JP2000051211A - Ultrasonic diagnostic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make obtainable a clear diagnostic picture which is uniformly high in definition from the shallow part of a subject through to its deep part by providing a dynamic enhancer temporally varying the degree of edge enhancing processing concerning an echo signal obtained based on the transmission/ reception wave of ultrasonic beams. SOLUTION: Ultrasonic waves are transmitted and received by an ultrasonic probe 1 and an echo signal obtained based on this wave is phase-synchronized by a beam former 2 to output an echo signal corresponding to each ultrasonic beam. Namely, concerning the beam-formed echo signal outputted from the beam former 2, a frequency pass-band is temporally varied by a dynamic filter 3 to execute filtering processing. In addition, the echo signal is detect-processed by a detecting circuit 4 and inputted to the dynamic enhancer 5 to temporally vary the degree of edge enhancing processing. In addition, the echo signal is sent to a scan-converter 6 to be stored as picture data and to be outputted as the diagnostic picture to a monitor 7.

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 echo signal processing technique for creating a diagnostic image from an echo signal obtained based on the transmission and reception of an ultrasonic beam.

[0002]

2. Description of the Related Art Generally, the attenuation characteristics of an ultrasonic echo change in accordance with the depth in a subject. That is, there is little attenuation in the shallow part, so that there are many high frequency components, and in the deep part, there are many low frequency components due to the attenuation. Therefore, if only echo signals of the same frequency component are always extracted, an appropriate image cannot be obtained.

Therefore, in the prior art, by using a so-called dynamic filter that changes the frequency pass band of the echo signal in accordance with the depth, an echo signal having an excellent S / N ratio without being affected by the depth is always obtained. I am getting it.

Further, in the prior art, an echo signal passed through a dynamic filter is subjected to edge enhancement.
In some cases, (edge enhancement) processing is performed to increase the sharpness of the outline so that the image becomes clear.

[0005]

However, in the prior art, the degree of edge enhancement processing is always the same with respect to the input echo signal regardless of the depth of the subject along the transmission / reception direction of the ultrasonic beam. It is configured to work.

In such conventional edge enhancement processing, since the frequency component of the echo signal becomes lower particularly at a deeper portion, the sharpness of the outline of the image also becomes lower, and the image becomes difficult to see.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is desirable to change the degree of edge enhancement processing for an echo signal based on an ultrasonic beam in accordance with the depth at which it can be obtained. It is another object of the present invention to obtain a diagnostic image with higher sharpness than before.

[0008]

The present invention adopts the following constitution in order to solve the above-mentioned problems.

That is, the present invention includes a dynamic enhancer for temporally changing the degree of edge enhancement processing on an echo signal obtained based on transmission and reception of an ultrasonic beam.

As a result, the degree of the edge enhancement processing is changed in accordance with the depth, so that a clear diagnostic image with high sharpness can be obtained uniformly from the shallow part to the deep part of the subject as compared with the related art.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In this embodiment, a sector scanning type ultrasonic diagnostic apparatus is assumed, but the present invention is not limited to this.
It is also applicable to convex type and linear scanning type.

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

In FIG. 1, reference numeral 1 denotes an ultrasonic probe for extracting an echo signal based on transmission and reception of ultrasonic waves, and is constituted by, for example, arranging a plurality of transducers in an array. 2
Is a beamformer for phase-combining (beamforming) echo signals obtained by each transducer constituting the ultrasonic probe 1 and outputting an echo signal corresponding to each ultrasonic beam. The beamformer 2 also includes a circuit for A / D converting the echo signal.

Reference numeral 3 denotes a dynamic filter for changing the frequency pass band of the echo signal for each one of the ultrasonic beams phase-combined by the beamformer 2 with time, and reference numeral 4 denotes an echo passed through the dynamic filter 3. This is a detection circuit that performs detection processing on a signal.

Numeral 5 denotes a dynamic enhancer for temporally changing the degree of edge enhancement processing on the echo signal. This dynamic enhancer 5 comprises a control circuit 10 and a filter coefficient RAM 1 as shown in FIG.
2, and an FIR filter.

The control circuit 10 switches the read address of the filter coefficient based on the address information in the transmitting and receiving directions of the ultrasonic beam. The filter coefficient RAM 12 stores filter coefficients corresponding to the address information from the control circuit 10, and reads out the filter coefficients according to the address designation from the control circuit 20. Further, the FIR filter 14 performs an edge enhancement process by executing a differential operation or the like on the echo signal data using the filter coefficient read from the filter coefficient RAM 12.

Reference numeral 6 denotes a scan converter for creating image data based on echo signal data, and reference numeral 7 denotes a monitor such as a CRT or LCD for displaying image data.

Next, the operation of the ultrasonic diagnostic apparatus having the above configuration will be described.

Ultrasonic waves are transmitted and received by the ultrasonic probe 1,
The echo signal obtained based on this is converted to a beamformer 3
And the echo signals corresponding to the respective ultrasonic beams are output. Then, the following processing is performed on the echo signal corresponding to each ultrasonic beam.

First, the echo signal after beamforming output from the beamformer 2 is subjected to a filtering process in which the frequency pass band is temporally changed by the dynamic filter 3. This means that the frequency of the echo signal is selected according to the depth of the subject along the direction of transmission and reception of the ultrasonic beam.

The echo signal that has passed through the dynamic filter 3 is subjected to detection processing in a detection circuit 4,
Input to the dynamic enhancer 5.

The dynamic enhancer 5 temporally changes the degree of edge enhancement processing on the echo signal. That is, the degree of the edge enhancement processing of the echo signal is changed according to the depth of the subject along the transmission / reception direction of the ultrasonic beam.

More specifically, the control circuit 10 switches the read address of the filter coefficient based on the address information in the transmitting and receiving directions of the ultrasonic beam. In response, the filter coefficients corresponding to the address information are read out from the filter coefficient RAM 12, and the FIR filter 14
Given to. The FIR filter 14 performs an edge enhancement process by performing a differential operation or the like on the echo signal data based on the filter coefficient given from the RAM 12. Therefore, for the echo signal at the portion corresponding to the shallow portion of the subject, the frequency component is high, so that the edge enhancement processing is executed loosely. The processing will be executed.

The echo signal edge-enhanced by the dynamic enhancer 5 is sent to the scan converter 6 and stored as image data. The echo signal is finally read out at a scanning speed corresponding to the TV display and diagnosed on the monitor 7. Output as an image.

Therefore, a diagnostic image with high sharpness can be obtained uniformly from the shallow part to the deep part of the subject.

[0026]

According to the present invention, the degree of edge enhancement processing of an echo signal is changed in accordance with the depth of a subject along the direction of transmission and reception of an ultrasonic beam.
A clear diagnostic image with high sharpness can be obtained uniformly from the shallow part to the deep part of the subject.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a specific configuration of a dynamic edge enhancer used in the apparatus of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ultrasonic probe, 2 ... Beam former, 3 ... Dynamic filter, 5 ... Dynamic enhancer, 6 ... Scan converter.

Claims (1)

[Claims] 1. An ultrasonic diagnostic apparatus comprising: a dynamic enhancer for temporally changing a degree of edge enhancement processing on an echo signal obtained based on transmission / reception of an ultrasonic beam.