title: MR-guided breast biopsy using an active marker: a phantom study.
abstract: OBJECTIVE
  To evaluate the advantages of using an active marker (active micro coil) for MR-guided breast biopsy procedures.
  
  
  METHODS
  An add-on breast biopsy guidance device used with a standard breast coil was equipped with an active marker. The marker's position was determined with a dedicated MRI sequence. In combination with custom software, the biopsy planning process was reduced basically to defining the target in the diagnostic MR images. Automatic control scans verified the settings of the biopsy guidance device. To measure the targeting accuracy, x-ray control of the needle placement was performed in phantoms containing 36 small titanium cylinders. The reliability of the procedure was evaluated in 24 core needle biopsies on phantoms. Workflow enhancements were analyzed.
  
  
  RESULTS
  The root mean square deviation of the needle position from the target perpendicular to the needle axis was 1.25 mm, in three-dimensions it was 1.35 mm. All targets were sampled successfully. The duration of a phantom biopsy was nine minutes.
  
  
  CONCLUSIONS
  The use of an active marker can offer advantages for MR-guided breast biopsies in terms of handling and procedure time as well as accuracy.
authors.affiliation: Section of Neuroradiology, Christian-Albrechts-Universität, Kiel, Germany.
authors.forename: Richard
authors.initials: R
authors.lastname: Werner
authors.forename: Sascha
authors.initials: S
authors.lastname: Krueger
authors.forename: Axel
authors.initials: A
authors.lastname: Winkel
authors.forename: Christoph
authors.initials: C
authors.lastname: Albrecht
authors.forename: Tobias
authors.initials: T
authors.lastname: Schaeffter
authors.forename: Martin
authors.initials: M
authors.lastname: Heller
authors.forename: Christian
authors.initials: C
authors.lastname: Frahm
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D001707:Biopsy, Needle / Q000379:methods*; D001940:Breast / Q000473:pathology*; D001941:Breast Diseases / Q000175:diagnosis; D001943:Breast Neoplasms / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D012685:Sepharose / Q000737:chemistry; D014965:X-Rays
chemical_list: D015415:Biomarkers; D012685:Sepharose