Image display method and apparatus

[0002] The present invention relates to an image display method and apparatus, and more particularly to an image display method and apparatus which enables the observation of a wide range of the wall surface of a three-dimensional tissue in one screen.

[0003] Japanese Patent Application Laid Open No. 10-31761 discloses an image display method and apparatus for producing and displaying an image of the wall surface of an internal space of a three-dimensional tissue (a structure in a living body, such as the digestive organs and the blood vessels) as seen from a viewpoint in the internal space, using data acquired by image information acquiring means such as an X-ray CT (computed tomography) apparatus and an MRI (magnetic resonance imaging) diagnostic apparatus.

[0004] While the technique disclosed in the above application can display a three-dimensional image of the wall surface of the digestive organs or the blood vessels as seen from their internal space, the three-dimensional image is simulant of an image as provided by an optical endoscope (straight vision endoscope) having a view angle of about 90°, and therefore does not enable the observation of a wide range in one screen.

[0005] It is an object of the present invention to provide an image display method and apparatus which enables the observation of a wide range of the wall surface of a three-dimensional tissue in one screen.

[0006] In accordance with a first aspect of the invention, there is provided an image display method for producing an image of the wall surface of an internal space of a three-dimensional tissue as seen from a viewpoint in the internal space using data acquired from a subject, and for displaying the image, wherein the image provides a view in a field-of-view centerline direction with a view angle greater than 180°.

[0007] It is difficult to give an optical endoscope a large view angle because of its physical limitations. On the other hand, there is no physical limitation when an image is produced from data acquired by an X-ray CT apparatus, an MRI apparatus or the like, and it is possible to expand a view angle although arithmetic processing is increased.

[0008] In the image display method as described regarding the first aspect, an image is produced and displayed with a view angle greater than 180°, instead of simulating an optical endoscope. Thus, a wide range of the wall surface of a three-dimensional tissue can be observed in one screen.

[0009] In accordance with a second aspect of the invention, there is provided an image display method for producing an image of the wall surface of an internal space of a three-dimensional tissue as seen from a viewpoint in the internal space using data acquired from a subject, and for displaying the image, wherein the image provides a view 360° around about the viewpoint with a view angle smaller than 180°.

[0010] In the image display method of the second aspect, an image is produced and displayed as if the three-dimensional tissue is cut into a short cylinder and unfolded so that the whole wall surface of its internal space can be observed. Thus, a wide range of the wall surface of a three-dimensional tissue can be observed in one screen.

[0011] In accordance with a third aspect of the invention, there is provided an image display method for producing an image of the wall surface of an internal space of a three-dimensional tissue as seen from a viewpoint in the internal space using data acquired from a subject, and for displaying the image, wherein a plurality of the images provide respective views from the viewpoint in directions of three orthogonal axes including the axis of a field-of-view centerline direction and having the viewpoint as an origin.

[0012] In the image display method of the third aspect, a screen is produced and displayed which enables the simultaneous observation of a combination of a plurality of images respectively providing front (in the field-of-view centerline direction), back, left, right, upward and downward views from a viewpoint in an internal space of a three-dimensional tissue. Thus, a wide range of the wall surface of the three-dimensional tissue can be observed in one screen.

[0013] In accordance with a fourth aspect of the invention, there is provided an image display apparatus for producing and displaying an image of the wall surface of an internal space of a three-dimensional tissue as seen from a viewpoint in the internal space using data acquired from a subject, comprising viewpoint/field-of-view centerline direction specifying means for specifying a viewpoint and a field-of-view centerline direction, and super wide-angle endoscopic screen producing and displaying means for producing and displaying a screen providing a view from the viewpoint in the field-of-view centerline direction with a view angle greater than 180°.

[0014] The image display apparatus of the fourth aspect can suitably implement the image display method as described regarding the first aspect.

[0015] In accordance with a fifth aspect of the invention, there is provided an image display apparatus for producing and displaying an image of the wall surface of an internal space of a three-dimensional tissue as seen from a viewpoint in the internal space using data acquired from a subject, comprising viewpoint/field-of-view centerline direction specifying means for specifying a viewpoint and a field-of-view centerline direction, and omnidirectional periscopic screen producing and displaying means for producing and displaying a screen providing a view 360° around about the viewpoint with a view angle smaller than 180°.

[0016] The image display apparatus of the fifth aspect can suitably implement the image display method as described regarding the second aspect.

[0017] In accordance with a sixth aspect of the invention, there is provided an image display apparatus for producing and displaying an image of the wall surface of an internal space of a three-dimensional tissue as seen from a viewpoint in the internal space using data acquired from a subject, comprising viewpoint/field-of-view centerline direction specifying means for specifying a viewpoint and a field-of-view centerline direction, and multi-image screen producing and displaying means for producing and displaying a screen having a plurality of images arranged providing respective views in directions of three orthogonal axes including the axis of the field-of-view centerline direction and having the viewpoint as an origin.

[0018] The image display apparatus of the sixth aspect can suitably implement the image display method as described regarding the third aspect.

