JP7386949B2 - Ophthalmology information processing device - Google Patents

Description

Embodiments relate to an ophthalmological information processing device.

Image diagnosis occupies an important position in the field of ophthalmology. In recent years, optical coherence tomography (OCT) has been increasingly utilized. OCT has come to be used not only to obtain B-scan images and three-dimensional images of the eye to be examined, but also to obtain en-face images such as C-scan images and shadowgrams.

Furthermore, it is also practiced to obtain an image in which a specific part of the eye to be examined is emphasized, and to obtain functional information. For example, a B-scan image or a frontal image (referred to as a blood vessel-enhanced image, angiogram, etc.) in which fundus blood vessels are emphasized can be constructed based on time-series data collected by OCT. This technique is called OCT angiography. Furthermore, information regarding blood flow can be acquired based on phase information of time-series data collected by OCT. This technique is called OCT blood flow measurement or the like.

Special Publication No. 2015-515894 Japanese Patent Application Publication No. 2013-184018

The purpose of the embodiment is to provide a new display mode of information obtained by OCT blood flow measurement.

The ophthalmological information processing device of the embodiment includes a storage section and a display processing section. The storage unit stores data obtained by applying OCT blood flow measurement to the fundus of the eye to be examined. The display processing unit is capable of displaying a blood flow graph representing time-series changes in blood flow based on data stored in the storage unit, and is capable of moving along a first time axis that is a time axis of the blood flow graph. a process of displaying a first widget, a process of displaying a second widget movable along a second time axis indicating a measurement period of OCT blood flow measurement, and a process of displaying a second widget that is movable along a second time axis indicating a measurement period of OCT blood flow measurement; 2. Processing to correspond to the position of the second widget with respect to the time axis is executed.

According to the embodiment, it is possible to provide a new display mode of information obtained by OCT blood flow measurement.

1 is a schematic diagram illustrating an example of the configuration of an ophthalmologic imaging apparatus according to an exemplary embodiment. FIG. 2 is a schematic diagram for explaining an example of a process executed by an ophthalmologic imaging apparatus according to an exemplary embodiment. 3 is a flowchart illustrating an example of the operation of the ophthalmologic imaging apparatus according to the exemplary embodiment. FIG. 2 is a schematic diagram for explaining an example of a process executed by an ophthalmologic imaging apparatus according to an exemplary embodiment. FIG. 2 is a schematic diagram for explaining an example of a process executed by an ophthalmologic imaging apparatus according to an exemplary embodiment. FIG. 2 is a schematic diagram for explaining an example of a process executed by an ophthalmologic imaging apparatus according to an exemplary embodiment. 1 is a schematic diagram illustrating an example of the configuration of an ophthalmological information processing apparatus according to an exemplary embodiment.

Exemplary embodiments of the invention will be described with reference to the drawings. Note that it is possible to combine any known technology including the disclosures of the documents cited in this specification into the embodiments.

The ophthalmologic information processing device and the ophthalmologic imaging device according to the embodiments have a function of displaying various information based on data obtained by applying OCT to the fundus of an eye to be examined. The ophthalmological information processing device according to the embodiment receives data obtained by applying OCT to the fundus of the eye to be examined by a separately provided OCT device, 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.

Data obtained by applying OCT to the fundus of the eye to be examined (fundus OCT data) may be data in any form. For example, 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 raw data (3) Intermediate data obtained during a series of processing to generate image data from raw data (4) Image data obtained by processing raw data Blood flow data (5) Intermediate data obtained during a series of processes to generate blood flow data from raw data

Note that the types of fundus OCT data are not limited to these. Embodiments may also process various information associated with fundus OCT data. Examples of such information include patient identification information, eye identification information, identification information indicating whether the eye to be examined is the left eye or right eye, photographing date and time, and photographing conditions.

The ophthalmologic information processing device and the ophthalmologic imaging device according to the embodiments include a processor that executes data display processing. The ophthalmological information processing device 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, a drive system, a control system, and a data processing system for performing OCT.

The ophthalmologic 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 that uses a broadband low-coherence light source and a spectrometer to acquire the spectrum of interference light by spatial division, and constructs an image by Fourier transforming the spectrum. Swept source OCT uses a wavelength swept light source (tunable wavelength 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. This is a method to do so. The OCT method is not limited to Fourier domain OCT, but may be time domain OCT or unfazed OCT.

The ophthalmologic information processing device and the ophthalmologic imaging device according to the embodiments may include a modality (for example, a modality 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 surgery microscopes. Further, the ophthalmologic information processing device and the ophthalmologic imaging device according to the embodiments may include a configuration for measuring characteristics of the eye and/or other parts, and a configuration for performing an examination.

The data processing functions (calculation functions, image processing functions, control functions, etc.) in the ophthalmological information processing device and the ophthalmological imaging device according to the embodiments include, for example, hardware such as a processor and a storage device, a calculation program, an image processing program, and a control function. This is achieved through cooperation with software such as programs. Note that a part of the hardware may be provided in an external device that can communicate with the ophthalmologic information processing device or the ophthalmologic imaging device according to the embodiment. Further, at least a part of the software may be stored in advance in the ophthalmological information processing device or ophthalmological imaging device according to the embodiment, and/or may be stored in advance in an external device.

<Ophthalmology imaging equipment>
<composition>
An ophthalmologic imaging device according to an exemplary embodiment will be described. FIG. 1 shows an example of the configuration of the ophthalmologic imaging apparatus of this embodiment. The ophthalmologic imaging device 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 expressing the morphology of the fundus. In this 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 distinguishable manner. Examples of fundus morphological images include B-scan images, C-scan images, projection images, shadowgrams, phase images, and blood vessel-enhanced images. Further, the fundus blood flow data is data representing the state of blood flow (blood flow dynamics) in the fundus blood vessels. Examples of fundus blood flow data include blood flow direction, blood flow velocity, time series changes in blood flow velocity, blood flow volume, blood flow volume per unit time, time series changes in blood flow volume per unit time, total blood flow volume, etc. .

In this embodiment, both a morphological image and blood flow data are formed based on data obtained by applying OCT blood flow measurement to the fundus of the eye. Note that an OCT scan (for example, B scan, 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. . Further, an OCT scan may be performed to obtain data other than these. For example, OCT angiography can be performed.

Part of the data used to display the information may be acquired by another device. For example, either the fundus morphological image or 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 information such as fundus morphological images, blood flow information, and blood vessel emphasis 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 imaging device 1 can send various information to a computer, a storage device, an ophthalmologic device, 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 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.

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

Further, 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 control unit 11 controls the OCT scanner 31. For example, the scan control unit 11 controls the OCT scanner 31 by controlling the light source, controlling the optical scanner, changing the optical path length of the measurement light and/or reference light, polarization adjustment, light amount adjustment, focus adjustment, change of the fixation position, etc. Control the various elements included. Some examples of processes 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 perform display control based on data stored in the storage unit 20.

The display control unit 12 can perform processing (generation, processing, composition, etc.) regarding 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>
The storage unit 20 stores various data. In this example, OCT data 21 is stored in the storage unit 20. Note that at least a portion of the OCT data may be stored in an externally provided storage device and provided to the ophthalmologic imaging apparatus 1 upon request. The storage unit 20 includes, for example, a storage device such as a hard disk drive or 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 ophthalmological imaging device 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 aforementioned fundus OCT data (2) and (4) are included in the OCT data 21.

<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 portion of the OCT data 21 stored in the storage unit 20). As described above, the data acquisition section 30 includes the OCT scanner 31, the image forming section 32, and the blood flow data generating section 33. Image forming section 32 includes a processor that executes an image forming program. The blood flow data generation unit 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 control unit 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 drive system, a data acquisition system (DAQ), a control system, etc., as in the conventional case.

The OCT optical system includes, for example, an interference optical system, an optical scanner, and a photodetector. The interference optical system splits the light output from the light source into measurement light and reference light, projects this measurement light onto the fundus, and generates interference light by superimposing the return light of the measurement light from the fundus with the reference light. do. The optical scanner includes a galvano scanner and the like, and deflects the measurement light. As a result, the projection position of the measurement light onto the fundus of the eye is moved. The photodetector detects (the spectrum of) the interference light generated by the interference optical system.

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

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 the cross section of interest that intersects the blood vessel of interest and collects data. The scan mode at this time is, for example, line scan (B scan). This line scan is repeatedly executed at a predetermined frequency, for example. Data collected through such repeated scanning is sent to the image forming section 32.

In OCT blood flow measurement, the OCT scanner 31 further performs a scan to determine 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 the blood vessel of interest. Here, the two cross sections can be placed near the cross section of interest.

Note that one of the two cross sections for determining the inclination angle of the blood vessel of interest may be the cross section of interest itself. The other cross section is set near 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.

In summary, typically, a scan 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 a combination of repeated scans of the cross-section of interest and scans of one other cross-section. It may also be combined with a scan.

The mode 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 area including the cross section of interest can be scanned (three-dimensional scan). As another example, a cross section that intersects the cross section of interest and is along the blood vessel of interest can be scanned. Note that OCT blood flow measurement will be detailed in the description of the blood flow data generation section 33.

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 executed, for example, by scanning each of a plurality of B cross sections (B scan planes) a predetermined number of times (for example, four times each). In other words, this raster scan is performed so that a plurality of B cross sections are sequentially scanned a predetermined number of times or according to a predetermined sequence. The three-dimensional data set collected by the OCT scanner 31 is sent to the image forming section 32.

The scan mode that can be executed by the OCT scanner 31 is not limited to the above-described mode. 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.

<Image forming section 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-section based on a three-dimensional data set collected by the OCT scanner 31. The image forming process at this time includes, for example, noise removal (noise reduction), filter processing, fast Fourier transform (FFT), etc., similar to conventional OCT technology.

The image forming unit 32 can construct stack data by embedding these cross-sectional images into a single three-dimensional coordinate system. In this stack data, a number of cross-sectional images corresponding to the number of scan repetitions are assigned to each B cross-section. Further, 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 scan repetitions are assigned to a position corresponding to each B cross section.

The image forming unit 32 performs rendering on stack data or volume data to create a B-scan image (vertical cross-sectional image, axial cross-sectional image), C-scan image (cross-sectional image, horizontal cross-sectional image), projection image, shadowgram. etc. can be formed.

An image of an arbitrary cross section, 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 with a preset thickness in the 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 part 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, or a shadowgram, that is viewed from the cornea side of the eye to be examined is called a frontal image.

The image forming unit 32 is capable of performing various types of image processing in addition to rendering. Examples include segmentation to find a specific tissue or tissue boundary, and size analysis to find 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 the B-scan image or the front image so that the specific layer becomes 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 in which an image region corresponding to a blood vessel (blood vessel region) is identified by analyzing OCT data, and is emphasized by changing the representation mode of this blood vessel region. A plurality of OCT data obtained by repeatedly scanning substantially the same area of the eye to be examined is used to identify the blood vessel region.

The blood vessel-enhanced image expresses, for example, the distribution of blood vessels in a three-dimensional region of the fundus scanned by OCT (that is, the three-dimensional distribution of blood vessels). There are several types of techniques for forming blood vessel-enhanced images. A typical method for this purpose will be explained. 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 eye to be examined. Note that fixation and tracking are methods for repeatedly scanning substantially the same cross-section B.

In the process of forming a blood vessel-enhanced image, first, alignment of a plurality of B-scan images is 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 feature region from each B-scan image and align the plurality of B-scan images by aligning the extracted feature regions.

Subsequently, a process is performed to identify a changing image area among the aligned B-scan images. This process includes, for example, a process of finding a difference between different B-scan images. Each B-scan image is brightness image data representing the morphology of the eye to be examined, and the image area corresponding to parts other than blood vessels is considered to be substantially unchanged. On the other hand, considering that the backscatter that contributes to the interference signal changes randomly due to blood flow, it is important to note that image regions where changes occur between the aligned B-scan images (e.g., pixels for which the difference is not zero, or Pixels for which the difference is greater than or equal to a predetermined threshold can be estimated to be blood vessel regions.

The image region identified in this way is assigned information indicating that it is a blood vessel region. By performing the above processing on a plurality of B cross sections, three-dimensionally distributed blood vessel regions are obtained. By rendering such a three-dimensional blood vessel-enhanced image, a frontal image representing blood vessel distribution, an image of an arbitrary cross section, a shadowgram of an arbitrary range, etc. are generated.

The process of forming a blood vessel enhanced image is not limited to this. For example, it is possible to identify a blood vessel region using a conventional technique using Doppler OCT or a conventional image processing technique. Further, by using different techniques depending on the region, it is possible to specify the blood vessel region for each region. For example, for the retina, a blood vessel region can be identified using the above-mentioned typical method or the Doppler OCT method, and for the choroid, a blood vessel region can be identified using an image processing method.

<Blood flow data generation unit 33>
The blood flow data generation unit 33 operates in OCT blood flow measurement. The blood flow data generation unit 33 generates data 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 OCT blood flow measurement and the inclination angle of the blood vessel of interest in the cross section of interest. Generate blood flow data representing the state of blood flow in the blood vessel of interest.

The data collected by the OCT scanner 31 in OCT blood flow measurement includes data collected by repeatedly scanning a cross section of interest that intersects the blood vessel of interest (first data), and data that intersects the blood vessel of interest and is different from the cross section of interest. 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 blood vessel of interest at the position of the cross-section of interest or a position near the cross-section of interest, which is acquired separately from OCT blood flow measurement, may be used. As an example, it is possible to use a tilt angle determined from a blood 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 data collected by the OCT scanner 31 in OCT blood flow measurement. The morphological image and 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 cross section of interest (cross section B) are obtained.

As mentioned above, in typical OCT blood flow measurement, two types of scans (auxiliary scan and main scan) are performed on the fundus of the eye. The auxiliary scan is performed to collect second data by scanning one or more cross sections different from the cross section of interest (cross sections near the cross section of interest). In a typical auxiliary scan, two or more cross-sections intersecting the blood vessel of interest are scanned with the 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 in order to collect first data by repeatedly scanning a cross section of interest intersecting the blood vessel of interest with the measurement light. The cross-section on which the auxiliary scan is performed is placed near the cross-section of interest. The main scan is Doppler measurement using OCT.

The target cross-sections of the auxiliary scan and the main scan are, for example, oriented perpendicular to the running direction of the blood vessel of interest. Further, the distance between the target cross-section of the auxiliary scan and the cross-section of interest (inter-cross-section distance) 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 a predetermined factor such as the curvature of the blood vessel of interest at or near the cross section of interest, or inspection accuracy. Alternatively, the user may set a desired inter-sectional distance.

Preferably, the scan is performed over at least one cardiac cycle of the patient's heart. Thereby, blood flow data in all time phases of the heartbeat can be obtained. 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.

For example, the image forming unit 32 generates a cross-sectional image representing the form of the first auxiliary cross-section and a second auxiliary cross-section based on data collected by auxiliary scanning of two auxiliary cross-sections set in the vicinity of the cross-section of interest. 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 using a technique such as averaging, or to select an optimal 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 data collected by main scans (repetitive scans) of the cross-section of interest. This processing is achieved, for example, by forming a cross-sectional image from data collected at each repetition of the scan.

The processing executed by the image forming unit 32 includes, for example, noise removal (noise reduction), filter processing, 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 similar to the morphological image forming process executed by the image forming unit 32.

Further, the image forming unit 32 forms a phase image representing a time-series change in phase difference in the cross section of interest based on 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-sectional image (group) of the cross-section of interest. Therefore, there is a natural positional correspondence between the cross-sectional image of the cross-section of interest and the phase image, and registration is self-evident.

An example of a method for forming a phase image will be explained. 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 for each pixel of the cross-sectional image of the cross-section of interest based on a time-series change in the pixel value (luminance value) of that pixel. For an arbitrary pixel, the image forming unit 32 considers a graph of a time-series change in luminance value. The image forming unit 32 determines the phase difference Δφ between two time points t1 and t2 (t2=t1+Δt) separated by a predetermined time interval Δt in this graph. This phase difference Δφ is defined as the phase difference Δφ(t1) at time t1 (more generally, any time between two time points t1 and t2). By executing this process for each of a large number of preset time points, time-series changes in the phase difference at the pixel can be obtained.

A phase image is an image that represents the phase difference value of each pixel at each point in time. This imaging process can be realized, for example, by expressing the value of the phase difference using a display color or brightness. At this time, the color (for example, red) representing that the phase has increased along the time series can be different from the color (for example, blue) that represents that the phase has decreased. Further, the magnitude of the amount of change in phase can also be expressed by the darkness of the display color. By adopting such an expression method, it becomes possible to express the direction and size of blood flow using color and density. A phase image is formed by performing the above processing for each pixel.

Note that the time-series change in the phase difference can be obtained by making the time interval Δt sufficiently small to ensure phase correlation. At this time, oversampling is performed in which the time interval Δt is set to a value less than the time corresponding to the resolution of the cross-sectional image in the measurement light scan.

The blood flow data generation unit 33 can execute, for example, a blood vessel region specifying 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 rate calculation process.

In the blood vessel region specifying process, the blood flow data generation unit 33 specifies a blood vessel region in each cross-sectional image corresponding to the blood vessel of interest. Further, the blood flow data generation unit 33 identifies a blood vessel region in the phase image that corresponds to the cross section of interest. The vascular region is identified by analyzing the pixel values of each image (for example, by threshold processing). The blood vessel region in the phase image may be specified 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 generation unit 33 calculates the inclination angle of the blood vessel of interest in the cross section of interest based on the image (group) formed from the data acquired by the auxiliary scan.

An example of the inclination angle calculation process will be explained. See FIG. 2. Reference numeral 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. Symbols B11 and B12 indicate two cross-sectional images (auxiliary cross-sectional images) in two supplementary cross-sections located near the cross-section of interest B0. The auxiliary cross-sectional image B11 depicts a blood vessel region V11 in the auxiliary cross-section B11 of the same blood vessel (vessel of interest) as the blood vessel region V0. Similarly, the auxiliary cross-sectional image B12 depicts a blood vessel region V12 in the auxiliary cross-section B12 of the blood vessel of interest.

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

The blood flow data generation 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 distance between cross sections. The inter-sectional distance may be the distance between the auxiliary sectional image B11 and the auxiliary sectional image B12. Alternatively, the inter-sectional distance may be defined by at least one of the distance between the auxiliary sectional image B11 and the sectional image of interest B0, and the distance between the auxiliary sectional image B12 and the sectional image of interest B0. good. Let L be the distance between the auxiliary cross-sectional image B11 (or B12) and the cross-sectional image of interest B0.

The A-scan direction shown in FIG. 2 (the direction pointed 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, an A-scan image located at 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 generation unit 33 can calculate the slope A of the blood vessel of interest in the cross section of interest based on the positional relationship between 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 generation unit 33 identifies feature points of each of the three blood vessel regions V0, V11, and V12, and connects these feature points. The feature points referred to here include the center position (axis position), the center of gravity position, and the top. Further, as methods for connecting these feature points, there are a method of connecting with line segments, a method of connecting with an approximate curve (spline curve, Bezier curve, etc.), and the like.

Furthermore, the blood flow data generation unit 33 calculates the slope A based on the line connecting these feature points. When a line segment is used, the blood flow data generation unit 33 generates, for example, a first line segment that connects 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. The slope A can be calculated based on 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 calculated. Furthermore, as an example of a case where the approximate curve is connected, the slope of the approximate curve at the intersection position of the approximate curve and the cross section of interest can be determined.

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

Further, in the above example, only one value of the slope A is calculated, but the slopes may be calculated for each of two or more positions (or areas) in the blood vessel region V0. In this case, the two or more obtained slope values can be used separately, or one value (for example, an 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 information regarding the blood vessel of interest based on the phase image formed based on the main scan (Doppler OCT) and the inclination angle determined 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 rate calculation process.

The blood flow data generation unit 33 can calculate the blood flow velocity in the cross section of interest of blood flowing in the blood vessel 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 point in time, or may be a time-series change in 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 R wave time phase). Moreover, the time range in the latter case is the entire time or an arbitrary part of the time during which the cross section of interest was scanned.

When the blood flow velocity change data is obtained, the blood flow data generation unit 33 can calculate the statistical value of the blood flow velocity in the relevant time range. These statistical values include an average value, standard deviation, variance, median value, maximum value, minimum value, local maximum value, local minimum value, etc. It is also possible to create a histogram of blood flow velocity values.

The blood flow data generation unit 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 that the scattered light of the measurement light undergoes n: Refractive index of the medium (blood) v: Flow velocity of the medium (blood flow velocity)
θ: Angle between the direction of incidence of the measurement light and the direction of flow of the medium (tilt angle)
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 both known, the Doppler shift Δf is obtained from a time-series change in the phase difference, and the tilt angle θ is determined by the tilt angle calculation process or blood vessel angle distribution. obtained from. The blood flow data generation unit 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 generation 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 that uses a frontal image of the fundus, and a second calculation method that uses a cross-sectional image.

When the first calculation method is applied, a part of the fundus including the position of the cross section of interest is photographed in advance. This fundus photography is performed, for example, by the front image acquisition unit 60. Alternatively, a front image of the fundus that has been acquired and stored in the past may be read. Alternatively, a blood vessel enhanced image may be used.

The blood flow data generation unit 33 calculates the size 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 imaging angle of view (imaging magnification), working distance, and information on the eyeball optical system. Set the scale in the front image. This scale represents the length in real space. As a specific example, this scale is a correspondence between the interval between adjacent pixels and the scale in real space (for example, pixel interval = 10 μm). Note that it is also possible to calculate the relationship between various values of the factors and the scale in real space in advance, and to store information expressing this relationship in a table format or a graph format. In this case, a scale corresponding to the above factors is 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 generation unit 33 can determine the maximum value and average value of the diameter of the blood vessel region in various directions. Alternatively, the blood flow data generation unit 33 can approximate the contour of the blood vessel region to a circle or an ellipse, and obtain the diameter of the circle or ellipse. Note that once the blood vessel diameter is determined, the area of the blood vessel region can be determined (substantially), so the area may be calculated instead of determining the blood vessel diameter.

The second calculation method will be explained. 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 from this. The scale in this cross-sectional image is determined according to the scanning mode 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 working distance and information on the eyeball optical system. For example, the blood flow data generation unit 33 can calculate 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.

In the blood flow calculation process, the blood flow data generation unit 33 calculates the flow rate of blood flowing in the blood vessel of interest based on the blood flow velocity calculation result and the blood vessel diameter calculation result. An example of this process will be described below.

It is assumed that the blood flow in a blood vessel is a Hagen-Poiseuille flow. Further, the blood vessel diameter is assumed to be w, and the maximum value of blood flow velocity is assumed to be Vm. In this case, the blood flow Q is expressed by the following relational expression.

The blood flow data generation unit 33 calculates the blood flow 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 expression. Q can be calculated.

<Operation unit 50>
The operation unit 50 is used by a user to input instructions to the ophthalmologic imaging apparatus 1 . The operation unit 50 may include a known operation device used in ophthalmological apparatuses and computers. 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, buttons, switches, 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. The processing 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, and the like.

In the second example, the front image acquisition unit 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 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 frontal image acquisition unit 60 can acquire a frontal image of the fundus of the eye to be examined, which is 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 using OCT. Examples of the OCT front image include a C scan image, a projection image, and a shadowgram.

<motion>
An example of the operation of the ophthalmologic imaging apparatus 1 according to this embodiment will be described. FIG. 3 shows an example of the operation of the ophthalmologic imaging apparatus 1. Preparatory processes 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, OCT optical path length adjustment, adjustment of the fixation position, and setting of the OCT scan range have already been performed. shall be.

(S1: Perform OCT blood flow measurement of the fundus)
The ophthalmologic imaging apparatus 1 performs OCT blood flow measurement on a cross section 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. Further, when there are a plurality of blood vessels passing through the cross section of interest, at least some of these blood vessels can be set as the blood vessels of interest. Conversely, it is also possible to set the cross section of interest so as to cross a plurality of blood vessels of interest.

In OCT blood flow measurement, the scan control unit 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 intersecting the blood vessel of interest at a preset measurement position (that is, the cross-section of interest) to collect first data, and further collects first data from the cross-section of interest. Second data is collected by scanning one or more auxiliary cross-sections that intersect the blood vessel of interest in the vicinity of the blood vessel of interest. Note that 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 repetitions of the scan. As a result, time-series B-scan images corresponding to the cross section of interest are obtained. Note that the number of morphological images that is smaller than the number of repetitions of scanning may be formed.

Furthermore, 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 OCT data 21.

(S3: Find the inclination angle of the blood vessel of interest)
The blood flow data generation unit 33 determines the inclination angle of the blood vessel of interest in the cross section of interest based on two or more morphological images of the plurality of morphological images formed in step S2. This processing uses, 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 the cross section of interest.

(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 OCT data 21.

(S5: Obtain blood flow data)
The blood flow data generation unit 33 generates blood flow data regarding 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 blood 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 the measurement period. Examples include time-series changes in blood flow per unit time.

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

(S6: Display 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. If OCT angiography is performed, the displayed morphological image may be a vessel-enhanced image. Further, 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 (blood vessel of interest), and is specified, 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: Analyzing a phase image to identify a blood vessel cross-sectional area; B-scan image and phase image of the cross-section of interest; A process of identifying an image region in a B-scan image that corresponds to a blood vessel cross-sectional region in a phase image using obvious registration between Alternatively, the blood vessel cross-sectional area in the B-scan image may be specified based on the brightness 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 the morphological 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 state images 131, 132, 133, and 134 at positions in the morphological image 120 corresponding to these four blood vessels, respectively. Note that, 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 in which the magnitude of blood flow velocity is expressed in color. The display control unit 12 determines the blood flow velocity at a predetermined time phase by referring to a predetermined lookup table (color map, density map, etc.) in which the relationship between the magnitude of blood flow velocity and color is recorded. A color (density) corresponding to the size is determined, and a blood flow state image 131 is displayed based on the determined color. Similar display control can be performed for the blood flow state images 132 to 134 as well. Further, similar display control can be performed even when blood flow per unit time is applied.

Further, the blood flow state image 131 may be an image expressing the direction of blood flow using colors. The display control unit 12 selects a color corresponding to the direction of blood flow in a predetermined time phase 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. is determined, and a blood flow state image 131 is displayed based on the determined color. Similar display control can be performed for the blood flow state images 132 to 134 as well. Further, similar display control can be performed even when blood flow per unit time is applied.

In a typical example, the blood flow state image 131 may be an image in which the direction of blood flow is expressed by color, and the magnitude of blood flow velocity is expressed by color density. For example, the blood flow from the optic disc to the capillary (i.e. blood flow in the artery) is represented in red, the blood flow from the capillary to the optic disc (i.e. blood flow in the vein) is represented in blue, Further, the lookup table is set such that the color density increases as the blood flow velocity increases. Similar display control can be performed for the blood flow state images 132 to 134 as well. Further, similar display control can be performed even when blood flow per unit time is applied.

(S7: Specify blood vessel)
The user uses the operation unit 50 to specify one of the blood vessels depicted in the morphological image displayed in step S6. This operation is performed, for example, by clicking on a desired blood vessel depicted in 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 specifies the identification information (for example, the above-mentioned position information) of the blood vessel specified in step S7, and reads 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.

An example of the 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. Furthermore, a blood flow graph 140 corresponding to the blood vessel cross-sectional area 132 is displayed on the display device 2 together with the morphological image 120 displayed in step S6.

The blood flow graph 140 represents time-series changes in blood flow in the blood vessel corresponding to the blood vessel cross-sectional area 132. The blood flow graph 140 of this example is expressed 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 a blood flow graph 140 is created based on (time-series) phase images over a 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 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 state image 132.

