CGM Safe to Use Near MRI Equipment, Case Study Finds

What This Study Found

A new case report followed a healthcare worker with Type 1 diabetes who wore a continuous glucose monitor (CGM) while working in a room containing powerful MRI-guided radiotherapy equipment. Over 122 working days, the CGM transmitted 96% of blood sugar readings successfully — and its readings closely matched traditional finger-stick blood sugar checks. There were no significant differences between the two methods, suggesting the device worked reliably in this specialized environment.

Why Does This Matter?

MRI machines produce strong magnetic fields. Many electronic medical devices — including some CGMs — carry warnings about use near MRI equipment. This creates a real dilemma for healthcare workers with diabetes who spend their shifts working in MRI suites or MRI-guided radiotherapy rooms.

Until now, there has been very little real-world data on whether CGMs stay accurate and function safely in these environments. This case report is the first of its kind to document in-person CGM use inside a 1.5T MR Linac — a machine that combines an MRI scanner with a cancer radiotherapy device.

For the growing number of people with Type 1 or Type 2 diabetes who work in medical imaging roles, this is an important step toward clearer guidance.

How Was the Study Done?

A single radiographer with Type 1 diabetes wore a FreeStyle Libre 2 CGM (made by Abbott Diabetes Care) every day at work for four months. The testing covered all areas of an Elekta Unity MR Linac suite. Every two hours during work shifts, the participant also took a traditional finger-stick blood glucose reading to compare against the CGM data.

Researchers used standard statistical tests to check whether the two methods agreed. They also tracked how often the CGM's wireless data transmission worked properly.

What the Results Showed

• 96% data transmission success — Almost all CGM readings were received by the cloud-based diabetes management system, even inside the MR Linac room.
• Strong agreement with finger-stick tests — A correlation score of 0.70 showed a positive match between CGM and manual readings.
• No significant difference — Statistical testing (p = 0.63) confirmed no meaningful gap between CGM and finger-stick values.

Important Limitations to Know

This is a single case report — meaning it followed just one person. Results cannot be applied broadly to all CGM brands, all MRI machine types, or all working environments. The authors are clear that more research is needed before formal guidelines can be updated. Always speak with your diabetes care team and employer before making decisions about CGM use near MRI equipment.

What This Means for People With Diabetes

If you or someone you know works in a medical imaging environment and relies on a CGM to manage diabetes, this study offers early reassurance — but not a blanket green light. The FreeStyle Libre 2 performed well in this specific setting, which is encouraging news. Workplace accommodations and open conversations with your healthcare team remain essential.

If you're managing diabetes and want to explore CGM-compatible monitoring supplies and resources, visit mdsdiabetes.com to see what's available to support your diabetes management routine.

Full Citation

Dobby, Nelder, Tallon (2025). A case report of continuous glucose monitoring for a radiographer working in a 1.5T MR Linac. Journal of Medical Imaging and Radiation Sciences. PMID: 40779973. DOI: 10.1016/j.jmir.2025.102063