Volume imaging system with different bias patterns

An ultrasound imaging system comprising:

• an array of ultrasonic transducers;
• and
• a controller configured to:
• selectively activate different portions of the array to determine whole or partial different two-dimensional images, each of the whole or partial two-dimensional images being based upon signals that are estimated to be received from a different first portion of the array,
• wherein each of the whole or partial two-dimensional images is based on element data output by the ultrasonic transducers of an array where a first electrical bias pattern is applied to a first and second portion of the array during a transmitting phase and a second electrical bias pattern is applied to the first portion and the second portion of the array during the receiving phase,
• wherein the second electrical bias pattern includes a non-zero electrical bias applied to at least one ultrasonic transducer of the second portion;
• and
• generate a volumetric image based on the different whole or partial two-dimensional images.