Abstract: A dual frequency transducer array includes one or more low frequency transducer arrays and a high frequency transducer array. Unfocused ultrasound such as plane waves are transmitted by the one or more low frequency transducer arrays in a number of different directions into an imaging region of the high frequency transducer array. High frequency echo signals produced by excited contrast agent in the imaging region are received by the high frequency transducer array to produce a contrast agent image. In another embodiment, the high frequency transducer produces unfocused ultrasound to excite the contrast agent in the imaging region and the low frequency transducer(s) receives low frequency echo signals from the excited contrast agent. A tissue image is created from echo signals received by the high or low frequency transducer. Echo data from the tissue image and the contrast agent image are combined to produce a combined tissue/contrast agent image.

Abstract: A dual frequency transducer array includes one or more low frequency transducer arrays and a high frequency transducer array. Unfocused ultrasound such as plane waves are transmitted by the one or more low frequency transducer arrays in a number of different directions into an imaging region of the high frequency transducer array. High frequency echo signals produced by excited contrast agent in the imaging region are received by the high frequency transducer array to produce a contrast agent image. In another embodiment, the high frequency transducer produces unfocused ultrasound to excite the contrast agent in the imaging region and the low frequency transducer(s) receives low frequency echo signals from the excited contrast agent. A tissue image is created from echo signals received by the high or low frequency transducer. Echo data from the tissue image and the contrast agent image are combined to produce a combined tissue/contrast agent image.