Quantitative Diagnosis For Colorectal Neoplasia Using Narrow Band Imaging (Nbi) Magnification

The narrow band imaging (NBI) is the newly developed technology that uses optical filters for RGB sequential illumination and narrows its bandwidth of spectral transmittance. We can observe the fine capillaries in the superficial mucosa of GI tract by NBI. The aim of this study is to clarify the clinical usefulness of NBI magnification in pit pattern diagnosis for colorectal hyperplasia, adenoma and early carcinoma. Materials and Methods: A total of 146 colorectal lesions including 16 cases of hyperplasia, 82 cases of tubular adenoma and 48 cases of early carcinoma. Histologic diagnosis was done according to WHO classification. For these lesions, magnifying observation was performed by both standard magnification with chromoendoscopy (indigo carmine or crystal violet) and NBI magnification without chromoendoscopy, and then pit pattern diagnosis (classification of Kudo & Tsuruta) was recorded. NBI magnification without chromoendoscopy was performed prior to standard magnification with chromoendoscopy. Magnifying videoendoscope used in this study is Olympus CF-Q260AZI. From these data, we examined the ability of pit pattern diagnosis of NBI magnification without chromoendoscopy in comparison with standard magnification with chromoendoscopy and, further, assess the clinical usefulness of NBI magnification in quantitative diagnosis for colorectal neoplasia. Results: Correspondent rate of pit pattern diagnosis between standard magnification with chromoendoscopy NBI magnification without chromoendoscopy was 88% (14/16) in type II, 98% (73/75) in type IIIL, 88% (7/8) in type IV, 79% (25/32) in type VI, and 100% (4/4) in type VN. On the other hand, brownish change of lesion based on the surface capillaries using NBI observation was detected in 6% (1/16) in hyperplasia and 99% (81/82) in tubular adenoma, respectively. There is a significant difference (p < 0.01). Conclusions: The NBI magnification without chromoendoscopy showed almost same ability of pit pattern diagnosis for colorectal neoplasia as well as standard magnification with chromoendoscopy. Furthermore, NBI observation can distinguish between hyperplasia and adenoma without chromoendoscopy.