Coherent artifacts in optical coherence tomography: observation and cancellation

OCT images can be degraded severely by coherent sidelobes of the source. Sidelobes, can introduce false targets if no targets are present at the sidelobe locations, and also add constructively or destructively to the targets that are present at the sidelobe locations, resulting in cancellation of the true targets or display of incorrect echo amplitudes of the targets. The authors introduce the use of CLEAN, a nonlinear deconvolution algorithm, to cancel coherent sidelobes in OCT images of extracted human teeth. The results show that CLEAN can reduce the coherent artifacts to the noise background, sharpen the air-enamel and enamel dentin interfaces and improve the image contrast.