KR20220127726A - Ct apparatus - Google Patents

Abstract

Provided in the present invention is a CT apparatus, which can acquire three-dimensional data of an object to be inspected without moving or rotating an inspection table, and can set a soft limit based on the three-dimensional data thereof. To this end, the present invention comprises: an inspection table (1) on which an object to be inspected (W) is loaded, and which is installed to be movable and rotatable in a horizontal direction; a radiation source (2) which projects a radioactive beam upon the object to be inspected (W); a detector (3) which is installed to be opposed to the radiation source (2) while placing the object to be inspected (W) therebetween, and outputs the transparent image of the object to be inspected (W); a three-dimensional information acquisition unit (4) which is installed at the upper side of the inspection table (1), and acquires the three-dimensional information of the object to be inspected (W) in a state in which the inspection table (1) is stopped; and a soft limit setting unit (94) which sets the approachable area of the object to be inspected (W) with respect to the radiation source (2) or the detector (3) based on the three-dimensional information.

Description

CT Apparatus {CT APPARATUS}

An embodiment of the present invention relates to a CT device.

A CT apparatus is provided with a radiation source which irradiates, for example, an X-ray beam as radiation, and a detector which is provided facing this radiation source and detects an X-ray beam. An inspection table on which an object to be inspected is placed is installed between the radiation source and the detector, and when the inspection table rotates once while the object to be inspected is irradiated with an X-ray beam, a fluoroscopic image from all directions is obtained. By reconstructing this perspective image, a CT image (cross-sectional image) of the object to be inspected is obtained.

In imaging an object to be inspected, the imaging position of the object is adjusted by moving the inspection table on which the object to be inspected is placed between the radiation source and the detector in the horizontal direction. In addition, in the acquisition of a CT image, the examination table is rotated. At this time, there is a fear that the inspection target collides with the radiation source or the detector by the movement or rotation of the inspection table.

In order to avoid such a collision, it is known to set an accessible area called a soft limit. By setting such a soft limit, it is possible to avoid in advance that the inspected object collides with the radiation source or the detector. Although the soft limit can also be set manually, since there exists a possibility that setting data may be incorrectly input, like patent document 1 or 2, it sets automatically based on the three-dimensional data acquired from the to-be-inspected object in many cases, for example.

Patent Document 1: Japanese Patent Laid-Open No. 2007-078557 Patent Document 2: Japanese Patent Laid-Open No. 2009-294047

However, also in these prior art, in order to acquire three-dimensional data of a to-be-tested object, it was necessary to move or rotate an examination table in the horizontal direction in the state which placed a to-be-inspected object. Such movement or rotation of the inspection table takes time, and it cannot be said that the movement of the inspection table at this time does not reduce the risk of colliding the inspection object with the radiation source or detector before setting the soft limit. In addition, as a method of setting the soft limit without moving or rotating the inspection table, it is also possible to acquire data of the inspection object from an image of an optical camera installed above the inspection table, but in this case, the height information of the inspection object is acquired Since it could not do it, it was insufficient as three-dimensional data for setting a soft limit.

In order to solve the above problems, the present embodiment aims to provide a CT device capable of acquiring three-dimensional data of an object to be inspected without moving or rotating the inspection table, and setting a soft limit based on the three-dimensional data. do.

The CT device of the embodiment has the following configuration.

(1) An inspection table on which the object to be inspected is placed and installed to be movable and rotatable in the horizontal direction.

(2) A radiation source for irradiating a radiation beam to the object to be inspected.

(3) A detector that is installed to face the radiation source with the object to be inspected interposed therebetween and outputs a fluoroscopic image of the object to be inspected.

(4) A three-dimensional information acquisition unit installed above the inspection table and acquiring three-dimensional information of the object to be inspected in a state where the inspection table is stopped.

(5) A soft limit setting unit for setting an area in which the inspection object can be approached with respect to the radiation source or the detector based on the three-dimensional information.

Moreover, the CT apparatus of embodiment is provided with the following structures.

(1) An inspection table on which the object to be inspected is placed and installed to be movable and rotatable in the horizontal direction.

(2) A radiation source for irradiating a radiation beam to the object to be inspected.

(3) A detector that is installed to face the radiation source with the object to be inspected interposed therebetween and outputs a fluoroscopic image of the object to be inspected.

