JP2021183291A - Ophthalmologic information processing device and ophthalmologic imaging device - Google Patents

Abstract

To provide a new display mode of information acquired by OCT blood flow measurement.SOLUTION: An ophthalmologic information processing device in an embodiment includes a storage part and a display processing part. The storage part stores data acquired by applying OCT blood flow measurement to the ocular fundus of an eye to be examined. The display processing part executes processing for displaying a form image of the ocular fundus on the basis of the data stored in the storage part, processing for displaying a blood flow graph indicating a time series change of a blood flow in an attention blood vessel, which is any one blood vessel visualized in the form image, on the basis of the data, processing for displaying a slider for presenting and setting a time phase of the blood flow, and processing for displaying a blood flow state image indicating a state of the blood flow in the time phase indicated by the slider at a position in the form image corresponding to the attention blood vessel.SELECTED DRAWING: Figure 5

Description

The embodiment relates to an ophthalmologic information processing apparatus and an ophthalmologic imaging apparatus.

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

Further, it is also performed to acquire an image emphasizing a specific part of the eye to be inspected and to acquire functional information. For example, based on the time-series data collected by OCT, a B-scan image or anterior image (called a blood vessel-enhanced image, angiogram, etc.) in which the 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 acquired based on the phase information of the time series data collected by OCT. This technique is called OCT blood flow measurement or the like.

Japanese Patent Publication No. 2015-515894 Japanese Unexamined Patent Publication No. 2013-184018

An object of the embodiment is to provide a novel display mode of information obtained by OCT blood flow measurement.

The ophthalmic information processing apparatus of the embodiment includes a storage unit and a display processing unit. The storage unit stores data acquired by applying OCT blood flow measurement to the fundus of the eye to be inspected. The display processing unit displays a process of displaying a morphological image of the fundus based on the data stored in the storage unit, and represents a time-series change in blood flow in a blood vessel of interest, which is one of the blood vessels depicted in this morphological image. The process of displaying the blood flow graph based on the data, the process of displaying the slider for presenting and setting the time phase of blood flow, and the blood flow state image showing the state of blood flow in the time phase indicated by the slider. The process of displaying at the position in the morphological image corresponding to the blood vessel of interest is executed.

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

It is a schematic diagram which shows an example of the structure of the ophthalmologic imaging apparatus which concerns on an exemplary embodiment. It is a schematic diagram for demonstrating an example of the process performed by the ophthalmologic imaging apparatus which concerns on an exemplary embodiment. It is a flowchart which shows an example of the operation of the ophthalmologic imaging apparatus which concerns on an exemplary embodiment. It is a schematic diagram for demonstrating an example of the process performed by the ophthalmologic imaging apparatus which concerns on an exemplary embodiment. It is a schematic diagram for demonstrating an example of the process performed by the ophthalmologic imaging apparatus which concerns on an exemplary embodiment. It is a schematic diagram for demonstrating an example of the process performed by the ophthalmologic imaging apparatus which concerns on an exemplary embodiment. It is a schematic diagram which shows an example of the structure of the ophthalmic information processing apparatus which concerns on an exemplary embodiment.

An exemplary embodiment of the present invention will be described with reference to the drawings. It should be noted that any known technique including the disclosure items of the documents cited in this specification can be combined with the embodiment.

The ophthalmologic information processing apparatus and the ophthalmologic imaging apparatus according to the embodiment have a function of displaying various information based on the data acquired by applying OCT to the fundus of the eye to be inspected. The ophthalmic information processing apparatus according to the embodiment receives, for example, data acquired by applying OCT to the fundus of the eye to be inspected by an OCT apparatus separately provided, and displays various information based on the data. On the other hand, the ophthalmologic imaging apparatus according to the embodiment applies OCT to the fundus of the eye to be inspected to acquire data, and displays various information based on the data.

The data (fundus OCT data) acquired by applying OCT to the fundus of the eye to be inspected may be any form of data. For example, the fundus OCT data may include any one or more of the following (1) to (5).
(1) Data collected by OCT scan of the fundus (raw data)
(2) Image data obtained by processing raw data (3) Intermediate data obtained in the middle of 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 type of fundus OCT data is not limited to these. In addition, the embodiment can process various information associated with the fundus OCT data. Examples of such information include subject identification information, eye identification information, identification information indicating whether the eye to be examined is the left eye or the right eye, shooting date and time, shooting conditions, and the like.

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

The ophthalmologic imaging apparatus of the embodiment is configured to be capable of performing, for example, a Fourier domain OCT. The Fourier domain OCT includes a spectral domain OCT and a 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 wideband low coherence light source and a spectroscope, and Fourier transforming the spectrum. Swept Source OCT uses a wavelength sweep light source (wavelength variable light source) and a photodetector (balanced photodiode, etc.) to acquire the spectrum of interference light in time divisions and construct an image by Fourier transforming it. It is a method to do. The method of OCT is not limited to Fourier domain OCT, and may be time domain OCT or EN FACE OCT.

