JP7383400B2 - Ultrasonic diagnostic equipment, scan control method and scan control program - Google Patents

Description

Embodiments of the present invention relate to an ultrasonic diagnostic apparatus, a scan control method, and a scan control program.

Conventionally, an ultrasound examination is performed by a technician or doctor operating an ultrasound probe on the body surface of a subject to obtain information on tissue structure, blood flow, etc. inside the human body. For example, a technician or doctor scans the inside of the subject with ultrasound by operating an ultrasound probe that transmits and receives ultrasound on the body surface, depending on the diagnosis site and diagnosis content, and uses ultrasound to show the tissue structure. Images and ultrasound images showing information such as blood flow are collected.

In such ultrasonic examinations, multiple types of ultrasonic probes are used to appropriately perform diagnosis. For example, in order to scan a wide range of areas such as the abdomen, a convex probe in which a plurality of piezoelectric vibrators are arranged in a fan shape is used. Further, for example, in order to scan peripheral blood vessels, superficial organs, etc., a linear probe in which a plurality of piezoelectric vibrators are arranged in a straight line is used. Here, such multiple types of ultrasonic probes may be switched and used depending on the purpose during an ultrasonic examination.

Furthermore, in linear probes, various techniques for controlling the angle of the scanning line are known. For example, in order to compensate for the narrow field of view in a linear probe, a trapezoid scan (trapezoidal scan, vector scan) is known in which the angle of the scanning line is controlled to ensure a wide field of view. For example, oblique scanning (oblique scanning) is known in which the scanning line of a linear probe is controlled to be orthogonal to the running direction of the blood vessel in order to make it easier to observe the state of blood flow in blood vessels parallel to the body surface. ing.

Japanese Patent Application Publication No. 2010-154980

A problem to be solved by embodiments of the present invention is to improve the throughput of ultrasonic testing.

The ultrasonic diagnostic apparatus of the embodiment includes an ultrasonic probe and a control section. In an ultrasound probe, a plurality of piezoelectric vibrators are arranged along a predetermined curvature. The control unit operates in a first scan mode in which a fan-shaped scan is executed, and in the first scan mode, a difference between a scan line interval at a first depth and a scan line interval at a second depth deeper than the first depth. The plurality of piezoelectric vibrators are controlled to execute a second scan mode in which the size of the piezoelectric vibrator is smaller than that of the second scan mode. The control unit is configured to drive a piezoelectric vibrator at a second position closer to the center in the array direction than the first position than the delay given to driving the piezoelectric vibrator at a first position in the array direction of the plurality of piezoelectric vibrators. The second scan mode is executed by increasing the delay given to driving the vibrator.

FIG. 1 is a block diagram showing an example of the configuration of an ultrasound diagnostic apparatus according to the first embodiment. FIG. 2A is a diagram for explaining an example of the first scan mode according to the first embodiment. FIG. 2B is a diagram for explaining an example of the second scan mode according to the first embodiment. FIG. 3 is a diagram schematically showing an ultrasound probe that is a convex probe according to the first embodiment. FIG. 4 is a diagram for explaining an example of scanning line control in the second scan mode according to the first embodiment. FIG. 5 is a diagram for explaining an example of coordinate transformation by the image generation function according to the first embodiment. FIG. 6 is a diagram illustrating an example of an ultrasound image generated in the second scan mode according to the first embodiment. FIG. 7 is a flowchart for explaining the processing procedure of the ultrasonic diagnostic apparatus according to the first embodiment. FIG. 8 is a diagram for explaining an example of the second scan mode according to the second embodiment. FIG. 9 is a diagram illustrating an example of an ultrasound image according to another embodiment.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an ultrasonic diagnostic apparatus, a scan control method, and a scan control program according to the present application will be described in detail with reference to the accompanying drawings. Note that the ultrasound diagnostic apparatus, scan control method, and scan control program according to the present application are not limited to the embodiments described below. Furthermore, in the following description, similar components are given common reference numerals, and redundant description will be omitted.

(First embodiment)
First, an ultrasonic diagnostic apparatus according to a first embodiment will be described. FIG. 1 is a block diagram showing an example of the configuration of an ultrasound diagnostic apparatus 1 according to the first embodiment. As shown in FIG. 1, an ultrasonic diagnostic apparatus 1 according to the present embodiment includes an ultrasonic probe 2, a display 3, an input interface 4, and an apparatus main body 5. and an input interface 4 are communicably connected to the device main body 5.

The ultrasonic probe 2 is connected to a transmitting/receiving circuit 51 included in the main body 5 of the apparatus. The ultrasonic probe 2 has, for example, a plurality of piezoelectric vibrators in the probe body, and these piezoelectric vibrators generate ultrasonic waves based on drive signals supplied from the transmitting/receiving circuit 51. Further, the ultrasound probe 2 receives reflected waves from the subject P and converts them into electrical signals. Further, the ultrasonic probe 2 includes, in the probe body, a matching layer provided on the piezoelectric vibrator and a backing material that prevents propagation of ultrasonic waves backward from the piezoelectric vibrator. Note that the ultrasonic probe 2 is detachably connected to the device main body 5. Here, the ultrasound probe 2 according to the present embodiment is a convex type ultrasound probe in which a plurality of piezoelectric vibrators are arranged along a predetermined curvature.

