To mark specific regions on the image by drawing free-form lines:
Click Diagnose in the menu bar.
Click Pencil 
 .
Draw free-form lines.
Note
The pencil annotation line thickness can be chosen.
Right-click to finish.
The line is shown in the viewer and added to the Annotation tab 
 on the SmartPanel™.  Click 
 to change the color or delete the lines. To move the  pencil annotation, click and drag the annotation on the viewer.