JPH04174657A - Supersonic diagnosing apparatus - Google Patents

Abstract

PURPOSE:To enable a plurality of differential images to be indicated by providing an image compounding means for compounding one of two dislocation image data of an origine for forming differential image data and the differential image data to generate the output a single image data to an image indicating means. CONSTITUTION:A B/S mode selecting switch 19 on an operation panel 9 is set to the B mode to activate a supersonic diagnosing apparatus. When one sheet of a dislocation image is written in a frame memory 12, a controller 16 reads out dislocation image data from the frame memory 12. The dislocation image is indicated nearly in real time on a screen of an image indicator 8. An operator searches for a diagnosing position he wants to indicate and fixes a supersonic probe 1 to the position he searched to change over the B/S mode selecting switch 19 to the mode in which B and S modes are simultaneously indicated. Thus, a section including an exercised structure position of a body to be inspected can be indicated as an overlapping images of a differential image and dislocation image by the supersonic so that the diagnosis is facilitated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an ultrasonic diagnostic apparatus, and particularly to an image display technique in an ultrasonic diagnostic apparatus that is capable of displaying a tomographic image and a difference image. .

[Conventional technology]

2. Description of the Related Art Ultrasonic diagnostic apparatuses have become extremely popular as medical image diagnostic apparatuses because ultrasound waves are non-invasive to living bodies and information inside living bodies can be visualized in real time.

Conventional ultrasonic diagnostic equipment combines various A-mode, B-mode, M-mode, D-mode, and CFM modes to display in-vivo organs, blood flow, etc. as two-dimensional tomographic images and waveforms. Ta. Among the above-mentioned modes, those that can display organs morphologically are the B mode, which displays tomographic images, and the CFM mode, which displays blood flow conditions as color images.

In contrast to these conventional techniques, research and development has been conducted on a technique that uses ultrasound to extract and display only images of moving tissues within a living body. That is, what can be called an ultrasonic differential image display method has been developed.

This technique is described, for example, in Japanese Patent Application Laid-Open No. 189054/1989, pages 291 to 292 of the 55th Japanese Society of Ultrasonics in Medicine (issued October 4, 1989), and the 56th Japanese Society of Ultrasonics in Medicine. It is described on pages 351 to 354 of the Proceedings of the Society of Ultrasound in Medicine (published in May 1990).

This ultrasonic differential image display method uses an ultrasonic transmitting/receiving means including an ultrasonic probe to sequentially change the direction of transmitting and receiving ultrasonic waves to obtain tomographic image data of cross sections containing moving tissue from inside the subject in a time-series manner. The captured tomographic image data is sequentially sent as a set of two images to the differential image data generating means, and one of the image data inputted by the differential image data generating means is used as a mask image, and this mask image and the other image are combined. Image data is subtracted by matching the pixel data addresses of each image to generate differential image data, and this differential image data is input to an image display means to display a differential image (subtraction image). The idea is to do so.

This ultrasonic differential image display method is used in digital subtraction angiography (Digital subtraction angiography) in the field of X-ray diagnostic technology.
It is highly safe as it does not require the use of a contrast agent like the DSA A) device, and it extracts the motion form image of the organ itself rather than extracting the organ through a contrast agent.
As reported on page 353 of the above-mentioned Proceedings of the 56th Japanese Society of Ultrasound in Medicine, when this ultrasound differential image display method is applied to the heart of a living body, it is possible to visualize premature ventricular contractions. This has the potential to open up new diagnostic fields in which ultrasonic diagnostic equipment can be applied in the future.

[Problem to be solved by the invention]

By the way, the techniques described in the above-mentioned Japanese Unexamined Patent Publication No. 189054/1989 and the two collections of papers display the difference image alone. That is, in the former case, a difference processing means is built into the ultrasonic diagnostic device, but the tomographic image and the difference image are displayed on the screen of a television monitor.

They displayed only tomographic images or only difference images. Therefore, when the difference image is displayed, other organs in the living body than the displayed organ (this is not displayed because it is stationary).

), it was difficult to grasp the relative positional relationship between the two, and it was considered difficult to diagnose.

