Potential Of Optical Coherence Tomography Research Articles

The prospects for early detection with optical coherence tomography (OCT) and OCT angiography in major depressive disorder

BackgroundResearch has shown the diagnostic potential of optical coherence tomography (OCT) and OCT angiography (OCTA) in various psychiatric disorders. However, there is few research focusing on changes specific to Major Depressive Disorder (MDD), and the diagnostic value of OCT combined with OCTA parameters for MDD remains unclear. MethodsIn this study, we investigated microvascular and morphology changes in the retina of MDD patients using a combination of OCTA and OCT parameters, and to examine their correlation with MDD mood and cognitive function in order to assess their diagnostic capability. ResultsOur findings revealed a significant decline in macular vessel density (MVD) in the superficial retinal capillary plexus (SRCP) across all subfields, except the NO area. We also observed a significant positive correlation between fovea and Stroop-1, as well as between temporal inner (TI) and Stroop-3 in MDD patients. Furthermore, we identified a negative correlation between fovea and Self-Rating Depression Scale, as well as between Superior outer (SO) and Difficulties in Emotion Regulation Scale-C in MDD patients. LimitationsThe sample size was small. Anatomical variables in blood flow may contribute to variability between subjects and outcomes. ConclusionsThe diagnostic value of OCTA suggests their potential as valuable tools for monitoring and diagnosing MDD.

Towards phase-sensitive optical coherence tomography in smart laser osteotomy: temperature feedback

Thermal effects during bone surgery pose a common challenge, whether using mechanical tools or lasers. An irrigation system is a standard solution to cool the tissue and reduce collateral thermal damage. In bone surgery using Er:YAG laser, insufficient irrigation raises the risk of thermal damage, while excessive water lowers ablation efficiency. This study investigated the potential of optical coherence tomography to provide feedback by relating the temperature rise with the photo-thermal expansion of the tissue. A phase-sensitive optical coherence tomography system (central wavelength of λ=1.288 μm, a bandwidth of 60.9 nm and a sweep rate of 104.17 kHz) was integrated with an Er:YAG laser using a custom-made dichromatic mirror. Phase calibration was performed by monitoring the temperature changes (thermal camera) and corresponding cumulative phase changes using the phase-sensitive optical coherence tomography system during laser ablation. In this experiment, we used an Er:YAG laser with 230 mJ per pulse at 10 Hz for ablation. Calibration coefficients were determined by fitting the temperature values to phase later and used to predict the temperature rise for subsequent laser ablations. Following the phase calibration step, we used the acquired values to predict the temperature rise of three different laser-induced cuts with the same parameters of the ablative laser. The average root-mean-square error for the three experiments was measured to be around 4 °C. In addition to single-point prediction, we evaluated this method’s performance to predict the tissue’s two-dimensional temperature rise during laser osteotomy. The findings suggest that the proposed principle could be used in the future to provide temperature feedback for minimally invasive laser osteotomy.

Evaluation of the diagnostic and prognostic potential of optical coherence tomography (OCT) of the pulmonary arteries during standardised right heart catheterisation in patients with pulmonary hypertension: a cross-sectional single-centre experience.

