JP5901930B2 - Image processing device - Google Patents

Description

  Embodiments described herein relate generally to an image processing apparatus.

  For myocardial analysis, it is possible to scan the entire heart with a high-resolution image diagnostic apparatus such as an X-ray computed tomography apparatus or a magnetic resonance imaging apparatus. In order to display the analysis result of the myocardium, a polar map and an MPR (Multi Planar Reconstruction) image are generated based on the volume data generated by the image diagnostic apparatus. The polar map is an image showing a spatial distribution of pixel values in a two-dimensional polar coordinate system defined by a rotation angle from a reference point around the axis of the myocardial region and a distance from the reference point on the axis. Therefore, the polar map is suitable for observing the entire myocardium. However, it is difficult to grasp the correspondence between the position on the polar map and the actual myocardial position. The MPR image shows a spatial distribution of pixel values in one cross section set in the myocardial region. Therefore, it is easy to grasp the correspondence between the position on the MPR image and the actual myocardial position. However, it is difficult to observe the entire myocardium with an MPR image.

  An object of the present invention is to provide an image processing apparatus capable of improving myocardial image diagnostic ability.

An image processing apparatus according to the present embodiment includes a storage unit that stores volume data relating to the heart, an extraction unit that extracts a myocardial region from the volume data, and an outer wall to an inner wall of the extracted myocardial region. A setting unit for setting a curved surface for display at a predetermined position, and a developed image generation for generating developed image data representing a spatial distribution of pixel values on the curved surface in a two-dimensional orthogonal coordinate system based on the volume data And a display unit for displaying a schematic image of the myocardial region together with the generated developed image.

1 is a diagram illustrating a configuration of an image processing apparatus according to an embodiment. The figure which shows the typical flow of the image process performed by control of the control part of FIG. The schematic diagram of the myocardial area extracted in step S2 of FIG. The figure for demonstrating the normalization process performed by the curved surface setting part in step S4 of FIG. The figure which shows the concept of the expansion | deployment image generation process performed by the expansion | deployment image generation part in step S7 of FIG. The figure which shows the detail of the expansion | deployment image generation process performed by the expansion | deployment image generation part in step S7 of FIG. The figure which shows the example of a display of the expansion | deployment image by a display part in step S8 of FIG. The figure which shows the other example of a display of the expansion | deployment image by a display part in step S8 of FIG. The figure which shows the other example of a display of the expansion | deployment image by a display part in step S8 of FIG. The figure which shows the other example of a display of the expansion | deployment image by a display part in step S8 of FIG. The figure which shows the detail of the other expansion | deployment image generation processing performed by the expansion | deployment image generation part in step S7 of FIG. The figure which shows the example of a display of the guide image generated by the guide image generation part of FIG. The figure for demonstrating the projection process performed by the projection process part of FIG. The figure which shows typically the typical flow of the superimposition process of the expansion | deployment image of the myocardial area | region and the expansion | deployment image of a blood vessel area | region performed under control of the control part which concerns on the application example 4. FIG. The figure which shows the example of a display of the polar map produced | generated by the polar map generation part of FIG. The figure which shows the example of a display of the curved surface image produced | generated by the curved surface image generation part of FIG.

  The image processing apparatus according to this embodiment will be described below with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration of an image processing apparatus 1 according to the present embodiment. As illustrated in FIG. 1, the image processing apparatus 1 includes a storage unit 11, an extraction unit 13, a display curved surface setting unit 15, a developed image generation unit 17, a display unit 19, an operation unit 21, and a control unit 23. .

  The storage unit 11 stores volume data generated by scanning the subject's heart with the diagnostic imaging apparatus. The volume data includes a pixel region related to the heart (hereinafter referred to as a heart region). Examples of the diagnostic imaging apparatus according to the present embodiment include an X-ray computed tomography apparatus, a magnetic resonance imaging apparatus, a PET apparatus, and a SPECT apparatus. In the case of an X-ray computed tomography apparatus, a contrast agent flows into the heart during a CT scan. In the case of a magnetic resonance imaging apparatus, blood flow can be imaged without a contrast agent, so that a contrast agent may or may not flow into the heart during MR scanning. An index value related to the heart shape index and an index value related to the heart function index are assigned to the voxels of the volume data. When the volume data is generated by an X-ray computed tomography apparatus, a CT value that is an index value of a form index is assigned to the volume data. When the volume data is a magnetic resonance imaging apparatus, a T1 value, a T2 value, or the like, which is an index value of a shape index, is assigned to the volume data. Examples of the function index include an analysis value calculated by perfusion analysis of volume data generated by an X-ray computed tomography apparatus or a magnetic resonance imaging apparatus. When the volume data is generated by a PET apparatus or a SPECT apparatus, the volume data includes an index value of a function index indicating the concentration distribution of the radioisotope, and index values of various function indexes calculated based on the index value. Assigned. The storage unit 11 further stores an image processing program executed by the control unit 23.

  For simplicity of the following description, when the index value of the form index and the index value of the function index are not particularly distinguished, these are collectively referred to as pixel values.

  The extraction unit 13 extracts a pixel region corresponding to a specific part from the volume data. Specifically, the extraction unit 13 extracts a pixel region corresponding to a myocardium (hereinafter referred to as a myocardial region) from the volume data, or a pixel region corresponding to a blood vessel (hereinafter referred to as a blood vessel region). And so on.)

  The display curved surface setting unit 15 sets a curved surface for display (hereinafter referred to as a display curved surface) at a designated position between the outer wall and the inner wall of the myocardial region. The display curved surface is a display surface of a developed image described later.

  The developed image generating unit 17 generates developed image data related to the display curved surface based on the volume data. The developed image is an image in which a spatial distribution of three-dimensional pixel values on the display curved surface is expressed by a two-dimensional orthogonal coordinate system.

