Season 1: When Alex is stuck in the MRI machine and is checking JD's hand for a wedding ring, I noticed she was feeling the right hand not the left. Why would they do that?

In the immortal words of JD's imaginary Opera singer: "Miiiiiiistaaaaaaaake" but seriously, i don't know. that's my best guess. but apparantly the ring hand depends on a person's culture. a lot of European men wear it on their right hand.

Because she couldn't see whilst she was inside the MRI machine and didn't know what hand she was feeling!