(4) A mirror that illuminates one side of the object to be inspected.

(5) installed opposite to the mirror with the object to be inspected therebetween, and in a state where the inspection table is stopped, both the other side of the object and the one side of the object reflected in the mirror are imaged, and the A three-dimensional information acquisition unit that acquires three-dimensional information of an object to be inspected.

(6) A soft limit setting unit for setting an area in which the inspected object can be approached with respect to the radiation source or the detector based on the three-dimensional information.

The CT device of the embodiment may further have the following configuration.

(1) an imaging position calculation unit for calculating an imaging position suitable for imaging the inspection target based on the three-dimensional information of the inspected object, the region, and predetermined parameters, wherein the inspection table includes: the imaging position Move the test object to

(2) a three-dimensional information display unit for displaying the object to be inspected in orthogonal two or three directions based on the three-dimensional information on the object, and an ROI for designating a region of interest in the object displayed on the three-dimensional information display unit Further comprising: a designation unit; an imaging position calculation unit for calculating an imaging position suitable for imaging the region of interest based on three-dimensional information of the object to be inspected, the region of interest, and predetermined parameters; Move the region of interest to the imaging position.

(3) A perspective image display unit for displaying the perspective image is further provided, wherein the perspective image display unit displays the region overlaid on the perspective image.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the CT apparatus which concerns on 1st Embodiment.
Fig. 2 is a functional block diagram showing a control unit according to the first embodiment.
Fig. 3 is a view showing a soft limit according to the first embodiment.
4 : is a figure explaining the movement of the to-be-inspected object W by the XY mechanism which concerns on 1st Embodiment.
It is a figure explaining calculation of the imaging position which concerns on 1st Embodiment.
6 is a diagram for explaining the setting of the ROI according to the first embodiment.
7 is a view for explaining the movement of the inspection target W by the XY mechanism in the case of setting the ROI according to the first embodiment.
Fig. 8 is a diagram for explaining calculation of the imaging position in the case of setting the ROI according to the first embodiment.
Fig. 9 is a diagram in which the soft limit and the ROI are superimposed and displayed on the perspective image according to the first embodiment.
Fig. 10 is a flowchart showing the operation of the CT apparatus according to the first embodiment.
11 is a schematic diagram showing a CT device according to a second embodiment.

[One. first embodiment]

[1-1. Configuration of the embodiment]

Hereinafter, the structure of the CT apparatus which concerns on embodiment is demonstrated, referring FIGS. The CT apparatus 100 irradiates the inspection target W with radiation, and detects the radiation that has passed through the inspection target W. Based on the detection result, the CT apparatus 100 generates a CT image of the object W to be inspected. As shown in FIG. 1 , the CT apparatus 100 includes an inspection table 1 on which an inspection target W is placed on its upper surface, a radiation source 2 and a detector 3 that capture a fluoroscopic image of the inspection target W, and a detector 3 . ) and a three-dimensional information acquisition unit 4 that is installed above the inspected object W and acquires three-dimensional information of the inspected object W. In addition, the CT apparatus 100 includes a control unit 9 for controlling the operation of the examination table 1 , the radiation source 2 , the detector 3 , and the three-dimensional information acquisition unit 4 , a fluoroscopic image, and a later-described view. A perspective image display unit M for superimposing and displaying the soft limits S of is provided.

The inspection table 1 is a table which has a mounting surface on which the to-be-inspected object W is mounted. The inspection table 1 includes a movement mechanism 11 for moving the placement surface in a direction parallel to or perpendicular to the placement surface, a rotation mechanism 12 for rotating the placement surface about the vertical direction as an axis, and a placement surface. The XY mechanism 13 which moves the to-be-tested object W in the direction parallel to a mounting surface is provided on it.

As the movement mechanism 11, for example, a ball screw mechanism driven by a servomotor can be used. That is, the moving mechanism 11 moves the inspected object W for each mounting surface in a direction parallel to or perpendicular to the mounting surface of the inspection table 1 by driving a servomotor.

The rotation mechanism 12 is provided on the movement mechanism 11 and is an actuator which includes, for example, a drive source such as a motor. The rotating mechanism 12 rotates the said mounting surface centering around the axis perpendicular|vertical to the mounting surface of the inspection table 1 . By this rotation, the to-be-inspected object W can be imaged from all directions, a perspective image can be acquired, and a CT image can be reconstructed from these perspective images.

The XY mechanism 13 is provided on the rotation mechanism 12, for example, a ball screw mechanism driven by a servomotor can be used. The XY mechanism 13 moves the to-be-inspected object W on the mounting surface of the examination table 1 . In other words, instead of moving the inspected object W for each rotational axis (rotational axis of the mounting surface) of the inspection table 1 like the moving mechanism 11, the inspected object W is moved on the mounting surface without changing the position of this rotational shaft. move it Thereby, the to-be-inspected object W can be moved to the center of the mounting surface of the inspection table 1 . In this way, the moving mechanism 11 and the XY mechanism 13 can each independently move the to-be-inspected object W in the direction parallel to a mounting surface.

The radiation source 2 irradiates a radiation beam to the object W to be inspected. The radiation beam is a radiation bundle that expands in a pyramid shape with a focal point as the apex. The radiation source 2 is, for example, an X-ray tube, and the radiation is, for example, X-rays. The detector 3 is installed to face the radiation source 2 with the examination table 1 and the object W interposed therebetween, and detects the two-dimensional distribution of the radiation intensity attenuated according to the transmission path of the radiation, , the perspective image is output to the image processing unit 93 and the perspective image display unit M, which will be described later. The detector 3 is comprised by flat panel detector FPD, for example.

The three-dimensional information acquisition unit 4 is, for example, a three-dimensional measuring device or a 3D camera. As a 3D camera, the thing of a ToF system, a stereo system, and a structured illumination system can be employ|adopted, for example. The three-dimensional information acquisition unit 4 can acquire distance information to the imaging target in addition to the appearance information of the imaging target. The three-dimensional information acquisition unit 4 is installed above the inspection table 1, and in a state where the inspection table 1 is stopped, the image to be inspected W is placed on the inspection table 1, and the inspected object W ) to obtain 3D information. Strictly speaking, the inspection table 1 in a state where the inspected object W is not placed in advance is imaged, and as the difference between this and the imaging in the state where the inspected object W is placed on the inspection table 1, Three-dimensional information of the inspected object W is acquired. The three-dimensional information acquisition part 4 outputs the acquired three-dimensional information of the to-be-inspected object W to the soft limit setting part 94, the imaging position calculation part 95, and the ROI setting part 96 mentioned later.

As shown in FIG. 2 , the control unit 9 includes a mechanism control unit 91 which controls the moving mechanism 11 and the rotation mechanism 12 of the examination table 1 , and a radiation source control unit 92 which controls the radiation source 2 . ), the image processing unit 93 that corrects and reconstructs the perspective image acquired from the detector 3 to generate a CT image, and the three-dimensional information of the inspected object W acquired from the three-dimensional information acquisition unit 4 . A soft limit setting unit 94 that sets the soft limit S based on Based on the three-dimensional information acquired in (4), the inspection target W is displayed in two orthogonal directions or three directions, and a region of interest (hereinafter referred to as ROI) is set on the inspection target W in this display image. and an ROI setting unit 96.

The control unit 9 is constituted by a computer and a driver circuit. A computer is constituted by storage such as HDD or SSD, RAM, CPU, and the like. In addition, an input unit (not shown) is connected to the control unit 9 , and the user causes the control unit 9 to control each configuration of the CT apparatus 100 through this input unit.

The instrument control unit 91 controls the movement mechanism 11 , the rotation mechanism 12 , and the XY mechanism 13 of the inspection table 1 to move and rotate the object W placed on the inspection table 1 . can In particular, the mechanism control unit 91 of the present embodiment controls the movement and rotation of the inspection table 1 so that the inspected object W does not come out from the soft limit S set by the soft limit setting unit 94 .

The radiation source control unit 92 controls the radiation source 2 and irradiates the object W with a radiation beam. Thereby, the fluoroscopic image of the to-be-inspected object W can be acquired from the detector 3 provided facing the radiation source 2 with the to-be-inspected object W interposed therebetween.

