An apparatus for imaging a body cavity has a light source that generates short coherence light and a probe housed within a transparent catheter, wherein the probe has a rotatable scanner optic that is disposed to convey light from the light source to and from the body cavity. An actuator apparatus coupled to the probe is configured to perform a helical scan by simultaneously rotating the scanner optic about an axis within the catheter and translating the scanner optic along the axis. A signal detector obtains an interference signal between a first portion of the coherent light scattered from the sample and a second portion of the coherent light reflected from a reference. A processor is programmed with instructions that coordinate actuation of the scanner mirror and acquisition of data from the signal detector and the camera and with instructions for volume image reconstruction.
