Patent attributes
An optical coherence tomography (OCT) system comprises: an imaging catheter; a calibration phantom removably arranged at least partially surrounding the distal end of the catheter; and a processor configured to control the catheter to acquire OCT images. The phantom has known dimensions and specific optical properties which provide non-changing calibration fiducials that span the imaging range of the system. The phantom is imaged by the catheter upon first connection to the system. The processor calculates a thickness of the phantom in the OCT image, and preforms z-offset calibration by setting the position of a phantom surface in the OCT image to a known nominal value. The known nominal value is related to one or more of the known thickness of the phantom or a diameter of the catheter sheath or a nominal angle of the light beam or the imaging range of the system.