JP2000201930A - Three-dimensional ultrasonograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily measure bloodstream with high accuracy. SOLUTION: This three-dimensional ultrasonograph is provided with signal collecting means 1, 2, 3 for collecting receive signals of ultrasonic echoes by scanning a three-dimensional area including a measured object blood passage in a subject, with ultrasonic beams; a bloodstream information acquiring means 5 for obtaining bloodstream information of the three-dimensional area from the receive signals collected by the signal collecting means; a bloodstream image recomposing means 7 for recomposing the bloodstream image of a cross section intersecting the longitudinal direction of the blood passage, on the basis of the bloodstream information obtained by the bloodstream information acquiring means; concerned area setting means 8, 10 for setting a concerned area on the bloodstream image recomposed by the bloodstream image recomposing means; and a bloodstream computing means for computing bloodstream passing through the concerned area set by the concerned area setting means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional ultrasonic diagnostic apparatus for measuring a blood flow using three-dimensional biological information.

[0002]

2. Description of the Related Art Conventionally, blood flow measurement is clinically important among blood flow measurements based on the ultrasonic Doppler effect using a medical ultrasonic diagnostic apparatus, and many attempts have been made to improve the measurement accuracy. (See, for example, US Pat.
No. 322). One of them is a region of interest (ROI) orthogonal to a plurality of ultrasonic beam scanning lines.
An apparatus is known which sets est) and measures the blood flow passing through the region of interest based on the blood flow information on the region of interest.

On the other hand, in recent years, a three-dimensional ultrasonic diagnostic apparatus for acquiring three-dimensional biological information has been proposed and attracted attention. In this device, a received signal from the three-dimensional area is collected by scanning a three-dimensional area of the subject with an ultrasonic beam, and this is reconstructed and displayed as three-dimensional volume information. In this case, 3 of the ultrasonic beam
As the dimensional scanning method, there are known a type in which a scan surface is moved manually or mechanically, and a type in which electronic scanning is performed in real time using a two-dimensional array probe.

[0004]

The above-mentioned conventional measuring method is for obtaining a blood flow volume, which is a volume on a two-dimensional tomographic image. It is necessary to assume that the flow velocity distribution is axially symmetric on both sides of the region. Also, in order to calculate the flow velocity in the blood flow path from the Doppler velocity along the scanning line direction of the ultrasonic beam, it is necessary to correct the angle between the scanning line and the blood flow path. The measurement is performed on two cross sections of the blood flow path orthogonal to each other. Therefore, in the conventional measurement of blood flow, a measurement error occurs due to the assumption that the flow velocity distribution in the region of interest is axially symmetric, and measurement on two cross sections for eliminating correction of the ultrasonic Doppler angle is generally complicated. There was such a problem.

On the other hand, although a three-dimensional ultrasonic diagnostic apparatus is also known as described above, it is not particularly conscious of a time resolution required for obtaining blood flow information. Therefore, the conventional three-dimensional ultrasonic diagnostic apparatus is unsuitable for measuring a blood flow in which time resolution is particularly important in blood flow information.

The present invention has been made in consideration of such conventional problems, and has as its object to provide a three-dimensional ultrasonic diagnostic apparatus capable of easily and accurately measuring a blood flow. I do.

[0007]

In order to achieve the above-mentioned object, the present inventor has proposed a tomographic image (hereinafter referred to as a "short-axis cross section") on an arbitrary cross section (hereinafter referred to as "short-axis cross section") intersecting the flow path in the longitudinal direction (axial direction). The blood flow information at a plurality of short-axis cross sections parallel to the short-axis cross section in the blood flow path is obtained by scanning the ultrasound beam to obtain the blood flow information for the region of interest in the “blood vessel short-axis image”. Then, the velocity distribution information in the region of interest was determined based on the obtained blood flow information, and the idea of an apparatus for measuring the blood flow using the velocity distribution information was obtained. This greatly reduces the measurement error due to the assumption of the flow velocity distribution axis symmetry and the positional deviation of the region of interest in the flow measurement based on the conventional two-dimensional image, and also makes the short-axis cross section of the blood flow path orthogonal to the ultrasonic beam scanning line. It has been found that the flow measurement without the angle dependence between the beam and the blood flow path can be performed by using the blood flow information of the cross section to be performed.

