4B-5 3-D Strain Imaging Using a Sparse Rectilinear 2-D Array

Under mechanical compression, tissue movements are inherently three-dimensional. 2-D strain imaging can suffer from decorrelation noise caused by out-of-plane tissue movement in elevation. With 3-D strain imaging, all tissue movements can be estimated and compensated, hence minimizing out-of-plane decorrelation noise. Promising 3-D strain imaging results have been shown using 1-D arrays with mechanical translation in elevation. However, the relatively large slice thickness and mechanical translation can degrade image quality. Using 2-D arrays, a better elevational resolution can be achieved with elevational focusing Furthermore, scanning with 2-D arrays is done electronically, which eliminates the need for mechanical translation. In this paper, we present our initial 3-D strain images of gelatin/agar phantoms using a 4 cm x 4 cm ultrasonic sparse rectilinear 2-D array operating at 5 MHz.