Optimum displacement for compound image generation in medical ultrasound.

Incoherent averaging of measurements made at different look directions can be used to reduce speckle noise in medical ultrasound images. An analytic expression for the correlation between two measurements made at different spatial positions is derived. Using this expression, the optimum aperture displacement for efficient incoherent averaging (i.e. compounding) is computed and found to equal approximately one-half the aperture length.