JP5222582B2 - Tomography equipment - Google Patents

Description

  The present invention relates to a tomography apparatus such as a tomosynthesis apparatus and a laminograph, and more particularly to a circular orbit type tomography apparatus that changes the irradiation direction of a subject along a cone.

  A circular orbit type tomography apparatus irradiates a subject with radiation (X-rays) generated from a radiation source. At this time, the subject is irradiated with respect to radiation by a rotation axis inclined with respect to the optical axis of the radiation. The radiation that is relatively rotated and transmitted from the subject at every predetermined rotational position in one rotation is detected by a radiation detector having a two-dimensional detection channel, and a tomographic image or three-dimensional image of the subject is detected from the detector output. Get data.

  As a reconstruction method for obtaining this tomographic image or three-dimensional data, a method of performing filter processing and back projection processing, a successive approximation method (ART: Algebraic Reconstruction Techniques method), or the like is used (Patent Document 1).

  In the display of tomographic images in this circular orbit type tomography apparatus, when only one tomographic image is displayed, it is difficult to grasp the entire image of the imaging region of the subject.

  Therefore, conventionally, after three-dimensional data (a plurality of continuous tomographic images) is reconstructed, one image is selectively displayed, and thereafter, the images are sequentially switched to the adjacent images by image turning operation to display the whole image. There is something that made it possible to grasp.

  As another cross-sectional image display example, MPR (Multi Planar Reconstruction) display already performed by a CT scanner is used, and cross-sectional positions are continuously displayed while simultaneously displaying a plurality of cross-sections having different directions on the same screen. There is one that has been changed to be able to grasp the whole image (Patent Document 2).

  Further, as another example of displaying a cross-sectional image, there is one that uses a three-dimensional display already performed by a CT scanner, projects three-dimensional data along a line of sight, and creates and displays a three-dimensional display image.

Further, a display that combines the above-described MPR display and three-dimensional display has been proposed (Patent Document 3).
JP 2004-108990 A JP 2005-300388 A JP 09-016814 A

  Therefore, in observing a tomographic image in a circular orbit tomography apparatus, it is desirable to sufficiently observe the details while grasping the entire image of the imaging region of the subject.

  However, in order to grasp the whole image, it is necessary to repeat the image turning operation at a high speed in order to grasp the whole image, so that the image turning operation is troublesome and reciprocates many times. The whole cannot be grasped unless the operation is repeated repeatedly. In addition, even when it is desired to reconstruct a small number of necessary cross-sectional images in a short time, it is necessary to reconstruct a large number of tomographic images in a section wider than necessary in order to understand the entire image. is there.

  The MPR display, which is another conventional display example, selects the position where the whole image can be grasped while changing the cross-sectional position in order to grasp the whole image. Similar to the turning operation, the entire position cannot be grasped unless the cross-sectional position is changed repeatedly. Moreover, it is necessary to reconstruct a larger number of tomographic images than necessary as in the image turning operation. In addition, since the cross-section conversion process is performed, there is a problem that a slight delay occurs in the cross-section switching response, and the operation until the entire state can be grasped is accompanied by an irritating feeling.

  Three-dimensional display, which is another conventional display example, includes a line-of-sight direction (a parameter that determines from which direction to view), a parameter indicating how to illuminate the subject, and transparency (in the case of translucent display, There are many settings of display conditions such as setting how much transparency is obtained for each CT value. As a result, the operation until the entire imaging region of the subject is displayed in a state where it can be grasped is troublesome. Further, there is a problem that a slight delay occurs in the response to the display change process, and the operation up to the overall grasp is accompanied by an irritating feeling as in the MPR display described above.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a tomographic apparatus that displays a tomographic image and a transmission image together and can easily grasp the entire image of the imaging region of the subject. To do.

In order to solve the above problems, the present invention provides a table on which a subject is placed, a radiation source that irradiates radiation toward the subject, and radiation that detects radiation transmitted through the subject with a two-dimensional detection channel. A tomography apparatus comprising: a detector; and a rotation means for rotating the subject and the radiation relative to a rotation axis that intersects the radiation optical axis of the radiation source at an angle of 90 ° or less. An imaging control unit that sequentially collects transmission images as the output of the radiation detector for each predetermined rotation angle position while being rotated by the rotation unit, and a plurality of transmission images collected by the imaging control unit And reconstructing means for reconstructing the tomographic image of the subject, and selecting at least one transmission image from the plurality of transmission images used for the reconstruction of the tomographic image, and reducing the selected transmission image Reconstruction And display control means for displaying alongside the tomographic image on one display screen with, the display control means, when selecting one transmission image from said plurality of transmission images, the left-right direction of the tomographic image to the display or The tomography apparatus selects the one transmission image such that the vertical direction and the horizontal direction or the vertical direction of the displayed transmission image are the same with respect to the subject .

