JP2007105221A - X-ray computed tomography apparatus and image processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus and an image processor, wherein data of a top plate which are not required in three-dimensional image data can be removed simply. <P>SOLUTION: The X-ray CT apparatus is provided with: a rack part 1 for photographing a patient P on the top plate 9 to collect X-ray projection data; a reconstitution processing part 4 for reconstituting the X-ray projection data to generate tomogram data; a data processing part 5 for generating the three-dimensional image data from the tomogram data in a photographing range; and a display part 6 for displaying the three-dimensional image data. The data processing part 5 searches a top plate area from patient data constituting the tomogram data and a side opposite to the patient data of the top plate data formed superposed on the patient data toward the side of the patient data, detects pixel data contained in the CT value range of the top plate 9, thereafter extracts pixel data connected to the pixel data and included in the CT area to prepare area data, and generates the three-dimensional image data from which the top plate data are removed based on the area data. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an X-ray CT apparatus and an image processing apparatus used for X-ray diagnosis, and more particularly to an X-ray CT apparatus and an image processing apparatus that generate three-dimensional image data.

  The X-ray CT apparatus includes an imaging unit for imaging a subject, a top plate for placing the subject for imaging and moving the imaging unit to the imaging unit.

  The imaging unit is disposed opposite to the X-ray generation unit that irradiates the subject with X-rays via the subject and the top plate, and is irradiated with the X-ray generation unit to irradiate the subject. An X-ray detection unit that detects transmitted X-rays, and a holding unit that rotatably holds the X-ray generation unit and the X-ray detection unit. The rotation of the holding unit and the movement of the top plate can be used from various directions of the subject. It is possible to shoot.

  The X-ray CT apparatus also generates a three-dimensional image data from a plurality of tomographic images, a reconstruction unit that reconstructs X-ray projection data generated by imaging from various directions by the imaging unit into tomographic image data. A data processing unit, a display unit for displaying three-dimensional image data, and an operation unit for operating the X-ray CT apparatus are provided.

  By the way, the 3D image data generated in the data processing unit includes the top plate data that obstructs the interpretation of the subject data when a doctor or the like makes a diagnosis. Work to remove data etc. is performed.

  This top plate data removing operation includes an operation for setting a CT value range of the top plate in advance, an operation for displaying 3D image data on the display unit, and an operation for selecting the top plate data by viewing the 3D image data. The operation unit is manually operated in the order of the operation of extracting the area of the top plate data, the deletion of the extracted top plate data, or the non-display operation by the mask process.

  However, the operation of removing unnecessary top plate data for diagnosis requires many operations while viewing the three-dimensional image data displayed on the display unit, and must be performed manually, which requires time and effort. There is. Also, if the image processing is stopped and reset in the middle of the image processing operation of the 3D image data performed after removing the top plate data, the removed top plate data is also reset to the 3D image data including the top plate data. There is a problem of going back.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an X-ray CT apparatus and an image processing apparatus that can easily remove unnecessary top plate data from three-dimensional image data. To do.

  In order to solve the above problem, an X-ray CT apparatus of the present invention according to claim 1 is directed to a top plate on which a subject is placed, and the subject is irradiated with X-rays. X-ray imaging means for detecting transmitted X-rays to generate X-ray projection data, reconstructing means for reconstructing X-ray projection data generated by the X-ray imaging means to generate image data, Based on the CT value range of the top plate stored from the storage means, the storage means for storing the CT value range of the top plate, and the CT value range of the top plate from the image data generated by the reconstruction means Image data processing means for generating three-dimensional image data excluding pixel data included, and display means for displaying the three-dimensional image data generated by the image data processing means are provided.

  According to a sixth aspect of the present invention, there is provided an image processing apparatus according to the present invention, comprising: storage means for storing a CT value range of a top plate on which a subject is placed; and first tomographic image data in the imaging range of the subject. Search the top plate area from the object data side to the object data side of the object data and the object data side of the table data formed to overlap the object data, and store the data Search means for detecting pixel data included in the CT value range of the top plate stored by the means, and pixel data included in the top plate CT value range connected to the pixel data detected by the search means. Extraction means for extracting and creating area data representing the area of the extracted pixel data, and 3D image data excluding the top plate data of the imaging range based on the area data created by the extraction means And image data processing means for forming, characterized by comprising a display means for displaying the 3-dimensional image data generated by the image data processing means.

  According to the present invention, three-dimensional image data excluding unnecessary top plate data can be easily generated, so that it is possible to perform image diagnosis quickly without taking time and effort. Even if the image processing operation is stopped and reset during the image processing operation of the 3D image data after removing the top plate data, the 3D image data excluding the top plate data can be easily generated in the subsequent operation. As a result, image processing can be performed with peace of mind.

  Embodiments of the present invention will be described below with reference to the drawings.

  An embodiment of an X-ray CT apparatus according to the present invention will be described with reference to FIGS.

  FIG. 1 is a block diagram showing a configuration of a multi-slice X-ray CT apparatus as an X-ray CT apparatus according to Embodiment 1 of the present invention. It is also applicable to a single slice X-ray CT apparatus.

