Imaging Production Flashcards
What is technique chart primarily used with AEC?
Fixed kVp
Which of the following occurs during bremsstrahlung radiation production?
Electron approaches nucleus, loses energy and changes direction
Increases kVp,
increases receptor exposure
The available gray scale of an imaging system is determined by:
Bit depth
Which test measures timer accuracy?
Spinning top test
What gives the appearance of structures being enlarged on TV monitors?
Magnification Mode
That part of the image-intensifier that converts light into electrons is known as the:
Photocathode
When using a grid, we must stay within a certain focal range as to not place beam along grid lines.
True
A low ratio grid compared to a high ratio grid will:
Absorb less secondary radiation & require less exposure to produce a given receptor exposure
The light field alignment should be within +/-:
2% of SID
What is the percentage of pixel area that is sensitive to x-ray?
Fill factor
The path of the electron flow from the photocathode to the output phosphor is controlled by:
Electrostatic lenses
Higher Signal to Noise Ratio:
Better visibility of our image
Primary display monitors should have an average luminance of:
300 - 500 cd/m2
X-ray tubes require ______ to function.
Alternating current ???
The plate reader does all of the following except:
Holds the laten image
A particular mAs, regardless of the combination of mA and time, will reproduce the same radiographic density. This is a statement of the
Reciprocity Law
What is the purpose of collimators?
Limits exposure and reduces secondary and scatter radiation
Selecting the central photocell on an AEC device while performing a PA chest x-ray exam would most likely result in _____
Overexposed image
The larger the detector element, the lower the spatial resolution.
True
A slit camera is used to measure:
Focal spot size
Which of the following is not a video camera device used for monitoring the fluoroscopic image?
When a quality control test is performed to ensure that the same exposure factors produce a consistent x-ray output, successive exposures must be within this amount of one another:
5%
In which ways does SID affect spatial resolution?
Spatial resolution is directly related to SID
(NOT propositional)
Which of the following system functions to compensate for changing patient/part thickness during fluoroscopic procedures?
Automatic Brightness Control (ABC)
In digital imaging, mAs selection has an effect on:
1. Receptor exposure
2. Patient dose
3. Brightness
1 and 2
When there is not enough exposure, _____ occurs
Quantum Noise
The primary source of scatter radiation is the
Patient
Grayscale standard display function should not vary more that +/-:
10%
As grid ratio is increased
Contrast increases, PT dose increases
What are the effects of scatter radiation on the radiograph?
Produces fog & Lessens contrast
In which of the following systems does the radiographer select the anatomic part from the console menu?
APR
Flat panel receptors have which of the following advantages over image intensifiers
1. smaller and lighter
2. distortion- free images
3. improved contrast resolution
All three
In most modern second-generation image intensifiers, the input phosphor is composed of:
Cesium iodide
How efficiently a system converts the x-ray input signal into a useful output image is known as:
Detective Quantum Efficiency (DQE)
Luminance is measured in
Candela per square meter
Involuntary motion can be controlled with proper communication.
False
In digital imaging terminology, RIS is the acronym that stands for
Radiology Information System
Using variable kVp charts - each cm of increase in patient thickness requires what adjustment to kV?
Increase 2 kV
In digital imaging, window level represents ________ while window width represents________
brightness, contrast
________ are used to measure the part of anatomy being imaged.
Calipers
How does filtration affect the primary beam?
Increases the average energy of the primary beam
The process of assigning a value to each pixel to represent a shade of gray is called:
Quantization
The backup timer in AEC is used to:
Prevent x-ray tube overheating
What is the voltage ripple associated with high frequency generators?
1%
What is the space between the center of a pixel to an adjacent pixel.
Pixel pitch
Spatial resolution can be evaluated using the following devices except:
Penetrometer
The range of receptor exposures that can be captured by the detectors is called:
Dynamic range
The larger the pixel size, the better the spatial resolution.
