Whole Brain Micro-Vascular Imaging Using Robot Assisted Optical Coherence Tomography Angiography

Optical coherence tomography angiography (OCTA) can provide depth resolved image of microvasculature but fail to acquire both high resolution and large field imaging of an irregular sample. The robotic arm can easily scan along the sample surface to ensure that the sample at the same depth is all in the same focal plane, so OCTA can be obtained without the effect of unevenly distributed resolution and fall off as occurred in conventional imaging with linear scanning of irregular sample. So, we integrated a 120 kHz OCT with a robotic arm and proposed a novel calibration method for robotic arm with a repeatability positioning accuracy of ∼60μm. A correlation mapping (CM) masked eigen decomposition OCTA was proposed with CM > 0.6 for binarization to improve the vascular visualization and CM > 0.99 for extraction of big vessels to enhance stitching efficacy. With the aid of robotic arm, micro-vascular OCTA of whole mouse brain was achieved for the first time, to our knowledge, over a volume size of 10 mm × 8.1 mm × 1 mm with a resolution of ∼4μm(axial) x ∼6μm(lateral). We believe robot assisted OCTA system will have great potential in biomedical application like intraoperative navigation and other fields.