Currently, I'm experimenting with Dicom viewers, and they're going seriously off the rails. I traced it in one of them (Invesalius3 in Mint), where it works in a dual boot Mint OS, but sucks in a VM. That's been traced to rendering. I have these installed
MITK:
http://mitk.org/wiki/MITK
Mango:
http://ric.uthscsa.edu/mango/
Slicer3D
https://www.slicer.org/
For these, you unpack in /opt, cd to the directory, and run the file. Slicer is over 1G installed, MITK is about 400M, and Mango somewhat less. Only slicer works any way acceptably; the other pair have major issues, and I greatly suspect rendering.
In Slackware, rendering is as good as it's going to get. I believe the core profile in Mesa is the newer OpenGL stuff only, assuring better performance. The alternative is a 'compatibility profile' including the older crappy instructions, and that this is a compile-time option. Software hasn't caught up yet, so of course distros use the compatibility option. Having said that, here's a hardware head in deep in software stuff :-/. I'm no expert here, and could be teetotally wrong.
On a separate plane entirely, there is the sucky nature of intel GPUs generally, and old ones in particular. Ivy Bridge was released ~2012. It won't render 3D, and these are 3D viewers (CTs & MRIs). Some Dicom files are available as examples from the Invesalius site
https://www.cti.gov.br/en/invesalius Look at the bottom. I've been using the brain MRI so we can both have the same files to compare results. You should get 3 views: Top-Bottom; Left-Right; Front-Back, or Nose to Nape.