Back in 1999, Pek Van Andel and three of his colleagues did a research study to take MRI images of a couple having sex. Now, the video is on the internet. Oh my.
It's sure not the sexiest piece of footage I've ever seen, but it's interesting. I guess? What's great is that the researchers were pretty upfront about there being no real point to this study other than just seeing if they could do it. Look at their objective!
Objective: To find out whether taking images of the male and female genitals during coitus is feasible and to find out whether former and current ideas about the anatomy during sexual intercourse and during female sexual arousal are based on assumptions or on facts.
This is exactly the kind of thing we'd do if you gave us any kind of equipment—test the limits of it. Also, can you imagine trying to have sex in an MRI tube? That's got to make the back seat of a compact car feel like a king-size bed by comparison.
Now that sex is done, we need to start the MRI on other bodily functions. Urination, defecation...I guess that's it. [Improbable Research]