title: Characterization of ferromagnetic or conductive properties of metallic foreign objects embedded within the human body with magnetic iron detector (MID): Screening patients for MRI.
abstract: OBJECTIVE
  A preliminary assessment of the MRI-compatibility of metallic object possibly embedded within the patient is required before conducting the MRI examination. The Magnetic Iron Detector (MID) is a highly sensitive susceptometer that uses a weak magnetic field to measure iron overload in the liver. MID might be used to perform a screening procedure for MRI by determining the ferromagnetic/conductive properties of embedded metallic objects.
  
  
  METHODS
  The study was composed by: (i) definition of MID sensitivity threshold; (ii) application of MID in a procedure to characterize the ferromagnetic/conductive properties of metallic foreign objects in 958 patients scheduled for MID examination.
  
  
  RESULTS
  The detection threshold for ferromagnetic objects was found to be the equivalent of a piece of wire of length 2 mm and gauge 0.8 mm(2) and, representing purely conductive objects, an aluminum sheet of area 2 × 2 cm(2) . Of 958 patients, 165 had foreign bodies of unknown nature. MID was able to detect those with ferromagnetic and/or conducting properties based on fluctuations in the magnetic and eddy current signals versus control.
  
  
  CONCLUSIONS
  The high sensitivity of MID makes it suitable for assessing the ferromagnetic/conductive properties of metallic foreign objects embedded within the body of patients scheduled for MRI.
authors.affiliation: Department of Physics, University of Genoa, Italy; S.C. Fisica Sanitaria, E.O. Ospedali Galliera, Genoa, Italy; National Institute of Nuclear Physics, Genoa, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Gianesin
authors.forename: Daniele
authors.initials: D
authors.lastname: Zefiro
authors.forename: Francesco
authors.initials: F
authors.lastname: Paparo
authors.forename: Alessio
authors.initials: A
authors.lastname: Caminata
authors.forename: Manuela
authors.initials: M
authors.lastname: Balocco
authors.forename: Paola
authors.initials: P
authors.lastname: Carrara
authors.forename: Sabrina
authors.initials: S
authors.lastname: Quintino
authors.forename: Valeria
authors.initials: V
authors.lastname: Pinto
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Bacigalupo
authors.forename: Gian Andrea
authors.initials: GA
authors.lastname: Rollandi
authors.forename: Mauro
authors.initials: M
authors.lastname: Marinelli
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Forni
mesh_terms: D000328:Adult; D000368:Aged; D000075202:Contraindications; D005260:Female; D005547:Foreign Bodies / Q000175:diagnosis*; D006801:Humans; D007501:Iron; D019190:Iron Overload / Q000175:diagnosis; D060526:Magnetic Fields; D008279:Magnetic Resonance Imaging / Q000379:methods*; D060306:Magnetometry / Q000295:instrumentation* / Q000379:methods*; D059346:Magnets; D008297:Male; D008403:Mass Screening; D008670:Metals; D008875:Middle Aged; D061214:Patient Safety; D019736:Prostheses and Implants; D012680:Sensitivity and Specificity
chemical_list: D008670:Metals; D007501:Iron
keywords: MRI safety; magnetic iron detector; magnetic resonance; susceptometer