Further, as the display control means of the present invention, when two or more transmission images are selected from the plurality of transmission images, the transmission images to be displayed are selected one after another based on the order collected from the plurality of transmission images, The transmission image to be displayed is updated one after another, thereby realizing a rotation moving image display of the transmission image on the display screen.

  Furthermore, the display control means of the present invention is characterized in that the selected transmission image or the displayed transmission image is stored and stored in association with the tomographic image to be displayed.

  Furthermore, the display control means of the present invention is characterized in that the selected transmission image or the displayed transmission image and the tomographic image to be displayed are stored and stored with a file name including the same tomographic identification name. To do.

  According to the present invention, a tomographic image that has been subjected to tomographic reconstruction processing is displayed together with a tomographic image with a certain directionality, so that a tomographic image that can easily grasp the entire image of the imaging region of the subject is obtained. An imaging device can be provided.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a conceptual configuration diagram (front view) illustrating a first embodiment of a tomography apparatus according to the present invention.

  In FIG. 1, 1 is an X-ray tube as a radiation source, and 2 is an X-ray detector as a radiation detection means. An X-ray beam 3, which is radiation generated from the X-ray focal point F of the X-ray tube 1, is irradiated toward a subject 4 obliquely below in the figure, and a part of the X-ray beam 5 passes through the subject 4, It is detected by the X-ray detector 2.

  The X-ray tube 1 is, for example, a transmission type microfocus X-ray tube, and has a small X-ray focal point F of about 1 μm.

  The X-ray detector 2 detects an X-ray beam 5 transmitted from the subject 4 on a detection surface 2a constituted by a two-dimensional detection channel (two-dimensional resolution). I. A combination of (X-ray image. Intensifier) and a television camera, an FPD (flat panel detector), or the like is used.

  The subject 4 is placed on the sample table 6, and an XY mechanism 7, a rotation mechanism 8, and an xz mechanism 9 that support and move the sample table 6 are provided below the sample table 6. These mechanisms 7 to 9 are moved in a predetermined direction based on a command from the outside, and have a role of setting the subject 4 to a predetermined position with respect to the X-ray beam 5.

  Note that the XY mechanism 7, the rotation mechanism 8, and the xz mechanism 9 are not limited to the stacking order in FIG. 1 and can be stacked in any order. The rotating mechanism 8 corresponds to rotating means described in the claims.

  The subject 4 is translated and set in the two directions X and Y orthogonal to each other along the table surface 6 a by the XY mechanism 7 together with the sample table 6. In addition, the subject 4 is rotated along the table surface 6 a by the rotation mechanism 8. Further, the subject 4 is translated in the two directions x and z by the xz mechanism 9 along the plane (detector tilting surface 10 = paper surface) orthogonal to the table surface 6a together with the rotation axis RA, and is set at a required position. The

  The X-ray beam 5 is designed so as to intersect only the subject 4 and the sample table 6 and not intersect with other components having strong X-ray absorption. For example, the rotation mechanism 8 has a large-diameter hollow shaft and a bearing at a portion off the X-ray beam 5, and the X-ray beam 5 passes through the hollow shaft. Similarly, the XY mechanism 7 and the xz mechanism 9 are devised so as not to intersect with components having strong X-ray absorption. The sample table 6 is made of a material having good X-ray transmission.

  The X-ray detector 2 is linearly moved in the xd direction along the detector tilting surface 10 (= paper surface) by the detector moving mechanism 11 and is simultaneously swung, so that the detection surface 2a always faces the X-ray focal point F. The position is set as follows. Alternatively, it may be moved in an arc shape as shown in FIG.

  The detector moving mechanism 11 can vary the lamino angle α by moving the X-ray detector 2 in the X-ray beam 3 within a range smaller than 90 degrees (0 degree to about 70 degrees). The lamino angle α is an angle formed between the rotation axis RA and the X-ray optical axis L.

  As a result, the rotation axis RA is inclined at a lamino angle α smaller than 90 degrees with respect to the X-ray optical axis L connecting the X-ray focal point F (X-ray source) and the center D of the detection surface 2a of the X-ray detector 2. Has been. The X-ray optical axis L is set so as to intersect with the rotation axis RA at one point (C point).

  The XY mechanism 7 has a sample table in the X and Y directions, which are two directions orthogonal to the rotation axis RA, so that a desired examination area of the subject 4 is positioned in the imaging area centered on the point C on the rotation axis RA. Used to move 6.

  The rotation mechanism 8 is used for rotating the subject 4 along the table surface 6a during tomography.

  The xz mechanism 9 is used for setting the inspection magnification (magnification ratio) and so-called visual field deviation correction for preventing the inspection area from deviating from the imaging area centered on the point C when the lamino angle (inclination angle) α changes. used.

  Each mechanism 7, 8, 9 is supplied with electric power from the mechanism control unit 13 and is controlled for positioning based on a control command. That is, the mechanism control unit 13 sends a control command to the required mechanism 7 (or 8, 9), receives position data as a control result from an encoder (not shown) attached to the mechanism 7, Control to set to the position to be.

  An X-ray control unit 14 is connected to the X-ray tube 1. The X-ray control unit 14 controls the X-ray tube 1 so as to obtain a tube voltage and a tube current that satisfy desired X-ray conditions.

  A data processing unit 15 includes a computer. The data processing unit 15 is externally provided with an input unit 16 such as a keyboard and a mouse, a display unit 17 and a storage device 18, and further includes an X-ray detector 2, a mechanism control unit 13, and an X-ray control unit 14. Connected, the detection output of the X-ray detector 2 is fetched, various control commands are transmitted, and other various control processes described later are executed. A storage device 18 may be provided inside the data processing unit 15.

  That is, the data processing unit 15 is provided with an imaging control unit 15a, a reconstruction unit 15b, and a display control unit 15c in terms of software.

  The imaging control unit 15a is a function for executing a series of sequence programs for performing tomographic imaging of the subject 4 under desired tomographic imaging conditions. Here, tomography is X-ray transmission data (transmission image) transmitted from the subject 4 at each rotation position at a constant angle rotation over one rotation with a lamino angle α set under tomography conditions. It is imaging | photography detected with the line detector 2. FIG.

  The reconstruction unit 15b has a function of creating a tomographic image of the subject 4 using transmission data (transmission image) collected by tomography. The transmission data (transmission image) collected by the imaging control unit 15a and the tomographic image created by the reconstruction unit 15b are divided into regions in the storage device 18 and stored.

  The display control unit 15 c has a function of selectively reading transmission data (transmission image) and tomographic image from the storage device 18 and displaying them on the display unit 17.

  In addition, although not shown in FIG. 1, components for supporting the X-ray tube 1, the xz mechanism 9, the detector moving mechanism 11, and the like, a housing for shielding X-rays, and the like are provided.

  Next, the operation of the tomography apparatus configured as described above will be described with reference to FIG. FIG. 2 is a diagram showing a series of processing flows for the whole tomography in the first embodiment.

  First, in step S1, tomography conditions are set prior to tomography. The tomographic conditions include tomographic X-ray conditions such as tube voltage and tube current of the X-ray tube 1, and tomographic geometric conditions such as the lamino angle α and the imaging position (including magnification) in the subject 4, There are a rotational speed, the number J of transmission images to be acquired during one rotation, and other necessary conditions.

  In step S1, specifically, after the subject 4 is placed on the sample table 6, when the operator inputs the X-ray condition and the geometric condition from the input unit 16, the imaging control unit 15a performs the X-ray condition and the geometric condition. A tomographic condition setting operation is performed in accordance with the condition input instruction.

  In other words, when receiving the X-ray condition input from the input unit 16, the imaging control unit 15 a sets X-ray conditions such as tube voltage and tube current to the X-ray tube 1 via the X-ray control unit 14. As the X-ray condition, a tube voltage and a tube current are set such that the transmitted image is not too dark or has no saturated portion.

  In addition, when the imaging control unit 15a receives a geometric condition input from the input unit 16, the imaging control unit 15a sets the geometric condition. That is, the imaging control unit 15a sends a control command to the mechanism control unit 13 according to the input geometric condition, moves the detector moving mechanism 11 in the xd direction, and sets the predetermined lamino angle α. Subsequently, the imaging control unit 15 a outputs a movement control command via the mechanism control unit 13, moves the imaging position (inspection area) on the rotation axis RA by the XY mechanism 7, and further passes through the xz mechanism 9 to be predetermined. The field of view is adjusted so that the center of the photographing position is aligned with point C.