  The display unit 19 displays a developed image or the like on a display device. Examples of the display device include a CRT display, a liquid crystal display, an organic EL display, and a plasma display.

  The operation unit 21 receives various commands and information input from the user via the input device. Examples of the input device include a pointing device such as a mouse and a trackball, a selection device such as a switch button, or a keyboard.

  The control unit 23 functions as the center of the image diagnostic apparatus. Specifically, the control unit 23 develops an image processing program stored in the storage unit 11, controls each unit according to the image processing program, and executes image processing according to the present embodiment.

  Hereinafter, details of image processing executed under the control of the control unit 23 will be described. In order to specifically describe the following, it is assumed that the volume data is generated by an X-ray computed tomography apparatus.

  FIG. 2 is a diagram illustrating a typical flow of image processing executed under the control of the control unit 23. The control unit 23 executes image processing in response to an instruction to start image processing via the operation unit 21 from the user. Further, the control unit 23 reads volume data relating to the heart imaged by the contrast agent from the storage unit 11 and supplies the volume data to the extraction unit 13 (step S1).

  When step S1 is performed, the control unit 23 causes the extraction unit 13 to perform extraction processing (step S2). In step S2, the extraction unit 13 extracts a myocardial region from the volume data using arbitrary image processing such as a region expansion method. FIG. 3 is a schematic diagram of the myocardial region R1. As shown in FIG. 3, the myocardial region R1 has a hollow, substantially conical shape. The extraction unit 13 sets the cusp PA and the base point PB of the myocardial region R1 according to the shape of the myocardial region R1. The tip of the myocardial region R1 is set to the cusp PA, and an arbitrary point on the base side of the myocardial region R1 is set to the base point PB. Then, the axis passing through the cusp PA and the base point PB is set to the central axis AC by the extraction unit 13.

  When step S2 is performed, the control unit 23 causes the curved surface setting unit 15 to perform cross-section setting processing (step S3). In step S3, the curved surface setting unit 15 sets a plurality of cross sections along the central axis AC as volume data. Typically, the plurality of cross sections are set to be orthogonal to the central axis AC. Note that the orientation of the plurality of cross sections is not limited to this. For example, the plurality of cross sections may be set to be inclined with respect to the axial axis AC.

  When step S3 is performed, the control unit 23 causes the curved surface setting unit 15 to perform normalization processing (step S4). In step S4, the curved surface setting unit 15 normalizes the distance between the inner wall and the outer wall of the myocardial region within a predetermined numerical range for each of the plurality of cross sections. FIG. 4 is a diagram for explaining the normalization process, and is a diagram schematically showing the myocardial region R1 in the cross section. As shown in FIG. 4, the curved surface setting unit 15 first extracts the inner wall WI and the outer wall WO of the myocardial region R1 for each cross section. More specifically, the curved surface setting unit 15 extracts a closed curve (inner wall) inside the myocardial region R1 by tracing the inner boundary of the myocardial region R1, and then traces the outer boundary of the myocardial region by tracing the outer boundary. A closed curve (outer wall) outside R1 is extracted. The inner boundary is a boundary closer to the heart axis of both walls of the myocardial region R1, and the outer boundary is a boundary farther from the heart axis of both walls of the myocardial region R1. Next, the curved surface setting unit 15 sets a plurality of straight lines LI extending radially from the central axis AC. In FIG. 4, four straight lines LI are shown for convenience, but in actual processing, it is preferable to set more than four straight lines LI. Next, the curved surface setting unit 15 specifies an intersection point PI between the straight line LI and the inner wall WI and an intersection point PO between the straight line LI and the outer wall WO. The curved surface setting unit 15 normalizes the distance between the intersection point PI and the intersection point PO on each straight line LI within a predetermined numerical range. For example, the predetermined numerical range is set to 0% to 100%. In this case, the curved surface setting unit 15 sets the position of the intersection point PI to 0% and the position of the intersection point PO to 100%. The position of each point on the straight line LI between the intersection point PI and the intersection point PO is such that the distance from the intersection point PI to the position of each point linearly changes from 0% to 100% as it proceeds from the intersection point PI to the intersection point PO. Set to As a result, normalization is performed. Hereinafter, the direction from the intersection point PI to the intersection point PO will be referred to as the thickness direction.

  When step S4 is performed, the control unit 23 waits for a user to specify a numerical value within a predetermined numerical value range (0% to 100% in the above example) via the operation unit 25 ( Step S5). The specified numerical value means the position of the display curved surface of the developed image. The user designates a desired numerical value not less than the lower limit value and not more than the upper limit value of the numerical value range via the operation unit 25. When the numerical value range is 0% to 100%, a desired numerical value of 0% to 100% is designated. The numerical value may be input via an input device such as a keyboard, a touch panel, or a mouse. Note that the numerical value indicating the position of the display curved surface of the developed image is not necessarily specified by the user via the operation unit 25. For example, the curved surface setting unit 15 may automatically specify a numerical value as 0% representing the inner wall or 100% representing the outer wall.

  When a numerical value is designated by the user, the control unit 23 causes the curved surface setting unit 15 to perform curved surface setting processing (step S6). In step S6, the curved surface setting unit 15 sets a display curved surface at a position on the myocardial region corresponding to the numerical value designated in step S5. Specifically, first, the curved surface setting unit identifies a pixel corresponding to a designated numerical value for each straight line LI of each cross section shown in FIG. Then, the curved surface setting unit 15 sets the specified set of all pixels as the display curved surface of the developed image.

  When step S6 is performed, the control unit 23 causes the developed image generation unit 17 to perform a developed image generation process (step S7). In step S7, the developed image generation unit 17 generates developed image data related to the display curved surface set in step S6 based on the volume data. Hereinafter, the developed image generation process will be described in detail.

  FIG. 5 is a diagram showing the concept of the developed image generation process. 5A shows the display curved surface PC before development, and FIG. 5B shows the display curved surface after development, that is, a developed image. As shown in FIG. 5, the developed image generation process is a process of developing the display curved surface PC so as to peel from the development start point PS.

  FIG. 6 is a diagram for explaining the developed image generation processing in detail. 6A shows a longitudinal section of the myocardial region R1, FIG. 6B shows a section CSn set in the myocardial region R1, and FIG. 6C shows a template for a developed image. ing. For the sake of illustration, FIG. 6A shows three cross sections CS1, CS2, and CSm. The number n of cross sections may be set to any number. The greater the number of cross sections n, the better the resolution of the developed image. As shown in FIG. 6B, it is assumed that the display curved surface DP is set at a position of 50% in the myocardial region R1.

  In the developed image generation process, first, the developed image generation unit 17 sets a development start point PS in each cross section CSn. In each cross section CSn, the development start point PS is set to the same angle around the axis AC. The angle of the development start point PS can be set to an arbitrary value via the operation unit 21 by the user. In order to specifically describe the following, it is assumed that the development start point PS is set to 0 °. Further, the developed image generator 17 sets the reference point PR in each cross section CSn. The reference point PR is set at the same angle different from the development start point PS in each cross section CSn. The reference point PR is aligned with the center of the X-axis of the developed image. For example, the reference point PR and the development start point PS are set such that the angle difference between the reference point PR and the development start point PS is ± 180 °.

  The developed image generation unit 17 uses the pixel values of the pixels on the circumference where the display curved surface DP and the cross section CSn intersect (hereinafter referred to as “circumferential pixels”) as the developed image shown in FIG. An unfolded image is generated by assigning it to a template for. As shown in FIG. 6C, the vertical axis (Y-axis) of the template is defined by the distance on the central axis AC. Specifically, the distance on the mandrel AC is defined as a distance along the mandrel AC from a reference position on the mandrel AC (for example, the cusp PA). The horizontal axis (X axis) of the template is the distance from the reference position (for example, the reference point PR) around the cardiac axis AC of the myocardial region R1. In other words, the horizontal axis (X axis) of the template is defined by the distance on the circumference. Specifically, the distance on the circumference is defined as a distance along the circumference from a reference position (for example, reference point PR) on the circumference where each cross section and the display curved surface intersect. As described above, the template has a two-dimensional orthogonal coordinate system defined by the distance on the axis and the distance on the circumference. The reference point PR of each cross section CSn is aligned with the center of the X axis of the template (ie, distance 0). For example, the clockwise direction from the reference point PR is defined as the + X direction of the template, and the counterclockwise direction from the reference point PR is defined as the −X direction of the template. The length along the X axis of the template is set to the maximum length among the circumferential lengths of the respective cross sections CSn. Note that the length of the X-axis of the template may be set longer than the maximum length.

  Here, the process of assigning pixel values to the template will be specifically described. First, the developed image generation unit 17 specifies a plurality of circumferential pixels on the circumference where the display curved surface DP and the section CSn intersect for each of the plurality of cross sections. Then, the developed image generation unit 17 specifies the template coordinates of each circumferential pixel. Specifically, first, the developed image generation unit 17 specifies the distance along the central axis AC from the cusp PA to each cross section CSn. Thereby, the Y-axis coordinate of the template is specified for each circumferential pixel. Next, the developed image generation unit 17 specifies the distance along the circumference from the reference point PR to each circumferential pixel for each cross-section CSn. Thereby, the X-axis coordinate of the template is specified for each circumferential pixel. Then, the developed image generation unit 17 assigns the pixel value of the circumferential pixel to the specified template coordinates for each circumferential pixel. Data of the developed image is generated by assigning the pixel values of the circumferential pixels.

  When step S7 is performed, the control unit 23 causes the display unit 19 to perform display processing (step S8). In step S8, the display unit 19 displays the developed image generated in step S7. FIG. 7 is a diagram illustrating an example of the developed image I1. As shown in FIG. 7, the developed image I1 is an image expressing the spatial distribution of pixel values on a three-dimensional display curved surface with two-dimensional orthogonal coordinates, as can be seen from such a generation process. The display unit 19 displays the developed image I1 in gray according to the pixel value, for example. The display unit 19 may display a mark indicating the distance along the circumference from the reference point PR on the developed image in order to easily grasp the position on the developed image I1. Examples of such a mark include a line LR1 indicating a distance 0 (reference point), a line LR2 indicating an intermediate distance ± Mid, and a line LR3 indicating a maximum distance ± Max as shown in FIG. The maximum distance ± Max is the maximum distance among the distances from the reference point to the development start point along the circumference of each cross section CSn. The intermediate distance ± Mid is half of the maximum distance ± Max. In addition, a mark is not limited to a dotted line, All existing lines, such as a solid line, a broken line, and a dashed-dotted line, are applicable. Further, the mark is not limited to a line, and may be a mark displayed at the end of the developed image I1.

  Compared with a polar map in which a spatial distribution of three-dimensional pixel values is expressed in two-dimensional polar coordinates, a user such as a doctor shows a correspondence between the position on the image and the actual myocardial position. Easy to grasp. Further, the display curved surface of the developed image is distributed over the entire myocardial region. Therefore, the user can observe the entire myocardial region in the developed image as compared with the MPR image expressing the spatial distribution of the pixel values in the cross section.

  When step S8 ends, the control unit 23 ends the image processing according to the present embodiment.

  Note that the display method of the developed image in step S8 is not limited to only gray display. For example, the display unit 19 may display the developed image I2 in a color corresponding to the pixel value as shown in FIG. At this time, the display unit 19 may display the color bar together with the developed image I2 in order to present the correspondence between the color and the pixel value to the user. The color display allows the user to grasp the difference in pixel value from the difference in color. As still another display method, the display unit 19 may display the developed image as a contour line as shown in FIG. 9, or as a three-dimensional graph as shown in FIG. As shown in FIG. 9, in the case of contour line display, the display unit 19 displays a developed image I3 in which pixels having equal pixel values are connected by lines (contour lines). The contour lines may be displayed in gray or in color according to the pixel value. As shown in FIG. 10, in the case of a three-dimensional graph display, the display unit 19 displays a developed image I4 expressed by a three-dimensional bar graph having a height corresponding to the pixel value. The bar graph may be displayed in gray or in color depending on the pixel value. Further, the position of the viewpoint in the three-dimensional graph display can be arbitrarily set by the user via the operation unit 21.

  As described above, the display unit 19 according to the present embodiment can perform contour line display and three-dimensional graph display of the developed image in addition to the normal display method. Further, these display methods can display in gray or color according to the pixel value. As described above, the image processing apparatus 1 has a number of display methods of the developed image. These display methods can be arbitrarily selected according to an instruction from the user via the operation unit 21. That is, the display unit 19 can display the developed image by a display method according to the user's preference, and can improve the efficiency of image diagnosis.

  The thickness of the myocardial region is not the same and varies depending on the site in the myocardial region. Therefore, when the position in the thickness direction of the myocardial region is designated by an absolute distance (distance before normalization), a certain part is close to the inner wall and another part is close to the outer wall. As described above, the image processing apparatus 1 normalizes the thickness of the myocardial region within a predetermined numerical range, and generates a developed image related to the display curved surface corresponding to an arbitrary designated value within this numerical range. By normalizing the thickness of the myocardial region in this way, the image processing apparatus 1 can determine the anatomically homogeneous position in the thickness direction of the myocardial region near the inner wall, the outer wall, the inside of the myocardium, or the like with a single designated value. You can specify all at once. Therefore, this normalization process can simplify the setting of the display curved surface and improve the image diagnostic ability.

  The user is not only interested in a specific position in the thickness direction of the myocardial region. For example, in myocardial infarction, the tissue dies from the myocardial intima side toward the myocardium outer membrane side. Therefore, it is clinically important to confirm how much tissue is dead along the thickness direction of the myocardium. The image processing apparatus 1 can display the developed image by browsing along the thickness direction of the myocardium. For example, when the user wants to observe a developed image relating to a display curved surface at a position different from the displayed developed image, the user can designate an arbitrary display curved surface position via the operation unit 21 as in step S5. When the display curved surface position is designated, the developed image generation unit 17 generates a developed image related to the designated display curved surface position, and the display unit 19 displays the generated developed image. In this way, the developed image generation unit 17 can update the display curved surface of the developed image in accordance with a display curved surface position change instruction from the user. As a result, the image processing apparatus 1 can display the spatial distribution of pixel values on the display curved surface at an arbitrary position in the thickness direction of the myocardial region as a developed image. By browsing display, a wide area can be observed in a short time.

  In the above description, the coordinate system of the developed image is the first orthogonal coordinate system defined by the distance on the central axis and the distance on the circumference. However, the present embodiment is not limited to this. For example, the coordinate system of the developed image may be a second orthogonal coordinate system defined by a distance on the central axis and a rotation angle around the central axis. Hereinafter, the developed image related to the first coordinate system is referred to as a mandrel-circumferentially developed image, and the developed image related to the second coordinate system is referred to as a mandrel-angle developed image. The developed image generation unit 17 generates a mandrel-angle developed image related to the display curved surface set in step S6 based on the volume data.

  Hereinafter, a method for generating a mandrel-angle developed image performed by the developed image generation unit 17 in step S7 will be described with reference to FIG. FIG. 11A shows a longitudinal section of the myocardial region R1, FIG. 11B shows a section CSn set in the myocardial region R1, and FIG. 11C shows a cardiac axis-angle developed image. Shows the template. As shown in FIG. 11C, the vertical axis (Y-axis) of the template for the core-angle-expanded image is a distance on the heart axis AC, specifically, a reference position ( For example, the distance is defined as the center axis AC from the cusp PA). The horizontal axis (X axis) of the template is defined by the rotation angle from the reference position (for example, the reference point PR) around the cardiac axis AC of the myocardial region R1. In other words, the horizontal axis (X-axis) of the template is defined by a rotation angle around the central axis AC, specifically, a rotation angle from a reference position (for example, the reference point PR) around the central axis AC. As described above, the template for the mandrel-angle developed image has a two-dimensional orthogonal coordinate system defined by the position on the mandrel and the rotation angle around the mandrel. Each reference point PR is aligned with the center of the X axis of the template (ie, an angle of 0 °). For example, clockwise from the reference point PR is defined in the + X direction of the template, and counterclockwise from the reference point PR is defined in the −X direction of the template.

  Here, the pixel value assignment processing will be specifically described. First, the developed image generation unit 17 specifies a plurality of circumferential pixels on the circumference where the display curved surface DP and the section CSn intersect for each of the plurality of sections CSn. Then, the developed image generation unit 17 specifies the template coordinates of each circumferential pixel. Specifically, first, the developed image generation unit 17 specifies the distance along the central axis AC from the cusp PA to each cross section CSn. Thereby, the Y-axis coordinate of the template is specified for each circumferential pixel. Next, the developed image generation unit 17 specifies the rotation angle around the axis AC from the reference point PR to each circumferential pixel for each cross-section CSn. Thereby, the X-axis coordinate of the template is specified for each circumferential pixel. Then, the developed image generation unit 17 assigns the pixel value of the circumferential pixel to the specified template coordinates for each circumferential pixel. A mandrel-angle developed image is generated by assigning the pixel values of the circumferential pixels.