Pulmonary hypertension (PH) is diagnosed based on an invasive evaluation of the mean pulmonary artery (PA) pressure. The morphological assessment of the pulmonary arteries was only recently not feasible. With the advent of optical coherence tomography (OCT)-imaging, an accessible tool allows to study PA morphology longitudinally. The primary hypothesis was that OCT distincts the PA structure of PH patients from control subjects. The secondary hypothesis was that PA wall thickness (WT) correlates with the progression of PH. This is a retrospective monocentric study of 28 paediatric patients with (PH group) and without PH (control group) who had undergone cardiac catheterisation including OCT imaging of the PA branches. OCT parameters analysed were WT and the quotient of WT and diameter (WT/DM) and those were compared between the PH group and the control group. In addition, the OCT parameters were aligned with the haemodynamic parameters to evaluate the potential of OCT as a risk factor for patients with PH. WT and WT/DM in the PH group were significantly higher compared to the control group {WT: 0.150 [0.230, range (R): 0.100-0.330] vs. 0.100 [0.050, R: 0.080-0.130] mm, P<0.001; WT/DM: 0.06 [0.05] vs. 0.03 [0.01], P=0.006}. There were highly significant correlations between WT and WT/DM with the haemodynamic parameters mean pulmonary arterial pressure (mPAP) [Spearman correlation coefficient (rs) =0.702, P<0.001; rs=0.621, P<0.001], systolic pulmonary arterial pressure (sPAP) (rs=0.668, P<0.001; rs=0.658, P<0.001) and WT and pulmonary vascular resistance (PVR) (rs=0.590, P=0.02). Also, there was a significant correlation between WT and WT/DM and the risk factors quotient of mPAP and mean systemic arterial pressure (mSAP) (mPAP/mSAP) (rs=0.686, P<0.001; rs=0.644, P<0.001) and pulmonary vascular resistance index (PVRI) (rs=0.758, P=0.002; rs=0.594, P=0.02). OCT can detect significant differences in WT of the PA in patients with PH. Furthermore, the OCT parameters correlate significantly with haemodynamic parameters and risk factors for patients with PH. More investigations are required to evaluate to what extent the impact of OCT can contribute to the clinical care of children with PH.

Optical Coherence Tomography Angiography for the Differentiation of Glaucoma from Pituitary Macroadenoma Related Optic Disc Measurements

ABSTRACT Objective To determine the potential of optical coherence tomography (OCT) and OCT angiography (OCTA) to distinguish between glaucoma and pituitary macroadenoma by optic disc appearance. Methods This prospective case-control study comprised 31 patients: 23 with glaucoma (18 male, 5 female) and 8 with pituitary macroadenoma and chiasmatic compression (3 male, 5 female). The corresponding mean ages were 72.8 years (range 58–90) and 60.7 years (range 43–73). All participants underwent complete ophthalmological examination, spectral domain OCT and OCTA, and visual field testing. Clinical, imaging, and visual field results were compared between the groups. Results On OCT analysis, the glaucoma group had relatively lower peripapillary retinal nerve fiber layer (RNFL) thickness (65.79 ± 15.46, 86.0 ± 11.37, respectively, P = .002) and lower rim area (1.00 ± 0.22 mm2 and 1.2 ± 0.15 mm2, respectively, P = .005). On OCTA, peripapillary vessel density was significantly lower in all quadrants in the glaucoma group. The significance of these between-group differences was maintained when patients were stratified by visual field mean deviation. Conclusions This is the first comparative analysis of optic disc morphology between glaucoma and pituitary macroadenoma using combined OCT and OCTA. The results yielded lower peripapillary RNFL thickness, lower rim area, and lower peripapillary vessel density in the glaucoma group. These parameters may aid in the initial differentiation between these two optic neuropathies.

Potential of optical coherence tomography and intravascular ultrasound in the detection of vulnerable plaques in coronary arteries

Intravascular imaging of vulnerable plaques in vivo has great potential for predicting coronary events. Currently, there are several methods of intravascular imaging, which make it possible to verify the components of the plaque and, accordingly, its vulnerability. The most common are virtual-histology intravascular ultrasound and optical coherence tomography. Several studies have shown that these imaging techniques can stratify the risk of adverse cardiovascular events, as well as assess the effectiveness of drug therapy. This article will describe the advantages and disadvantages of intravascular ultrasound and optical coherence tomography in identifying vulnerable coronary lesions.

Optical Coherence Tomography in Cardiac Allograft Vasculopathy: State-of-the-Art Review.

Cardiac allograft vasculopathy (CAV) is a challenging complication of heart transplantation. CAV pathophysiology is incompletely understood, standard screening modalities such as angiography have significant limitations, and currently available therapies have only modest efficacy in preventing progression. Optical coherence tomography is a light-based technique that provides microscopic level catheter-based intravascular imaging and has dramatically expanded our understanding of CAV, demonstrating it to be a complex, heterogeneous, and dynamic process. This review covers characteristics and uses of optical coherence tomography, including vessel characterization, serial use to assess progression of disease, guiding percutaneous intervention, and monitoring response to CAV therapies. We also discuss the potential of optical coherence tomography in providing individualized assessment and enable customized CAV therapies, which may lead to improvements in long-term transplant outcomes.

