Q: Mid 2011 iMac 12.5" main display for Windows PC

Hello, I have asked this question before but I must ask it again because a new idea came to my head.

I was wondering if I could use my Mid 2011 iMac as the main display for a windows PC that has a Thunderbolt connection on the mother board. Would it work?  

I really love the speakers on this old iMac and the display is great. I would rather not get rid of it because I love it and I don't want to have to buy a new monitor for my gaming PC build that I would like to make. It would take up almost all my desk space and would cost me a few hundred dollars that I could use on better components for the PC such as a better graphics card, faster processor, more RAM, an SSD, bigger hard drive, etc. 

If this is not possible it is ok. I would just go back to my original plan which was to build the PC, buy a monitor, and put the iMac right next to it and use it as a second computer for work and doing other things such as Facebook, Twitter, YouTube, browsing the web, etc while playing games on the PC.