patient ( communication).
Be mindful of other equipment in patients room.
Work with patients abilities
What are some radiation protection rules for mobile X-rays?
-Shield sensitive areas
-Request non- essential employees to leave room.
-Announce your making an exposure
-Have 2 lead aprons
Who invented the first mobile Radiography?
Marie Curie
Who invented fluoroscopy?
Thomas Edison
Fluoroscopy must have a minimum of ___________ lead shield to cover slot
0.25mm/Pb eq
Lead aprons and gloves must have a minimum of ______Pb/eq that must be worn?
O.5mm Pb/eq
What is Fluoroscopy?
A dynamic radiographic examination.
In Fluoroscopy what is the foot switch called? And what does it allow?
“ Dead Man” and allows the Operators to use their hands to position the carriage and or patient.
In Radiation Protection for Fluoroscopy what is the highest energy scatter angle of the beam?
90 degree
