Quantification of a straight line in the editor tool?

Hi,

For my master thesis in medicine I am using Slicer to analyse MRI images. In particular, I have to outline the same structure in every frame of the image, using the editor tool. Afterwards I can easily know the exact volume of the structure by quantification (label statistics). Now, it would also be interesting if I could measure the depth of the structure. To do so, I’d just have to draw a simple straight line. Then, I would need to know how long that line exactly is (depth).

I can not find a tool to draw straight lines in the editor section. The pencil function allows it, but when finishing your move with a right mouseclick, it always takes a circumcision.

So, I need a tool for just drawing straight lines, and afterwards be able to quantificate the line (knowing the exact length).

Does anyone know how to do this?

Thank you very much in advance.

Yes, you can make a ruler with the Annotations module:

https://www.slicer.org/wiki/Documentation/4.8/Modules/Annotations