title: Evaluation of a New Ultrasound Thoracoscope for Localization of Lung Nodules in Ex Vivo Human Lungs.
abstract: BACKGROUND
  Localization of small, nonvisible and nonpalpable nodules is challenging during video-assisted thoracoscopic surgery. We evaluated the feasibility of using a new ultrasound thoracoscope to localize nodules in resected ex vivo human lungs.
  
  
  METHODS
  The tumor was localized and measured in its greatest dimension with a prototype ultrasound thoracoscope (XLTF-UC180; Olympus Corporation, Tokyo, Japan) at different frequencies (5.0 to 12.0 MHz) and different lung specimen states (deflated, semiinflated). Measured tumor size and depth from lung surface were compared and correlated to the true diameter and depth from lung surface acquired from pathologic morphology.
  
  
  RESULTS
  Ex vivo evaluation was performed on 16 solid nodules and nine part solid ground-glass nodules. All tumors were successfully localized in the deflated lung specimens (average size, 13.7 ± 5.2 mm). The tumor boundaries were best evaluated with an ultrasound frequency of 10 MHz. Solid nodules were more easily visualized than ground-glass nodules. Part solid ground-glass nodules were not easily detected in the semiinflated specimen owing to peritumoral air surrounding the tumor. Tumor boundaries were also difficult to identify in deeply situated tumors and in lungs with underlying disease. A strong positive correlation existed between the ultrasound measurement and true measurement of tumor size (R2= 0.89, p < 0.001).
  
  
  CONCLUSIONS
  The ultrasound thoracoscope can be used to localize nodules in resected human lungs. The clarity of the tumor boundaries is influenced by the tumor type and depth and the underlying pulmonary disease. Complete lung deflation and the use of 10 MHz ultrasound frequency optimize the visualization of target tumors.
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Hideki
authors.initials: H
authors.lastname: Ujiie
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kato
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Hsin-Pei
authors.initials: HP
authors.lastname: Hu
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Suhaib
authors.initials: S
authors.lastname: Hasan
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Priya
authors.initials: P
authors.lastname: Patel
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Wada
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Daiyoon
authors.initials: D
authors.lastname: Lee
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Fujino
authors.affiliation: Department of Pathology, University Health Network, University of Toronto, Toronto, Ontario, Canada.
authors.forename: David M
authors.initials: DM
authors.lastname: Hwang
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Cypel
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: de Perrot
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Pierre
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Gail
authors.initials: G
authors.lastname: Darling
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Waddell
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Shaf
authors.initials: S
authors.lastname: Keshavjee
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada. Electronic address: kazuhiro.yasufuku@uhn.ca.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yasufuku
mesh_terms: D019160:Endosonography / Q000295:instrumentation*; D005240:Feasibility Studies; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D009924:Organ Culture Techniques; D011013:Pneumonectomy; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging* / Q000601:surgery*; D020775:Thoracic Surgery, Video-Assisted / Q000295:instrumentation*; D020708:Thoracoscopes