1. A method of analyzing movement of at least one of blood and anatomical structures within a region of interest, operating in conjunction with B-mode and/or color flow imaging modes, the method comprising: activating at least a portion of a multi-element transducer array to transmit ultrasonic beams through a transmit aperture along one or more scan directions that span the region of interest; receiving, by one or more elements in the multi-element transducer array, ultrasound echoes through a receive aperture; grouping echo data received by the one or more elements into at least one of a first sub-aperture data set and a second sub-aperture data set, wherein the first sub-aperture data set includes the echo data related to an inner sub-aperture and the second sub-aperture data set includes the echo data related to an outer sub-aperture; combining the echo data grouped into the first sub-aperture data set to generate a first partially focused data set; combining the echo data grouped into the second sub-aperture data set to generate a second partially focused data set; storing the first partially focused data set and the second partially focused data set during a storage period in a format that can be retrieved for later analysis; determining a first sound speed for a pre-determined metric by iteratively adjusting the first partially focused data set based on a plurality of trial sound speed values; determining a second sound speed for the pre-determined metric by iteratively adjusting the second partially focused data set based on the plurality of trial sound speed values; applying a first weight factor to the first partially focused data set and a second weight factor different from the first weight factor to the second partially focused data set during a post-storage period to create an adaptive receive aperture with the inner sub-aperture and the outer sub-aperture during the post-storage period, wherein the first weight factor and the second weight factor are selected for the inner sub-aperture and the outer sub-aperture to achieve a specific effective aperture size for the adaptive receive aperture; and generating an image for one or more construction lines based on the first partially focused data set weighted using the first weight factor, the first sound speed, the second partially focused data set weighted using the second weight factor, and the second sound speed.