  After the imaging control unit 15a sets the tomographic conditions as described above, the set tomographic conditions are given a file name (A) such as SAMPLE-A.cnd, as shown in FIG. Thus, the data is stored in the predetermined area 18a of the storage device 18. Here, SAMPLE-A is a name (tomographic identification name) for identifying the current tomography (subject and its tomography conditions) input from the input unit 16 by the operator, and .cnd is an extension indicating the data format. is there.

  Next, when the operator inputs a tomography start instruction from the input unit 16 under the set tomography conditions, the imaging control unit 15 performs tomography in the following step S2.

  In step S2, the imaging control unit 15 sends a rotation control command to the rotation mechanism 8 and normally transmits the subject 4 from the subject 4 at a constant rotation angle Δφ over one rotation while rotating the subject 4 with respect to the rotation axis RA. The transmitted transmission data (transmission image) is detected by the X-ray detector 2, and the transmission data is stored in a predetermined area 18 a of the storage device 18. In the case of half scan, over scan, helical scan, etc., it is not one rotation.

  FIG. 4 is a diagram showing the structure 4a in the examination region of the subject 4 as viewed from the rotation axis RA direction (z-axis direction) at the rotation angle φ of the subject 4 at the time of tomography in step S2. Here, the structure 4a has a structure in which another material 22 is embedded in one material 21, for example.

  In the same figure, p and q indicate two directions which are fixed to the subject 4 and which are orthogonal to each other in the rotation plane. Here, p and q are determined to coincide with the X direction and the Y direction, respectively, when the rotation angle φ = 0 °. 4A shows the rotation angle φ = 0 ° of the subject 4, FIG. 4B shows the rotation angle φ = 30 ° of the subject 4, and FIG. 4C shows the rotation angle φ = 270 ° of the subject 4. The direction of p and q is shown. In tomography, for example, when transmission images are detected every 1 ° (Δφ = 1 °) from a rotation angle of 0 ° to 359 °, 360 transmission images (the number of images to be taken J = 360) are collected.

  Therefore, the transmission image collected here is given a file name (b) such as SAMPLE-Aj.obl and stored in a predetermined area 18 a of the storage device 18. Here, SAMPLE-A is a name for identifying tomography, and is the same as the file name (A) described above. This represents tomography under the same subject 4 and the same tomography conditions. j is the view number (number indicating the rotation angle order) of the collected transmission images (transmission image number). For example, the rotation images are rotated from 0 ° to 359 ° and the transmission images are collected every 1 °. Then, it means a number (for example, integers 0, 1, 2,..., 359) indicating what number (order number) in the total number 360. Therefore, the view number j increases sequentially as the transmission images are collected. .Obl is an extension representing the data format of the collected transmission image.

  After storing the transmission image collected under the file name SAMPLE-Aj.obl as described above, a tomographic image is subsequently created by reconstruction processing in the reconstruction unit 15b (step S3).

  In step S3, when the operator inputs reconstruction conditions such as a reconstruction area, a voxel size, the number of matrices, and a filter function from the input unit 16, the reconstruction unit 15b, for example, uses the reconstruction conditions and the tomography conditions (SAMPLE described above). -A.cnd (A)) and a tomographic image condition are created, and for example, a file name (C) such as SAMPLE-A.inf is given and stored in a predetermined area 18a of the storage device 18. Here, SAMPLE-A is a name for identifying tomography, and .inf is an extension representing a data format of tomographic image conditions.

  The reconstruction unit 15b is based on SAMPLE-Aj.obl (j = 0 to J-1), which is a file name of transmission data (transmission image) obtained by the X-ray detector 2 at a constant rotation angle over one rotation. Then, transmission data (transmission image) is read, and a tomographic image is reconstructed.

  A conventionally known method is adopted as the reconstruction method. For example, as described in Patent Document 1, reconstruction is performed using filtering and back projection. Here, the filtering is performed by so-called frequency weight data | ω | in a direction orthogonal to the direction of the rotation axis projected on the transmission image. Then, a tomographic image of the subject 4 is obtained by back projection. Three-dimensional data can be obtained by continuously reconstructing a plurality of (K) tomographic images.

  The reconstruction unit 15b assigns a file name (d) such as SAMPLE-Ak.img to the tomographic image obtained by the reconstruction process, and sequentially stores it in the predetermined area 18a of the storage device 18. Here, SAMPLE-A is a name for identifying tomography, and is the same as the file names (A) and (B) described above. k is a tomographic image number attached in order from the end, and is represented by an integer from 0 to (K-1). .img is an extension indicating the data format of the tomographic image.

  Next, the display control unit 15c performs display control for displaying the tomographic image and the transmission image side by side on the display screen of the display unit 17 from the viewpoint of grasping the entire image of the examination region of the subject 4 (step S4). .

