JP3046424B2 - Ultrasound diagnostic equipment - 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 diagnostic apparatus provided with means for imaging blood flow information by a color Doppler method, so-called color flow mapping (CFM) method.

[0002]

2. Description of the Related Art In recent years, as the development of an ultrasonic diagnostic apparatus has progressed, attempts have been made to image blood flow information by a color Doppler method.

The color flow mapping (CFM) method is
This utilizes the Doppler effect of ultrasonic waves. That is, when the ultrasonic beam transmitted into the living body is reflected by the moving reflector (blood cell), the frequency of the reflected wave (reception frequency)
Uses the effect of shifting according to the moving speed of blood cells (Doppler effect) compared to the transmission frequency, obtains blood flow velocity data according to the shift frequency (Doppler signal), A blood image is generated by distributing the blood image in a predetermined two-dimensional space.

[0004] However, the position of the blood vessel in the living body fluctuates with the heart beat, and the blood flow velocity constantly changes with the heart beat. It was necessary to obtain one blood flow image in a relatively short period of time, so that the effective field of view of the blood flow image had to be narrowed. FIG. 10 to FIG. 13 are diagrams showing this state. As shown in the figure, the swing angle θ ₀ of the ultrasonic beam that can be transmitted and received in a relatively short time in the heart beat cycle naturally becomes narrow, and the effective field of view also becomes narrow according to the swing angle θ ₀ . As a result, the blood flow velocity in a wide range cannot be observed, and it becomes difficult to find an abnormal site such as a blood reservoir existing in a blood vessel, and precise ultrasonic diagnosis cannot be performed.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ultrasonic diagnostic apparatus capable of obtaining a blood flow image over a wide range.

[0006]

An ultrasonic diagnostic apparatus according to the present invention has a plurality of transducers arrayed in a matrix, and is a type of two-dimensional array probe that can be applied to a body surface of a subject. A means for outputting a signal corresponding to an electrocardiogram waveform of the subject, and a means for driving the two-dimensional array probe to repeatedly scan a fan-shaped two-dimensional scanning surface inside the subject with ultrasonic waves, particular in accordance with a signal corresponding to the ECG waveform
Means for electronically changing the angle of the two-dimensional scanning plane by a predetermined angle in synchronization with a heartbeat time phase of the two-dimensional array
Doppler signal based on the echo signal received through the
And a means for generating the image by repeating the two-dimensional scanning.
Stores all collected Doppler signals in association with the heartbeat phase
And input means for designating a desired heartbeat phase
And the designated one of the stored Doppler signals.
Means for obtaining three-dimensional blood flow image data for a specific heartbeat phase using a Doppler signal related to the heartbeat phase.

[0007]

According to the present invention, blood flow information obtained at the same time phase in a repetition cycle of an electrocardiogram waveform obtained from a subject is collected to obtain one blood flow image, thereby obtaining a heart image of a blood vessel. A blood flow image with a wide effective field of view can be obtained while suppressing the effects of fluctuations due to pulsation and changes in blood flow velocity. As a result, a wide range of blood flow can be observed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ultrasonic diagnostic apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a schematic configuration of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention, FIG. 2 is a diagram illustrating a timing of acquiring a blood flow image according to an electrocardiogram, and FIG. FIG. 4 is a diagram illustrating a time phase indicating an acquisition timing, and FIG. 4 is a diagram illustrating a transmission direction of an ultrasonic wave according to the time phase. The ultrasonic diagnostic apparatus employs a sector electronic scanning method, but may employ another scanning method, for example, a linear electronic scanning method.

The electrocardiogram detector 2 divides one cardiac cycle of the electrocardiogram waveform shown in FIG. 3 into a plurality of time phases, here, four time phases from a first time phase S ₁ to a fourth time phase S _4. Then, an electrocardiogram pulse is output for each time phase. The time interval between each time phase from the first time phase S ₁ to the fourth time phase S _4, preset multiple standard intervals provided for each case of a plurality of such cases of infant or adult It is also possible to select from among them, or to calculate each time based on the R, S, T and P waves of the electrocardiogram waveform of the subject obtained by providing a device for detecting the electrocardiogram waveform from the subject. It may be a thing.