False
Increasing the sampling frequency, will increase the spatial resolution.
True
Which of the following pathologies will require a decrease in technique?
Emphysema
What can be used to remove bright unexposed areas outside the collimated field?
Electronic masking
What is overexposure that can not be corrected?
Saturation
When anatomy is too large to fit on 1 imaging receptor - this feature can be used?
Stitching
The device that functions to terminate the x-ray exposure following ionization of a particular quantity of air is the:
AEC
Radiation fog increases spatial resolution on the radiographic image.
False
What converts the latent image to electronic signal?
Analog to digital converter
Which of the following will produce the highest quality radiographic image?
High SNR
Which of the following generators has a 100% voltage ripple?
Single phase
Which of the following has an effect on spatial resolution?
SID
OID
Focal spot size
All
What is the ration of number of photons at output phosphor to the number of x-ray photons at the input phosphor?
Flux Gain
PACS stands for
Picture Archiving and Communication System
Radiographs should be marked with ______.
Lead markers
True or false. Quantum noise limits the ability to see detail.
True
Ionizing radiation intensity decrease as:
Distance from the source of radiation increases
Smoothing does all of the following except:
improves spatial resolution
What processing correction allows for the image brightness to be corrected in the image receptor is over or under exposed?
Rescaling
What is the relationship between receptor exposure and appropriate/required tube filtration
Negligible effect
In modern rotating anodes, the rotating motion is accomplished by the use of a/an:
Induction Motor
Over-the-table fluoroscopic imaging systems result in higher radiation exposure to personnel than under the table systems. T/F
Ture
Alternating current is changed to direct current using a device called:
Rectifier
The input phosphor of the image intensifier converts:
x-ray to light
Which of the following devices is used to overcome variations in patient anatomy to provide a more uniform exposure?
Compensating Filter
The voltage ripple associated with the three-phase, twelve pulse rectified generator is:
4%
An increase in kilovoltage will:
increase photon energy
The less voltage ripple = the greater the radiation quality and quantity. T/F
True
Which of the following can increase or decrease the incoming voltage?
Transformers
What can help enhance the viewer perception of image brightness and contrast?
Low levels of ambient lighting
If a small focal spot is used, how will the spatial resolution be affected
increase in spatial resolution
Which is used to measure mAs linearity, reproducibility, and reciprocity?
Penetrometer
The unit of measure used to express resolution is:
Line Pairs Per Millimeter
Which of the following will increase the effective energy of the x-ray beam?
1. Increase in added filtration
2. Increase in kVp
3. Increase in mA
1,2
The greatest detriment to spatial resolution is:
Motion
Which of the following occurs with edge enhancement?
1. small high contrast structures more visible
2. image noise increase
3. image noise decreases
1,2
Size distortion will increase with:
A decrease in SID
The focusing cup on the cathode is primarily made up of:
Nickle
In fluoroscopy, the automatic brightness control is used to adjust:
kV and mA
When measuring mAs Reciprocity, there should be a variance of no more than +/-
10%
The quality of the x-ray beam is controlled by:
kVp
What material is the anode target in radiographic units primarily made up of?
Tungsten
What is the numeric value that is displayed on the processed image to indicate the level of x-ray exposure?
Exposure indicator
LCD monitors reflect more ambient light then CRT monitors.
T/F
False
A perfect modulation transfer function (ratio of an image to be accurately produced) would be:
100%
All the following are parts of the image intensifier except:
TV monitor
A grid artifact (aliasing artifact) that the laser scan lines run parallel with gridlines with is called:
Moire Pattern
Foreshortening of an object on a radiograph is a form of:
Distortion
Which of the following changes mechanical energy to electrical energy?
Generators
When using _______, the image can be reprocessed to only utilize a certain area of data.
Region of interest
The production of electrons at the filament of the x-ray tube is a result of which of the following processes?
Thermionic Emission
The photocathode layer of the image intensifier is compose of:
Cesium Antimony
