JPS6125539A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of orthopedics of the invention] The present invention relates to an ultrasonic diagnostic apparatus, mainly an ultrasonic diagnostic apparatus that obtains C-mode tomographic images.

[Technical background of the invention]

C-mode tomography is a plane 2-1.2-2 parallel to the scan plane l, as shown in Figure 4, using an ultrasonic diagnostic device or the like.
A technique (method) for obtaining a tomographic image of the subject 3 in B-mode tomography (a method of obtaining a tomographic plane perpendicular to the scan direction). is superior in that it requires less data (number of slices) and can obtain accurate information.

By the way, the ultrasonic diagnostic device is called an ultrasonic transmitter/receiver C emitter probe. ) to transmit ultrasonic waves to the internal C of the subject.
A tomographic image of the object is obtained by receiving the reflected wave of the ultrasound signal, but the ultrasound signal hardly propagates through the air. For this reason, current ultrasonic diagnostic apparatuses either bring the probe in close contact with the surface of the subject, or interpose a liquid or paste acoustic coupling material between the probe and the surface of the subject. In C-mode tomography, scanning is a surface scan, so unless the surface of the subject is flat, the latter method, ie, a method of transmitting and receiving data with an acoustic coupling material interposed between the probe and the surface of the subject, is used. By the way, when an acoustic coupling material is interposed in this way, a certain distance is necessarily required between the probe surface and the subject surface. Particularly, when the object to be examined is a part that has a difference in size or unevenness, such as a breast, the distance must be made considerably large.

[Problems with background technology]

Therefore, in C-mode tomography, it is necessary to appropriately set the distance of the tomographic plane of the desired image from the scan plane. This is because, especially in cases where there are individual differences in breast size and unevenness, an appropriate tomogram for diagnosis cannot be obtained unless the distance of the tomographic plane from the scan plane is changed depending on the person making the initial diagnosis. do not have. Therefore, if the distance is visually determined, it will take time and be inaccurate. In particular, in a mass medical examination system, it is extremely important to shorten examination time and eliminate erroneous data that causes misdiagnosis. Therefore, it is required to properly and quickly set the distance between the tomographic plane and the scan plane.

In addition, C-mode tomography uses a line (-dimensional) scan while B-mode tomography uses a plane scan (two-dimensional), so it takes time to scan, and at least with current technology, real-time display is extremely difficult. It's young.

[Purpose of the invention]

The present invention has been made to solve the above problems,
The purpose of this invention is to accurately and automatically set the distance of a tomographic plane from a scan plane.

[Summary of the invention]

To achieve the above object, the present invention provides an ultrasonic diagnostic apparatus that obtains tomographic images by interposing an acoustic coupling agent between an ultrasound probe and a subject. The present invention is characterized in that the position of the tomographic plane to be obtained is determined by detecting the .

[Embodiments of the invention]

The present invention will be described in detail below according to embodiments shown in the accompanying drawings.

FIG. 1 is a perspective view showing one specific example of the C-mode scanning method. In the figure, 1) is an electronic scan probe, 12-1, 12-2, and 12-n are ultrasound beams transmitted and received by the electronic scan probe 1), and the ultrasound beams 12-1, 12-2 ．． ...12-n
is obtained by electronically scanning in the direction shown by arrow A by electronically changing the wave transmitting/receiving direction. Then, by mechanically moving the electronic scan probe 1 in the direction shown by arrow B (perpendicular to the direction shown by arrow A) while performing electronic scanning in the direction shown by arrow A (2), surface scanning is enabled. .

Here, to explain C-mode tomography in more detail, it is considered that the speed of sound in a living body is approximately constant within the range in which a tomographic image is obtained. Even when using an acoustic coupling agent, as long as the acoustic coupling agent is selected to have the same speed of sound as that of a living body, the speed of sound can be considered to be constant in all parts. Therefore, a C-mode tomographic image can be obtained by collecting only reflected wave information whose time from wave transmission to reception is constant. By recording the received signal information one after another at regular time intervals, a plurality of tomographic images with different tomographic plane depths can be obtained in one scan.

FIG. 2 is a sectional view for explaining the relationship between the scanner section and the subject of the ultrasonic diagnostic apparatus of the present invention.

