JP3324806B2 - 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 for obtaining a tomographic image of a diagnostic part of a subject using ultrasonic waves, and more particularly, to displaying measurement information of a diagnostic part three-dimensionally in real time. The present invention relates to an ultrasonic diagnostic apparatus capable of performing the above.

[0002]

2. Description of the Related Art A conventional ultrasonic diagnostic apparatus transmits and receives an ultrasonic wave to and from a subject, drives the probe to generate an ultrasonic wave, and processes a received echo signal. An ultrasonic transmitting / receiving unit, a tomographic image generating circuit for inputting the reflected echo signal from the ultrasonic transmitting / receiving unit and digitizing it to generate a tomographic image of a diagnostic site, and converting image data from the tomographic image generating circuit into an analog signal And a control circuit for controlling the above components. In such an ultrasonic diagnostic apparatus, in order to three-dimensionally display an ultrasonic image of a diagnostic site of a subject, a three-dimensional scanning probe is used, and a tomographic image is transmitted by ultrasonic waves transmitted from the probe. Scanning is sequentially moved in a direction orthogonal to the tomographic scanning plane to collect a large number of tomographic images in the three-dimensional measurement space, and sends the collected many tomographic images to an image processing device other than the ultrasonic diagnostic device, In this image processing apparatus, a three-dimensional image is reconstructed by a voxel method or the like to form a three-dimensional image, and the image is displayed.

[0003]

However, in such a conventional ultrasonic diagnostic apparatus, a large number of tomographic images in a three-dimensional measurement space are once collected, and then the collected large number of tomographic images are converted into ultrasonic waves. Since it was sent to an image processing device other than the diagnostic device to reconstruct a three-dimensional image and display it as a three-dimensional image, a three-dimensional image was displayed in real time while scanning the diagnostic site in the subject with an ultrasonic beam. Images could not be displayed. Therefore, static or dynamic observation cannot be performed on the three-dimensional shape of the diagnostic site, and sufficient diagnostic information may not be obtained.

Accordingly, an object of the present invention is to provide an ultrasonic diagnostic apparatus capable of addressing such a problem and displaying three-dimensional measurement information of a diagnostic site in real time.

[0005]

In order to achieve the above object, an ultrasonic diagnostic apparatus according to the present invention is capable of moving an ultrasonic scan for transmitting and receiving an ultrasonic wave to and from a subject in a direction orthogonal to the scanning plane. A probe in which transducers are arranged, an ultrasonic transmission / reception unit that drives the probe and processes a received reflected echo signal, and inputs the processed reflected echo signal to create a tomographic image of a diagnostic site reflecting means and the ultrasonic scanning from above Kisagu probe means for obtaining a reflected echo signal of the tomographic scanning surface moved so with three-dimensional measuring space in a direction perpendicular to,該得was three-dimensional measuring space Body surface signal removing means for removing a signal component of the echo signal from the body surface of the subject less than a predetermined depth, means for removing high-frequency noise of the reflected echo signal from which the signal component has been removed, and Reflected energy from which noise has been removed Over signal detects a time phase that changes at a predetermined depth of the luminance value calculated luminance values according to the distance between the diagnostic region of preset viewpoint and the object based on the reflected echo signal in this time phase and means for out-feed, said transmission issued a bright
Input the signal of the degree value to increase the distance between the probe surface and the diagnostic site.
Display as a two-dimensional image with brightness difference between light and dark according to the proximity
And means for performing the operation.

[0006]

The ultrasonic diagnostic apparatus constructed as described above moves the ultrasonic scanning from the probe in a direction orthogonal to the tomographic scanning plane to obtain a reflected echo signal in the three-dimensional measurement space. Removing a signal component having a depth less than a predetermined depth from the body surface of the subject of the reflected echo signal in the obtained three-dimensional measurement space; removing high-frequency noise of the reflected echo signal from which the signal component has been removed; A phase in which the reflected echo signal from which the noise has been removed changes at a predetermined depth is detected, and a luminance value is calculated according to the distance between a preset viewpoint and the diagnosis site of the subject based on the reflected echo signal in this phase. This luminance value is transmitted, and
By inputting the output luminance value signal, the probe surface and
-Dimensional image with brightness difference between light and dark according to the distance of the distance
To be displayed on the display means . Thereby, the measurement information of the diagnostic site in the subject can be displayed three-dimensionally in real time.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of an ultrasonic diagnostic apparatus according to the present invention. This ultrasonic diagnostic apparatus can obtain a tomographic image of a diagnostic part of a subject using an ultrasonic wave and also can display a three-dimensional image. As shown in FIG. Transmission / reception unit 2, tomographic image creation circuit 3, image memory 4, television signal creation circuit 5
, A television monitor 6, and a control circuit 7, and further includes a body surface part signal removing circuit 8, a low-pass filter 9, and a signal detection processing circuit 10.

