1. Articles from Marisa Figueiredo

    1-16 of 16
    1. Tethered capsule en face optical coherence tomography for imaging Barrett’s esophagus in unsedated patients

      Tethered capsule en face optical coherence tomography for imaging Barrett’s esophagus in unsedated patients

      Objective Detection of Barrett’s esophagus (BE) at points of care outside the endoscopy suite may improve screening access and reduce esophageal adenocarcinoma mortality. Tethered capsule optical coherence tomography (OCT) can volumetrically image esophageal mucosa and detect BE in unsedated patients. We investigated ultrahigh-speed tethered capsule, swept-source OCT (SS-OCT) in unsedated patients, improved device design, developed procedural techniques, measured how capsule contact and longitudinal pullback non-uniformity affect coverage, and assessed patient toleration. Design OCT was performed in 16 patients prior to endoscopic surveillance/treatment. Unsedated patients swallowed the capsule with small sips of water and the esophagus imaged by retracting ...

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    2. Computer-Aided Analysis of Gland-Like Subsurface Hyposcattering Structures in Barrett’s Esophagus Using Optical Coherence Tomography

      Computer-Aided Analysis of Gland-Like Subsurface Hyposcattering Structures in Barrett’s Esophagus Using Optical Coherence Tomography

      (1) Background: Barrett’s esophagus (BE) is a complication of chronic gastroesophageal reflux disease and is a precursor to esophageal adenocarcinoma. The clinical implication of subsurface glandular structures of Barrett’s esophagus is not well understood. Optical coherence tomography (OCT), also known as volumetric laser endomicroscopy (VLE), can assess subsurface glandular structures, which appear as subsurface hyposcattering structures (SHSs). The aim of this study is to develop a computer-aided algorithm and apply it to investigate the characteristics of SHSs in BE using clinical VLE data; (2) Methods: SHSs were identified with an initial detection followed by machine learning. Comprehensive SHS ...

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    3. Feature Of The Week 10/08/2018: Clinical Utility of Ultrahigh-Speed Endoscopic Optical Coherence Tomography in Gastroenterology

      Feature Of The Week 10/08/2018: Clinical Utility of Ultrahigh-Speed Endoscopic Optical Coherence Tomography in Gastroenterology

      Barrett’s esophagus (BE) surveillance is limited by biopsy sampling error. Optical coherence tomography (OCT) enables microscopic resolution, high speed, volumetric imaging and is commercially available as volumetric laser endomicroscopy (VLE, NinePoint Medical). Studies investigated cross-sectional OCT dysplasia features, including a diagnostic algorithm (VLE-DA), however, many VLE studies used ex vivo specimens due to challenges in registering biopsy with OCT. We previously demonstrated ultrahigh-speed endoscopic OCT >10x faster than commercial instruments, enabling depth-resolved en face and cross-sectional imaging. This study investigated volumetric en face and cross-sectional OCT for identifying neoplasia. 74 OCT datasets with correlated biopsy/endoscopic mucosal resection histology ...

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    4. Assessment of Barrett’s esophagus and dysplasia with ultrahigh-speed volumetric en face and cross-sectional optical coherence tomography

      Assessment of Barrett’s esophagus and dysplasia with ultrahigh-speed volumetric en face and cross-sectional optical coherence tomography

      Background  This study aimed to evaluate the use of ultrahigh-speed volumetric en face and cross-sectional optical coherence tomography (OCT) with micromotor catheters for the in vivo assessment of Barrett’s esophagus and dysplasia. Methods  74 OCT datasets with correlated biopsy/endoscopic mucosal resection histology (49 nondysplastic Barrett’s esophagus [NDBE], 25 neoplasia) were obtained from 14 patients with Barrett’s esophagus and a history of dysplasia and 30 with NDBE. The associations between irregular mucosal patterns on en face OCT, absence of mucosal layering, surface signal > subsurface, and > 5 atypical glands on cross-sectional OCT vs. histology and treatment history were ...

