JP4176525B2 - Ultrasonic image processing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic image processing apparatus, and more particularly to an ultrasonic image processing apparatus that extracts a lumen region inside a tissue.
[0002]
[Prior art]
An ultrasonic image is formed based on echo data obtained by transmitting and receiving ultrasonic waves to a living body. For example, when a two-dimensional tomographic image is formed, each pixel value is calculated based on the level of echo data acquired in the two-dimensional echo data capturing area. When calculating the cross-sectional area of a tissue lumen region (for example, the lumen region of the left ventricle of a heart) using a two-dimensional tomographic image, it is necessary to accurately recognize the lumen region to be calculated. A structure (for example, papillary muscle) that hinders area calculation exists in the lumen region of the left ventricle. For this reason, it is necessary to remove these structures and extract a lumen region (a heart cavity portion from which structures such as papillary muscles have been removed).
[0003]
Patent Document 1 discloses a technique that can accurately recognize the contour (outer edge) of the lumen region and, as a result, accurately extract the lumen region itself. The method is as follows. First, a tomographic image is displayed on a monitor, and a boundary serving as a rough outline of the lumen region is set using a pointing device. Next, the scan line is extended radially from the start point set on the boundary, and the intersection with the manually set boundary is obtained on the line. Then, the detection range centered on this intersection is set, the tomographic image data in the detection range is binarized with a threshold value, the myocardium and the heart chamber are separated, and the boundary position to be corrected is detected and manually set Correct the boundary. Thereby, the contour of the lumen region is detected with high accuracy, and as a result, the lumen region itself is extracted with high accuracy.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-164834
[Problems to be solved by the invention]
As described above, the method described in Patent Document 1 requires a complicated device setting operation such as a user setting a boundary that is a guideline for the contour of the lumen region.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide an ultrasonic image processing apparatus that is easy to perform apparatus setting operations and that can accurately extract a lumen region.
[0007]
[Means for Solving the Problems]
(1) In order to achieve the above object, an ultrasonic image processing apparatus according to the present invention is a space obtained by transmitting and receiving ultrasonic waves to and from a space including a target tissue composed of a tissue part and a lumen region. An ultrasonic image processing apparatus that performs image processing based on a plurality of data corresponding to each position in the data, and binarizing each of the data, thereby separating each data into actual data or cavity data Binarizing means for recognizing cavity data belonging to the area surrounded by the tissue part as a representative point, and by performing a filling process starting from the representative point in the area surrounded by the tissue part including the representative point A lumen data set extracting means for extracting a lumen data set which is a set of a plurality of cavity data existing in the above, and replacing actual data surrounded by the lumen data set with cavity data. Ri, shall have a cavity region extracting means among which extracts a set area of the cavity data composed of a plurality of lumens data belonging to the lumen dataset and lumen data obtained by replacing the said cavity region.
[0008]
In the above configuration, the target tissue including the tissue part and the lumen region is, for example, a heart or a blood vessel. The plurality of data obtained by transmitting and receiving ultrasonic waves may be either data on a predetermined plane in the space or data on the entire area in the space. Further, the region surrounded by the tissue part may be a region surrounded by the tissue part and the edge of the ultrasonic image. Further, the filling process is a search for cavity data adjacent to the origin cavity data, search for cavity data further adjacent to the cavity data obtained as a result of the search, and repeat this to obtain a lump of cavity data. This is a process for extracting.
[0009]
The collection area of the cavity data extracted as the lumen area (for example, the lumen area of the left heart chamber) by the above configuration is obtained by removing the isolated actual data (for example, the papillary muscle in the left heart chamber). That is, the isolated actual data is removed, and the lumen region is extracted with high accuracy. Further, complicated apparatus setting operation is not required.
[0010]
Desirably, the lumen data set extraction means sets the representative point based on a specific position in an ROI (region of interest) set for the target tissue. Alternatively, the lumen data set extraction means sets an image center position of an ultrasonic image formed based on a plurality of data corresponding to each position in the space as a specific position, and the representative point based on the specific position Shall be set. Alternatively, the lumen data set extraction means sets the representative point based on a specific position designated by the user.