The probe 1 transmits and receives ultrasonic waves to a subject by mechanically or electronically performing linear scanning, sector scanning, and the like, and is not shown. A vibrator that is a source of a sound wave and receives a reflected echo is built in. The probe 1 according to the present invention
Are sequentially moved in a direction orthogonal to the tomographic scanning plane while performing, for example, linear scanning to obtain measurement information in a three-dimensional measurement space. Also, the ultrasonic transmitting / receiving unit 2
The probe 1 drives the probe 1 to generate an ultrasonic wave and processes a received echo signal. Although not shown, a pulser for sending a driving pulse to the probe 1 and the probe 1 And a preamplifier for amplifying the reflected echo signal received by the device. Further, the tomographic image creating circuit 3 receives the reflected echo signal output from the ultrasonic transmitting / receiving section 2 and converts it into a digital signal, thereby creating a monochrome tomographic image (B-mode image) of the diagnostic site.

The image memory 4 receives the monochrome tomographic image data created as described above, creates and stores, for example, 10 slices of an ultrasonic image, and has a storage capacity of several tens of frames. are doing. In addition, the television signal generation circuit 5
Is for inputting the ultrasonic image data read from the image memory 4 and converting it into a television signal (analog video signal) for image display. Further, the television monitor 6 receives the television signal from the television signal creation circuit 5 and displays an ultrasonic image. And
The image memory 4, the television signal creation circuit 5, and the television monitor 6 constitute an image display unit.

The control circuit 7 controls the operation of each of the above-mentioned components, and is composed of, for example, a CPU (Central Processing Unit), and sends a control signal to each of the components. The input circuit 11 connected to the control circuit 7 is for inputting control information for each of the above components, and the input control information is given to the control circuit 7.

In the present invention, a body surface signal removing circuit 8, a low-pass filter 9, and a signal detection processing circuit 10 are provided on the output side of the ultrasonic transmitting / receiving section 2. The body surface signal elimination circuit 8 is configured to sequentially move the tomographic scan by the ultrasonic wave transmitted from the probe 1 in a direction orthogonal to the tomographic scan plane and obtain each reflected echo in the three-dimensional measurement space. A signal is input from the ultrasonic transmission / reception unit 2 and serves as means for removing a signal component having a depth less than a predetermined depth from the body surface of the reflected echo signal. The input reflected echo signal and the 0 level signal are input to an input circuit. by switching through the control circuit 7 is input in accordance with the control signal G ₂ indicating a predetermined value sent in 11, signal components below certain depth is designed to remove. Moreover, low-pass filter 9, a means for removing high frequency noise of the reflected echo signals outputted from the body surface portion signal removing circuit 8 also so <br/>, characteristics of the filter are input by the input circuit 11 it is possible to set arbitrarily by the control signal G ₃ which is transmitted via the control circuit 7.

Furthermore, the signal detection processing circuit 10, the b
A time phase in which the reflected echo signal from which the high-frequency noise has been removed by the up-pass filter 9 changes at a predetermined depth is detected, and a predetermined viewpoint and a diagnosis site of the subject are determined based on the reflected echo signal at this time phase. calculated Me luminance value according to the distance, predetermined by the brightness value in which sends the image display unit (4, 5, 6), the low-pass filter 9 outputs signals for a constant from the body surface depth than from Is detected, a luminance value of the display is determined in accordance with the elapsed time, and this luminance signal is output to the image memory 4. The internal configuration thereof is as follows. As shown in FIG. 2, a differentiating circuit 12 for differentiating a signal input through the low-pass filter 9, a signal G ₆ differentiated by the differentiating circuit 12 and a signal G ₆ input by the input circuit 11 and passed through the control circuit 7. The predetermined value sent by A comparator 13 for comparing the controls signals G _4, timer for measuring the control signal G ₅ which is output from the control circuit 7 to the elapsed time from the beginning to receive the reflected echo signals from the diagnostic region by the probe 1 Circuit 1
And a luminance conversion circuit 15 which inputs the value of the elapsed time measured by the timer circuit 14, calculates the luminance value to be displayed by the image display unit (4, 5, 6), and outputs it.

