How safe is fMRI for pregnant technicians?

May 2, 2011 12:44 PM

As an ad hoc pregnant fMRI technician, how safe is it?

I work in fMRI research and, as a part of my job duties, I occassionally am required to perform scans. I have recently found out that I am 7 weeks pregnant, and while the new scanning protocol is not to resume for another couple of weeks, I am wondering how to handle scanning once it does.

While I am aware that we are not allowed to scan pregnant patients, I am having trouble finding concrete guidelines for pregnant fMRI techs (more along the lines of "scan at your own risk" or "don't be in the room once the scan is in session").

Additionally, I am reluctant to talk about this to my boss since I do not want to disclose my pregnancy for another 2 months or so. However, I have spoken to my OB and they have said that they will look into it.

Any advice, links, or anecdata would be helpful!

Thank you all.

posted by anonymous to Health & Fitness (10 answers total)

The lab or imaging center is prohibited from scanning you or having you enter the bore for any other reason. I'm not aware of any rules regarding pregnant women entering the scanner room. From a practical perspective, one might recall that the strength of the field falls away proportional with the square of the distance. So, whatever extremely marginal risk one experiences during a scan, that risk is reduced exponentially for individuals who aren't physically inside the scanner. The most immediate risk for individuals without metal implants or devices is increased body temperature. All scanners have failsafes that keep the technicians from cooking the patients, or coming anywhere close.
posted by Nomyte at 12:56 PM on May 2, 2011

We use MRI as an alternative to CT in pregnancy when imaging can't be avoided. However, I am not really sure what the recommendations are for techs. There is really not much research on this topic and most recommendations are based on theoretical risks. The magnetic field is supposed to be safe, the RF fields and noise generated are what is theorized to be the risk of MRI in pregnancy. As a tech, you should not be exposed to any RF fields during your work as the room is supposed to be shielded and you are not supposed to be in the room while sequences are running.

Since not much data is out there you will have to make a decision based on the risk you are willing to accept.
posted by Brennus at 12:59 PM on May 2, 2011

I have been given an MRI by a visibly pregnant MRI tech.

That doesn't directly answer your question, but my assumption is that if there were anything unsafe about it, she wouldn't be there so many months into her pregnancy.
posted by phunniemee at 1:02 PM on May 2, 2011

If you're doing fMRI research, your study design probably went through an IRB. Standard IRB forms designate protected classes: minors, prisoners, pregnant women, etc. If you want to do a study on members of any of those classes, you have to go through extra scrutiny. If you don't want to go through that scrutiny, you say you won't have any members of those classes in your study. That's probably why you aren't supposed to scan pregnant women.

Also, if you use any contrast agents, those might potentially affect a fetus.
posted by demiurge at 1:27 PM on May 2, 2011

In grad school I made a lot of money as an fMRI dummy for various research studies. They were not allowed to scan pregnant women because of any particular concerns with the fMRI, but because pregnant women are not generally allowed to participate in voluntary research studies unless they're of direct benefit of some sort or there is basically zero risk. Consent and risk issues are just too complicated; IRBs generally won't approve pregnant participants unless absolutely necessary.

So, bonus for me, I got $10 extra every study for taking a pregnancy blood draw before the study to prove I wasn't pregnant.

Anyway, if this is research fMRIs rather than diagnostic fMRIs for actual patients, the ban on pregnant patients is not related to the fMRI but to the IRB's decisions. I have had pregnant friends sent for diagnostic MRIs (as long as they or the body part in question will fit in the scanner); while I don't know anything about the risk, I would imagine it's considerably lower than with X-ray or anything like that, and you probably won't be in the room?

(On preview: What demiurge said.)
posted by Eyebrows McGee at 1:34 PM on May 2, 2011 [1 favorite]

I was part of a team conducting an fMRI study while extremely pregnant. I preferred not to go into the room with the magnet (well, basically I preferred not to get close enough to where carrying metal would be a bad idea), but there's no real reason not to. But running the scans (i.e., being at the computer outside of the shielded area), you're not exposed to any more electromagnetic fields than you would be using any other electronic equipment.
posted by amberwb at 1:59 PM on May 2, 2011

Since you work in fMRI research you know that it is non-ionizing radiation. As long as you don't accidentally inject yourself with gadolinium chelates you will be fine.
posted by koolkat at 2:13 PM on May 2, 2011

From fMRI researching friend:

"I talked about this with the tech here. She wanted me to stay out of the room but said if SHE needed to do the scans and was pregnant, she would go ahead and do them because it was part of her job and there's no evidence of it being a big risk factor. Since I was just running my experiment, though, she had me stay out of the scan room and stay in the control room, which is shielded. Also as many others said on the thread, we cannot scan pregnant patients unless it is a health reason (so they can't do research studies). So far Baby isn't showing any magnetic properties beyond normal cute babydom, so here's hoping the precautions worked! :) "
posted by k8t at 4:15 AM on May 3, 2011

We do anesthesia for MRIs nearly every day; so far none of the residents or CRNA's that have been pregnant over the last several years have had any problem with being in the room while a patient is being scanned.
posted by TedW at 6:58 AM on May 3, 2011

I was pregnant while doing running fMRI scans for research. You will be fine. The MRI rules on pregnancy are more of a "no one has conclusively shown it has NO harm, so it's easier just to not do it" IRB problem than a real health risk (as said above).
posted by katers890 at 9:06 AM on May 3, 2011