The Algorithm based on the Improved Image Intensity Subtraction for the Optical Coherence Tomography Angiography

We proposed an improved image intensity subtraction OCTA algorithm (IS-OCTA) to improve the contrast image of vasculature network to overcome the limitation in traditional OCTA. Optical coherence tomography angiography (OCTA) is a technology to provide three-dimensional vascular information. It demonstrated its unique abilities in reconstruct and view lesion in a 3-dimensional fashion non-invasively, without a need of dye injection. However, many OCTA approaches are sensitive to bulk motion noise, which will make the contrast image of vasculature network blurred. We performed experiments on flow phantoms, static phantoms to simulated blood flow, and animal models (mouse's ear) to verify the ability of IS-OCTA, and compared with the previous reported algorithms (SC-OCTA and ISUB-OCTA). IS-OCTA has able to improve the image contrast. Visual comparison of blood flow information and en face projection images which obtained by different algorithm, IS-OCTA has able to remove static information accurately from B-scans section image and has a notable effect on the suppression of the bulk motion noise.