JP4248673B2 - Ultrasonic diagnostic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a three-dimensional image creation method and an ultrasonic diagnostic apparatus, and more particularly to a three-dimensional image creation method and an ultrasonic diagnostic apparatus that can create a three-dimensional image free from noise and artifacts.
[0002]
[Prior art]
FIG. 8 is a block diagram of an example of an ultrasonic diagnostic apparatus having a conventional three-dimensional image creation function.
The ultrasonic diagnostic apparatus 500 generates a reception echo signal from a probe 1, a fundamental wave transmission unit 2 that transmits a transmission pulse of a fundamental frequency from the probe 1, and an ultrasonic echo received by the probe 1 and a beam. A reception delay unit 3 that performs forming, a DSC (Digital Scan Converter) 5 that creates a B-mode image, a CFM (Color Flow Mapping) image, and an M-mode image from the received echo signal, and a B-mode image and a CFM image An image memory 6 that stores a plurality of B-mode images and CFM images obtained by repeating the process as three-dimensional data, and a 3D processing unit 8 that creates a three-dimensional image from the three-dimensional data stored in the image memory 6. A CRT 9 for displaying the B-mode image, the CFM image, and the three-dimensional image; and an input unit 10 for an operator to input a command. It is equipped.
[0003]
[Problems to be solved by the invention]
FIG. 9 is an exemplary diagram of a three-dimensional image P (T) created based on three-dimensional data created from a plurality of B-mode images.
Since there is actually nothing in the cavity h, it should look black, but the noise n appears as if there is something.
This is because noise due to multiple reflection on the wall of the tissue was included in the original B-mode image.
[0004]
Although not shown in the drawing, motion artifacts are generated in a 3D image created from a plurality of CFM images and created based on the 3D data.
This is because a Doppler component resulting from moving the probe 1 is included in the original CFM image.
[0005]
Accordingly, an object of the present invention is to provide a three-dimensional image creation method and an ultrasonic diagnostic apparatus capable of creating a three-dimensional image free from noise due to the multiple reflection and the motion artifact.
[0006]
[Means for Solving the Problems]
In the first aspect, the present invention repeatedly creates a harmonic image by extracting a high-frequency component contained in the received ultrasonic wave, creates three-dimensional data from the obtained plural harmonic images, There is provided a 3D image creation method characterized by creating a 3D image based on 3D data.
In the three-dimensional image creation method according to the first aspect, three-dimensional data is created from a harmonic image created by extracting high-frequency components contained in received ultrasonic waves, and a three-dimensional image is created based on the three-dimensional data. create. Here, since the harmonic image is hardly affected by multiple reflection, it has a property that does not include noise due to multiple reflection. In addition, it has a property that does not include motion artifacts that occur in the CFM image. Therefore, it is possible to create a three-dimensional image free from the noise due to the multiple reflection and the motion artifact.
As for the properties of the above-mentioned harmonic image, for example, “71-S1-3 Tissue Harmonic Imaging: Mechanism that produces good omission; Soichiro Umemura; J Med Ultrasonics Vol.25 No.4 (1998)” and “71- S2-2 Tissue Harmonic Imaging in Diagnosis of Gastrointestinal Diseases: Yoshiki Sasaoka, Akihiro Ito, Ikuo Naito; J Med Ultrasonics Vol.25 No.4 (1998) ”.
[0007]
In a second aspect, the present invention extracts a high-frequency component contained in a probe and transmitting / receiving means for transmitting an ultrasonic wave having a fundamental frequency to the subject and receiving the ultrasonic wave from the subject, and a received ultrasonic wave. Harmonic image creating means for creating a harmonic image, 3D data creating means for creating 3D data from a plurality of harmonic images obtained by repeatedly creating the harmonic image, and the 3D data An ultrasonic diagnostic apparatus characterized by comprising a three-dimensional image creating means for creating a three-dimensional image based on the above.
In the ultrasonic diagnostic apparatus according to the second aspect, the three-dimensional image creation method according to the first aspect can be suitably implemented.
[0008]
In a third aspect, the present invention provides the ultrasonic diagnostic apparatus according to the second aspect, wherein the plurality of harmonic images are obtained by moving the probe in a direction substantially orthogonal to a scanning plane by sound rays. Provided is an ultrasonic diagnostic apparatus characterized by being either a harmonic image or a plurality of harmonic images obtained without moving a probe.
In the ultrasonic diagnostic apparatus according to the third aspect, in the case of a plurality of harmonic images obtained while moving the probe, two spatial axes defined by the harmonic image plane and one spatial axis in the moving direction of the probe are spatially separated. Three-dimensional data with three axes can be created. On the other hand, in the case of a plurality of harmonic images obtained without moving the probe, it is possible to create three-dimensional data with the two spatial axes defined on the harmonic image plane and the time axis as three spatial axes (this three-dimensional data). Is cut along a plane including the time axis, a so-called harmonic M-mode image is obtained.)
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention is not limited thereby.
[0010]
-First embodiment-
FIG. 1 is a block diagram showing an ultrasonic diagnostic apparatus according to the first embodiment of the present invention. This ultrasonic diagnostic apparatus 100 generates a reception echo signal from a probe 1, a fundamental wave transmission unit 2 that transmits a transmission pulse of a fundamental frequency from the probe 1, and an ultrasonic echo received by the probe 1 and a beam. A reception delay unit 3 that performs forming, a harmonic component extraction unit 4 that extracts a secondary high-frequency component included in the received echo signal and creates a harmonic component signal, and a B-mode image or a CFM image from the received echo signal DSC5 that creates a harmonic image from the harmonic component signal and a plurality of B-mode images and CFM images obtained by repeatedly creating the B-mode image, the CFM image, and the harmonic image And an image memory 6 for storing harmonic images as three-dimensional data, and a median filter for the three-dimensional data stored in the image memory 6 filter processing unit 7 that performs filter processing such as median filter) and morphology operation, 3D processing unit 8 that creates a 3D image from the filtered 3D data, the B-mode image, the CFM image, A CRT 9 for displaying a harmonic image and the three-dimensional image, and an input unit 10 for an operator to input a command and the like are provided.
[0011]
FIG. 2 is a flowchart showing the operation of the three-dimensional image display process by the ultrasonic diagnostic apparatus 100.
In step S1, the operator is inquired whether to use a harmonic image as the original data of the three-dimensional image. If the harmonic image is used, the process proceeds to step S2, and if the harmonic image is not used, the process proceeds to step S5.
[0012]
In step S2, DSC 5 is set to THI (Tissue Harmonic Imaging) mode. In other words, a mode for generating a harmonic image by extracting an n-th order high frequency component contained in the received echo signal is set. Here, n is an integer of 2 or more. Usually, n = 2.
In step S3, the probe 1 is moved in parallel as shown in FIG. The moving direction Md is a direction orthogonal to the scanning plane by sound rays. Thereby, a plurality of harmonic images F1 to FN which are tomographic images of the subject K are obtained. In addition, you may move the probe 1 so that it may beat. Further, the probe 1 may be moved manually by an operator, or may be automatically moved by some kind of probe moving mechanism. It is preferable to provide a detector for detecting the position / posture of the probe 1.
In step S4, a plurality of harmonic images F1 to FN are stored in the image memory 6 as the three-dimensional data V as shown in FIG. Note that it is preferable to create data between the harmonic images F1 to FN by interpolation calculation. Further, when the probe 1 is moved by the probe moving mechanism or when the position / orientation of the probe 1 is detected by a detector, it is preferable because the three-dimensional data V can be created in an accurate three-dimensional space arrangement.
Then, the process proceeds to step S8.
[0013]
In step S5, DSC 5 is set to B mode or CFM mode.
In step S6, the probe 1 is moved.
In step S7, a plurality of B-mode images or CFM images are stored in the image memory 6 as three-dimensional data V.
Then, the process proceeds to step S8.
[0014]
In step S8, a filtering process such as a median filter or a morphological operation is performed on the three-dimensional data V so that the region of interest is conspicuous. For example, the contrast between the tissue part and the cavity part is increased.
In step S9, a three-dimensional image is created from the filtered three-dimensional data V. For example, as shown in FIG. 5, a three-dimensional image P (T) is created by projecting along a specified line-of-sight direction T by the MIP (Maximum / Minimum Intensity Projection) method. Or the threshold value which can isolate | separate a tissue part and a cavity part is given, and a three-dimensional image is created by surface rendering (Surface Rendering). Further, a three-dimensional image such as an endoscopic image is created by projecting the viewpoint within the three-dimensional data V. Creating a three-dimensional image such as an endoscopic image is useful for diagnosing stenosis and aneurysms in blood vessels, stones and polyps in gallbladder, and the like.
In step S10, the three-dimensional image is displayed on the CRT 9.
Then, the three-dimensional image display process ends.
[0015]
FIG. 6 is an exemplary diagram of a three-dimensional image P (T) created from a plurality of harmonic images as three-dimensional data and created from the three-dimensional data.
The hollow portion h appears black and noise n as shown in FIG. 8 cannot be seen. There are also no movement artifacts.
This is because the original harmonic image does not include noise due to multiple reflection. Another reason is that it does not include motion artifacts that occur in the CFM image.
[0016]
-Second Embodiment-
In the second embodiment, the probe 1 is not moved in step S3 of FIG. The rest is the same as in the first embodiment.
In this case, in step S4 of FIG. 2, as shown in FIG. 7, a plurality of harmonic images F1 to FN are stored in the image memory 6 as three-dimensional data V. The three-dimensional data V is stored in the harmonic image plane. The three-dimensional data has the two spatial axes and the three time axes as the time axis. When this three-dimensional data V is cut along a plane including the time axis, an image like a M mode in which a temporal change in wall motion can be observed is a so-called harmonic M mode image.
Therefore, this second embodiment is useful for observing heart wall motion.
[0017]
【The invention's effect】
According to the three-dimensional image creating method and the ultrasonic diagnostic apparatus of the present invention, a three-dimensional image is created based on a harmonic image created by extracting a high-frequency component contained in received ultrasonic waves. It is possible to create a three-dimensional image free from noise and motion artifacts due to multiple reflections.
[Brief description of the drawings]
FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention.
FIG. 2 is a flowchart showing the operation of a three-dimensional image display process.
FIG. 3 is an exemplary view showing a state in which a probe is moved.
FIG. 4 is a conceptual diagram of a plurality of harmonic images and three-dimensional data.
FIG. 5 is a conceptual diagram showing creation of a three-dimensional image by MIP.
FIG. 6 is an exemplary view of a three-dimensional image according to the first embodiment of the present invention.
FIG. 7 is a conceptual diagram of three-dimensional data according to the second embodiment of the present invention.
FIG. 8 is a block diagram of an example of a conventional ultrasonic diagnostic apparatus.
FIG. 9 is a view showing an example of a conventional three-dimensional image.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 Ultrasonic diagnostic apparatus 1 Probe 2 Fundamental wave transmission part 3 Reception delay part 4 Harmonic component extraction part 5 DSC
6 Image memory 7 Filter processing unit 8 3D processing unit 9 CRT

Claims (3)

An ultrasonic diagnostic apparatus that displays a three-dimensional image of a subject,
Asks the operator whether to use harmonic image data as the original data of the three-dimensional image, and decides to use the harmonic image data, B-mode image data, or CFM image data. A decision means to
When an ultrasonic wave having a fundamental frequency is transmitted to the subject and an ultrasonic wave from the subject is received, and the position and orientation of the probe are fixed with respect to the subject, it corresponds to the two-dimensional data of the subject. A probe that receives ultrasonic waves and receives ultrasonic waves corresponding to a plurality of sets of two-dimensional data according to the movement of the position or posture of the probe when the position or posture of the probe is moved with respect to the subject And transmission / reception means;
A harmonic image creating means for extracting a high frequency component contained in the received ultrasonic wave and creating a harmonic image;
B-mode / CFM image creating means for creating a B-mode image or CFM image from the received ultrasound,
The harmonic image, B-mode image, or CFM image is created according to the movement of the probe position or orientation, and three-dimensional image data is created from the created harmonic image, B-mode image, or CFM image. 3D image data creating means for
An ultrasonic diagnostic apparatus comprising: a three-dimensional image creating unit that creates a three-dimensional image of the harmonic image, the B-mode image, or the CFM image based on the three-dimensional image data. The ultrasonic diagnostic apparatus according to claim 1,
The three-dimensional image creation means performs a filtering process on the three-dimensional image data received from the three-dimensional image data creation means, and generates the three-dimensional image based on the three-dimensional image data subjected to the filtering process. An ultrasonic diagnostic apparatus characterized by creating. The ultrasonic diagnostic apparatus according to claim 1 or 2,
The three-dimensional image creating means creates a three-dimensional image corresponding to a three-dimensional image by MIP (Maximum / Minimum Intensity projection) method, a three-dimensional image by surface rendering, or an endoscopic image. .

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