Pharyngula

Sex in the MRI

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This morning I got a question in e-mail, asking if I’d heard of a particular paper. Of course I had, it’s a very fun bit of research…and then I realized I’d never mentioned it on the weblog before. I guess it’s because it’s focused entirely on the phylum Chordata, specifically one rather peculiar species—Homo sapiens. I probably just assumed nobody would be interested, because there aren’t any arthropods or molluscs in it.

The paper is all about visualizing the arrangement of organs during coitus. People have tried to figure out how the pieces all fit together internally using cadavers and their imagination, by using a speculum and poking around with their fingers, and by clever tools, like hollow glass tubes shaped like a penis. This paper tries something different: the investigators had people have sex in an MRI tube, and snapped a few pictures while they were at it.

This wasn’t easy. If any of you have seen an MRI tube, they tend to be small and cramped, difficult for claustrophobics to handle, and a tight enough squeeze for one person, let alone two. The methods section is the most interesting I’ve ever read.

The participants (pairs of men and women) were recruited by personal invitation and through a local scientific television programme. Respondents were invited to participate if they met the following criteria: older than 18 years, intact uterus and ovaries, and a small to average weight/height index. The experimental procedure was explained in a letter sent to respondents along with an informed consent form. Participants were assured confidentiality, privacy, anonymity, and the possibility of withdrawing from the study at any time. After written informed consent had been obtained, the participants were invited to come for a scan when the equipment was available on a Saturday.

The tube in which the couple would have intercourse stood in a room next to a control room where the searchers were sitting behind the scanning console and screen. An improvised curtain covered the window between the two rooms, so the intercom was the only means of communication. Imaging was first done in a 1.5 Tesla Philips magnet system (Gyroscan S15) and later in a 1.5 Tesla magnet system from Siemens Vision. To increase the space in the tube, the table was removed: the internal diameter of the tube is then 50 cm. The participants were asked to lie with pelvises near the marked centre of the tube and not to move during imaging. After a preview, 10 mm thick sagittal images were taken with a half-Fourier acquisition single shot turbo SE T2 weighted pulse sequence (HASTE). The echo time was 64 ms, with a repetition time of 4.4 ms. With this fast acquisition technique, 11 slices of relatively good quality were obtained within 14 seconds.

The volunteers were shown the equipment in the two rooms, and personal and gynaecological histories were taken. The experimental procedure was explained, and all investigators left the imaging room. After a preliminary image for positioning the true pelvis of the woman was taken, the first image was taken with her lying on her back (image 1). Then the male was asked to climb into the tube and begin face to face coitus in the superior position (image 2). After this shot—successful or not—the man was asked to leave the tube and the woman was asked to stimulate her clitoris manually and to inform the researchers by intercom when she had reached the preorgasmic stage. Then she stopped the autostimulation for a third image (image 3). After that image was taken the woman restarted the stimulation to achieve an orgasm. Twenty minutes after the orgasm, the fourth image was taken (image 4). At the end of the experiment, the images were evaluated in the presence of the participants.

Science porn! Maybe the stuff about 1.5 Tesla magnets and T2 weighted imaging gets in the way of the romance, but it lets us cut straight to the action. Unfortunately, it sounds like action was hard to come by—while the ladies were willing, the guys seemed to have, umm, flopped. The researchers say the experiment was only possible thanks to the availability of a drug called sildenafil (aka Viagra), with one exception.

We did not foresee that the men would have more problems with sexual performance (maintaining their erection) than the women in the scanner. All the women had a complete sexual response, but they described their orgasm as superficial. Only the first couple was able to perform coitus adequately without sildenafil (experiments 1 and 2). The reason might be that they were the only participants in the real sense: involved in the research right from the beginning because of their scientific curiosity, knowledge of the body, and artistic commitment. And as amateur street acrobats they are trained and used to performing under stress.

Dang. My experimental animals are fish, Danio rerio. I wonder if I could switch my lab over to studying small, curious street acrobats?

Anyway, here is a sample of the results. We’re looking at the pelvic region of the two people rotated into an upright position; the woman is on the left, the man on the right. You’ll just have to stare at it a bit and let your imagination go to work, and you’ll figure out what’s where.

