MRIs Are for Lovers: Sex in a Scanner

Back in the 1990s, Dutch researchers stuck couples into MRI machines and took scans as they had sex.

Above is a scan of one couple sharing an intimate moment. (Click on the picture to, ahem, make it larger.)

Here's a key to the letters in the image:

P=penis, Ur=urethra, Pe=perineum, U=uterus, S=symphysis, B=bladder, I=intestine, L5=lumbar 5, Sc=scrotum

So what does this tell us?

Here are some take-home messages, courtesy of the study (which is eight years old but among the top viewed stories today on the website of the British Medical Journal):

During `missionary position' intercourse the penis has the shape of a boomerang

During female sexual arousal without intercourse the uterus rises and the anterior vaginal wall lengthens

The size of the uterus does not increase during sexual arousal

My favorite part of the study:

We did not foresee that the men would have more problems with sexual performance (maintaining their erection) than the women in the scanner. [Blogger note: They actually had to bring in Viagra.] All the women had a complete sexual response, but they described their orgasm as superficial.

Magnetic resonance imaging of male and female genitals during coitus and female sexual arousal [BMJ]