JP6225351B1 - Image processing apparatus, image processing program, and image processing method - Google Patents

Abstract

The image processing apparatus includes a visualization result image generation unit that generates a visualization result image obtained as a result of performing a visualization process viewed from at least two directions on the first reconstructed volume data, and at least two visualization result images. A display image generation unit that generates a display image in which a graphic representing a reconstruction range is superimposed on each of the visualization result images, and the remaining when the size or position of one graphic is changed A graphic changing unit that changes at least one of the size or position of the graphic in association with the reconstructed range specified by the graphic to generate second reconstructed volume data A generating unit.

Description

  The present invention relates to an image processing apparatus, an image processing program, and an image processing method for generating reconstructed volume data from a projection image corresponding to an area irradiated with X-rays.

  In CT (Computed Tomography) imaging, reconstruction volume data is calculated from a projection image corresponding to a region irradiated with X-rays, and a cross-sectional image is generated from the reconstruction volume data.

  When calculating reconstructed volume data, it is necessary to specify the voxel interval in each axial direction in advance. When reconfiguring the entire field of view (FOV), if the voxel interval in each axial direction is designated, the number of voxels in each axial direction of the reconstructed volume data is also uniquely determined. Conversely, it is possible to specify the number of voxels in each axial direction first, and in this case, the voxel interval in each axial direction can be uniquely obtained by specifying the number of voxels in each axial direction.

  In recent years, an X-ray imaging apparatus having a CT imaging mode has an X-ray detection unit that is large, and it is possible to ensure a wide FOV. However, when a wide FOV can be secured, the following trade-off [1] or [2] occurs.

[1] If the entire widened FOV is reconstructed without changing the voxel interval from the prior art, the number of voxels increases and the file size of the reconstructed volume data increases.
[2] If the entire widened FOV is reconstructed without changing the number of voxels from the conventional one, the voxel interval becomes larger than the conventional one and the spatial resolution becomes worse.

  As an approach to the trade-off described above, a reconstructed volume is created by designating a part of the FOV and reconfiguring the designated area with a sufficiently small voxel interval or a sufficiently large number of voxels. Patent Document 1 proposes a method of ensuring a sufficient spatial resolution while suppressing an increase in data file size.

Japanese Patent No. 4609960 JP 2005-245914 A JP 2006-127 A

  The image processing apparatus proposed in Patent Document 1 designates a partial region in the FOV with a cross-sectional image. According to such a designation method, for example, when it is desired to simultaneously confirm the position of the front tooth portion and the position of the molar portion, it is necessary to alternately designate the slice position of the cross-sectional image shown in FIG. 12 and the slice position of the cross-sectional image shown in FIG. Therefore, the user is forced to perform complicated work.

  Further, as another method for three-dimensionally specifying a part of the FOV as a reconstruction range, Patent Document 2 discloses an image obtained by photographing for positioning (referred to as a scano image in Patent Document 2). A method for designating a reconstruction range is also disclosed. However, in the case of fan beam CT or cone beam CT, there is a problem of the enlargement ratio that the subject closer to the radiation source is enlarged and projected onto the detector. It is difficult to specify accurately three-dimensionally.

  On the other hand, Patent Document 3 proposes a method of automatically estimating the position in the projection direction at the time of volume rendering with respect to the reconstruction range specified in the volume rendering image. However, in the case of a dental region, partial reconstruction of a specific tooth is often required, whereas in the method proposed in Patent Document 3, the entire dentition that is a hard tissue can be a candidate position regarding the projection direction. . Therefore, when the method proposed in Patent Document 3 is applied to a dental CT imaging apparatus, a wide range of the entire dentition is eventually reconstructed, which does not make sense for partial reconstruction.

  In view of the above situation, the present invention specifies an image processing apparatus, an image processing program, and an image that can reduce a user's workload when a part of an FOV is specified and the specified area is reconfigured. The object is to provide a processing method.

  In order to achieve the above object, an image processing apparatus according to the present invention generates a visualization result image that generates a visualization result image obtained as a result of performing a visualization process viewed from at least two directions on the first reconstructed volume data. A display image generation unit that generates at least two visualization result images and a display image in which a graphic representing a reconstruction range is superimposed on each of the visualization result images, and the size or position of the single graphic When changing at least one of the figure, the figure changing unit that changes at least one of the size or position of the remaining figure in conjunction with the reconstruction range specified by the figure is reconfigured to reconfigure the second reconstruction. A partial reconfiguration volume data generation unit that generates configuration volume data (first configuration).

  In the image processing apparatus having the first configuration, a cross-sectional image that generates a cross-sectional image viewed from a direction substantially perpendicular to the rotation trajectory of the X-ray detection unit included in the X-ray imaging apparatus using the first reconstructed volume data. It is preferable that the display unit further includes a generation unit, and the display image includes the cross-sectional image, and the graphic is superimposed on the cross-sectional image in the display image (second configuration).

