Comparative resolution and tracking performance in B-mode and short-lag spatial coherence (SLSC) images

Short-lag spatial coherence (SLSC) imaging is a novel imaging technique based on measurements of the spatial coherence of backscattered ultrasound waves received by individual transducer elements. SLSC images are formed by integrating spatial coherence measurements over the short-lag region (i.e. the region where there is a short distance, or lag, between elements). Received channel signals from point targets and diffuse scatterers were simulated using Field II. Point target widths were measured to determine resolution in matched B-mode and SLSC images. The autocorrelation of image texture in matched B-mode and SLSC images was measured to determine texture size. Diffuse scatterers were translated and tracked using normalized cross-correlation. Experimental images of point targets were also evaluated. The resolution of simulated and experimental SLSC images is highly sensitive to noise and is similar to B-mode images for a range of noise, clutter, and short-lag values. Tracking 0.1 μm to 0.3mm axial displacements in SLSC images yields comparable mean values to speckle tracking, with jitter similar to that of detected data.