JP2007271534A - X-ray ct apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray CT device capable of oblique fluoroscopic examination of an inspecting object based on high enlargement ratio, without lowering performance of CT radiography. <P>SOLUTION: In this X-ray CT device wherein a rotary table 3 loaded with the inspection object W and rotating about a rotating shaft R along the vertical direction is arranged between an X-ray generation device 1 and an X-ray detector 2 which face opposite in the horizontal direction, the second X-ray detector 6 is provided separately from the X-ray detector 2 for CT radiography. The second X-ray detector 6 is arranged at a position such that a line, connecting the center of the second X-ray detector 6 to an X-ray focal point 1a of the X-ray generation device, 1 forms a prescribed angle with respect to an X-ray optical axis L, and the second X-ray detector 6 is used for oblique fluoroscopic examination. Hereby, the oblique fluoroscopic examination of the inspection object W becomes possible with a high enlargement ratio, in the state where the rotation center of the inspection object W is not influenced by the gravity at CT radiographing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an industrial X-ray CT apparatus that inspects various industrial products and the like under non-destructive conditions.

  In general, an X-ray CT apparatus for industrial use employs a configuration in which an X-ray generator and an X-ray detector are arranged to face each other, and a rotary table is provided between the X-ray generator and the X-ray detector for providing rotation. The rotation axis of the rotary table is arranged so as to be orthogonal to a line (X-ray optical axis) connecting the X-ray focal point of the X-ray generator and the center of the X-ray detector (see, for example, Patent Document 1). In such an X-ray CT apparatus, a fluoroscopic image of the inspection object can be taken by irradiating the inspection object with X-rays without rotating the rotary table.

  By the way, when seeing through the object to be inspected, it is useful if it can be seen through from an oblique direction. However, no X-ray CT apparatus has an active apparatus configuration particularly for oblique see-through.

  On the other hand, the X-ray fluoroscopic apparatus is provided with a mechanism for tilting a table 23 disposed between the X-ray generator 21 and the X-ray detector 22 as shown in FIG. In addition, as shown in FIG. 3, there is known one provided with a tilting mechanism 24 for tilting the X-ray detector 22 (see, for example, Patent Document 2). In the fluoroscopic apparatus shown in FIG. 3, oblique fluoroscopic imaging can be performed with the table 23 on which the object to be inspected is in close contact with the X-ray generator, so that the oblique fluoroscopic apparatus as shown in FIG. There is no restriction such as interference with the X-ray generator 21 when the table 23 is tilted, and there is an advantage that the imaging magnification during oblique fluoroscopy can be further increased.

Conventionally, an apparatus as shown in FIG. 4 has been put to practical use as an apparatus capable of both X-ray CT imaging and high-magnification oblique fluoroscopic imaging. In the apparatus shown in FIG. 4, a CT unit 25 can be added to a fluoroscopic apparatus having a tilting mechanism (not shown) equivalent to that shown in FIG. The CT unit 25 is disposed adjacent to the X-ray generator 21 and includes a finger arm 51 that rotates about a horizontal rotation axis Rh, and holds a table on which the inspection object W is mounted and fixed. Thus, rotation can be applied about the horizontal rotation axis Rh.
JP 2005-351879 A Japanese Patent Laid-Open No. 2004-361099

  By the way, according to the apparatus shown in FIG. 4, although a high-magnification oblique fluoroscopic image and a tomographic image of the object to be inspected can be obtained, the rotation axis for rotating the object to be inspected during CT imaging is horizontal and the gravity Since it is perpendicular to the direction, there is a problem that high-accuracy CT imaging cannot be performed, for example, the rotation axis is affected by gravity.

  The present invention has been made in view of such circumstances, and provides an X-ray CT apparatus capable of obliquely seeing an object under high magnification without reducing the CT imaging performance. It is an issue.

  In order to solve the above problems, an X-ray CT apparatus of the present invention is an X-ray that connects an X-ray focal point of the X-ray generator and the center of the X-ray detector between the X-ray generator and the X-ray detector. A rotation table that rotates around a rotation axis orthogonal to the optical axis is provided, and X-ray projection data captured at every minute angle while mounting an inspection object on the rotation table and applying rotation. In an X-ray CT apparatus provided with reconstruction calculation means for reconstructing a tomographic image of an inspection object along a plane orthogonal to the rotation axis, the rotation axis is along the vertical direction and the X A second X-ray detector is provided separately from the line detector, and the second X-ray detector is a line connecting the center of the second X-ray detector and the X-ray focal point of the X-ray generator. Is disposed at a position that forms a predetermined angle with respect to the X-ray optical axis. Characterized (claim 1).

