JPH0614924A - Ultrasonic diagnostic system - Google Patents

Abstract

PURPOSE:To improve scanning line composite processing process, in order to solve the problem of incapability of smoothly connecting images due to difference in particle shape, etc., in any composite point because data of a scanning line is obtained by making a composition of plural echo data coming from plural focus areas. CONSTITUTION:A digital scan converter 11 comprises an input buffer 3 for memorizing an echo data on every scanning line; an arithmetic circuit 4 for inputting the echo data from the input buffer 3 and mutually correlating a plurality of echo data on every scanning line and a frame memory 5 for memorizing frame by frame the picture element data obtained by the arithmetic circuit 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is an ultrasonic wave transmitting ultrasonic wave from an ultrasonic probe to a subject, detecting an echo signal obtained by the ultrasonic wave detection, and performing TV scan conversion to display ultrasonic diagnostic information. More particularly, the present invention relates to an ultrasonic diagnostic apparatus that can perform a combination focus method (for example, a transmission multi-stage focus method).

[0002]

2. Description of the Related Art An ultrasonic diagnostic method in which an ultrasonic pulse is transmitted to a living body and biological information is obtained by reflected waves from each tissue in the living body is a contrast agent which does not have irradiation obstacles such as X-rays. It has the advantage that the soft tissue can be diagnosed without it. An array type (also referred to as an array type) piezoelectric vibrator is used as an ultrasonic probe used in a recent ultrasonic diagnostic apparatus capable of performing such an ultrasonic diagnostic method. An ultrasonic wave is generated by applying a drive signal to each transducer of this ultrasonic probe, and this ultrasonic wave is transmitted into the living body. Then, by giving a predetermined delay time to a received signal obtained from the same oscillator as the above-mentioned oscillator when transmitting from this living body, the ultrasonic beam is focused at a predetermined position, and a slice with excellent resolution is obtained. I try to get a statue.

The image quality of the above-mentioned tomographic image is the best in the region close to the focus. The combination focus method makes use of its characteristics.It sends multiple ultrasonic beams whose focal positions are changed from the shallow part to the deep part in the living body to each of the desired focus regions, and then echoes each focus region. By combining the data to obtain one scan data, and by combining a plurality of these scan data, a tomographic image with excellent image quality is obtained.

[0004]

As described above, in the ultrasonic diagnostic apparatus using the conventional combination focus method, one scan line data is obtained by synthesizing a plurality of echo data from a plurality of focus areas. As a result, there is a problem that images cannot be smoothly connected at each composite point due to differences in particle shape and the like. SUMMARY OF THE INVENTION It is an object of the present invention to provide an ultrasonic diagnostic apparatus which improves the above-mentioned scanning line synthesizing process and can display an ultrasonic image easily and smoothly.

[0005]

The present invention has taken the following means in order to solve the above problems and achieve the object. That is, the present invention provides a digital scan converter (DS
In C), there is provided means for performing a correlation process by an arithmetic circuit for averaging the echo data in the scanning line direction of the ultrasonic wave when each echo data is transferred from the input buffer to the frame memory.

[0006]

[Action] By taking such means, the following action is exhibited. By performing the correlation processing by the arithmetic circuit, that is, each echo data in the frame memory is obtained by averaging each echo data in the input buffer with a plurality of echo data before and after the same scanning line. Each echo data inside has a desired correlation with a plurality of echo data before and after the same scan line. Therefore, it is possible to smoothly connect images at each of the above-described combining points, and it is possible to improve ultrasonic image quality.

[0007]

Embodiments will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus using a combination focus method according to an embodiment of the present invention, and FIG. 2 is a signal waveform showing a transmission / reception timing according to the embodiment of the present invention. FIG. 3 is a diagram showing address positions in a frame memory of echo data of three focus areas according to the embodiment of the present invention, and FIG. 4 is a diagram showing correlation processing according to the embodiment of the present invention. Is.

The ultrasonic diagnostic apparatus comprises an ultrasonic probe 10, a transceiver 1 and a digital scan converter (DSC) 1.
1 has a TV monitor 7. In addition, the above-mentioned DSC11
It has an analog / digital (A / D) converter 2, an input buffer 3, an arithmetic circuit 4, a frame memory 5, a digital / analog (D / A) converter 6, a control circuit 8 and a CPU 9.

The ultrasonic probe 10 is provided with a plurality of ultrasonic transducers, and gives an appropriate electrical delay time to each ultrasonic transducer in order to perform scanning such as linear scanning and sector scanning. , Give a desired directivity and focus position to the ultrasonic beam.

In the DSC 11, the analog form echo signal from the transceiver 1 is converted into digital form echo data by the A / D converter 2, and the echo data from the A / D converter 2 is scanned by one line. Input buffer 3 for each line
The arithmetic circuit 4 intervenes in the course of transfer from the input buffer 3 to the frame memory 5 and performs correlation processing on each echo data stored in the input buffer 3. The data in the frame memory 5 is converted from digital form echo data into analog form echo signals by the D / A converter 6 and is output to the TV monitor 7 in synchronism with the TV monitor 7, which displays a tomographic image of the subject.

Next, referring to FIGS. 1 to 4, the operation of the embodiment configured as described above will be described. In this embodiment, in the case of three-step focus, that is, one scanning line is echo data from three focus areas. The screen synthesizing process will be described by taking as an example a case of being obtained by synthesizing.

In the screen synthesis in the input buffer 3, as shown in FIG. 2, an ultrasonic beam focused in the first focus area is transmitted by the first rate pulse 15, and the reflected wave from the first focus area is transmitted. Only the "L" period of the first enable pulse is received, and the echo data via the A / D converter 2 is written in the input buffer 3. The reflected waves of the second and third focus areas are similarly written in the input buffer 3 to capture the data of one scanning line, and the image data composition of one scanning line is realized.

The input buffer 3 is composed of two line memories. When the writing of data for one scanning line into one line memory is completed, this memory data is brought into a read state, and the read memory data is a frame. It is transferred to the memory 5 and written. At this time, the other line memory is in a write state, and the same processing is repeated. By alternately writing and reading the two line memories for each scanning line in this manner, the echo image data that has been A / D converted is stored in the frame memory 5 without interruption. .

When the memory data in the input buffer 3 is transferred to the frame memory 5, each echo data is calculated by the arithmetic circuit 4.
Correlation processing is performed by. As shown in FIG. 4, in the data array of each echo data A, B, C to End in the input buffer 21, the area between the addresses "2" and "3", that is, the area between the echo data C and D is the first. It is a composite point of the focus area data and the second focus area data. Data is sequentially read from the input buffer 21, for example, when data B is read, the data A and C before and after that are also read,
Image data b0 is obtained by associating the respective data A, B, and C with desired correlation constants α, β, and γ. The formula is as follows.

B0 = αA + βB + γC where α + β + γ = 1 The data obtained by performing the above calculation is stored in the frame memory 25.
Write at position b0. This process is sequentially performed from the addresses "0" to "end" in the input buffer 21, and a one-frame image can be obtained by repeating the number of scanning lines. However, correlation processing of data with no previous data or no subsequent data, that is, address "0"
Only the correlation processing of the data of (A) and "End" (End) follows the following formula. a0 = α ・ 0 + β ・ A + γ ・ B end0 = α ・ PEnd + β ・ End + γ ・ 0

As described above, according to the present embodiment, since one image data is obtained by averaging three echo data, an effect equivalent to that of a low pass filter is obtained and each composite point is blurred. By (gradually approximating), a smooth ultrasonic tomographic image that is easy to see can be obtained.

The present invention is not limited to the above embodiment. In the above-described embodiment, only the correlation processing of three echo data has been described, but the number of echo data for performing this correlation processing may be 3 or more. The above-mentioned correlation constants α, β, γ are normally α = 0.25, β =
Although 0.50 and γ = 0.25 are set, this correlation constant is arbitrary, and the correlation constant does not have to be fixedly set, and may be changed at any time depending on the diagnostic situation. In addition, it goes without saying that various modifications can be made without departing from the scope of the present invention.

[0019]

As described above, according to the present invention, each echo data in the frame memory is obtained by averaging each echo data in the input buffer with a plurality of echo data before and after the same scanning line. Therefore, each echo data in the frame memory has a predetermined correlation with the echo data before and after the same scanning line. Therefore, the images are smoothly connected at each of the above composite points,
An ultrasonic diagnostic apparatus capable of improving ultrasonic image quality can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing an ultrasonic diagnostic apparatus using a combination focus method according to an embodiment of the present invention.

FIG. 2 is a signal waveform diagram showing the timing of transmission / reception according to an embodiment of the present invention.

FIG. 3 is a diagram showing address positions in the frame memory of echo data of three focus areas according to the embodiment of the present invention.

FIG. 4 is a diagram showing a correlation process according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Transceiver, 2 ... Analog / digital converter, 3 ...
Input buffer, 4 ... Arithmetic circuit, 5 ... Frame memory, 6
… Digital / analog converter, 7… TV monitor, 8…
Control circuit, 9 ... CPU, 10 ... Ultrasonic probe, 11 ... Digital scan converter

Claims (1)

[Claims] 1. An ultrasonic probe transmits and receives ultrasonic waves with a plurality of focuses in accordance with ultrasonic transmission rate pulses from an ultrasonic probe, and an ultrasonic image is obtained based on an echo signal obtained by the ultrasonic wave. An image related to ultrasonic scanning is displayed on a predetermined TV through digital scan converter means.
In an ultrasonic diagnostic apparatus for converting a scan image and displaying the same, the digital scan converter means inputs the echo data for each scanning line, and the echo line is inputted from the input buffer means. An ultrasonic diagnostic apparatus comprising: arithmetic means for correlating a plurality of echo data of each echo data with each other; and frame memory means for memorizing the pixel data obtained by the arithmetic means for each frame.