JP2002177255A - Computerized tomography(ct) apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optimal projection image in each detector row of a multi-detector in a CT apparatus. SOLUTION: The CT apparatus, in which an X-ray tube 40 and an X-ray detector array 90 with plural detector rows face to each other with a subject 100 in-between, restructures a tomographic image of the subject based on a signal detected by the X-ray detector array. The CT apparatus has the X-ray tube 40 for generating an X-ray cone beam XLCB expanded in the direction of body axis of the subject by one or at least two focal points and a slice width collimator 50 for dividing the X-ray cone beam XLCB from the X-ray tube 40 into plural X-ray fan beams XLFB1-XLFB4 parallel or nearly parallel to the slice surface of the subject to irradiate each X-ray fan beam XLCB to one or at least two detector rows of the X-ray detector array 90.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray CT apparatus, and more particularly, to an X-ray detector in which an X-ray tube and an X-ray detector array having a plurality of detector rows face each other across a subject. The present invention relates to an X-ray CT apparatus that reconstructs a CT tomographic image of a subject based on an array detection signal.

In this type of X-ray CT apparatus, projection data for a plurality of rows can be obtained for one rotation of a scanning gantry.
The shooting speed is improved.

[0003]

2. Description of the Related Art FIGS. 8 and 9 are views (1) and (2) for explaining a conventional technique, and FIG. 8A is a perspective view of an X-ray imaging system (scanning gantry) in a conventional X-ray CT apparatus. Is shown. In FIG. 8A, reference numeral 40 'denotes a rotating anode type X-ray tube, 50' denotes a collimator for limiting an X-ray irradiation range (mainly in the body axis CLb direction), 100 denotes an object, and 20 denotes an object 1.
An imaging table 90 on which 00 is placed and moved in the direction of the body axis CLb. Reference numeral 90 denotes, for example, four rows (L1 to L4) in which a large number (n = about 1000) of X-ray detectors are arc-shaped (channel CH direction).
1 is an X-ray detector array (multi-detector). It should be noted that an orthogonal coordinate system (x, y, z) fixed to the scanning gantry unit is additionally shown in the figure. Here, the z-axis matches the direction of the body axis CLb of the subject 100.

The X-ray cone beam XLCB emitted from the focal point F of the X-ray tube 40 'is limited in its irradiation range (mainly in the direction of the body axis CLb) by a collimator 50' formed of two parallel plate slits. An X-ray fan beam XLFB is transmitted through the subject 100 and is opposed to the X-ray detector array 90.
All at once.

FIG. 8B is a partial cross-sectional view of a conventional X-ray tube 40 '. In the figure, reference numeral 61 denotes an envelope for keeping the inside of the tube vacuum, 62' a filament, and 63 'a filament. Focusing electrode, 64 'is a cathode sleeve, 65' is a target made of an umbrella-shaped tungsten disk or the like, 66 'is a focal point which is an X-ray source, 67 is a rotating anode that integrally supports the target 65', and 68 is a rotating anode. Bearing for supporting the anode element 67,
Reference numeral 69 denotes an anode shaft for fixedly supporting the anode side of the X-ray tube, and reference numeral 71 ′ denotes an X-ray tube window provided in the envelope 61. Further, reference numeral 70 denotes a housing made of aluminum or the like which covers the periphery of the X-ray tube 40 ', in which cooling oil is circulated to cool the X-ray tube 40'.

The rotating anode 67 is rotated at a high speed (about several thousand rpm) by a rotating magnetic field applied from a stator (not shown) provided around the envelope 61. In this state, the thermoelectrons generated in the filament 62 'are converted to high pressure (100
kV) and accelerate and focus to collide with the focal point 66 ′ on the target 65 ′.
A part of the line is emitted from the X-ray tube window 71 'to form a cone-shaped X-ray cone beam XLCB.

[0007] The shape of the X-ray focal point F is shown by a dotted line in FIG. The size of the focal point F is preferably as small as possible from the viewpoint of reducing blur at the time of photographing, but is generally longer in the y-axis direction as shown in the figure in order to obtain a necessary dose (mAs).
When viewed from directly below in the y-axis direction, it is shorter in the z-axis direction.

[0008]

However, as described above, a plurality of (for example, four) detector rows of the X-ray detector array 90 correspond to one focal point F of the X-ray tube 40 '. If there is, there is a problem that the image in the detector rows L1 and L4 at both ends is deteriorated. The details will be described below.

FIG. 9 shows a main part of an X-ray imaging system (scanning gantry). FIG. 9 (A) is a front view of the scanning gantry viewed from behind, and FIG. 9 (B) is a right side thereof. FIG. In FIG. 9A, the detection channels 1 to n-1 of the X-ray detector array 90 and the reference channel R at the end are shown.
ef are arranged on an arc having a radius R centered on the X-ray focal point F. The scanning gantry is the body axis C of the subject 100.
Rotate around Lb.

In FIG. 9B, when the four detector rows L1 to L4 of the X-ray detector array 90 correspond to one focal point F of the X-ray tube 40 ', especially at both ends. In the detector rows L1 and L4, the X-ray fan beam X
The LFB is no longer parallel to the tomographic plane (xy plane) of the subject 100, which causes an artifact called a virtual volume artifact.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art, and has as its object to provide an X-ray C-ray detector capable of obtaining an appropriate projection image for each detector row of a multi-detector.
T device.

[0012]

The above-mentioned problem is solved, for example, by referring to FIG.
Is solved. That is, the X-ray C of the present invention (1)
In the T apparatus, the X-ray tube 40 and the X-ray detector array 90 having a plurality of detector rows face each other with the subject 100 interposed therebetween.
An X-ray CT apparatus that reconstructs a CT tomographic image of a subject based on a detection signal of a ray detector array generates an X-ray cone beam XLCB extended in the body axis direction of the subject by one or more focal points. X-ray tube 40 and a plurality of X-ray fan beams XLFB1 parallel and / or substantially parallel to the tomographic plane of the subject.
To XLFB4, etc., and each is divided into an X-ray detector array 90.
And a slice width collimator 50 capable of irradiating the above one or more detector rows.

According to the present invention (1), the sectional view shape of the X-ray cone beam XLCB is extended in the body axis direction of the subject by one or more focal points (F, F1, F2, etc.). , The detector row L at the center of the X-ray detector array 90
2 and L3 as well as the X-ray fan beams XLFB1 and XLFB reaching the detector rows L1 and L4 at both ends.
4 can be parallel or almost parallel to the tomographic plane (xy plane) of the subject 100. Accordingly, an appropriate projection image can be obtained for each of the detector rows L1 to L4 of the X-ray detector array 90.

The tomographic plane (xy plane) of the subject
X-ray fan beam XL parallel and / or substantially parallel to
Specific examples of the FB1 to XLFB4 include an X-ray fan beam XLFB1 to XLFB4 parallel to the xy plane or an X-ray fan beam XLFB1 substantially parallel to the xy plane.
XLFB4, or XFB fan beams XLFB2, XLFB3 parallel to the xy plane, and XFB fan beams XLFB1, XLFB4 substantially parallel to the xy plane.

Preferably, in the present invention (2), in the present invention (1), the slice width collimator 50 is X
One or two or more source collimating plates 5 corresponding to positions (dividing) detector rows L1 to L4 of the line detector array 90
1, 52.

In the present invention (2), by providing the source collimating plates 51 and 52, the detector rows L1 to L1 are provided.
Each of L4 is irradiated with X-rays. That is, the X-ray tube 40
X-ray cone beam X scattered in all directions from
The LCB is applied to the subject 10 by the source collimating plates 51 and 52.
A plurality of X-ray fan beams XLFB1 to XLFB4 parallel and / or substantially parallel to the tomographic plane 0 are irradiated to the detector rows L1 to L4, respectively.

Preferably, in the present invention (3),
In the present invention (2), the arrangement position of the source collimating plate 52 is configured to be externally controllable.

According to the present invention (3), by controlling the arrangement position of the source collimating plate 52, these intervals are naturally changed, and the irradiation position and width of the X-ray fan beam are changed. Will be. Therefore, an X-ray fan beam corresponding to an arbitrary slice width can be easily obtained.

Preferably, in the present invention (4),
In the present inventions (1) to (3), one or two or more detector collimating plates 81 and 82 correspond to positions at which the detector rows L1 to L4 are defined (divided) at the front part of the X-ray detector array 90. Is provided.

Therefore, the X-ray fan beams XLFB1 to XLFB irradiated from directly above each of the detector rows L1 to L4
B4 is effectively directed to each detection channel.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the same reference numerals indicate the same or corresponding parts throughout the drawings.

