Structures containing gas and bone are very difficult to evaluate with ultrasound.
The ultrasound transducer converts electrical energy into a brief pulse of high frequency sound waves which are then transmitted into the animal's tissues. The transducer then functions as a receiver, detecting echoes of sound energy reflected from the tissues that are then analyzed by a computer to produce gray-scale images for interpretation by a veterinarian. Ultrasound has reduced the need for many contrast radiographic examinations and aids in guiding diagnostic or therapeutic needle aspirations and biopsies of organs or lesions for cytological, bacteriological or histopathological preparations. No ionizing radiation hazard or other known safety consideration is present with ultrasound. Ultrasound images may be produced in any anatomical plane by adjusting the orientation and angulation of the transducer and patient position.