JP3951748B2 - Ultrasonic diagnostic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus having a function of compressing and expanding image data obtained by a color Doppler method.
[0002]
[Prior art]
An ultrasonic diagnostic apparatus enters an ultrasonic beam into a subject (subject's body) and receives a reflected wave to obtain a tomographic image in the subject, or uses a Doppler phenomenon to obtain blood. It detects the velocity of the flow. In the color Doppler method, color mapping is performed based on data such as blood flow velocity, power, and dispersion obtained by the Doppler method, and color is displayed by palette conversion to display a color image on a B-mode tomographic image.
[0003]
The demand for digital storage of these still images or moving images has been rapidly increasing in the field of ultrasonic diagnostic apparatuses in recent years. Conventionally, in general, in order to reduce the recording capacity, data is stored using a lossy compression method such as JPEG or MPEG. When transferring image data via a network, it is usual to use a lossy compression method such as JPEG or MPEG.
[0004]
A method for compressing / decompressing image data obtained by the color Doppler method is conventionally configured as shown in FIG. The B-mode image palette conversion unit 21 performs palette conversion on the B-mode image data using the B-mode image palette data, and converts the data into RGB data. Similarly, the color Doppler image palette conversion unit 22 performs palette conversion on the color Doppler image data using the color Doppler image palette data to obtain RGB data. In this specification, palette conversion is used in a broad sense including gamma conversion and post-process conversion. These palette-converted B-mode image data and color Doppler image data are combined by the image combining unit 23, then compressed by the MPEG image compression unit 24, stored in a recording device, or transmitted via a communication network. To do.
[0005]
On the reproduction side or the reception side, the reproduced or received compressed image data is expanded / restored by the MPEG image expansion unit 25, sent to the image display unit 26, and displayed on a display device or the like.
[0006]
[Problems to be solved by the invention]
However, the conventional ultrasonic diagnostic apparatus does not have sufficient color reproducibility in color Doppler images, and may be displayed in a color different from the original image through a compression / decompression process, leading to misdiagnosis. It was a problem because it was dangerous.
[0007]
In an irreversible compression method such as JPEG or MPEG, generally, image data is converted into luminance-color difference, and the color difference is roughened compared to luminance or a component having a high spatial frequency is cut. For this reason, there is a shortage of information on hue in particular, and when it is restored, a color that does not exist in the original image called pseudo color may appear. When a color Doppler image is compressed and expanded, the amount of information as a hue is greatly lost, and the resolution is easily lost. For this reason, an image representing blood flow is displayed in a direction different from the original or a color of the flow velocity, and there is a risk of misdiagnosis if a diagnosis is made by observing this image.
[0008]
In view of the above, the present invention compresses and decompresses data so that an expanded / restored ultrasonic image does not become a color different from the original color even in the case of an irreversible compression method such as JPEG or MPEG. An object of the present invention is to provide an ultrasonic diagnostic apparatus which is improved so as to prevent misdiagnosis.
[0009]
[Means for Solving the Problems]
To achieve the above object, a color Doppler ultrasonic diagnostic apparatus according to the invention, to compress the B-mode image compression unit for compressing the B-mode image data before the pallet conversion, before the pallet converting the color Doppler image data An image compression unit, a B-mode image expansion unit that expands / restores compressed B-mode image data, a color Doppler image expansion unit that expands / restores compressed color Doppler image data, and an expanded / restored image A B-mode image palette conversion unit that converts the B-mode image data using the B-mode image palette data, and a color Doppler image palette data for the developed and restored color Doppler image data. Pallet conversion unit for color Doppler image for palette conversion, B-mode image data and color Doppler image for palette conversion Characterized in that it comprises an image synthesizing unit for image synthesis and data.
[0010]
Color Doppler image data is compressed before palette conversion, and palette conversion is performed after decompression and decompression of the compressed data. For this reason, image data to be compressed is only luminance data, and hue data is not included, so that the compression rate can be increased. In addition, since the hue data does not fluctuate due to the compression, the generation of pseudo colors at the time of development / restoration can be suppressed. Furthermore, since compression can be performed with a high resolution, a high spatial resolution can be maintained for a color Doppler image. Also for B-mode images, the amount of information has been lost because compression is performed in a state where the linearity is lost due to gamma conversion. However, since the compression is performed before the conversion, the loss of information amount is reduced. Can be reduced.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, in the ultrasonic diagnostic apparatus according to the present invention, both B-mode image data and color Doppler image data are compressed / decompressed before the palette conversion, and the palette conversion is performed on the expanded / restored data. After that, these image data are synthesized. Therefore, two MPEG image compressing units 11 and 12 and two MPEG image developing units 13 and 14 are provided.
[0012]
The MPEG image compression unit 11 is for compressing B-mode image data before palette conversion, whereas the MPEG image compression unit 12 is for compressing color Doppler image data before palette conversion. ing. The B-mode image data compressed by the B-mode image MPEG image compressing unit 11 and the color Doppler image data compressed by the color Doppler image MPEG image compressing unit 12 are stored in the recording device or transmitted via the communication network. Or
[0013]
When these compressed data are reproduced from the recording apparatus or received via a communication network, the compressed B-mode image data is expanded / restored by the MPEG image expansion unit 13, and the compressed color Doppler image data is converted by the MPEG image expansion unit. 14 is expanded and restored.
[0014]
On the other hand, the palette data for B-mode images and the palette data for color Doppler images are recorded / reproduced or transmitted / received without going through compression / decompression processes. The B-mode image palette converting unit 15 performs palette conversion on the developed and restored B-mode image data using the B-mode image palette data. In addition, the color Doppler image palette conversion unit 16 performs palette conversion on the color Doppler image data developed and restored using the color Doppler image palette data.
[0015]
The B-mode image data and the color Doppler image data thus colored and converted into RGB data are combined in the image combining unit 17 and then sent to the image display unit 18 for display on a display device or the like.
[0016]
As described above, both the B-mode image data and the color Doppler image data are compressed / decompressed before the palette conversion, and the palette conversion is performed on the decompressed / restored data, and then these image data are synthesized. The B-mode image data and the color Doppler image data are independently compressed as they are and are also independently developed, so that the accuracy in the compression / decompression process can be further increased. In a compression method such as MPEG, both data are processed as luminance data, so that it is possible to prevent the occurrence of pseudo color without causing a problem of hue information loss. In addition, the spatial resolution is not reduced.
[0017]
In the above description, the compression units 11 and 12, the expansion units 13 and 14, the palette conversion units 15 and 16, and the image composition unit 17 are described as hardware. Of course, it is also possible to realize it. In the above description, the compression / decompression is MPEG, but it goes without saying that other lossy compression methods such as JPEG can be adopted.
[0018]
【The invention's effect】
As described above, according to the ultrasonic diagnostic apparatus of the present invention, both B-mode image data and color Doppler image data are compressed / decompressed before pallet conversion, and pallet conversion is expanded / restored data. Since these image data are then synthesized, the color Doppler image after development, restoration, and image synthesis is suppressed from generating false colors, and the spatial resolution is not reduced. The amount is not lost and misdiagnosis can be prevented.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the present invention.
FIG. 2 is a block diagram showing a conventional example.
[Explanation of symbols]
11 B-mode image MPEG image compression unit 12 Color Doppler image MPEG image compression unit 13 B-mode image MPEG image expansion unit 14 Color Doppler image MPEG image expansion unit 15, 21 B-mode image palette conversion unit 16, 22 Color Doppler image palette conversion unit 17, 23 Image composition unit 18, 26 Image display unit 24 Composite image MPEG image compression unit 25 Composite image MPEG image expansion unit

Claims (1)

And B-mode image compression unit for compressing the pallet conversion before B-mode image data, and a color Doppler image for compressing section for compressing the color Doppler image data before the pallet conversion and development and restore the compressed B-mode image data A B-mode image expansion unit, a color Doppler image expansion unit that expands / restores compressed color Doppler image data, and a palette that uses B-mode image palette data for the expanded / restored B-mode image data A B-mode image palette conversion unit for converting, a color Doppler image palette conversion unit for converting color Doppler image palette data using the color Doppler image palette data, and a B-mode image for palette conversion And an image synthesizing unit that synthesizes data and color Doppler image data. Cross-sectional devices.

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