[0011]
Preferably, when the specific position corresponds to actual data, the lumen data set extraction unit searches for cavity data from data located in the vicinity of the actual data, and obtains one cavity obtained as a result of the search. Data shall be set as a representative point. According to the above configuration, even when the specific position corresponds to the actual data and the specific position cannot be used as the starting point of the filling process, the cavity data that can be the starting point of the filling is automatically searched. More preferably, the lumen data set extraction means searches for the cavity data one after another from data located closer to the actual data corresponding to the specific position in the search for the cavity data.
[0012]
Desirably, the lumen data set extraction means newly sets a representative point when actual data is included in a designated range centered on the set representative point. As representative points, those belonging to the region surrounded by the tissue part of the cavity data are required. However, since the representative point is set based on the specific position, depending on how the specific position is set, the cavity data set as the representative point may not belong to the region surrounded by the tissue part. For example, there is a possibility that a representative point is set in the cavity data existing as “skin” in the tissue part itself. In the above configuration, when actual data exists within the designated range centered on the representative point, it is determined that the representative point exists in the organization unit, and the representative point is newly set again. This improves the accuracy of setting the representative points that are finally set.
[0013]
(2) Moreover, in order to achieve the said objective, the ultrasonic image processing apparatus which concerns on this invention is a tomography obtained by transmitting / receiving an ultrasonic wave with respect to the tomographic plane of the heart which consists of a myocardium and a lumen | bore area | region. An ultrasonic image processing apparatus that performs image processing based on an echo value of each pixel constituting a surface, and binarizing the echo value of each pixel, thereby making each pixel an actual pixel or a cavity pixel Binarizing means for classifying the pixel into a region surrounded by the myocardium including the representative point by recognizing the cavity pixel belonging to the region surrounded by the myocardium as a representative point and performing a filling process starting from the representative point A lumen pixel set extracting means for extracting a lumen pixel set, which is a set of a plurality of cavity pixels existing in each, and an isolated real pixel surrounded by the lumen pixel set, respectively A lumen area extracting means for extracting, as the lumen area, a collection area of cavity pixels composed of a cavity pixel obtained by replacement and a plurality of cavity pixels belonging to the lumen pixel set by replacing with a pixel; Lumen area calculating means for calculating the area of the lumen area in the tomographic plane of the heart based on the number of cavity pixels belonging to the lumen area is provided.
[0014]
According to the above configuration, since the isolated real pixels (for example, corresponding to structures such as papillary muscles) are removed from the collective region of the cavity pixels extracted by the lumen region extraction means, a structure that hinders the operation. Area calculation without the influence of objects becomes possible.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
[0016]
FIG. 1 shows a preferred embodiment of an ultrasonic image processing apparatus according to the present invention, and FIG. 1 is a block diagram showing the overall configuration thereof. In the embodiment shown in FIG. 1, each unit (binarization processing unit, lumen pixel set extraction block, lumen region extraction unit, and lumen region area calculation unit) in the ultrasound image processing apparatus is incorporated in the ultrasound diagnostic apparatus. It is a form.
[0017]
The transmission / reception unit 12 controls the probe 10 to transmit / receive ultrasonic waves to / from a space including a left heart chamber (consisting of a myocardium and a lumen region) that is a target tissue. That is, the transmission / reception unit 12 functions as a transmission beamformer and a reception beamformer, acquires echo values of a plurality of pixels constituting the tomographic plane of the left heart ventricle, and outputs the acquired echo values to the binarization processing unit 14. FIG. 2 shows a tomographic image of the left ventricle of the heart composed of a plurality of pixels output by the transmission / reception unit (reference numeral 12 in FIG. 1). The left heart chamber is configured so that the myocardium 40 surrounds the heart chamber 42. In a region surrounded by the myocardium 40, a structure 44 such as a papillary muscle exists. In addition, there is an “unfill” 46 in the echo value portion lower than the normal value inside the myocardium 40 itself.
[0018]
Returning to FIG. 1, the binarization processing unit 14 binarizes the echo value of each pixel output from the transmission / reception unit 12, thereby classifying each pixel into an actual pixel or a cavity pixel. That is, the binarization processing unit 14 classifies each input pixel into an actual pixel that is greater than or equal to the threshold and a cavity pixel that is less than the threshold based on the threshold set for the echo value. In general, the heart chamber has a smaller echo value than the myocardium (the echo value of the heart chamber may be larger due to the influence of contrast agents, etc., but in the following explanation, the echo value of the heart chamber is smaller. As described). Therefore, by setting the threshold value to a value smaller than the value corresponding to the myocardium and larger than the value corresponding to the heart chamber, the myocardium and the heart chamber can be roughly separated based on the threshold value.
[0019]
FIG. 3 is a diagram showing the result of pixel classification performed by the binarization processing unit (reference numeral 14 in FIG. 1), and shows the result of binarization processing on the tomographic image of FIG. In FIG. 3, a real pixel set 50 is a pixel set made up of pixel portions determined by the binarization processing unit as real pixels, and a cavity pixel set 52 is created from pixel portions determined by the binarization processing unit as cavity pixels. A set of pixels. 3 is compared with FIG. 2, the real pixel set 50 in FIG. 3 includes the myocardium 40 and the structure 44 in FIG. 2. That is, when a real pixel is extracted as a pixel that is equal to or higher than the threshold by binarization processing, a structure such as a papillary muscle is extracted in addition to the myocardium. Also, the cavity pixel set 52 in FIG. 3 is composed of the heart cavity 42, “skin” 46, and background portion in FIG. 2. That is, if a cavity pixel is extracted as a pixel that is less than the threshold value by binarization processing, “don't care” is extracted in addition to the heart chamber in the left ventricle.
[0020]
Returning to FIG. 1, the classification result of each pixel by the binarization processing unit 14 is output to the lumen pixel set extraction block 16. The lumen pixel set extraction block 16 includes a specific position setting unit 18, a representative point setting unit 20, and a paint processing unit 22.
[0021]
The specific position setting unit 18 sets a specific position in the left ventricular image composed of a plurality of pixels output from the binarization processing unit 14. The specific position is set based on the ROI (region of interest) set for the left ventricle. For example, the center point of the ROI is set. Usually, since the ROI is set so that the entire left ventricle of the heart is within the ROI, the specific position set as the center point of the ROI is generally set near the center of the left heart chamber. The specific position is not limited to the center point of the ROI. In other words, the specific position may be another position in the ROI that is set near the center of the heart left chamber. The specific position may be set at the center of the tomographic image itself. When diagnosing the left ventricle of the heart, the center of the tomographic image is generally set in the vicinity of the center of the left ventricular chamber because the left ventricle of the heart is usually arranged at the center of the tomographic image. The specific position may be set by the user based on the tomographic image displayed on the display 28. Furthermore, the specific position may be set to the area centroid of the plurality of cavity pixels extracted by the binarization processing unit 14.
[0022]
The representative point setting unit 20 sets a representative point based on the specific position set in the heart left chamber by the specific position setting unit 18. As representative points, cavity data belonging to the heart cavity is required. When the set specific position corresponds to the cavity data, the representative point setting unit 20 sets the specific position as a representative point as it is. When the set specific position corresponds to the actual data, the representative point setting unit 20 searches the cavity data from the data located in the vicinity of the actual data. The search is first performed from eight surrounding data adjacent to the actual data corresponding to the specific position. If cavity data exists in the eight surrounding data, one of them is set as a representative point. If cavity data does not exist in the eight surrounding data, the search range is further expanded to search for 16 surrounding data surrounding the eight surrounding data. In this way, the search range is expanded step by step. When a plurality of cavity data are searched within the search range at the same stage, one cavity data may be determined according to a selection rule determined in advance.
[0023]
As described above, the representative point setting unit 20 sets the representative point based on the specific position. However, depending on how the specific position is set, the cavity data set as the representative point may not belong to the heart chamber. . For example, there is a possibility that a representative point is set in the cavity data of “Nuke” (symbol 46 in FIG. 2) inside the myocardium. The representative point setting unit 20 determines whether or not the set representative point belongs to the heart chamber based on whether or not actual data exists within a designated range centered on the representative point. Since the heart chamber is mainly composed of chamber data, if only the chamber data exists around the set representative point, the representative point exists in the heart chamber, while the representative point is actually around the representative point. If the data exists, it is determined that the representative point is “inner” inside the myocardium. When it is determined that the set representative point does not exist in the heart chamber, the representative point is newly set again so that the representative point is finally set in the heart chamber.
[0024]
The fill processing unit 22 performs a fill process using the representative point as a starting point, thereby extracting a lumen pixel set that is a set of a plurality of cavity pixels that exist in the region surrounded by the myocardium and include the representative point. Filling process is to search the cavity data adjacent to the starting cavity data, search the cavity data further adjacent to the cavity data obtained as a result of the search, and extract the cavity data mass obtained by repeating this It is processing to do.
[0025]
FIG. 4 is a diagram illustrating the extraction result of the lumen pixel set by the paint processing unit (reference numeral 22 in FIG. 1). In FIG. 4, the representative point 60 is set to the cavity pixel at the center of the image by the representative point setting unit (reference numeral 20 in FIG. 1). The lumen pixel set 62 is a pixel set extracted by the paint processing unit (reference numeral 22 in FIG. 1). As illustrated in FIG. 4, the cavity pixel set in the region surrounded by the myocardium is extracted as the lumen pixel set 62 by the filling process starting from the representative point 60. As described above, only the lumen pixel set 62 existing in the region surrounded by the myocardium is extracted from the plurality of cavity pixel sets (reference numeral 52 in FIG. 3). In addition to the lumen pixel set 62, there is an actual pixel set 50 that is surrounded by the lumen pixel set 62 and is isolated in the area surrounded by the myocardium.
[0026]
Returning to FIG. 1, the lumen region extraction unit 24 replaces each isolated pixel surrounded by the lumen pixel set with a cavity pixel in the image from which the lumen pixel set has been extracted by the fill processing unit 22. Thus, a collection area of cavity pixels composed of the cavity pixels obtained by the replacement and a plurality of cavity pixels belonging to the lumen pixel set is extracted as a lumen area. For the process of searching for an isolated real pixel and replacing it with a cavity pixel, a function (paint processing function) prepared in a commercially available program development language or the like can be used.
[0027]
FIG. 5 is a diagram for explaining the lumen region extraction processing by the lumen region extraction unit (reference numeral 24 in FIG. 1). In the painting processing unit (reference numeral 22 in FIG. 1), a lumen pixel set (reference numeral 62 in FIG. 4) is extracted. Therefore, in FIG. 5, only the lumen pixel set 62 is shown as the cavity pixel set. The lumen region extraction unit searches for an isolated real pixel 64 that is an isolated real pixel surrounded by the lumen pixel set 62, and replaces the isolated real pixel 64 obtained as a result of the search with a cavity pixel. FIG. 6 shows the result of replacing an isolated real pixel (reference numeral 64 in FIG. 5) with a cavity pixel. As shown in FIG. 6, the lumen region 70 is a region inside the myocardium from which structures such as papillary muscles have been removed. Further, the boundary 72 of the lumen can be identified as the boundary between the lumen region 70 and the remaining real pixels.
[0028]
Returning to FIG. 1, the lumen area calculation unit 26 calculates the area of the lumen region extracted by the lumen region extraction unit 24. That is, the number of cavity pixels belonging to the lumen area is counted, and area calculation based on the size of each pixel and the counted number is performed. The calculation result is displayed on the display 28. The display 28 may display an extraction result image in the lumen region extracting unit 24, that is, an image corresponding to FIG.
[0029]
In the embodiment described above, each unit (binarization processing unit, lumen pixel set extraction block, lumen region extraction unit, and lumen region area calculation unit) in the ultrasound image processing apparatus is incorporated in the ultrasound diagnostic apparatus. It was a thing. The embodiment of the ultrasonic image processing apparatus according to the present invention is not limited to the above-described form. For example, each part of the ultrasonic image processing apparatus may be configured in a computer by combining a computer and an ultrasonic diagnostic apparatus. Good.
[0030]
【The invention's effect】
As described above, the ultrasonic image processing apparatus according to the present invention makes it possible to easily perform apparatus setting operations and extract a lumen region with high accuracy.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an overall configuration of an ultrasonic diagnostic apparatus in which an ultrasonic image processing apparatus according to the present invention is incorporated.
FIG. 2 is a diagram showing a tomographic image of the left heart ventricle.
FIG. 3 is a diagram showing a tomographic image of the left ventricle subjected to binarization processing.
FIG. 4 is a diagram showing extraction results of a lumen pixel set.
FIG. 5 is a diagram for explaining a lumen region extraction process;
FIG. 6 is a diagram showing a result of extracting a lumen region.
[Explanation of symbols]
14 binarization processing unit, 18 specific position setting unit, 20 representative point setting unit, 22 fill processing unit, 24 lumen region extraction unit, 26 lumen region area calculation unit.

Claims (8)

Ultrasonic image processing that performs image processing based on a plurality of data corresponding to each position in the space obtained by transmitting and receiving ultrasonic waves to and from a space including the target tissue consisting of a tissue part and a lumen region A device,
Binarization means for separating each data into actual data or cavity data by binarizing each data;
A plurality of cavity data existing in the area surrounded by the tissue part including the representative point by recognizing the cavity data belonging to the area surrounded by the tissue part as a representative point and performing a filling process starting from the representative point. Lumen data set extraction means for extracting a lumen data set that is a set of
A set of cavity data composed of cavity data obtained by replacing the actual data surrounded and isolated by the lumen data set with the cavity data, and a plurality of cavity data belonging to the lumen data set. A lumen region extracting means for extracting a region as the lumen region;
An ultrasonic image processing apparatus comprising: The ultrasonic image processing apparatus according to claim 1,
The ultrasonic image processing apparatus, wherein the lumen data set extraction unit sets the representative point based on a specific position in an ROI (region of interest) set for the target tissue. The ultrasonic image processing apparatus according to claim 1,
The lumen data set extraction unit sets an image center position of an ultrasonic image formed based on a plurality of data corresponding to each position in the space as a specific position, and sets the representative point based on the specific position An ultrasonic image processing apparatus. The ultrasonic image processing apparatus according to claim 1,
The ultrasonic image processing apparatus, wherein the lumen data set extraction unit sets the representative point based on a specific position designated by a user. The ultrasonic image processing apparatus according to any one of claims 2 to 4,
When the specific position corresponds to actual data, the lumen data set extraction means searches for cavity data from data located in the vicinity of the actual data, and represents one cavity data obtained as a result of the search. An ultrasonic image processing apparatus characterized in that a point is set. The ultrasonic image processing apparatus according to claim 5,
The lumen data set extraction means searches the cavity data one after another from data at a position closer to the actual data corresponding to the specific position in the search for the cavity data. apparatus. The ultrasonic image processing apparatus according to any one of claims 2 to 4,
The ultrasonic image processing apparatus, wherein the lumen data set extraction unit newly sets a representative point when actual data is included in a designated range centered on the set representative point. An ultrasonic image processing apparatus that performs image processing based on the echo value of each pixel constituting a tomographic plane obtained by transmitting and receiving ultrasonic waves to and from the tomographic plane of the heart consisting of the myocardium and lumen region. And
Binarizing means for binarizing the echo value of each pixel to separate each pixel into a real pixel or a cavity pixel;
A set of a plurality of cavity pixels existing in the area surrounded by the myocardium including the representative point by recognizing the cavity pixels belonging to the area surrounded by the myocardium as a representative point and performing a filling process starting from the representative point A lumen pixel set extraction means for extracting a lumen pixel set which is:
A set of cavity pixels each consisting of a cavity pixel obtained by replacing each real pixel surrounded by the lumen pixel set and isolated by a cavity pixel and a plurality of cavity pixels belonging to the lumen pixel set A lumen region extracting means for extracting a region as the lumen region;
Lumen area calculating means for calculating the area of the lumen region in the tomographic plane of the heart based on the number of cavity pixels belonging to the lumen region;
An ultrasonic image processing apparatus comprising:

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