JPH07303646A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

PURPOSE:To display blood circulation data without missing the data of a low power value by comparing the power value of color flow data with 2 kinds of power threshold, comparing fault image data at the same position with a fault threshold, and judging either the fault image data or the color flow data should be displayed. CONSTITUTION:An echo signal emitted to and reflected from the interior of an organism is received by a probe 1 and a fault image data is generated from the received signal with a signal for fault processing circuit 5. Further, the reflected echo signal is subjected to a doppler signal processing with a doppler signal processing circuit 4 to generate color flow data. The power value of this color flow data is compared with a first and second power thresholds at a power threshold processing unit 10, and the fault image data at the position corresponding to the color flow data are compared with fault threshold. Based on the result of these comparisons and the discrimination of neighborhood data, either the fault image data or color flow data is selectively displayed on a display device 12.

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, and more particularly to an ultrasonic diagnostic apparatus for displaying in-vivo tomographic image data and color flow data.

[0002]

2. Description of the Related Art In an ultrasonic diagnostic apparatus used in the medical field, for example, the tomographic data of the heart is CR-reproduced in real time.
It is generally practiced to display the distribution on T or to measure the blood flow velocity at a specific site by the pulse Doppler method and display this distribution on the CRT. Also, in order to grasp the blood flow velocity two-dimensionally, the two-dimensional blood flow tomographic method (color flow display)
Has been adopted. This is to generate tomographic image data and Doppler signal-processed color flow data from a reflection echo signal from a living body, and synthesize them to display blood flow information in two dimensions in real time.

For example, a normal tomographic image is displayed in gray scale, and blood flow information is displayed thereon in color in accordance with the direction, speed and dispersion of the blood flow. As a method of displaying blood flow information, for example, the blood flow direction can be represented by red and blue colors, the velocity can be represented by its luminance, and the dispersion can be represented by a color tone by mixing green. In order to perform such a color flow display, the color flow data or the tomographic image data is compared with a set threshold value, and whether to output the color flow data or the tomographic image data is determined based on the comparison result. Select for each pixel. Generally, the following processing is performed as a method of selecting image data when displaying. The tomographic image data is displayed at a position where the power value of the color flow data is smaller than the power threshold value. The color flow data is displayed at a position where the power value of the color flow data is larger than the power threshold value and the tomographic image data at the same position is smaller than the tomographic threshold value. The tomographic image data is displayed at a position where the tomographic image data becomes larger than the tomographic threshold value.

In addition to this, a process using an average flow velocity value or a variance value of color flow data may be considered, but it is general to use a plurality of these processes together.

[0005]

In the above-described processing, it is determined that the color flow data is the actual blood flow information at the position where the power value of the color flow data is larger than the power threshold value, and Display flow data. At the position where the power value of the color flow data becomes smaller than the power threshold value, it is determined that the color flow data is noise and the tomographic image data is displayed.

When the power threshold value is set low, the noise portion of the color flow data is captured as blood flow data, and the noise portion different from the actual blood flow information is displayed in color on the display screen. The Rukoto.
In order to reduce this noise, it is possible to set the power threshold higher. However, the actual blood flow information includes color flow data having a low power value, which causes a problem that the blood flow information displayed on the screen is missing.

An object of the present invention is to remove noise in color flow data different from actual blood flow information when superimposing and displaying tomographic image data and color flow data,
It is possible to reliably display color flow data with a small power value.

[0008]

An ultrasonic diagnostic apparatus according to the present invention comprises a transmitting means, a receiving means, a tomographic image signal processing means, a blood flow signal processing means, a power threshold processing means, and a tomographic threshold. A hold processing means, a neighborhood data determination means, and a display means are provided. The transmitting means transmits the ultrasonic beam in the living body. The receiving means receives the reflected echo signal from the living body. The tomographic image signal processing means generates in-vivo tomographic image data based on the reflected echo signal. The blood flow signal processing means performs Doppler signal processing on the reflected echo signal to generate color flow data composed of average flow velocity, power value and velocity dispersion. The power threshold processing means compares the power value of the color flow data with the first and second power thresholds. The tomographic threshold processing means compares the tomographic image data at a position corresponding to the color flow data with a tomographic threshold value. When the power value of the color flow data is an intermediate value between the first and second power threshold values, the proximity data determining means determines the power value at the near position of the color flow data as the first and second power threshold values. And the tomographic image data corresponding to this position is compared with the tomographic threshold value. The display means
The tomographic image data and the color flow data are selectively displayed based on the processing results of the power threshold processing means, the tomographic threshold processing means and the neighborhood data discriminating means.

[0009]

In the present invention, when an ultrasonic beam is emitted into a living body and a reflection echo signal is obtained from the inside of the living body, the tomographic image signal processing means generates tomographic image data inside the living body. Further, the reflected echo signal is subjected to Doppler signal processing by the blood flow signal processing means, and color flow data composed of average flow velocity, power value and velocity dispersion is generated. The power value of the color flow data is compared with the first and second power thresholds by the power threshold processing means.
Further, the tomographic image data at the same position is compared with the tomographic threshold value by the tomographic threshold processing means. The display means displays the pixel corresponding to the position as the tomographic image data if the power value of the color flow data is a certain value or less based on the judgment results of the power threshold processing means and the tomographic threshold processing means. If the power value of the color flow data is above a certain value, the pixel at that position is output as color flow data as long as the tomographic image data at that position is below a certain value. When the power value of the color flow data is an intermediate value between the two threshold values, the same comparison is performed with respect to the data at the near position, and when it is determined that the blood flow information exists at the near position, the The image data at the position is displayed as color flow data. When it is determined that the data at the near position is tomographic image data, the color flow data at that position is determined as noise and the tomographic image data is displayed.

[0010]

1 is a block diagram showing a schematic configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. Probe 1
Is composed of a plurality of minute oscillators and is connected to the wave transmitting / receiving circuit 2. The transmission / reception circuit 2 includes a high-frequency pulse oscillator for transmitting an ultrasonic beam, a receiver for receiving and processing reflected echoes, a delay circuit for performing electronic scanning, a delay amount selection circuit, and the like.

An oscillator (OSC) 3 for generating a reference reference wave signal is connected to the transmission / reception circuit 2. The output signal of the wave transmission / reception circuit 2 is input to the Doppler signal processing circuit 4 and the tomographic signal processing circuit 5. The Doppler signal processing circuit 4 has two mixers and a 90 ° phase shifter which are not shown. The output of the wave transmitting / receiving circuit 2 and the output obtained by shifting the output of the oscillator 3 by 90 ° by the phase shifter are input to one of the mixers. The output of the wave transmitting / receiving circuit 2 and the output of the oscillator 3 are input to one of the mixers. Each mixer performs these mixings and detects the mixing output by 90 ° to obtain a Doppler signal.

The Doppler signal from the Doppler signal processing circuit 4 is input to the color flow mapping processing unit 6. The color flow mapping processing unit 6 calculates the color flow data composed of the average flow velocity value, the power value and the variance value of the blood flow data by the high speed calculation processing. The color flow data from the color flow mapping processing unit 6 is stored in the image memory 7 for blood flow data.

On the other hand, the tomographic signal processing circuit 5 is a circuit for obtaining tomographic data of a living body and has a detection function and the like. The output of the tomographic signal processing circuit 5 is A
It is stored in the image memory 9 for tomographic data via the / D conversion circuit 8. The image data stored in the image memories 7 and 9 is read out in synchronization with the TV signal, and the threshold processing unit 10 performs the threshold processing.
The threshold processing unit 10 determines whether to display tomographic image data or color flow data for each pixel of the display device. For example, when displaying the color flow data, the tomographic image data is replaced with a value of 0 (the tomographic image data does not exist), and when displaying the tomographic image data, the color flow data is 0 (the color flow data does not exist). Value.
The image data that has undergone the threshold processing by the threshold processing unit 10 is input to the color palette unit 11 and color processing is performed according to the input data, and the RGBT
It is output as a V signal. T from color palette 11
The V signal is displayed as a color image on the display device 12 such as a CRT monitor.

Next, the operation of the threshold processing unit 10 will be described with reference to the flowchart shown in FIG.
The image data stored in the image memories 7 and 9 is read out in synchronization with the TV signal and input to the threshold processing unit 10. Of these, the power values of the tomographic image data and the color flow data are shown by the waveforms as shown in FIGS. In step S1, the power value of the color flow data is set to the first power threshold T _{PL for} each pixel.
Compare with. If the power value is smaller than the first power threshold value T _PL , the process proceeds to step S5. Step S5
Then, the value of the color flow data is replaced with 0, and the tomographic image data is displayed at the pixel corresponding to this position.

Color flow data in step S1
Is the first power threshold T _PLIs greater than
If so, the process proceeds to step S2. Step S
In 2, the power value of the color flow data is set to the second power.
Threshold T_PHCompare with. Power value of color flow data
Is the second power threshold T_PHIs greater than
Move to step S3. At the same position in step S3
The tomographic image data of_FCompare with. Disconnection
Layer image data is tomographic threshold T_FIf is greater than
Moves to step S5, and the pixel at this position is
On the other hand, the tomographic image data is displayed. To step S3
And the tomographic image data is the tomographic threshold T _FLess than
If so, the process proceeds to step S4. Step
In step S4, the pixel corresponding to this position is colored
-Display flow data.

When it is determined in step S2 that the power value of the color flow data is smaller than the second power threshold value T _PH , the process proceeds to step S6. In step S6, the power value at the position near the color flow data used in steps S1 and S2 (for example, the color flow data of the adjacent pixel) is compared with the second power threshold value T _PH . When it is determined that the power value of the color flow data read in step S6 is larger than the second power threshold value T _{PH, the process proceeds} to step S3. When it is determined in step S6 that the power value of the selected color flow data is smaller than the second power threshold value T _{PH, the process} proceeds to step S7.
In step S7, the power value of the color flow data selected in step S6 is compared with the first power threshold value T _PL . If the power value of this color flow data is smaller than the first power threshold value T _PL , step S5.
Move to. When it is determined in step S7 that the power value of the color flow data is larger than the first power threshold value T _PL , the process proceeds to step S8. In step S8, the area for performing the threshold determination of the color flow data is further expanded (at the position adjacent to the color flow data selected in step S6, and from the pixels corresponding to the color flow data used in steps S1 and S2). Pixels farther away from the pixel), and the process proceeds to step S6.

For example, in the area A in FIG. 3, the first power threshold value T _PL of the power values of the color flow data is set.
The tomographic image data is displayed for the pixels determined to be smaller than the above (step S1) (step S1).
5). When the power value of the color flow data is larger than the first power threshold value T _PL , the comparison with the second power threshold value T _PH is further performed (step S2).
In the area A, the power value is smaller than the second power threshold value T _PH . Therefore, the power value of the color flow data regarding the pixel adjacent to the pixel of interest is _fetched and compared with the first power threshold T _PL and the second power threshold T _PH (steps S6 and S7). If the power value of the color flow data corresponding to the pixel adjacent to the pixel of interest is an intermediate value between the first and second power thresholds T _PL and T _PH ,
Further, the power value of the color flow data of the adjacent pixel is read (step S8). By repeating this, in the area A, the pixel where the power value of the color flow data is smaller than the first power threshold value T _PL is reached. Therefore, in the area A shown in FIG. 3, it is determined that the pixel having the power value of the color flow data larger than the first power threshold value T _PL is noise, and the image display of this area is sliced. It is displayed as image data (step S5).

In the region of FIG. 3B, similarly, tomographic image data is displayed for pixels whose power value of the color flow data becomes smaller than the first power threshold value T _{PL, and} the first power threshold value is displayed. If it is between T _PL and the second power threshold value T _PH , the power value of the color flow data of the adjacent pixel is judged as a threshold value to judge whether or not the color flow data is noise. Here, the power value of the color flow data is larger than the second power threshold value T _{PH at the} point H in FIG. 3B. In this case, the tomographic image data at the same position is compared with the tomographic threshold T _F (step S3), and when the tomographic image data is larger than the tomographic threshold T _F , the tomographic image data is displayed. Perform (step S5). As is clear from FIG. 3A, the tomographic image data at this point H is larger than the tomographic threshold T _F , and the image display at this point is tomographic image data.

In the region of FIG. 3D, the power value of the color flow data is larger than the first power threshold value T _PL and the second power threshold value T _PH , and the tomographic image data is the tomographic threshold value T _F. Therefore, it is determined that the color flow data here is the actual blood flow information, the tomographic image data is replaced with 0, and the color flow data is displayed on the display device 12 (step S4).

In areas C and E of FIG. 3, the power value of the color flow data is an intermediate value between the first power threshold value T _PL and the second power threshold value T _PH , and the power values of the pixels in the vicinity of each pixel are shown. The threshold value judgment will be performed on. When the area of the pixel for which the threshold value judgment is performed is expanded, the pixel located in the D area is reached. Some pixels in the D area have a power value of the color flow data larger than the second power threshold value T _PH, and accordingly, the power values of the color flow data in the C area and the E area are the first and the second power threshold values T _PH. It is determined that the pixel having the intermediate value between the second power thresholds T _PL and T _PH has color flow data having a power value larger than the second power threshold T _PH in the vicinity (step S6). . When the tomographic image data at the same position is compared with the tomographic threshold T _F (step S3), since the tomographic image data is smaller than the tomographic threshold T _F here, the color flow data at this position is actually calculated. Judge as blood flow information. Therefore, the color flow data is selected in the C area and the E area, and the color flow data corresponding thereto is displayed on the display device (step S).
4).

In the F area, tomographic image data is displayed in the same manner as in the B area, and in the G area, tomographic image data is selected and displayed in the same manner as in the A area. [Other Embodiments] (a) In FIG. 3, the horizontal axis indicates the beam depth direction, but it is effective to perform similar processing on a two-dimensional image. (B) It is possible to change the first and second power threshold values according to the average flow velocity. For example, if clutter noise such as heart wall or valve motion is not removed by the MTI filter, it is possible to remove clutter noise by increasing the power threshold in the low flow velocity region as shown in FIG. Becomes

[0022]

According to the present invention, the power value of the color flow data is compared with the first and second power threshold values, the tomographic image data at the same position is compared with the tomographic threshold value, and the tomographic image data and the color image data are compared. It is determined which of the flow data is to be displayed. Here, when the power value of the color flow data is an intermediate value between the first and second power threshold values, the power value in the vicinity of this color flow data is set to the first and second power threshold values. Then, the tomographic image data corresponding to this position is compared with the tomographic threshold value to determine whether or not the nearby color flow data has blood flow information. When the blood flow data exists in the vicinity, the color flow data is selected, and when the blood flow data does not exist, it is determined that the color flow data is noise and the tomographic image data is displayed. Therefore, noise is effectively removed from the color flow data, and blood flow data having a low power value can be displayed on the display device without being lost.

[Brief description of drawings]

FIG. 1 is a control block diagram of an ultrasonic diagnostic apparatus according to the present invention.

FIG. 2 is a control flowchart thereof.

FIG. 3 is a diagram showing signals of tomographic image data and color flow data.

FIG. 4 is a diagram showing an example of a power threshold according to another embodiment.

[Explanation of symbols]

1 probe 2 wave transmitting / receiving circuit 3 oscillator 4 Doppler signal processing circuit 5 signal processing circuit for tomography 6 color flow mapping processing unit 7 image memory for color flow data 8 A / D converter 9 image memory for tomographic image 10 threshold processing unit 11 Color palette 12 Display device T _PL 1st power threshold T _PH 2nd power threshold T _F tomographic threshold

Claims (1)

[Claims] 1. A transmitting means for transmitting an ultrasonic beam into a living body, a receiving means for receiving a reflected echo signal from the living body, and a tomographic section for generating tomographic image data in the living body based on the reflected echo signal. Image signal processing means, blood flow signal processing means for performing Doppler signal processing on the reflected echo signal to generate color flow data consisting of average flow velocity, power value, and velocity dispersion; And a power threshold processing means for comparing with a second power threshold value, a tomographic threshold processing means for comparing tomographic image data at a position corresponding to the color flow data with a tomographic threshold value, and The power value is the first and second
When the value is an intermediate value of the power thresholds of the color flow data, the power value at a position near the color flow data is compared with the first and second power thresholds, and the tomographic image data corresponding to this position is tomographic threshold. A display for selectively displaying the tomographic image data and the color flow data based on the processing result of the neighborhood data discriminating means for comparing with the value, the power threshold processing means, the fault threshold processing means and the neighborhood data discriminating means. An ultrasonic diagnostic apparatus comprising: