Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Data
  • Type

Search results

Number of results: 7
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

Optical coherence tomography (OCT) – a kind of optical counterpart of ultrasound imaging – is continually being improved as image contrast boosting techniques are developed.

Go to article

Authors and Affiliations

Karol Karnowski
Download PDF Download RIS Download Bibtex

Abstract

Optical Coherence Tomography (OCT) is one of the most rapidly advancing techniques. This method is capable of non-contact and non-destructive investigation of the inner structure of a broad range of materials. Compared with other methods which belong to the NDE/NDT group (Non-Destructive Evaluation/Non-Destructive Testing methods), OCT is capable of a broad range of scattering material structure visualization. Such a non-invasive and versatile method is very demanded by the industry. The authors applied the OCT method to examine the corrosion process in metal samples coated by polymer films. The main aim of the research was the evaluation of the anti-corrosion protective coatings using the OCT method. The tested samples were exposed to a harsh environment. The OCT measurements have been taken at different stages of the samples degradation. The research and tests results have been presented, as well as a brief discussion has been carried out.

Go to article

Authors and Affiliations

Paulina Antoniuk
Marcin Strąkowski
Jerzy Pluciński
Bogdan Kosmowski
Download PDF Download RIS Download Bibtex

Abstract

Hydroxyapatite (HAp) has been attracting widespread interest in medical applications. In a form of coating, it enables to create a durable bond between an implant and surrounding bone tissues. With addition of silver nanoparticles HAp should also provide antibacterial activity. The aim of this research was to evaluate the composition of hydroxyapatite with silver nanoparticles in a non-destructive and non-contact way. For control measurements of HAp molecular composition and solvent evaporation efficiency the Raman spectroscopy has been chosen. In order to evaluate dispersion and concentration of the silver nanoparticles inside the hydroxyapatite matrix, the optical coherence tomography (OCT) has been used. Five samples were developed and examined ‒ a reference sample of pure HAp sol and four samples of HAp colloids with different silver nanoparticle solution volume ratios. The Raman spectra for each solution have been obtained and analyzed. Furthermore, a transverse-sectional visualization of every sample has been created and examined by means of OCT.

Go to article

Authors and Affiliations

Maciej J. Głowacki
Marcin Gnyba
Paulina Strąkowska
Mateusz Gardas
Maciej Kraszewski
Michał Trojanowski
Marcin R. Strąkowski
Download PDF Download RIS Download Bibtex

Abstract

In this paper methods and their examination results for automatic segmentation and parameterization of vessels based on spectral domain optical coherence tomography (SD-OCT) of the retina are presented. We present three strategies for morphologic image processing of a fundus image reconstructed from OCT scans. A specificity of initial image processing for fundus reconstruction is analysed. Then, the parameterization step is performed based on the vessels segmented with the proposed algorithm. The influence of various methods on the vessel segmentation and fully automatic vessel measurement is analysed. Experiments were carried out with a set of 3D OCT scans obtained from 24 eyes (12 healthy volunteers) with the use of an Avanti RTvue OCT device. The results of automatic vessel segmentation were numerically compared with those prepared manually by the medical doctor experts.

Go to article

Authors and Affiliations

Tomasz Marciniak
ORCID: ORCID
Agnieszka Stankiewicz
Adam Dąbrowski
ORCID: ORCID
Marcin Stopa
Piotr Rakowicz
Elżbieta Marciniak
Download PDF Download RIS Download Bibtex

Abstract

The aim of the study was to determine the thickness of choroidal layers in mixed breed dogs suffering from retinal atrophy (RA) and showing symptoms of progressive retinal atrophy (PRA), with the use of SD-OCT. The study was performed on 50 dogs divided into two groups: 25 dogs diagnosed with retinal atrophy (RA) with PRA symptoms aged 1.5-14 years and 25 healthy dogs aged 2-12 years. The dogs were examined using slit-lamp biomicroscopy, tonometry, ophthalmoscopy, fundus camera and SD-OCT (Topcon 3D OCT 2000). Measurements of the choroidal layers: RPE-Bruch membrane-choriocapillaris complex (RPE-BmCc) with tapetum lucidum in tapetal fundus, medium-sized vessel layer, (MSVL), large vessel layer with lamina suprachoroidea and (LVLS) whole choroidal thickness (WCT) were taken manually with the use of the caliper function integrated with the SD-OCT software. The measurements were performed dorsally (D) and ventrally (V) at a distance of 5000-6000 μm, and temporally (T) and nasally (N) at a distance of 4000-7000 μm from the optic disc with enhanced depth scans. The measurements were conducted temporally and nasally both in the tapetal (TempT, Nast) and nontapetal (TempNT, NasNT) fundus. Statistical analysis was performed using Statistica 10 software (Mann Whitney U Test). In all dogs affected by retinal atrophy (RA) with PRA symptoms, a statistically significant (p≤0,05) reduction in thickness of MSVL was observed in all the measured regions. A statistically significant reduction in thickness of LVLS and WCT was found in all nontapetal areas (p≤0,05). RA in mixed breed dogs with PRA symptoms was accompanied by choroid disorders such as reduction in thickness of the large vessel layer and decreased whole choroidal thickness in the nontapetal fundus as well as the medium vessel layer in all fundus regions.
Go to article

Bibliography

Adhi M, Regatieri CV, Branchini LA, Zhang JY, Alwassia AA, Duker JS (2013) Analysis of the morphology and vascular layers of the choroid in retinitis pigmentosa using spectral-domain OCT. Ophthalmic Surg Lasers Imaging Retina 44: 252-259.

André C, Chaudieu G, Thomas A, Jongh O, Jegou JP, Chahory S, Clerc B, Pilorge P, Brenac O (2008) Hereditary retinopathies in the dog: Ge-netic fundamentals and genetic tests. Pratique Médicale et Chirurgicale de l’Animal de Compagnie 43: 75-84.

Balicki I, Szadkowski M, Balicka A, Lew M, Trbolova A (2018) Assessment of generalized progressive retinal atrophy (GPRA) in mixed breed dogs using spectral domain optical coherence tomography (SD‐OCT) and electroretinography. Abstracts: Annual Scientific Meeting of the European College of Veterinary Ophthalmologists, Florence, Italy May 10‐13, 2018. Veterinary Ophthalmology Vol. 21 Issue 5.

Barnett K C, Curtis R, Millichamp N J (1983): The differential diagnosis of retinal degeneration in the dog and cat. J Small Anim Pract 24: 663-673.

Bruè C, Mariotti C, De Franco E, Fisher Y, Guidotti JM, Giovannini A (2013) Solar Retinopathy: A Multimodal Analysis. Case Rep Ophthalmol Med 2013: 906920.

Brusini P (2018) OCT Glaucoma Staging System: a new method for retinal nerve fiber layer damage classification using spectral-domain OCT. Eye (Lond) 32: 113-119.

Downs LM, Hitti R, Pregnolato S, Mellersh CS (2014) Genetic screening for PRA ‐associated mutations in multiple dog breeds shows that PRA is heterogeneous within and between breeds. Vet Ophthalmol 17: 126-130.

Ekesten B, Komáromy AM, Ofri R, Petersen-Jones SM, Narfström K (2013) Guidelines for clinical electroretinography in the dog: 2012 update. Doc Ophthalmol 127: 79-87.

Finzi A, Cellini M, Strobbe E, Campos EC (2014) ET-1 plasma levels, choroidal thickness and multifocal electroretinogram in retinitis pigmentosa. Life Sci 118: 386-390.

Gabriele ML, Wollstein G, Ishikawa H, Kagemann L, Xu J, Folio LS, Schuman JS (2011) Optical coherence tomography: History, current status, and laboratory work. Invest Ophthalmol Vis Sci 52: 2425-2436.

Korte GE, Reppucci V, Henkind P (1984) RPE destruction causes choriocapillary atrophy. Invest Ophthalmol Vis Sci. 25: 1135-1145.

Lesiuk TP, Braekevelt CR (1983) Fine structure of the canine tapetum lucidum. J Anat. 136: 157-164.

Liu G, Liu X, Li H, Du Q, Wang F (2016) Optical coherence tomographic analysis of retina in retinitis pigmentosa patients. Ophthalmic Res 56: 111-122.

Maggs D, Miller P, Ofri R (2017). In: Slatter’s fundamentals of veterinary ophthalmology. 6th ed., Elsevier Health Sciences, St. Louis, pp 362-372.

McLellan GJ, Rasmussen CA (2012) Optical coherence tomography for the evaluation of retinal and optic nerve morphology in animal subjects: practical considerations. Vet Ophthalmol 15 (Suppl 2): 13-28.

Milam AH, Li ZY, Fariss RN (1998) Histopathology of the human retina in retinitis pigmentosa. Prog Retin Eye Res 17: 175-205.

Murthy RK, Haji S, Sambhav K, Grover S, Chalam KV (2016) Clinical applications of spectral domain optical coherence tomography in retinal diseases. Biomed J 39: 107-120.

Nickla DL, Wallman J (2010) The multifunctional choroid. Prog Retin Eye Res 29: 144-168.

Oh JK, Nuzbrokh Y, Lima de Carvalho JR Jr, Ryu J, Tsang SH (2020) Optical coherence tomography in the evaluation of retinitis pigmentosa. Ophthalmic Genet 41: 413-419.

Poornachandra B, Khurana AK, Sridharan P, Chatterjee P, Jayadev C, Yadav NK, Shetty R (2019) Quantifying microstructural changes in retinitis pigmentosa using spectral domain - optical coherence tomography. Eye Vis (Lond) 6: 13.

Rosolen SG, Rivière ML, Lavillegrand S, Gautier B, Picaud S, LeGargasson JF (2012) Use of a combined slit‐lamp SD‐OCT to obtain anterior and posterior segment images in selected animal species. Vet Ophthalmol 15 (Suppl 2): 105-115.

Saint-Geniez M, Kurihara T, Sekiyama E, Maldonado AE, D’Amore PA (2009) An essential role for RPE-derived soluble VEGF in the mainte-nance of the choriocapillaris. Proc Natl Acad Sci USA 106: 18751-18756.

Shintani K, Shechtman DL, Gurwood AS (2009) Review and update: Current treatment trends for patients with retinitis pigmentosa. Optometry 80: 384-401.

Singh SR, Vupparaboina KK, Goud A, Dansingani KK, Chhablani J (2019) Choroidal imaging biomarkers. Surv Ophthalmol 64: 312-333.

Xu J, Wang YX, Jiang R, Wei WB, Xu L, Jonas JB (2017) Peripapillary choroidal vascular layers: the Beijing Eye Study. Acta Ophthalmol 95: 619-628.

Zwolska J, Balicki I, Balicka A (2023) Morphological and morphometric analysis of canine choroidal layers using spectral domain optical coher-ence tomography. Int J Environ Res Public Health 20: 3121.

Zwolska J, Szadkowski M, Balicka A, Balicki I (2021) Morphometrical analysis of the canine choroid in relation to age and sex using spectral domain optical coherence tomography. Acta Vet Hung 69: 266-273.

Go to article

Authors and Affiliations

J. Zwolska
1
I. Balicki
1
A. Balicka
2
B. Kuduk
1

  1. Department and Clinic of Animal Surgery, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Głęboka 30, 20-612 Lublin, Poland
  2. Small Animals Clinic,University of Veterinary Medicine and Pharmacy in Košice, Komenského 73, 040 01 Košice, Slovakia
Download PDF Download RIS Download Bibtex

Abstract

This paper presents signal processing aspects for automatic segmentation of retinal layers of the human eye. The paper draws attention to the problems that occur during the computer image processing of images obtained with the use of the Spectral Domain Optical Coherence Tomography (SD OCT). Accuracy of the retinal layer segmentation for a set of typical 3D scans with a rather low quality was shown. Some possible ways to improve quality of the final results are pointed out. The experimental studies were performed using the so-called B-scans obtained with the OCT Copernicus HR device.

Go to article

Authors and Affiliations

Agnieszka Stankiewicz
Tomasz Marciniak
Adam Dąbrowski
Marcin Stopa
Piotr Rakowicz
Elżbieta Marciniak
Download PDF Download RIS Download Bibtex

Abstract

Optical low-coherence interferometry is one of the most rapidly advancing measurement techniques. This technique is capable of performing non-contact and non-destructive measurement and can be used not only to measure several quantities, such as temperature, pressure, refractive index, but also for investigation of inner structure of a broad range of technical materials. We present theoretical description of low-coherence interferometry and discuss its unique properties. We describe an OCT system developed in our Department for investigation of the structure of technical materials. In order to provide a better insight into the structure of investigated objects, our system was enhanced to include polarization state analysis capability. Measurement results of highly scattering materials e.g. PLZT ceramics and polymer composites are presented. Moreover, we present measurement setups for temperature, displacement and refractive index measurement using low coherence interferometry. Finally, some advanced detection setups, providing unique benefits, such as noise reduction or extended measurement range, are discussed.

Go to article

Authors and Affiliations

J. Pluciński
R. Hypszer
P. Wierzba
M. Strąkowski
M. Jędrzejewska-Szczerska
M. Maciejewski
B.B. Kosmowski

This page uses 'cookies'. Learn more