CN113012151A - OCT image correction method and system for SS-OCT operation navigation system - Google Patents
OCT image correction method and system for SS-OCT operation navigation system Download PDFInfo
- Publication number
- CN113012151A CN113012151A CN202110454010.2A CN202110454010A CN113012151A CN 113012151 A CN113012151 A CN 113012151A CN 202110454010 A CN202110454010 A CN 202110454010A CN 113012151 A CN113012151 A CN 113012151A
- Authority
- CN
- China
- Prior art keywords
- reference point
- region
- oct image
- oct
- area
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 48
- 238000003702 image correction Methods 0.000 title claims abstract description 20
- 238000012937 correction Methods 0.000 claims abstract description 9
- 238000012545 processing Methods 0.000 claims abstract description 5
- 230000011218 segmentation Effects 0.000 claims description 8
- 238000013519 translation Methods 0.000 claims description 7
- 230000008859 change Effects 0.000 claims description 6
- 230000005484 gravity Effects 0.000 claims description 6
- 238000004458 analytical method Methods 0.000 claims description 4
- 238000004891 communication Methods 0.000 claims description 3
- 238000001514 detection method Methods 0.000 claims description 3
- 238000000605 extraction Methods 0.000 claims description 3
- 238000012216 screening Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 10
- 230000008569 process Effects 0.000 abstract description 8
- 230000000007 visual effect Effects 0.000 abstract description 5
- 238000012014 optical coherence tomography Methods 0.000 description 96
- 210000001519 tissue Anatomy 0.000 description 29
- 238000003384 imaging method Methods 0.000 description 11
- 210000003128 head Anatomy 0.000 description 4
- 230000004075 alteration Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000001902 propagating effect Effects 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000005311 autocorrelation function Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 210000003161 choroid Anatomy 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 210000004087 cornea Anatomy 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 238000002059 diagnostic imaging Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 201000010099 disease Diseases 0.000 description 1
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 210000000554 iris Anatomy 0.000 description 1
- 238000002372 labelling Methods 0.000 description 1
- 230000003902 lesion Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 230000002207 retinal effect Effects 0.000 description 1
- 210000003583 retinal pigment epithelium Anatomy 0.000 description 1
- 210000003786 sclera Anatomy 0.000 description 1
- 210000001585 trabecular meshwork Anatomy 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/0002—Inspection of images, e.g. flaw detection
- G06T7/0012—Biomedical image inspection
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/10—Segmentation; Edge detection
- G06T7/187—Segmentation; Edge detection involving region growing; involving region merging; involving connected component labelling
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V10/00—Arrangements for image or video recognition or understanding
- G06V10/20—Image preprocessing
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V10/00—Arrangements for image or video recognition or understanding
- G06V10/20—Image preprocessing
- G06V10/25—Determination of region of interest [ROI] or a volume of interest [VOI]
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/10—Image acquisition modality
- G06T2207/10072—Tomographic images
- G06T2207/10101—Optical tomography; Optical coherence tomography [OCT]
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/20—Special algorithmic details
- G06T2207/20092—Interactive image processing based on input by user
- G06T2207/20104—Interactive definition of region of interest [ROI]
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V10/00—Arrangements for image or video recognition or understanding
- G06V10/20—Image preprocessing
- G06V10/24—Aligning, centring, orientation detection or correction of the image
- G06V10/247—Aligning, centring, orientation detection or correction of the image by affine transforms, e.g. correction due to perspective effects; Quadrilaterals, e.g. trapezoids
Abstract
The invention discloses an OCT image correction method and system for an SS-OCT operation navigation system, which comprises the following steps: 1) for the distorted OCT image, dividing a target area in the OCT image into three parts according to the relative position of a scalpel and a tissue structure, and recording the three parts as an area I, an area II and an area III; 2) correcting the vertical distortion of the area I; 3) correcting the distortion of the area II; 4) region iii is used as a reference and no processing is performed to obtain a corrected OCT image. The invention sets the datum point through the position relation of the scalpel and the tissue structure in the operation, divides the OCT image into regions by utilizing the datum point, and then performs distortion correction in a pertinence manner according to the characteristics of each region, thereby effectively eliminating the image distortion caused by refraction and scattering effects in the operation process, leading the OCT image to be more visual and vivid, and bringing great convenience to the positioning of focus, the observation of adjacent tissues and the implementation of the operation.
Description
Technical Field
The invention relates to the field, in particular to an OCT image correction method and system for an SS-OCT operation navigation system.
Background
Optical Coherence Tomography (OCT), as a non-contact tomographic imaging technique, has the characteristics of high resolution, high sensitivity, and the like, and is widely applied to medical imaging. At present, the OCT technology is mostly used for ophthalmic imaging, and not only can display macrostructures such as cornea, iris, sclera, and the like, but also can provide images of microstructures such as trabecular meshwork, visual cross tube, Schlemm's tube, and the like, and is an important auxiliary means in diagnosis and treatment of ophthalmic diseases. According to the OCT two-dimensional image collected before the operation, a doctor can plan an operation path, judge tissue lesion, navigate the operation in real time and evaluate the operation effect, so that the operation wound is reduced, and the operation time is shortened. OCT technology has become an indispensable loop in ophthalmic surgical navigation. With the development of the high-speed Swept-frequency optical coherence tomography (SS-OCT), the axial scanning speed of OCT reaches hundreds of kHz, and the imaging depth and sensitivity of OCT are greatly improved, so that the real-time imaging of internal faults of human tissues and surgical instruments in the surgical process is realized, and thus, the SS-OCT-based surgical navigation system is rapidly developed in the clinical field. However, in practical applications, a series of problems still exist in the SS-OCT based surgical navigation system, and the most problematic issue for the doctor is the image distortion caused by the refraction effect and scattering effect of different tissue structures during the imaging process.
Biological tissues are not completely transparent to light, photons can interact with the biological tissues when propagating in the tissues, and then absorption, scattering, refraction and reflection phenomena are generated, and SS-OCT extracts the amplitude, phase and polarization characteristics of light propagating in the biological tissues by utilizing a coherent gate method so as to obtain a chromatographic image of the biological tissues. However, in the imaging process, the refraction effect and the scattering effect of different tissues and physiological structures have a certain difference, so that the OCT image of the biological tissue sample is deformed and distorted to some extent. For such OCT image distortion caused by refraction and scattering effects, many image correction methods have been proposed. Chong et al, in an article (ultra high resolution imaging by visual light OCT with longitudinal imaging. biomed Opt express 2018; 9(4): 1477) 1491), compensates for the longitudinal chromatic aberration of the retinal OCT image by using a chromatic aberration compensation method, and an autocorrelation function of speckle shrinks twenty percent of the transverse direction in the axial direction, so that layered structures such as choroid, retinal pigment epithelium and the like are clearly displayed in a visual field in the imaging process, the longitudinal distortion is eliminated, and the image quality is improved. Sergio et al, in an article (Optical correction in Optical Coherence Tomography for quantitative ocular analysis segment by three-dimensional imaging. opt. express 18, 2782-. However, in the clinical use process of SS-OCT, only distortion correction is performed on tissue images, which cannot meet the requirements of doctors, doctors need to continuously perform real-time imaging on the position of a focus in the operation process, and intervention of surgical instruments brings more distortion and even shielding on focus area images, which brings serious influences on the positioning of the focus, observation of adjacent tissues and implementation of the operation.
Therefore, there is a need for a more reliable solution for correcting OCT images of SS-OCT surgical navigation systems.
Disclosure of Invention
The invention aims to solve the technical problem of providing an OCT image correction method and system of an SS-OCT surgical navigation system aiming at the defects in the prior art.
In order to solve the technical problems, the invention adopts the technical scheme that: an OCT image correction method for an SS-OCT surgical navigation system comprises the following steps:
1) dividing a target area in an OCT image collected in an SS-OCT operation navigation system into three parts according to the relative position of a scalpel and a tissue structure, and recording the three parts as an area I, an area II and an area III;
the SS-OCT surgical navigation system comprises a field I, a field II and a field III, wherein the field I has vertical distortion, the field I, the field II and the field III are sequentially connected in the transverse direction, a surgical knife adopted in the SS-OCT surgical navigation system comprises a knife handle and a knife head connected to the knife handle, and the knife head is provided with a knife tip;
wherein, the area I is a distortion area inside the tissue, and the knife tip ends at the junction of the scalpel and the tissue; the area II is a junction distortion area and comprises an area in a certain range of the junction of the scalpel and the tissue; the region III is a normal region outside the tissue, and the boundary of one end of the boundary distortion region, which is far away from the region I, is stopped at the tail end of the scalpel handle;
2) the vertical distortion of the region I is corrected: vertically translating the area I to stop when the continuity of the whole boundary of the scalpel in the translated image meets the preset requirement;
3) and (3) correcting the distortion of the area II: selecting a region corresponding to the region II in the distorted OCT image processed in the step 2) from the original OCT image without the scalpel, marking the region as a background II, covering the region II in the distorted OCT image processed in the step 2) with the background II in the original OCT image, connecting the upper and lower boundaries of the scalpel part in the region I with the upper and lower boundaries of the scalpel part in the region II respectively by using a white solid line, and setting the internal region of the connected scalpel part in the region II as black;
4) the area iii is used as a reference for the steps 2) and 3), and a corrected OCT image is obtained without processing.