Investigations on the potential of optical coherence tomography as an imaging tool for eustachian tube

The purpose of this study was to explore the feasibility of eustachian tube optical coherence tomography (ET-OCT) for imaging the pharyngeal region of the eustachian tube (ET). Ten subjects with ear complaints underwent ET-OCT guided by nasal endoscopy, and ET-OCT examination was performed on both sides of each subject's ETs. The process and resulting images were analysed. Ten subjects ranging from 21 to 73 years old (45 ± 14.77) were enrolled in this study. Eighteen ET-OCT imaging examinations were completed. The mean duration of each examination was 2.80 ± 1.62 min (ranging from 2 to 7 min). There were no adverse events or complications. In some subjects, the ET-OCT images clearly presented the microstructures of the ET wall, including the lumen, mucosa, submucosa, cartilage and plica. However, in some subjects, it showed different characteristics, such as an unclear hierarchy and secretions in the lumen. ET-OCT may help to distinguish the structural composition of the ET and elucidate related pathophysiological mechanisms. It is a valuable imaging tool suited for the ET, with potential diagnostic value in determining the morphology of the lumen, intraluminal mucosa and submucosal tissue in the pharyngeal region of the ET.

Imaging human skin autograft integration with optical coherence tomography.

Skin autografting is a common clinical procedure for reconstructive surgery. Despite its widespread use, very few studies have been conducted to non-invasively evaluate and monitor the vascular and structural features of skin grafts. This study, therefore, aims to demonstrate the potential of optical coherence tomography (OCT) alongside OCT-based angiography (OCTA) to non-invasively image and monitor human skin graft health and integration over time. An in-house-built clinical prototype OCT system was used to acquire OCT/OCTA images from patients who underwent split-thickness skin graft surgery following severe burn damage to the skin. The OCT imaging was carried out at multiple locations over multiple time points with a field of view of ~9 mm × 9 mm and a penetration depth of ~1.5 mm. In addition to obtaining high-resolution qualitative images, we also quantitatively measured and compared specific structural and vascular parameters, such as identifiable layer thickness and corresponding vascular area density and diameter. Two patients (patient #1 and #2) were enrolled for this preliminary study. Vascular and structural features were successfully imaged and measured in the graft tissue and integration layer immediately beneath at different time points. Revascularization, healing, and integration were monitored with patient-specific details. Results of the quantitative image analysis from patient #1 indicated that integration layer thickness 16-day post-surgery was significantly less (~50%) than that of 7-day post-surgery. Additionally, with patient #2, significant growth (~20%) was seen with the vascular area density of both the graft and corresponding integration layer beneath between 6 and 14 days post-surgery. Our preliminary studies show that OCT/OCTA has clinical potential to image and measure numerous features of human skin graft health and integration in the days and weeks following split-thickness surgery. For the first time, we demonstrate the applicability of non-invasive imaging technology for novel clinical uses that could eventually aid in the betterment of surgical practices and clinical outcomes.

OCT-Based Angiography and Surface Topography in Burn-Damaged Skin.

There is a clinical need for an accurate, non-invasive imaging tool that can provide the objective assessment of burn wounds. The aims of this study are to demonstrate the potential of optical coherence tomography (OCT) in evaluating burn wound healing, as well as exploring the physiological basis of human wound healing. This was a retrospective study. Seven patients with severe burn wounds who were admitted to Harborview Medical Center were imaged using an in-house-built, clinical-prototype OCT system. OCT imaging was carried out at multiple scan sites on the burned skin across two time points (imaging session #1 and #2) with a field of view of ~9 × 9 mm. Due to pathological differences among burn zones, scan sites were classified into red sites (zone of hyperemia), white sites (zone of coagulation), and mixed sites. In addition to obtaining qualitative en face vascular and surface topography maps, we quantified vascular area density and surface roughness for comparative purposes. En face vascular and surface topography maps demonstrated numerous morphological changes over both imaging sessions associated with burn injury, such as altered blood flow and loss of regular texture. Quantitative analyses revealed that during imaging session #1, vascular area density was significantly increased within the red sites compared with that of a healthy control (P = 0.0130), while vascular area density was significantly decreased within the white sites compared with that of a healthy control (P < 0.0001). During imaging session #2, vascular area density was significantly reduced to a more normal range within the red sites compared with imaging session #1 (P = 0.0215); however, vascular area density was still significantly lower within the white sites compared with that of a healthy control (P < 0.0001). Furthermore, vascular area density and surface roughness were significantly increased within the white sites during imaging session #2 compared with imaging session #1 (both P < 0.0001). OCT is clinically feasible to monitor vascular changes and alterations in skin surface roughness during the process of burn wound healing. Variations in vascular area density and roughness measurements within the burn wounds revealed by OCT offer some key insights into the underlying pathophysiological mechanisms responsible for wound healing, which may become critical biological indicators in future clinical evaluation and monitoring of wound healing. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