  The X-ray CT apparatus 10 is necessary for the top plate 9 on which the subject P is placed, the gantry unit 1 that generates X-ray projection data by X-ray imaging of the subject P, and X-ray irradiation in the gantry unit 1 A high voltage generator 2 for supplying a large amount of power, a mechanism 3 for moving the top plate 9, and a reconstruction processor 4 for generating first tomographic image data from the X-ray projection data output from the gantry 1 And.

  The X-ray CT apparatus 10 also outputs a data processing unit 5 that processes a plurality of first tomographic image data output from the reconstruction processing unit 4 and generates three-dimensional image data, and is output from the data processing unit 5. A display unit 6 for displaying three-dimensional image data, and other units such as an operation unit 7 for selecting and inputting various conditions such as subject information, imaging conditions, and display conditions of the subject P, and inputting various commands. And a system control unit 8 that controls the respective units of the X-ray CT apparatus 10 in an integrated manner.

  The gantry 1 includes a substantially cylindrical opening 14 into which the subject P on the top 9 is inserted, an X-ray generation unit 11 that irradiates the subject P with X-rays, and an X-ray through the subject P. An X-ray detector 12 that is arranged opposite to the generator 11 and detects X-rays to generate X-ray projection data, and a data collector 13 that collects X-ray projection data output from the X-ray detector 12 A rotation ring 15 that rotatably holds the X-ray generation unit 11, the X-ray detection unit 12, and the data collection unit 13 on the outer periphery of the opening 14, and a rotation mechanism control unit that drives and controls the rotation ring 15. 16.

  The X-ray generation unit 11 includes an X-ray tube, and forms an X-ray beam extending from an X-ray source in a slice direction parallel to the rotation center axis of the rotary ring 15 and a channel direction orthogonal to the slice direction. X-rays are irradiated to the subject P and the top plate 9 arranged so as to substantially coincide with the rotation center axis of the rotation ring 15.

  Although not shown, the X-ray detector 12 has X-ray detection elements arranged in a matrix of A in the slice direction (column direction) and B in the channel direction (row direction). X-rays transmitted through the subject P and the top plate 9 are detected by X-ray irradiation from the X-ray generation unit 11 and then added for each column in the slice direction to generate two-dimensional X-ray projection data. X-ray detection by the X-ray detection unit 12 is performed every predetermined angle of rotation of the rotating ring 15. For example, when it is repeated 1000 times during 1 rotation / second, X-ray projections corresponding to A × B are performed. Data is generated 1000 times / second and output to the data collection unit 13.

  The data collection unit 13 includes data collection elements corresponding to the X-ray detection elements in the a column and the B row in the channel direction, which are fewer than the A column in the slice direction in the X-ray detection element of the X-ray detection unit 12. The X-ray projection data output from the line detector 12 is subjected to processing such as amplification and A / D conversion for each X-ray detection element, and X-ray projection data for a slice of the subject P and the top 9 is collected. .

  The high voltage generator 2 generates a high voltage to be supplied to the X-ray generator 11 and the tube current, tube voltage, and irradiation in the high voltage generator 32 in accordance with an instruction signal from the system controller 8. And an X-ray control unit 21 that controls X-ray irradiation conditions such as time.

  The mechanism unit 3 includes a top plate moving mechanism 31 that horizontally moves the top plate 9 in a vertical direction and a longitudinal direction that is an insertion direction of the gantry unit 1 into the opening 14, and a top plate mechanism that controls the top plate moving mechanism 31. And a control unit 32.

  The reconstruction processing unit 4 stores the X-ray projection data output from the data collection unit 13 of the gantry 1 and performs reconstruction processing on the X-ray projection data stored in the storage unit 41. And a reconstruction unit 42 for generating one tomographic image data.

  The storage unit 41 temporarily stores the X-ray projection data output from the data collection unit 13 of the gantry unit 1 and then outputs it to the reconstruction unit 42. Further, the first tomographic image data which is the two-dimensional image data output from the reconstruction unit 42 is stored and output to the data processing unit 5.

  The reconstruction unit 42 performs imaging for a row slices from X-ray projection data of a predetermined rotation such as one rotation (360 degrees) at a desired position of the subject P, 180 degrees + X-ray irradiation angle, and the like. First tomographic image data, which is two-dimensional image data of an a × b slice (imaging range) reconstructed from b-fold X-ray projection data of a predetermined rotation that matches the range, is generated in the storage unit 41. Output.

  The data processing unit 5 includes a top panel area detection unit 51 that generates area data from the first tomographic image data output from the storage unit 41 of the reconstruction processing unit 4, and an area output from the top panel area detection unit 51. And an image data processing unit 52 that generates three-dimensional image data based on the data.

  The top plate area detecting unit 51 searches the pixel data in the range including the preset CT value of the top plate 9 from the first tomographic image data, and the pixel data detected by the searching unit 53. And an extraction unit 54 that extracts region data by extracting pixel data to be connected from the first tomographic image data.