Preferably, in the step 1), the target area is divided into an area i, an area ii and an area iii by 9 datum points, the area i, the area ii and the area iii are sequentially connected from left to right, and the 9 datum points are sequentially marked as datum points 1 to 9;
wherein, datum point 1 is the tool nose, datum points 2 and 3 are respectively the upper end point and the lower end point of the connection part of the tool bit and the tool shank, datum points 4, 5, 6 and 7 are 4 end points of the boundary of the region where the tool shank is intersected with the region II, and datum point 8 and datum point 9 are respectively the upper boundary point and the lower boundary point of the rightmost end of the tool shank.
Preferably, the method of extracting the reference points 1 to 9 in the distorted OCT image is:
1-1) searching the gravity center of the image, setting an ROI (region of interest) with pixels A multiplied by pixels B at the gravity center of the obtained image, and detecting the position of a reference point 1 in the ROI by using a corner point;
1-2) screening connected domains of the images, reserving the connected domain with the largest area, wherein the connected domain comprises the whole lower surface boundary of the scalpel, and the rightmost end point obtained by traversing the boundary is a reference point 9; searching a first white pixel point vertically upwards as a reference point 8 by taking the reference point 9 as a starting point;
1-3) extracting the lower surface boundary of the scalpel from a communication domain with the largest area through the reference point 1 and the reference point 9, then selecting a gradient change extreme point through gradient analysis of continuous pixel points, and combining the gradient change extreme point with a Shi-Tomasi corner detection result to obtain the positions of the reference point 3, the reference point 5 and the reference point 7;
1-4) searching the first white pixel point vertically upwards by using the reference point 3 as a reference point 2, searching the first white pixel point vertically upwards by using the reference point 5 as a reference point 4, and searching the first white pixel point vertically upwards by using the reference point 7 as a reference point 6 to finish 9 reference point extractions.
Preferably, in step 1), the segmentation method for the region i includes:
making a vertical line along the vertical direction of the distorted OCT image after passing through the reference point 1, and recording as a first vertical line; making a vertical line along the vertical direction of the distorted OCT image by passing through the reference point 4 and the reference point 5, and recording as a second vertical line;
a line segment 124 obtained by connecting reference point 1, reference point 2, and reference point 4 in this order by a straight line is taken as an upper boundary i, and a region surrounded by the first perpendicular line, the upper boundary i, the second perpendicular line, and the lower boundary of the distorted OCT image is divided into regions i.
The segmentation method of the area II comprises the following steps: making a vertical line along the vertical direction of the distorted OCT image by passing through the reference point 6 and the reference point 7, recording as a third vertical line, connecting the reference point 4 with the reference point 6 through a straight line, and taking an obtained line segment 46 as an upper boundary II; an area surrounded by the second vertical line, the upper boundary ii, the third vertical line, and the lower boundary of the distorted OCT image is divided as an area ii.
Preferably, the method for dividing the region iii comprises: making a vertical line along the vertical direction of the distorted OCT image by passing through the reference point 8 and the reference point 9, recording as a fourth vertical line, connecting the reference point 6 with the reference point 8 through a straight line, and taking an obtained line segment 68 as an upper boundary III; a region surrounded between the third vertical line, the upper boundary iii, the fourth vertical line, and the lower boundary of the distorted OCT image is divided as a region iii.
Preferably, the step 2) is specifically: vertically translating the whole area I, correspondingly marking the point distribution after the translation from the reference point 1 to the reference point 5 as a reference point 1 'to a reference point 5', connecting the reference point 2 'and the reference point 4' by a straight line as a line segment 2'4', connecting the reference point 4 'and the reference point 6 by a straight line as a line segment 4'6, and connecting the reference point 6 and the reference point 8 by a straight line as a line segment 68;
the judgment method for judging whether the continuity of the whole boundary of the scalpel in the translated image meets the preset requirement is that the continuity of the whole boundary of the scalpel in the translated image meets the requirement after the region I is translated: the difference between the gradient values of the line segment 4'6 and the line segment 68 is smaller than the set threshold K, and the difference between the gradient values of the line segment 2'4' and the line segment 68 is also smaller than the set threshold K.
