A system for analyzing a body lumen including a flexible conduit that is elongated along a longitudinal axis, the flexible conduit having a proximal end and a distal end at least one delivery waveguide and at least one collection waveguide extending along the flexible conduit, a transmission output of the at least one delivery waveguide and a transmission input of the at least one collection waveguide located along a distal portion of the conduit a spectrometer connected to the at least one delivery waveguide and the at least one collection waveguide, the spectrometer configured to perform diffuse reflectance spectroscopy, wherein the spectrometer emits at least one primary radiation signal of a wavelength having an absorption coefficient of between about 8 cm−1 and about 10 cm−1 when transmitted through a highly aqueous media a controller system configured to calculate at least one of an extent, area, and volume of highly aqueous media based on the amount of absorption of the at least one primary radiation signal measured through the highly aqueous media by the spectrometer.
