A catheter for placement within a body lumen, the catheter 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 lumen-expanding inflatable balloon disposed about a portion of the conduit, a transmission output of the at least one delivery waveguide and a transmission input of the at least one collection waveguide located within the balloon and, at least one elongate arm connected to the conduit and positioned within the balloon, the at least one elongate arm radially translatable with respect to the conduit, and wherein at least one of the transmission output and transmission input is coupled to the elongate arm.