JP2013027442A - Fundus imaging apparatus, fundus analyzing method and fundus analyzing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fundus imaging apparatus capable of performing diagnosis in detail without requiring time and effort.SOLUTION: The apparatus includes: an optical coherence tomography device which has an optical scanner for two-dimensionally scanning an eyeground to be examined with light emitted from a measurement light source and a detector for detecting the coherence between the measurement light emitted from the measurement light source and reference light, and obtains a three-dimensional tomographic image of the eyeground to be examined; and a display control means which extracts a plurality of tomographic images adjacent to each other relating to the scanning position on the eyeground on the basis of the three-dimensional tomographic image acquired by the optical coherence tomography device, and displays the plurality of the extracted tomographic images on a monitor in good order.

Description

  The present invention relates to a fundus imaging apparatus, a fundus analysis method, and a fundus analysis program for capturing a tomographic image of an eye to be examined.

  A fundus tomography device (for example, optical coherence tomography (OCT)) is used as a fundus imaging device that scans measurement light on the fundus using an optical scanning unit (for example, a galvanomirror) to obtain a fundus image. And a fundus front image capturing apparatus (for example, a scanning laser opthalmoscope (SLO)) are known (see Patent Document 1).

  When observing a lesioned part, the examiner confirms the lesioned part (target part) from the fundus frontal image and selects the position (part) of the lesioned part from the fundus frontal image. For example, when the examiner selects a desired scanning line on the fundus front image, one tomographic image corresponding to the selected scanning position is displayed.

JP 2008-29467 A

  However, when observing a plurality of fundus tomographic images, it is necessary for the examiner to select an observation position on the fundus front image for each position to be observed (see FIG. 3). Further, when it is desired to observe the state of the lesion as a whole, the examiner has to sequentially observe each tomographic image related to the lesion while changing the observation position finely. Therefore, it is difficult to evaluate the image on the entire lesion.

  In view of the above problems of the prior art, it is an object of the present invention to provide a fundus imaging apparatus capable of performing a detailed diagnosis without trouble.

  In order to solve the above problems, the present invention is characterized by having the following configuration.

(1) an optical scanner for two-dimensionally scanning the light emitted from the measurement light source on the fundus of the eye to be examined; a detector for detecting an interference state between the measurement light emitted from the measurement light source and the reference light; An optical coherence tomography device for obtaining a three-dimensional tomographic image of the fundus oculi to be examined, and a plurality of tomographic images that are close to each other with respect to the scanning position on the fundus based on the three-dimensional tomographic image acquired by the optical coherence tomography device A fundus imaging apparatus comprising: a display control unit configured to extract an image and display the extracted tomographic images side by side on a monitor.
(2) In the fundus imaging apparatus according to (1), the fundus imaging apparatus includes operation input means operated by an examiner,
The display control means changes a scanning area on the fundus to be extracted as a plurality of tomographic images based on an operation signal input from the operation input means, and uses a plurality of tomographic images corresponding to the changed scanning areas as a monitor. indicate.
(3) In the fundus imaging apparatus according to (2), the fundus imaging apparatus includes a front image observation device for acquiring a front image of the subject's eye, and the display control means includes the front image observation device together with the plurality of tomographic images. The acquired front image is simultaneously displayed on the monitor, and on the front image, a corresponding display indicating a region corresponding to a plurality of tomographic images displayed on the monitor is superimposed and displayed on the front image.
(4) In the fundus imaging apparatus according to (3), the display control unit is a display control unit that moves the position of the corresponding display on the front image based on an operation signal input from the operation input unit. The plurality of tomographic images corresponding to the scanning region on the fundus designated by the correspondence display are displayed side by side on the monitor.
(5) In the fundus imaging apparatus according to any one of (1) to (4), the display control unit displays the plurality of tomographic images sequentially in time series.
(6) In the fundus imaging apparatus according to any one of (2) to (5), the display control unit displays the plurality of tomographic images based on a third operation signal input from the operation input unit. Change the number of displayed images.
(7) an optical scanner for two-dimensionally scanning the light emitted from the measurement light source on the fundus of the eye to be examined; a detector for detecting an interference state between the measurement light emitted from the measurement light source and the reference light; An acquisition step of acquiring a three-dimensional tomographic image of the fundus of the eye to be inspected photographed by an optical coherence tomography device, and a plurality of adjacent scanning positions on the fundus based on the three-dimensional tomographic image acquired by the acquisition step And a display control step of displaying a plurality of extracted tomographic images side by side on a monitor.
(8) A fundus analysis program for executing the fundus analysis method according to (7) on a computer.

  According to the present invention, a detailed diagnosis can be performed without trouble.

  Embodiments according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram illustrating the configuration of the ophthalmologic photographing apparatus according to the present embodiment. In the present embodiment, the axial direction of the subject's eye (eye E) will be described as the Z direction, the horizontal direction as the X direction, and the vertical direction as the Y direction. The surface direction of the fundus may be considered as the XY direction.

  An outline of the apparatus configuration will be described. This apparatus is an optical coherence tomography device (OCT device) 10 for taking a tomographic image of the fundus oculi Ef of the subject's eye E. The OCT device 10 includes an interference optical system (OCT optical system) 100, a front observation optical system 200, a fixation target projection unit 300, and an arithmetic control unit (CPU) 70.

  The OCT optical system 100 irradiates the fundus with measurement light. The OCT optical system 100 detects the interference state between the measurement light reflected from the fundus and the reference light by the light receiving element (detector 120). The OCT optical system 100 includes an irradiation position changing unit (for example, the optical scanner 108 and the fixation target projection unit 300) that changes the irradiation position of the measurement light on the fundus oculi Ef in order to change the imaging position on the fundus oculi Ef. The control unit 70 controls the operation of the irradiation position changing unit based on the set imaging position information, and acquires a tomographic image based on the light reception signal from the detector 120.