Preferably, after the translation in step 2), the upper boundary ii becomes a line segment 4'6, and the region ii is specifically a region surrounded by the second vertical line, the line segment 4'6, the third vertical line and the lower boundary of the OCT image;
the step 3) is specifically as follows: selecting a region corresponding to the region II in the distorted OCT image processed in the step 2) from the original OCT image without the scalpel, marking the region as a background II, covering the region II in the distorted OCT image processed in the step 2) with the background II in the original OCT image, connecting the reference point 4 'with the reference point 6 by using a white solid line, connecting the reference point 5' with the reference point 7, and arranging the reference point 4', the reference point 6, the reference point 7 and the reference point 5' into black in a region surrounded by connecting the reference point 4', the reference point 6, the reference point 7 and the reference point 5' in sequence by straight lines, thereby completing the distortion correction of the region II.
Preferably, in the step 1-1), a ═ B ═ 100
The invention also provides an OCT image correction system for the SS-OCT surgical navigation system, which corrects the distorted OCT image obtained by the SS-OCT surgical navigation system by adopting the method.
The invention has the beneficial effects that: the OCT image correction method for the SS-OCT surgical navigation system, provided by the invention, has the advantages that the reference points are set according to the position relation between the surgical knife and the tissue structure in the operation, the OCT image is subjected to region division by utilizing the reference points, and then the distortion correction is performed pertinently according to the characteristics of each region, so that the image distortion caused by refraction and scattering effects in the operation process is effectively eliminated, the OCT image is more visual and vivid, and great convenience is brought to the positioning of a focus, the observation of adjacent tissues and the implementation of the operation.
Drawings
FIG. 1 is a flow chart of an OCT image rectification method for an SS-OCT surgical navigation system of the present invention;
FIG. 2 is an image of an aberrated OCT prior to correction in an embodiment of the invention;
FIG. 3 is a schematic diagram of the labeling of the reference points and the areas of the distorted OCT image according to the embodiment of the invention;
figure 4 is a corrected OCT image according to an embodiment of the present invention.
Detailed Description
The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.
It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.
Example 1
Referring to fig. 1, an OCT image correction method for an SS-OCT surgical navigation system of the present embodiment includes the following steps:
s1, dividing a target area in the OCT image into three parts according to the relative position of the scalpel and the tissue structure of the distorted OCT image collected in the SS-OCT surgical navigation system, and recording the three parts as an area I, an area II and an area III;
the SS-OCT surgical navigation system comprises a field I, a field II and a field III, wherein the field I has vertical distortion, the field I, the field II and the field III are sequentially connected in the transverse direction, a surgical knife adopted in the SS-OCT surgical navigation system comprises a knife handle and a knife head connected to the knife handle, and the knife head is provided with a knife tip; in this embodiment, an artificial gem scalpel is selected, the tissue structure below the scalpel is clearly visible, and the OCT image distortion caused by the refraction and scattering effects is small. In the embodiment, the rigidity characteristic of the scalpel is utilized to assist in correcting the distorted OCT image.
Wherein, the area I is a distortion area inside the tissue, and the knife tip ends at the junction of the scalpel and the tissue; the area II is a junction distortion area and comprises an area in a certain range of the junction of the scalpel and the tissue; the region III is a normal region outside the tissue, and the boundary of one end of the boundary distortion region, which is far away from the region I, is stopped at the tail end of the scalpel handle.
Referring to fig. 3, in step S1, the target area is divided into an area i, an area ii, and an area iii by selecting 9 reference points from the image, and the area i, the area ii, and the area iii are sequentially connected from left to right, and the 9 reference points are sequentially marked as reference points 1 to 9;
wherein, datum point 1 is the tool nose, datum points 2 and 3 are respectively the upper end point and the lower end point of the connection part of the tool bit and the tool shank, datum points 4, 5, 6 and 7 are 4 end points of the boundary of the region where the tool shank is intersected with the region II, and datum point 8 and datum point 9 are respectively the upper boundary point and the lower boundary point of the rightmost end of the tool shank.
Specifically, the method for extracting the reference points 1 to 9 from the distorted OCT image includes:
1-1) searching the gravity center of the image, setting a ROI (region of interest) with 100 pixels by 100 pixels at the gravity center of the obtained image, and detecting the position of a reference point 1 in the ROI by using a corner point;
1-2) screening connected domains of the images, reserving the connected domain with the largest area, wherein the connected domain comprises the whole lower surface boundary of the scalpel, and the rightmost end point obtained by traversing the boundary is a reference point 9; searching a first white pixel point vertically upwards as a reference point 8 by taking the reference point 9 as a starting point;
1-3) extracting the lower surface boundary of the scalpel from a communication domain with the largest area through the reference point 1 and the reference point 9, then selecting a gradient change extreme point through gradient analysis of continuous pixel points, and combining the gradient change extreme point with a Shi-Tomasi corner detection result to obtain the positions of the reference point 3, the reference point 5 and the reference point 7;
1-4) searching a first white pixel point vertically upwards by using the reference point 3 as a reference point 2, searching a first white pixel point vertically upwards by using the reference point 5 as a reference point 4, searching a first white pixel point vertically upwards by using the reference point 7 as a reference point 6, completing extraction of 9 reference points, and then segmenting three regions.
