Noise Index - GE Revolution CT User Manual

To indicate that an image was generated within a scan region where ODM is enabled, an
asterisk is added after the Noise Index value.

4.3.3 Noise Index

Noise Index is an indication or index of the level of reconstructed image noise requested for the
diagnostic imaging task being performed. As the Noise Index increases, the required exposure
(mA and/or kV level) decreases and image noise increases; conversely overall image noise
levels decrease and the required patient exposure increases with a decrease in the prescribed
Noise Index. You can specify the Noise Index in the Noise Index field. The Noise Index field is
enabled only when you enable SmartmA or ODM. A change in prescribed Noise Index
necessarily adjusts dose to the patient, which is viewable at the bottom center of the
Display area. Patient dose will be decreased or increased as the Noise Index is accordingly
increased or decreased.
You are unable to change the Noise Index after kV Assist is turned on. Set an appropriate Noise
Index prior to turning on kV Assist. kV Assist will adjust the Noise Index based on the clinical
task selected to maintain CNR.
Projected Noise Index can be viewed from the Image Quality widget on the Scan Settings
The
window.
NOTE: The
individual scan groups to display the
Image Quality widget will indicate if the prescribed Noise Index will be met. When the
The
projected noise is higher than the prescribed noise, the Projected Noise Index (PNI) will be
highlighted orange. When selected, [Adjust] will display recommended solutions to change scan
parameters to meet the prescribed Noise Index. The
recommended parameters, the change in noise and the change in DLP associated with the
change.
To make changes, click [Adjust] to view solutions for how to adjust the dose to achieve the
desired prescribed Noise Index.
Chapter 11 Scan
Illustration 19: Image Quality widget
Image Quality widget will not display if there are multiple scan groups. Select
Direction 5480385-1EN, Revision 1
Image Quality widget.
Solutions window displays the
Revolution CT User Manual
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