Null Subtraction Imaging (Better B-mode)

Null subtraction imaging is a nonlinear beamforming technique that can reduce or eliminate the presence of grating lobes. Figure 1 shows an image of a wire target using traditional beamforming techniques and with the NSI apodizations (DC offset Right, DC offset Left, Zero Mean apodization and full NSI). Figure 2 shows an animated gif of a tumor image with grating lobes apparent in the B-mode made with traditional beamforming approaches and using NSI where the grating lobes are removed revealing the speckle underneath. (Last updated 12/19/2022).

Figure 1. Images of a wire target using an L-14-5 array probe with corresponding grating lobes in the images except where they are removed in the NSI image (bottom panel).
Figure 2. Animated gif of tumor image using traditional beamforming and using NSI. Grating lobe artifacts are removed in the NSI image without image degradation.