  Here, in this invention, the structure (Claim 2) provided with the tilting mechanism which changes the angle with respect to the said X-ray optical axis of a 2nd X-ray detector can be employ | adopted suitably.

  The present invention maintains the performance of the rotation axis for rotating the inspection object of the X-ray CT apparatus as a vertical direction not affected by gravity, and moves the X-ray detector for CT imaging. Therefore, while maintaining the positional relationship between the X-ray detector for CT imaging and the X-ray generator, the second X-ray detector for oblique fluoroscopy is placed on the X-ray optical axis (in addition to the X-ray detector). It is intended to solve the problem by disposing it at a predetermined angle with respect to a line connecting the center of the X-ray detector for CT imaging and the X-ray focal point of the X-ray generator. .

  That is, when the object to be inspected is seen through from the direction along the horizontal X-ray optical axis, it is seen through using an X-ray detector for CT imaging as usual, while at a predetermined angle with respect to the X-ray optical axis. For example, when fluoroscopy is performed from a direction inclined by 60 °, a second X-ray detector for oblique fluoroscopy provided in that direction is used to perform CT imaging similarly to a normal X-ray CT apparatus. It is possible to perform oblique fluoroscopy under a high magnification ratio while rotating the inspection object around a vertical rotation axis that is not affected by gravity.

  Further, as in the invention according to claim 2, when a tilting mechanism that changes the angle of the second X-ray detector for oblique fluoroscopy with respect to the X-ray optical axis is provided, it is highly enlarged from an arbitrary angle within the tilting range. It is possible to perform an oblique perspective of the inspection object based on the rate.

  According to the present invention, an X-ray detector for CT imaging arranged orthogonal to a horizontal X-ray optical axis and an X-ray CT apparatus having a vertical rotation axis can be inspected without being affected by gravity. CT imaging of an object can be performed with high accuracy, and the second X-ray detector tilted by a predetermined angle with respect to the X-ray optical axis allows oblique inspection of the object under high magnification. It can be carried out.

  In addition to the above, when a tilting mechanism for changing the angle of the second X-ray detector with respect to the X-ray optical axis is provided as in the invention according to claim 2, in addition to the above, the object to be inspected is subjected to a high magnification ratio. It is possible to see through obliquely from an arbitrary angle.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of an embodiment of the present invention, and is a diagram illustrating a schematic diagram showing a mechanical configuration and a block diagram showing a system configuration.

  A first X-ray detector 2 is disposed horizontally facing the X-ray generator 1, and the center of the first X-ray detector 2 and the X-ray focal point 1 a of the X-ray generator 1 are connected. The connecting line, that is, the X-ray optical axis L is along the horizontal direction.

  Between the X-ray generator 1 and the X-ray detector 2, a rotary table 3 that rotates about a rotation axis R along the vertical direction is disposed. It is mounted in a state held by the sample holder 4. The rotary table 3 can be moved in the direction along the X-ray optical axis L by the table moving mechanism 5, and the imaging magnification at the time of CT imaging can be changed by the movement of the rotary table 3.

  A second X-ray detector 6 is disposed at a position obliquely above the X-ray optical axis L. The second X-ray detector 6 is supported by a detector tilting mechanism 7, and the second X-ray detector 6 is driven by the detector tilting mechanism 7 so that the second X-ray detector 6 is the X-ray focal point of the X-ray generator 1. It can be tilted in the range of 30 ° to 60 ° with respect to the X-ray optical axis L around 1a. The tilt angle is θ.

  The output of the first X-ray detector 2 and the output of the second X-ray detector 6 are taken into the data acquisition device 8 respectively. Of the data collected by the data collection device 8, data collected from the first X-ray detector 2 at the time of CT imaging is taken into the reconstruction calculation unit 9, and a tomographic image of the inspection object W is constructed and displayed. Displayed on the vessel 10.

  Further, data collected from the first X-ray detector 2 or the second X-ray detector 6 during fluoroscopic imaging is sent to the display 10 as frame data of a fluoroscopic image of the inspection object W.

