Novel Optical Technologies to Aid Diagnosis and Guide Therapy in Colorectal Medicine

Optical methods provide unique capabilities in terms of imaging resolution and sensitivity and are relatively low cost. This review presents an overview of emerging optical techniques and their potential roles in detection, mapping, staging, and therapy of dysplasia. In this article we will review the fundamental concepts of complex light interactions with tissue that result in these features. We will discuss a number of optical methods that are used or have the potential to be used in colorectal medicine. These include conventional colonoscopy, scattering-based methods such as optical coherence tomography, light scattering spectroscopy, and confocal endoscopy, fluorescence-based methods using both endogenous fluorophores and exogenous molecular contrast agents, and finally in vivo bioluminescence imaging. For all these methods, we will briefly review the underlying concepts as well as applications, capabilities, and limitations.