scholarly journals Post-Processing Method for Image Reconstruction Enhancement in Integrating-Bucket-Based Full-Field Optical Coherence Tomography

2020 ◽  
Vol 10 (3) ◽  
pp. 830
Author(s):  
Juhyung Lee ◽  
Taeil Yoon ◽  
Byeong Ha Lee

An integrating-bucket method is widely used as a reconstruction tool for full-field optical coherence tomography (FF-OCT). However, it requires high-precision adjustments of the phase modulation parameters. If the parameters are not optimal, the reconstructed tomogram will incur severe artifacts. We propose a post-processing method for removing or reducing such artifacts by utilizing a correction factor extracted from a pre-reconstructed tomogram. FF-OCT imaging created using a coin verifies the effectiveness of the method not only for a single en face image but also for an entire 3-D image. It is expected that the proposed method will expand the application of FF-OCT from biomedical imaging to semiconductor wafers or display panel inspections.

2016 ◽  
Vol 7 (2) ◽  
pp. 354-358
Author(s):  
Yu Ichioka ◽  
Akihito Uji ◽  
Nagahisa Yoshimura

Background: To present an intraoperative acute Descemet’s fold formation using swept-source optical coherence tomography (SS-OCT) imaging. Case Report: A 67-year-old man complaining of reduced visual acuity in the left eye. A 25-gauge pars plana vitrectomy combined with phacoemulsification cataract surgery was performed to remove the vitreomacular traction. When hydro-sealing was performed, striae rapidly spread in the cornea. SS-OCT B-scan images performed on postoperative day 1 revealed a wavy Descemet’s membrane that might correspond to Descemet’s folds. Pairs of hypo- and hyperreflective narrow lesions running from the wavy Descemet’s membrane to almost half of the thickness of the whole cornea were observed. En face OCT imaging clearly showed the stromal fold, which continuously spread from the Descemet’s fold. Conclusion: The stromal fold might be due to the focal bulge of the stroma posteriorly caused by the rapid volume increase of the stroma which could push Descemet’s membrane posteriorly, thereby forming a wavy Descemet’s membrane layer.


2020 ◽  
Vol 29 (9) ◽  
pp. 823-830
Author(s):  
Andrew J. Nelson ◽  
Zhongdi Chu ◽  
Bruce Burkemper ◽  
Brenda R. Chang ◽  
Benjamin Xu ◽  
...  

2019 ◽  
Vol 11 (2) ◽  
pp. 44 ◽  
Author(s):  
Maciej Wojtkowski ◽  
Patrycjusz Stremplewski ◽  
Egidijus Auksorius ◽  
Dawid Borycki

Optical Coherence Imaging (OCI) including Optical Coherence Tomography (OCT) and Optical Coherence Microscopy (OCM) uses interferometric detection to generate high-resolution volumetric images of the sample at high speeds. Such capabilities are significant for in vivo imaging, including ophthalmology, brain, intravascular imaging, as well as endoscopic examination. Instrumentation and software development allowed to create many clinical instruments. Nevertheless, most of OCI setups scan the incident light laterally. Hence, OCI can be further extended by wide-field illumination and detection. This approach, however, is very susceptible to the so-called crosstalk-generated noise. Here, we describe our novel approach to overcome this issue with spatio-temporal optical coherence manipulation (STOC), which employs spatial phase modulation of the incident light. Full Text: PDF ReferencesL. Wang, P. P. Ho, C. Liu, G. Zhang, and R. R. Alfano, "Ballistic 2-D Imaging Through Scattering Walls Using an Ultrafast Optical Kerr Gate", Science 253, 769-771 (1991). CrossRef D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K. Gregory, C. A. Puliafito, and et al., "Optical coherence tomography", Science 254, 1178-1181 (1991). CrossRef J. A. Izatt, E. A. Swanson, J. G. Fujimoto, M. R. Hee, and G. M. Owen, "Optical coherence microscopy in scattering media", Opt. Lett. 19, 590-592 (1994). CrossRef D. Borycki, M. Nowakowski, and M. Wojtkowski, "Control of the optical field coherence by spatiotemporal light modulation", Opt. Lett. 38, 4817-4820 (2013). CrossRef D. Borycki, M. Hamkalo, M. Nowakowski, M. Szkulmowski, and M. Wojtkowski, "Spatiotemporal optical coherence (STOC) manipulation suppresses coherent cross-talk in full-field swept-source optical coherence tomography", Biomed. Opt. Express 10, 2032-2054 (2019). CrossRef P. Stremplewski, E. Auksorius, P. Wnuk, L. Kozon, P. Garstecki, and M. Wojtkowski, "In vivo volumetric imaging by crosstalk-free full-field OCT", Optica 6, 608-617 (2019). CrossRef L. Vabre, A. Dubois, and A. C. Boccara, "Thermal-light full-field optical coherence tomography", Opt. Lett. 27, 530-532 (2002). CrossRef M. Laubscher, M. Ducros, B. Karamata, T. Lasser, and R. Salathé, "Video-rate three-dimensional optical coherence tomography", Opt. Express 10, 429-435 (2002). CrossRef Dubois and A. C. Boccara, Full-Field Optical Coherence Tomography, (Springer Berlin Heidelberg, Berlin, Heidelberg, 2008), pp. 565-591. CrossRef O. Thouvenin, K. Grieve, P. Xiao, C. Apelian, and A. C. Boccara, "En face coherence microscopy [Invited]", Biomedical Opt. Express 8, 622-639 (2017). CrossRef F. Fercher, C. K. Hitzenberger, M. Sticker, E. Moreno-Barriuso, R. Leitgeb, W. Drexler, and H. Sattmann, "A thermal light source technique for optical coherence tomography", Optics Commun. 185, 57-64 (2000). CrossRef R. A. Leitgeb, "En face optical coherence tomography: a technology review [Invited]", Biomed Opt Express 10, 2177-2201 (2019). CrossRef J. Fujimoto and W. Drexler, Introduction to Optical Coherence Tomography, (Springer, Berlin, Heidelberg, 2008), pp. 1-45. CrossRef J. A. Izatt, M. A. Choma, and A.-H. Dhalla, Theory of Optical Coherence Tomography, (Springer International Publishing, Cham, 2015), pp. 65-94. CrossRef


2013 ◽  
Vol 18 (12) ◽  
pp. 1 ◽  
Author(s):  
Paul M. McNamara ◽  
Hrebesh M. Subhash ◽  
Martin J. Leahy

2017 ◽  
Vol 28 (2) ◽  
pp. 234-240 ◽  
Author(s):  
Rita Serra ◽  
Alexandre Sellam ◽  
Florence Coscas ◽  
Elsa Bruyère ◽  
André Sieiro ◽  
...  

Purpose: To compare the optical coherence tomography angiography (OCT-A) findings of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in eyes with pseudophakic cystoid macular edema (PCME) with those of fluorescein angiography (FA) and spectral-domain optical coherence tomography (SD-OCT) and to compare PCME vascular density values of the SCP and DCP with those of healthy eyes. Methods: In this retrospective observational study, 13 eyes (12 patients) with PCME underwent comprehensive ophthalmologic examinations including visual acuity, FA, SD-OCT, and OCT-A. The vascular density of the SCP and DCP were measured using AngioAnalytics software in all PCME eyes and compared with 46 healthy eyes of 25 subjects. Results: In patients with PCME, at the level of SCP, the mean vascular density in the whole en face image was 44.48 ± 3.61% while it was 50.27 ± 5.30% at the level of the DCP. In contrast, the vascular density in the whole en face image was 50.35 ± 3.22 at the level of SCP while it was 56.15 ± 3.28 at the level of DCP in 46 healthy eyes of 25 subjects. The vascular density of patients with PCME was significantly lower than in healthy subjects at the SCP (p<0.0001) and at the DCP (p<0.0001). Conclusion: We report the OCT-A appearance of PCME and vascular density map with values that can be easily interpreted for quantitative evaluation of retina perfusion status using OCT-A. This approach might be the first step in helping us fully understand the pathophysiologic mechanisms underlying PCME.


2020 ◽  
Vol 8 (1) ◽  
pp. e001120 ◽  
Author(s):  
Atsuko Katsuyama ◽  
Sentaro Kusuhara ◽  
Shun-Ichiro Asahara ◽  
Shun-Ichiro Nakai ◽  
Sotaro Mori ◽  
...  

ObjectiveTo evaluate the usefulness of en face slab optical coherence tomography (OCT) imaging for monitoring diabetic retinal neurodegeneration with supporting animal experimental data.Research design and methodsWe retrospectively examined 72 diabetic eyes over 3 years using Cirrus-HD OCT. Two-dimensional en face slab OCT images of the innermost retina were reconstructed and graded according to the ratio of dark area to total area, and relative red, green, and blue color area ratios were calculated and used as indexes for each en face slab OCT image. Values from en face OCT images were used for statistical analyses. To obtain insight into the pathogenesis of diabetic retinal neurodegeneration, we used the InsPr-Cre;Pdk1flox/flox diabetic mouse model.ResultsBoth OCT grade and relative red color area ratio significantly increased with the advancing stage of diabetic retinopathy (p=0.018 and 0.006, respectively). After a mean follow-up period of 4.6 years, the trend was unchanged in the analyses of 42 untreated eyes (p<0.001 and 0.001, respectively). Visual acuity showed a weak but significant negative correlation with the red color ratio on en face slab OCT images, but central retinal thickness did not exhibit a clinically meaningful correlation with values obtained from en face slab OCT images. Immunohistochemical analyses of InsPr-Cre;Pdk1flox/flox diabetic mice demonstrated the loss of ganglion axon bundles and thinning of laminin without apparent retinal vascular change at the age of 20 weeks.ConclusionsEn face slab OCT imaging would be a novel useful modality for the assessment of diabetic retinal neurodegeneration as it could detect subtle optical changes occurring in the innermost retina in diabetic eyes. Our animal experimental data suggest that dark areas observed on en face slab OCT images might be the impairment of the extracellular matrix as well as neurons.


Author(s):  
Wanrong Gao ◽  
Siyu Liu

In this work, we report a method of removing scattering induced retardance in polarization sensitive full field optical coherence tomography (PS-FFOCT). First, the Mueller matrix that describes its operation is derived. The thickness invariant retardance induced by the scattering of collagenous fiber bundles is then used to find the accurate values of the birefringence of the layers that consist collagenous fibers. Finally, the initial en face birefringent images of in vitro beef tendon samples are presented to demonstrate the capability of our method.


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