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Digital IR System
Digital IR System #9
Question | Answer |
---|---|
General term for the process of aquiring images of the body using x-rays, displaying them digitally, viewing/storing on a computer | Digital Imaging |
Stores the image of the body part for Computed radiography | Photo stimuable phosphor plate |
A cassette less digital x-ray system or flat panel detector | Digital Radiography |
Two types categories of digital radiography | Indirect conversion, direct conversion |
In digital radiography the two step process in whic x-ray energy is converted into light, then to an electrical signal | Indirect conversion |
In digital radiography the process in whic detectors convert x-ray energy directly into an electrical signal or digital signal | Direct conversion |
A means for adjusting any digital image of a body part with computer software | Post Processing |
What material is used in a computed radiography imaging plate. | Phosphor |
To process a CR image you will need: | Computed Radiology reader unit, Computer system with monitors |
What does ALARA mean? | As low as reasonably achievable |
After using a CR imaging plate, an image is recovered the plate is erased with: | An intense white light |
In conventional radiography what items are needed to form an image of a body part? | film and intensifying screens within a cassette |
What are two common post processing techniques for CR? | Subtraction, Contrast enhancement |
A post processing technique that can remove anatomy such as bones or organs is called? | subtraction |
A post processing technique that can change contrast from very high to very low is called? | contrast enhancement |
What does PACS stand for? | Picture Archival and communication System |
What does AEC stand for? | Automatic Exposure time |
Storage phosphors in CR plates are hyper-sensitive to? | scatter radiation |
If a CR plate is used for two separate exposures, the side not receiving exposure must? | be covered with lead |
Exposure technique chart must be used when using? | a digital imaging system |
What should be used for body parts that have extreme difference in tissue density | A compensating filter |
What will occur in digital systems if there are too few photons reaching the image receptor | Quantum mottle |
What are the advantages of using CR and digital radiography systems? | The ability to see images quickly, A wide dynamic range is enabled, image density and contrast can easily be adjusted. |
Aprox. how many times can the phophor plate inside the CR cassette be used before replacing? | 10,000 times |
The CR digital system image plate is scanned with a _____________ ___________ after being inserted into the reader device. | lazer light |
Because of wider dynamic range of digital systems, a slightly higher ______ setting may be acceptable for radiography projections using a grid or bucky | kVp |
The erasure process will begin if the CR cassett is opened and plate is exposed for: | 15 seconds |
this glows when hit by an x-ray photon | scintillator |
Once the image is converted to light, the light is converted to an electrical signal, this is called | CCDs Charged Coupled devices |
A slightly higher ______ setting when using a bucky or grid will reduce exposure time and penitrate better | kVp |
___________ __________ must be placed near the center area of the CR plate | Body part |
The body part and collimated field should always be centered to the _________ __________ when possible | image receptor |
In CR or DR how may margins should be seen on IR when collimating? | All 4 if possible, but at least 2 |
How long can a CR cassette be opened and exposed to light once the exposure is made with out compromising the image? | less than 15 seconds |
CR cassette is not light tight but is designed to protect from? | dust, scratches |
T or False ID markers are not used in CR and DR because they can be easily added with computer software. | False, it is reccomended to use markers while preforming exrays to reduce errors. |