Multiple aperture ultrasound imaging systems and methods

A method of imaging an object with ultrasound energy, the method comprising the steps of:

• transmitting an un-focused and diverging ultrasound signal into a target medium from an apparent point source located behind an array of transducer elements on a concave probe surface;
• receiving echoes from a reflector in the target medium with an omnidirectional receive element in the array that is different than the apparent point source;
• determining a position of the reflector within the target medium by obtaining element position data describing a position of the spherical center point of the apparent point source and a position of the receive element, calculating a total path distance as a sum of a first distance between the spherical center point and the reflector and a second distance between the reflector and the receive element, and determining a locus of possible points at which the reflector may lie;
• and
• producing one or more images of the entire target medium that includes the reflector.