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Midsagittal image of the anatomy of sexual intercourse. P=penis, Ur=urethra, Pe=perineum, U=uterus, S=symphysis, B=bladder, I=intestine, L5=lumbar 5, Sc=scrotum

I have to admit, though, that although it sounds like an experiment that was a great deal of fun, they didn’t learn anything too surprising. They notice that the penis is more contorted than expected, although I had to wonder if that wasn’t just a consequence of the difficulty of having sex in a narrow tube. Intromission didn’t seem to do much to the female anatomy (no surprise, again), but one interesting observation was that the female reproductive tract does jigger itself around in curious ways during arousal and orgasm. Here are photos of the female pelvis at rest, just before and a short time after orgasm.

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Midsagittal images of sexual response in a multiparous woman: (left) at rest; (centre) pre-orgasmic phase; (right) 20 minutes after orgasm

What you should be able to see is that the uterus is progressively displace upwards, stretching the anterior wall of the vagina. So you see, guys, while all looks no different from the outside, strange and subtle things are shifting around on the inside. All we need to know for sure is to take an MRI of her brain during orgasm, or of her pelvis within 20 minutes or so.


Schultz WW, van Andel P, Sabelis I, Mooyaart E (1999) Magnetic resonance imaging of male and female genitals during coitus and female sexual arousal. BMJ 319:1596-1600.

Comments

  1. #1 Bored Huge Krill
    April 11, 2006

    …nd by clever tools, like hollow glass tubes shaped like a penis.

    I’m shocked. Would anybody do such a thing?

  2. #2 Andrew
    April 11, 2006

    PZ, Maybe you should put a little lead-in at the beginning explaining this is a repost from the old site, just so people who didn’t read it at that time know it’s nine months old. 😉

  3. #3 Bretty
    April 11, 2006

    I, for one, am willing to do my bit for science and have sex in an MRI tube… where do I sign up? 😛

  4. #4 idlemind
    April 11, 2006

    So I have to assume that this is your answer to the question posed in the previous post (i.e. “What is the most irresistibly linkable blog post in the world?”).

  5. #5 idlemind
    April 11, 2006

    Also, this just goes to show that when it comes to sex in the MRI, bigger [magnet] is better. Forget the “improvised curtain,” I simply can’t imagine doing the nasty in a cold metal cylinder that’s less than 20 inches in diameter!

  6. #6 Alexander Whiteside
    April 11, 2006

    “Maybe the stuff about 1.5 Tesla magnets and T2 weighted imaging gets in the way of the romance”

    I know a few people (myself included) who would think otherwise.

  7. #7 mike
    April 11, 2006

    The findings about uterine displacement is a little less impressive when you realize that the white object on the right of the image is getting bigger each time. That’s the bladder…

  8. #8 Kapitano
    April 11, 2006

    Many questions waiting to be answered using MRI (Magnetically Recorded Intercourse)…

    *What happens to the rectum during anal sex?
    *What do the muscles of the throat do during deepthroat?
    *What’s going on physiologically during female multiple orgasm?

  9. #9 Jason Malloy
    April 11, 2006

    This morning I got a question in e-mail, asking if I’d heard of a particular paper.

    Hey, you don’t fool me.

  10. #10 Bigdumbchimp
    April 11, 2006

    Where do I sign up for sex with an MRI tube?

    L. Ron Hoover, Deacon, First Church of Appliantology

  11. #11 Macrobe
    April 11, 2006

    “All we need to know for sure is to take an MRI of her brain during orgasm, or of her pelvis within 20 minutes or so.”

    And less reductive intepretations.
    http://www.newscientist.com/article.ns?id=dn7548

  12. #12 swiftee
    April 11, 2006

    And to think that people in Canada wait for months for an MRI opening to have their Astrocytomas diagnosed only to find that it has metastisized into a Glioblastoma Multiforme.

    Ahh, it’s good to be a “scientist” in the USA eh?

  13. #13 Brian
    April 11, 2006

    I like how they zoom in on the Uterus to exagerate what happens !

  14. #14 PZ Myers
    April 11, 2006

    The work was done in the Netherlands.

    The bottleneck isn’t the machines, but the highly trained, relatively scarce technical people and doctors who can make and analyze MRIs. No one died because scientists made use of an MRI for basic research.

    You’ve got a remarkable track record for making stupid, ignorant comments here, Mr Swiftee, but at least you’ve given up on posting under pseudonyms.

  15. #15 PZ Myers
    April 11, 2006

    I’m also curious…is there a problem in Canada with people dying while waiting for the sex workers to get out of the MRI? Or did Mr Swiftee imagine that we’d be impressed with his intelligence if he found an excuse to sling around a few 5 syllable words?

