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The adoption of emerging imaging technologies in the medical community is often hampered if they provide a new unfamiliar contrast that requires experience to be interpreted. Here, in order to facilitate such integration, we developed two complementary machine learning approaches, respectively based on feature engineering and on convolutional neural networks (CNN), to perform automatic diagnosis of breast biopsies using dynamic full field optical coherence tomography (D-FF-OCT) microscopy. This new technique provides fast, high resolution images of biopsies with a contrast similar to H&E histology, but without any tissue preparation and alteration. We conducted a pilot study on 51 breast biopsies, and more than 1,000 individual images, and performed standard histology to obtain each biopsy diagnosis. Using our automatic diagnosis algorithms, we obtained an accuracy above 88% at the image level, and above 96% at the biopsy level. Finally, we proposed different strategies to narrow down the spatial scale of the automatic segmentation in order to be able to draw the tumor margins by drawing attention maps with the CNN approach, or by performing high resolution precise annotation of the datasets. Altogether, these results demonstrate the high potential of D-FF-OCT coupled to machine learning to provide a rapid, automatic, and accurate histopathology diagnosis.

Optical coherence tomography, or in short OCT, is a measurement technique established in the early 1990s for the non-invasive imaging of interfaces in the bulk of biological tissues or other samples. A full-field OCT setup is built from a microscope combined with a Michelson interferometer, where the mirror in one arm is replaced by the sample. Using white light, which is temporally partially coherent, interference fringes disclose the presence of an interface whenever the lengths of both interferometer arms are nearly equal. Scanning one arm allows for a volumetric reconstruction of all interfaces inside the sample. While the importance of OCT in medicine is indisputable, it is hard to teach students the basic aspects of such technology as most available setups tend to be rather complex. It is our purpose to present a fully functional full-field OCT setup that is stripped-down to its essential components and to promote its use in an undergraduate lab course. The contribution is complemented by a description of the basic theory necessary to understand the working principle of OCT.

Background Although traditional intraoperative assessments (ie, frozen sections) may lower reoperation rates in patients with breast cancer, time/tissue limitations and accuracy concerns have discouraged their routine clinical use. Full-field optical coherence tomography (FFOCT) and dynamic cell imaging (DCI) are novel optical imaging techniques offering rapid histologic approximations that are unfettered by requisite handling steps. This study was conducted to determine the feasibility and diagnostic utility of FFOCT and DCI in examining breast and lymph node specimens during breast cancer surgery. Methods FFOCT and DCI were applied to normal and cancerous breast tissue, benign breast lesions, and resected axillary lymph nodes. The tissues were then subjected to conventional processing and staining (hematoxylin-eosin) for purposes of comparison. Results A total of 314 specimens, including 173 breast biopsies (malignant, 132; benign/normal, 41) and 141 resected lymph nodes (tumor-positive, 48; tumor-negative, 93), were obtained from 158 patients during breast surgery for prospective imaging evaluations. In breast cancer diagnosis, the minimum sensitivities (FFOCT, 85.6%; DCI, 88.6%) and specificities of optical imaging (FFOCT, 85.4%; DCI, 95.1%) were high, although they diverged somewhat in nodal assessments (FFOCT sensitivity, 66.7%; FFOCT specificity, 79.6%; DCI sensitivity, 83.3%; DCI specificity, 98.9%). Conclusions These timely and tissue-sparing optical imaging techniques proved highly accurate in diagnosing breast cancer and nodal metastasis. They compare favorably with routine histologic sections and demonstrate their promise in this setting.

Background Studies have reported the application of conventional optical coherence tomography (OCT) in the diagnosis of basal cell carcinoma (BCC). The new OCT provides cellular details similar to those in pathology slides and may reduce user learning time. This study aimed to demonstrate the quality of ex vivo full-field cellular-resolution OCT images and compare the diagnostic accuracy between physicians with varying pathology experience. Materials and methods Sixty histologically confirmed BCCs were selected. Tissue samples were sectioned and scanned using OCT, and their features were compared with those of hematoxylin and eosin (H&E)-stained sections. Thirty images were selected for the test administered to dermatology residents, dermatopathology fellows, and board-certified general pathologists without any OCT experience. The pretest learning included a 3-min instruction and 10-min self-study of four BCC variants. Results Histopathological BCC and normal histological features were clearly recognizable on the OCT images. The pathological BCC features observed in the OCT images correlated with those found in the H&E-stained sections. Seven participants completed the test. The correct answer rates of the residents, fellows, and pathologists were 71%, 68%, and 83% for BCC and 44%, 57%, and 57% for the BCC subtypes, respectively. Conclusion All the participants identified BCC in >70% cases with a learning time of only 13 minutes. The results indicated that cellular-resolution OCT provided high-quality images similar to the conventional pathology slides. Pathology experience did reflect the diagnostic accuracy. However, a longer training time is still needed at all levels to recognize the BCC subtypes correctly.

