Design of Multiband Switching Illumination With Low-Concentration Lugol Stain for Esophageal Cancer Detection

Narrowband imaging (NBI), flexible spectral imaging color enhancement (FICE), and Lugol chromoendoscopy (LCE) are used in endoscopy of head and neck cancers and esophageal cancers. The NBI and FICE techniques enhance the capillary pattern in cancerous areas, whereas in LCE, normal and cancerous areas are differentiated using Lugol solution. Although invasive, LCE is more sensitive than NBI and FICE for this purpose. In this study, we propose a relatively less invasive and highly sensitive technique for detecting cancerous areas that combines low-concentration Lugol stain and narrowband illumination. This combined technique requires the use of an endoscopic system that can acquire RGB images synchronized with narrowband illumination switching. This technique produces a large number of images that can potentially discriminate smaller differences in color than is possible with conventional RGB imaging. Experiments to predict the performance of the proposed method were performed using four resected specimens, including esophageal cancer, and promising results were obtained.