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

(S9: Observation finished?)
The user can specify other desired blood vessels (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 processing are repeated until observation of data and images regarding the eye to be examined is completed (S9: No). When the observation ends (S9: Yes), the process of this example ends (End).

FIG. 5 shows another example of information that can be displayed in this embodiment. Reference numeral 100 indicates a slider for presenting and setting the time phase of blood flow. The slider 100 includes a handle 110 that is movable along a time axis (bar) indicating a measurement period of OCT blood flow measurement.

Reference numeral 120 is a 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 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 morphological image correspond to each other.

In step S4, a phase image corresponding to the morphological image 120 is formed, and in step S5, blood flow data is generated from this phase image. This blood flow data may be, for example, time-series changes in blood flow velocity or time-series changes in blood flow 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 state of blood flow (blood flow velocity, blood flow volume per unit time, etc.) in the time phase indicated by the slider 100 in (at least) the morphological image 120 corresponding to the blood vessel of interest. Display in position.

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

The display control unit 12 also determines the direction of the 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 the blood flow and the color is recorded. The color corresponding to is determined, and the blood flow state image 131 is displayed based on the determined color. Similar display control can be performed for the blood flow state images 132 to 134 as well. Further, similar display control can be performed even when blood flow per unit time is applied.

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

The display control unit 12 displays a widget 150 that is 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 may be any display mode that makes the position on the time axis indicated by the widget 150 clear. Bye.

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 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 accordance with 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 (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 having different time phases, the time phase indicated by the handle 110 of the slider 100, the time phase indicated by the morphological image, and the time phase indicated by the blood flow state images 131 to 134 are selected. and the time phase indicated by the widget 150 correspond to each other.

Further, in this example, the display control unit 12 displays two widgets (slider 100 and 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 also possible to display three or more widgets. In this case, display control of at least two of the three or more widgets can be performed synchronously according to the time phase of blood flow.

Further, 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 same may apply to the operation of the widget 150.

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 in accordance with the time phase of the blood flow state images 131 to 134. In other words, the display control unit 12 can display the blood flow state images 131 to 134 and the morphological image 120 as a whole 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 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 to 134 (and the morphological image 120).

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 the blood vessel enhanced image acquired 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 (B-scan blood vessel-enhanced image) of the cross section of interest based on data acquired by OCT angiography. form. Further, the display processing unit 12 causes the display device 2 to display this B-scan blood vessel enhanced image as a morphological image (for example, morphological image 120 in FIG. 5).

When a blood vessel enhanced image is displayed together with the morphological image in step S6 of FIG. A blood vessel-enhanced image (frontal blood vessel-enhanced image) is created. An example of a blood vessel emphasized image in a predetermined cross section is a B-scan blood vessel emphasized image in the same cross section as the morphological image (that is, the cross section of interest). Examples of frontal blood vessel-enhanced images include frontal images corresponding to arbitrary depth regions of the fundus (e.g., superficial retina, deep retina, choriocapillary plate, sclera, etc.), and predetermined tissues of the fundus (e.g., inner border). membrane, nerve fiber layer, ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, outer limiting membrane, retinal pigment epithelium, Bruch's membrane, choroid, choroidoscleral border, sclera, these There is a front image corresponding to a portion of any of the above, a combination of at least two or more of these, etc.). Further, 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).

<Ophthalmology information processing device>
An ophthalmological information processing device according to an exemplary embodiment will be described. FIG. 6 shows an example of the configuration of the ophthalmological information processing apparatus of this embodiment. 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. do. Further, the ophthalmological information processing device 200 may be configured to store data acquired using OCT angiography and display information based on this data.

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

The ophthalmological information processing device 200 includes a control section 210, a storage section 220, a data processing section 230, a data input section 240, and an operation section 250. Control section 210 includes a display control section 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 imaging apparatus 1 described above. 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, and the storage unit 220 has the same configuration and function as the storage unit 20. The operating section 250 has the same configuration and function as the operating section 50.

The OCT data 221 may have the same format 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 raw data (3) Intermediate data obtained during a series of processing to generate image data from raw data (4) Image data obtained by processing raw data Blood flow data (5) Intermediate data obtained during a series of processes to generate blood flow data from raw data

The data processing unit 230 performs 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 generate an OCT image (morphological image, phase image, etc.). images, etc.).

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

The data input unit 240 inputs the OCT data 221 and/or its source data into the ophthalmological information processing apparatus 200 from the outside. 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.

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

<Action/Effect>
The operations and effects of the ophthalmologic imaging device and ophthalmologic information processing device according to the exemplary embodiments described above will be described.

The ophthalmologic imaging apparatus (1) according to the 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 eye to be examined. The display processing section causes the display means (display device 2) to display information.

