JP2000262511A - Tomograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To position an X-ray CT in a shorter time without increasing exposure. SOLUTION: The imaging section is determined by an ultrasonic diagnostic instrument. A location of a probable tumor is specified on an ultrasonic tomographic image and the movement of a bed top board 18 is controlled so that the specified point coincides with the imaging center of an X-ray CT. To make the coordinates of the ultrasonic diagnostic instrument match the coordinates of the X-ray CT, markers 26 and 14 are attached to a gantry of the X-ray CT and an ultrasonic probe 24 and the coordinates of the markers are previously measured by a position measuring device 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray computed tomography apparatus (hereinafter referred to as "X-ray CT") for imaging a tumor or the like in a body.
Apparatus), a magnetic resonance imaging apparatus (hereinafter, referred to as an apparatus)
The present invention relates to a tomographic apparatus with an image reconstructing process such as an MRI apparatus, a nuclear medicine diagnostic apparatus (hereinafter, referred to as a gamma camera), and particularly relates to imaging positioning.

[0002]

2. Description of the Related Art Conventionally, when imaging a tumor or the like with an X-ray CT apparatus, so-called fluoroscopic imaging is performed before tomographic imaging to determine an imaging section (actually, a range of the section). The most important problem of a diagnostic device and an imaging device using X-rays is the amount of X-ray exposure. It is preferable for the human body to reduce the exposure dose as much as possible. However, there is a drawback in that, when the fluoroscopic imaging is performed, the exposure dose increases accordingly. Here, even if the tomographic imaging is performed only from the outside of the body without performing the fluoroscopic imaging, the exposure dose increases for the following reasons. If the estimated imaging range is larger than the range necessary for the actual diagnosis, more radiation is given than necessary. Conversely, if the intended imaging range is smaller than the required range, it is not possible to obtain an image of the cross section to be interpreted in the imaging, so it is necessary to perform another imaging, and the exposure amount for the first imaging is reduced. It will be wasted.

On the other hand, in a lung cancer mass examination or mass examination using an X-ray CT apparatus, several tomographic images of the lung apex and the lung bottom are photographed in order to determine the photographing range. Decisions are being made. In this case, as in the case described above, the exposure is increased by the number of images of the lung apex and lung bottom taken. In addition, since the lung apex and lung bottom are photographed and positioned from outside the body, it is not always possible to capture the lung apex and lung bottom in the first imaging, and again the exposure dose increases due to retaking. Sometimes.

[0004] The problem of the positioning of the imaging section causes an increase in the imaging time in addition to the increase in the exposure dose. this is,
This is particularly serious in a group examination or the like in which a large number of subjects are efficiently photographed in a short time. Further, the problem of positioning of the imaging section may occur similarly in a tomographic apparatus such as an MRI apparatus and a gamma camera in addition to the X-ray CT apparatus.

[0005] In addition, during a surgical operation, it is sometimes desired to take an image of a tumor or the like with an X-ray CT apparatus, an MRI apparatus, or the like in order to confirm the effect of the operation. In this case, since the patient is very weak, it is important to perform minimally invasive (safe, reliable, short-time) imaging. This is because the exposure dose and tomographic imaging time greatly affect post-operative recovery, 5-year survival rate, and the like. From this point as well, it is desirable that accurate positioning be performed instantaneously and only necessary cross sections be photographed in a short time.

[0006]

As described above, in the conventional tomography apparatus with image reconstruction, there is a problem that the exposure dose increases or it takes time to determine the imaging position.

An object of the present invention is to provide a tomographic apparatus capable of performing imaging positioning without increasing the exposure dose or taking a long time.

[0008]

In order to solve the above problems and achieve the object, the present invention uses the following means.

(1) A tomographic apparatus according to the present invention comprises: a position measuring apparatus for obtaining a position of a probe of an ultrasonic diagnostic apparatus for obtaining an ultrasonic tomographic image of a subject and a position of an imaging center of the tomographic apparatus; An input device for designating a part to be imaged on an acoustic tomographic image, and positioning the subject so that the imaging part specified by the input device coincides with the imaging center.

