Portal to Pre-Screen Recumbent MRI Patients for Ferromagnetic Hazards

DESCRIPTION (provided by applicant): Ferromagnetic objects - both permanent magnets and magnetically permeable objects - turn into hazards near MRI (magnetic resonance imaging) systems because the strong magnetic gradients convert such objects into projectiles. Several accidents, including at least two fatalities, have occurred through the inadvertent introduction of such objects into the magnet room (called Zone IV). At present, MRI safety practices rely on training and signage to prevent transportation of hazards into Zone IV. Conventional metal detectors have been rejected for object screening because they alarm on non-ferromagnetic as well as ferromagnetic metals. Recently, Mednovus has introduced a hand-held scanner, called the SAFESCAN(r) MR Target Scanner(tm), that detects only ferromagnetic objects as it is passed over a patient's or staff member's body. This represents the first successful commercial introduction of a reliable technical means to exclude small ferromagnetic hazards carried on the person of a patient or staff member into Zone IV. Mednovus will shortly introduce into the market a portal for ambulatory patients to accomplish a similar objective automatically and without the need of technician assistance. This leaves unresolved the case of screening recumbent patients on gurneys. Mednovus proposes to develop an innovative portal specifically for the high-resolution screening of such patients - who may be unconscious or otherwise unresponsive - with high reliability and sensitivity, such that even ferrous aneurysm clips and other internal hazards can be detected. This system will automatically detect only ferromagnetic hazards, and will not alarm on extraneous materials. Phase I research will establish the feasibility of the proposed concept and produce a detailed portal design.