In the figure, 21 is an aquarium having an opening at the top, and 22 is a flexible thin film attached to the upper surface of the aquarium 21, which is attached to the aquarium 21 so as to close the opening.
The thin film 22 is used for the purpose of improving the adhesion with the subject and making the acoustic properties similar to those of living organisms. 24 is the acoustic coupling agent filled in the water tank 21 sealed by #22J2, and the electronic scan probe 1 shown in the first factor has an acoustic Water tank 21 filled with binder 24
Located inside. Reference numeral 25 designates a living body as a subject, which in this example is a breast.

The electronic scanning probe 1) performs surface scanning by mechanically moving in the direction of arrow B while electronically scanning in the direction shown by arrow A in a water tank 21 filled with acoustic coupling agent 24. FIG. 3 is a cross-sectional view of the binary I in FIG. 2 taken along a plane 90° different from the cross section. In the figure, B1 is the center point of the mechanical scan of the electronic scan probe 1), B2 is one end of the mechanical scan (left end in Figure 3), and B3 is the other end of the mechanical scan (right end in Figure 3). be. In addition, C1 is the closest distance between the surface of the electronic scan probe 1 in a certain state and the surface of the subject, and C2 is the distance between individuals in the size of the living body (breast in this example) and differences in contact methods. Among the tomographic planes to be obtained, the distance of the tomographic plane farthest from the electronic scanning probe 1), that is, the maximum upper distance is shown.

C1 is a value that changes each time, but C2 is a value that can be set in advance through experiments or the like.

Therefore, by predetermining the amount of information to be obtained (the number of C-mode tomographic planes) and automatically detecting C1, it becomes possible to set the positions of the C-mode tomographic planes at equal intervals.

Next, the method of automatic detection of C2θ in the present invention will be explained.

If a material with uniform acoustic properties is used as the acoustic coupling agent 24, the reflection in the coupling agent (for example, water) is extremely weak compared to biological reflection. Incidentally, reflection of ultrasonic waves occurs at the interface of materials with different acoustic properties.

By the way, it can be said that 01 is the location of the shortest distance (shortest time) of the first strong reflected wave while scanning the electronic scan probe 1) from B1 to B2.

That is, if the first strong reflected wave's clock is T1, and the ultrasonic wave is C, then C1 is expressed by the following equation.

C,=C·T1/2 Next, the data reading time interval Δt when attempting to take an image of a tomographic plane divided into N equal parts between C2 and C1 is expressed by the following formula.

△t=2 (C2-C1)/(N-1)/C Therefore,
While the electronic scan probe 1) is mechanically scanned from B1 to B2, C1 is calculated using the above formula, and after setting it, the electronic scan probe 1) is moved from B2 to B1 to B3 in order to capture C mode data. C-mode tomographic images suitable for diagnosis can be automatically obtained by mechanically scanning up to 1.

In addition, if the breast becomes flat due to being pressed against the thin film 22, and there is a margin in the number of divisions N, C3 is detected to obtain N tomographic images with different positions at regular time intervals. It is extremely effective for more precise diagnosis. Furthermore, it is easy to arbitrarily select or set the withdrawal interval using current technology.

〔Effect of the invention〕

As described above, according to the present invention, the position of the object surface is detected by the reflected ultrasound waves while the ultrasound probe scans a certain range, so that the position of the object surface is automatically detected from the scan plane of the C-mode tomographic plane. It is possible to set the distance between

[Brief explanation of drawings]

1 to 3 are for explaining one embodiment of the present invention, and FIG. 1 is a perspective view of an electronic scanning probe;
Figure 2 is a diagram of the equipment, and Figure 3 is the l shown in Figure 2.
FIG. 4 is a cross-sectional view taken along a plane 90 degrees different from the jI plane, and is an explanatory diagram of C-mode tomography. 2-1, 2-2...C mode fault plane, 1)...
・Ultrasonic probe, 24...acoustic coupling agent, 25・
...Subject. Agent Patent Attorney Kensuke Chika (and 1 other person) No.
1 Figure 12-n Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1) In an ultrasonic diagnostic device that obtains a tomographic image by interposing an acoustic coupling agent between an ultrasound probe and a subject, the tomographic plane to be obtained by detecting the position of the subject's surface using reflected ultrasound waves An ultrasonic diagnostic device characterized by determining the position of. (2) In an ultrasound diagnostic device that obtains tomographic images by interposing an acoustic coupling agent between an ultrasound probe and a subject, it detects the position of the subject's surface using reflected ultrasound waves, and also detects the position. An ultrasonic diagnostic apparatus characterized in that an acquisition pitch is calculated from the result and a preset number of tomographic planes.