The ophthalmologic information processing apparatus and ophthalmologic imaging apparatus according to the embodiment may include a modality for imaging the eye and / or other parts (for example, a modality other than OCT). Typical examples thereof include a fundus camera, a scanning laser ophthalmoscope (SLO), a slit lamp microscope, and a microscope for ophthalmic surgery. Further, the ophthalmologic information processing apparatus and the ophthalmologic imaging apparatus according to the embodiment may include a configuration for measuring the characteristics of the eye and / or other parts, and a configuration for performing an examination.

The data processing functions (calculation function, image processing function, control function, etc.) in the ophthalmic information processing apparatus and the ophthalmologic imaging apparatus according to the embodiment include, for example, hardware such as a processor and a storage device, an arithmetic program, an image processing program, and control. It is realized by cooperating with software such as programs. A part of the hardware may be provided in an external device capable of communicating with the ophthalmologic information processing apparatus or the ophthalmologic imaging apparatus according to the embodiment. Further, at least a part of the software may be stored in advance in the ophthalmologic information processing device or the ophthalmologic imaging device according to the embodiment, and / or may be stored in advance in an external device.

<Ophthalmology imaging device>
<composition>
An ophthalmologic imaging apparatus according to an exemplary embodiment will be described. FIG. 1 shows a configuration example of the ophthalmologic imaging apparatus of this embodiment. The ophthalmologic imaging apparatus 1 collects data on the fundus using OCT, generates a fundus morphology 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 the present embodiment, the fundus morphology image is an image in which at least the fundus blood vessels (retinal blood vessels, choroidal blood vessels, etc.) are visually identifiable. Examples of fundus morphological images include B-scan images, C-scan images, projection images, shadowgrams, phase images, blood vessel-enhanced images, and the like. 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 blood flow direction, blood flow velocity, time-series changes in blood flow velocity, blood flow, blood flow per unit time, time-series changes in blood flow per unit time, and total blood flow. ..

In this embodiment, both the morphological image and the blood flow data are formed based on the data obtained by applying the OCT blood flow measurement to the fundus. It should be noted that the OCT scan (for example, B scan, three-dimensional scan) for acquiring the morphological image and the OCT scan (OCT blood flow measurement) for acquiring the blood flow data may be executed separately. .. Further, an OCT scan for acquiring data other than these may be executed. For example, OCT angiography can be performed.

A part of the data used for displaying the information may be acquired by another device. For example, one of the fundus morphology image and the fundus blood flow data may be acquired by another device. Alternatively, another device may perform OCT angiography to obtain a vessel-enhanced image. The data acquired by the other device is input to the ophthalmologic imaging device according to the embodiment.

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

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

<Control unit 10>
The control unit 10 controls each unit of the ophthalmologic imaging apparatus 1. The control unit 10 includes a processor. The "processor" is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (for example, a SPLD (Simple , FPGA (Field Programgular Gate Array)) and the like. The control unit 10 can realize the function according to the embodiment by reading and executing a program stored in a storage circuit or a storage device (storage unit 20, an external device, etc.), for example.

Further, the control unit 10 may include a communication device for transmitting / 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 can 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, change the fixation position, and so on. Control the various elements involved. 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 the data stored in the storage unit 20.

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

<Memory unit 20>
Various data are stored in the storage unit 20. In this example, the OCT data 21 is stored in the storage unit 20. It should be noted that at least a part of the OCT data may be stored in an external storage device and provided to the ophthalmologic imaging device 1 as required. 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 above-mentioned fundus OCT data (1) to (5). Typically, the ophthalmologic imaging apparatus 1 generates a morphological image and blood flow data from the raw data collected by the OCT scan of the fundus, and stores the OCT data 21 including these in the storage unit 20. In other words, in a typical example, the fundus OCT data (2) and (4) described above are included in the OCT data 21.

<Data acquisition unit 30>
The data acquisition unit 30 applies OCT to the fundus of the eye to be inspected to acquire data (for example, at least a part of the OCT data 21 stored in the storage unit 20). As described above, the data acquisition unit 30 includes an OCT scanner 31, an image forming unit 32, and a blood flow data generation unit 33. The image forming unit 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 executes an OCT scan of the fundus under the control of the scan control unit 11. As a result, fundus data (raw data) is collected. The OCT scanner 31 includes a configuration for performing optical interference measurement using, for example, a spectral domain OCT or a swept source OCT. Such an OCT scanner 31 includes an OCT optical system, a drive system, a data collection system (DAQ), a control system, and the like, 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 divides the light output from the light source into measurement light and reference light, projects this 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 galvano scanner or the like and deflects the measurement light. As a result, the projection position of the measured light with respect to the fundus is moved. The photodetector detects (spectrum) the interfering light generated by the interfering optical system.

The drive system moves and operates the elements contained in the OCT optical system. The data collection system collects the detection results obtained sequentially by the OCT optical system. The control system controls the OCT optical system, the drive system, the data collection system, and the like 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 and collects 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, a line scan (B scan). This line scan is, for example, repeated at a predetermined frequency. The data collected by such repeated scanning is sent to the image forming unit 32.