  16. #16 HPLC_Sean
    April 11, 2006

    I wonder: Did the the Siemens Vision give us better semen vision than the Gyroscan?
    And: Why do the names of the instruments seem to lend themselves perfectly to the research?

  17. #17 Lucy
    April 11, 2006

    I think the lady may need to go to the lavatory, I would never believe a bladder could expand to those proportions inside you without causing some problems.

  18. #18 wamba
    April 11, 2006

    No cephalopods involved. Snooze.

  19. #19 KJ
    April 11, 2006

    This research has won the ignobel prize in the year 2000 http://www.ignobel.com/about/

    the man in the blue shirt is the genius here: http://home.hccnet.nl/h.blankesteijn/index/2000/Nrc/Wetenschap/00-10-07%20Wetenschap%20met%20zang%20en%20dans.htm

  20. #20 Blake Stacey
    April 11, 2006

    Involving cephalopods in this kind of Ig Nobel-winning research would push it over the edge into hentai, I think.

  21. #21 PZ Myers
    April 11, 2006

    That’s brilliant! That could be my niche!

    Unfortunately, we don’t have much in the way of high end medical equipment here in Morris, nor do we have any tiny street acrobats, nor do we <sniff> have any squid.

  22. #22 RavenT
    April 11, 2006

    Or did Mr Swiftee imagine that we’d be impressed with his intelligence if he found an excuse to sling around a few 5 syllable words?

    It’d be at least somewhat more impressive had he managed to spell “metastasized” correctly.

    nor do we have any squid

    I feel a grant proposal coming on…

  23. #23 craig
    April 11, 2006

    Before you have sex in the MRI, please remember to remove your genital piercings.

  24. #24 N/A
    April 11, 2006

    What is the point of this study? It’s not like this study is going to lead to a new breakthrough.

  25. #25 PaulC
    April 11, 2006

    And as amateur street acrobats they are trained and used to performing under stress.

    Dembski claims he’s a street acrobat… well, the phrase he used was “street theater” but it could involve some acrobatics. Maybe we’ve been unfair all this time, and he’s helped the advance of science after all.

  26. #26 Pfalz prophet
    April 11, 2006

    I suppose this was inevitable, after a female office worker had her butt photocopied on the new Xerox machine. “Hey, let’s try out the new Siemens!” “What would you like to see?” “Semen, of course!”

  27. #27 frumious b
    April 11, 2006

    nor do we have any squid

    It’s a preconception of mediocre minds that squids can only live in water.

  28. #28 PaulC
    April 11, 2006

    So, uh, they went to all this trouble and they didn’t image the spoons position?

  29. #29 Dianne
    April 11, 2006

    It’d be at least somewhat more impressive had he managed to spell “metastasized” correctly.

    Or gotten the biology straight. Some types of brain tumors can transform into Glioblastoma multiforme, but brain tumors, including GM almost never metastasize elsewhere in the body. They kill by direct damage to the brain, not by metastatic disease.

  30. #30 springbored
    April 11, 2006

    cue Chris Rock’s “No Sex in the MRI Tube” . . .

  31. #31 mothworm
    April 11, 2006

    The paper is all about visualizing the arrangement of organs during coitus.

    Was this really such a mystery?

    Maybe it was some sort of elaborate meta-joke about the popular image of scientists’ (lack of) knowledge regarding “getting it on”.

  32. #32 snarlymon
    April 11, 2006

    We did not foresee that the men would have more problems with sexual performance (maintaining their erection) than the women in the scanner.
    -men do need romance. at minimum dinner and a show.

  33. #33 kathaclysm
    April 11, 2006

    I’m pretty sure I saw this on TLC or Discovery Health or some similar channel… they had taken a few images in different positions, then made a “movie.” They definitely showed it too…

    And I coulda told ya, without the MRI, that was my bladder he was hitting….

  34. #34 dave
    April 11, 2006

    While interesting, I would like to see the shifting of organs due to position (relating to the earth), partner, and body/limb position. So while kathaclysm(no offense intended) could say it her bladder was being hit. I could see why and understand it. jmho.

  35. #35 Ian H Spedding
    April 11, 2006

    We did not foresee that the men would have more problems with sexual performance (maintaining their erection) than the women in the scanner.

    Surely, they just missed an obvious solution to erectile dysfunction: small iron implants the length of the penis, switch on the magnetic field and then it’s “Are we in an MRI scanner or are you just pleased to see me?”

  36. #36 Paul W.
    April 11, 2006

    Before you have sex in the MRI, please remember to remove your genital piercings.

    My understanding is that if your jewelry is reasonably small and made of high-grade surgical stainless steel (with no nickel in it), it’s not generally a safety problem. Metal jewelry in the wrong places can introduce tomography artifacts into the pictures, but the tech can generally tell if that’s happened right away, say “you have to take it out,” and do it over.

    (That said, it’s good to have nonmetallic placeholder jewelry ready if you don’t want to risk screwing up the pictures, or you have a tech who’s not down with it. Some techs some places don’t understand this stuff, but I live in Austin.)

    So I’d say leave them in, if you can. And post the pictures.

    (Disclaimer: I’m not a medical doctor or MRI tech; don’t take my word for this.)

  37. #37 Angus McIntyre
    April 11, 2006

    the woman was asked to … inform the researchers by intercom when she had reached the preorgasmic stage …

    SUBJECT (through intercom): Oh God! Oh God! Yes! Oh God, yes!

    EXPERIMENTER (writing on notepad): 10:25am – subject informs researchers that she has reached the pre-orgasmic stage.

  38. #38 sglover
    April 11, 2006

    What, no money shot?!?

  39. #39 Joe
    April 11, 2006

    That’s a weird looking penis

  40. #40 craig
    April 11, 2006

    The images were not was I was thinking about ruining. Huge powerful magnets are not a great thing to be near when you have wirey metal objects being held back by a small amount of flimsy skin. 🙂

  41. #41 Orac
    April 11, 2006

    All right, I’m a doctor. How come I can’t find a research project this interesting? Why waste my life trying to cure cancer when I could spend my life doing science porn? 😉

  42. #42 quovadis
    April 11, 2006

    Remember, when you have sex in an MRI, you’re having sex with everyone who ever used that MRI. And with their horrible tumors too.

    Seriously, they were SURPRISED that the guys couldn’t perform? It’s a doctor’s office, which are always freezing and have those awful fluorescent lights, and the MRI tube is a scary test thing that most people associate with being really sick and that probably feels like a coffin without the cushions. I can’t imagine there would have been problems…..

  43. #43 prismatic so prismatic
    April 11, 2006

    Reminds me of an old joke about the definition of sang-froid

  44. #44 Grey
    April 12, 2006

    To the guy who asked “what’s the point of this?”, how can you not find it interesting for its own sake?

  45. #45 stheory
    April 12, 2006

    For a more interesting research proposal, see http://www.geocities.com/stheory/proposal.html

  46. #46 Motel6
    April 12, 2006

    Hehehe, having sex for science is a great idea, but I think it’s even better when there’s a second girl there to “coach” you on your abilities. When you do it wrong, she pushes the other girl off and shows you how it’s done! That’s MY kind of science! 😀

  47. #47 SgtMeinz
    April 12, 2006

    I’m curious as to how authorization for this project was obtained. What did the researchers put in their proposal to justify use of the MRI, which by all accounts is fairly expensive? In any case, I’m glad they conducted this project; I agree with “stheory”‘s post as I am a big believer in research for the sake of research.(As long as none involved are harmed)

  48. #48 josh
    April 12, 2006

    WNN FCK WMN N MR!!!

    [I’m sorry. This is not the wall of a bathroom stall at your local rundown honky-tonk. PZ]

  49. #49 melior (in Austin)
    April 12, 2006

    I am still amused at the fact that the proper name, NMR, or nuclear magnetic resonance imaging, is considered too scary to use around patients. Shhhhh.

  50. #50 Linda
    April 14, 2006

    Utterly fascinating photos. Thank you for posting this!

    The only thing that would be even more interesting would be real time 3D ultrasound footage or other media capable of real time recording. It would be quite interesting to see the mechanism of female orgasm in such a way. Maybe someone will do this in a future study.

  51. #51 hapto
    April 16, 2006

    yes, but what happens if they do it in any of the myriad of other positions out there? what about different women/men of different shapes and sizes? how do they fit together then? (i know, you’d need a bigger MRI)

    as for the metal factor, a couple of underwires can cause some double Ds to take to flight when in an MRI. jah. that was fun.

  52. #52 Thursday
    August 25, 2006

    This is shameful. What a farse. I’m supposed to accept that this meaningless and transparent charade won a prize? Ha! Almost as bad is that you bothered to report it.

    Further, I’d say it is you who have a remarkable track record for making stupid, ignorant comments, Mr. Myers. Despite the fact that you’ve made it common practice to reply to your own articles, I find it extraordinary that when you do, you mention nothing of the other stupid ignorant comments which make up about 90% of everything I read here. Given the irreverent babbling that dominates your peanut gallery, it puzzling, but not altogether surprising that you’d chastise Swiftee. It seems your pattern here has been to insult the author of any ethical consideration. I’d rather read the obviously thorough foundation of rational arguments upon which your beliefs must surely lie.

    “…did Mr Swiftee imagine that we’d be impressed with his intelligence if he found an excuse to sling around a few 5 syllable words?”

    Firstly, you use “we” rather liberally when you actually mean just you. But that’s always been a clever device in any language to create a false sense of majority. Secondly, in regard to your question, I don’t know. But I imagine it’s what you expect from us. After all, this is your website, your article, and yet you actually post replies to yourself!

    Now that I’m here, you wont be getting away with all that anymore. Of course, you could block me and it would solve your relativly minor problem…no, not even; more like an irritation on some hobby site you run for fun. Maybe you don’t care, maybe you do, but I guess if you really want to prove my point, you’ll have to hid me to protect your audience.

    Good luck.

  53. #53 David Marjanović
    October 18, 2006

    Thursday, you surely don’t know the IgNobel Prize. If so, you are missing something in your life. http://www.ignobel.com

  54. #54 Danesha
    June 13, 2007

    Nice…if I write a paper on this, I’m gauranteed an A. Dayum I love science!!!

  55. #55 Justin Moretti
    June 14, 2007

    Dear “Thursday”, whoever you are.

    It seems your pattern here has been to insult the author of any ethical consideration.

    You have missed the point so grossly that you should, IMO, go back to school and learn how to read context. “Swiftee” also missed the point: this was not an MRI machine that people were desperate to get into to have their tumours diagnosed – this was an MRI machine that was going begging on a quiet weekend, or the researchers would never have been allowed to use it.

    As for the research subjects, they were told exactly what would be done with them and why, and they had the option first, to not even get involved, and second, to back out the instant they saw the machine and realized exactly what they were in for. Nobody forced them to do anything, nobody was disadvantaged – so don’t talk about ‘ethical points’ to this audience.

    I will count myself as one of PZ Myers’ “We”; Swiftee’s remark on MRI machines, waiting lists and the implied denial of service to sick and dying patients was at best ill-informed and at worst callous slander. It would also appear from the context that “Swiftee” has a record of such comments. Swiftee’s poor understanding of the matter is additionally shown by the comment about a low-grade glioma “metastasizing” into a high-grade glioblastoma – this process is transformation or dedifferentiation, not metastasis (which is the term used to describe spread of cancers away from the site of origin).

    As for the prize, the IgNobel Prize is in itself a work of humour – previous winners include a writeup on the first reported case of gay necrophilia in the mallard duck, just to put it in context.

    A sense of humour is clearly something you appear to lack, given the sense of moral outrage your post conveys. These failures of contextual perception and appreciation of humour suggest to me that you have rigid, ‘concrete’ thinking and maybe even an autistic spectrum disorder. A visit to your doctor (and an MRI scan to rule out a brain neoplasm) may be in order.

    I don’t always see eye-to-eye with PZ on everything, and at times he can be quite strident, but at least he has a good sense of humour and can give his blogwatchers a laugh.

  56. #56 Library Diva
    June 23, 2007

    Why didn’t they just try to find one of those “open MRI” machines for the experiment?

    Also, did the couples have to be “couples” in the true sense of the word? Wouldn’t that be a great story to tell your kids: “Well, I met your father during this study…”

  57. #57 Geciktirici
    November 27, 2007

    I think the lady may need to go to the lavatory, I would never believe a bladder could expand to those proportions inside you without causing some problems.

  58. #58 Svetlana
    December 1, 2007

    Hello! I’m Hrvoje from Croatia, working as a web developer and reading your blog via rss feeds.

  59. #59 Dizel
    December 3, 2007

    You have missed the point so grossly that you should

  60. I think the lady may need to go to the lavatory, I would never believe a bladder could expand to those proportions inside you without causing some problems.

  61. I think the lady may need to go to the lavatory, I would never believe a bladder could expand to those proportions inside you without causing some problems.

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