title: Image-guided bronchoscopy for peripheral lung lesions: a phantom study.
abstract: BACKGROUND
  Ultrathin bronchoscopy guided by virtual bronchoscopy (VB) techniques show promise for the diagnosis of peripheral lung lesions. In a phantom study, we evaluated a new real-time, VB-based, image-guided system for guiding the bronchoscopic biopsy of peripheral lung lesions and compared its performance to that of standard bronchoscopy practice.
  
  
  METHODS
  Twelve bronchoscopists of varying experience levels participated in the study. The task was to use an ultrathin bronchoscope and a biopsy forceps to localize 10 synthetically created lesions situated at varying airway depths. For route planning and guidance, the bronchoscopists employed either standard bronchoscopy practice or the real-time image-guided system. Outcome measures were biopsy site position error, which was defined as the distance from the forceps contact point to the ground-truth lesion boundary, and localization success, which was defined as a site identification having a biopsy site position error of < or = 5 mm.
  
  
  RESULTS
  Mean (+/- SD) localization success more than doubled from 43 +/- 16% using standard practice to 94 +/- 7.9% using image guidance (p < 10(-15) [McNemar paired test]). The mean biopsy site position error dropped from 9.7 +/- 9.1 mm for standard practice to 2.2 +/- 2.3 mm for image guidance. For standard practice, localization success decreased from 56% for generation 3 to 4 lesions to 31% for generation 6 to 8 lesions and also decreased from 51% for lesions on a carina vs 23% for lesions situated away from a carina. These factors were far less pronounced when using image guidance, as follows: success for generation 3 to 4 lesions, 97%; success for generation 6 to 8 lesions, 91%; success for lesions on a carina, 98%; success for lesions away from a carina, 86%. Bronchoscopist experience did not significantly affect performance using the image-guided system.
  
  
  CONCLUSIONS
  Real-time, VB-based image guidance can potentially far exceed standard bronchoscopy practice for enabling the bronchoscopic biopsy of peripheral lung lesions.
authors.affiliation: College of Engineering, Penn State University, University Park, PA.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Merritt
authors.affiliation: College of Engineering, Penn State University, University Park, PA.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Gibbs
authors.affiliation: Endographics Imaging Systems, Inc., State College, PA.
authors.forename: Kun-Chang
authors.initials: KC
authors.lastname: Yu
authors.affiliation: College of Medicine, Penn State University, Hershey, PA.
authors.forename: Viral
authors.initials: V
authors.lastname: Patel
authors.affiliation: College of Engineering, Penn State University, University Park, PA.
authors.forename: Lav
authors.initials: L
authors.lastname: Rai
authors.affiliation: College of Engineering, Penn State University, University Park, PA.
authors.forename: Duane C
authors.initials: DC
authors.lastname: Cornish
authors.affiliation: College of Medicine, Penn State University, Hershey, PA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Bascom
authors.affiliation: College of Engineering, Penn State University, University Park, PA. Electronic address: weh2@psu.edu.
authors.forename: William E
authors.initials: WE
authors.lastname: Higgins
mesh_terms: D001706:Biopsy / Q000379:methods; D001999:Bronchoscopy / Q000379:methods*; D004867:Equipment Design; D006801:Humans; D008171:Lung Diseases / Q000175:diagnosis*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*