Background The Electroretinogram is a mass potential, which reflects the summed electrical activity of the retina. Full-field ERG measures the electrical signals from the whole retina in response to a light stimulus. The weakness of the full-field ERG is that it cannot provide topographical information regarding the functional integrity of the retina and cannot detect subtle functional defects. The response is dominated by the peripheral retina due to its predominance of retinal cells. Aim of the Work to investigate the effect of axial length on fullfield (ffERG)and multifocal ERG (mfERG). Subjects and Methods Forty-four eyes of 44 healthy subjects were included in this case series study which has been conducted at Ain shams university hospitals after the approval of the research ethical committee in the faculty of medicine, Ain Shams University between July 2018 and September 2019. Full ophthalmologic examination was performed for all participants, including visual acuity assessment (Best corrected visual acuity) using Snellen chart, calculation of spherical equivalent (SE), slit Lamp biomicroscopy examination with IOP measurement via Goldmann applanation tonometry (GAT), and fundus examination by indirect ophthalmoscope or via 90 D VOLK lens to assess macular area. Axial length measurement, ffERG & mf-ERG. Results; We found that in the absence of fundus changes, mfERG parameters showed decreased amplitudes with increase in axial length. The Six- Rings Response Densities showed negative correlation with AL while there is no significant correlation between Six- Rings Response Densities and SE. The Six- Rings P1 Amplitude showed negative correlation with AL while there is no significant correlation between P1 Amplitude and SE. The Six- Rings N1 Amplitude showed negative correlation with AL while there is no significant correlation between P1 Amplitude and SE. The four- quadrant Response Densities showed negative correlation with AL while there is no significant correlation between four- quadrant Response Densities and SE. The four- quadrant P1 Amplitude showed negative correlation with AL while there is no significant correlation between P1 Amplitude and SE. The four- quadrant N1 Amplitude showed negative correlation with AL while there is no significant correlation between P1 Amplitude and SE. There is no significant correlation between full-field clinical ERG parameters and both AL and SE. Conclusion In the absence of fundus changes, mfERG parameters showed decreased amplitudes with increase in axial length. For correct interpretation of ERG responses in clinical practice, we recommend consideration of axial length measurement when evaluating mfERG responses.

Fourier-domain full-field optical coherence tomography (FD-FF-OCT) is a fast interferometric imaging technique capable of volumetric sample imaging. However, half of the backscattered light from a sample is lost as it passes through a 50/50 beam splitter, which is at the heart of almost every interferometer. Here, it is demonstrated that this light could be extracted by spatially splitting the illumination pupil plane and detecting it with a separate camera. When a line camera is used to detect the recovered signal, it enables real-time axial imaging of the human cornea in vivo, which serves as a useful visual feedback for aligning a patient for imaging.

Purpose To describe the feasibility of peripheral OCT imaging in retinal diseases using a novel full-field device. Methods A total of 134 consecutive eyes were referred and imaged on the Optos Silverstone swept-source OCT (SS-OCT) (Optos PLC; Dunfermline, UK). Scanning laser ophthalmoscope (SLO) images and the associated SS-OCT images were obtained in the posterior pole, mid-periphery or far periphery based on the nature of the referral and on new areas of interest observed in the optomap images at the time of imaging. Results A total of 134 eyes (96 patients) were enrolled in the study. One hundred and twenty-five eyes (91 patients) with 38 retinal pathologies were prospectively assessed and 9 eyes (5 patients) were excluded due to incomplete image acquisition. The average age of the subjects was 54 years (range 21–92 years). Thirty-nine out of 125 eyes (31%) had macular pathologies. Eighty-six out of 125 eyes (69%) had peripheral only pathologies, an area which cannot be visualized by standard OCT devices with a 50 degree field-of-view. Conclusions The ability to capture peripheral pathologies using an integrated SLO-UWF imaging with full-field swept-source provided high-grade anatomical insight that confirmed the medical and surgical management in a majority of cases. Its use in the mid- and far periphery provides a holistic clinical picture, which can potentially aid in the understanding of various retinal pathologies.

State-of-the-art adaptive optics optical coherence tomography (AO-OCT) presents important limitations, such as small field-of-view (FOV) and require complex, cumbersome hardware, preventing wide clinical deployment. Here, we introduce adaptive-glasses full-field OCT (FFOCT), a compact retinal imaging system allying high resolution, high frame rate (300Hz) and 5° FOV (footprint: 50 cm × 30 cm).

International audience; We propose a fast aid-to-diagnosis biopsy assessment method convenient at the point-of-care, on account of both the imaging technique and the algorithm applied. The procedure implies a pipeline of classification and localization of tumors in breast cancer biopsies imaged with a recently developed non-invasive imaging modality: Dynamic Cell Imaging (aka Dynamic Full Field Optical Coherence Tomography). This allows for fast and interpretable extemporaneous cancer detection with high confidence; we obtained a performance of 96% classification accuracy together with a coarse localization of tumors, even so for single isolated invasive cells.

In this work, we report on non-invasive observation of human esophagus, liver, and uterus samples with Full field optical coherence tomography (FFOCT). ln imaging process, fresh human samples were fixed in formalin immediately after excision and then imaged directly without staining and cutting the samples into a serial of thin slices. Tissue microstructures of each type of normal or cancerous tissue as well as their changes with the increase of the depth beneath tissue surface can be identified in the depth-resolved images. The results demonstrate the potential of applications of the en face images in clinic practice.

