WO2019198629A1

WO2019198629A1 - Image processing device and control method for same

Info

Publication number: WO2019198629A1
Application number: PCT/JP2019/015080
Authority: WO
Inventors: 宏治野里
Original assignee: キヤノン株式会社
Priority date: 2018-04-12
Filing date: 2019-04-05
Publication date: 2019-10-17
Also published as: JP2019180948A

Abstract

An image processing device that processes a plurality of cross-sectional images and a plurality of planar images of a photographed area of an object of examination. The image processing device has: a first generation means that generates a motion contrast image from the plurality of cross-sectional images; a second generation means that generates blood flow information from the plurality of planar images; and a control means that displays the blood flow information on the motion contrast image.

Description

Image processing apparatus and control method thereof

The present invention relates to an image processing apparatus and a control method therefor, and more particularly, to an image processing apparatus that processes an image of an eye to be examined and a control method therefor.

In recent years, as an ophthalmologic photographing apparatus, an SLO (Scanning Laser Ophthalmoscope) that irradiates a laser beam two-dimensionally on the fundus and receives the reflected light to obtain a planar image, or a low-coherence light. Imaging devices using interference have been developed. An imaging apparatus using interference of low-coherence light is called OCT (Optical Coherence Tomography), and is used particularly for the purpose of obtaining a tomographic image of the fundus or its vicinity. Various types of OCT have been developed, including TD-OCT (Time Domain OCT: Time Domain Method) and SD-OCT (Spectral Domain OCT: Spectral Domain Method).

In particular, in such an ophthalmologic photographing apparatus, in recent years, higher resolution has been promoted by increasing the NA of the irradiation laser. However, when photographing the fundus, the photograph must be taken through the optical tissue of the eye such as the cornea and the crystalline lens. For this reason, as the resolution increases, the aberrations of the cornea and the crystalline lens greatly affect the image quality of the captured image.

Therefore, research on AOSLO and AOOCT, in which an adaptive optics (AO) function for measuring aberrations of the eye and correcting the aberrations is incorporated in the optical system, is underway. For example, Non-Patent Document 1 discloses AOOCT. These AOSLO and AOOCT generally measure the wavefront of the eye using the Shack-Hartmann wavefront sensor method. In the Shack-Hartmann wavefront sensor system, measurement light is incident on the eye and the reflected light is received by a CCD camera through a microlens array to measure the wavefront. AOSLO and AOOCT can be imaged with high resolution by driving a deformable mirror and a spatial phase modulator to correct the measured wavefront and imaging the fundus oculi through them.

Recently, an angiographic method using OCT (OCT Angiography: OCTA) has been used as a method for imaging structures such as blood vessels of the retina without using a contrast agent. In OCTA, a blood vessel image (hereinafter referred to as an OCTA image) is generated by projecting three-dimensional motion contrast data acquired by OCT onto a two-dimensional plane. Here, the motion contrast data is data obtained by repeatedly photographing the same cross section of the measurement object by OCT and detecting a temporal change of the measurement object during the imaging. The motion contrast data is obtained, for example, by calculating a temporal change in the phase, vector, and intensity of the complex OCT signal from a difference, a ratio, or a correlation (Patent Document 1).

Similarly, in SLO and AOSLO, it is possible to identify the blood vessel region from the image and analyze the spatiotemporal image to analyze the movement of the particles in the blood vessel and the blood flow. Since the depth of focus is shallow in AOSLO, the range of the imaged layer is limited to several tens of μm, and the blood flow of only one layer of the retina can be analyzed.

Also, as in OCTA, in SLO and AOSLO, methods for generating blood vessel images (hereinafter referred to as SLOA and AOSLOA images) from the motion contrast data of the planar images have been studied. Similar to the OCTA motion contrast data, the SLO motion contrast data is data obtained by detecting temporal changes at the same imaging position of the measurement target. However, since the SLO image is a continuous moving image of a specific plane, it is possible to create motion contrast data without performing processing such as cutting out a specific slice like OCTA and projecting onto a plane.

JP2015-131107A

In OCTA, changes that can be drawn are limited by the performance of the OCT that captured the OCT image that is the original data. For example, in general OCT, since there is only a horizontal resolution of about 20 μm, structures and changes on the image below that resolution cannot be captured. In addition, since OCTA images the amount of change between tomographic images, the vascular structure of the retina can be depicted, but information such as the direction and velocity of blood flow in the blood vessel cannot be acquired. Since the fine structure of blood vessels and the direction of blood flow are unknown, it is difficult to determine whether the blood vessel being drawn is an artery or a vein.

On the other hand, AOSLO has a very high lateral resolution and can capture very minute changes in the cell level. If it is a blood vessel, it can also capture changes in the internal blood cell level. However, while AOSLO has a high lateral resolution, the field angle of view is relatively narrow with respect to a general fundus photographing apparatus, and it is difficult to grasp the entire image. In addition, since the SLO including the AOSLO is a plane imaging, it is possible to capture only a specific focus position, there is no information outside the focus depth, and it is difficult to grasp the structural relationship with the structure in the vertical direction.

In view of the above problems, the present invention analyzes a blood vessel structure on the retina that can be rendered with OCT or OCTA and blood flow information that can be captured with SLO or AOSLO, and provides information that cannot be acquired with a single image The purpose is to provide.

In order to solve the above problems, an image processing apparatus of the present invention is an image processing apparatus that processes a plurality of tomographic images and a plurality of planar images of an imaging region of an object to be inspected. First generation means for generating blood flow, second generation means for generating blood flow information from the plurality of planar images, and control means for displaying the blood flow information on the motion contrast image.

It is a schematic diagram of the structural example of the OCT apparatus in Embodiment 1 of this invention. It is a schematic diagram of the structural example of the AOSLO apparatus in Embodiment 1 of this invention. It is a schematic diagram of the structural example of the AOOCT-SLO apparatus in Embodiment 3 of this invention. 3 is a flowchart showing standard control steps in the first embodiment. 4 is a scan pattern example according to the first embodiment. 4 is a scan pattern example according to the first embodiment. It is an example of an image of OCT. It is an example of an image of OCT. It is an example of an image of OCT. It is an example of an image of AOSLO. It is an example of an image of AOSLO. It is an example of an image of AOSLO. It is an example of an image of AOSLO. It is an example of an image of AOSLO. It is an example of an image of AOSLO. It is an example of a photoreceptor cell image and blood flow analysis of AOSLO. It is an example of a photoreceptor cell image and blood flow analysis of AOSLO. It is an example of a photoreceptor cell image and blood flow analysis of AOSLO. FIG. 2 is a schematic diagram of an image processing unit configuration according to the first embodiment. 4 is a flowchart illustrating control steps of the image processing unit according to the first embodiment. 3 is an example of an analysis result display screen according to the first embodiment. 3 is an example of an analysis result display screen according to the first embodiment. 3 is an example of an analysis result display screen according to the first embodiment. 10 is a flowchart illustrating control steps of the image processing unit according to the second embodiment. 10 is a flowchart illustrating control steps of the image processing unit according to the third embodiment.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The following description is merely illustrative and exemplary in nature and is not intended to limit the present disclosure and its application or uses in any way. The relative configurations of components shown in the embodiments, and the steps, numerical expressions, and numerical values do not limit the scope of the present disclosure unless specifically indicated otherwise. Techniques, methods and devices well known by those skilled in the art may not have been discussed in detail because those skilled in the art do not need to know these details to enable the embodiments discussed below.

[Embodiment 1]
As Embodiment 1, a configuration of an imaging apparatus and an image processing unit that captures a fundus image to which the present invention is applied will be described with reference to FIGS. 1, 2, and 9.

In the present embodiment, an example will be described in which an OCT apparatus and an AOSLO apparatus that captures the fundus by correcting an aberration generated in the eye with an adaptive optical system using an object to be measured as an eye. .

FIG. 1 is a diagram showing a configuration of OCT, FIG. 2 is a diagram showing a configuration of AOSLO, and FIG. 9 shows a relationship with other configurations of an image processing unit that analyzes data obtained by these apparatuses. It is a block diagram.

In FIG. 1, 110 is an OCT unit. The main unit of the OCT unit 110 includes a light source 101, a fiber coupler 102, a reference optical system 111, a detection optical system 112, and an eyepiece optical system.

101 is a light source, and an SLD (Super Luminescent Diode) light source having a wavelength of 840 nm was used. The light source 101 only needs to have a low interference property, and an SLD having a wavelength width of 30 nm or more is preferably used. Further, an ultrashort pulse laser such as a titanium sapphire laser can be used as a light source.

The light emitted from the light source 101 is guided to the fiber coupler 102 through the single mode optical fiber. The measurement light path 103 and the reference light path 113 are branched by the fiber coupler 102. A fiber coupler having a branching ratio of 10:90 was used so that 10% of the input light amount went to the measurement light path 103.

The light that has passed through the measurement light path 103 is irradiated by the collimator 104 as parallel light with the measurement light 105. The polarization of the irradiated light is adjusted by a polarization adjuster (not shown) provided in the path of the single mode optical fiber 103. As another configuration, there is a configuration in which an optical component for adjusting polarization is arranged in the optical path after being emitted from the collimator 104. In some cases, an optical element for adjusting the dispersion characteristic of the measurement light and an optical element for adjusting the chromatic aberration characteristic are provided in the optical path.

The measuring beam 105 is relayed by reflecting mirrors 106-1 to 106-3, a lens (not shown), etc., and scanned one-dimensionally or two-dimensionally by the scanning optical system 107-1. In the present embodiment, two galvano scanners are used for the scanning optical system 107-1 for main scanning (fundus horizontal direction) and sub-scanning (fundus vertical direction). In order to bring each scanner in the scanning optical system 107-1 into an optically conjugate state, there may be an apparatus configuration that uses an optical element such as a mirror or a lens between the scanners. In this embodiment, the scanning optical system further includes a tracking mirror 107-2. The tracking mirror 107-2 is composed of two galvano scanners, and can further move the imaging region set on the fundus of the eye 109 in two directions. In another configuration, there is a configuration in which the scanning optical system 107-1 also serves as the tracking mirror 107-2. Further, in order to optically conjugate the 107-1 and 107-2, a relay optical system (not shown) is often used.

The measuring beam 105 scanned by the scanning optical systems 107-1 and 107-2 is irradiated to the eye 109 through the eyepieces 108-1 and 108-2. The measurement light 105 applied to the eye 109 is reflected or scattered by the retina of the fundus. By adjusting the positions of the eyepieces 108-1 and 108-2, it is possible to perform optimal irradiation in accordance with the diopter of the eye 109. Here, a lens is used for the eyepiece, but a spherical mirror or the like may be used.

Reflected light reflected or scattered from the retina of the fundus of the eye 109 travels in the reverse direction when entering, enters the optical fiber 103 through the collimator 104, and returns to the fiber coupler 102.

On the other hand, the reference light that has passed through the reference light path 113 is emitted by the collimator 114, reflected by the optical path length variable unit 116, and returned to the fiber coupler 102 again.

The reflected light and the reference light that have reached the fiber coupler 102 are combined to form interference light, which is guided to the detection optical system 112 through the optical fiber 117. The interference light that has entered the detection optical system 112 is emitted from the collimator 118 and is split by the grating 119 for each wavelength. The split light is applied to the line sensor 121 through the lens system 120. The line sensor 121 may be composed of a CCD sensor or a CMOS sensor.

Based on the interference light dispersed by the detection optical system 112, a tomographic image of the fundus is formed by the control unit 122. The control unit 122 can control the optical path length variable unit 116 and acquire an image at a desired depth position. The control unit 122 also controls the scanning units 107-1 and 107-2 at the same time, and can acquire an interference signal at an arbitrary position. In general, a scanning region set on the fundus is scanned by the scanning units 107-1 and 107-2, and an interference signal at each position is recorded simultaneously with the position information. Three-dimensional volume data is acquired by creating a tomographic image from the obtained interference signal.

