KaVo 3D eXam, Руководство оператора

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Kavo 3D eXam ® Operators’ Manual
k990400 September 19, 2007
A-8
Hounsfield Unit Calibration Offset
Before proceeding to the View Volume functions, first enter a
calculated offset into the General Setup for Hounsfield Units. The
value that is required is based on the RIO function.
1. Enable the Paging button.
2. Scroll to the tongue area in the axial view which is just above the
maxillary crowns. (look for a region that has relatively even
grayscales).
3. At this location, enable the ROI function.
4. Drag the cursor in the area between the dental arch, making sure
not to include any teeth or bone. This displays the Hounsfield
data.
The MEAN value is the data of interest in this calculation. It
reads a value (most likely a negative value). Whatever this
number is, we want to add a value that will result in the Mean
being around positive 50. In this example, the Mean reads -85
and we want the Mean to be +50, therefore the offset calculation
will be +135.
5. Click the General Setup button on the menu bar.