When ultrasonic waves are transmitted from the ultrasonic probe 2 to the subject P, the transmitted ultrasonic waves are successively reflected by discontinuous surfaces of acoustic impedance in the body tissues of the subject P, and are transmitted to the ultrasound probe as reflected wave signals. 2 is received by a plurality of piezoelectric vibrators included in the device. The amplitude of the received reflected wave signal depends on the difference in acoustic impedance at the discontinuity surface from which the ultrasound wave is reflected. Note that when a transmitted ultrasound pulse is reflected from a moving bloodstream or a surface such as a heart wall, the reflected wave signal depends on the velocity component of the moving object in the ultrasound transmission direction due to the Doppler effect. and undergo a frequency shift.

The ultrasonic probe 2 may be a one-dimensional ultrasonic probe in which a plurality of piezoelectric vibrators are arranged in a row, which mechanically oscillates a plurality of piezoelectric transducers, or an ultrasonic probe in which a plurality of piezoelectric transducers are arranged in a lattice pattern. The ultrasonic probe is a two-dimensional ultrasonic probe that is two-dimensionally placed in the center of the body, and is capable of scanning the subject P in three dimensions.

The display 3 displays a GUI (Graphical User Interface) for the operator of the ultrasound diagnostic device 1 to input various setting requests using the input interface 4, and displays ultrasound images and displays generated in the device body 5. Display information, etc. Further, the display 3 displays various messages and display information in order to notify the operator of the processing status and processing results of the apparatus main body 5. The display 3 also has a speaker and can output audio.

The input interface 4 accepts operations for setting a predetermined position (for example, a region of interest, etc.), setting the display direction of an image, inputting numerical values, switching modes, and the like. For example, the input interface 4 uses a trackball, a switch, a button, a mouse, a keyboard, a touchpad that performs input operations by touching the operation surface, a touch monitor with an integrated display screen and touchpad, and an optical sensor. This is realized by a non-contact input circuit, a voice input circuit, etc. The input interface 4 is connected to a processing circuit 55 to be described later, converts an input operation received from an operator into an electrical signal, and outputs the electrical signal to the processing circuit 55. Note that in this specification, the input interface 4 is not limited to one that includes physical operation parts such as a mouse and a keyboard. For example, an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the device and outputs this electrical signal to the processing circuit 55 is also included in the input interface example.

The device main body 5 includes a transmitting/receiving circuit 51, a B-mode processing circuit 52, a Doppler processing circuit 53, a memory 54, and a processing circuit 55. In the ultrasonic diagnostic apparatus 1 shown in FIG. 1, each processing function is stored in the memory 54 in the form of a computer-executable program. The transmitting/receiving circuit 51, the B-mode processing circuit 52, the Doppler processing circuit 53, and the processing circuit 55 are processors that read programs from the memory 54 and execute them to implement functions corresponding to each program. In other words, each circuit in a state where each program is read has a function corresponding to the read program.

The transmission/reception circuit 51 includes a pulse generator, a transmission delay circuit, a pulser, etc., and supplies a drive signal to the ultrasound probe 2. The pulse generator repeatedly generates rate pulses to form transmitted ultrasound waves at a predetermined rate frequency. In addition, in the transmission delay circuit, a pulse generator generates a delay time for each piezoelectric vibrator necessary for focusing the ultrasound generated from the ultrasound probe 2 into a beam shape and determining the transmission directivity. Give for each rate pulse. Further, the pulser applies a drive signal (drive pulse) to the ultrasound probe 2 at a timing based on the rate pulse. That is, the transmission delay circuit arbitrarily adjusts the transmission direction of the ultrasonic waves transmitted from the piezoelectric vibrator surface by changing the delay time given to each rate pulse.

Note that the transmitting/receiving circuit 51 has a function that can instantly change the transmitting frequency, transmitting drive voltage, etc. in order to execute a predetermined scan sequence based on instructions from a processing circuit 55, which will be described later. In particular, changing the transmission drive voltage is realized by a linear amplifier-type oscillation circuit that can instantly switch its value, or by a mechanism that electrically switches multiple power supply units.

The transmitting/receiving circuit 51 includes a preamplifier, an A/D (Analog/Digital) converter, a receiving delay circuit, an adder, etc., and performs various processing on the reflected wave signal received by the ultrasound probe 2 to reflect the reflected wave signal. Generate wave data. The preamplifier amplifies the reflected wave signal for each channel. The A/D converter performs A/D conversion on the amplified reflected wave signal. The reception delay circuit provides the delay time necessary to determine the reception directivity. The adder performs addition processing of the reflected wave signals processed by the reception delay circuit to generate reflected wave data. By the addition process of the adder, the reflected component from the direction corresponding to the receiving directivity of the reflected wave signal is emphasized, and a comprehensive beam of ultrasonic transmission and reception is formed by the receiving directivity and the transmitting directivity.

The B-mode processing circuit 52 receives reflected wave data from the transmitting/receiving circuit 51, performs logarithmic amplification, envelope detection processing, etc., and generates data (B-mode data) in which signal strength is expressed by brightness of luminance. .

The Doppler processing circuit 53 performs frequency analysis on velocity information from the reflected wave data received from the transmitting/receiving circuit 51, extracts blood flow, tissue, and contrast agent echo components due to the Doppler effect, and extracts moving body information such as velocity, dispersion, and power. Generate data extracted from multiple points (Doppler data). The moving body of this embodiment is a fluid such as blood flowing in a blood vessel or lymph fluid flowing in a lymphatic vessel.

Note that the B-mode processing circuit 52 and the Doppler processing circuit 53 are capable of processing both two-dimensional reflected wave data and three-dimensional reflected wave data. That is, the B-mode processing circuit 52 generates two-dimensional B-mode data from two-dimensional reflected wave data, and generates three-dimensional B-mode data from three-dimensional reflected wave data. Further, the Doppler processing circuit 53 generates two-dimensional Doppler data from two-dimensional reflected wave data, and generates three-dimensional Doppler data from three-dimensional reflected wave data. The three-dimensional B-mode data is data to which a luminance value is assigned according to the reflection intensity of the reflection source located at each of a plurality of points (sample points) set on each scanning line in the three-dimensional scanning range. In addition, in 3D Doppler data, a brightness value is assigned to each of multiple points (sample points) set on each scanning line in the 3D scanning range according to the value of blood flow information (velocity, dispersion, power). The data will be

The memory 54 stores the ultrasound image for display generated by the processing circuit 55. Further, the memory 54 stores data generated by the B-mode processing circuit 52 and the Doppler processing circuit 53. The memory 54 also stores various data such as control programs for transmitting and receiving ultrasound waves, image processing, and display processing, diagnostic information (e.g., patient ID, doctor's findings, etc.), diagnostic protocols, and various body marks. do.

The processing circuit 55 controls the entire processing of the ultrasound diagnostic apparatus 1. Specifically, the processing circuit 55 performs various processes by reading programs corresponding to the control function 551, image generation function 552, and display control function 553 shown in FIG. 1 from the memory 54 and executing them. Here, the control function 551 is an example of a control unit. Further, the image generation function 552 is an example of an image generation unit.

The control function 551 controls the transmitting/receiving circuit 51 , the B-mode processing circuit 52 , and the Doppler processing circuit based on various setting requests input by the operator via the input interface 4 and various control programs and various data read from the memory 54 . 53 is controlled. In addition, the control function 551 changes the transmission direction of the scanning line transmitted by the ultrasound probe 2, which is a convex probe, to create a first scan mode (convex scan mode) and a second scan mode (linear scan mode). mode). Note that the first scan mode and the second scan mode will be described in detail later.

The image generation function 552 generates an ultrasound image from the data generated by the B-mode processing circuit 52 and the Doppler processing circuit 53. That is, the image generation function 552 generates 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 circuit 52. The B-mode image data is data depicting the tissue shape within the area scanned by the ultrasound. Further, the image generation function 552 generates Doppler image data representing moving body information from the two-dimensional Doppler data generated by the Doppler processing circuit 53. The Doppler image data is velocity image data, dispersion image data, power image data, or image data that is a combination of these. The Doppler image data is data indicating fluid information regarding the fluid flowing within the region scanned by the ultrasound.

Here, the image generation function 552 generally converts (scan convert) a scanning line signal sequence of ultrasonic scanning into a scanning line signal sequence of a video format typified by television etc. Generate an image. Specifically, the image generation function 552 generates an ultrasonic image for display by performing coordinate transformation according to the scanning form of ultrasonic waves by the ultrasonic probe 2. Here, the image generation function 552 of this embodiment performs coordinate transformation according to the first scan mode and the second scan mode. Note that this coordinate transformation will be detailed later.

In addition to scan conversion, the image generation function 552 performs various image processing, such as image processing (smoothing processing) that regenerates an average luminance image using a plurality of image frames after scan conversion; Performs image processing (edge enhancement processing), etc. using a differential filter within the image. Further, the image generation function 552 synthesizes text information of various parameters, scales, body marks, etc. with the ultrasound image.

That is, the B-mode data and Doppler data are ultrasound image data before scan conversion processing, and the data generated by the image generation function 552 is an ultrasound image for display after scan conversion processing. Note that B-mode data and Doppler data are also called raw data.

Furthermore, the image generation function 552 generates three-dimensional B-mode image data by performing coordinate transformation on the three-dimensional B-mode data generated by the B-mode processing circuit 52. Further, the image generation function 552 generates three-dimensional Doppler image data by performing coordinate transformation on the three-dimensional Doppler data generated by the Doppler processing circuit 53. The three-dimensional B-mode data and three-dimensional Doppler data become volume data before scan conversion processing. That is, the image generation function 552 generates "three-dimensional B-mode image data or three-dimensional Doppler image data" as "volume data that is three-dimensional ultrasound image data."

Further, the image generation function 552 can perform rendering processing on the volume data in order to generate various two-dimensional image data (ultrasound images) for displaying the volume data on the display 3.

The display control function 553 controls the display 3 to display the ultrasound image for display stored in the memory 54 . The control function 551 also controls the display 3 to display the processing results of each function. For example, the control function 551 controls display information to be displayed on the display 3.

The overall configuration of the ultrasound diagnostic apparatus 1 according to the first embodiment has been described above. With this configuration, the ultrasound diagnostic apparatus 1 according to the first embodiment makes it possible to improve the throughput of ultrasound examinations. Specifically, the ultrasound diagnostic apparatus 1 according to the first embodiment has an ultrasound probe 2 that is a convex probe in a first scan mode (convex scan mode) and a second scan mode (linear scan mode). By switching between the two, it is possible to reduce the frequency of examinations that require changing the ultrasound probe and improve the throughput of ultrasound examinations.

As described above, in ultrasonic testing, appropriate probes are used depending on the characteristics of the object to be observed. In particular, when using a convex probe, due to its shape characteristics, the scanning line spacing in the deep part becomes wide, and the spatial resolution in the azimuth direction becomes relatively poor, so there have been cases where the inspection is performed by switching to a linear probe. In addition, with a convex probe, the scanning lines are fan-shaped and have different angles, so when observing the state of blood flow in blood vessels parallel to the body surface, the angle of the scanning line relative to the blood flow changes even if the blood flow is in a constant direction. It happens. That is, there are scanning lines that go toward the blood flow approaching the ultrasound probe 2 and scan lines that go toward the blood flow that goes away from the ultrasound probe 2, and the display of the blood flow may not be in a fixed direction. Therefore, when observing the state of blood flow in blood vessels parallel to the body surface, a linear probe is used.