  In the volume data, the myocardial region R1 has different spatial resolution regarding the angle depending on the position on the heart axis. Therefore, when the spatial resolution regarding the angle is relatively low, such as in the vicinity of the cusp PA, there is a possibility that an empty pixel to which no pixel value is assigned in the mandibular axis-angle development image may be generated. In this case, the developed image generation unit 17 calculates the pixel value of the empty pixel by interpolation. As an interpolation method, the nearest neighbor method that replaces the pixel value of the empty pixel with the pixel value of the pixel with the closest angle, or the bi-linear that estimates the pixel value of the pixel based on the pixel value distribution Any known interpolation method such as) method is applicable. By executing such an interpolation method, it is possible to lose empty pixels to which no pixel value is assigned. Therefore, the image diagnostic ability by the mandibular axis-angle developed image is improved.

  The generated mandibular axis-angle development image is displayed by the display unit 19. The display unit 19 superimposes the reference line indicating the rotation angle from the reference point PR around the axis AC on the axis-angle expanded image in order to easily grasp the position on the axis-circumferentially expanded image. It may be displayed. As such a reference line, for example, as shown in FIG. 11C, a line indicating 0 ° (reference point PR), a line indicating + 90 °, a line indicating −90 °, and ± 180 ° are indicated. A line is mentioned.

  Note that the mandrel-angle developed image may be generated from the mandrel-circumferentially developed image. In this case, the developed image generation unit 17 performs an interpolation process on the mandrel-circumferentially developed image so as to make the image width related to the X axis uniform, and generates a mandrel-angle developed image. For example, the developed image generation unit 17 specifies the maximum width related to the X axis of the mandrel-circumferentially developed image, and sets the specified maximum width as the reference width. Then, the developed image generation unit 17 performs interpolation processing on the mandrel-circumferentially developed image in order to expand the image width related to the X axis to the reference width for each Y axis coordinate. As a result, a mandrel-angle developed image is generated from the mandrel-circumferentially developed image. As the interpolation method, any known interpolation method such as the above-mentioned two-arrest neighbor method or bilinear method can be applied.

  Thus, according to the image processing apparatus 1 according to the present embodiment, the myocardial image diagnostic ability can be improved.

  Next, various application examples for improving the image diagnostic ability based on the developed image will be described. In the following application examples, the developed image can be applied to either a mandrel-circumferentially developed image or a mandrel-angular developed image. Accordingly, in the following description, unless otherwise specified, it is simply described as a developed image.

[Application Example 1]
As shown in FIG. 1, the image processing apparatus 1 further includes a guide image generation unit 25. The guide image generator 25 generates guide image data for clearly indicating the position of the display curved surface of the developed image being displayed. The display unit 19 displays the generated guide image side by side with the developed image. Details of the image processing apparatus 1 according to the application example 1 will be described below. In the following description, components having substantially the same functions as those of the present embodiment are denoted by the same reference numerals, and redundant description will be given only when necessary.

  FIG. 12 is a diagram illustrating a display example of the developed image I1 and the guide image GI. As shown in FIG. 12, the guide image GI is an image that schematically represents a myocardial region having a standard shape. For example, the guide image GI includes a three-dimensional schematic image GI1 that three-dimensionally represents a schematic myocardial region, and a planar schematic image GI2 obtained by viewing the schematic myocardial region from the base side. A line L2 indicating the position of the display curved surface of the developed image is superimposed on the three-dimensional schematic image GI1 and the planar schematic image GI2. In order to display the position of the display curved surface, the distance between the inner wall and the outer wall of the three-dimensional schematic image GI1 and the planar schematic image GI2 is normalized by the normalization numerical range in step S4 of FIG. The guide image generating unit 25 calculates positions in the three-dimensional schematic image GI1 and the planar schematic image GI2 corresponding to the numerical values specified in step S5, and superimposes the line L2 on the calculated position. The display unit 19 displays the three-dimensional schematic image GI1 and the planar schematic image GI2 on which the line L2 is superimposed. The guide image generating unit 25 may display the above-described reference lines LR1, LR2, and LR3 on the three-dimensional schematic image GI1 and the planar schematic image GI2. Thus, the user can more clearly and easily grasp the correspondence between the position on the developed image and the actual myocardial position.

  As described above, the image processing apparatus 1 can generate a guide image that clearly indicates the position of the display curved surface of the developed image, and display the guide image side by side with the developed image. By observing the guide image, the user can clearly and easily grasp the position of the display curved surface of the developed image in the myocardial region. Thus, according to the image processing apparatus 1 according to the application example 1, the image diagnostic ability of the myocardium is improved.

  In the above description, for the sake of illustration, the display unit 19 has viewed the schematic myocardial region three-dimensionally as a guide image, and the schematic myocardial region viewed from the base side. And a plane schematic image. However, the display unit 19 may display either a three-dimensional schematic image or a planar schematic image. Further, the display unit 19 may display an image schematically showing myocardial regions in different directions as the guide image.

[Application 2]
As shown in FIG. 1, the image processing apparatus 1 further includes a projection processing unit 27. The projection processing unit performs pixel value projection processing on a plurality of developed images related to a plurality of display curved surfaces to generate a single projection image. Details of the image processing apparatus 1 according to the application example 2 will be described below. In the following description, components having substantially the same functions as those of the present embodiment are denoted by the same reference numerals, and redundant description will be given only when necessary.

  The control unit 23 controls the developed image generation unit 17, the projection processing unit 25, and the display unit 19 in order to execute image processing according to the application example 2 in accordance with an instruction from the user via the operation unit 21. First, as shown in FIG. 13, the developed image generation unit 17 generates a plurality of developed image data related to a plurality of display curved surfaces from the inner wall to the outer wall based on the volume data. That is, the plurality of display curved surfaces are arranged along the thickness direction of the myocardial region. Next, the projection processing unit 25 performs pixel value projection processing on a plurality of development image data along a predetermined projection direction, and generates single projection image data from the plurality of development image data. The predetermined projection direction is defined in the thickness direction, for example. As the pixel value projection processing according to the present embodiment, the addition projection processing for setting the pixel value of the pixel through which the projection ray penetrates is set to the pixel value of the pixel of the projection image, and the maximum value is set to the pixel value of the pixel of the projection image. All existing projection processes such as maximum value projection processing, average value projection processing that sets the average value to the pixel value of the pixel of the projection image, and minimum value projection processing that sets the minimum value to the pixel value of the pixel of the projection image are applied Is possible. The type of pixel value projection processing to be executed can be arbitrarily selected by the user via the operation unit 21.

  Then, the display unit 19 displays the generated projection image. The display unit 19 may display the projected image in gray corresponding to the pixel value or in color. As can be seen from the generation process described above, the pixel value of each pixel of the projection image reflects the pixel values of all the pixels along the thickness direction of the myocardial region. Further, the projection image has the same orthogonal coordinate system as the developed image. Therefore, the user can grasp at a glance whether or not there is an abnormality in the myocardium, and furthermore, the position of the abnormal part by simply observing a single projection image.

  As described above, the image processing apparatus 1 generates data of a single projection image based on data of a plurality of developed images related to a plurality of display curved surfaces, and displays the generated projection image. The user can easily and clearly grasp the entire state of the myocardium by observing the projection image. Thus, according to the image processing apparatus 1 according to the application example 2, myocardial image diagnostic ability is improved.

[Application Example 3]
As shown in FIG. 1, the image processing apparatus 1 further includes a thickness calculation unit 29. The thickness calculator 29 calculates the thickness of the myocardial region for each pixel of the developed image. Details of the image processing apparatus 1 according to the application example 3 will be described below. In the following description, components having substantially the same functions as those of the present embodiment are denoted by the same reference numerals, and redundant description will be given only when necessary.

  In the application example 3, the control unit 23 performs the image processing according to the application example 3 in accordance with an instruction from the user via the operation unit 21, and the thickness calculation unit 29, the developed image generation unit 17, and the display unit 19. To control. First, for each of the plurality of pixels included in the developed image, the thickness calculation unit 29 determines the distance between the inner wall and the outer wall in the thickness direction of the myocardial region along the straight line L1 in FIG. 4, that is, the thickness of the myocardial region. Is calculated. The thickness of the myocardial region may be, for example, the number of pixels included between the inner wall and the outer wall, or a value obtained by multiplying the number of pixels by a predetermined constant. Next, the developed image generation unit 17 assigns the calculated thickness to the pixel value of the developed image for each of the plurality of pixels included in the developed image. Thereby, data of a developed image (hereinafter referred to as a thickness developed image) that expresses the spatial distribution of the thickness of the myocardial region with two-dimensional orthogonal coordinates is generated.

  The display unit 19 displays the generated thickness development image. The display method of the thickness development image may be displayed in gray according to the thickness value, or may be displayed in color. Further, the display unit 19 may display the thickness development image in a contour line or a three-dimensional graph.

  As described above, the image processing apparatus 1 according to the application example 3 generates a thickness development image that expresses the thickness of the myocardial region with two-dimensional orthogonal coordinates, and displays the generated thickness development image. The user can easily and clearly grasp the thickness of the myocardium by observing the thickness development image. Thus, according to the image processing apparatus 1 according to the application example 3, the myocardial image diagnostic ability is improved.

[Application Example 4]
The image processing apparatus 1 according to the application example 4 can display the blood vessel region so as to overlap the developed image. Hereinafter, the image processing apparatus 1 according to the application example 4 will be described. In the following description, components having substantially the same functions as those of the present embodiment are denoted by the same reference numerals, and redundant description will be given only when necessary.

  FIG. 14 is a diagram schematically illustrating a typical flow of image processing according to the application example 4 performed under the control of the control unit 23. In application example 4, the control unit 23 controls the extraction unit 13, the developed image generation unit 17, and the display unit 19 in order to execute image processing according to application example 4 in accordance with an instruction from the user. The extraction unit 13 extracts the myocardial region R1 and the blood vessel region R2 from the volume data. The blood vessel region R2 according to the application example 4 is typically a pixel region related to the coronary artery surrounding the heart (hereinafter referred to as a coronary artery region), but is a blood vessel region related to another blood vessel that feeds the myocardium. There may be. The type of blood vessel region to be extracted can be arbitrarily selected by the user via the operation unit 21.

  Next, the developed image generation unit 17 generates a developed image I1 of the myocardial region and a developed image I5 of the blood vessel region based on the volume data. The developed image I5 of the blood vessel region is generated by the same method as the developed image I1 of the myocardial region. If the image size of the developed image I5 of the blood vessel region and the developed image I1 of the myocardial region are different, the developed image I5 of the blood vessel region or the developed image I1 of the myocardial region is reduced or enlarged so as to have the same image size. . Then, the display unit 19 displays the developed image I5 of the vascular region superimposed on the developed image I1 of the myocardial region in a position-aligned manner.

  As described above, the image processing device 1 according to the application example 4 displays the developed image of the blood vessel region superimposed on the developed image of the myocardial region. With this display, the user can observe the properties of the myocardium and the properties of the blood vessels in association with each other. For example, when there is a blood vessel causing an abnormality such as stenosis, an abnormality also occurs in a myocardial region that is fed by the blood vessel. Therefore, as shown in Application Example 4, displaying the developed image of the vascular region superimposed on the developed image of the myocardial region is an effective technique for specifying the responsible result of the disease, and is very useful clinically. Thus, according to the image processing apparatus 1 according to the application example 4, myocardial image diagnostic ability is improved.

[Application Example 5]
As shown in FIG. 1, the image processing apparatus 1 according to the application example 5 further includes a polar map generator 31. The polar map generating unit 31 generates a polar map related to the display curved surface similar to the developed image based on the volume data. The display unit 19 displays the polar map and the developed image side by side. Hereinafter, the image processing apparatus 1 according to the application example 5 will be described in detail. In the following description, components having substantially the same functions as those of the present embodiment are denoted by the same reference numerals, and redundant description will be given only when necessary.

  FIG. 15 is a diagram illustrating a display example of the developed image I1 and the polar map I6. As shown in FIG. 15, the developed image I1 and the polar map I6 are displayed side by side by the display unit 19. For example, the polar map generator 31 generates a polar map I6 related to the display curved surface corresponding to the numerical value specified in step S5 based on the volume data. Accordingly, the displayed developed image I1 and polar map I6 have the same display curved surface. The user can check the property of the myocardium with respect to a single display curved surface both in the developed image I1 and the polar map I6. Therefore, the workflow for evaluating the infarct region and the ischemic region is improved.

  In addition, the polar map generation unit 31 can generate a polar map related to the display surface after the change in accordance with an instruction to change the position of the display surface via the operation unit 21 by the user. Therefore, the image processing apparatus 1 according to the application example 5 can change the display curved surface of the developed image I1 and the display curved surface of the polar map I6 in conjunction with each other. Thereby, the image processing apparatus 1 according to the application example 5 realizes the linked browsing display process of the developed image I1 and the polar map I6. Thus, according to the image processing apparatus 1 according to the application example 5, myocardial image diagnostic ability is improved.

[Application Example 6]
As illustrated in FIG. 1, the image processing apparatus 1 according to the application example 6 further includes a composite image generation unit 33. The composite image generation unit 33 can display a composite image of the developed image related to the form index and the developed image related to the function index. Hereinafter, the image processing apparatus 1 according to Application Example 6 will be described. In the following description, components having substantially the same functions as those of the present embodiment are denoted by the same reference numerals, and redundant description will be given only when necessary.

  The control unit 23 executes the image processing according to the application example 6 in accordance with an instruction from the user via the operation unit 21, so that the display curved surface setting unit 15, the developed image generation unit 17, the composite image generation unit 33, and the display The unit 19 is controlled. The display curved surface setting unit 15 sets the display curved surface at the position designated in step S5 of FIG. 2 for both the myocardial region included in the volume data related to the morphology index and the myocardial region included in the volume data related to the function index. It is assumed that the myocardial region included in the volume data related to the morphology index and the myocardial region included in the volume data related to the function index are aligned by an existing method. The developed image generation unit 17 generates developed image data related to the display curved surface based on the volume data related to the form index, and generates developed image data related to the display curved surface based on the volume data related to the function index. The composite image generation unit 33 combines the developed image related to the form index and the developed image related to the function index to generate a composite image. The display unit 19 displays a composite image.

  As described above, the image processing apparatus 1 according to the application example 6 can generate and display a composite image of the developed image related to the form index and the developed image related to the function index. With this display, the user can confirm the spatial distribution of the function index related to the myocardium on the developed image while clarifying the anatomical positional relationship. Thus, according to the image processing apparatus 1 according to the application example 6, the myocardial image diagnostic ability is improved.

[Application Example 7]
As illustrated in FIG. 1, the image processing apparatus 1 according to the application example 7 further includes a curved surface image generation unit 35. The curved surface image generation unit 35 generates data of a two-dimensional image (hereinafter referred to as a curved surface image) that three-dimensionally represents the spatial distribution of pixel values of the display curved surface based on the volume data. Hereinafter, the image processing apparatus 1 according to Application Example 7 will be described. In the following description, components having substantially the same functions as those of the present embodiment are denoted by the same reference numerals, and redundant description will be given only when necessary.

  The control unit 23 controls the display curved surface setting unit 15, the curved surface image generation unit 35, and the display unit 19 in order to execute the image processing according to the application example 7 in accordance with an instruction from the user via the operation unit 21. The curved surface image generation unit 35 generates curved surface image data relating to the display curved surface corresponding to the position designated in step S5 of FIG. 2 based on the volume data. For example, the curved surface image generation unit 35 cuts out a display curved surface from the volume data, executes rendering processing on the cut out display curved surface, and generates curved surface image data. In addition, the curved surface generation unit 35 may delete a region outside the display curved surface from the myocardial region, perform rendering processing on the remaining region, and generate curved surface image data. The position of the viewpoint and the direction of the line of sight can be arbitrarily set by the user via the operation unit 21. The display unit 19 displays the generated curved surface image.

  FIG. 16 is a diagram illustrating a display example of the curved surface image I7. As shown in FIG. 16, the display unit 19 can display, for example, the curved surface image I7 and the developed image I1 side by side. The display curved surface portion of the curved surface image I7 is displayed in a color corresponding to the index value of the function index. Since the curved surface image I7 expresses the spatial distribution of the pixel values of the display curved surface three-dimensionally, there is no distortion of the shape. That is, the curved surface image I7 faithfully reproduces the spatial distribution of the pixel values of the display curved surface. Therefore, the user can further clarify the correspondence between the position on the developed image I1 and the actual position by comparing the curved surface image I7 with the developed image I1. Thus, according to the image processing apparatus 1 according to the application example 7, the image diagnostic ability of the myocardium is improved.

  In Application Example 7, the composite image generation unit 33 generates a composite image of the curved image related to the form index and the curved image related to the function index related to the same display curved surface, and the display unit 19 displays the composite image. Also good.

  For example, the usefulness of this embodiment will be described in a case where a blood vessel is recessed into the myocardium. When a three-dimensional image related to the entire myocardial region is displayed, the blood vessel shape information is buried in the myocardial function information, and the user cannot observe the blood vessel shape information. However, according to this embodiment, the display curved surface can be moved to the inner side of the myocardium to the position where the blood vessel is running. Therefore, the image processing apparatus 1 according to the application example 7 sets a display curved surface including the position where the blood vessel is running, generates a composite image of the curved surface image related to the form index of the display curved surface and the curved surface image related to the function index, This composite image is displayed. By displaying the composite image, the user can observe the running of the blood vessel and the function information of the myocardium at the same time.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Image processing apparatus, 11 ... Memory | storage part, 13 ... Extraction part, 15 ... Display curved surface setting part, 17 ... Development | development image generation part, 19 ... Display part, 21 ... Operation part, 23 ... Control part, 25 ... Guide image generation 27: Projection processing unit, 29 ... Thickness calculation unit, 31 ... Polar map generation unit, 33 ... Composite image generation unit, 35 ... Curved surface image generation unit

Claims (19)

A storage unit for storing volume data relating to the heart;
An extraction unit for extracting a myocardial region from the volume data;
A setting unit that sets a curved surface for display at a predetermined position between the outer wall and the inner wall of the extracted myocardial region;
A developed image generating unit for generating data of a developed image representing a spatial distribution of pixel values on the curved surface in a two-dimensional orthogonal coordinate system based on the volume data;
A display unit for displaying a schematic image of the myocardial region together with the generated developed image;
An image processing apparatus comprising: A storage unit for storing volume data relating to the heart;
An extraction unit for extracting a myocardial region from the volume data;
A setting unit that sets a curved surface for display at a predetermined position between the outer wall and the inner wall of the extracted myocardial region;
A developed image generating unit for generating data of a developed image representing a spatial distribution of pixel values on the curved surface in a two-dimensional orthogonal coordinate system based on the volume data;
A display unit for displaying the generated developed image;
An image processing apparatus comprising :
The developed image generation unit updates the developed image by changing the position of the curved surface at the predetermined position along the thickness direction of the myocardial region based on an input operation.
Image processing device. The setting unit
Normalize the distance between the outer wall and the inner wall by a predetermined numerical range;
A predetermined numerical value within the numerical value range as the predetermined position is designated according to an instruction from a user or automatically,
Setting the curved surface corresponding to the designated numerical value in the myocardial region;
The image processing apparatus according to claim 1 or 2 . The image processing apparatus according to claim 2 , wherein the display unit displays a schematic image of the myocardial region together with the developed image. The display unit superimposes a mark indicating the position of the curved surface to the pattern image, the image processing apparatus according to claim 1 or 4, wherein. The predetermined position includes a plurality of positions between the outer wall and the inner wall,
The developed image generation unit generates a plurality of developed images corresponding to the plurality of positions based on the volume data, and generates a single projection image based on the generated plurality of developed images.
The image processing apparatus according to claim 1 or 2 . The image processing apparatus according to claim 6 , wherein the display unit displays the projection image. The image processing apparatus according to claim 7 , wherein the display unit displays the projection image in a color corresponding to a pixel value of a pixel of the projection image. The display unit, the developed image to contour lines or 3-D graph display of the image processing apparatus according to claim 1 or 2, wherein. The pixel value is a perfusion analysis value or thickness values of the myocardial region, the image processing apparatus according to claim 1 or 2, wherein. The extraction unit extracts a blood vessel region from the volume data,
The developed image generation unit generates an image in which the extracted blood vessel region is superimposed on the developed image in position alignment,
The display unit displays the superimposed image;
The image processing apparatus according to claim 1 or 2 . The orthogonal coordinate system of the developed image is defined by a distance from a first reference point on the heart axis of the myocardial region and a distance from a second reference point around the heart axis of the myocardial region. 1 of the coordinate system, or defined by a second coordinate system defined by the rotation angle from the distance between the arbor rotational Rino said second reference point from the first reference point on said mandrel And
The developed image includes a first developed image represented by the first coordinate system and a second developed image represented by the second coordinate system.
The image processing apparatus according to claim 1 or 2 . The developed image generation unit includes:
Setting a plurality of cross-sections arranged along the cardiac axis of the myocardial region in the myocardial region;
For each of the plurality of set cross sections, the first developed image is generated by assigning pixel values of pixels on the circumference where the cross section and the curved surface intersect to the first coordinate system. ,
The image processing apparatus according to claim 12 . The developed image generation unit includes:
Setting a plurality of cross-sections arranged along the cardiac axis of the myocardial region in the myocardial region;
For each of the plurality of set cross sections, the second developed image is generated by assigning pixel values of pixels on the circumference where the cross section and the curved surface intersect to the second coordinate system. ,
The image processing apparatus according to claim 12 . The image processing apparatus according to claim 12 , wherein the developed image generation unit generates the second developed image based on the first developed image. A polar map generating unit that generates a polar map related to the curved surface based on the volume data;
The display unit displays the developed image and the polar map side by side;
The image processing apparatus according to claim 1 or 2 . Further comprising a composite image generator,
The storage unit stores, as the volume data, morphological volume data relating to morphological indicators and functional volume data relating to functional indicators,
The developed image generation unit generates, as the developed image, morphologically developed image data relating to the curved surface based on the morphological volume data, and generates functionally developed image data relating to the curved surface based on the functional volume data,
The composite image generation unit generates a composite image of the form development image and the function development image,
The display unit displays the composite image;
The image processing apparatus according to claim 1 or 2 . Further comprising a 2-dimensional image generating unit that generates based on the data of the two-dimensional image three-dimensionally expressing the spatial distribution of the pixel value before Symbol song plane to the volume data,
The display unit displays the two-dimensional image;
The image processing apparatus according to claim 1 or 2 . Further comprising a composite image generator,
The storage unit stores, as the volume data, morphological volume data relating to morphological indicators and functional volume data relating to functional indicators,
The two-dimensional image generation unit generates, as the two-dimensional image, morphological two-dimensional image data relating to the curved surface based on the morphological volume data, and functional two-dimensional image data relating to the curved surface based on the functional volume data. Occur and
The composite image generation unit generates a composite image of the form two-dimensional image and the functional two-dimensional image,
The display unit displays the composite image;
The image processing apparatus according to claim 18 .

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