RESUMO
Objective To evaluate the narrow-band imaging (NBI) in differential diagnosis of colo-rectal proliferative lesions. Methods Suspected lesions in colon were examined with white light and NBI colonoscopy, respectively. The ensitivity and specificity in diagnosing colorectal inflammatory hyperplasia, adenoma, early cancer and advanced cancer were compared between NBI and conventional colonoscopy with reference to pathology as gold standard. The pit patterns and the surface microvessels of the lesions were also determined and scored with NBI combined with magnifying endoscopy, and were compared with pathological diagnosis. Results (1) A total of 368 lesions were detected in 280 patients with conventional colonoscopy and NBI. The sensitivity and specificity of NBI in differential diagnosis of colorectal lesions were superior to those of conventional colonoscopy. (2) The pit patterns of colorectal inflammatory hyperplasia were mainly type Ⅰ and Ⅱ , while in adenomas were mainly type Ⅱ and Ⅲ (94. 2%). The pit patterns of early cancer were type Ⅲ (18. 8%), Ⅳ (56. 3%) and Ⅴ (25.0%), and those of advanced cancer were mainly type Ⅴ (94. 0%). (3) The average scores of surface microvesseis of colorectal inflammatory hyperplasia, ade-noma, early cancer and advanced cancer were 1.35 ± 0. 72, 3. 86 ±1.07, 6. 52±2. 59 and 11.42 ± 3.59, respectively. Scores over 6. 5 was a strong indicator of malignant lesions. Conclusion NBI is superior to conventional eolonoscopy in differential diagnosis of colorectal lesions. Observing pit patterns and microves-sels of the lesion with combination of NBI and magnifying endoscopy is helpful in diagnosis.