[0019] Thus, according to the image display method and apparatus of the present invention, a wide range of the wall surface of a three-dimensional tissue can be observed in one screen, and lesion sites can be quickly detected.

[0020] Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.

[0021] FIG. 1 is a configuration diagram of an X-ray CT apparatus comprising an image display apparatus in accordance with one embodiment of the present invention.

[0022] FIG. 2 exemplarily shows a screen for specifying a viewpoint position and a field-of-view centerline direction.

[0023] FIG. 3 is a sectional end view illustrating the concept of looking 360° around about a viewpoint.

[0024] FIG. 4 exemplarily shows an omnidirectional periscopic screen.

[0025] FIG. 5 is a flow chart of a procedure of displaying a three-dimensional image in the endoscopic mode using the image display apparatus of FIG. 1.

[0026] FIG. 6 is a schematic representation of a plurality of original two-dimensional images for a three-dimensional image.

[0027] FIG. 7 illustrates a selected one of the two-dimensional images.

[0028] FIG. 8 is a sectional end view illustrating a view angle greater than 180°.

[0029] FIG. 9 is a sectional perspective view illustrating a view angle greater than 180°.

[0030] FIG. 10 exemplarily shows a super wide-angle endoscopic screen.

[0031] FIG. 11 is a sectional perspective view illustrating the concept of looking 360° around about a viewpoint.

[0032] FIG. 12 exemplarily shows another omnidirectional periscopic screen.

[0033] FIG. 13 illustrates the front, back left, right, upward and downward directions with respect to a viewpoint.

[0034] FIG. 14 exemplarily shows a multi-image screen.

[0035] The present invention will now be described in more detail with reference to embodiments shown in the accompanying drawings.

[0036] FIG. 1 is a configuration diagram of an X-ray CT apparatus 100 comprising an image display apparatus 101 in accordance with one embodiment of the present invention.

[0037] A scanner apparatus 1ascans a subject H at different slice positions (a slice represents a planar region to be imaged in tomography), and acquires scan data for a plurality of slices.

[0038] An image accumulating means 1baccumulates the scan data.

[0039] The image display apparatus 101 is comprised of an image processing apparatus 2, a display unit 3 and an input device 4.

[0040] The image processing apparatus 2 includes a two-dimensional image producing and displaying section 2a,a CT value range input section 2b,a viewpoint position/field-of-view centerline direction input section 2c,a screen mode selecting section 2d,a super wide-angle endoscopic screen producing and displaying section 2e,an omnidirectional periscopic screen producing and displaying section 2f,and a multi-image screen producing and displaying section 2g.

[0041] The two-dimensional image producing and displaying section 2aprocesses the scan data for the plurality of slices, produces two-dimensional image data for the slices, and displays two-dimensional images on the display unit 3.

[0042] A human operator reads a CT value range of the internal tissue whose three-dimensional image in the endoscopic mode is to be produced, from the two-dimensional image, and inputs the CT value range via the input device 4.

[0043] The CT value range input section 2breceives the input CT value range, and passes it to the super wide-angle endoscopic screen producing and displaying section 2e,the omnidirectional periscopic screen producing and displaying section 2f,and the multi-image screen producing and display section 2g.

[0044] The operator fixes a viewpoint position (a position of lens of an imaginary endoscope) in the internal space of the internal tissue, and inputs the viewpoint position via the input device 4. The operator also inputs a field-of-view centerline direction (an optical axis direction of the lens of the imaginary endoscope) via the input device 4.

[0045] The viewpoint position/field-of-view centerline direction input section 2creceives the input viewpoint position and field-of-view centerline direction, and passes them to the super wide-angle endoscopic screen producing and displaying section 2e,the omnidirectional periscopic screen producing and displaying section 2f,and the multi-image screen producing and display section 2g.

[0046] The operator then selects a mode of a screen to be displayed among a super wide-angle endoscopic screen, an omnidirectional periscopic screen and a multi-image screen via the input device 4.

[0047] The image mode selecting section 2deither activates the super wide-angle endoscopic screen producing and displaying section 2ewhen the super wide-angle endoscopic screen is selected, activates the omnidirectional periscopic screen producing and displaying section 2fwhen the omnidirectional periscopic screen is selected, or activates the multi-image screen producing and display section 2gwhen the multi-image screen is selected.

[0048] The super wide-angle endoscopic screen producing and displaying section 2eproduces a screen (see FIG. 10) providing a view from the viewpoint in the field-of-view centerline direction with a view angle greater than 180°, and displays the screen. The process is described in more detail later.

[0049] The omnidirectional periscopic screen producing and displaying section 2fproduces a screen (see FIG. 4) providing a view 360° around about the viewpoint with a view angle smaller than 180°, and displays the screen. The process is described in more detail later.

[0050] The multi-image screen producing and displaying section 2gproduces a screen (see FIG. 14) having a plurality of images arranged providing respective views in three orthogonal directions including the axis of the field-of-view centerline direction and having the viewpoint as an origin, and displays the screen. The process is described in more detail later.

[0051] FIG. 5 is a flow chart illustrating the operation for producing and displaying a three-dimensional image in the endoscopic mode by means of the image display apparatus 101.

