JPS62231631A - 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] [Objective of the Invention] (Industrial Application Field) The present invention is capable of displaying blood flow information obtained by ultrasound Doppler method in a tomographic image of a subject obtained by ultrasound reflection method. The present invention relates to an ultrasonic diagnostic device.

(Prior art) For example, observing the dynamics of blood flow in the heart or blood vessels simultaneously with a tomographic image of the area including the area obtained in real time is clinically useful in understanding the state of cardiac function. Very valuable. Therefore, in recent years, ultrasonic diagnostic apparatuses that can observe and display both of these conditions have been put into practical use.

As a method for detecting this blood flow information, the ultrasonic (pulse modulation) Doppler method is used because it has excellent distance resolution.

In other words, this type of device uses a sector electronic scanning type (sector electronic scanning method) ultrasonic diagnostic device, and uses a sector electronic scanning probe, which is a type of array transducer made up of multiple microscopic vibrating elements arranged in parallel, to perform ultrasonic diagnosis. A sound beam is transmitted by sequential sector scanning, and by receiving the echoes, an ultrasonic tomographic image is obtained and displayed. , by emitting an ultrasonic beam and receiving its echo, we obtain the frequency deviation of the transmitted and received waves, obtain information on blood flow velocity and direction from this, and display this observation information together with the tomographic image. This is how it was done. In addition, using a composite ultrasound probe equipped with such an array transducer and a single transducer, sector scanning is performed with the array transducer to obtain a B-mode image, and Doppler measurement is performed with the single transducer to detect blood pressure. Some provide information on flow velocity and direction.

Among these, in the former case: (1) When the resolution of the B-mode image is good and the direction of blood vessel travel is parallel to the transmitting and receiving surface of the transducer near the center of the image with little distortion, the Doppler beam will be at right angles to the blood vessel travel; Doppler detection ability is minimized.

That is, the Doppler detection frequency fd is the blood flow velocity,
If the carrier frequency is fO1, the sound velocity is C1, and each of the blood vessels and Doppler beams is θ, then fd-(2V-CO5θ/
C) is expressed as fo-(1). And Figures 4 and 5
As shown in the figure, when the blood vessel 1 runs parallel to the wave transmitting/receiving surface of the ultrasound probe 2, the blood vessel 1 at the end of the ultrasound scanning area 4, that is, the end of the ultrasound tomographic image, When performing Doppler observation, there is no problem because the Doppler beam 3a is incident on the blood vessel 1 at an angle, but if Doppler observation is performed on the blood vessel 1 located at the center of the ultrasound tomogram with the best image quality, The route will be designated by the symbol 3b, and the Doppler beam will have an inclination θ of a right angle. Therefore, even if one wishes to perform Doppler observation by referring to a tomographic image of a portion with good resolution, it is impractical due to accuracy issues. Therefore, for the blood vessel 1 located toward the edge of the ultrasound tomogram, if the blood vessels distributed in the direction parallel to the transmitting and receiving surface of the ultrasound probe are observed at the top, then the ultrasound tomogram with poor resolution will be used. The edges of the image must be used to position the route of the Doppler beam.

(2 Also, in order to improve the resolution of the B-mode image,
The ultrasound probe 2 can be a high-frequency probe, but the blood flow velocity ■ is V-(c/2fo-cos θ) fd
+2), so doing this will reduce the maximum detectable blood flow velocity.

In the latter case, (1) array transducer (for example, linear array 1inear array) or convex-7
As shown in Figures 6 and 7, the combination of Convex Array and Single Array transducers
In the ultrasonic probe 20 of the type in which a single transducer 22 for Doppler measurement is placed beside an array transducer 21 for the mode, the Doppler beam 24 is incident from the side of the ultrasonic beam b/A 23 of the B-mode image. Therefore, if the ultrasonic scanning area 23 of the B-mode image is made wider and the field of view width is set wider, the ultrasonic probe 1 has the disadvantage of becoming larger.

(2) Also, since the transducer 22 for Doppler observation is single, the steering of the Doppler beam cannot be performed electronically, so it must be moved mechanically, and therefore reliability is low. , the shape of the ultrasound probe also becomes larger.

(Because the B-mode image created by the 3-array transducer and the ultrasound beam bus created by the single transducer are different, the plane created by the B-mode raster and the Doppler beam are set at the same cross-sectional position as the scanning cross-sectional position of the B-mode image. It is difficult to confirm whether the

(4) In order to make the Doppler beam enter the same area as the scanning cross-sectional area of the B-mode image at a certain angle, it is necessary to create a space between the array transducer and the single transducer (see Figs. part A) and the protruding part of the single transducer (Fig. 5,
Part B in Figure 6) occurs, and contact with the body surface is significantly impaired. Kabra is needed to solve this problem.

There are drawbacks such as.

(Problems to be Solved by the Invention) In this way, the array transducer performs B-mode and Doppler, and the array transducer uses a hybrid ultrasonic probe equipped with an array transducer and a single transducer. There is a method that performs a sector scan to obtain a B-mode image and then performs Doppler measurement with a single transducer.In the former case, (1) the resolution of the B-mode image is good, and the blood vessels run near the center of the image with little distortion; When parallel to the transmitting/receiving surface of the transducer, the Doppler beam is perpendicular to the blood vessel course, resulting in insufficient Doppler detection ability. Therefore, if a blood vessel runs parallel to the wave transmitting/receiving plane of the ultrasound probe, Doppler observation of the blood vessel at the end of the ultrasound scanning area, that is, the end of the ultrasound tomographic image, is difficult. There is no problem because the Doppler beam enters the blood vessel at an angle, but if Doppler observation is performed on the blood vessel located in the center of the ultrasound tomogram, which has the best image quality, the Doppler beam inclination will be close to a right angle. Therefore, even if one wishes to perform Doppler observation by referring to a tomographic image of a portion with good resolution, it is impractical due to accuracy issues. Therefore, when performing Dotsupler observation on blood vessels located at the edges of an ultrasound tomogram, which are distributed in a direction parallel to the transmitting and receiving surface of the ultrasound probe, the edges of the ultrasound tomogram have poor resolution. You must use this to position the Dotsupura beam route.

(21Also, in order to improve the resolution of the B-mode image, it is sufficient to use a high-frequency probe as the ultrasound probe 2.
In this way, the maximum flow rate of blood flow that can be detected is reduced.

In the latter case, (1) array transducer and single array transducer
7 for B mode because it is a combination of transducers.
Since the method uses a single transducer for Doppler measurement placed beside the ray transducer, the Doppler beam enters from the side of the ultrasonic scanning area of the B-mode image, and the ultrasonic scanning area of the B-mode image is If the width of the field of view is set wide, the ultrasonic probe has the disadvantage of becoming larger. (2) Since the transducer for Doppler observation is single, the Doppler beam cannot be steered electronically, so it must be moved mechanically, which results in low reliability and The shape of the sonic probe also becomes larger.

(Since the B-mode image created by the 3-array transducer and the ultrasound beam bus created by the single transducer are different, the plane by the B-mode raster and the plane by the Doppler beam are set at the same cross-sectional position as the scanning cross-sectional position of the 8-mode image. It is difficult to confirm whether or not the gradient Doppler beam is
In order to make the light incident on the same area as the scanning cross-sectional area of the mode image, a space is created between the array transducer and the single transducer, and the single transducer also protrudes to prevent contact with the body surface. significantly damaged. There are drawbacks such as.

Therefore, the purpose of this invention is to eliminate the dead zone for Doppler detection, make it possible to perform Doppler observation at any position in the B-mode image, display a high-resolution 8-mode image, and enable measurement. It is an object of the present invention to provide an ultrasonic diagnostic device that can increase the maximum flow velocity of blood flow and can be made into a small ultrasonic probe.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention is configured as follows. In other words, as an ultrasonic diagnostic apparatus having a Doppler observation function, ultrasound is generated by an array transducer having a tomographic image acquisition area for sector scanning and a Doppler area set in a different area from this tomographic image acquisition area. a probe; an oscillation means for generating a drive pulse signal; an oscillation means for generating a continuous wave drive signal; a switching means for applying a selected one of the driving pulse signal or the continuous wave driving signal to the Doppler region of the ultrasound probe, and controlling a Doppler beam direction during Doppler observation to a desired setting direction; and means.

(Function) In such a configuration, the ultrasonic probe includes an array transducer having a tomographic image acquisition area for sector scanning and a Doppler area set in a different area from this tomographic image acquisition area. It is used, and
There are two types of ultrasonic drive signal generation means: oscillation means that generates a drive pulse signal and oscillation means that generates a continuous wave drive signal. The switching means applies the driving pulse signal to the tomographic image collecting area of the ultrasound probe during tomographic image acquisition, and applies a selected one of the driving pulse signal or the continuous wave driving signal to the above during Doppler observation. Apply to the Doppler area of the ultrasound probe. Furthermore, the Doppler beam direction during Doppler observation can be set in any direction since the ultrasound probe is an array transducer and can be electronically controlled to a desired setting direction. In other words, this device sends Doppler beams from outside the tomographic image collection area, and the Doppler beams always enter diagonally into blood vessels running parallel to the transmitting and receiving surface of the ultrasound probe, making Doppler detection difficult. It becomes possible to eliminate the dead zone due to
Since the beam direction is arbitrary, Doppler observation can be performed at any position in the tomographic image (B-mode image).

In addition, there are two types of oscillation means for generating drive signals: continuous wave and pulse Doppler, and either can be used for Doppler observation by selection, so the frequency of the drive pulse signal for pulse drive can be increased. It is possible to do so. By lowering the frequency of the continuous wave drive signal, if necessary, the drive signal for Doppler observation can be used for measurement while displaying a high resolution 8 mode image. The maximum flow rate of blood flow can be increased.

In addition, the ultrasound probe is an array transducer, which is divided into a tomographic image collection area and a Doppler area, and the scanning and beam direction can be set electronically, so that the cross-sectional area is the same as the scanning cross-sectional area of the tomographic image. Doppler
It will be possible to send a beam and perform Doppler observation of the target area. Furthermore, since the ultrasonic probe is an array transducer for sector scanning, it can be made into a small ultrasonic probe.

<Embodiment> An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a block diagram showing the configuration of this device, and FIGS. 2 and 3 are examples of the configuration of an ultrasonic probe used in this device.

In FIG. 1, 31 is an ultrasonic probe for sector electronic scanning.

As shown in FIG. 2 or 3, this ultrasonic probe 31 is used for electronic scanning using an array transducer forming a plurality of rows of ultrasonic imaging elements.
In addition, the array transducer is divided into two or four parts, that is, two or four sets of array transducer groups (1) to (4) are arranged in parallel. Note that this is just an example, and the number of divisions is not limited to this.

32 is a selection switch, and 33 is a transmitting/receiving circuit for transmitting and receiving B mode and pulsed Doppler as well as receiving continuous wave Doppler. The transmitter/receiver circuit 33 is a pulse wave oscillation means for oscillating a pulse wave (PW) driving pulse signal and a sector/receiver circuit for sector scanning for B mode.
A transmission delay means for delaying a drive signal to give it to a corresponding one of a group of arrays used for sector scanning with a predetermined delay time depending on the azimuth direction of the scan, and delaying the received signal by a delay time equivalent to the delay time at the time of transmission. and a reception delay means for applying the driving pulse signal to a corresponding one of a group of arrays used for Doppler observation with a predetermined delay R corresponding to the set azimuth direction of the Doppler beam for pulsed Doppler. It has a delay means for delaying the signal, and a reception delay means for delaying the Doppler received signal by a delay time equivalent to the delay time at the time of transmission. 3
4 is a continuous wave (CW) pulser that generates a continuous wave drive signal, and includes an oscillation means that generates a continuous wave drive signal, and a predetermined CW pulser for transmitting the generated drive signal according to the set azimuth direction of the Doppler beam. It has a transmission delay means for delaying a corresponding one of a group of arrays used for Doppler observation by a delay time. 35 is a controller that controls the Doppler beam direction, selects depending on the type of drive signal to be used, controls switching between B mode and Doppler mode, etc. The changeover switch 32 controls this controller 35. It is selectively connected between each array of the ultrasonic probes 31 and the transmitting/receiving side.

36 is an ultrasonic B mode detection/display unit, 37 is a Doppler signal detection unit, 38 is a system controller,
39 is a CRT display device.

The ultrasonic B-mode detection/display unit 36 includes a reception detection unit 36a that amplifies the B-mode reception signal, performs detection, filtering, etc., and stores the detection and filtered reception signal in a frame memory as a B-mode image. It is comprised of a display control section 36b which stores the data, reads it out in accordance with the scanning of the CRT display device 39, converts it into a video signal, and outputs the signal.

