Definitions within Scan Analysis

dd files are a result file from some type of operation on the scan data file. dd files are typically some form of view summed file that may have had some specific type of processing applied to it. For example, the processing applied to the raw data to calculate the position of the pin in ISO alignment results in a temporary file that is a view summed result that could be saved as a dd file. As long as two dd files have the same number of data elements in them, the two files may be added, subtracted, multiplied, or divided with each other.

One detector output row for each of the four 4x1.25, 4x2.5, 4x3.75, or 4x5 acquisition mode combinations for the detector. For most of the analysis functions, this provides either four selections for the detector row to be examined, or four sets of data results that correspond to the detector rows 2A, 1A, 1B, 2B.

Refer to Warp3 Detector Theory for further information.

This is usually the result of combining two or more views mathematically, which results in mean values for each channel in the views and an associated standard deviation for each channel in the views. In essence all of the user selected views in a scan file are summed together, resulting in a single “master view” that contains the averaged data from all of the views. The mean values represent the average data value from the channels, and the standard deviation values represent the amount of variability for that channel’s data values across all of the views. The higher the standard deviation, the more the channel output varied from view to view.

This is the information contained within the scan file that identifies the specific settings in effect when that scan file was created. The scan header includes information at several levels, including: Exam, Series, and Scan. Information identifying the technique selections, scan time, acquisition mode, and many others may be found in the scan header.

Within scan analysis, the cal vectors are only those vectors contained within the scan data file at the time that the scan was taken.

The auxiliary channels are data sampling “channels” in the MDAS that provide a way to place other data into the view besides the patient information coming from the detector. These include: Power Supply, Temperature, kV, mA, and other analog data values. These analog signals are sampled at the same rate as the patient image data and are a snapshot of those values at each view sample time.

These are some special purpose channels built into the detector that are used for several different special operations related to determining the x-ray beam position on the detector.

This is a way to graphically represent the data values from each channel for each view of data from the MDAS as a shade of grey. The display will have the views stacked vertically and the channels arranged across the display horizontally.