As described above, in ultrasonic examination, it may be necessary to change the grip of the ultrasonic probe, and changing the grip of the ultrasonic probe may reduce the throughput of the examination. Therefore, in the present application, by performing a linear scan similar to that of a linear probe using a convex probe, the number of times the ultrasound probe is changed is reduced, and the throughput of ultrasound examination is improved.

Details of the ultrasound diagnostic apparatus 1 according to the first embodiment will be described below. The control function 551 controls the difference between the first scan mode in which a fan-shaped scan is executed and the scanning line interval at a position near the transmitting/receiving surface of the ultrasound probe 2 and the scanning line interval at a position deeper than the position near the transmitting/receiving surface. A plurality of piezoelectric vibrators are controlled to execute a second scan mode in which the scan mode is smaller than the first scan mode. Specifically, the control function 551 controls the transmitting/receiving circuit 51 to change the delay time given to each rate pulse for forming the transmitted ultrasound, thereby switching between the first scan mode and the second scan mode. Control to run scan mode.

FIG. 2A is a diagram for explaining an example of the first scan mode according to the first embodiment. For example, the control function 551 controls the piezoelectric vibrator of the ultrasound probe 2 to execute a first scan mode in which a scanning line (ultrasonic beam) is transmitted in a fan shape, as shown in FIG. 2A. Specifically, as shown in FIG. 2A, the control function 551 controls the scanning line interval "b" at a deep position to be greater than the scanning line interval "a" at a position near the transmitting/receiving surface of the ultrasound probe 2. A wide, first scan mode is executed. That is, the control function 551 causes the first scan mode, which is a normal scan using a convex probe, to be executed.

In such a case, for example, the transmitting/receiving circuit 51, under the control of the control function 551, determines the number and position of piezoelectric vibrators used for transmitting the scanning line (ultrasonic beam) and the position of the scanning line based on the center of curvature. One scanning line is formed by giving a delay amount for each piezoelectric vibrator based on the scanning angle to each rate pulse corresponding to each piezoelectric vibrator. The transmitting/receiving circuit 51 executes the first scan mode by performing the above-described delay control on the piezoelectric vibrator for transmitting each scanning line. Note that control information regarding this delay control (for example, the amount of delay for forming each scanning line, etc.) is stored in the memory 54, and is read out and used when executing the first scan mode. Ru.

On the other hand, in the second scan mode, the control function 551 determines that the difference between the scanning line interval at a position near the transmitting/receiving surface of the ultrasound probe 2 and the scanning line interval at a position deeper than the position near the transmitting/receiving surface is the first one. Control so that it is smaller than the scan mode. That is, the control function 551 controls a plurality of scanning lines so that the difference between the scanning line interval at a position near the transmitting/receiving surface and the scanning line interval at a deep position is smaller than the difference "ba" in the first scan mode. Control the piezoelectric vibrator.

FIG. 2B is a diagram for explaining an example of the second scan mode according to the first embodiment. For example, as shown in FIG. 2B, the control function 551 sets the scanning line interval at a position near the transmitting/receiving surface to "a'" and the scanning line interval at a position deeper than the position near the transmitting/receiving surface to "a'". Control as follows. That is, the control function 551 controls the plurality of piezoelectric vibrators so that the scanning line interval at a position near the transmitting/receiving surface is the same as the scanning line interval at a position deeper than the position near the transmitting/receiving surface. In other words, the control function 551 controls to execute a linear scan using the ultrasonic probe 2, which is a convex probe.

In such a case, for example, under the control of the control function 551 implemented by the processing circuit 55, the transmitting/receiving circuit 51 controls the number and position of piezoelectric vibrators used for transmitting the scanning line (ultrasonic beam), and the number of adjacent piezoelectric vibrators. One scanning line is formed by giving a delay amount for each piezoelectric vibrator based on the distance from the scanning line to each rate pulse corresponding to each piezoelectric vibrator.

Hereinafter, how to determine the amount of delay will be explained with reference to FIG. FIG. 3 is a diagram schematically showing an ultrasound probe 2, which is a convex probe according to the first embodiment. Here, in FIG. 3, "A" indicates the beam origin position corresponding to the position of the piezoelectric vibrator provided in the ultrasound probe 2, and "B" indicates the delay calculation target position for which the delay amount is calculated. , and "C" indicates the center of curvature of the curved surface of the ultrasound probe 2. Further, in FIG. 3, "F" indicates the focus position, "r" indicates the radius of curvature, and "f" indicates the depth of focus. Further, in FIG. 3, "θ" indicates the angle from the probe center to the beam origin position A, and "φ" indicates the angle from the probe center to the delay calculation target position B.

In FIG. 3, a case will be described in which the beam is focused on a focus position F located directly below the beam origin position A. In such a case, the processing circuit 55 calculates the delay time with respect to the beam starting point position A at the delay calculation target position B when transmitting and receiving the ultrasound beam as follows. First, the distance x between the delay calculation target position B and the beam origin position A in the X-axis direction in FIG. 3 can be expressed by the following equation (1).