Furthermore, even in the latter paper, there is no mention of any improvements to the former problem, and this problem still remains unsolved.

In order to solve this problem, it is conceivable to display the tomographic image and the difference image in a superimposed manner. However, if the brightness level of both the tomographic image and the difference image is fixed, the brightness level of the difference image will be lower than the brightness level of the tomographic image depending on the diagnosis site or tissue, making it difficult to superimpose both images. There is a risk that the displayed meaning will be lost.

The present invention was made with the aim of simultaneously solving this new problem and the above-mentioned problem.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a tomographic scanning device that repeatedly obtains tomographic image data in a subject including moving tissue using an ultrasonic transmitting/receiving device at a predetermined period; It has means for performing subtraction between time-series images obtained by the tomographic scanning means to generate difference image data thereof, and image display means for displaying the difference image data generated by the difference image data generation means. In the ultrasonic diagnostic apparatus, an image synthesizing means is provided for synthesizing one of the two tomographic image data from which the differential image data was generated and the differential image data and outputting the synthesized image data to the image display means as a single image data, and The present invention further includes means for variably setting the brightness level of the tomographic image data output to the image synthesizing means (claim 1).

Further, in the ultrasonic diagnostic apparatus according to claim 1, the present invention provides a means for variably setting the brightness level of the tomographic image data outputted to the image synthesizing means, and a differential image data outputted to the image synthesizing means. The object is achieved by providing means for variably setting the brightness level of image data (claim 2).

Furthermore, the present invention achieves the object by adding means for variably setting the brightness level of the difference image data output to the image composition means to the ultrasonic diagnostic apparatus according to claim 1. Claim 3).

[For production]

In the ultrasonic diagnostic apparatus according to claim 1, the ultrasonic transmitting/receiving means receives ultrasonic waves into the subject including moving tissues, the tomographic image data is repeatedly obtained by the tomographic scanning means at a predetermined period, and the differential image data is obtained. Two pieces of time-series tomographic image data are supplied to the generation means to generate differential image data, and the data level of one of the tomographic image data from which the differential image data is generated is converted by the brightness level variable setting means. Then, the difference image data and the level-converted tomographic image data are supplied as a single image by the image synthesizing means to the image display means, and the difference image and the tomographic image are displayed in a superimposed manner. According to this, the brightness level of the difference image cannot be changed, but the brightness level of the tomographic image can be changed.
When the difference image is buried in the tomographic image and cannot be observed clearly, the difference image can be displayed in a highlighted manner.

Furthermore, the image synthesis means can display the tomographic image as a background (surrounding) image of the difference image.

In the ultrasonic diagnostic apparatus according to claim 2, contrary to the apparatus according to claim 1, the brightness level of the tomographic image cannot be changed, but the brightness level of the difference image can be changed by the brightness level variable setting means for the difference image. Levels can be changed. Thereby, when the difference image itself is difficult to see, it can be displayed with emphasis.

The ultrasonic diagnostic apparatus according to claim 3 can combine the above advantages.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. In the figure, reference numeral 1 denotes an ultrasound probe that transmits an ultrasound beam to a subject 30 using a built-in ultrasound transducer and receives ultrasound reflected within the subject 30. . Reference numeral 2 denotes an ultrasonic transmitting/receiving unit, which supplies driving pulses for transmitting ultrasonic beams to the ultrasonic transducer and processes received echo signals. Although not shown, it is a conventional ultrasonic diagnostic device. Similarly, the receiving phasing circuit consists of a transmitting pulser, a transmitting delay circuit, a transfer amplifier, a receiving delay circuit, and an adder.

700 circuits, a detection circuit, etc.

The ultrasonic probe 1 and the ultrasonic transmitter/receiver 2 constitute an ultrasonic transmitter/receiver, and the ultrasonic probe 1 transmits an ultrasonic beam to the subject 30 according to a control signal from a controller 16 (described later). The device scans the inside of the body in a predetermined direction to obtain one sheet (one frame) of tomographic image data, and also obtains tomographic image data sequentially in time series at predetermined time intervals.

Reference numeral 3 denotes a tomographic scanning means that scans and converts the tomographic image data obtained by the ultrasonic transmitting/receiving means in synchronization with the ultrasonic transmission and reception, and reads out the data asynchronously with the ultrasonic reception. ·converter(
(hereinafter referred to as rDSCJ). Unlike conventional devices, the DSC 3 in this embodiment is preferably configured to include two lines. This DS
As shown in FIG. 1, C3 includes an A/D converter 10 that converts the echo signal from the ultrasonic transmitter/receiver 2 into a digital signal, and an A/D converter 10 that converts the echo signal from the ultrasonic transmitter/receiver 2 into a digital signal. A plurality of line memories lla and llb that repeat writing and reading for each scanning line of the sound wave beam,
The image data output from these line memories lla and llb can be stored as tomographic image data for one frame by correlating the position or direction of the scanning line of each ultrasound beam, and is stored in a plurality of frame memories made of, for example, semiconductor memory. 12, and line memories 13a and 13b that output the time-series tomographic image data recorded in the plurality of frame memories 12 as two predetermined frames of tomographic image data under the control of the controller 16.

a first address generator 14 that generates an address when writing image data to the frame memory 12; a second address generator 15 that generates an address when reading image data from the frame memory 12; and a controller 16 consisting of a CPU that controls the constituent elements of the controller.

, 4 is a subtracter, and line memory 1 in the above DSC 3
s 5a and 5b are multipliers that subtract two frames of tomographic image data output from 3a and 13b by making the pixel addresses correspond to each other, and output difference data.
5b is for multiplying the difference data output by the subtracter 4 by a value corresponding to the output signal of the luminance level setter (1) 17, which will be described later, and 5b is for multiplying the difference data output by the subtracter 4 by a value corresponding to the output signal of the brightness level setter (1) 17, which will be described later. This is to multiply the tomographic image data by a value corresponding to an output signal of a brightness level setter (n) 18, which will be described later. Reference numeral 6 denotes an adder that adds the difference data outputted through one of the multipliers 5a and the tomographic image data outputted through the other multiplier 5b and synthesizes them into single image data. It is. 7 is a D/A converter for D/A converting the output signal of the adder 6; 8 is a D/A converter for converting the output signal of the adder 6;
This is an image display device that displays an image of the output signal of the converter 7, and consists of, for example, a monitor TV. And these D/A converters 7
and the image display device 8 constitute an image display means.

Reference numeral 9 denotes an operation panel, in addition to various switches in conventional ultrasonic diagnostic equipment, there is also a brightness level setter (1) 17 for arbitrarily variably setting the brightness level of a differential image, and a brightness level setting device (1) 17 for arbitrarily variably setting the brightness level of a tomographic image. Other brightness level setter (I
I) 18, and further switches and displays a tomographic image (B mode image) and a difference image (denoted as S mode image).
/S mode selection switch 19 is provided.

Next, the operation of the ultrasonic diagnostic apparatus configured as described above will be explained. First, the ultrasonic diagnostic apparatus is started by setting the B/S mode selection switch 19 on the operation panel 9 to B mode. Then, the ultrasonic probe 1 is brought into contact with the subject 30 to start transmitting and receiving ultrasonic waves.

Then, the ultrasonic transmitter/receiver 2 is controlled by the controller 16, and the ultrasonic beam is focused to a predetermined depth inside the subject 30 by the transmit delay circuit and the transmit pulser inside the ultrasonic probe. Ultrasonic waves are transmitted from 1.

At this time, the ultrasound waves are reflected at acoustic discontinuities or surfaces within the subject 30, and the echoes thereof are received by the ultrasound probe 1. The received echo signal is amplified by a transfer amplifier, phased by a transfer delay circuit and an adder to form a focused transfer beam signal, and then sent to a TGC circuit.

The signal is processed through a detection circuit and input to the DSC3.

The signal input to the DSC 3 is converted into a predetermined number of digital data by the A/D converter 10, and is stored in the line memory II.
It is temporarily stored in a. When one ultrasonic beam transmission and reception is completed in this way.

The controller 16 sends a control signal to the ultrasonic wave transmitting/receiving means so that the ultrasonic wave transmitting/receiving direction is sequentially shifted and the ultrasonic wave is transmitted/received. Then, if the beam address of the first transmitting/receiving beam is Ncil, then Nn2. Scanning is performed sequentially so that n ultrasonic beams are located on one plane as in Nα3°...&n. When the transmission/reception direction changes to the N1k2 direction, the changeover switches 20a and 20b are switched to the state shown by the broken line in the figure. , the echo signal of the beam NQI temporarily stored in the line memory 11a is written to the frame memory 12, and the echo signal in the direction of the storm 2 is written to the line memory llb. Thereafter, each time the transmission/reception direction changes, the changeover switches 20a, 20b and the line memory ll
Through the operations of a and llb, echo signals forming one tomographic image are written into the frame memory 12. Writing of the echo signal into the frame memory 12 is performed by an address signal W from the address generator 14 which is controlled by a signal from the controller 16.

After one tomographic image is written to the frame memory 12 in this manner, the controller 16 then reads the tomographic image data from the frame memory 12. This reading is performed in the X direction (scanning direction) when writing to the frame memory 12 is performed in the Y direction (depth direction), and is performed in the X direction (scanning direction), for example, on a monitor TV This is performed in synchronization with the horizontal scanning in (8). The read address is controlled by an address signal R1 generated by an address generator 15 controlled by an output from a controller 16. The echo signal read from the frame memory 12 is input to the multiplier 5b via the line memory 13b. The multiplier 5b will be described on the assumption that it is set to a value suitable for tomographic image scanning. Therefore, the multiplier 5b outputs a signal with a brightness level suitable for displaying only the tomographic image, and the signal is outputted to the D/A converter 7 and the image display 8 via the adder 6. Then, the tomographic image is displayed on the screen of the image display 8 in real time. In parallel with this image display operation, the ultrasound probe 1
The ultrasound transmission/reception direction is returned to the initial direction (N111 direction) and scanning is performed again, and the tomographic images are sequentially updated and displayed on the image display 8 accordingly.

By observing the displayed ultrasonic tomographic image, the operator changes the contact position or angle of the ultrasonic probe 1 with respect to the subject 3o to find the diagnostic region for which the difference image is to be displayed. Fix the ultrasonic probe 1 at B
/Switch the S mode selection switch 19 to a mode in which S mode and S mode are displayed simultaneously.

At this time, as described above, tomographic image data is stored in the frame memory 12 in response to instructions from the controller 16, including the ultrasonic probe 1, the ultrasonic transmitter/receiver 2, the A/D converter 10, the line memories lla and llb, and the switching Switches 20a and 20
It is taken in via b. The captured tomographic image data is then stored in the frame memories 12a and 12 in chronological order.
2b, 12c, ..., 12n, each frame image (ultrasonic beam & 1
image composed of n beams from Na n)
will be stored individually as .

Here, when a command for simultaneous S mode/S mode display is input to the controller 16, the controller 16 outputs the address generator 15. Operation commands are sent to the subtracter 4, multipliers 5a and 5b, and adder 6. Then, the address generator 15 outputs read address signals R and R2 to the frame memory 12.

As an initial setting, these address signals R1 and R2 are first applied to the first tomographic image stored in the frame memory 12a and the frame memory 12 adjacent to this frame memory 12a.
The second tomographic image stored in b is read out by associating the address of each image. Each read image data is
As shown, the signal is input to the subtracter 4 via line memories 13a and 13b.

The subtracter 4 subtracts input signals having corresponding pixel addresses. This subtraction is preferably performed in the second
It is preferable to subtract the old image from the new image, such as the first tomographic image from the tomographic image. The reason for this is as follows. That is, when image data are subtracted from each other, the difference value between signals from stationary parts within the subject 30 will be "zero", but for moving parts within the subject 30, the difference value will be "positive" or "zero". It becomes "negative". Both "positive" and "negative" are displayed by modulating the brightness, but it is easier to see if the brightness level of the state after the new movement is displayed brightly. In this way, the subtracter 4 sequentially outputs the difference data obtained by subtracting the first tomographic image from the inputted second tomographic image to the multiplier 5a as line data.

On the other hand, one of the tomographic images outputted to the line memory 13b and used as the source for generating the difference data (in this embodiment, this is set to the old image side, but either one is fine) is input to the multiplier 5b.
It is also output to The multipliers 5a and 5b calculate each value output from the controller 16 in accordance with the settings of the brightness level setter (1) 17 and brightness level setter (II) 18 provided on the operation panel 9. Multiplying the input data,
At this stage, the level of normal tomographic image display is ``1''.
The explanation will proceed assuming that the setting is to multiply and output the result. In this case, the multiplier 5a outputs the difference data input from the subtracter 4 as is.

The multiplier 5b outputs the first tomographic image data as it is, and the adder 6 adds and synthesizes the data by making the pixel addresses correspond to each other, and sequentially outputs the data to the D/A converter 7. The D/A converter 7 converts the input signal into an analog signal and outputs it to the image display 8. Then, a single image in which the tomographic image and the difference image are superimposed is displayed on the display screen of the image display 8.

The above operations are performed as the ultrasonic transmission and reception progresses, and next time, the operations are performed between the second tomographic image and the third tomographic image stored in the next frame memories 12b and 12c, respectively.
The difference image (tomographic image - second tomographic image) and the second tomographic image are displayed in a superimposed manner.

This operation is repeated in sequence.

In the display image in which the tomographic image and the difference image displayed as above are superimposed, if the brightness level of the difference image is insufficient and the difference image is buried in the tomographic image, making observation difficult. Suppose that occurs. Such cases may occur when the movement speed of the target organ is slow relative to the frame rate of the ultrasound diagnostic device, or when the amount of movement of the target organ itself is small, or when the target organ is microvessels or their collection parts. is assumed.

In such a case, in the apparatus of this embodiment, the operator sets the brightness level setting device (1) 17 for the difference image on the operation panel 9.
Increase the brightness level of the difference image by operating . That is, the multiplier 5a multiplies the difference data by a value larger than the previous value of 1''. Alternatively, the brightness level setter (II) 18 for tomographic images is operated. In other words, the brightness level of the tomographic image is lowered.
This is handled by making the value by which the tomographic image data is multiplied at a value smaller than the previous value "1". Furthermore, it is also possible to respond by operating the above two methods simultaneously.

Hereinafter, the operation of adjusting both the brightness level setter (1) 17 and the brightness level setter (n) 18 to make the displayed image easier to see, and the operation thereof will be described. The operator is
While observing the image 40 on the display screen of the image display 8,
First, the brightness level setter (II) 18 is operated to lower the brightness level of the tomographic image. Brightness level setter (
1)17. (II) Although 18 is not shown, it consists of a variable resistor 5 to which a constant voltage is applied, for example, and an A/D converter that converts the output voltage of the variable resistor into an A/D converter. The output of the multiplier is outputted via a controller 16 to multipliers 5a and 5b. Therefore, when the brightness level setter (n) 18 is operated as described above, its output signal is output from the controller 16 to the multiplier 5b as a digital value smaller than "1", and the multiplier 5b
At b, the tomographic image data sequentially input is multiplied by the numerical value and output. As a result, the brightness level of the tomographic image is lower than before.

Even if the brightness level of the tomographic image is lowered in this way, the difference image is still clearly I! If it is difficult to notice, then the brightness level setter (1) 17 is operated to increase the brightness level of the difference image. Then, the brightness level setting device (1)
The output signal of 17 is output from the controller 16 to the multiplier 5a as a digital value larger than "1", and the multiplier 5a
In step a, the sequentially input difference data is multiplied by the numerical value and output.

As a result, the brightness level of the difference image increases.

In this way, when a difference image of a moving organ is displayed together with a tomographic image, the brightness level of the difference image may be low, or the moving speed of the organ may be slow and the amount of data for which the difference data is "positive" may be small. If the difference image is buried in the tomographic image and difficult to observe, reduce the brightness level of the tomographic image, increase the brightness level of the difference image, or both. Can be displayed clearly. As for the actual device configuration.

It is possible to provide a brightness level setting device as required.

Moreover, although the present invention has been described above using an example in which the displayed image is displayed in monochrome, it is also possible to apply it to other modified examples, for example, an embodiment in which a difference image is displayed in color. When combining and displaying the difference image and tomographic image,
In order to distinguish between a difference image and a tomographic image, it is considered meaningful to add hue information to the difference image, display the difference image in color, and display the background tomogram in monochrome. In this case, a color encoder may be added between the line memory 13a and the adder 6 in FIG. This color encoder changes the difference data to, for example, "red" or "
If hue information of "blue" is given and the difference data and tomographic image data are combined and displayed, a color difference image can be displayed in a monochrome tomographic image. It goes without saying that the present invention can be applied to this case as well.

Further, in the above embodiment, the circuit configuration for changing the brightness level is implemented by a digital circuit, but the present invention is not limited thereto. For example, the output of the subtracter 4 and the output of the line memory 13b are /A conversion, the outputs thereof may be outputted via a variable gain amplifier, and then added.

〔Effect of the invention〕

As described above, the present invention provides: (1) According to claim 1, a cross section including a moving tissue region of a subject can be displayed as a superimposed image of a difference image and a tomographic image using ultrasound; Since the brightness level can be set variably, it is easy to understand how the moving tissue moves during the difference interval, and the relative position of the moving tissue within the subject can be easily determined from the surrounding tomograms displayed as the difference image. . In addition, the brightness level of the tomographic image can be set variably, so even if the movement speed of the moving tissue is slow or the amount of movement itself is small, there is a risk that the difference image will be buried in the tomographic image. By changing the difference, the difference image can be highlighted, and diagnosis using the difference image can be facilitated.

(2) According to claim 2, the brightness level of the difference image can be changed without changing the brightness level of the tomographic image, so the same effect as in claim 1 can be obtained.

(3) According to claim 3, since the brightness level of both the tomographic image and the difference image can be changed, the difference image of a region with little difference image information, such as a microvessel or a region where microvessels gather, can be emphasized. can be displayed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an ultrasonic diagnostic apparatus according to the present invention. 1... Ultrasonic probe, 2... Ultrasonic transmitter/receiver, 3
...DSC, 4...Subtractor, 5a, 5b...
Multiplier, 6... Adder, 8... Image display,
17... Brightness level setter (1), 18... Brightness level setter (II), 30... Subject.

Claims (3)

[Claims] (1) A tomographic scanning device that repeatedly obtains tomographic image data in the subject including moving tissue using an ultrasonic transmitting/receiving device at a predetermined period, and a tomographic scanning device that performs subtraction between the time-series images obtained by this tomographic scanning device to In an ultrasonic diagnostic apparatus having means for generating differential image data, and image display means for displaying the differential image data generated by the differential image data generating means, two cross-sectional tomograms from which the differential image data was generated are provided. An image synthesizing means for synthesizing one of the image data and the difference image data and outputting the synthesized image data to the image display means as single image data, and a means for variably setting the brightness level of the tomographic image data output to the image synthesizing means. An ultrasonic diagnostic device characterized by being provided with. (2) A tomographic scanning means that repeatedly obtains tomographic image data within the subject including moving tissues at a predetermined period using an ultrasonic transmitting and receiving means, and a tomographic scanning means that performs subtraction between the time-series images obtained by this tomographic scanning means. In an ultrasonic diagnostic apparatus having means for generating differential image data, and image display means for displaying the differential image data generated by the differential image data generating means, two cross-sectional tomograms from which the differential image data was generated are provided. An image synthesizing means is provided for synthesizing one of the image data and the differential image data and outputting it to the image display means as single image data, and a brightness level of the differential image data output to the image synthesizing means is variably set. An ultrasonic diagnostic apparatus characterized by comprising means. (3) The ultrasonic diagnostic apparatus according to claim 1, further comprising means for variably setting the brightness level of the differential image data output to the image synthesizing means.