In the OCT blood flow measurement, the OCT scanner 31 further performs a scan for obtaining 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 arranged in the vicinity of the cross section of interest.

In addition, one of the two cross sections for obtaining the inclination angle of the blood vessel of interest may be the cross section of interest itself. The other cross section is set in the vicinity of the cross section of interest. In this case, the data obtained by the repeated scanning of the above-mentioned cross section of interest can be used to calculate the inclination angle.

In summary, typically, the scan performed in the OCT blood flow measurement may be a combination of a repetitive scan of the section of interest and a scan of the other two sections, or a repetitive scan of the section of interest and another section. It may be combined with the scan of.

The mode of scanning for determining the tilt angle of the blood vessel of interest in the cross section of interest is not limited to these. For example, it is possible to scan three or more cross sections. Alternatively, it is possible to scan a three-dimensional region including a cross section of interest (three-dimensional scan). As another example, a cross section that intersects the cross section of interest and along the blood vessel of interest can be scanned. The OCT blood flow measurement will be described in detail in the description of the blood flow data generation unit 33.

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 executed so as to scan each of the plurality of B cross sections (B scan surface) a predetermined number of times (for example, four times each). In other words, this raster scan is performed so as to sequentially scan a plurality of B cross sections at 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 unit 32.

The form of scanning that can be performed by the OCT scanner 31 is not limited to the above-mentioned aspect. For example, the OCT scanner 31 can perform a line scan, a circle scan, a radial scan, a three-dimensional scan, or the like as an OCT scan for acquiring a morphological image.

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

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 repeated scans 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 the stack data. In this volume data, a number of voxel groups corresponding to the number of repeated scans are assigned to the positions corresponding to each B cross section.

The image forming unit 32 renders the stack data or the volume data to form a B-scan image (vertical cross-sectional image, axial cross-sectional image), a C-scan image (cross-sectional image, horizontal cross-sectional image), a projection image, and a shadow gram. 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 designated cross section from a three-dimensional data set. Alternatively, an image of an arbitrary cross section is formed by projecting a slice of a preset thickness in the thickness direction.

The projection image is formed by projecting stack data or volume data in a predetermined direction (Z direction, depth direction, A scan direction). The shadow gram is formed by projecting a part of stack data or volume data (for example, partial data corresponding to a specific layer) in a predetermined direction. A fundus image with the corneal side of the eye to be inspected as a viewpoint, such as a C-scan image, a projection image, and a shadow gram, is called a frontal image.

The image forming unit 32 can execute various image processes in addition to rendering. For example, there are segmentation for finding a specific tissue or tissue boundary, and size analysis for finding the size (layer thickness, volume, etc.) of the tissue. When a specific layer (or a specific layer boundary) is obtained 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. The blood vessel-enhanced image is an image in which an image region (blood vessel region) corresponding to a blood vessel is specified by analyzing OCT data, and the expression mode of this blood vessel region is changed to emphasize it. A plurality of OCT data obtained by repeatedly scanning substantially the same area of the eye to be inspected are used to identify the blood vessel region.

The blood vessel-enhanced image represents, for example, the distribution of blood vessels (that is, the three-dimensional distribution of blood vessels) in the three-dimensional region of the fundus scanned by OCT. There are several types of techniques for forming blood vessel-enhanced images. A typical method for that is explained. For this process, a three-dimensional data set containing a plurality of B-scan images arranged in chronological order for each B-section is used by repeatedly scanning each of the plurality of B-sections of the eye to be inspected. It should be noted that there are fixation and tracking as a method for repeatedly scanning substantially the same B cross section.

In the process of forming the blood vessel-enhanced image, first, the alignment of a plurality of B-scan images is executed for each B cross section. This alignment is performed, for example, using a known image matching technique. As a typical example thereof, extraction of a feature region in each B-scan image and alignment of a plurality of B-scan images by alignment of the extracted plurality of feature regions can be executed.

Subsequently, a process of identifying an image region that is changing among the plurality of aligned B-scan images is performed. This process includes, for example, a process of obtaining a difference between different B-scan images. Each B-scan image is luminance image data representing the morphology of the eye to be inspected, and it is considered that the image region corresponding to the portion other than the blood vessel is substantially unchanged. On the other hand, considering that the backscatter that contributes to the interference signal changes randomly due to the blood flow, the image region in which the change occurs between the plurality of aligned B-scan images (for example, pixels having a 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.

The image region thus identified is assigned information indicating that it is a blood vessel region. By performing the above processing on a plurality of B cross sections, a three-dimensionally distributed blood vessel region can be obtained. By rendering such a three-dimensional blood vessel-enhanced image, a front image showing the blood vessel distribution, an image of an arbitrary cross section, a shadow gram of an arbitrary range, and the like are generated.

The process of forming a blood vessel-enhanced image is not limited to this. For example, it is possible to specify the blood vessel region by a conventional method using Doppler OCT, or to specify the blood vessel region by using a conventional image processing method. In addition, it is possible to specify the blood vessel region for each site by using different methods depending on the site. For example, for the retina, the vascular region can be specified by using the above-mentioned typical method or the Doppler OCT method, and for the choroid, the vascular region can be specified by using the 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 is based on the image of the 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 section of interest. Generates blood flow data representing the blood flow state in the blood vessel of interest.