  In the image processing apparatus having the second configuration, the display image generation unit includes an image integration unit that generates an integrated image obtained by integrating the visualization result image and the cross-sectional image, and the visualization included in the integrated image. A configuration (third configuration) may be provided that includes an integrated image graphic superimposing unit that generates a display image in which a graphic representing the reconstruction range is superimposed on each of the result image and the cross-sectional image.

In the image processing apparatus having the second configuration, the display image generation unit includes a cross-sectional image graphic superimposing unit that generates a first display image in which a graphic representing a reconstruction range is superimposed on the cross-sectional image; , integration and visualization results image graphic superimposing unit for generating a second display image graphic representing the reconstruction area to the visualization results picture image is superimposed, a first display image and the second display image image (4th structure) provided with the display image integration part which produces | generates the display image which performed.

  In the image processing apparatus having any one of the first to fourth configurations, the visualization result image may be a volume rendering image (fifth configuration).

  In the image processing apparatus having the fifth configuration, the visualization result image generation unit includes at least one association or brightness of at least one color or opacity with respect to at least one of the voxel value, the differentiation of the voxel value, or the position of the voxel. Alternatively, a configuration (sixth configuration) may be employed in which at least one of contrast or contrast is changed and the volume rendering image is regenerated.

  In the image processing apparatus having any one of the first to fourth configurations, the visualization result image may be a surface rendering image (seventh configuration).

  In the image processing apparatus having the seventh configuration, the visualization result image generation unit includes a specified value of a voxel value to be visualized as an isosurface and a specified value of opacity corresponding to the voxel value to be visualized as an isosurface, Alternatively, a configuration (eighth configuration) in which at least one of the designated number of voxel values to be visualized as an isosurface is changed and the surface rendering image is generated again may be used.

  In the image processing device having any one of the first to eighth configurations, the visualization result image may have a configuration (9th configuration) that is an image based on parallel projection.

  In order to achieve the above object, the image processing program according to the present invention generates a visualization result image obtained as a result of performing a visualization process when the computer is viewed from at least two directions on the first reconstructed volume data. A result image generation unit, a display image generation unit that generates at least two visualization result images and a display image in which a graphic representing the reconstruction range is superimposed on each of the visualization result images; When at least one of the positions is changed, a graphic changing unit that changes at least one of the size or position of the remaining graphic in conjunction with each other, and a reconstruction range designated by the graphic are reconfigured to be second. It is made to function as a partial reconfiguration volume data generation unit that generates reconfiguration volume data.

  In order to achieve the above object, the image processing method according to the present invention generates a visualization result image that is generated as a result of visualizing the first reconstructed volume data from at least two directions. A display image generation step for generating a display image that includes at least two visualization result images and in which a graphic representing a reconstruction range is superimposed on each visualization result image, and the size or position of one of the graphics When changing at least one of the figure, a figure changing step for changing at least one of the size or position of the remaining figure in conjunction with the reconstruction area designated by the figure is reconfigured and the second reconstruction is performed. A partially reconstructed volume data generation step for generating configuration volume data.

  According to the present invention, since a partial region in the FOV is specified by the visualization result image, it is not necessary to specify the slice position of the cross-sectional image orthogonal to the axial direction calculated by projection. Therefore, for example, the position of the front tooth part and the position of the molar tooth part can be confirmed at the same time, and the work amount of the user when the partial area in the FOV is designated and the designated area is reconfigured is reduced.

The figure which shows the structure of an image processing apparatus The figure which shows an example of the functional block of an image processing program Flowchart showing an operation example of the image processing apparatus The figure which shows the example of a display of a visualization result image The figure which shows the other example of the functional block of an image processing program The figure which shows the specific example of the functional block shown in FIG. The figure which shows the other specific example of the functional block shown in FIG. Flowchart showing another operation example of the image processing apparatus The figure which shows the example of a display of a visualization result image and an axial image The figure which shows the other example of a display of a visualization result image and an axial image The figure which shows the further example of a display of a visualization result image and an axial image The figure which shows the cross-sectional image of the position of the front tooth part The figure which shows the cross-sectional image of the position of the molar part

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

  FIG. 1 is a diagram showing a configuration of an image processing apparatus 1 according to an embodiment of the present invention.

  The image processing apparatus 1 includes a CPU 11 that controls the entire image processing apparatus 1 according to programs stored in the ROM 12 and the HDD 17, a ROM 12 that records fixed programs and data, a RAM 13 that provides work memory, and an external device. A communication interface unit 14 for performing communication, a VRAM 15 for temporarily storing image data, a display unit 16 for displaying an image based on the image data stored in the VRAM 15, an HDD 17 to be described in detail, a keyboard, And an operation unit 18 such as a pointing device.

  A communication method between the communication interface unit 14 of the image processing apparatus 1 and the outside may be wired communication, wireless communication, or communication combining wired and wireless. An example of the image processing apparatus 1 is a personal computer.

  The HDD 17 includes various programs such as an image reconstruction processing program, an image display processing program, and a reconstruction range designation program, imaging data of CT imaging performed by an X-ray imaging apparatus, and a reconstruction volume generated by the image reconstruction processing program. Various data such as data and setting values of various parameters used when executing various programs are stored.

