Dr Cheng-Tang Chiu and colleagues from Taiwan identified the feasibility of the narrow-band imaging method in colonic polyps.
The investigators compared the results with that of conventional colonoscopy and chromoendoscopy for distinguishing neoplastic and nonneoplastic colonic polyps.
The investigative team enrolled 78 consecutive patients who underwent colonoscopy using a conventional colonoscope in 2006.
The patients had 110 colorectal polyps.
|The sensitivity for narrow-band imaging was 96%|
|American Journal of Gastroenterology|
During the procedure, conventional colonoscopy first detected lesions, and then the narrow-band imaging system was used to examine the capillary networks.
The investigators then sprayed indigo carmine directly on the mucosa surface prior to evaluating the crypts using a conventional colonoscope.
The pit patterns were characterized using the classification system proposed by Kudo.
Finally, the investigative team performed a polypectomy or biopsy for histological diagnosis.
Of the 110 colorectal polyps, 65 were adenomas, 40 were hyperplastic polyps, and 5 were adenocarcinomas.
The narrow-band imaging system and pit patterns for all lesions were analyzed.
For differential diagnosis of neoplastic and nonneoplastic polyps, the sensitivity of the conventional colonoscope for detecting neoplastic polyps was 83%.
The investigators found that the specificity of the conventional colonoscope for detecting neoplastic polyps was 80%, and diagnostic accuracy was 82%.
The team noted that this was significantly lower than those achieved with the narrow-band imaging system.
The sensitivity, specificity, and accuracy for both chromoendoscopy and narrow-band imaging was 96%, 88%, and 93%, respectively.
No significant difference existed between the 2 methods during differential diagnosis of neoplastic and nonneoplastic polyps.
Dr Chiu's team concludes, “The narrow-band imaging system identified morphological details that correlate well with polyp histology by chromoendoscopy.”