Method and apparatus for imaging with reduced level of off-axis artifacts

A method for imaging an object comprising:

• transmitting an ultrasound pulse toward the object so that the object reflects an acoustic signal;
• receiving the acoustic signal at an ultrasound detector, the ultrasound detector and the object forming a transducer axis therebetween, wherein a coupling element is positioned between the object and the ultrasound detector;
• generating and directing a probe beam toward the acoustic signal, the probe beam in a direction orthogonal to the transducer axis;
• receiving a deflected probe signal at a probe beam deflection detector resulting from an interaction between the probe beam and the acoustic signal, wherein the coupling element is positioned between the object and the probe beam deflection detector;
• determining, with Snell's law and from the deflected probe signal, an angle of incidence between the transducer axis and a direction of propagation of the acoustic signal;
• providing a filtered acoustic signal by removing portions of the acoustic signal at time intervals during which the determined angle of incidence is greater than a threshold range of angles;
• and
• forming an image of the object from the filtered acoustic signal.