<OCT optical system>
The OCT optical system 100 has an apparatus configuration of a so-called ophthalmic optical tomography (OCT: Optical coherence tomography) and takes a tomographic image of the eye E. The OCT optical system 100 splits the light emitted from the measurement light source 102 into measurement light (sample light) and reference light by a coupler (light splitter) 104. The OCT optical system 100 guides the measurement light to the fundus oculi Ef of the eye E by the measurement optical system 106 and guides the reference light to the reference optical system 110. Thereafter, the detector (light receiving element) 120 receives the interference light obtained by combining the measurement light reflected by the fundus oculi Ef and the reference light.

  The detector 120 detects an interference state between the measurement light and the reference light. In the case of Fourier domain OCT, the spectral intensity of the interference light is detected by the detector 120, and a depth profile (A scan signal) in a predetermined range is obtained by Fourier transform on the spectral intensity data. Examples include Spectral-domain OCT (SD-OCT) and Swept-source OCT (SS-OCT). Moreover, Time-domain OCT (TD-OCT) may be used.

  The optical scanner 108 scans light emitted from the measurement light source on the eye fundus. For example, the optical scanner 108 scans the measurement light two-dimensionally (XY direction (transverse direction)) on the fundus. The optical scanner 108 is arranged at a position substantially conjugate with the pupil. The optical scanner 108 is, for example, two galvanometer mirrors, and the reflection angle thereof is arbitrarily adjusted by the drive mechanism 50.

  Thereby, the reflection (advance) direction of the light beam emitted from the light source 102 is changed, and is scanned in an arbitrary direction on the fundus. Thereby, the imaging position on the fundus oculi Ef is changed. The optical scanner 108 may be configured to deflect light. For example, in addition to a reflective mirror (galvano mirror, polygon mirror, resonant scanner), an acousto-optic device (AOM) that changes the traveling (deflection) direction of light is used.

  The reference optical system 110 generates reference light that is combined with reflected light acquired by reflection of measurement light at the fundus oculi Ef. The reference optical system 110 may be a Michelson type or a Mach-Zehnder type. The reference optical system 110 is formed by, for example, a reflection optical system (for example, a reference mirror), and reflects light from the coupler 104 back to the coupler 104 by being reflected by the reflection optical system and guides it to the detector 120. As another example, the reference optical system 110 is formed by a transmission optical system (for example, an optical fiber), and guides the light from the coupler 104 to the detector 120 by transmitting the light without returning.

  The reference optical system 110 has a configuration in which the optical path length difference between the measurement light and the reference light is changed by moving an optical member in the reference optical path. For example, the reference mirror is moved in the optical axis direction. The configuration for changing the optical path length difference may be arranged in the measurement optical path of the measurement optical system 106.

<Front observation optical system>
The front observation optical system (front image observation device) 200 is provided to obtain a front image of the fundus oculi Ef. The observation optical system 200 includes, for example, an optical scanner that two-dimensionally scans the fundus of measurement light (for example, infrared light) emitted from a light source, and a confocal aperture that is disposed at a position substantially conjugate with the fundus. And a second light receiving element for receiving the fundus reflection light, and has a so-called ophthalmic scanning laser ophthalmoscope (SLO) device configuration.

  Note that the configuration of the observation optical system 200 may be a so-called fundus camera type configuration. The OCT optical system 100 may also serve as the observation optical system 200. That is, the front image may be acquired using data forming a tomographic image obtained two-dimensionally (for example, an integrated image in the depth direction of a three-dimensional tomographic image, at each XY position). Of the spectrum data, luminance data at each XY position in a certain depth direction, retina surface layer image, etc.).

<Fixation target projection unit>
The fixation target projecting unit 300 includes an optical system for guiding the line-of-sight direction of the eye E. The projection unit 300 has a fixation target presented to the eye E, and can guide the eye E in a plurality of directions.

  For example, the fixation target projection unit 300 has a visible light source that emits visible light, and changes the presentation position of the target two-dimensionally. Thereby, the line-of-sight direction is changed, and as a result, the imaging region is changed. For example, when the fixation target is presented from the same direction as the imaging optical axis, the center of the fundus is set as the imaging site. When the fixation target is presented upward with respect to the imaging optical axis, the upper part of the fundus is set as the imaging region. That is, the imaging region is changed according to the position of the target with respect to the imaging optical axis.

  As the fixation target projection unit 300, for example, a configuration in which the fixation position is adjusted by the lighting positions of LEDs arranged in a matrix, light from a light source is scanned using an optical scanner, and fixation is performed by lighting control of the light source. Various configurations such as a configuration for adjusting the position are conceivable. The projection unit 300 may be an internal fixation lamp type or an external fixation lamp type.

<Control unit>
The control unit 70 controls the entire apparatus such as each member of each configuration 100 to 300. The control unit 70 also serves as an image processing unit that processes the acquired image, an image analysis unit that analyzes the acquired image, and the like. The control unit 70 is realized by a general CPU (Central Processing Unit) or the like. As shown below, the control unit 70 analyzes the fundus oculi Ef based on the tomographic image.

  The control unit 70 obtains a tomographic image by image processing based on the light reception signal output from the detector 120 of the OCT optical system 100, and also detects the front surface based on the light reception signal output from the light receiving element of the front observation optical system 200. Get a statue. Further, the control unit 70 controls the fixation target projection unit 300 to change the fixation position.

  The memory (storage unit) 72, the display monitor 75, and the control unit 74 are electrically connected to the control unit 70, respectively. The control unit 70 controls the display screen of the monitor 75. The acquired fundus image is output to the monitor 75 as a still image or a moving image and stored in the memory 72. For example, the memory 72 records various types of information related to imaging such as a captured tomographic image (for example, a three-dimensional tomographic image), a front image, and imaging position information of each tomographic image. The control unit 70 controls each member of the OCT optical system 100, the front observation optical system 200, and the fixation target projection unit 300 based on the operation signal output from the control unit 74. The control unit 74 is connected to a mouse 74a as an operation member operated by the examiner.

  The monitor 75 may be a display monitor mounted on the apparatus main body, a display monitor of a personal computer, or a combination thereof.

  In the present embodiment, the case where the OCT optical system 100 also serves as the observation optical system 200 will be described as an example. The control unit 70 controls the optical scanner 108 to scan the measurement light two-dimensionally, and obtains a tomographic image and a front image as moving images based on the light reception signal output from the detector 120. The acquired tomographic image and front image are displayed on the monitor 75.

  The control operation of the apparatus having the above configuration will be described. The examiner instructs the subject to gaze at the fixation target of the fixation target projection unit 300, and then observes the anterior ocular segment observation image captured by the anterior ocular segment observation camera (not shown) on the monitor 75. The alignment operation is performed using a joystick (not shown) so that the measurement optical axis is at the center of the pupil of the eye to be examined.

  Then, the control unit 70 controls driving of the optical scanner 108, scans the measurement light on the fundus in a predetermined direction, and receives a light reception signal corresponding to a predetermined scanning area from an output signal output from the detector 120 during the scanning. To obtain a fundus image.

  Hereinafter, an example of a method for acquiring a fundus tomographic image (hereinafter referred to as a tomographic image) and a fundus frontal image (hereinafter referred to as a front image) according to the present embodiment will be described. The control unit 70 processes the spectral data detected by the detector 120 and forms a tomographic image and a front image by image processing. The tomographic image and the front image may be acquired at the same time, may be acquired alternately, or may be acquired sequentially. That is, the spectrum data is used for obtaining at least one of a tomographic image and a front image. Note that the acquired tomographic image and front image are displayed on the monitor 75.

  The examiner operates an imaging switch (not shown) at a desired position to start acquiring a three-dimensional tomographic image of a front image and a tomographic image displayed on the monitor 75, and stores the memory 72 as a still image. Is remembered.

  The control unit 70 controls the OCT optical system 100 and acquires a three-dimensional tomographic image corresponding to the set region. And the control part 70 acquires a three-dimensional tomogram at any time with the OCT optical system 100. FIG. The three-dimensional tomographic image includes image data in which A scan signals are arranged two-dimensionally in the XY directions, a three-dimensional graphic image, and the like.

  When obtaining a three-dimensional tomographic image, the control unit 70 controls the operation of the optical scanner 108 and acquires the three-dimensional tomographic image by scanning the measurement light in the XY directions two-dimensionally in the scanning range corresponding to the imaging region. To do. As a scanning pattern for obtaining a three-dimensional tomographic image, for example, a raster scan, a radial scan, or the like can be considered.

<Display image>
The control unit 70 extracts a plurality of tomographic images that are close to each other with respect to the scanning position on the fundus oculi based on the three-dimensional tomographic image acquired by the OCT device 10, and displays the extracted plurality of tomographic images side by side on the monitor 75. To do.

  The control unit 70 displays a front image and a tomographic image based on the acquired three-dimensional tomographic image on the monitor 75 screen. FIG. 2 is a diagram illustrating an example of a configuration on the screen of the monitor 75. In the upper right corner on the monitor 75, a front image P1 is displayed. On the left side of the monitor 75, the acquired tomographic images P2 are continuously displayed in time series. An image identification number display 93 is displayed at the upper left corner of each image in the plurality of tomographic images P2, and it is possible to identify the tomographic image acquired in the three-dimensional tomographic image.

  The displayable area S indicates an area in which a plurality of tomographic images P2 are displayed, and the enlargement / reduction process is performed so that a desired number of tomographic images fit in the displayable area S depending on the number of tomographic images.

  The frame F1 is a graphic indicating positions corresponding to the plurality of tomographic images P2 displayed on the monitor 75 on the front image P1. For example, the fundus region surrounded by the frame F1 is set to a range including a predetermined number (for example, 25) of B-scan images on the front image P1. The B scan images displayed adjacently on the monitor 75 are close to each other with respect to the scan position on the fundus. Regarding the proximity of scanning positions, in addition to a plurality of tomographic images with continuous scanning positions, a plurality of tomographic images (for example, about 150 μm) whose scanning positions are close to each other to the extent that continuity in tomographic observation is ensured can be considered. .

  The initial position of the frame F1 is set with reference to the center of the shooting range of the front image P1 (a position where the center coordinates of the shooting area coincide with the center coordinates of the frame F1). A scanning line B indicates a scanning line passing through the center of the frame F1. The frame F2 is a graphic for showing a tomographic image corresponding to the scanning line B in the plurality of tomographic images P2.

  The index display 91 is for changing the reference image. The examiner moves the arrow display 92 by operating the mouse 74a. The control unit 70 moves the arrow display 92 to change the reference image in the captured tomographic image, and accordingly moves the frame F1 and the scanning line B in the front image P1. For example, the closer the examiner moves the arrow display 92 to the left end, the closer to the tomographic image acquired first in the three-dimensional tomographic image, and the closer to the right end, the more tomographic image acquired last in the three-dimensional tomographic image. Approaching. Of course, the configuration may be such that the closer to the left end, the closer to the tomographic image acquired last, and the closer to the right end, the closer to the tomographic image acquired first.

  The sheet number setting display 94 is for setting the number of tomographic images P2 to be displayed on the monitor 75 at a time. The number of tomographic images displayed on the screen of the monitor 75 is changed by changing numerical values (for example, vertical and horizontal set values) of the display number setting unit 96. The number of tomographic images displayed is set to an odd number so that the number of tomographic images before and after the reference image is the same. For example, when the examiner changes the numerical value of the display number setting unit 96 from 5 × 5 to 7 × 7, the number of displayed tomographic images is changed from 25 to 49.

  The mode switching display 98 sorts a plurality of tomographic images P2 displayed on the monitor 75 under various conditions, whereby a plurality of tomographic images P2 displayed on the monitor 75 and a plurality of tomographic images P2 on the monitor 75 are respectively displayed. Used to change the display order of tomographic images. For example, the examiner switches the mode display of the mode setting unit 99 of the mode switching display 98 to display the tomographic images sorted under the conditions according to the mode (details will be described later).

<Control action>
The examiner makes a diagnosis by observing the tomographic image and the front image displayed on the screen of the monitor 75.

  In general, the control unit 70 simultaneously displays a front image acquired by the OCT optical system 100 on the monitor 75 together with a plurality of tomographic images. Further, the control unit 70 superimposes and displays a corresponding display indicating a region corresponding to a plurality of tomographic images displayed on the monitor 75 on the front image.

  In addition, the control unit 70 changes the scanning region on the fundus to be extracted as a plurality of tomographic images based on the operation signal input from the mouse 74a, and monitors a plurality of tomographic images corresponding to the changed scanning regions 75. To display. Further, the control unit 70 moves the position of the corresponding display on the front image based on the operation signal input from the mouse 74a, and monitors a plurality of tomographic images corresponding to the scanning region on the fundus designated by the corresponding display. 75 are displayed side by side.

  For example, a front image P1 and a plurality of tomographic images P2 are displayed on the monitor 75. In order to observe a tomographic image of the fundus region desired by the examiner, the examiner moves the position of the frame F1 in the vertical direction while observing the front image P1, thereby displaying a plurality of images displayed on the monitor 75. The tomographic image P2 is changed.

  When the examiner operates the mouse 74a to move the frame F1 in the front image P1, an operation signal is input to the control unit 70. The control unit 70 changes the position of the frame F <b> 1 by outputting a display signal to the monitor 75.

  The control unit 70 changes the position of the frame F1 and changes the plurality of tomographic images P2 displayed on the monitor 75. The control unit 70 acquires a tomographic image corresponding to the fundus region surrounded by the changed frame F1 from the memory 72 and continuously displays it on the screen on the monitor 75. The control unit 70 displays a plurality of tomographic images P2 to be displayed on the monitor 75 from a tomographic image of the fundus region surrounded by the frame F1 before the position of the frame F1 is changed, and the fundus region surrounded by the frame F1 after the change. Change to the tomographic image.

  Since the scanning line B is set as a scanning line passing through the center of the frame F1, the position of the scanning line B is sequentially changed as the frame F1 is changed. The control unit 70 changes the scanning line B and changes the tomographic image of the reference image selected by the frame F2. The control unit 70 moves the frame F2 to the tomographic image of the scanning line B that passes through the center of the frame F1 in the fundus region surrounded by the changed frame F1.

  Here, when the examiner observes a wider fundus region (more tomographic images), the examiner operates the mouse 74a to set the numerical value (set value) of the display number setting unit 96 of the number setting display 94. change. When the numerical value of the display number setting unit 96 is changed by the examiner, the control unit 70 acquires a continuous tomographic image before and after the reference image of the scanning line B from the memory 72 and displays it. For example, the examiner changes the numerical value of the display number setting unit 96 from 5 × 5 to 7 × 7. In this case, the tomographic images P2 before the change (5 × 5) display the tomographic images of 12 scanning lines in the vertical direction of the front image P1 with the scanning line B as the center (reference image in the scanning line B). And 25 tomographic images). After the change (7 × 7), a plurality of tomographic images P2 are displayed with 24 scanning lines in the vertical direction of the front image P1 centering on the scanning line B (49 together with the reference image in the scanning line B). Sheets of tomograms).

  When the numerical value of the display number setting unit 96 is changed by the examiner, the control unit 70 acquires the tomographic image from the memory 72 and displays it. At this time, the control unit 70 performs tomographic image enlargement / reduction processing so that the number of tomographic images set by the display number setting unit 96 is displayed in the displayable area S. For example, when the number of tomographic images increases, the control unit 70 reduces and displays the tomographic images. When the number of tomographic images decreases, the control unit 70 enlarges and displays the tomographic image.

  As described above, by continuously displaying a plurality of tomographic images, the examiner can observe a plurality of tomographic images around the desired fundus position. This eliminates the need for the examiner to select a region for obtaining a tomographic image from the front image for each fundus position. The examiner can simultaneously observe a plurality of tomographic images around the desired fundus position. Thereby, the examiner can compare between a plurality of tomographic images, and can perform more detailed diagnosis without taking time and effort.

  In the present embodiment, the tomographic image of the scanning line in the X direction (lateral direction) is continuously displayed with respect to the front image, but the present invention is not limited to this. If the spectral data detected by the light receiving element 83 is processed and a tomographic image and a frontal image are formed by image processing, the control unit 70 can scan lines for displaying a plurality of continuous tomographic images. The direction can be switched. For example, a configuration in which tomographic images of scanning lines in the Y direction (vertical direction) are continuously displayed with respect to the front image may be used. In this case, a configuration for switching the scanning line direction (for example, the control unit 70 displays a switching icon on the monitor 75) is provided. When the examiner operates the switching unit, the display on the monitor 75 is switched from the tomographic image display of the scanning line in the X direction to the tomographic image display of the scanning line in the Y direction.

  When the scanning line direction is switched to the Y direction, the control unit 70 switches the display of the frame F1 and the scanning line B. The examiner can change the tomographic image displayed on the monitor 75 by moving the frame F1 and the scanning line B1 switched for the Y direction.

  In the present embodiment, the acquired tomographic images are continuously displayed. However, the present invention is not limited to this. The acquired tomographic images may be displayed side by side at a predetermined interval. For example, one frame interval (the 51st acquired tomographic image, the 53rd acquired slice) may be displayed with a gap. For example, in the tomograms acquired in the 100th to 105th images, the control unit 70 displays the images on the monitor 75 at intervals of one frame (for example, displays the 100th, 102nd, and 104th images). Thus, the examiner can simultaneously observe a tomographic image of a wider fundus region.

  In the present embodiment, the tomographic images arranged continuously may be enlarged and displayed. In this case, the examiner selects a desired tomographic image among the plurality of tomographic images displayed on the monitor 75 by using the mouse 74a or the like. The control unit 70 enlarges and displays the selected tomographic image on the monitor 75. As a result, the examiner can observe the desired tomographic image in more detail.

  In the present embodiment, the scanning line passing through the center of the frame F1 is set as the scanning line B. However, the present invention is not limited to this. The scanning line B may be configured to be movable within the frame F1, or may be configured to be movable without limitation within the front image.

  In the present embodiment, the initial position of the frame F1 is set based on the center of the shooting range of the front image P1, but the present invention is not limited to this. It is good also as a structure by which an examiner is set arbitrarily. For example, the initial position is set so that the end of the front image P1 matches the end of the frame F1. By doing in this way, the examiner can observe sequentially from the tomographic image acquired first.

  In the present embodiment, the number of displayed tomographic images is changed by changing the numerical value (set value) of the display number setting unit 96 of the number setting display 94, but the present invention is not limited to this. Any structure may be used as long as the examiner operates the mouse 74a and changes the number of displayed images when displaying a plurality of tomographic images based on an operation signal input from the mouse 74a. For example, the display number of tomographic images may be changed by operating the mouse 74a and widening the frame F1.

  In the present embodiment, the examiner changes the display of the tomographic image by operating the frame F1 in the front image P1, but the present invention is not limited to this. Since the frame F1, the frame F2, the scanning line B, and the index display 91 are linked to each other, when any of these is changed, the other display is also changed. Therefore, the examiner can change the display of the tomographic image by operating any of these. For example, the examiner operates the arrow display 92 of the index display 91 to change the reference image in the photographed tomographic image and change the tomographic image displayed on the monitor 75. Accordingly, the frame F1 and the scanning line B in the front image P1 are moved. Further, since the reference image is also changed by the examiner operating the frame F2, the tomographic image displayed on the monitor 75 is changed.

  In the present invention, the examiner performs an operation using the mouse 74a as an operation input means operated by the examiner. However, the present invention is not limited to this. The control unit 74 is not limited to a mouse, and various operation input devices such as a push switch, a keyboard, a touch panel, and an electric joystick are used.

  In the present embodiment, the examiner can change the display of the tomographic image on the monitor 75 via any one of the frame F1, the frame F2, the scanning line B, and the index display 91 on the monitor 75. It is not limited to this. For example, the acquired tomographic image may be scrolled using a joystick or the like to change a plurality of tomographic images displayed on the monitor 75.

  In the present embodiment, the change in the number of displayed images is set to be an odd number so that the reference image is the center, but is not limited to this. It is only necessary that a continuous image before and after the reference image can be observed. For example, when the number of displayed images is an even number, the control unit 70 sets an image that is substantially in the center as a reference image, and displays tomographic images before and after the image (for example, in the case of 4 × 4, the eighth image or The ninth tomographic image is set as the reference image). Further, when the number of displayed sheets is an even number, a process of increasing or decreasing the set number of displayed sheets by one and setting the number of displayed sheets to be an odd number may be used.

  In the above description, when the tomographic images are displayed side by side, an image in which the tomographic images are not properly captured may not be displayed on the monitor 75. For example, when displaying the tomographic images side by side, the control unit 70 calculates the luminance value of the tomographic image so that the tomographic image that is equal to or less than a predetermined threshold is not displayed on the monitor 75. As a result, since the tomographic image that failed to be captured due to blinking or the like is not displayed, a plurality of tomographic images suitable for observation can be displayed on the monitor 75. Further, when tomographic images are displayed side by side, a display indicating that the tomographic images are not properly captured may be displayed on each tomographic image. Moreover, it is good also as a structure which can set whether an examiner displays arbitrarily.

<OCT sorting function>
Hereinafter, a method for sorting the tomographic images acquired in time series in the same eye based on the condition selected by the examiner will be described.

  The control unit 70 processes each tomographic image acquired by the OCT device 10 and stored in the memory 72 to acquire an analysis result of the tomographic image, and a plurality of tomographic images based on a predetermined standard regarding the acquired analysis result. Are rearranged, and a plurality of rearranged tomographic images are arranged and displayed on the monitor 75.

  The examiner operates the mouse 74 a to switch the mode of the mode setting unit 99 of the mode switching display 98. For example, the display mode includes a multi mode, a layer thickness mode, a differential mode, and the like. As described above, the multi mode is a mode in which a plurality of acquired tomographic images are continuously arranged and displayed in time series. In the present embodiment, the mode after shooting is set to the multi mode.

  The layer thickness mode is a mode in which the layer thickness is detected and displayed in the order of thin (or thick) layers. In the layer thickness mode, the control unit 70 processes each tomographic image stored in the memory 72 and measures the layer thickness information in each tomographic image as the analysis result of the tomographic image, and uses the magnitude of the layer thickness as a predetermined reference. Rearrange multiple tomographic images. In the layer thickness mode, since the tomographic image can be observed according to the thickness of the layer thickness, the examiner can use it for early detection of a lesioned part. For example, as glaucoma progresses, the layer thickness decreases. For this reason, an examiner can be useful for early detection of glaucoma by observing a thin part. In age-related macular degeneration, new blood vessels are generated and spread on the retinal surface, so that the retina is raised and the layer thickness is increased. For this reason, an examiner can be useful for the discovery of age-related macular degeneration by observing a thick part.

  The difference mode is a mode in which the difference between the layer thickness information of the normal eye database and the acquired layer thickness information of the tomographic image is acquired, and the tomographic images are arranged and displayed in the order of large (or small) difference. In the difference mode, the control unit 70 calculates the difference between the analysis results in each tomographic image with respect to the normal eye database, and rearranges the plurality of tomographic images using the magnitude of the difference as a predetermined reference. In the difference mode, since the difference from the information in the normal eye can be observed, the examiner can use it for diagnosis of an abnormal part of the eye to be examined (details will be described later).

  Note that the sorting method described below will be described using the differential mode as an example.

  The examiner operates the mouse 74a to change the mode of the mode setting unit 99 of the mode switching display 98 from the multi mode to the differential mode.

  In the difference mode, difference information of each tomographic image with respect to the normal eye is calculated by using the acquired tomographic image and the normal eye database. The normal eye database stores analysis results (interval between layers, shape of a predetermined part, size of a predetermined part, etc.) in a normal eye. The normal eye database is stored in the memory 72. For example, the control unit 70 calculates a difference in layer thickness information in each tomographic image with respect to the normal eye database. The control unit 70 measures the layer thickness at each position in the transverse direction, and calculates a difference between the measurement result and a measurement value (for example, a normal eye measurement value) in the normal eye database. The control unit 70 displays a plurality of tomographic images side by side based on the calculated difference.

  In the above analysis, the control unit 70 sorts the tomograms based on the difference calculation result, so that the examiner can observe the sorted tomograms and use it for diagnosis of an abnormal site.

  The operation will be described below. First, when the examiner switches the mode to the differential mode, the control unit 70 detects fundus layer information for each of the acquired tomographic images by image processing. When detecting a layer, for example, the luminance level of a tomographic image is detected, and a layer boundary corresponding to a predetermined retinal layer (for example, a retinal surface and a retinal pigment epithelium layer) is extracted by image processing. Then, the layer thickness is measured by measuring the interval between the layer boundaries.

  The control unit 70 calculates the difference between the measured layer thickness and the normal eye layer thickness at each position of the one frame tomogram in one frame tomogram. Of course, in the analysis using the layer thickness, the total value of a plurality of layer thicknesses may be used.

  When used for diagnosing the degree of progression of glaucoma, for example, the control unit 70 measures the thickness of the retinal nerve fiber layer and the ganglion cell layer, and specifies the abnormal site by calculating the difference between the measurement result and the normal eye database. To do. In this case, the thickness from the retinal nerve fiber layer to the ganglion cell layer to the intima layer may be measured and the difference calculated.

  FIG. 4 is a diagram illustrating an example of a screen on a monitor when tomographic images are displayed side by side based on a difference calculation result. The control unit 70 displays the tomographic images side by side based on the difference calculation result for the normal eye. For example, the control unit 70 compares the difference calculation results between a plurality of tomographic images, and displays them on the monitor 75 in order from the largest difference calculation result. In the present embodiment, the calculation result of the largest difference in each tomographic image is used as the difference calculation result in each tomographic image. The control unit 70 compares the difference calculated at each position of the tomographic image of one frame in order to obtain the calculation result of the largest difference. Of course, as a difference calculation result in each tomographic image, a difference result at a predetermined position (for example, the central portion) in one frame of the tomographic image may be used.

  A scanning line B1 indicates a region corresponding to a tomographic image (reference image) surrounded by a frame F2 in a plurality of tomographic images P2 arranged in order from the largest difference calculation result.

  The layer thickness histogram display 21 divides the area of the front image P1 for each difference size, and displays a histogram indicating how much each difference area occupies in the front image. In the layer thickness histogram display 21, a bar graph indicating the ratio of each difference area is displayed by coloring for each difference size (for example, as the difference increases, the bar graph indicating the ratio of the area displays red, As the difference gets smaller, the bar graph shows the percentage of that area as it gets lighter). In the layer thickness histogram display 21, for example, the bar graph 22a indicates a region having the largest difference, and the bar graph 22b indicates a region having the smallest difference. The bar graph indicates a region having a larger difference as the bar graph is closer to the bar graph 22a, and indicates a region having a smaller difference as the bar graph is closer to the bar graph 22b. By examining the layer thickness histogram display 21, the examiner can confirm at a glance how much the ratio of the regions divided for each difference size exists.

  The layer thickness histogram display 21 is provided with an arrow display 23 that can move between bar graphs. The examiner moves the arrow display 23 by operating the mouse 74a. When the arrow display 23 is moved, the control unit 70 changes the image to be displayed on the monitor 75 in the tomographic images arranged in order from the largest difference calculation result. For example, when the arrow display 23 is moved from the bar graph 22a to the bar graph 22b, the control unit 70 changes the image to be displayed on the monitor 75 to a plurality of tomographic images corresponding to the bar graph 22b, and changes the plurality of tomographic images. Images are displayed side by side in descending order of difference. By changing the reference image, the scanning line B1 of the frame F2 and the front image P1 is moved.

  As described above, when the mode is switched to the differential mode, the tomographic image displayed on the monitor 75 and the display order when displaying the tomographic image are changed. Thereby, the diagnosis of the examiner can be assisted, and the examiner contributes to the discovery etc. in the lesioned part. Further, even when there are a plurality of lesions in the fundus region, the lesions can be easily compared and a diagnosis can be suitably performed.

  In the present embodiment, when sorting under a predetermined condition is completed, an image displayed on the monitor 75 may be further changed. For example, in the difference mode, the tomographic image displayed on the monitor 75 or the display order when displaying the tomographic image is changed, and then the examiner selects a predetermined tomographic image from the tomographic images displayed on the monitor 75. select. The control unit 70 changes the tomographic image selected by the examiner as a reference image so that the tomographic images acquired before and after the tomographic image are displayed side by side. By doing in this way, the examiner can observe the tomographic image around the tomographic image with the sorted tomographic image as a reference image at the same time. For this reason, the examiner can perform more detailed diagnosis without trouble.

  In the present embodiment, the mode switching has been described by taking the differential mode as an example, but the present invention is not limited to this.

  The control unit 70 processes each tomographic image to acquire a tomographic image analysis result, rearranges each tomographic image based on a predetermined reference relating to the analysis result, and displays the rearranged tomographic images side by side on the monitor. Anything to do. For example, the mode described above may be a mode in which the layer thicknesses are detected and arranged in order of thin (or thick) layers, or a mode in which the layers are arranged and displayed based on the luminance value of the tomographic image.

  In the mode of displaying side by side based on the luminance value of the tomographic image, for example, the tomographic image is displayed side by side based on the evaluation value S. The evaluation value S is obtained from the equation S = ((average maximum luminance value of the image) − (average luminance value of the background region of the image)) / (standard deviation of the luminance value of the background region). That is, an image that is not good as an image has a large noise, and thus the evaluation value S is small. FIG. 5 is a diagram illustrating an example of a display screen on the monitor 75 when the display order of tomographic images is changed based on the evaluation value S. On the monitor 75, for example, the tomographic images P2 are displayed side by side in descending order of the evaluation value S. A scanning line B2 in the front image P1 indicates a region corresponding to the tomographic image (reference image) surrounded by the frame F2 in the plurality of tomographic images P2 arranged in descending order of the evaluation value S.

  The index display 31 is for changing the reference image. The examiner moves the arrow display 32 by operating the mouse 74a. The control unit 70 moves the arrow display 32 to change the reference image in the captured tomographic image, and accordingly, moves the scanning line B2 in the front image P1.

  The OCT confirmation display 33 is provided with an entire map display 36 and a confirmation method switching display 37. In the entire map display 36, the entirety of a plurality of tomographic images is displayed in different colors according to the result of the evaluation value S for each tomographic image (for example, those having a high SSI are displayed in red and low. For things, they are displayed in green). The confirmation method switching display 37 is for switching conditions for sorting the entire map display 36 under a predetermined condition. For example, the examiner switches the sorting condition of the confirmation method switching display 37 by operating the mouse 74a. Examples of the sort condition include a condition for rearranging the entire map display 36 in descending order of the evaluation value S and a condition for displaying the map in the order of photographing. As described above, the OCT confirmation display 33 allows the examiner to easily confirm how much photographing has been properly performed on the entire plurality of tomographic images.

  The present invention can also be used for follow-up observation. For example, a follow-up observation mode for performing follow-up observation using images taken at different dates and times for the same eye to be examined is provided. The memory 72 stores a plurality of first tomographic images acquired at the first examination date and time and a second plurality of tomographic images obtained at the second examination date and time. Further, the photographing date of each image and the identification information of the subject are stored.

  In the follow-up observation mode, the controller 70 divides and displays the first plurality of tomographic images and the second plurality of tomographic images simultaneously. At the same time, the control unit 70 rearranges each of the first plurality of tomographic images based on a predetermined standard regarding the acquired analysis result. Furthermore, the control unit 70 rearranges the second plurality of tomographic images under the same reference as the first plurality of tomographic images. The control unit 70 displays the rearranged first plurality of tomographic images and second plurality of tomographic images, respectively.

  FIG. 6 is a diagram illustrating an example of a display screen on the monitor 75 in the follow-up observation mode. On the monitor 75, tomographic images acquired at different dates and times are displayed. P3, P4, and P5 indicate front images acquired at different dates and times. In P6, the tomographic images of the area surrounded by the frame F3 in the front image of P3 are displayed side by side. In P7, the tomographic images of the area surrounded by the frame F4 in the front image of P4 are displayed side by side. In P8, the tomographic images of the area surrounded by the frame F5 in the front image of P5 are displayed side by side.

  The patient information display 11 displays information for identifying a patient (gender, age, etc.), photographing date and time of each tomographic image, and the like.

  The index display 13 is for changing the displayed tomographic image as described above. The examiner moves the arrow display 14 by operating the mouse 74a. The control unit 70 changes the tomographic images P6 to P8 according to the movement of the arrow display 14, and moves the frames F3 to F5 in the front images P3 to P5 accordingly. Of course, a configuration may be adopted in which scanning lines are provided in the frames F3 to F5, and a tomographic image indicated by the scanning lines is surrounded by a frame and displayed as a reference image. Moreover, it is good also as a structure which can each provide an index display to the front images P3-P5, and can each change a tomogram.

  As in the above description, the mode switching display 15 sorts the tomographic images displayed on the monitor 75 under various conditions, thereby changing the display order when displaying the tomographic images and tomographic images displayed on the monitor 75. Used to do.

  As described above, the follow-up observation can be performed in the same eye to be examined, and the progress of the lesion can be observed.

  Further, the present invention is not limited to the above-described embodiment, and the control unit 70 divides and displays the first plurality of tomographic images and the second plurality of tomographic images at the same time, and sets a predetermined standard regarding the obtained analysis result. The first plurality of tomographic images are rearranged below. Further, the control unit 70 rearranges the second plurality of tomographic images under the same reference as the first plurality of tomographic images. And the control part 70 may be the structure which each displays the rearranged 1st some tomogram and 2nd some tomogram. In this case, the memory 72 stores a first plurality of tomographic images related to the first subject and a second plurality of tomographic images related to the second subject.

  For example, the control unit 70 has the first plurality of tomographic images whose scanning positions are continuous with respect to the first patient, and the same scanning region as that of the first plurality of tomographic images, and the scanning positions are continuous with respect to the second patient. You may make it display on the monitor 75 so that it can compare with a 2nd some tomogram. As in FIG. 6, the control unit 70 changes a plurality of tomographic images to be displayed on the monitor 75 according to the movement of the arrow display 14, and accordingly, the frames F3 to F3 in the front images P3 to P5. Move F5. This makes it possible to compare the retina with other patients.

  In addition, when performing follow-up observation, it is possible to make a highly accurate diagnosis by correcting a positional shift between captured images with different shooting dates and times. For example, the control unit 70 detects misalignment information between a plurality of tomographic images acquired at different dates and corrects the misalignment information detected and misalignment between the tomographic images.

  For example, the control unit 70 uses the newest front image immediately after shooting as a reference. Of course, the examiner may select a reference image among the front images having different shooting dates and times. The control unit 70 detects the shift amount (parallel movement amount and rotation amount) of each front image with respect to the reference image based on the feature points (papillae, macula, blood vessels, etc.). The control unit 70 corrects the shift between the tomographic image and the front image based on the detected shift amount. The shift correction may be performed by detecting the shift amount from the three-dimensional tomogram without using the front image.

  In the present invention, a configuration in which the display state of various images can be changed may be provided. For example, a function for adjusting the contrast of the tomographic image and a function for enlarging or reducing the tomographic image may be provided. In the case of the enlargement / reduction function, when the examiner selects a tomographic image, a display for selecting enlargement / reduction is displayed, and the tomographic image is enlarged / reduced by operating those displays. At this time, even in the captured images taken at different dates and times, one image may be enlarged / reduced so that the other images are also enlarged / reduced synchronously.

  Note that the present invention is not limited to the apparatus described in this embodiment. For example, fundus analysis software (program) that performs the functions of the above embodiments is supplied to a system or apparatus via a network or various storage media. A computer of the system or apparatus (for example, a CPU) can also read and execute the program.

It is a schematic block diagram explaining the structure of the ophthalmologic imaging device which concerns on this embodiment. It is a figure which shows an example of a structure on a monitor screen. It is a figure which shows an example of the screen on a monitor in a conventional apparatus. It is a figure which shows an example of the screen on a monitor at the time of displaying a tomogram side by side based on the calculation result of a difference. It is a figure which shows an example of the display screen on a monitor at the time of changing the display order of a tomogram based on an evaluation value. It is a figure which shows an example of the display screen on a monitor in follow-up observation mode.

70 Control Unit 72 Memory 74 Control Unit 74a Mouse 75 Monitor 100 Interference Optical System (OCT Optical System)
108 optical scanner 120 detector 200 front image observation optical system 300 fixation target projection unit

Claims (8)

An optical scanner for two-dimensionally scanning the light emitted from the measurement light source on the fundus of the eye to be examined, and a detector for detecting an interference state between the measurement light emitted from the measurement light source and the reference light An optical coherence tomography device for obtaining a three-dimensional tomographic image of the fundus of the eye to be examined;
Display control means for extracting a plurality of tomographic images that are close to each other with respect to the scanning position on the fundus based on the three-dimensional tomographic image acquired by the optical coherence tomography device and displaying the extracted tomographic images side by side on a monitor When,
A fundus photographing apparatus comprising: The fundus imaging apparatus according to claim 1,
Having operation input means operated by the examiner;
The display control means changes a scanning area on the fundus to be extracted as a plurality of tomographic images based on an operation signal input from the operation input means, and uses a plurality of tomographic images corresponding to the changed scanning areas as a monitor. A fundus photographing device to display. The fundus photographing apparatus according to claim 2,
A front image observation device for acquiring a front image of the subject's eye;
The display control means simultaneously displays a front image acquired by a front image observation device together with the plurality of tomographic images on a monitor, and corresponds to the plurality of tomographic images displayed on the monitor on the front image. A fundus imaging apparatus that displays a corresponding display indicating a region superimposed on a front image. The fundus imaging apparatus according to claim 3,
The display control means is a display control means for moving the position of the corresponding display on the front image based on an operation signal input from the operation input means, and a scanning region on the fundus designated by the corresponding display A fundus imaging apparatus for displaying the plurality of tomographic images corresponding to the image on a monitor side by side. In the fundus imaging apparatus according to any one of claims 1 to 4,
The fundus imaging apparatus, wherein the display control means displays the plurality of tomographic images sequentially arranged in time series. In the fundus imaging apparatus according to any one of claims 2 to 5,
The fundus imaging apparatus, wherein the display control means changes the number of displayed images when displaying the plurality of tomographic images based on a third operation signal input from the operation input means. Light having an optical scanner for two-dimensionally scanning the light emitted from the measurement light source on the fundus of the eye to be examined, and a detector for detecting an interference state between the measurement light emitted from the measurement light source and the reference light An acquisition step of acquiring a three-dimensional tomographic image of the fundus of the eye to be examined, taken by a coherence tomography device;
A display control step of extracting a plurality of tomographic images adjacent to each other with respect to the scanning position on the fundus based on the three-dimensional tomographic image acquired by the acquiring step, and displaying the extracted tomographic images side by side on a monitor; ,
A fundus analysis method comprising:   A fundus analysis program for executing the fundus analysis method according to claim 7 on a computer.

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