title: Biopsy guided by real-time sonography fused with MRI: a phantom study.
abstract: OBJECTIVE
  The purpose of our study was to test the accuracy of sonographically guided biopsies in a phantom of structures not visible on sonography but shown on MRI by using commercially available sonography systems with image fusion software.
  
  
  METHODS
  A previously recorded MRI examination from a custom-made phantom was loaded into the sonography system. The phantom contained spheres that were invisible to sonography and contained red dye. The red dye was visible in the biopsy if it was successful. The images were coregistered using structures visible on both sonography and MRI, and biopsies were taken. The biopsy procedure was continued until a biopsy was successful, and the number of needle passes and time spent were registered.
  
  
  RESULTS
  A total of 130 targets were hit. Ten minutes was used for loading the MRI data set and the coregistration; 94 of the 130 biopsies (72.3%) were successful at the first needle pass. The median number of needle passes until a successful biopsy was obtained was one (range, 1-7).
  
  
  CONCLUSIONS
  The described method was successful in obtaining an adequate sample in a phantom.
authors.affiliation: Department of Radiology, Section of Ultrasound X-4123, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, DK-2100 Copenhagen OE, Denmark. caroline.ewertsen@dadlnet.dk
authors.forename: Caroline
authors.initials: C
authors.lastname: Ewertsen
authors.forename: Hanne Sønder
authors.initials: HS
authors.lastname: Grossjohann
authors.forename: Kristina Rue
authors.initials: KR
authors.lastname: Nielsen
authors.forename: Søren
authors.initials: S
authors.lastname: Torp-Pedersen
authors.forename: Michael Bachmann
authors.initials: MB
authors.lastname: Nielsen
mesh_terms: D001706:Biopsy / Q000379:methods*; D003199:Computer Systems; D007089:Image Enhancement / Q000379:methods*; D053783:Magnetic Resonance Imaging, Interventional / Q000295:instrumentation / Q000379:methods*; D013382:Subtraction Technique; D018084:Ultrasonography, Interventional / Q000295:instrumentation / Q000379:methods*