  In step S4, the display control unit 15c reconstructs the tomographic image so that the horizontal direction of the tomographic image SAMPLE-Ak.img to be displayed and the horizontal direction of the transmitted image to be displayed are the same direction with respect to the subject 4. One transmission image to be displayed is selected from the plurality of transmission images SAMPLE-Aj.obl (j = 0 to J-1) used.

Here, selection of a transmission image to be displayed will be described with reference to FIG.
Now, it is assumed that the transmission image is collected in such a direction that the left direction is the Y direction when viewed from the X-ray focal point F. Therefore, when reconstructing a tomographic image in which the p direction of the subject 4 is to the right, if a transmission image at a rotation angle φ = 270 ° is selected, the right direction of the transmission image is the p direction of the subject 4. 4C, it can be understood from FIG. 4C that the left and right directions of the tomographic image and the transmission image are the same p direction with respect to the subject 4. This transmission image is a transmission image of SAMPLE-Aj.obl (j = 270).

If the number of transmission images taken during 360 ° rotation is not 360 but generally J,
j = J · 270/360 (1)
The jth transmission image calculated by the following formula is selected. Note that the rotation angle of the transmission image to be selected is not generally 270 °, but varies depending on how to set the rotation start point and the orientation of the cross-sectional image at the time of reconstruction. Change.

  The display control unit 15c selects the jth SAMPLE-Aj.obl transmission image from Equation (1), and copies it as a display transmission image with another file name SAMPLE-A.bmp (e). Is stored in a predetermined area 18a of the storage device 18.

  Further, the display control unit 15c displays the selected transmission image on one screen side by side with one of the tomographic images reconstructed by reducing the selected transmission image, for example, the tomographic image of SAMPLE-A0.img. At this time, as the reduction processing, for example, the vertical and horizontal matrix numbers are reduced to 1/2 by thinning out every other vertical or horizontal matrix, or (N-1) vertical and horizontal matrices are thinned out every N columns in both vertical and horizontal directions. The numbers can also be 1 / N, respectively.

  FIG. 5 shows a display example in which the tomographic image 23 and the transmission image 24 are displayed side by side on the display screen 17 a of the display unit 17.

  As is clear from FIG. 5, in the tomographic image 23 and the transmission image 24, the horizontal direction is the p direction with respect to the subject 4 (the right side is the positive direction of p) throughout the image. Incidentally, the vertical direction of the tomographic image 23 and the transmitted image 24 displayed here do not exactly match. This is because the tomographic image 23 has the q direction in the vertical direction over the entire image, whereas the q direction of the transmission image 24 is in the vertical direction near the center (projection position of the rotation axis RA). This is because in the vicinity, the perspective is shifted from the vertical direction.

  In the operation area 25 excluding the image display area of the display screen 17a, operation buttons (not shown) for the operator to perform a desired processing instruction are displayed.

  Therefore, the operator can click a required operation button with the mouse serving as the input unit 16 or input a predetermined instruction from the keyboard serving as the input unit 16 to execute a desired process. For example, a tomographic image number is input, the corresponding tomographic image 23 is read from the storage device 18 and displayed on the display screen 17a, and a part of the displayed tomographic image is changed or a tomographic image is turned over. Thus, a plurality of tomographic images can be displayed continuously. It is also possible to change the brightness and contrast of the tomographic image.

  After a series of processing from tomography to tomographic image display is performed through the series of processing steps S1 to S4 as described above, the processing ends according to an end instruction from the input unit 16. Therefore, the files at this time are tomographic conditions (SAMPLE-A.cnd), collected transmission images (SAMPLE-Aj.obl) (j = 0 to J-1), tomographic conditions (SAMPLE-A.cnd). inf), a tomographic image (SAMPLE-Ak.img) (k = 0 to K-1), and a selected transmission image (SAMPLE-A.bmp) are stored in a predetermined area 18 a of the storage device 18.

  Among these files, the tomography conditions and the collected transmission images are automatically deleted, for example, at the next tomography or when the storage capacity is reduced, but other files are deleted unless the operator deletes them. It is remembered permanently.

  By the way, the tomographic apparatus of the present invention can display a tomographic image taken in the past separately from the series of processes shown in FIG. The display screen at this time is the same as in FIG. Specifically, the operator inputs a file read instruction from the input unit 16, displays a list of file names photographed in the past in the operation area 25, and selects a desired file name from the list to obtain a desired file name. The tomographic image 23 is displayed. At this time, the display control unit 15c searches for the corresponding file name, selects the transmission image 24 corresponding to the selected tomographic image, and displays it side by side with the tomographic image.

