JP4313910B2 - Image display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image display method and apparatus, and more particularly to an image display method and apparatus that allows an operator to associate a specific location on a medical image.
[0002]
[Prior art]
A shaded 3D image or weighted projection image is known as a convenient display method for facilitating the understanding of the three-dimensional positional relationship between a head blood vessel and a lesion, for example.
[0003]
Details of the shaded 3D image are described in, for example, Japanese Patent Application No. 6-14396, and details of the weighted projection image are described in Japanese Patent Application No. 8-267292. For example, as shown in FIG. 17, the weighted projection images are prepared with the same number of classification memories as the screen size within the CT value range to be observed, that is, (number of CT value 1 memories to CT value N memories). A three-dimensional memory having a screen size is prepared, and the presence / absence of an image taking the CT value of the classification memory on the projection line is recorded in the classification memory. Then, a product-sum operation is performed on the presence / absence information of the image stored in the memory and the weighting coefficient for each classified CT value, and a density value corresponding to the calculated value is recorded in the display memory, whereby a large weighting coefficient is obtained. A fluoroscopic image in which a specific part having a CT value is emphasized is displayed.
[0004]
[Problems to be solved by the invention]
However, these images have lost CT value information, for example, and there is a case where it is desired to refer to the original CT image used for 3D image reconstruction. It is impossible to display a shaded 3D image or a weighted projection image and know the CT value in the rectangle to be shaded.
[0005]
In addition, various organs may be displayed overlapping each other in a rectangle, making identification difficult.
[0006]
The present invention has been made in view of such circumstances, and displays where a region of interest specified on a shaded 3D image or a weighted projection image corresponds on the original 2D image to be shaded. An object of the present invention is to provide an image display method and apparatus capable of obtaining information on CT values at corresponding locations.
[0007]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a reconstruction means for reconstructing at least one of a shaded three-dimensional image and a weighted projection image reconstructed based on a plurality of tomographic images, and the reconstruction First display means for displaying a first synthesized image obtained by synthesizing the first region of interest on at least one of the shaded three-dimensional image and the weighted projection image reconstructed by the means; a first selection means for selecting one of a tomographic image of the tomographic image, on the tomographic image selected by said first selecting means, the tomographic a projection line passing through the first region of interest A second display means for displaying a second composite image obtained by synthesizing a second region of interest that is an area of an intersection with the image, and an instruction to change the first composite image to be displayed on the first display means The first instruction means and the first instruction means Thus, when the first composite image is changed, at least one of the shaded three-dimensional image and the weighted projection image that is the basis of the first composite image after the change, and the second Determining means for determining whether or not there is a usage relationship with a tomographic image that is a basis of the composite image of the first image, and a shading three-dimensional image that is a basis of the first composite image and weighting by the determination means When it is determined that there is no usage relationship between at least one of the projected images and the tomographic image that is the basis of the second composite image, the first selection unit is configured to perform the reconstruction. Selecting one tomographic image among a plurality of tomographic images having a usage relationship with at least one of the shaded three-dimensional image and the weighted projection image, and the second display means includes the first display unit One piece selected by the selection means And displaying the second composite image of a second region of interest on an image. As described above, the second region of interest corresponding to the first region of interest designated on the shaded 3D image or the weighted projection image can be displayed on the tomographic image, and the CT value information of the corresponding portion can be obtained. it can.
[0008]
When reconstructing at least one of the shaded three-dimensional image and the weighted projection image, the image may be reconstructed based on the original image portion designated from the display screen. Further, when displaying at least one of the reconstructed shaded three-dimensional image and the weighted projection image together with the original image, if any one of the images is changed, it is determined whether or not the usage relationship used at the time of reconstruction is used. However, the other image may be displayed in place of the other image so as to be a use-related image.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of an image display method and apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.
[0010]
First, the principle of the present invention will be described. As shown in FIG. 1A, the shaded 3D image or the weighted projection image 10 is displayed on the screen of the monitor 148. A region of interest 12 is set on the displayed image using a mouse or the like.