FIG. 2 is a block diagram of a main part of an X-ray CT apparatus according to the embodiment. The apparatus is roughly divided into a scanning gantry section for performing an axial / helical scan / read of the subject 100 by an X-ray fan beam XLFB. 30 and the subject 1
It is composed of an imaging table 20 on which 00 is placed and moved in the direction of the body axis CLb, and a remote operation console 10 operated by an operator.

In the scanning gantry unit 30, reference numeral 40 denotes a rotating anode type X-ray tube, 40A denotes an X-ray control unit, and 50 denotes a collimator (slice width) for limiting an X-ray irradiation range (mainly in the body axis CLb direction). Collimator), 50A is a collimator control unit, 90 is a large number (n = 1000) arranged in the channel CH direction.
X-ray detectors are, for example, four rows L in the direction of the body axis CLb.
An X-ray detector array (multi-detector) 91 arranged in 1 to L4, projection data g ₁ (X, θ) to g of the subject 100 based on a detection signal of the X-ray detector array 90
₄ Data collection unit (DA) that generates and collects (X, θ)
S), 30A scan the scanning gantry (X-ray imaging system)
It is a rotation control unit that rotates around the body axis CLb of 00.
Preferably, a detector collimator 80 described later is provided on the upper surface side of the X-ray detector array 90.

In the operation console unit 10, X is X
A central processing unit for performing main control and processing (scan control, CT tomographic image reconstruction processing, etc.) of the X-ray CT apparatus;
PU, 11b are RAM, ROM used by CPU 11a
A memory (MM) 12 for inputting commands and data including a keyboard, a mouse, and the like; 13, a display device (CRT) for displaying a scan plan, a CT tomographic image reconstructed, and the like; Are various control signals CS between the CPU 11a and the scanning gantry unit 30 and the imaging table 20.
And a control interface for exchanging monitor signals MS, 15 is a data collection buffer for temporarily storing projection data from the data collection unit 91, 16 is for storing and storing projection data from the data collection buffer 15, and X
It is a secondary storage device (such as a hard disk device) that stores various application programs necessary for operation of the line CT apparatus, various calculation / correction data files, and the like.

With such a configuration, the X-ray cone beam XLCB from the X-ray tube 40 is converted into the X-ray fan beams XLFB1 to XLFB4 by the slice width collimator 50, and each of the X-ray fan beams XLFB1 to XLFB4 passes through the subject 100 and passes through the X-ray detector array 90. Are simultaneously incident on the detector rows L1 to L4. The data collection unit 91 generates projection data g ₁ (X, θ) to g ₄ (X, θ) corresponding to each detection output of the X-ray detector array 90 and stores them in the data collection buffer 15. Further, the same projection as described above is performed at each view angle θ at which the scanning gantry is slightly rotated, and thus projection data for one rotation of the scanning gantry is collected and accumulated. At the same time, the imaging table 20 is intermittently / continuously moved in the body axis direction of the subject 100 according to the axial / helical scan method.
All projection data for the required photographing area of 0 is collected and accumulated, and these are finally stored in the secondary storage device 16. The CPU 11a reconstructs a CT tomographic image of the subject 100 based on the obtained projection data after the end of all the scans or following (parallel to) the scan execution, and displays these on the display device 13. . However, when reconstructing a tomographic image, the distances from the detector rows L1 to L4 to the X-ray focal point are slightly different.

FIG. 3 is a block diagram of a data collection / arithmetic system according to the embodiment. The data collection section 91 collects data for four systems corresponding to the detector rows L1 to L4 of the X-ray detector array 90. Units DAS1 to DAS4 are provided. Less than. The signal processing operation will be outlined. The fan beams XLFB1 to XLFB4 from the slice width collimator 50 pass through the subject 100 and simultaneously enter the detector rows L1 to L4 of the X-ray detector array 90. Now, focusing on the signal processing of the detector array L1 and the detection channel CH1, the X-ray detector X
D1 outputs a current signal corresponding to the transmission intensity of the X-ray beam, and integrator IG1 integrates the detection output current of X-ray detector XD1 with a predetermined time constant and outputs a corresponding dose detection voltage. Further, the amplifier A1 amplifies the output voltage of the integrator IG1, and the sample and hold circuit SH1 samples and holds the output voltage of the amplifier A1 at a predetermined timing. Above operation is the same for the signal processing of the other detection channel CH2~R _ef.

Further, the signal multiplexer SMPX multiplexes the output signals of the sample hold circuits SH1 to SHn at high speed, and the A / D converter A / D converts the output signal of the signal multiplexer SMPX at high speed. The above operation is the same for the signal processing of the other DAS2 to DAS4.

