title: A probe-based electromagnetic navigation system to integrate computed tomography during upper gastrointestinal endoscopy.
abstract: OBJECTIVE
  For preoperative work-up, an examination tool that visualizes separately compiled diagnostics in augmented reality would be desirable. We developed a probe-based electromagnetic navigation system, which can be passed through the working channel of an endoscope, to integrate computed tomography (CT) information during upper gastrointestinal endoscopy.
  
  
  METHODS
  The target registration error (TRE) of the system was evaluated experimentally and clinically. A total of 24 study patients with upper gastrointestinal cancer were included in the study. The cancerous lesion was endoscopically located (mean duration 8.4 minutes, range 7.1 - 23.2) and the TRE (coronal, transverse, sagittal layer) was measured by comparing the distance between the navigation probe (at the tip of the endoscope) and the target lesion shown on the corresponding CT cross section.
  
  
  RESULTS
  Experimental evaluations showed an accuracy in line with the system's inherent failure rate, with a median TRE of 2.8 mm (IQR 1.8 - 4.3), 2.2 mm (0.4 - 3.7), and 2.8 mm (1.1 - 5.9) in the coronal, transverse, and sagittal planes, respectively. Clinical evaluation revealed a median TRE of 4.8 mm (1.9 - 10.1), 3.9 mm (0.7 - 7.1), and 4.2 mm (0.9 - 8.9), respectively. No complications occurred during navigated endoscopy.
  
  
  CONCLUSIONS
  The probe-based electromagnetic navigation system revealed high accuracy (TRE < 5 mm), facilitating improved interpretation of endoluminal imaging.
authors.affiliation: Department of Surgery, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Kranzfelder
authors.affiliation: Department of Surgery, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Wilhelm
authors.affiliation: Research group MITI (Minimally invasive Interdisciplinary Therapeutical Intervention), Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: Manos
authors.initials: M
authors.lastname: Doundoulakis
authors.affiliation: Research group MITI (Minimally invasive Interdisciplinary Therapeutical Intervention), Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: Armin
authors.initials: A
authors.lastname: Schneider
authors.affiliation: Department of Surgery, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: Margit
authors.initials: M
authors.lastname: Bauer
authors.affiliation: Department of Surgery, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: Silvano
authors.initials: S
authors.lastname: Reiser
authors.affiliation: II. Department of Medicine, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Meining
authors.affiliation: Department of Surgery, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: Hubertus
authors.initials: H
authors.lastname: Feussner
mesh_terms: D000368:Aged; D015331:Cohort Studies; D055590:Electromagnetic Phenomena; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000295:instrumentation; D011300:Preoperative Care / Q000379:methods; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*