Method and apparatus for “thick-slice” 3-dimensional ultrasound imaging utilizing a multi-zone, multi-frequency ultrasound image reconstruction scheme with sub-zone blending

A handheld ultrasound device, comprising:

• a plurality of rows of ultrasonic elements, the rows arranged in parallel to form an array, the ultrasonic elements of the array characterized by an elevation pitch between ultrasonic elements in adjacent rows and an azimuth pitch between ultrasonic elements within the same row;
• a plurality of N-way multiplexers, each N-way multiplexer coupled to at least one element in each row;
• and
• a plurality of high-voltage pulsers configured to provide high voltage pulses to the ultrasonic elements via the plurality of multiplexers;
• a plurality of analog front-end receivers coupled to the N-way multiplexers and configured to amplify and digitize received ultrasonic signals;
• and
• a controller coupled to the plurality of N-way multiplexers, the plurality of high-voltage pulsers, and the plurality of analog front-end receivers, the controller configured to:
• set operational parameters of the ultrasonic array to use a multi-angle plane wave imaging scheme for a first depth zone of a target area of an object;
• acquire ultrasound data from the first depth zone by transmitting and receiving ultrasound signals using the multi-angle plane wave imaging scheme;
• update operational parameters of the ultrasonic array to use a tissue harmonic imaging scheme for a second depth zone of the target area;
• acquire ultrasound data from the second depth zone by transmitting and receiving ultrasound signals using the tissue harmonic imaging scheme;
• form a first 3D image of the first depth zone using the multi-angle plane wave imaging scheme;
• form a second 3D image of the second depth zone using focused transmitted tissue harmonic imaging;
• and
• generate a blended 3D image based on the first and second 3D images,
• wherein the first depth zone of the target area is imaged from a position near a surface of the object, and the second depth zone extends deeper into the object than the first depth zone.