RT 210- CR/DR digital definitions Flashcards
testing that occurs to ensure equipment or processes are functioning within acceptable limits
Acceptance testing
historical collection of images stored in PACS
archive
avoidable extraneous information on the image that interferes or distracts from image quality
artifacts
soft polymer that protects the back of the cassette
backing layer
label attached either to the cassette or to the imaging plate that identifies the plate for the purpose of matching the examination to the plate
barcode label
photostimulable phosphor located in the imaging plate
barium fluorohalide
contains a simple set of instructions for the computer to perform several basic functions, such as, boot up, run hardware diagnostics, interpret keyboard signals, and so on…
basic input/ output system (BIOS)
machine language of 1s and 0s
binary code
single unit of data
bit
series of connections, controllers, and chips that creates the information highway of the computer
bus
type of network setup in which each of the computers and network devices are connected to a single cable
bus topology
made up of 8 bits and is the amount of memory needed to store one alphanumeric character
byte
rigid plastic housing for the imaging plate
cassette
small chip found on the motherboard that manipulates data sent from a program; brains of the computer
central processing unit (CPU)
Newer type of amorphous silicon detector that uses a cesium iodide (CsI) scintillator; the scintillator is made by growing very thin crystalline needles (5 micrometers wide) that work as light-directing tubes, much like fiberoptics
cesium iodide scintillator (CsI)
coupling devices that act as cameras that link phosphor signals to a signal
charge-coupled device (CCD)
Similar to a server-based network, in that there is a centralized computer that controls the operations of the network, but rather than sending the entire original resource to the client for processing, the server processes the resource as requested by the client and returns only the result back to the client
client-based network
Area within the conductive layer where electrons are trapped
Color layer; also known as Phosphor Layer
Cassette-based digital radiography is the digital acquisition modality that uses storage phosphor plates to produce projection images
Computed Radiography (CR)
Programmable electronic device that can store, retrieve, and process data
Computer
Layer of material that will absorb and reduce static electricity
Conductive Layer
Alternative set of terms for total quality magement that includes maintenance of equipment, image acquistion, and processing standards
Continuous Quality Improvement (CQI
Conversion of the digital image using contrast enhancement parameters
Contrast manipulation
Measurement of how efficiently a system converts x-ray input signal into a useful output image
Detective Quantum Efficiency (DQE)
Actual physical size, length and width, of the x-ray detector
Detector Size
Digital imaging and communications in medicine; it is a global information technology standard that allows network communication between modality and PACS
DICOM
Any image acquisition process that produces an electronic image that can be viewed and manipulated on a computer
Digital Imaging
Cassette-less systems use an x-ray absorber material coupled to a flat panel detector or a charged-coupled device to form the image
Digital Radiography (DR)
digital storage device that can hold up to seven times more than the CD, which equates to about 9.4 (single-sided) to 17GB (double-sided) of data; in a DVD, there are multiple layers of the polycarbonate plastic
Digital Versatile Disc (DVD)
These devices convert the incident x-ray energy directly into an electrical signal, typically using a photoconductor as the x-ray absorber and a thin-film transistor as the signal collection area, and send the electrical signal to the computer for processing and viewing
Direct Capture Digital Radiography
Conversion of X-ray energy to electrical signals without the light-conversion step
Direct Conversion
Generally a display monitor where postprocessing occurs or where images can be viewed
Display workstation
Printer that uses heat to develop the film
Dry Imager
Enhancement occurs when fewer pixels in the neighborhood are included in the signal average; the smaller the neighborhood, the greater the enhancement
Edge Enhancement
Term used by Kodak to express exposure values
Exposure Index (EI)
Device that scans hard copy x-ray images and converts them to digital images
Film Digitizer
Detector that consists of a photoconductor, wihich holds a charge on its surface that can be read out by a thin-film transistor
Flat Panel Detector
The number of grid lines per inch
Grid Frequency
The ratio of the height of the grid line to the width of the interspace material
Grid Ratio
The main repository for programs and documents on the computer
Hard Drive
Graphic representation of all of the digitally recorded signals of a digital x-ray exposure, measures amount of light/signal going to pixels or voxels
Histogram
Health Level 7; Standard protocol used for medical data systems
HL-7
Information system used throughout the hospital, includes the direct patient care information, billing systems, and reporting systems
Hospital Information System (HIS)
Identification of the top or side of an image
Image Orientation
Process of “sewing” together multiple images to form one continuous image
Image Stitching
Process of sending the digital image to PACS or CD
Image Storage
Thin piece of plastic with several layers of material that capture and store image data
Imaging Plate
Devices that absorb x-rays and convert them into light; the light is then detected by an area-charge-coupled device or thin-film transistor array in concert with photodiodes, and then converted into an electrical signal that is sent to the computer for processing and viewing
Indirect Capture Direct Radiography
Two-step process in which x-ray photons are converted to light and then the light photons are converted to an electrical signal
Indirect Conversion
Acronym meaning: kilovoltage peak
kVp
Amplification of stimulated emission of radiation, a device that creates and amplifies a narrow, intense beam of coherent light