Further, each output data of DAS1 to DAS4 is multiplexed by a data multiplexer DMPX, and a series of obtained projection data g ₁ (X, θ) to g
₄ (X, θ) is temporarily stored in the data collection buffer 15 and is later processed by the CPU 11a. The projection data of each reference channel R _ef detector rows L1~L4 is used for reference compensation.

FIG. 4 is a view for explaining an X-ray tube according to the embodiment, and FIG. 4A is a partial sectional view of an X-ray tube 40 as an example. The basic structure of the X-ray tube 40 is shown in FIG.
This may be the same as the X-ray tube 40 'described in (B). However, the X-ray tube 40 has a different structure for obtaining a uniform X-ray cone beam (focal portion 66) extended (extended) in the z (body) axis direction. For example, a target 65 made of an umbrella-shaped tungsten disk or the like is extended in the z-axis direction, and accordingly, a configuration (corresponding to a cathode portion) composed of the filament 62 and the focusing electrode 63 is extended in the y-axis direction. Thereby, the sectional view shape of the X-ray cone beam XLCB is uniformly expanded in the z-axis direction.

The shape of the X-ray focal point F is shown by a dotted line in FIG. Also, the X-ray in this X-ray tube 40 is shown in the inset (b).
13 shows a cross-sectional shape of another example of the line cone beam XLCB.
Here, the filament 62 (that is, the cathode portion) of the X-ray tube 40 is divided into two in the y-axis direction, and accordingly, two X-ray cone beams XLCBa having the same sectional view shape in the z-axis direction. , XLCBb are obtained. Note that the filament 62 may be divided into three or more. Thus, one or two or more uniform X-ray cone beams XLCB extended (extended) in the z (body) axis direction as compared with the related art are obtained.

FIG. 4B shows another example of the X-ray generation unit. The target 65 in this example has a shape in which two conical targets 65a and 65b are overlapped with each other at their lower parts. . A pair of filaments 62a and focusing electrodes 63a and a pair of filaments 62b and focusing electrodes 63b are provided on opposite sides of the focal points 66a and 66b, respectively, so that two X-ray cones extended in the z-axis direction are provided. A beam XLCB is obtained. According to this structure, the necessary cone beam width in the z-axis direction can be easily covered even if the number of detector rows of the X-ray detector array 90 increases to, for example, eight rows, sixteen rows, or the like.

FIG. 5 is a diagram for explaining a collimator according to the embodiment. FIG. 5A shows an example of a slice width collimator 50 for limiting the X-ray irradiation range. FIG. 5A is a front view, FIG. 5B is a side sectional view, and FIG. FIG. The slice width collimator 50 is a fixed width collimator, and includes collimator plates 51a and 51b having inverted L-shaped cross sections at both ends, and rectangular flat collimator plates 52a to 52c at the inner side. Are arranged and fixed in parallel with the xy plane with an interval of.

Here, each of the collimating plates 51 and 52 is made of an X-ray absorbing material such as tungsten or molybdenum.
X-rays that are obliquely incident on the collimator plates 51 and 52 are well absorbed. Therefore, X-ray cone beam XLC
Among B, a ray bundle that does not contribute to imaging is effectively blocked on the upper surface side of the inverted L-shaped collimating plates 51a and 51b, and only a ray bundle necessary for imaging passes through the collimator 50.

Further, each of the collimating plates 51 and 52 has a predetermined height h1, and the height h1 is such that the X-ray cone beam XLCB emitted from the X-ray tube 40 in all directions (scattered). X-ray fan beams XLFB1 to XLLB that are substantially perpendicularly incident on the respective detector rows L1 to L4 (that is, are parallel to the xy plane).
It is high enough to allow only FB4 to pass.
Further, the inner collimating plates 52a to 52c correspond to the detector rows L
1 to L4 (that is, X-ray fan beams XLFB1 to XLF)
B4) are fixed at predetermined intervals so as to obtain a uniform dose.

Therefore, the X-rays from the X-ray detector array 90 side
Looking up at the source, it appears that there is only one focus of the correct size directly above each detector row L1-L4. That is, the same relationship exists between the detector rows L1 to L4 and the corresponding four focal points in this case, as if the single detector of the conventional single detector row and its single focal point existed. I do.

