JPS59120141A - 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] [Technical Field of the Invention] The present invention belongs to the field of medical devices for diagnosis, and more specifically, ultrasonic diagnosis that collects information on the quality of tissue within a subject using ultrasound waves. It is related to the device.

[Technical background of the invention and its problems]

An ultrasonic diagnostic apparatus scans an ultrasound beam into a living body and collects all reflected waves from within the living body to reproduce a tomographic image and perform a morphological diagnosis@. In recent years, advances in ultrasound technology have dramatically improved the resolution of tomographic images and as we approach the technical limits, clinicians are demanding to obtain information on the quality of living tissue that goes beyond the limits of morphological diagnosis. It's increasing.

In other words, it is the identification of tissue quality by ultrasonic diagnosis, and in recent years,
Characterization of this tissue war (Ti5su
Basic research on e-Characterizatton is becoming more popular. For example, when information on tissue quality is required, the presence of a tumor in the liver is detected in a single ultrasound tomogram, and it is impossible to determine whether the tumor is malignant or not based on morphological diagnosis alone. It may happen. In such a case, if a total of llx+1 of information regarding the quality of the tissue, such as the magnitude of attenuation of ultrasound waves and the speed of sound of ultrasound waves, is available, it can be used as new judgment material for diagnosis.

A specific method for determining the attenuation of ultrasound waves as information on the quality of tissue.1-) There is a method of analyzing the entire spectrum of an ultrasound reflection signal from a living body. This method was developed in 1981.
It was presented at the American Society of Ultrasound in Medicine in 2008 by J.P. JorLeJ' and others (Proceedings of the performance P11o8).

According to this method, the ultrasonic reflection signal used to obtain an ultrasonic tomographic image is divided into desired sections within the living body, and spectrum analysis of the ultrasonic signal in this section is performed for each section. Then, by comparing the spectrum of this section with the spectrum of another section, the attenuation of the ultrasonic waves in the two sections can be determined as a function of the frequency within the ultrasonic band.

The dual spectrum analysis method is based on the premise that the ultrasonic wave introduced into the living body is a temporally extremely short pulse 1 as shown in FIG. 1 (α). Since the temporally short ultrasonic pulse 1 has a wide frequency band, its frequency spectrum 2 has a wide frequency band as shown in FIG. 1(b). Therefore, spectrum analysis is required to obtain attenuation information for specific frequencies.

Furthermore, since the ultrasonic pulse 1 is short in time, the spectral intensity distribution of the foul signal changes due to the influence of the arrangement of microstructures within the fibers, resulting in a large number of scanning lines (ultrasonic beams).
It is necessary to perform an averaging process for . This is shown in Figure 2 (
This will be explained with reference to α) and Cb) ffi. Figure 2 (
d) and (b) show the schematic structure of the microstructure 6 and the reflection spectrum 2m 4. Because the interference effect of multiple reflections within the microstructure 6 differs for each frequency component depending on the spatial arrangement of the microstructure 3, the reflection spectrum 4 Unlike the spectrum 2 of the ultrasonic pulse produced by humans, it has a characteristic with many ripples. Therefore, in order to remove the shadow # due to the spatial arrangement of the micro-tissue 6, the average reflected signal intensity at the corresponding depth cannot be obtained unless an average is calculated for a large number of scanning lines.

As explained above, since tomographic images emphasize resolution, they require temporally short ultrasound pulses, but since these temporally short pulses are used as they are to obtain attenuation information, spectrum analysis And averaging processing is essential. Therefore, the large-scale storage means and calculation means required for spectrum analysis and averaging processing lead to an increase in the size of the apparatus, and there is no way to prevent delays in processing time.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and provides an ultrasonic diagnostic device that can obtain attenuation information of biological tissue with an extremely simple configuration and can significantly shorten processing time. The purpose is to

[Summary of the invention]

The outline of this invention for achieving the above object is as follows.

In an ultrasonic diagnostic apparatus that scans an ultrasound beam within the entire subject and detects reflected signals from within the subject to display a layered image, a burst wave generating means that generates a burst wave that continues in time. , a transmission means for inputting the burst wave and driving the entire burst of ultrasound so as to focus and deflect the tomographic image in a predetermined direction; an ultrasound probe for transmitting and receiving the ultrasound; A receiving means for applying a reception focus, and a signal processing means for outputting a display signal that receives all the reflected signals from the receiving means and obtains information on the ultrasonic attenuator 1'1 based on the reflection intensity and retraction position. It has all the characteristics.

[Embodiments of the invention]

An embodiment of the present invention will be explained below with reference to the drawings.

First, regarding the principle of this invention, Fig. 6(a), (
This will be explained with reference to A>. Conventionally, ultrasonic waves weakened
In order to obtain the information, temporally short ultrasound pulses were used. However, when focusing on obtaining ultrasonic attenuation information 'fr:, temporally short ultrasonic pulses are not necessarily necessary. If a temporally long ultrasonic wave 5 as shown in FIG. 6C(1) r is used, its reflection spectrum 6 will have an extremely narrow frequency band as shown in FIG. 6(h). Therefore, spectrum analysis is not required to obtain ultrasonic attenuation information for a specific frequency.

Furthermore, since the duration of the ultrasound waves 5 is long, the interference effect of the spatial arrangement of the pre-Rt microtissues B is averaged out. For example, for the duration of ultrasound 1 shown in FIG. 1 (α) I/C,
If the duration of the ultrasonic wave 5 shown in Figure (α)K is multiplied by 10,
The interference effect of the spatial arrangement of the microtissues 6 is averaged ten times.

Therefore, complicated 7JI] arithmetic averaging processing is also unnecessary. By the way, the ultrasonic wave 5 shown in FIG. 6 (α) is about 1
If the frequency of ultrasonic waves is 5 MHz, the wavelength is about 300 μm, and 15 wavelengths corresponds to 4.5 wavelengths.

As explained above, by using ultrasonic pulses with a long duration, it is possible to easily obtain ultrasonic attenuation information without the need for spectrum analysis or addition and averaging.

Next, one embodiment of this invention based on the above-mentioned principle will be described with reference to the drawings. FIG. 4 is a block diagram of an ultrasonic diagnostic apparatus that is one embodiment of the present invention. This embodiment VI1 is an application of the present invention to an electronic IJ near-scanning ultrasonic diagnostic apparatus. Therefore, the ultrasonic diagnostic apparatus according to the present invention has not only the means for performing all the usual electronic linear scans, but also means for emitting long-duration ultrasonic waves and ultrasonic waves based on the reflected waves. and means for displaying the reduction R of the sound wave.

First, a method for reconstructing the entire tomographic image by performing a normal multiplex linear scan will be explained. Capital of Vice-I Wholesale Count No. 10
emits a control signal for image reconstruction based on the emission of ultrasonic waves and their reflected waves. Pulsar drive signal generator 11
ri, the control signal generator 100 generates a pulser drive signal based on the control signal. The transmission delay circuit 14 inputs the pulser drive signal manually via the switch 16 and outputs a signal that provides a delay time for applying transmission focus to the ultrasonic waves from the simultaneously driven camera elements. Pulsar 1
5 emits a high voltage pulse to drive the ultrasonic transducer based on the output of the transmission delay circuit 14. This high-voltage pulse excites all of the predetermined simultaneously driven transducers of the ultrasound probe 17 via the transducer selection circuit 16 that selects simultaneously driven transducers, so that ultrasonic waves are emitted into the living body. ing.

The reflected wave from inside the living body is detected by the ultrasonic probe 17 and sent to the preamplifier 1 via the transducer selection circuit 16.
It is designed to be increased by 11 in 8. Late reception L! ;
ti11'i2 circuit 19&L front nL 11! Input the output of 1k×3ii18 for the 1st and 1st R, and add all of them during the delay time to apply the receive/1♂ focus and output the result. The first received signal processing circuit 21 performs ri! J j+
f'', the output of the receive h delay signal p1 circuit 19 is converted into the input 1~, this fr: display signal via the screen 20 and output. 9L Tsute Samurai (Ultrasonic 18T based on L valley display signal)
It is designed to play and display I Onzuka.

Next, a means for obtaining ultrasonic attenuation will be explained. The burst wave generation circuit 12 is for generating all the burst waves that are generated by ultrasonic waves having a long duration. This burst wave generation circuit 12 is arranged in parallel with the pulser drive signal generation section 11 before the switch 16. The burst wave generation circuit 12 generates the burst wave based on the ili control signal from the control signal generation section 10, and also outputs the burst wave to the transmission delay circuit 14 via the switch 16. It has become. The second received signal processing circuit 22 is a circuit designed to process all information from reflected waves based on long-duration ultrasonic waves. The second received signal processing circuit 22 is arranged downstream of the switch 20 and in parallel with the first received signal processing circuit 21 .

Here, one configuration of the second received signal processing circuit 22 is as follows.
This will be explained with reference to the figures. The logarithmic amplifier 60 is used to convert an exponentially changing signal into a linearly changing signal, considering that ultrasonic waves in a homogeneous medium generally attenuate exponentially. The detection circuit 61 includes the logarithmic amplifier 6
Converts high frequency signals from 0 to video signals. The amplitude adjustment circuit 62 is for correcting changes in the inherent reflection intensity due to the focusing or diffusion effect of the ultrasonic beam, and is controlled by the control signal from the control signal generating section 10.

! : Sea urchins are turning.

The operation of the ultrasonic diagnostic apparatus configured as described above will be explained with reference to FIG. 6.

The operation of performing the entire electronic linear scan and displaying the ultrasonic tomographic f security deposit is the same as the conventional method, so a description thereof will be omitted. Incidentally, when displaying the first tomographic image, the switch 16 is connected to the balser drive signal generating section In, and the switch 20 is connected to the first receiving I, i processing R interrogate 21.

Below, the operation of obtaining all attenuation of ultrasonic waves will be explained.

In order to transmit the ultrasonic beam in a desired direction of the tomographic image -L, the 1ljlJ control signal from the 1lilJ control signal generator 1o is sent to the transducer selection circuit 16. The signal is sent to the transmission delay circuit 14 and the reception delay addition circuit 19, where nine vibrators to be driven are selected, and the delay time of transmission and reception for the driven vibrator is set. Also, by modifying the control signal, the switch 16
is connected to the burst generation circuit 12, and the switch 20 is connected to the second reception processing circuit 22.

Next, the burst wave generation circuit 12 is driven by the control signal from the control signal generation circuit 10, and a burst wave is generated. This parsed wave) ei is sent to the transmission delay circuit 14 via the switch 16, and is output as a burst wave having a delay difference for each of the simultaneously driven oscillators. The pulser 15 is driven by this burst wave and generates burst pulse gold of the same pressure. This high-voltage burst wave drives all of the simultaneously driven transducers in the ultrasound probe 17 via the transducer selection circuit 16. Therefore, the ultrasonic wave with a long time (hereinafter referred to as burst ultrasonic wave) is emitted.The ultrasonic probe 1
7, and the transducer selection circuit 16. Preamplifier 1
8. The signal is input as an ultrasonic signal to the second received signal processing circuit 22 via the reception delay addition circuit switch 20.

Here, the change in the reflection intensity of the ultrasound signal based on the reflection position depends on the attenuation of the ultrasound in the living body and the change in the reflection intensity at the tissue boundary. Therefore, if the total reflection intensity is displayed as a function of the reflection position, the attenuation of the ultrasonic wave within the tissue and the change in the reflection intensity at the tissue boundary can be seen from the change in the reflection intensity.

