Chapter 14: Quality Assurance and Maintenance
5495975-1EN Rev.9
14-2
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Phantoms
There are two types of phantoms used in the QAP process. The first phantom is the Flat-Field Phantom
and the second is the MTF Phantom. The system prompts you as to which phantom to use from the
respective acquisition screens. There are recommended exposure techniques for the phantoms. The
exposure is automatically set by the system but you should verify the settings prior to making an expo-
sure.
The flat-field phantom (Figure 14-2) is used to check the following factors:
Brightness Non uniformity Global
Brightness Non uniformity Local
Signal to Noise Ratio (SNR) Non uniformity
Artifacts Number of Bad Pixels
Figure 14-2
Flat-field phantom
The MTF phantom is used to check MTF (Modulation Transfer Function).
Figure 14-3
MTF phantom