[0052] In Step V1, data for a plurality of two-dimensional images are acquired by scanning the subject H at a plurality of successive slice positions.

[0053] FIG. 6 shows exemplary two-dimensional images S1-S7 obtained from the plurality of successive slice positions.

[0054] In the two-dimensional images S1-S7, reference symbol D designates the large intestine, and reference symbol K designates the internal space, or the lumen, of the large intestine D.

[0055] The two-dimensional images S1-S7 are tomographic images in planes orthogonal to the z-axis. The z-axis represents an axis of movement for the subject H in the scanner apparatus 1a,the x-axis represents a horizontal axis perpendicular to the z-axis, and the y-axis represents a vertical axis perpendicular to the z-axis.

[0056] Returning to FIG. 5, in Step V2, the operator selects an appropriate one of the plurality of successive two-dimensional images using the input device 4. For example, a two-dimensional image S5 is selected, as shown in FIG. 7.

[0057] In Step V3, the operator reads a CT value range of the internal tissue whose three-dimensional image in the endoscopic mode is to be produced (e.g., the large intestine D) from the selected two-dimensional image, and inputs the CT value range. For example, if a CT value range for pixels representing the large intestine D is “equal to or greater than 300” in the two-dimensional image S5, the value “300” is input as a lower limit of the CT value range (if necessary, an upper limit may additionally be input).

[0058] In Step V4, the operator fixes a viewpoint position in the internal space of the internal tissue, and inputs the viewpoint, and also inputs a field-of-view centerline direction. For example, an image T of the internal tissue produced by extracting pixels within the CT value range input in Step V3 is displayed as shown in FIG. 2, and a viewpoint position E1 and a field-of-view centerline direction SC are input in the internal tissue image T.

[0059] In Step V5, the operator selects a mode of a screen to be displayed.

[0060] In Step V6, if the super wide-angle endoscopic screen is selected as the mode of a screen to be displayed, the process goes to Step V7, otherwise to Step V8.

[0061] In Step V8, if the omnidirectional periscopic screen is selected as the mode of a screen to be displayed, the process goes to Step V9, otherwise to Step V10.

[0062] In Step V7, a super wide-angle endoscopic image is produced and displayed. Then the process is terminated. Specifically, as shown by a sectional end view in FIG. 8 and by a sectional perspective view in FIG. 9, an image is produced and displayed providing a view from the viewpoint E1 in the field-of-view centerline direction SC with a view angle θ of about 200°, for example. The display image is exemplarily shown in FIG. 10. In the display image of FIG. 10, the position of the view angle 180° is indicated by a circle in broken line, and the position of the view angle θ is indicated by a circle in solid line. Moreover, one can observe a tumor Y. The tumor Y could not be observed by conventional endoscopic images having a view angle smaller than 180°.

[0063] Returning to FIG. 5, in Step V9, an omnidirectional periscopic image is produced and displayed. Then the process is terminated. Specifically, as shown by a sectional end view in FIG. 3 and by a sectional perspective view in FIG. 11, an image is produced and displayed providing a view from the viewpoint E1 in the field-of-view centerline direction SC with a view angle φ of about 90°, for example, and 360° around about a rotation center axis which is orthogonal to the field-of-view centerline direction SC and passes the viewpoint E1. The display image is exemplarily shown in FIG. 4. The display image of FIG. 4 shows the large intestine D as if it is cut into a short cylinder and unfolded into a strip-like shape so that its whole wall surface can be observed. The display image may be unfolded into a doughnut-like shape as shown in FIG. 12.

[0064] Returning to FIG. 5, in Step V10, a multi-image screen is produced and displayed. Then the process is terminated. Specifically, as shown by a sectional perspective view in FIG. 13, a screen is produced and displayed which enables the simultaneous observation of front (in the field-of-view centerline direction), back, left, right, upward and downward images providing respective views from the viewpoint E1 in three orthogonal directions including the axis of the field-of-view centerline direction and having the viewpoint E1 as an origin. The display image is exemplarily shown in FIG. 14.

[0065] Although the large intestine is taken as an example of a three-dimensional tissue which is an object to be displayed in the abovedescribed embodiment, the present image display method can be applied to image display of any three-dimensional tissue which may have a cavity therein, such as the small intestine, stomach, esophagus, trachea, urethra, vagina, uterus and oviduct.

[0066] Moreover, although image information is acquired by a scanner apparatus in an X-ray CT apparatus in the above embodiment, data acquired by, for example, an MRI apparatus may be employed. That is, data may be acquired by any means as long as three-dimensional information can be constructed from the data.

[0067] Furthermore, although data for a plurality of two-dimensional images are employed to produce a three-dimensional image in the above embodiment, three-dimensional volumetric data may be alternatively employed.

[0068] In addition, although the above description has been made on an image display apparatus of the present invention as incorporated in an X-ray CT apparatus, the image display apparatus may operate separately from image information acquisition means as long as the image display apparatus is placed under circumstances so as to have an access to accumulated image information.

[0069] Many widely different embodiments of the invention may be configured without departing from the spirit and the scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.