title: Safety considerations for magnetic fields of 10 mT to 100 mT amplitude in the frequency range of 10 kHz to 100 kHz for magnetic particle imaging.
abstract: Magnetic particle imaging (MPI) is a new imaging modality using oscillating magnetic fields in the frequency range of 10 kHz to 100 kHz. The duration of data acquisition becomes smaller, and signal-to-noise ratio improves if the amplitude of these fields is increased - technically amplitudes of up to 100 mT might be feasible for human-sized systems. On the other hand, with increasing field strength, adverse health effects must be expected: oscillating magnetic fields can stimulate nerves and muscle and heat up tissue. Thresholds for stimulation with magnetic fields in this frequency range are not precisely known, neither is the local temperature rise following exposure. The ICNIRP guidelines define reference levels for magnetic field exposure for the general public that contain large safety factors - for medical diagnostics, they might be exceeded for a short time. In this article, research and guidelines in this field are briefly reviewed, and new results are presented in order to contribute to a future definition of safety limits for oscillating magnetic fields in MPI.
authors.forename: Olaf
authors.initials: O
authors.lastname: Dössel
authors.forename: Julia
authors.initials: J
authors.lastname: Bohnert
mesh_terms: D003287:Contrast Media; D017408:Guidelines as Topic; D006801:Humans; D060526:Magnetic Fields / Q000009:adverse effects*; D008279:Magnetic Resonance Imaging / Q000009:adverse effects* / Q000592:standards*; D058185:Magnetite Nanoparticles / Q000009:adverse effects* / Q000592:standards; D008452:Maximum Allowable Concentration; D057054:Molecular Imaging / Q000009:adverse effects* / Q000592:standards*; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control*
chemical_list: D003287:Contrast Media; D058185:Magnetite Nanoparticles