JP4832211B2 - Ultrasonic diagnostic apparatus and image display apparatus - Google Patents

Description

  The present invention relates to an ultrasonic diagnostic apparatus and an image display apparatus.

An ultrasonic diagnostic apparatus that displays a so-called D-mode image is known (for example, Patent Document 1). In such an ultrasonic diagnostic apparatus, processing such as phase detection is performed on a received signal from a probe to acquire time series data including Doppler information, and a certain number of data points (window size: In order to obtain a Doppler spectrum by performing Fourier transform for each time range including “window size”), the Doppler spectrum is obtained several times while shifting the time range. Obtain a Doppler spectrum. Then, image data of the D mode image is generated based on the plurality of Doppler spectra.
JP-A-8-229035

  FIG. 7 is a diagram for explaining a conventional D-mode image. In the D-mode image of FIG. 7, the horizontal axis is time, the vertical axis is the speed of blood flow, and the luminance of each pixel is determined by the time of the horizontal axis and the power of the Doppler spectrum specified by the speed of the vertical axis. The higher it is, the higher it is. In FIG. 7, a region with low luminance is hatched.

  When calculating the Doppler spectrum at each time point (strictly, each time range), if the number of data points of the time-series data is increased, the luminance is lower than the surroundings (the power is lower) as shown in FIG. Multiple spots 501 are generated (low). In this case, the user feels that the sensitivity of the ultrasonic diagnostic apparatus is low.

  On the other hand, when the number of data points of the time-series data is reduced, as shown in FIG. 7B, a line image having a higher or lower luminance than the surroundings, that is, a vertical streak 502 is generated, and a region having a high luminance and a region having a low luminance. Jagged edges appear in the boundary region 503. In this case, it is difficult for the user to grasp the boundary of the region with high luminance.

  That is, the number of data points of time series data affects the image quality of the D-mode image. According to the general noise reduction technical idea, it seems that the image quality is likely to improve if the number of data points is increased. However, in actuality, not only when the number of data points of the time-series data is reduced, but the number of data points is also increased. In many cases, the image quality is deteriorated, and it is not easy to display a high-quality D-mode image only by adjusting the number of data of the time series data.

  Note that even in the same device, in the case of a D-mode image that is produced artificially experimentally and has a sufficiently strong and continuous sine wave having a constant frequency, Considering that the spots are not conspicuous, vertical stripes and spots are generated because the reflected sound from the living body is picked up, so that the received signal containing discontinuous frequency components is fast Fourier transformed. The reason is that sufficient signal strength is not always obtained.

  An object of the present invention is to provide an ultrasonic diagnostic apparatus and an image display apparatus that can improve the image quality of a D-mode image.

  The ultrasonic diagnostic apparatus of the present invention irradiates a subject with ultrasonic waves, converts the reflected ultrasonic waves into electrical signals, and outputs the time series data including Doppler information based on the signals from the probes. A plurality of time-series data generating means for generating Doppler spectrum data by performing Fourier transform on the time-series data in a predetermined time range of the time-series data to generate Doppler spectrum data. A spectrum data generating means for generating the Doppler spectrum data for a plurality of times, an image generating means for generating image data of a D-mode image based on the Doppler spectrum data for the plurality of times, and a D based on the image data. Display means for displaying a mode image, wherein the spectrum data generating means is a part of the time-series data in the predetermined time range. Generating the Doppler spectrum data by performing Fourier transform on the time series data of the number of data points, a plurality of times with different data points, generating a plurality of types of the Doppler spectrum data, and the image generating means, Image data of a combined D-mode image obtained by combining a plurality of types of D-mode images based on a plurality of types of Doppler spectrum data is generated.

  Preferably, the composite D-mode image is an image in which luminance is averaged between pixels corresponding to each other of the plurality of types of D-mode images.

  Preferably, the composite D-mode image is an image in which the maximum luminance is selected between pixels corresponding to each other of the plurality of types of D-mode images.

  Preferably, the composite D-mode image is image data obtained by combining another image in a predetermined region of any one of the plurality of types of D-mode images.

  Preferably, the predetermined area is an area where a spot having a predetermined size occurs in the one D-mode image, and the other image is the time series having a smaller number of data points than the one D-mode image. It is a D-mode image based on data.

  Preferably, the predetermined region is a region where a line along an axis indicating a physical quantity correlated with a Doppler shift frequency or a Doppler shift frequency is generated in the one D-mode image, and the other image is the one mode. The D-mode image is based on the time-series data having a larger number of data points than the D-mode image.

  Preferably, the time-series data having different data points in the predetermined time range is the time-series data in which all of the time-series data in a part of the time range among the time-series data of one data point are other data points. The time series data in the predetermined time range is selected.

  Preferably, the spectrum data generating means performs a Fourier transform after multiplying the time series data having different data points by a window function having a larger value on the time center side of the time series data, and performing the Fourier transform, Time-series data for which Doppler spectrum data is generated and whose data points are different from each other in the predetermined time range is selected from the time-series data in the predetermined time range so that the time centers of the respective time-series data are the same. Has been.

  An image display device of the present invention generates time-series data including time-series data including Doppler information, and generates Doppler spectrum data by performing Fourier transform on the time-series data in a predetermined time range of the time-series data. A plurality of times by shifting the predetermined time range by a predetermined time and generating the Doppler spectrum data at a plurality of times; and image data of the D-mode image based on the Doppler spectrum data at the plurality of times. And a display means for displaying a D-mode image based on the image data, wherein the spectrum data generating means has a predetermined number of data points in the time series data in the predetermined time range. The time series data is subjected to Fourier transform to generate Doppler spectrum data. Several times are performed to generate a plurality of types of Doppler spectrum data, and the image generation unit generates image data of a combined D-mode image obtained by combining a plurality of types of D-mode images based on the plurality of types of Doppler spectrum data. .

  Preferably, the composite D-mode image is an image in which luminance is averaged between pixels corresponding to each other of the plurality of types of D-mode images.

  Preferably, the composite D-mode image is an image in which the maximum luminance is selected between pixels corresponding to each other of the plurality of types of D-mode images.

  Preferably, the composite D-mode image is image data obtained by combining another image in a predetermined region of any one of the plurality of types of D-mode images.

  Preferably, the predetermined area is an area where a spot having a predetermined size occurs in the one D-mode image, and the other image is the time series having a smaller number of data points than the one D-mode image. It is a D-mode image based on data.

  Preferably, the predetermined region is a region where a line along an axis indicating a physical quantity correlated with a Doppler shift frequency or a Doppler shift frequency is generated in the one D-mode image, and the other image is the one mode. The D-mode image is based on the time-series data having a larger number of data points than the D-mode image.

  Preferably, the time-series data having different data points in the predetermined time range is the time-series data in which all of the time-series data in a part of the time range among the time-series data of one data point are other data points. The time series data in the predetermined time range is selected.

  Preferably, the spectrum data generating means performs a Fourier transform after multiplying the time series data having different data points by a window function having a larger value on the time center side of the time series data, and performing the Fourier transform, Time-series data for which Doppler spectrum data is generated and whose data points are different from each other in the predetermined time range is selected from the time-series data in the predetermined time range so that the time centers of the respective time-series data are the same. Has been.

  According to the present invention, the image quality of a D-mode image can be improved.

  FIG. 1 is a block diagram showing the main part of the overall configuration of an ultrasonic diagnostic apparatus 1 according to an embodiment of the present invention. The ultrasonic diagnostic apparatus 1 is configured as, for example, an ultrasonic diagnostic apparatus that obtains a D-mode image by a so-called pulse Doppler method. That is, the ultrasonic diagnostic apparatus 1 transmits and receives waves intermittently, such as transmitting an ultrasonic transmission wave as a pulse wave of a certain length, and sending the next pulse wave after the reflected wave returns. .

  The ultrasonic diagnostic apparatus 1 irradiates a subject with ultrasonic waves, receives a reflected ultrasonic wave, a transmission / reception unit 12 that transmits / receives an electrical signal between the probes 11, and a signal from the transmission / reception unit 12. A data processing unit 13 that generates data necessary for generating image data based on the data, an image processing unit 14 that generates image data based on the data generated by the data processing unit 13, and a signal from the image processing unit 14 A display unit 15 that displays an ultrasonic image based on the control unit 16, an operation unit 16 that receives a user input operation, and a control unit 17 that executes control of the units 12 to 15 based on a signal from the operation unit 16. ing.