The segmentation method of the region I comprises the following steps:
making a vertical line along the vertical direction of the distorted OCT image after passing through the reference point 1, and recording as a first vertical line; making a vertical line along the vertical direction of the distorted OCT image by passing through the reference point 4 and the reference point 5, and recording as a second vertical line;
a line segment 124 obtained by connecting reference point 1, reference point 2, and reference point 4 in this order by a straight line is taken as an upper boundary i, and a region surrounded by the first perpendicular line, the upper boundary i, the second perpendicular line, and the lower boundary of the distorted OCT image is divided into regions i.
The segmentation method of the area II comprises the following steps: making a vertical line along the vertical direction of the distorted OCT image by passing through the reference point 6 and the reference point 7, recording as a third vertical line, connecting the reference point 4 with the reference point 6 through a straight line, and taking an obtained line segment 46 as an upper boundary II; an area surrounded by the second vertical line, the upper boundary ii, the third vertical line, and the lower boundary of the distorted OCT image is divided as an area ii.
The segmentation method of the region III comprises the following steps: making a vertical line along the vertical direction of the distorted OCT image by passing through the reference point 8 and the reference point 9, recording as a fourth vertical line, connecting the reference point 6 with the reference point 8 through a straight line, and taking an obtained line segment 68 as an upper boundary III; a region surrounded between the third vertical line, the upper boundary iii, the fourth vertical line, and the lower boundary of the distorted OCT image is divided as a region iii.
S2, correcting vertical distortion of the region I
And vertically translating the area I to stop when the continuity of the whole boundary of the scalpel in the translated image meets the preset requirement. For the distortion area in the tissue, the distortion is only in the vertical direction under the influence of the scalpel, so the required correction can be realized through vertical translation.
The specific method comprises the following steps: vertically translating the whole area I, correspondingly marking the point distribution after the translation from the reference point 1 to the reference point 5 as a reference point 1 'to a reference point 5', connecting the reference point 2 'and the reference point 4' by a straight line as a line segment 2'4', connecting the reference point 4 'and the reference point 6 by a straight line as a line segment 4'6, and connecting the reference point 6 and the reference point 8 by a straight line as a line segment 68;
the judgment method for judging whether the continuity of the whole boundary of the scalpel in the translated image meets the preset requirement is that the continuity of the whole boundary of the scalpel in the translated image meets the requirement after the region I is translated: when the difference between the gradient values of the line segment 4'6 and the line segment 68 is smaller than the set threshold K, and the difference between the gradient values of the line segment 2'4 'and the line segment 68 is also smaller than the set threshold K, that is, the gradient values of the line segment 2'4', the line segment 4'6 and the line segment 68 are similar, the continuity of the whole boundary of the scalpel is good. Of course, the slope of the three line segments may be compared to determine that the continuity is good when the slopes of the three line segments (line segment 2'4', line segment 4'6, and line segment 68) are similar.
S3, correcting the distortion of the area II
For the distorted image of the tissue boundary, the distortion is too complex and the influence on the operation navigation is not large, so the requirement of covering the image at the boundary in the original OCT image can be met.
After the translation in step S2, the upper boundary ii becomes the line segment 4'6, and the region ii is specifically a region surrounded by the second vertical line, the line segment 4'6, the third vertical line, and the lower boundary of the OCT image;
the specific method for correcting the distortion of the region II comprises the following steps: in the original OCT image without the scalpel, a region corresponding to the region ii in the distorted OCT image processed in step S2 is selected and recorded as the background ii, the region ii in the distorted OCT image processed in step S2 is covered with the background ii in the original OCT image, the reference point 4 'and the reference point 6 are connected by a white solid line, the reference point 5' and the reference point 7 are connected, the region surrounded by the reference point 4', the reference point 6, the reference point 7, and the reference point 5' which are connected in sequence by straight lines is set to black, a continuous scalpel boundary is established, and the distortion of the region ii is corrected.
