JPH0328938B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is an ultrasonic image display device, particularly an ultrasonic image display device that can accurately and clearly determine the state of motion of a moving body within a subject or the state representing the properties of living tissue based on Doppler signals. The present invention relates to an ultrasonic image display device that can display images easily.

[Conventional technology]

The ultrasonic pulsed Doppler method has been put into practical use for measuring and displaying the motion state of moving bodies within a subject, such as organs such as the heart, blood flow and body fluid flow in the circulatory system and blood vessels, or the heart muscle. Therefore, the moving speed of the moving reflector within the subject can be electrically detected by the frequency shift of the reflected echo from the moving reflector within the subject.

As such a device, a speed calculation device using an autocorrelation method proposed by the present inventors has been applied for (Japanese Patent Laid-Open No. 188433/1983) and has already been put into practical use.

According to this device, a Doppler reception signal obtained from a motion reflector inside the subject is converted into a complex signal, the conjugate product and the complex product of the complex signal are determined by an autocorrelation method, and the frequency deviation is calculated from this autocorrelation value. It calculates the shift. This frequency shift corresponds to the speed of the moving reflector, and from the magnitude of this frequency shift, accurate speed or velocity dispersion is determined in real time and displayed as a two-dimensional image.

In addition, the present inventors have proposed an ultrasonic Doppler diagnostic device that determines the vector velocity without angular dependence with respect to the direction of motion of a motion reflector (patent application
60−292112).

The speed of these motion reflectors is processed by an ultrasonic image display device and displayed on a CRT screen in B mode, etc., which displays information such as blood flow speed and dispersion in different colors. Alternatively, information can be expressed by brightness, and information useful for image diagnosis can be provided.

[Problem that the invention seeks to solve]

Problems with the Prior Art However, with conventional display devices, the state of motion of a moving body within the subject or the state representing the properties of living tissue can be observed intuitively from a color-displayed CRT screen. Motion elements such as speed,
There was a problem that it was not possible to quantitatively observe dispersion, etc.

In other words, the velocity of the motion reflector is calculated for each point where ultrasonic pulses are transmitted and received, and each point is displayed in color, so that the velocity is displayed as if the points were aggregated as a whole. become.
Therefore, it has been difficult to quantitatively determine this speed using the speed displayed in color on a CRT screen. This also applies to other movement elements such as dispersion and direction of movement.

Purpose of the Invention The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide an ultrasound image that quantitatively displays two-dimensionally the state of motion such as velocity or dispersion, or the state representing the properties of living tissue. The purpose of this invention is to provide a display device.

[Means for solving problems]

In order to achieve the above object, the present invention emits ultrasonic pulses into a subject and processes the reflected signals to display a state of motion of a moving body within the subject or a state representing the properties of living tissue. In a two-dimensional ultrasound image display device, a variable reference signal generator that generates an analog reference signal for setting a state to an arbitrary value, and a comparator that compares the analog reference signal with an arithmetic-processed analog signal; It is characterized by displaying an area of the same value or a predetermined width in an arbitrarily specified state based on the output of the comparator on the screen as a variable line or surface marker, and also displaying the amount of the reference signal. do.

[Effect]

According to the present invention, first, the speed, dispersion, etc. indicating the motion state of a moving body or the state inside the subject expressing the properties of the living tissue are determined using an ultrasonic pulse beam emitted into the subject. Each element indicating these conditions is determined for each point on the object to which the ultrasonic pulse is transmitted and received, and is arithmetic processed as an image signal for each point.

Therefore, by connecting points indicating motion states or in-vivo states of the same or predetermined width and displaying them in the same color or brightness, a desired state can be indicated with a marker.

In this case, the same state of motion is displayed, for example, as a constant velocity line, and the state of motion with a predetermined width is displayed, for example, as a motion region with a predetermined speed width. Numerical values such as the velocity of the constant velocity line or area at this time are displayed at the same time.

