JP3871747B2 - Ultrasonic diagnostic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic diagnostic apparatus capable of displaying a B-mode image (image by B-mode display method: ultrasonic tomographic image).
[0002]
[Prior art]
As shown in FIG. 4, a conventional ultrasonic diagnostic apparatus of this type includes a probe 1 that transmits ultrasonic waves into the subject and receives ultrasonic reflected waves from the subject; An ultrasonic transmission / reception unit 2 that controls the probe 1 to transmit an ultrasonic wave and detects a reflected echo signal from the received reflected wave, and digitizes the reflected echo signal from the ultrasonic transmission / reception unit 2 / D converter 3, a memory unit 4 for storing image data sequentially output from the A / D converter 3, a display circuit unit 5 for converting image data read from the memory unit 4 into a video signal, An image display unit 6 for inputting a video signal from the display circuit unit 5 and displaying it as an image, an image data recording device 9 for recording image data displayed on the image display unit 6, and control of each of the above components Center for processing the input image data A calculation device 7, comprising an operation panel 8 for inputting various data and operation commands, such as connected to the diagnostic information to the central processing unit 7.
[0003]
In FIG. 4, reference numeral 10 denotes an external device connected to the central processing unit 7 via the input / output interface 11. Reference numeral 12 denotes an ultrasonic image of a diagnostic region in the subject, here a body mark displayed at the corner of the screen of the image display unit 6 when obtaining and diagnosing a B-mode image (ultrasonic tomographic image). Is an orientation mark indicating the orientation of the probe 1 on the body mark 12, and information on the diagnosis part is input from the operation panel 8.
[0004]
In such an ultrasonic diagnostic apparatus, an ultrasonic wave is transmitted to a diagnostic site in a subject, and an ultrasonic tomographic image of the diagnostic site is transmitted to the image display unit 6 and the image data recording device 9 by the reflected echo signal. can get.
Here, in the above conventional apparatus, even when there is an image (image data) of a similar part obtained by an image diagnostic apparatus other than the ultrasonic diagnostic apparatus such as an X-ray CT apparatus or an MRI apparatus, it is directly used at the time of ultrasonic diagnosis. Cannot be used effectively. Therefore, the image is recorded on, for example, a film, a photographic paper, etc., and a doctor or the like visually checks the desired part while moving the probe 1 based on anatomical knowledge, and ultrasonically observes the part. It was used to make a diagnosis.
[0005]
[Problems to be solved by the invention]
As described above, the conventional apparatus does not currently have means for obtaining information as to which part of the subject is used for diagnosis and transmitting / receiving ultrasonic waves. For this reason, even if there is an anatomical image (image data) from an X-ray CT apparatus, MRI apparatus, or the like for a similar part input via a network or a recording medium, the ultrasonic wave currently obtained by the ultrasonic diagnostic apparatus As described above, there is no way to do the positional relationship (especially the alignment) with the tomographic image except for visual inspection as described above. For example, work for confirming the position of the desired part requires time and effort. There was a problem of lack of accuracy.
[0006]
An object of the present invention is to automatically perform positional relationship (especially alignment) between an ultrasonic tomographic image currently obtained and an anatomical image of an area similar to that by an X-ray CT apparatus, an MRI apparatus, or the like. For example, an ultrasonic diagnostic apparatus capable of easily, quickly and accurately confirming the position of a desired site is provided.
[0007]
[Means for solving the problems]
In order to achieve the above object, the present invention provides an ultrasonic diagnostic apparatus that transmits and receives ultrasonic waves to a subject using a probe and displays a B-mode image using the received signals . said image recording means for recording a stereoscopic image data of a subject, the probe and the probe position detecting means for detecting the spatial position and orientation of probe, the three-dimensional image of the pixel position of the B-mode image object Means for converting the coordinates of the pixel of the data so as to correspond to the origin of the coordinate system of the probe, and for detecting the probe position when displaying a B-mode image of the specific tomographic position of the subject. Using the spatial position and orientation of the probe output from the means, a tomographic image having a position and orientation corresponding to the specific tomographic position of the B-mode image is obtained from the stereoscopic image data recorded in the image recording means. The B mode The first feature to be displayed together with the image.
