Pencil
To mark specific regions on the image by drawing free-form lines:
Click Annotate on 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 SmartPanel Annotation tab 
. Click 
to change the color or delete the lines. To move the pencil annotation, click and drag the annotation on the viewer.