Ultrasound diagnostic apparatus and ultrasound imaging method

1. An ultrasound diagnostic apparatus, comprising:

a transmitter and a receiver configured to perform a first set of ultrasound transmission and reception and a second set of ultrasound transmission and reception, on a same scanning line of an imaging region of a subject administered with a contrast agent, for a plurality of sets, to output reflected wave data for the plurality of the sets,

the first set of the ultrasound transmission and reception performing amplitude-modulated or amplitude- and phase-modulated ultrasound transmission transmitted a plurality of times and receiving reflected waves, and

the second set of the ultrasound transmission and reception being transmission and reception whose phase modulation being different from phase modulation of the first set of the ultrasound transmission and reception;

an adder or a subtractor configured to add or subtract, respectively, the reflected wave data for the plurality of the sets and output a result of the added or subtracted reflected wave data as data; and

an image generating unit configured to generate contrast image data based on the data output from the adder or subtractor, wherein

the transmitter and receiver are configured to perform each transmission of the first set of ultrasound transmission and reception and each transmission of the second set of ultrasound transmission and reception alternately, wherein

when performing alternately four or more sets in total including the first set of ultrasound transmission and reception and the second set of ultrasound transmission and reception, the transmitter and receiver are configured to invert transmission polarities between the first set of the ultrasound transmission and reception of an odd number of times and the first set of the ultrasound transmission of an even number of times, and configured to invert transmission polarities between the second set of the ultrasound transmission and reception of an odd number of times and the second set of the ultrasound transmission and reception of an even number of times.

2. The ultrasound diagnostic apparatus according to claim 1 , wherein the transmitter and the receiver are configured to perform, in the first set of the ultrasound transmission and reception, an amplitude modulation/phase modulation method that modulates both amplitudes and phases, and in the second set of the ultrasound transmission and reception, amplitude modulation method that modulates only amplitudes.

3. The ultrasound diagnostic apparatus according to claim 2 , wherein the transmission and receiver are configured to set the same polarity for the transmitted ultrasound waves whose amplitude modulation is largest in each of the first set of the ultrasound transmission and reception and the second set of the ultrasound transmission and reception.

4. The ultrasound diagnostic apparatus according to claim 1 , wherein the transmitter and receiver are configured to invert each of polarities of transmitted ultrasound waves performed for a plurality of times in the second set of the ultrasound transmission and reception from each of polarities of transmitted ultrasound waves performed for a plurality of times in the first set of the ultrasound transmission and reception.

5. The ultrasound diagnostic apparatus according to claim 1 , further comprising:

an input unit configured to receive a switching request from a first mode to a second mode and that further receives a number of sets performed in the second mode, the first mode performing one kind of ultrasound transmission and reception for performing ultrasound contrast imaging, and the second mode alternately performing a plurality of sets of the first set of the ultrasound transmission and reception and the second set of the ultrasonic transmission and reception; and

a control unit configured to set conditions of ultrasound transmission and reception in the second mode when the input unit receives the switching request and the number of the sets.

6. The ultrasound diagnostic apparatus according to claim 1 , further comprising:

an input unit configured to receive a switching request from a first mode to a second mode, the first mode performing one kind of ultrasound transmission and reception for performing ultrasound contrast imaging, and the second mode alternately performing a plurality of sets of the first set of ultrasound transmission and reception and the second set of ultrasonic transmission and reception; and

a control unit configured to set a number of transmission sets in the second mode based on a signal-to-noise ratio of contrast image data generated by changing a number of sets in the second mode when the input unit receives the switching request.

7. The ultrasound diagnostic apparatus according to claim 1 , wherein the transmitter and receiver are configured to perform parallel simultaneous reception processing using plane waves or diffuse waves as transmitted ultrasound waves.

8. The ultrasound diagnostic apparatus according to claim 1 , wherein the transmitter and receiver are configured to adjust transmission output of ultrasound waves in accordance with a total number of sets of the first set of the ultrasound transmission and reception and the second set of the ultrasound transmission and reception.

9. The ultrasound diagnostic apparatus according to claim 1 , wherein the transmitter and receiver are configured to adjust a gain in a depth direction in accordance with a total number of sets of the first set of the ultrasound transmission and reception and the second set of the ultrasound transmission and reception.

10. An ultrasound imaging method including:

performing, by a transmitter and a receiver, a first set of ultrasound transmission and reception and a second set of ultrasound transmission and reception, on a same scanning line of an imaging region of a subject administered with a contrast agent, for a plurality of sets, to output reflected wave data for the plurality of the sets,

the first set of the ultrasound transmission and reception performing amplitude-modulated or amplitude- and phase-modulated ultrasound transmission transmitted a plurality of times and receiving reflected waves, and

the second set of the ultrasound transmission and reception being transmission and reception at least whose phase modulation being different from phase modulation of the first set of the ultrasound transmission and reception;

adding or subtracting, by an adder or a subtractor, respectively, the reflected wave data for the plurality of the sets and outputting a result of the added or subtracted reflected wave data as data;

generating, by an image generating unit, contrast image data based on the data output from the adder or subtractor, wherein

each transmission of the first set of ultrasound transmission and reception and each transmission of the second set of ultrasound transmission and reception are performed alternately; and

when performing alternately four or more sets in total including the first set of ultrasound transmission and reception and the second set of ultrasound transmission and reception, inverting transmission polarities between the first set of the ultrasound transmission and reception of an odd number of times and the first set of the ultrasound transmission of an even number of times, and inverting transmission polarities between the second set of the ultrasound transmission and reception of an odd number of times and the second set of the ultrasound transmission and reception of an even number of times.

11. An apparatus, comprising:

circuitry configured to

perform a first set of ultrasound transmission and reception and a second set of ultrasound transmission and reception, on a same scanning line of an imaging region of a subject administered with a contrast agent, for a plurality of sets, to output reflected wave data for the plurality of the sets,

the first set of the ultrasound transmission and reception performing amplitude-modulated or amplitude- and phase-modulated ultrasound transmission transmitted a plurality of times and receiving reflected waves, and

the second set of the ultrasound transmission and reception being transmission and reception whose phase modulation being different from phase modulation of the first set of the ultrasound transmission and reception,

add or subtract the reflected wave data for the plurality of the sets and output a result of the added or subtracted reflected wave data as data, and

generate contrast image data based on the data output, wherein

the circuitry is configured to perform each transmission of the first set of ultrasound transmission and reception and each transmission of the second set of ultrasound transmission and reception alternately, and

when performing alternately four or more sets in total including the first set of ultrasound transmission and reception and the second set of ultrasound transmission and reception, the circuitry is configured to invert transmission polarities between the first set of the ultrasound transmission and reception of an odd number of times and the first set of the ultrasound transmission of an even number of times, and configured to invert transmission polarities between the second set of the ultrasound transmission and reception of an odd number of times and the second set of the ultrasound transmission and reception of an even number of times.