Background: Breast cancer in women is a major public health problem throughout the world. To reduce the morbidity and mortality associated with breast cancer, early detection becomes a very important job. Addition of breast Tomosyn-thesis to mammography examination reduced and eliminated tissue overlap especially in women with radiographically dense breast.Aim of Study: To evaluate the impact of adding Digital Breast Tomosynthesis (DBT) to Full Field Digital Mammog-raphy (FFDM) in detection, characterization and diagnosis of mammographically indeterminate breast lesions.Subjects and Methods: The study included 80 patients with 86 indeterminate findings on mammography. DBT ex-amination was done and imaging findings were evaluated before and after the use of DBT.Results: Tomosynthesis showed better diagnostic perform-ance compared to mammography. The sensitivity of Tomo-synthesis was 90%, the specificity was 91.1%, the positive predictive value of 88%, the negative predictive value was 92.7% and the diagnostic accuracy was 91%, while the sensi-tivity of mammography was 62.5%, the specificity was 59%, the positive predictive value was 52.1%, the negative predictive value was 68.8%, and the diagnostic accuracy was 60.4%.Conclusion: DBT significantly enhanced the detection and characterization of indeterminate breast lesions on digital mammography especially in the context of dense breast parenchyma.

Background: Dual Energy Contrast Enhanced Spectral Mammography (DE-CESM) is a new and advanced clinical application of full field (FFDM) and is easily implemented, fast, and reproducible, and breast doses are comparable to those of standard digital mammography, it might be useful for shifting expensive MRI to digital mammography.Aim of Study: To evaluate the enhancing power of the Contrast-Enhanced Spectral Mammography (CESM) on breast lesions and its ability to differentiate malignant from benign masses.Patients and Methods: A prospective study was carried on 20 patients referred to Radio-Diagnosis Department. At the Air Forces Hospital over 12 months for the evaluation of breast masses, all patients were examined by a dual energy contrast enhanced spectral mammography, a complementary B-mode ultrasound and a histopathological examination of all masses.Results: The study included 8 benign (40%) and 12 malignant (60%) masses, 17/20 (85%) of them were enhanced while 3/20 (15%) were not enhanced. The enhanced masses were further subdivided into faint & avid enhancement as well as homogenous, heterogeneous & ring enhancement. Contrast uptake was significantly more frequent by malignant masses (p-value

Background Mycoplasma synoviae (MS) is an important poultry pathogen worldwide. This bacterium may cause eggshell changes including an altered shell surface, thinning, and increased translucency in different areas, which leads to a greater incidence of eggshell cracks and breaks. In the present study the association between experimental infection of birds with two field strains of MS from different genotypes and the production of abnormal eggs is described. The analysis of those eggshells using a full-field optical coherence tomography (FF OCT) scanner is also reported. Results Eggshell samples were obtained from three experimental groups of chickens: one control and two infected tracheally with field strains of MS which produced abnormal eggs. In both experimental groups infected with MS a reduction of mean daily egg production by 11% was observed compared to the control group, which started at 21 to 42 dpi. Eggshell apex abnormalities increased to 24.5% of eggs and in some cases, soft-shelled eggs were produced. This study provides the first analysis of shells from anomalous eggs carried out using FF OCT, which allows three-dimensional structural imaging of an investigated sample at micrometre scale. FF OCT showed ultrastructural changes in eggshells and a smaller number of pores on the entire surface of the affected shells. Conclusions The eggshell pathology and the concomitant egg production losses that result from infections highlight the economic significance of MS in commercial poultry. There are differences in the strains of MS which may induce eggshell apex abnormalities (EAA) and egg production losses. The use of FF OCT, which is a noninvasive measurement method based on analysis of the light backscattered from the measured object, will confer the ability to control the quality of eggshells in flocks infected with MS.

espanolEn este trabajo se desarrollo un sistema optico facil de entender para el estudio de la tecnica de imagen medica conocida como tomografia optica de coherencia (OCT). Esta tecnica permite la reconstruccion volumetrica de muestras inhomogeneas, opacas y esparsivas tales como los tejidos biologicos. La implementacion se realizo usando componentes no disenados especificamente para OCT, bajo el esquema de un interferometro de Michelson utilizando una camara CCD para la captura de los patrones de interferencia en una configuracion conocida como OCT de campo completo (FFOCT). El sistema, explicado en detalle, se diseno usando componentes opticos comunmente encontrados en los laboratorios de optica, ya que nuestro enfoque es brindar una aproximacion accesible para entender las bases de OCT. El sistema obtenido posee una resolucion axial de 1.74 μm y resolucion lateral de 4.5 μm. Con el sistema descrito se obtuvieron tomogramas de dos muestras: una moneda metalica y un ala de insecto ex-vivo de la familia blattodea. EnglishIn this work, an easy to understand optical system was developed for the study of the medical imaging technique optical coherence tomography (OCT). This technique allows volumetric reconstruction of inhomogeneous, non-transparent and scattering samples such as biological tissues. The implementation was based on using non-specialized components for OCT under the scheme of a Michelson interferometer with a CCD camera to capture the interference patterns in a configuration known as full field OCT (FFOCT). Our system, explained in detail, was designed using components commonly found in most optical labs because our focus is to provide an accessible experimental setup for understanding the basics of OCT. The developed system possesses an axial resolution of 1.74 μm and a lateral resolution of 4.5 μm. With the described system, tomograms of two samples were obtained: a metal coin and an ex-vivo insect wing of the blattodea family.

International audience; The highest three-dimensional (3D) resolution possible in in-vivo retinal imaging is achieved by combining optical coherence tomography (OCT) and adaptive optics. However, this combination brings important limitations, such as small field-of-view and complex, cumbersome systems, preventing so far the translation of this technology from the research lab to clinics. Here, we mitigate these limitations by combining our compact time-domain full-field OCT (FFOCT) with a multi-actuator adaptive lens positioned just in front of the eye, in a technique we call the adaptive-glasses wavefront sensorless approach. Through this approach, we demonstrate that ocular aberrations can be corrected, increasing the FFOCT signal-to-noise ratio and enabling imaging of different retinal layers with a 2µm × 2µm × 8µm resolution over a 5 o × 5 o field-of-view, without major anisoplanatism influence.; La plus haute résolution tridimensionnelle (3D) possible en imagerie rétinienne in vivo est obtenue en combinant la tomographie par cohérence optique (OCT) et l'optique adaptative. Toutefois, cette combinaison présente des limites importantes, comme un champ de vision réduit et des systèmes complexes et encombrants, ce qui empêche jusqu'à présent la transposition de cette technologie du laboratoire de recherche aux cliniques. Ici, nous atténuons ces limitations en combinant notre OCT compacte à plein champ dans le domaine temporel (FFOCT) avec une lentille adaptative à actionneurs multiples placée juste devant l'œil, dans une technique que nous appelons l'approche des lunettes adaptatives. Grâce à cette approche, nous démontrons que les aberrations oculaires peuvent être corrigées, augmentant le rapport signal/bruit de la FFOCT et permettant l'imagerie de différentes couches de la rétine avec une résolution de 2µm x 2µm x 8µm sur un champ de vision de 5° x 5°, sans influence majeure d'anisoplanatisme.

Optical coherence tomography is widely used in the non-invasive detection of skin cancer. We are proposing an image guiding system integrated in a full-field OCT (FF-OCT) system and an image matching algorithm to register the guiding image onto a dermoscopic image. This guiding system takes the objective optics of FF-OCT system to observe the same vision with OCT. The FOV of the guiding image and FF-OCT is 2*2mm2 and 500*500μm2 respectively. The spatial relation between OCT and the guiding image system is fixed, the OCT imaging location can also be identified. The guiding image is then matched into the clinically used dermoscopic image which has a 20*20 mm2 FOV by an image matching algorithm. The FF-OCT image can be registered on the dermoscopic image through the guiding image. This allows physicians to target the scanning area precisely in the lesion, and record the scanned point to confirm the full lesion. This invention improves the efficiency of the entire examination and allows to follow-ups the lesion at different time.

The treatment of macular diseases requires frequent monitoring by optical coherence tomography (OCT). Home monitoring would reduce the burden of frequent clinical visits and increase therapy adherence. In a pilot study with 47 patients having different macular diseases we tested a proprietary self-examination low-cost full-field OCT (SELFF-OCT). For comparison, scans with a standard clinical spectral domain OCT were taken. Data was graded by a reading center. Patients were able to successfully acquire images that were clinically gradable for 85% of the included eyes. The sensitivity and specificity for an anti-VEGF treatment decision based on the SELFF-OCT was 0.94 and 0.95, respectively.

Dynamic FFOCT allows us to record the intrinsic motion of biological samples in 3D, over hours. We performed scratch assays on primary porcine RPE and human induced pluripotent stem cells derived RPE cell cultures. We plotted motion maps from the optical flow. For wounds

Recent OCT based investigations in humans and in experimental animals have shown that rods and cones outer segments elongate in response to light stimuli. In this manuscript we describe our efforts to implement phase-based “optoretinograms” (ORG) analysis framework to retinal images acquired with standard raster scanning FD-OCT system, that offers much lower phase stability compared to full field or line field OCT acquisition schemes. Our initial results, acquired in anesthetized mice in vivo, showcase successful extraction of phase-based ORG signal and its favorable comparison with intensity-based ORG signal extracted from the same data sets.

Dynamic-focusing optical coherence tomography (OCT) can provide ~1-μm isotropic resolution in extended depth of field, and Mirau design is preferred because of lower weight. In previous works, we reported a Mirau-type OCT based on high-radiance spatially-incoherent source. However, the illumination intensity is limited by the etendue. Besides, coherent artifacts increases with the partially coherent illumination scheme. In this report, we introduce a method to narrow illumination linewidth to 5 μm and reduce coherence area to 1 μm2. With spatially incoherent illumination, optimized throughput and low-weight design, low-speckle B-scan can be acquired within 0.25 second.

Blood flow functional imaging is widely applied in biological research to provide vascular morphological and statistical parameters. It relies on the absorption difference and is, therefore, easily affected by complex biological structures, and it cannot accommodate abundant functional information. We propose a full-field multifunctional angiography method to classify arteriovenous vessels and to display flow velocity and vascular diameter distribution simultaneously. Unlike previous methods, an under-sampled laser Doppler acquisition mode is used to record the low-coherence speckle, and multi-functional angiography is achieved by modulating the endogenous hemodynamic characteristics from low-coherence speckle. To demonstrate the combination of classified angiography, blood flow velocity measurement, and vascular diameter measurement realized using our method, we performed experiments on the flow phantom and living chicken embryos and generated multi-functional angiograms. The proposed method can be used as a label-free multi-functional angiography technique in which red blood cells provide a strong endogenous source of naturally hemodynamic characteristics. This article is protected by copyright. All rights reserved.

We present an optimized Fourier-domain full-field optical coherence tomography system for corneal in vivo imaging that uses a line camera for real-time cross-sectional preview and a multimode fiber for preventing retinal damage.

Purpose The treatment guidelines for many macular diseases rely on frequent monitoring with optical coherence tomography (OCT). However, the burden of frequent disease control leads to low therapy adherence in real life. OCT home monitoring would address this issue but requires an inexpensive and self-operable device. With self-examination low-cost full-field OCT (SELFF-OCT), our group has introduced a novel technology that may fulfill both requirements. In this pilot study, we report the initial experiences with a clinical prototype. Methods Fifty-one patients with different macular diseases were recruited in a cross-sectional study. The most common diseases were age-related macular degeneration (AMD; 39/51), diabetic macular edema (DME; 6/51), and retinal vein occlusion (RVO; 3/51). Patients received a short training in device usage and then performed multiple self-scans with the SELFF-OCT device. For comparison, scans with a standard clinical spectral domain (SD-)OCT were taken. Results After a brief training, 77% of the patients were able to successfully acquire images that were clinically gradable. No significant influence on success could be found for age (p = 0.08) or BCVA (p = 0.97). Relevant disease biomarkers in the most common retinal diseases could be detected. Conclusions SELFF-OCT was used successfully for retinal self-examination and in the future could be used for retinal home monitoring. Future improvements in technology are expected to improve success rates and image quality. Trial registration The Trial was registered in the German Trial Register under the number DRKS00013755 on 14.03.2018.

Background: Diagnosis of multiple sclerosis (MS) may sometimes be ascertained at the time of optic neuritis (ON) but other times require the advent of new disease activity. Objectives: The aim of this study was to examine the predictive value of optical coherence tomography (OCT) and visual evoked potential (VEP) measurements of the non-symptomatic, fellow eye of ON patients, for conversion to MS. Methods: This is a prospective cohort study in patients with acute ON. OCT thickness measurements of peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell layer–inner plexiform layer (GCLIPL), and multifocal (mf) VEP and full-field (ff) VEP, were performed. Univariate and multivariate Cox regression examined the value of predictors for the conversion to MS. Results: A total of 79 unilateral, acute ON patients, with no MS diagnosis or prior demyelination, were included. Of which, 28 patients developed MS during follow-up. Inferonasal GCLIPL, mean GCLIPL, and pRNFL thickness significantly predicted MS development in multivariate analysis (hazard ratio (HR) = 0.922–0.939, p = 0.0172–0.021). MfVEP mean latency (HR = 1.052, p = 0.006) only predicted MS conversion in univariate analysis. No significant predictive value was shown for the other parameters ( p > 0.2). Conclusion: While both mfVEP and OCT are useful tools in the evaluation of acute ON patients, only OCT measurements of fellow eyes may serve as an independent predictor of MS development.

The electroretinogram (ERG) is a functional test widely used in clinical practice to help diagnose diseases of the retina and optic nerve. In fact, it measures the electrical response to a light stimulus of retinal cells, and different ERG tests can be used to probe different retinal areas and cells.The stimulators most commonly used in visual electrophysiology are Ganzfeld stimulators, spherical devices used to perform full-field ERG, and flat monitors, which are not suited for the detection of peripheral early disfunctions, since they do not probe the entire human visual field. Clinical stimulators can use different technologies, but light emitting diodes (LEDs) are becoming very popular since they are almost ideal light sources. Recently, a three dimensional stimulus source based on LEDs able to perform peripheral pattern ERG (ppERG) has been developed.In this paper, a highly-configurable full-field stimulus source for electroretinography based on LEDs is presented. It is capable of presenting an arbitrary pattern of pixels to the entire visual field of a test subject, thus bringing together the functionalities of the existing stimulators. The pattern of pixels is configurable to present stimuli for multiple ERG protocols to any arbitrary sector of the visual field, giving also the possibility to use different colours. The device structure was designed in order to obtain uniform luminance stimuli and minimal light reflection. Moreover, programming and control of the device was widely explored, with a special focus on the development of an electronic design flexible enough to allow the implementation of different ERG protocols. Luminance uniformity of the device was analysed, obtaining satisfactory results. Considering the colour channel of greatest interest for pattern ERG (pERG) protocol, the contrast between black and white checks was much higher than the minimum 80% required by the standards. Finally, the prototyped device was able to elicit consistent flicker ERG and full-field ERG responses in a healthy volunteer subject.

