Dexcom G6 and CT Scan (computed tomography)

I have needed a few CT scans recently and have been really tired of popping out my transmitter each time (playing by Dexcom rules), popping it back in after CT scan and then wait for 45 minutes to 2 hours for the transmitter and receiver to sync back in. Today is 12/22/2020 and my 10-day sensor will expire on 12/25/2020 at which time will be the 100+ day end of life for my transmitter as well.

I decided with only 3 days to go before I need to put in both a new G6 sensor and a new transmitter that I would experiment wearing them during my CT scan and see if the Siemens dual source scanner, bombarding my sensor and transmitter with x-rays in any way disrupts, destroys or distorts the signal or information sent to my Dexcom receiver. I normally have also asked for the receiver to be taken out of the room and kept in the control room during this procedure. This time I kept the receiver in the room, next to, although not inside the scanner.

The CT Scan had absolutely no effect on either my sensor, transmitter or receiver. BG readings did not even skip 1 dot and stayed normal flatline during the procedure. So, from now on I always plan to just leave my CGM in place and not mess with it in any way when having a CT Scan.

CT scans are becoming increasingly ubiquitous so it would be nice to see others that have had experiences with their CGM and computed tomography to chime in.

Please note if you attempt to do this you are not abiding by Dexcom’s written procedures so you do so at your own risk. Dexcom statement is as follows:


No MRI/CT/Diathermy – MR Unsafe
Don’t wear your CGM (sensor, transmitter, receiver, or smart device) for magnetic resonance imaging (MRI), computed tomography (CT) scan, or high-frequency electrical heat (diathermy) treatment.

The G6 hasn’t been tested in those situations. The magnetic fields and heat could damage the components of the G6, which may cause it to display inaccurate G6 sensor glucose readings (G6 readings) or may prevent alerts. Without G6 readings or alarm/alert notifications, you might miss a severe low or high glucose event.


The real danger in those situations is that the metal could become super hot and burn you.
You don’t really need to worry about the magnetic field because platinum is not magnetic.
You can ask for a lead apron to cover your sensor since that part isn’t being scanned or at least I assume so.

I have had 2-3 ct scans at least, never took out transmitter, no problems. For mri of course I remove everything.

Interesting post, Guys.

I need to have a CT scan tomorrow, March 22, and just put in my current sensor yesterday, just before learning about the CT scan. I called Tandem, and was told that though I had to remove the pump, I could keep in the Dexcom – he even excused himself to go confirm that, when I told him it wasn’t what Dexcom said. So I tried again with a chat Dexcom person, and was still told I had to remove it (I’ve not yet been successful at removing the transmitter without messing up the sensor). Am considering … do already have new transmitter, current one started 3/12, so will be at 78 days. I am definitely having to remove it on 3/27 for CABG surgery, I’m told (anyone here persuaded operating room to use the Dexcom? Know I will be on insulin drip for a while)

Hi LZ1

Don’t worry about what Dexcom says. They need to cover themselves for any situation that has not been studied to death. I started needing several CT scans and at first, removed the Dexcom sensor each time, what a pain. It was such a pain that I gave up and started keeping Dexcom for all CT scans. The only time you can’t keep it is if you are having an MRI.

I have also not had an issue keeping it during Colonoscopy, ERCP, Kidney stone surgery etc. I have not required CABG so can’t advise you there but have found the major hospitals in the Boston area very accommodating when it comes to keeping Dexcom for any minor surgery. Most of the staff have no idea it is a CGM, often assume it is a pump and so this is something you need to talk to your surgeon about. I always brought a spare sensor along in case I was required to remove mine, but that was never the case.

CT person assured me it was fine, so wore it. if there’s a problem, it hasn’t manifested yet.