(2) The position measuring device comprises three cameras for specifying a plane including a marker arranged at the position measuring point, the two cameras specifying two vertical planes including the marker, and the remaining cameras Is a tomography apparatus according to (1), which specifies a plane that intersects the intersection of two vertical planes and includes a marker.

(3) The position measuring device measures at least three markers attached to the tomographic imaging device and the position of the marker at the center of imaging, and obtains a positional relationship between at least three markers and the imaging center. The tomography apparatus according to (1) or (2), characterized in that:

(4) The input device includes means for converting coordinates of a point on an ultrasonic tomographic image into coordinates represented by a coordinate system of the position measuring device (1) to (3). ).

(5) The tomographic imaging apparatus according to any one of (1) to (4), wherein the input device freezes an ultrasonic tomographic image and specifies an imaging region on the frozen image. is there.

(6) The tomography apparatus according to any one of (1) to (5), wherein the tomography apparatus is an X-ray computed tomography apparatus.

(7) The tomography apparatus according to any one of (1) to (5), wherein the tomography apparatus is a magnetic resonance imaging apparatus.

(8) The tomographic apparatus according to any one of (1) to (5), wherein the tomographic apparatus is a magnetic medical diagnostic apparatus.

(9) The second tomographic imaging apparatus of the present invention obtains the position of the imaging plane of the probe of the ultrasonic diagnostic apparatus for obtaining an ultrasonic tomographic image of the subject and the position of the imaging center of the tomographic imaging apparatus. A position measuring device, and an input device for designating a section to be photographed while viewing the display of the ultrasonic diagnostic apparatus, wherein a target point of the photographed section designated by the input device is coincident with a photographing center. This is for positioning the sample.

(10) The positioning system according to the present invention comprises means for determining the positional relationship between the marker of the tomographic apparatus and the imaging position, and the marker and monitor of the probe of the ultrasonic diagnostic apparatus for obtaining an ultrasonic tomographic image of the subject. Means for determining the positional relationship with the point, means for specifying a part to be imaged on a monitor, means for measuring the coordinates of the marker of the tomographic apparatus and the marker of the probe, the direction of the probe and The direction of the ultrasonic tomographic image displayed by the monitor is the same, and according to the positional relationship between the marker of the tomographic apparatus and the imaging position, and the positional relationship between the point on the monitor and the marker of the ultrasonic probe,
The part specified on the monitor is set as the imaging position of the tomographic imaging apparatus.

(11) Another positioning system according to the present invention includes means for determining a positional relationship between a marker of the tomographic imaging apparatus and an imaging position, and a marker of a probe of an ultrasonic diagnostic apparatus for obtaining an ultrasonic tomographic image of a subject. Means for determining a positional relationship with a point on a monitor, means for specifying a part to be imaged on the monitor, means for measuring the coordinates of the marker of the tomographic apparatus and the marker of the probe, and The size of the marker and the size of the ultrasonic tomographic image displayed by the monitor are the same, and are determined according to the positional relationship between the marker of the tomography apparatus and the imaging position, and the positional relationship between the point on the monitor and the marker of the ultrasonic probe. Then, the part specified on the monitor is set as the imaging position of the tomographic imaging apparatus.

(12) Still another positioning system according to the present invention is a means for determining a positional relationship between a marker of a tomographic apparatus and an imaging position, and a marker of a probe of an ultrasonic diagnostic apparatus for obtaining an ultrasonic tomographic image of a subject. Means for determining the positional relationship between the monitor and a point on the monitor, means for specifying a part to be imaged on the monitor, means for measuring the coordinates of the marker of the tomographic apparatus and the marker of the probe, the probe And the direction of the tomographic plane of the tomographic apparatus is the same, the positional relationship between the marker of the tomographic apparatus and the imaging position, and the positional relationship between the point on the monitor and the marker of the ultrasonic probe. In this case, the part specified on the monitor is set as the imaging position of the tomographic imaging apparatus.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a tomography apparatus according to the present invention will be described below with reference to the drawings.

First Embodiment FIG. 1 is a schematic diagram showing the overall configuration of a tomographic apparatus according to a first embodiment of the present invention. Here, an X-ray CT apparatus will be described as an example of a tomographic apparatus, but an MRI apparatus, a gamma camera, or the like may be used, and any apparatus that involves reconstruction processing may be used. Markers 14 are embedded in four or three corners of the gantry 12 of the X-ray CT apparatus. The marker 14 is for determining the position and orientation of the X-ray CT apparatus, and may be of any type as long as the position (three-dimensional coordinates) can be detected by a position measuring device 28 described later. Is selected as appropriate. Here, it is assumed that the position measurement device 28 receives the light from the marker 14 and detects the position of the marker. Therefore, a light emitting element such as an LED having a diameter of about 1 cm is used as the marker. Sleeper 1
At least three markers 22 are also attached to the patient 20 on the top plate 18. The patient marker 22 has a different emission color from the gantry marker 14. this is,
The position measuring device 28 can measure the position of each marker, but cannot distinguish which marker, so that the marker is distinguished based on the color difference.

In this embodiment, the image for positioning is X
It is not a fluoroscopic image (scanogram) or tomographic image taken by a line CT apparatus, but an ultrasonic tomographic image taken by an ultrasonic diagnostic apparatus having excellent real-time properties. Therefore, an ultrasonic probe 24 is provided, and at least three markers 26 are embedded in the probe 24. In order to perform imaging positioning, it is necessary to check at least the positional relationship between the probe 24 and the gantry 12 and, if necessary, the positional relationship between the patient 20 and the gantry 12.
A position measuring device 28 for obtaining coordinates 2 and 26 is provided. Measurement result of the position measurement device 28 (x, y, z coordinate values)
Is input to the position determination device 30. A mouse 34 for specifying the position of the tumor on the display device 32 for displaying an ultrasonic image (B-mode tomographic image) and a freeze key 36 for freezing the tomographic image when the tumor is found are also connected to the position determining device 30. . The position determining device 30 gives a position control signal to the bed controller 38 of the X-ray CT device, and controls the imaging position (cross section) by changing the position (sliding amount, height) of the top plate 18.

FIG. 2 shows an example of the position measuring device 28. The position measuring device 28 has three cameras 28a, 28b, 28c.
The left and right cameras 28a, 28c can identify two vertical planes 44a, 44c including the marker 42. Thereby, the x coordinate and the y coordinate of the marker 42 are obtained. For convenience of illustration, the marker 42 is illustrated as being located at the origin, but the marker 42 need not be at the origin. The middle camera 28b includes a marker 42 and specifies a horizontal surface 44b intersecting the two vertical planes, that is, the z coordinate of the marker 42. This coordinate system is one coordinate system defined by the position measuring device 28, and the position measuring device 28
Is moved, the coordinate system is unchanged. Thus, the positional relationship between the gantry 12, the ultrasonic probe 24, and the patient 20 is obtained.

In the present embodiment having the above-described configuration, the imaging section is positioned by the following procedure. In the present embodiment, a diagnosis site is specified on an ultrasonic tomographic image, and the position of the top plate 18 of the bed 16 is adjusted so that this position matches the imaging center of the X-ray CT apparatus. Therefore, it is necessary to determine the positional relationship between the X-ray CT apparatus and the ultrasonic tomographic image.

(1) First, the position of the X-ray CT apparatus is obtained. The position of the X-ray CT apparatus is the imaging center at the center of the gantry 12. As shown in FIG. 3, only the imaging space is imaged without a patient inside the gantry 12. At this time, one marker 50 for obtaining the photographing center is prepared and arranged at a place in the photographing space that is considered to be the photographing center. In this state, a scan for obtaining a tomographic image is performed, and the tomographic image is displayed on the monitor 52. The monitor 52 is located at the center of the screen (here,
The position of the marker 50 is adjusted such that the cross cursor is positioned at the center of the image capturing, and the image 50A of the marker 50 is located at the center of the screen. When the marker image 50A matches the center of the screen of the monitor 52, the position of the gantry marker 14 and the position of the center marker 50 are measured by the position measuring device 28. Thereby, the position of the photographing center with respect to the gantry 12 can be known. That is, if the coordinates of the marker 14 are known, the coordinates of the photographing center can be known without the marker 50. If the coordinates of the photographing center with respect to the gantry 12 are known in advance, the process (1) can be omitted. This process need not be executed for each positioning operation, but can be executed at the first positioning operation, and can be omitted from the second time if this information is stored in the position determination device 30.

(2) Next, the positional relationship between the ultrasonic tomographic image and the marker 26 of the ultrasonic probe 24 is determined. This is done so that the scale of the ultrasonic tomographic image displayed on the display 32 is the same as the actual scale of the patient.
This is performed by setting the display magnification of 2. That is, the distance of 1 cm on the screen is 1 cm even in the actual size. In this way, when the point Q is designated on the ultrasonic tomographic image screen, the coordinates of the point Q with respect to the marker 26 can be determined from the coordinates of the point Q on the screen. For example, assuming that a point Q 10 cm below the one of the three markers 26 closest to the patient in FIG. 4 (the coordinates are (0, 15, 0)) is specified, the coordinates of the point Q are (0, 5, 0). This step (2) may be executed only at the time of the first positioning, and can be omitted from the second time.

(3) X-ray CT by the position measuring device 28
Marker 14, ultrasonic probe 24 of gantry 10 of the apparatus
And the patient's marker 22 are photographed simultaneously. Thereby, the positions of all markers can be expressed in the coordinate system of the position measuring device 28. Gantry marker 1
Knowing the coordinates of 4 also means knowing the position of the shooting center 50, as described with reference to FIG. These pieces of position information are input to the position determination device 30.

(4) Thereafter, the patient 20 is placed on the top plate 18 of the bed 16 and the tomography is started. First, the ultrasonic probe 24 is applied to the patient 20 to photograph a B-mode tomographic image, and a tumor or the like to be photographed is searched based on the display image of the display device 32. The ultrasound probe 24 may be tilted not only in the vertical direction but also with respect to the patient's body surface to search for the imaging target.
When a tumor is seen, the freeze key 36 is pressed, and the ultrasonic tomographic image at that moment is frozen (moving image becomes a still image). The position of the marker 26 of the ultrasonic probe 24 and the position of the marker 22 of the patient 20 at the time of freeze are measured, and the coordinates are taken into the position determination device 30. Then, as shown in FIG. 5, on the freeze screen of the display device 32, the mouse cursor 54 is positioned at the position of the tumor 58 or the like to be imaged, and the mouse 34 is clicked. As described in the above (2), since the correspondence between the marker 26 of the ultrasonic probe 24 and the screen of the display device 32 is known, if the tumor 58 is specified on the ultrasonic image, The position 58, that is, the position in the coordinate system of the position measuring device 28 is obtained. The position information of the tumor is also input to the position determination device 30.

It should be noted that the position in the coordinate system of the position measuring device 28 is determined from the designated point on the ultrasonic image on the assumption that the patient is not moving between the above (3) and the time of freeze. . If the position of the patient marker 22 captured in (3) and the position of the patient marker 22 captured at the time of freeze are shifted, it is necessary to correct the calculated coordinates of the tumor by the amount of the shift. This correction is
Known in registration using markers, for example,
The following document describes it in detail.

"Simultaneous Usage of Homologous Poin
ts, Lines, and Planes for Optimal, 3-D, Linear Reg
istration of Multimodality Imaging Data ", Charles
R. Meyer, Gregg S. Leichtman, James A. Brunberg, R
ichard L. Wahl, and LeslieE.Quint, IEEE transacti
ons on Medical Imaging, Vol. 14, No. 1, March 1995 (5) By the processing described above, the position determination device 30 becomes an X-ray CT.
The position of the imaging center of the gantry 10 of the device and the position of the imaging region of the patient 20 (both are represented by the coordinate system of the position measuring device 28)
Can be requested. Therefore, the position determining device 30 controls the bed controller 38 to control the height of the top board 18 and the amount of sliding (the amount of insertion into the gantry 10) so that the two coincide with each other.

FIG. 6 is a flowchart showing the above five processes.

As described above, according to the present embodiment, since the position and orientation are represented in the same coordinate system as the gantry and the imaging region is specified using an ultrasonic tomographic image having excellent real-time properties, the exposure dose is Positioning can be performed in a short time without increasing the number of positions.

Hereinafter, another embodiment of the tomography apparatus according to the present invention will be described. In the description of the other embodiments, the same parts as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

Second Embodiment The block diagram of the second embodiment is the same as the block diagram of the first embodiment, and is not shown. In the first embodiment, in the process (4), one point of the ultrasonic tomographic image is designated and the photographing position is determined. However, it is also possible to decide only the section to be photographed without designating one point. This method is suitable for imaging a lung field or the like. Most of the processing is the same as in the first embodiment, but when the freeze key 36 is pressed, the display device 32
Is different in that the section displayed on the screen is designated as the imaging section and the section is specified, but the position is not specified. That is, the second embodiment does not require the mouse 34 for designating a tumor on the freeze screen.

FIG. 7 shows a state of positioning of a designated position of an imaging section in the second embodiment. In the first embodiment,
In the process of (4) for performing ultrasonic tomography, the direction of the ultrasonic probe 24 when searching for an imaging target may be not only vertical but may be inclined with respect to the patient's body surface. In this case, since the ultrasonic tomographic plane is an imaging section, it is preferable that the ultrasonic tomographic plane be substantially vertical. The reason is that, in the second embodiment, the position of the ultrasonic probe 24 in the body axis direction is the imaging surface. Therefore, when the position of a tumor or the like is away from the tip of the ultrasonic probe 24, the ultrasonic probe is tilted. This is because the more the position is tilted, the more the position of the tumor is shifted and the accuracy is reduced. Therefore, the above-mentioned (3) in which coordinates are first obtained
In the plane V, the ultrasonic probe 24 is set in the vertical direction.
The positions of the gantry 12, the probe 24, and the patient 20 are measured at the position. Next, the ultrasonic probe is translated, and a plane W including the tumor is searched for. When the coordinates of the plane W in the body axis direction are obtained, the position of the couch top 18 is adjusted so that the coordinates coincide with the coordinates of the imaging center of the gantry 12 in the body axis direction.

Although the imaging section is a vertical plane including the position where the ultrasonic probe 24 is in contact with the patient's body surface, the present invention is not limited to this. For example, a vertical plane passing through the center of gravity of the marker 26 may be used.

According to the second embodiment, in addition to the effect of the first embodiment, since positioning can be executed only by finding a cross section, there is an effect that a further reduction in time can be realized.

Modifications The present invention is not limited to the embodiments described above, but can be implemented in various modifications. For example, in the above description, an X-ray CT apparatus has been described as an example of a tomographic apparatus. However, another tomographic apparatus such as an MRI apparatus or a gamma camera may be used.

Although the freeze key 36 is provided independently, the place where the freeze key 36 is provided is not limited to this. The freeze key 36 may be attached to another place, for example, to the ultrasonic probe 24 as shown in FIG.

The markers 14, 22, and 26 are light emitting elements. However, when the position measuring device 28 irradiates the marker with light and receives the reflected light to perform measurement, a simple colored glass sphere or the like may be used. The size is not limited to a spherical shape of 1 cm, but may be a cube having a side of about 3 cm. Further, the material is not limited to glass, but may be plastic or the like.

Although the direction of the tomographic image to be photographed is vertical to the bed, the present invention is not limited to this, and may be oblique.

To correct the detected coordinates when the patient moves during positioning, a marker 22 is also attached to the patient. However, when it is expected that the patient hardly moves, this marker 2 is used.
2 can be omitted.

In the first embodiment, the position of the point designated by the mouse 34 is set as the photographing position. However, the designation method is not limited to this, and another method may be used. For example, the ultrasonic tomographic image may be binarized to automatically extract a region considered to be a tumor, and the center of gravity of the extracted region may be used.

The scale of the display device 32 for displaying the ultrasonic tomographic image is set to the actual size. However, the ratio may be known, and another scale, for example, 1/2 of the actual size may be used.

The ultrasonic tomographic image is taken on the same tomographic plane as the direction of the probe, and the direction of the display device 32 and the direction of the ultrasonic tomographic image are assumed to be the same. In recent years, a three-dimensional probe has been developed. The acoustic tomographic image is not necessarily limited to the same plane as the direction of the probe, and may be inclined (for example, 10 degrees) with respect to the direction of the probe.

In the first embodiment, the ultrasonic image is frozen and the position considered to be a tumor is designated. However, the designation method is not limited to this. For example, the mouse 34 may be used without freezing the image. May be the position at the moment when is clicked. Furthermore, one position that is considered to be a tumor was designated, and this was used as a tomographic image capturing device. However, the designation is not limited to one point. Other points, for example, three points, are designated, and the couch top 18 is moved to three places. It is also possible to move the camera to photograph a tumor or the like.

Although the ultrasonic tomographic image is frozen by pressing the freeze key 36, the method of freezing is not limited to this, and another method such as freezing by voice may be used.

Further, the photographing position of the photographing device is changed to the gantry 12.
However, as long as the position on the image with respect to the coordinates of the marker 14 is known, the center is not necessarily required.
Furthermore, if the position of the imaging center with respect to the gantry 12 is known,

[0050]

As described above, according to the present invention, the following effects can be obtained.

(1) Since the position to be imaged is specified by using an ultrasonic tomographic image having the same position and direction as the tomographic apparatus and having excellent real-time properties, X-ray fluoroscopy can be omitted, and exposure can be reduced. It can be reduced and time can be reduced.

(2) Since the position and direction are expressed in the same coordinate system as the tomographic apparatus and the tomographic region is specified using an ultrasonic tomographic image having excellent real-time properties, several images are required to determine the range to be imaged. Can be omitted, exposure can be reduced, and time can be shortened.

(3) Since the range to be photographed can be accurately specified, there is no need for re-photographing because photographing has failed, so that exposure can be reduced and time can be shortened.

(4) Since the position to be imaged is specified using an ultrasonic tomographic image which is expressed in the same coordinate system as the tomographic apparatus and has excellent real-time properties, a tumor or the like can be instantaneously imaged and positioned. Time can be shortened.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an X-ray CT apparatus having a positioning mechanism according to the present invention.

FIG. 2 is a diagram showing the principle of a position measuring device used for a positioning mechanism.

FIG. 3 is a diagram illustrating a positional relationship between a gantry marker and an imaging center.

FIG. 4 is a view for explaining a relationship between a marker of an ultrasonic probe and a monitor displaying an ultrasonic tomographic image.

FIG. 5 is a view for explaining a method of specifying a position on a monitor which is considered to be a tumor.

FIG. 6 is a flowchart illustrating a positioning process according to the first embodiment.

FIG. 7 is a view for explaining the principle of positioning according to the second embodiment;

FIG. 8 is a view showing a modification of the arrangement of the freeze key;

[Explanation of symbols]

 12 Gantry 14, 22, 26 Color marker 18 Top plate 20 Patient 24 Ultrasonic probe 28 Position measuring device 30 Position determining device 32 Display device 34 Mouse 36 Freeze key 38 Bed controller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) G01S 7/539 G01S 7/62 DF term (reference) 2F065 AA03 AA04 AA54 BB05 CC16 DD06 FF04 FF09 JJ03 JJ24 JJ26 4C093 AA22 CA15 CA17 CA34 EC41 ED06 ED07 EE01 EE02 EE30 FA36 FA43 FG05 FG12 FG13 4C096 AA18 AB36 AB38 AB46 AD18 AD23 DD09 DD12 DD13 EB05 EB06 EB08 FC17 FC20 4C301 CC02 EE13 EE14 EE19 EA02 EA01 GD02 KK01 EB02

Claims (9)

[Claims] 1. A position measuring device for obtaining a position of a probe of an ultrasonic diagnostic apparatus for obtaining an ultrasonic tomographic image of a subject and a position of an imaging center of a tomographic imaging device, and a part to be imaged on the ultrasonic tomographic image. A tomographic imaging apparatus, comprising: an input device for specifying the subject; and positioning the subject so that the imaging region specified by the input device coincides with the imaging center. 2. The position measuring device comprises three cameras for specifying a plane including a marker arranged at a position measuring point, two cameras for specifying two vertical surfaces including a marker, and the remaining cameras for specifying a plane including a marker. 2. The tomography apparatus according to claim 1, wherein a plane that intersects the intersection of the two vertical planes and includes a marker is specified. 3. The position measuring apparatus measures at least three markers attached to the tomographic apparatus and the positions of the markers at the photographing center, and obtains the positional relationship between the at least three markers and the photographing center. The tomographic apparatus according to claim 1 or 2, wherein 4. The input device according to claim 1, further comprising means for converting coordinates of a point on the ultrasonic tomographic image into coordinates represented by a coordinate system of the position measuring device. The tomographic imaging apparatus according to any one of the above. 5. The tomographic imaging apparatus according to claim 1, wherein the input device freezes the ultrasonic tomographic image and designates an imaging region on the frozen image. . 6. A position measuring device for obtaining a position of an imaging surface of a probe of an ultrasonic diagnostic apparatus for obtaining an ultrasonic tomographic image of a subject and a position of an imaging center of the tomographic imaging device, and a display of the ultrasonic diagnostic device. An input device for designating a section to be imaged, wherein the subject is positioned so that a predetermined point of the section to be imaged specified by the input device coincides with the center of imaging. 7. A means for determining a positional relationship between a marker of a tomographic imaging apparatus and an imaging position, and determining a positional relationship between a marker of a probe of an ultrasonic diagnostic apparatus for obtaining an ultrasonic tomographic image of a subject and a point on a monitor. Means for specifying a part to be imaged on a monitor; means for measuring coordinates of a marker of the tomographic apparatus and a marker of the probe; an ultrasonic tomographic image displayed by the monitor on the direction of the probe Direction is the same, and according to the positional relationship between the marker of the tomographic imaging apparatus and the imaging position, and the positional relationship between the point on the monitor and the marker of the ultrasonic probe, the part specified on the monitor is displayed on the tomographic imaging apparatus. A positioning system, characterized in that the photographing position is set to one of the following. 8. A means for determining a positional relationship between a marker of a tomographic imaging apparatus and an imaging position, and determining a positional relation between a marker of a probe of an ultrasonic diagnostic apparatus for obtaining an ultrasonic tomographic image of a subject and a point on a monitor. Means for designating a part to be imaged on a monitor; means for measuring the coordinates of the marker of the tomographic apparatus and the marker of the probe; and ultrasonic waves displayed on the monitor by the dimensions of the marker of the probe and the monitor. The dimensions of the tomographic image are the same, and the position specified on the monitor is changed according to the positional relationship between the marker of the tomographic apparatus and the imaging position and the positional relationship between the point on the monitor and the marker of the ultrasonic probe. A positioning system, which is used as a photographing position of a photographing device. 9. A means for obtaining a positional relationship between a marker of a tomographic imaging apparatus and an imaging position, and obtaining a positional relation between a marker of a probe of an ultrasonic diagnostic apparatus for obtaining an ultrasonic tomographic image of a subject and a point on a monitor. Means for designating a part to be imaged on a monitor; means for measuring coordinates of a marker of the tomographic apparatus and a marker of the probe; a plane on which the marker of the probe exists; The direction of the tomographic plane is the same, and according to the positional relationship between the marker of the tomography apparatus and the imaging position, and the positional relationship between the point on the monitor and the marker of the ultrasonic probe, A positioning system, which is used as an imaging position of a tomography apparatus.