Ultrasonic diagnostic apparatus

Abstract

To suppress noise appearing in a color Doppler image.SOLUTION: The data processing unit 14 performs a B-mode image generation process for generating B-mode image data based on the reception signal generated by the transmission / reception unit 12, an evaluation area setting process for setting the blood flow evaluation area 66 and the clutter evaluation area 70 in a region where the B-mode image data is generated, a wall filter process for the Doppler reception signal generated by the transmission / reception unit 12, and a Doppler image generation process for generating a Doppler image based on the Doppler reception signal subjected to the wall filter process. Color Doppler processing for generating color mapping data to a B-mode image, evaluation processing for obtaining a pixel evaluation value for each of a blood flow evaluation section 66 and a clutter evaluation section 70, and measurement condition setting processing for setting at least one of transmission / reception conditions in a transmission / reception part 12 and characteristics of wall filter processing according to each pixel evaluation value are executed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to ultrasonic transmission and reception conditions and wall filter processing. [Background technology]

[0002] One of the operating modes of ultrasound diagnostic equipment is color Doppler mode, which measures the blood flow velocity at the observation site and displays a color Doppler image by adding a color corresponding to the blood flow velocity to a B-mode image. When measuring in color Doppler mode, noise called clutter may appear on the color Doppler image depending on conditions such as the blood flow velocity at the observation site, the movement of biological tissue, and the characteristics of the wall filter.

[0003] Therefore, techniques have been devised for setting the characteristics of a wall filter according to the reception conditions of ultrasound waves, as shown in the following Patent Documents 1 and 2. Patent Document 1 describes changing the characteristics of a wall filter according to the pulse repetition frequency (PRF). Patent Document 2 describes changing the characteristics of a wall filter according to the amplitude of an echo signal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-005737 [Patent Document 2] Japanese Patent Application Publication No. 07-016227 Summary of the Invention [Problem to be solved by the invention]

[0005] Ultrasound diagnostic devices are used to observe various parts of a subject. In conventional technologies, the ultrasonic transmission and reception conditions and wall filter characteristics are not always appropriate for the observed part, and noise such as clutter is likely to occur depending on the observed part.

[0006] An object of the present invention is to suppress noise appearing in color Doppler images. [Means for solving the problem]

[0007] The ultrasonic diagnostic apparatus according to the present invention comprises a transceiver unit that transmits ultrasonic waves to a subject via an ultrasonic probe and receives, via the ultrasonic probe, reflected waves from the subject; and an information processing unit, wherein the information processing unit executes the following processes: a B-mode image generation process that generates B-mode image data based on received signals generated by the transceiver unit; an evaluation area setting process that sets a blood flow evaluation area and a clutter evaluation area in the area where the B-mode image data is generated; a wall filter process on Doppler received signals generated by the transceiver unit; a color Doppler process that generates color mapping data for the B-mode image data based on the Doppler received signals that have been subjected to the wall filter process; an evaluation process that calculates pixel evaluation values ​​for each of the blood flow evaluation area and the clutter evaluation area; and a measurement condition setting process that sets at least one of the transmission and reception conditions of the transceiver unit and the characteristics of the wall filter process in accordance with each pixel evaluation value.

[0008] In one embodiment, the information processing unit executes a display process for displaying a B-mode image based on the B-mode image data on a display device, and the evaluation area setting process includes a process for setting the blood flow evaluation area and the clutter evaluation area in accordance with an operation performed while the B-mode image is displayed.

[0009] In one embodiment, the measurement condition setting process includes a process of setting at least one of a transmission / reception condition in the transmission / reception unit and a characteristic of the wall filter process within a range determined according to an observation site.

[0010] In one embodiment, the information processing unit identifies the observation region in accordance with a preset operation that sets each control parameter for each function of the ultrasonic diagnostic apparatus.

[0011] In one embodiment, the information processing unit executes the evaluation process a plurality of times while changing at least one of the transmission and reception conditions and the characteristics of the wall filtering process, and searches for the transmission and reception conditions and the characteristics of the wall filtering process when a ratio of the pixel evaluation value for the blood flow evaluation area to the pixel evaluation value for the clutter evaluation area satisfies a predetermined condition, and the measurement condition setting process includes a process of setting at least one of the transmission and reception conditions and the characteristics of the wall filtering process so that the ratio satisfies the predetermined condition.

