Ultrasonic diagnostic apparatus
According to one embodiment, based on a reception signal, the Doppler signal generation unit generates a first Doppler signal attributed to motion of a living body in a ROI and a second Doppler signal attributed to slower motion. The velocity display scale determination unit determines first and second velocity display scales based on velocity distribution ranges for the first and second Doppler signals, respectively. The image generation unit generates first and second Doppler images based on the first and second Doppler signals, respectively. The display unit displays the first and second Doppler images with the first and second velocity display scales, respectively.
1. An ultrasonic diagnostic apparatus comprising:
an ultrasonic probe;
ultrasonic transmission circuitry, which transmits an ultrasonic wave to an object via the ultrasonic probe;
ultrasonic reception circuitry, which generates a reception signal based on a reflected wave of the ultrasonic wave;
Doppler signal generation circuitry, which generates a first Doppler signal and a second Doppler signal based on the reception signal, wherein the first Doppler signal is attributed to a first motion of a blood flow in a first range gate in a region of interest in a predetermined azimuthal direction, the second Doppler signal is attributed to a second motion of a tissue in a second range gate in the region of interest;
velocity display scale determination circuitry, which determines a first velocity display scale based on a velocity distribution range for the first Doppler signal and determines a second velocity display scale based on a velocity distribution range for the second Doppler signal;
image generation circuitry, which generates a blood flow Doppler image based on the first Doppler signal and generates a tissue Doppler image based on the second Doppler signal; and
a monitor, which displays the blood flow Doppler image with the first velocity display scale and displays the tissue Doppler image with the second velocity display scale, wherein
the image generation circuitry generates the tissue Doppler image with a luminance of a background of a Doppler waveform changed to a predetermined luminance, based on a frequency spectrum of the second Doppler signal, the luminance of the background distinguishing a time period during which the frequency spectrum of the second Doppler signal satisfies a predefined frequency criterion from a time during which the frequency spectrum of the second Doppler signal does not satisfy the predefined frequency criterion.
2. The apparatus of claim 1 , wherein the velocity display scale determination circuitry determines, as the second velocity display scale, a velocity display scale larger than the first velocity display scale.
3. The apparatus of claim 1 , wherein the velocity display scale determination circuitry determines, as the first velocity display scale, a velocity display scale smaller than the second velocity display scale.
4. The apparatus of claim 1 , further comprising:
input circuitry, which inputs a scale for determining the second velocity display scale; and
a memory, which stores a scale for determining the second velocity display scale, wherein
the velocity display scale determination circuitry determines the second velocity display scale based on at least one of the input scale, the stored scale, and the velocity distribution range for the second Doppler signal.
5. The apparatus of claim 1 , wherein
the Doppler signal generation circuitry further comprises a variable filter, and
the apparatus further comprises filter change circuitry, which changes a filter characteristic of the variable filter between a characteristic for extracting the first Doppler signal from the reception signal and a characteristic for extracting the second Doppler signal from the reception signal.
6. The apparatus of claim 1 , wherein the Doppler signal generation circuitry generates the second Doppler signal by performing a Fourier transformation of the reception signal using a sample count larger than a sample count used in a Fourier transformation for generation of the first Doppler signal.
7. The apparatus of claim 1 , wherein the image generation circuitry generates an image in which the tissue Doppler image is superimposed on the blood flow Doppler image such that times on a time axis of the blood flow Doppler image match with times on a time axis of the tissue Doppler image.
8. The apparatus of claim 1 , wherein the image generation circuitry generates the tissue Doppler image with a hue of a background of a Doppler waveform set to a predetermined hue based on a frequency spectrum of the second Doppler signal.
9. The apparatus of claim 1 , wherein the ultrasonic transmission circuitry transmits the ultrasonic wave under predetermined transmission conditions corresponding to a velocity of the first motion and a velocity of the second motion, respectively.
10. The apparatus of claim 9 , wherein the predetermined transmission conditions include a pulse repetition frequency.
11. The apparatus of claim 1 , wherein the ultrasonic reception circuitry receives the ultrasonic wave under predetermined reception conditions corresponding to a velocity of the first motion and a velocity of the second motion, respectively.