  Further, the operator selects the transmission image file name (SAMPLE-A.bmp) to display the transmission image 24 and, for example, the first tomographic image 23 (SAMPLE-A0.img) on the display screen 17a. Can do. At this time, the display control unit 15c searches for a file name and selects a tomographic image.

  When the operator displays a plurality of reduced transmission images side by side, and selects an observation target from the transmission images, the display control unit 15c arranges the selected transmission images and, for example, the corresponding top sectional images. indicate.

  Therefore, according to the embodiment as described above, when a tomographic image of the subject 4 is displayed, a transmission image obtained by seeing the subject 4 obliquely from above is automatically selected and displayed together on one display screen 17a. Therefore, it is possible to easily grasp the entire image of the imaging region of the subject 4 while observing the tomographic image and the transmission image.

  Further, according to the above-described embodiment, the tomographic image and the transmission image displayed together on the display screen 17a have the same p direction with respect to the subject 4 (the right side is the positive direction of p). The correspondence between images and transmitted images can be grasped intuitively.

  In addition, according to the above embodiment, necessary data and images are stored in association with each other under the file name, so that when a tomographic image is displayed in the past, the tomographic image is automatically displayed. A transmission image obtained by seeing through the specimen 4 obliquely from the upper side can be displayed together on one display screen 17a, and a troublesome operation as in the prior art can be omitted.

  Conversely, if a transmission image is selected, the corresponding tomographic images can be displayed side by side along with the transmission image, so that troublesome operations can be omitted.

  Further, according to the above embodiment, when displaying a tomographic image by selecting from a number of past tomographic images (subject and its tomographic conditions), a plurality of transmission images (**. Bmp) are displayed side by side. The corresponding tomogram can be displayed by selecting one from the selected state, so that the tomogram can be selected while grasping the entire imaging region of the subject 4, so the tomogram can be selected while observing sequentially. Compared to this, a desired tomographic image can be selected quickly.

  In addition, since a transmission image selected from a plurality of transmission images (that is, transmission images collected by tomography) used for reconstruction of a tomographic image is displayed, there is no need to separately perform a transmission image for display. Further, since the selected transmission images are simply reduced and displayed side by side, data processing is also simple.

(Modification of the first embodiment)
(1) In the first embodiment, the tomographic image and the transmission image are displayed side by side so as not to overlap. For example, as shown in FIG. The entire transmission image 24 (SAMPLE-A.bmp) may be displayed in an overlapping manner, or a part of the selected transmission image (SAMPLE-A.bmp) may be part of the tomographic image (SAMPLE-Ak.img) You may display so that it may overlap. In this case, a predetermined selection switching touch button (not shown) in the operation area 25 is touched to switch between display / non-display of the transmission image.

(2) In the first embodiment, only the extension “.bmp” is used as a commonly used file format, and the other files are special file formats. However, other file formats may be used. For example, .bmp may be a commonly used .jpg or .tif. In the present invention, the file format is not particularly limited.

(3) Further, the method of creating the file is not limited to the first embodiment. As an example,
B. Transmission image file (SAMPLE-A.obm): {= Tomography condition (SAMPLE-A.cnd) + Collected transmission image (SAMPLE-Aj.obl) (j = 0 to J-1)} ,
B. Tomographic image file (SAMPLE-Ak.imh) (k = 0 to K-1): {= tomographic image condition (SAMPLE-A.inf) + tomographic image (SAMPLE-Ak.img)} (k = 0 to K-1)} or K pieces,
C. Selected transmission image (SAMPLE-A.bmq): {= Tomographic image condition (SAMPLE-A.inf) + Selected transmission image (SAMPLE-A.bmp)} It becomes a file, and can be stored with a smaller number of files than in FIG. In this case, since the collected transmission image becomes one file, instead of selecting from the file name to select the jth transmission image, the start address of the jth transmission image determined in advance by the file format is used. To select a transmission image.

(4) In the first embodiment, “(SAMPLE-A)” representing the same tomographic image is attached to the file name, thereby associating the selected transmission image or the transmission image to be displayed with the corresponding tomographic image. However, the association method is not limited to this. For example, tomographic conditions and tomographic images can be stored in the same holder, or filed together.

(5) In the first embodiment, the selected transmission image is stored as it is, but may be stored after, for example, reduction processing (“storage of displayed transmission image” in claim 4). In this case, the stored transmission image can be displayed as it is.

