FUJI CR plates have 9 sections on them divided equally. If you've ever noticed the green horizontal orientation bar, that should be either placed at the head of your patient (for lengthwise exposures) or at the patient's right (for crosswise exposures). This is important to remember when using the EDR feature.
When using the EDR option, it can only be applied before image processing, and additionally, needs to be selected prior to scanning your cassette bar code associating it with the desired view. The EDR has four modes:
AUTOMATIC
SEMI-AUTO
SEMI-X
FIXED
Automatic - this is the default setting on most IIP's. This mode will sample the entire cassette if it is exposed in its entirety. It also, however, should detect collimated fields and if collimated properly, will only include the exposed areas inside that field as part of the "values of interest" in the histogram (see "Anatomy of a Histogram").
Semi-Auto - this mode will only take a sample from the central partition of the cassette (#5 in the above diagram). As you can suspect, positioning is key when selecting this option, but should be familiar to you if you are comfortable with utilizing the center cell with AEC.
Semi-X - allows you to select one of the nine partitions of the IP. Depending on the anatomical part or projection you are attempting to perform, selection of the proper partition is crucial, as is the need for proper cassette orientation.
Fixed - for those of us who were once comfortable utilizing film/screen combination radiography, this may just be an equally comfortable option to choose. Instead of a histogram and software equalization, whatever technical factors you select will be represented by the density and contrast on your image. A double in mAs will actually be a double in density, and you have the option of choosing a speed class (which is representative of the film/screen speed combo with conventional radiography).
This can be a lot to swallow or to know how to use appropriately... more specific posts for each option to come!
Do you know if Kodak has a similar functionality to the fixed option?
ReplyDeleteAs far as I know, Kodak does not offer any options like this... their plates will process information recognized within the collimated fields and develop a histogram based on those values. That's not to say they may be in the process of developing something new that I may be unaware of. I would love to hear about anything that any of the readers might know of :-)
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