Specifically, the display processing unit displays a fundus morphological image (120) based on the data (OCT data 21) acquired by the data acquisition unit. Furthermore, when any blood vessel depicted in the displayed morphological image is specified using the operation unit, the display processing unit generates a blood flow graph representing time-series changes in blood flow in the specified blood vessel as data. Display is performed based on the data (OCT data 21) acquired by the acquisition unit.

The ophthalmological information processing device (200) according to the embodiment includes a storage section (220), a display processing section (display control section 212, etc.), and an operation section (250). The storage unit stores data (OCT data 221) obtained by applying OCT blood flow measurement to the fundus of the eye to be examined. The display processing section causes the display means (display device 2) to display information.

Specifically, the display processing section displays a fundus morphological image (120) based on the data (OCT data 221) stored in the storage section. Furthermore, when any blood vessel depicted in the displayed morphological image is specified using the operation unit, the display processing unit generates a blood flow graph representing time-series changes in blood flow in the specified blood vessel as data. Display is performed based on the data (OCT data 221) acquired by the acquisition unit.

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

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

According to such a configuration, time-series changes in blood flow velocity and time-series changes in blood flow per unit time can be presented as a graph. Thereby, the user can easily understand the time-series changes in blood flow velocity and the time-series changes in blood flow per unit time.

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

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

In the embodiment, the display processing unit 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 a morphological image.

According to such a configuration, the user can easily understand blood flow dynamics from the morphological image.

Note that the blood flow state image may include an image in which the magnitude of blood flow velocity or the magnitude of blood flow per unit time is expressed 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, so the user can display the magnitude of the blood flow velocity and the magnitude of the blood flow per unit time. The size can be easily grasped.

Further, the blood flow state image may include an image in which the direction of blood flow is expressed in color. According to this configuration, since the direction of blood flow can be presented using color, the user can easily understand the direction of blood flow.

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

According to such a configuration, the user can grasp the distribution of fundus blood vessels in addition to the shape and blood flow dynamics of the fundus.

Note that the display processing unit can, for example, display a blood vessel emphasized 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, or a blood vessel enhanced image formed as a frontal image and a morphological image can be displayed in parallel.

In the ophthalmologic imaging apparatus according to the embodiment, the data acquisition unit (30) may be configured to execute the following series of processes in OCT blood flow measurement: Collect first data by repeatedly scanning one cross-section; collect second data by scanning one or more second cross-sections that intersect the blood vessel in the vicinity of this measurement position; determine the measurement position based on the second data; calculate the inclination angle of the blood vessel; based on the calculated inclination angle and the first data, obtain blood flow data representing time-series changes in blood flow in the blood vessel passing through the first cross section;

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

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

According to such a configuration, not only blood flow data but also a B-scan image can be acquired from data obtained by OCT blood flow measurement. Therefore, it is not necessary to perform an OCT scan for forming a B-scan image separately from OCT blood flow measurement. Furthermore, it is possible to obtain a plurality of B-scan images (time-series B-scan images) according to time-series changes in blood flow conditions.

The functions and effects of the embodiments are not limited to these, and the functions and effects provided by each item described as an embodiment and the functions and effects provided by a combination of multiple items should also be considered. Further, in order to obtain desired functions and/or effects or for other purposes, any of the embodiments described above, other embodiments, known techniques, etc. can be combined as desired.

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

1 Ophthalmology imaging apparatus 2 Display device 10 Control section 11 Scan control section 12 Display control section 20 Storage section 21 OCT data 30 Data acquisition section 31 OCT scanner 32 Image forming section 33 Blood flow data generation section 50 Operation section 120 Morphological images 131, 132 , 133, 134 Blood flow state image 140 Blood flow graph 200 Ophthalmic information processing device 210 Control section 212 Display control section 220 Storage section 221 OCT data 230 Data processing section 240 Data input section 250 Operation section

Claims (3)

a storage unit that stores data obtained by applying optical coherence tomography (OCT) blood flow measurement to the fundus of the eye to be examined;
a display processing unit that displays information on a display means;
The display processing section includes:
Displaying a blood flow graph representing time-series changes in blood flow based on the data,
displaying a first widget movable along a first time axis that is the time axis of the blood flow graph;
displaying a second widget movable along a second time axis indicating a measurement period of the OCT blood flow measurement;
making the position of the first widget with respect to the first time axis correspond to the position of the second widget with respect to the second time axis;
Ophthalmology information processing device. When the second widget is moved along the second time axis, the display processing unit changes the position of the first widget with respect to the first time axis in accordance with the movement of the second widget.
The ophthalmological information processing device according to claim 1. When the first widget is moved along the first time axis, the display processing unit changes the position of the second widget with respect to the second time axis in accordance with the movement of the first widget.
The ophthalmological information processing device according to claim 1 or 2.

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