The Oxygen Cylinder That Flew

An MRI scanner's superconducting magnet is always on, even between scans, and will pull any ferromagnetic (steel / iron) object into the bore with enormous force. In 2001 at a New York medical center, a steel portable oxygen cylinder — brought in after the piped oxygen failed — was pulled into the scanner and struck a sedated six-year-old undergoing a follow-up scan.

This is the defining MRI-safety catastrophe, cited in every ferromagnetic-projectile discussion and a driver of the ACR MR-safety zoning and screening standards. The hazard is environmental and absolute: the magnet never turns off. (Contemporaneous reporting; ACR MR-safety literature.)

1. The MRI suite's piped oxygen supply fails during a scan.
2. Staff bring a portable oxygen source into the room to continue.
3. The portable cylinder is ferromagnetic steel, not an MR-safe alternative.
4. The always-on magnet seizes the cylinder and accelerates it toward the bore.
5. The cylinder reaches the bore before anyone can intervene — a fatal ferromagnetic-projectile incident.

A landmark projectile fatality (2001); ferromagnetic-object incidents remain a recognized MRI hazard, not a single published rate.

A ferrous object becomes a projectile in the bore. Shown through the scanner, the bore, and a steel cylinder pinned against the magnet — never the patient.