〔Example〕

Hereinafter, a preferred embodiment of the present invention (an embodiment for displaying an exercise state) will be described based on the drawings.

FIG. 1 shows a circuit configuration of an ultrasound image display device according to the present invention, and FIG. 2 shows a block diagram of a two-dimensional ultrasound Doppler diagnostic device.
The diagram will be explained.

In FIG. 2, a transmitter 10 divides a high frequency wave generated by a high frequency oscillator to generate various synchronization signals required for the device. Further, pulses with a constant repetition frequency are transmitted to the probe 1 via the scanner 12.
4, which emits an ultrasonic pulse beam toward the subject. The reflected wave from the object is received by the probe 14, passed through the scanner 12, and amplified and detected by the receiver 16. This detected signal is then sent to the CRT display 18 and brightness-modulated on the CRT. On the other hand, the electron beam of the CRT is swept by a sweep voltage generated in the CRT display 18 by the synchronization signal from the transmitter 10, and the reflector on the ultrasound beam axis is displayed on the CRT screen.

On the other hand, the scanner 12 electronically or mechanically deflects the ultrasonic beam of the probe 14 in response to a scanning signal from the transmitter 10 to scan the inside of the subject. Also, in a synchronous relationship with this, a display scanning signal generated from the scanner 12 is applied to the CRT display 18, so that it corresponds to the scanning of the ultrasonic beam.
The CRT's electron beam is deflected and controlled, thereby obtaining a B-mode tomographic image.

Conventionally, in the improved Doppler diagnostic device, the other detected signal of the receiver 16 is transmitted to the velocity calculator 2.
Added to 0. Then, a speed signal is obtained by arithmetic processing of this detection signal. A method of performing this arithmetic processing at high speed and displaying blood flow superimposed on a B-mode tomographic image in real time is specifically explained in an already published patent application (Japanese Unexamined Patent Publication No. 188433/1983).

The present invention can be applied to tomographic images displaying such a two-dimensional distribution of velocity, etc., and is intended to quantitatively measure velocity, etc. on the tomographic image.

That is, the characteristic feature of the present invention is that the same or a predetermined width of the state inside the subject is displayed with a marker, and in the embodiment, the same value or a predetermined region of the motion state of a moving body is displayed with a marker. For this purpose, a variable marker display 30 is newly provided, and the detailed structure of this variable marker display 30 is shown in FIG.

Variable Marker Display Process In FIG. 1, the variable marker display 30 displays a predetermined value or area of a predetermined width of the motion state of a moving body within the subject using a line or surface marker. This is done by a variable reference signal generator and a comparator. The displayed marker is a variable marker that can be specified by the operator to any movement state. For this purpose, a variable reference signal generator 34 and two comparators 36 and 38 are provided. The speed signal obtained by the device shown in FIG. 2 described above is inputted from the terminal d. This signal is usually a digital signal, and is converted into an analog signal by the D/A converter 32 connected to the input terminal d.
The output of the A converter 32 is connected to the comparators 36 and 38, respectively.
is supplied to.

On the other hand, the output of the variable reference signal generator 34 is supplied to comparators 36, 38, where it is compared with the speed signal.

In the embodiment, the comparator 36 also includes a switch 44 for switching the comparator output between a speed region display and a constant velocity line display, an adder 42 that adds the output of the comparator 38 to the output of the comparator 36, and a variable reference signal generator. Vessel 3
A numerical value converter 40 is provided for converting the output of 4 into a numerical value.

The ultrasonic image display device of this embodiment has the above configuration, and its operation will be explained below.

A digital speed signal is supplied from terminal d, and after being converted to an analog speed signal, it is supplied from terminal a.
is sent to the CRT display 18, and the
The CRT is brightly modulated, and the higher the speed value, the brighter it will appear on the screen.

On the other hand, the variable reference signal generator 3 is connected to the comparators 36 and 38 to which the output of the D/A converter 32 is supplied.
A voltage E 1 is applied to the comparator 36, and a voltage _{E 2 (} E ₁ >E ₂ ) is applied to the comparator 38.