[0011]
When the region of interest 12 is set, as shown in FIG. 1B, one of a plurality of 2D tomographic images 14 used when reconstructing the shaded 3D image or the weighted projection image 10 is displayed on the right side of the screen. The region of interest 16 for each slice is synthesized and displayed on the 2D tomographic image 14.
[0012]
As shown in FIG. 2, the region of interest 16 for each slice is a region at the intersection of the projection line passing through the region of interest 12 set on the shaded 3D image 10 that is the projection plane and the original 2D tomographic image 14. In general, the position of the region of interest 16 for each slice changes for each 2D tomographic image 14 as shown in FIG.
[0013]
When the next button 18 or the previous button 20 displayed below the 2D tomographic image 14 shown in FIG. 1B is pressed, the next or previous 2D image is displayed, and the interest for each slice is displayed on the 2D tomographic image 14. The region 16 is synthesized and displayed. As a result, the region of interest 12 designated on the shaded 3D image or the weighted projection image 10 can be displayed on the original 2D tomographic image 14 to be shaded, and the CT value of the corresponding location can be displayed. Information can be obtained.
[0014]
FIG. 4 is a flowchart showing the image display procedure of the present invention.
[0015]
As shown in FIG. 1A, a shaded 3D image, a weighted projection image 10 and the like are displayed on the screen (step S20). In general, the viewpoint position and the line-of-sight direction when an image is reconstructed are arbitrary.
[0016]
The region of interest 12 is set on the screen image using a coordinate input device such as the mouse 150 (step S21). Although the region of interest 12 is displayed as a rectangle in FIG. 1A, the present invention is not limited to this and takes an arbitrary shape. When a graphic representing the region of interest 12 is input and the setting button 22 is clicked, the region of interest 12 is formally recorded in the memory.
[0017]
It is determined whether or not the comparison button 24 is on (clicked with the mouse 150 or the like) (step S22). When the comparison button 24 is pressed, the region of interest 16 for each slice is synthesized and displayed on the first sheet of the 2D tomographic image 14 as shown in FIG. 1B (step S24). The display of the first one of the 2D tomographic images 14 is for explanation, and generally a predetermined nth of the plurality of 2D tomographic images 14 is displayed.
[0018]
If the comparison button 24 is not pressed in step S22, it is determined whether or not the end button 26 is on (step S23). If the comparison button 24 has been pressed, the process ends. If not, the process returns to step 22.
[0019]
When the region of interest 16 for each slice is synthesized and displayed on the first sheet of the 2D tomographic image 14 in step S24, it is determined whether or not the next button 18 is on (step S25). If the next button 18 is pressed, as shown in FIG. 1B, the region of interest is synthesized and displayed at the corresponding position on the designated 2D image (step S28). The process returns to step S25.
[0020]
If the next button 18 is not pressed in step S25, it is determined whether the previous button 20 is on (step S26). If the previous button 20 has been pressed, the process proceeds to step S28, and if not, it is determined whether the end button 26 is on (step S27). If the end button 26 has been pressed, the process proceeds to step S29 and ends. If not, it is determined whether or not the continuous button 28 is on (step S30). If the continuous button 28 is pressed, the next image is displayed (step S31). If the continuous button 28 is not pressed, the process returns to step S25.
[0021]
When the next image is displayed in step S31, it is determined whether or not the end button 26 is on (step S32). If it has been pressed, the continuous display ends and the process returns to step S25.
[0022]
The above description is for parallel projection, but the region of interest 16 for each slice in the central projection changes not only in position but also in size as shown in FIG.
[0023]
Although the 2D image has been described with the tomographic image 14 reconstructed by measurement, as shown in FIG. 6, an interpolated tomographic image 30 parallel to the projection plane may be obtained by interpolation and combined with the region of interest 32 and displayed. In this case, the position of the region of interest 32 does not change with parallel projection. In the case of central projection, the size of the region of interest 32 changes from slice to slice.
[0024]
Next, a method for avoiding the case where various organs are displayed overlapping each other in a rectangle and the identification becomes difficult will be described with reference to FIGS.
[0025]
The initial parameters L and W in FIG. 7 are read from the magnetic disk and set (step S80). L is the distance from the reference plane (one end of the stacked image) of the selected partial tomographic image, and W is the distance from the top tomographic image to the lowest tomographic image of the selected partial tomographic image. Distance.
[0026]
When reconstructing a weighted projection image or a shaded 3D image, it is partially reconstructed based on the original image portion designated from the display screen and displayed (step S81). That is, a three-dimensional image, a weighted projection image, and the like are reconstructed and displayed based on the selected tomographic image determined by the distances L and W.
[0027]
It is determined whether or not L and W have been changed (step S82). If changed, the process returns to step S81.
[0028]
If not changed, it is determined whether or not the line-of-sight direction button 40 is on (step S83). If it is on, the angle is changed (step S85), and the process returns to step S81.
[0029]
If the line-of-sight direction button 40 is off in step S83, it is determined whether the end button 42 is on (step S84). If the end button 42 is on, the process ends. If it is off, the process returns to step S82.
[0030]
The selected tomogram in FIG. 7 is parallel to the original image, but is generally non-parallel as shown in FIG. Here, L ′ indicates the distance from the projection plane. This projection plane is arranged in parallel to the selected tomographic image. Further, the projection surface here is omitted because the drawing becomes complicated.
[0031]
Next, a method of associating a partially reconstructed weighted projection image or shaded 3D image with a 2D tomographic image will be described with reference to FIGS.
[0032]
As shown in FIG. 10, a 3D image, a weighted projection image 10 or the like 10 is displayed on the left side of the screen, and a 2D tomographic image 14 is displayed on the right side of the screen. On the right side of each image, slide bars 50 and 52 for changing pixel values are displayed. A weighting factor 54 is displayed below 10 such as a 3D image or a weighted projection image. In this way, when the 3D image, the weighted projection image 10 or the like 10 and the 2D tomographic image 14 are displayed side by side, if one of the images is replaced, it is determined whether or not the “use relationship” is used at the time of reconstruction. The other image is displayed in place of the related image.
[0033]
First, a 3D image, a weighted projection image, and the like are created based on the tomographic image 14 determined by the distances L and W, and stored in a recording medium such as a magnetic disk (step S90).
[0034]
Any one of the tomographic images and a 3D image or a weighted projection image 10 using the tomographic image are read from the recording medium and displayed (step S91).
[0035]
Therefore, it is determined whether another image is displayed (the display image is π) by turning on the next button 18 or the previous button 20 displayed below the tomographic image 14 in FIG. 10 (step S92). If yes, the process proceeds to step S101.
[0036]
Further, it is determined whether another image is displayed by turning on the next button 54 or the previous button 56 below the 10 such as the 3D image or the weighted projection image (step S93). If yes, the process proceeds to step S94, and if no, the process proceeds to step S96.
[0037]
It is determined whether the 3D image being displayed, the weighted projection image 10 or the like 10 uses the π (step S94). If yes, the process proceeds to step S96.
[0038]
The first (generally any image) tomographic image 14 used in the 3D image, the weighted projection image 10 or the like is displayed (step S95). Thereafter, the process returns to step S92. It is determined whether or not the continuous button 28 is on (step S96). If yes, the process proceeds to step S99. If no, the process proceeds to step S97.
[0039]
It is determined whether or not the end button 26 is ON (step S97). If yes, the process proceeds to step S98 and ends. If no, the process returns to step S92.
[0040]
The next tomographic image among the tomographic images 14 used in the 3D image, the weighted projection image 10 or the like is displayed (step S99).
[0041]
It is determined whether or not the end button 26 is ON (step S100). If no, the process returns to step S99. If yes, the process returns to step S92.
[0042]
It is determined whether the 3D image being displayed, the weighted projection image 10 or the like 10 uses the π (step S101). If yes, the process proceeds to step S93. If no, a 3D image using π or a weighted projection image 10 is displayed (step S102). Thereafter, the process returns to step S92.
[0043]
In the above description, a 3D image, a weighted projection image 10 or the like is created based on the tomographic image 14 determined by the distances L and W in step S90 and stored in a recording medium such as a magnetic disk. However, step S102 and step S95 are used. 3D image or weighted projection image 10 may be created and stored based on the tomographic image 14 determined by the distances L and W.
