JP2021087817A - Image processing apparatus and image processing method - Google Patents

Abstract

To generate images making it possible to identify tissues such as newborn blood vessels and fibrotic tissue which are difficult to identify.SOLUTION: An image processing apparatus includes: information acquisition means for acquiring three-dimensional polarization tomographic information and three-dimensional motion contrast information of a subject based on tomographic signals of differently polarized light, which differently polarized light is obtained by dividing multiplexed light obtained by synthesizing return light from the subject illuminated with measurement light and reference light corresponding to the measurement light; extraction means for extracting a lesion region of the subject using the three-dimensional polarization tomographic information; and image generation means for generating an image in which the lesion region is superimposed on a motion contrast image generated using the three-dimensional motion contrast information.SELECTED DRAWING: Figure 5

Description

The present invention relates to an image processing apparatus and an image processing method for processing an image of a subject.

Optical coherence tomography (hereinafter referred to as OCT) has been put into practical use as a non-destructive and non-invasive method for acquiring a tomographic image of a living body or the like. OCT is widely used in ophthalmic diagnosis of the retina because a tomographic image of the retina in the fundus of the eye to be examined is acquired, especially in the ophthalmic field.

OCT obtains a tomographic image by interfering the light reflected from the measurement target with the light reflected from the reference mirror and analyzing the time dependence or wave number dependence of the interfering light intensity. As such an optical coherence tomographic image acquisition device, a time domain OCT that obtains depth information of a measurement target by changing the position of a reference mirror is known. Further, a spectral domain OCT (SD-OCT: Spectral Domain Optical Coherence Tomography) using a wide band light source is known. Further, a wavelength sweep optical coherence tomography (SS-OCT) device using a wavelength variable light source device capable of changing the oscillation wavelength as a light source is known. In addition, SD-OCT and SS-OCT are collectively called Fourier domain OCT (FD-OCT: Fourier Domain Optical Coherence Tomography).

In recent years, a pseudo-angiography method using this FD-OCT has been proposed and is called OCT angiography (OCTA). Fluorescence, a common angiography technique in modern clinical practice, requires the injection of a fluorescent dye (eg, fluorescein or indocyanine green) into the body. The blood vessels that serve as the path of the fluorescent dye are displayed two-dimensionally. On the other hand, OCTA enables non-invasive and pseudo angiography and can display the network of blood flow sites three-dimensionally. Furthermore, it is attracting attention because it has a higher resolution than fluorescence contrast and can visualize microvessels or blood flow in the fundus.

A plurality of OCTA methods have been proposed depending on the difference in blood flow detection method. For example, Non-Patent Document 1 proposes a method of separating an OCT signal from a bloodstream by extracting only a time-modulated signal from an OCT signal. Further, a method utilizing a phase variation due to blood flow (Non-Patent Document 2), a method utilizing a strength variation due to blood flow (Non-Patent Document 3 and Patent Document 1), and the like have also been proposed. In the present specification, a signal obtained by displaying a time-modulated signal from an OCT signal as an image may be referred to as a motion contrast image, a pixel value thereof may be referred to as a motion contrast, and a data set thereof may be referred to as a motion contrast data.

On the other hand, the polarized OCT device developed as one of the functional OCT devices can visualize structural information such as the nerve fiber layer and the retinal layer. In Non-Patent Document 4, the polarized OCT device is used to integrate three-dimensional data per unit thickness in the thickness direction for a deflection parameter called retardation in the retinal nerve fiber layer (RNFL). A technique for obtaining an Enface map to be obtained is disclosed.

U.S. Patent Application Publication No. 2014/221827

Fingerr et al. "MoBiliity and transverse flow visualization using contrast contrast contrast dominant coherence tomography" Optics Express. Vol. 15, No. 20. pp12637-12655 (2007) Optics Letters Vol. 33, Iss. 13, pp. 1530-1532 (2008) "Speckle variance detection of optical coherence tomography" Mariampilai et al. , "Optimized speckle variance OCT imaging of optics culture," Optics Letters 35, 1257-1259 (2010). Invest Opthalmol Vis Sci. 2013 Jan 7, Zotter S et al. “Measurement retina nerve fiber layer birefiringence, retardation, andthickness sing wide-field, high-speed polarization sensitive spectrum OCT

Neovascularization, which is characteristic of age-related macular degeneration (AMD) with neovascularization, proliferates rapidly when it penetrates the choroid through the Bruch's membrane and grows under or above the retinal pigment epithelium (RPE). .. Leakage of blood from these new blood vessels impairs visual function and further forms fibrotic tissue around the leaked site. In order to provide appropriate treatment for AMD patients with neovascularization, it is necessary to distinguish and understand the neovascularization and fibrosis (fibrosis). For example, for blood leakage from new blood vessels, the growth of new blood vessels can be suppressed by administering a drug that inhibits vascular endothelial growth factor (VEGF), but it is already for fibrotic tissue. This is because no effect can be expected. In addition, it is necessary to understand the changes over time in each tissue in order to judge the effect of treatment.

However, in the brightness image obtained by the conventional OCT, the RPE, the fibrotic tissue, and the new blood vessel have the same high-intensity reflection region, and it is difficult to distinguish them. In addition, either OCTA or polarized OCT could not totally identify and grasp the tissues involved in the progression of AMD. In addition, it was difficult to grasp the temporal or spatial changes of these tissues. Therefore, it was difficult to grasp the progress of the disease.

One of the objects of the present invention has been made in view of the above problems, and is to generate an image capable of identifying a tissue that is difficult to distinguish, such as a new blood vessel or a fibrotic tissue. It should be noted that the other purpose of the present invention is not limited to the above-mentioned purpose, but is an action and effect derived by each configuration shown in the embodiment for carrying out the invention described later, and exerts an action and effect that cannot be obtained by the conventional technique. It can be positioned as one.

One of the image processing devices according to the present invention is
The subject is based on a tomographic signal of light having different polarizations obtained by dividing the combined wave light obtained by combining the return light from the subject irradiated with the measurement light and the reference light corresponding to the measurement light. Information acquisition means for acquiring 3D polarized tomographic information and 3D motion contrast information of a sample,
An extraction means for extracting a lesion region of the subject using the three-dimensional polarized tomographic information, and an extraction means.
The lesion region has an image generation means for generating an image superimposed on a motion contrast image generated by using the three-dimensional motion contrast information.

According to one of the present inventions, it is possible to generate an image capable of identifying a tissue that is difficult to identify, such as a new blood vessel or a fibrotic tissue.

The figure which shows the outline of an example of the whole structure of the apparatus in this embodiment. The figure which shows an example of the scan pattern in this embodiment. The figure which shows an example of the signal processing procedure in this embodiment. The figure which shows an example of the segmentation result in this embodiment. The figure which shows an example of GUI in this embodiment. The figure which shows an example of GUI in this embodiment. The figure which shows an example of the superimposition display of the RPE thickness map and the blood vessel image in this embodiment.

Hereinafter, the imaging apparatus according to the present embodiment will be described with reference to the attached drawings. The configuration and processing procedure shown in the following embodiments are merely examples, and the present invention is not limited to the following embodiments. Further, in the present embodiment, the subject is the human eye (fundus), but the present invention is not limited to this, and may be used, for example, on the skin or the like. Further, although the imaging target is the fundus of the eye in the present embodiment, the anterior eye may be the imaging target.

<Structure of polarized OCT device>
FIG. 1 is a diagram showing a configuration example of an image processing device according to the present embodiment. In this embodiment, a polarized OCT apparatus using SS-OCT will be described. It is also possible to apply the present invention to a polarized OCT apparatus using SD-OCT. The device in the present embodiment includes an optical interference tomographic acquisition unit 800 for acquiring an optical interference tomographic signal and a control unit 143. At this time, the optical interference tomographic acquisition unit 800 is an example of an image pickup apparatus, and is communicably connected to a control unit 143 which is an example of an image processing apparatus according to the present embodiment. In addition to this form, the device configuration may be such that the control unit 143 is built in the image pickup device and integrated. Here, the control unit 143 is further composed of a signal processing unit 144, a signal acquisition control unit 145, a display control unit 149, and a display unit 146. The signal processing unit 144 is further composed of an image generation unit and a map generation unit.

First, the configuration of the optical interference fault acquisition unit 800 will be described. The light source 801 is a wavelength sweep type (Swept Source: hereinafter SS) light source, and emits light while sweeping at a sweep center wavelength of 1050 nm and a sweep width of 100 nm, for example. The light emitted from the light source 801 is a single mode fiber (hereinafter referred to as SM fiber) 802, a polarization controller 803 connector 804, an SM fiber 805, a polarizer 806, and a polarization balancing (PM) fiber (hereinafter referred to as PM fiber). Description) It is guided to a beam splitter 810 via a 807, a connector 808, and a PM fiber 809, and is split into a measurement light (also referred to as an OCT measurement light) and a reference light (also referred to as a reference light corresponding to the OCT measurement light). The branching ratio of the beam splitter 810 is 90 (reference light): 10 (measurement light). The polarization controller 103 can change the polarization of the light emitted from the light source 101 to a desired polarization state. On the other hand, the polarizer 806 is an optical element having a characteristic of passing only a specific linearly polarized light component. Normally, the light emitted from the light source 801 has a high degree of polarization and is dominated by light having a specific polarization direction, but includes light having no specific polarization direction called a random polarization component. It is known that this random polarization component deteriorates the image quality of the polarized OCT image, and the random polarization component is cut by the polarizer. Since only light in a specific linearly polarized state can pass through the polarizer 806, the polarization state is adjusted by the polarization controller 803 so that a desired amount of light is incident on the eye to be inspected 118.

The branched measurement light is emitted via the PM fiber 811 and is converted into parallel light by the collimator 812. The measurement light that has become parallel light passes through the 1/4 wave plate 813 and then enters the eye to be inspected 818 via the galvano scanner 814, the scan lens 815, and the focus lens 816 that scan the measurement light in the fundus Er of the eye to be inspected 818. To do. Here, the galvano scanner 814 is described as a single mirror, but in reality, it is composed of two galvano scanners so as to raster scan the fundus Er of the eye 118 to be inspected. Further, the focus lens 816 is fixed on the stage 817, and the focus can be adjusted by moving in the optical axis direction. The galvano scanner 814 and the stage 817 are controlled by the signal acquisition control unit 145, and the measurement light is measured in a desired range (also referred to as a tomographic image acquisition range, a tomographic image acquisition position, and a measurement light irradiation position) of the fundus Er of the eye to be inspected 118. Can be scanned. The 1/4 wave plate 813 is an optical element having a characteristic of delaying the phase between the optical axis of the 1/4 wave plate and the axis orthogonal to the optical axis by 1/4 wavelength. In this embodiment, the optical axis of the 1/4 wave plate is rotated by 45 ° with respect to the direction of linearly polarized light of the measurement light emitted from the PM fiber 811, and the light incident on the eye to be inspected 118 is circular. Polarized. Although detailed description is not given in this embodiment, it is desirable that a tracking function for detecting the movement of the fundus Er and scanning the mirror of the galvano scanner 114 by following the movement of the fundus Er is provided. The tracking method can be performed using a general technique, and can be performed in real time or by post-processing. For example, there is a method using a scanning laser ophthalmoscope (SLO). This involves acquiring a two-dimensional image of the fundus Er in a plane perpendicular to the optical axis over time using SLO, and extracting feature points such as blood vessel branches in the image. Real-time tracking can be performed by calculating how the feature portion in the acquired two-dimensional image moves as the movement amount of the fundus Er, and feeding back the calculated movement amount to the galvano scanner 814.

The measurement light is incident on the eye to be inspected 118 by the focus lens 816 mounted on the stage 817 and is focused on the fundus Er. The measurement light that irradiates the fundus Er is reflected and scattered in each retinal layer, and returns to the beam splitter 810 in the above-mentioned optical path. The return light of the measurement light incident on the beam splitter 810 passes through the PM fiber 826 and is incident on the beam splitter 828.

On the other hand, the reference light branched by the beam splitter 806 is emitted via the PM fiber 819, and is converted into parallel light by the collimator 820. The reference light enters the PM fiber 827 via the 1/2 wavelength plate 821, the dispersion compensation glass 822, the ND filter 823, and the collimator 824. One end of the collimator lens 824 and the PM fiber 827 is fixed on the coherence gate stage 825, and the signal acquisition control unit 145 is driven in the optical axis direction in response to the difference in the axial length of the subject. Is controlled by. The 1/2 wavelength plate 821 is an optical element having a characteristic of delaying the phase between the optical axis of the 1/2 wavelength plate and the axis orthogonal to the optical axis by 1/2 wavelength. In this embodiment, the linearly polarized light of the reference light emitted from the PM fiber 819 is adjusted so as to be in a polarized state in which the major axis is tilted by 45 ° in the PM fiber 827. Although the optical path length of the reference light is changed in this embodiment, it is sufficient that the optical path length difference between the optical path of the measurement light and the optical path of the reference light can be changed.

The reference light that has passed through the PM fiber 827 is incident on the beam splitter 828. In the beam splitter 828, the return light of the reference light and the reference light are combined to form the combined light (interference light) and then split into two. The divided interference light is interference light having phases that are inverted from each other (hereinafter, referred to as a positive component and a negative component). The positive component of the divided interference light enters the polarization beam splitter 835 via the PM fiber 829, the connector 831 and the PM fiber 833. On the other hand, the negative polarization component of the interference light is incident on the polarization beam splitter 836 via the PM fiber 830, the connector 832, and the PM fiber 834.

In the polarizing beam splitters 835 and 836, the interference light is divided according to the two orthogonal polarization axes, and the vertical polarization component (hereinafter, V polarization component) and the horizontal (Horizontal) polarization component (hereinafter, H polarization component) are divided. It is divided into two lights. The positive interference light incident on the polarization beam splitter 835 is split into two interference lights, a positive V polarization component and a positive H polarization component, in the polarization beam splitter 835. The divided positive V-polarized light component is incident on the detector 841 via the PM fiber 837, and the positive H-polarized light component is incident on the detector 842 via the PM fiber 838. On the other hand, the negative interference light incident on the polarization beam splitter 836 is split into a negative V polarization component and a negative H polarization component in the polarization beam splitter 836. The negative V-polarized light component is incident on the detector 841 via the PM fiber 839, and the negative H-polarized light component is incident on the detector 842 via the PM fiber 840.

Both the detectors 841 and 842 are differential detectors, and when two interference signals whose phases are inverted by 180 ° are input, the DC component is removed and only the interference component is output.

The V-polarized light component of the interference signal detected by the detector 841 and the H-polarized light component of the interference signal detected by the detector 842 are output as electric signals according to the light intensity, respectively, and the signal processing unit is an example of the tomographic image generation unit. Enter in 144.

<Scan pattern>
Here, acquiring information about the tomographic fault of the subject 118 in the depth direction is called A-scan. In addition, information about the tomographic image of the subject in the direction orthogonal to A-scan, that is, the scanning direction for acquiring a two-dimensional image is scanned in the direction orthogonal to the tomographic image obtained by B-scan and B-scan. This is called C-scan. This is because when two-dimensional raster scanning is performed in the bottom surface of the eye when acquiring a three-dimensional tomographic image, the high-speed scanning direction is B-scan, and the low-speed scanning direction in which B-scan is arranged in the orthogonal direction is C-. Called scan. A two-dimensional tomographic image can be obtained by performing A-scan and B-scan, and a three-dimensional tomographic image can be obtained by performing A-scan, B-scan and C-scan. B-scan and C-scan are performed by the above-mentioned galvano scanner 114.

The X-axis scanner 114a and the Y-axis scanner 114b (not shown) are each composed of deflection mirrors arranged so that their rotation axes are orthogonal to each other. The X-axis scanner 114a scans in the X-axis direction, and the Y-axis scanner 114b scans in the Y-axis direction. Each of the X-axis direction and the Y-axis direction is a direction perpendicular to the eye axis direction of the eyeball and is a direction perpendicular to each other. Further, the line scanning direction such as B-scan and C-scan does not have to coincide with the X-axis direction or the Y-axis direction. Therefore, the line scanning direction of B-scan and C-scan can be appropriately determined according to the two-dimensional tomographic image or the three-dimensional tomographic image to be imaged.

Next, an example of the scan pattern of the present embodiment will be described with reference to FIG. Since OCT angiography measures the time change of the OCT interference signal due to blood flow, it is necessary to perform multiple measurements at the same place (or substantially the same place). In the present embodiment, the OCT apparatus repeats the B scan at the same location m times and performs a scan that moves to the y position at n locations. A specific scan pattern is shown in FIG. B scan is repeated m times for each of n positions of y1 to yn on the fundus plane. When m is large, the number of measurements at the same place increases, so that the accuracy of blood flow detection is improved. On the other hand, the scanning time becomes long, and there arises a problem that motion artifacts occur in the image due to eye movements (fixed vision fine movements) during scanning and a problem that the burden on the subject increases. In this embodiment, m = 4 is set in consideration of the balance between the two. The control unit 143 may change m according to the A scan speed of the OCT apparatus and the motion analysis of the fundus surface image of the subject 118.

In FIG. 2, p indicates the number of samples of A scan in one B scan. That is, the plane image size is determined by p × n. If p × n is large, a wide range can be scanned at the same measurement pitch, but the scanning time becomes long, and the above-mentioned motion artifact and patient burden problems occur. In this embodiment, n = p = 300 in consideration of the balance between the two. The above n and p can be freely changed as appropriate.

Further, Δx in FIG. 2 is the interval (x pitch) between adjacent x positions, and Δy is the interval (y pitch) between adjacent y positions. In the present embodiment, the x-pitch and y-pitch are determined as 1/2 of the beam spot diameter of the irradiation light on the fundus and set to 10 μm. By setting the x-pitch and y-pitch to 1/2 the diameter of the beam spot on the fundus, it is possible to form a high-definition image to be generated. Even if the x-pitch and y-pitch are made smaller than 1/2 of the fundus beam spot diameter, the effect of further increasing the definition of the generated image is small.

On the contrary, if the x-pitch and y-pitch are made larger than 1/2 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.

<Structure of control unit 143>
The configuration and function of the control unit 143 for controlling the entire apparatus will be described. The control unit 143 is composed of a signal processing unit 144, a signal acquisition control unit 145, a display unit 146, and a display control unit 149. Further, the signal processing unit 144 further includes an image generation unit 147 and a map generation unit 148. The signal processing unit 144 is an example of information acquisition means for acquiring three-dimensional polarization tomographic information and three-dimensional motion contrast information of a subject. Further, the image generation unit 147 has a function of generating a luminance image and a motion contrast image from electrical signals (interference signals) sent from the detectors 841 and 842, and the map generator 148 has a function of generating a luminance image and a motion contrast image from the luminance image, and the map generator 148 has layer information (segmentation of the retina) from the luminance image. ) Has a function to generate.

Further, the image generation unit 147 has a function of generating a polarization characteristic image from an electric signal sent to the signal processing unit 144, and the map generation unit 148 has a function of generating a fibrotic tissue image.

The signal acquisition control unit 145 controls each unit as described above. The signal processing unit 144 generates an image, analyzes the generated image, and generates visualization information of the analysis result based on the signals output from the detectors 841 and 842.

The image and analysis result generated by the signal processing unit 144 are sent to the display control unit 149, and the display control unit 149 displays the image and the analysis result on the display screen of the display unit 146. Here, the display unit 146 is a display such as a liquid crystal display. The image data generated by the signal processing unit 144 may be transmitted to the display control unit 149 and then to the display unit 146 by wire or wirelessly. Further, in the present embodiment, the display unit 146 and the like are included in the control unit 143, but the present invention is not limited to this, and the display unit 146 and the like may be provided separately from the control unit 143. An example tablet may be used. In this case, it is preferable that the display unit is equipped with a touch panel function so that the display position of the image can be moved, enlarged / reduced, the displayed image can be changed, and the like can be operated on the touch panel.

<Signal processing>
Hereinafter, the main signal processing performed by the control unit 143 will be described with reference to FIG.

[Generation of tomographic signals for each polarization component]
In step S301, the signal processing unit 144 sets the index i of the position yi to 1. In steps S302 and S303, the signal processing unit 144 extracts repeated B scan data (m times) of each of the V-polarized light component and the H-polarized light component output from the detectors 841 and 842 at the position yi. In steps S304 and S305, the signal processing unit 144 repeatedly sets the index j of the B scan to 1. In steps S306 and S307, the signal processing unit 144 extracts the j-th (1 ≦ j ≦ m) B scan data of each of the V-polarized light component and the H-polarized light component.

In steps S308 and S309, the signal processing unit 144 performs a general reconstruction process on the B scan data of each of the V-polarized light component and the H-polarized light component extracted in S306 and S307 in the image generation unit 147. That is, the image generation unit 147 performs the following for the B scan data of the V polarization component and the H polarization component, respectively. First, fixed pattern noise is removed from the B scan data. For fixed pattern noise removal, fixed pattern noise is extracted by moving the galvano scanner 814 to a position where the measurement light is not incident on the eye 118 and averaging the acquired multiple A scan data, and the input B scan data. It is done by subtracting from. Next, the image generation unit 147 performs a desired window function processing in order to optimize the depth resolution and the dynamic range, which are in a trade-off relationship when the Fourier transform is performed in a finite interval. After that, a tomographic signal is generated by performing FFT processing. By the above processing, two tomographic signals, that is, the tomographic signal Av of the V polarization component and the H polarization component AH, and the phase difference ΔΦ between them are generated.

In steps S310 and S311 the signal processing unit 144 repeatedly increments the index j of the B scan. In steps S312 and S313, it is determined whether the signal processing unit 144 is larger than m. That is, it is determined whether the luminance calculation of the B scan at the position y is repeated m times. In the case of no, the process returns to steps S306 and S307, and the luminance calculation of the repeated B scan at the same Y position is repeated. That is, the image generation unit 147 acquires tomographic signals (tomographic images) of a plurality of H and V polarized components of the subject indicating a tomography at substantially the same location of the subject.

[Brightness image generation]
If yes is determined in steps S312 and S313, the process proceeds to step S314, and the image generation unit 147 generates a luminance image.
The luminance image is basically the same as the tomographic image in the conventional OCT, and its pixel value r is calculated by Equation 1 from the tomographic signal AH of the H-polarized light component and the tomographic signal AV of the V-polarized light component.

［輝度平均化画像生成］
ステップＳ３１５において画像生成部１４７はおのおののｙｉポジションにおける繰り返しＢスキャン（ｍフレーム）の輝度画像の位置合わせをおこない輝度平均化画像を生成する。

[Brightness averaged image generation]
In step S315, the image generation unit 147 aligns the luminance image of the repeated B scan (m frame) at each y position to generate the luminance averaged image.

Specifically, first, the image generation unit 147 selects any one of the m frames as a template. For the frames selected as the template, the correlation may be calculated for all combinations of each other, the sum of the correlation coefficients may be obtained for each frame, and the frame having the maximum sum may be selected. Next, the image generation unit 147 collates each frame with the template and obtains the amount of misalignment (δX, δY, δθ). Specifically, the image generation unit 147 calculates Normalized Cross-Correlation (NCC), which is an index showing the degree of similarity while changing the position and angle of the template image, and determines the difference in image position when this value is maximized. Obtained as the amount of misalignment.

In the present invention, the index indicating the degree of similarity can be variously changed as long as it is a scale indicating the similarity between the features of the image in the template and the frame.

Next, the image generation unit 147 applies the position correction to the m-1 frame other than the template according to the amount of misalignment (δX, δY, δθ), and aligns the m frame.

The aligned luminance image ri (1 ≦ i ≦ m) is averaged by the equation 2, and the luminance averaging image is obtained.

を生成する。

To generate.

［線維化組織画像生成］
ステップＳ３１６において画像生成部１４７は、ＨとＶの偏光成分の断層象データから複屈折性の高い領域の画像と偏光の保たれている領域の画像を求め、その２つの画像から線維化組織画像を生成する。

[Fibrotic tissue image generation]
In step S316, the image generation unit 147 obtains an image of a region having high birefringence and an image of a region where polarization is maintained from the tomographic data of the polarized light components of H and V, and fibrous tissue image from the two images. To generate.

(Retention image)
The method of obtaining the image of the region with high birefringence is shown. First, the image generation unit 147 generates a retardation image from the tomographic data of the polarized light components of H and V. The value δ of each pixel of the retardation image is a numerical value of the phase difference between the vertically polarized light component and the horizontally polarized light component at the position of each pixel constituting the tomographic image, and is expressed from each tomographic signal AH and AV. Calculated by 3.

各Ｂスキャン画像に対して式３を計算することによってリターデーション画像（偏光の位相差を示す断層画像とも言う）を得ることができる。リターデーション画像を生成することにより、複屈折性のある層を把握することが可能となる。とくに線維化した組織など、輝度断層画像では判別できない構造を抽出することが可能となる。

A retardation image (also referred to as a tomographic image showing the phase difference of polarized light) can be obtained by calculating Equation 3 for each B-scan image. By generating a retardation image, it becomes possible to grasp the layer having birefringence. In particular, it is possible to extract structures that cannot be discriminated by luminance tomographic images, such as fibrotic tissues.

Next, a region having high birefringence is extracted. Here, the boundary of the region to be extracted is determined by, for example, specifying a pixel in which the amount of change in the retardation value in the depth direction exceeds a predetermined threshold value. The amount of change in the depth direction may be obtained from the difference between the retardation values of two adjacent pixels in each pixel, or may be obtained from the inclination of linear fitting of the retardation values of a plurality of adjacent pixels. Alternatively, the retardation values of a plurality of adjacent pixels may be polynomial-fitted and obtained by differentiating them from the slope of the tangent line in each pixel. Further, it may be obtained by processing a Sobel filter or a Prewitt filter. As a result, an image of a region having high birefringence is obtained.

(DOPU image)
The method of obtaining the image of the region where polarized light is maintained is shown. The image generation unit 147 calculates the Stokes vector S of each pixel from the acquired tomographic signals AH and AV and the phase difference ΔΦ between them by Equation 4.

ただし、ΔΦは２つの断層画像を計算する際に得られる各信号の位相ΦＨとΦＶからΔΦ＝ΦＶ−ΦＨとして計算する。次に、各Ｂスキャン画像を概ね測定光の主走査方向に７０μｍ、深度方向に１８μｍ程度の大きさのウィンドウを設定し、各ウィンドウ内において式４で画素毎に計算されたストークスベクトルの各要素を平均し、当該ウィンドウ内の偏光の均一性ＤＯＰＵ（Ｄｅｇｒｅｅ Ｏｆ Ｐｏｌａｒｉｚａｔｉｏｎ Ｕｎｉｆｏｒｍｉｔｙ）を式５により計算する。

However, ΔΦ is calculated as ΔΦ = ΦV−ΦH from the phases ΦH and ΦV of each signal obtained when calculating two tomographic images. Next, for each B-scan image, a window having a size of about 70 μm in the main scanning direction of the measurement light and about 18 μm in the depth direction is set, and each element of the Stokes vector calculated for each pixel by Equation 4 in each window. Is averaged, and the polarization uniformity DOPU (Degree Of Publication Uniformity) in the window is calculated by Equation 5.

ただし、Ｑｍ、Ｕｍ、Ｖｍは各ウィンドウ内のストークスベクトルの要素Ｑ，Ｕ，Ｖを平均した値である。この処理をＢスキャン画像内の全てのウィンドウに対して行うことで、ＤＯＰＵ画像（偏光の均一度を示す断層画像とも言う）が生成される。ＤＯＰＵは、偏光の均一性を表す数値であり、偏光が保たれている個所においては１に近い数値となり、偏光が解消された保たれない箇所においては１よりも小さい数値となるものである。網膜内の構造においては、網膜色素上皮が偏光状態を解消する性質があるため、ＤＯＰＵ画像において網膜色素上皮に対応する部分は、他の領域に対してその値が小さくなる。とくに病変で不連続になった網膜色素上皮など、輝度断層画像では判別できない構造を抽出することが可能となる。次に、ＤＯＰＵ画像を閾値処理（例えば、閾値０．７５）することで、偏光が保たれている領域と、偏光が解消されている領域とを分ける。これにより、偏光が保たれている領域の画像を得る。なお、偏光特性画像には、この偏光解消情報に基づくＤＯＰＵ画像の他に、例えば上述したリターデーション情報に基づく画像（リタデーション画像）、オリエンテーション情報に基づく画像、複屈折情報に基づく画像などがある。これら画像或いは情報は、３次元偏光断層情報を構成する。

However, Qm, Um, and Vm are values obtained by averaging the elements Q, U, and V of the Stokes vector in each window. By performing this process on all windows in the B-scan image, a DOPU image (also referred to as a tomographic image showing the uniformity of polarization) is generated. DOPU is a numerical value indicating the uniformity of polarized light, and is a numerical value close to 1 at a place where polarized light is maintained, and a numerical value smaller than 1 at a place where polarized light is not maintained. In the structure in the retina, since the retinal pigment epithelium has a property of eliminating the polarized state, the value of the portion corresponding to the retinal pigment epithelium in the DOPU image becomes smaller than that of other regions. In particular, it is possible to extract structures that cannot be discriminated by luminance tomographic images, such as retinal pigment epithelium that is discontinuous due to lesions. Next, the DOPU image is subjected to threshold processing (for example, a threshold of 0.75) to separate a region in which polarized light is maintained and a region in which polarized light is depolarized. As a result, an image of a region where polarized light is maintained is obtained. In addition to the DOPU image based on the depolarization information, the polarization characteristic image includes, for example, an image based on the above-mentioned retardation information (retention image), an image based on the orientation information, an image based on the birefringence information, and the like. These images or information constitute three-dimensional polarized tomographic information.

(Fibrotic tissue image)
From the image of the region having high birefringence and the image of the region where polarization is maintained obtained by the image generation unit 147 by the above method, the map generation unit 148 has high birefringence and the region where polarization is maintained. Can be generated as a fibrotic tissue image f by extracting as an example of the lesion region. In the fibrotic tissue image f, a pixel value different from that of the other regions is set for the region having high birefringence and maintaining polarization. For example, when the fibrous tissue image f is an 8-bit unsigned image, the pixel value 0 is assigned to the non-fibrous region, and the other values are assigned pixel values according to the degree of fibrosis. Good. Here, the degree of fibrosis may be determined according to the magnitude of birefringence. Here, for the sake of explanation, a method for obtaining a fibrotic tissue image using tomographic data of H and V polarized components of an arbitrary 1 frame from the tomographic image data of the polarized components of m frames obtained by repeated B scanning. As described above, a fibrous tissue image f may be generated and used by using a tomographic image of a polarized light component obtained by averaging m-frames.

[Layer information generation (segmentation)]
In step S317, the map generation unit 148 uses the luminance averaging image generated by the image generation unit 147 in step S315.

から、網膜の層情報生成（セグメンテーション）を行う。
網膜は１０層から構成される事が知られているが、本実施例においては図４（Ａ）および以下に示すように、いくつかの層をまとめて６つの層にセグメンテーションを行う。

From, layer information generation (segmentation) of the retina is performed.
It is known that the retina is composed of 10 layers, but in this example, as shown in FIG. 4 (A) and the following, some layers are grouped together and segmentation is performed into 6 layers.

Layer 1: Nerve Fiber Layer (NFL)
Layer2: Ganglion cell layer (GCL) and inner plexiform layer (IPL)
Layer3: Inner nuclear layer (INL) and outer plexiform layer (OPL)
Layer4: Outer nuclear layer (ONL) and external limiting membrane (ELM)
Layer5: Extrapyramidal junction (IS / OS), extrapyramidal end (COST) and retinal visual cortex epithelial layer (RPE)
Layer6: Choroidal Capillary Plate (CC)
Next, the brightness averaged image

をもとに層情報ｌを得る方法を示す。

The method of obtaining the layer information l based on the above is shown.

The map generation unit 148 is a brightness averaged image.

から抜き出した処理の対象とする断層像に対して、メディアンフィルタとＳｏｂｅｌフィルタをそれぞれ適用して画像を作成する（以下、それぞれメディアン画像、Ｓｏｂｅｌ画像ともいう）。次に、作成したメディアン画像とＳｏｂｅｌ画像から、Ａスキャン毎にプロファイルを作成する。メディアン画像では輝度値のプロファイル、Ｓｏｂｅｌ画像では勾配のプロファイルとなる。そして、Ｓｏｂｅｌ画像から作成したプロファイル内のピークを検出する。検出したピークの前後やピーク間に対応するメディアン画像のプロファイルを参照することで、網膜層の各領域の境界を抽出する。但し、Ｌａｙｅｒ６はＬａｙｅｒ５の脈絡膜側の境界から脈絡膜毛細管板を含む一定の距離、例えば１０μｍに相当する位置までとしてセグメンテーションされる。

An image is created by applying a median filter and a Sobel filter to the tomographic image to be processed extracted from the above (hereinafter, also referred to as a median image and a Sobel image, respectively). Next, a profile is created for each A scan from the created median image and Sobel image. The median image has a brightness value profile, and the Sobel image has a gradient profile. Then, the peak in the profile created from the Sobel image is detected. By referring to the profile of the median image corresponding to before and after the detected peak and between the peaks, the boundary of each region of the retinal layer is extracted. However, the Layer 6 is segmented from the boundary on the choroid side of the Layer 5 to a certain distance including the choroidal capillary plate, for example, a position corresponding to 10 μm.

Further, in the segmentation of Layer 5, the map generation unit 148 determines the boundary of the RPE by using the DOPU image obtained earlier. Since RPE has a property of eliminating the polarized state by the melanocytes contained therein, the value of the portion corresponding to RPE in the DOPU image becomes smaller than that of other regions. That is, since the DOPU image images the properties derived from the structure of the RPE, even when the RPE is deformed due to a disease, the RPE can be imaged more reliably than using only the change in brightness.

Further, the map generation unit 148 calculates and maps the thickness of the RPE from the determined boundary of the RPE, and stores this as an RPE thickness map in an internal memory (not shown). FIG. 4B shows an example thereof, and the values of the pixels constituting the map correspond to the thickness of the RPE. In this example, the region GA in the center of the map corresponds to the portion where the RPE is atrophied and the thickness becomes 0 due to atrophic age-related macular degeneration.

[Blood vessel image generation (motion contrast)]
In step S318, the image generation unit 147 generates a blood vessel image from the luminance image.

First, the image generation unit 147 calculates the motion contrast. In this embodiment, the dispersion value of the signal intensity (luminance) is calculated for each pixel at the same position from the brightness image of the m frame output by the signal processing unit 144 in step S314, and the dispersion value is used as the motion contrast. That is, the image generation unit 147 calculates the motion contrast using the corresponding pixel data between the calculated tomographic image data. In addition to the variance value, any of the standard deviation, the difference value, the uncorrelated value, and the correlated value may be used. Further, the phase may be used instead of the signal strength. Further, there are various methods for obtaining the motion contrast, and in the present invention, the type of the feature amount of the motion contrast can be applied as long as it is an index showing the change in the brightness value of each pixel of the plurality of B scan images at the same Y position. .. Further, for the motion contrast, it is also possible to use a coefficient of variation normalized by the average value for each pixel of each frame instead of the variance value for each pixel at the same position from the luminance image of the tomographic image of m frame. The obtained motion contrast data constitutes a part of the three-dimensional motion contrast information described later.

Next, the image generation unit 147 performs motion contrast threshold processing. The image generation unit 147 sets the value of the motion contrast corresponding to the region where each brightness is equal to or less than the threshold value to 0. This threshold processing makes it possible to reduce noise by removing motion contrast caused by a change in brightness due to random noise, and to distinguish between blood vessels and other parts. The threshold value may be determined using the layer information acquired in step S317. The larger the threshold value, the less noise, but the lower the sensitivity of motion contrast detection. Therefore, since the present invention focuses on new blood vessels related to RPE, the noise threshold value of motion contrast may be lowered in the vicinity of RPE or in the choroid. Further, the smoothing process may be performed before and after the threshold value process. By these processes, a blood vessel image b is generated.

[Generate volume data]
In step S319, the signal processing unit 144 increments the index i of the position yi. In step S320, the signal processing unit 144 determines whether i is larger than n. That is, it is determined whether or not the predetermined processing has been performed at all the y positions at n locations. In the case of no, the process returns to S302 and S303. In the case of yes, the process proceeds to the next step S321. After the above steps, a three-dimensional image is generated next. That is, in step S321, the image generation unit 147 is a three-dimensional brightness averaged image.

を生成する。ステップＳ３２２において画像生成部１４７は、３次元の血管画像ｂ３Ｄを生成する。ステップＳ３２３において画像生成部１４７は、３次元の繊維化組織画像ｆ３Ｄを生成する。このとき、あわせて独立した線維化組織の数をカウントし記録する。また、それぞれの線維化組織の体積を計算して求めておく。ステップＳ３２４においてマップ生成部１４８は、３次元の層情報ｌ３Ｄを生成する。

To generate. In step S322, the image generation unit 147 generates a three-dimensional blood vessel image b3D. In step S323, the image generation unit 147 generates a three-dimensional fibrated tissue image f3D. At this time, the number of independent fibrotic tissues is also counted and recorded. In addition, the volume of each fibrotic tissue is calculated and obtained. In step S324, the map generation unit 148 generates three-dimensional layer information l3D.

Further, in step S325, the image generation unit 147 records the position of the blood vessel extending across the Layer 5 from the three-dimensional blood vessel image b3D and the three-dimensional layer information l3D. In addition, the positions of blood vessels existing in the vicinity of Layer 6 to Layer 5 are also recorded.

<Display method>
In step S326, the three-dimensional luminance averaged image obtained in the above steps

と３次元血管画像ｂ３Ｄと３次元線維化組織画像ｆ３Ｄと３次元層情報ｌ３Ｄと、線維化組織の体積と数、層近傍の血管の数と、を表示部１４６に表示する。以下、これらの画像と情報一式をデータセットと呼ぶことにする。表示方法の一例を図５および図６に示す。

The three-dimensional blood vessel image b3D, the three-dimensional fibrotic tissue image f3D, the three-dimensional layer information l3D, the volume and number of fibrotic tissues, and the number of blood vessels in the vicinity of the layer are displayed on the display unit 146. Hereinafter, these images and a set of information will be referred to as a data set. An example of the display method is shown in FIGS. 5 and 6.

Three-dimensional luminance averaged image in the display area 51 of FIG.

、３次元血管画像ｂ３Ｄ、３次元線維化組織画像ｆ３Ｄ、３次元層情報ｌ３Ｄの全てあるいは任意の組み合わせを重畳して表示する。また、画像の側方にあるチェックボックス５２を用いて、重畳表示から並べて表示するように切り替えることが可能である。表示された３次元画像は、検者の操作、例えばマウス操作によって、自由に回転、移動、拡大縮小ができ、任意の位置、角度から画像を見ることができる。

, 3D blood vessel image b3D, 3D fibrotic tissue image f3D, 3D layer information l3D, all or any combination are superimposed and displayed. Further, by using the check box 52 on the side of the image, it is possible to switch from the superimposed display to the side-by-side display. The displayed three-dimensional image can be freely rotated, moved, and enlarged / reduced by an examiner's operation, for example, a mouse operation, and the image can be viewed from any position and angle.

Further, as shown in FIG. 6, it is also possible to switch the display of the display area 61 to the display of a two-dimensional tomographic image or an Enface image by using the check box 62. The figure is an example of an Enface image in which a fibrotic tissue image (an example of a polarized Enface image) and a blood vessel image (an example of a motion contrast Enface image) are superimposed, and is an example of a region where the tissue is fibrotic on the blood vessel image. (Shaded part) is displayed. This makes it possible to easily grasp the fibrotic region and the state of blood vessels in that region. In this way, when the Enface image is selected according to the operation of the examiner, the Enface image is generated using the information of the layer selected in the check box 65. When a tomographic image is selected according to the operation of the examiner, the tomographic image at an arbitrary position can be displayed and selected by operating the slide bar 67, and by pressing the button 64, the tomographic image is displayed like a slide show. It is possible to automatically switch and display the images in sequence. Even when the Enface image is selected according to the operation of the examiner, the depth position of the Enface image may be selected by the operation of the slide bar 67. Further, the check box 62 and the check box 65 are examples of determination means for determining a first region in the depth direction of the subject and a second region different from the first region. In this case, when determining the first region (for example, near the RPE) and the second region (for example, near the choroid), the determining means is determined according to the operation of the examiner as in the present embodiment. However, it may be automatically determined according to the purpose of diagnosis or the like. Further, when the examiner operates the check boxes 52 and 62 to change the images and information displayed in the display areas 51 and 61, the images can be displayed in the display areas 51 and 61 in any combination of the images and information. It will be possible. With the above configuration, it becomes possible to efficiently confirm the progress of AMD and the therapeutic effect.

For example, when a blood vessel image and a fibrotic tissue are selected as display targets, the blood vessel image and the fibrotic tissue are displayed in the display areas 51 and 61, and the arrangement and distribution of the blood vessel and the fibrotic tissue can be visually grasped. It will be possible. FIG. 5 is an example thereof, in which a three-dimensional blood vessel image b3D and a three-dimensional fibrotic tissue image f3D are superimposed and displayed as a 3D image in the display area 51. On the other hand, in FIG. 6, two types of images are superimposed and displayed as a two-dimensional plane image. In each case, the shaded area shows the area where fibrosis is progressing in the fibrotic layer image, and it is possible to grasp the blood vessels in the retinal layer and the part where the tissue is denatured due to the disease as a whole. You can.

Further, by selecting the layer to be displayed in the check boxes 55 and 65 as the display target area, it is possible to display the image and information of only the layer of interest in the display areas 51 and 61. As a result, when the target disease is AMD, it is possible to display the target as Layer 4 to Layer 6, and to display the new blood vessels that are considered to develop from the choroid and grow toward the inner layer of the retina.

Further, in the check boxes 52 and 62, it is possible to select to highlight and display the blood vessels in the vicinity of the layer. FIG. 5 shows an example of this, in which blood vessels in the vicinity of the layer are highlighted with arrows. The highlight display can take various forms other than the arrow, and the color may be changed, for example. In this way, by combining the highlight function of blood vessels in the vicinity of the layer with the display selection of the choroid and the RPE layer using the check boxes 55 and 65, it becomes possible to easily and visually grasp the new blood vessels related to AMD. ..

In addition, the display unit 146 has a function of reading and displaying a data set measured and acquired in the past of the same patient. Any data set can be read and displayed by the examiner by selecting the inspection number or the inspection date and time. In FIGS. 5 and 6, the data set is switched by sliding the slide bars 53 and 63. Further, by pressing the buttons 54 and 64, it is possible to automatically switch and display the images in order according to the time series like a slide show. At this time as well, the selection by the check boxes 52 and 62 and the check boxes 55 and 65 is effective, and the image, the part, and the information that the examiner pays attention to are displayed from the past data set.

Further, in the display areas 56 and 66, the number and volume of fibrotic tissues obtained in step S323 from the past data set are displayed in a graph on the vertical axis and time on the horizontal axis. The volume of fibrotic tissue can be selected to be the total volume contained in the examination region or within the region selected by the examiner (eg, the volume of fibrotic tissue in the selected layer). In FIGS. 5 and 6, the determination is made according to the selection in the check boxes 52 and 62 and the check boxes 55 and 65. Similarly, from the past data set, the number or density or length of the blood vessels across the layer and the blood vessels in the vicinity of the layer obtained in step 325 is plotted on the vertical axis and the time is plotted on the horizontal axis. It is possible to choose whether it is the total number or density or length contained in the test area, or within the area selected by the examiner (eg, the selected layer). In FIGS. 5 and 6, the determination is made according to the selection in the check boxes 52 and 62 and the check boxes 55 and 65. In addition, the above-mentioned graph is a graph showing the time-dependent change of the value of the parameter (for example, number and volume) indicating the lesion area such as fibrotic tissue, and the time-dependent change of the value of the parameter (for example, number and density) indicating blood vessels. This is an example of a graph showing. In the follow-up of exudative AMD with new blood vessels, treatment with anti-VEGF that suppresses the development of new blood vessels is performed, but when the growth of new blood vessels and bleeding from them stop, that part becomes fibrotic as scars. Conceivable. In that case, continuous treatment increases the burden on the patient, but no medical effect can be expected. Therefore, it is important to stop the treatment based on an objective basis. Therefore, as shown by the display areas 56 and 66, the volume of the blood vessel near the layer representing the new blood vessel to be treated and the volume of the area where the lesion is inactivated are displayed in parallel in chronological order. You can make decisions efficiently.

Further, FIG. 7 shows an example in which the above-mentioned RPE thickness map and the blood vessel image are superimposed and displayed. In the figure, 71 to 77 are the same as 61 to 67 in FIG. 6, so the description thereof will be omitted, but the RPE thickness map (denoted as retinal pigment epithelial thickness image in the figure) is selected as an option for the check box 72. Has been added. By selecting the RPE thickness map and the blood vessel image, these two types of images are superimposed and displayed in the display area 71.

Here, the image displayed in the display area 71 is synthesized with the blood vessel image using the pixel value of the RPE thickness map as the transparency, so that only the blood vessel image is displayed in the region where the RPE thickness is 0. It has become. Further, the slider 78 adjusts the relationship between the pixel value of the RPE thickness map and the transparency, and is set to the condition where the RPE transparency is the lowest in the figure. In this setting, the blood vessel image is drawn only when the RPE thickness is 0, and when the slider 78 is set upward, the transmittance gradually increases according to the value of the RPE thickness so that the blood vessel image can be seen through. become. By doing so, it becomes easy to grasp the relationship between the RPE atrophy region of AMD and the state of blood vessels in the vicinity thereof.

Further, the target range (layer) of the blood vessel image displayed by the map generation unit 148 may be automatically determined from the image showing the polarization characteristics of the eye to be inspected. For example, the map generator 148 analyzes the fibrotic tissue image and the DOPU image, detects the presence or absence of the fibrotic region and the atrophic region of RPE in the retina, and depending on the result, the check boxes 55, 65 or 75 are displayed. Check automatically. In the detection of the region, a region in which the pixel value of the fibrotic layer image exceeds a preset threshold value or a region in which the RPE thickness is equal to or less than the threshold value may be detected. These thresholds can be determined in advance by analyzing a plurality of cases of related diseases in advance.

The map generation unit 148 uses Layers 4, 5 and 6 as the display area of the blood vessel image when the fibrotic region exists in the eye to be inspected, and Layer 6 as the display area of the blood vessel image when the RPE atrophy exists, and at the same time automatically checks each check box. , The blood vessel image in the layer and the image selected at that time are superimposed and displayed. Alternatively, a fibrotic tissue image may be selected if fibrotic regions are present, and an RPE thickness map may be selected if RPE atrophy is detected. In this way, the vascular region most relevant to each lesion is automatically selected, which can greatly simplify the operation of the examiner. The relationship between this lesion and the target layer may be stored in advance in the map generation unit 148 in a modifiable form. By doing so, it becomes possible to select an appropriate layer according to the situation of understanding the pathological condition.