  The image reconstruction processing program is a program for reconstructing CT imaging data by the X-ray imaging apparatus to generate reconstruction volume data. The image display processing program is a program for generating image data corresponding to an image to be displayed on the display screen of the display unit 16 and displaying an image corresponding to the created image data on the display screen of the display unit 16. The reconstruction range designation program is a program for designating a reconstruction range.

  Each program stored in the HDD 17 may be preinstalled in the image processing apparatus 1, distributed in a form stored in a storage medium such as an optical disk, and installed in the image processing apparatus 1. And installed in the image processing apparatus 1. A part of each program and each data stored in the HDD 17 may be stored in the ROM 12 instead of the HDD 17.

  FIG. 2 is a diagram showing an example of functional blocks of an image processing program according to an embodiment of the present invention. An image processing program according to an embodiment of the present invention includes the above-described image reconstruction processing program, image display processing program, and reconstruction range designation program. In the example of FIG. 2, the image processing program according to the embodiment of the present invention is executed by the CPU 11 so that the hardware of the image processing apparatus 1 is converted into a visualization result image generation unit 171, a graphic change unit 172, and a display image generation unit. 173 and the partial reconfiguration volume data generation unit 174.

  First reconstruction volume data obtained by reconstructing imaging data of CT imaging by the X-ray imaging apparatus is input to the visualization result image generation unit 171. The visualization result image generation unit 171 generates a visualization result image obtained as a result of performing a visualization process viewed from at least two directions on the first reconstructed volume data. The visualization result image is preferably an image based on parallel projection. By making the visualization result image based on parallel projection in this way, the visualization result image can be prevented from being an image in which an enlargement ratio differs depending on the location, and the reconstruction range can be accurately three-dimensionally. It becomes easy to specify.

  Visualization result images are roughly classified into surface rendering images and volume rendering images.

  The surface rendering image is obtained by the “marching cube method” or the like, and can be divided into a translucent type and an opaque type. Here, the translucent type surface rendering image having the maximum opacity is the same as the opaque type surface rendering image. In the surface rendering image, two or more voxel values to be visualized as an isosurface can be designated. However, in the case of the semi-transparent type, when two or more voxel values to be visualized as an isosurface are designated, it is necessary to designate opacity for each designated voxel value.

  The volume rendering image includes a type visualized by the “ray casting method”, a type visualized by adding the square of the voxel value along the ray (hereinafter referred to as “sum of squares”), and a ray rendering image. Can be divided into types visualized by a method of adopting the maximum value of voxel values along the line (hereinafter referred to as “MIP (Maximum Intensity Projection)”). Volume rendered images of the type visualized by the “ray casting method” generally need to specify the voxel value, the differentiation of the voxel value, or the color and opacity with respect to the position of the voxel. On the other hand, the volume rendering image of the type visualized by “sum of squares” and the volume rendering image of the type visualized by “MIP” are special features of the volume rendering image of the type visualized by “ray casting method”. It can be regarded as an example, and it becomes a simple grayscale image. Therefore, for volume rendering images of the type visualized by “sum of squares” and volume rendering images of the type visualized by “MIP”, voxel values, derivatives of voxel values, or colors and inaccuracies with respect to voxel position. Instead of specifying transparency, contrast and brightness are adjusted.

  Here, returning to FIG. 2, the description of the functional block diagram of the image processing program according to the embodiment of the present invention will be continued.

  The reconstruction range data is input to the graphic change unit 172. The graphic changing unit 172 can change the size and position of the graphic representing the reconstruction range based on the reconstruction range data. The reconstruction range data may be data passed from the operation unit 18 to the graphic change unit 172, or may be data passed from the communication interface unit 14 to the graphic change unit 172. The graphic change unit 172 outputs graphic data representing the reconstruction range to the display image generation unit 173 and the partial reconstruction volume data generation unit 174. The format of the graphic data representing the reconstruction range is not particularly limited. For example, the graphic data may be a simple graphic such as a rectangular parallelepiped or the like in which the surface of the graphic is regarded as a set of points and the coordinates of each point are held as numerical data. For example, a format in which several parameters are held as numerical data can be adopted.

  The display image generation unit 173 generates a display image using the visualization result image output from the visualization result image generation unit 171 and the graphic data representing the reconstruction range output from the graphic change unit 172. That is, the display image generation unit 173 restores the graphic representing the reconstruction range from the graphic data representing the reconstruction range, and generates a display image in which the graphic representing the reconstruction range is superimposed on each visualization result image. The partial reconstruction volume data generation unit 174 reconstructs the reconstruction range designated by the graphic representing the reconstruction range based on the imaging data and the graphic data representing the reconstruction range output from the graphic changing unit 172. To generate second reconstructed volume data.

  FIG. 3 is a flowchart illustrating an operation example of the image processing apparatus 1. The operation subject of the flowchart shown in FIG. 3 is the image processing apparatus 1, but when the functional block shown in FIG. 2 is substantially the subject of the operation, the function block shown in FIG. .