Here, the angle φ is the angle between the line segment connecting the center of curvature C and the delay calculation target position B and the line segment drawn from the center of curvature C in the Y-axis direction, and the angle θ is the angle between the center of curvature C and the beam origin position. This is the angle formed by the line segment connecting A and the line segment drawn from the center of curvature C in the Y-axis direction. Further, the distance y between the delay calculation target position B and the beam origin position A in the Y-axis direction in FIG. 3 can be expressed by the following equation (2).

The processing circuit 55 calculates the distance x and the distance y according to the above equations (1) and (2). Furthermore, the processing circuit 55 calculates the distance IBF between the delay calculation target position B and the focus position F using the following equation (3) using the distance f, distance x, and distance y between the beam origin position A and the focus position F. demand. Note that the focus position F is a known position.

Here, since the distance IAF between the beam origin position A and the focus position F is the focus depth f, the processing circuit 55 transmits and receives the ultrasonic beam originating from the beam origin position A that is focused on the focus position F. The delay time dAB of the delay calculation target position B with respect to the beam origin position A in this case is calculated according to the following equation (4). Note that "v" in equation (4) indicates the speed of sound.

Since the transmitted ultrasound from the delay calculation target position B is delayed by dAB at the focus position F compared to the transmitted ultrasound from the beam origin position A, the processing circuit 55 transmits the transmitted ultrasound from the beam origin position A. By controlling the transmitter/receiver circuit 51 to delay by dAB, it is possible to reduce the delay in the arrival of the ultrasound at the focus position F.

Here, if the piezoelectric vibrator between position B and position A in FIG. 3 is taken as the beam origin position, the piezoelectric vibration between position B and position A is It is clear from FIG. 3 that the amount of delay given to the beam from the position of the child is reduced. That is, the processing circuit 55 controls the transmitting/receiving circuit 51 so that the closer to the center of the plurality of piezoelectric vibrators in the arrangement direction, the greater the delay is given to the driving of the piezoelectric vibrators. The transmitter/receiver circuit 51 executes the second scan mode by performing the above-described delay control on the piezoelectric vibrator for transmitting each scan line.

FIG. 4 is a diagram for explaining an example of scanning line control in the second scan mode according to the first embodiment. Although FIG. 4 shows only the scanning line L1 and the scanning line L2 at the apex of the curved surface of the probe for convenience of explanation, in reality, scanning is performed by many other scanning lines. For example, when forming the scanning line L1 shown in FIG. 4, the transmitting/receiving circuit 51 applies the above-mentioned delay amount to the rate pulse for the piezoelectric vibrator used to form the scanning line L1. Here, when a plurality of piezoelectric vibrators are used to form the scanning line L1, the transmitting/receiving circuit 51 controls so that the piezoelectric vibrators closer to the center in the arrangement direction are delayed. In other words, in forming the scanning line L1, the transmitting/receiving circuit 51 performs delay control such that piezoelectric vibrators located on the outer side in the arrangement direction are driven faster.

Further, for example, when forming the scanning line L2 shown in FIG. 4, the transmitting/receiving circuit 51 applies the above-mentioned delay amount to the rate pulse for the piezoelectric vibrator used to form the scanning line L2. Here, in the case where a plurality of piezoelectric vibrators are used to form the scanning line L2, the transmitting/receiving circuit 51 has a delay so that the center in the arrangement direction is the slowest and the piezoelectric vibrators on the outer side are driven faster toward both sides. Control. Note that control information regarding this delay control (for example, the amount of delay for forming each scanning line, etc.) is stored in the memory 54, and is read out and used when executing the second scan mode. Ru.

In this way, the control function 551 can perform control to perform normal scanning and linear scanning using the convex probe. Here, the first scan mode and the second scan mode can be arbitrarily switched by an operator such as a technician or a doctor, and can also be switched automatically according to observation conditions.

For example, when the input interface 4 receives a switching operation from an operator, the first scan mode and the second scan mode are switched. For example, when an operator observes a wide area by normal scanning (first scan mode) using the ultrasound probe 2 (convex probe) and observes a detailed part deep inside, the operator uses the input interface 4 (for example, a button) to switch to the second scan mode. Thereby, the operator can observe a deep image similar to a linear scan without changing hands of the ultrasound probe 2.

Furthermore, the observation conditions include a scan range, and the control function 551 switches between the first scan mode and the second scan mode according to the scan range. For example, the control function 551 estimates the scan range based on the scan target region included in the subject information, and if the estimated scan range is wider than the threshold value, switches to the first scan mode and estimates the scan range. If the scan range obtained is narrower than the threshold value, the mode is switched to the second scan mode. For example, the control function 551 identifies the scan range in the depth direction based on the set focus position, switches to the first scan mode when the focus position is shallower than the threshold value, and switches to the first scan mode when the focus position is deeper than the threshold value. If so, switch to the second scan mode. Note that the mode switching according to the scan range described above is just an example. For example, a scan range may be set on the ultrasound image, and the first scan mode and the second scan mode may be switched according to the set scan range.

For example, the observation conditions include an observation mode, and the control function 551 controls scanning in the first scan mode when collecting B-mode data, and controls scanning in the second scan mode when collecting Doppler data. do. For example, when the control function 551 receives an operation for collecting B-mode data, the control function 551 switches to the first scan mode. Further, the control function 551 switches to the second scan mode when receiving an operation for collecting Doppler data.

The image generation function 552 generates an ultrasound image for display by performing coordinate transformation on each scanning line signal sequence based on reflected wave signals received by a plurality of piezoelectric vibrators. For example, an ultrasonic image for display is generated by performing coordinate transformation on the scanning line signal train collected in the first scan mode in accordance with scanning by a normal convex probe.

On the other hand, when scanning is performed in the second scan mode, the image generation function 552 performs coordinate transformation according to linear scanning. Here, in this embodiment, since linear scanning is performed using a convex probe, accurate coordinate transformation cannot be performed simply by performing coordinate transformation according to scanning by linear scanning. That is, in the convex probe, since a plurality of piezoelectric vibrators are arranged along a predetermined curvature, the image generation function 552 performs a coordinate transformation including a transformation based on the predetermined curvature, thereby generating a superimposed image for display. Generate a sound wave image.

FIG. 5 is a diagram for explaining an example of coordinate transformation by the image generation function 552 according to the first embodiment. For example, the image generation function 552 calculates the distance from the tip position P1 of the ultrasound probe 2 to the starting point position of each scanning line for each scanning line, as shown in FIG. For example, the image generation function 552 calculates the starting point position P2 of the scanning line L3 based on the curvatures of the plurality of piezoelectric vibrators. The image generation function 552 then calculates the distance "d" from the tip position P1 to the starting point P2 of the scanning line L3. Then, the image generation function 552 performs coordinate transformation on the signal of the scanning line L3 according to the scanning by the linear scan, and also performs coordinate transformation based on the distance "d".

The image generation function 552 generates an ultrasound image for display by performing coordinate transformation on each scanning line, including the transformation based on the curvature described above. Note that the distance from the tip position P1 to the starting point position in each scanning line can be stored in the memory 54 as an offset value. That is, in the second scan mode, the image generation function 552 reads out the scanning line signal sequence, the coordinate conversion method according to the linear scan, and the offset value from the memory 54 and performs the coordinate conversion, thereby creating a display image. Generate ultrasound images. Note that the scanning line signal sequence data (B mode data or Doppler data) stored in the memory 54 includes information on the collected ultrasound probe (for example, convex probe, etc.) and information on the collected mode (for example, , second scan mode, etc.).

The display control function 553 controls the display 3 to display the ultrasound image for display generated by the image generation function 552. FIG. 6 is a diagram illustrating an example of an ultrasound image generated in the second scan mode according to the first embodiment. For example, the display control function 553 displays an ultrasound image obtained by linear scanning with a convex probe, as shown in FIG. Here, the ultrasound image shown in Fig. 6 was collected by a linear scan in which the scanning line spacing is not wide (dense) even in deep areas, so it is compared to a scan using a normal convex probe. , the lateral resolution in deep areas has been improved.

Next, the processing of the ultrasound diagnostic apparatus 1 according to the first embodiment will be described using FIG. 7. FIG. 7 is a flowchart for explaining the processing procedure of the ultrasound diagnostic apparatus 1 according to the first embodiment. Here, steps S101 to S103, S106, and S107 in FIG. 7 are steps that are realized by the processing circuit 55 reading out a program corresponding to the control function 551 from the memory 54 and executing it. Step S104 and step S108 are steps that are realized by the processing circuit 55 reading out a program corresponding to the image generation function 552 from the memory 54 and executing it. Step S105 is a step realized by the processing circuit 55 reading out a program corresponding to the display control function 553 from the memory 54 and executing it.

As shown in FIG. 7, in the ultrasound diagnostic apparatus 1 according to the first embodiment, the processing circuit 55 determines whether an operation for switching to the second scan mode has been received (step S101). Here, if the switching operation is accepted (step S101, affirmative), the processing circuit 55 transmits and receives ultrasound through delay control according to the second scan mode (step S102), and stores the reflected wave data in the memory. 54 (step S103).

Then, the processing circuit 55 coordinates transforms the reflected wave data stored in the memory based on the offset according to the curvature of the ultrasound probe 2 and the linear coordinate transformation method (step S104), and generates an ultrasound image. is displayed on the display 3 (step S105).

On the other hand, in step S101, if the switching operation to the second scan mode is not received (step S101, affirmative), the processing circuit 55 transmits and receives ultrasound by delay control according to the first scan mode. (Step S106), and the reflected wave data is stored in the memory 54 (Step S107).

Then, the processing circuit 55 coordinates transforms the reflected wave data stored in the memory based on the convex coordinate transformation method (step S108), and displays the ultrasound image on the display 3 (step S105).

As described above, according to the first embodiment, the ultrasound probe 2 has a plurality of piezoelectric vibrators arranged along a predetermined curvature. The control function 551 controls the difference between the first scan mode in which a fan-shaped scan is executed and the scanning line interval at a position near the transmitting/receiving surface of the ultrasound probe 2 and the scanning line interval at a position deeper than the position near the transmitting/receiving surface. A plurality of piezoelectric vibrators are controlled to execute a second scan mode in which the scan mode is smaller than the first scan mode. The control function 551 controls the piezoelectric vibrator at the second position closer to the center in the array direction than the first position than the delay given to the drive of the piezoelectric vibrator at the first position in the array direction of the plurality of piezoelectric vibrators. The second scan mode is executed by increasing the delay given to the drive. Therefore, the ultrasonic diagnostic apparatus 1 according to the first embodiment makes the scanning line interval at a deep position closer to the scanning line interval at a position near the transmitting/receiving surface than the position near the transmitting/receiving surface, and improves the azimuth resolution in the deep region. This makes it possible to reduce the frequency of changing hands of the ultrasound probe and improve the throughput of ultrasound examinations.

Further, according to the first embodiment, the control function 551 controls a plurality of scanning lines so that the scanning line interval at a position near the transmitting/receiving surface is the same as the scanning line interval at a position deeper than the position near the transmitting/receiving surface. Control the piezoelectric vibrator. Therefore, the ultrasonic diagnostic apparatus 1 according to the first embodiment enables linear scanning using a convex probe.

Further, according to the first embodiment, the image generation function 552 performs coordinate transformation including transformation based on a predetermined curvature for each scanning line signal sequence based on reflected wave signals received by a plurality of piezoelectric vibrators. By doing this, an ultrasound image for display is generated. Therefore, the ultrasonic diagnostic apparatus 1 according to the first embodiment makes it possible to accurately generate an ultrasonic image for display in a linear scan using a convex probe.

Further, according to the first embodiment, the control function 551 switches between the first scan mode and the second scan mode according to the observation conditions. Therefore, the ultrasonic diagnostic apparatus 1 according to the first embodiment makes it possible to perform a scan in an appropriate scan mode depending on the examination.

Further, according to the first embodiment, the observation conditions include the scan range, and the control function 551 switches between the first scan mode and the second scan mode according to the scan range. Therefore, the ultrasound diagnostic apparatus 1 according to the first embodiment makes it possible to perform a scan in an appropriate scan mode depending on the scan range.

Further, according to the first embodiment, the observation conditions include an observation mode, and the control function 551 switches to the first scan mode when the observation mode is B mode, and switches to the first scan mode when the observation mode is Doppler mode. switches to the second scan mode. Therefore, the ultrasound diagnostic apparatus 1 according to the first embodiment makes it possible to perform a scan in a scan mode suitable for the observation mode.

(Second embodiment)
In the first embodiment described above, a case has been described in which, as the second scan mode, the interval between the scanning lines is kept constant and the depth direction of the subject directly under the probe is scanned. In the second embodiment, a case will be described in which an oblique scan is performed in which the scanning line interval is kept constant and the angle is changed diagonally.

The control function 551 according to the second embodiment makes the scanning line interval at a position near the transmitting/receiving surface the same as the scanning line interval at a position deeper than the position near the transmitting/receiving surface, and transmits/receives using a plurality of piezoelectric vibrators. change the angle of the scan line. FIG. 8 is a diagram for explaining an example of the second scan mode according to the second embodiment. For example, as shown in FIG. 8, the control function 551 sets the scanning line interval at a position near the transmitting/receiving surface to "a'" and the scanning line interval at a position deeper than the position near the transmitting/receiving surface to "a'". A plurality of piezoelectric vibrators are controlled to perform oblique scanning in which the angle of each scanning line is tilted.

In such a case, for example, under the control of the control function 551, the transmitting/receiving circuit 51 determines the number and position of piezoelectric vibrators used for transmitting scanning lines (ultrasonic beams), the spacing between adjacent scanning lines, One scanning line is formed by giving a delay amount for each piezoelectric vibrator based on the tilt angle to each rate pulse corresponding to each piezoelectric vibrator. The transmitter/receiver circuit 51 executes the second scan mode by performing the above-described delay control on the piezoelectric vibrator for transmitting each scan line. Note that the angle at which the scanning line is tilted can be set arbitrarily.

Similarly to the first embodiment, the control function 551 can switch between the first scan mode and the above-described second scan mode according to the switching operation by the operator and the observation conditions. Here, the control function 551 controls the first scan mode, the second scan mode (second scan mode described in the first embodiment) in which the subject is scanned in the depth direction, and the second scan mode described above. The scan mode (oblique scan mode described in the second embodiment) can be arbitrarily switched according to the switching operation by the operator and the observation conditions.

For example, when collecting Doppler data for observing the state of blood flow in blood vessels parallel to the body surface, the control function 551 switches to the second scan mode of the oblique scan described above, thereby changing the scan line toward the blood flow. The direction can be kept constant, making it possible to accurately display blood flow.

In the second scan mode, the image generation function 552 according to the second embodiment reads a scanning line signal sequence, a coordinate conversion method according to oblique scan, and an offset value from the memory 54 and performs coordinate conversion. to generate an ultrasound image for display.

As described above, according to the second embodiment, the control function 551 makes the scanning line interval at a position near the transmitting/receiving surface the same as the scanning line interval at a position deeper than the position near the transmitting/receiving surface, and The angle of the scanning line transmitted and received by the plurality of piezoelectric vibrators is changed. Therefore, the ultrasound diagnostic apparatus 1 according to the second embodiment can maintain a constant blood flow display in blood vessels parallel to the body surface in a scan using a convex probe, and can reduce the frequency of changing hands of the ultrasound probe. This makes it possible to reduce and improve the throughput of ultrasound examinations.

(Other embodiments)
Although the first and second embodiments have been described so far, the present invention may be implemented in various different forms in addition to the first and second embodiments described above.

In the first and second embodiments described above, a case has been described in which the first scan mode and the second scan mode are performed separately. However, the embodiment is not limited to this, and for example, the scan mode may be changed for each area to be scanned.

FIG. 9 is a diagram illustrating an example of an ultrasound image according to another embodiment. For example, the control function 551 controls the area R1 and area R3 in FIG. 9 to be scanned in the first scan mode, and the area R2 to be scanned in the second scan mode. This makes it possible to observe areas that are not displayed in the second scan mode, making it possible to improve diagnostic efficiency.

In the embodiment described above, a case has been described in which the scanning line of the ultrasound probe 2, which is a convex probe, is controlled so as to perform a linear scan. However, the ultrasonic diagnostic apparatus 1 according to the present application can also generate a linear image from a scanning line signal sequence scanned in a fan shape. In such a case, for example, the image generation function 552 uses the collected scanning line signal train to reconstruct the fan-shaped image collected by the convex probe by reconfiguring it to focus pixel by pixel in all depths and all directions. It is possible to generate an ultrasound image similar to that obtained by performing a linear scan from the data.

Further, in the above-described embodiment, a case has been described in which the scanning line interval is controlled to be constant in the depth direction as the second scan mode, but the embodiment is not limited to this. For example, the second scan mode may be a scan in which the difference between the scan line interval at a position near the transmitting/receiving surface and the scan line interval at a deep position in the first scan mode is made smaller.

In such a case, the transmitter/receiver circuit 51, under the control of the control function 551, generates piezoelectric vibration based on the number and position of piezoelectric vibrators used for transmitting the scanning line and the scanning angle of the scanning line with respect to the center of curvature. A delay amount for each child is given to each rate pulse corresponding to each piezoelectric vibrator. Here, the transmitting/receiving circuit 51 according to another embodiment gives a delay amount calculated so that the scanning angle of the scanning line becomes narrower to each rate pulse corresponding to each piezoelectric vibrator.

Further, although FIG. 1 describes an example in which each of the above-mentioned processing functions is realized by a single processing circuit 55, the embodiment is not limited to this. For example, the processing circuit 55 may be configured by combining a plurality of independent processors, and each processor may implement each processing function by executing each program. Further, each processing function of the processing circuit 55 may be realized by being appropriately distributed or integrated into a single or multiple processing circuits.

The term "processor" used in the above description refers to, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an Application Specific Integrated Circuit (ASIC), a programmable logic device (for example, Refers to circuits such as a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA). A processor implements functions by reading and executing programs stored in memory. Note that instead of storing the program in the memory, the program may be directly incorporated into the circuit of the processor. In this case, the processor realizes its functions by reading and executing a program built into the circuit. Note that each processor of this embodiment is not limited to being configured as a single circuit for each processor, but may also be configured as a single processor by combining multiple independent circuits to realize its functions. good.

Note that each component of each device illustrated in the description of the above embodiments is functionally conceptual, and does not necessarily need to be physically configured as illustrated. In other words, the specific form of distributing and integrating each device is not limited to what is shown in the diagram, and all or part of the devices can be functionally or physically distributed or integrated in arbitrary units depending on various loads, usage conditions, etc. Can be integrated and configured. Furthermore, all or any part of each processing function performed by each device can be realized by a CPU and a program that is analyzed and executed by the CPU, or can be realized as hardware using wired logic.

Further, the scan control method described in the above-described embodiments can be realized by executing a scan control program prepared in advance on a computer such as a personal computer or a workstation. This scan control program can be distributed via a network such as the Internet. Further, this scan control program is recorded on a computer-readable non-temporary 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. , can also be executed by being read from a non-transitory storage medium by a computer.

As described above, according to the embodiment, it is possible to improve the throughput of ultrasonic examination.

Although several embodiments of the 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, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention as well as within the scope of the invention described in the claims and its equivalents.

1 Ultrasonic diagnostic device 55 Processing circuit 551 Control function 552 Image generation function 553 Display control function

Claims (6)

an ultrasonic probe in which a plurality of piezoelectric vibrators are arranged along a predetermined curvature;
a first scan mode in which a fan-shaped scan is executed; and a first depth range close to the transmitting and receiving surface of the ultrasound probe and a second depth range deeper than the first depth range. , the difference in scanning line interval between the corresponding depth in the first depth range and the depth in the second depth range based on the distance from the starting point of each depth range is calculated as a control unit that controls the plurality of piezoelectric vibrators to execute a second scan mode that is smaller than the first scan mode and larger than 0;
Equipped with
The control unit is configured to drive a piezoelectric vibrator at a second position closer to the center in the array direction than the first position than the delay given to driving the piezoelectric vibrator at a first position in the array direction of the plurality of piezoelectric vibrators. An ultrasonic diagnostic apparatus that executes the second scan mode by increasing the delay given to driving the transducer. The ultrasound diagnostic apparatus according to claim 1, wherein the control unit switches between the first scan mode and the second scan mode depending on observation conditions. The observation conditions include a scan range,
The ultrasound diagnostic apparatus according to claim 2, wherein the control unit switches between the first scan mode and the second scan mode according to the scan range. The observation conditions include an observation mode,
The control unit switches to the first scan mode when the observation mode is B mode, and switches to the second scan mode when the observation mode is Doppler mode. Ultrasound diagnostic equipment. A first scan mode in which a plurality of piezoelectric vibrators are arranged in an ultrasound probe arranged along a predetermined curvature to perform a fan-shaped scan, and a depth of transmission and reception of ultrasonic waves is controlled. When divided into a first depth range close to the transmitting/receiving surface of the ultrasound probe and a second depth range deeper than the first depth range, the correspondence is made based on the distance from the starting point of each depth range. a second scan in which the difference in scan line spacing between the depth in the first depth range and the depth in the second depth range is smaller than in the first scan mode and larger than 0; mode and run,
including that
The delay given to the driving of the piezoelectric vibrator at the first position in the array direction of the plurality of piezoelectric vibrators causes the drive of the piezoelectric vibrator at the second position closer to the center in the array direction than the first position. A scan control method, wherein the second scan mode is executed by increasing a given delay. A scan control program that causes a computer to execute the scan control method according to claim 5.

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