Patent ID: 8118745

Claim:
An ultrasound imaging apparatus comprising: a probe that transmits and receives ultrasound signals to and from an object to be examined; a transmission controller that controls the ultrasound signals to be transmitted from the probe; a signal processing unit that processes the ultrasound signals received by the probe, wherein the transmission controller is configured to control the probe so as to transmit a first transmission signal and a second transmission signal, the first transmission signal is a first ultrasound signal having a center frequency of nf, the second transmission signal is a second ultrasound signal having a center frequency of mf, in which n is an even natural number, m is an odd natural number, the least common multiple of n and m is nk 1 =mk 2 , and f is a frequency, the signal processing unit is configured to perform: a processing to obtain a first echo signal having a center frequency of nk 1 f by raising the first ultrasound signal received in response to the transmission of the first transmission signal to the power of k 1 ; a processing to obtain a second echo signal having a center frequency of mk 2 f by raising the second ultrasound signal received in response to the transmission of the second transmission signal to the power of k 2 ; and a processing to obtain a signed echo signal from the outcome of a phase-sensitive detection processing performed between the first echo signal and the second echo signal.