MR Conditional (MR in a triangle)
The definition FDA’s guidance adapts from ASTM F2503:
“An item with demonstrated safety in the MR environment within defined conditions including conditions for the static magnetic field, the time-varying gradient magnetic fields and the radiofrequency fields.”
ASTM F2503 (cited by FDA MR labelling guidance) · ASTM F2503, the practice FDA’s MR labelling guidance follows
What it means for you
A scan is possible only under the conditions the maker specifies — field strength, scanner settings, sometimes time since implantation. Those conditions are in the device’s MRI safety information, which the scanning team needs to see.
Whether a device is right for you is a question for your pharmacist, nurse or doctor.
- What it looks like
- The letters MR inside a triangle, point up.
- Where you see it
- Implant cards for stents, joint replacements, pacemakers and other implants; some wearable sensors and pumps.
- Other names
- MRI conditional; MR Conditional
What it does not tell you
It does not mean any scanner or any scan is fine; without the conditions the mark alone does not permit a scan.
Often confused with
An item which poses unacceptable risks to the patient, medical staff or other persons within the MR environment.
More symbols in “MR”
Sources
Taken from 3 publishers’ public documents. Each was fetched and read on the date shown:
- US Food and Drug Administration: Testing and Labeling Medical Devices for Safety in the Magnetic Resonance (MR) Environment — guidance issued 10 October 2023 — Defines MR Conditional as “a medical device with demonstrated safety in the MR environment within defined conditions including conditions for the static magnetic field, the time-varying gradient magnetic fields, and the radiofrequency fields”, and says devices with small metal markers “should be labeled MR Conditional”. Checked 2026-09-25.
- Boston Scientific: Symbols Glossary — Lists ASTM F2503-20 7.3.2 “MR Conditional — An item with demonstrated safety in the MR environment within defined conditions …” Checked 2026-09-25.
- NE Scientific: Master Symbol Glossary (CTF-100011 Rev 01) — Shows MR in a triangle for ASTM F2503 “MR Conditional”. Checked 2026-09-25.
Plain-language parts are in our own words; quotations are the sources’ wording.