  The probe 11 includes a transducer that performs mutual conversion between an ultrasonic wave and an electric signal, converts the input electric signal into an ultrasonic wave, transmits the ultrasonic wave to the subject, and receives the received ultrasonic wave (echo signal). Convert to electrical signal and output.

  The transmission / reception unit 12 outputs an electrical signal to the probe 11 at a predetermined repetition frequency based on the control signal from the control unit 17. In addition, an electrical signal from the probe 11 is output to the data processing unit 13.

  The data processing unit 13 includes a time series data generation unit 19 that generates time series data including Doppler information based on a signal from the transmission / reception unit 12, and a Fourier transform on the time series data generated by the time series data generation unit 19. And a spectrum data generation unit 20 for generating Doppler spectrum data. The data processing unit 13 is configured by a computer, for example.

  Although not particularly shown, the time series data generation unit 19 is, for example, a signal extraction unit that extracts a signal of a predetermined depth (see the sample volume 105 in FIG. 2) from the input signal, and orthogonally detects the input signal. A phase detector for outputting a Doppler signal and an AD converter for A / D conversion of the input analog signal are provided. The time-series data generation unit 19 generates time-series data that is discrete digital data by performing processing by the above-described units on the signal from the transmission / reception unit 12. The time-series data holds information on the intensity of the Doppler signal that vibrates at the Doppler shift frequency at regular time intervals (for example, every period corresponding to the repetition frequency in the pulse Doppler method). In addition, you may perform the process of the above-mentioned each part of the time series data generation part 19 in an appropriate order.

  The spectrum data generation unit 20 performs Fourier transform on the time series data generated by the time series data generation unit 19 to generate Doppler spectrum data that holds a power value for each Doppler shift frequency. The Fourier transform is performed by, for example, fast Fourier transform (FFT).

  In addition to the time series data generation unit 19 and the spectrum data generation unit 20, the data processing unit 13 includes a filter unit that removes noise from data (signal) and other modes (M mode, B mode, color mode). ) Includes various data generation units that generate data for generating an image.

  The image processing unit 14 generates image data based on the data generated by the data processing unit 13. For example, the image processing unit 14 generates a D-mode image based on the Doppler spectrum data generated by the spectrum data generation unit 20. The image processing unit 14 can generate image data of an image in another mode in addition to the image data of the D mode image. The image processing unit 14 outputs a video signal based on the generated image data to the display unit 15. The image processing unit 14 is configured by a computer, for example.

  The display unit 15 is configured by, for example, a CRT display or a liquid crystal display, and displays an image according to the video signal output from the image processing unit 14. The operation unit 16 is configured by, for example, a keyboard or a pointing device, and outputs a signal corresponding to the input operation to the control unit 17. The control unit 17 is configured by a computer, for example, and outputs control signals to the transmission / reception unit 12, the data processing unit 13, the image processing unit 14, and the display unit 15 based on an operation signal from the operation unit 16.

  FIG. 2 shows an example of an image displayed on the display unit 15. The image 101 is displayed on the screen of the display unit 15 in real time during transmission / reception of ultrasonic waves by the probe 11 or at an arbitrary time after the transmission / reception of ultrasonic waves by the probe 11 is completed.

  The image 101 includes a B mode image 102 and a D mode image 103. The B-mode image 102 is a tomographic image that represents the intensity of the echo signal in terms of luminance. In the B mode image 102, a sample volume 105 indicating the display target portion of the D mode image 103 is displayed. The position and size of the sample volume 105 are appropriately set by an input operation to the operation unit 16 by the user.

  In the D-mode image 103, the first axis (for example, the horizontal axis) is time, and the second axis (for example, the vertical axis) orthogonal to the first axis is a Doppler shift frequency or a physical quantity (for example, blood) correlated with the Doppler shift frequency. Hereinafter, both are collectively referred to as “Doppler shift frequency, etc.”), and the physical quantity correlating with the power or power of the Doppler spectrum in luminance (hereinafter, both are collectively referred to as “power, etc.”). It is an image showing. For example, the luminance increases as the power of the Doppler spectrum increases. In FIG. 2, a region with low luminance is hatched.

  Correspondence between the size of the D-mode image 103, the ranges of the vertical and horizontal axes, the luminance and the power can be appropriately set by an input operation to the operation unit 16 or the like. Also, the arrangement of the D mode image 103 can be set as appropriate, for example, the D mode image 103 and the B mode image 102 are arranged in the horizontal direction.