Note that substantially four focal points (X-ray fan beams XLFB1 to XLFB) are provided for the detector rows L1 to L4.
Although the case 4) is described above, the present invention is not limited to this. For example, one focus (a common X
The configuration may be such that the X-ray fan beam XLFBa) is associated with another set of focal points (common X-ray fan beam XLFBb) corresponding to the set of the detector rows L3 and L4.
In this case, it is sufficient that one focal point corresponds to the intermediate part of the detector rows L1 and L2 and one focal point corresponds to the intermediate part of the detector rows L3 and L4. Therefore, the width of the X-ray cone beam XLCB in the z-axis direction is sufficient. Can be reduced.

FIG. 5B shows an example of a detector collimator 80 provided on the upper surface side of the X-ray detector array 90. FIG. 5A is a front view, FIG. FIG. 3C is a top view. This detector collimator 80
The collimator plates 81a and 81b have fan-shaped (corresponding to the X-ray fan beam shape) front end shapes at both ends, and the same fan-shaped collimator plates 82a to 82c on the inner side. Array
Fixed.

Here, each of the collimating plates 81 and 82 is made of an X-ray absorbing material such as tungsten or molybdenum.
X-rays which are obliquely incident on the collimator plates 81 and 82 are well absorbed. Each of the collimator plates 81 and 82 has a predetermined height h2 in the traveling direction of the X-ray fan beam, and the height h2 is such that the output from the slice width collimator 50 leaks into an adjacent detector row. It is high enough to absorb X-rays (ie, so that it is not parallel to the xy plane).

Therefore, the synergistic action of the operation of the slice width collimator 50 and the operation of the detector collimator 80 causes the X-ray fan beams XLFB1 to XLFB4 to be perpendicular to the detector rows L1 to L4 (ie, x-fan beams). (parallelism with the y-plane) is remarkably improved.

FIG. 6 is a view for explaining a scanning gantry according to the embodiment. FIG. 6A is a side sectional view at the time of X-ray photography.
(B) shows an X-ray detector array 90 (detector collimator 80).
FIG. In FIG. 6A, the X-ray cone beam XLC emitted from the focal point 66 of the X-ray tube 40
B has its irradiation range limited by the slice width collimator 50, and is divided into four X-ray fan beams XLFB1 to XLFB4 substantially parallel to the xy plane.
00 and simultaneously enter the detector rows L1 to L4 of the opposing X-ray detector array 90. At this time, the X-ray tube 40
Is expanded in the z-axis direction, so that not only the X-ray fan beams XLFB2 and XLFB3 at the center, but also the X-ray fan beams XLFB1 and XLFB1 at both ends.
The XLFB4 also enters the corresponding detector rows L1 and L4 from almost directly above (in parallel with the xy plane).

Therefore, according to the present embodiment, the tomographic plane (x-
By improving the parallelism to the (y-plane), the partial volume artifact of the CT tomographic image is improved.

FIG. 7 is a view for explaining a slice width collimator 50 according to another embodiment. FIG. 7A is a front view, FIG. 7B is a side sectional view, and FIG. Is a bottom view. This slice width collimator 50 is a variable width collimator, and the positions of the collimator plates 51 and 52 are variable while maintaining the parallel state with the xy plane as in the case shown in FIG. It is supported to be.
The collimator plates 51a, 51b at both ends are screwed in a direction opposite to each other with two threaded shafts 53a, 53a 'which are developed, for example, perpendicular to these plates, and the shafts 53a, 53a'. Turns clockwise,
Correspondingly, the collimator plates 51a, 51b are widened in the vertical direction in the figure with respect to their center line z0, and conversely, when the shafts 53a, 53a 'rotate counterclockwise,
The distance between the collimator plates 51a and 51b is reduced in the direction of their center line z0. Inner collimating plates 52a, 52c
The same applies to. Also, the central collimating plate 52b
May be fixed or variable in position.

This variable width slice width collimator 50
Has the advantage that the effective slice width can be varied according to the number of detector rows of the X-ray detector array 90 or the number of detector rows used (4 rows, 8 rows, 16 rows, etc.).

FIG. 7B shows the slice width collimator 5.
Here is an example of using 0. In the figure, 50A corresponds to FIG.
Variable width slice width collimator similar to (A), 50B
Is a fixed width or variable width slice width collimator used in combination with the slice width collimator 50A.

The slice width collimator 50A corresponds to the X-ray cone beam XLCB that extends long in the z-axis direction, and divides it into four X-ray fan beams XLFB1 to XLFB4 that are relatively wide in the z-axis direction. These can be directly irradiated onto the X-ray detector arrays of, for example, eight detector rows L1 to L8. In this case, the detector rows L1 and L2 are covered by the X-ray fan beam XLFB1, and the process proceeds in the same manner, and the detector rows L7 and L8 are covered by the X-ray fan beam XLFB4.

In the illustrated example, however, another slice width collimator 50B is slid and inserted into the illustrated position from the z-axis direction (arrow b direction), for example, and used in combination. In this case, four X-ray fan beams XLF
B1 to XLFB4 are converted into eight X-ray fan beams XLFB1 ′ to XLFB8 ′ by the slice width collimator 50B.
Is divided into And the X-ray fan beam XLFB1 '
Cover the detector row L1 and proceed in the same manner as described above, and cover the detector row L8 with the X-ray fan beam XLFB8 '. Thus, an optimum X-ray fan beam can be obtained according to the purpose of imaging and the number of detector rows used.

In the above embodiment, the medical X-ray CT
Although an example of application to the apparatus has been described, the present invention can also be applied to an industrial X-ray CT apparatus.

In the above embodiment, the collimator 5
Although specific examples of 0 and 80 have been described, the present invention is not limited to this. It goes without saying that the collimators 50 and 80 can be configured in various other modes without departing from the spirit of the present invention.

Although the preferred embodiments of the present invention have been described, it goes without saying that various changes in the configuration, control, processing, and combinations thereof can be made without departing from the spirit of the present invention.

[0050]

As described above, according to the present invention, an appropriate projection image can be obtained for each detector row of the multi-detector, and this greatly contributes to the improvement of the image quality of the X-ray CT apparatus.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a main part configuration diagram of an X-ray CT apparatus according to an embodiment.

FIG. 3 is a block diagram of a data collection / arithmetic system according to the embodiment.

FIG. 4 is a diagram illustrating an X-ray tube according to the embodiment.

FIG. 5 is a diagram illustrating a collimator according to an embodiment.

FIG. 6 is a diagram illustrating a scanning gantry according to the embodiment.

FIG. 7 is a diagram illustrating a slice width collimator according to another embodiment.

FIG. 8 is a diagram (1) illustrating a conventional technique.

FIG. 9 is a diagram (2) illustrating a conventional technique.

[Explanation of symbols]

 Reference Signs List 10 operation console 11 central processing unit 11a CPU 11b main memory (MEM) 12 input device 13 display device (CRT) 14 control interface 15 data acquisition buffer 16 secondary storage device 20 imaging table 30 scanning gantry unit 30A rotation control unit 40 X-ray Tube 40A X-ray controller 50 Slice width collimator 50A Collimator controller 30A Rotation controller 80 Detector collimator 90 X-ray detector array 91 Data acquisition unit (DAS)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Akihiko Nishiide 4-7-7 Asahigaoka, Hino-shi, Tokyo Inside GE Yokogawa Medical Systems Co., Ltd. (72) Inventor Hideaki Uno 4-7 Asahigaoka, Hino-shi, Tokyo No. 127 G Yokogawa Medical System Co., Ltd. F-term (reference) 4C093 AA22 BA03 BA08 CA39 EA03 EA14 EB18 EB22

Claims (4)

[Claims] An X-ray tube and an X-ray detector array having a plurality of detector rows face each other across a subject, and a CT tomographic image of the subject is reproduced based on a detection signal of the X-ray detector array. An X-ray CT apparatus comprising: an X-ray tube that generates an X-ray cone beam extended in a body axis direction of a subject by one or more focal points; and an X-ray cone beam from the X-ray tube. And a slice width collimator capable of dividing into a plurality of X-ray fan beams parallel and / or substantially parallel to the tomographic plane and irradiating each of the plurality of X-ray fan beams corresponding to one or more detector rows on the X-ray detector array. Characteristic X-ray CT apparatus. 2. The X-ray CT apparatus according to claim 1, wherein the slice width collimator comprises one or more source collimating plates corresponding to positions defining a detector row of the X-ray detector array. . 3. The X-ray CT apparatus according to claim 2, wherein an arrangement position of the source collimating plate is configured to be controllable from outside. 4. The apparatus according to claim 1, further comprising one or more detector collimating plates corresponding to positions at least in front of the X-ray detector array that define the detector rows. 2. The X-ray CT apparatus according to claim 1.