title: [Preoperative marking and biopsy of nonpalpable breast lesions with a guidance system for the open Magnetom].
abstract: OBJECTIVE
  MRI-guided interventional maneuvers in the breast, when closed MRI scanners are employed are relatively complex and time consuming. The purpose of our investigations was to develop a special device for the localization and biopsy of breast lesions using an open low-field MRI Scanner (Magnetom Open, Siemens, Erlangen, Germany) permitting free access to the patient.
  
  
  METHODS
  Due to its particular material and construction characteristics, a newly developed device for localization and biopsy of breast lesions is appropriate to remain within the magnetic field during the examination without degrading image quality. We performed 125 tests in a phantom and 31 investigations in patients including 26 wire-localizations and 5 biopsies.
  
  
  RESULTS
  The interventional maneuvers in the phantom could be performed very precisely. In all 125 phantom studies, the needle (14 G coaxial biopsy cannula, Bard) was positioned close to the simulated lesion. In 25 out of 26 patients the needle was positioned within a distance less than 5 mm from the lesion. When using the 14 G coaxial biopsy cannula (Bard, Karlsruhe, Germany) the needle tip was found adjacent next to the lesion in all 12 cases (7 wire-localizations, 5 biopsies).
  
  
  CONCLUSIONS
  Our results indicate that our device allows very precise preoperative localization of breast lesions within the Magnetom Open. Using MRI-compatible, large-core needles, biopsy under direct MRI control resulted in good results.
authors.affiliation: Institut für Klinische Radiologie, Klinikum der Universität, Grosshadern, Marchioninistrasse 15, 81377 München.
authors.forename: H
authors.initials: H
authors.lastname: Sittek
authors.forename: E
authors.initials: E
authors.lastname: Linsmeier
authors.forename: C
authors.initials: C
authors.lastname: Perlet
authors.forename: P
authors.initials: P
authors.lastname: Schneider
authors.forename: C
authors.initials: C
authors.lastname: Baudrexel
authors.forename: M
authors.initials: M
authors.lastname: Untch
authors.forename: M
authors.initials: M
authors.lastname: Reiser
mesh_terms: D000368:Aged; D016477:Artifacts; D001707:Biopsy, Needle / Q000295:instrumentation*; D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000473:pathology*; D004867:Equipment Design; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008875:Middle Aged; D019047:Phantoms, Imaging; D012680:Sensitivity and Specificity; D013382:Subtraction Technique / Q000295:instrumentation