JPH02279144A - Ultrasonic diagnostic device - Google Patents

Abstract

PURPOSE:To easily execute the decision of an abnormal part by eliminating a signal of a normal tissue from reflected echo data, and extracting echo data of an abnormal part contained in the reflected echo data. CONSTITUTION:Echo data E converted to a digital signal of 6 bits by an A/D converting circuit 3, and a count value of an A/D clock counter are inputted to a difference data output ROM 10 as an (x) address and a (y) address, respectively. When echo data Ei of a prescribed level is inputted as the (x) address, as for the (y) address, since an A/D clock count value (i) is inputted in advance, difference data ei obtained by subtracting reference echo data Ai of the same timing from the echo data Ei is outputted to its output. In a subtracting circuit 14, an output emin of a minimum value output circuit 12 is subtracted from an output emax of a maximum value output circuit 11, by which in an output of the subtracting circuit 14, a level ey of the echo data itself of an abnormal part, etc., is detected, and the output ey is inputted as the (y) address to a gammaconverting ROM 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an ultrasonic diagnostic apparatus, and particularly to a received signal processing system thereof.

[Conventional technology]

Ultrasonic diagnostic devices are used in the medical field to obtain in-vivo tomographic information and the like. Generally, this device is
It consists of a probe, a transmission/reception system, and a CRT monitor.

When obtaining tomographic information, first the probe is driven by the transmission system to transmit an ultrasound beam into the living body. Then, the ultrasound beam is reflected from the acoustic impedance boundary of the in-vivo tissue. This reflected echo is received by the probe and input to the reception processing system. The reception processing system performs signal processing such as amplification and detection on the reflected echo signal, converts it into a television signal using a digital scan converter (DSC), and then displays the tomographic data on a CRT monitor.

[Problem to be solved by the invention]

As described above, conventional ultrasonic diagnostic apparatuses obtain tomographic images by displaying ultrasonic echoes reflected from the acoustic impedance boundaries of in-vivo tissues. However,
In cases where there is no clear acoustic impedance boundary between normal tissues, such as intrahepatic tumors, CR
A clear boundary does not appear in the tomographic image displayed on T, and a considerable amount of experience is required to determine it.

An object of the present invention is to use ultrasonic waves that can easily determine abnormal areas even in cases where there is no clear acoustic impedance boundary between the abnormal area to be observed and normal fibers. The objective is to provide diagnostic equipment.

[Means to solve the problem]

The ultrasound diagnostic apparatus according to the present invention receives and processes reflected echoes obtained by transmitting an ultrasound beam into a living body to obtain tomographic information inside the living body, and includes an echo signal extraction means and an echo data and conversion means.

The echo signal extraction means extracts an echo signal of a desired region by determining the difference between reflected echo data from a living body and reference reflected echo data obtained by measurement in advance. Further, the echo data converting means converts the output data of the echo signal extracting means with characteristics depending on the dynamic range of the apparatus and the signal waveform data obtained by the echo signal extracting means.

[Effect]

In this invention, the difference between reflected echo data from inside the living body and reference reflected echo data is determined. The reference reflection echo data is obtained in advance using a standard specimen (phantom).This allows normal tissue signals to be removed from the reflection echo data and echo data of abnormal areas included in the reflection echo data to be extracted. .

Next, the waveform data of the extracted data is converted so that the maximum value of the extracted data becomes approximately the upper limit of the dynamic range of the apparatus, and the minimum value of the extracted data becomes the lower limit of the dynamic range.

As a result, the abnormal region is highlighted and displayed, and the dynamic range of the device is effectively used to facilitate determination of the abnormal region.

〔Example〕

FIG. 2 shows a reception processing system of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. Note that the transmission system has the same configuration as a conventional ultrasonic diagnostic apparatus, so a description thereof will be omitted here. A probe 1 is connected to the transmission system and the reception processing system, and this probe 1 is composed of a plurality of microscopic vibrators. The echo processing circuit 2 connected to the probe 1 includes a delay circuit, an amplifier, a detection circuit, etc. for performing electronic scanning and the like. The output of the echo processing circuit 2 includes an A/D converter for converting the received and processed reflected echo into a digital signal.
A D conversion circuit 3 is connected, and the echo data converted into a digital signal here is stored in a main memory 5 via a preprocessing circuit 4. A D/A conversion circuit 6 is provided on the output side of the main memory 5, and the tomographic data converted into an analog signal here is sent to a CRT 7.
is now displayed.

FIG. 1 shows a specific configuration of the preprocessing circuit 4 shown in FIG. 2. As shown in FIG. The difference data output ROM10 that constitutes the preprocessing circuit 4 outputs difference data e obtained by subtracting the reference echo data from the echo data E, using the echo data E as the X address and the count value of the A/D clock counter as the y address. It is something to do. Here, echo data E consists of 6 bits (levels O to 63), and A
It is assumed that the count value of the /D clock counter consists of 9 bits (one scanning line consists of 512 pixels). The output of the difference data output ROM10 is connected to each of the maximum value output circuit 11, the minimum value output circuit 12, and the line buffer memory 13.

The maximum value output circuit 11 and the minimum value output circuit 12 each include a comparator, etc., and the line buffer memory 13 has a storage capacity for one scanning line.

The maximum value output circuit 11 and the minimum value output circuit 12 output the maximum value e1.8 and the minimum value e+sin of the difference data obtained by subtracting the reference echo data from the echo data E, respectively. Output e wax of maximum value output circuit 11
is connected to the subtraction circuit 14, and the output e+++in of the minimum value output circuit 12 is connected to the subtraction circuit 15. The subtraction circuit 14 subtracts the output eain of the minimum value output circuit 12 from the output e, , □ of the maximum value output circuit 11, and the subtraction circuit 15 subtracts the output eain of the minimum value output circuit 12 from the output el of the line buffer memory 13. 12 output esin is subtracted. The outputs ay and ex of the subtraction circuit 14 and the subtraction circuit 15 are connected as the X address and the X address of the γ conversion ROM 16, respectively.

Next, the operation will be explained.

First, the operation of the entire reception system of the device will be explained. A reflected echo received via the probe 1 is input to an echo processing circuit 2, where it undergoes processing such as amplification and detection.

The echo signal obtained in this way is converted into a digital signal by the A/D conversion circuit 3 and inputted to the preprocessing circuit 4 as tomographic data. The preprocessing circuit 4 extracts an abnormal region and converts data, as will be described in detail later. The tomographic data processed by the preprocessing circuit 4 is stored at a predetermined address in the main memory 5. Note that the preprocessing circuit 4 not only extracts and converts the echo signal as described above, but also performs processing such as calculating an average value with the previous frame. The signal converted into a television signal by the main memory 5 is converted into an analog signal by a D/A conversion circuit 6 and displayed on a CRT monitor 7.

Next, detailed operation of the preprocessing circuit 4 will be explained.

First, measure reference echo data in advance using a phantom. Normally, reflected echoes have a characteristic R that attenuates according to time t (corresponding to depth), as shown in Figure 3A.
o. On the other hand, the reflected echo E obtained by transmitting an ultrasound beam into an actual living body has a waveform in which a predetermined signal is superimposed on the reference echo data R0, as shown in Fig. 3B. It is data.

The echo data E converted into a 6-bit digital signal by the A/D conversion circuit 3 is used as the X address and as the A
The count value (9 bits) of the /D clock counter is input to the difference data output ROM10 as an X address. The contents of the difference data output ROM10 are shown in FIG. 4. As shown in this figure, the echo data E,
When is input as the X address, since the A/D clock count value l is input as the X address, the output is (E+ At), that is, the reference echo data of the same timing from the echo data E. Difference data eL obtained by subtracting A is output.

This difference data is input to a maximum value output circuit 11, a minimum value output circuit 12, and a line buffer memory 13, respectively. The maximum value output circuit 11 and the minimum value output circuit 12 compare the data sent one after another with the data sent last time, and determine the maximum value e ma for each scanning line.
In the zero-order subtraction circuit 14 that detects X and the minimum value e17, the output ewaLm of the minimum value output circuit 12 is subtracted from the output eaa of the maximum value output circuit 11. The level (height) e, (see FIG. 5) of the echo data itself of the site, etc., is detected. The output e of this subtraction circuit 14 is γ-transformed R as an X address.
Input to OM16.

On the other hand, the subtraction circuit 15 uses one line of signal data e! stored in the line buffer memory 13! The output e+++in of the minimum value output circuit 12 is subtracted from . As a result, waveform data as shown in FIG. 5 is obtained as the output e8 of the subtraction circuit 15. This is converted into γ conversion ROM16
Enter it as the X address.

The γ conversion ROM 16 converts the waveform data as shown in Fig. 5, and the minimum value e, i is almost the lower limit of the dynamic range D of the device, and the maximum value 4K e, □ is almost the upper limit of the dynamic range. do it like this. That is,
The γ conversion ROM 16 stores various T conversion curves as shown in the schematic diagram of FIG. For example, if the value obtained by subtracting the minimum value e0.7 from the maximum value e saw of the echo data (the output of the subtraction circuit 14) ey is C7, then the γ conversion curve C7 is selected using this level "7" as the X address. Then, C7, widens the dynamic range of the device. When using the γ conversion curve C1 with the X address “7”, the subtraction circuit 15 is
When the output ex is 0, it is "0", and when it is 1, it is "9".
”, if it is 2, it will be “18j”, if it is 3, it will be “27”,
...7, "63" is output respectively. Similarly, for example, when the output e of the subtraction circuit 14 is "10", the output eX of the subtraction circuit 15 is converted to the γ conversion curve C in FIG.
The data is converted by 3 degrees so that the waveform data can be displayed by effectively using the dynamic range D of the device.

In this embodiment, the difference between the actual echo data and the reference echo data is calculated, and the dynamic range of the device is effectively used according to this waveform data. can be displayed with emphasis, and the determination can be made easier.

[Other Examples]

In the above embodiment, the γ conversion curve to be used is changed for each scanning line, but changing the γ conversion curve is as follows:
It may be possible to change it only when the operator specifies it from the keyboard.

In other words, when examining the inside of the liver as in the example above, since the examination area is homogeneous, a stable display state can be obtained even if the γ conversion curve is changed for each scanning line, but the tomographic information When inspecting a site where the γ-conversion curve constantly changes, changing the γ conversion curve every l scanning lines may change the display state and make it difficult to see. In such a case, display is performed for each scanning line for a predetermined period, and
By pressing the operation key at the desired timing and fixing the γ conversion curve, it is possible to emphasize the abnormal area and enable the dynamic range for display, as in the previous embodiment, and to prevent the display state from constantly changing and becoming difficult to see. It can be prevented. This operation may be performed each time the inspection site is changed, and an appropriate γ conversion curve corresponding to the inspection site may be selected each time.

〔Effect of the invention〕

According to the present invention, by taking the difference between the actual echo data and the reference echo data, it is possible to emphasize and display, for example, abnormal tissue in the examination area, and the difference data can be used to maximize the dynamic range of the device. It can be effectively used and displayed, and abnormal tissues as described above can be easily determined.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a preprocessing circuit of an ultrasound diagnostic apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram of a receiving system of an ultrasound diagnostic apparatus according to an embodiment of the present invention, and FIG. 3A is a block diagram of a preprocessing circuit of an ultrasound diagnostic apparatus according to an embodiment of the present invention. Figure 3B is a diagram showing the reference echo data, Figure 3B is a diagram showing reflected echo data obtained by actual measurement, Figure 4 is a diagram showing the contents of the difference data output ROM shown in Figure 1, and Figure 5 is a diagram showing the contents of the difference data output ROM shown in Figure 1. FIG. 6 is a diagram showing the output waveform of the subtraction circuit 15 shown in FIG. 1, and FIG. 6 is a diagram showing the contents of the T-conversion ROM shown in FIG. 2...Echo processing circuit, 4...Preprocessing circuit, 5...
・Main memory, 7... CRT monitor, 10... Difference data output ROM, 11... Maximum value output circuit, 12.
... Minimum value output circuit, 14.15 ... Subtraction circuit, 16
...T conversion ROM. Patent applicant: Shimadzu Corporation

Claims (1)

[Claims] (1) In an ultrasonic diagnostic apparatus configured to receive and process reflected echoes obtained by transmitting an ultrasound beam into a living body to obtain tomographic information inside the living body, the reflected echo data from the living body; echo signal extraction means for determining the difference between reference reflected echo data obtained by measurement in advance and extracting an echo signal of a desired region; An ultrasonic diagnostic apparatus comprising: echo data converting means for converting output data of the echo signal extracting means.