JP6567122B2 - Ultrasonic diagnostic apparatus, control method, apparatus and program - Google Patents

Description

Embodiments described herein relate generally to an ultrasonic diagnostic apparatus , a control method , an apparatus, and a program .

  2. Description of the Related Art Conventionally, in ultrasonic image diagnosis, a method for imaging an image showing moving body information (for example, a blood flow image such as a color Doppler image) at a high frame rate is known. Conventionally, in ultrasonic image diagnosis, for example, a tissue image (B-mode image) and a blood flow image are simultaneously displayed.

  However, when a B-mode image and a blood flow image are simultaneously displayed by the conventional method, a B-mode scan is not performed in order to display a high-sensitivity blood flow image with low noise at a high frame rate. In addition, it is necessary to generate and display a B-mode image from a received signal for acquiring blood flow information. For this reason, for example, the image quality of the tissue image may deteriorate due to the reason that the received signal is saturated, the scanning line density is low, or the tissue harmonic imaging cannot be performed.

Japanese Patent No. 3724846 JP 2011-254862 A

  The problem to be solved by the present invention is to provide an ultrasonic diagnostic apparatus and a control method capable of improving the image quality of an image showing moving body information displayed simultaneously and a tissue image.

The ultrasonic diagnostic apparatus according to the embodiment includes an ultrasonic probe and a control unit. The ultrasonic probe transmits and receives ultrasonic waves. The control unit causes the ultrasonic probe to execute a first ultrasonic scan for acquiring information relating to the motion of the moving body within the first scan range, and acquires a tissue shape information within the second scan range. As the scan, the ultrasonic probe of each of the plurality of divided ranges obtained by dividing the second scan range is executed by the ultrasonic probe in a time division manner during the first ultrasonic scan. The control unit performs ultrasonic scanning based on a method of performing high-pass filter processing on a reception signal acquired by each of a plurality of scanning lines forming the first scanning range in a frame direction to acquire information on the motion of the moving body. the first is performed as ultrasonic scanning, prior SL according to the display frame rate of the generated frame rate and the display unit of the image data of the first scanning range produced by the first ultrasonic scanning, the first ultrasonic as the output frame rate of the image data of the first scanning range produced by the scanning is less than the display frame rate, adding a plurality of image data of said first scanning range generated by the first ultrasonic scanning Control is performed so that the averaged and averaged image data is output as image data in the first scanning range .

FIG. 1 is a block diagram illustrating a configuration example of the ultrasonic diagnostic apparatus according to the first embodiment. FIG. 2 is a diagram illustrating an example of processing performed by the B-mode processing unit. FIG. 3 is a block diagram illustrating a configuration example of the Doppler processing unit illustrated in FIG. 1. FIG. 4 is a diagram for explaining wall filter processing performed by the high frame rate method. FIG. 5A is a diagram (1) for explaining an example of the conventional method. FIG. 5B is a diagram (2) for explaining an example of the conventional method. FIG. 6 is a diagram illustrating an example of a problem of the conventional method. FIG. 7 is a diagram (1) for explaining the control unit according to the first embodiment. FIG. 8 is a diagram (2) for explaining the control unit according to the first embodiment. FIG. 9A is a diagram (1) illustrating an example of a display form according to the first embodiment. FIG. 9B is a diagram (2) illustrating an example of a display form according to the first embodiment. FIG. 10 is a flowchart for explaining an example of the ultrasonic scanning control process of the ultrasonic diagnostic apparatus according to the first embodiment. FIG. 11 is a diagram for explaining the second embodiment. FIG. 12 is a flowchart for explaining an example of output control processing of the ultrasonic diagnostic apparatus according to the second embodiment. FIG. 13A is a diagram (1) for explaining the third embodiment. FIG. 13B is a diagram (2) for explaining the third embodiment. FIG. 14A is a diagram (1) for explaining the fourth embodiment. FIG. 14B is a diagram (2) for explaining the fourth embodiment. FIG. 15 is a diagram (1) for explaining the fifth embodiment. FIG. 16 is a diagram (2) for explaining the fifth embodiment. FIG. 17 is a diagram (3) for explaining the fifth embodiment.

  Hereinafter, embodiments of an ultrasonic diagnostic apparatus will be described in detail with reference to the accompanying drawings.

(First embodiment)
First, the configuration of the ultrasonic diagnostic apparatus according to the first embodiment will be described. FIG. 1 is a block diagram illustrating a configuration example of the ultrasonic diagnostic apparatus according to the first embodiment. As illustrated in FIG. 1, the ultrasonic diagnostic apparatus according to the first embodiment includes an ultrasonic probe 1, a monitor 2, an input device 3, and an apparatus main body 10.

  The ultrasonic probe 1 is connected to the apparatus main body 10 in order to transmit and receive ultrasonic waves. The ultrasonic probe 1 includes, for example, a plurality of piezoelectric vibrators, and the plurality of piezoelectric vibrators generate ultrasonic waves based on a drive signal supplied from a transmission / reception unit 11 included in the apparatus main body 10 described later. The plurality of piezoelectric vibrators included in the ultrasonic probe 1 receives reflected waves from the subject P and converts them into electrical signals. The ultrasonic probe 1 includes a matching layer provided in the piezoelectric vibrator, a backing material that prevents propagation of ultrasonic waves from the piezoelectric vibrator to the rear, and the like. The ultrasonic probe 1 is detachably connected to the apparatus main body 10.

  When ultrasonic waves are transmitted from the ultrasonic probe 1 to the subject P, the transmitted ultrasonic waves are reflected one after another at the discontinuous surface of the acoustic impedance in the body tissue of the subject P, and the ultrasonic probe is used as a reflected wave signal. 1 is received by a plurality of piezoelectric vibrators. The amplitude of the received reflected wave signal depends on the difference in acoustic impedance at the discontinuous surface where the ultrasonic wave is reflected. Note that the reflected wave signal when the transmitted ultrasonic pulse is reflected by the moving blood flow or the surface of the heart wall depends on the velocity component of the moving object in the ultrasonic transmission direction due to the Doppler effect. And undergoes a frequency shift.

  In the first embodiment, even if the ultrasonic probe 1 is a 1D array probe that scans the subject P in two dimensions, the ultrasonic probe 1 is a mechanical 4D probe or 2D array probe that scans the subject P in three dimensions. Is applicable.

  The input device 3 includes a mouse, a keyboard, a button, a panel switch, a touch command screen, a foot switch, a trackball, a joystick, and the like. The input device 3 accepts various setting requests from an operator of the ultrasonic diagnostic apparatus, and transfers the accepted various setting requests to the apparatus main body 10.

  The monitor 2 displays a GUI (Graphical User Interface) for an operator of the ultrasonic diagnostic apparatus to input various setting requests using the input device 3, and displays ultrasonic image data generated in the apparatus main body 10. Or display.

  The apparatus main body 10 is an apparatus that generates ultrasonic image data based on a reflected wave signal received by the ultrasonic probe 1. The apparatus main body 10 shown in FIG. 1 can generate two-dimensional ultrasound image data based on a two-dimensional reflected wave signal, and can generate three-dimensional ultrasound image data based on a three-dimensional reflected wave signal. Device. However, the first embodiment is applicable even when the apparatus main body 10 is an apparatus dedicated to two-dimensional data.

  As illustrated in FIG. 1, the apparatus body 10 includes a transmission / reception unit 11, a buffer 12, a B-mode processing unit 13, a Doppler processing unit 14, an image generation unit 15, an image memory 16, and an internal storage unit 17. And a control unit 18.

  The transmission / reception unit 11 controls ultrasonic transmission / reception performed by the ultrasonic probe 1 based on an instruction from the control unit 18 described later. The transmission / reception unit 11 includes a pulse generator, a transmission delay circuit, a pulser, and the like, and supplies a drive signal to the ultrasonic probe 1. The pulse generator repeatedly generates a rate pulse for forming a transmission ultrasonic wave at a predetermined repetition frequency (PRF: Pulse Repetition Frequency). Further, the transmission delay circuit generates a delay time for each piezoelectric vibrator necessary for focusing the ultrasonic wave generated from the ultrasonic probe 1 into a beam and determining transmission directivity. Give for each rate pulse. The pulser applies a drive signal (drive pulse) to the ultrasonic probe 1 at a timing based on the rate pulse. That is, the transmission delay circuit arbitrarily adjusts the transmission direction of the ultrasonic wave transmitted from the piezoelectric vibrator surface by changing the delay time given to each rate pulse.

  The transmission / reception unit 11 has a function capable of instantaneously changing a transmission frequency, a transmission drive voltage, and the like in order to execute a predetermined scan sequence based on an instruction from the control unit 18 described later. In particular, the change of the transmission drive voltage is realized by a linear amplifier type transmission circuit capable of instantaneously switching the value or a mechanism for electrically switching a plurality of power supply units.

  The transmission / reception unit 11 includes an amplifier circuit, an A / D (Analog / Digital) converter, a reception delay circuit, an adder, a quadrature detection circuit, and the like. Various types of reflected wave signals received by the ultrasonic probe 1 are used. Processing is performed to generate reflected wave data. The amplifier circuit amplifies the reflected wave signal for each channel and performs gain correction processing. The A / D converter A / D converts the reflected wave signal whose gain is corrected. The reception delay circuit gives a reception delay time necessary for determining the reception directivity to the digital data. The adder performs addition processing of the reflected wave signal given the reception delay time by the reception delay circuit. By the addition processing of the adder, the reflection component from the direction corresponding to the reception directivity of the reflected wave signal is emphasized.

  Then, the quadrature detection circuit converts the output signal of the adder into a baseband in-phase signal (I signal, I: In-pahse) and a quadrature signal (Q signal, Q: Quadrature-phase). Then, the quadrature detection circuit stores the I signal and the Q signal (hereinafter referred to as IQ signal) in the buffer 12 as reflected wave data. The quadrature detection circuit may convert the output signal of the adder into an RF (Radio Frequency) signal and store it in the buffer 12. The IQ signal and the RF signal are signals (reception signals) including phase information. Hereinafter, the reflected wave data output from the transmission / reception unit 11 may be referred to as a reception signal.

  The transmitter / receiver 11 transmits a two-dimensional ultrasonic beam from the ultrasonic probe 1 when the subject P is two-dimensionally scanned. Then, the transmission / reception unit 11 generates two-dimensional reflected wave data from the two-dimensional reflected wave signal received by the ultrasonic probe 1. In addition, when the subject P is three-dimensionally scanned, the transmission / reception unit 11 transmits a three-dimensional ultrasonic beam from the ultrasonic probe 1. Then, the transmission / reception unit 11 generates three-dimensional reflected wave data from the three-dimensional reflected wave signal received by the ultrasonic probe 1.

  Further, the transmission / reception unit 11 can generate reflected wave data of a plurality of reception focus from the reflected wave signal of each piezoelectric vibrator obtained by one transmission of the ultrasonic beam. That is, the transmission / reception unit 11 is a circuit capable of performing parallel simultaneous reception processing. The first embodiment is applicable even when the transmission / reception unit 11 cannot execute the parallel simultaneous reception process.

  The buffer 12 is a buffer that temporarily stores the reflected wave data (IQ signal) generated by the transmission / reception unit 11. Specifically, the buffer 12 stores IQ signals for several frames or IQ signals for several volumes. For example, the buffer 12 is a first-in / first-out (FIFO) memory, and stores IQ signals for a predetermined frame. For example, when a new IQ signal for one frame is generated in the transmission / reception unit 11, the buffer 12 discards the IQ signal for one frame with the oldest generation time and newly generates one frame. The minute I / Q signal is stored.

  The B-mode processing unit 13 and the Doppler processing unit 14 are signal processing units that perform various types of signal processing on the reflected wave data generated from the reflected wave signal by the transmission / reception unit 11. FIG. 2 is a diagram illustrating an example of processing performed by the B-mode processing unit. As illustrated in FIG. 2, the B-mode processing unit 13 performs logarithmic amplification, envelope detection processing, logarithmic compression, and the like on the reflected wave data (IQ signal) read from the buffer 12, thereby generating a multipoint signal. Data (B mode data) whose intensity is expressed by brightness is generated.

  The B-mode processing unit 13 can change the frequency band to be visualized by changing the detection frequency by filtering. By using the filter processing function of the B-mode processing unit 13, harmonic imaging such as contrast harmonic imaging (CHI) and tissue harmonic imaging (THI) can be performed. That is, the B-mode processing unit 13 uses reflected wave data (harmonic data or frequency division) of harmonic components using a contrast medium (microbubbles, bubbles) as a reflection source from the reflected wave data of the subject P into which the contrast medium has been injected. Data) and the reflected wave data (fundamental wave data) of the fundamental wave component using the tissue in the subject P as a reflection source can be separated. The B-mode processing unit 13 can generate B-mode data for generating contrast image data from the reflected wave data (reception signal) of the harmonic component.

  Further, by using the filter processing function of the B-mode processing unit 13, the reflected wave data (received signal) of the harmonic component from the reflected wave data of the subject P in tissue harmonic imaging (THI). Harmonic data or split frequency data can be separated. The B-mode processing unit 13 can generate B-mode data for generating tissue image data from which noise components are removed from the reflected wave data (reception signal) of the harmonic component.

  In addition, when performing CHI or THI harmonic imaging, the B-mode processing unit 13 can extract harmonic components by a method different from the method using the filter processing described above. In harmonic imaging, an imaging method called an AMPM method combining an amplitude modulation (AM) method, a phase modulation (PM) method, an AM method, and a PM method is performed. In the AM method, PM method, and AMPM method, ultrasonic transmission with different amplitudes and phases is performed a plurality of times for the same scanning line. Thereby, the transmission / reception unit 11 generates and outputs a plurality of reflected wave data (reception signals) on each scanning line. The B-mode processing unit 13 extracts harmonic components by performing addition / subtraction processing on the plurality of reflected wave data (reception signals) of each scanning line in accordance with the modulation method. Then, the B-mode processing unit 13 performs envelope detection processing or the like on the reflected wave data (received signal) of the harmonic component, and generates B-mode data.

  For example, when the PM method is performed, the transmission / reception unit 11 scans each scan with ultrasonic waves having the same amplitude with the phase polarity reversed, for example (−1, 1), according to the scan sequence set by the control unit 18. Send twice on the line. Then, the transmission / reception unit 11 generates a reception signal by transmission of “−1” and a reception signal by transmission of “1”, and the B-mode processing unit 13 adds these two reception signals. Thereby, the fundamental wave component is removed, and a signal in which the second harmonic component mainly remains is generated. The B-mode processing unit 13 performs envelope detection processing or the like on the signal to generate THI B-mode data or CHI B-mode data.

  Alternatively, for example, in THI, a method of performing imaging using a second harmonic component and a difference sound component included in a received signal has been put into practical use. In the imaging method using the difference sound component, for example, transmission of a synthesized waveform obtained by synthesizing a first fundamental wave having a center frequency “f1” and a second fundamental wave having a center frequency “f2” greater than “f1”. Ultrasonic waves are transmitted from the ultrasonic probe 1. This synthesized waveform is a waveform obtained by synthesizing the waveform of the first fundamental wave and the waveform of the second fundamental wave whose phases are adjusted so that a differential sound component having the same polarity as the second harmonic component is generated. It is. The transmission unit 11 transmits, for example, twice the transmission ultrasonic wave having the composite waveform while inverting the phase. In such a case, for example, the B-mode processing unit 13 adds the two received signals, thereby removing the fundamental component and extracting the harmonic component in which the difference sound component and the second harmonic component mainly remain, Envelope detection processing is performed.

  Returning to FIG. 1, the Doppler processing unit 14 performs frequency analysis on the reflected wave data read from the buffer 12 to extract data (Doppler data) obtained by extracting motion information based on the Doppler effect of the moving body within the scanning range. Generate. Specifically, the Doppler processing unit 14 generates Doppler data obtained by extracting the average speed, the variance value, the power value, and the like over multiple points as the motion information of the moving object. Here, the moving body is, for example, a blood flow, a tissue such as a heart wall, or a contrast agent.

  Using the function of the Doppler processing unit 14 that can extract the motion information of the moving body, the ultrasonic diagnostic apparatus according to the present embodiment is a color Doppler method called color flow mapping (CFM) or tissue Doppler. TDI (Tissue Doppler Imaging) can be performed. In addition, the ultrasound diagnostic apparatus according to the present embodiment can also perform elastography using the function of the Doppler processing unit 14. In the color Doppler mode, the Doppler processing unit 14 extracts color Doppler data obtained by extracting an average velocity, a variance value, and a power value over multiple points in a two-dimensional space or a three-dimensional space as motion information of a blood flow that is a moving body. Generate.

  In the tissue Doppler mode, the Doppler processing unit 14 generates tissue Doppler data in which the average velocity, variance value, and power value are extracted over multiple points in a two-dimensional space or a three-dimensional space as motion information of a tissue that is a moving body. To do. In the elast mode, the Doppler processing unit 14 obtains the displacement by time-integrating the velocity distribution information obtained from the tissue Doppler data. And the Doppler process part 14 calculates | requires the local distortion | strain (strain: strain) of a structure | tissue by performing predetermined calculation (for example, spatial differentiation) with respect to the calculated | required displacement. Then, the Doppler processing unit 14 generates strain distribution information by color-coding the local strain value of the tissue. Since the hard tissue is harder to be deformed, the strain value of the hard tissue becomes smaller and the strain value of the soft biological tissue becomes larger. That is, the strain value is a value indicating the hardness (elastic modulus) of the tissue. In the elast mode, for example, when the operator manually shakes the ultrasonic probe 1 in contact with the body surface, the tissue is compressed and released to deform the tissue. Alternatively, in the elast mode, for example, a force is applied by acoustic radiation pressure to deform the tissue.

  Here, the B-mode processing unit 13 and the Doppler processing unit 14 illustrated in FIG. 1 can process both two-dimensional reflected wave data and three-dimensional reflected wave data. That is, the B-mode processing unit 13 generates two-dimensional B-mode data from the two-dimensional reflected wave data, and generates three-dimensional B-mode data from the three-dimensional reflected wave data. The Doppler processing unit 14 generates two-dimensional Doppler data from the two-dimensional reflected wave data, and generates three-dimensional Doppler data from the three-dimensional reflected wave data. In the present embodiment, the ultrasonic scanning performed in the Doppler mode and the elast mode and the processing performed by the Doppler processing unit 14 will be described in detail later.

  The image generation unit 15 generates ultrasonic image data from the data generated by the B mode processing unit 13 and the Doppler processing unit 14. The image generation unit 15 generates two-dimensional B-mode image data in which the intensity of the reflected wave is expressed by luminance from the two-dimensional B-mode data generated by the B-mode processing unit 13. The image generation unit 15 also generates two-dimensional Doppler image data representing moving body information from the two-dimensional Doppler data generated by the Doppler processing unit 14. The two-dimensional Doppler image data is velocity image data, distributed image data, power image data, or image data obtained by combining these.

  Here, the image generation unit 15 generally converts (scan converts) a scanning line signal sequence of ultrasonic scanning into a scanning line signal sequence of a video format represented by a television or the like, and displays ultrasonic waves for display. Generate image data. Specifically, the image generation unit 15 generates ultrasonic image data for display by performing coordinate conversion in accordance with the ultrasonic scanning mode of the ultrasonic probe 1. In addition to scan conversion, the image generation unit 15 performs various image processing, such as image processing (smoothing processing) for regenerating an average value image of luminance using a plurality of image frames after scan conversion, for example. Then, image processing (edge enhancement processing) using a differential filter is performed in the image. Further, the image generation unit 15 synthesizes character information, scales, body marks, and the like of various parameters with the ultrasonic image data.

  That is, the B mode data and the Doppler data are ultrasonic image data before the scan conversion process, and the data generated by the image generation unit 15 is display ultrasonic image data after the scan conversion process. The B-mode data and the Doppler data are also called raw data (Raw Data). The image generation unit 15 generates two-dimensional ultrasonic image data for display from the two-dimensional ultrasonic image data before the scan conversion process.

  Further, the image generating unit 15 generates three-dimensional B-mode image data by performing coordinate conversion on the three-dimensional B-mode data generated by the B-mode processing unit 13. In addition, the image generation unit 15 generates three-dimensional Doppler image data by performing coordinate conversion on the three-dimensional Doppler data generated by the Doppler processing unit 14. The image generation unit 15 generates “3D B-mode image data or 3D Doppler image data” as “3D ultrasonic image data (volume data)”.

  Further, the image generation unit 15 performs a rendering process on the volume data in order to generate various two-dimensional image data for displaying the volume data on the monitor 2. The rendering process performed by the image generation unit 15 includes, for example, a process of generating MPR image data from volume data by performing a cross-section reconstruction method (MPR: Multi Planer Reconstruction). The rendering process performed by the image generation unit 15 includes, for example, a volume rendering (VR) process that generates two-dimensional image data reflecting three-dimensional information.

  The image memory 16 is a memory for storing image data for display generated by the image generation unit 15. The image memory 16 can also store data generated by the B-mode processing unit 13 and the Doppler processing unit 14. The B-mode data and Doppler data stored in the image memory 16 can be called by an operator after diagnosis, for example, and become ultrasonic image data for display via the image generation unit 15. The image memory 16 can also store the reflected wave data output from the transmission / reception unit 11.

  The internal storage unit 17 stores various data such as a control program for performing ultrasonic transmission / reception, image processing and display processing, diagnostic information (for example, patient ID, doctor's findings, etc.), diagnostic protocol, and various body marks. To do. The internal storage unit 17 is also used for storing image data stored in the image memory 16 as necessary. The data stored in the internal storage unit 17 can be transferred to an external device via an interface (not shown). The internal storage unit 17 can also store data transferred from an external device via an interface (not shown).

  The control unit 18 controls the entire processing of the ultrasonic diagnostic apparatus. Specifically, the control unit 18 is based on various setting requests input from the operator via the input device 3 and various control programs and various data read from the internal storage unit 17. The processing of the processing unit 13, the Doppler processing unit 14, and the image generation unit 15 is controlled. Further, the control unit 18 controls the monitor 2 to display the ultrasonic image data for display stored in the image memory 16 or the internal storage unit 17.

  The transmission / reception unit 11 and the like built in the apparatus main body 10 may be configured by hardware such as an integrated circuit, but may be a program modularized in software.

  The overall configuration of the ultrasonic diagnostic apparatus according to the first embodiment has been described above. With this configuration, the ultrasonic diagnostic apparatus according to the first embodiment simultaneously displays, for example, B-mode image data that is tissue image data and color Doppler image data that is blood flow image data. In order to perform such display, the control unit 18 causes the ultrasonic probe 1 to execute a first ultrasonic scan for acquiring information related to the motion of the moving body within the first scan range. The first ultrasonic scan is, for example, an ultrasonic scan for collecting color Doppler image data in the color Doppler mode. Further, the control unit 18 causes the ultrasonic probe 1 to execute a second ultrasonic scan for acquiring information on the tissue shape in the second scan range together with the first ultrasonic scan. The second ultrasonic scanning is, for example, ultrasonic scanning for collecting B-mode image data in the B mode.

  The control unit 18 controls the ultrasonic probe 1 via the transmission / reception unit 11 to execute the first ultrasonic scanning and the second ultrasonic scanning. Note that, even if the first scanning range and the second scanning range are the same range, or the first scanning range is smaller than the second scanning range, the second scanning range is smaller than the first scanning range. There may be.

  Here, in a general color Doppler method, ultrasonic waves are transmitted a plurality of times in the same direction, and frequency analysis based on the Doppler effect is performed from the received signal to extract blood flow motion information. A data string of reflected wave signals from the same point of data irradiated multiple times in the same direction is called a packet. The packet size in the general color Doppler method is about 5 to 16, and the wall filter that suppresses the signal from the tissue (also called clutter signal) is applied to this packet to extract the signal from the bloodstream. To do. In a general color Doppler method, blood flow information such as average speed, variance, and power is displayed from the extracted signal.

  However, the general color Doppler method has the following problems. That is, in the general color Doppler method, since the packet is closed within the ultrasonic scan frame, the frame rate decreases when the packet size is increased. In general color Doppler method, an infinite impulse response type filter (IIR filter, IIR: Infinite Impulse Response) is often used as a wall filter. The characteristics of the IIR filter are deteriorated. The IIR filter is a kind of MTI (Moving Target Indicator) filter that is a high pass filter (HPF).

  In order to solve the above-mentioned problems, a method of imaging motion information of a moving body such as a blood flow at a high frame rate, that is, a high frame rate method is used. In this high frame rate method, a packet is not handled in a closed frame but a signal at the same place between frames is handled as a packet. In the high frame rate method, an ultrasonic scan similar to the B-mode scan is performed. That is, in the high frame rate method, ultrasonic transmission / reception is performed once for each of a plurality of scanning lines forming a scanning range of one frame. In the high frame rate method, the data sequence at the same position in each frame is processed in the frame direction.

  As a result, in the high frame rate method, the wall filter processing can be changed from finite-length data processing called packets to infinite-length data, and the performance of the IIR filter can be improved. Blood flow information can be displayed at the same frame rate.

  In other words, the high frame rate method has the advantage that the pulse repetition frequency (PRF) is the same as the frame rate, so that the folding speed becomes low and observation is possible up to a low flow rate.

  The Doppler processing unit 14 according to the present embodiment can execute the high frame rate method together with a general color Doppler method. Hereinafter, the Doppler processing unit 14 will be described with reference to FIGS. 3 and 4. FIG. 3 is a block diagram showing a configuration example of the Doppler processing unit shown in FIG. 1, and FIG. 4 is a diagram for explaining wall filter processing performed by the high frame rate method.

  As illustrated in FIG. 3, the Doppler processing unit 14 includes a wall filter 141, an autocorrelation calculation unit 142, an average speed / dispersion calculation unit 143, a power calculation unit 144, a power addition unit 145, and a logarithmic compression unit. 146. The Doppler processing unit 14 includes an average power calculation unit 147 and a power correction unit 148 as illustrated in FIG.

  The wall filter 141 is a processing unit that performs IIR filter processing, and is, for example, a fourth-order IIR filter. As illustrated in FIG. 4, the wall filter 141 obtains the IIR filter output data (blood flow signal) for the “n” frame, and the reflected wave data (received signal) of the “n” frame at the same position. The reflected wave data (received signal) of the past four frames (the “n−4” frame to the “n−1” frame) and the IIR filter output data (blood flow signal) of the past four frames are used. . As described above, these reflected wave data are reflected wave data generated by performing ultrasonic transmission and reception once for each of a plurality of scanning lines forming a scanning range (first scanning range) of one frame. is there. By the IIR filter processing of the wall filter 141, the blood flow signal from which the clutter signal is removed is extracted with high accuracy. In ultrasonic scanning executed by the high frame rate method, data is continuously input to the wall filter 141 with an infinite length, so that no transient response occurs in the wall filter processing.

  Returning to FIG. 3, the autocorrelation calculation unit 142 calculates an autocorrelation value by taking a complex conjugate of the IQ signal of the blood flow signal of the latest frame and the IQ signal of the blood flow signal of the previous frame. The average speed / dispersion calculator 143 calculates the average speed and variance from the autocorrelation value calculated by the autocorrelation calculator 142.