Next, an example of the scan pattern of this embodiment will be described with reference to FIGS. 5A and 5B. FIG. 5A is a diagram reflecting an arbitrary scan, and FIG. 5B is a diagram reflecting numerical values specifically executed in the present embodiment. In OCTA, since the time change of the OCT interference signal due to blood flow is measured, multiple measurements are required at the same place. In the present embodiment, the OCT apparatus performs a scan that moves to n y positions while repeating the B scan at the same location m times. A specific scan pattern is shown in FIG. 5A. The B scan is repeated m times for n positions y1 to yn on the fundus plane. If m is large, the number of times of measurement at the same place increases, so that blood flow detection accuracy is improved. On the other hand, the scan time becomes longer, and the problem of motion artifacts occurring in the OCTA image due to eye movement (fixation fine movement) during scanning increases the burden on the subject. In this embodiment, m = 4 (FIG. 5B) was implemented in consideration of the balance between the two. Note that the repetition number m may be changed according to the A-scan speed of the OCT apparatus and the motion analysis of the fundus surface image of the subject. In FIG. 5A, p indicates the sampling number of A scan in one B scan. That is, the plane image size is determined by p × n. When p × n is large, a wide range can be scanned at the same measurement pitch, but the scan time becomes long, and the above-mentioned motion artifact and patient burden problem occur. In the present embodiment, n = p = 300 was implemented in consideration of the balance between the two. The above n and p can be freely changed as appropriate. Further, Δx in FIG. 5A is an interval between adjacent x positions (x pitch), and Δy is an interval between adjacent y positions (y pitch). In this embodiment, the x pitch and the y pitch are determined as ½ of the beam spot diameter of the irradiation light on the fundus, and in this embodiment, 10 μm (FIG. 5B). An image to be generated can be formed with high definition by setting the x pitch and the y pitch to ½ of the beam spot diameter on the fundus. Even if the x pitch and the y pitch are smaller than ½ of the fundus beam spot diameter, the effect of further increasing the definition of the generated image is small. Conversely, if the x pitch and y pitch are made larger than ½ of the fundus beam spot diameter, the definition deteriorates, but a wide range of images can be acquired with a small data capacity. The x pitch and y pitch may be freely changed according to clinical requirements. The imaging range of the present embodiment is p × Δx = 3 mm in the x direction and n × Δy = 3 mm in the y direction (see FIG. 5B).

6A to 6C are examples of OCTA images. FIG. 6A shows an OCT tomographic image, and a plurality of tomographic images at the same position are taken for the construction of an OCTA image, which are 601 to 604, respectively. By calculating the difference between the respective tomographic images 601 to 604, a motion contrast image is generated. The OCTA image (FIG. 6B) is generated by aligning and stacking them in the three-dimensional direction, extracting motion contrast data of an arbitrary layer range, and projecting it in the depth direction. 6C is an enlarged view of the range 605 in FIG. 6B.

Next, a method for generating an OCTA image as shown in FIG. 6B will be described with reference to FIG.

In step S101, (see FIG. 9) The image processing unit 901 extract the repeated B-scan interfering signal at the position _{y k} (m sheets). In step S102, the image processing unit 901 extracts the j-th B scan interference signal.

In step S103, the image processing unit 901 subtracts the acquired background data from the interference signal.

In step S104, the image processing unit 901 converts the interference signal obtained by subtracting the background into a wave number function, and performs a Fourier transform. In the present embodiment, fast Fourier transform (FFT) is applied. Note that zero padding processing may be performed before Fourier transform to increase the interference signal. By performing the zero padding process, the gradation after Fourier transform is increased, and the alignment accuracy can be improved in step 109 described later.

In step S105, the image processing unit 901 calculates the absolute value of the complex signal obtained by the Fourier transform executed in step S104. This value becomes the intensity of the tomographic image of the scan.

In step S106, the image processing unit 901 determines whether the index j has reached a predetermined number (m). That is, it is determined whether the intensity calculation of the tomographic image at the position yk has been repeated m times. When the predetermined number is not reached, the process returns to step S102, and the intensity calculation of the tomographic image at the same Y position is repeated. When the predetermined number is reached, the process proceeds to the next step.

In step S107, the image processing unit 901 calculates image similarity between tomographic images at the same photographing position of m frames at a certain y _k position. Specifically, the image processing unit 901 selects any one of m frame tomographic images as a template, and calculates a correlation value with the remaining m−1 frame images.

In step S <b> 108, the image processing unit 901 selects an image having the highest correlation that has a correlation with another image that is equal to or greater than a certain threshold among the correlation values calculated in step S <b> 107. The threshold value can be arbitrarily set, and is set so as to exclude frames in which the correlation as an image has decreased due to blinking of the subject or slight eye movement. As described above, OCTA is a technique for discriminating the contrast between a flowing tissue (for example, blood) and a non-flowing tissue among subject tissues based on a correlation value between images. In other words, tissue with no flow is extracted based on the premise that the correlation between images is high, so if the correlation is low as an image, it will be erroneously detected when calculating the motion contrast, and the entire image will flow. It will be judged as if it is a certain organization. In this step, in order to avoid such erroneous detection, tomographic images with low correlation are excluded in advance as images, and only images with high correlation are selected. As a result of image selection, images of m frames acquired at the same position y _k are appropriately selected and become q frame images. Here, a possible value of q is 1 ≦ q ≦ m.

In step S109, the image processing unit 901 aligns the tomographic image of the q frame selected in step S108. For the frames to be selected as templates, correlations may be calculated for all combinations with each other, a sum of correlation coefficients may be obtained for each frame, and a frame having the maximum sum may be selected. Next, the position deviation amounts (δX, δY, δθ) are obtained by matching each frame with a template. Specifically, Normalized Cross-Correlation (NCC), which is an index representing similarity while changing the position and angle of the template image, is calculated, and the difference between the image positions when this value is maximized is obtained as the amount of positional deviation.

In the present embodiment, the index indicating the degree of similarity can be variously changed as long as it is a scale representing the similarity between the template and the image feature in the frame. For example, Sum of Absolute Difference (SAD), Sum of Squared Difference (SSD), Zero-means Normalized Cross-Correlation (ZNCC), Phase Only Correlation (POC), and Relative Correlation (POC).

Next, the image processing unit 901 applies position correction to (q−1) frames other than the template in accordance with the positional deviation amounts (δX, δY, δθ), and aligns the frames. If q is 1, this step is not executed.

In step S110, the image processing unit 901 calculates a motion contrast. In the present embodiment, a variance value is calculated for each pixel at the same position between q Intensity images selected in step S108 and aligned in step S109, and the variance value is used as a motion contrast. There are various ways of obtaining the motion contrast, and in the present invention, the motion contrast can be applied as long as it is an index representing a change in the motion contrast value of each pixel of a plurality of tomographic images at the same Y position. When q = 1, that is, when the correlation is low as an image due to the effect of blinking or fixation micromotion, and the motion contrast cannot be calculated at the same position y _k , different processing is performed. For example, the feature amount may be set to 0 and the step may be terminated, or when motion contrast in images before and after y _k−1 and y _{k + 1} is obtained, a value may be interpolated from the previous and next variance values. In this case, the abnormality may be notified that the feature quantity that could not be calculated correctly is a complementary value. Alternatively, the Y position where the feature amount could not be calculated may be stored, and rescanning may be performed automatically. Alternatively, a warning prompting remeasurement may be sent without performing automatic rescanning.

In step S111, the image processing unit 901 averages the intensity image that has been aligned in step S109, and generates an intensity averaged image.

In step S112, the image processing unit 901 performs the threshold processing for the motion contrast output in step S110. The threshold value is calculated by extracting an area where only random noise is displayed on the noise floor from the intensity averaged image output by the image processing unit 901 in step S111, calculating the standard deviation σ, and calculating the average motion contrast value of the noise floor. Set to + 2σ.

The image processing unit 901 sets the value of motion contrast corresponding to the area where each intensity is equal to or less than the threshold value to 0. By this threshold processing, noise can be reduced by removing motion contrast derived from random noise. As the threshold value is smaller, the motion contrast detection sensitivity increases, but the noise component also increases. Also, the larger the noise, the less noise, but the sensitivity of MC motion contrast detection decreases.

In this embodiment, the threshold is set as the average motion contrast value of the noise floor + 2σ, but the threshold is not limited to this.

In step S113, the image processing unit 901 determines whether the index k has reached a predetermined number (n). That is, it is determined whether image correlation calculation, image selection, alignment, intensity image averaging calculation, motion contrast calculation, and threshold processing have been performed at all the n Y positions. When the predetermined number is not reached, the process returns to step S101, and when the predetermined number is reached, the process proceeds to the next step S114. At the end of step S113, the intensity average image and motion contrast three-dimensional volume data (three-dimensional OCTA data) in the tomographic images at all the Y positions are generated.

In step S114, a motion contrast front image integrated in the depth direction is generated for the generated three-dimensional OCTA data. At this time, in generating the motion contrast front image, the image depth range to be integrated may be arbitrarily set. For example, the layer boundary of the fundus retina is extracted based on the intensity averaged image generated in step S111, and a motion contrast front image is generated so as to include a desired layer. After generating the motion contrast front image, the image processing unit 901 ends the signal processing flow.

By using the apparatus configuration, imaging method, and signal processing procedure described above, OCTA imaging and OCTA image generation can be performed in a desired area. In the present embodiment, the OCTA image is acquired under the condition of m = 4.

When the depth range to be integrated is limited to several layers on the retina surface layer side (from the inner boundary film to the center of the INL) with respect to the three-dimensional OCTA data created from the OCT tomographic image obtained by photographing the macular region as shown in FIG. 6A, FIG. As described above, a motion contrast image of the surface layer of the retina (Superficial Capillary) is obtained, and a fundus blood vessel image at the center of the macula can be extracted.

Next, the configuration of the AOSLO of this embodiment will be described with reference to FIG. The AOSLO of this embodiment has both a confocal imaging function that is almost limited to only reflected and scattered light from the focal position of the irradiation beam and a dark field imaging function that also images reflected and scattered light due to multiple scattering other than that. It was set as the structure which has.

In FIG. 2, 201 is a light source, and an SLD light source (Super Luminescent Diode) having a wavelength of 760 nm was used. Although the wavelength of the light source 201 is not particularly limited, about 750 to 1500 nm is preferably used for fundus imaging in order to reduce glare and maintain resolution of the subject. In this embodiment, an SLD light source is used, but a laser or the like is also used. In the present embodiment, light sources for fundus photographing and wavefront measurement are shared, but each may be a separate light source and combined in the middle of the optical path.

The light irradiated from the light source 201 passes through the single mode optical fiber 202 and is irradiated as a parallel light beam (measurement light 205) by the collimator 203. The polarization of the irradiated light is adjusted by a polarization adjuster (not shown) provided in the path of the single mode optical fiber 202. As another configuration, there is a configuration in which an optical component for adjusting polarization is arranged in the optical path after being emitted from the collimator 203.

The irradiated measurement light 205 is transmitted through a light splitting unit 204 formed of a beam splitter and guided to an optical system of adaptive optics.

The compensation optical system includes a light dividing unit 206, a wavefront sensor 215, a wavefront correction device 208, and reflection mirrors 207-1 to 20-4 for guiding them.

Here, the reflection mirrors 207-1 to 20-4 are installed so that at least the pupil of the eye 211, the wavefront sensor 215, and the wavefront correction device 208 are optically conjugate. In addition, a beam splitter is used as the light dividing unit 206 in the present embodiment.

The measurement light 205 transmitted through the light splitting unit 206 is reflected by the reflection mirrors 207-1 and 207-2 and enters the wavefront correction device 208. The measurement light 205 reflected by the wavefront correction device 208 is further reflected by the reflection mirrors 207-3 and 207-4 and guided to the scanning optical system.

In this embodiment, a deformable mirror is used as the wavefront correction device 208. The deformable mirror is a mirror in which the reflection surface is divided into a plurality of regions, and the wavefront of the reflected light can be changed by changing the angle of each region. As the wavefront correction device, a spatial phase modulator using a liquid crystal element instead of the deformable mirror can be used. In that case, two spatial phase modulators may be used to correct both polarizations of light from the eye to be examined.

In FIG. 2, the light reflected by the reflection mirrors 207-3 and 4 is scanned one-dimensionally or two-dimensionally by the scanning optical system 209-1. In the present embodiment, one resonance scanner and one galvano scanner are used for the main scanning (horizontal direction of the fundus) and the sub-scanning (vertical direction of the fundus) in the scanning optical system 209-1. In another configuration, two galvano scanners may be used for the scanning optical system 209-1. In order to bring each scanner in the scanning optical system 209-1 into an optically conjugate state, there may be an apparatus configuration that uses an optical element such as a mirror or a lens between the scanners.

In this embodiment, the scanning optical system further includes a tracking mirror 209-2. The tracking mirror 209-2 is composed of two galvanometer scanners, and can move the imaging region in two directions. In another configuration, the scanning optical system 209-1 also serves as the tracking mirror 209-2, the tracking mirror 209-2 is configured only in the resonance scanner direction of the scanning optical system 209-1, and the tracking mirror 209-2 is a two-dimensional mirror. There is also the structure which is. Further, in order to optically conjugate 209-1 and 209-2, a relay optical system (not shown) is often used.

The measuring light 205 scanned by the scanning optical systems 209-1 and 209-2 is irradiated to the eye 211 through the eyepiece lenses 210-1 and 210-2. The measurement light applied to the eye 211 is reflected or scattered by the fundus. By adjusting the positions of the eyepieces 210-1 and 210-2, it is possible to perform optimal irradiation in accordance with the diopter of the eye 211. Here, a lens is used for the eyepiece, but a spherical mirror or the like may be used.

The reflected light reflected or scattered from the retina of the eye 211 travels in the opposite direction along the incident path, and part of the reflected light is reflected by the wavefront sensor 215 by the light splitting unit 206 and used to measure the wavefront of the light beam. It is done. The light beam reflected by the light splitting unit 206 toward the wavefront sensor 215 passes through the relay optical systems 219-1 and 219-2 and enters the wavefront sensor 215. An aperture 220 is installed between the relay optical systems 219-1 and 219-2 so that unnecessary reflected and scattered light from a lens or the like is not incident on the wavefront sensor. In this embodiment, a Shack-Hartmann sensor is used as the wavefront sensor 215.

The wavefront sensor 215 is connected to the adaptive optics controller 217 and transmits the received wavefront to the adaptive optics controller 217. The wavefront correction device 208 is also connected to the adaptive optics controller 217, and performs modulation instructed by the adaptive optics controller 217. The adaptive optics control unit 217 calculates a modulation amount (correction amount) for each pixel of the wavefront correction device that corrects to a wavefront having no aberration based on the wavefront information acquired from the measurement result of the wavefront sensor 215, and the wavefront Commands the correction device 208 to do so. The measurement of the wavefront and the instruction to the wavefront correction device are repeatedly processed, and feedback control is performed so that the optimum wavefront is always obtained.

In FIG. 2, a part of the reflected light transmitted through the light dividing unit 206 is reflected by the light dividing unit 204, and is condensed near the hole of the perforated mirror 213 by the condenser lens 212. The hole of the perforated mirror 213 is often adjusted to a diameter in the vicinity of the diffraction limit of the measurement light 205 in order to obtain a confocal effect. When the diameter is large, the sensitivity is improved but the resolution is lowered. When the diameter is small, the resolution is high but the sensitivity tends to be lowered. The light that has passed through the hole of the perforated mirror 213 enters the optical sensor 214-1 and is converted into an electrical signal corresponding to the light intensity.

The optical sensor 214-1 is connected to the control unit 218. The control unit 218 constructs a planar image based on the obtained electrical signal and the position of optical scanning, and displays it on the display 219 as a confocal image.

The light reflected by the mirror portion other than the hole of the perforated mirror 213 is condensed again in the vicinity of the edge of the knife edge 216 through the relay optical system 215, and is divided into approximately half by the knife edge 216. The divided light enters the optical sensors 214-2 and 214-3. The optical sensors 214-2 and 214-3 are converted into electrical signals corresponding to the light intensity, output to the control unit 218, and imaged as a dark field photographed image. The knife edge 216 may divide the condensed light in any way, and the division direction in the horizontal direction and the vertical direction with respect to the paper surface and the division ratio are not half and non-uniform division such as 40:60 is also possible. . Further, it is possible to divide into more components instead of two. It is also possible to dynamically change such a division method during shooting.

The tracking mirror 209-2 is controlled by a tracking control unit (not shown). The tracking control unit obtains the image signal of the imaging unit from the control unit 218, calculates the amount of deviation due to fixation fixation in the imaging region set on the fundus of the eye 211, and controls the tracking mirror 209-2. Control is performed so that the photographing area is always kept at a predetermined position.

7A1 to C2 show examples of captured images taken with the AOSLO of this embodiment.

FIG. 7A1 is a confocal image (planar moving image). Since the blood vessel layer is focused, only blood cells in the blood vessel are partially observed with high brightness. FIG. 7B1 and FIG. 7C1 are dark-field images (planar moving images), which are generated based on signals detected on the right and left sides of the knife edge. Since these images simultaneously acquire the reflected light from the fundus using different methods, the images are constructed from signals derived from exactly the same shooting position. In AOSLO, such images are taken continuously, and each plane moving image is acquired.

As in OCTA, the image processing unit 901 creates a motion contrast image by analyzing the luminance change between each image captured continuously in AOSLO. A motion contrast image (FIG. 7A2) is obtained from the confocal image (FIG. 7A1), a motion contrast image as shown in FIG. 7B2 is obtained from FIG. 7B1, and a motion contrast image is obtained from FIG. 7C1.

7A1 and C2 are images focused on the blood vessel layer, but it is possible to photograph the dynamics of blood cells even when focused on the lower photoreceptor layer. FIGS. 8A to 8C are examples in which the photoreceptor layer is photographed. FIG. 8A is a confocal image, in which a white bright spot is a photoreceptor cell, in which a shadow of a black blood vessel is reflected. When a specific type of blood cell passes through the blood vessel, light is transmitted through that part, and the shadow disappears and is photographed as a bright spot. FIG. 8B shows an example of photographing at that time. Reference numeral 801 denotes a confocal image, and reference numeral 802 denotes a blood vessel shadow on the confocal image of the photoreceptor layer. Reference numeral 803 indicates a bright spot that is visible when light passes through only the position of the blood cell. When the blood cell moves, the bright spot moves while drawing a locus like 804. The direction and velocity of the blood flow are analyzed by spatiotemporal image analysis of the bright spot. FIG. 8C is a spatiotemporal image of the blood vessel 802. The spatiotemporal image 805 is arranged with respect to the time T with respect to the pixel row Pt along the blood vessel 802, and reference numeral 806 indicates a blood cell trajectory (white bright line in the spatiotemporal image). From this inclination, blood flow information such as the direction and speed of blood cell movement is calculated. Similar to creating spatiotemporal images from photoreceptor cell images and generating blood flow information, blood flow information can also be generated from confocal images focused on blood vessel layers and non-confocal images in the same way. Good.

Note that even in the case of an image of the photoreceptor cell layer as shown in FIG. 8A, it is possible to create a motion contrast image by analyzing the luminance change between each image of the moving image. In this case, since a blood vessel that forms a shadow in the photoreceptor cell layer is drawn, the motion contrast image often includes more layers of information than the motion contrast image focused on the blood vessel. On the other hand, since it is necessary to change the shadow, it is difficult to depict blood vessels whose shadow state does not change even when blood cells pass.

Next, the image processing unit will be described with reference to FIG. The image processing unit 901 is connected to the OCT apparatus 903 and the AOSLO apparatus 904, and can acquire respective data. The analyzed data is displayed on the display 902. Although the image processing unit 901 is described separately from the OCT apparatus 903 and the AOSLO apparatus 904 in FIG. 9, it can be implemented as one function of the OCT apparatus 903 and the AOSLO apparatus 904.

Next, the processing of the image processing unit 901 will be described with reference to FIG. In the present embodiment, when an operator selects an OCTA image, a matching AOSLO image is selected, and blood flow information as a result of analyzing the AOSLO image is displayed together with the OCTA image.

In step S201, an analysis target layer is selected in accordance with an instruction of the layer to be analyzed by the operator. In step S202, an OCTA image corresponding to the selected layer is acquired. In this step, an OCTA image may be acquired from an already generated OCTA image, or an OCTA image may be generated using the OCT data of the layer at this time. In step S203, the position in the plane direction to be analyzed is specified. The position in the plane direction may be based on SLO image information attached to the OCT data, or may be calculated as a distance from a reference point having a certain feature based on an OCT Enface image. In general, since the angle of view of AOSLO is smaller than that of OCT, an OCTA image is often generated by limiting the range in the plane direction from the acquired OCTA image. In step S204, the focus position in the corresponding AOSLO device is calculated from the depth information of the analysis layer. Based on the obtained focus information and position information, the AOSLO moving image is acquired in step S205. The acquired AOSLO moving image may be a confocal image, a dark-field captured image, or an image obtained by calculating them.

In step S206, the OCTA image and the AOSLO image are aligned. This alignment may be performed by comparing the OCTA image and the AOSLO moving image, or may be performed using a motion contrast image created from the AOSLO image.

In step S207, a blood vessel region is extracted from the OCTA image, and in step S208, a spatiotemporal image corresponding to the blood vessel region is created from the AOSLO moving image. The obtained spatiotemporal image is analyzed in step S209 to obtain blood flow information such as the moving direction and speed of the blood cells.

In step S210, an OCTA image is displayed. In step S211, a blood flow information display method is selected based on the operator's instruction, and in step S215, the blood flow information is displayed together with the OCTA image. Examples of the display method include displaying blood flow as a line on the blood vessel region as in step S212, changing the line width, color, and linearity according to the blood flow condition, or displaying the blood flow rate and blood as in step S213. The blood vessel region is colored according to the flow direction, or blood flow information is displayed as characters in the vicinity of the blood vessel region as in step S214.

FIG. 11A is a display example of each image. In this embodiment, an AOSLO moving image 1101 at the same location, an AOSLO motion contrast image 1102 (AOSLO angio) created based on the AOSLO moving image 1101, and an OCTA image 1103 at the position are displayed.

FIG. 11B shows an example in which the direction of blood flow is displayed on the OCTA image. A line 1104 indicating the direction of blood flow is superimposed on the blood vessel region of OCTA and displayed.

FIG. 11C shows an example in which the direction of blood flow and the blood flow velocity are displayed on the OCTA image. A line indicating the blood flow is 1105, and the display color is changed or the line width is changed according to the blood flow velocity. In addition, blood flow information is superimposed and displayed as characters 1106 in the vicinity of the blood vessel region. An arrow is shown as an example of blood flow, but the present invention is not limited to this, and a moving image display in which symbols such as white bright spots representing blood cells move along blood vessels according to the direction of blood flow / blood flow ( Animation display). Furthermore, a blood vessel region of AOSLO may be extracted and superimposed on a blood vessel corresponding to the OCTA image as a moving image.

Further, by analyzing the OCT tomographic image and the AOSLO plane image, the positional relationship between the position of the optic nerve head and the blood vessel to be analyzed can be understood, so that the blood vessel being analyzed based on the positional information and the direction of blood flow Whether it is an artery or a vein may be estimated and displayed as blood flow information in an identifiable manner.

In this embodiment, the AOSLO still image and the OCT tomographic image are not displayed, but these may be displayed and blood flow information may be displayed thereon. Further, in order to emphasize the blood flow information display, it is also possible to enlarge / reduce the image or moving image of the area.

Thus, by analyzing and displaying OCTA and blood flow information, the operator can comprehend the vascular blood flow state of the subject in a composite manner, and can determine the characteristics of each blood vessel and blood flow. It becomes possible.

[Embodiment 2]
An example of a method for controlling the fundus imaging apparatus having a different form from the first embodiment to which the present invention is applied will be described with reference to the flowchart of FIG. In this embodiment, the basic apparatus configuration is the same as that of the first embodiment. The basic flow of shooting is the same as that of the first embodiment, and only the processing of the image processing unit 901 is different.

In step S301, an AOSLO image is designated based on an instruction from the operator. For the selected AOSLO image, the focus position is specified in step S302, and the XY position is specified in step S303. In the AOSLO image data, the AO state at that time is stored as additional information, and the focus position taken from the AO state can be known. In general, in AO, the visual cell layer, which is the highest luminance layer, is often the focus origin, so that it is possible to know how much optical power has been applied and to know the amount of focus movement. More precisely, the exact amount of movement can be determined by using parameters such as the diopter of the subject and the pupil position at the time of imaging. However, since AOSLO has a certain depth of field, there is often no need for such strictness. In step S304, the layer in the retina is specified from the focus information.

In step S305, an OCTA image of the layer is acquired. In general, since the OCTA image has a larger imaging range than the AOSLO image, an OCTA image region in a range corresponding to the AOSLO imaging range is specified in step S306.

In step S307, OCTA and AOSLO are aligned.

In step S308, a blood vessel region is extracted from the OCTA image, and in step S309, a spatiotemporal image corresponding to the blood vessel region is created from the AOSLO moving image. The obtained spatiotemporal image is analyzed in step S310 to obtain blood flow information such as blood cell movement direction and velocity.

In step S311, an OCTA image is displayed. In step S312, a blood flow information display method is selected, and in step S316, blood flow information is displayed together with the OCTA image. An example of the display method is the same as in the first embodiment. Similar to the embodiment, the GUI display example has a configuration as shown in FIGS. 11A to 11C.

As described above, by selecting the analysis region from the AOSLO image, more detailed position designation is possible, and the operator can comprehend the vascular blood flow state of the subject in a composite manner. It is possible to determine the characteristics of the flow.

[Embodiment 3]
Next, as Embodiment 3, the configuration of a fundus imaging apparatus to which the present invention is applied will be described with reference to FIG. In the present embodiment, an example of adaptive optics OCT-SLO will be described in which an object to be measured is an eye and both functions of AOSLO and AOOCT are provided in the same apparatus.

In FIG. 3, 318 is an AOSLO unit, and 324 is an AOOCT unit.

First, the AOSLO unit will be described. In FIG. 3, 301 is a light source, and an SLD light source (Super Luminescent Diode) having a wavelength of 760 nm was used. Although the wavelength of the light source 301 is not particularly limited, about 750 to 1500 nm is preferably used for fundus imaging in order to reduce the glare of the subject and maintain the resolution. In this embodiment, an SLD light source is used, but a laser or the like is also used. In the present embodiment, light sources for fundus photographing and wavefront measurement are shared, but each may be a separate light source and combined in the middle of the optical path. In this embodiment, since a part of the optical system is shared with the OCT, a wavelength different from the wavelength of the OCT light source is selected in order to branch from the optical path to the OCT, and the optical path is branched by the dichroic mirror. .

