click below
click below
Normal Size Small Size show me how
RT 296 IT for RT
TEST 2 study
Question | Answer |
---|---|
Digital imaging | any imaging acquisition process that produces an electronic image that can be viewed and manipulated on a computer |
Soft copy images | reading images on the computer without hardcopy films |
Teleradiology | moving images via telephone lines to and from remote locations |
Computed radiography | cassette based digital radiography, uses storage phosphor plates to produce projection images |
Digital radiography | cassette-less system that uses an xray absorber material coupled to a flat panel detector or a change-coupled device to form an image |
Pixel | basic picture element on a display |
Brightness | level of intensity of a digital image on a display monitor |
Bit depth | the number of bits stored per pixel, defines the shades of gray available for each pixel |
Matrix | rectangular or square table of numbers that represent the pixel intensity to be displayed on the monitor |
Algorithm | a set of steps that are followed in order to solve a mathematical problem or to complete a computer process |
Exposure index | the amount of exposure received by the image receptor, not the patient |
LUT | (look up table) reference histogram of the luminance values derived during image acquisition |
What does CR require? | PSP plate, reader, monitor, printer, viewing station |
Indirect capture | absorb xrays, converts them into light and light then converted to electrical signal that is sent to the computer for processing and viewing |
Direct capture | devices convert the incident xray energy directly into an electrical signal then sends to computer |
CCD | change couple device |
TFT | thin-film transistor |
What does PACS stand for? | Picture archival and communication systems |
PACS | networked group of computer servers and archives that can be used to manage digital images |
What does DICOM stand for? | Digital imaging and communication in medicine |
DICOM | a global info tech standard that allows network communication between a modality and PACS |
How many bits in a byte? | 8 |
In binary code how is the 1 produced? | when the circuit is closed and current passes thru |
In binary code how is the 0 produced? | when no current passes because circuit is open |
Name some of the computer languages? | Fortran, Basic, Cobol, Pascal, C, C++, Visual C++, Basic Visual |
How many shades of grey can the human eye detect? | 32 |
Dynamic range | the ability of an imaging system to respond to varying levels of exposure |
Health care level 7 (HL-7) | standard protocol used for medical data systems, allows for communication between HIS and RIS |
Radiology info systems (RIS) | info system used in rad dept for ordering exams and reporting results |
Hospital info systems (HIS) | info system used throughout hospital, includes direct pt care info, billing systems, and reporting systems |
What is the PSP phosphor? | barium fluorohalide |
When should a CR cassette be erased if not used? | after 24-48hrs |
How long can a CR cassette hold an image? | 8 hrs |
What does a CR reader use to read the image? | infrared laser beam |
How much of the IR must be used exposed to produce an image? | 30% |
Noise | any type of signal interference in a digital image |
Annotation | add text to processed image |
Edge enhancement | increasing brightness along edges of structures to increase the visibility of margins |
Latitude | range of exposure factors that will produce an acceptable image |
SNR | signal to noise ratio |
Which is desirable to SNR, a high or low ratio? | high SNR |
Spatial resolution | detail |
contrast resolution | ability of digital imaging systems to display changes in gray scale values |
DQE/detective quantity efficiency | measures how efficiently a system converts an xray input signal into a useful output image |