Zhou, K.C. et al. Nat. Photon. http://doi.org/dbgq (2019).

Optical coherence tomography (OCT) is a label-free imaging technique based on low-coherence interferometry, and is widely used for tissue-imaging and in clinical applications. Long depth-of-focus OCT, which is used for imaging at depths within tissues, often has anistropic resolution, with lateral resolution being worse than axial resolution. In addition, conventional OCT images can be distorted due to refractive index inhomogeneity within samples. To overcome these limitations, Zhou et al. introduce optical coherence refraction tomography (OCRT). OCRT uses multiple OCT cross-sectional images, taken at diverse angles, to reconstruct high-resolution images. This works by extending the axial coherence gating that confers high axial resolution to the lateral dimension, and allowing differently distorted cross-sectional images to be de-warped and registered for correction. The researchers demonstrated the benefits of the approach by imaging several mouse organs as well as the human cornea.