The data collected by the OCT scanner 31 in the OCT blood flow measurement is different from the data (first data) collected by repeatedly scanning the cross section of interest that intersects the blood vessel of interest and that intersects the blood vessel of interest. It includes data (second data) obtained by scanning one or more cross sections (cross sections in the vicinity of the cross section of interest). 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 in the vicinity thereof, 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 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 the data collected by the OCT scanner 31 in the OCT blood flow measurement. The morphological image and the 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 a typical OCT blood flow measurement, two types of scans (auxiliary scan and main scan) are performed on the fundus. The auxiliary scan is performed to scan one or more cross sections (cross sections in the vicinity of the cross section of interest) different from the cross section of interest to collect second data. In a typical auxiliary scan, two or more cross sections intersecting the blood vessel of interest are scanned with measurement light. The data obtained by the auxiliary scan is used to determine the tilt angle of the blood vessel of interest in the cross section of interest. On the other hand, this scan is performed to collect the first data by repeatedly scanning the cross section of interest intersecting the blood vessel of interest with the measurement light. The section on which the auxiliary scan is performed is placed in the vicinity of the section of interest. This scan is a Doppler measurement using OCT.

The target cross sections of the auxiliary scan and the main scan are oriented so as to be orthogonal to the traveling direction of the blood vessel of interest, for example. Further, 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 inspection. 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 in or near the cross section of interest and the inspection accuracy. In addition, the user may set a desired distance between cross sections.

It is desirable that this scan be performed over at least one cardiac cycle of the patient's heart. Thereby, blood flow data at all time phases of the heartbeat can be obtained. The execution time of this scan may be a preset fixed time, or may be a preset time for each patient or each examination.

The image forming unit 32 has, for example, a cross-sectional image showing the morphology of the first auxiliary cross section and a second auxiliary based on the data collected by the auxiliary scan for the two auxiliary sections set in the vicinity of the section of interest. A cross-sectional image representing the morphology of the cross-section is formed. At this time, it is possible to improve the image quality by using a technique such as addition averaging, or to select the optimum one from two or more cross-sectional images of each auxiliary cross-section.

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

The processing executed by the image forming unit 32 includes, for example, noise removal (noise reduction), filter processing, fast Fourier transform (FFT), and the like, as in the conventional OCT technique. The process of forming the 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.

Further, the image forming unit 32 forms a phase image showing the time-series change of the phase difference in the cross section of interest based on the data collected by this scan for the cross section of interest. The data used for this process is the same as the data used to form a 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 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 for each pixel of the cross-sectional image of the cross section of interest based on the time-series change of the pixel value (luminance value) of the pixel. 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 a phase difference Δφ between two time points 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 the time point t1 (more generally, any time point between the two time points 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 in the pixel can be obtained.

The phase image represents the value of the phase difference at each time point of each pixel as an image. This imaging process can be realized, for example, by expressing the value of the phase difference by the display color or the brightness. At this time, the color indicating that the phase has increased along the time series (for example, red) and the color indicating that the phase has decreased (for example, blue) can be different. In addition, the magnitude of the amount of change in phase can be expressed by the depth of the display color. By adopting such an expression method, it becomes possible to express the direction and size of blood flow by color and density. 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 ensure the phase correlation. At this time, in scanning the measurement light, oversampling is executed in which the time interval Δt is set to a value less than the time corresponding to the resolution of the cross-sectional image.

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 may include, 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 specifying process, the blood flow data generation unit 33 identifies the 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 corresponding to the cross section of interest. The blood vessel region is specified by analyzing the pixel value of each image (for example, 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 the cross-sectional image and the phase image.

In the tilt angle calculation process, the blood flow data generation unit 33 calculates the tilt 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 tilt angle calculation process will be described. See FIG. Reference numeral B0 indicates a cross-sectional image (attention cross-sectional image) in the cross-sectional area of interest in which the blood vessel inclination angle is calculated. The blood vessel region V0 is depicted in the cross-sectional image B0 of interest. Reference numerals B11 and B12 indicate two cross-sectional images (auxiliary cross-sectional images) in two auxiliary cross-sections located in the vicinity of the section of interest B0. In the auxiliary cross-sectional image B11, the blood vessel region V11 in the auxiliary cross-section B11 of the same blood vessel (attention blood vessel) as the blood vessel region V0 is visualized. Similarly, the auxiliary cross-sectional image B12 depicts the 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. 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 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 the cross sections. The cross-sectional distance may be the distance between the auxiliary cross-sectional image B11 and the auxiliary cross-sectional image B12. Alternatively, the intersection distance may be defined by at least one of the distance between the auxiliary section image B11 and the attention section image B0 and the distance between the auxiliary section image B12 and the attention section image B0. good. Let L be the distance between the auxiliary cross-sectional image B11 (or B12) and the attention cross-sectional image B0.