  The CT value is a value in which the X-ray absorption coefficient of the substance is expressed as a relative value from the reference substance. In general, it is expressed as a relative value where water as a reference substance is 0, and air is expressed as -1000. The minimum unit pixel data constituting the two-dimensional image data and the minimum unit voxel data constituting the three-dimensional image data are represented by CT values.

  The image data processing unit 52 generates second tomographic image data by replacing the pixel data of the first tomographic image data corresponding to the region data output from the top plate region detecting unit 51 with a preset replacement value. Based on the second tomographic image data of the imaging range output from the replacing unit 55 and the tomographic image output from the replacing unit 55, for example, generation of three-dimensional image data by volume rendering method, tomographic image data of an arbitrary cross section by image processing, arbitrary A three-dimensional image data processing unit 56 for generating projection image data from the direction, three-dimensional image data for emphasizing a specified range by a volume rendering method, and the like.

  The display unit 6 includes a monitor such as a liquid crystal panel or a CRT, and displays the 3D image data output from the data processing unit 5.

  The operation unit 7 is an interactive interface including an input device such as a keyboard, a trackball, a joystick, a mouse, a display panel, and various switches, and includes subject information such as the ID and name of the subject P, and imaging. Various settings such as body position, imaging target region (target organ), imaging range in the body axis direction of the subject P, and data processing conditions such as CT value range and replacement value, and various commands are input. .

  The system control unit 8 includes a CPU and a storage circuit (not shown), such as an operator command signal supplied from the operation unit 7, imaging conditions such as an imaging position, an imaging range, a CT value range of the top plate 9, a replacement value, and the like. After temporarily storing information such as data processing conditions, the entire system is controlled such as generation of X-ray projection data based on these information, generation and display of various three-dimensional image data, and control related to each mechanism.

  Next, the operation of the X-ray CT apparatus 10 according to the first embodiment will be described with reference to FIGS. 1 to 3. FIG. 2 is a flowchart showing a procedure for generating three-dimensional image data in the X-ray CT apparatus 10.

  First, the operator of the X-ray CT apparatus 10 inputs the examination information of the subject P such as the subject information of the subject P and various imaging conditions of the subject P from the operation unit 7, thereby the X-ray CT apparatus. 10 starts the inspection (step S1). In addition, by the CT value range and replacement value setting operation of the operation unit 7 in advance, the system control unit 8 causes the internal storage circuit to set, for example, -100 to 0 as the CT value range of the top plate 9, and the CT value of air as the replacement value. -1000 is stored.

  The system control unit 8 stores the examination information of the subject P in the internal storage circuit by setting the examination information of the subject P such as the subject information and the imaging conditions in the operation unit 7 (step S2).

  Next, the subject P is placed on the top board 9. Then, by the X-ray imaging start operation of the operation unit 7, the system control unit 8 causes the gantry unit 1, the high voltage generation unit 2, and the mechanism unit based on the examination information of the subject P stored in the internal storage circuit. 3. The X-ray imaging start operation is instructed to the reconstruction processing unit 4, the data processing unit 5, and the display unit 6 (step S3).

  The top plate mechanism control unit 32 of the mechanism unit 3 inserts the top plate 9 into the opening 14 of the gantry 1 by the top plate moving mechanism 31 and moves the subject P to the position of the imaging range of the subject P. . Thereafter, the X-ray control unit 22 of the high voltage generation unit 2 causes the high voltage generator 21 to supply the X-ray imaging power to the X-ray generation unit 11 of the gantry unit 1.

  The rotation mechanism control unit 16 of the gantry unit 1 rotates the rotation ring 15. The X-ray generator 11 irradiates the imaging range of the subject P with X-rays while rotating. The X-ray detection unit 12 detects X-rays transmitted through the imaging range of the subject P and the top plate 9, generates X-ray projection data, and outputs the X-ray projection data to the data collection unit 13. The data collection unit 13 collects the X-ray projection data output from the X-ray detection unit 12 and outputs it to the reconstruction processing unit 4 (step S4).

  The storage unit 41 of the reconstruction processing unit 4 temporarily stores the X-ray projection data output from the data collection unit 13 and outputs it to the reconstruction unit 42. The reconstruction unit 42 reconstructs the X-ray projection data output from the storage unit 41 into first tomographic image data, attaches examination information of the subject P, and outputs it to the storage unit 41 (step S5). The storage unit 41 stores the first tomographic image data output from the reconstruction unit 42 and outputs it to the data processing unit 5.

  The search unit 53 in the top plate area detection unit 51 of the data processing unit 5 searches for the first tomographic image data output from the reconstruction processing unit 4 based on the CT value range information of the top plate 9 in the system control unit 8. When pixel data included in the CT value range of the top 9 is detected from the pixel data constituting the first tomographic image data, the coordinate information of the pixel data is output to the extraction unit 54. (Step S6).

  FIG. 3A is a diagram for explaining an example of first tomogram data output from the reconstruction processing unit 4 and a search direction in which the search unit 53 searches for the first tomogram data. . The first tomographic image data 90 includes two-dimensional subject data 91 corresponding to the subject P, two-dimensional top plate data 92 corresponding to the top plate 9, and air data 93 corresponding to air. .

  Then, subject data 91 is formed in the vicinity of the center of the first tomographic image data 90, and top plate data 92 on which the subject 9 is placed is formed so as to overlap in the drawing of the subject data 91. Therefore, by searching from the position of the air data 93 below the top panel data 92 toward the top panel data 92 in the direction of the arrow L1, that is, from the counter object data side of the top panel data to the subject side. The search unit 53 can detect pixel data indicating the top plate data 92 region included in the CT value range of the top plate 9 having a different CT value from the CT value −1000 of the air data 93 region.

  As described above, the first tomographic image data 90 is arrangement data in which the subject data 91 is formed near the center and the top plate data 92 is formed below the subject data 91. The top plate data can be detected by searching upward from the vicinity of the center of the top.

  The extraction unit 54 starts from the pixel data of the coordinate information output from the search unit 53 based on the CT value range information of the top plate 9 of the system control unit 8, and connects to this pixel data in the CT value range of the top plate 9. After the pixel data of the area of the top plate data included is extracted from the first tomographic image data, the area data is created and output to the replacement unit 55 of the image data processing unit 52 (step S7 in FIG. 2).

  FIG. 3B is a diagram showing the top panel area data generated from the first tomographic image data 90 by the extraction unit 54. The area data 94 is data that is obtained by extracting the top panel data 92 from the first tomographic image data 90 and defining the top panel area 95, and is composed of data of the top panel area 95 and the area 96 other than the top panel. The data of the plate area 95 includes the coordinate information of the top plate data 92 of the first tomographic image data 90. Note that the data of the top plate area 95 may be created by performing a process of enlarging a predetermined range or reducing the data within the boundary region to the data of the region 96 other than the top plate outside the boundary region of this region.

  The replacement unit 55 of the image data processing unit 52 is based on the replacement value information of the system control unit 8 and the region data output from the extraction unit 54. Among the pixel data of the first tomographic image data, the top panel data 92 is displayed. The CT value of the pixel data composing the pixel data is replaced with the CT value of the air to generate the second tomographic image data 97 and output it to the three-dimensional image data processing unit 56 (step S8 in FIG. 2). The replacement value is not limited to the air CT value of −1000, and may be a CT value near the air.

  FIG. 3C replaces the area of the top plate data 92 of the first tomographic image data 90 of FIG. 3A based on the pixel data of the top area 95 of the area data 94 of FIG. 3B. The second tomographic image data generated by processing is shown. The second tomographic image data 97 includes subject data 91 and air data 93, and the top plate data 92 is removed from the first tomographic image data 90 by the replacement process.

  Next, when the generation of the second tomographic image data in the replacement unit 55 of the image data processing unit 52 is completed, the three-dimensional image data processing unit 56 outputs the second imaging range generated and output from the replacement unit 55. The tomographic image data is stored, and at the same time, three-dimensional image data is generated from the second tomographic image data in advance by, for example, volume rendering, and displayed on the display unit 6 (step S9).

  In this 3D image data, since the area of the top plate data 92 is replaced with the CT value of air, 3D image data of only the subject data 91 is displayed on the display unit 6.

  Next, when an image processing operation for emphasizing a specific part is performed from the operation unit 7 by, for example, a volume rendering method (Yes in step 10), the three-dimensional image data processing unit 56 performs image processing of the system control unit 8. In response to the instruction, three-dimensional image data for emphasizing the range specified by the image processing operation by the volume rendering method is generated and output to the display unit 6 (step S11). If no image processing operation is performed on the operation unit 7 (No in step S10), the process proceeds to step S13.

  Next, when all of the desired parts are not included in, for example, the emphasis range of the three-dimensional image data displayed on the display unit 6 by the image processing operation, that is, when the desired image data is not included, the operation unit 7 is reset (step (Yes in S12), the image processing operation is stopped, and the process returns to step S9. As described above, when the 3D image data subjected to the image processing is reset, 3D image data not including the top plate data can be easily generated from the second tomographic image data and displayed on the display unit 6. It is like that.

  If desired three-dimensional image data can be obtained by image processing operation and there is no reset operation (No in step S12), an inspection end operation is performed from the operation unit 7. Thereby, the system control unit 8 stops the operations of the gantry unit 1, the high voltage generation unit 2, the mechanism unit 3, the reconstruction processing unit 4, the data processing unit 5, and the display unit 6. Then, the X-ray CT apparatus 10 ends the inspection (Step S13).

  According to the first embodiment of the present invention described above, the search is performed based on the CT value of the top plate data from the first tomographic image data in which the top plate data is formed together with the subject data in the imaging range. The pixel data constituting the plate data is detected, and the top plate data in the first tomographic image data corresponding to the top plate region of the region data created based on the coordinate information of the pixel data is detected in the vicinity of the air By generating 3D image data from the second tomographic image data generated by substituting the CT value of the 3D image, 3D image data excluding the top plate data can be easily generated. It can be performed.

