JP2002071817A - X-ray detecting device, radio-computed tomograph and method of manufacturing for x-ray detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray detecting device capable of easily positioning a detector to a collimator without using a special device such as an X-ray irradiator but by using a simple device such as a CCD camera. SOLUTION: This X-ray detecting device detecting X-rays passing the collimator having a plurality of collimator single plates 33 arranged along a channel direction C by a plurality of detector units 50 is provided with a collimator supporting part 40 supporting the collimator single plates 33 and a unit supporting part 40 detachably provided to the collimator supporting part 30 and integrally supporting the plurality of detector units 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray detection apparatus which is incorporated in an X-ray computed tomography apparatus (hereinafter referred to as "X-ray CT apparatus") and has a scintillator arranged in a two-dimensional array. X-ray CT with built-in X-ray detector
The present invention relates to a device and a method for manufacturing an X-ray detection device, and more particularly to a device capable of accurately positioning a detector unit at a desired position with respect to a collimator for removing scattered X-rays.

[0002]

2. Description of the Related Art With the demand for higher resolution and higher definition of X-ray CT images, a multi-slice type X-ray CT apparatus in which a scintillator block has the same two-dimensional array structure as a photodiode pattern is used. Are increasing and are being put to practical use.

[0003] Accordingly, individual scintillators / detectors in a plurality of detector units arranged in an arc-shaped collimator.
The required accuracy of the segment arrangement position has been increasing.

[0004]

The above-described conventional multi-slice type X-ray CT apparatus having the two-dimensionally arranged scintillator blocks has the following problems. That is, when adjusting and assembling the detector unit with respect to the collimator, high-precision adjustment is required. However, since the surface of the detector unit is coated with a reflective material, the pattern of the component to be aligned cannot be visually observed, and thus the alignment between the single collimator plate and the scintillator block cannot be performed. Therefore, conventionally, X
The photograph was taken by irradiating a line, and the positions of the collimator and the detector unit were adjusted.

On the other hand, when a trouble occurs in the detector unit after the product is shipped and the detector unit is replaced, the reflective material is peeled off using a solvent, or a photograph is taken by irradiating X-rays. It is necessary to adjust the relative position with respect to the collimator, and there is a problem that it takes time.

Accordingly, the present invention provides an X-ray detector that can easily position a detector with respect to a collimator by using a simple device such as a CCD camera without using a special device such as an X-ray irradiation device. An object of the present invention is to provide a X-ray detection apparatus, an X-ray CT apparatus incorporating the X-ray detection apparatus, and a method of manufacturing the X-ray detection apparatus.

[0007]

In order to solve the above-mentioned problems and to achieve the object, an X-ray detecting apparatus, an X-ray CT apparatus incorporating the X-ray detecting apparatus, and a method of manufacturing the X-ray detecting apparatus according to the present invention are provided. It is configured as follows.

(1) X having passed through a collimator having a plurality of single collimator plates arranged along the channel direction
In an X-ray detection apparatus for detecting a line with a plurality of detector units, a collimator support member for supporting the single collimator plate and the plurality of detector units detachably provided on the collimator support member are integrally supported. An X-ray detection device comprising: a unit support member.

(2) In the X-ray detecting apparatus according to the above (1), the X-ray is applied to the collimator support member with respect to the detection surface of the detector unit. An X-ray absorbing member that absorbs extends in the channel direction.

(3) An X-ray source for irradiating the subject with X-rays, an X-ray detection device for detecting X-rays emitted from the X-ray source, and the projection data of the subject in multiple directions. A calculation unit for performing a configuration calculation to obtain a tomographic image of the subject, wherein the X-ray detection apparatus is configured to perform X-ray detection according to (1) or (2) above.
It is a line detecting device.

(4) A method of manufacturing an X-ray detection device having a collimator support member for supporting a single collimator plate and a unit support member detachably provided on the collimator support member and supporting a detector unit.
A positioning step of positioning the incident surface of the detector unit with respect to the unit support member while observing a pattern of the incident surface, an application step of applying a reflective material to the incident surface of the detector unit, the collimator support member and the unit And assembling the support member.