  In addition, the power calculation unit 144 calculates power by adding the square of the absolute value of the real part of the IQ signal of the blood flow signal and the square of the absolute value of the imaginary part. The power is a value indicating the intensity of scattering by a reflector (for example, blood cell) smaller than the wavelength of the transmission ultrasonic wave. The power adder 145 adds the power of each point between arbitrary frames. The logarithmic compression unit 146 logarithmically compresses the output of the power addition unit 145. Data output from the average speed / dispersion calculation unit 143 and the logarithmic compression unit 146 is output to the image generation unit 15 as Doppler data. The Doppler processing unit 14 can execute a high frame rate method and a general color Doppler method. The Doppler processing unit 14 can also generate tissue motion information in addition to blood flow motion information.

  However, in the above high frame rate method, the clutter signal tends to pass through the wall filter 141, and motion artifacts may occur. In particular, when the ultrasonic probe 1 is moved, the entire screen is displayed as clutter. Further, even in the ultrasonic scanning performed by the above-described general color Doppler method, motion artifacts occur when the folding speed is lowered.

  In order to solve this problem, the Doppler processing unit 14 includes an average power calculation unit 147 and a power correction unit 148. The average power calculation unit 147 calculates an average power value in one frame or local region from the logarithmically compressed power addition value. The power correction unit 148 performs correction processing on points (pixels) where the average power value exceeds the threshold value. Specifically, the power correction unit 148 subtracts “a value obtained by multiplying the difference value between the average power value and the threshold value by a predetermined coefficient” from the power value of the pixel whose average power value exceeds the threshold value. Thereby, the power correction unit 148 corrects the power value of the pixel whose average power value exceeds the threshold value.

  The presence or absence of the power correction process can be set by the operator. When the power correction process is being executed, the data output by the power correction unit 148 is also output to the image generation unit 15 as Doppler data. When the power correction process is being performed, the image generation unit 15 generates blood flow image data in which information on power and direction (sign of speed) is depicted, for example. Note that the present embodiment is applicable even when the power correction process is not executed.

  Here, as a conventional method for simultaneously displaying tissue image data and blood flow image data, for example, there are the following three methods. However, these three methods have various problems. This will be described with reference to FIGS. 4, 5A, 5B, and 6. FIG. 5A and 5B are diagrams for explaining an example of the conventional method, and FIG. 6 is a diagram illustrating an example of problems of the conventional method.

  As described with reference to FIG. 4, the first method is a high frame rate method in which ultrasonic transmission / reception is performed once for each of a plurality of scanning lines forming a scanning range of one frame, using the same reflected wave data. In this method, blood flow signals and tissue signals are extracted and imaged. In other words, the first method is a method for making the first ultrasonic scanning and the second ultrasonic scanning the same.

  However, the first method has the following three problems. The first problem of the first method is that it is necessary to increase the gain of the preamplifier by the amplifier circuit of the transmission / reception unit 11 in order to obtain a blood flow signal with high sensitivity. That is, when the gain is increased, the reflected wave signal from the tissue having a high reflection intensity is likely to be saturated in the subsequent processing. When the saturation occurs, the gradation of the tissue having a high reflection intensity is lowered, resulting in B-mode image data with a low contrast.

  The second problem of the first method is a problem caused by the frame rate being PRF in the first method. That is, it is necessary to increase the frame rate in order to reduce the return of the blood flow velocity. However, if the raster density is increased in order to increase the frame rate, the resolution in the azimuth direction in the B-mode image data is deteriorated. As a result, the B-mode image displayed on the monitor 2 becomes an image with a large lateral flow and reduced image quality, as illustrated in FIG.

  The third problem of the first method is that transmission / reception with a fundamental wave is indispensable in order to obtain a blood flow signal with high sensitivity. For this reason, second-order harmonics that have become mainstream in tissue observation in recent years. The B-mode image data by the received THI cannot be generated and displayed.

  As illustrated in FIG. 5A, the second method of displaying the tissue image data and the blood flow image data at the same time includes a second ultrasonic scan for collecting tissue image data (B mode image), and blood flow image data ( The first ultrasonic scanning for collecting (color Doppler images) is alternately performed separately. In the ultrasonic scanning illustrated in FIG. 5A, the first scanning range for color Doppler is formed with “60” scanning lines, and the second scanning range for B mode is formed with “120” scanning lines. Yes. In FIG. 5A, in the first ultrasonic scanning and the second ultrasonic scanning, the ultrasonic scanning of each scanning line is performed at a constant period of “1 / PRF”. In FIG. 5A, the frame period is the sum of the time “60 / PRF” required for the first ultrasonic scan for one frame and the time “120 / PRF” required for the second ultrasonic scan for one frame. (60 + 120) / PRF ”.

  However, in the second method, high-quality B-mode image data can be collected, but there is a problem that the frame rate of the blood flow image data is lowered and the speed is easily turned back.

  The third method for displaying the tissue image data and the blood flow image data at the same time, as illustrated in FIG. 5B, constantly performs the first ultrasonic scan for collecting the blood flow image data (color Doppler image), This is a method of inserting a second ultrasonic scan for collecting tissue image data (B-mode image) at predetermined intervals. In the third method, the blood flow image signal during the second ultrasonic scanning period is estimated by interpolation processing using blood flow signals before and after the second ultrasonic scanning period. Then, the estimated image is displayed. In FIG. 5B, the frame period of the color Doppler image including the estimated image is “60 / PRF”, and the frame period of the B-mode image is “(60 × 4 + 120) / PRF”.

  However, since the wall filter is a high-pass filter, when the estimated signal is used, there is a problem that noise is generated and the blood flow image data includes noise. In addition, since the wall filter is an IIR filter, the influence of the noise extends to several frames before and after the estimation, so that the entire image becomes noisy.

  As described above, in the first to third methods, the image quality of the image indicating the moving body information displayed at the same time and the tissue image may be deteriorated. Therefore, the control unit 18 according to the first embodiment executes the second ultrasonic scanning as described below in order to improve the image quality of the image showing the moving body information displayed simultaneously and the tissue image. .

  That is, the control unit 18 according to the first embodiment performs ultrasonic scanning of each of the plurality of divided ranges obtained by dividing the second scanning range as the second ultrasonic scanning in a time division manner during the first ultrasonic scanning. The sound probe 1 is executed. In other words, in the first embodiment, a part of the second ultrasonic scan is performed during the first ultrasonic scan, and the second ultrasonic wave for one frame is performed during the period of performing the first ultrasonic scan for several frames. Complete the scan. Thereby, in the first embodiment, the ultrasonic transmission / reception conditions can be set independently for the first ultrasonic scanning and the second ultrasonic scanning.

  An example of the control process will be described with reference to FIGS. 7 and 8 are diagrams for explaining the control unit according to the first embodiment. For example, the control unit 18 divides the second scanning range into four divided ranges (first divided range to fourth divided range) based on an instruction from the operator, initially set information, and the like. Note that “B” illustrated in FIG. 7 indicates a range where ultrasonic scanning is performed using the transmission / reception conditions for the B mode. In addition, “D” illustrated in FIG. 7 indicates a range where ultrasonic scanning is performed using the transmission / reception conditions for the color Doppler mode. For example, “D” shown in FIG. 7 is a range in which ultrasonic scanning performed by the high frame rate method is performed. That is, the first ultrasonic scanning illustrated in FIG. 7 does not transmit an ultrasonic wave a plurality of times in the same direction and receive a reflected wave a plurality of times, as in a general color Doppler method. The ultrasonic transmission / reception is performed once. In other words, the control unit 18 executes an ultrasonic scan for collecting blood flow Doppler image data as the first ultrasonic scan. Then, the control unit 18 performs high-pass filter processing (for example, IIR filter processing) on the reception signals (reflected wave data) acquired by each of the plurality of scanning lines forming the first scanning range in the frame direction to move the moving body. The ultrasonic scanning based on the method for acquiring the information on is executed as the first ultrasonic scanning. The control unit 18 according to the first embodiment acquires reception signals of each of the plurality of scanning lines forming the first scanning range by performing ultrasonic transmission / reception once for each scanning line, and performs high-pass filter processing. An ultrasonic scan based on a method for acquiring a data string in the frame direction is executed as the first ultrasonic scan. That is, the control unit 18 according to the first embodiment performs ultrasonic transmission / reception once for each of the plurality of scanning lines forming the first scanning range as the first ultrasonic scanning, and reflects reflected waves for a plurality of frames. The ultrasonic scanning based on the method (high frame rate method) which acquires the information regarding the motion of a moving body is used.

  First, the control unit 18 executes an ultrasonic scan in the first divided range as the second ultrasonic scan (see (1) in FIG. 7), and the first ultrasonic scan in the second scan range (for one frame). (See (2) of FIG. 7). And the control part 18 performs the ultrasonic scan of a 2nd division | segmentation range as a 2nd ultrasonic scan (refer (3) of FIG. 7), and the 1st ultrasonic scan of a 2nd scan range (for 1 frame). (See (4) of FIG. 7). And the control part 18 performs the ultrasonic scan of a 3rd division range as a 2nd ultrasonic scan (refer (5) of FIG. 7), and the 1st ultrasonic scan of a 2nd scan range (for 1 frame). (See (6) of FIG. 7). And the control part 18 performs the ultrasonic scan of a 4th division range as a 2nd ultrasonic scan (refer (7) of FIG. 7), and the 1st ultrasonic scan of a 2nd scan range (for 1 frame). (See (8) of FIG. 7).