  First, the image processing apparatus 1 reconstructs substantially the entire FOV (Field of view) by a conventional general reconstruction algorithm according to an image reconstruction processing program, and generates reconstructed volume data (step S1).

  In step S2 following step S1, the visualization result image generation unit 171 generates a visualization result image in the axial direction orthogonal to the coronal image and a visualization result image in the axial direction orthogonal to the sagittal image. When the visualization result image is a volume rendering image, it may be generated using any of the ray casting method, the sum of squares, and MIP, or may be generated using a method other than those. When the visualization result image is a surface rendering image, it may be generated using a marching cube method or may be generated using a method other than these.

  In step S3 subsequent to step S2, the display image generation unit 173 displays an axial visualization result image 301 orthogonal to the coronal image and an axial visualization result image 302 orthogonal to the sagittal image, as shown in FIG. This is displayed on the part 16. FIG. 4 is a diagram when the visualization result images 301 and 302 are volume rendering images.

  A rectangular frame representing the reconstruction range is superimposed on each of these two images 301 and 302 and displayed. Further, an image adjustment window is also superimposed on each of the two images 301 and 302 and displayed. The image adjustment window may be displayed using at least one of selection button display, slide bar display, numerical display, and the like.

  In step S4 following step S3, the image processing apparatus 1 determines whether or not an operation for instructing a change of the display image has been performed on the operation unit 18.

  If an operation for instructing the change of the display image is not performed on the operation unit 18 (NO in step S4), the process directly proceeds to step S6. On the other hand, if an operation for instructing the change of the display image is performed on the operation unit 18 (YES in step S4), the image processing apparatus 1 determines at least one of the visualization result image generation unit 171 or the graphic change unit 172 according to the operation content. One changes the content of the output, and the display image generation unit 173 changes the display image in accordance with the change of the output content (step S5), and then proceeds to step S6.

  For example, an image adjustment window superimposed on the image 301 is an algorithm for visualizing the image 301 (for example, marching cube method, other surface rendering method, ray casting method, square sum, MIP, other volume rendering method) Etc.) may be included. The image adjustment window superimposed on the image 302 is the same as described above.

  Further, for example, when the image 301 is a surface rendering image, the image adjustment window superimposed on the image 301 is a display for changing the number of voxel values to be visualized as an isosurface of the image 301, and the object of visualization of the image 301 Display for designating opacity for each voxel value designated as, and a display for designating voxel values to be visualized as an isosurface of the image 301. When the image 302 is a surface rendering image, the image adjustment window superimposed on the image 302 is the same as described above.

  Also, for example, when the image 301 is a volume rendering image, an image adjustment window superimposed on the image 301 is a display for specifying a voxel value of the image 301, a differentiation of the voxel value, or a color for the position of the voxel, the image 301 Display for designating the voxel value, differentiation of the voxel value, or opacity with respect to the position of the voxel, display for adjusting the contrast of the image 301, display for adjusting the brightness of the image 301, and the like. . When the image 302 is a volume rendering image, the image adjustment window superimposed on the image 302 is the same as described above.

  By changing the image 301 using the image adjustment window superimposed on the image 301, it is possible to easily read desired information from the image 301. Similarly, it is possible to easily read desired information from the image 302 by changing the image 302 using an image adjustment window superimposed on the image 302.

  In addition, when the image processing apparatus 1 moves one of the positions of the rectangular frames superimposed on the two images 301 and 302, the other one of the rectangular frames is moved in conjunction with the two images. When the size of any one of the rectangular frames superimposed on 301 and 302 is changed, the size of the other rectangular frame is changed in conjunction.

  The above-described image change and rectangular frame size change may be realized, for example, by a user operation of a pointing device constituting the operation unit 18. Or when the operation part 18 includes the touch panel arrange | positioned on the display screen of the display part 16, you may implement | achieve by the user operation of a touch panel.

  In step S <b> 6, the image processing apparatus 1 determines whether an operation for instructing reconstruction has been performed on the operation unit 18.

  If an operation to instruct reconfiguration is not performed on the operation unit 18 (NO in step S6), the process returns to step S4. On the other hand, if an operation for instructing reconfiguration is performed on the operation unit 18 (YES in step S6), the process proceeds to step S7. The reconfiguration instruction may be realized by, for example, a user operation of a pointing device that constitutes the operation unit 18 or a user operation of a keyboard that constitutes the operation unit 18.

  In step S7, the partial reconstruction volume data generation unit 174 reconstructs the reconstruction range designated by the rectangular frame, that is, a partial area in the FOV, according to the conventional general reconstruction algorithm in accordance with the image reconstruction processing program. To generate reconstructed volume data. For example, the voxel interval is set so that the voxel interval increases as the reconstruction range specified by the rectangular frame increases. As an example of such a setting, a setting in which the volume of the reconstruction range and the voxel interval of each axis are directly proportional can be considered. Further, for example, the user may be able to determine the voxel interval or the number of voxels regardless of the size of the reconstruction range. The determination of the voxel interval or the number of voxels by the user may be realized by a user operation of a pointing device constituting the operation unit 18, for example. Or when the operation part 18 includes the touch panel arrange | positioned on the display screen of the display part 16, you may implement | achieve by the user operation of a touch panel.

  When the process of step S7 ends, the reconstructed volume data generation process is completed. After the reconstructed volume data generation process is completed, the cross-sectional image can be displayed using the reconstructed volume data obtained by the process of step S7.

  By performing the processing of steps S1 to S7 described above, it is possible to designate a reconstruction area designated by the rectangular frame, that is, a partial area in the FOV, and reconfigure the designated area.

  Furthermore, by performing the process of step S3 described above, information corresponding to a plurality of coronal images can be read from the visualization result image 301 in the axial direction orthogonal to the coronal image. This eliminates the need to change the slice position and reduces the amount of work for the user. Similarly, since information corresponding to a plurality of sagittal images can be read from the visualization result image 302 in the axial direction orthogonal to the sagittal image, it is possible to save time and labor for changing the slice position of the sagittal image as in Patent Document 1. The amount of work can be reduced.

  In X-ray imaging, when the target area for image diagnosis is narrow, conventionally, preliminary imaging is performed, and a step for matching the target area for image diagnosis with the FOV is necessary. However, if the FOV is widened and X-ray imaging is performed, there is a high possibility that the target area for image diagnosis is included in the FOV, and a part of the area in the FOV is set as a reconstruction range later without performing preliminary imaging. You can specify it. By implementing the present invention, as described above, the user's work amount relating to the designation of the reconstruction range is reduced, and therefore, the omission of preliminary shooting is promoted.

  The embodiment of the present invention has been described above, but the embodiment can be variously modified within the scope of the gist of the present invention. Hereinafter, some modified examples will be described.

  Functional blocks of an image processing program according to an embodiment of the present invention may be as shown in FIG. In the example of FIG. 5, the image processing program according to the embodiment of the present invention is executed by the CPU 11 so that the hardware of the image processing apparatus 1 is converted into a visualization result image generation unit 171, a graphic change unit 172, and a display image generation unit. 173, function as a partial reconstruction volume data generation unit 174 and a cross-sectional image generation unit 175. Hereinafter, description of the same parts as those in FIG. 2 will be omitted, and different parts from FIG. 2 will be described.

  The first reconstruction volume data is input not only to the visualization result image generation unit 171 but also to the cross-sectional image generation unit 175. The cross-sectional image generation unit 175 generates a cross-sectional image using the first reconstruction volume data.

  In the example of FIG. 5, the display image generation unit 173 displays the visualization result image output from the visualization result image generation unit 171, the cross-sectional image output from the cross-sectional image generation unit 175, and the reconstruction range output from the graphic change unit 172. A display image is generated using the graphic data to be represented. That is, in the example of FIG. 5, the display image generation unit 173 restores the graphic representing the reconstruction range from the graphic data representing the reconstruction range, and the graphic representing the reconstruction range is superimposed on each of the visualization result image and the cross-sectional image. Display image is generated.

  Two specific examples of the functional blocks shown in FIG. 5 are shown in FIGS. 6 and 7, respectively.

  In the specific example shown in FIG. 6, the display image generation unit 173 includes an image integration unit 173A and an integrated image graphic superimposition unit 173B. The image integration unit 173A generates an integrated image in which the visualization result image output from the visualization result image generation unit 171 and the cross-sectional image output from the cross-sectional image generation unit 175 are integrated. The integrated image graphic superimposing unit 173B generates a display image in which a graphic representing the reconstruction range is superimposed on each of the visualization result image and the cross-sectional image included in the integrated image output from the image integrating unit 173A.

In the specific example illustrated in FIG. 7, the display image generation unit 173 includes a cross-sectional image graphic superimposing unit 173C, a visualization result image graphic superimposing unit 173D, and a display image integrating unit 173E. The cross-sectional image graphic superimposing unit 173C generates a display image in which a graphic representing the reconstruction range is superimposed on the cross-sectional image output from the cross-sectional image generating unit 175. Visualization results image graphic superimposing unit 173D generates a display image graphic representing the reconstruction area to the visualization results picture image to be output from the visualization results image generator 171 is superimposed. Display image integration unit 173E generates the display image by integrating the display viewing image to be outputted from the display image and visualizing the resulting image graphic superimposing unit 173D outputted from the graphic superimposing unit 173C for cross-sectional images.

  FIG. 8 is a flowchart showing another operation example of the image processing apparatus 1. 8 is the image processing apparatus 1, but when the functional block shown in FIG. 5 is substantially the operating subject, description will be made using the functional block shown in FIG. .

  First, the image processing apparatus 1 reconstructs substantially the entire FOV (Field of view) by a conventional general reconstruction algorithm in accordance with an image reconstruction processing program to generate reconstructed volume data (step S11).

