JPS6315945A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to an ultrasonic diagnostic apparatus that diagnoses tissues within a subject using ultrasonic waves, and particularly! The ultrasonic propagation velocity of the fabric (hereinafter referred to as
This ultra-high-speed ultrasonic device is equipped with the function of measuring and displaying tissue characterization parameters such as sound velocity or waveform turbulence for diagnosis. Sonic diagnosis! This relates to the I'r device.

(Prior art) The ultrasonic propagation velocity in the object is L'! It is affected to some extent by the tissues present in the ultrasound propagation path in the specimen. In other words, this means that it is possible to detect lesions such as tumors in organs, liver cirrhosis, etc. in a living body based on the ultrasonic propagation velocity. Measuring this has great clinical value.

Therefore, attempts have been made to utilize this fact to obtain information on the ultrasonic propagation velocity in the living body and use this information to inspect the composition at a target position.

Conventionally, as a practical ultrasonic measurement method for such examinations, a method as shown in FIG. 8 (hereinafter referred to as the cross-mode method) using an electronic scanning ultrasonic diagnostic device has been proposed. There is.

That is, in the figure, 1 is a probe for ultrasonic linear electronic scanning, and this probe 1 is used to enter the body from one end A of the ultrasonic transmitting/receiving surface 2 that is in contact with the body surface (not shown).
Fires ultrasonic pulses in the direction.

Here, an electronic scanning type ultrasonic diagnostic device uses a probe with an ultrasonic transducer array in which a plurality of ultrasonic transducers (hereinafter simply referred to as transducers) are arranged in parallel. Several adjacent transducers are set as a group, and driving pulses are applied to each group of transducers with a predetermined delay time determined depending on the direction of the transmitted ultrasonic beam and the position of the transducer in the beam, respectively, This device excites ultrasonic waves, and the ultrasonic waves from each excited transducer propagate radially and interfere with each other, canceling each other out in some areas and reinforcing each other in other areas, resulting in an ultrasonic beam. This is a method to obtain Generally, the transmission is performed using the above group of transducers used for wave transmission, and the detection signals of the transducer group are delayed by the delay time during wave transmission to align the time axes, and then synthesized and received. Signal. Since the position of the generated ultrasonic beam is shifted by shifting the group of transducers by -bisotches, the transducer to be excited is electrically selected and the excitation timing is controlled to linearly shift the position of the generated ultrasound beam. - Scanning can be performed, and sector scanning can be performed at desired locations.

For example, if the ultrasonic pulse transmitted in the form of a beam in the θ direction is set in the liver tissue, it travels straight along the transmission path 4 in the liver tissue and is reflected at a point P. Here, among these reflected waves (echoes), we do not refer to the transducer group that transmitted the echo that reached the probe 1 following the receiving path 5, but to the transducer group at the incident position of the echo that arrived (the corresponding It is received by the transducer group at the right end B of the probe 1.

Since the distance y between A and B is known, if the propagation time t of the ultrasound propagating along path 4.5 is measured, the sound speed C in the liver tissue is C=)'/ (t -5inθ) ・(
1).

This principle is used to measure the speed of sound.

Since the speed of sound is unknown, θ is strictly unknown, and
Since there is no reflection point such as point P in a living body, various measures must be taken to obtain the speed of sound from equation (1) above.

Standardly, the speed of sound in living tissue is C, = 1530 (m/S)
Then, the ultrasound beam is θ. For radiation in the direction, the delay time τ between adjacent elements is required.

τo = (d/Co)−sinθo
(2), and each element is set to be driven with such a delay time difference.

If the sound speed in living tissue is C0, the ultrasound beam is θ. However, in general, it is not limited to C0, but is a different value C. The propagation direction θ of the ultrasonic wave at this time is stnθ/C=sinθo/Co from Snell's law.
-(The value is indicated by 31.

The peak value of the measured waveform indicates the reflected wave from point P,
By detecting the time (address) of the peak value, the propagation time can be determined. Substituting the above equation (3) into equation (11), the sound speed C in the living body becomes C= yCo/(t-3inθe) - f41.Furthermore, substituting equation (2) into (4)2, C= y
d/l lower re...(4'). y, d, τ. Since is already known, the value of the sound speed C is determined by performing the calculation in (4') 2 above using the propagation time t obtained by measurement.

(Problems to be Solved by the Invention) However, in conventional ultrasound diagnostic equipment, the intersection angle of ultrasound beams is fixed, which limits the measurable region of tissue characterization parameters, and tissue characterization can only be performed within a narrow range. The problem arises in that it is not possible to obtain the conversion parameters.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an ultrasonic diagnostic apparatus that expands the measurable region of tissue characterization parameters.

[Structure of the invention]

(Means for Solving the Problems) The present invention controls the display of marks indicating selectable ultrasound beam intersections, and also controls the mark display position and ultrasound beam intersection angle of the selectable ultrasound beam intersections. The system includes a system control means for performing change control, and an external input means for instructing the system control means a desired ultrasonic beam intersection angle.

(Operation) The system control means changes the ultrasonic beam intersection angle in accordance with the ultrasonic beam intersection angle instructed by the external input means. Since changing the ultrasound beam intersection angle means changing the position of the ultrasound beam intersection, by making the ultrasound beam intersection angle changeable, the range in which tissue characterization parameters can be measured is expanded.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples.

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes an ultrasonic probe, which is made up of, for example, 128 transducers T1 to T128 arranged in a straight line for transmitting and receiving ultrasonic waves. The parallel surface of transducers T1 to T128 is the first
This is the ultrasonic wave transmitting/receiving surface 2 of the probe 1 shown in FIG. here,
The ultrasonic probe 1 can be attached to and detached from the main body of the apparatus using a connector or the like. Therefore, by preparing various ultrasonic probes with different arrangement pitches of ultrasonic transducers, it is possible to change the ultrasonic probe as appropriate depending on the inspection target site. A probe with a small arrangement pitch of ultrasonic transducers has a small probe itself, and is effective when used, for example, between the ribs of the human body. On the other hand, a relatively large probe with a large arrangement pitch of ultrasound transducers is effective when used under the costal arch. The connectors of various probes are designed to generate an identification signal (signal corresponding to the ID number of the probe) of the probe when the probe is connected, for example by using contacts, etc., and this identification signal is taken into the system control means 25A. This system control means 25A is responsible for controlling the operation of the entire apparatus of this embodiment as will be described later, but here, in particular, it controls the display of marks indicating selectable ultrasound beam intersections, and also controls the display of marks indicating selectable ultrasound beam intersections. The mark display position of the ultrasound beam intersection and the ultrasound beam intersection angle are controlled to change, and the arrangement pitch of the ultrasound transducers in the ultrasound probe used is recognized from the identification signal, and the The display position of the mark at the intersection of the ultrasonic beams is automatically changed when the ultrasonic beam crosses.This is one of the features of the apparatus of this embodiment. Note that the mark display position of the ultrasound beam intersection, the ultrasound beam intersection angle, etc. will be described in detail later.

12 is a lead wire; 13 is a multiplexer which is a circuit selection switch; 5 is a transmission delay circuit for obtaining the amount of delay to be given to each of a group of vibrators to be excited;
4 is a pulser that generates pulses for ultrasonic excitation drive, 16
17 is a receiving delay circuit for obtaining the echo delay amount necessary for aligning the time axis etc. according to the receiving direction and element position for each of the group of transducers used for reception, and 17 is a receiving delay circuit for obtaining image, text information, etc. It is a display (display means) used for displaying.

18 is a calculation circuit that calculates the speed of sound and average value based on the output of the A/D converter 20, and 26 is a changeover switch that connects the cross mode sound speed measurement side X of the composite output of the receiving delay circuit 16. This is to select and switch the supply route to the ultrasonic device side B for obtaining an ultrasonic B-mode image. 27 is a receiving circuit on the ultrasonic device side, which performs amplification, detection, logarithmic conversion, etc. of the received signal. 28 is an A/D converter;
It converts the output of the receiving circuit 27 into a digital signal. 29 is a marker generator for displaying image data for displaying the measurement route (beam path route) of the cross-mode sound velocity measurement and for displaying time gate markers (hereinafter referred to as time gate markers) for measuring tissue characterization parameters. It generates image data. 30 is digital
It is a scan converter, which has a frame memory, and sequentially updates and stores the digital data output from the A/D converter 28 at an address corresponding to the beam position where the data is collected, and also performs readout. This is done in synchronization with the scanning timing of the display 17, so that the difference between the acquisition timing of the ultrasonic image and the display timing on the display 17 is converted without any problem by interposing this frame memory. Also,
The output of the marker generator 29 is written on the frame memory of the digital scan converter 30 at a position corresponding to the root of the cross mode sound velocity meter 11 of the B mode image.

The memory 22 also updates and stores the data of the A-mode image. Furthermore, although not shown, the display 17 has a video RAM which is a display image memory, and displays the sound speed data, A-mode image, time gate marker, and changes in the average sound speed calculated by the calculation circuit 18. It is controlled by the system control means 25A to store graphs such as patterns in a predetermined layout and a predetermined format.

Then, an image is displayed based on the image data on the video RAM and the output of the digital scan computer 30.

Reference numeral 50 denotes external human power means for instructing the system control means 25A to measure and display tissue parameters, ultrasound beam intersection angles, etc., such as various switches and tracks provided on the operation panel of the apparatus of this embodiment. Consists of balls etc. Therefore, when the operator wishes to change the ultrasonic beam intersection angle, he will instruct a new intersection angle via this external input means 50. The ultrasonic beam crossing angle is changed by the transmission delay circuit 15. under the control of the system control means 25A. This is done by changing the delay time of the receiving delay circuit 16 and changing the transmitting/receiving directivity angle of the ultrasonic beam.

Next, the system control means 25A will be explained in detail.

This system control means 25A includes a CPU (central processing unit W), ROM (read only memory), and RAM.
(random access memory), etc. In the ROM, a table is created with gate addresses for sound speed measurement calculated from the required sound speed value range for each depth of the intersection, and each time an intersection is set for transmitting and receiving ultrasonic waves, the corresponding gate address is set. It is configured to be read out. Here, the necessary sound velocity value range is determined by taking into consideration whether the target region, for example, the liver, is normal or abnormal. The system control means 25A outputs the gate address as is to the marker generation means 29 unless there is an instruction to move the gate marker from the external input means 50, and if there is an instruction to move the gate marker, the system control means 25A outputs the gate address as it is to the marker generation means 29. The subsequent new gate address is output to the marker generator 29, and the ultrasonic reflection component within the time gate marker setting area is selected as sound speed measurement information. Furthermore, this system control means 25A controls the operation of the multiplexer 13, sets the delay times of the transmission delay circuit 15 and reception delay circuit 16, controls writing and reading of the memory 22, and It controls the operation of the calculation circuit 18, the switching control of the changeover switch 26, the marker output control of the marker generator 29, etc., and normally performs ultrasonic scanning for B mode, while performing cross scan (at predetermined timings). It controls the transmission and reception of ultrasonic waves for mode sound speed measurements, displays B-mode in real time, calculates sound speed measurements and displays the results, and calculates and plots the average sound speed of all beam paths.

In addition, if you want to display the average A-mode image by averaging, freeze the B-mode image when the B-mode scan is completed, then measure the cross-mode sound velocity, calculate the sound velocity, display it, and measure the cross-mode sound velocity. A frozen A-mode image, an average A-mode image, and an average sound speed change diagram or local sound speed change diagram of one selected beam path are displayed based on the measured data for each beam path.

Regarding the cross mode sound velocity measurement, for example, the operation of the multiplexer 13 is controlled as follows.

That is, as shown in Fig. 2, this device measures the local sound velocity of the abnormal part included in the reflection points (measurement points) Pz and P1□ at the upper boundary and the reflection point (measurement point) Poo at the lower boundary. For this, the ultrasonic beam transmission and reception paths are A, -P, .
→B, A-P, I-C, B→P0゜→A, B-P, □-
There are four routes. That is, each of the A and B positions of the probe 1 is used as an ultrasonic beam transmitting position and also as a receiving position. Then, the wave is transmitted from position A and Po. is reflected at position B, and then received at position A.
The wave is transmitted from position P, the wave reflected at P is received at position C, then the wave is transmitted from position B, the wave reflected at Po0 is received at position A, then the wave is transmitted from position B, and PI2 By switching the transmission and reception so that what is reflected at position D is received at position D, symmetry is created in the measurement path, and the directional directions of the transmission and reception directions of the ultrasonic beam are made to be at the same angle θ. There is. In addition, by making the measurement route symmetrical,
This prevents the average from becoming statistically non-uniform, thereby making it possible to reduce errors.

Next, the operation of the embodiment device configured as described above will be explained.

With this device, cross-mode sound velocity measurements are performed using four routes Bl, B2, . B3. Measurement shall be made using B4. Then, at a predetermined timing between the ultrasonic electronic scans in B mode,
6 is temporarily switched from the terminal B side to the X side, and sound velocity measurement is performed.

To explain specifically, first, the system control means 2
The selector switch 26 is switched to the terminal B side under the control of the delay circuit 15.5A, and the multiplexer 13 is selected for linear electronic scanning, and the delay circuit 15.
Delay times 16 for linear electronic scanning are set, and ultrasonic waves are transmitted and received by the transducer group selected by the multiplexer 13 using these delay times. The combined output of this received signal is amplified and detected by the receiving circuit 27,
The data is converted into digital data by the A/D converter 28 and input to the digital scan converter 30. The data is then stored in the frame memory location of the digital scan converter 30 corresponding to the ultrasound scan position. While sequentially shifting the scan position,
These ultrasound scans are sequentially processed into digital
An ultrasonic B-mode image is formed on the scan converter 30. In addition, the beam path marker for cross mode sound velocity measurement set by the marker generator 29 is output, and the frame signal of the digital scan converter 30 is output.
The marker is stored in memory at a location corresponding to the cross-mode sound velocity measurement location. The image data on the frame memory of the digital scan converter 30 is read out in accordance with the scanning of the display 17, and is provided to the display 17 for display.

At a predetermined timing, the system control means 25A switches the selector switch 26 to the terminal X side and enters cross mode sound velocity measurement. This sound velocity measurement is first performed on route B1.

That is, under the control of the system control means 25A,
The delay time of the transmission/reception delay circuit 15 is set. This delay time is the delay time difference τ between adjacent oscillators. is τ
. = (d/Co)s +nθ. (Formula (2) above)
The relationship is set as follows. Then, by the switching operation of the multiplexer 13, the transducer group T1 to T32 belonging to the point A of the probe and the output end of the pulser 14 are connected.

Further, a rate pulse is generated by the clock oscillator 21, and this is input to the pulser 14 via the transmission delay circuit 15. Then, an excitation pulse is outputted from the pulser 14 at a timing shifted by the delay time of the corresponding transmission delay circuit 15, and is input to the corresponding one of the transducers T1 to T32, and the transducer emits ultrasonic waves. occurs. Then, the ultrasonic beam is transmitted in a predetermined direction θ determined by the delay time.

On the other hand, under the control of the system control means 25A, the delay time of the receiving delay circuit 16 is set, and the multiplexer 13
By this switching operation, the transducer groups T97 to T128 belonging to point B of the probe 1 are connected to the input terminal of the receiving delay circuit 16. As a result, in the ultrasonic beam transmitted toward the subject from the transducer group belonging to point A of probe 1, the reflected portion at point P0° is received by the transducer group belonging to point B of probe 1. , the echo is sent to the reception delay circuit 1
6, the signals are combined and output after being given the same time difference as in the case of transmission.

The reception echo synthesis output from this reception delay circuit 16 is
After being amplified and detected by the receiving circuit 19, it is converted into a data signal by the A/D converter 20 and written into the memory 22. In the memory 22, the address is updated at a predetermined timing every time an ultrasound beam is transmitted by the clock signal output from the clock oscillator 20, and writing control is performed by the system control means 25A to record the echo from the measurement point. The signal is stored in a form that corresponds to time. This becomes A-mode image data.

When the above-mentioned ultrasonic transmission and reception is performed multiple times by the transducer groups belonging to each of the points A and B of the probe 1,
By the action of the processing circuit 23, the received echoes are averaged.

When this work is completed, the system control means 25A switches the changeover switch 26 to the terminal B side again, and starts collecting B-mode images. Then, at a predetermined timing, the system control means 25A switches the changeover switch 26 again to the terminal X side,
Let's move on to measuring the cross-mode sound velocity on route B2.

Then, the multiplexer 13 operates under the control of the system control means 25A, and this time, instead of the transducer group belonging to point B, the transducer group belonging to the 0 point of the probe 1 is connected to the input terminal of the receiving delay circuit 16. The reflected component of the ultrasonic wave transmitted from the transducer group belonging to the point A of the probe 1 at the point Pl+ is received by the transducer group belonging to the zero point of the probe 1.

The reception echoes are given the same time difference as in the case of transmission by the reception delay circuit 16, and then synthesized and output.

The combined output of the received echoes is amplified and detected by the receiving circuit 19 in the same way as in the case described above, and is then used to measure the time t2 from transmitting the ultrasonic wave to receiving the wave on the route B2.

When this work is completed, the system control means 25A switches the changeover diameter switch 26 again to the terminal B side, and starts collecting B-mode images. Then, at a predetermined timing, the system control means 25A switches the changeover switch 26 to the terminal X side, and
Let's move on to measuring the cross-mode sound speed along the route.

Then, the multiplexer 13 operates under the control of the system control means 25A, and this time, instead of the transducer group belonging to the A point, the transducer group T97 to T1 belonging to the B point of the probe 1 is activated.
28 and the output end of the balsa 14 are connected, and the transducer group belonging to the A point of the probe 1 is connected to the receiving delay circuit 16 instead of the transducer group belonging to the 0 point. Then, ultrasonic waves are transmitted from the transducer group belonging to point B of the probe 1,
A reflected component of the transmitted ultrasonic wave at point P0° is received by the transducer group belonging to point A of the probe 1. The reception echoes are given the same time difference as in the case of transmission by the reception delay circuit 16, and then synthesized and output.

The combined output of the received echoes is amplified and detected by the receiving circuit 19 in the same way as in the case described above, and is then used to measure the time t3 from transmitting the ultrasonic wave to receiving the wave on the route B3.

When this work is completed, the system control means 25A switches the changeover switch 26 to the terminal B side again, and starts collecting B-mode images. Then, at a predetermined timing, the system control means 25A switches the changeover switch 26 to the terminal X side, and
Let's move on to cross-mode sound velocity measurement, which follows route 4.

The multiplexer 1 is controlled by the system control means 25A.
3 operates, and this time, instead of the transducer group belonging to point A, the transducer group belonging to point D of probe 1 and the receiving delay circuit 16 are activated.
is connected to the input terminal of

When an ultrasonic wave is transmitted from the transducer group belonging to point B of probe 1, the reflected component of the transmitted ultrasonic wave at point P12 is received by the transducer group belonging to point D of probe 1. be done. Then, the reception echoes are given a time difference similar to that in the case of transmission by the reception delay circuit 16, and then synthesized and applied.

The combined output of the received echoes is amplified and detected by the receiving circuit 19 in the same way as in the case described above, and then used to measure the time t4 from transmitting the ultrasonic waves on the route B4 to delivery.

When this work is completed, the system control means 25A switches the changeover switch 26 to the terminal B side again, and starts collecting B-mode images. Then, at a predetermined timing, the system control means 25A switches the changeover switch 26 to the terminal X side, and
Let's move on to measuring the cross-mode sound speed along the route. These operations are repeated to display a real-time B-mode image and average the cross-mode sound velocity measurement data.

In this way, the data that has been averaged a predetermined number of times and stored is read out from the memory 22, and the waveform analysis circuit 24 examines the data indicating the peak, and the information of the address where the data is stored is converted into time information. As calculation circuit 1
Sent to 8th. Based on this, the calculation circuit 18 calculates Bl, B2°B3. Time tl, t2 . from transmission of ultrasonic wave to the above peak for each route of B4. t3. t4 is calculated. After that, the sound speed value Vl for each route is further determined.

V2. V3. The average sound velocity value ■ in V4 and the entire beam path is calculated and the result is displayed on the display 17.

Therefore, in the normal state, only the B-mode image, the measured sound speed, and the average sound speed time change diagram are updated and displayed one after another. Other items such as A-mode images are displayed only when frozen, except for those that have already been displayed.

Examples of the display on the display 17 are shown in FIGS. 3 and 4.

FIG. 3 shows the display in the normal state, and FIG. 4 shows the display in the freeze state.

In FIG. 3, 60 is a B-mode image of the region of interest of the subject measured in real time, 61 is a beam path marker indicating the route of the set beam path for the above-mentioned cross-mode sound velocity measurement in this region of interest, and 62 is the above-mentioned beam path. Real-time A-mode images for each beam path and route obtained by the cross-mode sound velocity measurement, 63 are each sound velocity value for each beam path and route obtained by the cross-mode sound velocity measurement, and 64 are these beams. - It is a diagram of changes in the average sound speed value of the target region, which is obtained based on each sound speed value for each path/route. Also,
In FIG. 4, 71 is a B-mode image, 72 is a beam path marker indicating the route of the set beam path for the above-mentioned cross-mode sound velocity measurement in this region of interest, and 73 is the beam obtained by the above-mentioned cross-mode sound velocity measurement.・Freeze A-mode image by path/route, 74 is each sound velocity value for each beam path/route obtained by the above-mentioned cross mode sound velocity measurement, 75 is based on each sound velocity value for each beam path/route FIG. 3 is a diagram of changes in the average sound velocity value of the target region determined in FIG.

The beam path marker 72 indicates the routes (11 to (4) above), and the sound velocity value 63°74 indicates the sound velocity value of the route (1) above among these routes. The sound speed value of the route 2) is numerically displayed as ■2, the sound speed value of the route (3) above as ■3, and the sound speed value of the route (4) above as v4. This is the average sound speed value. 75 is the dispersion value, and 77 is the average A-mode image of each route. Also, the above average sound speed value change diagram 75 shows the time change of this average sound speed value. It is.

In addition, the A mode image 73 has roots (1) and (3) as Bl and B3, and roots (2) and (4) as 82.
It is displayed as ゜B4. In Fig. 3 and Fig. 4, real-time A mote' (elephant 62°73
Above, time gate markers 65, 66.67°68.7
8, 79, 80.81 are shown superimposed. 65.66
and 78.79 is Beam 1 .

3, and 67, 68 and 80° 81 are gate markers for beam 2.4. This time 'y'
The I-marker is displayed under the control of the system control means 25A.

Next, the echo waveform received in the device of this embodiment and the Mi
The relationship between the time gates for measuring the weave characteristic parameters will be explained based on FIG. 5.

In FIG. 5, 83 is the temporal waveform of an echo, and in addition to the image 84 from the intersection, it also includes an image 85 from other than the intersection (which is due to non-target echoes, for example, the abdominal wall layer, etc.). There is. Note that the start address is indicated from the zero point. 86 is a time gate for measuring the Mi'tH characterization parameter, which is normally connected to the system control means 25A.
The setting is based on information read from the internal ROM. 8
7 is a real-time A mode image (ASA start address, ADL: data length), and this A mode image is displayed on the display 17, and gate markers 88 and 89 are superimposed and displayed on this A mode image. The markers 88 and 89 match the falling timing of the time gate 86, respectively. Then, the echo data within the setting area of the markers 88 and 89, that is, the echo data (DL: indicated by data length) corresponding to the high level of the time gate 86, is selected under the control of the system control means 25A (SA start address ), this is taken into the waveform analysis circuit 24 as an eco one-hour waveform 90 for measuring the speed of sound, and is used for peak value detection. As a result, non-target echoes existing outside the gate marker setting area are not subjected to peak value detection for sound speed measurement. Note that 91 is the average A-mode waveform displayed during freezing. Therefore, the operator can accurately determine whether or not accurate sound speed measurement is to be performed based on the relationship between the real-time A mode image 87 displayed on the display 17 and the time gates 88 and 89. It is conceivable that the image 85 resulting from the non-target echo may enter the setting area of the gate marker 88.89 due to the thickness of the abdominal wall layer of the subject. In such a case, the gate marker 88.89 is All you have to do is move it.

In addition, when transmitting and receiving ultrasonic waves in cross-mode sound velocity measurement, this device measures the moving distance of the center position in the transducer arrangement direction of the transducer group belonging to point A and the transducer group belonging to point D, and the distance of movement of the center position in the transducer arrangement direction of the transducer group belonging to point A and the transducer group belonging to point D. The moving distances of the center positions of the transducer group and the transducer group belonging to the zero point in the transducer arrangement direction are the same distance Δy, as shown in FIG. 2. Also,
The deflection angle θ of the ultrasonic beam is equal to θ° in both cases. Therefore, as a result, point pH and point P, □ are in a line-symmetric positional relationship with respect to a line that passes through point P0° and is perpendicular to the ultrasound transmission/reception wave surface of probe 1.
Moreover, the distance therebetween is Δy.

Next, the algorithm in the calculation circuit 18 will be explained.

The calculation circuit 18 performs the following calculations.

Δt= ((tl-t2)+(t3-t4))/2-(
(t1+t3)/21- ((t2+t4)/2]...
・00) Δt obtained by executing the calculation of this QOI2 is the point P
This is an estimated value of the propagation time of the ultrasonic wave propagating along the path between one point z and one point P0° and one point P1□.

Therefore, the average sound speed CA of the ultrasonic waves propagating along the path between the point P, one point P0° and one point P1□ is determined by the following equation.

ch= (Δy”Co/ (Δy−sinθO)
”' cυThe average sound velocity calculated by this OD formula is local to the internal tissue of the subject (in this case, point P, , P, .
represents the speed of sound at the region (including P1□).

In this way, it is possible to calculate the sound velocity locally in the internal tissue of the subject from the reflected components of the ultrasound at the three points pH, P6゜+Pl□, so the transducer used for transmitting and receiving the ultrasound By using the multiplexer 13 to change the position of the intersection of the directional directions in the transmission and reception of the ultrasound waves, it is possible to determine the sound velocity at multiple locations in the internal tissue of the subject without changing the deflection angle θ.

FIG. 6 is a diagram showing a region where the local sound velocity can be made constant by changing the vibrator. Generally, the delay time that determines the pointing direction is obtained by a delay element, but this delay element has a limited range of delay times that can be set. Therefore, since the above-mentioned intersection point is specified, the marker generator 29 is configured to be able to output a beam path passing through this possible intersection position as a marker, and when a measurement route is set, Select and output the beam path as a marker.

In the figure, 97 is the measurable region of local sound velocity, and this region 9
7, the sign P0°~P? F.'' indicated by l is the intersection point (beam intersection point) of the ultrasonic wave transmission/reception directional directions.

In this case, as described above (Po.+PII+Pl□
).

(P z, P z+, P z□), (P +□,
Pzz, P2:l), (Pg1゜P31+ p
3□); (P2□, P32. Pat), (
Pg:l, P33゜P*a), ..., in line with the abnormal part to be measured, pass through the first intersection, and with respect to the ultrasonic wave transmitting/receiving surface of the probe 1. The second one is located in a line-symmetrical position with respect to the perpendicular line. It can be measured by selecting a combination of the three reflection points at the third intersection, performing the above measurement on the reflected waves that follow the route described above at the three intersections, and calculating the average sound speed by calculating the 00 formula. The distribution of the average sound speed at a desired local area within the region 31 can be determined.

Here, control for changing the mark display position of the ultrasonic beam intersection and the ultrasonic beam intersection angle that can be selected in the apparatus of this embodiment will be explained.

When the ultrasonic probe 1 is connected to the apparatus main body, the arrangement pitch of the ultrasonic transducers of this probe 1 is recognized by the system control means 25A, and the system control means 25A
Accordingly, mark display control at beam intersections is performed according to the arrangement pitch. In other words, the arrangement of ultrasonic transducers Bi-7
When the ultrasonic probe 1 is changed to a different ultrasonic probe 1, the mark display position of the selectable ultrasonic beam intersection point is automatically changed under the control of the system control means 25A. Therefore, in the apparatus of this embodiment, a plurality of ultrasonic probes with different arrangement pitches of ultrasonic transducers can be selected as appropriate depending on the region to be inspected, and the inspectable area can be expanded.

Further, when the ultrasonic beam intersection angle is set via the external input means 50, the system control means 25A controls the transmission delay circuit 15. By changing the delay time of the receiving delay circuit 16, the transmission/reception directivity angle of the ultrasonic beam is changed, and the beam intersection angle is changed. With this change, the ultrasound beam intersection point moves in the depth direction of the subject, so the testable region is expanded in the depth direction of the subject.

Figure 7 (al, (bl, C1 to Figure 9 (al,
(bl, (C1 shows the relationship between changes in the ultrasound probe, changes in the ultrasound beam intersection angle, and the testable area. Applying probes with a relatively small array pitch,
The ultrasonic beam intersection angle is set to θ8. θ2. θ3(θ,
This shows the case where the change is made to 〈θ2 × θ3), and Fig. 8 (
a), (bl, (C1) shows the case where a probe with a larger array pitch of ultrasonic transducers than in the case of Fig. 7 is applied, and the ultrasonic beam intersection angles are changed to θ1, θ2, and θ3, respectively. , FIGS. 9(al), (b), and (C) use a probe in which the arrangement pitch of the ultrasonic transducers is larger than that in FIG. 8, and the ultrasonic beam intersection angle is set to θ8.
．． The case where the angle is changed to θ2°θ3 is shown. It can be clearly seen that the inspectable area is changed by changing the probe and beam intersection angle.

The sound velocity value of the desired local area calculated by the calculation circuit 18 is displayed on the display 1 after being subjected to brightness modulation or color modulation.
7 can also be displayed as a sound velocity distribution. Also,
If you want to see the average A-mode image, the system control means 25
Give A a freeze command. Although not shown, a freeze command switch or the like is provided and operated by the operator. Upon receiving this command, the system control means 25
After collecting data on all the ultrasound beam transmission and reception paths used for measurement to obtain the ultrasound propagation velocity information, A performs control so that the obtained ultrasound tomographic images are sequentially frozen. Then, the estimated sound speed for each route is determined and displayed on the display 17, and the average value is plotted and displayed. Further, an average A-mode image is generated from the data stored in the memory 22, and an A-mode image using the average value on the same route is obtained by the calculation circuit 18, and each is given to the display 17 as shown in FIG. (The image is displayed frozen in a predetermined position and in a predetermined format.)

, Since the displayed image at this time, including the B-mode image, has almost completely failed in terms of time, if this is recorded and saved, it will be extremely useful as comprehensive measurement data at a certain point in time.

When the freeze command is released, the measurement display returns to the normal mode described above, and the mode image display and the sound velocity measurement data are sequentially updated in real time.

The embodiment device described in detail above not only controls the display of marks indicating selectable ultrasound beam intersections, but also controls changes in the mark display position and ultrasound beam intersection angle of selectable ultrasound beam intersections. System control means 25
A, and an external input means 50 for instructing the system control means 25A to a desired ultrasound beam intersection angle. Therefore, by changing the ultrasound beam intersection angle, the testable area, that is, the tissue characterization parameters can be changed. The measurable area can be expanded, and the ability to diagnose a subject can be effectively improved. In addition, in the device of this embodiment,
A plurality of ultrasonic probes having different arrangement pitches of ultrasonic transducers can be appropriately selected and used, and by changing the probes in this way, the testable area can be further expanded. Of course, the object of the present invention can also be sufficiently achieved by changing only the ultrasonic beam intersection angle without changing the probe.

Furthermore, the temporal waveform of the ultrasound reflected component from the subject,
A time gate marker movable on the time axis by an external human power means 50 is displayed on the display means (display) 17, and within this time gate marker setting area (corresponding to the high level period of the gate waveform 86 in FIG. 5). The ultrasonic reflection component of is selected as information for sound speed measurement under the control of the system control means 25A, and sound speed information is obtained based on this selection result, so non-target echoes can be easily and reliably removed. It is possible to obtain highly reliable sound speed information. Furthermore, the time gate marker is
By superimposing and displaying the time waveform of the ultrasonic reflection component (real-time A mode image), it is possible to easily determine whether only the echo waveform from the target area is within the gate, and external input Another advantage is that the gate marker can be quickly moved by operating the means 50.

Furthermore, normally, cross-mode sound velocity measurements for 1 hour are inserted between scans of the B-mode image, and only the B-mode image and sound velocity measurements are updated, and other average A-mode images, etc. Since the generation, display, calculation, and update of other images and information are not performed, the time required for this is no longer required, and therefore, the B-mode image can be displayed in real time. At the same time, it becomes possible to successively measure and update the sound velocity values at multiple locations in the internal tissue of the subject. Also, if you want to see the sound velocity measurement value or B-mode image at a certain point, including the average A-mode image, you can give a freeze command to freeze the B-mode image immediately after measuring the cross-mode sound velocity of 4 routes. Since the calculation of the sound velocity value and the generation of the average A-mode image are performed, the B-mode image, the average A-mode image, and the sound velocity value at the same time phase can be displayed together. Therefore, the ultrasonic diagnostic apparatus can obtain extremely useful information for diagnosis.

In particular, this device performs real-time observation and freezes as necessary to obtain sound velocity information that reflects macroscopic changes in a predetermined part of the subject, such as the entire liver, and the average A of the sound velocity information measurement route. Comprehensive information, including modal images, etc., can be stored and observed in a single image, and it is especially useful for diagnosing organs such as the liver, whose flesh tissue is homogeneous under normal conditions.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within the scope of the gist thereof. be.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide an ultrasonic diagnostic apparatus that expands the measurable range of Ml texture characteristic variation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the ultrasonic beam transmission and reception path in the apparatus of this embodiment, and FIGS. 3 and 4 are diagrams of the apparatus of this embodiment. An explanatory diagram of a display example, FIG. 5 is a waveform diagram for explaining the relationship between the echo waveform and the time gate, FIG. 6 is an explanatory diagram of the measurement point setting possible area in the probe of this embodiment device, and FIG.
Figure (a). (b), fcl, Fig. 8 (a), (b), (C1
, FIG. 9 (al, (bl, C1 is an explanatory diagram showing the relationship between changing the ultrasonic probe, changing the ultrasonic beam intersection angle, and the inspectable area, and FIG. 10 is an explanation of the principle of cross-mode sound velocity measurement. It is a diagram. 1... Ultrasonic probe, 17... Display (display means), 25A...
System control means, 50...External human power means. Agent Patent Attorney Ken Nori Chika Kanshu Norio Ogo Condolence Figure 2 Figure 3 Condolence Figure 5 Bi Figure 10 e+ 82 Figure 7 e3 Figure 91 e2 Condolence Figure 9

Claims (2)

[Claims] (1) Equipped with an ultrasonic probe consisting of multiple ultrasonic transducers arranged in an array, and transmits and receives ultrasonic beams to the target area of the subject using multiple ultrasonic wave transmission and reception paths. In order to perform this, a group of ultrasound transducers for transmitting and receiving different ultrasound beams are selected, and the reflected waves from the ultrasound beam intersections are captured, and based on this, the tissue characterization parameters of the target region are determined. In an ultrasonic diagnostic apparatus used for diagnosis, the display of marks indicating selectable ultrasound beam intersections is controlled, and the mark display position and ultrasound beam intersection angle of the selectable ultrasound beam intersections are controlled to be changed. An ultrasound diagnostic apparatus comprising: a system control means; and an external input means for instructing the system control means a desired ultrasound beam intersection angle. (2) The system control means recognizes the arrangement pitch of the ultrasound transducers in the ultrasound probe used, and changes the mark display position of the ultrasound beam intersection according to this arrangement pitch. The ultrasonic diagnostic device according to item 1.