Ultrasound diagnosis apparatus and image processing apparatus
An ultrasound diagnosis apparatus includes filter coefficient acquiring circuitry configured to, based on a result of a principal component analysis using first data strings that are sets of data generated based on echo signals caused by transmission of ultrasound waves on the same scan line, obtain a filter coefficient that suppresses clutter components; deriving circuitry configured to use the filter coefficient to obtain, from target data strings contained in a region of interest among the first data strings, a second data string that is a set of data derived from echo signals based on a moving body present in the region of interest, and derive waveform information indicating temporal changes of the moving body by performing a frequency analysis on the second data string; and control circuitry configured to generate a waveform information image based on the wave information and cause a monitor to display the waveform information image.
1. An ultrasound diagnosis apparatus for performing a Pulse Wave Doppler (PWD) method, the apparatus comprising:
calculating circuitry configured to generate an averaged data string by averaging first data strings which are obtained for different positions on a scan line on which a range gate is set, and calculate a correlation matrix based on the averaged data string;
filter coefficient acquiring circuitry configured to, based on a result of a principal component analysis using the correlation matrix, obtain a filter matrix including a filter coefficient that suppresses clutter components;
deriving circuitry configured to
obtain a target data string by adding the first data strings which are obtained for the different positions on the scan line on which the range gate is set,
obtain a filtered data string by filtering the target data string using the filter matrix,
select only a part of the filtered data string,
store the selected part of the filtered data string in a memory,
determine whether a suitable amount of data to perform a Fast Fourier Transform (FFT) has been accumulated in the memory, and
derive waveform information indicating temporal changes of a moving body in the range gate, by performing the FFT on a second data string consisting of the stored data when it is determined that the suitable amount of data has been accumulated in the memory; and
control circuitry configured to generate a waveform information image based on the waveform information and cause a monitor to display the waveform information image,
wherein the deriving circuitry is configured to determine a number of principal components to be suppressed in the principal component analysis based on a threshold that is changed in accordance with a magnitude of an eigenvalue of the correlation matrix.
2. The ultrasound diagnosis apparatus according to claim 1 , wherein the filter coefficient acquiring circuitry is further configured to use, as each of the first data strings, a data string of data based on a continuous echo signal acquired from a same position by repeating a scanning form in which transmission and reception of ultrasound waves are executed one time on each scan line in a scanning range formed of a plurality of scan lines.
3. The ultrasound diagnosis apparatus according to claim 2 , wherein the filter coefficient acquiring circuitry is further configured to use, as each of the first data strings, a data string on a scan line on which a region of interest has been set.
4. The ultrasound diagnosis apparatus according to claim 3 , wherein the deriving circuitry is further configured to
set, as pieces of data that form the second data string, a certain number of pieces of data that form output data strings obtained by processing the target data strings with the filter coefficient, and
when the pieces of data that form the second data string have accumulated to correspond to a number of FFT points, perform the FFT on the second data string to derive the waveform information.
5. The ultrasound diagnosis apparatus according to claim 2 , wherein the filter coefficient acquiring circuitry is further configured to use, as the first data strings, data strings on a plurality of scan lines including at least a scan line on which a region of interest has been set.
6. The ultrasound diagnosis apparatus according to claim 5 , wherein the deriving circuitry is further configured to
set, as pieces of data that form the second data string, a certain number of pieces of data that form output data strings obtained by processing the target data strings with the filter coefficient, and
when the pieces of data that form the second data string have accumulated to correspond to a number of FFT points, perform the FFT on the second data string to derive the waveform information.
7. The ultrasound diagnosis apparatus according to claim 2 , wherein the deriving circuitry is further configured to
set, as pieces of data that form the second data string, a certain number of pieces of data that form output data strings obtained by processing the target data strings with the filter coefficient, and
when the pieces of data that form the second data string have accumulated to correspond to a number of FFT points, perform the FFT on the second data string to derive the waveform information.
8. The ultrasound diagnosis apparatus according to claim 1 , wherein the filter coefficient acquiring circuitry is further configured to use, as each of the first data strings, a data string on a scan line on which a region of interest has been set.
9. The ultrasound diagnosis apparatus according to claim 8 , wherein the deriving circuitry is further configured to
set, as pieces of data that form the second data string, a certain number of pieces of data that form output data strings obtained by processing the target data strings with the filter coefficient, and
when the pieces of data that form the second data string have accumulated to correspond to a number of FFT points, perform the FFT on the second data string to derive the waveform information.
10. The ultrasound diagnosis apparatus according to claim 1 , wherein the filter coefficient acquiring circuitry is further configured to use, as the first data strings, data strings on a plurality of scan lines including at least a scan line on which a region of interest has been set.
11. The ultrasound diagnosis apparatus according to claim 10 , wherein the deriving circuitry is further configured to
set, as pieces of data that form the second data string, a certain number of pieces of data that form output data strings obtained by processing the target data strings with the filter coefficient, and
when the pieces of data that form the second data string have accumulated to correspond to a number of FFT points, perform the FFT on the second data string to derive the waveform information.
12. The ultrasound diagnosis apparatus according to claim 1 , wherein the deriving circuitry is further configured to
set, as pieces of data that form the second data string, a certain number of pieces of data that form output data strings obtained by processing the target data strings with the filter coefficient, and
when the pieces of data that form the second data string have accumulated to correspond to a number of FFT points, perform the FFT on the second data string to derive the waveform information.
13. The ultrasound diagnosis apparatus according to claim 1 , wherein a data length of each of the target data strings and a number of pieces of data that are redundant in adjacent pieces of data in the target data strings are previously determined.
14. An image processing apparatus for performing a Pulse Wave Doppler (PWD) method, the method comprising:
calculating circuitry configured to generate an averaged data string by averaging first data strings which are obtained for different positions on a scan line on which a range gate is set, and calculate a correlation matrix based on the averaged data string;
filter coefficient acquiring circuitry configured to, based on a result of a principal component analysis using the correlation matrix, obtain a filter matrix including a filter coefficient that suppresses clutter components;
deriving circuitry configured to
obtain a target data string by adding the first data strings which are obtained for the different positions on the scan line on which the range gate is set,
obtain a filtered data string by filtering the target data string using the filter matrix,
select only a part of the filtered data string,
store the selected part of the filtered data string in a memory,
determine whether a suitable amount of data to perform a Fast Fourier Transform (FFT) has been accumulated in the memory, and
derive waveform information indicating temporal changes of a moving body in the range gate, by performing the FFT on a second data string consisting of the stored data when it is determined that the suitable amount of data has been accumulated in the memory; and
control circuitry configured to generate a waveform information image based on the waveform information and cause a monitor to display the waveform information image,
wherein the deriving circuitry is configured to determine a number of principal components to be suppressed in the principal component analysis based on a threshold that is changed in accordance with a magnitude of an eigenvalue of the correlation matrix.