Narrow-Band Imaging in diagnosis of colorectal neoplasm

Abstract

Objective To evaluate the efficacy of narrow-band imaging （NBI） in diagnosis of colorectal neoplasm. Methods A total of 96 eolorectal neoplasm from 78 patients were observed under NBI, and the findings were compared with those from magnifying chromo-endoscopy and pathologic examinations. Resuits The sensitivity of conventional colonoscopy in diagnosis of polyps was 78. 7% , which was increased to 99% （ P 〈 0. 05 ） under NBI, with the clear identification of the shape and boundary of the lesions. Magnifying NBI colonoscopy provided images of pit patterns similar to those from chromo-endoscopy in diagnosis of type Ⅱ , ⅢL, Ⅳ andⅤN, which showed better recognition than conventional colonoscopy, but less sensitivity than chromo-endoscopy. Superficial vascular morphologic features could be better classified with NBI, with sensitivity of 100% and specificity at 87. 8%, which was superior to conventional colonoscopy but inferior to chromo-endoscopy. Conclusion Both chromo-endoscopy and NBI colonoscopy have better sensitivity and specificity in detection of colon polyps, while chromo-endoscopy reveals clear superficial structure of lesion and pit pattern, and NBI demenstrates capillary morphology, which can distinguish neoplasm from nonneoplasm colorectal lesions. NBI, easy and convenient to switch, is an effective technique to make early diagnosis of colorectal neoplasm. Key words: Colonic neoplasm ; Endoscopy ; Narrow-band imaging; Chromo-endoscopy