title: A new method to combine contrast-enhanced magnetic resonance imaging during live ultrasound of the breast using volume navigation technique: a study for evaluating feasibility, accuracy and reproducibility in healthy volunteers.
abstract: OBJECTIVE
  To evaluate feasibility, accuracy and reproducibility of combined US-MR of the breast using volume navigation technique.
  
  
  METHODS
  Five healthy females underwent bilateral contrast-enhanced MR (CE-MR) of the breast in supine position, after positioning three couples of markers on the breast. After CE-MR data uploading in the ultrasound (US) database, manual co-registration was obtained during live US of the breast by means of an electromagnetic transmitter positioned near the subject under examination and two electromagnetic sensors were mounted on the transducer bracket. Transmitter and sensors were connected to a position-sensing unit embedded in the US equipment allowing to track probe position and orientation within the electromagnetic field. Live US image were co-registered to the previously loaded breast CE-MR volume by coupling markers. For each subject, two independent radiologists recorded the examination time and verified twice image alignment using five fixed checkpoints. Pair t Student test and Wilcoxon test were used for statistical analysis.
  
  
  RESULTS
  In all subjects US and CE-MR images were successfully combined. The examination time was 10±2 vs. 9±4 min, respectively (p=0.642; NS). A total of one hundred measurements of images misalignment were performed: the measurements recorded between the two operators were 0.42±0.32 cm and 0.58±0.41 cm (p=0.161; NS), and 0.50±0.32 cm and 0.56±0.52 cm (p=0.928; NS), respectively.
  
  
  CONCLUSIONS
  In our preliminary experience, volume navigation technique appears to be a accurate and reproducible method to combine CE-MR image during unilateral US of the breast.
authors: Department of Human Pathology and Oncology, Section of Radiological Science, University of Siena, Strada delle Scotte 2, 53100 Siena, Italy. afausto@sirm.org
authors: Alfonso
authors: A
authors: Fausto
authors: Giorgio
authors: G
authors: Rizzatto
authors: Alessandro
authors: A
authors: Preziosa
authors: Luca
authors: L
authors: Gaburro
authors: Michael J
authors: MJ
authors: Washburn
authors: Domenico
authors: D
authors: Rubello
authors: Luca
authors: L
authors: Volterrani
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008536:Meglumine / Q000031:analogs & derivatives; D008875:Middle Aged; D009942:Organometallic Compounds; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D016683:Supine Position; D016217:Ultrasonography, Mammary / Q000379:methods*
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine