JP3602025B2 - Ultrasound diagnostic equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ultrasonic diagnostic apparatus, and more particularly, to an ultrasonic diagnostic apparatus that displays a Doppler image.
[0002]
[Prior art]
When forming a color Doppler image (two-dimensional Doppler image), it is necessary to transmit and receive an ultrasonic pulse a plurality of times (for example, 10 times) for each sound ray (beam direction) in order to improve measurement accuracy. Therefore, due to the relationship with the frame rate, it is impossible to increase the number of sound rays constituting the color Doppler image. That is, the sound ray interval is larger than the two-dimensional tomographic image (B-mode image). Therefore, data is supplemented by interpolation processing between sound rays.
[0003]
[Problems to be solved by the invention]
However, even if the interpolation processing is performed, it is difficult to increase the resolution because of the originally small number of sound rays, and therefore, an unconnected unnatural image portion is likely to occur. For example, when observing a color Doppler image, a mosaic or blocky portion may occur, which is caused by insufficient sound rays as described above. In particular, when electronic sector scanning is applied, the Doppler image tends to be mosaic inevitably because the sound ray interval greatly increases in the deep portion of the fan-shaped scanning surface. On the other hand, if the number of sound rays is increased or the number of transmissions per sound ray is reduced in order to avoid this, another problem of lowering the frame rate or lowering the image quality occurs. This problem is remarkable in a color Doppler image, but the same problem occurs in other images.
[0004]
The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to improve the image quality of an ultrasonic image.
[0005]
It is another object of the present invention to adaptively correct unnatural portions in an ultrasound image, thereby forming a natural ultrasound image.
[0006]
[Means for Solving the Problems]
(1 )Book According to the invention, a window is provided on an ultrasonic image over a plurality of sound rays. Determine Window setting means, Before or after setting the window, means for performing a normalization process to classify each original data in the ultrasound image, In the window After normalization A comparison pattern table storing a plurality of comparison patterns to be compared with the actual pattern of the data group; and After normalization A pattern determination unit that determines a specific comparison pattern that matches the actual pattern of the data group; a correction condition table storing a plurality of correction conditions corresponding to the plurality of comparison patterns; and A specific correction condition corresponding to a specific comparison pattern is determined, and according to the specific correction condition, Original attention data or multiple data And adaptive processing means for performing a correction process on the data.
[0007]
According to the above configuration, a window is set on the ultrasound image and cut out by the window. After normalization The actual pattern for the data group is compared with a plurality of comparison patterns. According to a specific correction condition corresponding to a specific comparison pattern that matches the actual pattern, the actual pattern in the window is Original attention data or multiple data Is adaptively executed. Therefore, considering the characteristics of the ultrasonic image, Comparison Registered as a pattern and Comparison By defining the correction conditions according to the pattern, the image can be corrected automatically and adaptively.
[0008]
The above window has a certain extent based on the pixel of interest Two-dimensional Area. At a certain window position, the pixel of interest (Attention data) Only day Osamu Ta Correction may be performed, but multiple pixels in the window containing the pixel of interest (Multiple data) About Day Osamu Ta Correction may be performed. Preferably, the window position is scanned on the ultrasonic image, and at each window position, the actual pattern and the comparison pattern are compared.
[0009]
A plurality of comparison pattern sets (and a plurality of correction condition sets) are prepared, and either automatically or manually according to measurement conditions (e.g., ultrasonic frequency, measurement area size, and patient characteristics). It is desirable that the comparison pattern set (and the correction condition set) can be selected and used.
[0010]
The pair consisting of the comparison pattern and the correction condition can be managed together or separately. When separately managed, it is desirable to use an identifier or the like to clarify the correspondence between them. Correction conditions corresponding to the comparison pattern can be directly described in a file defining the comparison pattern.
[0011]
The above processing means can be constituted by hardware or software as a logic circuit, but when real-time processing is considered, the former is appropriate.
[0012]
(2) Preferably, the ultrasonic image is a Doppler image constituted by Doppler data. Since the Doppler image tends to be a mosaic image for the above-described reason, the effect of the processing according to the present invention is remarkable.
[0013]
In a desirable mode of the present invention, a window setting means for setting a window over a plurality of sound rays on an ultrasound image as a Doppler image, and before or after setting the window, each original Doppler data in the Doppler image Means for executing a normalization process for classifying the data, a comparison pattern table storing a plurality of comparison patterns to be compared with the actual patterns of the data group after the normalization process in the window; and A pattern determination unit that determines a specific comparison pattern that matches the actual pattern of the data group after the normalization processing in the window, a correction condition table storing a plurality of correction conditions corresponding to the plurality of comparison patterns, From among the plurality of correction conditions, a specific correction condition corresponding to the specific comparison pattern is determined. According constant of adjustment conditions, wherein the adaptive processing means for performing a correction processing on the original target Doppler data or Doppler data within said window, If there is a boundary in the window, one side and the other side of the boundary Original A wrap determining means for determining the presence or absence of a fold based on Doppler data is provided, and the correction processing is performed in consideration of the presence or absence of the wrap.
[0014]
According to this configuration, it is possible to focus on a folding phenomenon peculiar to the Doppler image, and to perform a process corresponding to the folding phenomenon. For example, the correction process can be performed as long as the return does not occur. Alternatively, it is possible to express the fold remarkably or make the fold less noticeable. For accurate diagnosis, it is often desirable to clearly indicate the return.
[0015]
In a desirable mode of the present invention, a window setting means for setting a window over a plurality of sound rays on an ultrasonic image, and a standard for classifying each original data in the ultrasonic image before or after setting the window. Means for executing a normalization process; a comparison pattern table storing a plurality of comparison patterns to be compared with the actual patterns of the data group after the normalization process in the window; Pattern determination means for determining a specific comparison pattern that matches the actual pattern of the data group after the normalization processing, a correction condition table storing a plurality of correction conditions corresponding to the plurality of comparison patterns, and the plurality of corrections From the conditions, a specific correction condition corresponding to the specific comparison pattern is determined, and according to the specific correction condition, Wherein the adaptive processing means for performing a correction processing on the original target data or the data in the serial window, The plurality of comparison patterns include a comparison pattern for corner portion determination, and the plurality of correction conditions include a correction condition corresponding to the comparison pattern for corner portion determination, A correction condition for alleviating the sharpness is included.
[0016]
In particular, in the case of a Doppler image, a mosaic-shaped portion is likely to occur, and such a portion is likely to cause a sense of incongruity. If the corner portion is determined and the corner portion is rounded, the mosaic can be reduced to make it closer to a natural Doppler image. In addition, it is desirable to prepare various types of comparison patterns other than the above, such as a comparison pattern for whisker determination and a comparison pattern for black spot determination.
[0017]
Preferably, the plurality of comparison patterns include a comparison pattern for determining a convex corner portion, and the plurality of correction conditions include a correction pattern corresponding to the comparison pattern for determining a convex corner portion. The condition includes a correction condition for alleviating the sharpness of the convex corner portion. Preferably, the plurality of comparison patterns include a comparison pattern for concave corner portion determination, and the plurality of correction conditions include a correction condition corresponding to the comparison pattern for concave corner portion determination. In addition, a correction condition for alleviating the sharpness of the concave corner portion is included.
[0018]
It is desirable to prepare four types of comparison patterns for judging the convex corner portion and the concave corner portion, for example, corresponding to the four corners of the rectangle.
[0019]
Desirably, the correction condition for alleviating the sharpness of the corner portion includes a condition for performing weighting according to a distance and an azimuth from a vertex of the corner portion. In this case, it is desirable to set the weighting conditions according to the shape of the window and according to the sound ray structure forming the ultrasonic image. For example, when setting a rectangular window in which the length in the depth direction (r direction) is relatively long and the length in the beam scanning direction (φ direction) is relatively short, the effect of weighting in the depth direction is set. Can be set to appear larger.
[0020]
In a desirable mode of the present invention, a window setting means for setting a window over a plurality of sound rays on an ultrasonic image, and a standard for classifying each original data in the ultrasonic image before or after setting the window. Means for executing a normalization process; a comparison pattern table storing a plurality of comparison patterns to be compared with the actual patterns of the data group after the normalization process in the window; Pattern determination means for determining a specific comparison pattern that matches the actual pattern of the data group after the normalization processing, a correction condition table storing a plurality of correction conditions corresponding to the plurality of comparison patterns, and the plurality of corrections From the conditions, a specific correction condition corresponding to the specific comparison pattern is determined, and according to the specific correction condition, Wherein the adaptive processing means for performing a correction processing on the original target data or the data in the serial window, The plurality of comparison patterns include a comparison pattern for beard portion determination, and the plurality of correction conditions include a correction condition corresponding to the comparison pattern for beard portion determination, A correction condition for alleviating the sharpness is included.
[0021]
Preferably, the correction condition for alleviating the sharpness of the whisker portion includes a condition for performing weighting according to the distance from the vertex of the whisker portion.
[0022]
(3) In order to achieve the above object, according to the present invention, a window is set over a plurality of sound rays while scanning a window position on a Doppler image. Determine Window setting means, Doppler Construct an image Original Classify each Doppler data into either positive, negative or zero category Execute the normalization process Classification means, and After normalization Comparing means for determining a comparison category pattern that matches the actual category pattern for the data group; and Original Doppler data or multiple Doppler data Adaptive processing means for performing correction processing on Only, on the Doppler image, the correction process is adaptively performed only on a specific portion where the actual category pattern matches the comparison category pattern. It is characterized by the following.
[0023]
According to the above configuration, the category of each data is determined, the actual category pattern for the data group in the window is compared with a plurality of comparison category patterns, and the correction corresponding to the specific comparison category pattern matching the actual category pattern is performed. According to the requirements, Featured Doppler data or multiple Doppler data Is corrected. Therefore, since pattern comparison can be performed after data classification, the processing load for that can be reduced, and the processing speed can be improved. In determining the category of data, generally, two thresholds of a positive threshold and a negative threshold (or one dual-purpose threshold considering the sign) are used.
[0024]
Preferably, the comparison category pattern includes a pattern for determining at least one of a corner portion and a beard portion having an unnatural sharpness as a Doppler image, and the correction condition includes the corner portion and the beard. A correction condition for reducing the sharpness of at least one of the portions is included. Preferably, the correction condition for alleviating the sharpness is set in the window. At This is a condition for performing gradation processing by weighting. By this gradation processing, a natural Doppler image can be formed.
[0025]
Preferably, when a boundary is included in the window, one side and the other side of the boundary are included. Original A wrap determining means for comparing the Doppler data with each other to determine the presence or absence of a wrap; At A gradation process based on the weighting is performed.
[0026]
Desirably, the turn-back determining means includes the one side and the other side. Original Means for calculating the difference between the Doppler data; means for comparing the difference between the Doppler data with a predetermined value; and means for determining the presence or absence of a fold based on the result of the comparison.
[0027]
It is desirable to compare the Doppler data in a complex data format. According to such a configuration, the weighting standard can be obtained by dividing the argument (phase difference) between two data by a predetermined number.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.
[0029]
FIG. 1 shows the concept of image processing executed in the ultrasonic diagnostic apparatus according to the present invention.
[0030]
The scanning surface 8 is formed, for example, by scanning the ultrasonic beam 9 with an electronic sector. Here, the symbol r indicates the depth direction, and the symbol φ indicates the scanning direction. FIG. 1 shows such a fan-shaped scanning surface 8, but the present invention is naturally applicable to various scanning methods such as electronic linear scanning.
[0031]
A plurality of data are acquired in the scanning plane 8 by the scanning of the ultrasonic beam 9 as described above, and an original image 10 is configured by the data. In FIG. 1, the original image 10 is represented as a rectangular area for convenience. The original image 10 is, for example, a Doppler image.
[0032]
The original image 10 is subjected to a ternarization process, that is, each data (Doppler data) constituting the original image 10 is normalized to a positive, negative, or zero value. That is, the ternary image 12 is created according to the sign of the speed information included in the Doppler data.
[0033]
A window 14 having a predetermined size is set for the ternary image 12, and a data group in the window 14 is cut out. This is represented as data block 16 in FIG. Incidentally, the window 14 is scanned with respect to the ternary image 12, and a data group in the window 14 is extracted at each scan position.
[0034]
Incidentally, the data block 16 is a fixed area centered on the target pixel 16A, and in the present embodiment, is a block having a size of 5 lines (sound rays) × 19 pixels.
[0035]
A data pattern included in the data block 16, specifically, a pattern formed by each data having a positive, negative, or 0 value is compared with a plurality of comparison patterns 20. Here, the plurality of comparison patterns 20 constitute a comparison pattern set 18.
[0036]
Each comparison pattern 20 is for specifying an unnatural data pattern as an ultrasonic image, and is a pattern for specifying, for example, a mosaic-like image portion or an image portion having a beard.
[0037]
When a specific comparison pattern in the plurality of comparison patterns 20 matches the actual pattern included in the data block 16, a correction condition corresponding to the comparison pattern is specified, and the window 14 in the original image 10 is specified according to the correction condition. Correction processing is performed on the data group in the table. That is, for example, when a mosaic-like image portion exists, such a mosaic-like image portion is subjected to a correction process so as to become a natural image as an ultrasonic image.
[0038]
Therefore, according to the above-described image processing, an image pattern to be subjected to image processing is registered in advance as a comparison pattern 20, and if an appropriate correction condition is defined for each comparison pattern, the original pattern can be obtained. It is possible to specify an unnatural image portion over the entire image 10 and automatically perform necessary correction processing only on such unnatural image portion.
[0039]
In particular, according to the above-described image processing, correction is not always performed over the entire area of the original image 10, but correction processing can be adaptively performed only on a specific portion in the original image 10. There is an advantage that the image quality can be locally improved without deteriorating the image quality.
[0040]
Therefore, especially when the above-described image processing is applied to the ultrasonic Doppler image, a good image quality can be obtained as a result even when the number of sound rays is small.
[0041]
FIG. 2 is a schematic diagram illustrating the overall configuration of the ultrasonic diagnostic apparatus according to the present embodiment.
[0042]
The probe 30 transmits and receives an ultrasonic pulse. The probe 30 is used, for example, in contact with a body surface or inserted into a body cavity.
[0043]
The transmission / reception unit 32 is a circuit that supplies a transmission signal to the probe 30 and performs a predetermined process such as phasing and addition on the reception signal from the probe 30. The transmitting and receiving unit 32 forms a transmission beam and a reception beam.
[0044]
The Doppler processing unit 34 is configured by a quadrature detector, an autocorrelator, and the like, converts a received signal into a complex signal as in a conventional ultrasonic diagnostic apparatus, and performs an autocorrelation operation on the complex signal. This is a circuit for calculating speed information (Doppler data) for each Doppler data. In FIG. 1, the image after such processing is shown as an original image 10. The image processing unit 36 is configured by, for example, a digital scan converter (DSC) or the like, and performs interpolation between sound rays, correlation processing between frames, or conversion of data coordinates from a transmission / reception wave coordinate system to a display coordinate system. This is a circuit that executes various processes. In the present embodiment, the image processing unit 36 has a pattern correction unit 38.
[0045]
The pattern correction unit 38 is a circuit that executes the image processing conceptually shown in FIG. 1, and a specific configuration example will be described later in detail with reference to FIG. The pattern correction unit 38 performs adaptive image processing on each portion of the Doppler image, and as a result, an unnatural image portion included in the Doppler image is corrected.
[0046]
The display 40 displays the Doppler image after the correction. Here, the Doppler image is, for example, a two-dimensional color Doppler image, in which the speed component on the positive side is expressed in red, for example, and the speed component on the negative side is expressed in blue, for example. The luminance value corresponds to the magnitude of each speed.
[0047]
Of course, the display unit 40 may display a two-dimensional Doppler image superimposed on the B-mode image.
[0048]
FIG. 3 shows a specific configuration example of the pattern correction unit 38 shown in FIG.
[0049]
The original image data is input to the ternarization unit 46 via the window processing unit 42. In this embodiment, the window processing unit 42 includes, for example, four line memories 44. The line memories 44 are connected in series with each other, and each line of Doppler data is stored.
[0050]
The data for five lines in the data block 16 shown in FIG. 1 are input to the ternarization unit 46 one by one in parallel. The ternarization unit 46 is configured by five ternarization circuits 48 in the present embodiment, and each ternarization circuit 48 performs a ternarization process on sequentially input Doppler data. Specifically, based on the sign and the absolute value of each Doppler data, each Doppler data is converted into a positive, negative, or zero value. That is, normalization processing is performed. Here, when the ternarization processing is performed, each Doppler data is compared with a predetermined threshold. Here, two thresholds are set on the positive side and the negative side. One threshold value may be used in consideration of the sign of the data.
[0051]
Each data after the ternarization processing output from the ternarization unit 46 is input to the determination unit 52 via the shift register 50. Here, the determination unit 52 is a circuit that performs comparison between the data pattern in the window after the ternarization processing and a plurality of comparison patterns stored in the comparison pattern table 53. Here, in the comparison pattern table 53, a plurality of data patterns to be subjected to image processing are registered in advance as comparison patterns.
[0052]
If there is no comparison pattern that matches the data pattern in the window, the determination unit 52 outputs a signal to that effect to the correction execution unit 54. In this case, the correction executing unit 54 does not perform the image correction on the window. On the other hand, when the determination unit 52 specifies a comparison pattern that matches the data pattern in the window, the identifier of the comparison pattern is output to the correction execution unit 54.
[0053]
The correction execution unit 54 is a circuit to which original image data is input and adaptively executes a correction process on the data in the window according to the determination result of the determination unit 52. In the present embodiment, only the data of the pixel of interest forming the center point of the window is sequentially input to the correction execution unit 54. Of course, the output from each line memory 40 is provided to the correction execution unit 54 in parallel. It may be. In any case, the correction execution unit 54 temporarily stores data to be corrected in accordance with the determination result of the determination unit 52, that is, data blocks, and performs pattern correction as needed on such a data group. Is executed. Incidentally, the data group in the window is stored, for example, on a buffer 51 provided in the correction execution unit 54. Of course, the pixel data may be corrected for each target pixel by appropriately setting the comparison pattern.
[0054]
A plurality of correction conditions corresponding to a plurality of comparison patterns are stored in the correction condition table 55, and the correction execution unit 54 refers to the correction conditions corresponding to the comparison pattern specified by the determination unit 52, and performs correction. Correction processing is performed on the data group in the window according to the conditions. Specific examples of the processing are shown in FIGS.
[0055]
In the present embodiment, as shown in FIG. 3, the comparison pattern table 53 and the correction condition table 55 are provided separately, but they may be integrated. Further, the correction condition can be defined in the form of a function or an arithmetic expression.
[0056]
The correction execution unit 54 according to the present embodiment includes a return determination unit 57. The return determination unit 57 is a circuit that determines whether there is a return phenomenon that is a phenomenon unique to the ultrasonic Doppler image. Then, the correction executing unit 54 performs an appropriate image correction according to the presence or absence of the return. For example, if no wrapping occurs as described below, the gradation processing is executed as it is according to the registered correction condition. , To make it stand out. Thereby, when observing the ultrasonic Doppler image, the aliasing phenomenon can be more easily specified, and as a result, the accuracy of disease diagnosis can be improved.
[0057]
A plurality of comparison pattern sets and correction condition sets are stored in the comparison pattern table 53 and the correction condition table 55, and any appropriate comparison pattern set and correction condition are set according to measurement conditions such as transmission / reception conditions and patient characteristics. A condition set may be selected and used. The selection of such a set can be made manually or automatically, for example, such switching is performed by control signals 60, 62, 64 from the main controller.
[0058]
By the image processing by the correction execution unit 54 as described above, an unnatural image portion on the Doppler image is adaptively corrected, and as a result, corrected image data is obtained. Such corrected image data is output to the display unit 40 shown in FIG.
[0059]
In the image processing section 36, the above-described image correction processing can be performed either before or after the coordinate conversion. In addition, it can be performed both before and after inter-line interpolation and inter-frame correlation.
[0060]
FIG. 4 shows an example of the correction processing of the pattern correction section 38 shown in FIG. For example, in the case where an unnatural high luminance portion like a beard exists in the original image shown in (A), by performing weighting processing on the tip of the beard as shown in (B), for example, as shown in (C). Such a display image can be obtained. That is, if appropriate weighting is performed according to the distance to the tip of the beard or the distance from the tip, the sharpness of the beard can be rounded. In FIG. 4, each numeral represents a pixel value, and here, the pixel value I can take a value of 0 or more and 24 or less. In FIG. 4, pixel values other than the whisker-like portion in the window are assumed to be 0, for example.
[0061]
FIGS. 5 and 6 conceptually show an example of image correction processing for a concave corner portion and a convex corner portion.
[0062]
First, as shown in FIG. 5A, when a concave corner exists in the original image, such a pattern is specified by comparison with a comparison pattern. By the way, in FIG. 5, reference numeral 100 denotes a data area constituting a corner portion, and here, for example, 24 is given as a pixel value. This pixel value 24 is used as a reference value when applying a correction condition. Reference numeral 102 denotes an image portion serving as a background. For example, the pixel value of the image portion serving as a background is 0.
[0063]
When the image portion as shown in FIG. 5A is specified by comparison with the comparison pattern, new data is added to the area surrounded by the concave corner portion as shown in FIG. In this case, as described above, the addition of the data is performed according to the correction condition corresponding to the comparison pattern. Such added data is shown at 104.
[0064]
Here, the pixel values are weighted in accordance with the distance from the apex of the concave corner portion and the azimuth thereof, and a natural display image conceptually shown in (C) is obtained by such weighting. Is possible. Here, reference numeral 106 represents the added image portion.
[0065]
Therefore, if the processing as shown in FIG. 5 is performed, the sharpness of the unnatural concave corner portion on the Doppler image can be reduced and the rounded portion can be rounded, so that there is an advantage that a natural Doppler image can be constructed. .
[0066]
In the example shown in FIG. 5, as shown in FIG. 5 (B), the data interpolation area is extended in the vertical direction, that is, in the line direction in the figure. is there.
[0067]
FIG. 6 shows an example of an image correction process for a convex corner portion. In the original image shown in (A), reference numeral 110 indicates a convex corner portion, and reference numeral 108 indicates a background image portion. Such an image pattern is specified by comparison with a comparison pattern, and the image is corrected according to a correction condition according to the comparison pattern. This is shown in (B). That is, weighting is performed on the pixel value according to the distance and the azimuth of the corner from the vertex. Incidentally, reference numeral 112 indicates a range in which weighting is performed.
[0068]
By such weighting processing, it is possible to obtain a display image as shown in FIG. Here, reference numeral 114 denotes an area after the weighting process is performed on the corner portion.
[0069]
The image processing shown in FIGS. 5 and 6 can be applied to both the Doppler image and the B-mode image. In the Doppler image, in particular, each data has a code. There is a need. In particular, it is necessary to deal with the aliasing phenomenon unique to Doppler images.
[0070]
As described above, the return phenomenon is determined by the return determination unit 57 shown in FIG. 3, and specifically, the return is determined using the method shown in FIG.
[0071]
In FIG. 7, (A) and (B) each show a complex plane for representing Doppler data as a complex signal, (A) shows a state in which there is an aliasing, and (B) Shows a state in which there is no return. In the complex plane, the horizontal axis is the real axis R, and the vertical axis is the imaginary axis I. As is well known, when a complex signal (Doppler data) as an autocorrelation result is represented on a complex plane, it is represented as a vector as shown in FIG.
[0072]
In (A), reference numeral 116 represents a reference value vector as a luminance value of a substantial image data portion, and reference numeral 118 represents a luminance value vector forming a background of the image portion. The phase difference Δθ between the two vectors 116 and 118 is equal to or greater than π, and in this case, it is determined that there is aliasing. That is, it is highly probable that the Doppler data has turned back over the boundary between the image portion and the background. Therefore, in that case, the weighting process is applied to the range of 2π−Δθ. That is, the image is corrected based on the transition of the pixel value within the range. Naturally, in this case, the boundary is prominent, but it emphasizes the folding phenomenon and is useful in diagnosis. Incidentally, FIG. 7A shows the concept of division when the vector from the reference value 116 to the vector 118 of the background luminance value is divided into eight equal parts. Is used as an index of the pixel value at the time of. This will be described in detail later.
[0073]
On the other hand, as shown in FIG. 7B, if the phase difference Δθ between the reference value vector 122 and the background vector 124 is smaller than π, it is determined that there is no aliasing in this case, and the two vectors 122 , 124 are divided into, for example, eight, and weighting is performed using a vector at each division position. Incidentally, the number of divisions can be set to a desired value in accordance with the stage of weighting.
[0074]
Next, with reference to FIGS. 8 to 33, a specific processing example of the reentrant portions and the protruding portions included in the Doppler image will be described on the premise of the above-described return determination. As described above, the Doppler data is ternarized, that is, normalized to positive, negative, or zero. It is represented in each figure as red, blue and black, respectively. A represents an image portion with respect to the background, and B represents the background itself.
[0075]
FIG. 8 shows a general concept of processing of a reentrant portion. Reference numeral 132 represents an actual image portion A, reference numeral 130 represents a background portion B, and circles in the figure represent data to be filled by interpolation processing.
[0076]
Here, as shown in FIG. 9, when A is red and B is black, that is, when the background image is 0 and the data having a positive sign on the background is a concave angle, When a part is configured, interpolation data is added under weighting conditions as shown in FIG. Here, in FIG. 9, i represents a weight value, and the pixel value of each interpolation data is determined based on the weight value i and the condition as shown in FIG. In the example shown in FIG. 9, some pixel values having a red luminance value are added to the outside of the red image portion, specifically, to the surrounding region of the concave red image portion. As a result, the sharpness of the concave image portion is reduced, and the concave image portion is corrected as a round concave image portion.
[0077]
A specific example of the processing shown in FIG. 9 is shown in FIG. Incidentally, it is assumed that the pixel value ranges from +31 to -32.
[0078]
FIG. 11 shows a processing example in the case where the image part A is blue and the background B is black, as in the processing example shown in FIG. In this case as well, some interpolation data is added inside the concave image portion as described above. A specific example of the processing is shown in FIG.
[0079]
Next, FIG. 13 shows a processing example in a case where the image part A is red, the background part is blue, and there is no turn-back. In this case, for example, a specific process as shown in FIG. 14 is performed.
[0080]
FIG. 15 shows a case where the substantial image portion A is blue and the background image portion B is red. FIG. 16 shows a specific example in which such processing is performed. It is shown. In any case, since no aliasing phenomenon occurs, a natural gradation process from blue to red is performed. This makes it possible to construct a Doppler image without a sense of incongruity.
[0081]
On the other hand, FIG. 17 shows a processing example in the case where the substantial image portion A is red, the background image portion is blue, and a fold occurs at the boundary between them. In this case, a pixel value is assigned to each piece of interpolation data according to the processing policy shown in FIG. A specific example is shown in FIG. In this case as well, the rounding process is performed on the concave corner portion, but the image stands out in the boundary area.
[0082]
This is the same in the case shown in FIG. 19, and a processing example in that case is shown in FIG.
[0083]
Next, FIG. 21 shows a general concept of image processing for a convex corner portion. As in each of the above-described examples, the symbol A represents a substantial image portion, and the symbol B represents an image portion serving as the background. Further, circle symbols indicate pixels to be weighted by image processing.
[0084]
First, as shown in FIG. 22, when the substantial image portion A is red and the background image portion B is black, a predetermined weight is applied to the target pixel value as illustrated, As a result, for example, a processing result as shown in FIG. 23 is obtained. This is the same under the condition shown in FIG. 24, and in that case, the processing result as shown in FIG. 25 is obtained.
[0085]
Next, FIG. 26 shows a case where the substantial image portion is red and the background image portion B is blue. In this case, a gradation process is performed as shown. Specifically, image processing as shown in FIG. 27 is performed. Thereby, a natural color transition can be expressed, and this is the same in the case shown in FIG. 28, and a specific example of the processing in that case is shown in FIG.
[0086]
On the other hand, FIG. 30 shows an example in which the substantial image portion A is red, the background image portion B is blue, and folding occurs between these boundaries. In this case, as shown in FIG. 31, for example, the sharpness of the convex portion is reduced, but the boundary becomes prominent. This makes it possible to express the folding itself. This is the same in the case as shown in FIG. 32, and a processing example in that case is shown in FIG.
[0087]
The image processing for the concave corner portion and the image processing for the convex corner portion described above are, of course, examples, and it is desirable to perform a correction process on various image patterns in addition to the above. For example, it is desirable to perform an appropriate correction process on an image portion such as a beard-shaped image portion shown in FIG.
[0088]
Incidentally, in the present embodiment, four types of determination patterns for concave corners and four types of determination patterns for convex corners are prepared corresponding to the four corners of the square.
[0089]
In the above-described embodiment, the Doppler image processing has been described, but the same processing as described above may be applied to other images. Further, if the same processing is applied to each of the Doppler image and the B-mode image and then the two images are combined, there is an advantage that a more natural combined image can be formed.
[0090]
【The invention's effect】
As described above, according to the present invention, it is possible to perform adaptive and local image processing on an ultrasonic image to improve the image quality.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram illustrating an example of image processing according to an embodiment.
FIG. 2 is a block diagram showing the overall configuration of the ultrasonic diagnostic apparatus according to the embodiment.
FIG. 3 is a block diagram illustrating a specific configuration example of a pattern correction unit illustrated in FIG. 2;
FIG. 4 is a conceptual diagram illustrating a processing example of a beard-shaped image portion according to the embodiment;
FIG. 5 is a diagram illustrating an example of image processing on a concave corner portion.
FIG. 6 is a diagram illustrating an example of image processing on a convex corner portion.
FIG. 7 is a diagram for explaining return determination.
FIG. 8 is a diagram for explaining preconditions for image processing on a concave corner portion.
FIG. 9 is a diagram showing image processing conditions.
FIG. 10 is a diagram illustrating a processing example based on the image processing conditions illustrated in FIG. 9;
FIG. 11 is a diagram showing image processing conditions.
FIG. 12 is a diagram illustrating a processing example based on the image processing conditions illustrated in FIG. 11;
FIG. 13 is a diagram showing image processing conditions.
FIG. 14 is a diagram illustrating a processing example based on the image processing conditions illustrated in FIG. 13;
FIG. 15 is a diagram showing image processing conditions.
FIG. 16 is a diagram illustrating a processing example based on the image processing conditions illustrated in FIG. 15;
FIG. 17 is a diagram showing image processing conditions.
18 is a diagram illustrating a processing example based on the image processing conditions illustrated in FIG.
FIG. 19 is a diagram showing image processing conditions.
20 is a diagram illustrating a processing example based on the image processing conditions illustrated in FIG. 19;
FIG. 21 is a diagram for describing preconditions for image processing on a convex corner portion.
FIG. 22 is a diagram illustrating image processing conditions.
FIG. 23 is a diagram illustrating a processing example based on the image processing conditions illustrated in FIG. 22;
FIG. 24 is a diagram showing image processing conditions.
FIG. 25 is a diagram illustrating a processing example based on the image processing conditions illustrated in FIG. 24;
FIG. 26 is a diagram illustrating image processing conditions.
FIG. 27 is a diagram illustrating a processing example based on the image processing conditions illustrated in FIG. 26;
FIG. 28 is a diagram showing image processing conditions.
FIG. 29 is a diagram illustrating a processing example based on the image processing conditions illustrated in FIG. 28;
FIG. 30 is a diagram showing image processing conditions.
FIG. 31 is a diagram illustrating a processing example based on the image processing conditions illustrated in FIG. 30;
FIG. 32 is a diagram showing image processing conditions.
FIG. 33 is a diagram illustrating a processing example based on the image processing conditions illustrated in FIG. 32;
[Explanation of symbols]
8 scanning plane, 9 ultrasonic beam, 10 original image, 12 ternary image, 14 window, 16 data block (data group), 18 comparison pattern set, 20 comparison pattern, 22 correction image, 30 probe, 32 transmitting / receiving unit, 34 Doppler processing unit, 36 image processing unit, 38 pattern correction unit, 40 display unit, 42 window processing unit, 46 ternarization unit, 48 ternarization circuit, 52 determination unit, 53 comparison pattern table, 54 correction execution unit, 55 Correction condition table, 57 Return judgment unit.

Claims (13)

On an ultrasound image as a Doppler image, window setting means for setting a window over a plurality of sound rays,
Before or after setting the window, means for performing a normalization process of classifying each original Doppler data in the Doppler image,
A comparison pattern table storing a plurality of comparison patterns to be compared with the actual pattern of the data group after the normalization processing in the window,
Pattern determination means for determining, from the plurality of comparison patterns, a specific comparison pattern that matches the actual pattern of the data group after the normalization processing in the window,
A correction condition table storing a plurality of correction conditions corresponding to the plurality of comparison patterns,
From the plurality of correction conditions, a specific correction condition corresponding to the specific comparison pattern is determined, and the original attention Doppler data or the plurality of Doppler data in the window is corrected according to the specific correction condition. Adaptive processing means for performing processing;
Including
In the case where a boundary exists in the window, based on the original Doppler data on one side and the other side of the boundary, including a wrap determination unit that determines whether there is a wrap,
An ultrasonic diagnostic apparatus wherein the correction processing is performed in consideration of the presence / absence of the return. Window setting means for setting a window over a plurality of sound rays on the ultrasound image;
Before or after setting the window, means for performing a normalization process to classify each original data in the ultrasound image,
A comparison pattern table storing a plurality of comparison patterns to be compared with the actual pattern of the data group after the normalization processing in the window,
Pattern determination means for determining, from the plurality of comparison patterns, a specific comparison pattern that matches the actual pattern of the data group after the normalization processing in the window,
A correction condition table storing a plurality of correction conditions corresponding to the plurality of comparison patterns,
From the plurality of correction conditions, a specific correction condition corresponding to the specific comparison pattern is determined, and a correction process is performed on the original target data or the plurality of data in the window according to the specific correction condition. Adaptive processing means to be applied;
Including
The plurality of comparison patterns include a comparison pattern for corner portion determination,
An ultrasonic diagnostic apparatus, wherein the plurality of correction conditions include a correction condition corresponding to the comparison pattern for determining a corner portion, the correction condition mitigating sharpness of a corner portion. The device according to claim 2,
Among the plurality of comparison patterns, a comparison pattern for convex corner portion determination is included,
The plurality of correction conditions include a correction condition corresponding to the comparison pattern for determining the convex corner portion, and a correction condition for reducing the sharpness of the convex corner portion. Ultrasound diagnostic device. The device according to claim 2,
The plurality of comparison patterns include a comparison pattern for concave corner portion determination,
Ultrasound diagnosis, wherein the plurality of correction conditions include a correction condition corresponding to the comparison pattern for determining the concave corner portion, the correction condition mitigating sharpness of the concave corner portion. apparatus. The apparatus according to any one of claims 2 to 4,
The ultrasonic diagnostic apparatus according to claim 1, wherein the correction condition for alleviating the sharpness of the corner portion includes a condition for performing weighting according to a distance and a direction from a vertex of the corner portion. Window setting means for setting a window over a plurality of sound rays on the ultrasound image;
Before or after setting the window, means for performing a normalization process to classify each original data in the ultrasound image,
A comparison pattern table storing a plurality of comparison patterns to be compared with the actual pattern of the data group after the normalization processing in the window,
Pattern determination means for determining, from the plurality of comparison patterns, a specific comparison pattern that matches the actual pattern of the data group after the normalization processing in the window,
A correction condition table storing a plurality of correction conditions corresponding to the plurality of comparison patterns,
From the plurality of correction conditions, a specific correction condition corresponding to the specific comparison pattern is determined, and a correction process is performed on the original target data or the plurality of data in the window according to the specific correction condition. Adaptive processing means to be applied;
Including
The plurality of comparison patterns include a comparison pattern for beard portion determination,
The ultrasonic diagnostic apparatus according to claim 1, wherein the plurality of correction conditions include a correction condition corresponding to the comparison pattern for beard portion determination, the correction condition mitigating sharpness of the beard portion. The device according to claim 6,
The ultrasonic diagnostic apparatus according to claim 1, wherein the correction condition for alleviating the sharpness of the beard includes a condition for performing weighting according to a distance from a vertex of the beard. The apparatus according to any one of claims 1 to 7,
A comparison pattern set is selected from a plurality of comparison pattern sets according to measurement conditions,
An ultrasonic diagnostic apparatus, wherein a plurality of comparison patterns constituting the selected comparison pattern set are used for comparison with the actual pattern. The apparatus according to any one of claims 1 to 8,
The ultrasonic diagnostic apparatus, wherein the means for executing the normalization process classifies each original Doppler data into a positive, negative, or zero category. Window setting means for setting a window over a plurality of sound rays while scanning the window position on the Doppler image;
Classification means for performing a normalization process of classifying each of the original Doppler data constituting the Doppler image into one of positive, negative, and zero categories,
Comparing means for determining a comparison category pattern that matches the actual category pattern for the data group after the normalization processing in the window;
Adaptive processing means for performing a correction process on the original Doppler data or a plurality of Doppler data in the window according to the correction condition corresponding to the comparison category pattern,
Including
On the Doppler image, the correction process is adaptively performed only for a specific portion where the actual category pattern matches the comparison category pattern ,
The comparison category pattern includes a pattern for determining at least one of a corner portion and a whisker portion having an unnatural sharpness as a Doppler image,
An ultrasonic diagnostic apparatus, wherein the correction condition includes a correction condition for reducing sharpness of at least one of the corner portion and the beard portion. The device according to claim 10 ,
An ultrasonic diagnostic apparatus, wherein the correction condition for alleviating the sharpness is a condition for performing gradation processing by weighting in the window. Window setting means for setting a window over a plurality of sound rays while scanning the window position on the Doppler image;
Classification means for performing a normalization process of classifying each of the original Doppler data constituting the Doppler image into one of positive, negative, and zero categories,
Comparing means for determining a comparison category pattern that matches the actual category pattern for the data group after the normalization processing in the window;
Adaptive processing means for performing a correction process on the original Doppler data or a plurality of Doppler data in the window according to the correction condition corresponding to the comparison category pattern,
Including
On the Doppler image, the correction process is adaptively performed only for a specific portion where the actual category pattern matches the comparison category pattern ,
In the case where a boundary is included in the window, the original Doppler data on one side and the other side of the boundary are compared with each other to include a wrap determination unit that determines whether or not there is a wrap,
The ultrasonic diagnostic apparatus, wherein the correction processing is performed in the window when there is no return. The apparatus according to claim 12 ,
The return determination means,
Means for calculating the difference between the original Doppler data on the one side and the other side;
Means for comparing the difference of the Doppler data with a predetermined value,
Means for determining the presence or absence of a return based on the result of the comparison,
An ultrasonic diagnostic apparatus comprising:

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