title: CT-guided liver biopsy with electromagnetic tracking: results from a single-center prospective randomized controlled trial.
abstract: OBJECTIVE
  The purpose of this study is to evaluate the effectiveness of electromagnetic tracking in assisting CT-guided liver biopsies.
  
  
  METHODS
  This was a single-center prospective randomized controlled trial comparing nonfluoroscopic CT-guided liver biopsy using an advance-and-scan technique with and without electromagnetic tracking. Fifty patients with a liver lesion referred for biopsy (women, 52%; mean age, 59.7 years; mean lesion size, 3.6 cm) were enrolled in the study and were randomly assigned to either arm. The primary and secondary objectives were to assess and quantify differences in the number of intraprocedural scans, cumulative effective radiation dose, number of needle manipulations, and procedure time from skin-stick to the target lesion with and without assistance.
  
  
  RESULTS
  Electromagnetic tracking significantly decreased the number of scans, effective radiation dose, number of manipulations per procedure, and time from skin-stick to the target lesion. The ratio of the number of scans (electromagnetic tracking to control) was 0.55 (95% CI, 0.42-0.73; p<0.0001). The mean difference in effective radiation dose (electromagnetic tracking-control) was -4.7 mSv (95% CI, -7.01 to -2.44 mSv; p=0.0001), and the median difference was -5.1 mSv (95% CI, -7.01 to -3.56 mSv; p<0.0001). The ratio of the number of manipulations (electromagnetic tracking to control) was 0.36 (95% CI, 0.24-0.54; p<0.0001). The mean difference for the time from skin-stick to the target lesion was -247.6 seconds (95% CI, -394.34 to -100.83 seconds; p=0.0014) and the median difference was -253.0 seconds (95% CI, -325.00 to -124.00 seconds; p=0.0001).
  
  
  CONCLUSIONS
  Electromagnetic tracking assistance has the potential to decrease the number of intraprocedural CT scans and needle manipulations and to reduce patient radiation dose during CT-guided liver biopsy.
authors.affiliation: 1 Department of Interventional Radiology, Mount Sinai Medical Center, One Gustave L. Levy Pl, Box 1234, New York, NY 10029.
authors.forename: Edward
authors.initials: E
authors.lastname: Kim
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Ward
authors.forename: Rahul S
authors.initials: RS
authors.lastname: Patel
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Fischman
authors.forename: Scott
authors.initials: S
authors.lastname: Nowakowski
authors.forename: Robert A
authors.initials: RA
authors.lastname: Lookstein
mesh_terms: D004574:Electromagnetic Fields; D005260:Female; D006801:Humans; D061705:Image-Guided Biopsy / Q000379:methods*; D008099:Liver / Q000473:pathology*; D008113:Liver Neoplasms / Q000473:pathology*; D008297:Male; D055617:Micro-Electrical-Mechanical Systems / Q000379:methods*; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: CT guidance; electromagnetic tracking; liver biopsy