As described above, according to the present invention, by presenting the polarization characteristics of the eye to be inspected and the image of OCT angiography at the same time, the lesion can be effectively displayed and the diagnosis can be performed efficiently.

(Other embodiments)
The present invention is also realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiment is supplied to the system or device via a network or various storage media, and the computer (or CPU, MPU, etc.) of the system or device reads the program. This is the process to be executed.

One of the image processing devices according to the present invention is
Using a three-dimensional motion contrast information of the subject and the returning light and the reference light corresponding to the measurement light obtained using a tomographic signal relating multiplexed obtained was combined light from the subject irradiated with measurement light Te, extracting means for extracting a blood vessel region of the subject,
Image generating means for generating a motor Activation contrast image image using a pre-Symbol 3-dimensional motion contrast information,
The generated image is displayed on the display means, and is within a region corresponding to each other in a plurality of motion contrast images having different inspection dates and times that can be selected according to an instruction from the examiner, and according to an instruction from the examiner. It has a display control means for causing the display means to display a graph showing a time-dependent change of information about a blood vessel obtained by using the blood vessel region in the selected region .

Claims (20)

The subject is based on a tomographic signal of light having different polarizations obtained by dividing the combined wave light obtained by combining the return light from the subject irradiated with the measurement light and the reference light corresponding to the measurement light. Information acquisition means for acquiring 3D polarized tomographic information and 3D motion contrast information of a sample,
An extraction means for extracting a lesion region of the subject using the three-dimensional polarized tomographic information, and an extraction means.
An image generation means for generating an image in which the lesion region is superimposed on a motion contrast image generated by using the three-dimensional motion contrast information.
An image processing device characterized by having. The extraction means extracts a three-dimensional lesion region of the subject using the three-dimensional polarized tomographic information.
The first aspect of the image generation means is to generate a three-dimensional image in which the three-dimensional lesion region is superimposed on the three-dimensional motion contrast image generated by using the three-dimensional motion contrast information. The image processing apparatus described. The image processing apparatus according to claim 2, wherein the image generation means generates an Enface image of a specific region of the subject using the three-dimensional image. The extraction means extracts a two-dimensional lesion region of the subject using the three-dimensional polarized tomographic information.
The image processing according to claim 1, wherein the image generation means generates an image in which the two-dimensional lesion region is superimposed on the motion contrast Enface image generated by using the three-dimensional motion contrast information. apparatus. The image processing apparatus according to any one of claims 1 to 4, further comprising a display control means for displaying the superimposed image on the display means. The extraction means extracts the blood vessels of the subject using the three-dimensional motion contrast information.
The image processing apparatus according to claim 5, wherein the display control means causes the display means to display a value of a parameter indicating the lesion area and a value of a parameter indicating the blood vessel. The extraction means extracts the blood vessels of the subject using the three-dimensional motion contrast information.
5. The display control means is characterized in that the display means displays a graph showing the time-dependent change of the value of the parameter indicating the lesion area and a graph showing the time-dependent change of the value of the parameter indicating the blood vessel. The image processing apparatus according to. The subject is based on a tomographic signal of light having different polarizations obtained by dividing the combined wave light obtained by combining the return light from the subject irradiated with the measurement light and the reference light corresponding to the measurement light. Information acquisition means for acquiring 3D polarized tomographic information and 3D motion contrast information of a sample,
A determination means for determining a first region in the depth direction of the subject and a second region different from the first region.
An extraction means for extracting the first region using the three-dimensional polarized tomographic information, and
The polarized Enface image of the first region generated by using the three-dimensional polarized tomographic information and the motion contrast Enface image of the second region generated by using the three-dimensional motion contrast information are superimposed. An image generation means for generating a two-dimensional image and
An image processing device characterized by having. It is communicably connected to an image pickup device having a detection means for detecting light having differently polarized light.
The information acquisition means acquires the three-dimensional polarized tomographic information and the three-dimensional motion contrast information based on the tomographic signal obtained by detecting the light having different polarizations by the detection means. The image processing apparatus according to any one of claims 1 to 8. The image processing apparatus according to any one of claims 1 to 9, wherein the subject is an eye to be inspected. The subject is based on a tomographic signal of light having different polarizations obtained by dividing the combined wave light obtained by combining the return light from the subject irradiated with the measurement light and the reference light corresponding to the measurement light. The process of acquiring 3D polarized tomographic information and 3D motion contrast information of a sample,
A step of extracting a lesion region of the subject using the three-dimensional polarized tomographic information, and
A step of generating an image in which the lesion region is superimposed on a motion contrast image generated by using the three-dimensional motion contrast information, and
An image processing method characterized by having. In the extraction step, the three-dimensional lesion region of the subject is extracted using the three-dimensional polarized tomographic information.
The eleventh aspect of claim 11, wherein in the generation step, a three-dimensional image in which the three-dimensional lesion region is superimposed on the three-dimensional motion contrast image generated by using the three-dimensional motion contrast information is generated. The image processing method described. The image processing method according to claim 12, wherein an Enface image of a specific region of the subject is generated using the three-dimensional image in the generation step. In the extraction step, a two-dimensional lesion region of the subject is extracted using the three-dimensional polarized tomographic information.
The image processing according to claim 11, wherein in the generation step, an image in which the two-dimensional lesion region is superimposed on the motion contrast Enface image generated by using the three-dimensional motion contrast information is generated. Method. The image processing method according to any one of claims 11 to 14, further comprising a step of displaying the superimposed image on the display means. In the extraction step, the blood vessels of the subject are extracted using the three-dimensional motion contrast information.
The image processing method according to claim 15, wherein in the step of displaying, the value of the parameter indicating the lesion area and the value of the parameter indicating the blood vessel are displayed on the display means. In the extraction step, the blood vessels of the subject are extracted using the three-dimensional motion contrast information.
15. The display control means is characterized in that the display means displays a graph showing the time-dependent change of the value of the parameter indicating the lesion area and a graph showing the time-dependent change of the value of the parameter indicating the blood vessel. The image processing method described in. The subject is based on a tomographic signal of light having different polarizations obtained by dividing the combined wave light obtained by combining the return light from the subject irradiated with the measurement light and the reference light corresponding to the measurement light. The process of acquiring 3D polarized tomographic information and 3D motion contrast information of a sample,
A step of determining a first region in the depth direction of the subject and a second region different from the first region.
A step of extracting the first region using the three-dimensional polarized tomographic information, and
The polarized Enface image of the first region generated by using the three-dimensional polarized tomographic information and the motion contrast Enface image of the second region generated by using the three-dimensional motion contrast information are superimposed. The process of generating a two-dimensional image and
An image processing method characterized by having. The image processing method according to any one of claims 11 to 18, wherein the subject is an eye to be inspected. A program comprising causing a computer to execute each step of the image processing apparatus according to any one of claims 11 to 19.

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