A prospective comparative study of narrow-band imaging, chromoendoscopy, and conventional colonoscopy in the diagnosis of colorectal neoplasia

• Published in: Gut Vol. 56; no. 3; pp. 373 - 379
• Main Authors: Chiu, Han-Mo, Chang, Chi-Yang, Chen, Chien-Chuan, Lee, Yi-Chia, Wu, Ming-Shiang, Lin, Jaw-Town, Shun, Chia-Tung, Wang, Hsiu-Po
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and British Society of Gastroenterology 01.03.2007; BMJ; BMJ Publishing Group LTD; BMJ Group
• Subjects: Accuracy; Adenoma - diagnosis; Adult; Aged; Aged, 80 and over; Biological and medical sciences; Biopsy; Colon Cancer; Colonic Polyps - diagnosis; Colonoscopy - methods; Colorectal cancer; Colorectal Neoplasms - diagnosis; Coloring Agents; CRC; Diagnosis, Differential; Digestive system. Abdomen; Endoscopy; Epidemiologic Methods; Female; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Image Processing, Computer-Assisted - methods; Indigo Carmine; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Middle Aged; narrow-band imaging; NBI; negative predictive value; NPV; positive predictive value; PPV; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Studies; Tumors; Taiwan; Human; Rectal disease; Mucosa; Colorectal cancer; Malignant tumor; Narrow band; Colonic disease; Histopathology; Colonoscopy; Blood vessel; Rectum; Digestive diseases; Intestinal disease; Medical imagery; Colon; Diagnosis; Endoscopy; Comparative study
• ISSN: 0017-5749; 1468-3288
• DOI: 10.1136/gut.2006.099614

Background: Discrimination between neoplastic and non-neoplastic lesions is crucial in colorectal cancer screening. Application of narrow-band imaging (NBI) in colonoscopy visualises mucosal vascular networks in neoplastic lesions and may improve diagnostic accuracy. Aim: To compare the diagnostic efficacy of NBI in differentiating neoplastic from non-neoplastic colorectal lesions with diagnostic efficacies of standard modalities, conventional colonoscopy, and chromoendoscopy. Methods: In this prospective study, 180 colorectal lesions from 133 patients were observed with conventional colonoscopy, and under low-magnification and high-magnification NBI and chromoendoscopy. Lesions were resected for histopathological analysis. Endoscopic images were stored electronically and randomly allocated to two readers for evaluation. Sensitivity, specificity and diagnostic accuracy of each endoscopic modality were assessed by reference to histopathology. Results: NBI and chromoendoscopy scored better under high magnification than under low magnification in comparison with conventional colonoscopy. The diagnostic accuracy of NBI with low or high magnification was significantly higher than that of conventional colonoscopy (low magnification: p = 0.0434 for reader 1 and p = 0.004 for reader 2; high magnification: p<0.001 for both readers) and was comparable to that of chromoendoscopy. Conclusion: Both low-magnification and high-magnification NBI were capable of distinguishing neoplastic from non-neoplastic colorectal lesions; the diagnostic accuracy of NBI was better than that of conventional colonoscopy and equivalent to that of chromoendoscopy. The role of NBI in screening colonoscopy needs further evaluation.