Narrow Band Imaging of Oral Mucosa, Cancer and Pre-cancerous Lesions

Narrow band imaging (NBI) enhances the diagnostic capability of endoscopy for tissue characterization. The procedure uses using narrow-bandwidth filters in a sequential red-green-blue illumination system. The blue filter corresponds to the peak absorption spectrum of hemoglobin and thus emphasizes images of capillary vessels on the surface mucosa. Here, we examined the applicability of the NBI system to evaluate oral mucosa, and the status of 6 patients with oral squamous cell carcinoma and 5 with oral pre-cancerous lesions. Regular, orderly, thin-caliber vessels in the tongue, floor of the mouth, buccal mucosa, soft palate and lip were clearly distinguished by NBI. However, small vessel branches are difficult to evaluate in the gingival and hard palate mucosa. Adding the patterns of capillary branches to find mucosal patterns appeared to improve the diagnostic value for detecting the borders of oral cancer or pre-cancerous lesions by NBI. The vascular pattern revealed by NBI defined the margin of hyperkeratotic lesions. Although appropriate criteria for oral cancer lesions remain to be established, the NBI system should be useful in the diagnosis of patients with oral cancer and pre-cancerous lesions