Long-term in vivo visualization of cortical blood perfusion after photothrombotic stroke with needle-shaped beam optical coherence tomography angiography

High-resolution optical imaging is accompanied by a limited depth of field, making it challenging to obtain non-stitched, high-resolution images of samples with uneven surfaces without performing Z-axis scanning. To solve this problem, we introduced diffractive optical elements into the conventional OCT system and develop a needle-shaped beam OCT system with both long DOF and high resolution, which maintains 8 mu m lateral resolution over a depth range of 620 mu m. The system was then employed to perform a 10-day cortical blood perfusion observation after stroke, providing visual and mechanistic insight into stroke, deepening our understanding of the brain response after stroke.