| [ Summary ] |
The observation of micro-capillary (MC) vessels using Narrow Band Imaging (NBI) magnification, which requires no application a dye solution, is useful to diagnose colorectal lesions. However, the diagnostic accuracy of colorectal lesions for NBI observation is controversial. The aim of this study was to clarify diagnostic accuracy when using NBI magnification for differentiated diagnosis or diagnosis of depth of colorectal lesion infiltration. Lesions were evaluated through both pit patterns and capillary patterns (CP) according to Sano's classification as obtained from our database. Diagnostic accuracy, sensitivity, and specificity were analyzed on the basis of individual pathological reports after endoscopic removal or surger y. >From October 2005 to July 2008, 1,130 qualified lesions were observed in this study. The diagnostic accuracy, sensitivity, and specificity to distinguish between non-neoplastic and neoplastic lesions were 96.8%, 97.3%, and 91.8% respectively and was equivalent to that for pit pattern classification. The diagnostic accuracy, sensitivity, specificity, negative predictive values（ NPV） and positive predictive values（ PPV） for depth of infiltration of neopastic lesions were 97.7%, 77.6%, 98.7%, 98.8% and 76.0%. Our results regarding depth of infiltration, especially for PPV, were slightly inferior to those for evaluation using pit pattern classification. NBI was the most reliable method to distinguish between non-neoplastic and neoplastic lesions. In contrast, the diagnostic ability for NBI magnifying observation of lesions infiltrating deeper into the submucosal layer was inferior to diagnosis of pit patterns with dye solutions. |