Advancements in Magnetic Resonance Imaging (MRI) technology have made it possible for scientists to build videos from MRI scans that illustrate what happens inside the body during live birth, sexual intercourse, and other activities, Joss Fong writes this week in Vox.
How do MRI scanners work?
MRI scanners generate real-time images of the human body by mapping the location of hydrogen protons—which reside in water molecules and the body's fat tissue.
When a patient is inside an MRI scanner, the strong magnetic field of the machine forces their hydrogen protons to align. The machine uses pulses of energy sent by radio waves to alter the behavior and orientation of the protons. When the radio waves are stopped, the protons realign based on the magnetic field and emit radio waves that communicate their position in the body to the MRI machine.
Dutch researcher Pek van Andel in 1999 studied sexual intercourse through an MRI scanner as part of a study on the feasibility of recording images inside an MRI machine.
Unsurprisingly, the participants in the study said the experience was not very comfortable. One participant said, "Confined by the space we [made] the best of it [so that it was] not so uncozy," noting that the researchers directed the participants through every movement, even telling them in some cases when they were allowed to breathe.
The researchers were able to turn the experiment into a video using hundreds of scans. [The video can be viewed here, but be warned that it may be considered unsuitable for viewing at work.]
Similarly, University of Chicago researchers in 2011 recorded how a live birth appears through an MRI scanner. The scientists turned off the machine once the baby's head emerged, so as not to harm its hearing with the loud sounds made by MRI machines.
According to Vox, there are many other MRI videos illustrating various movements, including videos of a beating heart and a person drinking juice (Fong, Vox, 9/22; Matthews, Huffington Post, 9/20; Rickman, Independent, 9/21).