Narrow-Band Imaging in the Diagnosis of Colorectal Mucosal Lesions: A Pilot Study

Background and Study Aims: A newly developed narrow-band imaging (NBI) technique, in which modified optical filters were used in the light source of a video endoscope system, was applied during colonoscopy in a clinical setting. This pilot study evaluated the clinical feasibility of the NBI system for evaluating colorectal lesions.
Patients and Methods: A total of 43 colorectal lesions in 34 patients were included in the study. The quality of visualization of colorectal lesions and the accuracy of differentiation between neoplastic and non-neoplastic lesions using the NBI system were evaluated in comparison with results from conventional colonoscopy and with chromoendoscopy.
Results: For pit pattern delineation, NBI was superior to conventional endoscopy (P < 0.001), but inferior to chromoendoscopy (P < 0.05). NBI achieved better visualization of the mucosal vascular network and of the hue of lesions than conventional endoscopy (P < 0.05). However there was no significant difference between NBI and chromoendoscopy in differentiating neoplastic from non-neoplastic lesions (both techniques had a sensitivity of 100 % and a specificity 75 %). This was better than the results of conventional colonoscopy (sensitivity 83 %, specificity 44 %; P < 0.05 for specificity).
Conclusions: These results suggest that in the examination of colonic lesions the NBI system provides imaging features additional to those of both conventional endoscopy and chromoendoscopy. For distinguishing neoplasms from non-neoplastic lesions, NBI was equivalent to chromoendoscopy.

References

• 1 Kudo S, Hirota S, Nakajima T. et al . Colorectal tumors and pit pattern.  J Clin Pathol. 1994;  47 880-885
• 2 Kudo S, Kashida H, Nakajima T. et al . Endoscopic diagnosis and treatment of early colorectal cancer.  World J Surg. 1997;  21 694-701
• 3 Fujii T, Hasegawa R T, Saitoh Y. et al . Chromoscopy during colonoscopy.  Endoscopy. 2001;  33 1036-1041
• 4 Kato S, Fujii T, Koba I. et al . Assessment of colorectal lesions using magnifying colonoscopy and mucosal dye spraying: can significant lesions be distinguished?.  Endoscopy. 2001;  33 306-310
• 5 Konishi K, Kaneko K, Kurahashi T. et al . A comparison of magnifying and nonmagnifying colonoscopy for diagnosis of colorectal polyps: a prospective study.  Gastrointest Endosc. 2003;  57 48-53
• 6 Sanbongi M, Igarashi M, Obi T. et al . Analysis of spectral reflectance using normalization method from endoscopic spectroscopy system.  Opt Rev. 2002;  9 238-243
• 7 Gono K, Yamazaki K, Doguchi N. et al . Endoscopic observation of tissue by narrow-band illumination.  Opt Rev. 2003;  10 1-5
• 8 Gono K, Yamaguchi M, Ohyama N. Improvement of image quality of the electroendoscopy by narrowing spectral shapes of observation light.  Proc Int Congress Imaging Sci. 2002;  399-400
• 9 Gono K, Obi T, Yamaguchi M. et al . Appearance of enhanced tissue features in narrow-band endoscopic imaging.  J Biomed Opt. 2004;  9 568-577
• 10 Sano Y, Kobayashi M, Hamamoto Y. et al . New diagnostic method based on color imaging using narrow-band imaging (NBI) system for gastrointestinal tract [abstract].  Gastrointest Endosc. 2001;  53 AB125
• 11 Pathology and genetics. Tumours of the digestive system. In: Hamilton SR, Aaltonen LA (eds.) World Health Organization classification of tumours. Lyon; IARC Press 2000
• 12 The Paris endoscopic classification of superficial neoplastic lesions: esophagus, stomach, and colon [review]. The Paris Workshop; 2002 Nov 30 - Dec 1; Paris, France.  Gastrointest Endosc. 2003;  58 Suppl S3-S43
• 13 Fawcett D W, Raviola E. Intestines. In: Fawcett DW, Raviola E (eds.) Bloom and Fawcett: a textbook of histology. 12th edn. New York; Chapman and Hall 1994: 617-651
• 14 Risau W. Mechanisms of angiogenesis.  Nature. 1997;  386 671-674
• 15 Hanahan D. Signaling vascular morphogenesis and maintenance.  Science. 1997;  277 48-50
• 16 Konerding M A, Fait E, Gaumann A. 3D microvascular architecture of precancerous lesions and invasive carcinomas of the colon.  Br J Cancer. 2001;  84 1354-1362