BULK MOTION SUBTRACTION IN OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

摘要

PROBLEM TO BE SOLVED: To provide a method of removing decorrelation noise due to bulk motion in optical coherence tomography angiography (OCTA).SOLUTION: OCTA B-frames are divided into segments within which the bulk motion velocity could be assumed constant. This velocity is recovered using linear regression of decorrelation versus reflectance along axial lines (A-lines) identified as bulk tissue by percentile analysis. The fitting parameters are used to calculate a reflectance-adjusted threshold for bulk motion velocity. Below this threshold, voxels are identified as non-flow tissue, and their flow values are set to zeros. Above this threshold, the voxels are identified as flow tissue and bulk motion velocity is subtracted from each voxel using a nonlinear decorrelation-velocity relationship.SELECTED DRAWING: Figure 1