A Multiple Aperture Ultrasound Imaging (MAUI) probe or transducer is uniquely capable of simultaneous imaging of a region of interest from separate apertures of ultrasound arrays. Some embodiments provide systems and methods for designing, building and using ultrasound probes having continuous arrays of ultrasound transducers which may have a substantially continuous concave curved shape in two or three dimensions (i.e. concave relative to an object to be imaged). Other embodiments herein provide systems and methods for designing, building and using ultrasound imaging probes having other unique configurations, such as adjustable probes and probes with variable configurations.