Ultrasound diagnosis apparatus and ultrasound diagnosis method
An ultrasound diagnosis apparatus according to an embodiment includes transmitter and receiver circuitry and Doppler processing circuitry. The transmitter and receiver circuitry is configured to transmit ultrasound and receive an echo signal corresponding to the ultrasound. The Doppler processing circuitry is configured to perform principal component analysis of a first signal data string obtained from the echo signal, and is configured to extract a second signal data string from the first signal data string by reducing a predetermined Doppler frequency component, on the basis of at least one of an eigenvalue and an eigenvector obtained by the principal component analysis.
1 . An ultrasound diagnosis apparatus, comprising:
an ultrasound probe;
transmitter and receiver circuitry configured to transmit ultrasound via the ultrasound probe and receive an echo signal corresponding to the transmitted ultrasound;
Doppler processing circuitry configured to perform principal component analysis of a first signal data string obtained from the echo signal and extract a second signal data string from the first signal data string by reducing a predetermined Doppler frequency component, based on at least one of an eigenvalue and an eigenvector obtained by the principal component analysis; and
processing circuitry configured to generate an ultrasound image using the ultrasound probe based on the second signal data string,
wherein the Doppler processing circuitry is further configured to extract the second signal data string based on a mean phase difference in the eigenvector.
2 . The ultrasound diagnosis apparatus according to claim 1 , wherein the transmitter and receiver circuitry is further configured to transmit the ultrasound in plural directions in a same phase that is a first phase in one frame and thereafter is configured to transmit the ultrasound in the plural directions in a second phase opposite to the first phase.
3 . The ultrasound diagnosis apparatus according to claim 1 , wherein the Doppler processing circuitry is further configured to extract the second signal data string based on a basis of a magnitude of a complex amplitude of the eigenvector.
4 . The ultrasound diagnosis apparatus according to claim 1 , wherein the Doppler processing circuitry is further configured to extract a bloodstream signal as the second signal data string, by extracting a harmonic component from the first signal data string.
5 . The ultrasound diagnosis apparatus according to claim 1 , wherein the first signal data string is data that have been sampled at unequal intervals.
6 . The ultrasound diagnosis apparatus according to claim 1 , further comprising:
a vibrator configured to vibrate, at a certain frequency, an object inserted in a subject where the ultrasound is transmitted, wherein the mean phase difference of the predetermined Doppler frequency component is larger than a predetermined threshold and the eigenvalue is larger than a first threshold and the predetermined Doppler frequency component eigenvalue is less than a second threshold, wherein the generated ultrasound image is an enhanced image of the object.
7 . The ultrasound diagnosis apparatus according to claim 1 , wherein
the transmitter and receiver circuitry is further configured to transmit the ultrasound while phase-modulating the ultrasound, and
the Doppler processing circuitry is further configured to extract the second signal data string by extracting a harmonic component from the first signal data string.
8 . The ultrasound diagnosis apparatus according to claim 7 , wherein the transmitter and receiver circuitry is further configured to transmit the ultrasound while phase-modulating the ultrasound by 120 degrees.
9 . The ultrasound diagnosis apparatus according to claim 7 , wherein
the transmitter and receiver circuitry is further configured to transmit the ultrasound while phase-modulating the ultrasound by 180 degrees, and
the Doppler processing circuitry is further configured to generate a third signal data string having an even-order harmonic component extracted therein, by adding the second signal data string corresponding to ultrasound transmission having phases different from each other by 180 degrees.
10 . The ultrasound diagnosis apparatus according to claim 9 , wherein
the Doppler processing circuitry is further configured to perform principal component analysis of the third signal data string, and is further configured to extract a fourth signal data string from the third signal data string by reducing a predetermined Doppler frequency component, based on at least one of an eigenvalue and an eigenvector obtained by the principal component analysis of the third signal data string.
11 . The ultrasound diagnosis apparatus according to claim 10 , wherein the Doppler processing circuitry is further configured to extract a bloodstream signal as the fourth signal data string, by extracting a harmonic component from the third signal data string.
12 . The ultrasound diagnosis apparatus according to claim 1 , wherein the Doppler processing circuitry is further configured to extract the second signal data string further based on the eigenvalue.
13 . The ultrasound diagnosis apparatus according to claim 12 , wherein the Doppler processing circuitry is further configured to extract the second signal data string by reducing: a Doppler frequency component having a mean phase difference larger than a predetermined threshold and the eigenvalue larger than a first threshold; and a Doppler frequency component having the eigenvalue less than a second threshold.
14 . The ultrasound diagnosis apparatus according to claim 1 , further comprising:
a vibrator configured to vibrate, at a certain frequency, an object inserted in a subject where the ultrasound is transmitted, wherein
the Doppler processing circuitry is further configured to extract the second signal data string by reducing the certain Doppler frequency component.
15 . The ultrasound diagnosis apparatus according to claim 14 , wherein
the object is a puncture needle, and
the ultrasound diagnosis apparatus further comprises a needle connector configured to connect the vibrator and the object to each other.
16 . An ultrasound diagnosis apparatus, comprising:
an ultrasound probe;
transmitter and receiver circuitry configured to transmit ultrasound via the ultrasound probe and receive an echo signal corresponding to the transmitted ultrasound;
Doppler processing circuitry configured to perform principal component analysis of a first signal data string obtained from the echo signal and extract a second signal data string from the first signal data string by reducing a predetermined Doppler frequency component, based on at least one of an eigenvalue and an eigenvector obtained by the principal component analysis, and
processing circuitry configured to generate an ultrasound image using the ultrasound probe based on the second signal data string,
wherein the Doppler processing circuitry is further configured to extract the second signal data string based on a correlation value between (1) a unit vector n=cos θ+i sin θ corresponding to a transmission modulation phase, and (2) the eigenvector.
17 . An ultrasound diagnosis method, including:
transmitting ultrasound via an ultrasound probe and receiving an echo signal corresponding to the transmitted ultrasound;
performing principal component analysis of a first signal data string obtained from the echo signal;
extracting a second signal data string from the first signal data string by reducing a predetermined Doppler frequency component, based on a mean phase difference in an eigenvector obtained by the principal component analysis; and
generating an ultrasound image using the ultrasound probe based on the second signal data string.