Observations on the presence of bile using red dichromatic imaging 3 in peroral cholangioscopy.

Abstract

Peroral cholangioscopy (POCS) was developed as a diagnostic modality to directly observe bile duct lesions that are difficult to visualize by cholangiography 1 2 3 4 . However, there are several shortcomings to this technique, including poor image quality, poor operability, and especially a risk of high intra-bile-duct pressure due to repeated saline injections to wash out bile and thus obtain a clear image. Here we discuss red dichromatic imaging (RDI), a new image-enhancement technology using light colored red, amber, and green instead of the three primary colors, namely red, blue, and green. RDI is one of the functions of a new-generation endoscopy system [EVIS X1] (Olympus Marketing, Tokyo, Japan) that also provides enhanced depth-of-field imaging that improves near-distance image quality.