  In step S12 following step S11, the visualization result image generation unit 171 generates a visualization result image in the axial direction orthogonal to the coronal image and a visualization result image in the axial direction orthogonal to the sagittal image, and the cross-sectional image generation unit 175 Generate an axial image. When the visualization result image is a volume rendering image, it may be generated using any of the ray casting method, the sum of squares, and MIP, or may be generated using a method other than those. When the visualization result image is a surface rendering image, it may be generated using a marching cube method or may be generated using a method other than these.

  In step S13 subsequent to step S12, the display image generation unit 173 performs the axial visualization result image 301 orthogonal to the coronal image, the axial visualization result image 302 orthogonal to the sagittal image, and the axial as shown in FIG. The image 303 is displayed on the display unit 16. FIG. 9 is a diagram when the visualization result images 301 and 302 are volume rendering images.

  Here, the reason for displaying the axial image 303 will be described. When the subject is a person, the size of the subject is longer in the body axis direction than in the direction orthogonal to the body axis direction of the subject (an example of a direction substantially perpendicular to the rotation trajectory). For this reason, the visualization result image viewed from the body axis direction is an image that is visually difficult to understand. Therefore, it is preferable to display not a visualization result image but a simple cross-sectional image (axial image) with respect to the body axis direction.

  A rectangular frame representing the reconstruction range is superimposed on each of the three images 301 to 303 and displayed. Further, an image adjustment window is also superimposed on each of the three images 301 to 303 and displayed. The image adjustment window may be displayed using at least one of selection button display, slide bar display, numerical display, and the like.

  In step S <b> 14 following step S <b> 13, the image processing apparatus 1 determines whether an operation for instructing change of the display image has been performed on the operation unit 18.

  If an operation for instructing the change of the display image is not performed on the operation unit 18 (NO in step S14), the process directly proceeds to step S16. On the other hand, if an operation for instructing the change of the display image is performed on the operation unit 18 (YES in step S14), the image processing apparatus 1 displays the visualization result image generation unit 171, the figure change unit 172, or the cross section according to the operation content. At least one of the image generation units 175 changes the content of the output, and the display image generation unit 173 changes the display image in accordance with the change of the output content (step S15), and then the process proceeds to step S16.

  For example, an image adjustment window superimposed on the image 301 is an algorithm for visualizing the image 301 (for example, marching cube method, other surface rendering method, ray casting method, square sum, MIP, other volume rendering method) Etc.) may be included. The image adjustment window superimposed on the image 302 is the same as described above.

  Further, for example, when the image 301 is a surface rendering image, the image adjustment window superimposed on the image 301 is a display for changing the number of voxel values to be visualized as an isosurface of the image 301, and the object of visualization of the image 301 Display for designating opacity for each voxel value designated as, and a display for designating voxel values to be visualized as an isosurface of the image 301. When the image 302 is a surface rendering image, the image adjustment window superimposed on the image 302 is the same as described above.

  Also, for example, when the image 301 is a volume rendering image, an image adjustment window superimposed on the image 301 is a display for specifying a voxel value of the image 301, a differentiation of the voxel value, or a color for the position of the voxel, the image 301 Display for designating the voxel value, differentiation of the voxel value, or opacity with respect to the position of the voxel, display for adjusting the contrast of the image 301, display for adjusting the brightness of the image 301, and the like. . When the image 302 is a volume rendering image, the image adjustment window superimposed on the image 302 is the same as described above.

  Further, for example, the image adjustment window superimposed on the image 303 may include a display for adjusting the contrast of the image 303, a display for adjusting the brightness of the image 303, and the like.

  By changing the image 301 using the image adjustment window superimposed on the image 301, it is possible to easily read desired information from the image 301. Similarly, it is possible to easily read desired information from the image 302 by changing the image 302 using an image adjustment window superimposed on the image 302. Similarly, it is possible to easily read desired information from the image 303 by changing the image 303 using an image adjustment window superimposed on the image 303.

  When one of the straight line superimposed on the image 301 or the straight line superimposed on the image 302 is moved, the image processing apparatus 1 moves the other straight line in conjunction with the slice position of the axial image. And the axial image after the slice position change is displayed on the display unit 16 as the axial image 303.

  In addition, when the image processing apparatus 1 moves any one position of the rectangular frames superimposed on the three images 301 to 303, the other one or two rectangular frames are moved in conjunction with each other, When the size of any one of the rectangular frames superimposed and displayed on each of the three images 301 to 303 is changed, the sizes of the other one or two rectangular frames are changed in conjunction with each other.

  The above-described image change and rectangular frame size change may be realized, for example, by a user operation of a pointing device constituting the operation unit 18. Or when the operation part 18 includes the touch panel arrange | positioned on the display screen of the display part 16, you may implement | achieve by the user operation of a touch panel.

  In step S <b> 16, the partial reconfiguration volume data generation unit 174 determines whether an operation for instructing reconfiguration has been performed on the operation unit 18.