An Intraoral OCT Probe to Enhanced Detection of Approximal Carious Lesions and Assessment of Restorations.

Caries, the world’s most common chronic disease, remains a major cause of invasive restorative dental treatment. To take advantage of the diagnostic potential of optical coherence tomography (OCT) in contemporary dental prevention and treatment, an intraorally applicable spectral-domain OCT probe has been developed based on an OCT hand-held scanner equipped with a rigid 90°-optics endoscope. The probe was verified in vitro. In vivo, all tooth surfaces could be imaged with the OCT probe, except the vestibular surfaces of third molars and the proximal surface sections of molars within a "blind spot" at a distance greater than 2.5 mm from the tooth surface. Proximal surfaces of 64 posterior teeth of four volunteers were assessed by intraoral OCT, visual-tactile inspection, bitewing radiography and fiber-optic transillumination. The agreement in detecting healthy and carious surfaces varied greatly between OCT and established methods (18.2–94.7%), whereby the established methods could always be supplemented by OCT. Direct and indirect composite and ceramic restorations with inherent imperfections and failures of the tooth-restoration bond were imaged and qualitatively evaluated. The intraoral OCT probe proved to be a powerful technological approach for the non-invasive imaging of healthy and carious hard tooth tissues and gingiva as well as tooth-colored restorations.

Initial Study for the Determination of the Sequence of Intersecting Lines between Gel Pens and Seals by Optical Coherence Tomography.

Determining the sequence of intersecting lines is a significant issue in the forensic document examination that can reveal the fraud or distinguish between different allegations. Optical coherence tomography (OCT) is a high-resolution cross-sectional imaging technique that has been introduced into forensic science field recently. The potential of OCT as a novel method to determine the sequence of intersecting lines was examined for the first time. In this study, a spectral-domain OCT system with a center wavelength of 900nm was employed to perform nondestructive examination on determining the sequence of 18 heterogeneous intersecting line samples produced using three types of gel pens and three brands of stamp pad ink seals. Two-dimensional (2D) cross-sectional, and three-dimensional (3D) volumetric images of the intersecting lines were obtained by the OCT system. Several features were noted and analyzed to successfully determine the sequence of all the 18 samples. Blind tests were also conducted to demonstrate the effectiveness of OCT technique. The results illustrate that OCT technology can provide an effective and accurate method for sequencing intersecting lines of gel pen ink and seal ink, which may complement the conventional methods used in the examination of questioned documents.

Inner retinal layer thinning in radiologically isolated syndrome predicts conversion to multiple sclerosis.

Individuals with radiologically isolated syndrome (RIS) are at increased risk of converting to multiple sclerosis (MS). Early identification of later converters is crucial for optimal treatment decisions. The purpose of this study was to assess the predictive potential of optical coherence tomography (OCT) measures in individuals with RIS regarding conversion to MS. This prospective observational cohort study included 36 individuals with RIS and 36 healthy controls recruited from two German MS centers. All individuals received baseline OCT and clinical examination and were longitudinally followed over up to 6years. The primary outcome measure was the conversion to MS. During clinical follow-up of 46 (26-58) months (median, 25%-75% interquartile range), eight individuals with RIS converted to MS. Individuals converting to MS showed a thinning of the peripapillary retinal nerve fiber layer (pRNFL) and the common ganglion cell and inner plexiform layer (GCIP) at baseline and during follow-up. Individuals with a pRNFL of 99µm or lower or a GCIP of 1.99mm3 or lower were at a 7.5- and 8.0-fold risk for MS conversion, respectively, compared to individuals with higher measures. After correction for other known risk factors, Cox proportional hazards regression revealed a hazard ratio of 1.08 for conversion to MS for each 1µm decline in pRNFL. Reduction of the pRNFL might be a novel and independent risk factor for conversion to MS in individuals with RIS. OCT might be useful for risk stratification and therapeutic decision-making in individuals with RIS.

Optical coherence tomography for thyroid pathology: 3D analysis of tissue microstructure

To investigate the potential of optical coherence tomography (OCT) to distinguish between normal and pathologic thyroid tissue, 3D OCT images were acquired on ex vivo thyroid samples from adult subjects (n=22) diagnosed with a variety of pathologies. The follicular structure was analyzed in terms of count, size, density and sphericity. Results showed that OCT images highly agreed with the corresponding histopatology and the calculated parameters were representative of the follicular structure variation. The analysis of OCT volumes provides quantitative information that could make automatic classification possible. Thus, OCT can be beneficial for intraoperative surgical guidance or in the pathology assessment routine.

Quantitative Evaluation of Skin Surface Roughness Using Optical Coherence Tomography &lt;italic&gt;In Vivo &lt;/italic&gt;

The quantitative monitoring of skin topography is important in the field of cosmetics and dermatology. The most widespread method for determining skin roughness in vivo is to use skin microrelief, PRIMOS device, which allows a noninvasive, fast, and direct measurement of the skin surface. However, it has drawbacks, such as the interference of backscattering from volumetric skin and motion artifacts. In this study, we demonstrate the potential of optical coherence tomography (OCT) for providing reliable and quantitative skin surface roughness. In order to evaluate the performance of OCT for skin surface analysis, different types of skin phantoms are fabricated and measured. We utilize OCT to identify the effect of cosmetics as well as human skin topology for various aging groups and different skin regions. Skin surface roughness parameters based on ISO 25178 part 2 standard definitions are then derived from home-built image processing software and compared with one acquired from PRIMOS. Our results show that skin surface geometry acquired from three-dimensional OCT images is well quantified to complex wrinkle structure and robust to the angle of the subject. Since OCT enables to present quantitative skin topology and volumetric skin anatomy simultaneously, it would be a useful tool to deliver comprehensive and intuitive information in dynamic skin observations.

Modern acrylic paints probed by optical coherence tomography and infrared reflectography

Contemporary art is particularly delicate as the synthetic materials used for their realization are of poorer quality and durability than the traditional materials. It follows that the contemporary artworks often require imminent restorations as well as in-depth analytical studies of the constituting materials. The non-invasiveness of the scientific methods is a key issue in the diagnostics of contemporary art because it minimizes the need of sampling. In this respect, the potential of Optical Coherence Tomography (OCT) imaging to probe the internal structure of the commercial acrylic paint layers, as a function of their thickness, was investigated and compared with that of the near infrared (NIR) reflectography. In support of these measurements, micro-profilometry, an interferometric technique with micrometric depth resolution, was used to measure the paint layer thicknesses. We show that for some painted materials there is a limited possibility to visualize the underdrawings, when investigated by both OCT and NIR reflectography. This is owed to either the absorption of the illumination wavelength by the paint layer (Cobalt-based paints) or the multiple photon scattering effect (presence of TiO2).

Using speckle to measure tissue dispersion in optical coherence tomography.

Tissue dispersion could be used as a marker of early disease changes to further improve the diagnostic potential of optical coherence tomography (OCT). However, most methods to measure dispersion, described in the literature, rely on the presence of distinct and strong reflectors and are, therefore, rarely applicable in vivo. A novel technique has been developed which estimates the dispersion-induced resolution degradation from the image speckle and, as such, is applicable in situ. This method was verified experimentally ex vivo and was applied to the classification of a set of normal and cancerous colon OCT images resulting in 96% correct classification.

