Handling an MRI with pump & CGM

My doctor wants me to have another MRI. It’s been a while. This will be my first one since starting on a pump and CGM.

I’ll talk to my doctors, of course, but figured it doesn’t hurt to ask here. Any tips, tricks, suggestions?

Since the machine uses high-intensity magnetic waves, I’ll have to disconnect the pump and remove the Dexcom sensor & transmitter.

Dexcom’s FAQ says to try to schedule it for around when the sensor is due to be replaced anyway. Does that mean they won’t send me a replacement sensor?

So, basically, I get no insulin and no CGM readings for however long it takes to finish the scan this time, hope that I have no emergencies, and make up for it afterwards?

How do you handle it? Do you take an extra bolus before disconnecting? Or just risk going high for a while and fix it after? You definitely don’t want to go low during the scan.

Any thoughts or suggestions?

It’s been a while since I’ve had scans and I used to schedule around my sensor expiration, which was not always possible. At one point Dexcom told me they would replace one if I had to remove it to avoid radiation. I don’t know if that has changed since though.
I think the longest I was in scan was an hour or so. I think I was little high afterwards and took a correction. Would prefer that to going low in the middle of things!
All the best to you.

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Dexcom will replace the sensor if you have to take it off for any medical procedure, even at day 9, no worries. Your pump can’t be in the mri room, they usually provide a locker or basket for your tech stuff.

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PG @WearsHats, I’ve had several surgeries and a few MRI since I began using a pump and CGM and everything worked out wonderfully for me. Yes, you will need to remove both your pump and at least the CGM transmitter and keep those devices far away from ALL magnetic devices at the facility - not just the machine you will slide into. Unless you have an extraordinarily high basal rate per hour, I don’t see a need for an extra bolus.

As far as not having continuous BGL readings and a dribble of basal insulin shouldn’t give you concern for, at most, disconnecting for 90 minutes. You have been in this “diabetes thing” for a long while and up until the last few years you got along well with maybe a handful of BG/BS fingersticks daily.

A tip, if you are using an iAIDs or AIDs and receive CGM data on your pum and / phone, I suggest that you turn off your hone and ut your pump to sleep so those alarms don’t “alarm” too many bystanders because the ump and phone will declare you. “out-of-range”. As an aside, CIQ has been awesome maintaining me on-target during surgery, especially my most recent when I was put-under for over three hours.


It occurred to me that I did without a CGM for a quarter century. I wouldn’t worry about it too much. Except that with the pump I don’t have any basal insulin if it’s disconnected. I don’t have NPH or Lantus in my system. It’s scary how high my BG can get in just a couple of hours without basal. The very first time I inserted a pump cannula, it didn’t go in right (one of several points where my trainer did not have a good handle on things) and my BG hit record highs and was very hard to get even close to under control. It left an impression. And a situation like that is exactly when you need a CGM the most.

But, yeah, even with contrast, an MRI doesn’t usually take more than an hour or so.

Good thought about the alarms. I’ll have to stop the CGM sensor entirely anyway, so that shouldn’t be a problem. But my phone is linked to both the pump and CGM. But I can just turn the phone off. So that just leaves the pump’s cannula disconnection alarm, right? I can disable that for up to an hour when I disconnect. I’ll have to look into how to turn it off longer than that. I think I’ll leave the Dexcom transmitter at home and just start a new sensor when I get back. Unless my endocrinologist has a different suggestion.

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I too use a CGM and Omnipod pump. Have had a number of MRI recently due to complications from back surgery.
Since CGM and Omnipod needed to be removed, the timing was more complicated. BTW…Dexcom is very understanding of these situations and will replace your CGM. I believe Omnipod will do the same if necessary. I tried to coordinate for when Omnipod was expiring.
For those of us who predate CGM and insulin pumps, carrying Novolog, syringe and blood glucose testing with you to dose after your procedure if necessary is not a terrific hardship. The MRI lasts no longer than 45 minutes and is often shorter. Being without your basal dosing for a short period of time will be ok. Of course, you should consult your Endo for suggestions. Best of luck!

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Yeah, I had a bunch of MRIs in the 90s and early 2000s. It takes a lot longer when the doc orders it with and without contrast. First they do the regular scan, then give you the dye intravenously (which is a problem because I have difficult veins, and we just bruised all the good ones with a course of IV treatments), wait for that to work its way through the system, then run the full scan again. Still, yeah, I don’t think it should take more than an hour. I hope. Machines have improved significantly in recent years, I’m told, but that means more detailed scans. So I’m not sure if that means longer or shorter scan times.

I did send a message to my endocrinologist. I’ll see what she says. But I figured it might help to reach out here, too. Maybe I should call the imaging center, too…

As far as tubed pumps, I left mine on until they were ready to put me in the scanner, and then put it in a locker. One time I forgot, and the technician allowed me to put it in their work area - that may not be recommended but I’m just being honest here. I was able to plug back in quickly as needed.
If you expect to be in the scanner for a long time and your numbers so tend to rise more than you’re comfortable with you could switch to injections for the day - and more depending on your basal insulin.

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I scheduled my MRI near the end of my Dexcom and Omnipod time. . I never thought to reach out to them for replacement. Good info.
I had some anxiety because I’m so used to always knowing my numbers and having control. I made sure I ate 2 hours before and was in good control when I removed the devices right before the test. I took my finger stick supplies so I could check immediately after and had an insulin pen with me just in case. Everything was fine.
Good luck!

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