  If an operation for instructing reconfiguration is not performed on the operation unit 18 (NO in step S16), the process returns to step S14. On the other hand, if an operation for instructing reconfiguration is performed on the operation unit 18 (YES in step S16), the process proceeds to step S17. The reconfiguration instruction may be realized by, for example, a user operation of a pointing device that constitutes the operation unit 18 or a user operation of a keyboard that constitutes the operation unit 18.

  In step S17, the partial reconstruction volume data generation unit 174 reconstructs the reconstruction range designated by the rectangular frame, that is, a partial area in the FOV, by a conventional general reconstruction algorithm according to the image reconstruction processing program. To generate reconstructed volume data. For example, the voxel interval is set so that the voxel interval increases as the reconstruction range specified by the rectangular frame increases. As an example of such a setting, a setting in which the volume of the reconstruction range and the voxel interval of each axis are directly proportional can be considered. Further, for example, the user may be able to determine the voxel interval or the number of voxels regardless of the size of the reconstruction range. The determination of the voxel interval or the number of voxels by the user may be realized by a user operation of a pointing device constituting the operation unit 18, for example. Or when the operation part 18 includes the touch panel arrange | positioned on the display screen of the display part 16, you may implement | achieve by the user operation of a touch panel.

  When the process of step S17 ends, the reconstructed volume data generation process is completed. After the reconstructed volume data generation process is completed, a cross-sectional image can be displayed using the reconstructed volume data obtained by the process of step S17.

  By performing the processes of steps S11 to S17 described above, it is possible to designate a reconstruction area designated by the rectangular frame, that is, a partial area in the FOV, and to reconstruct the designated area.

  Furthermore, by performing the process of step S13 described above, information corresponding to a plurality of coronal images can be read from the visualization result image 301 in the axial direction orthogonal to the coronal image. This eliminates the need to change the slice position and reduces the amount of work for the user. Similarly, since information corresponding to a plurality of sagittal images can be read from the visualization result image 302 in the axial direction orthogonal to the sagittal image, it is possible to save time and labor for changing the slice position of the sagittal image as in Patent Document 1. The amount of work can be reduced.

  In X-ray imaging, when the target area for image diagnosis is narrow, conventionally, preliminary imaging is performed, and a step for matching the target area for image diagnosis with the FOV is necessary. However, if the FOV is widened and X-ray imaging is performed, there is a high possibility that the target area for image diagnosis is included in the FOV, and a part of the area in the FOV is set as a reconstruction range later without performing preliminary imaging. You can specify it. By implementing the present invention, as described above, the user's work amount relating to the designation of the reconstruction range is reduced, and therefore, the omission of preliminary shooting is promoted.

  Instead of the display shown in FIG. 9, the display shown in FIG. 10, that is, a display in which only one image adjustment window acting in common with the images 301 to 303 may be employed.

  Instead of the display shown in FIG. 10, the display shown in FIG. 11, that is, a display to which a “synchronize” button is added may be adopted. When the synchronization button is not selected, different visualization algorithms can be specified in the visualization result images 301 and 302. On the other hand, when the synchronization button is selected, when the visualization algorithm is changed in one of the two types of visualization result images 301 or 302, the image processing apparatus 1 has two types according to the changed visualization algorithm. The images 301 and 302 are simultaneously recreated. Therefore, in the state where the synchronization button is selected, the two types of visualization result images 301 and 302 are always generated by the same visualization algorithm. When the synchronization button is selected and the visualization result images 301 and 302 are surface rendering images, the number of voxel values to be visualized as an isosurface is changed, and the opacity for each voxel value designated as a visualization target The designation of voxel values to be visualized as isosurfaces is also synchronized.

  When the synchronization button is selected, if the visualization result images 301 and 302 are volume rendering images, the voxel value, the differentiation of the voxel value, or the designation of the color with respect to the position of the voxel, the voxel value, the differentiation of the voxel value, Or, specification of opacity with respect to the position of the voxel, contrast adjustment, brightness adjustment, and the like are also synchronized.

  The image reconstruction processing program, the image display processing program, and the reconstruction range designation program may be independent programs, or at least two programs may be integrated. As an example of program integration, a mode in which the reconstruction range designation program is included in the image reconstruction processing program (a mode in which the function of the image reconstruction processing program is expanded), and a mode in which the reconstruction range designation program is included in the image display processing program (image A form in which the function of the display processing program is extended).

  Further, the number of programs for realizing the function of the display image generation unit 173 in the functional block diagram of FIG. 5 is not particularly limited.

  In the above-described embodiment and its modification, the image processing apparatus 1 has a configuration including a reconstruction range designation program. However, the image processing apparatus 1 may be configured not to include a reconstruction range designation program. In this case, for example, the image processing apparatus 1 may acquire the reconstruction range designation data via the communication interface unit 14.

1 Image processing device 11 CPU
12 ROM
13 RAM
14 Communication interface 15 VRAM
16 Display unit 17 HDD
171 Visualization result image generation unit 172 Graphic change unit 173 Display image generation unit 173A Image integration unit 173B Integrated image graphic superimposition unit 173C Cross-sectional image graphic superimposition unit 173D Visualization result image graphic superimposition unit 173E Display image integration unit 174 Partial reconstruction Volume data generation unit 175 Cross-sectional image generation unit 18 Operation unit 301 Visualization result image in the axial direction orthogonal to the coronal image 302 Visualization result image in the axial direction orthogonal to the sagittal image 303 Axial image

Claims (10)

A visualization result image generation unit that generates a visualization result image obtained as a result of performing visualization processing viewed from at least two directions on the first reconstructed volume data;
A display image generation unit that generates a display image including at least two visualization result images and in which a graphic representing a reconstruction range is superimposed on each of the visualization result images;
A figure changing unit that changes at least one of the size or position of the remaining figure in association with at least one of the size or position of the one figure; and
A partially reconstructed volume data generating unit that reconstructs the reconstruction range specified by the graphic to generate second reconstructed volume data;
A cross-sectional image generation unit that generates a cross-sectional image viewed from a direction substantially perpendicular to the rotation trajectory of the X-ray detection unit included in the X-ray imaging apparatus using the first reconstruction volume data ;
The visualization results image Ri virtual stereoscopic image der,
The display image includes the cross-sectional image;
In the display image, the figure is superimposed on the cross-sectional image,
An image processing apparatus , wherein the visualization result image is located in a predetermined area of the display image, and the cross-sectional image is located in an area other than the predetermined area of the display image . The display image generation unit
An image integration unit that generates an integrated image obtained by integrating the visualization result image and the cross-sectional image;
2. The integrated image graphic superimposing unit that generates a display image in which a graphic representing a reconstruction range is superimposed on each of the visualization result image and the cross-sectional image included in the integrated image. The image processing apparatus described. The display image generation unit
A cross-sectional image graphic superimposing unit for generating a first display image in which a graphic representing a reconstruction range is superimposed on the cross-sectional image;
A visualization result image graphic superimposing unit that generates a second display image in which a graphic representing a reconstruction range is superimposed on the visualization result image;
The image processing apparatus according to claim 1, further comprising: a display image integration unit that generates a display image obtained by integrating the first display image and the second display image. The image processing apparatus according to claim 1, wherein the visualization result image is a volume rendering image. The visualization result image generation unit changes the volume by changing at least one of a voxel value, a differentiation of a voxel value, at least one color or opacity corresponding to at least one of voxel positions, or brightness or contrast. The image processing apparatus according to claim 4, wherein the rendered image can be regenerated. The image processing apparatus according to claim 1, wherein the visualization result image is a surface rendering image. The visualization result image generation unit includes a designated value of a voxel value to be visualized as an isosurface and a designated value of opacity corresponding to the voxel value to be visualized as an isosurface, or a designated value of a voxel value to be visualized as an isosurface The image processing apparatus according to claim 6, wherein the surface rendering image can be regenerated by changing at least one of the number of the images. The image processing apparatus according to claim 1, wherein the visualization result image is an image based on parallel projection. Computer
A visualization result image generation unit that respectively generates a visualization result image obtained as a result of performing a visualization process viewed from at least two directions on the first reconstructed volume data;
A display image generation unit that generates a display image that includes at least two visualization result images and in which a graphic representing a reconstruction range is superimposed on each of the visualization result images;
A figure changing unit that changes at least one of the size or position of the remaining figure in association with at least one of the size or position of the one figure;
A partially reconstructed volume data generating unit that reconstructs the reconstructed range specified by the graphic and generates second reconstructed volume data; and
A cross-sectional image generation unit that generates a cross-sectional image viewed from a direction substantially perpendicular to the rotation trajectory of the X-ray detection unit included in the X-ray imaging apparatus using the first reconstruction volume data;
An image processing program for functioning as
The visualization result image is a virtual stereoscopic image,
The display image includes the cross-sectional image;
In the display image, the figure is superimposed on the cross-sectional image,
An image processing program, wherein the visualization result image is located in a predetermined area of the display image, and the cross-sectional image is located in an area other than the predetermined area of the display image. A visualization result image generation step for generating a visualization result image obtained as a result of performing a visualization process viewed from at least two directions on the first reconstructed volume data;
A display image generation step of generating a display image that includes at least two visualization result images and in which a graphic representing a reconstruction range is superimposed on each of the visualization result images;
A figure changing step of changing at least one of the size or position of the remaining figure in association with at least one of the size or position of the one figure; and
A partially reconstructed volume data generating step of reconstructing a reconstructed range designated by the graphic to generate second reconstructed volume data;
A cross-sectional image generation step of generating a cross-sectional image viewed from a direction substantially perpendicular to the rotational trajectory of the X-ray detection unit provided in the X-ray imaging apparatus using the first reconstruction volume data,
The visualization result image is a virtual stereoscopic image,
The display image includes the cross-sectional image;
In the display image, the figure is superimposed on the cross-sectional image,
An image processing method, wherein the visualization result image is located in a predetermined area of the display image, and the cross-sectional image is located in an area other than the predetermined area of the display image.