Marking tumors and solid objects in the body with ultrasound

Abstract

A technique for subspeckle visibility in ultrasound imaging by using the speckle signatures to differentiate soft tissue from dense tissue and solid or compact objects. The information provided by a disparity mapper is used to automatically mark or tag these objects based on the observation that slight natural motion in soft tissue, as caused by breathing or probe compression, changes the details of a speckle pattern. This results from differential displacements among scatterers which alter the phase relations between their scattered fields. A small, compact object is displaced and distorted less, implying that its reflectivity pattern should be relatively stable, as compared to the fluctuating background reflectivity. This difference in the way the speckle patterns respond to body motion is detected by the disparity mapper. The output of the disparity mapper serves a marker or tag of dense tissue such as tumors or compact objects such as bits of shrapnel. Such techniques may be used by trained hospital sonographers and physicians to improve the location and identification of tumors and foreign objects in the tissue of a patient.