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CTP486 Image uniformity module
The image uniformity module is cast from a uniform material. The material’s CT number
is designed to be within 2% (20H) of water’s density at standard scanning protocols.
The typically recorded CT numbers range from 5H to 18H. This module is used for
measurements of spatial uniformity, mean CT number and noise value.
The precision of a CT system is evaluated by the measurement of the mean value and
the corresponding standard deviations in CT numbers within a region of interest (ROI).
These measurements are taken from different locations within the scan eld.
The mean CT number and standard deviation of a large number of points, (say 1000 for
example) in a given ROI of the scan, is determined for central and peripheral locations
within the scan image for each type of scanning protocol. Inspect the data for changes
from previous scans and for correlation between neighboring slices.
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