S4 and region iii are referred to in step S2 and step S3, and a corrected OCT image is obtained without processing. The partial image is used as a reference for adjusting an internal distorted image and a tissue boundary distorted image of a normal image outside the tissue, and is not distorted and not subjected to redundant processing.
Referring to fig. 2, the distorted OCT image before correction in the present embodiment is shown, and for the sake of easy understanding, each region, boundary, and reference point in the distorted OCT image are labeled in detail in fig. 3. The image 4 is the corrected OCT image in this embodiment, and it can be seen that in the corrected OCT image, image distortion caused by refraction and scattering effects is substantially eliminated, and the requirements of SS-OCT surgical navigation can be initially met.
Example 2
The embodiment provides an OCT image correction system for an SS-OCT surgical navigation system, which corrects a distorted OCT image obtained by the SS-OCT surgical navigation system by adopting the method of embodiment 1.
While embodiments of the invention have been disclosed above, it is not limited to the applications listed in the description and the embodiments, which are fully applicable in all kinds of fields of application of the invention, and further modifications may readily be effected by those skilled in the art, so that the invention is not limited to the specific details without departing from the general concept defined by the claims and the scope of equivalents.
Claims (9)
1. An OCT image correction method for an SS-OCT surgical navigation system is characterized by comprising the following steps:
1) dividing a target area in an OCT image collected in an SS-OCT operation navigation system into three parts according to the relative position of a scalpel and a tissue structure, and recording the three parts as an area I, an area II and an area III;
the SS-OCT surgical navigation system comprises a field I, a field II and a field III, wherein the field I has vertical distortion, the field I, the field II and the field III are sequentially connected in the transverse direction, a surgical knife adopted in the SS-OCT surgical navigation system comprises a knife handle and a knife head connected to the knife handle, and the knife head is provided with a knife tip;
wherein, the area I is a distortion area inside the tissue, and the knife tip ends at the junction of the scalpel and the tissue; the area II is a junction distortion area and comprises an area in a certain range of the junction of the scalpel and the tissue; the region III is a normal region outside the tissue, and the boundary of one end of the boundary distortion region, which is far away from the region I, is stopped at the tail end of the scalpel handle;
2) the vertical distortion of the region I is corrected: vertically translating the area I to stop when the continuity of the whole boundary of the scalpel in the translated image meets the preset requirement;
3) and (3) correcting the distortion of the area II: selecting a region corresponding to the region II in the distorted OCT image processed in the step 2) from the original OCT image without the scalpel, marking the region as a background II, covering the region II in the distorted OCT image processed in the step 2) with the background II in the original OCT image, connecting the upper and lower boundaries of the scalpel part in the region I with the upper and lower boundaries of the scalpel part in the region II respectively by using a white solid line, and setting the internal region of the connected scalpel part in the region II as black;
4) the area iii is used as a reference for the steps 2) and 3), and a corrected OCT image is obtained without processing.
2. The OCT image correction method for the SS-OCT surgical navigation system of claim 1, wherein the target region is divided into region I, region II, and region III in step 1) by 9 fiducial points, and the region I, region II, and region III are connected in sequence from left to right, and the 9 fiducial points are sequentially marked as fiducial points 1 to 9;
wherein, datum point 1 is the tool nose, datum points 2 and 3 are respectively the upper end point and the lower end point of the connection part of the tool bit and the tool shank, datum points 4, 5, 6 and 7 are 4 end points of the boundary of the region where the tool shank is intersected with the region II, and datum point 8 and datum point 9 are respectively the upper boundary point and the lower boundary point of the rightmost end of the tool shank.
3. The OCT image correction method for an SS-OCT surgical navigation system according to claim 2, wherein a method of extracting reference point 1 to reference point 9 in the distorted OCT image is:
1-1) searching the gravity center of the image, setting an ROI (region of interest) with pixels A multiplied by pixels B at the gravity center of the obtained image, and detecting the position of a reference point 1 in the ROI by using a corner point;
1-2) screening connected domains of the images, reserving the connected domain with the largest area, wherein the connected domain comprises the whole lower surface boundary of the scalpel, and the rightmost end point obtained by traversing the boundary is a reference point 9; searching a first white pixel point vertically upwards as a reference point 8 by taking the reference point 9 as a starting point;
1-3) extracting the lower surface boundary of the scalpel from a communication domain with the largest area through the reference point 1 and the reference point 9, then selecting a gradient change extreme point through gradient analysis of continuous pixel points, and combining the gradient change extreme point with a Shi-Tomasi corner detection result to obtain the positions of the reference point 3, the reference point 5 and the reference point 7;
1-4) searching the first white pixel point vertically upwards by using the reference point 3 as a reference point 2, searching the first white pixel point vertically upwards by using the reference point 5 as a reference point 4, and searching the first white pixel point vertically upwards by using the reference point 7 as a reference point 6 to finish 9 reference point extractions.