OCT Angiography-Based Detection and Quantification of the Neovascular Network in Exudative AMD.

To investigate the potential of optical coherence tomography (OCT) angiography to detect and quantify the neovascular network in exudative AMD. Treatment-naïve eyes that were diagnosed with exudative AMD were prospectively examined by OCT angiography (OCT-A). The extent of the neovascular network was measured by three independent readers. Interclass-correlation coefficient and area overlap coefficients (OC) were calculated to assess locally precise agreement between measurements. As a reference for interreader agreement, the extent of the neovascular network was further measured on fluorescein angiography (FA) images. A total of 31 eyes (27 patients, mean age 82.5 years, 15 female) were included in the study. Neovascularization subtype was classified as type I in 5, type II in 11, type III in 9, and mixed in 6 eyes, respectively. Interreader agreement for measurements of the neovascular network was 0.884 for OCT-A and 0.636 for FA. Overlap coefficient was 0.705 (interquartile [IQR]: 0.450-0.76) for OCT-A and 0.704 (IQR: 0.673-0.750) for FA, respectively. Area agreement was weaker in type III and mixed lesions. Optical coherence tomography angiography-based measurements of the new vessel complex in neovascular AMD are feasible with interreader agreement comparable with the values obtained for FA. The results underscore the potential of OCT-A as a noninvasive diagnostic tool in neovascular AMD. Yet, further studies will be required to reveal the origin of poor agreement observed in single eyes and to advance OCT-A toward dependable use (e.g., in a reading center context).

Diagnostic potential of optical coherence tomography for small choroidal melanomas

To investigate the sequence of OCT manifestations in choroidal melanoma (CM) with account to its growth. A total of 28 CM patients were examined. Of them, 18 patients with early CM, 10 - with medium-sized CM. The mean patient age at diagnosis was 60.54±5.31 years. Tumor location was macular (15 eyes) or perimacular (13 eyes), its prominence varied from 0.98 to 4.9 mm and basal diameter - from 5.08 to 18.9 mm. Additionally to OCT, tumor autofluorescence was studied in all cases. The sequence of OCT manifestations in CM has been investigated with account to its growth. Our findings include an early change in choroidal profile with often uneven configuration and a plateau in the most prominent part of the lesion. Along with changes in the retinal pigment epithelium (RPE), one could see signs of an initially local small neuroepithelial detachment (NED) with alterations in the photoreceptor layer. We have identified three types of photoreceptor damage. Destruction of all retinal layers (its morphofunctional disorder) indicates the transition of an early CM to a medium one. As to autofluorescence RESULTS: there were lipofuscin deposits in RPE cells detected in OCT scans that showed an evident hyperautofluorescence. The central part the tumor was notable for its hypoautofluorescence. The periphery of the lesion was hyperautofluorescent due to NED. Qualitative changes in the retina overlying choroidal melanoma develop early in the course of the disease, practically in the moment of the first shift of choroidal profile. Destruction begins with the RPE and neuroepithelium (detachment and structural changes). As the tumor grows, retinal architectonics gets irreversibly distorted: the tissue becomes thicker due to edema, cysts, and intraretinal deposits. This process is, of course, accompanied by changes in metric parameters of all retinal layers and the choroid within the area of interest.

Optical coherence tomography detects structural abnormalitiesof the nasal mucosa in patients with cystic fibrosis

BackgroundChronic inflammation and remodeling of the airways remain a hallmark of cystic fibrosis (CF). However, knowledge of the associated mucosal micro-anatomical changes is limited. We evaluated the potential of optical coherence tomography (OCT) for in vivo imaging of the upper airway mucosa in CF patients. MethodsA flexible OCT probe was used for cross-sectional imaging of the nasal mucosa in 25 CF patients and 25 healthy controls. ResultsOCT images showed mucosal details including epithelium, basement membrane, lamina propria with seromucinous glands, and underlying cartilaginous structures. Mean nasal mucosa and epithelial layer thickness were increased in CF compared to controls. In CF patients, antibiotic therapy was associated with reduced nasal mucosa thickening. ConclusionsOCT detected mucosal changes associated with upper airway inflammation and response to antibiotic therapy in CF patients. OCT may be a useful tool for quantitative in vivo assessment of structural changes of the airway mucosa.