The A-scan direction (direction pointed by the arrow pointing downward) shown in FIG. 2 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 inclination A of the blood vessel of interest in the cross section of interest based on the positional relationship of the three blood vessel regions V0, V11 and V12. This positional relationship is obtained, for example, by connecting three vascular regions V0, V11 and V12. More specifically, the blood flow data generation unit 33 identifies the 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 a method of connecting these feature points, there are a method of connecting with a line segment, a method of connecting with an approximate curve (spline curve, Bezier curve, etc.) and the like.

Further, 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 is, for example, a first line segment connecting a feature point of the blood vessel region V0 in the attention section image B0 and a feature point of the blood vessel region V11 in the auxiliary cross section 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 the two line segments can be obtained. Further, as an example of connecting with an approximate curve, the slope of the approximate curve at the intersection position of the approximate curve and the cross section of interest can be obtained.

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

Further, although only one value of the inclination A is obtained in the above example, the inclination may be obtained for each of two or more positions (or regions) in the blood vessel region V0. In this case, the obtained two or more 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 relates to the blood vessel of interest based on the phase image formed based on this scan (Doppler OCT) and the inclination 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 in 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 a 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 in a predetermined time phase of an electrocardiogram (for example, the time phase of an R wave). Also, the time range in the latter is the entire or arbitrary part of the time taken to scan the section of interest.

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 time range. The statistics include mean, standard deviation, variance, median, maximum, minimum, maximum, and minimum. It is also possible to create a histogram of the value of blood flow velocity.

The blood flow data generation unit 33 can calculate the blood flow velocity by 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 flow velocity)
θ: The angle (inclination angle) formed by the incident direction of the measured light and the flow direction 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 measured light are known, the Doppler shift Δf is obtained from the time-series change of the phase difference, and the tilt angle θ is the tilt angle calculation process or the 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. As an example of this calculation method, there are a first calculation method using a frontal image of the fundus and a second calculation method using a cross-sectional image.

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

The blood flow data generation unit 33 is based on various factors that determine the relationship between the scale on the image and the scale in the real space, such as the shooting angle of view (shooting 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 associates the spacing between adjacent pixels with the scale in real space (for example, the spacing between pixels = 10 μm). It is also possible to calculate in advance the relationship between various values of the above factors and the scale in real space, and store information expressing this relationship in a table format or a graph format. In this case, the scale corresponding to the above factor 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 obtain the maximum value and the average value of the diameters of the blood vessel regions 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 the ellipse. Since the area of the blood vessel region can be determined (substantially) once the blood vessel diameter is determined, the area may be calculated instead of obtaining the blood vessel diameter.

The second calculation method will be described. In the second calculation method, a cross-sectional image of the fundus in the cross section of interest is used. This cross-sectional image may be a cross-sectional image based on this scan, or may be obtained separately. 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. The blood flow data generation unit 33 can obtain, for example, the distance between adjacent pixels based on the length of the cross section of interest, and can 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 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 calculation result of the blood flow velocity and the calculation result of the blood vessel diameter. An example of this process will be described below.

It is assumed that the blood flow in the blood vessel is Hagen-Poiseuille flow. Further, the blood vessel diameter is w, and the maximum value of blood flow velocity is Vm. In this case, the blood flow rate Q is expressed 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 of the blood flow velocity obtained by the blood flow velocity calculation process into the above relational expression, thereby causing the blood flow volume. Q can be calculated.

<Operation unit 50>
The operation unit 50 is used for the user to input an instruction to the ophthalmologic photographing apparatus 1. The operation unit 50 may include a known operation device used in an ophthalmic device or a computer. For example, the operation unit 50 may include a mouse, a touch pad, a trackball, a keyboard, a pen tablet, an operation panel, a joystick, a button, a switch, 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 process for acquiring the front image is optional. 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 eye to be inspected from an external device. For example, the front image acquisition unit 60 may include a communication device for transmitting / receiving data via a communication line such as a LAN, the Internet, or a dedicated line. In this case, the front image acquisition unit 60 can acquire, for example, the front image of the fundus of the eye to be inspected stored in the electronic medical record system or the image archiving system, using the patient ID, DICOM tag, or the like as a search query.

In the third example, the front image acquisition unit 60 may include a processor that forms a front image by OCT. The OCT front image includes a C scan image, a projection image, a shadow gram, and the like.

<motion>
An example of the operation of the ophthalmologic imaging apparatus 1 according to the present embodiment will be described. FIG. 3 shows an example of the operation of the ophthalmologic imaging apparatus 1. Preparatory processing such as input of patient ID, alignment of optical system with respect to the eye to be inspected, focus adjustment of optical system, adjustment of OCT optical path length, adjustment of fixation position, setting of OCT scan range, etc. has already been performed. And.

(S1: Perform OCT blood flow measurement of the fundus)
The ophthalmologic imaging apparatus 1 performs OCT blood flow measurement on a cross section of interest of a blood vessel of interest in the fundus of the eye to be inspected. OCT blood flow measurement is performed for each of one or more 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 a part of these blood vessels can be designated as the blood vessel of interest. Conversely, the cross section of interest can be set to cross a plurality of blood vessels of interest.

In the OCT blood flow measurement, the scan control unit 11 controls the light source and the optical scanner included in the OCT scanner 31. Under the control of the scan control unit 11, the OCT scanner 31 repeatedly scans the first cross section intersecting the blood vessel of interest at a preset measurement position (that is, the cross section of interest) to collect the first data, and further, 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 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 as the number of repeated scans can be formed. As a result, a time-series B-scan image corresponding to the cross section of interest can be obtained. It should be noted that the number of morphological images may be formed to be smaller than the number of repeated scans.

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 OCT data 21.

(S3: Find the tilt angle of the blood vessel of interest)
The blood flow data generation unit 33 obtains 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. For this process, 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 OCT data 21.

(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 blood vessel of interest. As an example of such data, a time-series change in blood flow velocity during the measurement period of OCT blood flow measurement performed in step S1 (typically, a period having a length of one cardiac cycle or more) and the measurement period. There is a time-series change in blood flow per unit time in.

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

(S6: Display a 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, a 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 blood vessel-enhanced image. Further, the displayed morphological image may be a phase image formed in step S4.

The displayed morphological image may include a blood flow state image synthesized in the blood vessel cross-sectional region in this B-scan image. The blood flow state image will be described later. The blood vessel cross-section region in the B-scan image is a region corresponding to the cross-section of the blood vessel (blood vessel of interest), and is specified by, for example, 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 performs the following series of processes: a process of analyzing a phase image to identify a blood vessel cross section region; a B scan image and a phase image of a cross section of interest. A process of identifying an image region in a B-scan image corresponding to a blood vessel cross-sectional region in a phase image using the obvious registration between and. Alternatively, the blood vessel cross-sectional region 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 the blood flow state images 131, 132, 133, and 134 at positions in the morphological image 120 corresponding to these four blood vessels, respectively. 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 the blood flow velocity is expressed in color. The display control unit 12 refers to a default look-up 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 velocity in a predetermined time phase is recorded. 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 performed for the blood flow state images 132 to 134. Further, the same display control can be executed even when the blood flow rate per unit time is applied.

Further, the blood flow state image 131 may be an image expressing the direction of blood flow in color. The display control unit 12 refers to a default look-up table (color map, etc.) in which the relationship between the direction of blood flow and the color is recorded, and the color corresponding to the direction of blood flow in a predetermined time phase. Is obtained, and the blood flow state image 131 is displayed based on the obtained color. Similar display control can be performed for the blood flow state images 132 to 134. Further, the same display control can be executed even when the blood flow rate 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 nerve papilla to the capillaries (that is, the blood flow in the artery) is expressed in red, and the blood flow from the capillaries to the optic nerve papilla (that is, the blood flow in the vein) is expressed in blue. Further, the lookup table is set so 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. Further, the same display control can be executed even when the blood flow rate per unit time is applied.

(S7: Specify a blood vessel)
The user designates one of the blood vessels drawn in the morphological image displayed in step S6 by using the operation unit 50. 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 identifies the blood vessel identification information (for example, the above-mentioned position information) designated in step S7, and reads out the blood flow data corresponding to the specified position information from the storage unit 20. Further, 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. It is assumed that the blood vessel corresponding to the blood flow state image 132 is designated in step S7. The display control unit 12 changes the display mode of the blood flow state image 132. That is, the blood flow state image 132 is displayed in a mode different from the blood flow state images 131, 133 and 134. Further, the display device 2 displays the blood flow graph 140 corresponding to the blood vessel cross-sectional region 132 together with the morphological image 120 displayed in step S6.

The blood flow graph 140 represents a time-series change in blood flow in the blood vessel corresponding to the blood vessel cross-sectional region 132. The blood flow graph 140 of this example is represented by a two-dimensional Cartesian 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 a (time series) phase image over the measurement period of the 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 or the like). It may be a statistic. This statistic may be, for example, an average value, a maximum value, a 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, a pixel located at the center, a 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 in which the horizontal axis indicates time and the vertical axis indicates blood flow rate per unit time can be displayed.

(S9: End of observation?)
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 designated blood vessel. Two or more blood vessels can be specified. In that case, two or more blood flow graphs corresponding to two or more designated blood vessels can be displayed in parallel. Such operations and processes are repeated until the observation of the data or the image of the eye to be inspected is completed (S9: No). When the observation is completed (S9: Yes), the processing of this example is completed (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 can be moved 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 images corresponding to the time phase actually presented by the slider 100. That is, the position (time phase) of the handle 110 of the slider 100 and the time phase shown in 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, a time-series change in blood flow velocity or a time-series change in blood flow per unit time. In the example shown in FIG. 5, the time-series change of the blood flow velocity (v) is adopted.

The display control unit 12 displays a blood flow state image showing the blood flow state (blood flow velocity, blood flow volume per unit time, etc.) in the time phase indicated by the slider 100 in the morphological image 120 corresponding to (at least) the blood vessel of interest. Display at the 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 the four blood vessels, respectively. The display control unit 12 refers to a default look-up table (color map, density map, etc.) in which the relationship between the magnitude of the blood flow velocity and the color is recorded, and the blood flow in the time phase indicated by the slider 100. A color (density) corresponding to the magnitude of the velocity is obtained, and the blood flow state image 131 is displayed based on the obtained color. Similar display control can be performed for the blood flow state images 132 to 134. Further, the same display control can be executed even when the blood flow rate per unit time is applied.

Further, the display control unit 12 refers to a default look-up table (color map or the like) in which the relationship between the direction of blood flow and the color is recorded, and thereby, the direction of blood flow in the time phase indicated by the slider 100. The color corresponding to is obtained, and the blood flow state image 131 is displayed based on the obtained color. Similar display control can be performed for the blood flow state images 132 to 134. Further, the same display control can be executed even when the blood flow rate per unit time is applied.

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

The display control unit 12 displays a widget 150) that can be moved 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 the display mode may be such that the position on the time axis indicated by the widget 150 is clear. Just do it.

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. On the contrary, 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 of the handle 110 (time phase) 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. Further, when a plurality of morphological images having different time phases are selectively displayed, the time phase indicated by the handle 110 of the slider 100, the time phase indicated by the morphological image, and 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.

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

Further, the operation of the slider 100 is performed by, for example, dragging the handle 110 using a pointing device (mouse or the like) included in the operation unit 50. The same may be applied 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 corresponding to the time phase of the blood flow state images 131 to 134. That is, the display control unit 12 can display the entire blood flow state images 131 to 134 and the morphological image 120 as a moving image.

Further, the display control unit 12 sets 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) as a blood flow state image as a moving image. It can be changed in synchronization with 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 display the blood vessel-enhanced image acquired by OCT angiography on the display device 2. The blood vessel-enhanced image is displayed together with the morphological image, for example, in step S6 of FIG. Alternatively, the blood vessel-enhanced image is displayed as the morphological image of step S6 in FIG.

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

When the blood vessel-enhanced image is displayed together with the morphological image of step S6 of FIG. 3, for example, the image forming unit 32 has a blood vessel-enhanced image or a frontal image in a predetermined cross section based on the data acquired by OCT angiography. 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, there is a B-scan blood vessel-enhanced image in the same cross section as the morphological image (that is, a cross section of interest). Examples of anterior anterior vessel-enhanced images include anterior images corresponding to any depth region of the fundus (eg, superficial retina, deep retina, choroidal capillary plate, strong membrane, etc.) and predetermined tissue of the fundus (eg, inner border). Membrane, ganglion cell layer, ganglion cell layer, inner reticular layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, outer border membrane, retinal pigment epithelium, Bruch's membrane, choroid, choroidal choroid border, strong membrane, these There is a frontal image corresponding to any part, at least two or more combinations 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 of FIG. 5).

<Ophthalmology information processing device>
An ophthalmic information processing apparatus according to an exemplary embodiment will be described. FIG. 6 shows a configuration example of the ophthalmic information processing apparatus of this embodiment. The ophthalmic information processing apparatus 200 stores the data of the fundus acquired by using the OCT blood flow measurement, generates the fundus morphology image and the 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 acquired by using OCT angiography and display information based on this data.

The ophthalmology information processing apparatus 200 can display various information such as a fundus morphology image, blood flow information, and blood vessel enhancement image on the display device 2. The display device 2 may be a part of the ophthalmic information processing device 200, or may be an external device connected to the ophthalmic information processing device 200. Further, the ophthalmology information processing device 200 can send various information to a computer, a storage device, an ophthalmology device, and the like.

The ophthalmic 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. The 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 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. It has a function, and the operation unit 250 has the same configuration and function as the operation unit 50.

The OCT data 221 may be data having the same form as the OCT data 21. For example, the OCT data 221 may include any one or more of the following (1) to (5).
(1) Data collected by OCT scan of the fundus (raw data)
(2) Image data obtained by processing raw data (3) Intermediate data obtained in the middle of 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 unit 230 may have the same configuration and function as the image forming unit 32. For example, when the OCT data 221 includes at least one of the above OCT data (1) and (3), the data processing unit 230 performs the same processing as the image forming unit 32 to perform an OCT image (morphological image, phase). Images etc.) can be formed.

The data processing unit 230 may have the same configuration and function as the blood flow data generation unit 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 processing as the blood flow data generation unit 33 to perform blood flow. 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 original data to the ophthalmic 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 execute control for displaying the same information as at least one of FIGS. 4A, 4B, and 5 on the display device 2.

<Action / effect>
The operation and effect of the ophthalmologic photographing apparatus and the ophthalmologic information processing apparatus according to the above-described exemplary embodiment will be described.

The ophthalmologic imaging apparatus (1) according to the embodiment includes a data acquisition unit (30), a display processing unit (display control unit 12, etc.), and an operation unit (50). The data acquisition unit acquires data by applying at least OCT blood flow measurement to the fundus of the eye to be inspected. The display processing unit causes the display means (display device 2) to display the information.

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

The ophthalmic information processing apparatus (200) according to the embodiment includes a storage unit (220), a display processing unit (display control unit 212, etc.), 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 eye to be inspected. The display processing unit causes the display means (display device 2) to display the information.

Specifically, the display processing unit displays the morphological image (120) of the fundus based on the data (OCT data 221) stored in the storage unit. Further, when any of the blood vessels depicted in the displayed morphological image is designated by using the operation unit, the display processing unit displays a blood flow graph showing the time-series change of blood flow in the designated blood vessel. It is displayed 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 by the morphological image. Further, the ophthalmologic imaging apparatus (1) or the ophthalmology information processing apparatus (200) can display a blood flow graph corresponding to a blood vessel designated 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 embodiments, the blood flow graph may be configured to be represented by a two-dimensional Cartesian 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, the time-series change of the blood flow velocity and the time-series change of the blood flow rate per unit time can be presented as a graph. As a result, the user can easily grasp the time-series change of the blood flow velocity and the time-series change of the blood flow rate 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 cross section while observing the morphology and / or the phase state of the B cross section of the fundus.

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

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

The blood flow state image may include an image in which the magnitude of the blood flow velocity or the magnitude of the blood flow volume per unit time is expressed 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 by using colors, so that the user can present 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 expressing the direction of blood flow in color. According to this configuration, the direction of the blood flow can be presented by using the color, so that the user can easily grasp the direction of the blood flow.

At least one of the ophthalmologic imaging apparatus and the ophthalmologic information processing apparatus according to the embodiment can handle the 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 so that data can be acquired 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 the data acquired by applying OCT angiography to the fundus. Further, the display processing unit of the ophthalmologic imaging apparatus and / or the ophthalmologic information processing apparatus may be configured to display a blood vessel-enhanced image based on the data acquired by OCT angiography.

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

The display processing unit can display, for example, a blood vessel-enhanced image formed as a B-scan image as a morphological image, 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 and a morphological image formed as a frontal image can 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: a first crossing a blood vessel at a preset measurement position. Repeatedly scan one section to collect first data; scan one or more second sections that intersect the blood vessel in the vicinity of this measurement position to collect second data; measurement position based on the second data. Calculate the tilt angle of the blood vessel in the blood vessel; based on the calculated tilt angle and the first data, the blood flow data representing the time-series change of the blood vessel in the blood vessel passing through the first cross section is acquired.

According to such a configuration, OCT blood flow measurement can be suitably performed to generate blood flow data, and a blood flow graph or a blood flow state image can be displayed based on the 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 the first data collected by the repeated scan of the first cross section. Can be done.

According to such a configuration, not only the blood flow data but also the B scan image can be acquired from the data obtained by the OCT blood flow measurement. Therefore, it is not necessary to perform the OCT scan for forming the 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) according to the time-series changes in the blood flow state.

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

The configuration described above is only an example for preferably carrying out the present invention. Therefore, any modification (omission, substitution, addition, etc.) within the scope of the gist of the present invention can be appropriately applied.

1 Ophthalmic imaging device 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 formation unit 33 Blood flow data generation unit 50 Operation unit 120 Morphological images 131, 132 133, 134 Blood flow status image 140 Blood flow graph 200 Ophthalmology information processing device 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 (5)

A storage unit that stores data acquired by applying optical coherence tomography (OCT) blood flow measurement to the fundus of the eye to be inspected,
Including a display processing unit that displays information on the display means,
The display processing unit is
Based on the data, the morphological image of the fundus is displayed.
A blood flow graph showing 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, is displayed based on the data.
Display a slider for presenting and setting the time phase of blood flow,
A blood flow state image showing the state of blood flow in the time phase indicated by the slider is displayed at a position in the morphological image corresponding to the blood vessel of interest.
Ophthalmic information processing device. The blood flow state indicated by the blood flow state image is at least one of blood flow velocity and blood flow volume per unit time.
The ophthalmic information processing apparatus according to claim 1. The display processing unit corresponds to the time phase presented by the slider when a plurality of morphological images corresponding to the cross section of interest of the fundus to which the OCT blood flow measurement is applied are stored in the storage unit. A morphological image is selected from the plurality of morphological images and displayed.
The ophthalmic information processing apparatus according to claim 1 or 2. The slider includes a handle that can be moved along a time axis indicating the measurement period of the OCT blood flow measurement.
The display processing unit associates the position of the handle on the time axis with the time phase indicated by the morphological image selected and displayed from the plurality of morphological images.
The ophthalmic information processing apparatus according to claim 3. A data acquisition unit that acquires data by applying optical coherence tomography (OCT) blood flow measurement to the fundus of the eye to be inspected,
Including a display processing unit that displays information on the display means,
The display processing unit is
Based on the data, the morphological image of the fundus is displayed.
A blood flow graph showing 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, is displayed based on the data.
Display a slider for presenting and setting the time phase of blood flow,
A blood flow state image showing the state of blood flow in the time phase indicated by the slider is displayed at a position in the morphological image corresponding to the blood vessel of interest.
Ophthalmic imaging device.

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