4D optical coherence tomography-based micro-angiography achieved by 1.6-MHz FDML swept source

We demonstrate the use of an ultra-high-speed swept-source optical coherence tomography (OCT) to achieve optical micro-angiography (OMAG) of microcirculatory tissue beds in vivo. The system is based on a 1310-nm Fourier domain mode-locking (FDML) laser with 1.6-MHz A-line rate, providing a frame rate of 3.415 KHz, an axial resolution of similar to 10 mu m and signal to noise ratio of 102 dB. Motion from blood flow causes change in OCT signals between consecutive B-frames acquired at the same location. Intensity-based inter-frame subtraction algorithm is applied to extract blood flow from tissue background without any motion correction. We demonstrate the capability of this 1.6MHz OCT system for 4D OMAG of in vivo tissue at a volume rate of 4.7 volumes/s (volume size: 512 x 200 x 720 voxels). (C) 2015 Optical Society of America