OCT Patterns in Ulcerative Colitis

Background Resolvins originate from ω-3 PUFA (polyunsaturated fatty acid) precursors and play a role in the resolution of inflammation. The aim of this study was to determine the serum Resolvin E1 levels in patients with ulcerative colitis (UC) and to evaluate the relationship between the serum Resolvin E1 levels and ulcerative colitis disease activity. Methods In this observational study, serum samples were collected from 51 patients with UC and 30 healthy controls for the determination of Resolvin E1 levels. Firstly, we compared the serum Resolvin E1 levels between the UC patients and the control group. Subsequently, Resolvin E1 levels were analyzed in patients with active UC and UC in remission. Finally, the correlation between Resolvin E1 and C-reactive protein (CRP) and partial Mayo score (p-MS) was analyzed to determine the efficacy of Resolvin E1 in predicting disease activity. Results Serum Resolvin E1 level was determined in the UC group (3126 ± 1413 ng/ml) and in the control group (2758 ± 1065 ng/ml) (p = 0.187). Serum Resolvin E1 levels were determined in patients with active UC (3114 ± 1166 ng/ml) and patients in remission (3132 ± 1520 ng/ml) (p = 0.749). In the UC group, a low-grade positive significant association was found between Resolvin E1 and CRP (r = 0.303, p = 0.031). There was no significant association between Resolvin E1 and partial Mayo score (r = −0.207, p = 0.146). Conclusions There was no sufficient evidence that Resolvin E1 was an appropriate inflammatory marker to determine disease activity in UC.

P178 - A pilot study of elemental diet for chronic pouchitis

Optical coherence tomography (OCT) has become a very useful tool to study in vivo different ocular structures and to improve differential diagnosis and management of many ocular pathologies. This study aims to identify pterygium alterations that trigger characteristic OCT images, and analyze if this pattern correctly demarcates lesion boundary. Thirty-two patients, 22 men, and ten women, aged between 26 and 56 (mean age 40.5 ± 6.9) with symptomatic primary pterygium were recruited. After excision, lesion images were obtained by high-definition OCT. Specimens were stained with hematoxylin–eosin (H&E), antivimentin for all mesenchymal origin cells and altered limbal basal cells, CD45 for lymphocyte and macrophage cells, CD1a for Langerhans cells, and S100 for melanocyte and Langerhans cells. The typical OCT wedge-shape hyperreflective mass was evident only by vimentin antibody and included, mainly, fibroblasts but also immune cells (verified by CD45) in a rich network of collagen fibers. The mass apex, often extended centripetally as a thin subepithelial line, hyperreflective by OCT, was formed by a row of fibroblasts under an apparently intact Bowman’s layer, as vimentin samples revealed. Hyperreflective epithelium overlying the mass showed a great number of vimentin-positive infiltrated cells such as melanocytes, Langerhans cells, and lymphocytes (identified by the other biomarkers). H&E staining revealed the presence of goblet cells. Nevertheless, only vimentin staining revealed the presence of altered basal cells above partially dissolved or apparently intact Bowman’s layer, coinciding in this last case with the fibroblast subepithelial line. In most of the cases (72 %), the altered cells occupied a basal segment shorter than the fibroblast subepithelial line but in some specimens, these cells exceeded the fibroblast line length. This study demonstrated the great visual accordance between pterygium OCT images and vimentin staining. Alteration in collagen arrangement, infiltration of inflammatory cells, and fibroblast subepithelial line in the lesion apex were the main histological changes responsible for the anomalous hyperreflectivity of the OCT pattern. By contrast, altered basal cells located in the basal epithelial layer of the pterygium head could not be detected by OCT, which might generate lesion size underestimation.