The image processing unit 93 includes an acquisition unit 931 that acquires various data such as offset data and gain data from the detector 3, a correction unit 932 that corrects a perspective image based on the various data, and A reconstruction unit 933 for reconstructing a perspective image is provided. For reconstruction, for example, FeldKamp's FBP method is used, and a CT image is generated by performing filtering and back projection (reverse projection) for each fluoroscopic image after correction.

The soft limit setting unit 94 sets the soft limit S based on the three-dimensional information of the to-be-inspected object W acquired from the three-dimensional information acquisition unit 4 . The soft limit S is a region in which the inspected object W can be approached to the radiation source 2 or the detector 3 . In other words, the soft limit S is an area in which the inspected object W is not likely to collide with the radiation source 2 or the detector 3 . The soft limit S of this embodiment is set centering around the rotation axis of the inspection table 1 . Hereinafter, the setting of the soft limit S will be described in detail with reference to FIG. 3 .

The soft limit setting unit 94 sets a cylindrical region including the inspected object W based on the three-dimensional information of the inspected object W acquired from the three-dimensional information acquiring unit 4 . When seen from the upper surface of FIG. 3, this cylindrical area|region becomes a circumscribed circle of the to-be-inspected object W. As shown in FIG. If the radius of the circumscribed circle is r1, and the distance from the center of the circumscribed circle to the rotation axis of the mounting surface of the inspection table 1 is r2, the radius of the outer trajectory when the inspected object W is rotated is r1+r2. The distance obtained by adding the distance β of the margin to the radius r1+r2 is the radius of the soft limit S. The extra distance β can be set arbitrarily. In addition, as the setting of the height direction of the soft limit S, for example, the height of the inspected object W obtained based on the three-dimensional information of the inspected object W plus the extra distance β may be used. . In this way, the soft limit setting unit 94 sets the soft limit S around the rotation axis of the inspection table 1 . Moreover, the soft limit setting part 94 outputs the soft limit S to the imaging position calculating part 95 and the perspective image display part M.

By setting the soft limit S, the proximity movement distance md1 of the inspection table 1 with respect to the radiation source 2 is obtained by the following equation. In addition, FCD in the formula is the distance from the focal point of the radiation source 2 to the center of the rotation axis of the examination table 1 , and α is the distance from the focal point of the radiation source 2 to the window.

md1 = FCD-α-(radius of soft limit (S))

= FCD-α-(r1+r2)-β

Similarly, the proximity movement distance md2 of the inspection table 1 with respect to the detector 3 is calculated|required by the following formula. In addition, FDD in the formula is the distance from the focal point of the radiation source 2 to the inspection table 3 .

md2= (FDD-FCD)-(radius of soft limit (S))

= (FDD-FCD)-(r1+r2)-β

The imaging position calculation unit 95 is configured to image the inspected object W based on the three-dimensional information of the inspected object W acquired from the three-dimensional information acquisition unit 4, the soft limit S, and predetermined parameters. A suitable imaging position is calculated. The predetermined parameters are various parameters, such as the height of the mounting surface of the examination table 1 with respect to the radiation source 2, the imaging range of the detector 3, and the magnification of a perspective image. An imaging position suitable for imaging the inspected object W is, for example, in the close-movable range defined by the soft limit S, the detector 3 is the maximum magnification of the inspected object W. It is a position where a perspective image can be acquired. Calculation of an imaging position is demonstrated in detail below, referring FIG.4 and FIG.5.

First, the imaging position calculation unit 95 acquires the central position of the circumscribed circle of the inspected object W and the central position of the rotation axis of the inspection table 1 based on the three-dimensional information of the inspected object W . The imaging position calculation unit 95 outputs this information to the mechanism control unit 91 . As a result, as shown in FIG. 4 , the instrument control unit 91 attaches the inspected object ( W) is moved.

Next, the imaging position calculation unit 95 is configured such that, in a state where the circumscribed circle center position of the inspection target W is concentric with the rotation axis of the inspection table 1 , the inspection target W or an extra distance β enters the radiation beam It is a position, and the perspective image of the to-be-inspected object W becomes the maximum magnification, and the imaging position which is within the close-movable range prescribed|regulated by the soft limit S is computed. Moreover, you may prescribe the upper limit of the maximum magnification based on the predetermined parameter mentioned above. The imaging position calculation unit 95 outputs the imaging position to the mechanism control unit 91 . Thereby, as shown in FIG. 5, the mechanism control part 91 makes the moving mechanism 11 move the circumscribed-circle center position of the to-be-inspected object W to the imaging position calculated by the imaging position calculation part 95. . In addition, since r2 = 0 at this time, the soft limit S set centering around the rotation axis of the examination table 1 shown in FIG. 5 is small compared with FIG.

The ROI setting unit 96 includes a three-dimensional information display unit 961 and an ROI designation unit 962 . The three-dimensional information display unit 961 includes, for example, liquid crystal or organic EL, and based on the three-dimensional information of the object W acquired from the three-dimensional information acquisition unit 4, the object W ) is indicated in two orthogonal directions or three directions. Hereinafter, it demonstrates as what displays the to-be-inspected object W in two directions parallel to the mounting surface of the inspection table 1, mutually orthogonal, and three directions of one direction orthogonal to these two directions.

Here, the direction in which the radiation source 2 and the detector 3 are arranged is the X direction, parallel to the mounting surface of the inspection table 1, and the direction orthogonal to the X direction is the Y direction, the X direction and the direction orthogonal to the Y direction. When is set to the Z direction, the inspected object W is displayed in three orthogonal directions: the Z direction (XY plane), the X direction (YZ plane), and the Y direction (XZ plane), as shown in FIG. 6 .

The ROI designation unit 962 designates an ROI for the inspection target W displayed on the three-dimensional information display unit 961 . Specifically, as shown in FIG. 6 , in each of the XY plane, YZ plane, and XZ plane, a circular or rectangular ROI is designated for the object W to be inspected. Thereby, the ROI is designated as a cylindrical region. That is, the ROI is designated as a three-dimensional region.

In this way, when the ROI is set on the object W by the ROI setting unit 96, the imaging position calculating unit 95 calculates an imaging position suitable for imaging the location where the ROI is set. Calculation of the imaging position in the case of setting ROI is demonstrated in detail below, referring FIG.7 and FIG.8.

First, the imaging position calculation unit 95 acquires the central position of the ROI set on the inspected object W and the central position of the rotation axis of the inspection table 1 based on the three-dimensional information and the ROI of the inspected object W . The imaging position calculation unit 95 outputs this information to the mechanism control unit 91 . As a result, as shown in FIG. 7 , the instrument control unit 91 attaches the XY mechanism 13 to the inspection subject ( W) is moved.

Next, the imaging position calculation unit 95, in a state where the central position of the ROI set on the inspection object W is concentric with the rotation axis of the inspection table 1 (viewed from the top view), is set on the inspection object W This is the position at which the ROI enters the radiation beam, and an imaging position is calculated at which the perspective image of the ROI becomes the maximum magnification, and is within the range that can be moved in proximity defined by the soft limit S. Moreover, you may prescribe the upper limit of the maximum magnification based on the predetermined parameter mentioned above. The imaging position calculation unit 95 outputs the imaging position to the mechanism control unit 91 . Thereby, as shown in FIG. 8, the mechanism control part 91 is the imaging position calculated by the imaging position calculation part 95, The center position of the ROI set by the moving mechanism 11 to the to-be-inspected object W. move it

The perspective image display unit M includes, for example, liquid crystal or organic EL, and as shown in FIG. 9 , the perspective image of the inspection object W acquired by the detector 3 and the soft limit setting unit 94 ) superimposes the set soft limit (S). In addition, when the ROI setting unit 96 sets the ROI, the perspective image display unit M may display the ROI overlaid on the perspective image. Further, in the perspective image display unit M, the ROI set by the ROI setting unit 96 is displayed at a corresponding position and magnification on the perspective image.

[1-2. Action of the embodiment]

The setting of the soft limit, the calculation of the imaging position, and the generation of the CT image of the present embodiment will be described with reference to the flowchart of FIG. 10 .

(1) Soft limit setting

The three-dimensional information acquisition unit 4 acquires three-dimensional information of the inspected object W in a state where the inspection table 1 is stopped, and sets the soft limit setting unit 94, the imaging position calculation unit 95 and the ROI. output to the unit 96 (step S01). The soft limit setting unit 94 sets the soft limit S around the rotation axis of the inspection table 1 based on the three-dimensional information of the inspected object W acquired from the three-dimensional information acquisition unit 4 ( step S02). The soft limit S can be set from the center position of the circumscribed circle of the to-be-inspected object W at the time of seeing from an upper surface, the rotation axis center position of the inspection table 1, and the distance of the surplus, for example. The proximity movement distance of the to-be-inspected object W is prescribed|regulated by this soft limit S.

(2) Calculation of the imaging position

The imaging position calculation part 95 is based on the three-dimensional information of the to-be-inspected object W acquired from the soft limit setting part 94, and the soft limit S acquired from the soft limit setting part 94, the detector 3 An imaging position suitable for imaging the temporarily inspected object W is calculated. Incidentally, it is assumed that no ROI is set here (NO in step S03).

First, the imaging position calculation unit 95 acquires the central position of the circumscribed circle of the inspected object W and the central position of the rotation axis of the inspection table 1 based on the three-dimensional information of the inspected object W . The imaging position calculation unit 95 outputs this information to the instrument control unit 91 , and the instrument control unit 91 adjusts the central position of the circumscribed circle of the inspected object W to the central position of the rotation axis of the inspection table 1 . , The object W is moved to the XY mechanism 13 . Next, the imaging position calculation unit 95 is configured such that, in a state where the circumscribed circle center position of the inspection target W is concentric with the rotation axis of the inspection table 1 , the inspection target W or an extra distance β enters the radiation beam It is a position, and the perspective image of the to-be-inspected object W becomes the maximum magnification, and the imaging position within the close-movable range prescribed|regulated by the soft limit S is computed (step S04-1).

In addition, when the imaging position calculation unit 95 outputs this imaging position to the instrument control unit 91 , the instrument control unit 91 controls the moving mechanism 11 and returns the center of the circumscribed circle of the object W to the imaging position. is moved (step S05). After this, it progresses to step S06 mentioned later.

Next, the case of setting the ROI will be described (YES in step S03). When an ROI is set by the ROI designation unit 962 for the inspection target W displayed on the three-dimensional information display unit 961, the imaging position calculation unit 95 determines the inspection target W according to the ROI. Calculate the imaging position.

First, the imaging position calculation unit 95 acquires the central position of the ROI set on the inspected object W and the central position of the rotation axis of the inspection table 1 based on the three-dimensional information and the ROI of the inspected object W . The imaging position calculation unit 95 outputs this information to the instrument control unit 91 , and the instrument control unit 91 adjusts the center position of the ROI set on the object W to match the center position of the rotation axis of the examination table 1 . , The object W is moved to the XY mechanism 13 . Next, the imaging position calculation unit 95, in a state where the central position of the ROI set on the inspection object W is concentric with the rotation axis of the inspection table 1, the ROI set on the inspection object W enters the radiation beam It is a position, and the perspective image of the ROI becomes the maximum magnification, and the imaging position which is within the close-movable range prescribed|regulated by the soft limit S is computed (step S04-2). Thereafter, the process proceeds to step S05 described above, and further proceeds to step S06.

(3) Generation of CT images

After moving the inspection table 1 to the imaging position, rotation of the inspection table 1 under the control of the instrument control unit 91 and irradiation of the radiation beam from the radiation source 2 under the control of the radiation source control unit 92 are simultaneously performed. , the detector 3 acquires the inspected object W from all directions or a perspective image of the ROI set on the inspected object W (step S06). The correction unit 32 of the image processing unit 93 performs correction processing on this perspective image, and the reconstruction unit 933 reconstructs the corrected perspective image to generate a CT image (step S07).

[1-3. [Effect of embodiment]

(1) In this embodiment, the soft limit setting part 94 sets the soft limit S based on the three-dimensional information of the to-be-inspected object W which the three-dimensional information acquisition part 4 acquired. Thereby, even if it does not move or rotate the test|inspection table 1, the soft limit S can be set. Moreover, since the soft limit S is set based on three-dimensional information, the effective soft limit S can be set also about the height direction of the to-be-inspected object W.

(2) In the present embodiment, the imaging position calculation unit 95 calculates an imaging position suitable for imaging of the inspected object W based on the three-dimensional information and the soft limit S of the inspected object W. can Thereby, for example, in the close-movable range defined by the soft limit S, the detector 3 is inspected at the imaging position at which the perspective image of the inspected object W can be acquired at the maximum magnification. The object (W) can be moved.

