JPH0548129B2 - - Google Patents

Description

[Detailed description of the invention]

[Objective of the invention] (Industrial application field) The present invention uses ultrasound to obtain anatomical information such as a B-mode image of a living body, movement information of moving organs in a living body such as an M-mode image, and a Doppler. Regarding ultrasonic diagnostic equipment that obtains and visualizes functional information associated with the movement of a moving object within a living body, such as two-dimensional blood flow velocity information using effects, in particular, two-dimensional The present invention relates to an ultrasonic diagnostic apparatus that superimposes dimensional blood flow velocity information and displays it in color. (Prior art) Ultrasonic diagnostic methods use anatomical information, typically represented by B-mode images, movement information of in-vivo organs, typically represented by M-mode images, and the Doppler effect, typically represented by blood flow imaging. Functional information associated with the movement of moving objects within a living body is used for diagnosis. Here, the M-mode image obtained by fixed scanning in the same direction represents temporal changes in the ultrasonic wave transmitting/receiving site, and is particularly suitable for diagnosis of moving organs such as the heart. On the other hand, the ultrasonic drape method, whose representative example is blood flow imaging, is a method of obtaining functional information associated with the movement of a moving object within a living body and visualizing it, and this will be described in detail below. That is, the ultrasonic drape method utilizes the ultrasonic drape effect in which when an ultrasonic wave is reflected by a moving object, the frequency of the reflected wave shifts in proportion to the moving speed of the moving object. Specifically, by transmitting ultrasonic rate pulses or continuous waves into a living body, and obtaining frequency polarization due to the drape effect from the phase change of the reflected wave echo, the moving object at the depth position where the echo was obtained. You can obtain exercise information. This refers to the direction of blood flow, the state of the flow (disturbed or regular), the flow pattern,
Blood flow conditions such as the absolute value of velocity can be known. Next, the device will be explained. That is, as shown in FIGS. 3 and 4, ultrasonic waves are transmitted from the probe 21 driven by the wave transmitting/receiving circuit 22 in the direction A shown in the figure, and from the ultrasonic echoes received by the wave transmitting/receiving circuit 22. , a drape shift signal is detected by the phase detector 23. In this case, the detected drape shift signal is captured at each of, for example, 256 sample points SP provided in the direction of the ultrasound beam. The drape shift signal captured for each sample point SP in this way is calculated by the blood flow calculation section 24, and the obtained blood flow signal is sent to the DSC 25 and the display section 26 to display a blood flow image in the A direction. display on the monitor. Next, the ultrasound beam is shifted in direction B and the same operation as described above is performed to scan the display range in real time, detecting blood flow information in each direction and displaying blood flow signals, thereby detecting two-dimensional blood flow. To obtain flow images in real time. In this case, the wave transmitting/receiving circuit 22 separates the echo component from an immovable object such as a tissue and the echo component from a moving object such as a blood cell from the ultrasonic echo.
The former is used for B or M mode image formation, and the latter is used for detecting a Doppler shift signal by the phase detector 23. Then, echo components from a stationary object are formed as a B or M mode image and displayed with varying brightness levels in black and white, and echo components from a moving object are formed as a two-dimensional blood flow velocity image and displayed in color brightness levels. There is a configuration in which both images are displayed in a superimposed manner. (Problems to be Solved by the Invention) In such a conventional configuration, a B or M mode image displayed in black and white (brightness) is simply superimposed and displayed with two-dimensional blood flow velocity information displayed in color (brightness). Therefore, the problem is that the hue of superimposed areas, especially where the echo level is low and the blood flow is slow, becomes distorted, resulting in an unnatural image, making it impossible to make an accurate diagnosis. It was hot. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an ultrasonic diagnostic apparatus that allows accurate diagnosis as a natural image without disturbing the hue of the area even when the echo level is low and the blood flow velocity is slow. be. [Object of the Invention] (Means for Solving the Problems) The present invention has a configuration in which the following measures are taken to solve the above problems and achieve the objects. That is, the present invention transmits and receives ultrasonic waves within a subject to obtain B or M mode image information of the subject, performs black-and-white processing based on the echo level, and also performs two-dimensional blood processing using scattered ultrasound in the transmitted and received waves. In an ultrasonic diagnostic apparatus that obtains flow velocity information, performs color processing based on the blood velocity, and displays both in a superimposed manner, a black and white threshold is attached to the B or M mode image information, and a color threshold is attached to the B or M mode image information. The present invention is characterized in that it includes a display control means attached to the two-dimensional blood flow velocity information and giving priority to either black and white display or color display depending on the magnitude of the echo level and the magnitude of the blood flow velocity. (Function) In this way, the display control means gives priority to either black and white display or color display depending on the magnitude of the echo level and the magnitude of the blood flow velocity, so that the echo level is low and the blood flow velocity is low. Since a predetermined black and white display or color display is performed for a region where the speed is low, accurate diagnosis can be performed as a natural image without disturbing the hue of the region. (Embodiment) An embodiment of the ultrasonic diagnostic apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the main parts of this embodiment. In FIG. 1, a color frame memory 1 stores blood flow data detected from echo data obtained by transmitting and receiving ultrasonic waves in the form of digital signals. The black-and-white frame memory 2 stores echo data, for example, for forming a B-mode image by transmitting and receiving ultrasonic waves, in the form of digital signals. The ROM (read-on memory) 3 is for converting the blood flow data in the color frame memory 1 into RGB signals corresponding to the size thereof. The latch circuit 4 temporarily holds the RGB signal blood flow data stored in the ROM 3. The latch circuit 5 temporarily holds the echo data stored in the monochrome frame memory 2. The V threshold value setting circuit 6 is used to set a color brightness threshold for forming a two-dimensional blood flow velocity, and its value can be set to a desired value. The comparator 8 is a V threshold setting circuit 6
Compare the color brightness threshold by the signal
COLTH, blood flow velocity V data from color frame memory 1 is input as the compared signal, and the blood flow velocity V data is the color luminance threshold COLTH.
When the blood velocity V data is larger than the color luminance threshold COLTH, an H level signal is output, and when the blood flow velocity V data is smaller than the color luminance threshold COLTH, an L level signal is output. The input/output relationship of this comparator 8 is shown below.
Shown in the table.

[Table] The B/W threshold setting circuit 7 is for setting a black and white luminance threshold for echo data for B-mode image formation, for example, and the value can be set to a desired value. . The comparator 9 inputs the black-and-white luminance threshold set by the B/W threshold value setting circuit 7 as a comparison signal B/WTH, and inputs the echo data B/W from the black-and-white frame memory 2 as a compared signal, so that the echo data B/W is black and white. When the luminance threshold B/WTH is greater, an H level signal is output, and when the echo data B/W is less than the monochrome luminance threshold B/WTH, an L level signal is output. The input/output relationship of this comparator 9 is shown in Table 2 below.

[Table] The switching logic generation circuit 10 includes comparators 8 and 9.
, and outputs a select signal to an input terminal S of a multiplexer 11, which will be described later, based on the input/output relationship shown in Table 3 below. That is,
The output of the switching logic generating circuit 10 is set to "H" only when the output of the comparator 8 is "H" and the output of the comparator 9 is "L", and is set to "L" in all other states.

[Table] The multiplexer 11 selects which of the latch circuits 4 and 5 to output according to the contents of the select signal of the switching logic generating circuit 10, as shown in Table 4 below, and outputs the signal to each of the RGB outputs. That is,
When S=“L”, the output of the multiplexer 11 is sent to the latch circuit 5 for echo data (B or M mode image).
When S="H", the output of the multiplexer 11 is the output of the latch circuit 4 for blood flow data (two-dimensional blood flow velocity image).

[Table] Next, the operation of this embodiment configured as described above will be explained. That is, when the blood flow velocity V is smaller than the color luminance threshold COLTH, the output of the comparator 8 = "L", and when the echo data B/W is smaller than the monochrome luminance threshold B/HTH, the output of the comparator 9 = Since it becomes "L", the output of the switching logic generating circuit 10 becomes "L". According to Table 4, multiplexer 1
Since the output of latch circuit 5 is given to the output of signal 1, the contents of black and white frame memory 2 for echo data are output. Therefore, the B or M mode image is displayed in black and white. As above, V<COLTH and B/W>B/
The B or M mode image is also displayed in black and white during WTH. Furthermore, V>COLTH and B/W<B/WTH
The two-dimensional blood flow velocity image is also displayed in color. Furthermore, V>COLTH and B/W>B/
At WTH, the B or M mode image is displayed in black and white. This case is clinically appropriate in the following cases. That is, since the walls of the heart and the like exhibit very rapid movement similar to the blood flow, according to the conventional technology, the walls themselves are displayed in color. this is,
It will appear as if there is blood flow there (wall). Therefore, since the echo of walls is quite strong relative to blood flow, areas where the B/W level is above a certain value (B/WTH) are recognized as not blood flow, even if the movement (v) is fast. By displaying in B/W, the wall is displayed as a wall in B/W, thereby eliminating confusion with blood flow. Figure 2 shows the above relationship, and shows the black and white luminance threshold B/W of the echo level B/W.
The magnitude of blood flow velocity V with respect to WTH and the magnitude of blood flow velocity V with respect to color luminance threshold COLTH indicates that priority is given to either monochrome luminance display or color luminance display. As described above, according to this embodiment, even in areas where the echo level is low and the blood flow is slow, such as the boundary between the blood vessel wall and the blood flow, the hue can be natural without being disturbed. Clear images are displayed and accurate diagnosis can be made. In addition, the black-and-white brightness threshold B/WTH, which determines black-and-white brightness display, and the color brightness threshold, COLTH, which determines color brightness display, can be set to desired values. Even in the case of low-velocity blood cells such as those in the abdomen, the blood flow velocity image is displayed naturally and clearly without any color disturbance, and as a result, the low-velocity flow detection ability has been improved, making it useful for diagnosis of the liver and kidneys. It will also be applied. Note that in the conventional simple superimposition, the dynamic range of the B or M mode image in the part where the color luminance is displayed is reduced, but in this embodiment, this reduction is small, so there is an advantage in terms of image diagnosis. The present invention is not limited to the above-described embodiments, and display may be performed using elements other than brightness in black and white and color display, and various other modifications may be made without departing from the gist of the present invention. It is something that can be implemented. [Effects of the Invention] As described above, in the ultrasonic diagnostic apparatus provided with the display control means according to the present invention, priority is given to either black and white display or color display depending on the magnitude of the echo level and the magnitude of blood flow velocity. By doing so, a predetermined black and white display or color display is performed for areas where the echo level is low and the blood flow rate is slow, so the hue of the area is not disturbed and accurate diagnosis can be made as a natural image. It has the effect of being able to do the following.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of essential parts of an embodiment of the ultrasonic diagnostic apparatus according to the present invention, Fig. 2 is a diagram showing the operation of the embodiment, and Fig. 3 shows the principle of ultrasonic scanning. 4 are schematic block diagrams of an apparatus capable of detecting blood flow velocity images. 1...Color frame memory for blood flow data, 2
...Black and white frame memory for echo data, 3...
RGB conversion ROM, 4, 5...Latch circuit, 6...
Blood flow data V threshold setting circuit, 7... Echo data B/W threshold setting circuit, 8, 9... Comparator,
10...Switching logic generation circuit, 11...Multiplexer.

Claims (1)

[Scope of Claims] 1 Ultrasonic waves are transmitted and received within a subject to obtain B or M mode image information of the subject, and black-and-white processing is performed based on the echo level, and the Doppler shift ultrasonic wave in the transmitted and received waves is An ultrasound diagnostic device that obtains two-dimensional blood flow information from sound waves, performs color processing based on the blood flow velocity, and selectively displays either a black-and-white processed first image or a color-processed second image. A first image forming apparatus that compares the pixel brightness of the first image with a black-and-white threshold for each pixel and outputs a comparison result.
a second comparing means that compares pixel brightness and color threshold of the second image pixel by pixel and outputs a comparison result; an output of the first comparing means; 2. An ultrasonic diagnostic apparatus comprising: display control means for displaying either the first image or the second image for each pixel based on the output of the comparison means of FIG. 2. The display control means displays the second image only when the pixel brightness of the first image is lower than a black and white threshold and the pixel brightness of the second image is higher than a color threshold; The ultrasonic diagnostic apparatus according to claim 1, wherein the first image is displayed in this case. 3. The ultrasonic diagnostic apparatus according to claim 1 or 2, wherein the value of at least one of the black-and-white threshold and the color threshold is variable.