title: Magnetic resonance imaging of the metal clip in a breast: safety and its availability as a negative marker.
abstract: OBJECTIVE
  This study assesses magnetic resonance (MR) safety of the stainless-steel clip inserted after stereotactic-guided directional vacuum-assisted biopsy (DVAB) of the breast, and evaluates its imaging value.
  
  
  METHODS
  We used a sausage as a substitute breast and inserted the clip into it. The MR images of the substitute were scanned using a breast coil, and it was then dissected. After the substitute experimentation, MR scanning of the breast was performed using a dynamic contrast enhanced technique, in which a clip was placed after DVAB for suspicion of ductal carcinoma was seen as grouped amorphous calcifications on mammography.
  
  
  RESULTS
  On every magnetic resonance image of the substitute, the clip was seen as a spotty signal void, with no surrounding artifact. There was no movement and no evidence of increased clip temperature on dissected of the substitute, confirming the safety of breast MR with a clip in place. There was no patient complaint of feeling heat or pain during the MRI examination and there were only biopsy scars on the surgically excised breast specimen material. On the breast MR images, a spreading region of the tumor adjoining the position of the signal void was identified as an early enhancing lesion.
  
  
  CONCLUSIONS
  The safety and reliability of breast MR examination using a mammotome clip was demonstrated by both the mock examination and the breast examination. It is possible to localize of tumor spread regions based on the marker position using the clip as a negative signal marker.
authors.affiliation: Department of Radiology, Faculty of Medicine, Tokyo Medical and Dental University, Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kubota
authors.forename: Naoya
authors.initials: N
authors.lastname: Gomi
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Wakita
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shibuya
authors.forename: Masaki
authors.initials: M
authors.lastname: Kakimoto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Osanai
mesh_terms: D001943:Breast Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D002114:Calcinosis / Q000209:etiology / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D013525:Surgical Instruments; D016896:Treatment Outcome