JP3082096B2 - Ultrasound diagnostic equipment - Google Patents

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 capable of extracting a moving component of a diagnostic part of a subject, for example, a moving part such as a blood vessel or a heart using an ultrasonic wave and displaying the extracted component as a differential image. More particularly, the present invention relates to an ultrasonic diagnostic apparatus that can obtain a frequency distribution (so-called histogram) of the luminance of a difference image signal in an arbitrary range in a display image, graph the result, and simultaneously display the difference image.

[0002]

2. Description of the Related Art A conventional ultrasonic diagnostic apparatus having a function of rendering a difference image is disclosed in Japanese Patent Application Laid-Open No. 62-189054. The ultrasonic diagnostic apparatus described in this publication uses ultrasonic transmitting / receiving means (probe and ultrasonic transmitting / receiving unit) for transmitting and receiving ultrasonic waves to and from a subject, and uses a reflected echo signal from the ultrasonic transmitting / receiving means. Scanning means (digital scan converter) which repeatedly obtains tomographic image data in a subject including a moving part at a predetermined period, and calculates a difference between time-series images obtained by the tomographic scanning means and obtains a difference image between them. Means for generating data (difference processor)
And image display means (television monitor) for displaying the difference image data from the difference image data generation means. In this case, if the moving part in the subject moves during the time lapse of capturing the image of the previous scan and the image of the current scan in the time-series images obtained by the tomographic scanning means, the moving part For, there is a difference in the image data between the previous image and the current image, and for the still part, the image data is the same between the two images, the difference data becomes zero, and only the moving part is displayed as an image.

In the ultrasonic diagnostic apparatus, a histogram is obtained for the luminance of the image signal of the obtained tomographic image,
Attempts to graphically display this and use it for diagnosis have been made, for example, in "Ultrasonics Medicine," Vol. 13, No. 6, Issued in 1986, 19-
Pages 27 and 15 (2) (1988), pp. 42-46,
It is described on pages 47-53 and the like. In these papers, a region of interest is set on a tomogram for the mammary gland, thyroid, liver, kidney, etc., the frequency distribution of the luminance of the image signal is obtained within that range, normalized and graphed, Next, parameters such as the shape of the distribution, the average tone value, the standard deviation value, and the mode value are obtained from this graph, and the relationship between these parameters and the disease is discussed.

[0004]

However, Japanese Patent Application Laid-Open No. Sho 62-189
In the ultrasonic diagnostic apparatus described in Japanese Patent No. 054, two tomographic images are extracted from the image data output from the tomographic scanning means, and subtraction is performed once between these tomographic images to generate difference image data. Only the difference image was displayed. Therefore, only one difference image at the present time is displayed on the screen of the image display means in real time, and the frequency distribution of the luminance cannot be obtained for the generated difference image signal. And could not be displayed. Further, in the ultrasonic diagnostic apparatus described in the article of the above-mentioned publication "ultrasonic medicine", a region of interest is set on a tomographic image, and a frequency distribution of luminance of an image signal is obtained within the range, It does not calculate the frequency distribution of luminance for the difference image signal.

Accordingly, in any of the above conventional examples,
It is not possible to obtain the frequency distribution of the luminance of the image signal with respect to the difference image obtained for the diagnostic site and display it in a graph, and to grasp the displacement amount due to the movement of the moving region using a so-called image signal histogram. It was impossible. From this, in the conventional ultrasonic diagnostic apparatus described in Japanese Patent Application Laid-Open No. 62-189054, an observer such as a doctor looks at a displayed differential image of a diagnostic region and obtains a displacement amount due to the movement of the moving region. Was subjectively judged and evaluated. Therefore, there is a case where a doctor or the like has an individual difference and cannot make an accurate judgment.

Accordingly, the present invention addresses such a problem, and the luminance of the difference image signal is arbitrarily determined within a display image.
It is an object of the present invention to provide an ultrasonic diagnostic apparatus capable of obtaining a frequency distribution , graphing the frequency distribution , and simultaneously displaying the difference image.

[0007]

To achieve the above object, according to the Invention The ultrasonic diagnostic apparatus according to the present invention, by driving the ultrasonic probe for transmitting and receiving ultrasonic waves into a subject, the probe ultrasonic tomographic image data in the object including a transducing means for processing the reflected echo signals received at the said probe with generating sound waves, the motion region using the reception was processed echo signals
And a digital scan converter having storage means for storing the obtained image data in a time-series manner for each screen, and reading the stored time-series image data.
In the ultrasonic diagnostic apparatus having a means for performing a difference operation between the images and generating the difference image data and an image display means for displaying the generated difference image data, Area designating means for designating an arbitrary image range on the difference image, and a luminance frequency obtained for the difference image signal within the designated image range.
Means for graphing the cloth, and the degree of the luminance graphed
Movement of the moving part in the subject by the number distribution and its shape
Means for providing speed or thickness information; and
Means for simultaneously displaying a graph of frequency distribution of luminance having information and a difference image .

The storage means in the digital scan converter has a storage capacity for storing tomographic image data of one or more heartbeats in time series, and the storage means for one or more heartbeats is provided at the subsequent stage of the difference image data generating means. Storage means having a storage capacity for storing the difference image data in time series.

[0009]

In the ultrasonic diagnostic apparatus constructed as described above, an arbitrary image range is designated on the difference image displayed on the image display means by the area designation means, and designated by the area designation means by the graphing means . with the differential image signal in the image range
Graphs the frequency distribution of the luminance obtained by
Frequency distribution of luminance graphed by the above graphing means
The velocity or thickness of the moving part in the subject depending on its shape
Information and the above information by means of simultaneous display
Of frequency distribution of luminance having information given by means
And the difference image are simultaneously displayed on the image display means .

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing a first embodiment of the ultrasonic diagnostic apparatus according to the present invention. This ultrasonic diagnostic apparatus is capable of extracting and displaying a component of the movement of a diagnostic part of a subject, particularly a moving part such as a blood vessel or a heart using an ultrasonic wave. As shown in FIG. 1, a transmission signal generator 2, a reception signal processor 3, a digital scan converter (hereinafter abbreviated as "DSC") 4, a difference processor 5, a second image memory 6, a line Memory 7
, A D / A converter 8, an image display 9, a controller 10, an address generation circuit 11, a read / write control circuit 12, an area designation circuit 13, a character generation circuit 14, a graphic It comprises a memory 15 and an adder 16.

The probe 1 transmits and receives an ultrasonic wave to and from a subject by mechanically or electronically scanning a beam. Although not shown, the probe 1 is a source of ultrasonic waves and includes An oscillator for receiving the reflected echo is built in.

The transmission signal generator 2 serves as a means for driving the probe 1 to generate an ultrasonic wave of a predetermined frequency. The transmission signal generator 2 generates a transmission signal for generating the ultrasonic wave and searches for it. It is sent to the tentacle 1. The received signal processor 3 serves as a means for processing a reflected echo signal from the subject received by the probe 1, amplifies the received reflected echo signal, and performs phasing and addition. , Compression, detection, etc. Then, the probe 1 is driven by the transmission signal generator 2 and the reception signal processor 3 to generate ultrasonic waves.
And processes the reflected echo signal received by the probe 1.
The transmitting and receiving means is connected to the probe 1 via a switch 17, and the transmitting signal generator 2 switches when transmitting ultrasonic waves and the receiving signal processor 3 when receiving reflected echo. Connected to the probe 1.

The DSC 4 uses the reflected echo signal output from the received signal processor 3 to obtain tomographic image data of the inside of the subject including the moving part at an ultrasonic transmission cycle and display the data. Read out synchronously, controller 10
And the tomographic scanning means, and the received signal processor 3
A / which converts the reflected echo signal from the
A D converter 18 and a digital signal output from the A / D converter 18 are repeatedly written and read to and from a line memory for each scanning line or a plurality of scanning lines of the ultrasonic beam, and transmitted to an image memory 20 described later. Prefix image memory 1
9 and an image memory 20 serving as storage means for storing image data output from the pre-image memory 19 in a time-series manner for each screen, and having a storage capacity of a plurality of frames (for example, three frames). Note that this image memory 20
For example, it is composed of a semiconductor memory and serves as a first image memory with respect to a second image memory 6 described later.