Structural Features Associated With the Development and Progression of RORA Secondary to Maternally Inherited Diabetes and Deafness

In this paper, five types of tissues, human enamel, human cortical bone, human trabecular bone, muscular tissue, and fatty tissue were imaged <i>ex vivo</i> using optical coherence tomography (OCT). The specimens were prepared in blocks of 5 x 5 x 3 mm (width x length x height). The OCT imaging system was a swept source OCT system operating at wavelengths ranging between 1250 nm and 1360 nm with an average power of 18 mW and a scan rate of 50 to 100 kHz. The imaging probe was placed on top of a 2 x 2 cm stabilizing device to maintain a standard distance from the samples. Ten image samples from each type of tissue were obtained. To acquire images with minimum inhomogeneity, imaging was performed multiple times at different points. Based on the observed texture differences between OCT images of soft and hard tissues, spatial and spectral features were quantitatively extracted from the OCT images. The Radon transform from angles of 0 deg to 90 deg was computed, averaged over all the angles, normalized to peak at unity, and then fitted with Gaussian function. The mean absolute values of the spatial frequency components of the OCT image were considered as a feature, where 2-D fast Fourier transform (FFT) was done to OCT images. These OCT features can reliably differentiate between a range of hard and soft tissues, and could be extremely valuable in assisting dentists for <i>in vivo</i> evaluation of oral tissues and early detection of pathologic changes in tissues.

EVALUATION OF POROSITY AND BIOFILM FORMATION IN RELINE RESINS THROUGH OPTICAL COHERENCE TOMOGRAPHY

Three-Dimensional Optical Coherence Tomography on Endoscopic Mucosal Resection Specimens Confirms Identification of Malignant From Metaplastic Lesions in Patients With Barrett's Esophagus

Previous studies have demonstrated that optical coherence tomography (OCT) could be used to delineate alterations in the microstructure of cartilage, and have suggested that changes in the polarization state of light as detected by OCT could provide information on the birefringence properties of articular cartilage as influenced by disease. In this study we have used both OCT and polarization sensitive optical coherence tomography (PS-OCT) technologies to evaluate normal and abnormal bovine articular cartilage according to established structural, organizational, and birefringent characteristics of degenerative joint disease (DJD) in order to determine if this technology can be used to differentiate various stages of DJD as a minimally invasive imaging tool. Fresh bovine femoral-tibial joints were obtained from an abattoir, and 45 cartilage specimens were harvested from 8 tibial plateaus. Whole ex vivo specimens of normal and degenerative articular cartilage were imaged by both OCT and PS-OCT, then fixed and processed for histological evaluation. OCT/PS-OCT images and corresponding histology sections of each specimen were scored according to a modified Mankin structural grading scale and compared. OCT and PS-OCT imaging allowed structural evaluation of intact articular cartilage along a 6 mm surface length to a depth of 2 mm with a transverse resolution of 12 microm and an axial resolution of 10 microm. The OCT and PS-OCT images demonstrated characteristic alterations in the structure of articular cartilage with a high correlation to histological evaluation (kappa = 0.776). The OCT images were able to demonstrate early to advanced structural changes of articular cartilage while the optical phase retardation images obtained by PS-OCT imaging were able to discriminate areas where disorganization of the cartilage matrix was present, however, these characteristics are much different than those reported where OCT images alone were used to characterize tissue birefringence. No evidence of differences in OCT or PS-OCT images were detected between specimens of similar structural characteristics where proteoglycan was judged present or absent by safranin-O Fast Green staining. The combined use of OCT and PS-OCT technologies to obtain images from a single system is able to demonstrate and discriminate between characteristics of very early stages of surface irregularities not previously reported for OCT imaging, to deep clefts and collagen matrix disorganization for tissue at depths of up to 2 mm with good correlation to histology. PS-OCT and accumulated optical phase retardation images of articular cartilage as constructed from alterations in Stokes vector parameters appear to give a valuable but different assessment of alterations in tissue birefringence and organization than have been reported for OCT images obtained with the use of polarized or non-polarized light sources. This is the first time that alterations in the polarization state of light reflected from within the tissue have been demonstrated to be consistent with changes observed in the orientation and organization of the collagen matrix in advanced stages of DJD. The degree of phase transformation of light reflected from within the tissue as determined by PS-OCT imaging does not appear to be altered by the presence or absence of proteoglycan.