  Further, even if the image processing is stopped and reset during the image processing operation of the 3D image data after removing the top plate data, the 3D image data excluding the top plate data can be easily generated. It is possible to carry out the image processing operation of the three-dimensional image data.

A second embodiment of the X-ray CT apparatus according to the present invention will be described below with reference to FIG.
The second embodiment shown in FIG. 4 differs from the first embodiment in FIG. 1 in that the data processing unit 5 in FIG. This is the point of replacement. The configuration and operation of the image data processing unit 52a will be described. Since the configuration other than the image data processing unit 52a according to the second embodiment is the same as that of the first embodiment, the description thereof is omitted.

  The image data processing unit 52 a includes a 3D region data creation unit 57 that creates 3D region data from the region data output from the top plate region detection unit 51, and a 3D region output from the 3D region data creation unit 57. Based on the data, generation of 3D image data by volume rendering method, tomographic image data of an arbitrary section by image processing, projection image data from an arbitrary direction, 3D image data that emphasizes a specified range by volume rendering method, etc. And a three-dimensional image data processing unit 56a to be generated.

  The three-dimensional region data creation unit 57 creates three-dimensional region data from the region data in the imaging range output from the extraction unit 54 of the top plate region detection unit 51, and outputs it to the three-dimensional image data processing unit 56a.

  The three-dimensional image data processing unit 56 a generates three-dimensional image data from the first tomographic image data in the imaging range output from the storage unit 41 of the reconstruction processing unit 4, and then from the three-dimensional region data creation unit 57. Masked 3D image data that hides the region of the 3D image data corresponding to the output 3D region data is generated and output to the display unit 6.

  The display unit 6 displays the 3D image data output from the 3D image data processing unit 56a. Since this three-dimensional image data acts so that the area of the top plate data is hidden by the mask process, only the subject data is displayed on the display unit 6.

  Next, when there is an image processing operation on the operation unit 7, the 3D image data processing unit 56 a performs image processing on the 3D image data obtained by masking the top plate data in accordance with an image processing instruction from the system control unit 8. Is output to the display unit 6, and the display unit 6 displays the three-dimensional image data subjected to the image processing. If 3D image data subjected to desired image processing is not obtained by image processing and the image processing reset operation is performed by the operation unit 7, 3D image data obtained by masking the top plate data is generated again and displayed on the display unit 6. Output.

  According to the second embodiment of the present invention described above, the first tomographic image data in the imaging range is directed from the anti-subject data side to the subject data side of the top plate data formed by overlapping the subject data. By searching the top plate area, pixel data constituting the top plate data can be detected. Then, three-dimensional area data is created based on the coordinate information of the detected pixel data, and then the three-dimensional data generated from the first tomographic image data in the imaging range corresponding to the three-dimensional top plate area of the three-dimensional area data. By performing mask processing for hiding the image data area, it is possible to easily generate 3D image data excluding the top plate data. By generating this three-dimensional image data, image diagnosis can be performed quickly.

  Further, even if the image processing is stopped and reset in the middle of the image processing operation of the 3D image data excluding the top plate data, the 3D image data excluding the top plate data can be easily generated. It is possible to carry out the image processing operation of the three-dimensional image data.

A third embodiment of the X-ray CT apparatus according to the present invention will be described below with reference to FIGS.
The third embodiment shown in FIG. 5 differs from the first embodiment in FIG. 1 in that the data processing unit 5 in FIG. 1 is replaced with a data processing unit 5b. The configuration and operation of the data processing unit 5b will be described with reference to FIGS. Since the configuration other than the data processing unit 5b according to the third embodiment is the same as that of the first embodiment, the description thereof is omitted.

  The data processing unit 5b is output from the top plate region detection unit 51b that creates three-dimensional region data from the first tomographic image data in the imaging range output from the reconstruction processing unit 4, and output from the top plate region detection unit 51b. An image data processing unit 52b that generates three-dimensional image data based on the three-dimensional region data.

  The top plate area detecting unit 51b generates three-dimensional image data from the first tomographic image data and searches for voxel data included in a preset CT value range, and is detected by the searching unit 53b. An extraction unit 54b that extracts the voxel data connected to the voxel data from the three-dimensional image data to create the three-dimensional region data is provided.

  The search unit 53b generates three-dimensional image data from the first tomographic image data output from the reconstruction processing unit 4, and then generates a three-dimensional image based on information on the imaging position and CT value range of the system control unit 8. Explore data. Then, after detecting voxel data included in the preset CT value range of the top plate 9 from the voxel data constituting the three-dimensional image data, the coordinate information of the voxel data is output to the extraction unit 54b. .

  FIG. 6 is a diagram for explaining the 3D image data generated by the search unit 53b and the search direction for searching the 3D image data.

  FIGS. 6A to 6D are diagrams showing examples of three-dimensional image data when the imaging position of the subject P is the supine position, the prone position, the lower right position, and the lower left position. The three-dimensional image data 100a to 100d includes three-dimensional object data 101a to 101d corresponding to the object P in the imaging range and three-dimensional table data 102a to 102d corresponding to the top 9 on which the object P is placed. The three-dimensional image data 100a to 100d are formed in a direction in which the subject P is viewed from the front in the initial setting, and the three-dimensional subject data 101a to 101d are substantially central portions of the three-dimensional image data 100a to 100d. Formed.

  In the upper diagram of FIG. 6 (a), the three-dimensional image data 100a has the three-dimensional table data 102a formed behind the three-dimensional object data 101a. By searching to the right in the direction of the arrow L2 from the vicinity of the left center of the three-dimensional table data 102a without the subject data 101a interposed, the three-dimensional table data 102a region included in the CT value range of the table 9 is displayed. Voxel data can be detected.

  In the upper diagram of FIG. 6B, since the three-dimensional image data 100b has the three-dimensional table data 102b formed in front of the three-dimensional object data 101b, the three-dimensional image data 100b is three-dimensional. By searching to the left in the direction of the arrow L3 from the vicinity of the center on the right side of the three-dimensional top panel data 102b without the subject data 101b interposed, the three-dimensional top panel data 102b area included in the CT value range of the top panel 9 is obtained. Voxel data can be detected.

  In the upper diagram of FIG. 6C, the three-dimensional image data 100c is formed on the left side of the three-dimensional subject data 101c. Therefore, in the lower diagram viewed from the same direction as the upper diagram, the three-dimensional subject data 101c is interposed. The voxel data of the 3D top panel data 102c region included in the CT value range of the top panel 9 is detected by searching from the left center vicinity of the left 3D top panel data 102c to the right in the direction of the arrow L4. Can do.

  In the upper diagram of FIG. 6D, the three-dimensional image data 100d has the three-dimensional table data 102d formed on the right side of the three-dimensional object data 101d. The 3D table data 102d region included in the CT value range of the table 9 is searched from the right center vicinity of the 3D table data 102d without interposing the 3D object data 101d to the left in the direction of the arrow L5. Voxel data can be detected.

  5 extracts the voxel data included in the CT value range of the top board 9 by connecting to the voxel data of the coordinates output from the search unit 53b based on the CT value range information of the system control unit 8. Three-dimensional image data is extracted from the three-dimensional image data, and three-dimensional region data representing the extracted voxel data region (three-dimensional top plate region) is generated and output to the image data processing unit 52. Note that the three-dimensional top plate region may be created by performing a process of enlarging a predetermined range to a three-dimensional region other than the top plate outside the boundary region of this region or reducing it within the boundary region.

  The image data processing unit 52b replaces the pixel data in the region of the first tomographic image data with a preset replacement value based on the three-dimensional region data output from the top plate region detection unit 51b. A replacement unit 55b that generates tomographic image data; generation of three-dimensional image data of an imaging range from the second tomographic image data output from the replacement unit 55b; and extraction processing of a specific organ extracted from the three-dimensional image data And a three-dimensional image data processing unit 56 that performs image processing such as the above. The three-dimensional image data processing unit 56 is the same as that of the first embodiment shown in FIG.

  The replacement unit 55b creates the three-dimensional region data output from the extraction unit 54b of the top plate region detection unit 51b for each two-dimensional region data for one slice based on the replacement value information of the system control unit 8. Generation of second tomographic image data in which the CT value of the pixel data of the first tomographic image data output from the reconstruction processing unit 4 corresponding to the top plate region of the two-dimensional region data is replaced with the CT value of air And output to the three-dimensional image data processing unit 56b.

  According to the third embodiment of the present invention described above, the three-dimensional image data is generated from the first tomographic image data in the imaging range, and the three-dimensional image data is applied to the subject data based on the information on the imaging position. The voxel data constituting the top plate data can be detected by searching the top plate region from the anti-subject data side to the subject data side of the top plate data formed in an overlapping manner.

  Then, after generating three-dimensional area data based on the coordinate information of the detected voxel data, the pixel data of the first tomographic image data corresponding to the top area of the two-dimensional area data generated from the three-dimensional area data Tomographic data is generated by generating second tomographic image data by replacing CT with a CT value near the air, and generating three-dimensional image data from the second tomographic image data in the imaging range. Can be easily generated. Image diagnosis can be performed quickly by generating the three-dimensional image data.

  Further, even if the image processing is stopped and reset during the image processing operation of the 3D image data after removing the top plate data, the 3D image data excluding the top plate data can be easily generated. It is possible to carry out the image processing operation of the three-dimensional image data.

  Note that the present invention is not limited to the third embodiment described above, and the image data processing unit 52b in FIG. 5 is replaced with the first imaging range output from the reconstruction processing unit 4 as shown in FIG. After generating the three-dimensional image data from the tomographic image data, generating the three-dimensional image data by masking the region of the three-dimensional image data corresponding to the three-dimensional region data output from the top plate region detection unit 51b, or this mask The processed 3D image data is replaced with an image data processing unit 52c that generates tomographic image data of an arbitrary cross section by image processing, projection image data from an arbitrary direction, 3D image data that emphasizes a specified range by volume rendering, and the like. The data processing unit 5c may be configured.

  Thereby, three-dimensional image data is generated from the first tomographic image data in the imaging range, and the top plate data is formed by overlapping the three-dimensional image data with the subject data based on the information on the imaging posture. The voxel data constituting the top plate data can be detected by searching the top plate region from the opposite subject data side toward the subject data side.

  Then, three-dimensional region data is created based on the detected coordinate information of the voxel data, and then the three-dimensional top plate region of the three-dimensional region data of the three-dimensional image data generated from the first tomographic image data in the imaging range. By performing mask processing for hiding the corresponding area, it is possible to easily generate three-dimensional image data excluding the top plate data. By generating this three-dimensional image data, image diagnosis can be performed quickly.

  Further, even if the image processing is stopped and reset during the image processing operation of the three-dimensional image data excluding the top plate, the three-dimensional image data excluding the top plate can be easily generated. It is possible to perform an image processing operation on the dimensional image data.

  A fourth embodiment of the image processing apparatus according to the present invention will be described with reference to FIG. FIG. 8 is a block diagram showing the configuration of the image processing apparatus according to the present invention.

  The image processing apparatus 130 stores the first tomographic image data in the imaging range obtained by the X-ray imaging of the X-ray CT apparatus 140 via the interface 121, and is stored in the storage unit 122. A data processing unit 5 that processes the first tomographic image data in the imaging range being generated to generate three-dimensional image data, a display unit 6 that displays the three-dimensional image data output from the data processing unit 5, and a three-dimensional An operation unit 123 that selects and inputs various conditions related to image data generation and display, and inputs various commands, and a control unit 124 that controls the above-described units in an integrated manner.

  Next, the operation of the image processing apparatus 130 according to the fourth embodiment of the present invention will be described. The data processing unit 5 and the display unit 6 are the same as those in the first embodiment shown in FIG.

  The storage unit 122 includes a memory device such as a magnetic disk, is reconstructed by the X-ray CT apparatus 140, is attached with imaging conditions such as an imaging position, and is output to the image processing apparatus 130. The first tomographic image data of the imaging range is output. Is temporarily stored and then output to the data processing unit 5.

  The operation unit 123 is an interactive interface including an input device such as a keyboard, a trackball, a joystick, and a mouse, a display panel, and various switches, and sets a CT value range, a replacement value, and inputs various commands. To do.

  Then, by the CT value range and replacement value setting operation of the operation unit 123, the CT value range of the top plate of the X-ray CT apparatus 140 and the CT value near the air are set as the CT value range in advance.

  The control unit 124 includes a CPU and a storage circuit (not shown) and temporarily stores information such as an operator command signal, CT value range, and replacement value supplied from the operation unit 123, and then stores the CT value range and replacement value as data. While outputting to the process part 5, control of the whole system, such as control regarding the production | generation and display of three-dimensional image data based on such information, is performed.

  According to the fourth embodiment of the present invention described above, as in the first embodiment, the three-dimensional image data excluding the top plate data can be easily generated.

  The present invention is not limited to the fourth embodiment, and the image data processing unit 52 of the data processing unit 5 in FIG. 8 is replaced with the image data processing unit 52a of the second embodiment in FIG. Thus, similar to the second embodiment, the three-dimensional image data excluding the top plate data can be easily generated.

  Embodiment 5 of an image processing apparatus according to the present invention will be described with reference to FIG. FIG. 9 is a block diagram showing the configuration of the image processing apparatus according to the present invention.

  The image processing apparatus 130 a captures and stores the first tomographic image data of the imaging range obtained by the X-ray imaging of the X-ray CT apparatus 140 via the interface 121, and the image processing apparatus 130 a is stored in the storage unit 122. A data processing unit 5b that generates first three-dimensional image data by processing first tomographic image data in the imaging range, a display unit 6 that displays the three-dimensional image data output from the data processing unit 5b, and a three-dimensional An operation unit 123 that selects and inputs various conditions related to image data generation and display, and inputs various commands, and a control unit 124a that performs overall control of each unit are provided.

  Next, the operation of the image processing apparatus 130a according to the fifth embodiment of the present invention will be described. The interface 121, the storage unit 122, the display unit 6, and the operation unit 123 are the same as those in the fourth embodiment shown in FIG. The data processing unit 5b is the same as that of the third embodiment shown in FIG.

  The control unit 124a includes a CPU and a storage circuit (not shown), temporarily stores information such as an operator command signal, CT value range, and replacement value supplied from the operation unit 123, and then stores the CT value range and replacement value as data. While outputting to the process part 5b, control of the whole system, such as control regarding the production | generation and display of 3D image data based on such information, is performed.

  According to the fifth embodiment of the present invention described above, as in the third embodiment, the three-dimensional image data excluding the top plate data can be easily generated.

  The present invention is not limited to the fifth embodiment, and the data processing unit 5b shown in FIG. 9 may be replaced with the data processing unit 5c shown in FIG.

  Thereby, three-dimensional image data is generated from the first tomographic image data in the imaging range, and the top plate data is formed by overlapping the three-dimensional image data with the subject data based on the information on the imaging posture. The voxel data constituting the top plate data can be detected by searching the top plate region from the opposite subject data side toward the subject data side.

  Then, three-dimensional region data is created based on the detected coordinate information of the voxel data, and then the three-dimensional top plate region of the three-dimensional region data of the three-dimensional image data generated from the first tomographic image data in the imaging range. By performing mask processing for hiding the corresponding area, it is possible to easily generate three-dimensional image data excluding the top plate data. By generating this three-dimensional image data, image diagnosis can be performed quickly.

  Further, even if the image processing is stopped and reset during the image processing operation of the three-dimensional image data excluding the top plate, the three-dimensional image data excluding the top plate can be easily generated. It is possible to perform an image processing operation on the dimensional image data.

1 is a block diagram showing the configuration of Embodiment 1 of an X-ray CT apparatus according to the present invention. 3 is a flowchart showing the operation of the X-ray CT apparatus according to Embodiment 1 of the present invention. The figure for demonstrating the procedure of the removal of the top plate data which concerns on the Example of this invention. The block diagram which shows the structure of Example 2 of the X-ray CT apparatus by this invention. The block diagram which shows the structure of Example 3 of the X-ray CT apparatus by this invention. The figure for demonstrating the imaging position and search direction which concern on Example 3 of this invention. The block diagram which shows the modification of the data processing part which concerns on Example 3 of this invention. The block diagram which shows the structure of Example 4 of the image processing apparatus by this invention. The block diagram which shows the modification of the data processing part which concerns on Example 4 of this invention.

Explanation of symbols

P subject 1 gantry unit 2 high voltage generation unit 3 mechanism unit 4 reconstruction processing unit 5 data processing unit 6 display unit 7 operation unit 8 system control unit 9 top plate 10 X-ray CT apparatus 11 X-ray generation unit 12 X-ray detection Unit 13 Data processing unit 41 Storage unit 42 Reconstruction unit 51 Top plate area detection unit 52 Image data processing unit 53 Search unit 54 Extraction unit 55 Replacement unit 56 Three-dimensional image data processing unit

Claims (6)

A top plate on which the subject is placed;
X-ray imaging means for irradiating the subject with X-rays, detecting X-rays transmitted through the subject and the top plate, and generating X-ray projection data;
Reconstructing means for reconstructing the X-ray projection data generated by the X-ray imaging means to generate image data;
Storage means for storing a CT value range of the top plate;
Based on the CT value range of the top plate stored by the storage unit, three-dimensional image data is generated by excluding pixel data included in the CT value range of the top plate from the image data generated by the reconstruction unit. Image data processing means,
An X-ray CT apparatus comprising: display means for displaying three-dimensional image data generated by the image data processing means. The image data processing means includes the object data constituting the image data generated by the reconstructing means, and the object data side of the top plate data formed to overlap the object data. Search means for searching the top plate region from the subject data side to detect pixel data included in the CT value range;
Extracting the pixel data connected to the pixel data detected by the search means and extracting the pixel data included in the CT value range, and further creating area data representing the area of the extracted image data;
The X-ray CT apparatus according to claim 1, wherein the top plate data is excluded based on the area data created by the extraction unit.   The image data processing means has a replacement means for generating image data in which pixel data of the image data corresponding to the area data created by the extraction means is replaced with a CT value near the air, and generated by the replacement means 3. The X-ray CT apparatus according to claim 2, wherein three-dimensional image data is generated from the processed image data. The image data processing means includes three-dimensional area data creation means for creating three-dimensional area data from the area data created by the extraction means,
After generating the three-dimensional image data from the image data generated by the reconstruction unit, the region of the three-dimensional image data corresponding to the three-dimensional region data generated by the three-dimensional region data generation unit is hidden. The X-ray CT apparatus according to claim 2, wherein mask processing is performed to generate three-dimensional image data. The image data processing unit generates the three-dimensional image data from the image data generated by the reconstruction unit, and then, based on the imaging position information of the subject attached to the image data, the three-dimensional image Search the top plate area from the object data side to the subject data side of the subject data constituting the data and the anti-subject data side of the top plate data formed overlapping the subject data, Search means for detecting voxel data included in the top CT value range set by the CT value range setting means;
Extraction means connected to the voxel data detected by the search means and extracting voxel data included in the top CT value range, and further creating three-dimensional area data representing an area of the extracted voxel data; Have
2. The X-ray CT apparatus according to claim 1, wherein three-dimensional image data excluding the top plate data is generated based on the three-dimensional area data created by the extracting means. Storage means for storing the CT value range of the top plate on which the subject is placed;
Object data from the object data side of the object data constituting the first tomographic image data in the imaging range of the object and the data of the top plate formed to overlap the object data Search means for searching the top plate area toward the side, and detecting pixel data included in the CT value range of the top plate stored by the storage means;
Extraction means connected to the pixel data detected by the search means and extracting pixel data included in the top CT value range, and further creating area data representing the area of the extracted pixel data;
Image data processing means for generating three-dimensional image data excluding the top plate data of the imaging range based on the area data created by the extraction means;
An image processing apparatus comprising: display means for displaying three-dimensional image data generated by the image data processing means.

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