Jane has a three year old MacBook running Snow Leopard, and CDs she gets from her doctors won't run on it. Leo says that Jane should make sure it's a CD, not a DVD. It may be that her drive doesn't support DVDs, just CDs. Leo says that the program needed was called "Rosetta," and that's an old emulator program designed to run older, proprietary software. Leo says Jane doesn't want to install that because OSX has moved beyond it. Leo recommends asking the doctor to install a program that works with modern Macs. But there may also be a Windows program and that's why they don't get a lot of complaints.
Leo also suggests just browsing around the folder to see if there's jpgs or movs and Jane can just open them with her Mac natively.
The chatroom found a free program called OsiriX Viewer, designed for opening these files. It will allow her to look at the DICOM images (images with a .dcm extension).