Compensation of motion artifacts in intracoronary optical frequency domain imaging and optical coherence tomography.

Intracoronary optical coherence tomography and optical frequency domain imaging (OFDI) have been utilized for two-dimensional and three-dimensional imaging of vascular microanatomy. Image quality and the spatial accuracy of multidimensional reconstructions, however, can be degraded due to artifacts resulting from relative motion between the intracoronary catheter and the vessel wall. To track the relative motion of a catheter with regard to the vessel, a motion tracking system was incorporated with a standard OFDI system by using wavelength division multiplexing techniques. Motion of the vessel was acquired by a frequency shift of the backscattered light caused by the Doppler effect. A single monochromatic beam was utilized for tracking the relative longitudinal displacements of a catheter-based fiber probe with regard to the vessel. Although two tracking beams are, in general, required to correct for longitudinal motion artifacts, the accurate reconstruction in a longitudinal view was achieved by the Doppler frequency information of a single beam. Our results demonstrate that the single beam based motion tracking scheme is a cost-effective, practical approach to compensating for longitudinal distortions due to cardiac dynamics, thus leading to accurate quantitative analysis of 3D intracoronary OFDI.