In the embodiment, the comparator 36 compares its input with the variable reference signal to determine whether the speed is greater than or equal to the speed determined by the voltage E ₁ and the speed value is the same as the speed determined by the voltage E ₁ , that is. Processing is being performed to display the distribution of constant velocity lines. In the case of speed domain display, a comparator 36 compares the speed signal with a variable reference signal, and outputs a constant voltage to the output terminal A when the speed V satisfies the condition of V≧ _E1 .

Fig. 3 shows the relationship between the speed signal, the comparator output signal, and the variable marker in the display image. When displaying the speed region under the condition of V≧E ₁ , output to output terminal b. The resulting signal will be the voltage signal shown in Figure b, which is the voltage of the variable reference signal.
This indicates a speed range equal to or higher than the speed V defined by _E1 .

Therefore, as shown in the screen display shown in Figure d, t ₁
~ _t2 , a voltage _E0 is generated, which is added to the V signal inside the CRT display 18 to modulate the CRT's brightness, so that in the period of _t1 ~ _t2 with respect to the scanning direction OP of sector scanning. Displays the line in between brightly.

Then, by sequentially changing the scanning angle and scanning sectors, the surface of the illustrated Q area is brightly displayed as a variable marker.

Also, if you want to display the distribution of the same velocity values, use
If the signal at only the point where V=E ₁ (output terminal B), that is, the voltage signal at t1 and t2 in FIG. It will be done.

This variable marker 200 is a constant velocity line, and corresponds to a contour line used on a map or the like. Therefore, by using a plurality of comparators, the velocity distribution within the subject can be displayed as an image using a plurality of constant velocity lines.

In the embodiment, the comparator 38 performs processing to display another constant velocity line, and the variable reference signal generator 34 outputs the variable reference signal E ₂ to the comparator 38.

That is, the variable reference signal E ₂ has a relationship of E ₂ =E ₁ -ΔE, and is set at a somewhat low speed. Although this variable reference signal can be freely designated by an operator or the like, ΔE is set to a constant value in the embodiment.

The output of the comparator 38 compared with such a variable reference signal E ₂ becomes a voltage signal shown as T ₁ and T ₂ in FIG. The signal is supplied to the display 18.

Therefore, it becomes a constant velocity line of the variable marker 201 shown in the figure, and by displaying it simultaneously with the variable marker 200, the velocity distribution inside the subject can be known.
In this case, since ΔE is constant, the difference between variable markers 200 and 201, which are constant velocity lines, indicates a constant velocity, and by observing the interval between the constant velocity lines, it can be determined whether there is a sudden change or a gradual change. The velocity gradient can be easily determined.

Another advantage is that by displaying a plurality of constant velocity lines like this, it is possible to determine the velocity gradient between two points within the subject between the two variable markers, providing useful information for image diagnosis. has.

In the embodiment, the variable markers 200, 201,
When displaying Q as an image, a value indicating the motion state of the moving object, here a velocity value, is also displayed. This is performed by a numerical value converter 40, which converts the variable reference signal output from the variable reference signal generator 34 into a numerical value of the actual speed and displays it. This indication may be used alone or
This is done by displaying it on the CRT screen of the CRT display 18. Therefore, it is possible to specify the required distribution state of velocity values while viewing the image display and perform arbitrary observation.

Furthermore, by aligning the variable markers 200, 201, and Q with a region within the subject that is desired to be quantitatively observed, it is also possible to quantitatively know the speed of the specific region from the displayed numerical value. When the velocity distribution constantly fluctuates, such as in the case of blood flow in the heart, the constant velocity line fluctuates, but by changing the reference signal so that the constant velocity line passes through the desired area and reading the values at this time, Velocity distribution can be measured.

Ordinary velocity has angle dependence, so if the direction of velocity flow is known, the angle can be corrected, measured quantitatively, and used as a velocity signal. As mentioned above, a calculation method without angle dependence has also been proposed, and in this case, quantitative measurement becomes easier.

Furthermore, the motion state of the moving object in the present invention is not limited to speed, but can also display dispersion, etc., and these can also be displayed in color. The present inventor has proposed a device that displays the speed in color (Japanese Patent Application Laid-open No. 59-1998-
20820).

Next, a case where the present invention is applied to the color display device will be explained based on FIG. 4.

In the figure, the CRT 52 in the CRT display 18 is equipped with blue (B), red (R), and green (G) control grids.
Control voltages of signals g, r, and b are applied to each of the control grids. These control voltages control the flow so that, for example, a flow approaching the probe is displayed in a warm color, a flow in a direction away from the probe is displayed in a cool color, a fast flow is displayed in a bright color, and the color of green increases depending on the amount of deviation that indicates dispersion. .

In an embodiment, the control voltage applied to the R,B control grid is provided by an electronic switch 56 driven by a drive circuit 54.
is switched to the DC voltage source 58 side. The b signal input to the drive circuit 54 is the output signal of the comparators 36 and 38 in FIG. 1, and the b and c signals in FIG.
is the voltage signal shown in . Therefore, the electronic switch 56 is activated only during the period when the constant velocity line is displayed by this b signal.
operates, and the voltage from the DC voltage source 58 is applied only to the R and B control grids, so the variable marker representing the constant velocity line or region is displayed in purple.

On the other hand, when the b signal is not output and the electronic switch 56 is not operating, the speed is displayed in warm or cool colors on the CRT screen depending on the a signal from terminal a of the variable marker display 30. The variable markers 200, 201, and Q have colors that do not belong to any of these colors, so that the same movement state can be clearly identified.

In the above embodiment, the motion state of the moving body was explained, but the present invention is not limited to the above-mentioned speed and dispersion.
It is also effective for quantitatively measuring quantities representing properties, such as the amount of attenuation of tissue, on images in tissue diagnosis where the properties of a subject's tissue are displayed as images.

〔Effect of the invention〕

As explained above, according to the present invention, the state of motion of the same or predetermined width is displayed as a line or surface, so that the speed, dispersion, or property of the living tissue indicating the state of motion of the moving body is displayed. It is possible to provide an accurate and useful diagnostic device that can quantitatively display the amount of attenuation of tissue that indicates the state, and can show the state inside the subject.

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram showing a preferred embodiment (variable marker display device 30) of an ultrasonic image display device according to the present invention, and FIG. 2 is a block diagram showing a circuit configuration up to displaying the motion state of a moving object. 3 are explanatory diagrams showing processing for forming variable markers, and FIG. 4 is a block diagram showing a circuit configuration for color display. 10... Transmitter, 12... Scanner, 14... Probe,
16...Receiver, 18...CRT display, 20...Speed calculator, 30...Variable marker display, 32...D/A
Converter, 34... Variable reference signal generator, 36, 38
... Comparator, 40... Numerical converter, 200, 201,
Q...Variable marker.

Claims (1)

[Scope of Claims] 1. Emit ultrasonic pulses into the subject, and calculate and process signals obtained from reflected waves to display the state of motion of a moving body within the subject or the state representing the properties of living tissue. In a two-dimensional ultrasound image display device, a variable reference signal generator that generates an analog reference signal for setting a state to an arbitrary value, and a comparator that compares the analog reference signal with an arithmetic-processed analog signal; It is characterized by displaying an area of the same value or a predetermined width in an arbitrarily specified state based on the output of the comparator on the screen as a variable line or surface marker, and also displaying the amount of the reference signal. Ultrasonic image display device. 2. The ultrasonic image display device according to claim 1, characterized in that a plurality of variable reference signal generators or comparators are provided. 3. The ultrasonic image display device according to claim 1, characterized in that the motion state of the moving body is displayed as a motion speed, and is displayed in a color that is distinguishable from colors representing other motion states. Device.