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    5. Ultrahigh-speed endoscopic optical coherence tomography and angiography enables delineation of lateral margins of endoscopic mucosal resection: a case report

      Ultrahigh-speed endoscopic optical coherence tomography and angiography enables delineation of lateral margins of endoscopic mucosal resection: a case report

      Endoscopic mucosal resection (EMR) is a common technique for resecting dysplastic lesions in Barrett’s esophagus (BE), stomach, and colon, 1 but precise delineation of dysplastic margins before resection and verification of complete removal after resection remain challenging. 2 , 3 Endoscopic optical coherence tomography (OCT) enables three-dimensional visualization of tissue microstructure and is commercially available as Volumetric Laser Endomicroscopy (NinePoint Medical, Bedford, MA, USA). 4 , 5 We recently developed an ultrahigh-speed endoscopic OCT system which operates more than 10 times faster than commercial instruments, generating volumetric images with higher transverse resolution and voxel density. 6 , 7 This allows visualization of ...

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    6. Endoscopic optical coherence tomography angiography microvascular features associated with dysplasia in Barrett's esophagus: a pilot study (with video)

      Endoscopic optical coherence tomography angiography microvascular features associated with dysplasia in Barrett's esophagus: a pilot study (with video)

      Background and Aims Angiogenesis is associated with neoplastic progression of Barrett’s esophagus (BE). Volumetric optical coherence tomography angiography (OCTA) visualizes subsurface microvasculature without exogenous contrast agents. We investigated the association of OCTA microvascular features with low-grade dysplasia (LGD) and high-grade dysplasia (HGD). Methods Fifty-two patients undergoing BE surveillance or endoscopic eradication therapies for dysplasia were imaged using volumetric OCTA and corresponding histological diagnoses obtained, to yield 97 data sets (non-dysplastic BE (NDBE): N=74; LGD: N=10; HGD: N=13). After evaluating OCTA image quality, 54 datasets (NDBE: N=35; LGD: N=8; HGD: N=11) from 32 patients ...

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

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

      To the Editor: Dysplasia in Barrett’s Esophagus (BE) is patchy ( 1 ) and sometimes missed by random biopsies. Optical coherence tomography (OCT) can image large areas of the esophagus; however, slow imaging speeds in earlier studies limited visualization to cross-sections. 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 ). Narrow-band imaging (NBI) visualizes ...

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    8. Feature Of The Week 03/08/2015: Endoscopic Optical Coherence Angiography Enables Three Dimensional Visualization of Subsurface Microvasculature

      Feature Of The Week 03/08/2015: Endoscopic Optical Coherence Angiography Enables Three Dimensional Visualization of Subsurface Microvasculature

      Endoscopic imaging technologies such as confocal laser endomicroscopy (CLE) and narrowband imaging (NBI) have been used to investigate vascular changes as hallmarks of early cancer in the GI tract. However, the limited frame rate and field of view make CLE imaging sensitive to motion artifacts, whereas NBI has limited resolution and visualizes only the surface vascular pattern. Endoscopic optical coherence tomography (OCT) enables high speed volumetric imaging of subsurface features at near-microscopic resolution, and can image microvasculature without exogenous contrast agents such as fluorescein, which obliterates the image in areas of bleeding, or after biopsies and resections. OCT has been ...

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    9. Endoscopic Optical Coherence Angiography Enables Three Dimensional Visualization of Subsurface Microvasculature

      Endoscopic Optical Coherence Angiography Enables Three Dimensional Visualization of Subsurface Microvasculature

      Endoscopic imaging technologies such as confocal laser endomicroscopy1 and narrow band imaging (NBI)2 have been used to investigate vascular changes as hallmarks of early cancer in the gastrointestinal tract. However, the limited frame rate and field of view make confocal laser endomicroscopy imaging sensitive to motion artifacts, whereas NBI has limited resolution and visualizes only the surface vascular pattern. Endoscopic optical coherence tomography (OCT) enables high-speed volumetric imaging of subsurface features at near-microscopic resolution,3, 4 and can image microvasculature without exogenous contrast agents,5 such as fluorescein, which obliterates the image in areas of bleeding, or after ...

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    10. Ultrahigh speed endoscopic optical coherence tomography for gastroenterology

      Ultrahigh speed endoscopic optical coherence tomography for gastroenterology

      We describe an ultrahigh speed endoscopic swept source optical coherence tomography (OCT) system for clinical gastroenterology using a vertical-cavity surface-emitting laser (VCSEL) and micromotor imaging catheter. The system had a 600 kHz axial scan rate and 8 µm axial resolution in tissue. Imaging was performed with a 3.2 mm diameter imaging catheter at 400 frames per second with a 12 µm spot size. Three-dimensional OCT (3D-OCT) imaging was performed in patients with a cross section of pathologies undergoing upper and lower endoscopy. The use of distally actuated imaging catheters enabled OCT imaging with more flexibility, such as volumetric imaging ...

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    11. Endoscopic Optical Coherence Angiography Enables 3-Dimensional Visualization of Subsurface Microvasculature

      Endoscopic Optical Coherence Angiography Enables 3-Dimensional Visualization of Subsurface Microvasculature

      Endoscopic imaging technologies such as confocal laser endomicroscopy 1 and narrow band imaging (NBI) 2 have been used to investigate vascular changes as hallmarks of early cancer in the gastrointestinal tract. However, the limited frame rate and field of view make confocal laser endomicroscopy imaging sensitive to motion artifacts, whereas NBI has limited resolution and visualizes only the surface vascular pattern. Endoscopic optical coherence tomography (OCT) enables high-speed volumetric imaging of subsurface features at near-microscopic resolution, 3,4 and can image microvasculature without exogenous contrast agents, 5 such as fluorescein, which obliterates the image in areas of bleeding, or after ...

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    12. Ultrahigh speed endoscopic swept source optical coherence tomography using a VCSEL light source and micromotor catheter

      Ultrahigh speed endoscopic swept source optical coherence tomography using a VCSEL light source and micromotor catheter

      We developed an ultrahigh speed endoscopic swept source optical coherence tomography (OCT) system for clinical gastroenterology using a vertical-cavity surface-emitting laser (VCSEL) and micromotor based imaging catheter, which provided an imaging speed of 600 kHz axial scan rate and 8 μm axial resolution in tissue. The micromotor catheter was 3.2 mm in diameter and could be introduced through the 3.7 mm accessory port of an endoscope. Imaging was performed at 400 frames per second with an 8 μm spot size using a pullback to generate volumetric data over 16 mm with a pixel spacing of 5 μm in ...

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    13. Structural markers observed with endoscopic 3-dimensional optical coherence tomography correlating with Barrett's esophagus radiofrequency ablation treatment response (with videos)

      Structural markers observed with endoscopic 3-dimensional optical coherence tomography correlating with Barrett's esophagus radiofrequency ablation treatment response (with videos)

      Background Radiofrequency ablation (RFA) is effective for treating Barrett's esophagus (BE) but often involves multiple endoscopy sessions over several months to achieve complete response. Objective Identify structural markers that correlate with treatment response by using 3-dimensional (3-D) optical coherence tomography (OCT; 3-D OCT). Design Cross-sectional. Setting Single teaching hospital. Patients Thirty-three patients, 32 male and 1 female, with short-segment (<3 cm) BE undergoing RFA treatment. Intervention Patients were treated with focal RFA, and 3-D OCT was performed at the gastroesophageal junction before and immediately after the RFA treatment. Patients were re-examined with standard endoscopy 6 to 8 weeks later ...

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    14. Comparison of Tissue Architectural Changes between Radiofrequency Ablation and Cryospray Ablation in Barrett’s Esophagus Using Endoscopic Three-Dimensional Optical Coherence Tomography

      Comparison of Tissue Architectural Changes between Radiofrequency Ablation and Cryospray Ablation in Barrett’s Esophagus Using Endoscopic Three-Dimensional Optical Coherence Tomography

      Two main nonsurgical endoscopic approaches for ablating dysplastic and early cancer lesions in the esophagus have gained popularity, namely, radiofrequency ablation (RFA) and cryospray ablation (CSA). We report a uniquely suited endoscopic and near-microscopic imaging modality, three-dimensional (3D) optical coherence tomography (OCT), to assess and compare the esophagus immediately after RFA and CSA. The maximum depths of architectural changes were measured and compared between the two treatment groups. RFA was observed to induce 230~260 

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    15. Characterization of buried glands before and after radiofrequency ablation by using 3-dimensional optical coherence tomography (with videos)

      Characterization of buried glands before and after radiofrequency ablation by using 3-dimensional optical coherence tomography (with videos)

      Background: Radiofrequency ablation (RFA) is an endoscopic technique used to eradicate Barrett's esophagus (BE). However, such ablation can commonly lead to neosquamous epithelium overlying residual BE glands not visible by conventional endoscopy and may evade detection on random biopsy samples.Objective: To demonstrate the capability of endoscopic 3-dimensional optical coherence tomography (3D-OCT) for the identification and characterization of buried glands before and after RFA therapy.Design: Cross-sectional study.Setting: Single teaching hospital.Patients: Twenty-six male and 1 female white patients with BE undergoing RFA treatment.Interventions: 3D-OCT was performed at the gastroesophageal junction in 18 patients before attaining complete ...

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    16. Effective treatment of chronic radiation proctitis using radiofrequency ablation

      Effective treatment of chronic radiation proctitis using radiofrequency ablation

      Endoscopic argon plasma coagulation and bipolar electrocautery are currently preferred treatments for chronic radiation proctitis, but ulcerations and strictures frequently occur. Radiofrequency ablation (RFA) has been successful for mucosal ablation in the esophagus. Here we report the efficacy of RFA with the BarRx Halo90 system in three patients with bleeding from chronic radiation proctitis. In all cases, the procedure was well tolerated and hemostasis was achieved after 1 or 2 RFA sessions. Re-epithelialization of squamous mucosa was observed over areas of prior hemorrhage. No stricturing or ulceration was seen on follow-up up to 19 months after RFA treatment. Real-time endoscopic ...

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    1-16 of 16
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    1. (16 articles) Massachusetts Institute of Technology
    2. (16 articles) James G. Fujimoto
    3. (16 articles) Hiroshi Mashimo
    4. (14 articles) Hsiang-Chieh Lee
    5. (13 articles) Osman O. Ahsen
    6. (11 articles) Benjamin M. Potsaid
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    Effective treatment of chronic radiation proctitis using radiofrequency ablation Characterization of buried glands before and after radiofrequency ablation by using 3-dimensional optical coherence tomography (with videos) Comparison of Tissue Architectural Changes between Radiofrequency Ablation and Cryospray Ablation in Barrett’s Esophagus Using Endoscopic Three-Dimensional Optical Coherence Tomography Structural markers observed with endoscopic 3-dimensional optical coherence tomography correlating with Barrett's esophagus radiofrequency ablation treatment response (with videos) Ultrahigh speed endoscopic swept source optical coherence tomography using a VCSEL light source and micromotor catheter Ultrahigh speed endoscopic optical coherence tomography for gastroenterology Endoscopic Optical Coherence Angiography Enables Three Dimensional Visualization of Subsurface Microvasculature Feature Of The Week 03/08/2015: Endoscopic Optical Coherence Angiography Enables Three Dimensional Visualization of Subsurface Microvasculature Volumetric Mapping of Barrett’s Esophagus and Dysplasia With en face Optical Coherence Tomography Tethered Capsule Endoscopic optical coherence tomography angiography microvascular features associated with dysplasia in Barrett's esophagus: a pilot study (with video) Direct inverse linearization of piezoelectric actuator’s initial loading curve and its applications in full-field optical coherence tomography (FF-OCT) Peripapillary Retinal and Choroidal Perfusion in Nonarteritic Ischemic Optic Neuropathy Using Optical Coherence Tomography Angiography