The light irradiated from the light source 301 passes through the single mode optical fiber 302 and is irradiated as a parallel light beam (measurement light 305) by the collimator 303. The polarization of the irradiated light is adjusted by a polarization adjuster (not shown) provided in the path of the single mode optical fiber 302. As another configuration, there is a configuration in which an optical component for adjusting polarization is arranged in the optical path after being emitted from the collimator 303.

The irradiated measurement light 305 passes through a light splitter 304 formed of a beam splitter, and further passes through a beam splitter 319 for splitting with OCT, and is guided to an optical system of adaptive optics.

The compensation optical system includes a light splitting unit 306, a wavefront sensor 314, a wavefront correction device 308, and reflection mirrors 307-1 to 307-1 for guiding them. Here, the reflection mirrors 307-1 to 307-1 are installed so that at least the pupil of the eye 311 and the wavefront sensor 314 and the wavefront correction device 308 are optically conjugate. In addition, a beam splitter is used as the light splitting unit 306 in the present embodiment.

The measurement light 305 transmitted through the light splitting unit 306 is reflected by the reflection mirrors 307-1 and 307-2 and enters the wavefront correction device 308. The measurement light 305 reflected by the wavefront correction device 308 is further reflected by the reflection mirrors 307-3 and 307-4 and guided to the scanning optical system.

In this embodiment, a deformable mirror is used as the wavefront correction device 308. The deformable mirror is a mirror in which the reflection surface is divided into a plurality of regions, and the wavefront of the reflected light can be changed by changing the angle of each region. As the wavefront correction device, a spatial phase modulator using a liquid crystal element instead of the deformable mirror can be used. In that case, two spatial phase modulators may be used to correct both polarizations of light from the eye to be examined.

The light reflected by the reflection mirrors 307-3 and 4 is scanned one-dimensionally or two-dimensionally by the scanning optical system 309-1. In this embodiment, one resonance scanner and one galvano scanner are used for the main scanning (horizontal direction of the fundus) and the sub-scanning (vertical direction of the fundus) in the scanning optical system 309-1. In another configuration, two galvano scanners may be used for the scanning optical system 309-1. In order to bring each scanner in the scanning optical system 309-1 into an optically conjugate state, there may be an apparatus configuration that uses an optical element such as a mirror or a lens between the scanners. In this embodiment, the scanning optical system further has a tracking mirror 309-2. The tracking mirror 309-2 is composed of two galvanometer scanners, and can move the imaging region in two directions. In another configuration, the scanning optical system 309-1 also serves as the tracking mirror 309-2, the tracking mirror 309-2 is configured only in the resonance scanner direction of the scanning optical system 309-1, and the tracking mirror 309-2 is a two-dimensional mirror. There is also the structure which is. Further, in order to optically conjugate 309-1 and 309-2, a relay optical system (not shown) is often used.

The measuring light 305 scanned by the scanning optical systems 309-1 and 309-2 is irradiated to the eye 311 through the eyepieces 310-1 and 310-2. The measurement light applied to the eye 311 is reflected or scattered by the fundus. By adjusting the positions of the eyepieces 310-1 and 310-2, it is possible to perform optimal irradiation in accordance with the diopter of the eye 311. Here, a lens is used for the eyepiece, but a spherical mirror or the like may be used.

Reflected light reflected or scattered from the retina of the eye 311 travels in the reverse direction when incident, and is partially reflected by the light splitting unit 306 to the wavefront sensor 314 and used to measure the wavefront of the light beam. It is done. The light beam reflected by the light splitting unit 306 toward the wavefront sensor 314 passes through the relay optical systems 316-1 and 316-2 and enters the wavefront sensor 314. An aperture 317 is installed between the relay optical systems 316-1 and 316-2 so that unnecessary reflected and scattered light from a lens or the like is not incident on the wavefront sensor. In this embodiment, a Shack-Hartmann sensor is used as the wavefront sensor 314.

The wavefront sensor 314 is connected to the adaptive optics controller 315 and transmits the received wavefront to the adaptive optics controller 315. The wavefront correction device 308 is also connected to the adaptive optics controller 315 and performs modulation instructed by the adaptive optics controller 315. The adaptive optics control unit 315 calculates a modulation amount (correction amount) for each pixel of the wavefront correction device that corrects to a wavefront having no aberration based on the wavefront acquired from the measurement result of the wavefront sensor 314, and corrects the wavefront. Commands device 308 to do so. The measurement of the wavefront and the instruction to the wavefront correction device are repeatedly processed, and feedback control is performed so that the optimum wavefront is always obtained.

The reflected light that has passed through the light splitting unit 306 is partly reflected by the light splitting unit 304, collected by the condensing lens 312 on the optical sensor 313 having a pinhole, and converted into an electrical signal corresponding to the light intensity.

The optical sensor 313 is connected to the control unit 334, and the control unit 334 constructs a planar image based on the obtained electrical signal and the position of optical scanning, and displays it on the display 335 as an SLO image.

Next, the AOOCT unit 324 will be described.

324 is an AOOCT unit, which includes a light source 320, a fiber coupler 321, a reference optical path 325, and a spectrometer 326 as main units.

320 is a light source, and an SLD light source having a wavelength of 840 nm was used. The light source 320 only needs to have a low interference property, and an SLD having a wavelength width of 30 nm or more is preferably used. Further, an ultrashort pulse laser such as a titanium sapphire laser can be used as a light source. In this embodiment, in order to share a part of the optical system with the SLO, it is desirable that the wavelength is different from that of the light source of the SLO and the light is branched by a dichroic mirror or the like.

The light emitted from the light source 320 is guided to the fiber coupler 321 through the single mode optical fiber. The fiber coupler 321 branches the signal light path 322 and the reference light path. A fiber coupler having a branching ratio of 10:90 was used, and 10% of the input light amount went to the signal light path 322.

The light that has passed through the signal light path 322 is irradiated with measurement light as parallel light by the collimator 323. The polarization of the irradiated light is adjusted by a polarization adjuster (not shown) provided in the path of the single mode optical fiber 322. As another configuration, there is a configuration in which an optical component for adjusting polarization is arranged in the optical path after being emitted from the collimator 323. In some cases, an optical element for adjusting the dispersion characteristic of the measurement light and an optical element for adjusting the chromatic aberration characteristic are provided in the optical path.

The measurement light is combined with the SLO measurement light by the beam splitter 319 for light branching, and follows the same optical path as the SLO as the measurement light 305 to irradiate the eye 311 to be examined. Similar to SLO, the light scattered and reflected from the eye 311 travels in the same direction as the forward path in the opposite direction, is reflected by the beam splitter 319, and returns to the fiber coupler 321 through the optical fiber 322.

The wavefront of the OCT light is also measured by the wavefront sensor 314 and corrected by the wavefront correction device 308. The wavefront correction method is not limited to such a method, and an optical filter is added in front of the wavefront sensor 314 when measuring only the wavefront of OCT light or measuring only the wavefront of SLO light. It is supposed to be configured. Also, it is possible to control to switch the light to be measured by dynamically inserting and removing or changing the optical filter.

On the other hand, the reference light that has passed through the reference light path is emitted by the collimator 327, reflected by the optical path length variable unit 329, and returned to the fiber coupler 321 again.

The signal light and the reference light that have reached the fiber coupler 321 are combined and guided to the spectroscope 326 through the optical fiber. The light that enters the spectroscope 326 is emitted from the collimator 330 and is split by the grating 331 for each wavelength. The split light is applied to the line sensor 333 through the lens system 332. The line sensor 333 may be composed of a CCD sensor or a CMOS sensor. Based on the interference light information spectrally separated by the spectroscope 326, a tomographic image of the fundus is constructed by the control unit 334. The control unit 334 controls the optical path length variable unit 329 and can acquire an image at a desired depth position. The control unit 334 also controls the scanning units 309-1 and 309-2 at the same time, and can acquire an interference signal at an arbitrary position. Three-dimensional volume data is acquired by creating a tomographic image from the obtained interference signal.

The OCT scan pattern control and the OCTA image construction method are the same as those in the first embodiment.

Next, the control method of the image processing unit in this embodiment will be described with reference to FIG.

This embodiment is an apparatus in which AOOCT and AOSLO are combined, and both images are acquired simultaneously. The shooting position of both images is the same as the focus position, and in AOOCT shooting, since the focus is generally designated for the layer of interest, the focus position and the position of the layer to be analyzed are also the same. Therefore, by specifying either the AOOCT image or AOSLO, the position and layer to be analyzed are determined, and the target AOOCT and AOSLO data are determined.

In step S401, an AOOCT image to be analyzed is selected based on an instruction from the operator. In step S402, an AOSLO image corresponding to the selected layer is acquired. In this step, an AOSLO image recorded at the same timing may be acquired.

Next, in step S403, a blood vessel region is extracted from the OCTA image.

In step S404, a spatiotemporal image corresponding to the blood vessel region is created from the AOSLO moving image. The obtained spatiotemporal image is analyzed in step S405 to obtain blood flow information such as the direction and speed of blood cells.

In step S406, an OCTA image is displayed. In step S407, a blood flow information display method is selected, and in step S411, the blood flow information is displayed together with the OCTA image. An example of the display method is selected in steps S408, S409, and S410 as in steps S212, S213, and S214 of the first embodiment. Similar to the first embodiment, the GUI display example has a configuration as shown in FIGS. 11A to 11C.

In this way, simply by specifying the AOOCT or AOSLO image that the operator is interested in, a plurality of images are automatically analyzed, and the operator can comprehend the subject's vascular blood flow state in a complex manner. It is possible to determine the characteristics of each blood vessel and blood flow.

[Other Examples]
In the above-described embodiment, the case where the object to be inspected is an eye is described. However, the present invention can also be applied to an object to be inspected other than the eye, such as skin or organ. In this case, the present invention has an aspect as a medical device such as an endoscope other than the ophthalmologic photographing apparatus. Therefore, it is preferable that the present invention is grasped as an image processing apparatus exemplified by an ophthalmologic photographing apparatus, and the eye to be examined is grasped as one aspect of the inspection object.

The present invention can also be achieved by configuring the apparatus as follows. That is, a recording medium (or storage medium) that records software program codes (computer programs) that implement the functions of the above-described embodiments may be supplied to the system or apparatus. In addition to the form of the recording medium, a computer-readable recording medium may be used. Then, the computer (or CPU or MPU) of the system or apparatus reads and executes the program code stored in the recording medium. In this case, the program code itself read from the recording medium realizes the functions of the above-described embodiment, and the recording medium on which the program code is recorded constitutes the present invention. The embodiment can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

The present invention is not limited to the above embodiment, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, in order to make the scope of the present invention public, the following claims are attached.

This application claims priority on the basis of Japanese Patent Application No. 2018-077137 filed on April 12, 2018, the entire contents of which are incorporated herein by reference.

Claims

An image processing apparatus that processes a plurality of tomographic images and a plurality of planar images of an imaging region of an inspection object,
First generation means for generating a motion contrast image from the plurality of tomographic images;
Second generation means for generating blood flow information from the plurality of planar images;
An image processing apparatus comprising: control means for displaying the blood flow information on the motion contrast image.
2. The image processing apparatus according to claim 1, wherein the control means displays a symbol and a character indicating the blood flow information or an animation superimposed on the motion contrast image.
3. The image processing apparatus according to claim 1, wherein the blood flow information is a direction and / or speed of a blood flow.
A detection means for detecting a blood vessel region from the motion contrast image;
4. The image processing apparatus according to claim 1, wherein the control unit colors the detected blood vessel region according to the blood flow information. 5.
A detection means for detecting a blood vessel region from the motion contrast image;
The image processing apparatus according to claim 1, wherein the second generation unit generates blood flow information from the planar image based on position information of the blood vessel region.
Detecting means for detecting a blood vessel region from the motion contrast image;
A determination means for determining whether the detected blood vessel is an artery or a vein;
The image processing apparatus according to any one of claims 1 to 3, wherein the control means displays the blood flow information and whether it is an artery or a vein so as to be identifiable.
The second generation means includes
Obtaining the position information of the layer of the tomographic image that generated the motion contrast image;
Calculating a focus position corresponding to the position information of the layer;
The image processing apparatus according to claim 1, wherein blood flow information is created using the planar image acquired at the focus position.
A control method for an image processing apparatus that processes a plurality of tomographic images and a plurality of planar images of an imaging region of an inspection object,
A first generation step of generating a motion contrast image from the plurality of tomographic images;
A second generation step of generating blood flow information from the plurality of planar images;
A control step of displaying the blood flow information on the motion contrast image.
A program for realizing the image processing apparatus according to any one of claims 1 to 7 by a computer.
A computer-readable storage medium storing the program according to claim 9.