Here, as illustrated in FIG. 7, the control unit 18 sets the intervals at which the first ultrasonic scanning is performed as equal intervals. That is, “point X” on “a scanning line” in the first scanning range is scanned once by the first ultrasonic scanning of (2), (4), (6) and (8) of FIG. However, the scanning interval is controlled to be a constant “T”. Specifically, the control unit 18 sets the time required for each divided scanning performed in the second ultrasonic scanning to be the same, and sets the intervals at which the first ultrasonic scanning is performed to be equal intervals. For example, the control unit 18 controls the time required for the divided scanning of the second ultrasonic scanning performed in (1), (3), (5), and (7) of FIG. 7 to be always the same time. . The control unit 18 makes the size of each divided range obtained by dividing the second scanning range, the number of scanning lines, the scanning line density, the depth, and the like the same. For example, if the number of scanning lines is the same, the time required for each divided scanning of the second ultrasonic scanning is the same. As shown in FIG. 7, the Doppler processing unit 14 applies a data string (X _n−3 , X _n−2 , X _n−1 , X _n ) at the same position between “D” frames. By performing the above IIR filter processing, the motion information of the blood flow at “Point X” is output.

  As described above, in the first embodiment, since the ultrasonic transmission / reception conditions can be set independently for the first ultrasonic scanning and the second ultrasonic scanning, the above-described problems can be solved. First, since the gain of the preamplifier can be optimized for each of the first ultrasonic scanning and the second ultrasonic scanning, saturation of the reflected wave signal from the tissue can be avoided.

  In addition, since the second ultrasonic scan is performed a plurality of times in the divided scan during the first ultrasonic scan for one frame, the frame rate generated by performing the second ultrasonic scan for one frame. The degree of the decrease can be suppressed. As a result, the blood flow folding speed can be increased.

  In addition, since the second ultrasonic scan of one frame is performed a plurality of times in the divided scan, the scanning line density in the B mode can be increased, and for example, the occurrence of a lateral flow in the B mode image data can be avoided. .

  In addition, since the ultrasonic transmission / reception conditions can be set independently for the first ultrasonic scanning and the second ultrasonic scanning, tissue image data can be collected by THI. That is, the second ultrasonic scanning can be executed under ultrasonic transmission / reception conditions for performing THI by the above-described filter processing. The second ultrasonic scanning is an imaging method that performs ultrasonic transmission at a plurality of rates for one scanning line, such as the above-described AM method, PM method, AMPM method, or method using a difference sound component. It can be executed under ultrasonic transmission / reception conditions for performing THI based.

  However, in the method of the first embodiment, the frame rate of the tissue image is slowed as a trade-off. For example, in the example shown in FIG. 7, blood flow information for one frame is output at “T” intervals. That is, the frame rate of the blood flow image (color Doppler image) is “1 / T”. In the example shown in FIG. 7, partial B-mode data (tissue image) is also output at “T” intervals, but “1” of the entire second scanning range is output while outputting a blood flow image of one frame. Only / 4 "is scanned.

  That is, in the example illustrated in FIG. 7, the frame rate at which scanning of the entire second scanning range is completed is “1 / (4T)”. In addition, when performing THI based on an imaging method that performs ultrasonic transmission at a plurality of rates for one scanning line, the number of ultrasonic transmissions for obtaining a reception signal for one frame increases. It is necessary to increase the number of divisions of the second scanning range as compared with the case where THI is performed by mode imaging or filter processing. For example, when the PM method is performed, the second scanning range is changed from 4 divisions to 8 divisions. In such a case, the frame rate at which scanning of the entire second scanning range is completed is “1 / (8T)”. Thus, in the method according to the first embodiment, the frame rate of the tissue image is slower than the frame rate of the blood flow image. This is because the purpose of ultrasonic scanning performed by this method is to increase the frame rate of the blood flow image. That is, the blood flow folding speed is determined by the frame rate “1 / T” of the blood flow image obtained by the high frame rate method.

  Here, as described above, in the high frame rate method, the PRF is the same as the frame rate. Therefore, in order to observe a fast blood flow without turning back, it is necessary to increase the scan rate “1 / T”. There is. That is, “T” needs to be reduced. However, if the number of scanning lines of the tissue image and blood flow image to be finally displayed in order to reduce “T” is reduced, the image quality of the tissue image and blood flow image is degraded. Therefore, in order to maintain the image quality of the tissue image and the blood flow image, it is preferable to reduce the number of scanning lines while maintaining the scanning line density in one divided scan for the B mode. As a trade-off of performing such processing, as described above, the frame rate at which a complete tissue image is displayed is reduced. However, when displaying a tissue image and a blood flow image at the same time, generally, the main purpose is blood flow observation, and the tissue image is a guide for observing the blood flow image. The problem due to the rate drop is small.

  However, in the method of the first embodiment, when the second ultrasonic scanning illustrated in FIG. 7 is performed, the control unit 18 does not update the tissue image at “4T” intervals, but for each divided scanning range. Update organizational picture. Such update control will be described using the second ultrasonic scanning exemplified in FIG. As illustrated in FIG. 8, the control unit 18 newly performs the first division while the B-mode image data in the first to fourth division ranges (see “1 to 4” in the figure) is displayed. When the B mode image data of the range (see “5” in the figure) is generated, the B mode image data “1” of the first divided range is updated to “5”.

  Then, as illustrated in FIG. 8, when new B-mode image data in the second divided range (see “6” in the drawing) is generated, the control unit 18 generates a B-mode image in the second divided range. Data “2” is updated to “6”. Then, as illustrated in FIG. 8, when new B-mode image data in the third divided range (see “7” in the drawing) is generated, the control unit 18 generates a B-mode image in the third divided range. Data “3” is updated to “7”. Then, although not shown, when the B mode image data (“8”) in the fourth divided range is newly generated, the control unit 18 changes the B mode image data “4” in the fourth divided range to “8”. Update.

  And the control part 18 performs display control as shown to FIG. 9A and FIG. 9B, for example. 9A and 9B are diagrams illustrating an example of a display form according to the first embodiment. For example, the monitor 2 displays a B-mode image (tissue image) on the left side and a B-mode image and a color Doppler image (blood flow image) on the right side as shown in FIG. 9A under the control of the control unit 18. The superimposed display is performed. In the example shown in FIG. 9A, the first scanning range is set within the second scanning range.

  FIG. 9B shows a case where the B-mode image shown in FIG. 9A is a “B-mode image generated by THI” and the color Doppler image shown in FIG. 9A is a power image. Note that the B-mode image shown in FIG. 9A may be a normal B-mode image. Further, the color Doppler image shown in FIG. 9A may be an image in which velocity data and distributed data are combined. Further, the image displayed on the right side of the monitor 2 may be only a blood flow image. When the power correction process described above is executed, the blood flow image displayed on the right side of the monitor 2 may be a blood flow image in which information on power and direction (sign of velocity) is depicted. good.

  Next, an example of the ultrasonic scanning control process of the ultrasonic diagnostic apparatus according to the first embodiment will be described with reference to FIG. FIG. 10 is a flowchart for explaining an example of the ultrasonic scanning control process of the ultrasonic diagnostic apparatus according to the first embodiment. FIG. 10 is a flowchart showing a case where the second scanning range is divided into four.

  As shown in FIG. 10, the control unit 18 of the ultrasonic diagnostic apparatus according to the first embodiment determines whether or not an ultrasonic scanning start request has been received (step S <b> 101). Here, when a scanning start request is not received (No at Step S101), the control unit 18 waits until a scanning start request is received.

  On the other hand, when the scanning start request is received (Yes at Step S101), the control unit 18 scans the first divided range of the second scanning range under the B mode condition (Step S102), and then the first scanning range is colored. Scanning is performed under Doppler mode conditions (step S103). Then, the control unit 18 scans the second divided range of the second scan range under the B mode condition (step S104), and then scans the first scan range under the color Doppler mode condition (step S105).

  Then, the control unit 18 scans the third divided range of the second scan range under the B mode condition (step S106), and then scans the first scan range under the color Doppler mode condition (step S107). Then, the control unit 18 scans the fourth division range of the second scan range under the B mode condition (step S108), and then scans the first scan range under the color Doppler mode condition (step S109).

  And the control part 18 determines whether the completion | finish request | requirement of an ultrasonic scan was received (step S110). If the scanning end request is not accepted (No at Step S110), the control unit 18 returns to Step S102 and scans the first divided range of the second scanning range under the B mode condition.

  On the other hand, when the scanning end request is received (Yes at Step S110), the control unit 18 ends the ultrasonic scanning control process. In the example shown in FIG. 10, the case where the divided scanning of the second ultrasonic scanning is first performed has been described. However, the first embodiment may be performed even when the first ultrasonic scanning is performed first. good. In the example illustrated in FIG. 10, a case has been described in which it is determined whether or not a scan end request has been accepted when all the divided ranges of the second scan range are completed. In the first embodiment, the second scan is performed. It may be a case where it is determined whether or not a scanning end request has been accepted each time scanning of each divided range of the range or scanning of the first scanning range is completed.

  As described above, in the first embodiment, the first ultrasonic scan and the first ultrasonic scan are performed by performing the second ultrasonic scan a plurality of times in the divided scan during the first ultrasonic scan for one frame. The ultrasonic transmission / reception conditions can be set independently by two ultrasonic scans. That is, in the first embodiment, it is possible to set an optimal ultrasonic transmission / reception condition for the B mode and to set an optimal ultrasonic transmission / reception condition for the color Doppler mode. For example, in the first embodiment, an ultrasonic transmission / reception condition optimal for THI such as the PM method can be set as the ultrasonic transmission / reception condition of the second ultrasonic scanning. Therefore, in the first embodiment, it is possible to improve the image quality of a blood flow image (an image showing moving body information) and a tissue image that are displayed simultaneously.

  Further, in the first embodiment, by setting the intervals at which the first ultrasonic scanning is performed to be equal intervals, it is possible to adjust the frame rate so that the blood flow image is not folded.

(Second Embodiment)
In the second embodiment, a case of performing output control of image data generated by performing the scanning control described in the first embodiment will be described with reference to FIG. FIG. 11 is a diagram for explaining the second embodiment.

  The ultrasound diagnostic apparatus according to the second embodiment has the same configuration as the ultrasound diagnostic apparatus according to the first embodiment described with reference to FIG. However, the control unit 18 according to the second embodiment further performs the first scan generated by the first ultrasonic scan according to the time required for one first ultrasonic scan and the display frame rate of the monitor 2. Control is performed so that a plurality of image data in a range is output as one image data.

  In the first embodiment, every time the color Doppler mode ultrasonic scan (first ultrasonic scan) and the B mode ultrasonic scan divided scan (second ultrasonic scan divided scan) are performed once, One frame of blood flow image data and tissue image data updated by “1 / number of divisions” are output. Here, when the generation frame rate of the blood flow image data is larger than the display frame rate of the monitor 2, a frame that is not displayed appears. For example, when the frame rate of the blood flow image is 120 fps, only “½” of the image data output from the image generation unit 15 can be displayed on the monitor 2 that is TV-scanned at 60 fps. For example, when the frame rate of the blood flow image is 1800 fps, only “1/30” of the image data output from the image generation unit 15 can be displayed on the monitor 2.

  In the ultrasonic diagnostic apparatus, when the operator presses the freeze button of the input device 3, all frames stored in the image memory 16 are played back slowly, and frames that could not be displayed during real-time display are displayed on the monitor 2. Can do. However, in the case of blood flow in the abdomen at a low flow rate, even if blood flow information of 60 fps or more is output by slow reproduction, a similar image is displayed, so that meaningful information is provided to the observer. It won't happen. Conversely, when performing cine reproduction after freezing, the operator operates the trackball to increase the number of frames to be framed, which is a burden.

  Therefore, in the second embodiment, the control unit 18 generates M pieces of blood flow image data generated by repeating the pair of “B” and “D” illustrated in FIG. The data is output to the monitor 2 and the image memory 16 as data. Note that “M” is calculated by the control unit 18, for example. In FIG. 11, since “M = 2”, the control unit 18 determines any one of the two pieces of blood flow image data or the addition average image data of the two pieces of blood flow image data as “n”. "And blood flow image data of the" n + 1 "th frame.

  In the second embodiment as well, the first ultrasonic scanning is performed by the first ultrasonic scanning based on the high frame rate method described in the first embodiment. In this case, the display frame rate is “1 / (M × T)”, but the PRF remains “1 / T”.

  Next, an example of output control processing of the ultrasonic diagnostic apparatus according to the second embodiment will be described with reference to FIG. FIG. 12 is a flowchart for explaining an example of output control processing of the ultrasonic diagnostic apparatus according to the second embodiment. FIG. 12 illustrates a case where the frame rate output to the monitor 2 is adjusted during playback display after freezing.

  As shown in FIG. 12, the control unit 18 of the ultrasonic diagnostic apparatus according to the second embodiment determines whether a display request for image data stored in the image memory 16 has been received (step S201). Here, when a display request is not received (No at Step S201), the control unit 18 waits until a display request is received.

  On the other hand, when the display request is received (Yes at Step S201), the control unit 18 adjusts the number of output frames according to the frame rate of the first ultrasonic scanning and the display frame rate of the monitor 2 (Step S202), and processing Exit. In the second embodiment, as described above, the number of output frames may be adjusted when image data is stored in the image memory 16.

  As described above, in the second embodiment, the number of output frames output for storage and the output frames output for display according to the frame rate of the first ultrasonic scan and the display frame rate of the monitor 2 Adjust the number. Specifically, in the second embodiment, the blood flow image output frame rate is adjusted to be equal to or lower than the display frame rate of the monitor 2. Thereby, in 2nd Embodiment, the number of output data of the blood flow information of a low flow velocity can be suppressed, for example, and the frame advance at the time of cine reproduction | regeneration can be performed without an uncomfortable feeling with respect to an observer. In the above, the display frame rate “1 / (M × T)” is controlled to be equal to or lower than the monitor frame rate (60 fps). However, as a method for determining the number of repetitions “M”, other than this, You may make it become below the arbitrary frame rate set beforehand.

(Third embodiment)
In the first and second embodiments, the case where a tissue image and a blood flow image of a two-dimensional slice are displayed by two-dimensional scanning has been described. However, in the first and second embodiments, three-dimensional tissue image data and three-dimensional blood flow image data are generated by three-dimensional scanning, and MPR images and volume rendering images of these volume data are generated. Even when displaying, it is applicable.

  That is, in the third embodiment, “D” shown in FIG. 7 and FIG. 11 is the first ultrasonic scan for one volume, and “B” shown in FIG. 7 and FIG. This is divided scanning of the acoustic wave scanning. The processing of the blood flow information “D” shown in FIGS. 7 and 11 is performed on a data string between volume data at the same position.

  However, in the third embodiment, the volume rate is the PRF of the color Doppler image. Therefore, for example, the control unit 18 performs the control shown in FIGS. 13A and 13B in order to increase the volume rate. 13A and 13B are diagrams for explaining the third embodiment.

  For example, as illustrated in FIG. 13A, the control unit 18 performs parallel simultaneous reception in order to increase the volume rate. In the example shown in FIG. 13A, a case where 8-beam parallel simultaneous reception is performed is shown. In FIG. 13A, the central axis in the depth direction of the transmitted ultrasonic waves is indicated by a solid line arrow, and the eight reflected wave beams simultaneously received at the first time are indicated by broken line arrows. The transmission / reception unit 11 receives the reflected wave signals on the eight scanning lines from the ultrasonic probe 1 in one ultrasonic transmission / reception. Thereby, the transmission / reception part 11 can produce | generate the reflected wave data on eight scanning lines by one ultrasonic transmission / reception. Note that the number of parallel simultaneous receptions can be set to an arbitrary value in accordance with the required volume rate within a range equal to or less than the upper limit number that the transmission / reception unit 11 can receive simultaneously.

  Further, for example, as shown in FIG. 13B, the control unit 18 increases the number of divisions and decreases the number of scanning lines performed in one division scanning in order to increase the volume rate.

  Note that the control unit 18 may perform both parallel reception and increase in the number of divisions in order to increase the volume rate. In addition, in order to increase the volume rate, the control unit 18 performs the first ultrasonic scanning and the parallel scanning with the first ultrasonic scanning or the parallel scanning with the second ultrasonic scanning. Parallel simultaneous reception may be executed in both of the second ultrasonic scans. Note that the second ultrasonic scanning performed by the three-dimensional scanning is, for example, an ultrasonic scanning for THI based on the AM method, the PM method, or the like.

  In the third embodiment, even when three-dimensional scanning is performed, the image quality of a blood flow image and a tissue image displayed at the same time can be improved. Note that the control unit 18 may perform both or both of the parallel simultaneous reception and the increase in the number of divisions in order to increase the frame rate. Further, even when the two-dimensional scanning described in the first embodiment is performed, the control unit 18 may perform both or both of the parallel simultaneous reception and the increase in the number of divisions in order to increase the frame rate.

(Fourth embodiment)
In the first to third embodiments, the case where the first ultrasonic scanning of the high frame rate method is performed in order to acquire blood flow information has been described. However, the first ultrasonic scanning of the high frame rate method is applicable to the above-described TDI and elastography. That is, any reflected wave signal from a moving body that moves can be used as Doppler information. Therefore, even if the information related to the movement of the moving body is information related to the movement of the tissue, the processing described in the first to third embodiments can be applied. In other words, the control unit 18 may execute an ultrasonic scan for collecting Doppler image data of the tissue as the first ultrasonic scan. Alternatively, the control unit 18 may execute an ultrasonic scan for collecting elastography as the first ultrasonic scan.

  14A and 14B are diagrams for explaining the fourth embodiment. In the fourth embodiment, when the tissue Doppler mode is set, the monitor 2 displays a B-mode image (tissue image) on the left side and the right side as illustrated in FIG. 14A under the control of the control unit 18. The superimposed display is performed by superimposing the B-mode image and the tissue Doppler image on each other.

  In the fourth embodiment, when the elast mode is set, the monitor 2 displays a B-mode image (tissue image) on the left side as illustrated in FIG. 14B under the control of the control unit 18, Superimposition display is performed by superimposing a B-mode image and elastography on the right side.

  In the fourth embodiment, it is possible to improve the image quality of an image showing tissue exercise information and a tissue image displayed simultaneously.

(Fifth embodiment)
In the fifth embodiment, with reference to FIGS. 15 to 17, a case where ultrasonic scanning of a form different from the first ultrasonic scanning described in the first to fourth embodiments is performed as the first ultrasonic scanning will be described with reference to FIGS. 15 to 17. explain. 15 to 17 are diagrams for explaining the fifth embodiment.

  In the first ultrasonic scanning described in the first to fourth embodiments, one ultrasonic transmission / reception is performed by one scanning line to receive a reflected wave, and reflected wave data generated from the reflected wave ( Receive signal). As a result, a reception signal is obtained on each scanning line forming the first scanning range. Then, the Doppler processing unit 14 performs MTI filter processing (for example, IIR filter processing) on the data string of the reception signal of the latest frame and the reception signal group for the past several frames in each scanning line. Generate Doppler data.

  On the other hand, the first ultrasonic scanning according to the fifth embodiment is a method of performing high-pass filter processing on a data string in the frame direction, similarly to the first ultrasonic scanning described in the first to fourth embodiments. Is an ultrasonic scan based on However, the control unit 18 according to the fifth embodiment executes, as the first ultrasonic scan, an ultrasonic scan in which ultrasonic transmission / reception is performed a plurality of times for each scan line. And the transmission / reception part 11 or the Doppler process part 14 performs an addition average process with respect to the several received signal of each scanning line by control of the control part 18 which concerns on 5th Embodiment. Thereby, the reception signals of each of the plurality of scanning lines forming the first scanning range are acquired. Then, the Doppler processing unit 14 performs high-pass filter processing on the data string in the frame direction to generate Doppler data.

  In the first ultrasonic scanning according to the fifth embodiment, first, a plurality of reception signals are obtained by one scanning line. In the first ultrasonic scanning according to the fifth embodiment, an averaging process is performed on a plurality of reception signals obtained by one scanning line, and finally one reception is performed by one scanning line. A signal is output. The plurality of received signals that are subjected to the averaging process are signals having phase information, such as IQ signals and RF signals. That is, the averaging process performed in the fifth embodiment is a coherent addition process. By performing coherent addition, the signal / noise ratio (S / N) of the received signal can be improved. As a result, in the fifth embodiment, for example, the S / N of color Doppler image data can be improved.

  For example, in the first ultrasonic scanning according to the fifth embodiment, ultrasonic transmission / reception is performed four times for each scanning line forming the first scanning range. In the first ultrasonic scanning according to the fifth embodiment, for example, an addition averaging process is performed on four sets of reflected wave data (received signals) obtained by one scanning line. One reception signal is output by one scanning line. For example, S / N is improved by “6 dB” by averaging four sets of received signals.

  However, in the first ultrasonic scanning described above, when performing ultrasonic scanning for one frame, since ultrasonic transmission / reception is performed four times on each scanning line, the frame rate is lowered. Therefore, in the first ultrasonic scanning according to the fifth embodiment, the control unit 18 executes parallel simultaneous reception when performing ultrasonic transmission / reception a plurality of times for each scanning line forming the first scanning range. Also good. Hereinafter, before explaining the case where the first ultrasonic scanning according to the fifth embodiment is performed by parallel simultaneous reception, the first supersonic to which the parallel simultaneous reception described in the third embodiment is applied will be described with reference to FIG. An example of acoustic wave scanning will be described.

  In FIG. 15, the raster direction (scanning direction) is shown in the left-right direction and the time direction (frame direction) is shown in the up-down direction. In addition, the example illustrated in FIG. 15 illustrates a case where the number of scanning lines (raster number) forming the first scanning range is “16” and four directions of reflected waves are simultaneously received by parallel simultaneous reception. In the example shown in FIG. 15, the number of scanning lines is “16” and the number of parallel simultaneous receptions is “4”, so that the first scanning range is formed by four ranges formed by four scanning lines ( 1st range, 2nd range, 3rd range, 4th range).

  The ultrasonic probe 1 performs ultrasonic transmission using the center position of the first range in the raster direction as a transmission scanning line, and simultaneously receives the reflected waves of the four scanning lines forming the first range. As a result, four reception signals in the first range are generated. Similar processing is performed in the second range, the third range, and the fourth range, and reception signals of 16 scanning lines forming the first scanning range are obtained. “A”, “B”, and “C” illustrated in FIG. 15 indicate reception signals of the same scanning line of “(n−2) frame, (n−1) frame, n frame”, respectively. The Doppler processing unit 14 executes the MTI filter process on the data string “A, B, C” at the same point in these consecutive frames.

  On the other hand, when applying parallel simultaneous reception to the 1st ultrasonic scan concerning a 5th embodiment, control part 18 performs the 1st method or the 2nd method. In the first method, the control unit 18 performs parallel simultaneous reception by dividing the first scanning range into a plurality of ranges so that adjacent ranges do not overlap. In the second method, the control unit 18 divides the first scanning range into a plurality of ranges so that adjacent ranges overlap each other, and executes parallel simultaneous reception.

  FIG. 16 shows an example in which parallel simultaneous reception is applied to the first ultrasonic scanning according to the fifth embodiment based on the first method. FIG. 17 shows an example in which parallel simultaneous reception is applied to the first ultrasonic scanning according to the fifth embodiment based on the second method.

  16 and 17, the raster direction (scanning direction) is shown in the left-right direction and the time direction (frame direction) is shown in the up-down direction, as in the example described in FIG. 16 and 17, similarly to the example described in FIG. 15, the number of scanning lines (raster number) forming the first scanning range is “16”, and reflected waves in four directions are received by parallel simultaneous reception. The case of simultaneous reception is illustrated. Further, “T1” in FIGS. 16 and 17 indicates a sampling period. Further, “T2” in FIGS. 16 and 17 indicates an addition width. Further, “T3” in FIGS. 16 and 17 indicates a frame period. The frame period “T3” is a pulse repetition period in the normal Doppler mode.

  In the first method, as shown in FIG. 16, as in the example shown in FIG. 15, the first scanning range includes four ranges (first range, second range, and third range) formed by four scanning lines. , The fourth range). However, in the first method, for example, as shown in FIG. 16, parallel simultaneous reception is repeated four times in each range. As a result, as shown in FIG. 16, four sets of reception signals at the same point on the same reception scanning line are obtained in the (n-2) frame. In FIG. 16, these four sets of data are indicated by “a1, a2, a3, a4”. Similarly, as shown in FIG. 16, in the (n-1) frame, four sets of reception signals at the same point on the same reception scanning line are obtained. In FIG. 16, these four sets of data are indicated by “b1, b2, b3, b4”. Similarly, as shown in FIG. 16, four sets of reception signals at the same point on the same reception scanning line are obtained in n frames. In FIG. 16, these four sets of data are indicated by “c1, c2, c3, c4”.

  For example, the transmission / reception unit 11 outputs “A = (a1 + a2 + a3 + a4) / 4”. For example, the transmission / reception unit 11 outputs “B = (b1 + b2 + b3 + b4) / 4”. Further, the transmission / reception unit 11 outputs “C = (c1 + c2 + c3 + c4) / 4”. As a result, the S / N is improved by “6 dB” compared to before the averaging. Then, the Doppler processing unit 14 performs the MTI filter process on the data string “A, B, C” at the same point in the consecutive frames.

  In terms of Doppler frequency, a low pass filter (LPF) is applied by adding four data, but the velocity component cut by the sampling period “T1” and the addition width “T2” is the frame period “T3”. The speed is sufficiently high compared to the above, so there is no problem in observing a low flow rate.

  In the second method, for example, as shown in FIG. 17, four-way parallel reception is performed by shifting the position of the transmission scanning line by one scanning line. Thus, as in the first method, as shown in FIG. 17, four sets of reception signals “a1, a2, a3, a4” at the same point on the same reception scanning line are obtained in the (n−2) frame. "A = (a1 + a2 + a3 + a4) / 4" is output. Similarly to the first method, as shown in FIG. 17, four sets of reception signals “b1, b2, b3, b4” at the same point on the same reception scanning line are obtained in the (n−1) frame. , “B = (b1 + b2 + b3 + b4) / 4” is output. Similarly to the first method, as shown in FIG. 17, four sets of received signals “c1, c2, c3, c4” at the same point of the same reception scanning line are obtained in n frames, and “C = (C1 + c2 + c3 + c4) / 4 "is output. As a result, the S / N is improved by “6 dB” compared to before the averaging. 16 and 17, the frame rate of the Doppler image data is the same.

  In the example shown in FIG. 17, the scanning line that can obtain only two sets of received signals performs the averaging of two sets of received signals, and the scanning line that obtains only three sets of received signals has 3 A set of received signals is averaged. In the example shown in FIG. 17, in a scanning line from which only one set of reception signals can be obtained, this reception signal becomes data to be processed by the Doppler processing unit 14. Further, in the second method, for example, the position of the transmission scanning line may be shifted by two scanning lines according to the number of sets of reception signals to be added and averaged.

  The advantage of performing the second method will be described below. When the first method is performed, in the first ultrasonic scanning, the ranges in which multiple simultaneous receptions are performed do not overlap. In the first method illustrated in FIG. 16, since the transmission positions for obtaining four reception signals on the same scanning line are the same, the phase does not change due to the transmission beam. However, in the first method illustrated in FIG. 16, the ranges where four parallel simultaneous receptions are performed do not overlap. For this reason, in the first method illustrated in FIG. 16, streak artifacts may occur between the ranges of every four rasters.

  On the other hand, when the second method is performed, in the first ultrasonic scanning, parallel simultaneous reception is performed once in each range in which adjacent ranges are overlapped. In the second method illustrated in FIG. 17, a slight phase shift occurs because transmission positions for obtaining four received signals on the same scanning line are different, but such a phase shift can be removed by an MTI filter. And in the 2nd method illustrated in FIG. 17, since each range where parallel simultaneous reception is performed overlaps 3 scanning lines, a streak-like artifact does not generate | occur | produce.

  As described above, in the fifth embodiment, the HPF process in the frame direction is performed using a reception signal obtained by coherently adding a plurality of reception signals obtained in each scanning line. As a result, in the fifth embodiment, although the frame rate is reduced as compared with the first ultrasonic scanning described in the first to fourth embodiments, the received signal for generating an image indicating moving body information S / N can be improved. In the above description, the case where the number of parallel simultaneous receptions is “4” has been described as an example, but the number of parallel simultaneous receptions can be set to an arbitrary number. Further, as described first, the first ultrasonic scanning according to the fifth embodiment can be executed even when parallel simultaneous reception is not performed. In addition, the transmission / reception unit 11 or the Doppler processing unit 14 performs LPF processing similar to addition averaging processing on a plurality of received signals obtained on each scanning line under the control of the control unit 18 according to the fifth embodiment. May be executed. The contents described in the first to fourth embodiments can also be applied to the fifth embodiment except that the form of the first ultrasonic scanning is different.

  In the above-described embodiment, each component of each illustrated device is functionally conceptual and does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each device is not limited to that shown in the figure, and all or a part thereof may be functionally or physically distributed or arbitrarily distributed in arbitrary units according to various loads or usage conditions. Can be integrated and configured. Further, all or any part of each processing function performed in each device may be realized by a CPU and a program analyzed and executed by the CPU, or may be realized as hardware by wired logic.

  The control method related to ultrasonic scanning described in the first to fifth embodiments can be realized by executing a control program prepared in advance on a computer such as a personal computer or a workstation. This control program can be distributed via a network such as the Internet. The control program is recorded on a computer-readable non-transitory recording medium such as a hard disk, a flexible disk (FD), a CD-ROM, an MO, a DVD, a flash memory such as a USB memory and an SD card memory. It can also be executed by being read from a non-transitory recording medium by a computer.

  As described above, according to the first to fifth embodiments, it is possible to improve the image quality of the image showing the moving body information displayed simultaneously and the tissue image.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Ultrasonic probe 2 Monitor 3 Input device 10 Apparatus main body 11 Transmission / reception part 12 Buffer 13 B mode processing part 14 Doppler processing part 15 Image generation part 16 Image memory 17 Internal storage part 18 Control part

Claims (13)

An ultrasound probe that transmits and receives ultrasound; and
The first ultrasonic scan for acquiring information related to the motion of the moving body in the first scan range is executed by the ultrasonic probe, and the second ultrasonic scan for acquiring information on the tissue shape in the second scan range is used. A control unit that causes the ultrasonic probe to execute ultrasonic scanning of each of the plurality of divided ranges obtained by dividing the two scanning ranges in a time division manner during the first ultrasonic scanning;
With
The control unit performs ultrasonic scanning based on a method of performing high-pass filter processing on a reception signal acquired by each of a plurality of scanning lines forming the first scanning range in a frame direction to acquire information on the motion of the moving body. the first is performed as ultrasonic scanning, prior SL according to the display frame rate of the generated frame rate and the display unit of the image data of the first scanning range produced by the first ultrasonic scanning, the first ultrasonic as the output frame rate of the image data of the first scanning range produced by the scanning is less than the display frame rate, adding a plurality of image data of said first scanning range generated by the first ultrasonic scanning An ultrasonic diagnostic apparatus that controls to average and output the image data after the addition and averaging as image data of the first scanning range .   The control unit obtains reception signals of the plurality of scanning lines forming the first scanning range by performing ultrasonic transmission / reception once for each scanning line, and performs a data sequence in the frame direction for performing the high-pass filter processing. The ultrasonic diagnostic apparatus according to claim 1, wherein an ultrasonic scan based on a method for acquiring the first ultrasonic scan is executed as the first ultrasonic scan.   The control unit performs an averaging process on a plurality of received signals of each scanning line obtained by performing ultrasonic transmission / reception a plurality of times for each scanning line, or a low pass similar to the adding average process. Ultrasonic scanning based on a method of acquiring received signals of a plurality of scanning lines forming the first scanning range by executing filter processing and acquiring a data string in a frame direction for performing the high-pass filter processing, The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic diagnostic apparatus is executed as the first ultrasonic scan.   The super control unit according to claim 3, wherein the control unit performs parallel simultaneous reception when performing ultrasonic transmission / reception plural times for each scanning line forming the first scanning range in the first ultrasonic scanning. Ultrasonic diagnostic equipment.   The controller divides the first scanning range into a plurality of ranges and performs parallel simultaneous reception, or divides the first scanning range into a plurality of ranges so that adjacent ranges overlap, The ultrasonic diagnostic apparatus according to claim 4, wherein reception is executed.   The control unit according to any one of claims 1 to 5, wherein the time required for each of the divided scans performed in the second ultrasonic scan is the same, and the intervals at which the first ultrasonic scan is performed are equally spaced. An ultrasonic diagnostic apparatus according to 1.   The ultrasonic diagnostic apparatus according to claim 1, wherein the control unit causes parallel simultaneous reception to be executed in at least one of the first ultrasonic scanning and the second ultrasonic scanning.   The ultrasonic diagnostic apparatus according to claim 1, wherein the control unit causes the Doppler image data or the ultrasonic scan to collect elastography to be executed as the first ultrasonic scan.   The control unit updates an existing divided image in the divided range with the newly generated divided image every time a divided image is newly generated in the divided range in which the second ultrasonic scanning is performed. The ultrasonic diagnostic apparatus according to claim 1. The control unit causes the ultrasonic probe that transmits and receives ultrasonic waves to execute a first ultrasonic scan for acquiring information on the motion of the moving body in the first scan range, and the tissue shape in the second scan range is obtained. Performing ultrasonic scanning of each of the plurality of divided ranges obtained by dividing the second scanning range as the second ultrasonic scanning for acquiring information in a time division manner during the first ultrasonic scanning;
Including
The control unit performs ultrasonic scanning based on a method of performing high-pass filter processing on a reception signal acquired by each of a plurality of scanning lines forming the first scanning range in a frame direction to acquire information on the motion of the moving body. the first is performed as ultrasonic scanning, the first according to the display frame rate of the generated frame rate and the display unit of the image data of the first scanning range produced by the ultrasonic scanning, the first ultrasonic scanning The plurality of image data in the first scanning range generated by the first ultrasonic scanning is averaged so that the output frame rate of the image data in the first scanning range generated by the step is equal to or lower than the display frame rate. And controlling so that the image data after the averaging is output as the image data of the first scanning range . Ultrasound alternately between a first ultrasonic scan for generating Doppler image data within the first scan range and a second ultrasonic scan for generating partial B-mode image data within the second scan range It has a control unit to be executed by the probe,
The control unit has an output frame rate of the Doppler image data equal to or less than the display frame rate according to a generation frame rate of the Doppler image data generated by the first ultrasonic scanning and a display frame rate of the display unit. As described above, the plurality of Doppler image data generated by the first ultrasonic scanning is averaged, and the Doppler image data after the addition averaging is controlled to be output as Doppler image data in the first scanning range. Equipment. On the computer,
A first ultrasonic scan that performs high-pass filter processing on the received signals acquired at each of the plurality of scan lines forming the first scan range in the frame direction to acquire information regarding the motion of the moving object within the first scan range, A first process that is executed by an ultrasonic probe that transmits and receives ultrasonic waves;
As a second ultrasonic scan for acquiring information on the tissue shape in the second scan range, each of the plurality of divided ranges obtained by dividing the second scan range is time-divisionally divided between the first ultrasonic scans. A second process to be executed by the ultrasonic probe;
The image of the first scanning range generated by the first ultrasonic scanning according to the generation frame rate of the image data of the first scanning range generated by the first ultrasonic scanning and the display frame rate of the display unit. A plurality of image data in the first scanning range generated by the first ultrasonic scanning is averaged so that an output frame rate of the data is equal to or less than the display frame rate, and the image data after the addition averaging is calculated as the first average. A third process for controlling to output as image data of one scanning range;
A program for running On the computer,
Ultrasound alternately between a first ultrasonic scan for generating Doppler image data within the first scan range and a second ultrasonic scan for generating partial B-mode image data within the second scan range A first process to be executed by the probe;
In accordance with the generation frame rate of the Doppler image data generated by the first ultrasonic scanning and the display frame rate of the display unit, the output frame rate of the Doppler image data is equal to or less than the display frame rate. A second process of controlling to average the plurality of Doppler image data generated by ultrasonic scanning and to output the Doppler image data after the addition average as Doppler image data in the first scanning range;
A program for running