4. The OCT image correction method for the SS-OCT surgical navigation system of claim 3, wherein in step 1), the segmentation method for the region I is as follows:
making a vertical line along the vertical direction of the distorted OCT image after passing through the reference point 1, and recording as a first vertical line; making a vertical line along the vertical direction of the distorted OCT image by passing through the reference point 4 and the reference point 5, and recording as a second vertical line;
a line segment 124 obtained by connecting reference point 1, reference point 2, and reference point 4 in this order by a straight line is taken as an upper boundary i, and a region surrounded by the first perpendicular line, the upper boundary i, the second perpendicular line, and the lower boundary of the distorted OCT image is divided into regions i.
The segmentation method of the area II comprises the following steps: making a vertical line along the vertical direction of the distorted OCT image by passing through the reference point 6 and the reference point 7, recording as a third vertical line, connecting the reference point 4 with the reference point 6 through a straight line, and taking an obtained line segment 46 as an upper boundary II; an area surrounded by the second vertical line, the upper boundary ii, the third vertical line, and the lower boundary of the distorted OCT image is divided as an area ii.
5. The OCT image correction method for the SS-OCT surgical navigation system of claim 4, wherein the region III segmentation method is: making a vertical line along the vertical direction of the distorted OCT image by passing through the reference point 8 and the reference point 9, recording as a fourth vertical line, connecting the reference point 6 with the reference point 8 through a straight line, and taking an obtained line segment 68 as an upper boundary III; a region surrounded between the third vertical line, the upper boundary iii, the fourth vertical line, and the lower boundary of the distorted OCT image is divided as a region iii.
6. The OCT image correction method for the SS-OCT surgical navigation system of claim 5, wherein the step 2) is specifically: vertically translating the whole area I, correspondingly marking the point distribution after the translation from the reference point 1 to the reference point 5 as a reference point 1 'to a reference point 5', connecting the reference point 2 'and the reference point 4' by a straight line as a line segment 2'4', connecting the reference point 4 'and the reference point 6 by a straight line as a line segment 4'6, and connecting the reference point 6 and the reference point 8 by a straight line as a line segment 68;
the judgment method for judging whether the continuity of the whole boundary of the scalpel in the translated image meets the preset requirement is that the continuity of the whole boundary of the scalpel in the translated image meets the requirement after the region I is translated: the difference between the gradient values of the line segment 4'6 and the line segment 68 is smaller than the set threshold K, and the difference between the gradient values of the line segment 2'4' and the line segment 68 is also smaller than the set threshold K.
7. The OCT image correction method for the SS-OCT surgical navigation system of claim 6, wherein after the translation of step 2), the upper boundary II becomes a line segment 4'6, and the region II is specifically a region surrounded by the second vertical line, the line segment 4'6, the third vertical line, and the lower boundary of the OCT image;
the step 3) is specifically as follows: selecting a region corresponding to the region II in the distorted OCT image processed in the step 2) from the original OCT image without the scalpel, marking the region as a background II, covering the region II in the distorted OCT image processed in the step 2) with the background II in the original OCT image, connecting the reference point 4 'with the reference point 6 by using a white solid line, connecting the reference point 5' with the reference point 7, and arranging the reference point 4', the reference point 6, the reference point 7 and the reference point 5' into black in a region surrounded by connecting the reference point 4', the reference point 6, the reference point 7 and the reference point 5' in sequence by straight lines, thereby completing the distortion correction of the region II.
8. The OCT image correction method for an SS-OCT surgical navigation system according to claim 3, wherein in step 1-1), a-B-100.
