This paper presents basic principles of optical coherence tomography, review of applications and basic categorization of these systems. Paper also deals with the typical properties of images from optical coherence tomography, especially speckle pattern. This paper also provides an overview of the origin of speckle noise and utilization of its dependence on microstructure of probed tissue for image classification based on textural analysis. Experimental part of this paper consists of phantom preparation, data acquisition by OCT system, implementation of speckle analysis in MATLAB and of testing of its functionality on standard textural dataset and also on acquired image phantom data. Speckle analysis is used for phantom image data segmentation.

[pt] Foram desenvolvidas fontes ópticas para obtenção de imagens por tomografia de coerência óptica com alta resolução. Dois tipos de abordagens foram realizados, uma com um laser contínuo sintonizável, que neste trabalho foi instrumentado com marcadores de frequência óptica, outra com uma fonte óptica pulsada de banda larga. Mediante um processo de calibricação desenvolvido neste trabalho, a fonte contínua forneceu resoluções de 8 μm e alcances até 0,5 mm, enquanto que a fonte pulsada forneceu resoluções de 3 μm e alcances de 300 μm. A fonte pulsada permitiu ainda a obtenção de imagens em tempo real com capacidade de captura de movimento do objeto. / [en] Optical sources to obtain images through high resolution optical coherence tomography were developed. Two approaches were taken, one with a continuously tunable external cavity laser which, in this work, was modified to produce optical frequency markers, the other with an ultra-wideband pulsed source. Using a calibration process we developed in this work the continuously tunable source continued to achieve resolutions 8 μm and ranges of 0.5 mm, while the pulsed source achieved resolutions of 3.3 μm and ranges of 300 μm. The pulsed source has the capacity to capture real time images.

Glaucoma is the second leading cause of blindness in the world. The disease is characterized by irreversible damage to retinal ganglion cells. Once glaucoma is detected, further vision loss can be prevented by pharmacological or surgical treatment. However, current diagnostic methods lack the necessary sensitivity and up to 40% of vision maybe irreversibly lost before detection occurs. A Swept Source Polarization-Sensitive Optical Coherence Tomography (SS-PSOCT) instrument for high sensitivity cross-sectional imaging of optical anisotropy in turbid media has been designed, constructed, and verified. A multiple-state nonlinear fitting algorithm was used to measure birefringence of the retinal nerve fiber layer with less than 1%± average uncertainty. To perform eye imaging efficiently a slit-lamp based interface for the SS-PSOCT instrument with a Line Scanning Laser Ophthalmoscope (LSLO) was used. This interface allowed for repeatable, stable, and registered measurements of the retina. A fixation target was used to stabilize the volunteer’s eye and image desired areas of the retina. The LSLO allowed for an optimization of the location of OCT scans on the retina and provided a fundus blood vessel signature for registration between different imaging sessions. The SS-PSOCT system was used to measure depth-resolved thickness, birefringence, phase retardation and optic axis orientation of the retinal nerve fiber layer in normal volunteers. The peripapillary area around the optic nerve head (ONH) is most sensitive to glaucoma changes and hence data was acquired as concentric ring scans about the ONH with increasing diameters from 2mm to 5mm. Imaging of normal patients showed that higher values of phase retardation occurred superior and inferior to the optic nerve head especially next to blood vessels and thicker parts of the retinal nerve fiber layer. / text

In laser materials processing, the direct measurement and characterization of material and process depth is traditionally a diffcult task. This is particularly difficult when such information needs to be obtained in real-time for feedback and dynamic analysis applications. This thesis outlines a novel method and apparatus for real-time depth measurement during laser processes such as welding, drilling, cutting and ablation called inline coherent imaging (ICI). The approach borrows the coherent imaging ideas from the primarily medical field of optical coherence tomography and adapts them to the new application. Without requirements for flawless image quality and limitations on sample exposure the design is free to emphasize speed in acquisition and processing. Furthermore, the imaging optics are specialized for compatibility with off-the-shelf beam delivery systems. Several generations of the imaging technique and relevant design equations are described and shown and realized. Also described is the design and construction of two laser processing stations used for testing ICI in macro- and micro-processing applications. A variety of applications for ICI in the understanding of percussion drilling and welding of metals and other industrial materials are discussed. The imaging technique is further extended to provide manual and fully automatic closed-loop control of drilling and ablation processes in industrial materials. Finally, some important applications of ICI in the processing of bone in both open and closed-loop configurations are demonstrated. / Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2012-11-20 15:31:21.708

<p>Advancements in retinal imaging technologies have drastically improved the quality of eye care in the past couple decades. Scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) are two examples of critical imaging modalities for the diagnosis of retinal pathologies. However current-generation SLO and OCT systems have limitations in diagnostic capability due to the following factors: the use of bulky tabletop systems, monochromatic imaging, and resolution degradation due to ocular aberrations and diffraction. </p><p>Bulky tabletop SLO and OCT systems are incapable of imaging patients that are supine, under anesthesia, or otherwise unable to maintain the required posture and fixation. Monochromatic SLO and OCT imaging prevents the identification of various color-specific diagnostic markers visible with color fundus photography like those of neovascular age-related macular degeneration. Resolution degradation due to ocular aberrations and diffraction has prevented the imaging of photoreceptors close to the fovea without the use of adaptive optics (AO), which require bulky and expensive components that limit the potential for widespread clinical use. </p><p>In this dissertation, techniques for extending the diagnostic capability of SLO and OCT systems are developed. These techniques include design strategies for miniaturizing and combining SLO and OCT to permit multi-modal, lightweight handheld probes to extend high quality retinal imaging to pediatric eye care. In addition, a method for extending true color retinal imaging to SLO to enable high-contrast, depth-resolved, high-fidelity color fundus imaging is demonstrated using a supercontinuum light source. Finally, the development and combination of SLO with a super-resolution confocal microscopy technique known as optical photon reassignment (OPRA) is demonstrated to enable high-resolution imaging of retinal photoreceptors without the use of adaptive optics.</p> / Dissertation

Background: Optical coherence tomography (OCT), multifocal electroretinography (mfERG) and full-field electroretinography (ffERG) give important information about retinal structure and function. Purpose: To collect normative data of macular Cirrus Spectral domain (SD)-OCT assessments and of mfERG measurements of healthy children (papers I and II). To assess the macular thickness with Cirrus SD-OCT and the retinal function with ffERG in 6.5-year-old children born extremely preterm and in children born at term (papers III and IV). Methods: Study participants aged 5-15 years and living in Uppsala County were randomly chosen from the Swedish Birth Register (papers I and II). In papers III and IV, the study participants consisted of children born extremely preterm and children born at term – all were aged 6.5 years. In paper III, the children were living in Stockholm and Uppsala health care regions and, in paper IV, in Uppsala health care region only. Macular thickness was assessed with Cirrus SD-OCT and macular function with mfERG, using the Espion Multifocal system and DTL-electrodes. The retinal function was assessed with ffERG and DTL-electrodes, using the Espion Ganzfield system. Results: Altogether, 58 children participated in paper I and 49 children in paper II. In paper I, the repeatability and reproducibility of the OCT assessments were good. In paper II, the results of the mfERG measurements were in accordance with retinal cone density and there were no significant differences between the right and left eyes. In paper III, 134 preterm children and 145 children born at term constituted the study population. The central macular thickness was significantly thicker in the preterm group than in the control group. Within the preterm group, gestational age (GA), former retinopathy of prematurity (ROP) and male gender were all important risk factors for an increased macular thickness. In paper IV, 52 preterm children and 45 control children constituted the study population. Significantly lower amplitudes and prolonged implicit times of the combined rod and cone responses, as well as of the isolated cone responses, were found in the preterm group when compared with the control group. In paper IV, there was no association between GA, ROP or male gender and the ffERG assessments. Conclusion: Normative data of Cirrus SD-OCT and mfERG assessments were reported. The results of the assessments were reliable. Children aged 6.5 years, born extremely preterm, had a significantly thicker central macula and both rod and cone function were significantly reduced in comparison to children born at term. ROP had an influence on retinal structure but not retinal function in the present cohorts. Our results suggest that retinal development is abnormal in children born extremely preterm. Long-term follow-up studies are necessary in order to evaluate the functional ophthalmological outcome in this vulnerable population of children growing up today.

OBJETIVO: Utilizar a tomografia de coerência óptica (TCO) de domínio Fourier para avaliar as camadas internas da retina de olhos de pacientes com esclerose múltipla (EM) ou neuromielite óptica (NMO), com ou sem história de neurite óptica (NO), e compará-los entre si e com os olhos de controles normais. Investigar a correlação entre os achados da TCO e os achados do campo visual nesse grupo de pacientes. MÉTODOS: Cento e oitenta e dois indivíduos foram estudados incluindo 74 com diagnóstico de EM, 33 com NMO, 30 com mielite transversa aguda longitudinal extensa (MTALE) e 45 controles normais. Todos os indivíduos foram submetidos a exame oftalmológico completo incluindo a perimetria computadorizada e a TCO de domínio Fourier. Os olhos estudados foram divididos em 5 grupos: olhos de pacientes com EM e episódio prévio de neurite óptica (EM-NO) olhos de pacientes com EM sem episódio prévio de neurite óptica (EM-sNO), olhos de pacientes com NMO e história de neurite olhos de pacientes com MTALE e olhos de controles normais. Foram analisadas as seguintes medidas obtidas pela TCO: a espessura da camada de fibras nervosas retiniana (CFNR) peri-papilar, a espessura macular total (EMT) avaliada em 8 setores de acordo com o mapa do \"Early Treatment Diabetes Retinopathy Treatment Trial\" e medidas segmentadas da CFNR na mácula, da camada de células ganglionares (CCG), camada nuclear interna (CNI). Os resultados da perimetria foram avaliados levando em consideração o \" mean deviation ( desvio médio)\" (MD) e os valores de diferentes regiões do campo visual divididos de acordo com a sua correspondência no disco óptico seguindo o mapa de Garway-Heath. A comparação dos achados entre os diferentes grupos foi feita usando modelos \"generalized estimated equations\" (GEE) de tal forma a fazer a compensação pela interdependência dos dois olhos de um mesmo indivíduo. Foram também calculadas e comparadas as áreas sob as áreas sob as curvas ROC (\"Receiver operating characteristics\") nos diferentes grupos. Foram calculadas as correlações de Spearman ou Pearson dependendo da distribuição dos valores. RESULTADOS: Não houve diferença significativa em relação à idade média e à distribuição dos pacientes quanto ao sexo nos 5 grupos estudados. Quando comparados ao grupo controle, os 4 grupos de olhos dos doentes apresentaram a espessura da CFNR peri-papilar e a CFNR macular significativamente menor que as medidas dos controles normais. Em relação à CCG e à EMT, os grupos NMO, EM-NO e EM-sNO apresentaram espessura estatisticamente menor que os controles enquanto que no grupo MTALE esta diferença não foi evidenciada. Quando a CNI foi estudada não houve diferença entre os controles e os 2 grupos com EM, enquanto que os grupos NMO e MTALE apresentaram espessura estatisticamente maior que os controles. Os dois grupos com história prévia de NO (NMO e EM-NO) apresentaram a espessura da CFNR peri-papilar e macular, da CCG e da EMT menores do que seus grupos correspondentes sem história prévia de NO (respectivamente MTALE e EM-sNO). Quando os grupos NMO e EM-NO foram comparados entre si não houve diferença de espessura em nenhuma camada exceto na CNI onde o grupo NMO foi estatisticamente mais espesso. Houve correlação entre os achados do TCO e aqueles da campimetria para ambas as doenças e esta correlação foi maior na NMO do que na EM, em especial quando a EMT foi o parâmetro do TCO utilizado na comparação. CONCLUSÕES: A TCO é capaz de demonstrar a perda neural nos doentes com EM ou NMO e evidencia perda neural subclínica tanto em olhos com MTALE como em pacientes com EM, sem história de NO prévia e demonstra aumento da CNI nos olhos de pacientes com NMO ou MTALE. Além do já conhecido mecanismo de lesão do nervo óptico por desmielinização o fato da CNI estar alterada no espectro NMO mostra que outros processos podem estar envolvidos na patogênese destas doenças e que esta camada pode ajudar na diferenciação entre as duas doenças, EM e NMO / PURPOSE: To evaluate, by the using of Fourier domain optical coherence tomography (OCT) the retinal inner layers of eyes with or without previous history of optic neuritis (ON) in multiple sclerosis (MS) or neuromyelitis optica (NMO) patients and compare them with normal controls. To investigate the correlation between the OCT and the visual field fidings. METHODS: One hundred two subjects were studied, 74 diagnosed as MS, 33 as NMO, 30 as longitudinally extensive transverse myelitis (LETM) and 45 nolmal controls. All patients were submitted to a complete ophthalmic evaluation including automated perimetry and Fourier domain OCT. The studied eyes were divided in 5 groups: eyes of MS patients with previous episodes of optic neuritis (MS-ON, group 1), eyes of MS patients without previous episodes of optic neuritis (MS-nON, group 2), eyes of NMO patients (group 3), eyes of LETM patients (group 4) and eyes of normal controls (group 5). The retinal layers measured by OCT were from the optic nerve, peri-papillary retinal nerve fiber layer (RNFL) and from the macula: the total macular thickness (TMT), which was sub-divided in 8 sectors according to \"Early treatment diabetic retinopathy study\", and the segmented inner macula layers, RNFL, ganglion cell layer (CGL) and inner nuclear layer (INL). Regard to automated perimetry we analyzed the \"mean deviation\" (MD) and different sectors of the visual field according to their correspondence to Garway-Heath optic nerve map. Generalized estimation equation (GEE) models accounting for age and within-patient, inter-eye correlations, were used to compare the results among different groups. We also compare the area under ROC (receiver operating charactheristics) curve among the different groups. We also compute either Spearman or Pearson correlation according to values distributions. RESULTS: There was no statistical difference among the groups regard to sex or mean age. All 4 diseased groups presented peri-papillary RNFL and macular RNFL thicknesses statistically thinner than normal controls. Regarding to GCL thickness and TMT, the NMO, MS-ON and MS-nON groups were statistically thinner than controls, on the other hand the LETM group was not statistically different. When the INL thickness was studied, there was no statistical difference between controls and both MS groups, whereas the NMO and LETM groups were statistically thicker than controls. Both groups with previous history of ON (NMO and MS-ON) presented peri-papillary RNFL, macular RNFL, GCL and TMT thinner than theirs corresponding groups without previous history of ON (LETM and MS-nON, respectively). When NMO and MS-ON were compared, there was no statistical difference in any layer, except the INL, which was thicker in NMO group. There was statistical correlation between OCT and automated perimetry findings for both, MS and NMO, diseases and the correlation was bigger in NMO, particularly when TMT was the OCT parameter used. CONCLUSION: The OCT is able to demonstrate the neural loss in MS and NMO patients and it also shows sub-clinical neural loss in LETM and MS-nON patients. Besides the already known mechanism of optic nerve injury caused by demyelination, the presence of a abnormal INL in the NMO and LETM patients suggest that different processes may be involved in the pathogenesis of these diseases and also that the INL may help differentiating between NMO and MS

OBJETIVO: Avaliar a capacidade do eletrorretinograma de padrão reverso (PERG) de campo total de detectar alterações funcionais da retina em olhos com papiledema resolvido de pacientes com a síndrome do pseudotumor cerebral (PTC). Utilizar a tomografia de coerência óptica de domínio Fourier (FD-OCT) para avaliar a espessura total e das camadas internas da retina (após segmentação dos dados) na área macular e a camada de fibras nervosas retinianas (CFNR) peripapilar em pacientes com PTC, e compará-las com aquelas de olhos normais. Estudar a correlação entre as amplitudes do PERG, as medidas da tomografia de coerência óptica (OCT) e a perda de campo visual (CV) avaliada pela perimetria computadorizada. MÉTODOS: Cinquenta e dois olhos com papiledema clinicamente resolvidos de 29 pacientes portadores de PTC foram submetidos a exame oftalmológico completo, CV, PERG e OCT. As seguintes medidas obtidas pelo OCT foram analisadas: a espessura da CFNR peripapilar, a espessura macular total (EMT), avaliada em oito setores, de acordo com o mapa do Early Treatment Diabetes Retinopathy Study, e medidas segmentadas na região da mácula da CFNR, da camada de células ganglionares (CCG) e da camada nuclear interna (CNI). Os resultados do CV foram avaliados, levando em consideração o mean deviation (MD) e os valores de diferentes regiões do CV divididos, de acordo com sua correspondência no nervo óptico, seguindo o mapa de Garway-Heath. Foram, também, calculados os desvios médios de 12 ou de 16 pontos centrais do CV, que estimulam áreas semelhantes àquelas avaliada pelo OCT macular e pelo PERG. Os achados foram comparados utilizando-se as equações de estimativas generalizadas para compensação da interdependência dos dois olhos de um mesmo indivíduo. Foram, também, calculadas e comparadas as áreas sob as curvas ROC (receiver operating characteristics). As correlações entre os achados do PERG, do OCT e do CV foram avaliadas pela correlação de Pearson ou Spearman. RESULTADOS: Comparadas aos controles, as espessuras do OCT, da CFNR peripapilar, CFNR macular, CCG macular e EMT foram significativamente menores em pacientes com PTC. Com relação ao PERG, houve redução da amplitude de N95 e P50+N95, e aumento do tempo de pico de N95, ambos para o estímulo de 48\', em olhos doentes, quando comparados ao grupo controle. Correlações estatisticamente significantes foram encontradas entre os valores de amplitude do PERG e da espessura retiniana do OCT. As reduções de espessura das camadas retinianas do OCT também foram significativamente associadas à perda de sensibilidade do CV. CONCLUSÕES: O PERG e o OCT foram capazes de demonstrar a perda anatômica e funcional dos doentes com papiledema decorrente de PTC, apresentando significativa correlação entre os métodos analisados. Tanto o OCT avaliando as medidas maculares como o PERG podem ser úteis na monitorização da perda neural retiniana de pacientes com papiledema decorrente da síndrome do PTC / PURPOSE: To evaluate the ability of the full field pattern electroretinogram (PERG) to detect functional changes of retina in eyes with resolved papiledema from patients with pseudotumor cerebri (PTC). To analyze full thickness macular measurements, peripapillary retinal nerve fiber layer (RNFL) thickness as well as segmented inner retinal layers in patients with PTC using of Fourier domain optical coherence tomography (FD-OCT) and compare them with normal eyes. To study the correlation between the PERG parameters, the optical coherence tomography (OCT) measurements and the visual field (VF) sensitivity loss, using standard automated perimetry. METHODS: Fifty-two eyes with resolved papilledema of 29 patients with PTC syndrome were submitted to a complete ophthalmic examination including VF, PERG and OCT. The following OCT measurements were analyzed: the peripapillary RNFL thickness, the total macular thickness (TMT), which was sub-divided in 8 sectors according to the Early Treatment Diabetes Retinopathy Study map, and the segmented inner macula layers, RNFL, the ganglion cell layer (GCL) and inner nuclear layer (INL). The VF results were analyzed through the mean deviation (MD) and the different sectors of the VF according to their correspondence to Garway-Heath optic nerve map. Central mean deviation, an average from VF sensitivity for the 12 and 16 central points, an area roughly equivalent to the area tested by macular cube scan protocol and PERG, was evaluated in patients and controls. Generalized estimating equation models accounting for inter-eye correlations were used to compare the results among different groups. Areas under ROC (receiver operating characteristics) curves were also calculated and compared. The correlations between the findings of the PERG, OCT and VF were assessed by Pearson correlation coefficients or Spearman\'s rank correlation coefficients. RESULTS: Compared to controls, the OCT thickness of the peripapillary RNFL, macular RNFL, macular GCL and TMT were significantly thinner in eyes with PTC. When PERG was studied, the amplitude of P50 and N95 + N95 were significantly reduced and N95 peak time increased, both based on 48 min check size, in patients when compared with normal controls. Significant correlations were found between the PERG amplitude and OCT retinal thickness. The decreased thickness of the OCT retinal layers was also significantly associated with VF sensitivity loss. CONCLUSIONS: PERG and OCT were able to demonstrate anatomical and functional loss in patients with resolved papiledema from PTC, showing significant correlation between the methods analyzed. It is known that the main morbidity of this disease is visual impairment. It is therefore of great importance to monitor the visual function during treatment. Whereas papilledema may be reversible at early stages, permanent visual loss may occur. These findings suggest that both measurements can be complementary in assessing axonal loss in patients with PTC