International audience; Full-field optical coherence tomography (FFOCT) is an imaging technique of biological tissue based on tissue light reflectance analysis. We evaluated the feasibility of imaging fresh digestive mucosal biopsies after a quick mounting procedure (5 min) using two distinct modalities of FFOCT. In static FFOCT mode, we gained high-resolution images of general gut tissue-specific architecture, such as oesophageal papillae, gastric pits, duodenal villi and colonic crypts. In dynamic FFOCT mode, we imaged individual epithelial cells of the mucosal lining with a cellular or subcellular resolution and identified cellular components of the lamina propria. FFOCT represents a promising dye-free imaging tool for on-site analysis of gut tissue remodelling.

We demonstrate functional in vivo imaging of photoreceptor and neuronal layers within the living human retina by looking at the expansion of their optical path length. To this end, we use a special full-field swept-source optical coherence tomography system that acquires all lateral points in parallel, achieving a high-speed data acquisition with up to 200 volumes per second. A combination of computational motion and aberration correction with a suitable phase evaluation scheme yields minuscule changes after exposing the photoreceptors to a white light stimulus.

To achieve 3D high-cellular resolution, a great effort, in the past years, was made to develop Adaptive Optics (AO)-OCT systems. However, such systems require quite complex, expensive and cumbersome hardware, making clinical transfer challenging. Recently, we demonstrated that the use of spatially incoherent illumination in Time-Domain Full-Field (FF)-OCT offers a valuable advantage: the lateral resolution is almost insensitive to ocular aberrations that only affect the FF-OCT signal level. We took advantage of this property to image in-vivo photoreceptor mosaic without using an AO technique. Nevertheless, the FF-OCT technique was still facing some challenges in providing consistent and reproducible images, mainly due to axial eye motion and reduced signal level. Here, we present the Adaptive Glasses-assisted FF-OCT, where an adaptive lens is placed just in front of the eye, like spectacles, enabling correction of the first 10 Zernike polynomials, increasing the FF-OCT signal level.

Using phase-sensitive full-field swept-source optical coherence tomography we already showed that morphological changes in the photoreceptor outer segments are detectable. Those signals manifest themselves in an elongation of the optical path length. Using improved post.processing we report on progress in detecting signals in the neuronal layers of the human retina. The spatially resolved signals show a characteristic time course and by combining these with simultaneous measurements of the photoreceptors we were able to generate a wiring map of the neuronal retina.

We present the preliminary results of our depth-resolved PSF measurement in static scattering phantoms. This forms a basis for correcting the degradation of the point spread function by optical scattering.

In optical coherence tomography a broadband light source is used for high axial resolution. Here we show high-resolution sectioning in full-field optical coherence microscopy using longitudinal spatial coherence properties of a monochromatic light source.

In recent years, the use of Convolutional Neural Networks (CNNs) in medical imaging has shown improved performance in terms of mass detection and classification compared to current state-of-the-art methods. This paper proposes a fully automated framework to detect masses in Full-Field Digital Mammograms (FFDM). This is based on the Faster Region-based Convolutional Neural Network (Faster-RCNN) model and is applied for detecting masses in the large-scale OPTIMAM Mammography Image Database (OMI-DB), which consists of 80,000 FFDMs mainly from Hologic and General Electric (GE) scanners. This research is the first to benchmark the performance of deep learning on OMI-DB. The proposed framework obtained a True Positive Rate (TPR) of 0.93 at 0.78 False Positive per Image (FPI) on FFDMs from the Hologic scanner. Transfer learning is then used in the Faster R-CNN model trained on Hologic images to detect masses in smaller databases containing FFDMs from the GE scanner and another public dataset INbreast (Siemens scanner). The detection framework obtained a TPR of 0.91±0.06 at 1.69 FPI for images from the GE scanner and also showed higher performance compared to state-of-the-art methods on the INbreast dataset, obtaining a TPR of 0.99±0.03 at 1.17 FPI for malignant and 0.85±0.08 at 1.0 FPI for benign masses, showing the potential to be used as part of an advanced CAD system for breast cancer screening This work is partially supported by SMARTER project funded by the Ministry of Economy and Competitiveness of Spain, under project reference DPI2015-68442-R, and the ICEBERG project (Ref. RTI2018- 096333-B-I00) funded by the Ministry of Science, Innovation and Universities. R. Agarwal is funded by the support of the Secretariat of Universities and Research, Ministry of Economy and Knowledge, Government of Catalonia Ref. ECO/1794/2015 FIDGR-2016

We present a crosstalk-free Fourier-domain full-field optical coherence tomography system that uses a fast deformable membrane for spatial coherence reduction. It enables the visualization of the choroids and helps to better delineate the retinal layers.

We present spatially incoherent Fourier-domain full-field optical coherence tomography system that reduces crosstalk noise in retina images and enables corneal imaging. It is achieved by using a fast deformable membrane to reduce spatial coherence.

Objectives To summarise and compare the performance of magnification mammography and digital zoom utilising a full-field digital mammography (FFDM) system in the detection and diagnosis of microcalcifications. Methods We ran an extended search in MEDLINE, EMBASE, CINAHL, Engineering Village and Web of Science. Diagnostic test studies, experimental breast phantom studies and a Monte Carlo phantom study were included. A narrative approach was selected to summarise and compare findings regarding the detection of microcalcifications, while a hierarchical model with bivariate analysis was used for the meta-analysis of sensitivity and specificity for diagnosing microcalcifications. Results Nine studies were included. Phantom studies suggested that the size of microcalcifications, magnification or zoom factor, exposure factors and detector technology determine whether digital zoom is equivalent to magnification mammography in the detection of microcalcifications. Pooled sensitivity for magnification and zoom calculated from the diagnostic test studies was 0.93 (95% CI 0.84–0.97) and 0.85 (95% CI 0.70–0.94), respectively. Pooled specificity was 0.55 (95% CI 0.51–0.58) and 0.56 (95% CI 0.50–0.62), respectively. The differences between the sensitivities and specificities were not statistically significant. Conclusions Digital zoom may be equivalent to magnification mammography. Diagnostic test studies and phantom studies using newer detector technology would contribute additional knowledge on this topic. Key Points • The performance of digital zoom is comparable to magnification for detecting microcalcifications when newer detector technology and optimised imaging procedures are utilised. • The accuracy of digital zoom appears equivalent to geometric magnification in diagnosing microcalcifications.

Optical coherence tomography can differentiate brain regions with intrinsic contrast and at a micron scale resolution. Such a device can be particularly useful as a real‐time neurosurgical guidance tool. We present, to our knowledge, the first full‐field swept‐source optical coherence tomography system operating near a wavelength of 1310 nm. The proof‐of‐concept system was integrated with an endoscopic probe tip, which is compatible with deep brain stimulation keyhole neurosurgery. Neuroimaging experiments were performed on ex vivo brain tissues and in vivo in rat brains. Using classification algorithms involving texture features and optical attenuation, images were successfully classified into three brain tissue types., Optical coherence tomography can differentiate brain regions with intrinsic contrast and at a micron scale resolution. We present, to our knowledge, the first full‐field swept‐source optical coherence tomography system operating near a wavelength of 1310 nm. The proof‐of‐concept system was integrated with an endoscopic probe tip, which is compatible with deep brain stimulation keyhole neurosurgery. Using classification algorithms involving texture features and optical attenuation, images were successfully classified into three brain tissue types.

The International Society for Clinical Electrophysiology of Vision (ISCEV) Standard for full-field electroretinography (ERG) describes a minimum procedure, but encourages more extensive testing. This ISCEV extended protocol describes an extension to the ERG Standard, namely the photopic negative response (PhNR) of the light-adapted flash ERG, as a well-established technique that is broadly accepted by experts in the field. The PhNR is a slow negative-going wave after the b-wave that provides information about the function of retinal ganglion cells and their axons. The PhNR can be reduced in disorders that affect the innermost retina, including glaucoma and other forms of optic neuropathy. This document, based on existing literature, provides a protocol for recording and analyzing the PhNR in response to a brief flash. The protocol includes full-field stimulation, a frequency bandwidth of the recording in which the lower limit does not exceed 0.3 Hz, and a spectrally narrowband stimulus, specifically, a red flash on a rod saturating blue background. Suggested flash strengths cover a range up to and including the minimum required to elicit a maximum amplitude PhNR. This extended protocol for recording the PhNR provides a simple test of generalized retinal ganglion cell function that could be added to standard ERG testing.

We compared the performance characteristics of 297,629 full field digital (FFDM) and 416,791 screen film mammograms (SFM). Sensitivity increased with age, decreased with breast density, and was lower for more aggressive and lobular tumors. While sensitivity did not differ significantly by modality, specificity was generally 1–2 percentage points higher for FFDM than for SFM across age and breast density categories. The lower recall rate for FFDM vs. SFM in our study may partially explain performance differences by modality. In this large healthcare organization, modest gains in performance were achieved with the introduction of FFDM as a replacement for SFM.

Congenital achromatopsia or rod monochromatism is a rare autosomal recessive condition defined by a severe loss of cone photoreceptor function in which rods purportedly retain normal or near-to-normal function. This report describes the results of electroretinography in two siblings with CNGB3-associated achromatopsia.Full field light- and dark-adapted electroretinograms (ERGs) were recorded using standard protocols detailed by the International Society for Clinical Electrophysiology of Vision (ISCEV). We also examined rod-mediated ERGs using series of stimuli that varied over a 6 log unit range of retinal illuminances (-1.9-3.5 log scotopic trolands).Dark-adapted ERGs in achromatopsia patients exhibited severely reduced b-wave amplitudes with abnormal b:a ratios (1.3 and 0.6). In comparison, the reduction in a-wave amplitude was less marked. The rod-mediated ERG took on an electronegative appearance at high-stimulus illuminances.Although the defect that causes achromatopsia is primarily in the cone photoreceptors, our results reveal an accompanying disruption of rod function that is more severe than has previously been reported. The differential effects on the b-wave relative to the a-wave points to an inner-retinal locus for the disruption of rod function in these patients.

Full-field swept-source optical coherence tomography (FF-SS-OCT) achieves high-resolution high-speed images of the sample by parallel interferometric detection. However, the image quality is very susceptible to the cross-talk-generated noise [1]. This issue results from the so-called signal degrading speckles [2], and can be reduced, if the spatially incoherent light source (thermal lamp or LED) is employed [1] but reduces the imaging speed. Recently, it was demonstrated that, the PSF of the FF-OCT with spatially incoherent illumination is almost insensitive to low-order geometrical aberrations, e.g. defocus [3]. These results lead to a hypothesis that the cross-talk-generated noise and low-order geometrical aberrations can be overcome by damping the spatial coherence of the incident light beam. Here, we present a novel method, in which the cross-talk-generated noise is suppressed with the spatiotemporal optical coherence (STOC) manipulation. In STOC, the phase of incident light is modulated in time with a set of phase patterns displayed sequentially on the spatial light modulator (SLM). Light modulation is synchronized with light acquisition to effectively control the spatial coherence of the detected light.

Full-field optical coherence tomography with ultra-precise positioning of the PZT by polynomial hysteresis compensation enables depth-dependent spectral data extraction from raw OCT interferometric data. Spectral analysis could quantify molecular/chemical composition of the tissue constituents.

We investigated the downstream workup and costs associated with digital breast tomosynthesis (DBT) compared with 2-dimensional full field digital mammogram (FFDM) when employed as initial follow-up imaging in breast conservation therapy.Between the years 2015 and 2017, 450 consecutive breast conservation therapy patients, ages 32 to 89, with a follow-up DBT (n=162) or FFDM (n=288) were retrospectively reviewed. The primary endpoints were further workup after follow-up mammogram and associated health care costs at 1 year. A single DBT costs an estimated $149 compared with $111 for FFDM, based on Centers for Medicare claims data from the Oncology Care Model.The first posttreatment mammogram was received within 3 (20%), 3 to 6 (32%), or after 6 months (48%) following radiation. Younger patients and those undergoing hypofractionated radiation were more likely to get DBT. There were no differences in stage, receptor status, or mammogram timing between those in the FFDM and DBT groups.The following downstream workup ensued for DBT compared with FFDM imaging: 18% versus 29% short-interval (6-mo) mammogram (odds ratio=1.83, P=0.01), 6% versus 11% breast magnetic resonance imaging (odds ratio=1.90, P=0.08), 4% ultrasound for each, and 3% biopsy for each (1 positive in the FFDM group). Including downstream workup, the estimated cost per patient in the DBT group was $216.14 compared with $237.83 in the FFDM group. Independent predictors for reduced downstream workup per multivariable analysis were the use of DBT and first follow-up mammogram at least 6 months after radiation (P0.05).Excess workup was reduced with DBT compared with FFDM in the posttreatment setting, which translated to an improvement in cost efficiency in this study.

Aberration-corrected imaging of human photoreceptor cells, whether hardware or software based, presently requires a complex and often expensive setup. Here, we demonstrate a simple and inexpensive off-axis full-field time-domain optical coherence tomography approach to acquire volumetric data of in vivo human retina. Full volumetric, laterally phase stable data are recorded. The lateral phase stability allows computational aberration correction, which enables us to visualize single photoreceptor cells. In addition, our approach is able to correct large aberrations and is thus feasible for the numerical correction of ametropia in post processing. Our implementation of full-field OCT combines a low technical complexity with the possibility to use the phase of the recorded light for computational image correction.

Full-Field Optical Coherence Tomography (FFOCT) is an effective technique for tissue anatomy imaging, allowing cancer detection through the observation of disorders in the tissue microarchitecture. Moreover, with the temporal analysis of the FFOCT signal variations, a functional dimension is added, allowing the distinction of cell types through their intracellular activity. This complementary imaging mode, called Dynamic Cell Imaging (DCI), has shown the ability to identify normal cells, cancer cells and immune cells in different types of tissue such as breast, liver or lung. On samples ranging from cell cultures to entire tissue resections, DCI signals are recorded and analyzed in order to characterize the involved endogenous biomarker at the subcellular scale. Longitudinal studies of these samples over a few hours are performed under different environment perturbations intended to modify the cell metabolism. The potential of bimodal FFOCT is evaluated through a clinical study organized at the department of breast surgery of Peking University People’s Hospital in Beijing. More than 200 breast samples and lymph nodes are included. A part of the images will be directly compared to histology to identify reading criteria and build a reference atlas. The other part will be read on a blind study to measure the ability of cancer detection with respect to histology. To take full advantage of the FFOCT and the DCI information richness for faster cancer assessment during surgeries, a computer-aided diagnostic system based on Machine Learning, and more specifically Deep Learning, is investigated.

We demonstrate the feasibility of deriving quantitative measures of corneal transparency from objective analysis of stromal light backscattering with full-field optical coherence tomography (FF-OCT), addressing an unmet need in ophthalmology.