Microaneurysms (MAs) are pathognomonic signs that help clinicians to detect diabetic retinopathy (DR) in the early stages. Automatic detection of MA in retinal images is an active area of research due to its application in screening processes for DR which is one of the main reasons of blindness amongst the working-age population. The focus of these works is on the automatic detection of MAs in en face retinal images like fundus color and Fluorescein Angiography (FA). On the other hand, detection of MAs from Optical Coherence Tomography (OCT) images has 2 main advantages: first, OCT is a non-invasive imaging technique that does not require injection, therefore is safer. Secondly, because of the proven application of OCT in detection of Age-Related Macular Degeneration, Diabetic Macular Edema, and normal cases, thanks to detecting MAs in OCT, extensive information is obtained by using this imaging technique. In this research, the concentration is on the diagnosis of MAs using deep learning in the OCT images which represent in-depth structure of retinal layers. To this end, OCT B-scans should be divided into strips and MA patterns should be searched in the resulted strips. Since we need a dataset comprising OCT image strips with suitable labels and such large labelled datasets are not yet available, we have created it. For this purpose, an exact registration method is utilized to align OCT images with FA photographs. Then, with the help of corresponding FA images, OCT image strips are created from OCT B-scans in four labels, namely MA, normal, abnormal, and vessel. Once the dataset of image strips is prepared, a stacked generalization (stacking) ensemble of four fine-tuned, pre-trained convolutional neural networks is trained to classify the strips of OCT images into the mentioned classes. FA images are used once to create OCT strips for training process and they are no longer needed for subsequent steps. Once the stacking ensemble model is obtained, it will be used to classify the OCT strips in the test process. The results demonstrate that the proposed framework classifies overall OCT image strips and OCT strips containing MAs with accuracy scores of 0.982 and 0.987, respectively.

Few studies have been published that evaluate the usefulness of different caries- diagnostic modalities in general dental practice. The goal of this study was to compare the results of screening for coronal dental caries in a general dental practice using clinical observations, radiographs, laser fluorescence (DIAGNOdent™) (LF), and optical coherence tomography (OCT). Diagnostic agreement between OCT and LF versus standard clinical techniques for detecting caries was determined in 40 subjects. Forty patients with >1 coronal carious lesion as determined by prescreening using clinical examination and radiographs were enrolled in this study. Subjects with gross caries were excluded. Subsequently each patient underwent a full detailed dental examination by an experienced clinician, using visual examination and radiographs according to standard clinical practice. The coronal surfaces of a total of 932 teeth were examined and charted. Teeth were then photographed, rediagnosed using the LF system, and imaged using OCT. Two blinded pre-standardized examiners reviewed radiographic and OCT images and assigned caries status. Based on manufacturer's cutoff values, sensitivity and specificity for coronal caries using LF technique (i) on unaltered tooth surfaces were 73.7% and 94.1%, respectively and (ii) in previously restored or sealed teeth, they were 19.2% and 95.8%, respectively. LF technique was unable to assess tissue health underneath sealants and restorations. Clinician agreement (kappa [k]) regarding caries diagnosis using OCT imaging was overall 0.834 (SE = 0.034). Sensitivity and specificity for caries using OCT technique (i) on unaltered tooth surfaces approximated 74.1% and 95.7%, respectively and, (ii) in previously restored or sealed teeth, they approximated 76.0% and 95.6%, respectively. Although OCT was able to detect lesions beneath many resin restorations and sealants, results varied considerably between materials. OCT imaging was unable to detect caries when caries was >2 mm below the tooth surface. These findings support the usefulness of LF for primary caries detection, and the clinical utility of OCT for early caries detection and monitoring under dental resin restorations and sealants. Lasers Surg. Med. 48:924-928, 2016. © 2016 Wiley Periodicals, Inc.

