JPH0779975A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

PURPOSE:To intend to realize CMF function at the time of the injection of a contrast medium for ultrasonic waves and to realize CMF display in accordance with presence of injection of a contrast medium for ultrasonic waves and to switch CMF function in accordance with the injection of the contrast medium for ultrasonic waves. CONSTITUTION:Measuring means 1, 2 comprised of first measurement and second measurement for measuring seperately in accordance with injection of a contrast medium into blood vessels of the subject, measuring means for calculating tomograph images 2 to calculate B mode tomograph image from the first measurement, means for calculating doppler 21, 3 for extracting doppler signals by switching gain in accordance with the injection of a contrast medium from the second measurement and from these doppler signals blood flow doppler signals in accordance with the injection of a contrast medium are detected by elimination of fixtures in accordance with the injection of a contrast medium. And the apparatus is further comprised of DSC measure 4 which superimposes 21 B mode tomograph images obtained by the calculating means 2 and speed and other data obtained by the CFM calculating means 32-34 in accordance with the injection of the contrast medium and houses the image data obtained by these superimposition in the memory of images and a monitor 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus having a color flow mapping (CFM) function.

[0002]

2. Description of the Related Art The Doppler measurement method is a blood flow measurement method utilizing the Doppler effect in which a reflected wave of ultrasonic waves from a blood flow is frequency-shifted according to the speed of the blood flow. Doppler measurement method,
There are a continuous wave Doppler measurement method for continuously emitting and measuring ultrasonic waves and a pulse Doppler measurement method for intermittently emitting and measuring burst wave ultrasonic waves. CFM is a blood flow obtained by the pulse Doppler measurement method. The distribution of the frequency shift related to is obtained on the tomographic plane of the ultrasonic tomographic image, and this is to be displayed in color by being superimposed on the tomographic plane. This allows two-dimensional mapping of blood flow on a tomographic image.

FIG. 2 shows a block diagram of an ultrasonic diagnostic apparatus having this CFM function. This device includes a probe 1, an ultrasonic diagnostic unit 100, a control circuit 7 for controlling the ultrasonic diagnostic unit 100, and a panel 8 which is an input device. The panel 8 is operated by an operator (for example, CFM function mode designation, B mode designation, etc.), and the control circuit 7 receives the instruction and input data and each circuit 2, 3, 4, 6, of the ultrasonic diagnostic unit 100.
Control of 20, 21, 30, and 31 is performed. C ₁ ... C _n is the control signal. This control includes timing control and processing control, which are dependent on the substance of each circuit.

The ultrasonic body 2 calculates (reconstructs) B-mode tomographic image data by measuring B-mode ultrasonic waves from the probe 1. Further, the ultrasonic body 2 performs pulse Doppler measurement and sends this Doppler measurement signal to the Doppler calculator 3.
The Doppler calculator 3 obtains a Doppler signal (consisting of two signals of a real number part and an imaginary number part) from the change in the phase of the measured value before and after the Doppler measurement signal.

As shown in FIG. 2, the Doppler calculator 3 includes mixers 24, 25, LPFs 26, 27, oscillators 29, 9
It comprises a 0 ° phaser 28. Doppler measurement signal and oscillator 29
The mixer 24 mixes the Doppler measurement signal with a signal having a 90 ° phase difference between the oscillation output and the mixer 25, and outputs the frequency difference and the addition as a mixer output. Intermediate frequency). The output of the mixer 24 is treated as a real part and the output of the mixer 25 is treated as an imaginary part. The LPFs 26 and 27 remove the high frequency components by addition, and extract only the frequency difference. This frequency difference indicates the phase shift due to Doppler. There is also an example in which another mixing means is provided on the output side of the LPFs 26 and 27 in order to distinguish whether the blood flow approaches or moves away (base shift).

The Doppler signal obtained by the Doppler arithmetic unit 3 is converted into a digital signal by the AD converters 30 and 31, and FFT2
0 and CFM circuit 6. The FFT (Fast Fourier Transform) 20 performs frequency analysis of the Doppler signal,
The spectrum is sent to DSC (Digital Scan Converter) 4. The DSC 4 converts this frequency spectrum into luminance and stores it in a required display position on the image memory.

The CFM circuit 6 is composed of MTI (moving target indicator) circuits 32 and 33 and a CFM calculator 34. MTI filter 32,
The reference numeral 33 removes a signal related to a fixed portion (structure) such as a blood flow wall and extracts a Doppler signal related to a moving blood flow. The MTI filters 32 and 33 perform extraction processing using the velocity and the reflection intensity as parameters. C
The FM calculation unit 34 uses the blood flow Doppler signals output from the MTI filters 32 and 33 to calculate the blood flow velocity f (mean flow velocity; so-called Doppler shift frequency), variance σ ² , intensity p.
And are calculated by the following formula.

[0008]

[Equation 1] This calculation is performed for each point (position) of blood flow.

The superimposing circuit 21 reads the B-mode tomographic image data already stored in the image memory in the DSC 4 for each point, and the read B-mode tomographic image data for each point and each point of the CFM calculator 34. Calculation output for each (f, σ ² , p)
And superimpose. Superimposing means selecting a pixel having a CFM calculation output so that the CFM calculation output is given priority in color display (in addition, B mode tomographic image data of this pixel is erased), and a pixel having no CFM calculation output. Regarding, there is a case where the B-mode tomographic image data is selected to be displayed as it is. In addition to this, there may be a case where the B-mode tomographic image data exists and the CFM calculation output exists. In that case, a certain criterion is given. Then, either the B-mode tomographic image data or the CFM calculation output is selected according to the standard. Selected B above
The mode tomographic image data or CFM calculation output is returned to DSC.
The image memory in 4 is read and written in the same position.

The DSC 4 takes in the B-mode tomographic image data from the ultrasonic body 2 and writes it in the pixel positions of corresponding points on the image memory one after another. This once written data is sent to the superimposing circuit 21 again, is selected with the CFM output, and is again written to the same pixel position. Thus, the B-mode tomographic image and the CFM color image existing in the blood flow portion are stored in the image memory. on the other hand,
The output of the FFT 20 is stored in the image memory, but in general, the output of the FFT 20 is often displayed in a display area separate from the B-mode tomographic image. Therefore, the output of the FFT 20 is stored in the pixel position corresponding to the different display area on the image memory.

The monitor circuit 5 displays the contents of this image memory. As a result, CFM display is performed.

With the above structure, it is possible to display a B-mode ultrasonic tomographic image and also display in color the velocity, dispersion, and intensity of blood flow in a direction perpendicular to the tomographic plane.

[0013]

In Doppler measurement, the amplitude of the signal component due to the blood flow is extremely smaller than the amplitude of the signal component from the blood vessel wall. This is because the signal component due to the blood flow is obtained from the reflected signal from the blood cells in the blood and the size and number of the blood cells themselves are limited.
Then, what was developed in order to increase the amplitude of the reflection signal from the blood cells is an ultrasonic contrast agent that increases the ultrasonic reflection intensity. By injecting this ultrasonic contrast agent into blood vessels and attaching it to blood cells, and measuring the blood cells with the contrast agent by Doppler measurement,
A strong reflection signal from the contrast agent is measured to obtain a Doppler signal with a large amplitude.

However, the conventional ultrasonic diagnostic apparatus having the CFM function does not consider the case of injecting an ultrasonic contrast agent. That is, on the assumption that the amplitude of the reflected signal from the blood cells is extremely small, the Doppler circuit, CFM circuit, D
The SC circuit is configured, and there is no idea that the reflected signal from the blood cells will be extremely large.

An object of the present invention is to provide an ultrasonic diagnostic apparatus capable of achieving Doppler measurement and CFM function by injecting an ultrasonic contrast agent.

[0016]

According to the present invention, when performing pulse Doppler measurement by injecting an ultrasonic contrast agent, an image extraction capability matched to the characteristics of the ultrasonic contrast agent is provided so that the CFM function can be processed from this pulse Doppler measurement. I had it. Further, in the present invention, the image extraction ability is switched depending on the presence or absence of the injection of the ultrasonic contrast agent.

Further, according to the present invention, the presence or absence of the injection of the ultrasonic contrast agent is displayed on the display screen.

Further, according to the present invention, the ultrasonic contrast agent is automatically detected and switched depending on the presence or absence of the injection, or the switching is performed manually.

[0019]

According to the present invention, when the ultrasonic contrast agent is injected, it is possible to obtain the image extraction ability suitable for this injection.
Further, according to the present invention, the image extraction ability can be switched depending on whether or not the ultrasonic contrast agent is injected.

Further, according to the present invention, the presence or absence of the injection of the ultrasonic contrast agent can be displayed on the display screen, and the switching can be achieved automatically or manually.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an embodiment of an ultrasonic diagnostic apparatus of the present invention in which the function can be switched depending on the presence or absence of injection of an ultrasonic contrast agent. What is newly added (including the function) in this embodiment is as follows in comparison with FIG. Attenuator 22 ... Switching means for switching the attenuation degree of the Doppler measurement signal when the ultrasonic contrast agent is injected and when it is not injected. Superimposing circuit 21 ... Switching means for judging criteria for superimposing a CFM color image and a black and white B-mode tomographic image with and without injection of an ultrasonic contrast agent.

MTI control circuit 23 ... Means for switching judgment criteria for separating blood flow and structures (fixed objects) such as blood vessel walls with and without injection of ultrasonic contrast agent. . The CFM circuit 34 ... And the function of switching the judgment standard for body motion correction, with and without injection of the ultrasonic contrast agent, were added. External input terminal 14 ... An input terminal that is automatically turned on in association with injection of an ultrasonic contrast agent. Switch 15 ... A switch that is manually turned on when the operator recognizes that the ultrasonic contrast agent has been injected. Control circuit 7 ... Control signals C _{11 to} C ₁₄ are circuits 21, 2
2, 23, and 34 are controlled. This will be specifically described.

(1) Attenuator 22. The Doppler measurement signal greatly differs in appearance depending on whether or not the ultrasonic contrast agent is injected. FIG. 3 shows the relationship with the horizontal axis of velocity and the vertical axis of reflection intensity. The solid line shows the time when the contrast agent was not injected, and the dotted line shows the time when the contrast agent was injected. Examples of blood vessel walls are a and a ', and examples of blood flow are b and b'. Although a and a ′ do not change so much, a large difference appears between b and b ′. That is, in a fixed part such as a blood vessel wall,
The influence of the contrast agent is small because it appears only on the inner wall.
However, in the blood flow portion, the ultrasonic waves are largely reflected by the contrast agent, and the a-to-a 'changes, and the a'has a reflection intensity higher than the reflection intensity b (or b') of the fixed portion. It suffices if such a large reflection intensity a'can be processed as it is by the Doppler circuit 3, but this may lead to circuit saturation or A
If the D conversion capability is exceeded, the fidelity of calculation will be impaired. Therefore, the attenuator 22 is controlled so that b'is constantly attenuated when the contrast agent is injected, and b is not attenuated when the contrast agent is not injected. Note that the size of b'may vary depending on the type of contrast agent or the rate of dissolution that changes with time after injection of the contrast agent. It may be set to the value of. Gain control of amplification may be performed instead of the attenuator.

(2) The superposition circuit 21. Although the CFM image and the B-mode tomographic image are superimposed in the superposition circuit 21, the concept of superposition differs depending on whether the ultrasonic contrast agent is injected or not. In the conventional measurement in which the contrast agent is not injected, (a) the B-mode tomographic image does not exist in the flow portion. (B) The flow in the high density portion of the B-mode tomographic image is an error (which causes so-called artifact).
Stand on the way of thinking. However, when the contrast agent is injected (c), the intensity of the reflection from the contrast agent is high, so that the density of the B-mode tomographic image is high and the flow is present. Becomes Therefore, if the process according to (b) is performed, the blood flow will be deleted, which is a problem. Therefore, when a state such as (c) appears at the time of injecting a contrast agent, it is necessary to erase the B-mode tomographic image at that position and instead perform a color display regarding the blood flow of the strong flow. A function for performing switching for this purpose is added to the superposition circuit 21. FIG. 4 shows a specific example of the logic (judgment standard) for this switching.

The upper part of FIG. 4 is the logic when the contrast agent is not injected, and the lower part is the logic when the contrast agent is injected. In the former case, if the B-mode tomographic image data is large, the B-mode tomographic image data is selected regardless of the size of the CFM data, and if the B-mode tomographic image data is small, the size of the CFM data is large or small. Regardless of the CFM data selected.
On the other hand, the latter differs from the former only in that when both the B-mode tomographic image data and the CFM data are large, the CFM data is selected. This becomes large as shown in b'as shown in FIG. 3, and even if it is attenuated by the attenuator 22, b'is about the same size as a ', so the CFM data itself is selected according to (c). I made it happen.

(3) The MTI control circuit 23. It has been described in the conventional example of FIG. 2 that the MTI filters 32 and 33 are intended to remove fixed matters such as blood vessel walls. Two parameters, velocity and reflection intensity, are used for this removal. Examples thereof are shown in FIGS. 5 and 6. FIG. 5 shows an example at the time of normal measurement in which no contrast agent is injected, and FIG. 6 shows an example at the time of injection of a contrast agent. The horizontal axis shows the velocity and the vertical axis shows the reflection intensity. Figure 5
5A shows the spectrum of the fixed matter, and FIG. 5B shows the spectrum of the blood flow. It can be seen that the spectrum of the blood flow is extremely smaller than the spectrum of the fixed matter. Therefore, it is assumed that what is included in the hatched rectangle B is due to blood flow, this is extracted, and the waveform a is deleted to remove M.
Set TI filter. On the other hand, in FIG. 6, the spectrum of the blood flow becomes large as shown by b ', and the spectrum of the fixed object does not change much as shown by a'. At this time, a rectangle B'is set, and what is included in this is due to blood flow. The control circuit 23 performs such switching between B and B '. There are various forms of B and B '.

(4) CFM circuit 34. Furthermore, the subject may move or blood vessels may move during the measurement. In order to prevent this movement from being erroneously determined as the flow of blood flow, it is necessary to perform processing to eliminate it even if there is movement. This is body movement correction. In the body movement correction, a signal having a high reflection intensity and moving in a fixed direction is removed.
However, a blood flow signal is a signal having a high reflection intensity and moving in a fixed direction when a contrast agent is injected. So CF
In the M circuit 34, a determination standard is set depending on the presence / absence of the injection of the contrast agent, and the body movement is corrected by using the result of comparison with this standard. When it is determined that the body is moving, the CFM output at that point (pixel) at that time is set to zero, and this zero output is input to the circuit 21.

(5) Control circuit 7. This is new in that it not only has the function of performing the same control as the conventional one (FIG. 2), but also controls each circuit 21, 22, 23, 34 depending on the presence or absence of the injection of the contrast agent.

(6), external input terminal 14, switch 1
5. This is a means for automatic detection of contrast agent injection or manual instruction, an example in which the input terminal 14 is automated by automatic detection, and an example in which the switch 15 is manual. In the former case, the control circuit 7 works without turning on the switch 15,
The circuits 21, 22, 23, 34 are automatically switched. In the latter case, the control circuit 7 operates by turning on the switch 15,
Switching of each circuit 21, 22, 23, 34 is performed.

Next, the operation of the above configuration will be briefly described. The ultrasonic body 2 uses the probe 1 to measure a B-mode tomographic image signal and pulse Doppler measurement. A B-mode tomographic image is obtained from the B-mode tomographic image signal, and a pulse Doppler measurement signal is sent to the Doppler circuit 3. The Doppler circuit 3 extracts the Doppler signal and sends it to the FFT 20 and the CFM circuit 6. The CFM circuit 6 removes the reflection signal from the fixed object by the MTI filter from the Doppler signal and extracts only the reflection signal from the blood flow, and performs each calculation processing of velocity, intensity, and dispersion. This result is passed through the superposition circuit 21 to the DSC circuit 4
Then, the DSC circuit 4 stores the B-mode tomographic image and the CFM image, and the output spectrum of the FFT 20 in its own image memory, and the monitor 5 displays this.

Next, the above operation is performed by turning on the switch 15.
Alternatively, when the input terminal 14 is turned on, the function of the control circuit 7 switches the presence / absence of injection of the ultrasonic contrast agent. In the normal measurement without the injection of the contrast agent, the circuits 21, 22, 23, 34 suitable for the normal measurement
The above-mentioned operation is performed by utilizing the control result of 1., and in the contrast agent measurement in which the contrast agent is injected, the circuit 21 suitable for the measurement,
The above operation is performed by utilizing the switching result of 22, 23 and 34. Thus, when a contrast agent is injected, blood flow measurement and CFM display are realized by this injection.

Further, in this embodiment, in the monitor 5,
At the time of displaying a CFM image by injecting a contrast agent, the fact is displayed on the screen according to an instruction from the control unit 7. As a result, it is possible to determine on the screen whether or not the screen is based on the injection of the contrast agent. Further, since there are different types of contrast agents, it is advisable to display the type, the concentration of the contrast agent, the injection site, the injection time, and the injection time (switching time) together. .

The input terminal 14 can be automatically turned on by injecting the contrast agent by interlocking with the contrast agent injector.

In this embodiment, four switching examples are shown, but
It does not mean that other examples of switching by injection of a contrast agent are excluded. Further, although the example in which each switch is provided outside is described, it may be incorporated inside the circuit to be switched. The division of analog and digital is not particularly limited. Further, the configuration of the diagnostic device is not limited to that shown in FIG. 1 and can be applied to all diagnostic devices for CFM display by pulse Doppler measurement based on various ideas. There are different types of contrast agents and higher concentrations, and it is also possible to switch the function according to such types and concentrations.

[0035]

According to the present invention, it is possible to correctly perform an ultrasonic diagnosis having a CFM function even when an ultrasonic contrast agent is injected.

Further, according to the present invention, it is possible to distinguish between the time of injection of the ultrasonic contrast agent and the time of non-injection. Further, according to the present invention, it is possible to switch gain, superimposition, fixed object, and body motion correction depending on the presence / absence of contrast agent injection.

[Brief description of drawings]

FIG. 1 is an embodiment diagram of an ultrasonic diagnostic apparatus of the present invention.

FIG. 2 is a diagram showing a conventional ultrasonic device.

FIG. 3 is a diagram showing a relationship between velocity and reflection intensity depending on the presence / absence of injection of an ultrasonic contrast agent.

FIG. 4 is a diagram showing an example of logical conditions of a superposition circuit of the present invention.

FIG. 5 is a diagram showing characteristics of an MTI filter when a contrast agent is not injected.

FIG. 6 is a diagram showing characteristics of an MTI filter when injecting a contrast agent.

[Explanation of symbols]

 1 Ultrasonic probe 2 Ultrasonic wave main body 3 Doppler arithmetic circuit 4 DSC circuit 5 Monitor circuit (CRT display device) 6 CFM circuit 7 Control circuit 8 Panel unit (input device) 14 External input terminal 15 Changeover switch 20 FFT 21 Superposition Circuit 22 Attenuator 23 MTI control circuit 24, 25 Mixer 26, 27 LPF 32, 33 MTI filter 34 CFM calculator

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiroya Kondo 2-12-12 Tamagawa, Fukushima-ku, Osaka-shi, Osaka

Claims (11)

[Claims] 1. An ultrasonic diagnostic apparatus having an image extracting ability adapted to the characteristics of an ultrasonic contrast agent. 2. A CF according to whether or not an ultrasonic contrast agent is injected.
An ultrasonic diagnostic apparatus adapted to switch the image extraction capability by M. 3. Measuring means for performing a first measurement for obtaining a B-mode tomographic image and a second measurement by a pulse Doppler method by injecting an ultrasonic contrast agent into a blood vessel of a subject, and from the first measurement to B A tomographic image calculation unit for obtaining modal tomographic image data, a Doppler calculation unit for extracting a Doppler signal at the time of contrast agent injection from the second measurement, and a blood flow Doppler signal at the time of contrast agent injection by removing a fixed object from this Doppler signal CFM calculating means for detecting blood flow velocity f, intensity p, and variance σ ² from the blood flow Doppler signal, B-mode tomographic image data obtained by the tomographic image calculating means, and CFM calculating means. The output (velocity f, intensity p, variance σ ² ) is superposed at each pixel point in consideration of the presence or absence of contrast medium injection, and the DSC means for storing the image data obtained by this superposition in an image memory. , A table displaying the contents of this image memory An ultrasonic diagnostic apparatus comprising: an indicating means; 4. The ultrasonic diagnostic apparatus according to claim 2, wherein the switching of the image extraction capability is a determination criterion for distinguishing an amplitude (gain) of a Doppler measurement signal, a fixed object such as a blood vessel wall and a blood flow. An ultrasonic diagnostic apparatus which uses at least one of a criterion for superimposing B-mode tomographic image data and CFM output for each pixel, and a criterion for body movement correction. 5. The ultrasonic diagnostic apparatus according to claim 2 or 4, wherein the switching is performed automatically in conjunction with a contrast agent injector or manually. apparatus. 6. The ultrasonic diagnostic apparatus according to claim 2, further comprising display means for displaying a CFM image by superimposing on a B-mode tomographic image on the basis of the presence or absence of injection of a contrast agent. An ultrasonic diagnostic device that also displays the presence or absence of injection of a contrast agent on the screen. 7. The ultrasonic diagnostic apparatus according to claim 6, wherein in addition to the presence / absence of the injection of the contrast agent, when the injection is performed, the name of the contrast agent,
An ultrasonic diagnostic apparatus that displays at least one of concentration, injection site, injection time, and switching time. 8. A measuring means comprising a first measurement for obtaining a B-mode tomographic image and a second measurement for separately measuring whether or not an ultrasonic contrast agent is injected into a blood vessel of a subject, and A tomographic image calculation unit that obtains B-mode tomographic image data from the first measurement, a Doppler calculation unit that extracts the Doppler signal based on the gain switching depending on the presence or absence of the injection of the contrast agent from the second measurement, and the contrast from the Doppler signal. CFM calculating means for removing the fixed matter depending on the presence or absence of the agent injection, detecting the blood flow Doppler signal depending on the presence or absence of the contrast agent injection, and calculating the velocity f, the intensity p, and the variance σ ² from the blood flow Doppler signal; The B-mode tomographic image data obtained by the tomographic image calculating means and the output (velocity f, intensity p, variance σ ² ) obtained by the CFM calculating means are superimposed on each pixel point according to the presence / absence of injection of a contrast agent. , Image data obtained by this superposition An ultrasonic diagnostic apparatus comprising DSC means for storing in an image memory and display means for displaying the contents of the image memory. 9. The ultrasonic diagnostic apparatus according to claim 8, wherein the presence or absence of the injection of the contrast medium is classified by either automatic determination in conjunction with a contrast medium injector or an instruction from an operator. Ultrasonic diagnostic equipment. 10. The ultrasonic diagnostic apparatus according to claim 8 or 9, wherein the display screen of said display means displays the presence or absence of contrast agent injection, and when injection is performed, the contrast agent name is further displayed.
An ultrasonic diagnostic apparatus that displays at least one of concentration, injection site, injection time, and injection time. 11. The ultrasonic diagnostic apparatus according to claim 8, wherein a frequency spectrum obtained according to the presence or absence of injection of a contrast agent is also displayed on the display screen. Ultrasonic diagnostic equipment.