[0044]
In the above description, W is manually determined. However, W may be automatically obtained from, for example, Equation 1 from the slice thickness at the time of measurement.
[0045]
[Expression 1]
Slice thickness × W = predetermined value Equation 1
As the slice thickness is increased, fewer images are used.
[0046]
In FIG. 10, two types of images are displayed side by side on one screen, but may be displayed side by side on a plurality of screens. Further, by operating with the pixel value changing icon, it is easy to see the part to be seen.
[0047]
Further, as shown in FIGS. 12A, 12B, and 12C, when the upper limit value tl and the lower limit value t2 of the tomographic image are changed, the weighting factor is automatically changed in conjunction with each other. Also good. Instead of changing the upper limit value tl and the lower limit value t2, an intermediate value LV between the upper limit value tl and the lower limit value t2 and the difference WD between the upper limit value tl and the lower limit value t2 may be changed. The angles α, β and the length ratios a: b and c: d are recorded on the magnetic disk and can be changed by the operator.
[0048]
Further, as shown in FIG. 13, a duplicate of the cursor may be created on a screen on which a plurality of images having different timings, modalities, and processing methods are displayed so as to be easily associated with each other. An arrow (actual cursor) 60 is linked to the mouse, and if it is not on the image, only one arrow is displayed. When moving on any image, the duplicate cursor 62 is displayed on the other image at the corresponding position and interlocked with the real cursor 60. When the real cursor 60 is removed from the image, only one display is displayed again. This mode may be set only during continuous display.
[0049]
The original image is generally stored in a magnetic disk and is read out to the main memory as necessary. In addition, the calculation results and parameters at the time of calculation are stored in the magnetic disk as necessary.
[0050]
The screen described above is summarized as shown in FIGS. As shown in FIG. 14, a patient number (ID) 105 is displayed on the left side of the center of the screen, and a slide bar 102 is displayed on the right side of the ID 105. A CT original image 106 corresponding to the ID 105 is displayed on the center left side of the screen. A projection method is selected in the projection method selection box 100, a start viewing angle that is the first viewpoint angle is set in the start viewing angle setting box 120, an end viewing angle that is the last viewpoint angle is set in the end viewing angle setting box 122, and reconstruction is performed. The number of reconstruction frames is set in the number setting box 124, and the interval that is the rotation angle of the viewpoint is set in the interval setting box 126. The maximum number of original images used for reconstruction is set in the maximum number setting box 101. Further, a plurality of registered weighting factors 110 are selected with a radio button 113, display luminance is set with a display luminance setting bar 109, gamma conversion of display density is selected with a gamma conversion selection button 108, and a composite range setting slide bar 107 is selected. The product-sum range with the number classified by the CT value is set, and the calculation start button 128 is clicked.
[0051]
By clicking the calculation start button 128, the calculation result 130 is displayed on the left side of the center of the screen as shown in FIG. On the right side of the screen, the original image 106 used for reconstruction of the calculation result 130 is displayed according to the set projection method, start viewing angle, end viewing angle, reconstruction number, and interval. Slide bars 103b and 103 are displayed above the calculation result 130 and the original image 106, respectively, and the maximum CT value L1 having a pixel value of 0 and the minimum CT value L2 having a pixel value of 255 can be changed. it can.
[0052]
A mode selection box 132 is displayed below the original image 106. When the still mode is selected, the mode can be changed by the slide bar 104. When the moving image mode is selected, the original image used to reconstruct the calculation result 130 is displayed. Repeatedly displayed continuously. The daylay between images during continuous display can be adjusted by the dayray bar 112. When the whole moving image mode is selected, all original images are repeatedly displayed continuously. When 1 is selected in the cursor selection box 111, only the actual cursor is displayed, and when n is selected, when the actual cursor is positioned on the image, the duplicate cursor is displayed at the corresponding position of the other image.
[0053]
Also, a function button 134 for functions such as distance measurement, a registration button 136, and an end button 138 are displayed at the left corner of the screen.
