JP7297133B2 - Ophthalmic information processing device and ophthalmic photographing device - Google Patents

Description

The embodiments relate to an ophthalmologic information processing apparatus and an ophthalmologic imaging apparatus.

Image diagnosis occupies an important position in the field of ophthalmology. In recent years, the utilization of optical coherence tomography (OCT) is progressing. OCT has come to be used not only for acquiring B-scan images and three-dimensional images of an eye to be inspected, but also for acquiring front images (en-face images) such as C-scan images and shadowgrams.

Furthermore, acquisition of an image in which a specific portion of the subject's eye is emphasized and acquisition of functional information are also performed. For example, based on time-series data collected by OCT, a B-scan image or a frontal image (called a blood vessel-enhanced image, angiogram, etc.) in which fundus blood vessels are emphasized can be constructed. This technique is called OCT angiography or the like. In addition, information on blood flow can be obtained based on phase information of time-series data collected by OCT. This technique is called OCT blood flow measurement or the like.

Japanese translation of PCT publication No. 2015-515894 JP 2013-184018 A

An object of the embodiments is to provide a novel display mode for information obtained by OCT blood flow measurement and information obtained by OCT angiography.

An ophthalmologic information processing apparatus according to an embodiment includes a storage unit and a display processing unit. The storage unit stores in advance first data acquired by applying OCT blood flow measurement to the fundus of the subject's eye and second data acquired by applying OCT angiography. The display processing unit displays a morphological image of the fundus oculi based on the first data stored in the storage unit, and displays a front vessel-enhanced image based on the second data stored in the storage unit. a process of displaying, based on the first data, a blood flow graph representing a time-series change in blood flow in a blood vessel of interest, which is one of the vessels depicted in the morphological image based on the first data; A process of displaying a slider for presenting and setting a time phase, and a process of displaying a blood flow state image showing the state of blood flow in the time phase indicated by the slider at a position within the morphological image corresponding to the blood vessel of interest. to run.

According to the embodiments, it is possible to provide a novel display mode of information obtained by OCT blood flow measurement and information obtained by OCT angiography.

1 is a schematic diagram illustrating an example configuration of an ophthalmic imaging apparatus according to an exemplary embodiment; FIG. FIG. 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; 4 is a flow chart representing an example of the operation of an ophthalmic imaging apparatus according to an exemplary embodiment; FIG. 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; FIG. 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; FIG. 4 is a schematic diagram for explaining an example of processing executed by an ophthalmologic imaging apparatus according to an exemplary embodiment; 1 is a schematic diagram showing an example of the configuration of an ophthalmologic information processing apparatus according to an exemplary embodiment; FIG.

Exemplary embodiments of the invention will be described with reference to the drawings. It should be noted that any known technology, including the disclosures of documents cited in this specification, can be combined with the embodiments.

An ophthalmologic information processing apparatus and an ophthalmologic imaging apparatus according to an embodiment have a function of displaying various types of information based on data obtained by applying OCT to the fundus of an eye to be examined. The ophthalmologic information processing apparatus according to the embodiment receives data obtained by, for example, applying OCT to the fundus of the subject's eye by a separately provided OCT apparatus, and displays various information based on this data. On the other hand, the ophthalmologic imaging apparatus 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.

The data obtained by applying OCT to the fundus of the subject's eye (fundus OCT data) may be data 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 scanning of the fundus (raw data)
(2) Image data obtained by processing raw data (3) Intermediate data obtained during a series of processes for generating image data from raw data (4) Obtained by processing raw data Blood flow data (5) Intermediate data obtained during a series of processes for generating blood flow data from raw data

Note that the types of fundus OCT data are not limited to these. Embodiments can also process a variety of information associated with 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, photographing date and time, photographing conditions, and the like.

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

The ophthalmologic imaging apparatus of the embodiment is configured to be able to perform Fourier domain OCT, for example. Fourier-domain OCT includes spectral-domain OCT and swept-source OCT. Spectral domain OCT is a method of constructing an image by acquiring a spectrum of interference light by spatial division using a broadband low-coherence light source and a spectroscope and performing a Fourier transform on it. Swept source OCT uses a wavelength swept light source (tunable light source) and a photodetector (balanced photodiode, etc.) to acquire the spectrum of interference light in a time-division manner, and constructs an image by Fourier transforming it. It is a method to The OCT method is not limited to Fourier domain OCT, and may be time domain OCT or amphasic OCT.

The ophthalmologic information processing apparatus and ophthalmologic imaging apparatus according to the embodiments may include modalities (for example, modalities other than OCT) for imaging the eye and/or other parts. Typical examples include fundus cameras, scanning laser ophthalmoscopes (SLO), slit lamp microscopes, and ophthalmic surgical microscopes. Further, the ophthalmologic information processing apparatus and the ophthalmologic imaging apparatus according to the embodiment may include a configuration for measuring characteristics of the eye and/or other parts and a configuration for performing an examination.

Data processing functions (arithmetic functions, image processing functions, control functions, etc.) in the ophthalmologic information processing apparatus and ophthalmologic imaging apparatus according to the embodiments include, for example, hardware such as processors and storage devices, arithmetic programs, image processing programs, and control functions. It is realized by cooperating with software such as a program. Part of the hardware may be provided in an external device capable of communicating with the ophthalmologic information processing apparatus or ophthalmologic imaging apparatus according to the embodiment. Also, at least part of the software may be pre-stored in the ophthalmologic information processing apparatus or ophthalmic imaging apparatus according to the embodiment, and/or may be pre-stored in an external device.

〈Ophthalmic imaging device〉
<composition>
An ophthalmic imaging apparatus according to an exemplary embodiment is described. FIG. 1 shows a configuration example of an ophthalmologic imaging apparatus according to this embodiment. The ophthalmologic imaging apparatus 1 collects fundus data using OCT, generates a fundus morphological image and fundus blood flow data based on the collected data, and displays various information based on these.

Here, the fundus morphology image is an image representing the morphology of the fundus. In the present embodiment, the fundus morphological image is an image in which at least fundus blood vessels (retinal blood vessels, choroidal blood vessels, etc.) are expressed in a visually identifiable manner. Examples of fundus morphological images include B-scan images, C-scan images, projection images, shadowgrams, phase images, and blood vessel-enhanced images. The fundus blood flow data is data representing the blood flow state (blood flow dynamics) in the fundus blood vessels. Examples of fundus blood flow data include direction of blood flow, blood flow velocity, time-series change in blood flow velocity, blood flow, blood flow per unit time, time-series change in blood flow per unit time, and total blood flow. .

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 (for example, a B scan, a three-dimensional scan) for acquiring a morphological image and an OCT scan (OCT blood flow measurement) for acquiring blood flow data may be performed separately. . Also, an OCT scan may be performed to acquire data other than these. For example, OCT angiography can be performed.

Part of the data used to display 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, other devices may perform OCT angiography to obtain vessel-enhanced images. Data acquired by another device is input to the ophthalmologic imaging device according to the embodiment.

The ophthalmologic imaging apparatus 1 can display various types of information such as fundus morphological images, blood flow information, and blood vessel enhanced images on the display device 2 . The display device 2 may be a part of the ophthalmologic imaging apparatus 1 or may be an external device connected to the ophthalmologic imaging apparatus 1 . Further, the ophthalmologic photographing apparatus 1 can send various information to a computer, a storage device, an ophthalmologic apparatus, and the like.

The ophthalmologic imaging apparatus 1 includes a control section 10 , a storage section 20 , a data acquisition section 30 , an operation section 50 and a front image acquisition section 60 . The controller 10 includes a scan controller 11 and a display controller 12 . The data acquisition unit 30 includes an OCT scanner 31 , an image formation unit 32 and a blood flow data generation unit 33 .

<Control unit 10>
The control unit 10 controls each unit of the ophthalmologic imaging apparatus 1 . Control unit 10 includes a processor. "Processor" includes, for example, CPU (Central Processing Unit), GPU (Graphics Processing Unit), ASIC (Application Specific Integrated Circuit), programmable logic device (e.g., SPLD (Simple Programmable Logic Device), CP LD (Complex Programmable Logic Device) , FPGA (Field Programmable Gate Array)). The control unit 10 can realize the functions according to the embodiment by, for example, reading and executing a program stored in a memory circuit or a memory device (the memory unit 20, an external device, etc.).

Also, the control unit 10 may 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.

<Scan control unit 11>
The scan controller 11 controls the OCT scanner 31 . For example, the scan control unit 11 controls the OCT scanner 31 to control the light source, control the optical scanner, change the optical path length of the measurement light and/or the reference light, adjust the polarization, adjust the amount of light, adjust the focus, and change the fixation position. Controls the various elements it contains. Some examples of processing that can be executed by the scan control unit 11 will be described later.

<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 .

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

<Storage unit 20>
Various data are stored in the storage unit 20 . In this example, OCT data 21 is stored in the storage unit 20 . At least part of the OCT data may be stored in an external storage device and provided to the ophthalmologic imaging apparatus 1 upon request. The storage unit 20 includes, for example, storage devices such as a hard disk drive and a semiconductor memory.

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

<Data acquisition unit 30>
The data acquisition unit 30 acquires data (for example, at least part of the OCT data 21 stored in the storage unit 20) by applying OCT to the fundus of the subject's eye. As described above, the data acquisition unit 30 includes the OCT scanner 31, the image formation unit 32, and the blood flow data generation unit 33. Image forming unit 32 includes a processor that executes an image forming program. The blood flow data generator 33 includes a processor that executes a blood flow data generation program.

<OCT scanner 31>
The OCT scanner 31 performs an OCT scan of the fundus under the control of the scan controller 11 . Thereby, fundus data (raw data) is collected. The OCT scanner 31 includes a configuration for performing optical interferometry using, for example, spectral domain OCT or swept source OCT. Such an OCT scanner 31 includes an OCT optical system, a driving system, a data acquisition system (DAQ), a control system, etc., as in the conventional art.

The OCT optical system includes, for example, an interference optical system, an optical scanner, and a photodetector. The interference optical system divides the light output from the light source into measurement light and reference light, projects the measurement light onto the fundus, and superimposes the return light of the measurement light from the fundus on the reference light to generate interference light. do. The optical scanner includes a galvanometer scanner or the like, and deflects measurement light. Thereby, the projection position of the measurement light with respect to the fundus is moved. The photodetector detects (the spectrum of) the interference light generated by the interference optics.

The drive system moves or operates the elements included in the OCT optical system. A data collection system collects detection results obtained sequentially by the OCT optics. The control system controls the OCT optical system, drive system, data acquisition system, etc. under the control of the scan controller 11 (or other elements of the controller 10).

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

In the OCT blood flow measurement, the OCT scanner 31 also scans to obtain the inclination angle of the target blood vessel in the target cross section. This scan is performed, for example, on two cross-sections that intersect the vessel of interest. Here, two cross-sections can be placed near the cross-section of interest.

Note that one of the two cross sections for obtaining the inclination angle of the target blood vessel may be the target cross section itself. The other cross section is set near the cross section of interest. In this case, data obtained by repeated scanning of the cross section of interest can be used to calculate the tilt angle.

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

The mode of scanning for obtaining 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 area containing the section of interest can be scanned (three-dimensional scan). As another example, a cross-section that intersects the cross-section of interest and along the vessel of interest can be scanned. The OCT blood flow measurement will be described in detail in the explanation of the blood flow data generator 33. FIG.

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

The manner of scanning that can be performed by the OCT scanner 31 is not limited to the manner described above. For example, the OCT scanner 31 can perform line scans, circle scans, radial scans, three-dimensional scans, etc. as OCT scans for obtaining morphological images.

<Image forming unit 32>
The image forming unit 32 forms an OCT image based on 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 a three-dimensional data set acquired by the OCT scanner 31 . The image formation processing at this time includes, for example, noise removal (noise reduction), filtering, fast Fourier transform (FFT), etc., as in the conventional OCT technology.

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 scanning repetitions is assigned to each B cross-section. Furthermore, the image forming unit 32 can form volume data (voxel data) by performing interpolation processing or the like on this stack data. In this volume data, a number of voxel groups corresponding to the number of scanning repetitions are assigned to positions corresponding to each B section.

The image forming unit 32 renders stack data or volume data to produce 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, and so on. etc. can be formed.

An arbitrary cross-sectional image, such as a B-scan image or a C-scan image, is formed by selecting pixels (pixels, voxels) on a specified cross-section from a three-dimensional data set. Alternatively, an image of an arbitrary cross-section is formed by projecting a slice of preset thickness in its thickness direction.

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 portion of stack data or volume data (for example, partial data corresponding to a specific layer) in a predetermined direction. A fundus image such as a C-scan image, a projection image, and a shadowgram whose viewpoint is the cornea side of the subject's eye is called a front image.

The image forming unit 32 can perform various image processing other than rendering. For example, there are segmentation for obtaining specific tissues and tissue boundaries, and size analysis for obtaining sizes of tissues (layer thickness, volume, etc.). If a particular layer (or a particular layer boundary) is determined by segmentation, it is possible to reconstruct the B-scan or frontal image so that the particular layer is flat. Such an image is called a flattened image.

The image forming unit 32 can form a blood vessel enhanced image. A blood vessel-enhanced image is an image obtained by specifying an image region (blood vessel region) corresponding to a blood vessel by analyzing OCT data and enhancing the blood vessel region by changing the expression mode of the blood vessel region. A plurality of OCT data obtained by repeatedly scanning substantially the same range of the subject's eye is used to identify the blood vessel region.

A blood vessel-enhanced image expresses, for example, the distribution of blood vessels in a three-dimensional region of the OCT-scanned fundus (that is, the three-dimensional distribution of blood vessels). There are several types of techniques for forming a blood vessel-enhanced image. A typical method for that purpose will be described. For this processing, 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 the plurality of B-sections of the subject's eye. As a technique for repeatedly scanning substantially the same B section, there are fixation and tracking.

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

A process is then performed to identify image regions that are changing between the registered B-scan images. This processing includes, for example, finding differences between different B-scan images. Each B-scan image is brightness image data representing the morphology of the subject's eye, and it is considered that the image area corresponding to the site other than blood vessels is substantially unchanged. On the other hand, considering that the backscatter that contributes to the interference signal varies randomly with blood flow, image regions where changes occur between multiple registered B-scan images (e.g. pixels with non-zero difference, or A pixel whose difference is equal to or greater than a predetermined threshold can be estimated to be a blood vessel region.

Information indicating that the image region is a blood vessel region is assigned to the image region specified in this way. Three-dimensionally distributed blood vessel regions are obtained by performing the above processing on a plurality of B cross-sections. By rendering such a three-dimensional blood vessel-enhanced image, a front image representing blood vessel distribution, an image of an arbitrary cross section, a shadowgram of an arbitrary range, and the like are generated.

Processing for forming a blood vessel-enhanced image is not limited to this. For example, it is possible to identify the blood vessel region by a conventional method using Doppler OCT, or to identify the blood vessel region by using a conventional image processing method. Also, by using different techniques depending on the site, it is possible to specify the blood vessel region for each site. For example, for the retina, the above-described typical technique or Doppler OCT technique can be used to identify the vascular area, and for the choroid, the image processing technique can be used to identify the vascular area.

<Blood flow data generator 33>
The blood flow data generator 33 operates in OCT blood flow measurement. The blood flow data generation unit 33, 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, Blood flow data representing the state of blood flow in the vessel of interest is generated.

The data collected by the OCT scanner 31 in the OCT blood flow measurement are data (first data) collected by repeatedly scanning a cross section of interest intersecting the blood vessel of interest, and crossing the blood vessel of interest and different from the cross section of interest. and data (second data) obtained by scanning one or more cross-sections (cross-sections in the vicinity of the cross-section of interest). Note that instead of the second data, for example, the inclination angle of the target blood vessel at the position of the target cross section or its vicinity, which is acquired separately from the OCT blood flow measurement, can be used. As an example, it is possible to use the tilt angle obtained from the vessel-enhanced image obtained by OCT angiography.

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. A morphological image and a phase image obtained by OCT blood flow measurement are images corresponding to the same cross section. Typically, a morphological image and a phase image corresponding to the section of interest (section B) are obtained.

As mentioned above, in a typical OCT blood flow measurement, two types of scans (auxiliary scan and main scan) are performed on the fundus. Auxiliary scanning is performed to scan one or more cross-sections different from the cross-section of interest (cross-sections in the vicinity of the cross-section of interest) to acquire second data. In a typical auxiliary scan, two or more cross-sections intersecting the vessel of interest are scanned with the measurement light. The data acquired by the auxiliary scan are used to determine the inclination angle of the vessel of interest on the section of interest. On the other hand, the main scan is performed to acquire the first data by repeatedly scanning the section of interest that intersects the blood vessel of interest with the measurement light. A cross-section on which the auxiliary scan is performed is placed near the cross-section of interest. This scan is Doppler measurement using OCT.

The target cross sections of the auxiliary scan and the main scan are oriented, for example, so as to be orthogonal to the running direction of the blood vessel of interest. In addition, the distance between the target cross section of the auxiliary scan and the cross section of interest (distance between cross sections) is set in advance or set for each examination. As an example of the latter, it is possible to set the distance between cross-sections based on predetermined factors such as the curvature of the target blood vessel in or near the target cross-section or the inspection accuracy. Alternatively, the user may set a desired cross-sectional distance.

This scan is preferably performed over at least one cardiac cycle of the patient's heart. This provides blood flow data for all phases of the heartbeat. The execution time of the main scan may be a preset constant time, or may be a time set for each patient or each examination.

For example, the image forming unit 32 generates a cross-sectional image representing the morphology of the first auxiliary cross section and a second A cross-sectional image representing the morphology of the target cross section is formed. At this time, it is possible to improve the image quality by using a technique such as averaging, or to select an optimum one from two or more cross-sectional images of each auxiliary cross-section.

Further, the image forming unit 32 forms a group of cross-sectional images representing time-series changes in the cross section of interest based on the data collected by the main scan (repetitive scan) of the cross section of interest. This processing is accomplished, for example, by forming cross-sectional images from the data collected for each scan iteration.

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 process of forming a cross-sectional image of the cross section of interest described here is the same as the morphological image forming process executed by the image forming unit 32 .

Furthermore, the image forming unit 32 forms a phase image representing the 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 for this processing is the same as the data used for forming the cross-sectional image(s) of the target cross-section. Therefore, there is a natural positional correspondence between the cross-sectional image of the cross section of interest and the phase image, and the registration is self-evident.

An example of a method of 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 of this example is formed based on time-series changes in the pixel values (luminance values) 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 time-series changes in its luminance value. The image forming unit 32 obtains the phase difference Δφ between two times t1 and t2 (t2=t1+Δt) separated by a predetermined time interval Δt in this graph. Then, this phase difference Δφ is defined as the phase difference Δφ(t1) at time t1 (more generally, any time between two times t1 and t2). By executing this process for each of a large number of preset time points, a time-series change in the phase difference at the pixel is obtained.

A phase image is an image representing the phase difference value of each pixel at each point in time. This imaging processing can be realized, for example, by expressing the value of the phase difference by display color or brightness. At this time, the color (for example, red) indicating that the phase has increased along the time series can be made different from the color (for example, blue) that indicates that the phase has decreased. Also, the magnitude of the phase change amount can be expressed by the intensity of the display color. By adopting such an expression method, it becomes possible to express the direction and size of blood flow with colors and densities. A phase image is formed by executing the above processing for each pixel.

The time-series change of the phase difference can be obtained by sufficiently reducing the time interval Δt to secure the 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 scanning of the measurement light.

The blood flow data generation unit 33 can execute, for example, a blood vessel region identification process, an inclination angle calculation process, and a blood flow data generation process. The blood flow data generation process includes, for example, at least a blood flow velocity calculation process, and may further include a blood vessel diameter calculation process and a blood flow volume calculation process.