(5) A method of manufacturing an X-ray detection device comprising: a collimator support member for supporting a single collimator plate; and a unit support member detachably provided on the collimator support member and supporting a detector unit.
A unit removal step of removing a detector unit attached to one of two detector units attached to two adjacent attachment units of the detector unit, and attaching the detector unit to the other attachment unit Reflector removing step of removing at least a part of the reflecting material on the incident surface of the detector unit, and the one attaching portion based on the pattern of the incident surface of the detector unit attached to the other attaching portion. And a coating step of coating a reflecting material on the incident surface of the detector unit.

[0013]

FIG. 1 shows an outline of a configuration of an X-ray CT apparatus 10 incorporating a two-dimensional array type X-ray detector 20 according to a first embodiment of the present invention and a method of using a CCD camera. FIG. 2 is a longitudinal sectional view of the X-ray detection device 20,
FIG. 3 is a perspective view showing a state where the X-ray detection device 20 is separated. 1 and 2, the arrow S indicates the slice direction of the X-ray CT apparatus, and the arrow C indicates the channel direction.

As shown in FIG. 1, the X-ray CT apparatus 10
The apparatus includes an X-ray source 11 and an X-ray detector 20 arranged around the X-ray source 11. In FIG. 1, R is X
The irradiation direction of the line, W indicates the subject.

The X-ray detector 20 includes a collimator 30
And a unit section 40 provided detachably on the collimator section 30.

The collimator section 30 has a function of removing scattered X-rays. A pair of collimator supports 31 and 32 arranged in the slice direction S and a channel direction C between the collimator supports 31 and 32 are provided. And a plurality of collimator veneers 33 arranged along the base plate and lead and the like provided on the collimator supports 31 and 32 and disposed outside the slice direction S with respect to the collimator veneers 33 and extending in the channel direction. Strip 3 made of heavy metal material
4 and 35 and side blocks 36 and 3 disposed at both ends of the collimator direction C between the collimator supports 31 and 32.
7 is provided. The single collimator plate 33 is formed of a material having a high X-ray absorptivity such as a Mo plate. When the X-ray detection device 20 is incorporated in the X-ray CT device 10, the surface of the single collimator plate 33 is arranged so as to be parallel to the slice direction S, and the surfaces of all the single collimator plates 33 The X-ray source 11 is arranged so as to be located on an extension of the above. Furthermore, since the collimator supports 31 and 32 are formed with grooves (not shown) in advance, and the single collimator plates 33 are inserted into the grooves, those having the same pitch and having a small accumulated error are manufactured.

The unit section 40 includes a collimator support 3
A pair of unit supports 41 and 42 provided detachably with respect to 1 and 32, respectively, and side blocks 43 and 44 arranged between the unit supports 41 and 42.
And a plurality of detector units 50 arranged along the channel direction.

The detector unit 50 has a function of outputting the intensity of the incident X-ray as an electric signal.
1, photodiode chips 52 arranged on the substrate 51, and scintillators provided corresponding to the incident surface (left end in FIG. 2) of the photodiode chips 52 are two-dimensionally arranged via a reflective material. A scintillator block 53 that emits visible light by receiving integrated X-rays, and a function of integrating outputs from a photodiode chip 52 provided on a substrate 51 and switching outputs for changing slice thickness. And a semiconductor chip 54 having The scintillator block 53
The reflecting material H is applied to the incident surface (left end in FIG. 2).

In the X-ray detector 20 configured as described above, the alignment between the collimator single plate 33 and the detector unit 50 is performed as follows. First, the detector unit 50 is attached to the unit supports 41 and 42. At this point, the scintillator block 5 of the detector unit 50
No reflecting material H is applied to the entrance surface of No. 3. For this reason, as shown in FIG. 4A, on the X-ray incidence side of the unit section 40, it is possible to visually recognize the images of the plurality of scintillators and the reflecting material arranged between these scintillators. That is, a pattern indicating the state of the arrangement of the individual scintillators constituting the scintillator block 53 can be observed from outside with visible light. Then, two CCD cameras with microscopes are arranged at two places in the slice direction on the X-ray incidence side. It should be noted that the two-dot chain lines P1 and P2 in the figure indicate the imaging area of the CCD camera.