MP74-17 POTENTIAL OF OPTICAL COHERENCE TOMOGRAPHY (OCT) AND PROBE-BASED CONFOCAL LASERENDOMICROSCOPY (PCLE) IN THE INVESTIGATION OF THE TESTIS – A FEASIBILITY STUDY

You have accessJournal of UrologyInfertility: Therapy1 Apr 2015MP74-17 POTENTIAL OF OPTICAL COHERENCE TOMOGRAPHY (OCT) AND PROBE-BASED CONFOCAL LASERENDOMICROSCOPY (PCLE) IN THE INVESTIGATION OF THE TESTIS – A FEASIBILITY STUDY Matthias Trottmann, Sabine Kölle, Christian Homann, Herbert Stepp, Daniel Döring, Regina Leeb, Sven Reese, Christian G. Stief, and Ronald Sroka Matthias TrottmannMatthias Trottmann More articles by this author , Sabine KölleSabine Kölle More articles by this author , Christian HomannChristian Homann More articles by this author , Herbert SteppHerbert Stepp More articles by this author , Daniel DöringDaniel Döring More articles by this author , Regina LeebRegina Leeb More articles by this author , Sven ReeseSven Reese More articles by this author , Christian G. StiefChristian G. Stief More articles by this author , and Ronald SrokaRonald Sroka More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.2672AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Male infertility is often due to azoospermia which is mainly addressed surgically by testicular sperm extraction. As no imaging technique for the detection of spermatozoa in vivo is available to date, the positive sperm retrieval rate is merely 50%. Therefore the aim of this study was the investigation of the potential of probe-based confocal laser endomicroscopy (pCLE) and optical coherence tomography (OCT) for micron-scale imaging of testis microarchitecture. METHODS Specimens of bovine testes and epididymides were obtained after slaughter (n=14). For OCT imaging FDA-approved probe-based Niris Imaging System (probe diameter 2.7 mm; axial resolution (AR) 10-20 μm, lateral resolution (LR) 25-50 μm; 1310 nm, Imalux, Cleveland, Ohio, USA) and microscopic style OCT system (AR 5 μm; LR 8-15μ m; Telesto 1325 nm, Ganymede 930 nm, Thorlabs Inc., Dachau, Germany) were used. All obtained images were compared to histological findings after H&E staining. For pCLE Cellvizio® system (Mauna Kea Technologies, France) images were correlated to those obtained by confocal laser microscopy, light microscopy and phase contrast microscopy. For pCLE, the probes ProFlex™ S1500 (LR 3.3 μm; surface imaging) and ProFlex™ Ultra Mini O (LR 1.4 μm; imaging depth of 60 μm) were used. As fluorescent agents 0.001% fluorescein isothiocyanate (FITC), 5% cresyl violet solution (CV), 0,001% TO-PRO®-3 Iodide (T3) and 0.04 % acriflavine (AF) were used. RESULTS By microscopic OCT imaging the testicular and epididymal microarchitecture including ducts and tubules could be identified. Furthermore intra-tubular content and diameter of the tubules could be were analysed. As optical resolution of probe-based Niris Imaging System was distinctly reduced, imaging of testicular tissue did not provide detailed information on single spermatozoa. By pCLE real-time imaging, cells of spermatogenesis and supporting Leydig cells could be identified as well as different cell compartments in the testis. Contrary to OCT, single viable spermatozoa were identified. CONCLUSIONS Microscopic OCT and pCLE techniques looks promising for ex-vivo imaging of specific testicular tissue areas thus discovering spermatozoa fertile areas looks feasible. In comparison to pCLE OCT does not need any fluorescence labelling. The results imply that application of these novel imaging techniques might improve sperm retrieval rates during testicular sperm extraction (TESE) by optical guidance. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e945-e946 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Matthias Trottmann More articles by this author Sabine Kölle More articles by this author Christian Homann More articles by this author Herbert Stepp More articles by this author Daniel Döring More articles by this author Regina Leeb More articles by this author Sven Reese More articles by this author Christian G. Stief More articles by this author Ronald Sroka More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...