(6) The display control unit 15c in the first embodiment selects one transmission image so that the left-right direction is the same as the tomographic image, but instead of making such a selection, the tomographic image A plurality of transmission images SAMPLE-Aj.obl (j = 0 to J-1) used for reconstruction can be selected sequentially, in the order of acquisition, or in the reverse order. At this time, if the selected transmission image is displayed while being reduced in sequence without being stored and the display is updated, the transmission image can be displayed as a moving image side by side with the tomographic image. Rotated to be With such a rotating moving image display, the entire image of the imaging region of the subject 4 can be grasped better.

  In such a transmission image selection display, for example, if the selection is made by thinning out every other or every other image, the rotational speed of the rotating moving image display can be flexibly adjusted.

(7) About the said modification (6), a deformation | transformation is also considered as follows. For example, the acquired transmission image SAMPLE-Aj.obl (j = 0 to J-1) is sequentially reduced while being selected in the order of acquisition or in reverse order, and the transmission image SAMPLE-Aj.bmp for moving image display (j = 0 to J-1) may be stored and the moving image display transmission image may be displayed.

  According to this modification, even after the collected transmission image SAMPLE-Aj.obl is deleted, the moving image display transmission image SAMPLE-Aj.bmp (j = 0 to J-1) is used to display the display unit. The moving image can be displayed in FIG. 17, and since the video has already been reduced when the moving image is displayed, the moving image can be displayed without reduction processing.

  Such a rotating moving image display makes it possible to better understand the entire image of the imaging region of the subject 4.

  In this modified example, if the transmission images collected as described above are selected by thinning out every other or every other two images, the rotational speed of rotating moving image display can be adjusted and the storage capacity can be reduced. it can.

(8) In the first embodiment, X-rays are used as radiation, but other transmissive radiation may be used.

(9) In the first embodiment, the tomography is performed by rotating the subject 4, but other movements may be used as long as the X-ray beam 5 and the subject 4 move relatively the same.

  That is, any movement that rotates the subject 4 and the X-ray beam 5 relative to the rotation axis RA that intersects the X-ray optical axis L at an angle of 90 ° or less is sufficient. In other words, as long as the movement of the circular orbit type tomography apparatus in which the radiation irradiation direction changes along the cone when viewed from the subject 4 side, any movement may be employed. .

FIG. 7 is a diagram illustrating a tomographic movement according to the modification (9).
For example, FIG. 7A may be a movement that rotates around the rotation axis RA while maintaining the X-ray focal point F and the X-ray detector 2 in an integrated state (FIG. 7A). Further, the X-ray detector 2 may be fixed, and the X-ray focal point F may move so that only the X-ray focal point F rotates about the rotation axis RA (FIG. 7B), and the movement of FIG. On the other hand, the movement may be such that the subject 4 revolves around the rotation axis RA (FIG. 7C).

  Further, the X-ray focal point F is fixed, the subject surface 4a is rotated around the rotational axis RA while the table surface 6a is orthogonal to the rotational axis RA passing through the X-ray focal point F, and the subject 4 is transmitted. Similarly, the X-ray detector 2 that detects the X-ray beam 5 may be moved around the rotation axis RA (FIG. 7D).

  Alternatively, the X-ray detector 2 may be fixed while maintaining the movement shown in FIG. 7D (FIG. 7E).

In addition, the X-ray tube 1 and the X-ray detector 2 are fixed, and in the X-ray beam 5, while precessing so that the normal 6b of the table surface 6a moves on the conical surface with respect to the sample table 6, The configuration may be such that the subject 4 on the sample table 6 is imaged (FIG. 7 (f)).
(10) In the first embodiment, one data processing unit 15 is configured to perform tomography, reconstruction processing, and tomographic image display, but may be configured to perform shared processing by a plurality of data processing units. . For example, a first data processing unit that performs processing up to tomography, a tomography condition (SAMPLE-A.cnd) and a transmission image (SAMPLE-Aj.obl) (j = 0 to J-1), and may be divided into a second data processing unit that performs processing from reconstruction processing to display. At this time, data transmission between the two data processing units can use a dedicated wiring or a LAN. It is also possible to exchange data using a medium such as a DVD.

(11) In addition, the tomographic image condition (SAMPLE-A.inf), the tomographic image (SAMPLE-Ak.img) and the selected transmission image (SAMPLE-A.bmp) obtained in the first embodiment are Although it is stored in the storage device 18 of the apparatus and displayed, it may be transmitted to another personal computer via, for example, a LAN or DVD, and displayed on the personal computer. However, at this time, the other personal computer needs to have a display control function corresponding to the display control unit 15c of the first embodiment.

