2. In one of the viewports, right-click on the view type active annotation and select Histogram
or X Section.
○
If you select a view type of histogram, you will immediately view a volume histogram
which includes the entire 3D model. No other action is required. Place the cursor on the
voxel reference line and hold <Shift>. The image displays the range of voxel class
boundary lines by highlighting them in green.
○
If you select a view type of X Section, the view will display
Undefined
histogram until you
start to define the trace.
○
Both the volume and cross-section histograms contain the same information with the
exception of the name and measurement units. Cross-section histograms show total
area, while volume histograms show the total volume for the entire object without cut
planes.
3. For a cross-section (X Section) histogram, in the viewport containing the anatomy of
interest, press <Shift> and simultaneously click the image to deposit points on the area of
interest to create a trace.
NOTE:
The histogram values and statistics are those of the current 3D model, not those of
the original exam. If the 3D model contains only a given range of voxel values, only
voxels within that range will appear in the histograms. Statistics and computed values
of surface area or volume displayed on the histograms are subject to the same
accuracy limitations as other on-view measurements. This tool can be used for cross-
section and volume measurements of specific anatomic features if the feature to be
measured can be clearly defined by a range (class) of voxel values.
4.3 Create an MPVR view
Use this procedure to create an Multi-Projection Volume Reformation (MPVR) view. This type of
thick slab reformatted image is often used to see vessels in Computed Tomography
Angiography (CTA) scans.
1. Open
Reformat
.
2. Click the red annotation in the upper-left corner of the viewport and select 3D or MIP render
mode. The selections available are dependent on the view type.
MIP is used most often in CTA models to demonstrate the most intense voxels.
3. Click the [Oblique Mode] icon .
4. Click and drag the yellow line on the image.
5. Place the cursor over the red thickness annotation to do one the following options.
○
Type the desired thickness and press <Enter>.
○
Middle-click and drag to the desired thickness.
Revolution CT User Manual
Direction 5480385-1EN, Revision 1
Chapter 16 Reformat
465
