title: Performance of novel tissue harmonic echo imaging using endoscopic ultrasound for pancreatic diseases.
abstract: OBJECTIVE
  Recently, tissue harmonic echo (THE) imaging has advanced with the development of a new endoscopic ultrasound (EUS) monitor/processing unit. With this new technology, penetration (THE-P) and resolution (THE-R) images can be obtained. The aim of this study was to investigate the performance of this novel THE imaging using a new processing unit for pancreatic diseases.
  
  
  METHODS
  Fifty patients with pancreatic lesions (38 cystic, 12 solid) were retrospectively analyzed. At each examination, 3 EUS images of the same pancreatic lesion were obtained using B-mode, THE-P mode, and THE-R mode imaging. Each set of EUS images was randomly arranged and evaluated independently by 4 physicians blinded to the imaging technique. Images were compared using a Likert scale 5-point grading system for each parameter.
  
  
  RESULTS
  For cystic lesions, THE-P mode images were significantly superior to conventional B-mode images for visualizing the boundary, septum, nodules, and total image quality (P < 0.05). THE-R mode images were significantly superior to conventional B-mode images for visualizing the boundary, septum, and total image quality (P < 0.05). However, for solid lesions, there was no significant difference in all the evaluation points between THE-P and conventional B-mode images. THE-R mode images were inferior to conventional B-mode images for visualizing the boundary, internal structure, and total image quality (P < 0.05).
  
  
  CONCLUSIONS
  For pancreatic cystic lesions, THE mode images provided better lesion characterization than conventional B-mode images. Further research is required to determine if this improvement will result in improved EUS diagnostics.
authors.affiliation: Center for Gastroenterology, Teine-Keijinkai Hospital, Hokkaido, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Matsumoto
authors.affiliation: Center for Gastroenterology, Teine-Keijinkai Hospital, Hokkaido, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Katanuma
authors.affiliation: Center for Gastroenterology, Teine-Keijinkai Hospital, Hokkaido, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Maguchi
authors.affiliation: Center for Gastroenterology, Teine-Keijinkai Hospital, Hokkaido, Japan.
authors.forename: Kuniyuki
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Center for Gastroenterology, Teine-Keijinkai Hospital, Hokkaido, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Osanai
authors.affiliation: Center for Gastroenterology, Teine-Keijinkai Hospital, Hokkaido, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Yane
authors.affiliation: Center for Gastroenterology, Teine-Keijinkai Hospital, Hokkaido, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Kin
authors.affiliation: Center for Gastroenterology, Teine-Keijinkai Hospital, Hokkaido, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Takaki
authors.affiliation: Center for Gastroenterology, Teine-Keijinkai Hospital, Hokkaido, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Matsumori
authors.affiliation: Center for Gastroenterology, Teine-Keijinkai Hospital, Hokkaido, Japan.
authors.forename: Katsushige
authors.initials: K
authors.lastname: Gon
authors.affiliation: Center for Gastroenterology, Teine-Keijinkai Hospital, Hokkaido, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Tomonari
authors.affiliation: Center for Translational Research, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Nojima