(12) Furthermore, the display control unit 15c in the first embodiment displays the left and right directions of the tomographic image and the left and right directions of the transmission image so as to be the same p direction with respect to the subject 4 as shown in FIG. However, for example, the display may be such that the vertical direction of the tomographic image and the vertical direction of the transmission image are the same p direction with respect to the subject 4. In this case, for example, the tomographic image 23 and the transmission image 24 shown in FIG.

(13) The image reduction referred to in the present invention is to reduce the number of image matrices. In the first embodiment, the transparent image is reduced by thinning, but the reduction is not limited to this. For example, the number of vertical and horizontal matrices may be reduced to 1 / N by averaging by N rows in both vertical and horizontal directions. Moreover, it can also be converted into an arbitrary number of matrices by interpolation calculation.

(14) In the first embodiment, the reconstructed tomographic image, the transmission image selected and displayed, and the collected transmission image are stored without compression processing, but may be stored after compression processing. Good. The compression process is a well-known process, can be stored with a reduced amount of data, and can be used by returning to the original data in the return process when reading the data.

  In addition, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS The conceptual block diagram explaining 1st embodiment of the tomography apparatus which concerns on this invention. The flowchart which shows a series of processing procedures of the whole tomography in the tomography apparatus which concerns on this invention. The figure which shows the example of preservation | save by the file name of the data relevant to tomography, and an image. The figure explaining rotation of the subject at the time of tomography. The figure which shows an example of the display screen which displayed the tomogram and the transmission image together. The figure which shows the other example of the display screen which displayed the tomogram and the transmission image together. FIG. 3 is an exemplary diagram for explaining the relative movement of an X-ray focal point, a subject, and an X-ray detector during tomography.

Explanation of symbols

  1 ... X-ray tube, 2 ... X-ray detector. 2a ... detection surface, 3 ... X-ray beam, 4 ... subject, 4a ... structure in the examination area of the subject, 5 ... partial X-ray beam to be detected, 6 ... sample table, 7 ... XY mechanism, 8 Rotating mechanism, 9 ... xz mechanism, 10 ... detector tilting surface, 11 ... detector moving mechanism, 13 ... mechanism control unit, 14 ... X-ray control unit, 15 ... data processing unit, 15a ... imaging control unit, 15b ... Reconstruction unit, 15c ... display control unit, 16 ... input unit, 17 ... display unit, 17a ... display screen, 18 ... storage device, 23 ... tomographic image, 24 ... transmission image, 25 ... operation region, F ... X-ray focus , L: X-ray optical axis, RA: rotational axis, α: lamino angle.

Claims (4)

A table on which the subject is placed; a radiation source that irradiates the subject with radiation; a radiation detector that detects radiation transmitted through the subject with a two-dimensional detection channel; and a radiation optical axis of the radiation source; In a tomography apparatus having a rotation means for rotating the subject and the radiation relative to a rotation axis intersecting at an angle of 90 ° or less,
Imaging control means for sequentially collecting transmission images as outputs of the radiation detector for each predetermined rotation angle position while being rotated by the rotation means;
Reconstructing means for reconstructing a tomographic image of the subject from a plurality of transmission images collected by the imaging control means;
At least one transmission image is selected from the plurality of transmission images used for reconstruction of the tomographic image, and the selected transmission image is reduced and displayed side by side with the reconstructed tomographic image on one display screen. Display control means ,
When the display control unit selects one transmission image from the plurality of transmission images, the horizontal direction or vertical direction of the tomographic image to be displayed and the horizontal direction or vertical direction of the transmission image to be displayed are determined on the subject. A tomographic apparatus, wherein the one transmission image is selected so as to be in the same direction . The tomography apparatus according to claim 1,
When selecting two or more transmission images from the plurality of transmission images , the display control unit selects the transmission images to be displayed one after another based on the order collected from the plurality of transmission images, and displays the transmission images to be displayed. The tomographic apparatus is characterized in that a rotation moving image display of a transmission image is realized on the display screen by successively updating. The tomography apparatus according to claim 1 or 2 ,
The tomography apparatus, wherein the display control means stores and stores the selected transmission image or the displayed transmission image in association with the tomographic image to be displayed. The tomography apparatus according to claim 3 .
The tomography apparatus, wherein the display control means stores and saves the selected transmission image or the displayed transmission image and the tomographic image to be displayed with a file name including the same tomographic identification name.

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