JPH056969Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to an ultrasonic diagnostic device, and more specifically, a method for emphasizing and displaying only the echo signal level in a specific range (hereinafter referred to as echo level). The present invention relates to an ultrasonic diagnostic apparatus having a so-called window processing function.

(B) Conventional technology Generally, in an ultrasound diagnostic device, the level of the echo signal obtained by transmitting ultrasound waves to a subject and receiving the reflected waves is expressed as a γ curve as shown in Fig. 5. (echo level/gray level conversion curve) and displays the image using gradation. However, depending on the subject, the echo level may be concentrated within a specific range. In such a case, the change in gray level corresponding to the change in echo level is insufficient, making it difficult to perform accurate diagnosis.

For example, in many cases, soft organs of the human body, which are areas of interest, are displayed concentrated at intermediate brightness levels,
In order to distinguish between a diseased area and a normal area, doctors need to identify more subtle differences in brightness levels within intermediate brightness levels, but such subtle discrimination is difficult.

For this reason, conventionally, Figure 4A or Figure 4B
A window processing function that sets a specific target range, that is, a window W, in consideration of the average echo level obtained from the diagnosis target site as shown in , and emphasizes and displays the error level within this window W. There is an ultrasonic diagnostic device equipped with the following.

However, even when the window W is set in this way, there are cases where the frequency of a particular echo level is extremely low in a part of the window W, as shown in FIG. 2, for example. However,
Even in such a case, conventionally all echo levels are uniformly emphasized as shown by the straight lines S in Figure 4 A and B. may become insufficient, and subtle differences in echo levels within the window W may not be emphasized sufficiently.

(c) Problems to be solved by the invention The present invention was developed in view of the above points, and its purpose is to sufficiently emphasize slight differences in echo levels within a window. do.

(d) Means for solving the problem In order to achieve the above-mentioned purpose, the present invention creates a histogram of the echo level distribution within the window of the original image based on the echo signal from the image memory, and A γ curve is created based on the γ curve, and the echo level from the image memory is converted to a gray level suitable for image display and output using this γ curve, that is, contrast equalization is performed. .

(e) Effects Therefore, with the present invention, contrast equalization can be performed to sufficiently emphasize the frequently occurring echo levels within the window, and it is possible to sufficiently emphasize minute echo level differences within the window. It becomes possible to emphasize

(F) Embodiments Examples of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram of one embodiment of the present invention. In the figure, 1 is an ultrasonic probe that transmits ultrasonic waves to a subject (not shown), receives the reflected waves, and outputs a corresponding echo signal; It also amplifies and amplifies the echo signal output from the ultrasonic probe 1.
3 is an A/D converter that digitizes the echo signal from the wave transmitting/receiving circuit 2; 4 is an image memory that stores the digitized echo signal; 5 is an echo level output from the image memory 4; For γ-conversion as a conversion circuit that converts it into a gray level and outputs it to the display circuit 6 as described later.
RAM 7 is a CRT for displaying images.

The ultrasonic diagnostic apparatus of this embodiment includes a histogram creation circuit 8 that creates a histogram of the echo level distribution of the original image within a specific echo level range, that is, within a window, based on the echo signal from the image memory 4; A quantization circuit 9 that creates and outputs an echo level/gray level conversion curve (γ curve) for emphasizing frequently occurring echo levels and performing optimal quantization based on the histogram data from the histogram creation circuit 8; and a control circuit 10 for controlling. Histogram creation circuit 8, quantization circuit 9 and control circuit 1
0 is realized by, for example, a microcomputer.

The histogram creation circuit 8 creates a histogram of the echo level distribution of the original image within the window W, as shown in FIG. 2, for example, based on the echo signal from the image memory 4. Based on the histogram shown in FIG. 2, the quantization circuit 9 performs echo level graying for optimal quantization (contrast equalization) so that frequently occurring echo levels are sufficiently emphasized within the window W. A level conversion curve, i.e., a γ curve, is created as shown in Figure 3 for γ-conversion.
Output to RAM5.

The operation of the ultrasonic diagnostic apparatus of the present invention having the above configuration will be explained. First, a drive signal is given to the ultrasound probe 1 from the wave transmitting/receiving circuit 2 . The ultrasonic probe 1 is excited by this drive signal and transmits ultrasonic waves to the subject. The reflected wave from the subject is received by the ultrasound probe 1 again and output to the wave transmitting/receiving circuit 2 as a corresponding echo signal. The transmitter/receiver circuit 2 amplifies and amplifies the echo signal from the ultrasound probe 1.
The signal is detected and output to the A/D converter 3. This A/D
The echo signals digitized by the converter 3 are sequentially stored in a predetermined storage area of the image memory 4.

The echo signal in the image memory 4 is applied to a histogram creation circuit 8, a histogram of the echo level distribution of the original image within the window W is created, and the histogram is applied to the quantization circuit 9. This window W
is input into the control circuit 10 by the operator in advance. In this histogram creation circuit 8, for example,
A histogram as shown in FIG. 2 is created. In the quantization circuit 9, in order to perform optimal quantization based on the histogram shown in FIG. 2, a γ curve shown in FIG. 3 is created to emphasize the frequently occurring echo level ranges a and b. γ-conversion RAM
given to 5.

Further, the echo signals from the image memory 4 are sequentially read out, subjected to contrast equalization based on the γ curve, and given to the display circuit 6, and after predetermined signal processing, are displayed on the CAT7. .

In this way, since frequently occurring echo levels are emphasized in the window W, minute differences in echo levels can be sufficiently emphasized, allowing precise diagnosis.

(g) Effects of the invention As described above, according to the invention, the echo signals from the ultrasound probe are written into the image memory, and the echo signals from the image memory are sequentially read out to emphasize the echo signal level in a specific range. an ultrasonic diagnostic apparatus equipped with a window processing function for displaying images on a display device; , a quantization circuit that creates a conversion curve (γ curve) for performing contrast equalization to emphasize frequently occurring echo signal levels based on the histogram from the histogram creation circuit; and a conversion circuit that converts the echo signal level from the image memory into a gray level suitable for image display based on the conversion curve and outputs the converted signal, thereby emphasizing frequently occurring echo levels in the specific range. Therefore, it is possible to sufficiently emphasize minute differences in echo levels, enabling precise diagnosis.

For example, soft organs of the human body, which are areas of interest, are generally displayed concentrated at intermediate brightness levels;
In the present invention, the area with high luminance distribution, therefore,
Since luminance changes at intermediate luminance levels are emphasized, subtle differences between a lesion and a normal region in the region of interest can be easily distinguished.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention;
The figure shows a histogram of the echo signal level distribution within the window of the original image, FIG. 3 shows the conversion curve (γ curve) of the embodiment of FIG. 1, and FIGS.
The figure is a diagram showing a conversion curve (γ curve) of a conventional example. 1... Ultrasonic probe, 4... Image memory, 5...
...RAM for γ-conversion, 8... histogram creation circuit, 9... quantization circuit.

Claims (1)

[Scope of claim for utility model registration] Echo signals from an ultrasonic probe are written into an image memory, and the echo signals from this image memory are sequentially transmitted.
In an ultrasonic diagnostic apparatus equipped with a window processing function that reads and emphasizes an echo signal belt in a specific range and displays it on a display, the echo signal level of the original image within the specific range is determined based on the echo signal from the image memory. A histogram creation circuit that creates a histogram of a distribution, and an echo level/gray level conversion curve (γ
and a conversion circuit that converts the echo signal level from the image memory to a gray level suitable for image display based on the conversion curve from the quantization circuit and outputs the gray level. An ultrasonic diagnostic device featuring: