Automated segmentation and characterization of esophageal wall in vivo by tethered capsule optical coherence tomography endomicroscopy

Abstract

Optical coherence tomography (OCT) is an optical diagnostic modality that can acquire cross-sectional images of the microscopic structure of the esophagus, including Barrett's esophagus (BE) and associated dysplasia. We developed a swallowable tethered capsule OCT endomicroscopy (TCE) device that acquires high-resolution images of entire gastrointestinal (GI) tract luminal organs. This device has a potential to become a screening method that identifies patients with an abnormal esophagus that should be further referred for upper endoscopy. Currently, the characterization of the OCT-TCE esophageal wall data set is performed manually, which is time-consuming and inefficient. Additionally, since the capsule optics optimally focus light approximately 500 µm outside the capsule wall and the best quality images are obtained when the tissue is in full contact with the capsule, it is crucial to provide feedback for the operator about tissue contact during the imaging procedure. In this study, we developed a fully automated algorithm for the segmentation of in vivo OCT-TCE data sets and characterization of the esophageal wall. The algorithm provides a two-dimensional representation of both the contact map from the data collected in human clinical studies as well as a tissue map depicting areas of BE with or without dysplasia. Results suggest that these techniques can potentially improve the current TCE data acquisition procedure and provide an efficient characterization of the diseased esophageal wall. prospective trial comparing unsedated esophagoscopy via transnasal and transoral routes using a 4-mm video endoscope with conventional endoscopy with sedation," Endoscopy 37(6), 559-565 (2005).

Wide‐field optical property mapping and structured light imaging of the esophagus with spatial frequency domain imaging

“…Recently, Optical Coherence Tomography (OCT) has been introduced for volumetric imaging of the esophageal epithelium to identify low‐grade and high‐grade dysplasia. Tearney et al have developed an endomicroscopy capsule that is swallowed by the patient and acquires OCT cross‐sectional images along the entire esophagus . The capsule spiral scans a laser along the esophageal wall as it is pulled upwards, and has a 30 μm lateral and 7 μm axial resolution to produce high resolution cross‐sectional images without any sedation of the patient .…”

Recent advances in Barrett's esophagus

“…This marking system may also help mark areas for ablation or resection, and the precise energy delivery may also render this a therapeutic tool for targeted ablation in the future. The tethered capsule OCT may allow an office‐based nonendoscopic screening and possible surveillance of at‐risk patients and help identify patients at risk for progression to cancer early, when they are yet most likely to benefit from interventions. However, as with CLE, these modalities have yet to be proven broadly applicable in community‐based practices where the pretest probability of dysplasia is lower compared to academic centers.…”

Volumetric Mapping of Barrett’s Esophagus and Dysplasia With en face Optical Coherence Tomography Tethered Capsule

“…Cross-sectional OCT detected high-grade dysplasia with sensitivity/specificity of ~80% (2,3). Tethered OCT capsules were demonstrated for cross-sectional imaging in unsedated screening to detect BE (4,5). Our group recently developed ultrahigh-speed OCT for en face and angiographic imaging, using micromotor probes in patients (6,7) and large field-of-view tethered capsule devices in swine (8).…”