A proposta deste estudo in vitro foi otimizar o método microbiológico para a produção de lesão de mancha branca em esmalte que possa ser validada por ensaio não destrutivo (tomografia por coerência óptica - OCT) para possibilitar a utilização posterior dos espécimes em outros experimentos. Foram obtidos 168 fragmentos retangulares de esmalte bovino com janelas centrais de desmineralização de 3,0 x 3,0 mm. Os grupos experimentais foram compostos a partir de 3 fatores de variação: microrganismo (S. mutans UA 159, S. sobrinus 3347 e S. mutans + S. sobrinus), fonte de carboidrato (sacarose 1% e sacarose 1% + amido 1%) e tempo (1, 2, 3, 4, 5, 6 e 7 dias). Assim, formaram-se seis grupos experimentais: G1 (S. mutans + sacarose), G2 (S. mutans + sacarose + amido), G3 (S. sobrinus + sacarose), G4 (S. sobrinus + sacarose + amido), G5 (S. mutans + S. sobrinus + sacarose), G6 (S. mutans + S. sobrinus + sacarose + amido), testados em 7 tempos de desafio cariogênico. Terminada esta etapa, foram obtidas imagens em escala de cada espécime pelo OCT, e em seguida os espécimes foram processados e submetidos à análise através de microscópio de luz polarizada. Em cada um dos métodos, foram realizadas 5 mensurações de profundidade da região desmineralizada. O teste estatístico de Análise de Variância (ANOVA) (p<0.05) detectou que os desafios cariogênicos testados foram capazes de desmineralizar o esmalte em profundidade, sendo influenciados pelo tipo de microrganismo, fonte de carboidrato e tempo (p=0,000). O Teste de Correlação de Pearson apresentou uma correlação significativa (p=0,000) entre as medidas de profundidade de desmineralização aferidas através dos métodos de luz polarizada e OCT. Logo, a tomografia por coerência óptica é um método não destrutivo válido para aferir a profundidade de desmineralização de lesões de mancha branca, que pode ser muito útil quando se objetiva obter substrato desmineralizado padronizado para estudos laboratoriais. Concluiu-se ainda que o desafio cariogênico realizado com microrganismo S. mutans UA 159, suplementado com sacarose como fonte de carboidrato por 6 dias, é capaz de produzir mancha branca de esmalte padronizada. Desta maneira, seria obtido um substrato modificado relevante para estudos laboratoriais. / The aim of this in vitro study was to optimize the microbiological method for the production of white spot lesions in enamel that can be validated by non-destructive test (optical coherence tomography - OCT) to enable the subsequent use of the specimens in other experiments. A hundred and sixty eight bovine enamel fragments with central windows of demineralization measuring 3,0 x 3,0 mm were obtained. The experimental groups were composed from three variation factors: the microorganism (S. mutans UA 159, S. sobrinus 3347 and S. mutans + S. sobrinus), carbohydrate source (1% sucrose and 1% sucrose + 1% starch) and time (1, 2, 3, 4, 5, 6 and 7 days). Thus, six experimental groups were formed: G1 (S. mutans + sucrose), G2 (S. mutans + starch + sucrose), G3 (S. sobrinus + sucrose), G4 (S. sobrinus + starch + sucrose), G5 (S. mutans + S. sobrinus + sucrose), G6 (S. mutans + S. sobrinus + sucrose + starch) tested in 7 periods of cariogenic challenge. After this step, images in scale were obtained from each specimen with OCT, and then the specimens were processed and analysed by polarized light microscopy. In each of the methods were performed 5 measurements of demineralization depth. The statistical test Analysis of Variance (ANOVA) (p<0.05) detected that the cariogenic challenges tested were able to demineralize enamel in depth, regardless of the type of microorganism, carbohydrate source and time (p=0,000). The Pearson\'s Correlation Test showed a significant correlation (p=0,000) between the measurements of depth demineralization measured with polarized light microscopy and OCT. Therefore, the optical coherence tomography is a non-destructive method valid to measure the depth of demineralization of white spot lesions, which can be very useful when the objective is to obtain standard demineralized substrate for laboratory studies. It was also concluded that the cariogenic challenge performed with the microorganism Streptococcus mutans UA159, supplemented with sucrose as carbohydrate source for 6 days, is capable to produce standard white spot lesions in enamel. In this way, a modified substract relevant for laboratory studies could be obtained.

Bancos de Tecidos de diversas regiões do mundo têm estocado cartilagens humanas obtidas de doadores post mortem para uso em diversos tipos de cirurgias reconstrutivas. Para garantir que tais tecidos não estejam contaminados, estes têm sido esterilizados com radiação ionizante. Entretanto, altas doses de radiação gama podem causar efeitos indesejáveis nos tecidos. No presente trabalho, avaliamos a viabilidade de utilizar duas técnicas, Tomografia por Coerência Óptica (OCT) e Termogravimetria (TGA), para identificar possíveis modificações estruturais causadas na cartilagem costal humana em decorrência dos métodos de preservação e doses de radiação ionizante utilizadas. As cartilagens obtidas de doadores cadavéricos foram congeladas a -70 ºC ou preservadas em glicerol. A seguir, as amostras foram irradiadas por fontes de 60Co com doses de 15, 25 e 50 kGy. Nos resultados de TGA verificamos que as cartilagens preservadas em glicerol e irradiadas com diferentes doses de radiação não apresentaram diferenças estatisticamente significantes quando comparadas ao grupo controle, no que tange a taxa de desidratação do tecido, sendo que o mesmo não ocorre com cartilagens congeladas a -70 ºC e irradiadas com doses de 15 kGy. Em relação ao uso da técnica de OCT, por meio do cálculo do coeficiente de atenuação óptica total, verificamos que doses de 15 kGy promovem a criação de ligações cruzadas entre as fibrilas de colágeno, corroborando os resultados de TGA. Ainda, os valores do coeficiente de atenuação óptica total são diretamente proporcionais à tensão de ruptura das cartilagens, o que nos possibilitará, em um futuro próximo, predizer a qualidade de um enxerto sem a necessidade de perda de material biológico, visto ser o OCT um método não destrutivo. Por meio das imagens de PS-OCT podemos verificar que as doses de radiação utilizadas para esterilizar as amostras não provocam danos à rede de colágeno a ponto de que sua birrefringência seja perdida. Assim, o TGA e OCT são técnicas que podem ser utilizadas por bancos de tecidos de forma a verificar a qualidade dos tecidos antes de serem transplantados em pacientes. / Tissue Banks around the world have stored human cartilages obtained from post mortem donors for use in several kinds of reconstructive surgeries. To ensure that such tissues are not contaminated, they have been sterilized with ionizing radiation. However, high doses of gamma radiation may cause undesirable changes in the tissues. In this work, we evaluated the possibility of use Optical Coherence Tomography (OCT) and Thermogravimetric Analysis (TGA) to identify possible structural modifications caused by both preservation methods of cartilage and gamma irradiation doses. Cartilages were obtained from cadaveric donors and were frozen at -70 ºC or preserved in glycerol. Irradiation was performed by 60Co source with doses of 15, 25 and 50 kGy. Our TGA results showed that glycerolized cartilages irradiated with different doses of radiation does not presented statistical differences when compared to the control group for the dehydration rate. However, the same was not observed for deep-fronzen cartilages irradiated with 15 kGy. The results of OCT associated to total optical attenuation coefficient showed that doses of 15 kGy promote cross-link between collagen fibrils, corroborating the results obtained from TGA. Moreover, total optical attenuation coefficient values are proportionals to stress at break of cartilages, what will be very useful in a near future to predict the quality of the allografts, without unnecessary loss of biological tissue, once OCT is a nondestructive technique. By PS-OCT images, we found that high doses of ionizing radiation does not promote sufficient impairments to promote complete loss of tissue birefringence. Thus, TGA and OCT are techniques that can be used for tissue banks to verify tissue quality before its transplant.