no it doesn't mean anything. many people get stressed out during an mri due to the lengthy procedure and the confined space so just be glad that you had an enjoyable experience. i don't think medical science has an explanation your unexpected pleasurable mri.
mri/mra felt fantastic - like a massage to the brain. i had an mri/mra earlier this year for undiagnosed symptoms. during the mri/mra i felt amazing. it was like someone had gotten inside my skull and was providing the best massage of my life to my brain of all things. . even after the mri/mra i continued to feel great for a day or so before i digressed back to the norm. when i asked my doctor he said that he had only heard it described that way once before but he wouldn't say anymore. i was always curious though. does this mean anything?