The second received signal processing circuit 22 performs the following operations. As mentioned above, the logarithmic amplifier 30 in the second received signal processing circuit 22 is configured to round off the fact that ultrasonic waves in a homogeneous medium generally decay exponentially, and to reduce the ultrasonic waves that change exponentially. Converts a sound wave signal into a linearly varying signal. The output of the logarithmic amplifier 60 is transmitted to the detection circuit 61
The video signal is converted into a VC signal by the amplitude adjustment circuit 62, and the changes in the inherent reflection intensity due to the focusing and diffusion effects of the ultrasonic beam are corrected and output to the second received signal processing circuit 22. FIG. 6 shows the contents of an image displayed on the display device 26 based on the output of the second receiving 1g signal processing circuit 22. In FIG. 6, the right side of the drawing shows an ultrasonic tomogram 66 and a burst ultrasonic wave 64 that is displayed as a bright spot or a dark spot on the tomographic image 66. Further, in the left flltl portion of FIG. 6, the reflected signal strength 37 is displayed, with the horizontal @ representing the reflected signal strength and the vertical axis representing the depth from the body surface. In addition, the 0-reverse signal intensity 37 shown in the figure 66 is a distance marker indicating the depth from the body surface, and in a homogeneous part, it changes linearly with the depth from the body surface, and this slope is the same as the biological tissue e. This shows the attenuation of ultrasound waves at . Therefore, from the slope of the tomographic curve 36 and the reflected signal intensity 37, it is possible to know the attenuation of the ultrasonic wave at a desired part of the living tissue. For this reason, it is possible to identify the quality of biological tissue from the ultrasound attenuation information, and the diagnosis IU'
r f+# improvement (r- can be achieved).

Note that the resolution in the distance direction deteriorates due to the use of ultrasonic waves with a long duration, and the resolution in the scanning line type I11 direction, that is, the azimuth direction, due to the use of a large number of scanning lines in the averaging process essential for conventional spectrum analysis. It is equivalent to the inspiration of Therefore, in terms of resolution, this method is not inferior to conventional methods.

This invention is not limited to the above-mentioned embodiments, nor does it encompass various modifications within the scope of the gist of the invention. For example, the second received signal processing circuit 22 may have the configuration shown in FIG. 7.

The second received signal processing circuit 22 shown in FIG. 7 includes several differentiating circuits 68 after the constituent means shown in FIG. Second received signal processing 1-1 path 22 having the same configuration as above
An example of how an image can be displayed on the display shield 26 based on the output is shown in FIG. In this case, as shown on the right side of FIG.
Therefore, the total damping of the supersonic wave +6L can be shown on the side 1111.

In addition, in the previous 6 [2nd IJI/here, we used an ultrasonic probe to apply one fault iron and an ultrasonic probe to emit burst ultrasonic waves, but this They can also be placed separately. This will be explained with full reference to FIG. As shown in FIG. 9, an ultrasonic probe 40 for emitting burst ultrasonic waves is placed separately from an ultrasonic probe 17 for obtaining fault force, and an angle adjustment device 41 The direction in which the burst ultrasonic waves are emitted is set, and the angle is detected by a full-angle detection device 42. This configuration has the advantage that efficient ultrasonic probes can be designed separately for burst driving. For example, using an ultrasonic probe consonant with a fundamental center frequency of 500 KHz, the high frequency l, 5 AfHz, 2.5 A
l11z, 5.5AIIIz.

It is possible to perform burst driving at odd multiples of frequencies such as 4 and 5 MHz, and efficiently generate burst ultrasonic waves at these frequencies. In this way, it becomes possible to obtain attenuation information for different frequencies.

Furthermore, it goes without saying that the present invention is applicable not only to the electronic linear scanning ultrasonic diagnostic apparatus described above, but also to electronic sector scanning ultrasonic diagnostic apparatuses or mechanical scanning ultrasonic diagnostic apparatuses. In this case, the ultrasonic probe and the transmitting/receiving means may be used together with the valley means for obtaining the layer image, as in the case of failure #iii mentioned above.