  An example of setting will be described. In the case of a 600 (vertical) × 800 (horizontal) pixel CRT display, the size of the D-mode image 103 may be set to 300 (vertical) × 600 (horizontal) to 600 (vertical) × 300 (horizontal) pixels. . The D-mode image 103 may be set to landscape display such as 200 (vertical) × 600 (horizontal) pixels, 300 (vertical) × 600 (horizontal) pixels, 400 (vertical) × 600 (horizontal) pixels, It may be set to a vertically long display such as 600 (vertical) × 300 (horizontal) pixels. In addition, in the case where the display size (inch) is different or in the case of a liquid crystal display, the difference in the basic number of dots from the 600 (vertical) × 800 (horizontal) pixel CRT display is taken into account or not. May be set appropriately. The range of the horizontal axis of the D mode image 103 may be set to 1.0 to 16.0 (s), and the range of the vertical axis may be set to 10 to 100 (cm / s). As the luminance, 0 to 63 gradations (6 bits) may be assigned to a voltage (power) obtained by converting sound pressure into an electrical signal. The ultrasonic diagnostic apparatus 1 performs preamplifier amplification, digital conversion, compression, filtering, and the like on a voltage of several volts obtained by converting sound pressure into an electrical signal, and finally sets a luminance value of 0 to 63. It has gained. That is, by assigning a predetermined range of luminance values to a predetermined range of voltage, the predetermined range of luminance values is indirectly assigned to the predetermined range of power.

  FIG. 3 is a diagram for explaining the operation of the data processing unit 13. Note that FIG. 3 is for conceptually explaining the operation of the data processing unit 13, and the number of data points illustrated in FIG. 3 is merely for convenience in drawing.

  First, an operation similar to the conventional one in the data processing unit 13 will be described. As shown in FIG. 3, the time-series data generating unit 19 generates time-series data D0 including a plurality (15 illustrated in FIG. 3) of time data DC. The sampling period (time interval) T1 of the plurality of time point data DC is the reciprocal of the repetition frequency and is constant. The repetition frequency depends on the sampling position, but is, for example, 100 to 10 kHz.

  The spectrum data generation unit 20 performs Fourier transform on the time series data DA1 of which the number of data points (the number of time point data DC) in the time series data D0 is N1 (six examples are illustrated in FIG. 3). Doppler spectrum data based on DA1 is generated. Similarly, time-series data DA2, DA3 (hereinafter simply referred to as “time-series data DA”), which is different in time position from time-series data DA1 and has N1 data points, may not be distinguished. .) Are sequentially subjected to Fourier transform to generate a plurality of Doppler spectrum data.

  That is, the spectrum data generation unit 20 performs Fourier transform on the time-series data in the predetermined time range T2 to generate Doppler spectrum data by shifting the predetermined time range T2 by a predetermined time and a plurality of times. Generate Doppler spectral data. The predetermined time range T2 is sampling period T1 × number of data points.

  In addition to the above-described conventional operation, the spectrum data generation unit 20 uses time-series data DB1 to DB3 (hereinafter, four data points N2 are different from the data point N1 of the time-series data DA). Simply referred to as “time-series data DB”, DB1 to DB3 may not be distinguished.) Fourier transform is sequentially performed to generate a plurality of Doppler spectrum data.

  That is, the spectrum data generation unit 20 performs Fourier transform on the time series data of a predetermined number of data points out of the time series data of the predetermined time range T2 to generate Doppler spectrum data a plurality of times with different data points. (In the embodiment, the number of data points is N1 and N2 is twice), and multiple types (two types in the embodiment) of Doppler spectrum data are generated.

  The time series data DB is composed of all the time point data DC in a part of the time range in the time series data DA, and the sampling period of the time series data DA and the sampling period of the time series data DB are the same (T1). It is. Further, the time series data DB is set to a partial time range in the center of the time series data DA, and the time center Tac of the time series data DA and the time center Tbc of the time series data DB coincide with each other. .

  For example, N1 = 60 to 90 and N2 = 30 to 36.

  FIG. 4 is a conceptual diagram illustrating the operation of the image processing unit 14. As described above, two types of Doppler spectrum data are generated by the spectrum data generation unit 20. Therefore, the image processing unit 14 based on the two types of Doppler spectrum data, the D-mode image 103A (FIG. 4A) in the case of N1 data points and the D-mode image 103B in the case of N2 data points (FIG. 4). (B)) and two types of D-mode image data can be generated. Here, as described above, the spot 501 is generated in the D-mode image 103A having a relatively large number of data points. In the D-mode image 103B having a relatively small number of data points, vertical stripes 502 are generated.

  Therefore, the image processing unit 14 generates image data of a combined D-mode image 103C (FIG. 4C) obtained by combining the D-mode image 103A and the D-mode image 103B. Thereby, a high-quality D-mode image in which the spots 501 and the vertical stripes 502 are reduced is obtained.

  The synthesis may be performed by various methods. Further, the synthesis method may be selectable from various synthesis methods by operating the operation unit 16 or the like. For example, an image in which luminance is averaged between pixels corresponding to each other in the D-mode image 103A and the D-mode image 103B may be used as the combined D-mode image 103C. Pixels corresponding to each other are pixels having the same time (horizontal axis), Doppler shift frequency and the like (vertical axis).

  That is, as shown by hatching in FIG. 4, the pixel PA at the time point t1 and the Doppler shift frequency etc. f1 in the D-mode image 103A, and the pixel PB at the time point t1 and the Doppler shift frequency etc. f1 in the D-mode image 103B. Corresponding to each other, the average of the luminances of these pixels PA and PB may be combined so as to be the luminance of the pixel PC at f1 such as the time point t1 and the Doppler shift frequency in the combined D-mode image 103C.

  In addition, for example, an image in which the higher luminance (the maximum luminance when there are three or more D-mode images to be combined) is selected between the corresponding pixels of the D-mode image 103A and the D-mode image 103B. May be the composite D-mode image 103C.

  Further, the synthesis may be performed on the entire D-mode image, or may be performed only on a partial region of the D-mode image. For example, the D mode image 103B may be synthesized only in the region 505 where the spot 501 occurs in the D mode image 103A, or the D mode image 103A may be synthesized only in the region 506 where the vertical streak 502 occurs in the D mode image 103B. Good. In the synthesis in this case, the average luminance or the high luminance may be selected for each pixel as described above.

  When various combinations as described above are performed, for example, in a D-mode image 103B having a small number of data points, when a portion having a low signal intensity is continuous in the vertical direction (there is a vertical line), the portion has the number of data points. Luminance increases due to averaging and replacement with many D-mode images 103A, and vertical stripes become inconspicuous. The same applies to spots. Then, the two images compensate for each other's drawbacks, whereby a high-quality D-mode image 103C is obtained.

  FIG. 5 is a flowchart for explaining an example of a procedure for generating a D-mode image of the ultrasonic diagnostic apparatus 1. Specifically, an example of the operation of the spectrum data generation unit 20 (steps S1 to S5) and the operation of the image processing unit 14 (steps S6 to S10) when the D-mode image 103 is displayed in real time is shown.

  The ultrasonic diagnostic apparatus 1 determines whether or not the time series data generation unit 19 newly generates the time series data DA having the data point N1 (step S1), and the time series data DA having the data point N1 is newly generated. If it is determined that the time series data DA of the data point number N1 is multiplied by a window function (step S2), the time series data DA of the data point number N1 is Fourier transformed to generate Doppler spectrum data (step S3).

  The window function reduces an error caused by performing Fourier transform on time series data cut out in a finite interval. As the window function, a known appropriate one such as a rectangular window, a Hanning window, a Hamming window, or a Gaussian window may be selected. In general, a window function other than a rectangular window is a function whose variable is the order along the time axis of the time point data DC, and the function value (time series data is multiplied) near the center (time center) of the finite interval. Weight) is maximized.

  Next, as in steps S2 and S3, the ultrasound diagnostic apparatus 1 multiplies the time series data DB with the number of data points N2 by a window function (step S4), Fourier transforms the time series data DB with the number of data points N2, and performs Doppler. Spectral data is generated (step S5). Note that the window function used in step S4 is the same as the window function used in step S2. However, different window functions may be used.

  Thereafter, the ultrasonic diagnostic apparatus 1 determines whether it is time to generate image data (step S6). For example, it is determined whether or not the acquisition of the time series data DA has been performed a predetermined number of times and whether or not it is time to update the screen at a predetermined frame rate. If it is determined that the image data generation time has not arrived, the process returns to step S1. If it is determined that the image data generation time has arrived, areas (for example, areas 505 and 506) where the D-mode image 103A and the D-mode image 103B are to be combined are detected (step S7). Note that step S7 is omitted when the entire image is synthesized.

  The detection of the regions 505 and 506 is performed by, for example, the power of each Doppler shift frequency of the Doppler spectrum data and the corresponding Doppler shifts of one to a plurality of Doppler spectrum data temporally before and after the Doppler spectrum data. Compared with power such as frequency and the like, and when there is a sudden change, it is determined that there are spots 501 or vertical stripes 502, or the generated Doppler spectrum data and a predetermined size prepared in advance This is performed by performing pattern matching with the reference Doppler spectrum when the spot 501 or the vertical streak 502 occurs.

  In step S8, the ultrasonic diagnostic apparatus synthesizes the spectrum data obtained by Fourier transforming the time series data having the data points N1 and the spectrum data obtained by performing the Fourier transform on the time series data having the data points N2. That is, two types of power such as the same time and Doppler frequency are averaged, or one of the two types of power is selected to obtain combined Doppler spectrum data. In the case of performing synthesis only for the detected synthesis region 505 or 506, in one data of the two Doppler spectrum data, the other data is synthesized only for the data corresponding to the synthesis region to obtain synthesized Doppler spectrum data. .

  In step S10, the ultrasound diagnostic apparatus generates image data of the combined D-mode image 103C based on the combined Doppler spectrum data (step S9), and outputs and displays a video signal based on the generated image data on the display unit 15. The screen of the unit 15 is updated (step S10).

  According to the above embodiment, the Fourier transform is performed on the time series data DA having the data points N1 and the time series data DB having the data points N2, and two types of Doppler spectrum data are generated, and the two types of Doppler spectrum data are converted into the two types of Doppler spectrum data. Since the image data of the composite D-mode image 103C obtained by combining the two types of D-mode images 103A and 103B based on it is generated, out of the spots 501 generated when the number of data points is large and the vertical stripe 502 generated when the number of data points is small At least one of them is reduced and the image quality is improved.

  For example, when the synthesized D-mode image 103C is an image in which the luminance is averaged between pixels corresponding to each other in the D-mode images 103A and 103B, both the spots 501 and the vertical stripes 502 are reduced.

  For example, if the composite D-mode image 103C is an image in which the maximum luminance is selected between the corresponding pixels of the D-mode images 103A and 103B, the spots 501 are well filled, giving the user a good impression of sensitivity. be able to.

  For example, if the synthesized D-mode image 103C is image data obtained by synthesizing another image in a predetermined region of any one of the D-mode images 103A and 103B, only the portion that causes a reduction in image quality. Can effectively improve the image quality.

  The time series data DB is all the time series data in a part of the time range of the time series data DA, and the sampling period of the time series data DA of the time series data DA and the sampling period of the time series data DB are the same. is there. Accordingly, the sampling frequency and the maximum frequency of the two types of generated Doppler spectra are the same, and the Doppler spectrum data having a small number of data points is obtained by deleting the low frequency data from the Doppler spectrum data having a large number of data points. become. Therefore, it becomes easy to specify data points (power, etc.) having the same Doppler shift frequency in the two types of Doppler spectra, and the synthesis algorithm is simplified.

  Before the Fourier transform, the time series data DA and DB are multiplied by a window function, and the time series data DB is selected so that the time center of the time series data DA and the time center of the time series data DB coincide. . On the other hand, as described above, the window function generally has a large value near the center. Accordingly, the window function multiplied by the time series data DA and the window function multiplied by the time series data DB substantially coincide with each other at the peak time. As a result, the error between the two Doppler spectra due to the influence of the window function is reduced, and generation of new noise due to synthesis is suppressed.

  In the above embodiment, the image processing unit 14 is an example of the image generation unit of the present invention, and the combination of the data processing unit 13, the image processing unit 14, and the display unit 15 is an example of the image display device of the present invention. .

  The present invention is not limited to the above embodiment, and may be implemented in various aspects.

  The ultrasonic diagnostic apparatus may be any apparatus that can obtain time-series data contributing to the D-mode image, and is not limited to an apparatus that obtains time-series data by the pulse Doppler method. For example, time series data may be obtained by a continuous Doppler method.

  The generation of the image data of the combined D-mode image obtained by combining the plurality of types of D-mode images based on the plurality of types of Doppler spectrum data is sufficient if the image data of the combined D-mode image is generated as a result. Thus, it is not limited to what is performed by combining a plurality of types of Doppler spectrum data and then generating image data. For example, a plurality of D-mode image data may be generated based on each of a plurality of types of Doppler spectrum data, and the combined D-mode image data may be generated by combining the plurality of D-mode image data. . In such a case, the image generation unit may detect pixels having the same coordinates in a plurality of types of D-mode images as corresponding pixels. Even in this case, the time of each pixel, the Doppler shift frequency, and the like still correspond. The same applies when the number of pixels does not match the number of data due to the enlargement / reduction of the D-mode image.

  The composition is not limited to the one that averages and selects the luminance (power, etc.) of a plurality of D-mode images for each pixel. For example, a predetermined area of one image may be replaced with a corresponding area of another image. You may compare and select a brightness | luminance for every time or a Doppler shift frequency etc. to which a some D mode image mutually respond | corresponds. The luminance of pixels corresponding to each other in three or more types of D-mode images may be multiplied by a weighting factor and added. When combining is performed only in a predetermined region, the predetermined region is not limited to that detected by the ultrasonic diagnostic apparatus as in the embodiment, and may be set by the user.

  The time-series data having different data points is not limited to that shown in FIG. 3 as long as Fourier transform for a predetermined time range is sequentially performed while shifting the predetermined time range.

  For example, as shown in FIG. 6A, a predetermined time range T21 (time series data DA11 to DA14 having a large number of data points) may partially overlap each other. Furthermore, although not shown, the time series data DB11 to DB14 with a small number of data points may partially overlap each other. Conversely, as shown in FIG. 6B, the predetermined time range T21 (time series data DA21 to DA23 having a large number of data points) may be separated from each other. Note that the predetermined time range and the time range of the time-series data having the largest number of data points in the predetermined time range do not have to coincide with each other.

  Further, for example, as shown in FIG. 6C, the time center Tac of the time series data DA1 to DA3 having a large number of data points coincides with the time center Tbc ′ of the time series data DB31 to DB33 having a small number of data points. It does not have to be.

  Further, for example, as shown in FIG. 6D, the sampling period T1 of the time series data DA1 to DA3 having a large number of data points and the sampling period T3 of the time series data DB41 to DB43 having a small number of data points (shown by hatching). Only the time-series data DB41 to DB43) may not coincide with each other.

The block diagram which shows the principal part of the structure of the ultrasound diagnosing device which concerns on embodiment of this invention. The figure which shows an example of the image which the ultrasonic diagnostic apparatus of FIG. 2 displays. The conceptual diagram explaining operation | movement of the data processing part of the ultrasonic diagnosing device of FIG. The conceptual diagram explaining operation | movement of the image process part of the ultrasonic diagnosing device of FIG. The flowchart explaining the procedure which produces | generates D mode image of the ultrasound diagnosing device of FIG. The figure which shows the modification of the data processing method of the ultrasonic diagnosing device of FIG. The figure explaining the conventional D mode image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ultrasound diagnostic apparatus, 11 ... Probe, 19 ... Time series data generation part, 20 ... Spectral data generation part, 14 ... Image processing part, 15 ... Display part, DA, DB ... Time series data, 103C ... Composite D mode image.

Claims (16)

A probe that irradiates a subject with ultrasonic waves, converts the reflected ultrasonic waves into electrical signals, and outputs a probe;
Time-series data generating means for generating time-series data including Doppler information based on a signal from the probe;
Generating Doppler spectrum data by performing Fourier transform on the time series data in a predetermined time range among the time series data is performed a plurality of times while shifting the predetermined time range by a predetermined time, and the Doppler spectrum data at a plurality of times Spectral data generating means for generating
Image generating means for generating image data of a D-mode image based on the multiple-time Doppler spectrum data;
Display means for displaying a D-mode image based on the image data;
With
The spectrum data generation means performs Fourier transform on the time series data of a predetermined number of data points among the time series data in the predetermined time range to generate Doppler spectrum data a plurality of times with different data points. Generating a plurality of types of the Doppler spectrum data,
The ultrasonic diagnostic apparatus, wherein the image generation unit generates image data of a combined D-mode image obtained by combining a plurality of types of D-mode images based on the plurality of types of Doppler spectrum data. The ultrasonic diagnostic apparatus according to claim 1, wherein the composite D-mode image is an image in which luminance is averaged between pixels corresponding to each other of the plurality of types of D-mode images. The ultrasonic diagnostic apparatus according to claim 1, wherein the synthesized D-mode image is an image in which maximum luminance is selected between pixels corresponding to each other of the plurality of types of D-mode images. The composite D-mode image is image data obtained by combining another image in a predetermined region of any one of the plurality of types of D-mode images. Ultrasound diagnostic equipment. The predetermined region is a region where a spot of a predetermined size occurs in the one D-mode image,
The ultrasonic diagnostic apparatus according to claim 4, wherein the other image is a D-mode image based on the time-series data having a smaller number of data points than the one D-mode image. The predetermined region is a region where a line along an axis indicating a Doppler shift frequency or a physical quantity correlated with the Doppler shift frequency is generated in the one D-mode image,
The ultrasonic diagnostic apparatus according to claim 4, wherein the other image is a D-mode image based on the time-series data having more data points than the one D-mode image. The time series data having different data points in the predetermined time range is such that all of the time series data in a part of the time range among the time series data of one data point becomes time series data of other data points. The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic diagnostic apparatus is selected from time-series data in the predetermined time range. The spectrum data generation means performs a Fourier transform after multiplying the time series data having different data points by a window function having a larger value on the time center side of the time series data, and converts the plurality of types of Doppler spectrum data into Generate
The time-series data having different data points in the predetermined time range is selected from the time-series data in the predetermined time range so that the time centers of the respective time-series data are the same. The ultrasonic diagnostic apparatus according to any one of 7. Time series data generating means for generating time series data including Doppler information;
Generating Doppler spectrum data by performing Fourier transform on the time series data in a predetermined time range among the time series data is performed a plurality of times while shifting the predetermined time range by a predetermined time, and the Doppler spectrum data at a plurality of times Spectral data generating means for generating
Image generating means for generating image data of a D-mode image based on the multiple-time Doppler spectrum data;
Display means for displaying a D-mode image based on the image data;
With
The spectrum data generation means performs Fourier transform on the time series data of a predetermined number of data points among the time series data in the predetermined time range to generate Doppler spectrum data a plurality of times with different data points. Generating a plurality of types of the Doppler spectrum data,
The image generation unit generates image data of a combined D-mode image obtained by combining a plurality of types of D-mode images based on the plurality of types of Doppler spectrum data. The image display device according to claim 9, wherein the composite D-mode image is an image in which luminance is averaged between pixels corresponding to each other of the plurality of types of D-mode images. The image display device according to claim 9, wherein the composite D-mode image is an image in which maximum luminance is selected between pixels corresponding to each other of the plurality of types of D-mode images. The composite D-mode image is image data in which another image is synthesized in a predetermined region of any one of the plurality of types of D-mode images. Image display device. The predetermined region is a region where a spot of a predetermined size occurs in the one D-mode image,
The image display device according to claim 12, wherein the other image is a D-mode image based on the time-series data having a smaller number of data points than the one D-mode image. The predetermined region is a region where a line along an axis indicating a Doppler shift frequency or a physical quantity correlated with the Doppler shift frequency is generated in the one D-mode image,
The image display device according to claim 12, wherein the other image is a D-mode image based on the time-series data having a larger number of data points than the one D-mode image. The time series data having different data points in the predetermined time range is such that all of the time series data in a part of the time range among the time series data of one data point becomes time series data of other data points. The image display device according to claim 9, wherein the image display device is selected from time-series data in the predetermined time range. The spectrum data generation means performs a Fourier transform after multiplying the time series data having different data points by a window function having a larger value on the time center side of the time series data, and converts the plurality of types of Doppler spectrum data into Generate
The time-series data having different data points in the predetermined time range is selected from the time-series data in the predetermined time range so that the time centers of the time-series data are the same. The image display device according to any one of 15.

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