There are certain situations that I save the .rstimg file for future use.  Not forever, but a bit. 

This is a case that came in today from a bike accident over the weekend.  He is going to need an implant on #9 due to a horizontal root fracture.  Today at the diagnosis appointment, we took a cone beam scan with the XG3D and also an Omnicam scan to create the .ssi fle for guide fabrication.  However, this is going to be a difficult restorative case because it's a single central AND the tooth is rotated.  So, you save the .rstimg file as well so you can use biocopy when you get to the restorative phase (it's a virgin tooth).

You do not want to save these .rstimg files on the Omnicam because of hard drive space limitations, so I just have a folder on my office computer (or you could use a removable thumbdrive) that I store the file until I need it.