Ophthalmic image processing method and ophthalmic image processing program

Abstract

To provide an ophthalmic image processing method and an ophthalmic image processing program capable of allowing a user to preferably observe, a desired tissue, from OCT data in which a depth range is expanded.SOLUTION: An ophthalmic image processing method which is executed by a calculation control part of an ophthalmic device 1 comprises at least, an acquisition step, a setting step, and a display control step. In the setting step, a plurality of pieces of B scan OCT data of a tissue of an eye to be examined in which scan positions are different each other, is acquired. In the setting step, an extraction region is set to the plurality of pieces of B scan OCT data, so that in each B scan OCT data, the image of the eye to be examined is included. In the display control step, the plurality of pieces of extracted OCT data extracted from respective pieces of B scan OCT data, is displayed in a predetermined display region in a manner of capable of switching the data to be displayed and alternatively.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to an ophthalmic image processing method and an ophthalmic image processing program for processing OCT data of tissue of a subject's eye. [Background technology]

[0002] In recent years, optical coherence tomography (OCT), which is a device for capturing tomographic images of tissues in a subject's eye, has been attracting attention in the field of ophthalmology.

[0003] In conventional OCT devices, the effective imaging range in the depth direction, called the depth range, was narrow, so when capturing OCT data, the entire imaging range was displayed as is (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP2016-55122A Summary of the Invention [Problem to be solved by the invention]

[0005] When the depth range was expanded, the imaging range in the depth direction that was actually required was different for each examined eye. For example, when photographing the fundus, the height difference of the fundus tissue varies from person to person due to the axial length and the curvature of the fundus, so that the imaging range in the depth direction that was actually required is thought to be different for each examined eye.

[0006] In addition, as the depth range becomes wider, the proportion of the image of the subject's eye in the OCT data becomes smaller and the proportion of the blank space becomes larger. Therefore, as in Patent Document 1, if the entire imaging range is displayed as is, the display range on the screen will become enlarged, or the proportion of the image of the subject's eye will be small, making it difficult to observe the tissue.

[0007] The present disclosure has been made based on the problems of the conventional technology, and has an objective of providing an ophthalmic image processing method and an ophthalmic image processing program that enable good observation of desired tissues from OCT data with an extended depth range. [Means for solving the problem]

[0008] An ophthalmological image processing method according to a first aspect of the present disclosure is an ophthalmological image processing method performed by a computer, covered B-Scan OCT Data of Opthalmography Tissue The scan lines captured at one time as included in one scan pattern are different from each other. multiple B-scan OCT data The method includes an acquisition step of acquiring data, a setting step of collectively setting extraction regions for the plurality of B-scan OCT data so that an image of the subject's eye is included in each of the plurality of B-scan OCT data, and a display control step of selectively and switchably displaying the plurality of extracted OCT data extracted from each of the B-scan OCT data in a predetermined display region.

[0009] An ophthalmologic image processing program according to the second aspect of the present disclosure is executed by a processor of a computer, whereby the ophthalmologic image processing method according to the first aspect is executed by the computer. Effect of the Invention

[0010] According to the present disclosure, it is easy to observe desired tissues well from OCT data with an extended depth range. [Brief description of the drawings]

[0011] [Figure 1]FIG. 1 is a diagram showing a schematic configuration of an OCT system according to an embodiment. [Diagram 2] FIG. 1 is a diagram showing an OCT optical system according to an embodiment. [Diagram 3] 11 is a flowchart illustrating an operation. [Figure 4] FIG. 1 shows OCT data acquired at different scan lines. [Figure 5A] FIG. 1 shows OCT data acquired at a scan density of 1024pt / 9mm. [Figure 5B] FIG. 1 shows OCT data acquired at a scan density of 512pt / 9mm. [Figure 6A] FIG. 13 is a diagram showing a state in which the entire OCT data is displayed in a display area. [Figure 6B] FIG. 13 is a diagram showing a state in which extracted OCT data is displayed in a display area. [Figure 7A] FIG. 13 is a diagram showing a radial scan pattern. [Figure 7B] FIG. 13 is a diagram showing a cross-scan scan pattern. [Figure 7C] FIG. 13 is a diagram showing a multi-cross scan pattern. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] <Summary> The following describes embodiments of the present disclosure. Note that the items grouped in <> below can be used independently or in conjunction with each other.

[0013] <Overall composition> Hereinafter, one embodiment of the present disclosure will be described. First, an OCT system according to the embodiment will be described. The OCT system is used to capture an image of a subject's eye and display OCT data that is the result of the capture.

[0014] In this embodiment, the OCT system includes at least an OCT optical system, an image processor, and a computer (see FIG. 1). The ophthalmic image processing program according to the embodiment is stored in a non-volatile memory that can be read by a processor of the computer. The OCT optical system, the image processor, and the computer may be integrated as an OCT device (for example, see the examples). Also, some of the OCT optical system, the image processor, and the computer may be separate from other parts.

[0015] <OCT optical system> The OCT optical system (see FIG. 2) is used to capture OCT data of the eye to be examined. The OCT optical system detects the spectral interference signal between the measurement light guided to the tissue of the eye to be examined and the reference light.

[0016] The OCT optical system may be, for example, an SD-OCT optical system or an SS-OCT optical system. The OCT optical system is preferably suitable for acquiring OCT data with a wide depth range. Note that the OCT light source included in the SS-OCT optical system may be a VCSEL type wavelength-sweeping light source.

[0017] The OCT optical system may include at least one of a light splitting unit, a scanning unit (also called an optical scanner), and a detector. The light splitting unit splits light from an OCT light source into a measurement light and a reference light. The scanning unit is a device for scanning the measurement light on the tissue of the subject's eye. The scanning unit may be, for example, a combination of two optical scanners having different scanning directions. The detector outputs a spectral interference signal by receiving the measurement light and the reference light guided to the subject's eye. The OCT optical system may scan the measurement light along a plurality of predetermined scan lines on the tissue of the subject's eye and capture OCT data of each of the plurality of scan lines. The scan lines may be set at any position based on an instruction from the examiner. Also, a scan line corresponding to the scan pattern may be set by selecting one of a plurality of predetermined scan patterns. Various scan patterns such as line, cross, multi, map, radial, and circle are known.

[0018] <Image processor> The image processor processes the spectral interference signal output from the OCT optical system to obtain OCT data of the subject's eye. The image processor may be shared with a control unit that controls the operation of the entire OCT device, or may be an image processing device separate from the control unit.

[0019] <OCTデータ> The OCT data may be signal data or visualized image data. For example, the OCT data may be at least one of tomographic image data showing reflection intensity characteristics of the test eye, OCT angio data (e.g., OCT motion contrast data) of the test eye, Doppler OCT data showing Doppler characteristics of the test eye, and polarization characteristic data showing polarization characteristics of the test eye.

[0020] In addition, the OCT data may be at least any of B-scan data (e.g., B-scan tomographic image data, two-dimensional OCT angiogram data, etc.), en face data (e.g., OCT en face data, en face motion contrast data, etc.), three-dimensional data (e.g., three-dimensional tomographic image data, three-dimensional OCT angiogram data, etc.), etc.

[0021] <Computer> The computer acquires the OCT data of the subject's eye generated by the image processor, and displays it, for example, on a monitor. However, the OCT data may be displayed in an electronic report or a paper report. The computer includes at least a processor (arithmetic and control unit). The arithmetic and control unit may be configured with a CPU, RAM, ROM, etc. The processor executes an ophthalmic image observation program, causing the computer to execute each step described below. The ophthalmic image observation program may be stored in a non-volatile storage medium accessible from the arithmetic and control unit.

[0022] <Acquisition steps> First, the subject's eye is photographed via the OCT optical system. As a result of the photographing, an image processor generates OCT data of the subject's eye. Then, the OCT data generated by the image processor is acquired by a computer 1. In this embodiment, a plurality of B-scan OCT data of tissues of the subject's eye having different scan positions are acquired. At this time, the plurality of B-scan OCT data may have the same scan pattern but different scan positions.

[0023] <Setup steps> Next, in a setting step, an extraction region is set for the plurality of B-scan OCT data. In this embodiment, the extraction region for the plurality of B-scan OCT data is set by the computer 1. The extraction region is set so as to include an image of the subject's eye in each of the plurality of B-scan OCT data.

[0024] In addition, the extraction region may be set so that both the image of the test eye having the shallowest upper end position and the image of the test eye having the deepest lower end position among the multiple B-scan OCT data are not cut off in the depth direction.

[0025] In the case of fundus OCT, the position of the upper end of the image of the subject's eye may be, for example, the upper end of the retinal surface, or the upper end of the boundary surface of the vitreous body on the retina side, and the position of the lower end of the image of the subject's eye may be, for example, the lower end of the choroid.

[0026] The upper and lower ends of the image of the subject's eye may be obtained by image processing of the OCT data. For example, they can be obtained based on the detection result of the layer boundary. They can also be obtained based on brightness information in the depth direction in the B-scan OCT data.

[0027] When the upper and lower ends are obtained by image processing, at least one of the upper and lower ends may be set with a predetermined margin for the position of the tissue detected from the OCT data. This allows the extraction region to be set so as to include tissues (such as the vitreous body and the deep choroid) that are difficult to detect by image processing.

[0028] <Changing the range of the cross direction in which the extraction area is set> In the present embodiment, the range in the transverse direction in which the extraction region is set may be changeable in the plurality of B-scan OCT data. In this case, the extraction region is set collectively for the selected range in the transverse direction in each of the plurality of B-scan OCT data.

[0029] In a plurality of B-scan OCT data, the transverse range in which the extraction region is set may be selectable from among a plurality of different ranges. The selectable range may be prepared in advance. For example, in the case of fundus OCT data, the range may be selected from at least two ranges: a first range which is the fundus center (periphery of the fovea) and a second range which includes the fundus center and the peripheral area around the fundus center.

[0030] The wider depth range allows areas with greater elevation differences to be imaged in a single B-scan. This means that the transverse imaging range in B-scan OCT data can also be made longer (wider angle) than before. However, today, in observation and diagnosis using fundus OCT, information on the center of the fundus is considered more important than information on the peripheral areas. Therefore, by being able to change the transverse range in which the extraction region is set in multiple B-scan OCT data, areas important for diagnosis and observation can be properly displayed as extracted OCT data, even if the transverse imaging range is longer.

[0031] <Correction step> Furthermore, a correction step may be performed to correct the relative positional relationship between the plurality of B-scan OCT data. A setting step may be performed after the correction step. That is, after the relative positional relationship between the plurality of B-scan OCT data is corrected, an extraction region may be set for each corrected B-scan OCT data. In the correction step, the relative positional relationship between the B-scan OCT data may be corrected so that the same features are located at the same depth. For example, a predetermined feature may be detected in each B-scan OCT data, and the relative positional relationship may be corrected so that the positions (positions in the transverse direction and the depth direction) of the detected feature are aligned. The feature may be any one of the macula, the papilla, blood vessels, and a specific layer (or layer boundary). In this case, an extraction region is set for each B-scan OCT data so that the positional relationships between the feature and the extraction region in each B-scan OCT data match each other.

[0032] In the correction step, the relative positions of the B-scan OCT data may be corrected taking into account the curvature of the tissue in a direction intersecting with the cross section from which the B-scan OCT data was obtained. In this case, the correction may be performed so that the image of the tissue in each B-scan OCT data is located at a depth position that reflects the curvature. In this case, extraction regions are set in each B-scan OCT data at depth positions that correspond to each other while taking into account the curvature.

[0033] When correcting the relative positions, for example, affine transformation (translation, shear correction, rotation correction) may be performed.

[0034] In addition, the image of the subject's eye in the B-scan OCT data may be tilted due to imaging being performed in a state of misalignment, or at an inappropriate timing for fixation. The tilting increases the height difference of the image of the subject's eye, which may limit the enlarged display of the image of the subject's eye in the display area. In response to this, in this embodiment, tilting correction may be performed on each B-scan OCT data. For example, the tilt of the tissue of the subject's eye relative to the optical axis may be estimated based on the alignment state at the time of imaging, and the B-scan OCT data may be corrected according to the estimated amount of tilt. As a result, the extraction area can be set more appropriately.

[0035] <Display control steps> In the display control step, a plurality of extracted OCT data are displayed in a predetermined display area. At least the size of the display area on the display medium is predetermined. Furthermore, the arrangement on the display medium may be predetermined. The plurality of extracted OCT data are extracted from the extracted areas in the respective B-scan OCT data. The plurality of extracted OCT data are alternatively and switchably displayed in the display area. Note that the aspect ratio or the number of pixels (the number of device pixels) in the vertical and horizontal directions of the display area is predetermined. In this embodiment, even when B-scan OCT data with a wide depth range is acquired, a depth area including the image position of the tissue is extracted and displayed from the B-scan OCT data, not the entire B-scan OCT data. Since the image of the tissue of the subject's eye is displayed in a more enlarged manner with respect to the predetermined display area, the state of the tissue of the subject's eye can be easily grasped through the extracted OCT data. In this case, in this embodiment, the area (extracted OCT data) extracted and displayed in the display area in the plurality of B-scan OCT data is set so as to include the image of the subject's eye in each of the plurality of B-scan OCT data. Therefore, when each extracted OCT data is alternatively and switchably displayed in a predetermined display area, the image of the subject's eye is appropriately displayed. That is, regardless of individual differences in the shape of the subject's eye, the image of the subject's eye is prevented from exceeding the display area in the depth direction (being cut off).

[0036] Furthermore, since the relative positions of the multiple B-scan OCT data are corrected in the correction step, it becomes easier to appropriately enlarge and display the image of the subject's eye within the display area.

[0037] <Magnification adjustment> In the display control step, the horizontal magnification of the extracted OCT data on the display area may be maintained constant between B-scan OCT data having different scan densities. In this case, the horizontal magnification may be adjusted according to the scan density of the B-scan OCT data on which the extracted OCT data is based so that the horizontal magnification is constant.

[0038] <Display settings for each scan pattern> When the extracted OCT data is displayed by a plurality of B-scan OCT data with different scan positions in the same scan pattern, it may be predetermined whether or not the B-scan OCT data at each scan position is set together with other B-scan OCT data for each type of scan pattern. For example, when the extracted OCT data is displayed based on B-scan OCT data with the same scan direction as in one-way multi-scan, the extracted region may be set together for the B-scan OCT data at each scan position. On the other hand, for OCT data with orthogonal scan directions as in cross-scan, it may be less necessary to match the extracted regions. Therefore, in this case, the extracted region for each B-scan OCT data may be set individually based on the position of the image in each OCT data.

[0039] <Delete information outside the extracted area and save> In this embodiment, by setting the extraction region, data in regions other than the extraction region may be reduced (deleted or compressed). As a result, data in the extraction region (i.e., extracted OCT data) may be stored in memory. The extracted OCT data may be stored alternatively to the original OCT data (e.g., the original OCT data may be overwritten). Even if the depth range increases, the amount of OCT data to be stored can be reduced.

[0040] "Example" An OCT system (optical coherence tomography system) shown in FIGS. 1 and 2 will be described below as an embodiment.

[0041] 1, the OCT system according to the embodiment includes at least an optical unit 10 and a control unit 50, which corresponds to the computer of the embodiment. In the embodiment, the optical unit 10 and the control unit 50 are integrated as an OCT device.

[0042] The optical unit 10 includes an OCT optical system 100 (see FIG. 2). Further, the control unit 50 is a computer in this embodiment, and includes at least an arithmetic control unit (processor) 70 that controls the entire OCT system. The arithmetic control unit (hereinafter simply referred to as the control unit) 70 is constituted by, for example, a CPU and a memory. As an example, in this embodiment, the control unit 70 also serves as an image processor in the OCT system.

[0043] In addition, the OCT system may be provided with a storage unit (memory) 72, an input interface (operation unit) 75, a monitor 80, and the like. Each unit is connected to the control unit 70.

[0044] Various programs, initial values, etc. for controlling the operation of the OCT device may be stored in the memory 72. For example, a hard disk drive, a flash ROM, a USB memory detachably attached to the OCT device, etc. can be used as the memory 72. In addition to the OCT images generated from the OCT data, various information related to imaging may be stored in the memory 72. The monitor 80 may display OCT data (OCT images).

[0045] <OCT optical system> Next, with reference to FIG. 2, the OCT optical system 100 in this embodiment will be described.

[0046] The OCT light source 11 of this embodiment emits low-coherent and broadband light. For example, the OCT light source 11 may be an SLD light source.

[0047] The light splitter 15 splits the light from the OCT light source 11 into a measurement light and a reference light. In FIG. 1, the light splitter 15 is shown as a fiber coupler. As shown in FIG. 1, the measurement light is irradiated onto the subject's eye via the light guiding optical system 40. Also, the return light from the subject's eye is guided back through the light guiding optical system 40 to the spectroscopic optical system 20. The reference light is guided to the spectroscopic optical system 20 via the reference optical system 30. In FIG. 1, the return light of the measurement light and the reference light are combined by a coupler (for example, the light splitter 15 in FIG. 1) and then guided to the spectroscopic optical system 20.

[0048] 1, the light guiding optical system 40 may include an optical scanner 41 and an objective optical system 45. The optical scanner 41 is used to scan the measurement light on the tissue of the subject's eye. The measurement light scanned by the optical scanner 41 is scanned on the tissue of the subject's eye via the objective optical system 45.

[0049] When obtaining a fundus OCT scan, the measurement light passing through the objective optical system 45 may be rotated around one point (called a pivot point) as shown in Fig. 1. The pivot point is positioned at the anterior segment by alignment, whereby the fundus OCT scan is obtained.

[0050] The optical path length adjustment unit adjusts the optical path length difference between the measurement light and the reference light. When photographing fundus OCT, the optical path length difference is corrected according to individual differences in axial length for each subject eye. When photographing anterior segment OCT, the optical path length difference is adjusted to a predetermined value. The optical path length adjustment unit changes the optical path length of at least one of the measurement optical path and the reference optical path. In FIG. 1, the optical path length is changed by moving the exit end of the fiber in the light-guiding optical system 40 in the optical axis direction.

[0051] The spectroscopic optical system 20 of this embodiment is used as a spectrometer. The spectroscopic optical system 20 detects a spectral interference signal between the return light of the measurement light and the reference light.

[0052] <Getting depth information> The control unit 70 processes (Fourier analyzes) the spectral signal detected by the detector 120 to obtain OCT data of the eye to be examined. More specifically, the spectral interference signal may be rewritten as a function of the wavelength λ and converted into an equally spaced function I(k) with respect to the wave number k (=2π / λ). Further, the information after Fourier transform may be represented as a signal including a real component and an imaginary component in the Z space. The control unit 70 may obtain OCT data by obtaining the absolute values of the real component and the imaginary component in the signal in the Z space.

[0053] <Operation description> Next, an ophthalmic image processing method executed in the OCT system of the embodiment will be described according to the flowchart shown in FIG. 3. Each process of the flowchart may be executed by the control unit 70 based on an ophthalmic image processing program. In this embodiment, by executing each process of the flowchart, a plurality of OCT data acquired by a certain scan pattern are displayed on the monitor 80. For convenience, the OCT data in the following description are all B-scan data. Also, the OCT data corresponding to the scan line is also referred to as a slice.

[0054] <S1: Acquisition step> First, after various adjustments of the OCT optical system 100, the OCT data of the eye to be examined is taken. The OCT data may be taken in any of a plurality of predetermined scan patterns. First, here, the case where a multi-scan in one direction is performed will be described. Also, unless otherwise specified, in this embodiment, the OCT data will be described as being taken with a scan length of 9 mm.

[0055] The captured OCT data may be stored (saved) in the memory of the device in association with information indicating the scanning speed. As a result, the captured OCT data is acquired by the control unit 70 as a captured image (S1). When multiple pieces of OCT data are captured at once, the multiple pieces of OCT data are acquired in step S1. In addition, information indicating a scan pattern when the multiple pieces of OCT data are acquired (scan pattern information) is acquired (S2). The scan pattern information may be associated with the multiple pieces of OCT data. The scan pattern information may further include information indicating a scan position in each piece of OCT data.

[0056] <Misalignment correction> An example of multiple OCT data acquired in step S1 is shown in Fig. 4. The OCT data A, B, and C are different from each other in scanning positions in a multi-scan in one direction. Since the multiple OCT data are captured at different times, the image positions in each OCT data may differ due to changes in the positional relationship between the device and the eye between captures, changes in the state of eye accommodation, etc.

[0057] In contrast, in this embodiment, image processing is performed to correct the relative positions of the multiple OCT data (S3). In this embodiment, the correction is performed by affine transforming the other OCT data using one of the multiple OCT data as a reference so that the position of at least one feature common to each OCT data coincides. As an example, in this embodiment, the relative positions of the multiple OCT data are adjusted so that the positions of the IS / OS of the fovea coincide.

[0058] <Resolution normalization> In the OCT data, the number of A-scan OCT data (number of points) constituting the OCT data may differ with respect to the scan length. In this case, the display magnification in the horizontal direction differs according to the number of points (resolution) with respect to the scan length. In contrast, in this embodiment, the horizontal magnification in the OCT data is normalized to be constant. In detail, A-scans are interpolated (or thinned out) so that the number of horizontal points in each OCT data becomes a constant value with respect to the scan length. For example, the 512pt / 9mm OCT data shown in FIG. 5B is A-scan interpolated according to the 1024pt / 9mm OCT data shown in FIG. 5A. As a result, the 512pt / 9mm OCT data shown in FIG. 5B is stretched twice in the horizontal direction, and an image with a substantially identical appearance to that of FIG. 5A is obtained. In this embodiment, the number of points with respect to the scan length in each OCT data is normalized, so that the tissue of the subject eye can be easily observed without the user being aware of the A-scan settings at the time of shooting.

[0059] <Extraction area settings> Next, an extraction region is set for the multiple OCT data after the misalignment correction (S4). Here, Fig. 6A shows the relationship between the display region 300 and the OCT data 200 when the entire OCT data 200 is displayed in the display region 300. As shown in Fig. 6A, if the entire OCT data 200 is displayed, the region where the image of the subject's eye does not exist may occupy most of the display region. Also, as shown in Fig. 6A, the aspect ratio of the image 200 and the display region 300 does not match, so that the image of the subject's eye becomes relatively smaller.

[0060] In contrast, in this embodiment, an extraction region 400 is set in a part of the OCT data 200, and the image region (extracted OCT data) included in the extraction region 400 is enlarged and displayed as shown in Fig. 6B. In this case, first, a depth range in the OCT data 200 that includes the image of the subject's eye is detected. The detected range becomes the extraction region 400.

[0061] Here, in this embodiment, the extraction regions are set at the same position for the plurality of OCT data. In detail, the extraction regions are set at the same position between the plurality of OCT data after the positional deviation correction so that the image of the subject's eye is included in each of the plurality of OCT data. In this embodiment, the extraction regions are set for the plurality of OCT data so that the positional relationship of the extraction regions is consistent with the position of the IS / OS of the fovea in the plurality of OCT data. In this case, the extraction regions may be set so that both the image of the subject's eye whose upper end is located at the shallowest position and the image of the subject's eye whose lower end is located at the deepest position among the plurality of OCT data after the deviation correction are not cut off in the depth direction.

[0062] In this embodiment, the upper end and the lower end of the image of the subject's eye are obtained based on the detection result of the layer boundary for the OCT data. The upper end of the extraction region is set based on the upper end of the layer boundary on the shallowest side among the multiple layer boundaries detected by layer detection (segmentation processing). Similarly, the lower end of the extraction region is set based on the lower end of the layer boundary on the deepest side among the multiple layer boundaries detected. At this time, the upper end and the lower end of the extraction region may be set with a margin at a position a certain distance away from the upper end and the lower end of the layer boundary on the deepest side. At this time, the upper end side margin may be provided so that the vitreous body is depicted within the extraction region. The lower end side margin may be provided so that the deep choroid layer is depicted within the extraction region.

[0063] The extracted OCT data is displayed enlarged according to the aspect ratio of the display area 300. The aspect ratio of the display area 300 is determined in advance. If the extracted OCT data (extraction area 400) is wider than the display area 300, a magnification is calculated when the extracted OCT data is enlarged so that the width of the extracted OCT data matches the width of the display area 300. Similarly, if the extracted OCT data (extraction area 400) is wider than the display area 300, a magnification is calculated when the extracted OCT data is enlarged so that the vertical widths of the extracted OCT data and the display area 300 match.

[0064] <Display Control> In the display area 300 on the monitor 80, a plurality of extracted OCT data based on the multi-scan is selectively displayed (S6). The extracted OCT data displayed in the display area 300 is automatically or manually switched to extracted OCT data of another scan position. At this time, the same position in the displayed plurality of OCT data is extracted, so that it is easy to appropriately grasp the difference in tissue between the scan lines. In addition, the extracted OCT data corresponding to each scan position is set after considering the position of the image in the plurality of OCT data obtained at each scan position in advance, so that the image of the subject's eye is unlikely to be cut off from the display area 300. In addition, the magnification when the extracted OCT data corresponding to each scan position is displayed in the display area 300 is constant, so that the examiner is unlikely to feel uncomfortable before and after the extracted OCT data is switched to that of another scan position.

[0065] <Editing the extracted area> In this embodiment, the OCT data on which the extracted OCT data is based remains even after the extracted OCT data is displayed. An operation to correct the extracted region may be accepted on a screen on which the extracted OCT data based on the initial extracted region is displayed. The position of the boundary in the extracted region (the position of the boundary in either the transverse direction or the depth direction) may be corrected. Based on the operation, the extracted OCT data based on the corrected extracted region is displayed. This allows the examiner to properly confirm the tissue even if the initial extraction range is not set to the range desired by the examiner. For example, the set position of the extracted region may be changed by scrolling the mouse wheel or by operating a key on the keyboard.

[0066] <Display settings for each scan pattern> In this embodiment, for each type of scan pattern, it is predefined whether the B-scan OCT data at each scan position is set to an extraction region together with other B-scan OCT data. For example, in the case of the above-mentioned one-way multi-scan, the extraction region is set for all OCT data collectively. That is, the misalignment correction and the setting of the extraction region are performed collectively for all OCT data constituting the multi-scan. The same is true for the radial scan shown in FIG. 7A. In contrast, as shown in FIGS. 7B and 7C, in the cross scan and multi-cross, the OCT data constituting the scan pattern is divided into groups for each scan direction (groups F and G in FIGS. 7B and 7C, respectively), and the extraction region is set collectively for each OCT data included in each group.

[0067] "Example of transformation" While the present disclosure has been described above based on the embodiment and examples, it is not necessarily limited to these and various modifications are permissible.

[0068] For example, in the above example, the scan length of the OCT data acquired by the device was fixed at 9 mm. On the other hand, in recent years, the angle has become wider, and devices with longer scan lengths exist. However, in observation and diagnosis using fundus OCT, information on the center of the fundus is more important than information on the peripheral area.

[0069] Therefore, in a device with a long scan length (e.g., 15 mm or more), the range of the extraction region in the transverse direction may be switchable between two predetermined values. For example, it may be switchable between a range around the fovea (e.g., a range of about 9 mm) and the maximum range of the device. In this case, GUI widgets corresponding to these two ranges may be provided on the screen together with the display area 300. The range of the extraction region in the transverse direction is switched by operating the GUI widget. Note that it may be preset as to whether the initial value of the extraction region is the range around the fovea or the maximum range.

[0070] In the above embodiment, the extracted OCT data is displayed on the monitor 80, but this is not necessarily limited to the present invention. When the extracted OCT data is displayed in a report, it may be displayed in accordance with the display area of ​​the report. The report may be in electronic form or paper form.

[0071] For example, in the above embodiment, an ophthalmologic imaging device for capturing OCT data of a subject's eye has been described as an example, but the present invention is not limited thereto. For example, the present embodiment may be applied to an apparatus for capturing OCT data of a subject. For example, the subject may be a living body such as an eye, skin, or blood vessel, or may be a non-living body sample such as a resin body. [Explanation of symbols]

[0072] 1 OCT device 70 Calculation control unit 200 OCT data 300 display area 400 extraction area

Claims

1. 1. A computer-implemented ophthalmic image processing method, comprising: An acquisition step of acquiring B-scan OCT data of a tissue of a subject's eye, the B-scan OCT data being different from each other in scan lines captured at one time as included in one scan pattern; a setting step of collectively setting extraction regions for the plurality of B-scan OCT data so that an image of the subject's eye is included in each of the plurality of B-scan OCT data; and a display control step of selectively and switchably displaying a plurality of extracted OCT data extracted from each of the B-scan OCT data in a predetermined display area.

2. A correction step of correcting a mutual positional relationship of the plurality of B-scan OCT data, The ophthalmologic image processing method according to claim 1 , wherein in the setting step, the relative positional relationship between the images is corrected, and then the extraction region is set for each corrected B-scan OCT data.

3. 3. The ophthalmologic image processing method according to claim 1 or 2, wherein in the display control step, a horizontal magnification of the extracted OCT data on the display area is adjusted according to the scan density of the B-scan OCT data on which the extracted OCT data is based, so that the horizontal magnification of the extracted OCT data on the display area is constant between B-scan OCT data having different scan densities.

4. The ophthalmologic image processing method according to claim 3 , wherein whether or not the extraction region is set collectively with other B-scan OCT data for each scan line is determined in advance for each type of scan pattern.

5. In the setting step, a transverse range in which the extraction region is set in a plurality of B-scan OCT data can be selected from among a plurality of different ranges; The ophthalmologic image processing method according to claim 1 , wherein the extraction regions are set collectively for selected transverse ranges of each of a plurality of B-scan OCT data.

6. An ophthalmic image processing method as described in any one of claims 1 to 5, further comprising a storage execution step in which data of areas other than the extraction area in each of the plurality of B-scan OCT data is reduced, and extracted OCT data, which is data among the plurality of B-scan OCT data corresponding to the extraction area, is stored in memory.

7. An ophthalmologic image processing program, which, when executed by a processor of the computer, causes the computer to execute the ophthalmologic image processing method according to any one of claims 1 to 6.

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