[0008] A three-dimensional ultrasonic diagnostic apparatus according to the present invention comprises:
It is completed based on the above idea.

That is, according to the first aspect of the present invention, there is provided a signal collecting means for collecting a reception signal of an ultrasonic echo by scanning a three-dimensional region including a blood flow path to be measured in a subject with an ultrasonic beam. Blood flow information obtaining means for obtaining the blood flow information of the three-dimensional region from the received signals collected by the signal collecting means; and blood flow information of the blood flow path based on the blood flow information obtained by the blood flow information obtaining means. Blood flow image reconstruction means for reconstructing a blood flow image of a cross section that intersects in the longitudinal direction, and a region of interest setting means for setting a region of interest on a blood flow image reconstructed by the blood flow image reconstruction means, A blood flow calculating means for calculating a blood flow passing through the region of interest set by the region of interest setting means.

According to a second aspect of the present invention, there is provided a signal collecting means for collecting a reception signal of an ultrasonic echo by scanning a three-dimensional region including a blood flow path of a measurement object of an object with an ultrasonic beam, and the signal collection means. Tomographic image obtaining means for obtaining a three-dimensional tomographic image of the three-dimensional area from the received signals collected by the collecting means, and a region of interest setting means for setting a region of interest on the three-dimensional tomographic image obtained by the tomographic image obtaining means A blood flow information obtaining unit that obtains blood flow information of only the region of interest by scanning the region of interest set by the region of interest with an ultrasonic beam, and a blood flow information obtaining unit that obtains the blood flow information. And a blood flow calculating means for calculating a blood flow passing through the region of interest based on the obtained blood flow information.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the region of interest includes a plurality of cross sections parallel to a cross section intersecting the longitudinal direction of the blood flow path, and the blood flow is controlled. The calculating means is means for calculating a blood flow passing through the region of interest from the blood flow information of the plurality of cross sections.

According to a fourth aspect of the present invention, in the first aspect of the present invention, a cross section crossing the blood flow path is a cross section orthogonal to a scanning line of the ultrasonic beam. It is characterized by the following.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, a blood flow image of a cross section intersecting the blood flow path and a blood flow image of a reference surface of the blood flow path are provided. It is characterized by further comprising means for displaying a flow image on the same screen.

According to a sixth aspect of the present invention, in the invention of the fifth aspect, means for designating information on a blood flow direction on a reference plane of the blood flow path, and information on the blood flow direction designated by the means. Means for calculating the absolute value of the blood flow velocity by utilizing the method.

According to a seventh aspect of the present invention, in the first aspect of the present invention, the means for designating a plurality of the regions of interest and the plurality of regions of interest respectively designated by the means are passed. Means for calculating the blood flow to be performed;
Means for calculating another characteristic amount from the blood flow rates of the plurality of regions of interest calculated by this means.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a three-dimensional ultrasonic diagnostic apparatus according to the present invention will be described with reference to the drawings.

The three-dimensional ultrasonic diagnostic apparatus shown in FIG. 1 is connected to a system controller 11, which is a control center of the whole, an apparatus main body SS which operates under the control of the controller 11, and this apparatus main body SS. 2D array probe 1. Of these, the device main body SS
Transmitting system 2, receiving system 3, B-mode processing system 4, Doppler processing system 5, digital scan converter (DSC) 6,
3D digital scan converter (3D-DS
C) 7, display system 8, flow rate calculation unit 9, and ROI input unit 1
0 is included.

The 2D array probe 1 has a configuration in which a plurality of ultrasonic transducers are arranged in a two-dimensional array. Each of the transducers receives a drive signal from the transmission system 2 and is driven under a predetermined delay pattern condition. As a result, as shown in FIG. 2, the ultrasonic beam 3DB is applied to a measurement-symmetric blood flow path (blood vessel) in the subject OB.
A volume scan (three-dimensional scan) is performed so as to be spatially focusable in a three-dimensional region including the BL, and a reception signal of an ultrasonic echo from each point in the three-dimensional region in the ultrasonic beam 3DB is collected, and is collected. Send to receiving system 3. The reception signal obtained for each direction of the ultrasonic beam 3DB by the receiving system 3 is converted into tomographic image data by the B-mode processing system 4 and is converted into blood flow information by the Doppler processing system 5, respectively. The image based on these data is DSC
It is displayed on the monitor of the display system 8 via the 6 and 3D-DSC7.

In the 3D-DSC 7, a 3D coordinate calculator 10 and its 3D memory 11 are provided as shown in FIG.
And a reconstructed image calculation unit 12 and its memory 13. Therefore, the data for each beam direction is converted into data corresponding to the real space by the 3D coordinate calculation unit 10, stored in the 3D memory 11, and the reconstructed image calculation unit 12 converts an arbitrary An operation for creating and displaying a projection image or a volume image on a cross section is performed, and these data are stored in the memory 13. Then, the reconstructed image is displayed on the screen of the display system 8 as a projection image or a volume image. As this display method, any of a normal two-dimensional display, a divisional simultaneous display of a plurality of sections, a 3D display by volume rendering, and the like can be set.

In this state, blood flow measurement is performed. The principle of this blood flow measurement will be described with reference to FIG. First, in a short-axis cross section PL1 orthogonal to the axial direction (long-axis direction) AX in the blood flow path BL shown in FIG. 4, the flow rate Q of the blood flow is determined by the cross-sectional area S0 of the short-axis cross section PL1 and the blood flow path. By the inner product of the flow velocity v0 in the axial direction AX of BL,

(Equation 1) It can be obtained by the integral equation.

Here, in the blood flow measurement based on the ultrasonic Doppler effect, the velocity along the scanning line direction BL of the ultrasonic beam is detected as the Doppler velocity vd instead of the velocity v0 in the axial direction of the blood flow path BL. . Therefore, a short-axis cross section (C plane) PL2 orthogonal to the scanning line LA is considered in the blood flow path BL, and when the angle between the scanning line LA and the axial direction AX of the blood flow path BL is θ, the above-described angle is obtained. The flow velocity v0 and the cross-sectional area S0 are calculated using the Doppler velocity vd and the cross-sectional area S of the short-axis cross section PL2 orthogonal to the scanning line direction BL.

(Equation 2) Can be represented by

By substituting this [Equation 2] into the above [Equation 1],

(Equation 3) Is obtained.

Accordingly, when the cross-sectional area S of the short-axis cross section PL2 orthogonal to the scanning line direction in the blood flow path BL and the Doppler velocity vd are obtained, the product of the two does not use θ, that is, the angle dependence is reduced. It can be seen that the blood flow can be calculated directly without any calculation.

At the time of such a blood flow measurement, a blood flow image including the blood flow path BL at the measurement site is displayed on a monitor of the display system 8 in a normal two-dimensional display, a multi-section simultaneous display, or a 3D display by volume rendering. And the like, and the ROI including the marker can be specified on the image. The ROI is operated by an operator via an ROI input unit 10 such as a trackball or a mouse.

Here, an example of setting the blood flow image and the ROI will be described with reference to FIGS.

FIG. 5 shows a blood flow image (hereinafter referred to as "blood vessel long-axis image") IM1 and its blood vessel long-axis image I on the reference plane A1 of the blood flow path.
A rectangular ROI 30 that can be specified at an arbitrary measurement site where the blood flow on M1 is to be obtained is shown. The ROI 30 is set perpendicular to the scanning line direction so as to designate a short-axis cross section perpendicular or substantially perpendicular to the scanning line direction of the ultrasonic beam as a measurement site cross section, and measures blood flow information only in the ROI 30. By matching the Doppler scan area to the ROI position as sometimes obtained, scanning at other locations can be omitted, and a blood flow image with improved time resolution can be obtained.

Further, since the ROI 30 has a thickness in the depth direction, it includes a plurality of short-axis cross-sections, whereby a plurality of pieces of blood flow information can be obtained. By using the plurality of pieces of blood flow information, accuracy can be stabilized by the average effect of the measured values, and errors due to relative displacement of the ROI 30 can be reduced. The thickness of the ROI 30 and the number of included cross sections can be arbitrarily set and changed. Also, this ROI
It is also possible to set a plurality of 30s. In this case,
Another characteristic amount can be calculated based on the blood flow rates obtained in the plurality of blood channels.

On the reference plane A1 of the blood flow path, an angle marker MA1 for specifying the direction of the blood flow is displayed as shown in the figure, and the blood flow velocity is determined by using the information on the direction specified by the marker MA1. Can be set so as to be obtained by the flow rate calculation unit 9.

FIG. 6 shows an example in which a similar blood vessel long-axis image IM1 is displayed as a three-dimensional CFM image. In this case, R which can be arbitrarily set / changed so as to narrow the Doppler scan area
OI (ROI of ACM etc.) 31 is displayed.

FIG. 7 shows a blood vessel short-axis image IM2 and a blood vessel short-axis image I in a short-axis cross section of a blood flow channel orthogonal to the scanning line direction.
The ROI 40 set on M2 is shown. By displaying the blood vessel short-axis image IM2 in the short-axis cross-section in this way and specifying the ROI 40 on this short-axis image IM2, it is possible to select a measurement site while confirming a plurality of short-axis cross-sections on the display screen. Blood flow can be measured, and intuitive operability is greatly improved.

FIG. 8 shows a blood vessel long axis image IM1 and a blood vessel short axis image I.
A case where M2 is displayed on the same screen is shown. By displaying the blood vessel long-axis image IM1 on the reference plane of the measurement site and the blood vessel short-axis image IM2 on the short-axis cross section on the same screen, the visibility of the measurement site is further improved, and operations such as ROI designation and the like are performed. The properties are further improved. As an example of increasing the number of screen display options, for example, as shown in FIG. 9, various blood flow measurement values DS2 such as a flow time waveform DS1 such as a change in flow velocity per unit time and a cardiac output (stroke volume).
May be displayed, or as shown in FIG. 10, a blood vessel long-axis image IM1 on a plane A2 orthogonal to the reference plane A1 of the measurement site may be displayed.

When the operator designates the blood flow path of the measurement site with the ROI while looking at the blood flow images shown in FIGS. 5 to 10, the flow rate calculation unit 9 performs processing based on the above measurement principle (for example, CPU (Execution of an algorithm for flow rate calculation). As a result, the instantaneous flow rate of each frame of the blood flow image is calculated from the short-axis cross section based on the blood flow velocity information including the Doppler velocity obtained by the Doppler processing system 5, and this instantaneous flow rate is calculated for each frame on the time axis. By performing the above integration (the width of the time integration, that is, the time of interest can be arbitrarily set and changed), the blood flow at the measurement site can be measured.

Therefore, according to this embodiment, it is not necessary to assume an axial object when measuring the blood flow, so that the measurement accuracy can be greatly improved as compared with the prior art, and the short-axis cross section of the object to be measured is extremely small. Since it is orthogonal to the sound wave beam, there is no angle dependence, and it is not necessary to perform measurement in two cross sections orthogonal to each other, so that simpler measurement than in the past can be realized.

Although the present embodiment employs a real-time three-dimensional scanning method using a two-dimensional array probe, the present invention is not limited to this. For example, FIG. As shown in (b), it is also possible to apply a method in which the ultrasonic probe 1 is mechanically rotated and moved about the axial direction AX thereof to scan the ultrasonic beam 2DB in a three-dimensional area.

[0035]

As described above, according to the present invention, the blood flow rate is measured based on the flow velocity distribution in the short-axis cross section of the flow channel, so that the measurement accuracy is greatly improved without the assumption of axial symmetry or angle dependence. Can be increased.

[Brief description of the drawings]

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

FIG. 2 is a conceptual diagram illustrating a method for collecting three-dimensional data.

FIG. 3 is a schematic block diagram showing each unit in a 3D-DSC.

FIG. 4 is a conceptual diagram illustrating the principle of blood flow measurement.

FIG. 5 is a longitudinal axis image and ROI of a blood vessel on a reference plane of a blood flow channel.
The schematic diagram which shows the example of a display of.

FIG. 6 is a schematic diagram showing another display example of a short-axis image of a blood vessel and an ROI.

FIG. 7 is a schematic diagram showing a display example of a short-axis image of a blood vessel and a ROI of a cross section intersecting with the longitudinal direction of a blood flow channel.

FIG. 8 is a schematic diagram showing a display example of a blood vessel long axis image and a blood vessel short axis image on the same screen.

9 is a schematic diagram showing a case where another blood flow measurement display is added to the display example of FIG. 8;

FIG. 10 is a schematic diagram showing a case where a blood vessel long axis image and a ROI display of a cross section orthogonal to a reference plane are added to the display example of FIG. 8;

FIGS. 11A and 11B are conceptual diagrams illustrating a three-dimensional data collection method in which a probe is mechanically rotated.

[Explanation of symbols]

1 2D array probe 2 Transmitting system 3 Receiving system 4 B mode processing system 5 Doppler processing system 6 Digital scan converter (DSC) 7 3D digital scan converter (3D-
DSC) 8 display system 9 flow rate calculation unit 10 ROI input unit 11 controller 20 3D coordinate calculation unit 21 3D memory 22 reconstructed image calculation unit 23 memory

Claims (7)

[Claims] 1. A signal collecting means for collecting a reception signal of an ultrasonic echo by scanning a three-dimensional region including a blood flow path of a measurement target in a subject with an ultrasonic beam, and a signal collected by the signal collecting means. Blood flow information obtaining means for obtaining the blood flow information of the three-dimensional region from the received signal, and a blood flow having a cross section intersecting in the longitudinal direction of the blood flow path based on the blood flow information obtained by the blood flow information obtaining means. Blood flow image reconstruction means for reconstructing a flow image, a region of interest setting means for setting a region of interest on a blood flow image reconstructed by the blood flow image reconstruction means, and a region of interest set by the region of interest setting means And a blood flow calculating means for calculating a blood flow passing through the region of interest. 2. A signal collecting means for collecting a reception signal of an ultrasonic echo by scanning a three-dimensional area including a blood flow path of a measurement target of an object with an ultrasonic beam, and a signal collected by the signal collecting means. Tomographic image obtaining means for obtaining a three-dimensional tomographic image of the three-dimensional area from a received signal, a region of interest setting means for setting a region of interest on the three-dimensional tomographic image obtained by the tomographic image obtaining means, and a region of interest setting A blood flow information obtaining unit that obtains blood flow information only for the region of interest by scanning the ultrasonic beam on the region of interest set by the unit; and a blood flow information obtained by the blood flow information obtaining unit. And a blood flow calculating means for calculating a blood flow passing through the region of interest. 3. The invention according to claim 1, wherein the region of interest includes a plurality of cross-sections parallel to a cross-section intersecting the longitudinal direction of the blood flow path, and the means for calculating the blood flow rate includes: A three-dimensional ultrasonic diagnostic apparatus, which is means for calculating a blood flow passing through the region of interest from blood flow information of a plurality of cross sections. 4. The invention according to claim 1, wherein the cross section intersecting the blood flow path is a cross section orthogonal to a scanning line of the ultrasonic beam. Dimensional ultrasonic diagnostic equipment. 5. The apparatus according to claim 1, wherein a blood flow image of a cross section intersecting the blood flow channel and a blood flow image of a reference surface of the blood flow channel are displayed on the same screen. A three-dimensional ultrasonic diagnostic apparatus, further comprising: means for displaying on the top. 6. The invention according to claim 5, wherein means for designating information on a blood flow direction on a reference plane of said blood flow path, and blood flow using information on the blood flow direction designated by said means. Means for determining an absolute value of the velocity. 7. The apparatus according to claim 1, wherein a plurality of the regions of interest are specified,
A means for calculating a blood flow amount passing through each of the plurality of regions of interest designated by the means; and a means for calculating another characteristic amount from the blood flow amounts of the plurality of regions of interest calculated by the means. A three-dimensional ultrasonic diagnostic apparatus characterized by the above-mentioned.