This PDF file contains the front matter associated with SPIE Proceedings Volume 11620, including the Title Page, Copyright information, and Table of Contents.

Celiac disease (CD) is an autoimmune disease that damages the small intestine's villi upon gluten ingestion. Intestinal biopsy via esophagogastroduodenoscopy is the current diagnostic gold standard for CD, but this procedure requires sedation and suffers from sampling error. Here, we conducted a clinical study to test whether image biomarkers derived from duodenal OCT tethered capsule endomicroscopy (TCE) can be used to diagnose CD. Results showed a statistically significant difference in OCT image metrics (villus height & width, contrast, and homogeneity with p<0.0001) among active CD, inactive CD and healthy subjects, demonstrating the potential of TCE for the diagnosis of CD.

In this paper, we demonstrate deep learning-based denoising of high-speed (180 fps) confocal images obtained with our low-cost SECM device. The CARE network was trained with 3090 high- and low-SNR image pairs on the Google Colab platform and tested with 45 unseen image pairs. The CARE prediction showed significant increase of SSIM and PSNR, and reduction of the banding noise while maintaining the cellular details. The preliminary results show the potential of using a deep learning-based denoising approach to enable high-speed SECM imaging.

The rotational distortion of endoscopic Optical Coherence Tomography (OCT) is caused by friction of optical fiber and motor instabilities. On-line rotational distortion compensation is essential to provide real-time feedback. We proposed a new method that integrates a Convolutional Neural Network based warping parameters prediction algorithm to correct the azimuthal position of each image line. This method solves the problem of drift in iterative processing by an overall shifting parameter predicting nets with a processing time of 145ms/frame and variation reduction of 88.9% for the data obtained in ex-vivo and in-vivo experiments.

For OCT-tethered capsule endomicroscopy (TCE) to be a useful minimally invasive tool for evaluating Crohn’s disease, the capsule must be able to be localized within the terminal ileum where the disease often manifests. Here, we developed a machine learning algorithm to assign OCT images of the small intestine into their corresponding anatomical regions. We selected a convolutional neural network and trained it on a set of 2108 cross-sectional images obtained from four swine ex vivo imaging studies to classify images into duodenum, jejunum, or terminal ileum. The model achieved 93±1.72% (95% confidence interval) accuracy on a separate test set of 846 images. These results suggest machine learning may be used to automatically determine when the capsule is in the terminal ileum, enabling microscopic evaluation of this anatomical segment that exhibits pathology in Crohn’s disease.

In this work, we demonstrate the ability to image and quantify airway changes, edema, and epithelial layer separation using OCT and automated tissue boundary identification in the rabbit large airways as early as 30-minutes post-chlorine gas exposure. We propose this novel approach will enable further investigations into using OCT for pre-hospital and point-of-care diagnostics of large airway injury due to airway toxic chemical exposure. With enhanced portability over conventional bronchoscopy, we believe our system is capable of field hospital deployment and investigating airway conditions in warfighters. Combining OCT with bronchoscopy would enhance the assessment and treatment of large airway chemical injury.

We present an endomicroscopic OCT probe for in vivo examination of the mucosa in the nose based on a voice coil actuator. The side-viewing endoscope has a tip diameter of 3 mm and a usable length of 7 cm. A graded-index (GRIN) lens optics achieve a lateral resolution of 3 µm. At an actuator frequency between 40 Hz and 100 Hz the scanning range is up to 2 mm. A supercontinuum laser based mOCT system enables an axial resolution of 1 µm at a depth range of 700 µm. The postprocessing includes the linearization of the sinusoidal scan pattern and a registration of the time series from B-scans. The potential of the new design was demonstrated on ex-vivo mouse trachea. Essential morphological structures such as epithelium with ciliated cells, glands, blood and lymph vessels and also mucus transport were be visualized.

We present a motorized distal scanning endoscope with an outer diameter of 1.35 mm and 52 fps rotation speed for in vivo imaging in the peripheral airways of lungs [1]. Lung segments of an asthma patient pre and post bronchial thermoplasty (BT) treatment were imaged [2]. Optical coherence tomography (OCT) intensity images, attenuation coefficient (AC) images and polarization sensitive OCT (PS-OCT) images showing both birefringence, optic axis uniformity (OAxU) and optic axis (OA) orientation were extracted from the acquired data. PS-OCT endoscopy visualized airway smooth muscle layer thickness and location pre and post BT treatment as means to predict its effectiveness.

Early, accurate diagnosis of interstitial lung disease (ILD) is critical for clinical management and therapeutic decision-making, especially distinguishing idiopathic pulmonary fibrosis (IPF) from non-IPF ILD. Unfortunately, current diagnostic imaging methods are limited in resolution and surgical biopsy methods are invasive. In this study, we evaluate the accuracy of endobronchial optical coherence tomography (EB-OCT) as a low-risk method for in vivo ILD diagnosis in patients undergoing surgical biopsy. EB-OCT was able to distinguish diagnostic microanatomical features of IPF from non-IPF ILDs, independently compared against surgical biopsy. These findings support the potential of OCT as a minimally-invasive method for IPF diagnosis.

Barrett’s esophagus is the main pre-cancer risk factor for the development of esophageal adenocarcinoma. Over the last decades, the incidence rate of esophageal adenocarcinoma increases exponentially in the Western World. Endoscopic screening and minimally-invasive treatment of Barrett’s esophagus are challenging due to large surface area of the lining (1-20 cm). Current microendoscopy technologies have shown high specificity; however, its sensitivity is low due to tiny field-of-view (the probe diameter is 100-1000 μm). Therefore, we proposed a novel approach with end-expandable optical fiber brush to collect endoscopic sparse imaging data and deep learning super-resolution enhancement to provide high yield diagnostics.

Here we present a forward-looking endoscope for dynamic microscopic OCT reaching a lateral resolution of 1.3 µm and 0.8 mm field of view. Since tissue motion degrades dynamic imaging, tissue was immobilized by suction. The endoscope was placed in a 4 mm stainless-steel sheath, which was connected to a vacuum pump. In mice, the endoscope can access various inner organs using open surgery or laparoscopy. The potential of the dynamic endo-microscopic OCT was demonstrated on relevant murine tissue such as liver, spleen and kidney. Otherwise invisible cellular and subcellular structures were imaged by dynamic mOCT with high contrast.

Endoscopic submucosal dissection (ESD) is a minimally invasive treatment for early stage colorectal cancer that can be performed in teleoperation with a robotized flexible interventional endoscope. However, the tissue elevation step which requires submucosal needle insertion still requires manual operation. In this work we present robotic needle placement using image-guidance that combines white-light camera images to control the alignment of the needle and the OCT catheter. OCT images are used to determine the position of the needle tip during its insertion. This procedure is experimentally tested in an optical phantom that simulates the tissue layers of the colon.

We have developed endoscopes for the fallopian tubes that contain multispectral fluorescence imaging, optical coherence tomography, and/or cell collecting wires. The ability to expand the lumen of the fallopian tube with saline or balloon pressure has been proposed as a method for assuring high quality imaging and increasing the lumen diameter. Using ex vivo porcine and human tissue, we found that fallopian tubes can tolerate pressurization of up to 15 psi. Movement of balloons within the fallopian tube can denude the epithelial layer. The external diameter of tubes expanded by a minimal amount under pressurization, indicating sub-mm diameter endoscopes are required.

Using optical coherence tomography (OCT) intraoperatively for pituitary gland and adenoma differentiation, might lead to a more distinct resection of tumor tissue. Therefore, more gland tissue would be preserved and invasively grown adenoma tissue can be detected and removed. We evaluate the feasibility of laser scanning microscope based OCT for differentiation of healthy and tumor tissue on biopsies resected during surgery. The OCT images are compared to histopathological results. Resolution reduced OCT images are automatically analyzed to estimate the performance parameters for a possible endoscopic translation.

A screening test for early detection of pancreatic cancer (PC) is a critical unmet need as PC is usually detected late when mortality is unavoidable. Pancreatic fluid (PF), excreted to the duodenum by the Ampulla of Vater (AoV), offers a promising sample for early stage pancreatic cancer screening as it is the richest source of PC bioanalytes. The successful identification of the AoV is critical to develop a minimally invasive and inexpensive capsule-based PC screening test. With our recently developed tether capsule endomicroscopy (TCE) technique, we imaged 27 subjects and analyzed 353 duodenal OCT-TCE datasets. Using relative positions of the major and minor ampulla, and influx of bile into the duodenum, we distinguished the major from the minor. At least one ampulla was identified in 100%, major ampulla identified in 85%, and minor ampulla identified in 67% of all subjects. The measured mean max. diameter of the major ampulla was 6.49 ± 2.23 mm, and 6.09 ± 2.05 mm for the minor.

The Tearney Lab at the Massachusetts General Hospital (MGH) has conducted a study using Tethered Capsule Endomicroscopy (TCE), a technique that involves swallowing a tethered capsule device that circumferentially scans an optical coherence technology (OCT) beam inside the body as it traverses the gastrointestinal tract. Throughout the procedure, microscopic images of the esophagus are acquired in real time in an unsedated subject. OCT TCE was used to screen for Barrett’s Esophagus in a setting of 2 primary care practices at MGH.The OCT TCE show promising results identifying BE in a primary care population.