[0013] Incidentally, the timer circuit 14, the comparison signal G ₇ is reset and started by the control signal G ₅ from the control circuit 7 shown in FIG. 1, is output from the comparator 13
By stopping at, the elapsed time is measured. The luminance converting circuit 15 is a conversion table memory the correspondence between calculated and viewpoint data and the luminance value given by the control signal G ₉ from the elapsed time and the control circuit 7 to be measured as described above, for example, It consists of a ROM (Read Only Memory). Note that the luminance conversion circuit 15
The conversion is not limited to the OM, but may be calculated and converted by a high-speed arithmetic unit such as a CPU.

Next, the operation of displaying a three-dimensional image in the ultrasonic diagnostic apparatus configured as described above will be described. First, the control signals G ₁ from the control circuit 7 shown in FIG. 1,
The ultrasonic transmission / reception unit 2 drives the probe 1 and controls the launch position of the ultrasonic beam to transmit / receive ultrasonic waves to / from the subject, and the ultrasonic wave is transmitted from the probe 1 as shown in FIG. The tomographic scanning by the ultrasonic beam is sequentially moved at appropriate intervals in a direction orthogonal to the tomographic scanning plane to obtain measurement information in the three-dimensional measurement space. At this time, for example, a spherical organ is considered as the target object 16 in the subject, and tomographic scan planes shifted at predetermined intervals are defined as S ₁ , S ₂ ,..., Sn. Scanning for obtaining measurement information in the three-dimensional measurement space is performed on each tomographic scanning plane S ₁ to S ₁ .
When viewed in a plane perpendicular to Sn, the tomographic scanning planes S ₁ to S _{1 are} arranged on a plane indicated by reference F in FIG. Scanning is performed as the movement of the ultrasonic beams S ₁ ′, S ₂ ′,..., Sn ′ corresponding to Sn. By such scanning, each reflected echo signal reflected from the object 16 is received by the probe 1 and converted into an electric signal, processed by the ultrasonic transmission / reception unit 2 and converted into a luminance signal of the reflected echo. Become.

Here, in order to display a three-dimensional image of the object 16 based on the measurement information in the three-dimensional measurement space collected as shown in FIG. 3, as shown in FIG. The fact that a difference in lightness and darkness appears due to the difference in the distance L to the surface of the object 16 when the object is viewed. That is, the brightness of each point of the object 16 may be changed and displayed according to the difference in the distance L. In this case, as shown in FIG. 4B, if the probe 1 shown in FIG. 3 is placed between the viewpoint E and the object 16, the surface 17 _{1 of the} object 16 is viewed from the viewpoint E. The distance L from the viewpoint E to the probe surface P and the distance L ₁ from the probe surface P to the surface 17 _{1 of the} object 16 are determined.
Represented as the sum of the distance L ₂ to.

FIG. 5A is a rewritten version of FIG.
In point displaced from the probe center P ₁ by a distance di Pi
Assuming that the distance from the viewpoint E to the surface 17i of the object 16 measured by the ultrasonic beam transmitted and received at the point 17 is Li, and the distance from the viewpoint E to the surface 17i of the object 16 is Di, the surface 1
By applying the Pythagorean theorem to a right triangle .DELTA.QRE with 7i as a point Q, the distance Di is obtained as follows. Di ² = (L ₁ + Li) ² + di ² (1) From this, a certain tomographic scanning plane Sm in FIG.
In, that together determine the distance Li from the probe surface P for each ultrasonic beam to the surface 17i of the object 16, determining the distance di from the probe center P ₁ of the launch position Pi of the ultrasonic beam Thus, the distance Di can be obtained using the above equation (1). Then, the brightness of each point of the object 16 may be changed according to the distance Di from the viewpoint E to an arbitrary point 17i on the surface of the object 16.
For example, when the distance Di is small and close, the display is bright,
Where Di is large and distant, it may be displayed dark.

[0017] FIG. 5 (b) is a diagram as viewed three-dimensionally FIG. 5 (a), x which is perpendicular to the probe center P ₁ as the origin, takes y, z coordinates, the x axis, y-axis, respectively any angle θx relative to the z-axis, [theta] y, without the [theta] z, the distance from the origin P ₁ even when the L ₁ 'to become moved point a new perspective E', Fig. Similarly to FIG. 5A, the distance Li ′ from the point A on the probe surface P to the point B on the object 16 can be measured for each ultrasonic beam, and the distance Li ′ from the probe center P ₁ can be measured. If the distance di 'to A can be measured, the object 1
6 can be displayed three-dimensionally. That is, FIG.
In this case, the viewpoint E ', the launch position A of the ultrasonic beam, and the launch direction of the ultrasonic beam are known, and the distance Li' can be measured by this. Therefore, the point B on the object 16 from the viewpoint E ' The distance Di 'can be calculated by the following equation.

(Equation 1)

In the description of FIGS. 4 (b) and 5 (a), one point on a straight line perpendicular to the probe plane P is taken as the viewpoint E. By previously determining the point as a viewpoint, FIG.
As shown in FIG.
6, the distance Li 'to the point on the object 16 is measured, and the distance Di' to the surface of the object 16 measured from an arbitrary viewpoint E 'is obtained.
What is necessary is just to change the brightness of each point on the object 16 according to this distance Di '.

Next, the procedure for obtaining the distance Li from the probe plane P to the surface of the object 16 shown in FIGS. 4B and 5A will be described with reference to FIG. First, the echo signal reflected on the surface of the object 16 is received by the probe 1 shown in FIG. 1, converted into an electric signal, processed by the ultrasonic transmission / reception unit 2, and shown in FIG. Thus, it becomes a luminance signal of the reflection echo. Next, the luminance signal of the reflected echo is input to the body surface part signal removing circuit 8 shown in FIG.
(B), the signal component E ₁ of FIG. (A) the shallow from the body surface than the predetermined depth d shown moiety (body surface portion) is removed. Thereafter, the signal from the body surface signal removal circuit 8 is input to the low-pass filter 9 shown in FIG.
As shown in (c), high frequency components as noise included in the input signal are removed. Next, the signal from the low-pass filter 9 is applied to the signal detection processing circuit 1 shown in FIG.
0, and the change E ₂ (see FIG. 6 (c)) of the signal intensity due to reflection at the boundary (see the symbol d) of the composition of the living tissue included in the signal is different from the differential shown in FIG. Circuit 1
2 and the time point t _{1 of the} change is detected as shown in FIG.

At this time, in the signal processed by the differentiating circuit 12, a state of change of the reflected echo signal appears as an amplitude as shown in FIG. For this reason, the time T from when the probe 1 starts receiving the reflected echo signal to the time t ₁ at which a change of an arbitrary magnitude appears is determined by the comparator 1 shown in FIG.
3 and the timer circuit 14. At this time, the comparator 13 controls the control signal G from the control circuit 7 shown in FIG.
To detect changes in any magnitude indicated by _4, 6 signals after differentiation processing shown in (d) G ₆ and the control signal G ₄
Is compared with a predetermined value indicated by. Then, when the signal G ₆ after the above-described differentiation processing matches a predetermined value according to the control signal G ₄ or when the signal G ₆ increases, the signal G ₇ is sent to the next timer circuit 14. The timer circuit 14 starts the time measurement by the control signal G ₅ indicating the time the reflected echo signal received starting from the control circuit 7, and ends the time measurement by the input signals G ₇ from the comparator 13. Thus, as shown in FIG. 6 (d), the period T from the probe 1 begins to receive the reflected echo signals to time t ₁ in which a change in any size appears is measured. In this case, the boundary portions in the depth d When the surface of the object 16 shown in FIG. 4 (b), of the object 16 from the probe surface P by the time T up to the time t ₁ of the change The distance Li to the surface is obtained.

Thereafter, the signal of the time T measured by the timer circuit 14 is input to the luminance conversion circuit 15 in FIG. 2, and the conversion table memory in the luminance conversion circuit 15 is used to obtain the signal of the measured time T. Depending on the magnitude of the value, it is converted into a corresponding luminance value for image display and digitized. Incidentally, the conversion table memory is located plurality every viewpoint position, and is selected by the control signal G ₉ indicating the viewpoint position information. Then, it is transmitted to the image memory 4 shown in FIG. 1 as a luminance signal for display. Thereafter, the image memory 4, the control signal G ₈ sent from the control circuit 7 obtains the position information of the transmission and reception of the ultrasonic beam, for recording the digitized luminance signal on the basis of the position information.

Hereinafter, FIG.
In a certain tomographic scanning plane Sm shown in (b), the distance Li from the probe plane P to the surface of the object 16 is obtained for each ultrasonic beam, and converted into a luminance value corresponding to the distance Li. each 3 tomographic scanning surface S ₁ ~
The above distance Li is obtained for Sn and converted into a luminance value. Thus, in a state where the entire spherical object 16 shown in FIG. 3 is sliced, luminance signals for image display are obtained side by side along the movement trajectories of the ultrasonic beams S ₁ ′ to Sn ′ corresponding to the slice plane. And stored in the image memory 4. When this image data is displayed on the television monitor 6 via the television signal generation circuit 5 shown in FIG. 1, as shown in FIG.
Are displayed bright when the distance Li is small, and dark when the distance Li is large, and are displayed as a two-dimensional image having a brightness difference between light and dark according to perspective. As a result, the display image shown in FIG. 7 is observed as a three-dimensional image expressing the brightness difference between light and dark with respect to the shape of the target object 16, and the shape of the object and the like can be grasped well.

In FIG. 1, the tomographic image creation circuit 3
Although only the black-and-white tomographic image generating means is provided, the present invention is not limited to this, and a color Doppler image generating circuit may be provided in parallel.

[0024]

The present invention has been configured as described above.
The ultrasonic scanning from the probe is moved in a direction orthogonal to the tomographic scanning plane to obtain a reflected echo signal of the three-dimensional measurement space, and the reflected echo signal of the obtained three-dimensional measurement space is obtained by examining the object. Removing a signal component less than a predetermined depth from the body surface, removing high-frequency noise of the reflected echo signal from which the signal component has been removed, and changing the reflected echo signal from which the high-frequency noise has been removed at a predetermined depth A time phase is detected, and a brightness value is obtained in accordance with a distance between a preset viewpoint and a diagnosis part of the subject based on a reflected echo signal at the time phase, and the brightness value is transmitted.
Then, the signal of the transmitted luminance value is input to diagnose the probe surface.
The brightness difference between light and dark was made according to the distance of the cut site.
It can be displayed on the display means as a two-dimensional image . Thereby, the measurement information of the diagnostic site in the subject can be displayed three-dimensionally in real time. Therefore, static or dynamic observation can be performed on the three-dimensional shape of the diagnostic site, and more diagnostic information can be obtained. In particular, the depiction of a biological tissue such as a fetus and the display of its moving body can be displayed three-dimensionally in real time, which is effective.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing an internal configuration of a signal detection processing circuit;

FIG. 3 is an explanatory diagram showing a state in which measurement information in a three-dimensional measurement space is obtained by transmitting and receiving an ultrasonic beam from a probe;

FIG. 4 is an explanatory diagram showing a principle of displaying a three-dimensional image of an object based on the measurement information.

FIG. 5 is a diagram illustrating a three-dimensional image display of an object by rewriting FIG. 4B;

FIG. 6 is a timing chart for explaining a procedure for obtaining a distance from a probe surface to a surface of an object;

FIG. 7 is an explanatory diagram showing a display example of a three-dimensional image according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Probe, 2 ... Ultrasonic transmission / reception part, 3 ... Tomographic image creation circuit, 4 ... Image memory, 5 ... Television signal creation circuit,
6 TV monitor, 7 Control circuit, 8 Body surface signal removal circuit, 9 Low pass filter, 10 Signal detection processing circuit, 12 Differentiator circuit, 13 Comparator,
14: timer circuit, 15: luminance conversion circuit, E: visual
Point, L ... Distance.

Claims (1)

(57) [Claims] 1. A probe in which vibrators are arranged so as to be capable of moving an ultrasonic scan for transmitting and receiving an ultrasonic wave to and from a subject in a direction perpendicular to a scanning surface thereof, and a reflection device which drives the probe and receives the same. means for creating an ultrasonic transceiver unit for processing echo signals, a tomographic image of a diagnostic region by entering the reflected echo signals the processing, orthogonal ultrasound scan from top Kisagu probe on the tomographic scanning surface Means for obtaining a reflected echo signal in the three-dimensional measurement space by moving the reflected echo signal in the three-dimensional measurement space, and removing a signal component having a depth less than a predetermined depth from the body surface of the subject of the obtained reflected echo signal in the three-dimensional measurement space. Body surface signal removing means, means for removing high frequency noise of the reflected echo signal from which the signal component has been removed, and detecting a time phase at which the reflected echo signal from which the high frequency noise has been removed changes at a predetermined depth. Based on the reflected echo signal at this time phase, The luminance value calculated luminance values according to the distance between the diagnostic region of preset viewpoint and the subject Hazuki
Means for exiting feed, enter the signal of said transmission out luminance values
Brightness of light and dark depending on the distance between the probe surface and the diagnostic site
Means for displaying the image as a two-dimensional image with a difference .