Laer
The amount of error that can be made in exposure factor choices and still result in the capture of a quality image
Latitude
Image manipulation parameter that changes screen image contrast usually through the use of a mouse
Level
Small area networked with a series of cables or wireless access points so that the computers can share information and devices on the same network
Local Area Network (LAN)
A term used by Agfa to express exposure to the imaging plate
Logarithm of the Median Exposure (IgM)
Reference histgram of the luminance values derived during image acquisition
Look-up table (LUT)
Short-term magnetic disk storage, usuallly found in arrays (RAID)
Magnetic Disk Storage
Term for enlargement of an image in all dimensions without loss of sharpness
Magnification
Acronym meaning: milliamperage per seconds
mAs
Rectangular or square table of numbers that represent the pixel intensity to be displayed on the monitor
Matrix
Used to store information being currently processed within the central processing unit
Memory
The ability of a system to record available spatial frequencies
Modulation Transfer Function
Grid line or image noise pattern that occurs when either the alignment of the grid to the laser scan direction is incorrect or when spatial frequency is greater than the Nyquist frequency; a wraparaound image will result
moire
Largest circuitry board inside the computer; it contains many important small components to make the computer function properly
Motherboard
Two or more objects sharing resources and informatio; interconnected computers, terminals, and servers connected by communication channels sharing data and program resources
Network
When sampling a signal such as the conversion from an analog to a digital image, the sampling frequency must be greater than twice the bandwidth of the input signal so that the reconstruction of the original image will be nearly perfect
Nyquist Theorem
Software that controls the computer hardware and acts as a bridge between applications and the hardware
Operating System (OS)
Acronym meaning: Picture Archival and Communication System; consists of digital acquisition, display workstations, and storage devices interconnected through a network
PACS
Input information regarding patient age, identifying number, ordering physician, and so on
Patient Demographics
Layer of photostimuable phosphor that “traps” electrons during exposure; usually made of phosphors form the barium fluorohalide family (e.g., barium fluorohalide, chlorohalide, or bromohalide crystals)
Phosphor Layer
Device used to measure the luminescence of areas on the monitor
Photometer
Electronic device that amplifies light energy- image directly obtained (no cassette/film)
Photomultiplier
Light produced by a phosphor when struck by light or x-ray photons
Photostimulable Luminescence
Networked group of computers, servers, and archives that can be used to manage digital images
Picture Archival and Communication System
The smallest/ basic picture element on a display
Pixel
Delivers all electricity and provides connections to power devices in the computer
Power Supply
Periodic testing of equipment and materials before problem occurrence
Preventative Maintenance (PM)
Very thin, tough, clear plastic covering in the imaging plate for protection of the phosphor layer
Protective Layer
Another term for quality management, which is now considered antiquated; typically focuses on the person rather than the process
Quality Assurance (QA)
Subdivision of quality management that focuses on equipment functions
Quality Control (QC)
A dedicated computer and monitor for the purpose of reviewing images
Quality Control (QC) station
Failure of an imaging system to record densities usually caused by a lack of x-ray photons
Quantum Mottle
Recording error in the digital image
Quantum Noise
The information system used in the radiology department for ordering examinations and reporting results
Radiology Information System (RIS)
Zigzag electron scanning pattern
Raster
Composed of serveral magnetic disks or hard drives that are linked together in an arrya
Redundant Array o Independent Disks (RAID)
Layer in the imaging plate that sends light in a forward direction when released in the cassette reader; this may be black to reduce the spread of stimulating light and the escape of emitted light; some detail is lost in this process
Reflective Layer
Number of pixels contained on a display
Resolution
Synonomous with preventitive maintainance of equipment that occurs before problem occurrences
Routine Maintenance
Term used by Fuji Medical to express exposure
S, sensitivity number
Computer that manages resources for other computers, servers, and networked devices
Server
Used to blacken out the white collimation borders in a digital image, effectively eliminating veil glare
Shuttering
Also known as low-pass filtering, the result of averaging each pixel’s frequency with surrounding pixel values to remove high frequency noise
Smoothing
Reading images on the computer without hardcopy films
Softcopy
Amount of detail or sharpness in a digital image
Spatial Frequency Resolution
In conventional radiography, speed is determined by the size and layers of crystals in the film and screen; computed radiography system “speeds” are a reflection of the amount of photostimulable luminescence given off by the imaging plate while being scanned by the laser
Speed
Network that has the devices connected to a central hub or switch
Star Topology
Semigrid material in the imaging plate that gives the imaging sheet some strength
Support Layer
Moving images via telephone lines to and from remote locations
Teleradiology
The organization that accredits health care organizations, such as hospitals, clinics, and labs
The Joint Commission
Photosensitive array, made up of small (about 100 to 200 micrometer) pixels, converts the light into electrical charges
Thin-Film Transistor (TFT)
Physical (geometric) layout of the connected devices on a network
Topology
Network that spans a large area, city, state, nation, continent, and/or world
Wide Area Network (WAN)
Image manipulation parameter that changes screen image brightness usually through the use of a mouse
Window
