JPH11206750A - Radiation irradiation positioning, radiation irradiation/ detection device and radiation tomographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly irradiate radiation beams by uniformly dividing the radiation beams in a thickness direction and irradiating them on a specified column number of radiation detection element arrays based on the respective radiation detection signals of at least one each radiation detection element. SOLUTION: Prior to image pickup, an X-ray irradiation position in a detector array 24 is adjusted and the thickness of the X-ray beam 410 is uniformly divided into the two columns of X-ray detectors 242 and 244. That is, when it is not uniformly divided, for instance, the light receiving surface not shielded by an X-ray shielding plate 290 of an X-ray detection element 258 is exposed to an X-ray and the part shielded by the X-ray shielding plate 290 of the X-ray detection element 278 is not exposed to the X-ray. Thus, X-ray detection signals are generated in the X-ray detection element 258 and they are not generated in the X-ray detection element 278. Based on that, a central processing unit corrects irradiation position deviation and performs uniform exposure. In such a manner, uniform irradiation is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation irradiating position adjusting method, a radiation irradiating / detecting apparatus, and a radiation tomography apparatus. The present invention relates to a radiation irradiating / detecting device, a radiation irradiating position adjusting method for such a radiation irradiating / detecting device, and a radiation tomography apparatus having such a radiation irradiating / detecting device.

[0002]

2. Description of the Related Art As an example of a radiation tomography apparatus, there is, for example, an X-ray computed tomography (CT) apparatus. In an X-ray CT apparatus, X-rays are used as radiation. An X-ray tube is used for X-ray generation. Then, the radiation irradiation / detection system, that is, the X-ray irradiation / detection system is rotated (scanned) around the subject, and the subject is exposed to X-rays in a plurality of views around the subject. Is measured, and a tomographic image is generated (reconstructed) based on the projection data.

An X-ray irradiator has an X-ray beam (b) having a width encompassing an imaging range and having a predetermined thickness in a direction perpendicular thereto.
eam). The thickness of the X-ray beam is determined by the collimator (colli
meter).

The X-ray detecting apparatus detects X-rays by a multi-channel X-ray detector in which a large number of X-ray detecting elements are arranged in an array in the direction of the width of the X-ray beam. The multi-channel X-ray detector has a length (width) corresponding to the width of the X-ray beam in the direction of the width of the X-ray beam.
In addition, it has a length (thickness) greater than the thickness of the X-ray beam in the direction of the thickness of the X-ray beam.

[0005] Some X-ray detectors have an array of X-ray detecting elements in two rows so that projection data for two slices can be obtained at once. There, two rows of arrays are arranged adjacent to and parallel to each other, and the X-ray beam is uniformly distributed in the thickness direction and irradiated. The thickness of the X-ray beam applied to each of the two arrays at the isocenter of the subject determines the slice thickness of the tomographic image.

In the X-ray tube, the focal point of the X-ray moves due to thermal expansion or the like due to a rise in temperature during use, and this shift appears as a displacement in the thickness direction of the X-ray beam through the aperture of the collimator. When the X-ray beam is displaced in the thickness direction, 2
The distribution ratio of the thickness of the X-ray beam in the row array changes, and the slice thickness of the subject projected on the two arrays is not uniform.

Therefore, the X-ray count (coupe) in the reference channel of the two-row array is considered.
(nt) is monitored, and since the ratio is no longer 1, the deviation of the X-ray irradiation position is recognized, and the irradiation position is corrected.

[0008]

When the suitability of the X-ray irradiation position is recognized as described above, the difference in sensitivity between the X-ray detecting elements or the difference in gain between the amplifiers, etc. causes the irradiation. There is a problem that the X-ray count ratio does not always become 1 even if the position is proper, and that the irradiation position is not necessarily proper even if the X-ray count ratio becomes 1.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a radiation irradiation alignment method and a radiation irradiation / detection apparatus for uniformly irradiating a radiation beam to a two-row array radiation detector. And a radiation tomography apparatus including such a radiation irradiation / detection apparatus.

[0010]

Means for Solving the Problems (1) According to a first aspect of the present invention, one of two directions perpendicular to an irradiation direction and perpendicular to each other has a relatively large width in one of the two directions. A radiation irradiating unit that irradiates a radiation beam having a relatively small thickness, and a plurality of radiation detection elements having a length greater than the thickness of the radiation beam in the direction of the thickness of the radiation beam form two rows. A radiation irradiation alignment method for a radiation irradiation / detection device, comprising: a radiation detection element array arranged in the direction of the width of the radiation beam, and the radiation beam is distributed in the thickness direction and irradiated. With respect to at least one radiation detecting element in the radiation detecting element array, the radiation beam is uniformly distributed in the thickness direction on the two rows of radiation detecting element arrays. A portion excluding the irradiation range of the radiation beam formed when the irradiation is performed in a divided state is set as a light receiving surface, and the two rows of the radiation detection element arrays are based on each radiation detection signal of the at least one radiation detection element. The radiation beam is adjusted so that the radiation beam is evenly distributed in the thickness direction and irradiated.
This is a method for aligning the irradiation position of the detection device.

(2) A second aspect of the present invention for solving the above-mentioned problem is that one of two directions perpendicular to the irradiation direction and perpendicular to each other has a relatively large width and the other has a relatively small width. A radiation irradiating means for irradiating a radiation beam having a thickness, and a plurality of radiation detection elements having a length larger than the thickness of the radiation beam in the direction of the thickness of the radiation beam, forming two rows, and A radiation detection element array arranged in the direction, and the radiation beams are distributed in the thickness direction and irradiated respectively, and at least one radiation detection element array is provided in the two rows of radiation detection element arrays. And the radiation beam formed when the two rows of radiation detection element arrays are irradiated with the radiation beam evenly distributed in the thickness direction. A radiation detecting element having a light-receiving surface excluding an irradiation range, and a thickness of the radiation beam on the two rows of radiation detecting element arrays based on radiation detection signals of the at least one radiation detecting element. Adjusting means for adjusting so as to irradiate the light evenly in the direction.

(3) A third aspect of the present invention for solving the above-mentioned problems is that one of two directions perpendicular to the irradiation direction and perpendicular to each other has a relatively large width and the other has a relatively small width. A radiation irradiating means for irradiating a radiation beam having a thickness, and a plurality of radiation detection elements having a length larger than the thickness of the radiation beam in the direction of the thickness of the radiation beam, forming two rows, and A radiation detecting element array arranged in a direction, and the radiation beams are distributed in the thickness direction and irradiated, and at least one of the radiation detecting element arrays is provided in the two rows of the radiation detecting element arrays. A portion excluding an irradiation range of the radiation beam formed when the radiation beam is irradiated while being uniformly distributed in the thickness direction is used as a light receiving surface. And line detecting element, wherein at least one
Adjusting means for adjusting the radiation beams so as to be uniformly distributed in the thickness direction on the two rows of radiation detection element arrays based on the respective radiation detection signals of the radiation detection elements provided one by one; A tomographic image generating unit configured to generate a tomographic image of a passage area of the radiation beam based on radiation detection signals of a plurality of views by the element array.

In the second invention or the third invention, at least one radiation detecting element provided at least one by one is provided for each of a plurality of thicknesses of the radiation beam. Preferred for adaptation.

[0014] In the second or third aspect of the present invention, the radiation detecting element provided at least one of the radiation detecting elements may have a portion other than the light receiving surface shielded by a radiation shielding member. This is preferable in that a radiation detection element having the same configuration as the other radiation detection elements in the array is used.

(Operation) In the present invention, a portion excluding the irradiation range of the radiation beam formed when the radiation beam is irradiated to the two rows of radiation detection element arrays in a state of being uniformly distributed in the thickness direction is defined as a light receiving surface. Radiation detection element
A signal indicating that the distribution of the radiation beam has deviated from the uniform state is obtained. By providing at least one such radiation detection element in each of the two rows of radiation detection element arrays, the direction of displacement can be identified and the irradiation position of the radiation beam can be corrected.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiment.

FIG. 1 shows a block diagram of the X-ray CT apparatus. This device is an example of an embodiment of the present invention. The configuration of the present apparatus shows an example of an embodiment relating to the apparatus of the present invention. An example of an embodiment of the method of the present invention is shown by the operation of the present apparatus.

(Configuration) As shown in FIG. 1, the present apparatus includes a scanning gantry 2, a photographing table 4, and an operation console 6.

The scanning gantry 2 has an X-ray tube 20 as a radiation source. An X-ray (not shown) emitted from the X-ray tube 20 is shaped by the collimator 22 into, for example, a fan-shaped X-ray beam, and is applied to the detector array 24. The X-ray tube 20 and the collimator 22 are an example of an embodiment of a radiation irradiation unit in the present invention.

The detector array 24 is an example of an embodiment of the radiation detecting element array according to the present invention. The detector array 24 has a plurality of X-ray detection elements arranged in an array in the direction of the width of the fan-shaped X-ray beam. The configuration of the detector array 24 will be described later.

The X-ray tube 20, collimator 22 and detector array 24 constitute an X-ray irradiation / detection system. The configuration of the X-ray irradiation / detection system will be described later. A data collection unit 26 is connected to the detector array 24. The data collection unit 26 collects detection data of individual X-ray detection elements of the detector array 24.

The irradiation of X-rays from the X-ray tube 20 is controlled by an X-ray controller (controller) 28. The illustration of the connection relationship between the X-ray tube 20 and the X-ray controller 28 is omitted.

The collimator 22 is controlled by a collimator controller 30. The illustration of the connection relationship between the collimator 22 and the collimator controller 30 is omitted.

The above-described X-ray tube 20 to collimator controller 30 are mounted on the rotating unit 32 of the scanning gantry 2. The rotation of the rotation unit 32 is controlled by a rotation controller 34. The illustration of the connection relationship between the rotation unit 32 and the rotation controller 34 is omitted.

The imaging table 4 carries a subject (not shown) into and out of the X-ray irradiation space of the scanning gantry 2. The relationship between the subject and the X-ray irradiation space will be described later.

The operation console 6 has a central processing unit 60. The central processing unit 60 is, for example, a computer
(computer) etc. To the central processing unit 60, a control interface (interface) 62 is connected. The scanning gantry 2 and the imaging table 4 are connected to the control interface 62.

The central processing unit 60 has a control interface 6
2, the scanning gantry 2 and the imaging table 4 are controlled. The data acquisition unit 26, the X-ray controller 28, the collimator controller 30, and the rotation controller 34 in the scanning gantry 2 are controlled by the control interface 62. It should be noted that illustration of individual connections between these units and the control interface 62 is omitted.

Central processing unit 60, control interface 6
2. Collimator controller 30 and collimator 22
Is an embodiment of the adjusting means in the present invention.

A data collection buffer 64 is also connected to the central processing unit 60. Data collection buffer 6
4 is connected to the data collection unit 26 of the scanning gantry 2. The data collected by the data collection unit 26 is input to the data collection buffer 64. Data collection buffer 6
4 temporarily stores the input data.

The part comprising the X-ray tube 20, the collimator 22, the detector array 24, the central processing unit 60, the control interface 62, and the collimator controller 30 is an example of the embodiment of the radiation irradiation / detection device of the present invention.

The central processing unit 60 also has a storage device 6
6 are connected. The storage device 66 stores various data, reconstructed images, programs, and the like.
The display device 68 and the operation device 70 are also connected to the central processing unit 60. The display device 68 displays a reconstructed image and other information output from the central processing unit 60. The operation device 70 is operated by an operator, and inputs various instructions and information to the central processing unit 60.

FIG. 2 shows a schematic configuration of the detector array 24. The detector array 24 has a large number (for example, 1000)
X-ray detectors 242 and 244 of two rows in which the X-ray detection elements 24 (i) are arranged in an arc shape are formed. i is a channel number, for example, i = 1 to 1000
It is. The X-ray detectors 242 and 244 are adjacent to each other in parallel.

FIG. 3 shows the mutual relationship among the X-ray tube 20, collimator 22, and detector array 24 in the X-ray irradiation / detection system. 3A is a front view, and FIG. 3B is a side view. As shown in FIG.
The rays are shaped into a fan-shaped X-ray beam 40 by the collimator 22 and are applied to the detector array 24. FIG. 3A shows the spread of the fan-shaped X-ray beam 40, that is, the width of the X-ray beam 40. FIG. 3B shows the thickness of the X-ray beam 40. The X-ray beam 40 has two rows of X-ray detectors 242,
Irradiation is performed with the thickness uniformly distributed to 244.

By making the body axis cross the fan surface of such an X-ray beam 40, for example, as shown in FIG.
Is placed in the X-ray irradiation space. X
A projection image of the subject 8 sliced by the line beam 40 is projected on the detector array 24. Each half of the thickness of the X-ray beam 40 at the isocenter of the subject 8 gives two slice thicknesses th of the subject 8. The slice thickness th is determined by the X-ray passing aperture of the collimator 22.