[0012] Furthermore, an ultrasonic diagnostic apparatus according to the present invention includes a transmitting / receiving unit that transmits ultrasonic waves to a subject via an ultrasonic probe and receives, via the ultrasonic probe, reflected waves from the subject, and an information processing unit, wherein the information processing unit performs wall filtering on Doppler reception signals generated by the transmitting / receiving unit, color Doppler processing that generates color mapping data for a B-mode image based on the Doppler reception signals that have been subjected to the wall filtering, and measurement condition setting processing that sets the transmission / reception conditions in the transmitting / receiving unit and the characteristics of the wall filtering processing in accordance with an observation region.

[0013] In one embodiment, the information processing unit identifies the observation region in accordance with a preset operation that sets each control parameter for each function of the ultrasonic diagnostic apparatus.

[0014] In one embodiment, the cutoff frequency of the wall filtering characteristic is set to a frequency predetermined for the observation region. [Effects of the Invention]

[0015] According to the present invention, noise appearing in a color Doppler image can be suppressed. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing the configuration of an ultrasound diagnostic apparatus according to a first embodiment. [Figure 2] FIG. 10 is a diagram illustrating Doppler shift frequency components and high-pass filter characteristics. [Figure 3] FIG. 10 is a diagram showing an example of a B-mode image displayed on a display. [Figure 4] FIG. 1 is a diagram showing an ultrasound probe equipped with multiple ultrasound transducers. [Figure 5] FIG. 10 is a diagram showing an example of linear scanning of an ultrasonic beam. [Figure 6] FIG. 10 is a diagram showing the configuration of an ultrasound diagnostic apparatus according to a second embodiment. [Figure 7] FIG. 10 is a diagram showing the configuration of an ultrasound diagnostic apparatus according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of the present invention will be described with reference to the drawings. Identical components shown in multiple drawings are designated by the same reference numerals to simplify their description. FIG. 1 shows the configuration of an ultrasound diagnostic apparatus 100 according to a first embodiment of the present invention. The ultrasound diagnostic apparatus 100 includes an ultrasound probe 10, a transmitter / receiver unit 12, an information processing unit 14, an operation unit 16, a display 18, and a memory 20. The information processing unit 14 may include a processor that executes a program to configure a B-mode image generation processing unit 22, an image formation unit 24, a display processing unit 26, a transmission / reception condition determination unit 28, a wall filter processing unit 30, a color Doppler processing unit 32, an S / N evaluation unit 34, and a control unit 36. The control unit 36 ​​performs overall control of the operation of the information processing unit 14. Note that, for simplification, FIG. 1 shows representative arrows indicating signals input and output from the control unit 36.

[0018] The operation unit 16 functions as a man-machine interface and may include a mouse, a switch, a lever, a trackball, etc. The operation unit 16 may form a touch panel together with the display 18. The control unit 36 ​​controls the ultrasound diagnostic apparatus 100 based on operation information output from the operation unit 16 in response to user operations.

[0019] The ultrasonic probe 10 includes multiple ultrasonic transducers. The transmitter / receiver 12 outputs a transmission signal to each ultrasonic transducer included in the ultrasonic probe 10. Each ultrasonic transducer generates an ultrasonic wave in response to the transmission signal. The transmitter / receiver 12 adjusts the delay time of the transmission signal output to each ultrasonic transducer so that the ultrasonic transmission beam is directed in a specific direction and a focus is formed. The transmitter / receiver 12 also scans the subject with the ultrasonic transmission beam by changing the delay time of the transmission signal output to each ultrasonic transducer.

[0020] Ultrasonic waves transmitted to the subject are reflected by the subject's biological tissue. The reflected waves generated by the biological tissue are received by each ultrasonic transducer. Each ultrasonic transducer converts the received ultrasonic waves into an electrical signal and outputs the electrical signal to the transceiver unit 12. Based on the reflected waves arriving from the direction of the ultrasonic transmission beam, the transceiver unit 12 adjusts the delay time of each electrical signal so that the electrical signals output from each ultrasonic transducer reinforce each other, and adds up each electrical signal. This phasing addition obtains a received signal based on the reflected waves arriving from the direction of the ultrasonic transmission beam, and an ultrasonic reception beam is formed in the direction of the ultrasonic transmission beam.

[0021] The transmitter / receiver 12 scans an ultrasonic transmission beam and an ultrasonic reception beam (hereinafter, the ultrasonic transmission beam and the ultrasonic reception beam are collectively referred to as an ultrasonic beam) and outputs the reception signals obtained for each direction or position of the ultrasonic beam to the B-mode image generation processing unit 22 and the wall filter processing unit 30.

[0022] The B-mode image generation processing unit 22 generates B-mode image data based on the received signals obtained for each direction or position of the ultrasound beam, and outputs the data to the image forming unit 24. The image forming unit 24 outputs the B-mode image data to the display processing unit 26, and the display processing unit 26 generates a video signal based on the B-mode image data as display processing, and outputs the video signal to the display 18. The display 18 may be a display device such as a liquid crystal panel or an organic EL panel, or a portable information processing device such as a tablet computer that functions as a display device. The display 18 displays a B-mode image based on the video signal.

[0023] The operating modes of the ultrasound diagnostic apparatus 100 include a B-mode in which a B-mode image is displayed on the display 18 by the above-described processing, as well as a color Doppler mode. The color Doppler mode is an operating mode in which the blood flow velocity at the observation site is measured and a color Doppler image in which a B-mode image is colored according to the blood flow velocity is displayed on the display 18.

[0024] Color Doppler mode operation is accompanied by B-mode operation, and B-mode and color Doppler mode operations are performed in a time-sharing manner. That is, B-mode operation is performed in one time period, and color Doppler mode operation is performed in the next time period, and this process is repeated. Color Doppler mode uses B-mode image data generated by the B-mode operation that was previously performed.

[0025] As components for performing operation in color Doppler mode, the information processing unit 14 includes a wall filter processing unit 30 and a color Doppler processing unit 32. In the following description, the received signal output by the transmitting and receiving unit 12 to the wall filter processing unit 30 will be referred to as a Doppler received signal to distinguish it from the received signal output by the transmitting and receiving unit 12 to the B-mode image generation processing unit 22. The wall filter processing unit 30 performs high-pass filtering as wall filtering on the Doppler received signal output from the transmitting and receiving unit 12, and outputs the signal to the color Doppler processing unit 32.

[0026] The color Doppler processing unit 32 determines a Doppler shift frequency for each depth in the ultrasound beam direction in the subject based on the value of the Doppler reception signal corresponding to each depth in the ultrasound beam direction. Here, the Doppler shift frequency refers to the difference in frequency between the Doppler reception signal and the transmission signal. In color Doppler mode, ultrasound pulses are repeatedly transmitted multiple times in each ultrasound beam direction, and reflected waves for each ultrasound pulse are received. The color Doppler processing unit 32 determines a Doppler shift frequency for each depth in the ultrasound beam direction based on the transmission and reception of ultrasound pulses multiple times. When blood flow is toward the ultrasound probe 10, the Doppler shift frequency is positive, and when blood flow is away from the ultrasound probe 10, the Doppler shift frequency is negative.

[0027] The color Doppler processing unit 32 determines the Doppler shift frequency at each depth in the ultrasound beam direction for each direction or position of the ultrasound beam scanned on the subject. The color Doppler processing unit 32 thereby determines the distribution of Doppler shift frequencies in the ultrasound beam scanning range. The color Doppler processing unit 32 further generates color mapping data for applying colors to the B-mode image so that positions where the Doppler shift frequency is positive are associated with, for example, a first color, and positions where the Doppler shift frequency is negative are associated with, for example, a second color, and outputs the color mapping data to the image forming unit 24.

[0028] The image forming unit 24 generates color Doppler image data and outputs it to the display processing unit 26. Here, the color Doppler image data is data representing a color Doppler image in which colors determined by the color mapping data are applied to each position on the B-mode image. The image forming unit 24 outputs the color Doppler image data to the display processing unit 26, and the display processing unit 26 generates a video signal based on the color Doppler image data as display processing and outputs it to the display 18. The display 18 displays the color Doppler image based on the video signal.

[0029] In Doppler mode, the distribution of Doppler shift frequencies in the scanning range of the ultrasound beam is determined based on the Doppler reception signal that has been subjected to high-pass filtering. By subjecting the Doppler reception signal to high-pass filtering, Doppler shift frequency components due to the movement of organs such as the heart are reduced compared to Doppler shift frequency components due to blood flow. This suppresses clutter that appears in the color Doppler image. Clutter is noise due to the movement of organs.