〔Effect of the invention〕

As explained above, according to the present invention, by using ultrasonic waves with a long duration (burst ultrasonic waves), complex processing such as spectrum analysis and averaging processing is not required, and the configuration is extremely simple. It is possible to provide an ultrasonic diagnostic apparatus that can display ultrasonic attenuation information in real time.

[Brief explanation of the drawing]

Figure 1 (tz) and (&) are characteristic diagrams of the temporal waveform of ultrasound and its frequency spectrum, which are usually used to obtain a cross-sectional image (fr), and Figure 2 (a) is a schematic diagram of in-vivo microtissues. and a characteristic diagram showing ultrasonic waves with a short duration, Fig. 2 (
b) is a characteristic diagram showing the frequency spectrum of the reflected wave due to the ultrasonic wave shown in aJ. Figure (α)
FIG. 4 is a block diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention, and FIG. 5 is a block diagram showing an example of a second received signal processing circuit. 6 is a schematic explanatory diagram showing an example of an image display based on the output of the second receiving signal processing circuit shown in FIG. 5, and FIG. 7 is a diagram showing another example of the second receiving signal processing circuit. FIG. 8C is a schematic explanatory diagram showing an example of an image display based on the output of the second received signal processing circuit shown in FIG. 7, and FIG. 9 is a modified example of the ultrasound probe according to the present invention. FIG. 12...Burst wave generating means, 14.15°16
...transmission means, 19...reception means, 22...
Signal processing means. Agent Patent attorney Noriyuki Chika (and 1 other person) 1 Figure 1 ----- Vice particle school 2 Figure 5/; x') Figure 6 Figure 7 Figure 0NTIN γ Figure 8

Claims (3)

[Claims] (1) In an ultrasonic diagnostic device that scans an ultrasonic beam inside the subject, detects the reflected signal from within the subject, and displays a layer image, burst waves are generated that are continuous over time. means, a transmitting means for inputting the entire burst wave and driving the ultrasonic waves in bursts so as to focus and deflect them in a predetermined direction on the tomographic image, an ultrasonic probe for transmitting and receiving the ultrasonic waves, and a reflected signal. and a signal processing means for inputting the reflected signal from the receiving means and outputting a display signal for obtaining attenuation information of the ultrasonic wave from the reflection intensity and reflection position. Features of ultrasonic diagnostic equipment. (2) The ultrasonic diagnostic apparatus according to claim 1, wherein each means for obtaining a tomographic image is used as the transmitting means and receiving means of the ultrasonic probe 9. (3) The signal processing means has an exponential function U! of the input signal.
(''i''iiUi(fjcfm~11''1'・11
It is characterized by comprising a detector that converts the output of the logarithmic amplifier into a full video signal, and an amplitude adjustment circuit that inputs the output of the detector and outputs the reflected intensity change specific to the ultrasound beam as an extraction (-). The ultrasonic diagnostic apparatus according to claim 1 VC. □ - (4) The signal processing means includes a logarithmic amplifier that converts an exponential change in an input signal into a linear change, and an output of the logarithmic amplifier that converts an exponential change in an input signal into a linear change. A detector that converts it into a video signal, a manual input of the output of the detector, and changes in reflected intensity specific to the ultrasound beam.
f: The ultrasonic wave according to claim 1, comprising an amplitude adjustment circuit that corrects and outputs it, and a differentiation circuit that inputs the output of the amplitude adjustment circuit, differentiates it, and outputs it. Examination F! fr1□ device.
:(5) The previous "'d '(-7) wave generation means is.../(-
′) Wave 0. The patent application is characterized in that the frequency can be controlled by OT variation.
1. The ultrasonic diagnostic apparatus according to item 1.
1□