Described herein are imaging catheter system. In an exemplary embodiment, a catheter comprises a handle assembly having distal and proximal ends, a catheter sheath connected to the distal end of the handle assembly, and an elongated flexible tube connected to the proximal end of the handle assembly. The catheter further comprises an imaging core slidably received within the catheter sheath, the handle assembly and the elongated tube. The imaging core also includes a slide member, e.g., knob, extending from the imaging core and passing through an elongated slot in the handle assembly, allowing a physician to manually pullback and advance the imaging core within the catheter by sliding the slide member back and forth. Preferably, the elongated tube is long enough so that the motor drive coupled to the proximal end of the catheter is kept outside the sterile field during the imaging procedure.