[0030] 2 shows the Doppler shift frequency components (52, 54) contained in the Doppler reception signal and the high-pass filter characteristic 50 in the wall filter processing unit 30. The horizontal axis indicates the absolute value of the Doppler shift frequency, and the vertical axis indicates the power of the Doppler reception signal or the amount of attenuation of the high-pass filter characteristic. The high-pass filter characteristic 50 shown in FIG. 2 increases in the downward direction of the vertical axis. In the following description, the high-pass filter characteristic in the wall filter processing unit 30 may be referred to as the wall filter characteristic.

[0031] In the wall filter characteristic 50, in the frequency range lower than the cutoff frequency fc, the attenuation increases as the frequency approaches 0. In the frequency range higher than the cutoff frequency fc, the attenuation is smaller or zero compared to the frequency range lower than the cutoff frequency fc. In the example shown in FIG. 2, among the Doppler shift frequency components, a component 54 due to organ movement extends from 0 frequency toward the high frequency range, to the low frequency side of a component 52 due to blood flow. The component 52 due to blood flow overlaps the high frequency side of the component 54 due to organ movement and extends even higher. The cutoff frequency fc of the wall filter characteristic 50 is set at a position on the Doppler frequency axis higher than the component 54 due to organ movement, where the component 52 due to blood flow exists. As a result, the component 52 due to blood flow becomes dominant in the Doppler shift frequency components of the wall-filtered Doppler reception signal.

[0032] The wall filter characteristics of the wall filter processing unit 30 in this embodiment are defined by a cutoff frequency and a slope at frequencies below the cutoff frequency. The cutoff frequency is defined as the frequency at which the attenuation increases from a minimum value (e.g., 0 dB) from high frequencies to low frequencies and reaches 3 dB. The slope indicates, for example, the rate of increase in attenuation when the frequency is reduced by one-tenth, and is expressed in units such as [dB / dec].

[0033] Here, as an example of a wall filter characteristic, one in which the vertical and horizontal axes are decibel scales and the attenuation changes linearly is shown, but the wall filter characteristic may have various characteristics that indicate high-pass filter characteristics.

[0034] The ultrasound diagnostic device 100 may be used to observe various regions of a subject. In conventional ultrasound diagnostic devices, the ultrasound transmission / reception conditions and wall filter characteristics are not always appropriate for the region to be observed, and clutter is likely to occur depending on the region to be observed. Therefore, in this embodiment, the ultrasound transmission / reception conditions and wall filter characteristics are determined based on the S / N evaluation process described below.

[0035] The S / N evaluation process is performed when the ultrasound diagnostic apparatus 100 is operating in B-mode. Fig. 3 shows an example of a B-mode image displayed on the display 18. Fig. 3 shows a vascular wall 60 and a noise region 62. In response to a user's operation on the operation unit 16, the control unit 36 ​​sets a blood flow evaluation region 66 in an intravascular region 64 sandwiched between two vascular walls 60, and sets a clutter evaluation region 70 in an extravascular region 68 outside the intravascular region 64, as an evaluation region setting process. The blood flow evaluation region 66 and the clutter evaluation region 70 may be regions calculated on a virtual cross-sectional plane within the subject from which a B-mode image is acquired.

[0036] A B-mode image is a collection of multiple pixels, and the blood flow evaluation area 66 and the clutter evaluation area 70 may be polygonal, approximately circular, or approximately elliptical regions containing multiple pixels. In the example shown in FIG. 3, the blood flow evaluation area 66 and the clutter evaluation area 70 are each rectangular. Under control of the control unit 36, the S / N evaluation unit 34 calculates a blood flow evaluation value as the pixel evaluation value for the blood flow evaluation area 66 and a clutter evaluation value as the pixel evaluation value for the clutter evaluation area 70. The pixel evaluation value is a value that indicates the tendency of pixel size in the area in which it is calculated. The blood flow evaluation value may be a statistical value such as the average, median, or mode for multiple pixels included in the blood flow evaluation area 66. The clutter evaluation value may be a statistical value such as the average, median, or mode for multiple pixels included in the clutter evaluation area 70.

[0037] The S / N evaluation unit 34 calculates an S / N evaluation value by dividing the blood flow evaluation value by the clutter evaluation value as the ratio of the blood flow evaluation value to the clutter evaluation value, and outputs the S / N evaluation value to the control unit 36. The control unit 36 ​​controls the transmission / reception condition determination unit 28 based on the S / N evaluation value, and sets the transmission / reception conditions for transmitting and receiving ultrasonic waves in the ultrasound probe 10.

[0038] The transmission and reception conditions include ultrasonic wave distribution, beam depth, pulse repetition frequency, etc. FIG. 4 schematically shows an ultrasonic probe 10 equipped with a plurality of ultrasonic transducers 72. In the ultrasonic probe 10, the plurality of ultrasonic transducers 72 are arranged in the horizontal direction (longitudinal direction). The beam depth D refers to the distance between the aperture plane on which the ultrasonic transducers 72 are arranged and the point where the focus F of the ultrasonic beam 74 is formed. The ultrasonic wave distribution may be defined, for example, as the maximum width W of the range in which ultrasonic waves having power exceeding a predetermined threshold are distributed on a plane a predetermined distance away from the aperture plane. The pulse repetition frequency is defined as the reciprocal of the transmission interval of ultrasonic pulses when the ultrasonic pulses are repeatedly transmitted in Doppler mode.

[0039] The transmission and reception conditions also include the intensity of the ultrasonic waves transmitted from the ultrasonic probe 10 and the scanning interval of the ultrasonic transmission beam when scanning with the ultrasonic beam. The scanning interval may be expressed in units of the interval at which the ultrasonic transducers 72 are arranged. Fig. 5 shows an example in which an ultrasonic beam 80 extending in a direction perpendicular to the aperture plane is linearly scanned in the direction in which the ultrasonic transducers 72 are arranged. The scanning interval shown in Fig. 8(a) is twice the scanning interval shown in Fig. 8(b).

[0040] A transmission / reception condition candidate database (referred to as DB in the drawings) 38 stored in the memory 20 stores multiple pieces of information for setting such transmission / reception conditions. A transmission / reception condition candidate reading unit 40 provided in the memory 20 is hardware for reading information from the transmission / reception condition candidate database 38. The transmission / reception condition determining unit 28 reads one of the multiple pieces of information for setting the transmission / reception conditions via the transmission / reception condition candidate reading unit 40 in the memory 20, and sets the transmission / reception conditions in the transmission / reception unit 12.

[0041] Furthermore, the control unit 36 ​​may control the transmission / reception condition determination unit 28 and the wall filter processing unit 30 based on the S / N evaluation value to set the wall filter characteristics. The wall filter characteristics are determined by, for example, a cutoff frequency and a slope, as described above. The wall filter characteristics change by changing at least one of the cutoff frequency and the slope. A wall filter candidate database (represented as DB in the drawings) 42 stored in the memory 20 stores multiple sets of filter tap coefficients for setting the wall filter characteristics. A filter coefficient candidate reading unit 44 included in the memory 20 is hardware for reading information from the wall filter candidate database 42. The wall filter processing unit 30 includes a digital filter whose characteristics are determined by inputting the filter tap coefficient sets. The wall filter processing unit 30 reads one of the multiple sets of filter tap coefficients via the filter coefficient candidate reading unit 44 in the memory 20 to set the wall filter characteristics of the wall filter processing unit 30.

[0042] The control unit 36 ​​may search for transmission / reception conditions and wall filtering characteristics when the S / N evaluation value satisfies a predetermined condition, and may execute a measurement condition setting process to set at least one of the transmission / reception conditions and the wall filtering characteristics so that the S / N evaluation value satisfies the predetermined condition. This predetermined condition may be a condition that the S / N evaluation value exceeds a predetermined threshold value or a condition that the S / N evaluation value is maximized.

[0043] The control unit 36 ​​repeatedly executes the process of acquiring the S / N evaluation value from the S / N evaluation unit 34 multiple times while, for example, changing at least one of the transmission / reception conditions and the wall filter characteristics. The control unit 36 ​​causes the transmission / reception condition determination unit 28 and the wall filter processing unit 30 to set the transmission / reception conditions and wall filter characteristics when the S / N evaluation value exceeds a predetermined threshold, respectively. Then, the control unit 36 ​​causes the transmission / reception condition determination unit 28 and the wall filter processing unit 30 to maintain the transmission / reception conditions and wall filter characteristics when the S / N evaluation value exceeds the predetermined threshold.

[0044] As described above, the ultrasound diagnostic apparatus 100 includes a transceiver unit 12 that transmits ultrasound waves to a subject via the ultrasound probe 10 and receives reflected waves from the subject via the ultrasound probe 10, and an information processing unit 14. By executing a program, the information processing unit 14 configures a B-mode image generation processing unit 22, an image forming unit 24, a display processing unit 26, a transmission / reception condition determination unit 28, a wall filter processing unit 30, a color Doppler processing unit 32, an S / N evaluation unit 34, and a control unit 36, and performs the following processes: That is, the information processing unit 14 performs B-mode image generation processing, wall filter processing, color Doppler processing, evaluation processing, and measurement condition setting processing.

[0045] The B-mode image generation process is a process of generating B-mode image data based on the reception signals generated by the transmitter-receiver 12. The evaluation area setting process is a process of setting a blood flow evaluation area 66 and a clutter evaluation area 70 in the region where the B-mode image data is generated. The wall filter process is a process for the Doppler reception signals generated by the transmitter-receiver 12. The color Doppler processing is a process of generating color mapping data for the B-mode image based on the Doppler reception signals that have been subjected to wall filter processing. The evaluation process is a process of calculating pixel evaluation values ​​for each of the blood flow evaluation area 66 and the clutter evaluation area 70. The measurement condition setting process is a process of setting at least one of the transmission and reception conditions in the transmitter-receiver 12 and the characteristics of the wall filter processing according to each pixel evaluation value.

[0046] According to the ultrasound diagnostic apparatus 100 of this embodiment, S / N evaluation values ​​are calculated for the blood flow evaluation area 66 and the clutter evaluation area 70 set by the user. Then, transmission and reception conditions and wall filter characteristics are set based on the S / N evaluation values. As a result, appropriate transmission and reception conditions and wall filter characteristics are set based on the blood flow evaluation area 66 and the clutter evaluation area 70 that have been appropriately set based on the user's knowledge and experience, and clutter that appears in the color Doppler image is suppressed.

[0047] 6 shows the configuration of an ultrasound diagnostic apparatus 102 according to the second embodiment. The ultrasound diagnostic apparatus 102 differs from the ultrasound diagnostic apparatus 100 in that the control unit 36 ​​includes an observation region specifying unit 46 and an observation condition setting table 48.

[0048] The control unit 36 ​​executes a preset that sets each control parameter for each function of the ultrasound diagnostic apparatus 102. By activating a preset for a certain function, for example, each control parameter is set to a default value (standard value) for that function. For a certain control parameter, the display processing unit 26 displays an input format image for inputting the control parameter on the display 18. For the input format image, the control parameter is set by the user operating the operation unit 16. There are presets for various diagnostic categories such as early obstetrics, thyroid diagnosis, abdominal diagnosis, and chest diagnosis, and the diagnostic category is selected by the user operating the operation unit 16.

[0049] The control parameters include, for example, the depth of the observation range (diagnostic range), the gain for the received signal, time gain control, focus, and echo enhancement level. The time gain control is a control parameter that adjusts the state in which the gain is increased over the reception time. The focus is a control parameter that indicates the degree to which the ultrasound beam is converged. The echo enhancement level is a control parameter that indicates the degree to which the contours of the B-mode image are emphasized.

[0050] The observation site specifying unit 46 in the control unit 36 ​​may specify an observation site in the subject in accordance with the preset operation. In this case, the observation site specifying unit 46 specifies a diagnosis site such as the heart, carotid artery, blood vessels in the lower limbs, or liver, based on, for example, the diagnosis category for which the preset was executed and each control parameter set in the preset.

[0051] Generally, for each diagnostic region of a subject, there are appropriate transmission / reception conditions and wall filter characteristics for forming a color Doppler image. That is, because the observation position and observation range differ depending on the diagnostic region, the appropriate focal depth and appropriate ultrasound distribution also differ depending on the diagnostic region. In addition, the tendency of the magnitude of blood flow velocity differs depending on the diagnostic region, and the tendency of the spectrum of the Doppler shift frequency component of blood flow also differs depending on the diagnostic region. Therefore, the appropriate wall filter characteristics differ depending on the diagnostic region.

[0052] Therefore, the control unit 36 ​​executes a measurement condition setting process to set the transmission and reception conditions and wall filter processing characteristics in the transmission and reception unit 12 according to the observation region. The control unit 36 ​​pre-stores an observation condition setting table 48 that associates information indicating predetermined appropriate transmission and reception conditions and wall filter characteristics with information specifying the diagnosis region. The control unit 36 ​​references the observation condition setting table 48 to acquire the setting information. The setting information indicates the transmission and reception conditions and wall filter characteristics appropriate for the diagnosis region specified by the observation region specifying unit 46.

[0053] The control unit 36 ​​controls the transmission / reception condition determination unit 28 to set the transmission / reception conditions in the transmission / reception unit 12 to the transmission / reception conditions indicated by the setting information. The transmission / reception condition determination unit 28 reads, from the transmission / reception condition candidate database 38, information that matches the setting information among multiple types of information, via the transmission / reception condition candidate reading unit 40 in the memory 20, and sets the transmission / reception conditions in the transmission / reception unit 12 to the transmission / reception conditions indicated by the setting information.

[0054] The control unit 36 ​​controls the wall filter processing unit 30 to set the wall filter characteristics to the characteristics indicated by the setting information. The wall filter processing unit 30 reads, from the wall filter candidate database 42, a filter tap coefficient group that matches the setting information among a plurality of filter tap coefficient groups via a filter coefficient candidate reading unit 44 in the memory 20, and sets the wall filter characteristics in the wall filter processing unit 30.

[0055] According to this process, appropriate transmission and reception conditions and wall filter characteristics for the region to be diagnosed can be quickly set.

[0056] 7 shows an ultrasonic diagnostic apparatus 104 according to the third embodiment. The ultrasonic diagnostic apparatus 104 is obtained by adding an observation part specifying unit 46 and an adjustment range setting table 90 to the control unit 36 ​​of the ultrasonic diagnostic apparatus 100 according to the first embodiment.

[0057] As described above, the observation region specifying unit 46 specifies the diagnosis region and generates information for specifying the diagnosis region. The adjustment range setting table 90 is a table in which information specifying the diagnosis region is associated with information indicating the respective adjustment ranges of the transmission and reception conditions and the wall filter characteristics. The adjustment range of the transmission and reception conditions may be represented by lower and upper limit values ​​of each numerical value representing the transmission and reception conditions. The adjustment range of the transmission and reception conditions includes appropriate values ​​for each numerical value representing the transmission and reception conditions. The adjustment range of the transmission and reception conditions may be represented by lower and upper limit values ​​of, for example, the ultrasound distribution, beam depth, pulse repetition frequency, scanning interval of the ultrasound transmission beam, and intensity of the ultrasound transmitted from the ultrasound probe 10.

[0058] The adjustment range of the wall filter characteristics is represented by the lower limit and upper limit of each numerical value representing the wall filter characteristics. The adjustment range of the wall filter characteristics includes appropriate values ​​for each numerical value representing the wall filter characteristics. The adjustment range of the wall filter characteristics may be represented by the lower limit and upper limit of each of the cutoff frequency, slope, etc., for example.

[0059] The control unit 36 ​​refers to the adjustment range setting table 90 and acquires the adjustment ranges of the transmission and reception conditions and the adjustment ranges of the wall filter characteristics for the diagnostic region identified by the observation region identifying unit 46 .

[0060] The control unit 36 ​​controls the transmission and reception condition determination unit 28 based on the S / N evaluation value within the adjustment range of the transmission and reception conditions, and sets the transmission and reception conditions when transmitting and receiving ultrasound in the ultrasound probe 10. The control unit 36 ​​also controls the wall filter processing unit 30 based on the S / N evaluation value within the adjustment range of the wall filter characteristics, and sets the wall filter characteristics.

[0061] The control unit 36 ​​acquires the S / N evaluation value from the S / N evaluation unit 34 while varying at least one of the transmission / reception conditions and the wall filter characteristics, for example, within the adjustment ranges of the transmission / reception conditions and the adjustment ranges of the wall filter characteristics. The control unit 36 ​​causes the transmission / reception condition determination unit 28 and the wall filter processing unit 30 to set the transmission / reception conditions and the wall filter characteristics when the S / N evaluation value exceeds a predetermined threshold, respectively. Then, the control unit 36 ​​causes the transmission / reception condition determination unit 28 and the wall filter processing unit 30 to maintain the transmission / reception conditions and the wall filter characteristics when the S / N evaluation value exceeds the predetermined threshold.

[0062] According to this process, the process of setting the transmission / reception conditions and the wall filter characteristics is performed within the adjustment range of the transmission / reception conditions and the adjustment range of the wall filter characteristics. Since the adjustment range for setting appropriate transmission / reception conditions and the adjustment range for setting appropriate wall filter characteristics are limited, the process of setting the transmission / reception conditions and the wall filter characteristics is performed quickly. [Explanation of symbols]

[0063] 10 ultrasound probe, 12 transmission and reception unit, 14 information processing unit, 16 operation unit, 18 display, 20 memory, 22 B-mode image generation processing unit, 24 image formation unit, 26 display processing unit, 28 transmission and reception condition determination unit, 30 wall filter processing unit, 32 color Doppler processing unit, 34 S / N evaluation unit, 36 control unit, 38 transmission and reception condition candidate database, 40 transmission and reception condition candidate readout unit, 42 wall filter candidate database, 44 filter coefficient candidate readout unit, 46 observation region identification unit, 48 observation condition setting table, 50 wall filter characteristics (high-pass filter characteristics), 52 Doppler shift frequency component based on blood flow, 54 Doppler shift frequency component based on organ movement, 60 blood vessel wall, 62 noise region, 64 intravascular region, 66 blood flow evaluation region, 70 clutter evaluation region, 90 adjustment range setting table, 100, 102, 104 ultrasound diagnostic device.

Claims

1. a transmitting / receiving unit that transmits ultrasonic waves to a subject via an ultrasonic probe and receives reflected waves from the subject via the ultrasonic probe; and an information processing unit; The information processing unit a B-mode image generation process for generating B-mode image data based on the received signal generated by the transmitting and receiving unit; an evaluation area setting process for setting a blood flow evaluation area and a clutter evaluation area in the area where the B-mode image data is generated; Wall filtering of the Doppler reception signal generated by the transmitting and receiving unit; color Doppler processing for generating color mapping data for the B-mode image data based on the Doppler reception signal that has been subjected to the wall filter processing; an evaluation process for obtaining pixel evaluation values ​​for the blood flow evaluation area and the clutter evaluation area; and performing a measurement condition setting process for setting at least one of a transmission / reception condition in the transmission / reception unit and a characteristic of the wall filter processing in accordance with each of the pixel evaluation values.

2. The ultrasound diagnostic apparatus according to claim 1, The information processing unit executes a display process for displaying a B-mode image based on the B-mode image data on a display device; The evaluation area setting process includes: An ultrasonic diagnostic apparatus comprising: a process for setting the blood flow evaluation area and the clutter evaluation area in response to an operation performed while the B-mode image is displayed.

3. 3. The ultrasound diagnostic apparatus according to claim 1, The measurement condition setting process includes:

10. An ultrasonic diagnostic apparatus comprising: a process for setting at least one of a transmission / reception condition in the transmission / reception unit and a characteristic of the wall filter processing within a range determined according to an observation region.

4. The ultrasonic diagnostic apparatus according to claim 3, The information processing unit An ultrasonic diagnostic apparatus, characterized in that the observation region is specified in accordance with a preset operation that sets each control parameter for each function of the ultrasonic diagnostic apparatus.

5. 3. The ultrasound diagnostic apparatus according to claim 1, The information processing unit executing the evaluation process a plurality of times while changing at least one of the transmission / reception conditions and the characteristics of the wall filtering process; searching for the transmission / reception conditions and the characteristics of the wall filtering process when a ratio of the pixel evaluation value for the blood flow evaluation area to the pixel evaluation value for the clutter evaluation area satisfies a predetermined condition; The measurement condition setting process includes: An ultrasonic diagnostic apparatus comprising a process for setting at least one of the transmission and reception conditions and the characteristics of the wall filtering process so that the ratio satisfies the predetermined condition.

6. a transmitting / receiving unit that transmits ultrasonic waves to a subject via an ultrasonic probe and receives reflected waves from the subject via the ultrasonic probe; and an information processing unit; The information processing unit Wall filtering of the Doppler reception signal generated by the transmitting and receiving unit; color Doppler processing for generating color mapping data for a B-mode image based on the Doppler reception signal that has been subjected to the wall filter processing; and executing a measurement condition setting process for setting transmission and reception conditions in the transmission and reception unit and characteristics of the wall filter processing in accordance with an observation region.

7. 7. The ultrasonic diagnostic apparatus according to claim 6, The information processing unit An ultrasonic diagnostic apparatus, characterized in that the observation region is specified in accordance with a preset operation that sets each control parameter for each function of the ultrasonic diagnostic apparatus.

8. The ultrasound diagnostic apparatus according to claim 6 or 7, An ultrasonic diagnostic apparatus, characterized in that a cutoff frequency of the characteristics of the wall filtering process is set to a frequency predetermined for the observation region.

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