The cassette is fed into this that removes the imaging plate and scans it with a laser to release the stored electrons.
Source of stimulating light.
Beam Shaping Optics
It keeps the laser beam constant size, shape, speed and intensity.
Light Collecting Optics
Emitted light from the IP, is channeled into a funnel like fiber optic collection assembly and is directed at the photodetector, photomultiplier tube (PMT) photodiode (PD) or charge-coupled device (CCD).
It filters the light before photodetection occurs.
It receives light from the fiber optic collection assembly, and transmits a time-varying analog signal to a computer system.
1.) Protective Layer 2.) Phosphor or Active Layer 3.) Reflective Layer 4.) Conductive Layer 5.) Color Layer 6.) Support Layer 7.) Conductor Layer 8.) Light Shield Layer 9.) Backing Layer
What are the layers of the imaging plate?
A very thin, tough, clear plastic that protects the phosphor layer.
Phosphor or Active Layer
Holds the Photostimulable phosphor (PSP), which is the active component in the plate.
It sends light in a forward direction when released in the cassette reader. This layer may be black to reduce the spread of stimulating light and the escape of emitted light.
The material in this layer absorbs and reduces static electricity.
It is located between the active and support layers of the IP that absorbs the stimulating light but reflects emitted light.
A semi-rigid material that gives the imaging sheet some strength and a base on which to coat the other layers.
It grounds the plate to eliminate electrostatic problems and absorb light to increase sharpness.
Light Shield Layer
It prevents light from erasing data on the imaging plate or leaking through the backing, decreasing the spatial resolution.
A soft polymer that protects the back of the cassette.
It is defined as light produced by a phosphor (active layer) when struck by light or x-ray photons. It occurs following x-ray exposure. However, it also occurs some time later when exposed to a different light source (laser beam).
The ___________ of the laser beam affects the spatial resolution of the CR system.
Scanning of the IP by a laser occurs in a ____ as the plate is fed through the processor.
It is largely automatic in digital.
It is performed to optimize the appearance of the image for purpose of better detecting pathology.
It is the process of labeling the image.
Window and Level
Expands the digital grayscale to visible.
This improves visualization and spatial resolution.
Image Flip and Image Inversion
Reorients image presentation and makes white black and black white.
Improves image contrast.
Registering the image to correct for patient motion.
Region of Interest (ROI)
Determines average pixel value in quantitative imaging.
Various computed radiography images receptors is different for each manufacturer.
Exposure sensitivity of the imaging plate ranges from __ mR up to maximum of __ mR.
In order to evaluate the exposure for CR image, most manufacturers have an ______ that provides information on the average amount of radiation used for an image.
_____ uses a sensitive number (S number) that is related to the amount of amplification required by the PM tube to adjust the digital image.
______ CR indicator system is called the exposure index, which is directly proportional to the radiation striking the IP.
_____ system uses a log median exposure (LgM), it compares the exposure level of an image to a baseline established for the department.