An ultrasound imaging system for shear wave imaging comprising: an ultrasound transducer configured to acquire echoes responsive to ultrasound pulses transmitted toward a target tissue; a beamformer configured to: transmit, from the ultrasound transducer, tracking pulses in response to a push pulse, wherein the push pulse generates a shear wave in the target tissue and the tracking pulses are spatially planned to intersect the shear wave at one or more locales; and receive, from the ultrasound transducer, echo signals where the tracking pulses intersected the shear wave; and a processor in communication with the beamformer and configured to: determine a displacement amplitude of the shear wave propagating through the target tissue at two or more laterally-spaced points within the target tissue based on the received echo signals, determine a displacement amplitude decorrelation value by comparing the determined displacement amplitude at consecutive pairs of the laterally-spaced points within the target tissue, determine a reference displacement amplitude decorrelation value by comparing the determined displacement amplitude at consecutive pairs of the laterally-spaced points within a reference tissue, compare the displacement amplitude decorrelation value to the reference displacement amplitude decorrelation value, and based on the comparison, generate the qualitative tissue elasticity map; and generate a quantitative tissue elasticity map of the target tissue based on time-of-flight of the received echo signals, determine a boundary of a region of increased stiffness within the target tissue by combining the qualitative tissue elasticity map with the quantitative tissue elasticity map. an ultrasound transducer configured to acquire echoes responsive to ultrasound pulses transmitted toward a target tissue; a beamformer configured to: transmit, from the ultrasound transducer, tracking pulses in response to a push pulse, wherein the push pulse generates a shear wave in the target tissue and the tracking pulses are spatially planned to intersect the shear wave at one or more locales; and receive, from the ultrasound transducer, echo signals where the tracking pulses intersected the shear wave; and a processor in communication with the beamformer and configured to: determine a displacement amplitude of the shear wave propagating through the target tissue at two or more laterally-spaced points within the target tissue based on the received echo signals, determine a displacement amplitude decorrelation value by comparing the determined displacement amplitude at consecutive pairs of the laterally-spaced points within the target tissue, determine a reference displacement amplitude decorrelation value by comparing the determined displacement amplitude at consecutive pairs of the laterally-spaced points within a reference tissue, compare the displacement amplitude decorrelation value to the reference displacement amplitude decorrelation value, and based on the comparison, generate the qualitative tissue elasticity map; and generate a quantitative tissue elasticity map of the target tissue based on time-of-flight of the received echo signals, determine a boundary of a region of increased stiffness within the target tissue by combining the qualitative tissue elasticity map with the quantitative tissue elasticity map. transmit, from the ultrasound transducer, tracking pulses in response to a push pulse, wherein the push pulse generates a shear wave in the target tissue and the tracking pulses are spatially planned to intersect the shear wave at one or more locales; and receive, from the ultrasound transducer, echo signals where the tracking pulses intersected the shear wave; and a processor in communication with the beamformer and configured to: determine a displacement amplitude of the shear wave propagating through the target tissue at two or more laterally-spaced points within the target tissue based on the received echo signals, determine a displacement amplitude decorrelation value by comparing the determined displacement amplitude at consecutive pairs of the laterally-spaced points within the target tissue, determine a reference displacement amplitude decorrelation value by comparing the determined displacement amplitude at consecutive pairs of the laterally-spaced points within a reference tissue, compare the displacement amplitude decorrelation value to the reference displacement amplitude decorrelation value, and based on the comparison, generate the qualitative tissue elasticity map; and generate a quantitative tissue elasticity map of the target tissue based on time-of-flight of the received echo signals, determine a boundary of a region of increased stiffness within the target tissue by combining the qualitative tissue elasticity map with the quantitative tissue elasticity map.