High-Definition and 3-dimensional Imaging of Macular Pathologies with High-speed Ultrahigh-Resolution Optical Coherence Tomography

Objective To investigate the imaging features of optical coherence tomography (OCT) in diabetic retinopathy (DR). Methods From January 2015 to December 2017, 104 cases (208 eyes) with DR in the Ophthalmology Department of Inner Mongolia Hospital of Traditional Chinese Medicine were collected, and 289 cases (578 eyes) with DR in Tongren Ophthalmology Center of Beijing Tongren Hospital affiliated to Capital Medical University were collected. A total of 393 cases (786 eyes) were included in the two sites. Among them, there were 181 cases (356 eyes) and 212 cases (430 eyes). The age was 22~88 years, with an average age of (47.30 + 5.42) years. Name, sex, age, address, diabetes history, clinical diagnosis, fundus color photography and OCT report were recorded. Summarize and extract features in each phase of OCT inspection. Results According to the clinical staging standard of DR in 2002, 393 cases (786 eyes) were divided into three groups: 51 cases (102 eyes), 83 cases (166 eyes), 124 cases (248 eyes), 46 cases (92 eyes), 57 cases (114 eyes) and 32 cases (64 eyes) of DR stage VI. Eye only. The OCT of DR stage I was characterized by microangioma, occasional or minor bleeding spots between the retinal neuroepithelial layers; the OCT of DR stage II was characterized by rigid exudation and bleeding spots between the retinal neuroepithelial layers; the OCT of DR stage III was characterized by cotton flocculent plaques in addition to hard exudation and bleeding spots; and the OCT of DR stage IV was characterized by cotton flocculent plaques. In addition to hard exudation, bleeding spots and cotton wadding spots, there are also edema or cystoid edema and/or vitreous hemorrhage; in DRV stage, the OCT features are not only hard exudation, bleeding spots, cotton wadding spots, edema and vitreous hemorrhage, but also organic film; in DRVI stage, the OCT features are hard exudation, bleeding spots and vitreous hemorrhage. There were also traction retinal detachment outside cotton spots, edema, vitreous hemorrhage and organic membrane. In addition, according to the different stages of DR, blood flow OCT imaging (OCTA) can clearly show the characteristics of microangioma, hard exudation, hemorrhage, cystic edema, no perfusion area and neovascularization. Conclusion In the examination results of OCT, DR can appear characteristic image according to different stages. Mastering and using OCT can determine the clinical stages of DR and guide the clinical diagnosis and treatment. Key words: Diabetic retinopathy; Clinical stages; Diagnose; Optical coherence tomography

To investigate morphological variations in the macular area with optical coherence tomography (OCT) after vitrectomy for diabetic fibrovascular proliferation. We reviewed 108 cases using OCT 7-15 months after vitrectomy. Of these, 32 received OCT within 3 months postoperatively. Morphological variations were categorized and correlated with visual outcome. Only 24 cases (21.4%) had no obvious abnormalities. The most frequent findings were epiretinal membrane (52.8%), macular thickening (37.0%) and macular cysts (28.7%). Multivariate regression showed that diffuse macular thickening, loss of foveal depression and diffuse retinal thinning were significantly associated with poor visual acuity. Sequential OCT (< 3 and >or= 7 months) revealed that epiretinal membrane and oedema outside of fovea changed significantly between two examinations. OCT may identify diverse morphological changes in the macular area after diabetic vitrectomy for fibrovascular proliferation. Macular appearance may change over time, and certain types of morphological changes may be associated with poor visual function.

To evaluate the feasibility of detecting macrophage content on atherosclerotic plaques by optical coherence tomography (OCT) technique. Thirty New Zealand white rabbits were equally divided into 3 groups at random: Control group (fed normal rabbit chow, n = 10); lipid diet group (fed regular chow supplemented with cholesterol, n = 10) and balloon injury+ lipid diet group (balloon catheter injury of the common carotid artery after 2 weeks lipid diet, n = 10). After 12 weeks, all rabbits underwent pharmacological triggering with Chinese Russell's viper venom (CRVV, 15 mg/kg, i.p.) and histamine (0.02 mg/kg, i.v.). Common carotid arteries were detected with OCT and the Movat pentachrome stain respectively. OCT and histological examination results were compared and the correlation was analyzed. The intra thickness measured by Movat pentachrome stain and by the OCT was (15.2 ± 0.9) µm and (20.2 ± 7.6) µm, the medial thickness was (434.2 ± 86.5) µm and (453.8 ± 87.2) µm, the plaque thickness was (330.2 ± 87.1) µm and (392.2 ± 134.5) µm, the fibrous cap thickness was (58.3 ± 5.6) µm and (61.2 ± 4.9) µm, respectively (all P > 0.05). The normalized standard deviation of the OCT signal (NSD) was compared with immunohistochemical detection. The OCT signal within the cap is relatively homogeneous for low macrophage density in high lipid diet group. For the raw OCT data, a correlation of r = 0.846 (P < 0.01) was found between OCT NSD and a CD68 area<10%, whereas for the base 10 logarithm OCT data, a correlation of r = 0.646 (P < 0.05) was found between OCT NSD and a CD68 area<10%. In balloon injury + high lipid diet group, the OCT signal within the cap was relatively heterogeneous for high macrophage content. For the raw OCT data, a correlation of r = 0.906 (P < 0.01) was found between OCT NSD and a CD68 area >10%, whereas for the base 10 logarithm OCT data, a correlation of r = 0.593 (P < 0.05) was found between OCT NSD and a CD68 area >10%. For the raw OCT signal NSD, a range of NSDs (7.12% to 7.35%) demonstrated 100% sensitivity and specificity (Kappa value 1.0) for differentiating caps containing >10% CD68 staining. For the base 10 logarithm OCT signal, NSD values ranging from 7.81% to 7.92% provided 70% sensitivity and 75% specificity (value 0.44) for identifying caps containing >10% CD68 staining. OCT is an effective tool to determine macrophage content in this model. OCT imaging can clearly visualize different types of atherosclerotic plaques and provide detailed information on plaque characteristics.

This study aims to characterize biochemical and morphological variations of the clinically relevant anatomical locations of in vivo oral tissue (ie, alveolar process, lateral tongue and floor of the mouth) by using hybrid Raman spectroscopy (RS) and optical coherence tomography (OCT) technique. A total of 1049 in vivo fingerprint (FP: 800-1800 cm-1 ) and high wavenumber (HW: 2800-3600 cm-1 ) Raman spectra were acquired from different oral tissue (alveolar process = 331, lateral tongue = 339 and floor of mouth = 379) of 26 normal subjects in the oral cavity under the OCT imaging guidance. The total Raman dataset were split into 2 parts: 80% for training and 20% for testing. Tissue optical attenuation coefficients of alveolar process, lateral tongue and the floor of the mouth were derived from OCT images, revealing the inter-anatomical morphological differences; while RS uncovers subtle FP/HW Raman spectral differences among different oral tissues that can be attributed to the differences in inter- and intra-cellular proteins, lipids, DNA and water structures and conformations, enlightening biochemical variability of different oral tissues at the molecular level. Partial least squares-discriminant analysis implemented on the training dataset show that the integrated tissue optical attenuation coefficients and FP/HW Raman spectra provide diagnostic sensitivities of 99.6%, 82.3%, 50.2%, and specificities of 97.0%, 75.1%, 92.1%, respectively, which are superior to using either RS (sensitivities of 90.2%, 77.5%, 48.8%, and specificities of 95.8%, 72.1%, 88.8%) or optical attenuation coefficients derived from OCT (sensitivities of 75.0%, 78.2%, 47.2%, and specificities of 96.2%, 67.7%, 85.0%) for the differentiation among alveolar process, lateral tongue and the floor of the mouth. Furthermore, the diagnostic algorithms applied to the independent testing dataset based on hybrid RS-OCT technique gives predictive diagnostic sensitivities of 100%, 76.5%, 51.3%, and specificities of 95.1%, 77.6%, 89.6%, respectively, for the classifications among alveolar process, lateral tongue and the floor of the mouth, which performs much better than either RS or optical attenuation coefficient derived from OCT imaging. This work suggests that inter-anatomical morphological and biochemical variability are significant which should be considered as an important parameter in the interpretation and rendering of hybrid RS-OCT technique for oral tissue diagnosis and characterization.