[0054]
FIG. 16 is a block diagram illustrating a hardware configuration of the image display apparatus. This image display device records and displays medical image data collected for a target region of a subject with, for example, an X-ray CT apparatus, and displays a central processing unit (CPU) 140 that controls the operation of each component, A main memory 142 in which the control program is stored, a magnetic disk 144 in which a plurality of tomographic images and an image reconstruction program are stored, a display memory 146 for storing the reconstructed image data, and this A CRT monitor 148 for displaying image data from the display memory 146, a mouse 150 as a position input means, and the state of the mouse 150 are detected and signals such as the position of the mouse pointer on the CRT monitor 148 and the state of the mouse 150 are output. A mouse controller 152 for outputting to the CPU 140, a keyboard 154 for inputting various operation commands, etc. Constructed from a common bus 156 which connects the components.
[0055]
【The invention's effect】
As described above, according to the present invention, the region of interest specified on the shaded 3D image or the weighted projection image can be displayed on the original 2D image to be shaded. Information on the CT value of the corresponding location can be obtained.
[Brief description of the drawings]
FIG. 1 is a screen configuration diagram showing the concept of an image display method and apparatus according to the present invention. FIG. 2 is an explanatory diagram showing how to obtain a region of interest for each slice in parallel projection. FIG. 4 is a flowchart showing a procedure for displaying a region of interest in association with the image display method of the present invention. FIG. 5 is a diagram showing how to obtain a region of interest for each slice in the central projection. FIG. 6 is an explanatory diagram showing an interpolation image parallel to the projection plane. FIG. 7 is an explanatory diagram showing a tomographic image selection method. FIG. 8 is a flowchart showing a tomographic image selection method. FIG. 10 is a diagram illustrating a method for selecting an image. FIG. 10 is a screen configuration diagram illustrating a procedure for associating a partially reconstructed weighted projection image or shaded 3D image with an original image. FIG. 11 is a partially reconstructed image. Weighted projection image, shaded 3D image and original image FIG. 12 is an explanatory diagram showing a method for linking a CT conversion table and a weighting factor. FIG. 13 is an explanatory diagram showing a method for displaying a duplicate of a cursor. FIG. 14 is an image display device according to the present invention. Fig. 15 is a diagram showing the screen configuration of the image display device of the present invention. Fig. 16 is a diagram showing the hardware configuration applicable to the present invention. Fig. 17 is an explanatory diagram showing a weighted projection image.
DESCRIPTION OF SYMBOLS 10 ... Shaded 3D image, weighted projection image, etc. 12, 16 ... Region of interest, 14 ... Tomographic image, 60 ... Real cursor, 62 ... Duplicate cursor, 140 ... CPU, 148 ... CRT monitor, 150 ... Mouse

Claims (6)

Reconstructing means for reconstructing at least one of a shaded three-dimensional image and a weighted projection image reconstructed based on a plurality of tomographic images;
First display means for displaying a first synthesized image obtained by synthesizing the first region of interest on at least one of the shaded three-dimensional image and the weighted projection image reconstructed by the reconstruction means;
First selection means for selecting one tomogram among the plurality of tomograms;
A second synthesized image obtained by synthesizing a second region of interest, which is a region of intersection between the projection line passing through the first region of interest and the tomographic image, on the tomographic image selected by the first selection unit. Second display means for displaying
First instruction means for instructing change of the first composite image to be displayed on the first display means;
When the first combined image is changed by the first instruction unit, at least one of a shaded three-dimensional image and a weighted projection image that are a basis of the changed first combined image And a judging means for judging whether or not there is a use relationship between the tomographic image that is a basis of the second composite image;
With
There is a usage relationship between at least one of the shaded three-dimensional image and the weighted projection image that is the basis of the first composite image and the tomographic image that is the basis of the second composite image by the determination unit. If it is determined that there is no tomographic image, the first selecting means selects a plurality of tomographic images having a use relationship with at least one of the reconstructed shaded three-dimensional image and the weighted projection image. Select one tomogram,
The image display apparatus, wherein the second display means displays a second synthesized image obtained by synthesizing the second region of interest on a single tomographic image selected by the first selecting means . Second selection means for selecting the plurality of tomographic images used in the reconstruction means ;
A second instruction means for instructing a change of the second synthesized image to be displayed before Symbol second display means,
Before SL if it is changed before Symbol second synthesized image by the second finger 示手 stage of the shaded three-dimensional image and the weighted projection image which is the basis of the first synthesis image after the change Determination means for determining whether or not there is a use relationship between at least one image and a tomographic image that is a basis of the second composite image ;
With
Between the first at least one image and the second composite image group and ing cross Sozo of composite image group and ing shade shadow three-dimensional image and the weighted projection image in said determining means for use when the relationship is determined that there is no, the second selecting means selects the tomographic images plurality of related use with the single tomographic image,
The reconstruction unit reconstructs at least one of a shaded three-dimensional image and a weighted projection image based on a plurality of tomographic images selected by the second selection unit,
The first display means includes at least one of a shaded three-dimensional image and a weighted projection image reconstructed based on a plurality of tomographic images selected by the second selection means in the reconstruction means. The image display apparatus according to claim 1, wherein a first synthesized image obtained by synthesizing the first region of interest is displayed thereon. In the reconstruction means, comprising weighting function changing means for changing a parameter of a weighting function used at the time of reconstruction of the weighted projection image,
The image display device according to claim 1, wherein the reconstruction unit reconstructs the weighted projection image when a parameter of the weighting function is changed by the weighting function changing unit. Third display means for displaying a plurality of related images including the first composite image or the second composite image on one screen;
A pointing device,
Cursor display means for displaying a real cursor at a position commanded by the pointing device, wherein the real cursor is positioned on one of the plurality of images displayed by the third display means; When a duplicate cursor is displayed at a position corresponding to the position of the real cursor on another image among the plurality of images displayed by the display means of 3, and when the real cursor is not located on the image, Cursor display means for displaying only the actual cursor;
The image display apparatus according to claim 1, further comprising:   Reconstructing means for reconstructing at least one of a shaded three-dimensional image and a weighted projection image reconstructed based on a plurality of tomographic images;
  First display means for displaying a first synthesized image obtained by synthesizing the first region of interest on at least one of the shaded three-dimensional image and the weighted projection image reconstructed by the reconstruction means;
  First selection means for selecting one tomogram among the plurality of tomograms;
  A second synthesized image obtained by synthesizing a second region of interest that is a region of intersection of the projection line passing through the first region of interest and the tomographic image on the tomographic image selected by the first selection unit. Second display means for displaying
  Determining means for determining whether there is a use relationship between at least one of the shaded three-dimensional image and the weighted projection image and the tomographic image;
  First instruction means for instructing change of the first composite image to be displayed on the first display means;
  With
  When the first composite image is changed by the first instruction unit, the first selection unit includes the shaded three-dimensional image and the weighted projection image that are a basis of the first composite image. Selecting one tomographic image out of a plurality of tomographic images determined to have a use relationship by at least one of the images and the determining means,
  The second display means displays a second synthesized image obtained by synthesizing a second region of interest on one tomographic image selected by the first selecting means.   Second selection means for selecting the plurality of tomographic images used for reconstruction of at least one of the shaded three-dimensional image and the weighted projection image;
  Second instruction means for instructing change of the second composite image to be displayed on the second display means;
  With
  When the second composite image is changed by the second instruction unit, the second selection unit performs shading reconstructed using a tomographic image that is a basis of the second composite image. Selecting at least one of a three-dimensional image and a weighted projection image and a plurality of tomographic images determined to be used by the determining means;
  The reconstruction unit reconstructs at least one of a shaded three-dimensional image and a weighted projection image based on a plurality of tomographic images selected by the second selection unit,
  The first display means includes at least one of a shaded three-dimensional image and a weighted projection image reconstructed based on a plurality of tomographic images selected by the second selection means in the reconstruction means. 6. The image display device according to claim 5, wherein a first synthesized image obtained by synthesizing the first region of interest is displayed thereon.

Images