[0008]
In the ultrasonic diagnostic apparatus according to the first aspect of the present invention, the stereoscopic image data may be provided with position information corresponding to the space by pointing the pixel at a position that is the origin of the probe. If the position of an arbitrary pixel of the B-mode image can be expressed by a position vector from the pixel that is the origin of the probe, the stereoscopic image is The third feature is that the image data is recorded so that the position of the pixel can be expressed by a position vector from the pixel whose origin is the origin. In the ultrasonic diagnostic apparatus of the third feature, the B-mode image is an ultrasonic wave. A fourth feature is that the position of the pixel on the B-mode image is obtained from the origin set in the probe by a position vector from the beam direction, the time when the reflected wave is observed, and the speed of sound.
[0009]
Furthermore, in the ultrasonic diagnostic apparatus having any one of the above features, the present invention indicates the position of the pixel in the stereoscopic image and the position of the pixel in the B-mode image at the position that is the origin of the probe, and corresponds in space. By performing calibration for storing an image including a three-dimensional image recorded as a position for four or more points that are not on the same plane, the position of the probe and the pixel in the three-dimensional image corresponding to the pixel on the B-mode image are determined. The fifth feature is to find out, and in the ultrasonic diagnostic apparatus having any one of the above features, the sixth feature is that the stereoscopic image is obtained from an X-ray CT apparatus or an MRI apparatus.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of an ultrasonic diagnostic apparatus according to the present invention.
As shown in FIG. 1, this ultrasonic diagnostic apparatus includes a probe 1, an ultrasonic transmission / reception unit 2, an A / D converter 3, a memory unit 4, a display circuit unit 5, and an image display unit 6. An image data recording device 9, a central processing unit 7, an operation panel 8, an external device 10, and an input / output interface 11. Further, a transmitter 15 and a receiver 16 for obtaining a position in a three-dimensional space, an input / output interface 14 for connecting them to the central processing unit 7, and an image data input for inputting image data from the outside. Device 24.
[0011]
In this case, the probe 1 transmits an ultrasonic wave toward a diagnostic site in the subject and receives a reflected wave thereof. Although not shown, an ultrasonic wave generation source ( A transducer for receiving a reflected wave is provided. The ultrasonic transmission / reception unit 2 controls the probe 1 to transmit ultrasonic waves and detects a reflected echo signal from the received reflected waves. , Receiving amplifiers and their control circuits.
[0012]
The A / D converter 3 receives the reflected echo signal output from the ultrasonic transmission / reception unit 2 and converts it into a digital signal.
The memory unit 4 stores image data sequentially output from the A / D converter 3, here, B-mode image (ultrasonic tomographic image) data, and includes, for example, a memory buffer.
[0013]
The display circuit unit 5 converts the ultrasonic tomographic image data read from the memory unit 4 into an analog signal to be used as a display video signal. A D / A converter and a video signal conversion circuit are included in the display circuit unit 5. Is provided.
The image display unit 6 receives the video signal output from the display circuit unit 5 and displays it as an image, and is composed of, for example, a television monitor.
[0014]
The image data recording device 9 records an image displayed on the screen of the image display unit 6 and image data stored in the memory unit 4, and includes, for example, a magneto-optical disk or a color video printer. . When a video printer is used as the image data recording device 9, it is possible to hard copy an image displayed on the image display unit 6 by simultaneously taking in video signals input to the image display unit 6.
[0015]
The central processing unit 7 controls the above-described components and processes input image data, and includes a CPU, for example.
The operation panel 8 is connected to the central processing unit 7 and inputs various data such as diagnostic information and operation commands. The operation panel 8 includes, for example, a keyboard, a trackball or a joystick.
The external device 10 connected via the input / output interface 11 is controlled by the central processing unit 7 and stores image data according to an operation command from the operation panel 8 to the central processing unit 7 or is stored therein. Diagnosis information (for example, measurement conditions and image data itself) is read.
[0016]
Reference numeral 12 denotes a body mark displayed at the corner of the screen of the image display unit 6 when diagnosis is performed by obtaining an ultrasonic tomographic image of a diagnostic site in the subject. Reference numeral 13 denotes the orientation of the probe 1 on the body mark 12. The diagnostic part information is input from the operation panel 8 with the orientation mark shown.
[0017]
Here, in the present invention, the transmitter 15 and the receiver 16 are connected to the central processing unit 7 via the input / output interface 14. The central processing unit 7, the input / output interface 14, the transmitter 15 and the receiver 16 constitute a main configuration of the image position relation display means 23. Here, the image positional relationship display means 23 displays the ultrasonic tomographic image of the specific diagnostic region of the specific subject, and the same position corresponding to the tomographic position of the ultrasonic tomographic image (usually a matching position). A tomographic image of the same diagnostic region of the specimen is obtained from an image from an image data input device, which will be described later, and is displayed side by side or superimposed on the ultrasonic tomographic image, or alternately at regular time intervals. In the present invention, an image data input device 24 is also connected via the input / output interface 11. Hereinafter, these will be described.
[0018]
That is, the image data input device 24 includes a device that reads a recording medium recorded by another image diagnostic device (not shown) such as an X-ray CT device or an MRI device, or a host computer in a network. This image data input device 24 is controlled by the central processing unit 7 and is a stereoscopic image such as a plurality of diagnostic images, here, a plurality of X-ray CT images by volume scanning, and a plurality of MRI images (including volume images) by an MRI apparatus. Necessary image data among the image data is given to the memory unit 4.
[0019]
The transmitter 15 and receiver 16 obtain information for knowing in which part of the subject the probe 1 is located, and each has a unique three-axis orthogonal coordinate space. In addition, it is possible to know the position of the receiver 16 in the coordinate space set by the transmitter 15 and to know the twist (Euler angle etc.) between the coordinate axes of the three-axis orthogonal system of the receiver 16. used. For example, the transmitter 15 includes a magnetic field generating coil that generates a three-axis orthogonal magnetic field, and the receiver 16 includes a detection coil that can detect the three-axis orthogonal magnetic field. For example, the transmitter 15 is fixed at an arbitrary position on a table (subject table) on which the subject is placed, and the receiver 16 is provided on the side surface or inside of the probe 1. In some cases, the transmitter 15 may be fixed to the subject using a belt or the like. The positions of the transmitter 15 and the receiver 16 may be reversed.
[0020]
FIG. 2 is a perspective view showing an example of the probe 1 incorporating the receiver 16.
As shown in FIG. 2, the probe 1 has three axes x, y, and z orthogonal to each other. Here, the polarity display mark 17 is set on the outer surface of the probe 1 in accordance with the positive direction of the x-axis so that the direction of the orientation mark 13 can be easily set.
[0021]
Next, the calculation of the distance between the transmitter 15 and the receiver 16 and the twist between the coordinate axes of the three-axis orthogonal system will be described. First, the transmitter 15 and the receiver 16 shown in FIG. 1 are arranged so that the coil surfaces of the three-axis orthogonal magnetic field generating coil and magnetic field detecting coil are orthogonal to each other. Then, an alternating current is passed through each coil of the transmitter 15 to generate an alternating magnetic field. The alternating magnetic field generated by the transmitter 15 is detected by the three detection coils of the receiver 16 and converted into an electrical signal. At this time, in order to clarify which of the three coils of the transmitter 15 generates the magnetic field, the frequency may be changed for each coil, or the alternating magnetic field may be generated by time division. A magnetic dipole can be assumed by the current flowing through the detection coil of the receiver 16, and the distance between the magnetic field generating coil of the transmitter 15 and the detection coil of the receiver 16 and the angle formed by the direction vector of the magnetic dipole are determined by the detection coil. And the magnetic dipole moment given by the transmitter 15. Thereby, the distance between the transmitter 15 and the receiver 16 and the twist between the coordinate axes of the three-axis orthogonal system can be calculated.
[0022]
When magnetism is used in this way, the position error can be measured with an accuracy within 2 to 3 mm within a radius of about 40 cm, for example. It can be observed with an error of ~ 3 °. By using such a transmitter 15 and receiver 16, the magnetic field generated from each coordinate axis of the three-axis orthogonal system of the transmitter 15 is detected by the receiver 16, and the transmitter is determined from each direction component and the magnetic field strength. 15 and the distance between the receiver 16 and the position, and the twist (Euler angle etc.) between the coordinate axes of the three-axis orthogonal system.
[0023]
Next, the use of the ultrasonic diagnostic apparatus including the transmitter 15 and the receiver 16 as described above will be described. First, the transmitter 15 is fixed at an arbitrary position such as a subject table, for example, and a pen-type stylus sensor (not shown) that can obtain the position coordinates in the coordinate system of the transmitter 15 is used. Thus, the position coordinates of an arbitrary point α in the coordinate system are measured. Next, as shown in FIG. 2, a point in the coordinate system of the x, y, and z axes set to the probe 1, for example, one intersection 18a of the x axis and the probe case 1a coincides with the point α. The probe 1 is moved and fixed as shown. Then, the Euler angles (θx, θy, θz) between the position coordinates (x1, y1, z1) of the receiver 16 in the probe 1 and the coordinate axes of the transmitter 15 are measured.
[0024]
Since the position of the point α is measured by the stylus sensor, the position vector from the origin of the receiver 16 in the coordinate space set by the transmitter 15 to the intersection 18a between the x-axis and the probe case 1a. If the coordinates of the point α are (x0, y0, z0),
(X0-x1, y0-y1, z0-z1)
It can be expressed as Then, by rotating this point by the Euler angles (θx, θy, θz), a position vector in the coordinate system of the receiver 16 is obtained.
[0025]
Similarly to the intersection 18a between the x-axis and the probe case 1a in FIG. 2, the other intersection 18b between the x-axis and the probe case 1a and the intersection 19 between the y-axis and the probe case 1a. When the position vector in the coordinate system of the receiver 16 is obtained, the relationship between the coordinate space set by the transmitter 15 and the coordinate system of the receiver 16 is obtained, and the position of the receiver 16 and the coordinate system thereof are obtained. Can be detected. Thereby, the positional relationship between the transmitter 15 and the receiver 16 is obtained.
[0026]
Next, the transmitter 15 is fixed, for example, at a predetermined position on the subject table so that the positional relationship with the subject is fixed. Thereafter, if the positional relationship of the subject in the coordinate system of the transmitter 15 is grasped using the stylus sensor, the positional relationship between the subject and the probe 1 is obtained by coordinate conversion. At this time, it is necessary to always fix the positional relationship between the origin and coordinate axes of the transmitter 15 and the subject, or to measure the positional relationship each time. The positional relationship between the receiver 16 and the probe 1 is the same. If the positional relationship between the transmitter 15 and the subject and the receiver 16 and the probe 1 is constant, the relative positional relationship between the transmitter 15 and the receiver 16 can be measured almost in real time. The relative positional relationship of the child 1 can be calculated, and the relative position of the probe 1 on the subject can be known.
[0027]
FIG. 3 is a diagram for explaining an example of the spatial coordinates set regardless of the coordinate space of the transmitter 15.
That is, in FIG. 3, the subject table 21 on which the subject 20 is placed is set on the XY plane (22 is the origin) (FIG. 3B), and the subject table 21 is placed on the subject table 21. The Z axis is set so as to pass vertically through the chest of the specimen 20 (FIG. 3A). The Z axis does not necessarily pass through the chest of the subject 20, and may be set at another position that is optimal for selecting the body mark 12 as long as it is perpendicular to the XY plane.
[0028]
The position of a pixel in a stereoscopic image (X-ray CT image obtained by volume scanning of the X-ray CT apparatus, volume image obtained by the MRI apparatus) obtained by an X-ray CT apparatus, MRI apparatus, etc. Are matched in the following way.
First, each pixel of the stereoscopic image is expressed by the same method as the three-dimensional spatial coordinates set by the ultrasonic diagnostic apparatus. That is, when the position of an arbitrary pixel of the ultrasonic tomographic image can be expressed by a position vector from the pixel serving as the origin, the image is represented so that the position of the pixel of the stereoscopic image can be expressed by a position vector from the pixel serving as the origin. Record it. In addition, for images (ultrasound tomograms) obtained by an ultrasound diagnostic apparatus, the position of the pixel on the image is searched from the direction of the emitted ultrasound beam, the time until the reflected wave is observed, and the speed of sound. It is obtained from the position vector from the origin set for the touch element 1. Thus, the position of the pixel in the set coordinate system is obtained from the position and orientation of the probe 1 in the set coordinate system and the position of the subject 20 in the set coordinate system measured in advance.
[0029]
As described above, coordinate conversion can be performed so that the position of the pixel of the ultrasonic tomographic image matches the position of the pixel in the stereoscopic image obtained by the X-ray CT apparatus, the MRI apparatus, or the like. Specifically, the pixel in the stereoscopic image is pointed at the position that is the origin of the probe 1 and recorded as a corresponding position in the space. If this calibration is performed for four or more points that are not on the same plane, the position of the probe 1 and the pixel in the stereoscopic image corresponding to the pixel on the ultrasonic tomographic image can be found.
[0030]
The actual procedure is as follows. That is, the operation of the probe 1, the ultrasonic transmission / reception unit 2, and the A / D converter 3 transmits an ultrasonic wave toward a diagnostic site in the subject 20, receives the reflected wave, and receives the diagnostic site. Is recorded and collected in the memory unit 4. At this time, the signal transmitted from the transmitter 15 is received by the receiver 16 attached to the probe 1, and this signal is given to the central processing unit 7 via the input / output interface 14. The central processing unit 7 analyzes the given signal to determine the position of the probe 1. From this position information, the position of each pixel of the ultrasonic tomographic image is obtained by the central processing unit 7, and each pixel in the stereoscopic image corresponding to these pixel positions, here in the same position, is imaged from a network or a recording medium. Data is sequentially read out using the data input device 24, reconstructed into a two-dimensional image (tomographic image), and written in the memory unit 4. The display circuit unit 5 converts the image data written in the memory unit 4 into a video signal and displays it as an image on the image display unit 6. The method of display is generally a method of displaying the image display unit 6 side by side on the top or bottom or left and right of the same screen, but other methods such as alternately displaying at the same position on the same screen at regular intervals. Also good.
[0031]
In the above example, the image position association display unit 23 is mainly configured by the central processing unit 7, the input / output interface 14, the transmitter 15, and the receiver 16, but is not limited thereto. The transmitter 15 and the receiver 16 are not limited to those using a magnetic field generating coil or a magnetic field detecting coil.
[0032]
【The invention's effect】
As described above, according to the present invention, the positional relationship (especially alignment) between the currently obtained ultrasonic tomographic image and the anatomical image of the same part by an X-ray CT apparatus, MRI apparatus, or the like. For example, there is an effect that the position of the desired part can be confirmed easily, quickly and accurately.
[0033]
In particular, according to the above-described embodiment, the relative position and direction of the subject and the probe can be detected in an arbitrarily set coordinate space. From this, the image data from the image data input device can be detected in the three-dimensional coordinate space. Calibrating so that each part of the subject can be aligned, and then performing a diagnosis, the positional relationship between each tissue in the diagnostic image and the body surface (probe position) can be detected, Information about the diagnostic part of the subject can also be obtained, and synthesis with the input diagnostic image is simplified. Thereby, the tomographic image of the X-ray CT apparatus and the tomographic image of the MRI apparatus corresponding to the ultrasonic tomographic plane being examined by the ultrasonic diagnostic apparatus are displayed on the same screen as the ultrasonic tomographic image, and the examination is performed while comparing them. Will be able to. In addition, when it is desired to inspect the blood flow information of a part of interest at the time of X-ray CT examination or MRI examination in real time by CFM (color flow mapping) or the like, the alignment can be easily performed. If position measurement can be performed with higher accuracy, it is possible to perform diagnosis by combining the superior parts of each diagnostic device by combining CFM images with tomographic images of X-ray CT and MRI devices combined from position information. The effect of becoming is obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a device of the present invention.
FIG. 2 is a perspective view showing an example of a probe incorporating the receiver in FIG.
FIG. 3 is a diagram for explaining an example of spatial coordinates set regardless of the coordinate space of the transmitter in FIG. 1;
FIG. 4 is a block diagram of a conventional apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Probe, 2 ... Ultrasonic transmission / reception part, 3 ... A / D converter, 4 ... Memory part, 5 ... Display circuit part, 6 ... Image display part, 7 ... Central processing unit, 8 ... Control panel, 9 DESCRIPTION OF SYMBOLS ... Image data recording device, 10 ... External device, 11, 14 ... Input / output interface, 12 ... Body mark, 13 ... Orientation mark, 15 ... Transmitter, 16 ... Receiver, 23 ... Image positional relationship display means, 24 ... Image data input device.

Claims (6)

In an ultrasonic diagnostic apparatus that transmits and receives ultrasonic waves to a subject using a probe and displays a B-mode image using the received signal ,
An image recording means for recording a stereoscopic image data of the subject obtained by the image diagnostic apparatus, a probe position detecting means for detecting the spatial position and orientation of the probe, and the pixel position of the B-mode image wherein a means for coordinate transformation so as to correspond to the origin of the coordinate system of the probe and the position of a pixel of the stereoscopic image data of a subject, said Upon display of B-mode images of a particular fault location of the object The tomographic image of the position and orientation corresponding to the specific tomographic position of the B-mode image is recorded in the image recording means using the spatial position and orientation of the probe output from the probe position detecting means. An ultrasonic diagnostic apparatus that is obtained from the obtained stereoscopic image data and displayed together with the B-mode image.   The ultrasonic diagnostic apparatus according to claim 1, wherein the stereoscopic image data points to the pixel at a position that is an origin of the probe and is given position information corresponding to the space.   When the position of an arbitrary pixel in the B-mode image can be expressed by a position vector from a pixel that is the origin of the probe, the image data is expressed so that the position of the pixel of the stereoscopic image can be expressed by a position vector from the pixel that is the origin. The ultrasonic diagnostic apparatus according to claim 1, wherein recording is performed. The B-mode image is obtained from a position vector from the origin set in the probe based on the direction of the ultrasonic beam, the time at which the reflected wave is observed, and the speed of sound, and the pixel position on the B-mode image. The ultrasonic diagnostic apparatus according to claim 3.   A calibration that stores an image including a stereoscopic image that is recorded as a corresponding position in the space by indicating the position of the pixel in the stereoscopic image and the position of the pixel in the B-mode image at the position that is the origin of the probe. The superposition according to any one of claims 1 to 4, wherein a pixel in a stereoscopic image corresponding to a position of a probe or a pixel on a B-mode image is searched for by performing four or more points that are not on the same plane. Ultrasonic diagnostic equipment.   The ultrasonic diagnostic apparatus according to claim 1, wherein the stereoscopic image is obtained from an X-ray CT apparatus or an MRI apparatus.

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