Segment measurement
On a 2D grayscale viewer, segments can be measured.
Click Measure in the menu bar.
Click Segment 
.
Click the first point.
Note
When indicating this point on an uncalibrated image, the calibration will start automatically.
Click the second point or right-click to cancel.
Click the next point. Repeat this step as often as required.
Right-click to finish.
The segment measurement is shown in the viewer and added to the Annotation tab 
on the smart panel under the group of 2D Measurements. A measurement can be edited by dragging the control points. To avoid overlapping labels, move the labels by dragging them.