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


OBJECTIVE
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.


CONCLUSIONS
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.
Chiu
Han-Mo
HM
Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
Chang
Chi-Yang
CY
Chen
Chien-Chuan
CC
Lee
Yi-Chia
YC
Wu
Ming-Shiang
MS
Lin
Jaw-Town
JT
Shun
Chia-Tung
CT
Wang
Hsiu-Po
HP
D000236:Adenoma / Q000175:diagnosis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003111:Colonic Polyps / Q000175:diagnosis; D003113:Colonoscopy / Q000379:methods; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D004396:Coloring Agents; D003937:Diagnosis, Differential; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007203:Indigo Carmine; D008297:Male; D008875:Middle Aged
D004396:Coloring Agents; D007203:Indigo Carmine