Further, the Doppler signal detection unit 37 performs orthogonal detection and sampling of the Doppler signal output from the transmitting/receiving circuit 33, and a quadrature detection processing section 37a that performs filtering to obtain a frequency shift, and Fourier transforms the processed output. Fourier transform calculation unit 37F for obtaining sound speed information)
The sound speed information obtained thereby is displayed in the display control section 36.
b and is displayed on the CRT display device 39 together with the B-mode image. Incidentally, the system controller 38 sets which region 1 of the four divided regions (transducer groups ■ to ■) of the ultrasonic probe 31 is to be used for B mode and which region is to be used for Doppler use. The pulsed Doppler transmitting means of the transmitting/receiving circuit 33 is selected by a command and also depending on whether pulsed Doppler or continuous wave Doppler is used.

``It has a function of controlling the selection of one of the continuous wave pulsers 34 and setting the Doppler signal detection unit 37 in order to perform observation appropriate to the selected one.

In such a configuration, the system controller 3
8, the ultrasonic probe 31 is divided into four or two regions (transducer groups ■ to ■).
It is set which of these areas is to be used for 8 modes and which area is to be used for Doppler. As a result, the system controller 38 selects the set areas in correspondence with each other. The operator also gives an external command to set whether to use pulse Doppler or continuous wave Doppler. As a result, the system controller 38 selects and controls one of the pulse Doppler transmitting means 1M continuous wave pulsers 34 of the transmitting/receiving circuit 33, and also sets and controls the Doppler signal detecting unit 37 to perform observation in accordance with the selection. The operator also sets the Doppler beam direction from the outside. In response to this, the controller 35 controls the Doppler beam direction, selects the type of drive signal to be used, and controls switching between B mode and Doppler mode. The changeover switch 32 is controlled under the control of the controller 35 to alternately and repeatedly selectively connect each array of the ultrasonic probes 31 to the transmitter/receiver at a predetermined timing.

Then, at the B mode selection timing, the PW wave for the B mode is controlled to be transmitted and received from the selected transducer area by sector scanning, and at the Doppler observation timing, the selected CW or PW Doppler beam is Transmission and reception are controlled so that transmission and reception are performed in the set direction. The received signal is received and processed via the receiving circuit 33, and if it is for B mode, the ultrasonic B mode detection/display section 36 performs amplification, transverse wave, filtering processing, etc. in the receiving detection section 36a, and then this processing is performed. The completed reception signal is sent to the display control section 36b.

This is then stored as a B-mode image in the -H frame memory, read out in synchronization with the scanning of the CRT display device 39, converted into a video signal, and output. This video signal is given to the CRT display device 39, where B
Display it as a mode image.

In addition, the received signal for Doppler observation is received and processed through the transmitting/receiving circuit 33, sent to the Doppler signal detection unit 37, orthogonally detected in this quadrature detection processing section 37a, and sampled and filtered to obtain a frequency shift. .

This is then Fourier transformed to obtain sound speed information. The sound velocity information obtained thereby is given to the display control section 36b and displayed on the CRT display device 39 together with the B-mode image. B mode and Doppler are repeated alternately at a predetermined timing, and the beam path of Doppler is changed by a marker generator (not shown) to the set direction of the set position.
Since it is displayed superimposed on the mode image, real-time B
Doppler observation can be performed by setting the desired orientation while observing the mode image.

By the way, the ultrasonic probe 31 used in this device is for electronic scanning using an array transducer forming a plurality of ultrasonic transducer arrays, as shown in FIG. 2 or 3. The array transducer is divided into two or four parts, that is, two or four sets of array transducer groups 1 to 2 are arranged side by side.

Since one array transducer group is used for sector 8 mode and another array transducer group is used for Doppler observation, it is possible to scan from outside the scanning cross-sectional area of the 8-mode image in an oblique direction to the cross-sectional area. , and the Doppler beam can be incident in any direction, so the B-mode image and Doppler can be [1] by matching the cross-sectional positions. Furthermore, Doppler can be used in both continuous waves and pulsed waves, and can be selectively used depending on the purpose. In particular, even if the frequency of the pulse wave is increased to improve the resolution of the B-mode image, high-velocity blood flow can be measured with sufficient accuracy by lowering the frequency of the continuous wave.

Furthermore, since the sector scan method is used, the ultrasonic probe can be made smaller.

In FIG. 2, the steering angles α and β of the sector scans and the left and right deviation angles of each sector scan with respect to the vertical direction are arbitrary. Furthermore, the center frequencies of the two types of sector scans may be arbitrarily determined. Furthermore, the four array transducer groups (■ to ■) divided in the configuration shown in Fig. 3 are for B mode, PW Doppler, and CW.
The use may be defined by group, such as for Doppler. In this case, control becomes easier. Moreover, in this way, it is possible to observe using both PW Doppler and CW Doppler.

As described above, the present device is an ultrasonic diagnostic device having a Doppler observation function, and includes an array having a tomographic image acquisition area for sector scanning and a Doppler area set in a different area from the tomographic image acquisition area.・An ultrasonic probe using a transducer is used, and an oscillation means that generates a drive pulse signal and an oscillation means that generates a continuous wave drive signal are provided, and when collecting tomographic images, the drive pulse signal is transmitted to the tomogram of the ultrasonic probe. and at the time of Doppler observation, a selected one of the driving pulse signal or the continuous wave driving signal is applied to the Doppler area of the ultrasonic boolobe;
This allows the Doppler beam direction to be set to a desired direction during Doppler observation.

In other words, this device sends Doppler beams from outside the tomographic image collection area, and the Doppler beams always enter diagonally into blood vessels running parallel to the sending and receiving surface of the ultrasound probe. It has become possible to eliminate the dead zone for detection, and it has also become possible to eliminate Doppler
Since the beam direction is arbitrary, Doppler observation can be performed at any position in the tomographic image (B mode m).

In addition, there are two types of oscillation means for generating drive signals: continuous wave and pulse Doppler, and either can be used for Doppler observation by selection, so the frequency of the drive pulse signal for pulse drive can be increased. It is possible to do so. By lowering the frequency of the continuous wave drive signal, if necessary, the continuous wave drive signal for Doppler observation can be used to display a high-resolution B-mode image while making measurements possible. The maximum flow rate of blood flow can be increased. In addition, the ultrasonic probe is an array transducer, and it is divided into a cross-section wIm acquisition 1fR1 section and a Doppler area, and the scanning and beam direction can be set electronically, so that the cross-sectional area is the same as the scanning cross-sectional area of the tomographic image. It is possible to send a Doppler beam and perform Doppler observation of the target area. Furthermore, since the ultrasonic probe is an array transducer for sector scanning, it can be made into a small ultrasonic probe.

It should be noted that 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.

〔Effect of the invention〕

As described in detail above, according to the present invention, the dead zone for Doppler detection is eliminated, Doppler observation can be performed at any position in the B-mode image, and it is possible to perform Doppler observation at any position in the B-mode image. It is possible to provide an ultrasonic diagnostic apparatus that can increase the maximum measurable flow velocity of blood flow and can also be made into a small ultrasonic probe.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the configuration of this device, Figures 2 and 3.
The figure shows an example of the structure of an ultrasonic probe used in the present apparatus, and FIGS. 4 to 7 show examples of the structure of an ultrasonic probe used in a conventional apparatus. 31... Ultrasonic probe, 32... Selection switch,
33... Transmission/reception circuit, 34... Continuous wave (CW) pulser, 35... Controller, 36... Ultrasonic B mode detection/display section, 37... Doppler signal detection unit, 38...・System controller, 39...CR
T display device. Applicant's representative Patent attorney Takehiko Suzue? 4s14FM 5th w 6th r
3rd ma of 7 tons of tassels and 2 tatami mats

Claims (1)

[Claims] As an ultrasonic diagnostic apparatus having a Doppler observation function, an ultrasonic probe using an array transducer has a tomographic image collecting area for sector scanning and a Doppler area set in a different area from this tomographic image collecting area. , oscillation means for generating a drive pulse signal, oscillation means for generating a continuous wave drive signal, applying the drive pulse signal to the tomographic image collection area of the ultrasound probe during tomographic image acquisition, and applying the drive pulse signal to the tomographic image acquisition area of the ultrasound probe during Doppler observation; switching means for applying a selected one of the pulse signal or the continuous wave drive signal to the Doppler region of the ultrasound probe; and means for controlling the Doppler beam direction during Doppler observation to a desired setting direction. An ultrasonic diagnostic device comprising: