Ophthalmology information processing device

Abstract

To provide a novel display mode of information on the eye.SOLUTION: A data input unit of an ophthalmologic information processing device inputs first OCT data configured by a first ophthalmologic imaging device applying OCT scanning to a predetermined cross section of the ocular fundus, and second OCT data configured by a second ophthalmologic imaging device different from the first ophthalmologic imaging device applying OCT blood flow measurement to a blood vessel passing through the cross section. By compositing a blood flow state image in which the magnitude of blood flow velocity of the blood vessel based on the second OCT data is expressed by color in the cross section region of the blood vessel in a B scan image of the cross section based on the first OCT data, a display processing unit causes a composite image of the B scan image and the blood flow state image to be displayed in display means.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The embodiment relates to an ophthalmologic information processing apparatus. [Background technology]

[0002] Image diagnosis plays an important role in the field of ophthalmology. In recent years, the use of Optical Coherence Tomography (OCT) has been increasing. OCT is now being used not only to obtain B-scan images and 3D images of the examined eye, but also to obtain en-face images such as C-scan images and shadowgrams.

[0003] Furthermore, it is also possible to obtain images that emphasize specific parts of the examinee's eye, and to obtain functional information. For example, based on the time-series data collected by OCT, it is possible to construct a B-scan image or a frontal image (called a blood vessel-emphasized image, angiogram, etc.) in which the fundus blood vessels are emphasized. This technology is called OCT angiography, etc. Also, based on the phase information of the time-series data collected by OCT, it is possible to obtain information about blood flow. This technology is called OCT blood flow measurement, etc. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2015-515894 [Patent Document 2] JP 2013-184018 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the embodiment is to provide a novel display manner of eye information. [Means for solving the problem]

[0006] The ophthalmologic information processing device of the embodiment includes a data input unit and a display processing unit. The data input unit inputs first image data of a subject's eye constructed by a first ophthalmologic imaging device and second image data of the subject's eye constructed by a second ophthalmologic imaging device different from the first ophthalmologic imaging device. The data input unit causes a display unit to display composite information of a first image based on the first image data and a second image based on the second image data. Effect of the Invention

[0007] According to the embodiment, it is possible to provide a novel display mode of eye information. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram illustrating an example of a configuration of an ophthalmologic imaging apparatus according to an exemplary embodiment. [Diagram 2] 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; FIG. [Diagram 3] 10 is a flowchart illustrating an example of an operation of an ophthalmologic imaging apparatus according to an exemplary embodiment. [Figure 4A] 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; FIG. [Figure 4B] 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; FIG. [Diagram 5] 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; FIG. [Figure 6] FIG. 1 is a schematic diagram illustrating an example of a configuration of an ophthalmological information processing apparatus according to an exemplary embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Exemplary embodiments of the present invention will be described with reference to the drawings. Any known technology including the disclosures of documents cited in this specification can be combined with the embodiments.

[0010] The ophthalmic information processing device and ophthalmic imaging device according to the embodiment have a function of displaying various information based on data acquired by applying OCT to the fundus of the subject's eye. The ophthalmic information processing device according to the embodiment receives data acquired by applying OCT to the fundus of the subject's eye by a separately provided OCT device, for example, and displays various information based on this data. On the other hand, the ophthalmic imaging device according to the embodiment acquires data by applying OCT to the fundus of the subject's eye, and displays various information based on this data.

[0011] Data acquired by applying OCT to the fundus of the subject's eye (fundus OCT data) may be in any form. For example, the fundus OCT data may include any one or more of the following (1) to (5): (1) Data collected by OCT scan of the fundus (raw data) (2) Image data obtained by processing the raw data (3) Intermediate data obtained during the process of generating image data from raw data (4) Blood flow data obtained by processing the raw data (5) Intermediate data obtained during the process of generating blood flow data from raw data

[0012] The types of fundus OCT data are not limited to these. In addition, the embodiment can process various information associated with the fundus OCT data. Examples of such information include subject identification information, subject eye identification information, identification information indicating whether the subject eye is the left eye or the right eye, shooting date and time, shooting conditions, etc.

[0013] The ophthalmic information processing apparatus and the ophthalmic imaging apparatus according to the embodiment include a processor that executes data display processing. The ophthalmic information processing apparatus according to the embodiment may further include a processor that processes raw data and intermediate data. The ophthalmic imaging apparatus according to the embodiment further includes an optical system, a drive system, a control system, and a data processing system for performing OCT.

[0014] The ophthalmic imaging apparatus of the embodiment is configured to be able to perform, for example, Fourier domain OCT. Fourier domain OCT includes spectral domain OCT and swept source OCT. Spectral domain OCT is a method of acquiring the spectrum of interference light in a spatial division manner using a wideband low coherence light source and a spectrometer, and constructing an image by Fourier transforming it. Swept source OCT is a method of acquiring the spectrum of interference light in a time division manner using a wavelength swept light source (wavelength tunable light source) and a photodetector (balanced photodiode, etc.), and constructing an image by Fourier transforming it. The OCT method is not limited to Fourier domain OCT, and may be time domain OCT or unfath OCT.

[0015] The ophthalmic information processing device and ophthalmic imaging device according to the embodiments may include a modality (e.g., a modality other than OCT) for imaging the eye and / or other parts. Typical examples include a fundus camera, a scanning laser ophthalmoscope (SLO), a slit lamp microscope, an ophthalmic surgical microscope, etc. The ophthalmic information processing device and ophthalmic imaging device according to the embodiments may also include a configuration for measuring characteristics of the eye and / or other parts and a configuration for performing an examination.

[0016] The data processing functions (computational functions, image processing functions, control functions, etc.) in the ophthalmic information processing device and ophthalmic imaging device according to the embodiment are realized by, for example, hardware such as a processor or a storage device working in cooperation with software such as a computation program, an image processing program, or a control program. Note that a part of the hardware may be provided in an external device capable of communicating with the ophthalmic information processing device or ophthalmic imaging device according to the embodiment. Also, at least a part of the software may be pre-stored in the ophthalmic information processing device or ophthalmic imaging device according to the embodiment, and / or may be pre-stored in the external device.

[0017] Ophthalmic imaging equipment <composition> An ophthalmic imaging apparatus according to an exemplary embodiment will be described. An example of the configuration of the ophthalmic imaging apparatus of this embodiment is shown in Fig. 1. The ophthalmic imaging apparatus 1 collects fundus data using OCT, generates fundus morphological images and fundus blood flow data based on the collected data, and displays various information based on these.

[0018] Here, the fundus morphological image is an image that represents the morphology of the fundus. In this embodiment, the fundus morphological image is an image that represents at least the fundus blood vessels (retinal blood vessels, choroidal blood vessels, etc.) in a visually identifiable manner. Examples of the fundus morphological image include a B-scan image, a C-scan image, a projection image, a shadowgram, a phase image, and a blood vessel enhancement image. The fundus blood flow data is data that represents the blood flow state (blood flow dynamics) in the fundus blood vessels. Examples of the fundus blood flow data include the direction of blood flow, blood flow velocity, time series changes in blood flow velocity, blood flow rate, blood flow rate per unit time, time series changes in blood flow rate per unit time, and total blood flow rate.

[0019] In this embodiment, both morphological images and blood flow data are formed based on data obtained by applying OCT blood flow measurement to the fundus. Note that an OCT scan (e.g., B scan, 3D scan) for obtaining a morphological image and an OCT scan (OCT blood flow measurement) for obtaining blood flow data may be performed separately. Also, an OCT scan for obtaining data other than these may be performed. For example, an OCT angiogram may be performed.

[0020] A part of the data used for displaying the information may be acquired by another device. For example, one of the fundus morphological image and the fundus blood flow data may be acquired by another device. Alternatively, the other device may perform OCT angiography to acquire a vascular enhancement image. The data acquired by the other device is input to the ophthalmologic imaging device according to the embodiment.

[0021] The ophthalmic photographing apparatus 1 can display various information such as a fundus morphological image, blood flow information, and a blood vessel enhancement image on a display device 2. The display device 2 may be a part of the ophthalmic photographing apparatus 1, or may be an external device connected to the ophthalmic photographing apparatus 1. In addition, the ophthalmic photographing apparatus 1 can send various information to a computer, a storage device, an ophthalmic apparatus, etc.

[0022] The ophthalmologic imaging apparatus 1 includes a control unit 10, a storage unit 20, a data acquisition unit 30, an operation unit 50, and a front image acquisition unit 60. The control unit 10 includes a scan control unit 11 and a display control unit 12. The data acquisition unit 30 includes an OCT scanner 31, an image forming unit 32, and a blood flow data generating unit 33.

[0023] <Control unit 10> The control unit 10 controls each unit of the ophthalmologic imaging apparatus 1. The control unit 10 includes a processor. The "processor" refers to a circuit such as a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), a field programmable gate array (FPGA)), etc. The control unit 10 can realize the functions according to the embodiment by reading and executing a program stored in a memory circuit or a storage device (the storage unit 20, an external device, etc.), for example.

[0024] The control unit 10 may also include a communication device for transmitting and receiving data via a communication line such as a local area network (LAN), the Internet, or a dedicated line.

[0025] <Scan control unit 11> The scan control unit 11 controls the OCT scanner 31. For example, the scan control unit 11 controls various elements included in the OCT scanner 31, such as control of a light source, control of an optical scanner, change of an optical path length of a measurement light and / or a reference light, polarization adjustment, light amount adjustment, focus adjustment, change of a fixation position, etc. Some examples of processes that the scan control unit 11 can execute will be described later.

[0026] <Display control unit 12> The display control unit 12 executes control for displaying information on the display device 2. The display control unit 12 can execute display control based on data stored in the storage unit 20.

[0027] The display control unit 12 can perform processes (generation, processing, synthesis, etc.) related to the information displayed on the display device 2. Such processes may be performed by cooperation between the display control unit 12 and other elements (other elements of the control unit 10, the data acquisition unit 30, etc.).

[0028] <Storage section 20> Various data are stored in the storage unit 20. In this example, OCT data 21 is stored in the storage unit 20. Note that at least a part of the OCT data may be saved in an external storage device and provided to the ophthalmic imaging apparatus 1 upon request. The storage unit 20 includes a storage device such as a hard disk drive or a semiconductor memory.

[0029] <OCT data 21> The OCT data 21 includes any one or more of the above-mentioned fundus OCT data (1) to (5). Typically, the ophthalmologic imaging apparatus 1 generates a morphological image and blood flow data from raw data collected by an OCT scan of the fundus, and stores the OCT data 21 including these in the storage unit 20. In other words, in a typical example, the OCT data 21 includes the above-mentioned fundus OCT data (2) and (4).

[0030] <Data Acquisition Unit 30> The data acquisition unit 30 applies OCT to the fundus of the subject's eye to acquire data (for example, at least a part of the OCT data 21 stored in the storage unit 20). As described above, the data acquisition unit 30 includes an OCT scanner 31, an image formation unit 32, and a blood flow data generation unit 33. The image formation unit 32 includes a processor that executes an image formation program. The blood flow data generation unit 33 includes a processor that executes a blood flow data generation program.

[0031] <OCT Scanner 31> The OCT scanner 31 performs an OCT scan of the fundus under the control of the scan control unit 11. This allows data (raw data) of the fundus to be collected. The OCT scanner 31 includes a configuration for performing optical interference measurement using, for example, spectral domain OCT or swept source OCT. The OCT scanner 31 includes an OCT optical system, a drive system, a data acquisition system (DAQ), a control system, and the like, as in the conventional case.

[0032] The OCT optical system includes, for example, an interference optical system, an optical scanner, and an optical detector. The interference optical system splits light output from a light source into measurement light and reference light, projects the measurement light onto the fundus, and generates interference light by superimposing return light of the measurement light from the fundus onto the reference light. The optical scanner includes a galvano scanner or the like and deflects the measurement light, thereby moving the projection position of the measurement light on the fundus. The optical detector detects (the spectrum of) the interference light generated by the interference optical system.

[0033] The drive system moves and operates the elements included in the OCT optical system. The data collection system collects the detection results sequentially obtained by the OCT optical system. The control system controls the OCT optical system, the drive system, the data collection system, etc. under the control of the scan control unit 11 (or other elements of the control unit 10).

[0034] In OCT blood flow measurement, the OCT scanner 31 repeatedly scans a cross section intersecting a blood vessel at a preset measurement position to collect data. In other words, the OCT scanner 31 repeatedly scans a cross section of interest intersecting a blood vessel of interest to collect data. The scan mode at this time is, for example, a line scan (B scan). This line scan is repeatedly executed at, for example, a predetermined frequency. The data collected by such repeated scanning is sent to the image forming unit 32.

[0035] In the OCT blood flow measurement, the OCT scanner 31 further performs a scan to obtain the inclination angle of the blood vessel of interest in the cross section of interest. This scan is performed, for example, on two cross sections that intersect with the blood vessel of interest. Here, the two cross sections can be positioned near the cross section of interest.

[0036] One of the two cross sections for calculating the inclination angle of the blood vessel of interest may be the cross section of interest itself. The other cross section is set in the vicinity of the cross section of interest. In this case, data obtained by repeatedly scanning the cross section of interest described above can be used to calculate the inclination angle.

[0037] In summary, typically, the scans performed in OCT blood flow measurement may be a combination of repeated scans of a cross section of interest and scans of two other cross sections, or a combination of repeated scans of a cross section of interest and scans of one other cross section.

[0038] The manner of scanning for determining the inclination angle of the blood vessel of interest in the cross section of interest is not limited to these. For example, three or more cross sections can be scanned. Alternatively, a three-dimensional region including the cross section of interest can be scanned (three-dimensional scanning). As another example, a cross section that intersects with the cross section of interest and runs along the blood vessel of interest can be scanned. The OCT blood flow measurement will be described in detail in the explanation of the blood flow data generating unit 33.

[0039] When performing OCT angiography, the OCT scanner 31 scans a three-dimensional region of the fundus. The scan mode at this time is, for example, raster scan (three-dimensional scan). This raster scan is performed, for example, to scan each of a plurality of B-sections (B-scan planes) a predetermined number of times (for example, four times each). In other words, this raster scan is performed to scan a plurality of B-sections sequentially a predetermined number of times, or to scan according to a predetermined sequence. The three-dimensional data set collected by the OCT scanner 31 is sent to the image forming unit 32.

[0040] The scanning modes that can be performed by the OCT scanner 31 are not limited to the above modes. For example, the OCT scanner 31 can perform line scan, circle scan, radial scan, three-dimensional scan, etc. as OCT scans for acquiring morphological images.

[0041] <Image forming unit 32> The image forming unit 32 forms an OCT image based on the data collected by the OCT scanner 31. For example, in OCT blood flow measurement, the image forming unit 32 forms a plurality of cross-sectional images (B-scan images) for each B cross section based on the three-dimensional data set collected by the OCT scanner 31. The image forming process at this time includes, for example, noise removal (noise reduction), filtering, fast Fourier transform (FFT), and the like, similar to conventional OCT technology.

[0042] The image forming unit 32 can construct stack data by embedding these cross-sectional images in a single three-dimensional coordinate system. In this stack data, a number of cross-sectional images corresponding to the number of scan repetitions is assigned to each B cross-section. Furthermore, the image forming unit 32 can form volume data (voxel data) by performing an interpolation process or the like on this stack data. In this volume data, a number of voxel groups corresponding to the number of scan repetitions is assigned to a position corresponding to each B cross-section.

[0043] The image forming unit 32 can generate B-scan images (longitudinal cross-sectional images, axial cross-sectional images), C-scan images (transverse cross-sectional images, horizontal cross-sectional images), projection images, shadowgrams, etc. by rendering the stack data or volume data.

[0044] An image of an arbitrary plane, such as a B-scan or C-scan image, can be generated by selecting pixels (voxels) on a specified plane from a 3D data set, or by projecting a slice of a predefined thickness along its thickness.

[0045] A projection image is formed by projecting stack data or volume data in a predetermined direction (Z direction, depth direction, A-scan direction). A shadowgram is formed by projecting a part of stack data or volume data (e.g., partial data corresponding to a specific layer) in a predetermined direction. A fundus image viewed from the cornea side of the subject's eye, such as a C-scan image, a projection image, or a shadowgram, is called a front image.

[0046] The image forming unit 32 can perform various kinds of image processing other than rendering. For example, there is segmentation for determining a specific tissue or tissue boundary, and size analysis for determining the size of the tissue (layer thickness, volume, etc.). When a specific layer (or a specific layer boundary) is determined by segmentation, it is possible to reconstruct a B-scan image or a front image so that the specific layer is flat. Such an image is called a flattened image.

[0047] The image forming unit 32 can form a vascular emphasis image. A vascular emphasis image is an image in which an image region (vascular region) corresponding to blood vessels is identified by analyzing OCT data, and the vascular region is emphasized by changing the representation mode of the vascular region. A plurality of OCT data obtained by repeatedly scanning substantially the same area of ​​the subject's eye is used to identify the vascular region.

[0048] The vessel enhancement image represents, for example, the distribution of blood vessels in a three-dimensional region of the fundus scanned by OCT (i.e., the three-dimensional distribution of blood vessels). There are several types of techniques for forming a vessel enhancement image. A typical technique will be described. In this process, a three-dimensional data set including a plurality of B-scan images arranged in time series for each B-section is used by repeatedly scanning each of a plurality of B-sections of the subject's eye. Note that fixation and tracking are techniques for repeatedly scanning substantially the same B-section.

[0049] In the process of forming a vessel-weighted image, first, the alignment of a plurality of B-scan images is performed for each B slice. This alignment is performed, for example, using a known image matching technique. As a typical example, it is possible to extract a characteristic region in each B-scan image and align the plurality of B-scan images by aligning the extracted characteristic regions.

[0050] Next, a process is performed to identify image regions that have changed between the aligned B-scan images. This process includes, for example, a process of calculating the difference between different B-scan images. Each B-scan image is luminance image data that represents the shape of the subject's eye, and image regions that correspond to areas other than blood vessels are considered to be substantially unchanged. On the other hand, considering that backscattering that contributes to the interference signal changes randomly due to blood flow, image regions that have changed between the aligned B-scan images (for example, pixels with a difference that is not zero, or pixels with a difference that is equal to or greater than a predetermined threshold) can be estimated to be blood vessel regions.

[0051] The image region identified in this way is assigned information indicating that it is a vascular region. By executing the above process for multiple B-sections, a 3D distributed vascular region is obtained. By rendering such a 3D vascular-weighted image, a frontal image showing the vascular distribution, an image of an arbitrary section, a shadowgram of an arbitrary range, etc. are generated.

[0052] The process of forming a vascular emphasis image is not limited to this. For example, it is possible to specify a vascular region by a conventional method using Doppler OCT, or to specify a vascular region by using a conventional image processing method. In addition, it is possible to specify a vascular region for each part by using a different method depending on the part. For example, for the retina, the vascular region can be specified by using the typical method described above or the Doppler OCT method, and for the choroid, the vascular region can be specified by using an image processing method.

[0053] <Blood flow data generating unit 33> The blood flow data generating unit 33 operates in the OCT blood flow measurement. The blood flow data generating unit 33 generates blood flow data representing the blood flow state in the blood vessel of interest based on the image of the cross section of interest formed by the image forming unit 32 based on the data collected by the OCT scanner 31 in the OCT blood flow measurement and the inclination angle of the blood vessel of interest in the cross section of interest.

[0054] Data collected by the OCT scanner 31 in OCT blood flow measurement includes data (first data) collected by repeatedly scanning a cross section of interest that intersects with the blood vessel of interest, and data (second data) obtained by scanning one or more cross sections (cross sections near the cross section of interest) that intersect with the blood vessel of interest and are different from the cross section of interest. Note that instead of the second data, for example, the inclination angle of the blood vessel of interest at the position of the cross section of interest or a position near the cross section of interest, which is obtained separately from the OCT blood flow measurement, can be used. As an example, the inclination angle obtained from a blood vessel enhancement image obtained by OCT angiography can be used.

[0055] The image forming unit 32 forms a morphological image and a phase image of the fundus based on the data collected by the OCT scanner 31 in the OCT blood flow measurement. The morphological image and the phase image obtained in the OCT blood flow measurement correspond to the same cross section. Typically, the morphological image and the phase image corresponding to the cross section of interest (cross section B) are obtained.

[0056] As described above, in a typical OCT blood flow measurement, two types of scans (auxiliary scan and main scan) are performed on the fundus. The auxiliary scan is performed to collect second data by scanning one or more cross sections (cross sections adjacent to the cross section of interest) different from the cross section of interest. In a typical auxiliary scan, two or more cross sections intersecting the blood vessel of interest are scanned with measurement light. The data acquired by the auxiliary scan is used to determine the inclination angle of the blood vessel of interest in the cross section of interest. On the other hand, the main scan is performed to collect first data by repeatedly scanning the cross section of interest intersecting the blood vessel of interest with measurement light. The cross section on which the auxiliary scan is performed is positioned adjacent to the cross section of interest. The main scan is a Doppler measurement using OCT.

[0057] The target sections of the auxiliary scan and the main scan are oriented, for example, perpendicular to the running direction of the blood vessel of interest. The distance between the target section of the auxiliary scan and the blood vessel of interest (inter-section distance) is set in advance or set for each examination. As an example of the latter, the inter-section distance can be set based on a predetermined factor such as the curvature of the blood vessel of interest on or near the inter-section of interest, or the examination accuracy. Alternatively, the user may set a desired inter-section distance.

[0058] It is desirable that the main scan is performed for at least one cardiac cycle of the patient's heart. This allows blood flow data to be obtained at all time phases of the heartbeat. The execution time of the main scan may be a fixed time set in advance, or may be a time set for each patient or each examination.

[0059] The image forming unit 32 forms a cross-sectional image showing the shape of the first auxiliary cross section and a cross-sectional image showing the shape of the second auxiliary cross section based on data collected by auxiliary scans of two auxiliary cross sections set near the cross section of interest, for example. At this time, it is possible to improve image quality by using a technique such as averaging, or to select an optimal image from two or more cross-sectional images of each auxiliary cross section.

[0060] Furthermore, the image forming unit 32 forms a group of cross-sectional images representing time-series changes in the cross-section of interest based on data collected by the main scan (repetitive scan) of the cross-section of interest. This process is realized, for example, by forming cross-sectional images from data collected for each repetition of the scan.

[0061] The processing executed by the image forming unit 32 includes, for example, noise removal (noise reduction), filtering, fast Fourier transform (FFT), etc., similar to conventional OCT technology. Note that the processing for forming a cross-sectional image of the cross-section of interest described here is similar to the morphological image forming processing executed by the image forming unit 32.

[0062] Furthermore, the image forming unit 32 forms a phase image representing a time series change of the phase difference in the cross section of interest based on the data collected by the main scan of the cross section of interest. The data used in this process is the same as the data used to form the cross section image(s) of the cross section of interest. Therefore, there is a natural positional correspondence between the cross section image of the cross section of interest and the phase image, and the registration is self-evident.

[0063] An example of a method for forming a phase image will be described. In a typical example, a phase image is obtained by calculating the phase difference between adjacent A-line complex signals (signals corresponding to adjacent scan points). In other words, the phase image in this example is formed based on the time series change of the pixel value (luminance value) of each pixel of the cross-sectional image of the cross-section of interest. For any pixel, the image forming unit 32 considers a graph of the time series change of the luminance value. The image forming unit 32 obtains a phase difference Δφ between two time points t1 and t2 (t2=t1+Δt) that are separated by a predetermined time interval Δt in this graph. Then, this phase difference Δφ is defined as the phase difference Δφ(t1) at the time point t1 (more generally, any time point between the two time points t1 and t2). By performing this process for each of a large number of time points set in advance, the time series change of the phase difference at the pixel is obtained.

[0064] A phase image is an image that represents the phase difference value of each pixel at each time point. This imaging process can be realized, for example, by representing the phase difference value with a display color or brightness. In this case, a different color (e.g., red) can represent an increase in phase along the time series, and a different color (e.g., blue) can represent a decrease. The magnitude of the amount of change in phase can also be represented by the intensity of the display color. By adopting such a representation method, it becomes possible to represent the direction and magnitude of blood flow with color and intensity. A phase image is formed by performing the above process for each pixel.

[0065] The time series change of the phase difference can be obtained by making the above-mentioned time interval Δt sufficiently small to ensure phase correlation. At this time, oversampling is performed by setting the time interval Δt to a value less than the time corresponding to the resolution of the cross-sectional image in the measurement light scan.

[0066] The blood flow data generating unit 33 can execute, for example, a vascular region specifying process, a tilt angle calculating process, and a blood flow data generating process. The blood flow data generating process includes, for example, at least a blood flow velocity calculating process, and may further include a blood vessel diameter calculating process and a blood flow amount calculating process.

[0067] In the vascular region identification process, the blood flow data generating unit 33 identifies a vascular region in each cross-sectional image corresponding to the blood vessel of interest. Furthermore, the blood flow data generating unit 33 identifies a vascular region in a phase image corresponding to the cross-section of interest. The vascular region is identified by analyzing pixel values ​​of each image (e.g., threshold processing). The vascular region in the phase image may be identified based on the vascular region in the cross-sectional image corresponding to the cross-section of interest and the result of registration between this cross-sectional image and the phase image.

[0068] In the inclination angle calculation process, the blood flow data generating unit 33 calculates the inclination angle of the blood vessel of interest in the cross section of interest based on the image(s) formed from the data acquired by the auxiliary scan.

[0069] An example of the inclination angle calculation process will be described with reference to FIG. 2. Reference B0 denotes a cross-sectional image (cross-sectional image of interest) in a cross-section of interest for which a blood vessel inclination angle is calculated. A blood vessel region V0 is depicted in the cross-sectional image of interest B0. References B11 and B12 denote two cross-sectional images (auxiliary cross-sectional images) in two auxiliary cross-sections located near the cross-section of interest B0. A blood vessel region V11 in the auxiliary cross-section B11 of the same blood vessel as the blood vessel region V0 (blood vessel of interest) is depicted in the auxiliary cross-section B11. Similarly, a blood vessel region V12 in the auxiliary cross-section B12 of the blood vessel of interest is depicted in the auxiliary cross-section B12.

[0070] The blood flow data generating unit 33 calculates the inclination of the blood vessel of interest in the cross section of interest based on the cross section of interest B0 and the auxiliary cross section images B11 and B12. Note that the number of auxiliary cross section images to be referred to is not limited to two, and may be any number equal to or greater than one.

[0071] The blood flow data generating unit 33 calculates the inclination of the blood vessel of interest in the cross section of interest based on the blood vessel regions V0, V11, and V12 and the cross section distance. The cross section distance may be the distance between the auxiliary cross section image B11 and the auxiliary cross section image B12. Alternatively, the cross section distance may be defined by at least one of the distance between the auxiliary cross section image B11 and the cross section image of interest B0 and the distance between the auxiliary cross section image B12 and the cross section image of interest B0. The distance between the auxiliary cross section image B11 (or B12) and the cross section image of interest B0 is defined as L.

[0072] 2 (the direction indicated by the arrow pointing downward) indicates, for example, the direction of the A-scan image included in the cross-sectional image of interest B0. This A-scan image may be, for example, the A-scan image located at the center of the multiple A-scan images included in the cross-sectional image of interest B0.

[0073] In a typical example, the blood flow data generating unit 33 can calculate the gradient A of the blood vessel of interest in the cross section of interest based on the positional relationship of the three blood vessel regions V0, V11, and V12. This positional relationship is obtained, for example, by connecting the three blood vessel regions V0, V11, and V12. More specifically, the blood flow data generating unit 33 identifies characteristic points of each of the three blood vessel regions V0, V11, and V12, and connects these characteristic points. The characteristic points referred to here include the center position (axis position), the center of gravity position, and the top. Methods for connecting these characteristic points include a method of connecting them with a line segment, a method of connecting them with an approximation curve (spline curve, Bezier curve, etc.), and the like.

[0074] Furthermore, the blood flow data generating unit 33 calculates the slope A based on a line connecting these feature points. When a line segment is used, the blood flow data generating unit 33 can calculate the slope A based on, for example, the slope of a first line segment connecting a feature point of the blood vessel region V0 in the target cross-sectional image B0 and a feature point of the blood vessel region V11 in the auxiliary cross-sectional image B11, and the slope of a second line segment connecting the feature point of the blood vessel region V0 and a feature point of the blood vessel region V12 in the auxiliary cross-sectional image B12. As an example of this calculation process, the average slope of the two line segments can be calculated. Also, as an example of connecting with an approximate curve, the slope of the approximate curve at the intersection position of the approximate curve and the target cross section can be calculated.

[0075] In this example, the vascular regions in three cross sections are considered, but it is also possible to obtain the inclination by considering the vascular regions in two cross sections. As a specific example, the inclination A of the blood vessel of interest in the cross section of interest can be obtained based on the blood vessel region V11 in the auxiliary cross section image B11 and the blood vessel region V12 in the auxiliary cross section image B12. Alternatively, the inclination A of the blood vessel of interest in the cross section of interest can be obtained based on the blood vessel region V11 in the auxiliary cross section image B11 and the blood vessel region V0 in the cross section of interest B0. For example, the inclination of the first or second line segment described above can be obtained and used as the inclination A of the blood vessel of interest.

[0076] In the above example, only one value of the slope A is obtained, but the slope may be obtained for two or more positions (or regions) in the vascular region V0. In this case, the obtained two or more slope values ​​can be used separately, or one value (for example, the average value) obtained statistically from these slope values ​​can be used as the slope A.

[0077] In the blood flow data generation process, the blood flow data generation unit 33 generates blood flow data on the blood vessel of interest based on a phase image formed based on the main scan (Doppler OCT) and the tilt angle calculated by the blood flow data generation unit 33. As described above, in a typical example, the blood flow data generation process includes a blood flow velocity calculation process, a blood vessel diameter calculation process, and a blood flow amount calculation process.

[0078] The blood flow data generating unit 33 can calculate the blood flow velocity of blood flowing through a blood vessel of interest in a cross section of interest based on the time series change in the phase difference obtained as a phase image. The value calculated by this process may be the blood flow velocity at a certain time point, or may be the time series change in blood flow velocity (blood flow velocity change data). In the former case, for example, it is possible to selectively obtain the blood flow velocity in a specific time phase of an electrocardiogram (for example, the time phase of an R wave). In the latter case, the time range is the entire time during which the cross section of interest is scanned, or any part of it.

[0079] When blood flow velocity change data is obtained, the blood flow data generating unit 33 can calculate statistical values ​​of the blood flow velocity in the time range. These statistical values ​​include the average value, standard deviation, variance, median, maximum value, minimum value, local maximum value, local minimum value, etc. Also, a histogram of the blood flow velocity values ​​can be created.

[0080] The blood flow data generating unit 33 can calculate the blood flow velocity using the Doppler OCT technique as described above. The blood flow velocity is calculated using, for example, the following relational expression.

[0081]

number

[0082] Δf: Doppler shift of the scattered light of the measurement light n: refractive index of the medium (blood) v: Flow velocity of the medium (blood flow velocity) θ: Angle between the incident direction of the measurement light and the direction of the medium flow (inclination angle) λ: central wavelength of measurement light

[0083] In a typical example, the refractive power n of the medium and the central wavelength λ of the measurement light are known, the Doppler shift Δf is obtained from the time series change in the phase difference, and the tilt angle θ is obtained from the tilt angle calculation process or the blood vessel angle distribution. The blood flow data generating unit 33 can calculate the blood flow velocity v by substituting these values ​​into the above relational expression.

[0084] In the blood vessel diameter calculation process, the blood flow data generating unit 33 calculates the diameter of the blood vessel of interest in the cross section of interest. Examples of this calculation method include a first calculation method using a front image of the fundus and a second calculation method using a cross-sectional image.

[0085] When the first calculation method is applied, an image of a portion of the fundus including the position of the cross section of interest is captured in advance. This fundus image is captured, for example, by the front image capture unit 60. Alternatively, a front image of the fundus previously captured and stored may be read out. A blood vessel emphasis image may also be used.

[0086] The blood flow data generating unit 33 sets the scale in the front image of the fundus based on various factors that determine the relationship between the scale on the image and the scale in real space, such as the photographing angle of view (photographing magnification), working distance, and information on the ocular optical system. This scale represents the length in real space. As a specific example, this scale corresponds to the interval between adjacent pixels and the scale in real space (e.g., pixel interval=10 μm). It is also possible to calculate the relationship between various values ​​of the above factors and the scale in real space in advance and store information expressing this relationship in a table format or graph format. In this case, the scale corresponding to the above factors is selectively applied.

[0087] The blood flow data generating unit 33 calculates the diameter of the blood vessel of interest in the cross section of interest, i.e., the diameter of the blood vessel region, based on this scale and the pixels included in the blood vessel region. As a specific example, the blood flow data generating unit 33 can calculate the maximum or average value of the diameters in various directions of the blood vessel region. Alternatively, the blood flow data generating unit 33 can approximate the contour of the blood vessel region to a circle or an ellipse and calculate the diameter of the circle or ellipse. Note that since the area of ​​the blood vessel region can be (substantially) determined once the blood vessel diameter is determined, the area may be calculated instead of the blood vessel diameter.

[0088] The second calculation method will be described. In the second calculation method, a cross-sectional image of the fundus in the cross-section of interest is used. This cross-sectional image may be a cross-sectional image based on the main scan, or may be obtained separately. The scale in this cross-sectional image is determined according to the scanning state of the measurement light. The length of the cross-section of interest is determined based on various factors that determine the relationship between the scale on the image and the scale in real space, such as the working distance and information on the ocular optical system. The blood flow data generating unit 33 can, for example, obtain the interval between adjacent pixels based on the length of the cross-section of interest, and calculate the diameter of the blood vessel of interest in the cross-section of interest in the same manner as the first calculation method.

[0089] In the blood flow calculation process, the blood flow data generating unit 33 calculates the flow rate of blood flowing through the blood vessel of interest based on the calculation results of the blood flow velocity and the blood vessel diameter. An example of this process will be described below.

[0090] Assume that the blood flow in the blood vessel is the Hagen-Poiseuille flow. Also, the blood vessel diameter is w, and the maximum blood flow velocity is Vm. In this case, the blood flow rate Q is expressed by the following equation.

[0091]

number

[0092] The blood flow data generating unit 33 can calculate the blood flow volume Q by substituting the blood vessel diameter w obtained by the blood vessel diameter calculation process and the maximum value Vm of the blood flow velocity obtained by the blood flow velocity calculation process into the above relational equation.

[0093] <Operation unit 50> The operation unit 50 is used by a user to input instructions to the ophthalmic imaging apparatus 1. The operation unit 50 may include a known operation device used in an ophthalmic apparatus or a computer. For example, the operation unit 50 may include a mouse, a touch pad, a trackball, a keyboard, a pen tablet, an operation panel, a joystick, a button, a switch, etc.

[0094] The operation unit 50 may include a touch panel. In this case, the display control unit 12 can display a GUI for inputting instructions and information on the touch panel.

[0095] <Front image acquisition unit 60> The front image acquisition unit 60 acquires a front image of the fundus. The process for acquiring the front image is arbitrary. In the first example, the front image acquisition unit 60 may include a configuration for photographing the fundus. For example, the front image acquisition unit 60 may include an optical system of a fundus camera, an optical system of an SLO, etc.

[0096] In the second example, the front image acquiring unit 60 may include a configuration for acquiring a front image of the fundus of the subject eye from an external device. For example, the front image acquiring unit 60 may include a communication device for transmitting and receiving data via a communication line such as a LAN, the Internet, or a dedicated line. In this case, the front image acquiring unit 60 can acquire a front image of the fundus of the subject eye stored in, for example, an electronic medical record system or an image archiving system, using a patient ID, a DICOM tag, or the like as a search query.

[0097] In a third example, the front image acquisition unit 60 may include a processor that forms a front image by OCT. The OCT front image may be a C-scan image, a projection image, a shadowgram, or the like.

[0098] <Operation> An example of the operation of the ophthalmic imaging apparatus 1 according to this embodiment will be described. An example of the operation of the ophthalmic imaging apparatus 1 is shown in Fig. 3. It is assumed that preparatory processes such as input of a patient ID, alignment of the optical system with the subject's eye, focus adjustment of the optical system, adjustment of the OCT optical path length, adjustment of the fixation position, and setting of the OCT scan range have already been performed.

[0099] (S1: Perform fundus OCT blood flow measurement) The ophthalmologic imaging apparatus 1 performs OCT blood flow measurement on a cross section of a blood vessel of interest in the fundus of the subject's eye. The OCT blood flow measurement is performed on each of one or more cross sections of interest in each of one or more blood vessels of interest. In addition, when there are multiple blood vessels passing through the cross section of interest, at least some of these blood vessels can be set as the blood vessel of interest. Conversely, the cross section of interest can also be set to cross multiple blood vessels of interest.

[0100] In OCT blood flow measurement, the scan controller 11 controls the light source and the optical scanner included in the OCT scanner 31. Under the control of the scan controller 11, the OCT scanner 31 repeatedly scans a first cross section that intersects with the blood vessel of interest at a preset measurement position (i.e., a cross section of interest) to collect first data, and further scans one or more auxiliary cross sections that intersect with the blood vessel of interest in the vicinity of the cross section of interest to collect second data. Note that the order of collecting the first data and the second data is arbitrary.

[0101] (S2: Forming a morphological image) The image forming unit 32 forms one or more anatomical images (B-scan images) corresponding to the cross section of interest based on the first data collected by repeatedly scanning the cross section of interest in step S1. Typically, the same number of anatomical images as the number of times the scan is repeated can be formed. This allows time-series B-scan images corresponding to the cross section of interest to be obtained. Note that the number of anatomical images formed may be less than the number of times the scan is repeated.

[0102] Furthermore, the image forming unit 32 forms morphological images (B-scan images) corresponding to each auxiliary cross section based on the second data collected by scanning one or more auxiliary cross sections in step S2.

[0103] Each morphological image formed in step S2 is stored in the storage unit 20 as OCT data 21.

[0104] (S3: Calculate the inclination angle of the blood vessel of interest) The blood flow data generating unit 33 obtains the inclination angle of the blood vessel of interest in the cross section of interest based on two or more anatomical images among the multiple anatomical images formed in step S2. For example, a combination of two anatomical images corresponding to two auxiliary cross sections, or a combination of a anatomical image corresponding to one auxiliary cross section and a anatomical image corresponding to the cross section of interest is used in this process.

[0105] (S4: Form a phase image) The image forming unit 32 forms a phase image corresponding to the cross section of interest based on the first data collected by repeatedly scanning the cross section of interest in step S1.

[0106] The phase image formed in step S4 is stored in the storage unit 20 as OCT data 21.

[0107] (S5: Obtain blood flow data) The blood flow data generating unit 33 generates blood flow data for the blood vessel of interest passing through the cross section of interest based on the inclination angle of the blood vessel of interest calculated in step S3 and the phase image formed in step S4. This blood flow data includes, for example, data representing a time series change in blood flow in the blood vessel of interest. Examples of such data include a time series change in blood flow velocity during the measurement period (typically a period of one cardiac cycle or longer) of the OCT blood flow measurement performed in step S1, and a time series change in blood flow rate per unit time during the measurement period.

[0108] The blood flow data generated in step S5 is stored in the storage unit 20 as OCT data 21. When multiple blood vessels of interest are considered, blood flow data is obtained for each of the multiple blood vessels of interest. Furthermore, for each of the multiple blood vessels of interest, its identification information (e.g., position information of the blood vessel of interest) and the corresponding blood flow data are stored in the storage unit 20 in association with each other.

[0109] (S6: Display morphological image) The display control unit 12 causes the display device 2 to display an anatomical image of the cross section of interest. The displayed anatomical image includes, for example, a B-scan image of the cross section of interest formed in step S2. When OCT angiography is performed, the displayed anatomical image may be a vessel-enhanced image. The displayed anatomical image may also be a phase image formed in step S4.

[0110] The displayed morphological image may include a blood flow state image synthesized with the blood vessel cross-sectional area in the B scan image. The blood flow state image will be described later. The blood vessel cross-sectional area in the B scan image is an area corresponding to a cross section of a blood vessel (a blood vessel of interest), and is identified, for example, by analyzing at least one of the B scan image and the phase image. Typically, the display control unit 12 and / or the data acquisition unit 30 executes the following series of processes: a process of analyzing the phase image to identify the blood vessel cross-sectional area; a process of identifying an image area in the B scan image corresponding to the blood vessel cross-sectional area in the phase image by utilizing a self-evident registration between the B scan image and the phase image of the cross section of interest. Alternatively, the blood vessel cross-sectional area in the B scan image may be identified based on the luminance distribution or pattern of the B scan image.

[0111] An example of the anatomical image displayed in step S6 is shown in Fig. 4A. Reference numeral 120 denotes an example of the anatomical image displayed in step S6. The example shown in Fig. 4A represents a case where four blood vessels are detected in the cross section of interest. The display control unit 12 displays blood flow status images 131, 132, 133, and 134 at positions in the anatomical image 120 corresponding to these four blood vessels. As mentioned above, it is not essential to display the blood flow status images.

[0112] The blood flow status image 131 is, for example, an image in which the magnitude of blood flow velocity is expressed by color. The display control unit 12 obtains a color (density) corresponding to the magnitude of blood flow velocity in a predetermined time phase by referring to a predefined lookup table (such as a color map or a density map) in which the relationship between the magnitude of blood flow velocity and color is recorded, and displays the blood flow status image 131 based on the obtained color. The same display control can be performed for the blood flow status images 132 to 134. Also, the same display control can be performed when the blood flow rate per unit time is applied.

[0113] The blood flow status image 131 may be an image in which the direction of blood flow is expressed by color. The display control unit 12 obtains a color corresponding to the direction of blood flow in a predetermined time phase by referring to a predefined lookup table (such as a color map) in which the relationship between the direction of blood flow and color is recorded, and displays the blood flow status image 131 based on the obtained color. The same display control can be performed for the blood flow status images 132 to 134. The same display control can also be performed when the blood flow rate per unit time is applied.

[0114] In a typical example, the blood flow condition image 131 may be an image in which the direction of blood flow is represented by color and the magnitude of blood flow velocity is represented by color density. For example, a lookup table is set so that blood flow from the optic disc toward the capillaries (i.e., blood flow in the arteries) is represented by red, blood flow from the capillaries toward the optic disc toward the capillaries (i.e., blood flow in the veins) is represented by blue, and the color density increases as the blood flow velocity increases. A similar display control can be performed for the blood flow condition images 132 to 134. A similar display control can also be performed when the blood flow rate per unit time is applied.

[0115] (S7: Specify blood vessels) The user designates any one of the blood vessels depicted in the anatomical image displayed in step S6 using the operation unit 50. This operation is performed, for example, by clicking a desired one of the blood vessels depicted in the anatomical image with a pointing device. The display control unit 12 can change the display mode of the blood vessel designated in step S7.

[0116] (S8: Display blood flow graph) The display control unit 12 specifies identification information (e.g., the above-mentioned position information) of the blood vessel specified in step S7, and reads out blood flow data corresponding to the specified position information from the storage unit 20. Furthermore, the display control unit 12 (and / or the data acquisition unit 30) causes the display device 2 to display a blood flow graph based on the read blood flow data.

[0117] An example of information displayed in step S8 is shown in Fig. 4B. It is assumed that a blood vessel corresponding to the blood flow state image 132 is specified in step S7. The display control unit 12 changes the display mode of the blood flow state image 132. That is, the blood flow state image 132 is displayed in a mode different from the blood flow state images 131, 133, and 134. Furthermore, on the display device 2, a blood flow graph 140 corresponding to the blood vessel cross-sectional area 132 is displayed together with the morphological image 120 displayed in step S6.

[0118] The blood flow graph 140 represents a time series change in blood flow in a blood vessel corresponding to the blood vessel cross-sectional region 132. The blood flow graph 140 in this example is expressed by a two-dimensional orthogonal coordinate system in which the horizontal axis (first coordinate axis) represents time t and the vertical axis (second coordinate axis) represents blood flow velocity (v).

[0119] Such a blood flow graph 140 is created based on (time-series) phase images over the measurement period of OCT blood flow measurement. In this case, the blood flow velocity (v) on the vertical axis may be, for example, a statistical value of the values ​​of multiple pixels included in the blood flow condition image 132 in the corresponding time phase (i.e., a value corresponding to the magnitude of the blood flow velocity, etc.). This statistical value may be, for example, an average value, a maximum value, a minimum value, etc. Alternatively, the blood flow velocity (v) on the vertical axis may be the value of a predetermined pixel (for example, a pixel located at the center, a pixel located at the center of gravity, etc.) in the blood flow condition image 132.

[0120] Similarly, when blood flow rate per unit time is applied, for example, a blood flow graph can be displayed in which the horizontal axis indicates time and the vertical axis indicates blood flow rate per unit time.

[0121] (S9: Observation over?) The user can specify another desired blood vessel (S7). The display control unit 12 causes the display device 2 to display a blood flow graph corresponding to the newly specified blood vessel. Two or more blood vessels can be specified. In that case, two or more blood flow graphs corresponding to the two or more specified blood vessels can be displayed in parallel. Such operations and processing are repeated until observation of data and images of the subject's eye is completed (S9: No). When observation is completed (S9: Yes), the processing of this example is completed (End).

[0122] Another example of information that can be displayed in this embodiment is shown in Fig. 5. Reference numeral 100 denotes a slider for displaying and setting the time phase of blood flow. The slider 100 includes a handle 110 that can be moved along a time axis (bar) that indicates the measurement period of OCT blood flow measurement.

[0123] Reference numeral 120 denotes an anatomical image of the cross section of interest displayed in step S6. When a plurality of anatomical images corresponding to the cross section of interest are formed in step S2, the display control unit 12 can select and display an anatomical image corresponding to the time phase currently presented by the slider 100. That is, the position (time phase) of the handle 110 of the slider 100 and the time phase indicated by the anatomical image correspond to each other.

[0124] In step S4, a phase image corresponding to the morphological image 120 is formed, and in step S5, blood flow data is generated from the phase image. The blood flow data may be, for example, a time series change in blood flow velocity or a time series change in blood flow rate per unit time. In the example shown in Fig. 5, a time series change in blood flow velocity (v) is used.

[0125] The display controller 12 displays a blood flow state image indicating the state of blood flow (blood flow velocity, blood flow rate per unit time, etc.) in the time phase indicated by the slider 100 at a position in the morphological image 120 corresponding to (at least) the blood vessel of interest.

[0126] In the example shown in Fig. 5, blood flow status images 131, 132, 133, and 134 are displayed at positions in the morphological image 120 corresponding to four blood vessels. The display control unit 12 determines the color (density) corresponding to the magnitude of the blood flow velocity in the time phase indicated by the slider 100 by referring to a predefined lookup table (color map, density map, etc.) in which the relationship between the magnitude of the blood flow velocity and color is recorded, and displays the blood flow status image 131 based on the determined color. The same display control can be performed for the blood flow status images 132 to 134. Also, the same display control can be performed when the blood flow rate per unit time is applied.

[0127] Moreover, the display control unit 12 obtains a color corresponding to the direction of blood flow in the time phase indicated by the slider 100 by referring to a predetermined lookup table (such as a color map) in which the relationship between the direction of blood flow and color is recorded, and displays the blood flow status image 131 based on the obtained color. Similar display control can be performed for the blood flow status images 132 to 134. Also, similar display control can be performed when the blood flow rate per unit time is applied.

[0128] In this way, the position (phase) of the handle 110 of the slider 100 and the phases indicated by the blood flow condition images 131 to 134 correspond to each other.

[0129] The display control unit 12 displays a widget 150 movable along the time axis (horizontal axis) of the blood flow graph 140 corresponding to the blood flow status image 132. In this example, the widget 150 is displayed on the blood flow graph 140, but the display mode of the widget 150 is not limited to this and may be any display mode that clearly indicates the position on the time axis indicated by the widget 150.

[0130] When the handle 110 of the slider 100 is moved, the display control unit 12 changes the position of the widget 150 with respect to the time axis in response to the movement of the handle 110. Conversely, when the position of the widget 150 with respect to the time axis is moved, the display control unit 12 changes the handle 110 of the slider 100 in response to the movement of the widget 150. In this way, the position (time phase) of the handle 110 of the slider 100 and the position of the widget 150 (i.e., the time phase on the time axis indicated by the widget 150) correspond to each other.

[0131] As described above, the time phase indicated by the handle 110 of the slider 100, the time phase indicated by the blood flow condition images 131-134, and the time phase indicated by the widget 150 correspond to one another. Furthermore, when multiple morphological images with different time phases are selectively displayed, the time phase indicated by the handle 110 of the slider 100, the time phase indicated by the morphological images, the time phase indicated by the blood flow condition images 131-134, and the time phase indicated by the widget 150 correspond to one another.

[0132] In this example, the display control unit 12 displays two widgets (the slider 100 and the widget 150) and synchronously controls the display of these two widgets according to the phase of the blood flow. However, the number of widgets displayed may be one. Alternatively, it is also possible to display three or more widgets. In this case, the display control of at least two of the three or more widgets can be synchronously performed according to the phase of the blood flow.

[0133] The slider 100 is operated, for example, by dragging the handle 110 using a pointing device (such as a mouse) included in the operation unit 50. The widget 150 may be operated in the same manner.

[0134] The display control unit 12 can display the blood flow condition images 131 to 134 as a moving image. In this case, the display control unit 12 can sequentially update the morphological image 120 in accordance with the time phases of the blood flow condition images 131 to 134. In other words, the display control unit 12 can display the entire blood flow condition images 131 to 134 and the morphological image 120 as a moving image.

[0135] Furthermore, the display control unit 12 can change the time phase indicated by the slider 100 (i.e., the position of the handle 110) and the time phase indicated by the widget 150 (i.e., the position of the widget relative to the time axis) in synchronization with the blood flow status images 131-134 (and the morphological image 120) as videos.

[0136] When OCT angiography is performed in addition to OCT blood flow measurement, the display controller 12 can display a vascular pattern image acquired by OCT angiography on the display device 2. The vascular pattern image is displayed together with the morphological image in step S6 of Fig. 3, for example. Alternatively, the vascular pattern image is displayed as the morphological image in step S6 of Fig. 3.

[0137] 3, when a vascular enhancement image is displayed as the morphological image in step S6, for example, the image forming unit 32 forms a B-scan image (B-scan vascular enhancement image) of the cross section of interest based on data acquired by OCT angiography. Furthermore, the display processing unit 12 causes the display device 2 to display this B-scan vascular enhancement image as a morphological image (for example, the morphological image 120 in FIG. 5).

[0138] When the blood vessel enhancement image is displayed together with the morphological image in step S6 of FIG. 3, for example, the image forming unit 32 forms a blood vessel enhancement image in a predetermined cross section or a blood vessel enhancement image as a front image (front blood vessel enhancement image) based on data acquired by OCT angiography. An example of a blood vessel enhancement image in a predetermined cross section is a B-scan blood vessel enhancement image in the same cross section as the morphological image (i.e., the cross section of interest). An example of a front blood vessel enhancement image is a front image corresponding to an arbitrary depth region of the fundus (e.g., the shallow part of the retina, the deep part of the retina, the choriocapillaris, the sclera, etc.) or a front image corresponding to a predetermined tissue of the fundus (e.g., the internal limiting membrane, the nerve fiber layer, the ganglion cell layer, the inner plexiform layer, the inner nuclear layer, the outer plexiform layer, the outer nuclear layer, the external limiting membrane, the retinal pigment epithelium, the Bruch's membrane, the choroid, the choroid-scleral boundary, the sclera, any part of these, a combination of at least two or more of these, etc.). Furthermore, the display processing unit 12 causes the display device 2 to display the formed blood vessel enhancement image in parallel with the morphological image (e.g., the morphological image 120 in FIG. 5).

[0139] <Ophthalmology information processing device> An ophthalmological information processing device according to an exemplary embodiment will be described. An example of the configuration of the ophthalmological information processing device of this embodiment is shown in FIG. 6. The ophthalmological information processing device 200 stores fundus data acquired using OCT blood flow measurement, generates fundus morphological images and fundus blood flow data based on the stored data, and displays various information based on these. Furthermore, the ophthalmological information processing device 200 may be configured to store data acquired using OCT angiography and display information based on this data.

[0140] The ophthalmological information-processing device 200 can display various information such as a fundus morphological image, blood flow information, and a blood vessel emphasis image on the display device 2. The display device 2 may be a part of the ophthalmological information-processing device 200, or may be an external device connected to the ophthalmological information-processing device 200. In addition, the ophthalmological information-processing device 200 can send various information to a computer, a storage device, an ophthalmological device, etc.

[0141] The ophthalmologic information-processing device 200 includes a control unit 210, a storage unit 220, a data processing unit 230, a data input unit 240, and an operation unit 250. The control unit 210 includes a display control unit 212. The storage unit 220 stores OCT data 221.

[0142] Each element of the ophthalmologic information-processing device 200 has, for example, the same configuration and function as the corresponding element included in the above-mentioned ophthalmologic imaging device 1. That is, the control unit 210 has the same configuration and function as the control unit 10, the display control unit 212 has the same configuration and function as the display control unit 12, the storage unit 220 has the same configuration and function as the storage unit 20, and the operation unit 250 has the same configuration and function as the operation unit 50.

[0143] The OCT data 221 may be data in the same form as the OCT data 21. For example, the OCT data 221 may include any one or more of the following (1) to (5). (1) Data collected by OCT scan of the fundus (raw data) (2) Image data obtained by processing the raw data (3) Intermediate data obtained during the process of generating image data from raw data (4) Blood flow data obtained by processing the raw data (5) Intermediate data obtained during the process of generating blood flow data from raw data

[0144] The data processing unit 230 executes various data processing. The data processing unit 230 may have the same configuration and function as the image forming unit 32. For example, when the OCT data 221 includes at least one of the above OCT data (1) and (3), the data processing unit 230 executes the same processing as the image forming unit 32 to form an OCT image (such as a morphological image or a phase image).

[0145] The data processing unit 230 may have the same configuration and function as the blood flow data generating unit 33. For example, when the OCT data 221 includes at least any one of the above OCT data (1), (4), and (5), the data processing unit 230 can generate blood flow data (blood flow velocity, blood flow amount, etc.) by executing processing similar to that of the blood flow data generating unit 33.

[0146] The data input unit 240 inputs the OCT data 221 and / or data on which the OCT data 221 is based from the outside to the ophthalmologic information-processing device 200. The data input unit 240 may include, for example, a communication interface for performing data communication with an external device, a device for reading data from a recording medium, and the like.

[0147] The display control unit 212 can execute control for causing the display device 2 to display information similar to at least one of FIG. 4A, FIG. 4B, and FIG.

[0148] <Action and Effects> The operation and effects of the ophthalmologic imaging apparatus and the ophthalmologic information processing apparatus according to the exemplary embodiment described above will be described.

[0149] The ophthalmologic imaging apparatus (1) according to the embodiment includes a data acquisition unit (30), a display processing unit (such as a display control unit 12), and an operation unit (50). The data acquisition unit acquires data by applying at least OCT blood flow measurement to the fundus of the subject's eye. The display processing unit displays information on a display means (display device 2).

[0150] Specifically, the display processing unit displays a morphological image (120) of the fundus based on the data acquired by the data acquisition unit (OCT data 21). Furthermore, when any blood vessel depicted in the displayed morphological image is designated using the operation unit, the display processing unit displays a blood flow graph showing the time series change of blood flow in the designated blood vessel based on the data acquired by the data acquisition unit (OCT data 21).

[0151] The ophthalmologic information processing device (200) according to the embodiment includes a storage unit (220), a display processing unit (such as a display control unit 212), and an operation unit (250). The storage unit stores data (OCT data 221) acquired by applying OCT blood flow measurement to the fundus of the subject's eye. The display processing unit causes a display means (display device 2) to display information.

[0152] Specifically, the display processing unit displays a morphological image (120) of the fundus based on the data stored in the memory unit (OCT data 221). Furthermore, when any blood vessel depicted in the displayed morphological image is designated using the operation unit, the display processing unit displays a blood flow graph showing the time series change of blood flow in the designated blood vessel based on the data acquired by the data acquisition unit (OCT data 221).

[0153] According to this embodiment, the user can specify a desired blood vessel depicted in the anatomical image while observing the anatomical image of the fundus. Furthermore, the ophthalmologic imaging device (1) or the ophthalmologic information processing device (200) can display a blood flow graph corresponding to the blood vessel specified by the user. According to this novel information display mode, the user can easily observe the blood flow graph corresponding to the desired blood vessel.

[0154] In an embodiment, the blood flow graph may be configured to be represented by a two-dimensional Cartesian coordinate system in which a first coordinate axis indicates time and a second coordinate axis indicates blood flow velocity or blood flow rate per unit time.

[0155] With this configuration, the time series changes in blood flow velocity and blood flow volume per unit time can be presented as graphs, allowing the user to easily grasp the time series changes in blood flow velocity and blood flow volume per unit time.

[0156] In an embodiment, the display processor may be configured to display at least one of a B-scan image and a phase image as a morphological image.

[0157] According to this configuration, the user can easily grasp the state of blood flow in the B cross section while observing the morphology and / or phase state of the B cross section of the fundus.

[0158] In an embodiment, the display processing unit may be configured to display, as a morphological image, a B-scan image and a blood flow state image synthesized in a blood vessel cross-sectional area in the B-scan image.

[0159] With this configuration, the user can easily understand the dynamics of blood flow from the morphological image.

[0160] The blood flow status image may include an image in which the magnitude of the blood flow velocity or the magnitude of the blood flow volume per unit time is expressed by color. With this configuration, the magnitude of the blood flow velocity or the magnitude of the blood flow volume per unit time can be presented by using color, so that the user can easily grasp the magnitude of the blood flow velocity or the magnitude of the blood flow volume per unit time.

[0161] The blood flow status image may include an image in which the direction of blood flow is expressed by color. According to this configuration, since the direction of blood flow can be presented by using color, the user can easily understand the direction of blood flow.

[0162] At least one of the ophthalmic imaging device and the ophthalmic information processing device according to the embodiment can handle data acquired by applying OCT angiography to the fundus. That is, the data acquisition unit of the ophthalmic imaging device according to the embodiment may be configured to acquire data by applying OCT angiography to the fundus. Meanwhile, the storage unit of the ophthalmic information processing device according to the embodiment may be configured to store data acquired by applying OCT angiography to the fundus. Furthermore, the display processing unit of the ophthalmic imaging device and / or the ophthalmic information processing device may be configured to display a vascular emphasis image based on the data acquired by OCT angiography.

[0163] According to this configuration, the user can grasp the distribution of blood vessels in the fundus in addition to the morphology and blood flow dynamics of the fundus.

[0164] The display processing unit can, for example, display a vascular enhancement image formed as a B-scan image as a morphological image, can display a vascular enhancement image formed as a B-scan image and a morphological image based on OCT blood flow measurement in parallel, or can display a vascular enhancement image formed as a frontal image and a morphological image in parallel.

[0165] In the ophthalmic imaging device according to the embodiment, the data acquisition unit (30) may be configured to execute the following series of processes in OCT blood flow measurement: repeatedly scanning a first cross section that intersects with a blood vessel at a preset measurement position to collect first data; scanning one or more second cross sections that intersect with the blood vessel near the measurement position to collect second data; calculating an inclination angle of the blood vessel at the measurement position based on the second data; and acquiring blood flow data representing time-series changes in blood flow in the blood vessel passing through the first cross section based on the calculated inclination angle and the first data.

[0166] According to such a configuration, OCT blood flow measurement can be suitably performed to generate blood flow data, and further, a blood flow graph and a blood flow status image can be displayed based on this blood flow data.

[0167] In the ophthalmologic imaging apparatus according to the embodiment, the data acquisition unit (30) can acquire one or more B-scan images corresponding to the first cross section based on first data collected by repeatedly scanning the first cross section.

[0168] With this configuration, not only blood flow data but also B-scan images can be obtained from the data obtained by OCT blood flow measurement. Therefore, it is not necessary to perform an OCT scan to form a B-scan image separately from the OCT blood flow measurement. In addition, it is possible to obtain multiple B-scan images (time-series B-scan images) according to the time-series changes in blood flow conditions.

[0169] The actions and effects of the embodiments are not limited to these, and the actions and effects provided by each item described as an embodiment and the actions and effects provided by a combination of multiple items should also be considered. In addition, any of the above-described embodiments, other embodiments, known techniques, etc. can be arbitrarily combined to obtain desired actions and / or effects or for other purposes.

[0170] The above-described configuration is merely one example for implementing the present invention, and any modifications (omissions, substitutions, additions, etc.) may be made as appropriate within the scope of the gist of the present invention. [Explanation of symbols]

[0171] 1 Ophthalmic imaging equipment 2. Display Device 10 Control section 11 Scan control section 12 Display control section 20 Memory section 21 OCT data 30 Data Acquisition Section 31 OCT Scanner 32 Image forming section 33 Blood flow data generation unit 50 Control section 120 Morphological Images 131, 132, 133, 134 Blood flow status images 140 Blood flow graph 200 Ophthalmology information processing device 210 Control section 212 Display control unit 220 Storage section 221 OCT data 230 Data Processing Unit 240 Data Entry Section 250 Operation section

Claims

1. a data input unit for inputting first image data of the subject's eye constructed by a first ophthalmic photographing apparatus and second image data of the subject's eye constructed by a second ophthalmic photographing apparatus different from the first ophthalmic photographing apparatus; a display processing unit that displays, on a display means, composite information of a first image based on the first image data and a second image based on the second image data; Including, the data input unit inputs, as the first image data, first OCT data constructed by the first ophthalmic imaging device applying an optical coherence tomography (OCT) scan to a predetermined cross section of the fundus of the subject's eye, and inputs, as the second image data, second OCT data constructed by the second ophthalmic imaging device applying an OCT blood flow measurement to a blood vessel passing through the predetermined cross section; the display processing unit synthesizes a blood flow status image, which expresses the magnitude of the blood flow velocity of the blood vessel with a color based on the second OCT data, onto a cross-sectional area of ​​the blood vessel in the B-scan image of the predetermined cross section based on the first OCT data, thereby causing the display unit to display a synthesized image of the B-scan image and the blood flow status image as the synthesized information. Ophthalmology information processing device.

2. The display processing unit forms a phase image based on the second OCT data, and analyzes at least one of the B-scan image and the phase image to identify a position of the cross-sectional region of the blood vessel in the B-scan image. The ophthalmologic information processing device according to claim 1 .

3. the display processing unit obtains a color corresponding to the magnitude of the blood flow velocity in a predetermined time phase by referring to a predefined lookup table in which a relationship between the magnitude of the blood flow velocity and a color is recorded, and displays the composite image by synthesizing the blood flow state image expressed in the obtained color with the cross-sectional area of ​​the blood vessel. The ophthalmologic information processing device according to claim 1 or 2.

Images