(3) In the present embodiment, the ROI designation unit 962 can designate an ROI for the inspected object W displayed on the three-dimensional information display unit 961 . Since the inspected object W is displayed in three orthogonal directions by the three-dimensional information display unit 961, the ROI can also be designated as a three-dimensional region, similarly to the inspected object W. Since the imaging position calculation unit 95 can calculate the imaging position in consideration of the ROI as such a three-dimensional area, for example, in the close-movable range defined by the soft limit S, the detector 3 ) can move the inspected object W to an imaging position where the perspective image of the ROI set on the inspected object W can be acquired at the maximum magnification.

(4) In the present embodiment, the perspective image of the inspected object W and the soft limit S can be superimposed and displayed on the perspective image display unit M. Thereby, the user can visually recognize the range of the soft limit S with respect to the to-be-inspected object W.

[2. second embodiment]

[2-1. composition]

The configuration of the CT device 100 of the present embodiment will be described with reference to FIG. 11 . The second embodiment has the same basic configuration as that of the first embodiment. Hereinafter, only the points different from the first embodiment will be described, and the same reference numerals are given to the same parts as those of the first embodiment, and detailed description will be omitted.

In the CT apparatus 100 of the present embodiment, as shown in FIG. 11 , the three-dimensional information acquisition unit 4 is provided in the vicinity of the radiation source 2 , for example, directly above the examination table 1 , rather than above the examination table 1 . do. The CT apparatus 100 of the present embodiment further includes a mirror 5 . The mirror 5 is installed above the detector 3 so as to illuminate the back surface of the inspected object W (the surface on the side opposite to the detector 3) when viewed from the three-dimensional information acquisition unit 4 side. . That is, the three-dimensional information acquisition unit 4 captures the back surface of the inspected object W through the mirror 5 in addition to the surface (the surface on the side opposite to the radiation source 2) of the inspected object W. can do.

The imaging of the back surface of the to-be-inspected object W by the three-dimensional information acquisition part 4 is demonstrated in detail. The three-dimensional information acquisition unit 4 can obtain an equation representing the plane of the mirror 5 by acquiring positional information of a plurality of marks (not shown) provided on the mirror 5 . Distance information from the three-dimensional information acquisition unit 4 to the back surface of the inspected object W can be calculated from this plane equation and the position information of the back surface of the inspected object W reflected in the mirror 5 . That is, the three-dimensional information acquisition unit 4 may calculate the position information of the back surface of the inspection object W through the mirror 5 . Thereby, the three-dimensional information acquisition unit 4 acquires the three-dimensional information of the inspected object W from the surface of the inspected object W directly imaged and the back surface of the inspected object W imaged indirectly. can In addition, this technique is described in detail, for example, in "Shape measurement using a mirror surface by a three-dimensional measuring instrument" (Gifu Prefectural Information Technology Research Institute Research Report (11), pp. 30-34, 2009).

[2-2. Action]

The setting of the soft limit S, the calculation of the imaging position, and the generation of the CT image of the present embodiment are basically the same as those of the first embodiment, and thus description thereof will be omitted.

[2-3. effect]

In the present embodiment, the three-dimensional information acquisition unit 4 is provided directly above the radiation source 2 . In 1st Embodiment, when the to-be-inspected object W has an umbrella-like structure, the shaded part of an umbrella cannot be imaged. For this reason, when the ROI is designated as a three-dimensional region for the inspection object W, problems such as data loss may occur. For example, the circumscribed circle of the inspection object W when viewed from the top It was necessary to make up for this missing part with a cylinder or the like used as the base. However, in this embodiment, since imaging is performed by the three-dimensional information acquisition unit 4 and the mirror 5 provided just above the radiation source 2, such a problem does not occur.

[3. other embodiment]

In this specification, although the some embodiment which concerns on this invention was demonstrated, these embodiment is shown as an example, and it is not intending limiting the scope of the invention. The above embodiments can be implemented in other various forms, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope of the invention and the scope of equivalents thereof, as well as included in the scope and gist of the invention.