9. An OCT image correction system for an SS-OCT surgical navigation system, characterized in that it corrects a distorted OCT image obtained by the SS-OCT surgical navigation system using the method according to any one of claims 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110454010.2A CN113012151B (en) | 2021-04-26 | 2021-04-26 | OCT (optical coherence tomography) image correction method and system for SS-OCT operation navigation system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110454010.2A CN113012151B (en) | 2021-04-26 | 2021-04-26 | OCT (optical coherence tomography) image correction method and system for SS-OCT operation navigation system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113012151A true CN113012151A (en) | 2021-06-22 |
| CN113012151B CN113012151B (en) | 2024-02-13 |
Family
ID=76380364
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110454010.2A Active CN113012151B (en) | 2021-04-26 | 2021-04-26 | OCT (optical coherence tomography) image correction method and system for SS-OCT operation navigation system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113012151B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114445353A (en) * | 2022-01-12 | 2022-05-06 | 广州永士达医疗科技有限责任公司 | OCT image deformation detection method and device |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1719477A (en) * | 2005-05-19 | 2006-01-11 | 上海交通大学 | Calibration method of pick up camera or photographic camera geographic distortion |
| US20090003666A1 (en) * | 2007-06-27 | 2009-01-01 | Wu Dee H | System and methods for image analysis and treatment |
| CN103698301A (en) * | 2014-01-03 | 2014-04-02 | 北京航空航天大学 | Improved SD-OCT (spectral domain-optical coherence tomography) system |
| CN110996836A (en) * | 2017-07-27 | 2020-04-10 | 阿莱恩技术有限公司 | System and method for processing orthodontic appliances by optical coherence tomography |
| JP2020137672A (en) * | 2019-02-27 | 2020-09-03 | 株式会社トプコン | Ophthalmologic information processing apparatus, ophthalmologic apparatus, ophthalmologic information processing method, and program |
-
2021
- 2021-04-26 CN CN202110454010.2A patent/CN113012151B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1719477A (en) * | 2005-05-19 | 2006-01-11 | 上海交通大学 | Calibration method of pick up camera or photographic camera geographic distortion |
| US20090003666A1 (en) * | 2007-06-27 | 2009-01-01 | Wu Dee H | System and methods for image analysis and treatment |
| CN103698301A (en) * | 2014-01-03 | 2014-04-02 | 北京航空航天大学 | Improved SD-OCT (spectral domain-optical coherence tomography) system |
| CN110996836A (en) * | 2017-07-27 | 2020-04-10 | 阿莱恩技术有限公司 | System and method for processing orthodontic appliances by optical coherence tomography |
| JP2020137672A (en) * | 2019-02-27 | 2020-09-03 | 株式会社トプコン | Ophthalmologic information processing apparatus, ophthalmologic apparatus, ophthalmologic information processing method, and program |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114445353A (en) * | 2022-01-12 | 2022-05-06 | 广州永士达医疗科技有限责任公司 | OCT image deformation detection method and device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113012151B (en) | 2024-02-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10893797B2 (en) | User interface for efficiently displaying relevant OCT imaging data | |
| EP1976424B1 (en) | A method of eye examination by optical coherence tomography | |
| Bagci et al. | Thickness profiles of retinal layers by optical coherence tomography image segmentation | |
| US20200000333A1 (en) | Ophthalmic diagnosis support apparatus and ophthalmic diagnosis support method | |
| JP5739323B2 (en) | Optical coherence tomography eye registration method | |
| CN111616800B (en) | Ophthalmic surgery navigation system | |
| Tian et al. | Automatic anterior chamber angle assessment for HD-OCT images | |
| EP1085834B1 (en) | Imaging and analyzing movement of individual erythrocytes in blood vessels | |
| JP7368568B2 (en) | ophthalmology equipment | |
| US20180353066A1 (en) | Image processing apparatus and image processing method | |
| CN108765388A (en) | The automatic division method and system of esophagus endoscopic OCT image level structure | |
| CN113012151A (en) | OCT image correction method and system for SS-OCT operation navigation system | |
| JP6516597B2 (en) | Image processing apparatus and image processing method | |
| JP6504903B2 (en) | Ophthalmic imaging apparatus, operation method thereof, and computer program | |
| Medhi et al. | Analysis of maculopathy in color fundus images | |
| CN105411523A (en) | Cornea image processing method | |
| Samawi et al. | Optic disc segmentation in retinal fundus images using morphological techniques and intensity thresholding | |
| JP6604743B2 (en) | Information processing apparatus, operating method thereof, and computer program | |
| JP6882242B2 (en) | Ophthalmic equipment and its control method | |
| JP6602043B2 (en) | Information processing apparatus, operating method thereof, and computer program | |
| Wang et al. | Primary acute angle-closure glaucoma: three-dimensional reconstruction imaging of optic nerve heard structure in based on optical coherence tomography (OCT) | |
| Tang et al. | Correction of refractive and scattered image distortions in optical coherence tomography based on scalpel | |
| Pchelkina et al. | An Algorithm for Automatic Image Segmentation Using the Sobel Method for an Optical Coherence Tomography | |
| Williams et al. | A 3D segmentation framework for cornea segmentation in anterior segment OCT images using level set technique with shape prior | |
| CN118015066A (en) | OCT image-based boundary pixel height acquisition method and application of optical biological measuring instrument calibration device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |