title: Evaluation of the Feasibility and Efficacy of Forward-Viewing Endoscopic Ultrasound.
abstract: We aimed to evaluate the feasibility and efficacy of a forward-viewing linear endoscopic ultrasound (FV-EUS) in diagnostic EUS procedures compared to standard oblique-viewing EUS (OV-EUS).
  
  
  
  This study was a prospective, randomized study that permitted cross-over. Fifty-one patients with subepithelial pancreatobiliary and upper gastrointestinal lesions underwent FV-EUS and OV-EUS sequentially, in random order. The EUS visualization was performed by a novice endosonographer, and the image quality of specific lesions was scored by an expert endosonographer. If fine-needle aspiration (FNA) was indicated, it was performed using both echoendoscopes by an expert endosonographer.
  
  
  
  Both of the EUS procedures had similar visualization times and image quality. In general, the visualization time was inversely related to the diameter of the specific lesions. In subepithelial lesions of the stomach and duodenum, the visualization time (98.8±62.2 seconds vs 139.0±66.6 seconds, p=0.008) and image quality (4.1±1.3 vs 3.3±1.7, p=0.02) of FV-EUS were significantly superior to OV-EUS. FV-EUS-guided FNA of pancreatic masses was successful in seven patients (87.5%).
  
  
  
  FV-EUS may increase the ease of access to gastrointestinal subepithelial lesions compared to conventional OV-EUS. The performance of FV-EUS for evaluating pancreatobiliary diseases and performing interventions was comparable to conventional OV-EUS.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Seohyun
authors.initials: S
authors.lastname: Lee
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Dong Wan
authors.initials: DW
authors.lastname: Seo
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Korea.
authors.forename: Jun-Ho
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Do Hyun
authors.initials: DH
authors.lastname: Park
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Lee
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sung Koo
authors.initials: SK
authors.lastname: Lee
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Myung-Hwan
authors.initials: MH
authors.lastname: Kim
mesh_terms: D000368:Aged; D001661:Biliary Tract Neoplasms / Q000000981:diagnostic imaging*; D018592:Cross-Over Studies; D019160:Endosonography / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D011446:Prospective Studies
keywords: Endoscopic ultrasound guided intervention; Forward-viewing endoscopic ultrasound; Oblique-viewing endoscopic ultrasound