In the blood vessel region identification process, the blood flow data generator 33 identifies the blood vessel region in each cross-sectional image corresponding to the target blood vessel. Furthermore, the blood flow data generator 33 identifies a blood vessel region in the phase image corresponding to the cross section of interest. Identification of the blood vessel region is performed by analyzing the pixel values of each image (for example, thresholding). The blood vessel region in the phase image may be identified based on the blood vessel 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.

In the inclination angle calculation process, the blood flow data generator 33 calculates the inclination angle of the target blood vessel in the target cross section based on the image (group) formed from the data acquired by the auxiliary scan.

An example of the tilt angle calculation process will be described. Please refer to FIG. Reference character B0 indicates a cross-sectional image (cross-sectional image of interest) in the cross-section of interest for which the blood vessel inclination angle is calculated. A blood vessel region V0 is depicted in the cross-sectional image of interest B0. Reference numerals B11 and B12 indicate two cross-sectional images (auxiliary cross-sectional images) in two auxiliary cross-sections located near the target cross-section B0. In the auxiliary cross-sectional image B11, a blood vessel region V11 in the auxiliary cross-section B11 of the same blood vessel (target blood vessel) as the blood vessel region V0 is depicted. Similarly, the auxiliary cross-sectional image B12 depicts a blood vessel region V12 in the auxiliary cross-section B12 of the target blood vessel.

The blood flow data generator 33 calculates the inclination of the target blood vessel in the target cross section based on the target cross-sectional image B0 and the auxiliary cross-sectional images B11 and B12. The number of auxiliary cross-sectional images to be referred to is not limited to two, and may be any number of one or more.

The blood flow data generator 33 calculates the inclination of the target blood vessel in the target cross section based on the blood vessel regions V0, V11, and V12 and the inter-section distance. The cross-sectional distance may be the distance between the auxiliary cross-sectional image B11 and the auxiliary cross-sectional image B12. Alternatively, the cross-sectional distance may be defined by at least one of the distance between the auxiliary cross-sectional image B11 and the cross-sectional image of interest B0 and the distance between the auxiliary cross-sectional image B12 and the cross-sectional image of interest B0. good. Let L be the distance between the auxiliary cross-sectional image B11 (or B12) and the target cross-sectional image B0.

The A-scan direction (the direction indicated by the arrow pointing downward) shown in FIG. 2 indicates, for example, the orientation of the A-scan image included in the target cross-sectional image B0. This A-scan image may be, for example, an A-scan image located in the center of a plurality of A-scan images included in the cross-sectional image of interest B0.

In a typical example, the blood flow data generator 33 can calculate the inclination A of the target blood vessel in the target cross section based on the positional relationship between the three blood vessel regions V0, V11 and V12. This positional relationship is obtained, for example, by connecting three blood vessel regions V0, V11 and V12. More specifically, the blood flow data generator 33 identifies feature points of the three blood vessel regions V0, V11 and V12, and connects these feature points. Feature points referred to here include the center position (axis position), the center of gravity position, the top, and the like. Methods of connecting these feature points include a method of connecting with a line segment, a method of connecting with an approximation curve (spline curve, Bezier curve, etc.).

Furthermore, the blood flow data generator 33 calculates the slope A based on the line connecting these feature points. When line segments are used, the blood flow data generation unit 33 generates, for example, a first line segment connecting the feature point of the blood vessel region V0 in the cross-sectional image of interest B0 and the feature point of the blood vessel region V11 in the auxiliary cross-sectional image B11. and the slope of the second line segment connecting the feature point of the blood vessel region V0 and the feature point of the blood vessel region V12 in the auxiliary cross-sectional image B12. As an example of this calculation process, the average value of the slopes of two line segments can be obtained. Also, as an example of connecting with an approximate curve, it is possible to obtain the slope of the approximate curve at the intersection position of the approximate curve and the section of interest.

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

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

In the blood flow data generation process, the blood flow data generation unit 33 generates data related to the blood vessel of interest based on the phase image formed based on the main scan (Doppler OCT) and the tilt angle obtained by the blood flow data generation unit 33. Generate blood flow data. 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 volume calculation process.

The blood flow data generation unit 33 can calculate the blood flow velocity in the cross section of interest of the blood flowing through the blood vessel of interest based on the time series change of the phase difference obtained as the phase image. The value calculated by this process may be the blood flow velocity at a certain point in time, or may be the time series change in the blood flow velocity (blood flow velocity change data). In the former case, for example, it is possible to selectively acquire the blood flow velocity at a predetermined time phase of the electrocardiogram (for example, the time phase of the R wave). Also, the time range in the latter is the whole or an arbitrary part of the time when the section of interest is scanned.

When the blood flow velocity change data is obtained, the blood flow data generator 33 can calculate the statistic value of the blood flow velocity in the range of time. These statistics include mean, standard deviation, variance, median, maximum, minimum, maximum and minimum. It is also possible to create a histogram of blood velocity values.

The blood flow data generator 33 can calculate the blood flow velocity using the Doppler OCT method as described above. For example, the following relational expression is used to calculate the blood flow velocity.

Δf: Doppler shift received by scattered light of measurement light n: Refractive index of medium (blood) v: Flow velocity of medium (blood velocity)
θ: Angle (tilt angle) formed by the incident direction of the measurement light and the direction of the flow of the medium
λ: Center wavelength of measurement light

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

In the blood vessel diameter calculation process, the blood flow data generator 33 calculates the diameter of the target blood vessel in the target cross section. 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.

When the first calculation method is applied, the part of the fundus including the position of the cross section of interest is photographed in advance. This fundus photographing is performed by the front image acquiring unit 60, for example. Alternatively, a previously acquired and stored front image of the fundus may be read. A blood vessel-enhanced image may also be used.

The blood flow data generation unit 33 calculates the fundus of the eye based on various factors that determine the relationship between the scale on the image and the scale in the real space, such as the angle of view (magnification), the working distance, and information on the eyeball optical system. Sets the scale for the front image. This scale represents length in real space. As a specific example, this scale is obtained by associating the interval between adjacent pixels with the scale in real space (for example, the interval between pixels=10 μm). It is also possible to previously calculate the relationship between the various values of the above factors and the scale in the real space, and to store information expressing this relationship in a table format or a graph format. In this case, scales corresponding to the above factors are selectively applied.

The blood flow data generation unit 33 calculates the diameter of the blood vessel of interest in the cross section of interest, that is, 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 generator 33 can obtain the maximum value and average value of diameters in various directions of the blood vessel region. Alternatively, the blood flow data generator 33 can approximate the contour of the blood vessel region to a circle or ellipse, and obtain the diameter of the circle or ellipse. 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 obtaining the blood vessel diameter.

A second calculation method will be described. In the second calculation method, a cross-sectional image of the fundus on the target cross-section is used. This cross-sectional image may be a cross-sectional image based on the main scan, or may be obtained separately. The scale of this cross-sectional image is determined according to the scanning mode of the measurement light. The length of the section of interest is determined based on various factors that determine the relationship between the scale on the image and the scale in the real space, such as working distance and eyeball optical system information. The blood flow data generator 33 can, for example, find 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 in the first calculation method.

In the blood flow rate calculation process, the blood flow data generator 33 calculates the flow rate of blood flowing through the vessel of interest based on the blood flow velocity calculation result and the blood vessel diameter calculation result. An example of this processing is described below.

Assume that the blood flow in the blood vessel is Hagen-Poiseuille flow. Let w be the diameter of the blood vessel, and Vm be the maximum value of the blood flow velocity. In this case, the blood flow Q is represented by the following relational expression.

The blood flow data generation unit 33 substitutes the blood vessel diameter w obtained by the blood vessel diameter calculation process and the maximum value Vm in the blood flow velocity obtained by the blood flow velocity calculation process into the above relational expression to obtain the blood flow volume Q can be calculated.

<Operation unit 50>
The operation unit 50 is used by the user to input instructions to the ophthalmologic imaging apparatus 1 . The operation unit 50 may include known operation devices used in ophthalmologic apparatuses and computers. For example, the operation unit 50 may include a mouse, touch pad, trackball, keyboard, pen tablet, operation panel, joystick, button, switch, and the like.

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.

<Front image acquisition unit 60>
The front image acquisition unit 60 acquires a front image of the fundus. Processing for acquiring a front image is optional. In the first example, the front image acquisition section 60 may include a configuration for photographing the fundus. For example, the front image acquisition unit 60 may include a fundus camera optical system, an SLO optical system, and the like.

In the second example, the front image acquiring section 60 may include a configuration for acquiring a front image of the fundus of the subject's eye from an external device. For example, the front image acquisition section 60 may include a communication device for transmitting and receiving data via a communication line such as a LAN, Internet, or dedicated line. In this case, the front image acquiring unit 60 can acquire the 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.

In a third example, the frontal image acquisition unit 60 may include a processor that forms a frontal image by OCT. OCT front images include C-scan images, projection images, shadowgrams, and the like.

<motion>
An example of the operation of the ophthalmologic imaging apparatus 1 according to this embodiment will be described. An example of the operation of the ophthalmologic imaging apparatus 1 is shown in FIG. Preparatory processing such as input of patient ID, alignment of the optical system with respect to the eye to be examined, focus adjustment of the optical system, adjustment of the OCT optical path length, adjustment of the fixation position, setting of the OCT scan range, etc. has already been performed. and

(S1: Execute OCT blood flow measurement of the fundus)
The ophthalmologic imaging apparatus 1 performs OCT blood flow measurement on a section of interest of a blood vessel of interest in the fundus of an eye to be examined. OCT blood flow measurement is performed for each of one or more cross sections of interest in each of one or more blood vessels of interest. Also, when there are a plurality of blood vessels passing through the target cross section, at least some of these blood vessels can be set as target blood vessels. Conversely, a section of interest can also be set so as to cross a plurality of blood vessels of interest.

In OCT blood flow measurement, the scan controller 11 controls the light source and optical scanner included in the OCT scanner 31 . Under the control of the scan control unit 11, the OCT scanner 31 repeatedly scans a first cross section that intersects the target blood vessel at a preset measurement position (that is, target cross section) to collect first data. Second data is acquired by scanning one or more auxiliary cross-sections intersecting the vessel of interest in the vicinity of . The order of collecting the first data and collecting the second data is arbitrary.

(S2: form a morphological image)
The image forming unit 32 forms one or more morphological 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 morphological images can be formed as the number of scanning repetitions. As a result, time-series B-scan images corresponding to the cross section of interest are obtained. Note that the number of morphological images may be formed in a number smaller than the number of repetitions of scanning.

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

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

(S3: Find the inclination angle of the target blood vessel)
The blood flow data generator 33 obtains the inclination angle of the target blood vessel in the target cross section based on two or more morphological images among the plurality of morphological images formed in step S2. For this processing, for example, a combination of two morphological images corresponding to two auxiliary cross sections, or a combination of a morphological image corresponding to one auxiliary cross section and a morphological image corresponding to a cross section of interest is used.

(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.

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

(S5: Obtain blood flow data)
The blood flow data generation 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 obtained in step S3 and the phase image formed in step S4. This blood flow data includes, for example, data representing time-series changes in blood flow in the vessel of interest. Examples of such data include time-series changes in blood flow velocity during the measurement period (typically, a period longer than one cardiac cycle) of the OCT blood flow measurement performed in step S1, and time-series changes in blood flow volume per unit time.

The blood flow data generated in step S5 is stored in the storage unit 20 as the OCT data 21. FIG. When considering a plurality of vessels of interest, blood flow data is obtained for each of the plurality of vessels of interest. Furthermore, for each of the plurality of vessels of interest, the identification information (for example, the position information of the vessel of interest) and the corresponding blood flow data are associated with each other and stored in the storage unit 20 .

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

The displayed morphological image may include a blood flow state image combined with the blood vessel cross-sectional area in this 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 the cross-section of the blood vessel (vessel of interest), and is specified by analyzing at least one of the B-scan image and the phase image, for example. Typically, the display control unit 12 and/or the data acquisition unit 30 execute the following series of processes: process of analyzing the phase image to identify the blood vessel cross-sectional area; B-scan image and phase image of the cross section of interest. A process that identifies the image region in the B-scan image that corresponds to the vessel cross-sectional region in the phase image using the trivial registration between . Alternatively, the blood vessel cross-sectional area in the B-scan image may be specified based on the luminance distribution or pattern of the B-scan image.

An example of the morphological image displayed in step S6 is shown in FIG. 4A. Reference numeral 120 is an example of a morphological image displayed in step S6. The example shown in FIG. 4A represents a case where four blood vessels are detected in the section of interest. The display control unit 12 displays blood flow state images 131, 132, 133 and 134 at positions in the morphological image 120 corresponding to these four blood vessels. In addition, as described above, it is not essential to display the blood flow state image.

The blood flow state image 131 is, for example, an image expressing the magnitude of the blood flow velocity in color. The display control unit 12 refers to a predetermined lookup table (color map, density map, etc.) in which the relationship between the magnitude of the blood flow velocity and the color is recorded to determine the blood flow velocity at a predetermined time phase. A color (density) corresponding to the size is obtained, and the blood flow state image 131 is displayed based on the obtained color. Similar display control can be executed for the blood flow state images 132 to 134 as well. Also, similar display control can be executed when the blood flow rate per unit time is applied.

Also, the blood flow state image 131 may be an image that expresses the direction of blood flow in color. The display control unit 12 refers to a predetermined lookup table (such as a color map) in which the relationship between the direction of blood flow and the color is recorded, so that the color corresponding to the direction of blood flow in a predetermined time phase is displayed. is obtained, and the blood flow state image 131 is displayed based on the obtained color. Similar display control can be executed for the blood flow state images 132 to 134 as well. Also, similar display control can be executed when the blood flow rate per unit time is applied.

In a typical example, the blood flow state image 131 may be an image that expresses the direction of blood flow in color and the magnitude of blood flow velocity in color density. For example, the blood flow from the optic nerve head to the capillaries (that is, the blood flow in the arteries) is expressed in red, the blood flow from the capillaries to the optic nerve head (that is, blood flow in the veins) is expressed in blue, Furthermore, the lookup table is set so that the color density increases as the blood flow velocity increases. Similar display control can be executed for the blood flow state images 132 to 134 as well. Also, similar display control can be executed when the blood flow rate per unit time is applied.

(S7: Designate a blood vessel)
The user uses the operation unit 50 to specify one of the blood vessels drawn in the morphological image displayed in step S6. This operation is performed, for example, by clicking a desired blood vessel drawn on the morphological image with a pointing device. The display control unit 12 can change the display mode of the blood vessel specified in step S7.

(S8: Display blood flow graph)
The display control unit 12 identifies the identification information (for example, the position information described above) of the blood vessel designated in step S7, and reads blood flow data corresponding to the identified 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.

An example of information displayed in step S8 is shown in FIG. 4B. Assume 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 manner different from the blood flow state images 131 , 133 and 134 . Further, the display device 2 displays a blood flow graph 140 corresponding to the blood vessel cross-sectional area 132 together with the morphological image 120 displayed in step S6.

A blood flow graph 140 represents time series changes in blood flow in a blood vessel corresponding to the blood vessel cross-sectional area 132 . The blood flow graph 140 of this example is represented by a two-dimensional orthogonal coordinate system in which the horizontal axis (first coordinate axis) indicates time t and the vertical axis (second coordinate axis) indicates blood flow velocity (v). .

Such blood flow graph 140 is created based on (time-series) phase images over the measurement period of OCT blood flow measurement. At this time, the blood flow velocity (v) on the vertical axis is, for example, the value of a plurality of pixels included in the blood flow state image 132 in the corresponding time phase (that is, the value corresponding to the magnitude of the blood flow velocity, etc.). It may be a statistical value. This statistic may be, for example, an average value, maximum value, minimum value, or the like. Alternatively, the blood flow velocity (v) on the vertical axis may be the value of a predetermined pixel (for example, the pixel located at the center, the pixel located at the center of gravity, etc.) in the blood flow state image 132 .

Similarly, when the 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 the blood flow rate per unit time.

(S9: End of observation?)
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. Note that two or more blood vessels can be specified. In that case, two or more blood flow graphs corresponding to two or more specified blood vessels can be displayed in parallel. Such operations and processes are repeated until observation of data and images of the subject's eye is completed (S9: No). When the observation ends (S9: Yes), the processing of this example ends (END).

Another example of information that can be displayed in this embodiment is shown in FIG. Reference numeral 100 denotes a slider for presenting and setting the time phase of blood flow. The slider 100 has a handle 110 movable along a time axis (bar) indicating the measurement period of OCT blood flow measurement.

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

A phase image corresponding to the morphological image 120 is formed in step S4, and blood flow data is generated from the phase image in step S5. This blood flow data may be, for example, time-series changes in blood flow velocity or time-series changes in blood flow volume per unit time. In the example shown in FIG. 5, time-series changes in blood flow velocity (v) are employed.

The display control unit 12 displays a blood flow state image indicating the blood flow state (blood flow velocity, blood flow volume per unit time, etc.) in the time phase indicated by the slider 100 (at least) in the morphological image 120 corresponding to the target blood vessel. display in position.

In the example shown in FIG. 5, blood flow state images 131, 132, 133 and 134 are displayed at positions within the morphological image 120 corresponding to four blood vessels. The display control unit 12 refers to a predetermined lookup table (color map, density map, etc.) in which the relationship between the magnitude of the blood flow velocity and the color is recorded, so that the blood flow in the time phase indicated by the slider 100 is displayed. A color (density) corresponding to the magnitude of velocity is obtained, and a blood flow state image 131 is displayed based on the obtained color. Similar display control can be executed for the blood flow state images 132 to 134 as well. Also, similar display control can be executed when the blood flow rate per unit time is applied.

In addition, the display control unit 12 refers to a predetermined lookup table (such as a color map) in which the relationship between the direction of blood flow and the color is recorded to determine the direction of blood flow in the time phase indicated by the slider 100. A color corresponding to is obtained, and a blood flow state image 131 is displayed based on the obtained color. Similar display control can be executed for the blood flow state images 132 to 134 as well. Also, similar display control can be executed when the blood flow rate per unit time is applied.

Thus, the position (time phase) of the handle 110 of the slider 100 and the time phase indicated by the blood flow state images 131 to 134 correspond to each other.

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 state 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 any display mode that makes the position on the time axis indicated by the widget 150 clear may be used. Just do it.

When the handle 110 of the slider 100 is moved, the display control section 12 changes the position of the widget 150 with respect to the time axis in accordance with 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 correspondence with the movement of the widget 150 . Thus, the position (time phase) of the handle 110 of the slider 100 and the position of the widget 150 (that is, the time phase on the time axis indicated by the widget 150) correspond to each other.

As described above, the time phase indicated by the handle 110 of the slider 100, the time phase indicated by the blood flow state images 131 to 134, and the time phase indicated by the widget 150 correspond to each other. Furthermore, when selectively displaying a plurality of morphological images with different time phases, the time phase indicated by the handle 110 of the slider 100, the time phase indicated by the morphological images, and the time phase indicated by the blood flow state images 131 to 134 are displayed. and the phase indicated by the widget 150 correspond to each other.

In this example, the display control unit 12 displays two widgets (the slider 100 and the widget 150), and controls the display of these two widgets synchronously according to the time phase of blood flow. It has become. However, only one widget may be displayed. Alternatively, it is possible to display more than two widgets. In this case, display control of at least two of the three or more widgets can be synchronously executed according to the time phase of blood flow.

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

The display control unit 12 can display the blood flow state images 131 to 134 as moving images. In this case, the display control unit 12 can sequentially update the morphological image 120 corresponding to the time phases of the blood flow state images 131-134. In other words, the display control unit 12 can display the whole of the blood flow state images 131 to 134 and the morphological image 120 as a moving image.

Furthermore, the display control unit 12 converts the time phase indicated by the slider 100 (that is, the position of the handle 110) and the time phase that is indicated by the widget 150 (that is, the position of the widget with respect to the time axis) into a blood flow state image as a moving image. 131-134 (and the morphological image 120) can be changed synchronously.

When OCT angiography is performed in addition to OCT blood flow measurement, the display control unit 12 can cause the display device 2 to display a blood vessel-enhanced image obtained by the OCT angiography. The blood vessel-enhanced image is displayed together with the morphological image in step S6 of FIG. 3, for example. Alternatively, the blood vessel-enhanced image is displayed as the morphological image in step S6 of FIG.

When a blood vessel-enhanced image is displayed as the morphological image in step S6 of FIG. 3, for example, the image forming unit 32 generates a B-scan image (a B-scan blood vessel-enhanced image) of the cross section of interest based on data acquired by OCT angiography. to form Furthermore, the display processing unit 12 causes the display device 2 to display this B-scan vessel-enhanced image as a morphological image (for example, the morphological image 120 in FIG. 5).

When a blood vessel-enhanced image is displayed together with the morphological image in step S6 of FIG. to form a blood vessel-enhanced image (frontal blood vessel-enhanced image) as . An example of a blood vessel-enhanced image in a predetermined cross section is a B-scan blood vessel-enhanced image in the same cross section as the morphological image (that is, the target cross section). Examples of frontal blood vessel-enhanced images include a frontal image corresponding to an arbitrary depth region of the fundus (e.g., superficial retina, deep retina, choroidal capillary plate, sclera, etc.), and a predetermined tissue of the fundus (e.g., inner boundary membrane, nerve fiber layer, ganglion cell layer, inner reticular layer, inner nuclear layer, outer reticular layer, outer nuclear layer, outer limiting membrane, retinal pigment epithelium, Bruch's membrane, choroid, choroid-scleral junction, sclera, these There is a frontal image corresponding to a portion of any, such as a combination of at least two or more of these. Furthermore, the display processing unit 12 causes the display device 2 to display the formed blood vessel-enhanced image in parallel with the morphological image (for example, the morphological image 120 in FIG. 5).

<Ophthalmic information processing device>
An ophthalmologic information processing apparatus according to an exemplary embodiment will be described. FIG. 6 shows a configuration example of the ophthalmologic information processing apparatus of this embodiment. The ophthalmologic information processing apparatus 200 stores fundus data acquired using OCT blood flow measurement, generates a fundus morphological image and fundus blood flow data based on the stored data, and displays various information based on these. do. Further, the ophthalmic information processing apparatus 200 may be configured to store data obtained using OCT angiography and display information based on this data.

The ophthalmologic information processing apparatus 200 can display various types of information such as fundus morphological images, blood flow information, and blood vessel enhanced images on the display device 2 . The display device 2 may be a part of the ophthalmologic information processing apparatus 200 or may be an external device connected to the ophthalmologic information processing apparatus 200 . In addition, the ophthalmologic information processing apparatus 200 can send various types of information to a computer, a storage device, an ophthalmologic apparatus, and the like.

The ophthalmologic information processing apparatus 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 . Control unit 210 includes a display control unit 212 . OCT data 221 is stored in the storage unit 220 .

Each element of the ophthalmologic information processing apparatus 200 has, for example, the same configuration and function as the corresponding element included in the ophthalmologic photographing apparatus 1 described above. That is, the control unit 210 has the same configuration and functions as the control unit 10, the display control unit 212 has the same configuration and functions as the display control unit 12, and the storage unit 220 has the same configuration and functions as the storage unit 20. The operating unit 250 has the same configuration and functions as the operating unit 50 .

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 (1) to (5) below.
(1) Data collected by OCT scanning of the fundus (raw data)
(2) Image data obtained by processing raw data (3) Intermediate data obtained during a series of processes for generating image data from raw data (4) Obtained by processing raw data Blood flow data (5) Intermediate data obtained during a series of processes for generating blood flow data from raw data

The data processing unit 230 executes various data processing. The data processing section 230 may have the same configuration and functions as the image forming section 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 performs the same processing as the image forming unit 32 to perform OCT images (morphological images, phase images). images, etc.).

The data processor 230 may have the same configuration and functions as the blood flow data generator 33 . For example, when the OCT data 221 includes at least one of the OCT data (1), (4) and (5), the data processing unit 230 performs the same processing as the blood flow data generation unit 33 to Flow data (blood velocity, blood flow, etc.) can be generated.

The data input unit 240 inputs the OCT data 221 and/or its source data to the ophthalmologic information processing apparatus 200 from the outside. The data input unit 240 may include, for example, a communication interface for data communication with an external device, a device for reading data from a recording medium, and the like.

The display control unit 212 can perform control for displaying information similar to at least one of FIGS. 4A, 4B, and 5 on the display device 2 .

〈Action and effect〉
Actions and effects of the ophthalmic photographing apparatus and the ophthalmic information processing apparatus according to the exemplary embodiment described above will be described.

An ophthalmologic imaging apparatus (1) according to an embodiment includes a data acquisition section (30), a display processing section (display control section 12, etc.), and an operation section (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 causes the display means (display device 2) to display information.

Specifically, the display processing unit displays the fundus morphological image (120) based on the data (OCT data 21) acquired by the data acquisition unit. Furthermore, when one of the blood vessels drawn in the displayed morphological image is designated using the operation unit, the display processing unit displays a blood flow graph representing time-series changes in blood flow in the designated blood vessel as data. It is displayed based on the data (OCT data 21) acquired by the acquisition unit.

An ophthalmologic information processing apparatus (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 the display means (display device 2) to display information.

Specifically, the display processing unit displays the fundus morphological image (120) based on the data (OCT data 221) stored in the storage unit. Furthermore, when one of the blood vessels drawn in the displayed morphological image is designated using the operation unit, the display processing unit displays a blood flow graph representing time-series changes in blood flow in the designated blood vessel as data. It is displayed based on the data (OCT data 221) acquired by the acquisition unit.

According to such an embodiment, the user can designate a desired blood vessel depicted in the morphological image while observing the morphology of the fundus using the morphological image. Furthermore, the ophthalmologic imaging apparatus (1) or the ophthalmologic information processing apparatus (200) can display a blood flow graph corresponding to a blood vessel specified by the user. According to such a novel information display mode, the user can easily observe the blood flow graph corresponding to the desired blood vessel.

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

According to such a configuration, it is possible to present time-series changes in blood flow velocity and time-series changes in blood flow per unit time as graphs. As a result, the user can easily comprehend time-series changes in blood flow velocity and time-series changes in blood flow volume per unit time.

In the embodiment, the display processing section may be configured to display at least one of the B-scan image and the phase image as the morphological image.

According to such a configuration, the user can easily grasp the blood flow state in the B-section while observing the morphology and/or phase state of the B-section of the fundus.

In the embodiment, the display processing section may be configured to display the B-scan image and the blood flow state image combined with the blood vessel cross-sectional area in the B-scan image as the morphological image.

With such a configuration, the user can easily grasp blood flow dynamics from the morphological image.

The blood flow state image may include an image that expresses the magnitude of blood flow velocity or the magnitude of blood flow per unit time in color. According to this configuration, the magnitude of the blood flow velocity and the magnitude of the blood flow per unit time can be presented using colors. The size can be easily grasped.

Also, the blood flow state image may include an image that expresses the direction of blood flow in color. According to this configuration, since the direction of blood flow can be presented using colors, the user can easily grasp the direction of blood flow.

At least one of the ophthalmologic imaging apparatus and the ophthalmologic information processing apparatus according to the embodiment can handle data acquired by applying OCT angiography to the fundus. That is, the data acquisition unit of the ophthalmologic imaging apparatus according to the embodiment may be configured to acquire data by applying OCT angiography to the fundus. On the other hand, the storage unit of the ophthalmologic information processing apparatus 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 ophthalmologic imaging apparatus and/or ophthalmologic information processing apparatus may be configured to display a blood vessel-enhanced image based on data acquired by OCT angiography.

With such a 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.

Note that the display processing unit can display, for example, a blood vessel-enhanced image formed as a B-scan image as a morphological image, or display a blood vessel-enhanced image formed as a B-scan image and a morphological image based on OCT blood flow measurement. can be displayed in parallel, and a blood vessel-enhanced image formed as a front image and a morphological image can also be displayed in parallel.

In the ophthalmologic imaging apparatus according to the embodiment, the data acquisition unit (30) may be configured to perform the following series of processes in OCT blood flow measurement: Collecting first data by repeatedly scanning one section; Collecting second data by scanning one or more second sections intersecting the blood vessel in the vicinity of the measurement position; Collecting second data; Measurement position based on the second data obtaining 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;

According to such a configuration, it is possible to appropriately perform OCT blood flow measurement to generate blood flow data, and display a blood flow graph and a blood flow state image based on the blood flow data. can.

In the ophthalmologic imaging apparatus according to the embodiment, a data acquisition unit (30) acquires one or more B-scan images corresponding to the first cross section based on first data acquired by repeated scanning of the first cross section. can be done.

According to such a configuration, not only blood flow data but also B-scan images can be acquired from the data obtained by OCT blood flow measurement. Therefore, there is no need to perform an OCT scan to form a B-scan image separately from the OCT blood flow measurement. In addition, it is possible to acquire a plurality of B-scan images (time-series B-scan images) corresponding to time-series changes in the blood flow state.

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

The configuration described above is merely an example for suitably implementing the present invention. Therefore, any modification (omission, substitution, addition, etc.) within the scope of the gist of the present invention can be applied as appropriate.

1 ophthalmic imaging apparatus 2 display device 10 control unit 11 scan control unit 12 display control unit 20 storage unit 21 OCT data 30 data acquisition unit 31 OCT scanner 32 image forming unit 33 blood flow data generation unit 50 operation unit 120 morphological images 131 and 132 , 133, 134 Blood flow state image 140 Blood flow graph 200 Ophthalmic information processing apparatus 210 Control unit 212 Display control unit 220 Storage unit 221 OCT data 230 Data processing unit 240 Data input unit 250 Operation unit

Claims (6)

First data obtained by applying optical coherence tomography (OCT) blood flow measurement to the fundus of an eye to be examined and second data obtained by applying OCT angiography to the fundus are stored in advance. a storage unit;
a display processing unit that causes the display means to display information;
The display processing unit
displaying a morphological image of the fundus based on the first data;
displaying a front vessel-enhanced image based on the second data;
displaying, based on the first data, a blood flow graph representing a time-series change in blood flow in a blood vessel of interest, which is one of the blood vessels depicted in the morphological image;
Display a slider for presenting and setting the time phase of blood flow,
displaying a blood flow state image showing the state of blood flow in the time phase indicated by the slider at a position within the morphological image corresponding to the blood vessel of interest;
Ophthalmic information processing device. The display processing unit displays a front image corresponding to a predetermined depth region of the fundus as the front blood vessel-enhanced image.
The ophthalmologic information processing apparatus according to claim 1. The display processing unit provides, as the front vessel-enhanced image, a front image corresponding to the superficial portion of the retina of the fundus, a front image corresponding to the deep portion of the retina, a front image corresponding to the choroidal capillary plate, and a front image corresponding to the sclera. displaying at least one of the front images;
The ophthalmologic information processing apparatus according to claim 2. The display processing unit displays a front image corresponding to a predetermined tissue of the fundus as the front blood vessel-enhanced image,
The ophthalmologic information processing apparatus according to any one of claims 1 to 3. The display processing unit generates, as the front vessel-enhanced image, a front image corresponding to at least a portion of the internal limiting membrane of the fundus, a front image corresponding to at least a portion of the nerve fiber layer, and at least a portion of the ganglion cell layer. an anterior image corresponding to at least a portion of the inner plexiform layer; an anterior image corresponding to at least a portion of the inner nuclear layer; an anterior image corresponding to at least a portion of the outer plexiform layer; Frontal image corresponding to a portion, Frontal image corresponding to at least a portion of the outer limiting membrane, Frontal image corresponding to at least a portion of the retinal pigment epithelium, Frontal image corresponding to at least a portion of Bruch's membrane, At least one of the choroid displaying at least one of a frontal image corresponding to the region, a frontal image corresponding to at least a portion of the choroid-scleral boundary, and a frontal image corresponding to at least a portion of the sclera;
The ophthalmologic information processing apparatus according to claim 4. a data acquisition unit that acquires first data by applying optical coherence tomography (OCT) blood flow measurement to the fundus of the subject's eye and acquires second data by applying OCT angiography to the fundus; ,
a display processing unit that causes the display means to display information;
The display processing unit
displaying a morphological image of the fundus based on the first data;
displaying a front vessel-enhanced image based on the second data;
displaying, based on the first data, a blood flow graph representing a time-series change in blood flow in a blood vessel of interest, which is one of the blood vessels depicted in the morphological image;
Display a slider for presenting and setting the time phase of blood flow,
displaying a blood flow state image showing the state of blood flow in the time phase indicated by the slider at a position within the morphological image corresponding to the blood vessel of interest;
Ophthalmic imaging equipment.

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