X-ray beam 40 for detector array 24
FIG. 5 shows a more detailed schematic diagram of the irradiation state of FIG. As shown in FIG.
By displacing 0, 222 in a direction to narrow the X-ray passage opening, the slice thickness th of the projected image in the X-ray detectors 242, 244 can be reduced. In addition, by moving the collimator pieces 220 and 222 in a direction to widen the X-ray passage opening, the slice thickness th of the projected image can be increased.

By simultaneously moving the collimator pieces 220 and 222 with the slice thickness th set while maintaining the relative positional relationship, the X on the detector array 24 is maintained.
The irradiation position of the line beam 40 in the thickness direction is changed. Note that the irradiation position in the thickness direction is changed by displacing the detector array 24 relative to the collimator 22 in the thickness direction of the X-ray beam 40, as shown by a dashed arrow, instead of moving the collimator pieces 220 and 222. May be performed. With this configuration, two systems can be separately provided for the slice thickness adjustment mechanism and the irradiation position control mechanism in the thickness direction, and multilateral control is possible. On the other hand, if all the operations are performed by the collimator 22 as described above, the control system can be unified into one system, and the demand for simplification can be met.

The X-ray irradiation / detection system including the X-ray tube 20, the collimator 22, and the detector array 24 rotates (scans) around the body axis of the subject 8 while maintaining their mutual relationship. A plurality (for example, 100
Projection data of the subject is collected at the view angle of 0).
The collection of projection data is performed by a system including the detector array 24, the data collection unit 26, and the data collection buffer 62.

Based on the projection data of two slices collected in the data collection buffer 62, the central processing unit 60 generates tomographic images of two slices, that is, performs image reconstruction. The central processing unit 60 is an example of an embodiment of a tomographic image generation unit according to the present invention. Image reconstruction is 1
For example, projection data of, for example, 1000 views obtained by the rotation scan is processed by, for example, a filtered back-projection method.

FIG. 6 shows an example of the configuration of the X-ray incident surface of the detector array 24. As shown in the figure, at the end of the detector array 24, for example, ten X-ray detection elements 250 to 258, 270 to 278 for detecting the irradiation position are provided.
The X-ray detection elements 250 to 258 are a part of the X-ray detector 242. The X-ray detection elements 270 to 278 are part of the X-ray detector 244. X-ray detection element 250
258, 270 to 278 are examples of the embodiment of the radiation detecting element in the present invention. These X
The line detecting elements are 250 and 270, 252 and 272,.
258 and 278 form a pair.

The X-ray detecting elements 250 to 25
Detector array 24 provided with 8,270 to 278
Is outside the range in which the transmission image of the subject 8 is projected, whereby X-rays from the X-ray tube 20 are directly irradiated without passing through the subject 8.

X-ray detecting elements 250 to 258, 270 to 2
Reference numeral 78 indicates that the X-ray receiving surface is partially shielded by an X-ray shielding plate 290 made of, for example, a lead plate, and the other portion is a light receiving surface. The X-ray shielding plate 290
For the line detecting elements 250 and 270, for example, the X-ray beam 401 having a slice thickness of 1 mm at the isocenter is used.
Are uniformly distributed to the X-ray detectors 242 and 244, and are irradiated with X-rays.

Similarly, as for the X-ray detection elements 252 and 272, for example, the area where the X-ray beam 403 having a slice thickness of 3 mm falls is shielded, and the X-ray detection elements 254 and 272 are blocked.
74, for example, X with a slice thickness of 5 mm
X-ray detection element 2
For 56 and 276, for example, the slice thickness is 7 mm
X-ray beam 407 is shielded, and X-ray detection elements 258 and 278 are shaped so as to block the area where X-ray beam 410 having a slice thickness of 10 mm is applied.

Such X-ray detecting elements 250 to 258,
When the X-ray beams are uniformly distributed and irradiated to the X-ray detectors 242 and 244 instead of covering the light receiving surface with the X-ray shielding plate 290, the X-ray beams
Needless to say, the light receiving surface may be configured to have a light receiving surface in a region other than the region corresponding to the reference numerals 1 to 410.

Such X-ray detecting elements 250 to 258,
The X-ray detection signals from 270 to 278
Through the data collection buffer 64. The central processing unit 60 detects an X-ray irradiation position in the detector array 24 based on the X-ray detection signals, and adjusts the X-ray irradiation position.

Detection and adjustment of the irradiation position of an X-ray beam having a slice thickness of 1 mm are performed using detection signals of the X-ray detection elements 250 and 270. Similarly, slice thicknesses 3, 5, 7, 1
The detection and adjustment of the irradiation position of the 0-mm X-ray beam are performed by the X-ray detection elements 252, 272, 254, 274, and 2 respectively.
The detection is performed using the detection signals 56, 276, 258, and 278.

The detection and adjustment of the X-ray irradiation position will be described later. It is preferable to provide an X-ray detecting element having the same configuration at the other end of the detector array 24 in order to more accurately detect and adjust the X-ray irradiation position.

(Operation) The operation of the present apparatus will be described. Prior to imaging, the X-ray irradiation position on the detector array 24 is adjusted, and the X-ray
2,244.

Hereinafter, the slice thickness at the isocenter is set to 10
An example of an X-ray beam of mm will be described. Now, as shown in FIG. 7, the X-ray beam 410 is
Assuming that the X-rays 44 are unequally distributed, the X-ray detection element 258 is irradiated with X-rays on the light receiving surface that is not shielded by the X-ray shield 290, and the X-ray detection element 278 is irradiated with the X-ray shield 2.
X-rays impinge on the portion shielded at 90. Therefore, the X-ray detection element 258 generates an X-ray detection signal, and the X-ray detection element 2
Reference numeral 78 does not generate an X-ray detection signal.

The central processing unit 60 includes the X-ray detecting element 25
8, 278 based on the combination of such X-ray detection signals, the irradiation position of the X-ray beam 410 is determined by the X-ray detector 2.
It recognizes that it is shifted to the 42 side. Then, by controlling the collimator 22, the irradiation position deviation is corrected. Alternatively, when a position adjusting mechanism for the detector array 24 is provided, the irradiation position shift is corrected by changing the position of the detector array 24.

As the correction proceeds, the X-ray receiving area of the X-ray detecting element 258 decreases, and the X-ray detection signal decreases accordingly. When the distribution of the X-ray beams 410 becomes uniform, as shown in FIG. 8, the X-ray beams 410 come to hit only the area shielded by the X-ray shield plate 290, so that the X-ray detection elements 258 and 278 Both X-ray detection signals become 0. The central processing unit 60 recognizes that the irradiation position of the X-ray beam 410 has been optimized based on such a signal state, and ends the adjustment.

When the slice thickness is 1, 3, 5, 7 mm, the X-ray detecting elements 250, 270, 252,
The same irradiation position adjustment is performed using the X-ray detection signals of 272, 254, 274, 256, and 276. In either case, since the X-ray detection signals of the pair of X-ray detection elements both become 0, it is recognized that the irradiation position is appropriate. Therefore, the sensitivity difference between the X-ray detection elements or the amplification of those signals is performed. , Etc., is not affected by differences in the gains of the amplifiers.

After the adjustment of the irradiation position as described above, the subject 8 is scanned by the X-ray irradiation / detection system.
The 0-view projection data is collected in the data collection buffer 62. Based on the projection data, the central processing unit 60 performs image reconstruction using, for example, a filtered back projection method.

Since the detector array 24 has two parallel rows of X-ray detectors, it is possible to obtain tomographic images of two adjacent slices at once by one scan. As a result, the efficiency in performing a multi-slice scan or a helical scan is improved, and two slices have the same slice thickness. The reconstructed image is displayed on the display device 68 and stored in the storage device 66.

In the process of executing the scan, even if the irradiation position of the X-ray beam 40 shifts due to a rise in the temperature of the X-ray tube 20 or the like, it is corrected in the same manner as described above, and the scan is always performed with an even slice thickness. .

Although the example using X-rays as radiation has been described above, the radiation is not limited to X-rays, but may be other types of radiation such as γ-rays. However,
At present, X-rays are preferred because practical means for generating, detecting, controlling, and the like are the most substantial.

[0056]

As described above in detail, according to the present invention, a radiation irradiation position adjusting method and a radiation irradiation / detection apparatus for uniformly irradiating a radiation beam to a two-row array of radiation detectors, and the like. A radiation tomography apparatus equipped with a simple radiation irradiation / detection apparatus can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram of a device according to an example of an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a detector array in an apparatus according to an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of an X-ray irradiation / detection system in an apparatus according to an embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of an X-ray irradiation / detection system in an apparatus according to an embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of an X-ray irradiation / detection system in an apparatus according to an embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a detector array in the device according to an example of the embodiment of the present invention.

FIG. 7 is a schematic view showing a state in which a detector array is irradiated with X-rays in an apparatus according to an embodiment of the present invention.

FIG. 8 is a schematic diagram showing a state of irradiating a detector array with X-rays in an apparatus according to an embodiment of the present invention.

[Explanation of symbols]

2 Scanning Gantry 20 X-ray Tube 22 Collimator 24 Detector Array 26 Data Collection Unit 28 X-ray Controller 30 Collimator Controller 32 Rotation Unit 34 Rotation Controller 4 Imaging Table 6 Operation Console 60 Central Processing Unit 62 Control Interface 64 Data Collection Buffer 66 Storage Device 68 Display device 70 Operating device 242,244 X-ray detector 40,401,403,405,407,410 X-ray beam 8 Subject 220,222 Collimator piece 24 (i), 250-258,270-278 X-ray detection Element 290 X-ray shielding plate

Claims (3)

[Claims] 1. A radiation irradiating means for irradiating a radiation beam having a relatively large dimension width in one of two directions perpendicular to the irradiation direction and perpendicular to each other, and a relatively small dimension thickness in the other direction. A plurality of radiation detection elements having a length greater than the thickness of the radiation beam in the direction of the thickness of the radiation beam are arranged in two rows in the direction of the width of the radiation beam, and the radiation beam is distributed in the thickness direction. A radiation irradiation element alignment method for a radiation irradiation / detection device, comprising: a radiation detection element array for irradiating each of the radiation detection element arrays; The radiation beam formed when the radiation beam is applied to the radiation detection element array in a state of being uniformly distributed in the thickness direction. A portion excluding the irradiation range is set as a light receiving surface, and the radiation beam is uniformly distributed in the thickness direction and irradiated onto the two rows of radiation detection element arrays based on each radiation detection signal of the at least one radiation detection element. The radiation irradiation / positioning method of the radiation irradiation / detection device. 2. A radiation irradiating means for irradiating a radiation beam having a relatively large dimension width in one of two directions perpendicular to the irradiation direction and perpendicular to each other, and a relatively small dimension thickness in the other direction. A plurality of radiation detection elements having a length greater than the thickness of the radiation beam in the direction of the thickness of the radiation beam are arranged in two rows in the direction of the width of the radiation beam, and the radiation beam is distributed in the thickness direction. And a radiation detecting element array for irradiating each of the radiation detecting element arrays, wherein at least one of the radiation detecting element arrays is provided in the two rows of the radiation detecting element arrays, and the radiation is detected by the two rows of the radiation detecting element arrays. A portion excluding the irradiation range of the radiation beam formed when the beam is irradiated while being uniformly distributed in the thickness direction is used as a light receiving surface. A line detection element, and adjusting the radiation beam to be uniformly distributed in the thickness direction on the two rows of radiation detection element arrays based on each radiation detection signal of the at least one radiation detection element. A radiation means for detecting and irradiating the radiation. 3. A radiation irradiating means for irradiating a radiation beam having a relatively large dimension width in one of two directions perpendicular to each other and perpendicular to the irradiation direction, and a relatively small dimension thickness in the other direction. A plurality of radiation detection elements having a length greater than the thickness of the radiation beam in the direction of the thickness of the radiation beam are arranged in two rows in the direction of the width of the radiation beam, and the radiation beam is distributed in the thickness direction. A radiation detection element array for irradiating the radiation beam, and at least one radiation detection element array provided in the two rows of the radiation detection element arrays, wherein the radiation beams are uniformly distributed in the thickness direction to the two rows of the radiation detection element arrays. A radiation detecting element having a light receiving surface at a portion excluding an irradiation range of the radiation beam formed when irradiating; Adjusting means for adjusting the radiation beams so as to be uniformly distributed in the thickness direction on the two rows of radiation detection element arrays based on the respective radiation detection signals of the provided radiation detection elements; and A tomographic image generating means for generating a tomographic image of a region through which the radiation beam passes based on the radiation detection signals of a plurality of views according to the above.