JP2825358B2 - Ultrasonic 3D image display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic three-dimensional image display device for three-dimensionally displaying ultrasonic echo information of a three-dimensional region inside a subject.

[0002]

2. Description of the Related Art There is known an ultrasonic diagnostic apparatus which transmits an ultrasonic wave to a subject, receives a reflected wave reflected from the inside of the subject, and displays a tomographic image in the subject. Used in the field.

In recent years, there has been proposed an ultrasonic three-dimensional image display apparatus which transmits and receives ultrasonic waves to and from a three-dimensional region in a subject to acquire echo data, and forms and displays the acquired echo data in a grayscale image. Proposed.

In this ultrasonic three-dimensional image display apparatus, in order to spatially (sterically) represent an arbitrary object in a three-dimensional area inside the subject, the ultrasonic three-dimensional image display apparatus is generally located on the near side of the object as viewed from the operator. Is used to increase the luminance of the image and to decrease the luminance toward the back of the object.

Therefore, according to such an ultrasonic three-dimensional image display device, it is possible to provide spatial information which cannot be provided by a conventional ultrasonic diagnostic device, and there is a demand for its practical use in medical treatment.

[0006]

However, in the above-described ultrasonic three-dimensional image display apparatus, when an object inside a subject is displayed in black and white shades, the surface of the object is recognized three-dimensionally by a shaded image. On the other hand, when it is desired to view the cross section of the object, since the cross section itself is also displayed in black and white, the brightness in the cross section area is almost the same, and a clear display cannot be performed. . Therefore, there has been a demand for clearly observing a cross-sectional image in a B-mode display as in a conventional ultrasonic diagnostic apparatus.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems.
An object of the present invention is to provide an ultrasonic three-dimensional image display device capable of displaying the surface of an object to be displayed three-dimensionally by performing grayscale display, and performing a B-mode display on a cross section of the object to form a clear image. Is to do.

[0008]

In order to achieve the above object, the present invention provides a three-dimensional data memory for storing echo data of a three-dimensional region inside a subject captured by transmitting and receiving ultrasonic waves; and a cross-sectional position setting means for setting the position of the cross-section of the object to be displayed in the original area, the first threshold
First threshold setting means for setting a value, and
Second threshold setting means for setting a second threshold that is also large, for each line-of-sight direction from the three-dimensional data memory , read the echo data at the position of the set cross section ,
Echo data larger than the first threshold
A cross section extracting means for extracting as echo data of a cross section of the object, from the three-dimensional data memory, the cross-section of the object
For each gaze direction for which no echo data was extracted,
Echo data on the back side of the set cross-section position
Echoes larger than the second threshold value.
And surface extraction means for extracting the data as echo data of a surface of the object, the cross-sectional image forming means for forming an echo data of the extracted cross-section B-mode tomographic image, the echo data of the extracted the object surface According to the depth coordinates viewed from the viewpoint, a surface image forming unit that forms the surface of the object into a three-dimensional grayscale image, and a display unit that combines and displays the formed cross-sectional image and surface image. comprises, for the echo data of the cross section of the object by performing a tomographic image processing corresponding to the echo level without processing the three-dimensional gray-scale image corresponding to the depth coordinates, a three-dimensional image display of the object It is characterized by performing.

[0009]

According to the above configuration, sectional extracting means and the surface extraction
By means, cross sections and tables from the three-dimensional data memory
The echo data corresponding to the surface is extracted, and the slice image
Extracted by the forming means and the surface image forming means, respectively.
B-mode tomographic image and 3D
A black-and-white grayscale image is formed .

Therefore, for example, the whole of a specific organ in a subject
Display an arbitrary section of the organ while displaying the image
Etc. are possible, and the positional relationship between the entire image and the cross-sectional image is easy.
To the image that actually cuts the object
It becomes a very close display, increasing the sense of reality and three-dimensional grasp
It becomes possible .

A first threshold value setting unit and a second threshold value setting unit;
By providing the means, it is possible to
Depending on the condition of the tissue to be displayed or of the object to be displayed.
As a result, it is possible to form appropriate cross-sectional images and surface images .

According to the present invention, the disconnection using the first threshold value is performed.
Extraction of the echo data of the surface is performed in advance, and the
If no echo data was extracted, then the first
Surface echo detection using a second threshold greater than the threshold
Data extraction is performed. Sectional echo data is relatively strong
Low intensity, while the surface echo data is relatively strong.
However, according to the present invention, the characteristic of such ultrasonic echo is
A data search that matches the property of can be performed. Ma
In addition, since the cross-sectional echo data is determined in advance,
Data processing can be performed rationally .

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a preferred embodiment of an ultrasonic three-dimensional image display device according to the present invention.

In FIG. 1, an ultrasonic diagnostic apparatus 10 transmits an ultrasonic wave to a three-dimensional area in a subject, receives a reflected wave from the subject, and outputs a received signal (echo data). Is what you do.

Here, the data acquisition in the ultrasonic diagnostic apparatus 10 uses a three-dimensional data acquisition ultrasonic probe, and the direction of the ultrasonic beam and the direction of the ultrasonic beam are determined by an angle detector provided in the probe. The angle can be detected.

A signal received from the ultrasonic diagnostic apparatus 10,
That is, the ultrasonic echo data is stored in the three-dimensional data memory 16 via the peripheral control unit 12 and further via the bus 14. Here, the data writing to the three-dimensional data memory 16 is stored in the corresponding address of the three-dimensional data memory 16 in accordance with the three-dimensional position of each of the acquired echo information. That is, each address of the three-dimensional area in the subject corresponds to each address of the three-dimensional data memory 16.

In the figure, reference numeral 18 denotes a central control unit, which is a peripheral control unit 12 and the three-dimensional data memory 1.
6 and devices to be described later. The high-speed arithmetic processor 20 connected to the bus 14 is controlled by the central control unit 18 and performs arithmetic processing such as extraction of a cross section / surface of an object and formation of a cross-sectional image and a surface image, which will be described later.

The bus 14 has a section position setting unit 25.
And the threshold β and γ setting units 27 are connected respectively.
The cross-section position setting unit 25 sets the position of the cross-section of the object to be displayed. In the present embodiment, the cross-section position setting unit 25 is configured to be arbitrarily and freely changeable with a dial.
The threshold value β, γ setting unit 27 is for setting a threshold value β and a threshold value γ, which will be described later. In the present embodiment, the threshold value β and γ are configured by a dial and configured to be able to freely change the values. I have.

In FIG. 1, a depth information memory 24 connected to a bus 14 temporarily stores depth information when a front surface image is formed, as described later.

A frame buffer memory 26 connected to the bus 14 stores image information of an object to be displayed formed by the high-speed arithmetic processor 20, that is, luminance information. Stores the luminance information of both the surface image and the cross-sectional image of the displayed object.

The output R of the frame buffer memory 26,
G and B are input to D / A converters 28, 30, and 32, respectively. Then, each of the D / A converted data is
It is displayed on the CRT 34.

Next, the principle of extracting the surface of the three-dimensionally displayed object Q will be described with reference to FIG. In FIG.
P is a virtual viewpoint for three-dimensionally displaying the object Q, and a line through the object Q from this viewpoint P is a line of sight L. The ultrasonic echo data in such a case is shown in FIG.
It is indicated by 0. As can be understood from the ultrasonic echo data 50, the echo data 5
By setting an appropriate threshold β with a high level of 0, it is possible to extract the presence of the object Q and its surface position from the echo data 50 having a β value or more. Next, the principle of determining the surface / cross section of the object Q will be described with reference to FIG. In FIG. 3, W indicates a cross-sectional position of the object Q input and specified from the outside, and the position of W can be arbitrarily specified.

The principle of surface / cross section determination will be described.
First, the echo data at the point A, which is the intersection of the line of sight L1 and the cross section W, is read, and it is determined whether or not the echo data at the point A is larger than the set threshold β. That is, when the echo data at the point A is larger than the threshold value β, it is determined that the data is the cross-sectional position data of the object Q.

As shown by the line of sight L2 in FIG. 3, when the point B, which is the intersection of the cross section W and the line of sight L2, is outside the object Q, that is, when the echo data is smaller than the threshold value β, the line of sight L2 Are sequentially moved along the point to be determined along, the echo data and the threshold β are compared for each movement,
The surface of the object Q is determined. That is, at the point C, since the echo data exceeds the threshold value β, the surface position of the object Q can be determined. Thus, the line of sight L and the cross section W
The value of the echo data located at the intersection with the threshold value β is compared with the threshold value β, and when the echo data is smaller than the threshold value β, the echo data is sequentially compared along the line of sight L to obtain the surface of the object Q and The position of the cross section can be determined.

In the above description, when the echo data is smaller than the threshold value β, the determination point is moved along the line of sight L in the direction opposite to the viewpoint P. It can be applied as appropriate according to the position of the cross section and the shape of the object Q.

However, if the cross section is extracted only with the threshold value β, echo data having relatively low echo intensity is excluded, and there is a problem that a tomographic image with high accuracy cannot be formed. In other words, since the threshold value β is uniquely set over the entire captured three-dimensional area, such echo data is excluded even in a tomographic image that originally wants to display echo data with low echo intensity, and as a result, the accuracy is high. A tomographic image cannot be formed. Therefore, in the present embodiment, as shown in FIG. 4, a threshold γ that is effective only on the cross section W, in other words, effective only in tomographic image formation, is set as another threshold. Then, at the time of forming a cross-sectional image of the object Q, the echo data in the cross-sectional W plane is compared with a threshold γ, and a tomographic image (B-mode tomographic image) is formed by the echo data having the threshold γ or more. As described above, by extracting the echo data with the two threshold values, it is possible to combine the rough display image of the object and the fine tomographic image and provide them at the same time.

Next, a process of forming a display image of the ultrasonic three-dimensional image display device according to the present invention will be described with reference to FIG.

In FIG. 5, in step 101, an ultrasonic wave is transmitted into the subject using the ultrasonic diagnostic apparatus 10,
A reflected wave from the inside of the subject is received, and echo data of an ultrasonic wave is captured. At about the same time, step 1
In 02, the echo data captured in step 101 is written to the three-dimensional data memory 16.

In step 103, the section position setting section 25
Is used to input and specify the position of the cross section of the object to be displayed, and the two thresholds β and γ are specified using the threshold β and γ setting unit 27. It is preferable that the setting of the threshold value is appropriately determined according to the tissue to be diagnosed.

In step 104, the cross-section / surface determination described with reference to FIG. 3 is performed, and echo data corresponding to the cross-section and surface are extracted from the three-dimensional data memory 16 according to the determination result. Then, Step 105
If the data extracted in step 104 is that of a cross section, the process proceeds to step 106, whereas if the extracted data is that of a surface, the process proceeds to step 107.

In step 106, a cross-sectional image (B-mode display image) is formed from the extracted data. That is, a cross-sectional image is formed by making the luminance correspond to the size of the echo data in the cross-section.

On the other hand, in step 107, a gray-scale image processing depending on the distance from the surface image, ie, the viewpoint P, is performed from the extracted echo data. That is, the surface of the displayed object is processed into a grayscale image such that the brightness is higher (brighter) on the near side and lower (darker) on the far side when viewed from the operator.

At step 108, the images formed at steps 106 and 107 are stored in the frame buffer memory 26, respectively.

In step 109, the image data stored in the frame buffer memory 26 is displayed on the CRT 34. FIG. 7 shows a display example of the object Q displayed on the CRT 34 for reference. Here, the cross section of the object Q is displayed in the B-mode display (gray scale display), and the surface of the object Q is displayed in shades according to the distance from the operator.

Next, a specific processing example of steps 104 to 108 (shown by A in FIG. 5) described in FIG. 5 will be described with reference to FIG.

In FIG. 6, first, in step 201, the position of the intersection between the line of sight L and the cross section W described with reference to FIG. 3 is calculated.

In step 202, the echo data of the intersection obtained in step 201 is stored in the three-dimensional data memory 16
Is read from.

In step 203, it is determined whether or not the data X read in step 202 is larger than the threshold value γ described in FIG. Here, when the echo data X is larger than the threshold value γ, that is, when it is determined that the echo data is a cross-section echo data, step 204
Move to

In step 204, the echo data X is converted into luminance data for writing in the frame buffer memory 26. In the case where the echo data stored in the three-dimensional data memory 16 can be used as it is as luminance data, the step 204 need not be performed. In step 205, the luminance data converted in step 204 is stored in the frame buffer memory 26.

Then, in step 206, it is determined whether or not all the cross-section / surface image processing has been completed for the object Q. If not, in step 213, the line of sight L is moved to the next one. The process from step 201 described above is repeated.

On the other hand, in step 203, the echo data X
Is smaller than the threshold value γ, that is, it is determined that the value is outside the range of the object Q, the process proceeds to step 207.

In this step 207, the next echo data X on the line of sight L is read from the three-dimensional data memory 16. That is, as described with reference to FIG. 3, this is for obtaining the surface position of the object. In step 208, it is determined whether or not the echo data X read in step 207 is smaller than a threshold value β. Here, if the echo data X is smaller than the threshold value β, it is not the echo data of the surface of the object Q, and the process proceeds to step 207 to read the next data.

On the other hand, when it is determined in step 208 that the echo data X is larger than the threshold value β, that is, when it is determined that the echo data X is the echo data of the surface of the object Q, the process proceeds to step 209.

In step 209, step 2 to be described later
In order to convert each echo data into luminance data in accordance with the distance from the viewpoint B at 11, information on the distance (depth) between the viewpoint P and the position of the echo data X is stored in a depth information memory 24 storing depth information. Is done. Here, the storage of the data in the depth information memory 24 is performed by writing the depth information to an address corresponding to the position of each pixel of the actually displayed image.

Then, in step 210, it is determined whether or not all the surface / cross-section determinations have been performed on the object Q. If the determination has not been completed, in step 214, the line of sight L is moved to the next one. It moves and the process from step 201 is repeated again.

If it is determined in step 210 that the depth data corresponding to all surfaces of the object Q has been stored in the depth information memory 24, the process proceeds to step 211.

In this step 211, each depth data stored in the depth information memory 24 is read out and converted into luminance data according to the size of the depth information, that is, the distance from the viewpoint P.

Then, in step 212, step 2
Each of the luminance data processed in step 11 is stored in the frame buffer memory 26.

Therefore, steps 206 and 21
When Step 2 is completed, the luminance information of the entire area of the displayed image is stored in the frame buffer memory 26. As described above, according to this ultrasonic three-dimensional image display device, it is possible to simultaneously display the surface image and the cross-sectional image of a desired object inside the subject, so that, for example, the position and size of the affected part can be displayed in space. It is possible to easily and easily recognize, and it is possible to improve the diagnostic accuracy.

Further, display is performed by sequentially moving the cross-sectional position of the object to be displayed. For example, the surface of the object is colored to express perspective by changing the hue. It is possible to take various display forms, such as coloring and displaying the image as if it were cut.

[0051]

As described above, according to the ultrasonic diagnostic three-dimensional image display apparatus according to the present invention, the surface of an object displayed three-dimensionally is displayed in shades, and the cross section of the object is displayed in B mode. Therefore, the positional relationship between the entire object and its cross section can be easily recognized.

Further, the displayed object becomes a display close to an image obtained by actually cutting the object, thereby increasing the sense of reality and improving the three-dimensional recognition of, for example, a tumor inside the object. It has the effect of.

Further, by providing the first threshold value setting means and the second threshold value setting means, it is possible to extract the echo data of the cross-sectional image and the echo data of the surface image under independent level conditions, respectively. This has the effect that a stable image can be formed. In particular, when accuracy in the cross-sectional image is required, the surface image is kept as it is,
Since the brightness of the echo data in the cross-sectional image can be increased or decreased, there is an effect that the affected part can be appropriately grasped.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an ultrasonic three-dimensional image display device according to the present invention.

FIG. 2 is an explanatory diagram showing a principle of extracting a surface of a displayed object.

FIG. 3 is an explanatory diagram showing a principle of determining a surface / cross section.

FIG. 4 is an explanatory diagram showing extraction of echo data in a cross section W;

FIG. 5 is a flowchart of image formation.

FIG. 6 is a flowchart showing a specific example of a processing step in a process range A shown in FIG. 5;

FIG. 7 is a conceptual diagram showing a display example.

[Explanation of symbols]

 Reference Signs List 10 Ultrasound diagnostic apparatus 16 Three-dimensional data memory 20 High-speed arithmetic processor 24 Depth information memory 25 Section position setting unit 26 Frame buffer memory

Continuation of front page (56) References JP-A-2-196383 (JP, A) JP-A-2-148278 (JP, A) JP-A-2-1082 (JP, A) JP-A-62-169280 (JP) , A) JP-A-1-295373 (JP, A) Meloni Illustrated Medical Dictionary 1984.10.1 Nankodo P51. P342, P430

Claims (1)

(57) [Claims] 1. A three-dimensional data memory for storing echo data of a three-dimensional area inside a subject captured by transmission and reception of ultrasonic waves, and setting a position of a cross section of an object to be displayed, which is included in the three-dimensional area. Sectional position setting means, first threshold setting means for setting a first threshold, and second setting for setting a second threshold larger than the first threshold
Threshold setting means, from the three-dimensional data memory, for each line-of-sight direction , read the echo data at the position of the set cross section ,
Echo data larger than the first threshold
A cross section extracting means for extracting the data as echo data of a cross section of the object, from the three-dimensional data memory, an echo of the cross-section of the object
For each gaze direction for which no data was extracted,
Echo data on the back side of the position of the section
Surface extraction means for reading and extracting echo data larger than the second threshold value as echo data of the surface of the object; cross-sectional image for forming the extracted cross-sectional echo data into a B-mode tomographic image Forming means, from the viewpoint of the extracted echo data of the object surface
A surface image forming unit that forms the surface of the object into a three-dimensional grayscale image according to the viewed depth coordinates; and a display unit that combines and displays the formed cross-sectional image and surface image. for the cross-section of the echo data, perform tomographic image processing corresponding to the echo level without processing the three-dimensional gray-scale image corresponding to the depth coordinates, and performs three-dimensional image display of the object Ultrasonic three-dimensional image display device.