Spatial compounding in 3D imaging of limbs.

Effects of spatial compounding on image resolution and speckle noise are studied. Using computer simulation, it is shown that spatial compounding using averaged reconstruction can significantly improve lateral resolution while slightly deteriorate axial resolution. The amount of net resolution improvement depends mainly on the compound angle, but is insensitive to the number of component images used in compounding. While the fact that spatial compounding can effectively reduce speckle noise is well known, the analysis in this paper indicates that to maximize speckle reduction, the component echo amplitudes must meet two conditions: to be mutually independent and to have the same mean power. These findings provide useful guidelines for the analysis and optimization of the performance of an ultrasound scanning system that has been specially developed for imaging residual limbs.