Feasibility of a simplified narrow-band imaging classification system for Barrett’s esophagus for novice endoscopists

  • Hiroto Furuhashi
  • Kenichi GodaEmail author
  • Yuichi Shimizu
  • Masayuki Kato
  • Masakazu Takahashi
  • Akira Dobashi
  • Koji Hirata
  • Ayane Oba
  • Taku Shigesawa
  • Masaki Inoue
  • Hiroaki Matsui
  • Chika Kinoshita
  • Yoshitaka Ando
  • Masahiro Ikegami
  • Tadakazu Shimoda
  • Mototsugu Kato
Original Article—Alimentary Tract



Narrow-band imaging (NBI) classifications for Barrett’s esophagus have been proposed for the detection of early esophageal adenocarcinoma. We developed a simplified classification system with demonstrated high diagnostic accuracy and reproducibility among experienced endoscopists, but the feasibility of this system among novice endoscopists was unclear.


In the present study, eight novice endoscopists with no experience of magnification endoscopy were asked to review 248 images of Barrett’s esophagus (72 dysplastic, 176 non-dysplastic) obtained using high-definition magnification endoscopy with NBI 6 weeks before (1st test), immediately after (2nd test), and 6 weeks after (3rd test) being taught the simplified classification system. The primary outcomes were differences in diagnostic accuracy for dysplasia among the three tests.


The specificity and overall accuracy improved significantly in the 2nd vs. 1st test [97% vs. 80% (p < 0.001) and 94% vs. 82% (p < 0.001), respectively], but sensitivity was comparable (87% in both tests; p = 0.42). In the 3rd test, the sensitivity and overall accuracy decreased significantly compared with the 2nd test [82% vs. 87% (p < 0.001) and 93% vs. 94% (p < 0.05), respectively], but there was no significant difference in specificity (97% in both tests; p = 0.16). The kappa values for interobserver agreement for the mucosal pattern, vascular pattern, and predicted histology were substantial, and improved significantly in the 2nd vs. 1st test (0.78 vs. 0.59, 0.70 vs. 0.53, and 0.79 vs. 0.66, respectively; p < 0.001 for all).


The simplified NBI classification system may be appropriate for novice endoscopists to use in providing high accuracy and reproducibility.


Barrett’s esophagus Esophageal adenocarcinoma Magnification endoscopy Narrow-band imaging Classification 



The authors thank Professor Hisao Tajiri for the management and composition of this study and Dr. Shinichi Hirooka for advice on histopathological findings.

Compliance with ethical standards

Conflict of interest

Akira Dobashi holds a patent on application No. US-62628024.

Supplementary material

535_2018_1537_MOESM1_ESM.docx (37 kb)
Supplementary material 1 (DOCX 36 kb)


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Copyright information

© Japanese Society of Gastroenterology 2019

Authors and Affiliations

  • Hiroto Furuhashi
    • 1
  • Kenichi Goda
    • 2
    Email author
  • Yuichi Shimizu
    • 3
  • Masayuki Kato
    • 4
  • Masakazu Takahashi
    • 5
  • Akira Dobashi
    • 1
  • Koji Hirata
    • 5
  • Ayane Oba
    • 5
  • Taku Shigesawa
    • 5
  • Masaki Inoue
    • 5
  • Hiroaki Matsui
    • 1
  • Chika Kinoshita
    • 6
  • Yoshitaka Ando
    • 6
  • Masahiro Ikegami
    • 7
  • Tadakazu Shimoda
    • 8
  • Mototsugu Kato
    • 9
  1. 1.Department of EndoscopyThe Jikei University School of MedicineTokyoJapan
  2. 2.Department of GastroenterologyDokkyo Medical UniversityMibuJapan
  3. 3.Division of EndoscopyHokkaido University HospitalSapporoJapan
  4. 4.Department of EndoscopyThe Jikei University Katsushika Medical CenterTokyoJapan
  5. 5.Department of Gastroenterology and HepatologyHokkaido University Graduate School of MedicineSapporoJapan
  6. 6.Division of Gastroenterology and Hepatology, Department of Internal MedicineThe Jikei University School of MedicineTokyoJapan
  7. 7.Department of PathologyThe Jikei University School of MedicineTokyoJapan
  8. 8.Division of PathologyShizuoka Cancer CenterShizuokaJapan
  9. 9.National Hospital Organization Hakodate HospitalHakodateJapan

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