(1) Although the three-dimensional information display part 961 of the said embodiment displayed the to-be-tested object W in three orthogonal directions, it may display in two orthogonal directions. Even in this case, since the ROI can be designated from two directions, the ROI can be designated as a three-dimensional area. It is also possible to set the shape of the ROI in the cylindrical region in advance. In this way, for example, even if the ROI is specified in a rectangular shape from two orthogonal directions of the X-direction (YZ plane) and the Y-direction (XZ plane), the ROI designation as a cylindrical region can be performed similarly to FIG. 6 . Note that the shape of the ROI designated from the three directions or the ROI set in advance is not limited to the cylindrical region, and may be a rectangular region or a rectangular parallelepiped region.

(2) Although the three-dimensional information acquisition part 4 of 1st Embodiment was made into a three-dimensional measuring machine or a 3D camera, it can also be set as the apparatus using not only this but an ultrasonic wave or a laser beam.

(3) In the second embodiment, the three-dimensional information acquisition unit 4 is provided on the radiation source 2 side and the mirror 5 is provided on the detector 3 side, but the present invention is not limited thereto. If the three-dimensional information of the inspection target W for setting the soft limit S can be acquired, the three-dimensional information acquisition unit 4 is connected to the detector 3 side, and the mirror 5 is connected to the radiation source 2 . It may be installed on the side, or it may be installed anywhere else.

100: CT device 1: examination table
11: moving mechanism 12: rotating mechanism
2: Radiation source 3: Detector
4: 3D information acquisition unit 5: Mirror
9: control unit 91: instrument control unit
92: radiation source control unit 93: image processing unit
931: acquisition unit 932: correction unit
933: reconstruction unit 94: soft limit setting unit
95: imaging position calculation unit 96: ROI setting unit
961: three-dimensional information display unit 962: ROI designation unit
M: Perspective image display unit S: Soft limit
W: Inspection object

Claims (7)

An inspection table on which the object to be inspected is placed and installed to be movable and rotatable in the horizontal direction;
a radiation source irradiating a radiation beam to the object to be inspected;
a detector installed to face the radiation source with the inspected object interposed therebetween and outputting a fluoroscopic image of the inspected object;
a three-dimensional information acquisition unit installed above the inspection table and acquiring three-dimensional information of the object to be inspected in a state in which the inspection table is stopped;
and a soft limit setting unit for setting an area to which the inspection object can be approached with respect to the radiation source or the detector based on the three-dimensional information. An inspection table on which the object to be inspected is placed and installed to be movable and rotatable in the horizontal direction;
a radiation source irradiating a radiation beam to the object to be inspected;
a detector installed to face the radiation source with the inspected object interposed therebetween and outputting a fluoroscopic image of the inspected object;
A mirror that illuminates one side of the object to be inspected,
It is installed to face the mirror with the object to be inspected therebetween, and in a state where the inspection table is stopped, both the other side of the object and the one side of the object reflected in the mirror are imaged, and the object to be inspected is a three-dimensional information acquisition unit for acquiring three-dimensional information;
and a soft limit setting unit for setting an area to which the inspection object can be approached with respect to the radiation source or the detector based on the three-dimensional information. The method according to claim 1 or 2, further comprising: an imaging position calculation unit that calculates an imaging position suitable for imaging the inspected object based on three-dimensional information of the inspected object, the region, and a predetermined parameter,
wherein the examination table moves the object to be inspected to the imaging position. The method according to claim 1 or 2, further comprising: a three-dimensional information display unit for displaying the object to be inspected in two orthogonal directions or three directions based on the three-dimensional information of the object;
an ROI designator for designating a region of interest in the object to be inspected displayed on the three-dimensional information display unit;
Further comprising an imaging position calculation unit for calculating an imaging position suitable for imaging the region of interest based on the three-dimensional information of the object to be inspected, the region of interest, and a predetermined parameter,
wherein the examination table moves the region of interest to the imaging position. According to claim 1 or 2, further comprising a perspective image display unit for displaying the perspective image,
and the perspective image display unit displays the region superimposed on the perspective image. According to claim 3, further comprising a perspective image display unit for displaying the perspective image,
and the perspective image display unit displays the region superimposed on the perspective image. According to claim 4, further comprising a perspective image display unit for displaying the perspective image,
and the perspective image display unit displays the region superimposed on the perspective image.

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