The difference processor 5 serves as means for subtracting the image data output from the DSC 4 between two tomographic images to generate difference image data therebetween. With respect to the sequentially output two-frame image data, for example, time-series adjacent tomographic images are subtracted by associating pixel addresses, and difference data is output. An arithmetic RAM is written in such a manner that the position information of the image is used as an address and the difference in luminance at that position is output as difference data.

The second image memory 6 includes the difference processor 5
And stores the difference image data generated in step (1), for example, a semiconductor memory. The line memory 7 sequentially writes image data sent for display from the second image memory 6 and reads out the image data in synchronization with a television synchronization signal for each television scanning line. Consists of

The D / A converter 8 receives the image data output from the line memory 7 and converts it into an analog signal. The image display 9 receives the video signal output from the D / A converter 8 and displays a difference image, and is composed of, for example, a television monitor. The D / A converter 8 and the image display 9 constitute an image display means.

Further, the controller 10 controls the entire operation of each of the above-mentioned components, and comprises, for example, a CPU. The address generating circuit 11 generates addresses for writing and reading data to and from the preceding image memory 19, the first image memory 20, the second image memory 6, the line memory 7, and the graphic memory 15 described later. , And operates under the control of the controller 10. The read / write control circuit 12 selects which of the memories 19, 20, 6, 7, and 15 is to be accessed, and controls whether the memory is to be written or read. Similarly, it operates under the control of the controller 10.

Here, in the present invention, the controller 10 is provided with an area designating circuit 13 and a character generating circuit 1.
4 is connected, a graphic memory 15 is connected to a stage subsequent to the character generation circuit 14, and an adder 16 is provided on the output side of the graphic memory 15 and the second image memory 6. A switch 21 is provided on the output side of the adder 16. In FIG. 1, reference numeral 22 denotes a known image stop circuit.

The area designating circuit 13 serves as a means for the operator to look at the difference image displayed on the image display 9 and to designate an arbitrary image range on the difference image as a region of interest. Or a joystick or the like. The area designating circuit 13 is connected to the controller 10 and calculates a frequency distribution (histogram) of the luminance of the difference image signal within the image range designated by the area designating circuit 13 by the arithmetic means in the controller 10. It has become. The character generation circuit 14
Is the difference image signal within the specified image range
The obtained frequency distribution of luminance is graphed, and
In the subject, the frequency distribution of the
It is a means to add information on the movement speed or thickness of the movement part.
Shall in being adapted to generate a character for graphing enter the data of the histogram obtained by the controller 10, a character such as a graphic or numeric lines, scale, etc. required for its graphing It is composed of a ROM (read only memory) storing data, and outputs required character data in accordance with an instruction from the controller 10. In addition, graphic memory 1
Numeral 5 stores character data for graphing the histogram output from the character generation circuit 14 and rewrites as necessary, and has a storage capacity equivalent to a television screen as the image display 9. I have.

The adder 16 is provided in the graphic memory 1.
The character data for graphing the histogram output from the image data 5 and the differential image data output from the second image memory 6 are combined, so that the image of the diagnostic image is displayed on the screen of the image display 9. And the histogram graph are displayed at the same time. The switch 2
1 switches between the data of the combined image output from the adder 16 and the data of the tomographic image output from the first image memory 20 under the control of the controller 10, whereby the image display 9 is displayed. The displayed image can be switched between the tomographic image of the diagnostic site and the difference image.

Next, the operation of the ultrasonic diagnostic apparatus thus configured will be described. First, the transmission signal generator 2
Generates a transmission signal by providing a time difference between a plurality of transducer elements in the probe 1 so as to converge an ultrasonic beam to a designated portion in a subject. Next, the switch 17 switches the signal path according to the signal indicating whether the signal is transmitted or received from the controller 10. In the transmission state, the transmission signal is transmitted to the probe 1, the probe 1 generates an ultrasonic wave, and transmits the ultrasonic wave toward the diagnostic part of the subject. In the receiving state, the echo reflected from the diagnostic site is received by the probe 1, and the reflected echo signal converted into an electric signal is sent to the receiving signal processor 3. Then, the received signal processor 3 amplifies the reflected echo signal, performs phasing, addition, compression, detection, and the like, and combines a plurality of received signals into one signal.

Next, the reflected echo signal output from the reception signal processor 3 is input to an A / D converter 18 in the DSC 4, and is converted from an analog signal to a digital signal. Then, the digital signal output from the A / D converter 18 is written into, for example, a first line memory in the pre-image memory 19. Thereby, image data of the first ultrasonic scanning line is configured. Next, the scanning direction is shifted and the transmission and reception of ultrasonic waves are performed in the same manner as described above, and the second
The image data of the ultrasonic scanning line is constructed and written in the second line memory in the pre-image memory 19. During this time, the image data of the first ultrasonic scanning line is read from the first line memory in the pre-image memory 19 and written to the first image memory 20. Next, transmission and reception of ultrasonic waves are further performed while shifting the scanning direction to form image data of a third ultrasonic scanning line, which is written in the first line memory in the pre-image memory 19. .
During this time, the image data of the second ultrasonic scanning line is read from the second line memory in the pre-image memory and written to the first image memory 20. By repeating the above operation sequentially, the first image memory 2
One ultrasonic tomographic image is formed in 0 and becomes the first image.

When the first image is formed in this way,
Next, the controller 10 initializes the ultrasonic scanning line direction, repeats transmission and reception in the same procedure as described above, and forms a second ultrasonic tomographic image. This is the second image.
During this time, the read / write control circuit 12 controls the selection of each of the memories 19 and 20 and whether the memory is in the read state or the write state. The address generation circuit 11 generates a read or write address for each of the memories 19 and 20 in accordance with the control state of the read / write control circuit 12. By repeating such an operation, an ultrasonic tomographic image is sequentially obtained and at least a third image is formed, and these three image data are stored in the first image memory 20.
To memorize.

Next, in accordance with an instruction from the controller 10, for example, a first image and a second image are designated from the first image memory 20, and both image data are read by associating the pixels of both images with each other. Output to the difference processor 5. The difference processor 5 performs subtraction for each of the corresponding input data (image data), and sequentially outputs difference image data between the first image and the second image. And the difference processor 5
The difference image data between the first image and the second image output from is written into the first difference image storage area of the second image memory 6 controlled by the controller 10. This is the first difference image. Here, assuming that the luminance range of the image display 9 is n gradations from 0 to n, the difference calculation result in the above difference image is a value from −n to n. Since there is no negative luminance in the image display, the result of the difference calculation is halved and an offset of n / 2 is added, and the result is converted into a value corresponding to 0 to n in the display luminance range. This conversion is applied to all subsequent difference images.

During the generation of the first difference image and the transfer to the second image memory 6, the DSC 4 obtains the next tomographic image, for example, as a fourth image. Is updated by updating another storage area. Then, this time, for example, the third image and the fourth image are designated and read out from the first image memory 20 and subtracted by the difference processor 5 to form a second difference image. 6 is written. Hereinafter, by repeating the above operation, tomographic images are formed in time series, and difference images are sequentially formed in real time and displayed.

In forming such a tomographic image and a difference image, a frequency distribution (histogram) of the luminance of the image is obtained.
Graph and display the frequency distribution of luminance
Depending on the shape, information on the movement speed or thickness of the movement part in the subject
Information. That is, the operator observes a tomographic image extracted in real time on the screen of the image display 9, and uses the image stop circuit 22 when an image necessary for diagnosis is obtained.
The image is stopped as shown in FIG. FIG. 2A shows an example in which a tomographic image of a heart is displayed, for example. Then, a marker 23 is displayed on the stop screen as shown in FIG. 2B, and the marker 23 is moved on the screen by using the area specifying circuit 13 shown in FIG. Enclose the necessary range on the tomographic image as shown in FIG. In order to make the explanation easy to understand, the screen of the image display 9 is set to have the horizontal direction as the x-axis and the vertical direction as the y-axis, as shown in FIG.
The right end of the axis is (X, 0), the upper end of the y axis is (0, Y),
The lower end of the TV scanning line is set to 0. In addition, the marker 23
The designated area surrounded by the circles has an arbitrary shape. Here, for simplification of description, the point A of (Xmin, Ymin) and the point A of (Xmax, Y
max) point B as a diagonal rectangular area.

FIG. 3 shows a storage area for one screen in the second image memory 6 which stores difference image data for obtaining a histogram. The image data is read from the scanning lines Y,
.., 0 in the order of Y-1, Y-2,.
Then, when the storage area of each scanning line is looked at in more detail, x
Pixels 0, 1, 2,...
They are stored in the order of X. In this state, the television scanning starts from the point (0, Y) in FIG.
Scan in the direction. Then, sequentially, Y, Y-1, Y-
Scanning is repeatedly performed in the order of 2,..., 0. At this time, the controller 10 shown in FIG. 1 causes the address generation circuit 11 and the read / write control circuit 1 to sequentially read the differential image data in the second image memory 6 from the scanning line Y.
2 to transfer the read image data to the controller 10. Inside the controller 10, a memory address in the area is calculated from the position information at the time of specifying the area shown in FIG. 2C, and when this numerical value matches the numerical value of the address generation circuit 11, The read difference image data is stored in an arithmetic memory in the controller 10. In this way, the controller 10
In the difference image data read into the image, the luminance frequency is calculated by the calculation procedure shown in FIG.

FIG. 4 is a flowchart showing the procedure of calculating the luminance frequency in the controller 10. First,
As described above, the difference image data S _{1 to} Sm are read into the controller 10 (step). Next, a class J representing the luminance is set to obtain the frequency distribution of the luminance (step). In this embodiment, the description will be made on the assumption that the luminance is n gradations from 1 to n and the number of classes is n. Then, the class J is initially initialized as 1. Next, the data S ₁ of the first difference image is read from the operation memory in the controller 10 and it is determined whether or not the set class J is equal to S ₁ (step). When J and the S ₁ is not equal, the process proceeds to step, to one count up class J. Then, return to the step again, and the next class J
And the S ₁ determines whether or not equal to. Repeat this, if the class J and S ₁ is equal, the step proceeds to the "YES" side and enters step. In this step, class J
Count K (J) is incremented by 1 and the controller 1
Write to the arithmetic memory in 0. Next, it is determined whether the calculation has been completed for all the difference images (step). If not, the process proceeds to the “NO” side, and the number i of the differential image is incremented by one in a step. Then, the process returns to the step before reading the data S ₂ of the next second difference image from the controller 10. Thereafter, steps 1 to 5 are repeated in the same manner as described above. When the calculation is completed for all the difference images, the step is “YE
Proceed to the S "side to end the processing.

Next, when the histogram is obtained in this manner, the controller 10 first displays necessary graphs such as a vertical axis, a horizontal axis, a scale, a number, etc., in order to display a graph of the histogram at a predetermined graph display position. An address is created so that data is read from the character generation circuit 14, and the graphic data is transferred to the graphic memory 15. At this time, since the graphic memory 15 has a storage area for a television screen image, the graphic memory 15 is controlled by the address generation circuit 11 so as to generate a graphic memory address corresponding to a display position on the image display 9.
Then, the controller 10 calculates the display coordinates for displaying the graph from the graph display position and the frequency K (J) of each class J, and stores the graphic data in the graphic memory 15 in the same manner as the graph axis display described above. Write. However, in the initial state, the contents of the graphic memory 15 are cleared.

Next, the graphic data read from the graphic memory 15 and the differential image data read from the second image memory 6 are input to an adder 16 and synthesized. Next, the image data synthesized by the adder 16 and the tomographic image data read from the first image memory 20 are input to the switch 21, and either of the two images is instructed by the controller 10. Is output. Thereafter, addition data of the difference image data and the data obtained by graphing the histogram or tomographic image data is written into the line memory 7 shown in FIG. 1 and then read out in synchronization with the television synchronization signal in units of television scanning lines. . Then, after being converted into an analog video signal by the D / A converter 8, it is input to the image display 9 and displayed as an image.
At this time, the histogram graph is displayed on the same screen simultaneously with the difference image. FIG. 5 shows a display example according to the above procedure.

Next, the effect of the exercise state of the exercise part on the histogram shape will be described. 6, 7, and 8
Is an example of a wall-like moving body such as a ventricular wall or a blood vessel wall,
The luminance distribution is shown when the movement speed is zero, low speed, and high speed, respectively. First, FIG. 6 shows a case where the movement speed is zero. FIG. 7A shows the luminance of the tomographic image (corresponding to the above-described first image) at time t ₁ ,
FIG. 6B shows the luminance of the tomographic image (corresponding to the above-described second image) at time t ₂ , and FIG. (Corresponding to a difference image), and FIG. 4D shows a frequency distribution (histogram) of the luminance of the difference image.
Here, for the sake of simplicity, the brightness of the wall as the moving part is set to n which is the highest brightness, and the other portions are set to 0 which is the lowest brightness. When the movement speed is zero, the position of the wall does not change in FIGS. 6A and 6B, and therefore the luminance distribution does not change, and the difference calculation result between the two images becomes zero. As described above, after the difference calculation result is halved, n / 2 is further added, so that the luminance of the difference image in this case is only n / 2 as shown in FIG. 6C. . Accordingly, in the histogram shape of the difference image, only the frequency of the center luminance n / 2 increases as shown in FIG.

Next, FIG. 7 shows a case where the movement speed is low. 6A to 6D show the brightness of the tomographic image and the difference image at times t ₁ and t ₂ , and the histogram of the difference image, respectively, as in the case of FIG. When the movement speed is low, the position of the wall is slightly changed in FIGS. 7A and 7B, and thus the luminance distribution is also slightly changed.
And -n. Also in this case, since the difference calculation result is halved, n / 2 is further added. Therefore, in this case, as shown in FIG. 7C, the components of 0 and n appear as the luminance of the difference image. I do. Therefore, the histogram form of this difference image
As shown in FIG. 7D, the frequency of the luminance n / 2 at the center is slightly lower, and the frequencies of the luminances 0 and n appear on both sides.

Next, FIG. 8 shows a case where the movement speed is high. 6A to 6D show the brightness of the tomographic image and the difference image at times t ₁ and t ₂ , and the histogram of the difference image, respectively, as in the case of FIG. When the movement speed is high, the position of the wall is greatly changed in FIGS. 8A and 8B, and thus the luminance distribution is also greatly changed. And -n. In this case as well, the same processing as in the case of FIG. 7 is performed, and the luminance of the difference image is calculated as shown in FIG.
As shown in the figure, components of 0 and n appear. However, FIG.
Unlike the above, the components of 0 and n increase. Therefore,
In the histogram shape of the difference image, as shown in FIG. 8D, the frequency of the center luminance n / 2 is further reduced, and the frequencies of the luminances 0 and n are slightly higher on both sides thereof.

Next, a display example of a histogram when the thickness of a wall-shaped moving body such as a ventricle wall or a blood vessel wall changes will be described with reference to FIGS. 9 and 10. FIG. FIG. 9 shows a case where the thickness d of the wall does not change. In FIG.
FIGS. 6A to 6D are diagrams of FIG. 6A to FIG.
1 to (d). in this case,
9 (a) and 9 (b), the position of the wall is changed, but the thickness d is not changed, and eventually the state is the same as that of FIG. 7 or FIG. Accordingly, the luminance of the difference image in this case is as shown in FIG.
As shown in (c), components of 0 and n appear. At this time, the displacement amounts at both ends of the wall are the same, and the frequency of luminance 0 and n becomes equal. Therefore, the histogram form of this difference image
As shown in FIG. 9 (d), the shape appears on both sides of the center of the luminance n / 2 at a height at which the frequencies of the luminances 0 and n are equal.

Next, FIG. 10 shows a case where the wall thickness changes like d ₁ and d ₂ . Also in FIG.
FIGS. 6A to 6D are diagrams of FIG. 6A to FIG.
1 to (d). in this case,
In FIGS. 10 (a) and 10 (b), as the position of the wall changes, its thickness changes like d ₁ and d ₂ . Accordingly, in the luminance of the difference image in this case, although the components of 0 and n appear as shown in FIG. 10C, the displacement amounts at both ends of the wall are different, and the frequencies of the luminance 0 and n are equal. No.
Therefore, the histogram shape of this difference image is shown in FIG.
As shown in (d), the frequencies of the luminance 0 and the luminance n appear at different heights on both sides of the luminance n / 2.

In the above description, the designation of an arbitrary range on the image by the area designating circuit 13 shown in FIG. 1 is performed on the tomographic image displayed on the image display 9. The present invention is not limited to this, and an area may be specified on the difference image. Further, in the example of the frequency distribution of luminance, an example in which normalization is not performed has been described, but normalization may be performed. Further, the difference image is obtained by performing the difference once between the two tomographic images. However, the present invention is not limited to this, and the second difference is performed between the two difference images obtained as described above. Alternatively, a second-order difference image may be used. In this case, the second-order difference image approximately represents the temporal change rate of the displacement amount of the moving part, and the frequency distribution of the luminance is graphed and displayed, thereby comparing the temporal change rate of the displacement amount as a numerical value. can do.

FIG. 11 is a block diagram showing a main part of a second embodiment of the present invention. This embodiment is shown in FIG.
The first image memory 20 in the SC 4 has a storage capacity for storing time-series tomographic image data of one or more heartbeats.
It is necessary to have a storage capacity for storing difference image data of a heartbeat or more in a time-series manner, and to obtain a luminance level over a period of one heartbeat or more.
The number distribution can be observed. Further, in FIG. 11, the switching unit 24 switches between the difference image data from the difference processing unit 5 and the image data from a third image memory 27 to be described later and sends them to the second image memory 6. is there. The other switch 25 switches the differential image data output from the second image memory 6 to either the switch 21 shown in FIG. 1 or an adder 26 described later and sends it. The adder 26 combines the difference image data output from the second image memory 6 via the switch 25 and the histogram data from the graphic memory 15 shown in FIG. The third image memory 27 temporarily stores data obtained by combining the two images by the adder 26.

Next, the operation of the second embodiment configured as described above will be described. First, the probe 1 transmits and receives ultrasonic waves and the DSC 4 repeatedly obtains tomographic image data in the same manner as in the first embodiment shown in FIG. At this time, the first image memory 20 stores the tomographic image data in a time series over a period of one or more heartbeats. Next, the difference processor 5 performs difference processing in the same manner as described in the first embodiment, and sends the result to the switch 24. In this state, the controller 10 switches the signal path of the switch 24 to the difference processor 5 side. Then, the difference image data output from the difference processor 5 is input to the second image memory 6. At this time, the difference image data is stored in the second image memory 6 in a time series over a period of one or more heartbeats.

Next, the operator stops the image displayed on the image display 9 by using the image stop circuit 22 shown in FIG. 1 when necessary. Then, in the same manner as described in the first embodiment, the region is designated for the image, and the frequency distribution (histogram) of the luminance of the image data is obtained for the first difference image. Created.

Next, the data of the first difference image is read from the second image memory 6 and sent to the adder 26 by switching the signal path of another switch 25. This adder 2
In step 6, the input difference image data and data obtained by graphing the histogram read from the graphic memory 15 are combined. The synthesized image data is input to the next third image memory 27 and is temporarily stored.

Next, the combined image data is read out from the third image memory 27, and is switched to the second image memory via the switch 24 switched to the third image memory 27 side. Sent to 6. At this time, in the second image memory 6, the area of the first difference image is updated, and the histogram graph is written in the first difference image. By sequentially performing the above operation for all the images written in the second image memory 6, a histogram graph can be obtained for all the difference images in the period of one heartbeat or more, and the difference image and the histogram are obtained. Displayed at the same time.

[0042]

According to the first aspect of the present invention , an arbitrary image range is designated on the difference image displayed on the image display means by the area designating means. , The brightness of the difference image signal obtained within the image range specified by the area specifying means by the graphing means .
Graphing frequency distribution (histogram) and providing information
By the frequency of the luminance graphed by the graphing means
Depending on the shape of the cloth, the movement speed of the moving part in the subject or
Thickness information is added and the above information is added by means of simultaneous display.
Graph of the frequency distribution of the luminance having the information given by the giving means.
And the difference image can be simultaneously displayed on the image display means. Therefore, the brightness of the image displayed with this difference image
By the shape of the frequency distribution, the displacement amount due to the movement of the moving part of the subject can be quantitatively and objectively grasped. From this, an observer such as a doctor can objectively determine and evaluate the magnitude of the displacement due to the movement of the moving part while viewing the difference image, and can perform an accurate diagnosis without individual differences. .

According to the second aspect of the present invention, the digital
The storage means (20) in the digital scan converter 4 is 1
Storage capacity to store tomographic data over the heartbeat in chronological order
After the differential image data generating means (5).
The stage stores difference image data for one or more heartbeats in time series.
Storage means (6) having a storage capacity of
In all difference images in the period of one or more heartbeats
A graph of the cloth is obtained and displayed simultaneously with the difference image. So
Then, observe the frequency distribution of the brightness of this difference image and make a diagnosis.
Can be used.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of an ultrasonic diagnostic apparatus according to the present invention;

FIG. 2 is an explanatory diagram showing a state in which an arbitrary image range is specified for a display image;

FIG. 3 is an explanatory diagram showing a storage area for one screen of a second image memory storing difference image data;

FIG. 4 is a flowchart showing a procedure for calculating a frequency of luminance of a difference image;

FIG. 5 is an explanatory diagram showing a procedure for displaying a histogram.

FIG. 6 is an explanatory diagram showing a display example of a histogram when the exercise speed is zero,

FIG. 7 is an explanatory diagram showing a display example of a histogram when the exercise speed is low,

FIG. 8 is an explanatory diagram showing a display example of a histogram when the exercise speed is high;

FIG. 9 is an explanatory diagram showing a display example of a histogram when the thickness of the moving body does not change;

FIG. 10 is an explanatory diagram showing a display example of a histogram when the thickness of a moving body changes,

FIG. 11 is a block diagram showing a main part of a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Probe, 2 ... Transmission signal generator, 3 ... Receiving signal processor, 4 ... DSC, 5 ... Difference processor, 6 ... Second image memory, 8 ... D / A converter, 9 ... Image display,
10 controller, 13 area designating circuit, 14
... Character generation circuit, 15 ... Graphic memory,
16, 26 ... adder, 18 ... A / D converter, 20
... first image memory, 23 ... marker, 27 ... third image memory.

Claims (2)

(57) [Claims] And 1. A probe for transmitting and receiving ultrasonic waves into the subject, the reflected echo signals received at the said <br/> probe with generating ultrasonic waves by driving the probe Transmitting and receiving means for processing
And a storage means for obtaining tomographic image data in a subject including a moving part using the received and processed reflected echo signals, and storing the obtained image data in a time series for each screen. Scan converter and this case
Ultrasound diagnostic apparatus having means for reading stored time-series image data, performing a difference operation between the images to generate the difference image data, and image display means for displaying the generated difference image data An area designating means for designating an arbitrary image range on the difference image displayed on the image display means, and a method for graphing a frequency distribution of luminance obtained for a difference image signal within the designated image range.
Steps and their shapes in this graphed luminance frequency distribution
More information on the movement speed or thickness of the movement part in the subject
Means for providing the
An ultrasonic diagnostic apparatus, comprising: means for simultaneously displaying a frequency distribution graph and a difference image . 2. The storage means in the digital scan converter has a storage capacity for storing tomographic image data for one or more heartbeats in a time series, and a storage unit for one or more heartbeats is provided at a subsequent stage of the difference image data generating means. 2. The ultrasonic diagnostic apparatus according to claim 1, further comprising a storage unit having a storage capacity for storing the difference image data in time series.