  The operations of the rotation of the rotary table 3, the movement of the rotary table 3 by the table moving mechanism 5, and the tilting of the second X-ray detector 6 by the detector tilting mechanism 7 are signals supplied from the control unit 11. Controlled by An operation unit 12 including a joystick, a mouse, a keyboard, and the like is connected to the control unit 11, and each operation described above can be executed by operating the operation unit 12 by an operator. The control unit 11 also puts the data collection device 8 and the reconstruction calculation unit 9 under control, and selects the type of imaging by operation of the operation unit 12, that is, X-ray CT imaging, or the first X-ray detector 2. In response to the selection of the fluoroscopic imaging according to the above, or the oblique fluoroscopic imaging by the second X-ray detector 6, a command is issued to each data collection device 8 and the reconstruction calculation device 9 to perform an appropriate operation.

  In the above embodiment of the present invention, at the time of CT imaging, the rotary table 3 is rotated while irradiating the inspection object W on the rotary table 3 from the X-ray generator 1 to obtain a predetermined minute rotation angle. Each time, the output of the first X-ray detector 2 is collected, and the reconstruction calculation unit uses the data to construct a tomographic image of the object W along the plane orthogonal to the rotation axis R, and the display 10 To display.

  In addition, when seeing through the front side of the inspection object W (in the direction along the X-ray optical axis), the inspection object W is irradiated with X-rays while the rotary table 3 is positioned at an arbitrary rotation angle. Data from the first X-ray detector 2 is taken in and a fluoroscopic image of the inspection object W is displayed on the display 10.

  On the other hand, when obliquely seeing the object to be inspected, the second X-ray detector 6 is tilted to a required angle θ and the rotating table 3 is positioned at an arbitrary rotation angle to the object W to be inspected. X-rays are irradiated, data from the second X-ray detector 6 is captured, and a fluoroscopic image of the inspection object W is displayed on the display 10.

  In the above-described embodiment of the present invention, a point to be particularly noted is that, as the X-ray CT apparatus, the inspection object W is rotated around the vertical rotation axis R, and therefore the rotation center of the inspection object W is influenced by gravity. Therefore, the X-ray CT apparatus does not deteriorate in performance, and in addition to fluoroscopy from the front, the object to be inspected at an arbitrary angle of 30 to 60 ° by the dedicated second X-ray detector 6 W can be seen obliquely under high magnification.

  In the above-described embodiment, the example in which the tilt angle with respect to the X-ray optical axis L of the second X-ray detector 6 can be changed by the detector tilting mechanism 7 has been described. The X-ray detector 6 may be fixed at, for example, 60 ° with respect to the X-ray optical axis L, and the second X-ray detector 6 may be modified such that the distance from the X-ray focal point 1a is variable. Is also possible.

In the configuration diagram of the embodiment of the present invention, a schematic diagram showing a mechanical configuration and a block diagram showing a system configuration are shown together. It is a figure which shows the structural example of the conventional X-ray fluoroscope. It is a figure which shows the structural example of the other conventional X-ray fluoroscope. It is a figure which shows the structural example of the conventional X-ray fluoroscope which enabled CT imaging by adding CT unit to X-ray fluoroscope.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 X-ray generator 1a X-ray focus 2 1st X-ray detector 3 Rotary table 4 Sample holder 5 Table moving mechanism 6 2nd X-ray detector 7 Detector tilting mechanism 8 Data acquisition device 9 Reconstruction calculating part 10 Display 11 Control unit 12 Operation unit W Inspected object L X-ray optical axis R Rotating axis

Claims (2)

Between the X-ray generator and the X-ray detector, there is provided a rotary table that rotates around a rotation axis orthogonal to the X-ray optical axis connecting the X-ray focal point of the X-ray generator and the center of the X-ray detector. The X-ray projection data captured at every minute angle while mounting the inspection object on the rotary table and applying rotation is used to determine the inspection object along the plane orthogonal to the rotation axis. In an X-ray CT apparatus provided with reconstruction calculation means for reconstructing a tomogram,
The rotation axis is along the vertical direction, and a second X-ray detector is provided separately from the X-ray detector, and the second X-ray detector is the center of the second X-ray detector. And an X-ray CT apparatus, wherein a line connecting the X-ray focal point of the X-ray generator and the X-ray focal point of the X-ray generator is disposed at a predetermined angle with respect to the X-ray optical axis.   The X-ray CT apparatus according to claim 1, further comprising a tilting mechanism that changes an angle of the second X-ray detector with respect to the X-ray optical axis.

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