The beam direction controller 3 controls the switching of the transmission angle B of the ultrasonic beam transmitted from the probe 1 in synchronization with the ECG pulse given from the ECG detector 2. The transmission angle B is, as shown in FIG.
This refers to the direction of each ultrasonic beam with respect to the direction of arrow SD. Here, the transmission angles are B ₁ , B ₂ , B ₃ ,
Assumed to be set in the four directions of B _4, the spreading angle defined by the transmission angle B _1, B ₄ between the endmost theta ₁₀
, And the difference between adjacent transmission angles is θ _d , and they are all the same.

[0011] The ultrasonic probe 1, as shown in FIG. 4, be those transmits ultrasound beams from the desired ultrasonic wave transmission and reception point P ₀ of the subject surface PS in vivo, it receives the echo signal Then, under the control of the beam direction controller 3, the ultrasonic beam is transmitted as shown in FIG. That is, the first to fourth time phases S ₁ to S 4 divided into four in the same heart cycle H
Transmitted in the same transmission angle B for each S _4, and transmits the transmission angle B from the first in cardiac cycle again the transmission angle switching in synchronization with the switching spite of H B every fourth time phase. This transmission operation is repeated four times (ie, four heartbeat cycles), and one cycle is completed. Specifically, in the first cardiac cycle H ₁ transmitted four times from the first to the transmission angle B ₁ direction in the fourth time phase each S ₁ to S _4, in the second cardiac cycle H ₂ transmission angle B ₂ send 4 times from a first direction to a fourth time phase each S ₁ to S _4, likewise transmit while changing the transmission angle to the fourth cardiac cycle H ₄ or less,
The first cycle ends. In this embodiment, the collection of original data (16 CFM image data) for obtaining a blood flow image with a wide effective field of view is completed at the end of each cycle, and one transmission is the same as in the conventional case. Swing angle θ ₀
In this range, the ultrasonic beam is transmitted in a fan-shape within one range to obtain one CFM image data. In addition, the transmission angle may be changed by providing a mechanism for physically tilting the probe 1 under the control of the beam direction controller 3, or a two-dimensional array in which a plurality of transducers are arranged in a matrix. An array probe may be adopted to cope with the problem.

The CFM image generating section 4 generates a color flow mapping image (hereinafter abbreviated as “CFM image”) from the echo signal obtained by the probe 1. The data is supplied to the serial memory 6 via the memory.

The changeover switch 5 switches the storage area E of the serial memory 6 in synchronization with an electrocardiogram pulse from the electrocardiogram detector 2. FIG. 5 is a diagram showing the changeover switch 5, the serial memory 6, and the changeover switch 15. The changeover switch 5 includes a terminal T ₀ connected to the CFM image generation unit 4 and terminals T ₁ , T ₂ , T ₃ , and T _4.
Alternatively, the connection is made in accordance with the input from the electrocardiogram detector 2, and the connection relationship is switched in accordance with the change of the cardiac cycle. That is, the terminal T ₀ is connected to the first heartbeat H ₁
In the case of (transmission direction B ₁ ), the terminal T ₁ is connected. In the case of the second heartbeat H ₂ (transmission direction B ₂ ), the terminal T ₂ is connected.
When the heart rate is H ₃ (transmission direction B ₃ ), connect to terminal T ₃ ,
At the time of the fourth heartbeat H ₄ (transmission direction B ₄ ), it is connected to the terminal T ₄ and selects the storage area E of the serial memory 6.

The serial memory 6 stores the CFM image data generated by the image generation unit 4 in storage areas E _{11 to} E ₁₆ divided in a matrix for each transmission direction and for each time phase. . As shown in FIG. 5, wherein the storage area E ₁₁ to E ₁₆ are be divided into 16, CFM which according changeover of the changeover switch 5, to obtain the same cardiac cycle
The image data is stored in the same row, and the CFM image data obtained in the same time phase is stored in the same column. Then, the stored CFM image data is passed through the changeover switch 15 to the interpolator 7.
Is supplied to the three-dimensional memory 9 via the changeover switch 8.

The changeover switch 15 has the same configuration as the changeover switch 5, and operates in accordance with an input from the display control unit 11.
The terminal T _10, and alternatively connected to either the terminal _{T 11, T 12, T 13} , T 14, storage area E ₁₁ of the serial memories 6 ~
And it outputs each data of the same time phase from the sixteen CFM image data stored in the E _16.

The interpolator 7 performs an interpolation process for each CFM image data of the same time phase (here, four CFM image data) output through the changeover switch 15 to create high-density three-dimensional image data. The data is supplied to the three-dimensional memory 9 via the changeover switch 8. FIG. 6 shows an example of this interpolation processing method. That is, CFMs adjacent to each other
Image data, wherein the target I ₁₁ and I ₂₁ is the new point P _h between a point P _n of a point on the I ₁₁ P _m and I ₂₁ provided,
Data values DP _m of the point P point data values DP _h of _h P _m and the point P _n, is calculated using equation (1) below on the basis of the DP _n. Note that the point P _m and the point P _n, the image I ₁₁ and the image I
₂₁ are the same relative positions on each plane, and the point P
The distance between _m and the point P _h and alpha, the distance between the point P _n and the point P _h and beta. _{DP h = (α / α +} β) × DP m + (β / α + β) × DP n ... (1)

The three-dimensional memory 9 has, as shown in FIG.
A plurality of regions, here four regions R ₁ , according to four phases,
The three-dimensional image data 3DD divided into R ₂ , R ₃ , and R ₄ and generated by the interpolator 7 for each of the four time phases is converted into each time phase according to the switching of the changeover switch 8 similar to the changeover switch 15. In each case, three-dimensional image data relating to the first time phase S _{1 is} stored in the area R ₁ , three-dimensional image data relating to the second time phase S _{2 is} stored in the area R ₂ , and three-dimensional image data relating to the third time phase S ₃ data area R _3, respectively store the three-dimensional image data regarding the fourth time phase S ₄ in the region R _4.

The display control unit 11 includes a changeover switch 15,
The switching switch 10 controls the switching operation so as to read out the three-dimensional image data 3DD of any one of the time phases stored in the three-dimensional memory 9; And a display output command to the analog / D / A converter 13.

The three-dimensional image reconstructor 12 outputs the three-dimensional image data 3 of any one of the phases output from the three-dimensional memory 9.
By reconstructing the DD, a blood flow image of the subject P is converted into a three-dimensional image,
Here, it is assumed that two projected images for the left and right eyes are generated and provided for stereo display. Note that the three-dimensional image creation method is not limited to the stereo image creation method, and other creation methods, such as a method of creating a so-called pseudo three-dimensional image in which the surface image is oblique, may be adopted. FIG. 8 is a diagram showing the creation of the projection image. The three-dimensional image reconstructor 12 uses the simple addition projection method or the maximum value projection method based on the designated viewpoint and the line-of-sight directions D _R and D _L to project the right-eye projection image I
Obtaining and _R, and a projection image I _L for the left eye. Projection image I _L of the projected image I _R and the left eye of a right eye, at the time of display, are displayed alternately, right or left corresponding to each display image using the glasses to switch shutter in accordance with the alternating display A method of viewing the image only with the eyes and obtaining a three-dimensional sensation is to adopt a so-called time-division stereo display method, but other stereo display methods, such as a peep-type stereo display method and a deflection stereo display using deflection glasses. Of course, the law may be adopted.

The D / A converter 13, the projected image is reconstructed by three-dimensional image reconstructor 12 I _R, the display 1 I _L
4, and D / A converted. The display 14 is for displaying a projection image I _R, the I _L alternately. Next, the operation of this embodiment will be described.

As described above, FIG. 2 is a time chart showing the acquisition timing of the blood flow image according to the electrocardiogram. As shown in FIG. 2, during the first cycle H ₁ , the time phase S ₁
, The ultrasonic beam is transmitted and received in a fan shape at the transmission angle B ₁ , and the first CFM image I ₁₁ is transmitted through the CFM image generation unit 4.
There is stored in the storage area E ₁₁ of the serial memory 6, and, similarly transmitted in time phase S ₂ angle B ₁ 2 sheet of CFM image I ₁₂ of the fan ultrasonic beam is obtained is transmitted and received
There is stored in the storage area E _12, the same applies hereinafter to the CFM image I ₁₃ are storage areas E ₁₃ obtained in time phase S _3, stores CFM image I ₁₄ obtained in the time phase S ₄ is area E ₁₄
Are stored respectively. Incidentally, during the first period H _1, the switching switch 5 is connected to the terminal T _1.

Then, during the second cycle H ₂ , the transmission angle is changed to the transmission angle B ₂ , and obtained in the time phases S ₁ , S ₂ , S ₃ , and S ₄ , similarly to the case of the first cycle H _1. CF
The M images I ₂₁ , I ₂₂ , I ₂₃ , I ₂₄ are stored in the corresponding storage areas E ₂₁ , E ₂₂ , E ₂₃ , E ₂₄ of the serial memory 6. Incidentally, during the second period H _2, the switching switch 5
It is connected to the terminal T _2.

During the third period H ₃ and the fourth period H ₄ , the transmission angle is changed to the transmission angle B ₃ and the transmission angle B ₄ , respectively, and the respective time phases S ₁ , S ₂ , S ₃ and S _{4 are changed.} Each time, CF
M images I ₃₁ , I ₃₂ , I ₃₃ , I ₃₄ , CFM images I ₄₁ ,
I ₄₂ , I ₄₃ , and I ₄₄ are obtained, and the respective images in the serial memory 6 are stored in the corresponding storage areas E ₃₁ , E ₃₂ , E ₃₃ , E ₃₄ , and E ₄₁ , E ₄₂ , E ₄₃ , and E _44. You. Incidentally, during the third period H ₃ selector switch 5 be connected to the terminal T _3, during the fourth period H ₄ is connected to the terminal T _4.

Thus, the data collection and CFM image creation operation for the first cycle is completed. Then, the 16 CFM images obtained for each of the four time phases and four transmission angles stored in the serial memory 6 are output via the changeover switch 15 for each of the four CFM images for the same time phase. Is done. First, the changeover switch 15 is connected to the terminal T _11,
Four CFM images I ₁₁ obtained in the first time phase S _1, I _21,
I ₃₁ and I ₄₁ are output, and the interpolator 7 and the changeover switch 8
Via a 3-dimensional relates time phase S ₁ first data 3DD ₁
Is stored in a region R ₁ in the three-dimensional memory 9 corresponding to the first time phase S ₁ . Changeover switch 8 at this time
It is is connected to the terminal T _21.

When the output and storage of the four CFM images I ₁₁ , I ₂₁ , I ₃₁ and I ₄₁ obtained in the first time phase S ₁ are completed, the changeover switch 15 is switched to the terminal T ₁₂ and the second time phase S 1 The four CFM images I ₁₂ , I ₂₂ , I ₃₂ , and I ₄₂ obtained in S ₂ are output, and similarly through the interpolator 7 and the changeover switch 8, as three-dimensional data 3DD ₂ relating to the second time phase S _2. Are stored in a region R ₂ in the three-dimensional memory 9 corresponding to the second time phase S ₂ . During this time, the changeover switch 8 is been switched to connect to the terminal T _22.

[0026] Similarly, CFM images _{I 13, I 23, I 33} , the third time phase obtained from I ₄₃ S ₃ on 3D data 3DD ₃ is 3-dimensional memory 9 obtained in the third time phase S ₃ And three-dimensional data 3DD ₄ relating to the fourth time phase S ₄ obtained from the CFM images I ₁₄ , I ₂₄ , I ₃₄ , and I ₄₄ obtained in the fourth time phase S ₄ are stored in the region R ₃ . Region R in three-dimensional memory 9
₄ will be stored.

As described above, the four three-dimensional data 3DD ₁ , 3DD ₂ , 3D obtained for each of the four phases in the first cycle
The storage of D ₃ and 3DD ₄ ends. Using these four three-dimensional data, a three-dimensional image to be used for diagnosis, here a projected image, is created.

When the observer designates which time phase the user wants to diagnose in the display control section 11, the changeover switch 10 switches the connection relation in accordance with the designation. For example,
When the first time phase S _{1 is} designated, the changeover switch 10 turns on the terminal T _{30 and the} terminal T _31, and the three-dimensional data 3DD on the first time phase S ₁ stored in the region R ₁ is stored.
₁ is output. If another phase is specified,
The changeover switch 10 switches to a connection relationship according to the designation, and outputs three-dimensional data in a time phase according to the designation.

The 3 selectively output from the three-dimensional memory 9
Dimensional data 3DD ₁ is sent to the three-dimensional image reconstruction unit 12, display instruction instructed from the display control unit 11, i.e. on the basis of the viewpoint position and viewing direction, two of the projected image I _R for the right and left eyes, It is created in I _L. These projected images I _R and I _L
Is a three-dimensional blood flow image, which is alternately displayed on the display 14 via the D / A converter 13 based on the time-division stereo display method as described above. Observer, by viewing the projected image I _R, the I _L alternately, to obtain a 3-dimensional sense can be to observe a wide range of blood flow diagnosis. In addition, four types of projection images may be obtained from all three-dimensional data 3DD of each time phase and displayed simultaneously, or a so-called animation display in which each projection image is continuously displayed while switching each image may be used. It is possible to observe how the blood flow changes over time.

As described above, according to the present embodiment, the beam direction of the probe 1 is switched in synchronism with the heart beat of the subject P, and the beat cycle is divided into predetermined time intervals, so that each time phase is changed. Blood flow image data can be obtained, so that even if the position of a blood vessel moves or the blood flow velocity changes with the pulsation of the heart, echoes from a wide range of the same time phase are not affected by them. A signal can be obtained, and as a result, a wide-range blood flow image can be obtained. In this embodiment,
Since the three-dimensional data is generated, the blood flow data to be imaged can be displayed as a three-dimensional image, and information such as a three-dimensional positional relationship of the blood flow can be obtained.

Next, a second embodiment will be described. This embodiment is different from the first embodiment in that three-dimensional data is obtained, but a plurality of CFMs obtained in different periods and at the same time phase are obtained.
The images are displayed by connecting the images with their boundaries. FIG. 9 is a diagram showing transmission of an ultrasonic beam by the apparatus of the present embodiment, and FIG. 10 is a diagram showing a plurality of C beams obtained by the transmission.
FIG. 5 is a diagram illustrating one composite CFM image obtained by composing FM images.

As shown in FIG. 9, for example, in a first time phase S ₁ of a first cycle H ₁ , a plurality of ultrasonic beams R _{11 to} R _1m are transmitted and received at a swing angle θ _{d ′} and a first CFM image is formed. Second
In the first time phase S ₁ of the cycle H ₂ , the previous ultrasonic beam R ₁₁
A plurality of ultrasonic beams R _{21 to} R _2m are transmitted / received at a swing angle θ _{d ′} in the extension direction of R _1m to obtain a second CFM image, and similarly in the case of the third cycle H ₃ or the fourth cycle H ₄ obtaining a third, fourth CFM image, respectively, in phase S _1. Note that the angle θ
₁₀ is four times the swing angle θ _{d '} . And the first to fourth
Are synthesized at the boundary of the four CFM images to obtain one synthesized CFM image.

[0033] As shown in FIG. 10, the display angle of the composite CFM image obtained by this embodiment is an angle theta _10,
Compared to the display angle θ _d of the conventional CFM image indicated by the dotted line,
A wide viewing angle can be obtained. As mentioned above,
According to this embodiment, a wide range of blood flow images can be obtained as in the previous embodiment.

The present invention is not limited to the above embodiment, but can be implemented with various modifications. For example, in the above embodiment, the heart beat cycle is divided into four time phases, but may be divided into more or less. In this case, a more accurate blood flow image can be obtained.

[0035]

As described above, according to the present invention, one blood flow image is obtained by collecting blood flow information obtained at the same time phase in a repetition cycle of an electrocardiogram waveform obtained from a subject. As a result, it is possible to obtain a blood flow image with a wide effective field of view while suppressing the effects of fluctuations in blood vessel heart beat and changes in blood flow velocity, thereby observing the state of blood flow over a wide range. It is possible to provide an ultrasonic diagnostic apparatus capable of performing the above.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention.

FIG. 2 is a time chart showing a data collection timing of the apparatus shown in FIG. 1;

FIG. 3 is a view for explaining a time phase shown in FIG. 2;

FIG. 4 is a view for explaining a transmission angle shown in FIG. 2;

FIG. 5 is a view showing storage areas in the serial memory shown in FIG. 1 corresponding to a plurality of CFM images obtained at the data collection timing shown in FIG. 2;

FIG. 6 is a view showing an example of an interpolation process of the interpolator shown in FIG. 1;

FIG. 7 is a diagram showing storage areas corresponding to each time phase in the three-dimensional memory shown in FIG. 1;

FIG. 8 is a view for explaining projection image creation as an example of a three-dimensional image method in the three-dimensional image reconstructor shown in FIG. 1;

FIG. 9 is a view for explaining a data collection operation in the second embodiment.

FIG. 10 shows one synthetic CF obtained by the second embodiment.
The figure which shows an example of an M image.

FIG. 11 is a diagram illustrating an example of a conventional data collection operation for a CFM image.

FIG. 12 is a view showing an effective field of view of the CFM image obtained in FIG. 11;

FIG. 13 is a view for explaining another example of a conventional data collection operation for a CFM image.

FIG. 14 is a view showing an effective field of view of the CFM image obtained in FIG. 13;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ultrasonic probe, 2 ... Electrocardiogram detector, 3 ... Beam direction control part, 4 ... CFM image generation part, 5 ... Changeover switch,
6 serial memory, 7 interpolator, 8 switch
9: three-dimensional memory, 10: changeover switch, 11: display controller, 12: three-dimensional image reconstruction unit, 13: D / A converter, 14: display.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61B 8/00-8/15

Claims (4)

(57) [Claims] 1. A two-dimensional array probe having a plurality of transducers arranged in a matrix and applied to a body surface of a subject, and outputting a signal corresponding to an electrocardiogram waveform of the subject. means for, the two-dimensional scanning plane of the fan-shaped inside the subject by driving the 2-dimensional array probe together repeatedly scan ultrasonically the specific heartbeat time phase in accordance with a signal corresponding to the electrocardiogram waveform Means for electronically changing the angle of the two-dimensional scanning plane by a predetermined angle in synchronization with an echo signal received through the two-dimensional array probe.
Means for generating a Doppler signal based on all the Doppler signals collected by repeating the two-dimensional scanning.
Means for storing a signal in association with a heartbeat phase; input means for specifying a desired heartbeat phase; and the specified heartbeat in the stored Doppler signal.
Means for obtaining three-dimensional image data of a blood flow relating to a specific heartbeat time phase using a Doppler signal related to the time phase. 2. The method according to claim 1, wherein the means for obtaining the three-dimensional image data includes a plurality of waveforms corresponding to a plurality of phases of the electrocardiogram waveform for each transmission angle.
A memory for storing a number of images, and data based on the same time phase stored in the memory.
And a three-dimensional memory for storing the generated three-dimensional image data.
The ultrasonic diagnostic apparatus according to claim 1, further comprising:
Place. 3. A method for obtaining three-dimensional image data, comprising :
Interpolation processing is performed on images of the same time phase stored in the memory
Interpolating means for obtaining the three-dimensional image data by
The ultrasonic diagnostic apparatus according to claim 2, wherein: 4. A means for obtaining the three-dimensional image data,
From multiple 3D image data with different heartbeat phases,
A plurality of projection images having different phases are created, and the plurality of projection images are
It has a function to switch and display heartbeat phases.
2. The ultrasonic diagnostic apparatus according to claim 1, wherein: