can a cd with xrays be viewed on a DVD player?

You should be able to view the x-rays on the CD if your computer has a DVD *drive*.  DVD drives are usually able to read CD. 

I'm assuming the x-rays are in a common standard image format. If they are, you probably have the software on your computer that can render the images. If they are encrypted and you don't have a key or are stored in proprietary format, you might not be able to view them. 

usually, yes.  the required software is on the CD/DVD and starts automatically when it is inserted in the disc drive

it won't hurt you. just try it

A DVD player only reads phyiscal media. Most can read CDs (I'm not going to say "all" because there's probably some obscure model out there that doesn't.) It doesn't care what's on it. You'll need software able to view whatever file type the xrays are stored as, and that won't generally care if it's on CD, DVD, USB drive or cassette tape.

If the DVD player can display images and the image format is one the player can display.

Won't hurt to try. 

only VIDEO DVDs can be viewed on a DVDplayer.
those discs usually have software for computers specifically to use. you can ask your doctor, or just stick it in your DVD player to see.