The present invention is directed to a scanning system that uses uniform rotary motion of an optical reflector to create reciprocal linear scanning. The system converts uniform rotation into uniform longitudinal scanning. The system thereby creates mechanical reciprocal linear scanning free of reciprocally moving mechanical parts common in conventional scanning systems. In a preferred embodiment of the invention, the scanning system is incorporated within an imaging catheter for medical scanning. The optical reflector is rotatable and includes a spiral reflecting portion. The spiral reflecting portion may be a single uniform reflecting surface or may include several reflection surfaces arranged in a spiral configuration.