By taking images of, for example, the upper end 53a and the lower end 53b of the scintillator block 53 with a CCD camera, the relative positioning state of the adjacent detector units 50 in the slice direction can be observed. At this time, the CCD camera is
When the first and second fittings 42 and 42 are fitted to the collimator supports 31 and 32 (the state shown in FIG. 2), the pattern in the slice direction of the scintillator block 53 and the collimator single plate 33 are ± 20 μm.
It is adjusted so as to be parallel at about m.

Accordingly, the adjacent detector units 5
By observing the boundary between the upper end 53a and the lower end 53b of the 0 scintillator blocks 53 with a CCD camera, the boundary can be adjusted in parallel to the single collimator plate 33, and the boundary between the upper end 53a and the lower end 53b. Partial clearance ω
By making 1, ω2 the same and conforming to the design value, the intervals between the adjacent detector units 50 can be maintained at the same pitch. Further, the amount of deviation in the vertical direction at the upper end portion 53a and the lower end portion 53b is not adjusted so as to coincide with one of them, but is well-balanced and the collimator support 3 is not adjusted.
When the middle parallel line between 1 and 32 is the center position,
Adjustment is made so that the deviation of the center line of the scintillator block 53 from the center position in the slice direction is minimized.

For example, the CC shown in FIGS.
According to the image from the D camera, since the detector unit 50 disposed on the right side is shifted upward, the downward correction amount is adjusted as (δ1 + δ2) / 2.

In the above-described example, two CCD cameras are used. However, as shown in FIGS.
The same effect can be obtained by observing only the central portion 53c of the scintillator block 53. Note that ω in FIG. 5B indicates the gap amount.

Next, the collimator section 30 and the unit section 40
And assemble. The collimator supports 31, 32
As shown in FIG. 2, the positioning of the unit supports 41 and 42 in the slice direction S
By abutting and engaging a, 32b and 41a, 42b, the shift amount can be reduced to a negligible level.

Next, the adjustment in the channel direction C will be described. As described above, the detector unit 50 has the same pitch in the channel direction C with respect to the unit supports 41 and 42, and the vertical displacement in the slice direction S is adjusted to be equal to or smaller than the standard.

As shown in FIG. 1, the gap between the side surface 51a of the substrate 51 of the outermost detector unit 50 and the outermost collimator plate 33 is determined by the two CCD cameras 60 mounted with the microscope lens. Observe from diagonally rear at 61. The CCs shown in FIGS. 6A and 6B obtained by this observation
The gaps formed between the detector unit 50 and the single collimator plate 33 based on the images from the D cameras 60 and 61 are adjusted so that the gap amounts α1 and α2 on the left and right sides are almost the same with good balance.

It should be noted that the X-ray detection device 20 according to the present embodiment has a structure for preventing a defect of the semiconductor chip 54 from occurring. That is, the length of the collimator single plate 33 in the slice direction is designed to be longer than the length of the scintillator block 53 in the slice direction S, so that the X-ray path is not inadvertently interrupted during measurement.

As a result, X-rays of relatively high intensity are exposed to the semiconductor chip 54 in this state, and the chip function may be damaged or broken in some cases. In the X-ray detection device 20, the provision of the band-shaped members 34 and 35 can shield X-rays,
4 is prevented from being exposed to the semiconductor chip 54.
Can be suppressed beforehand.

On the other hand, the collimator section 30 and the unit section 40
And the detector unit 5
0, a new detector unit 50
The replacement work is also easy. That is, the defective detector unit 50 is removed, and a part of the reflector H of the scintillator block 53 of the removed detector units 50 on both sides is removed with a solvent. In FIG. 7A, the upper end 53a
7B shows a state where the reflecting material H of the central portion 53c is removed. By removing the reflector H, the pattern of the scintillator block 53 is exposed, so that a new detector unit 50 can be positioned using a CCD camera. After the positioning is performed, the reflective material H is again applied only to the exposed portion of the pattern.
Is applied.

As described above, according to the X-ray detector 20 of the present embodiment, the collimator 30 and the unit 4
Since 0 is detachably formed, there is no shield on the X-ray incidence side, and the mounting of the detection unit 50 to the unit supports 41 and 42 becomes easy. In particular, by observing the pattern of the scintillator block with a CCD camera or the like before applying the reflective material H to the scintillator block 53, the detector unit can be easily and accurately adjusted. That is, there is no need to use a special device or technique such as an X-ray irradiation device.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

[0032]

According to the present invention, the detector can be easily positioned with respect to the collimator by using a simple device such as a CCD camera without using a special device such as an X-ray irradiation device. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of an X-ray CT apparatus in which an X-ray detection apparatus according to a first embodiment of the present invention is incorporated.

FIG. 2 is a longitudinal sectional view showing the X-ray detection device.

FIG. 3 is an exploded perspective view showing a collimator unit and a unit unit constituting the X-ray detection device.

FIG. 4 is an explanatory diagram showing an example of a method of adjusting a unit constituting the X-ray detection apparatus.

FIG. 5 is an explanatory view showing another example of a method for manufacturing the X-ray detection device.

FIG. 6 is an explanatory diagram showing a method of positioning a collimator unit and a unit unit of the X-ray detection device.

FIG. 7 is a front view showing an adjustment method at the time of replacement of the detector unit in the unit section incorporated in the X-ray detection apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... X-ray CT apparatus 20 ... X-ray detection apparatus 30 ... Collimator part 31, 32 ... Collimator support 33 ... Collimator single plate 40 ... Unit part 41, 42 ... Unit support 50 ... Detector unit 51 ... Substrate 52 ... Photodiode chip 53 ... Scintillator block

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G01T 7/00 G01T 7/00 BC

Claims (5)

[Claims] 1. An X-ray detection apparatus for detecting X-rays passing through a collimator having a plurality of single collimator plates arranged along a channel direction by a plurality of detector units, comprising: a collimator support for supporting the single collimator plate. An X-ray detection apparatus comprising: a member; and a unit support member integrally supporting the plurality of detector units detachably provided on the collimator support member. 2. An X-ray absorbing member, which absorbs the X-rays with respect to the collimator support member, extends in a channel direction with respect to the detection surface of the detector unit. The X of claim 1, wherein
Line detector. 3. An X-ray source for irradiating an object with X-rays,
An X-ray detection device for detecting X-rays emitted from the X-ray source; and a calculation unit for reconstructing and calculating multi-directional projection data of the subject to obtain a tomographic image of the subject. An X-ray computed tomography apparatus, wherein the detection apparatus is the X-ray detection apparatus according to claim 1. 4. A method of manufacturing an X-ray detection apparatus comprising: a collimator support member for supporting a single collimator plate; and a unit support member detachably provided on the collimator support member and supporting a detector unit. A positioning step of positioning with respect to the unit support member while observing the pattern of the incident surface of the detector unit; a coating step of applying a reflective material to the incident surface of the detector unit; the collimator support member and the unit support member And an assembling step of assembling the X-ray detector. 5. A method of manufacturing an X-ray detection apparatus comprising: a collimator support member for supporting a single collimator plate; and a unit support member detachably provided on the collimator support member and supporting a detector unit. A unit removing step of removing the detector unit attached to one of the two detector units attached to two adjacent attachment sites of the detector unit, and attaching the detector unit to the other attachment site. A reflector removing step of removing at least a part of the reflecting material on the incident surface of the detector unit; and detecting the one of the attaching portions based on the pattern of the incident surface of the detector unit attached to the other attaching portion. A unit mounting step for positioning and mounting the detector unit, And a coating step of coating a reflective material.