Optical coherence tomography (OCT) is an emerging technique for cross-sectional imaging, originally developed for biological structures. When OCT is employed for material investigation, high-resolution and short measurement times are required, and for many applications, only transversal (en-face) scans yield substantial information which cannot be obtained from cross-sectional images oriented perpendicularly to the sample surface alone. In this work, we combine transversal with ultra-high resolution OCT: a broadband femto-second laser is used as a light source in combination with acousto-optic modulators for heterodyne signal generation and detection. With our setup we are able to scan areas as large as 3 x 3 mm2 with a sensitivity of 100 dB, representing areas 100 times larger compared to other high-resolution en-face OCT systems (full field). We demonstrate the benefits of en-face scanning for different applications in materials investigation.
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http://dx.doi.org/10.1364/opex.13.001015 | DOI Listing |
Pract Radiat Oncol
January 2025
Department of Radiation Oncology, Christiana Care, Helen F. Graham Cancer Center & Research Institute, Newark, Delaware.
Superficial lesions of the face are often treated with an electron beam and surface collimation utilizing a conformal lead shield with an opening around the region of treatment (ROT). To fabricate the lead shield, an imprint of the patient face is needed. Historically, this was achieved using a laborious and time-consuming process that involved a gypsum imprinted model (GIM) of the patient topography.
View Article and Find Full Text PDFOphthalmol Sci
October 2024
Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
Purpose: Spectral-domain OCT angiography (SD-OCTA) scans were used in an algorithm developed for swept-source OCT angiography (SS-OCTA) scans to determine if SD-OCTA scans yielded similar results for the measurement of hyperreflective foci (HRF) in intermediate age-related macular degeneration (iAMD).
Design: Retrospective study.
Participants: Forty eyes from 35 patients with iAMD.
Microcirculation
January 2025
Eye Research Center, The Five Senses Health Institute, Moheb Kowsar Hospital, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
Purpose: To assess the colocalization of ellipsoid zone (EZ) disruption with nonperfusion in choriocapillaris (CC), retinal superficial capillary plexus (SCP), and deep capillary plexus (DCP) in diabetic patients using en face optical coherence tomography (OCT) and OCT angiography (OCTA).
Methods: Macular OCT and OCTA scans (3 × 3 mm) of 41 patients with diabetic retinopathy were obtained using an RTVue XR Avanti instrument. After correcting the shadow artifacts, EZ integrity was assessed in the en face OCT slab using the Gaussian mixture model clustering method compared with the corresponding EZ en face OCT of 11 age-matched normal patients.
Transl Vis Sci Technol
December 2024
Department of Ophthalmology, The Second People's Hospital of Foshan, Foshan, China.
Purpose: Accurate diagnosis of retinal disease based on optical coherence tomography (OCT) requires scrutiny of both B-scan and en face images. The aim of this study was to investigate the effectiveness of fusing en face and B-scan images for better diagnostic performance of deep learning models.
Methods: A multiview fusion network (MVFN) with a decision fusion module to integrate fast-axis and slow-axis B-scans and en face information was proposed and compared with five state-of-the-art methods: a model using B-scans, a model using en face imaging, a model using three-dimensional volume, and two other relevant methods.
Ophthalmol Retina
December 2024
Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. Electronic address:
Purpose: The foveal avascular zone (FAZ) area has been explored as a measure of macular ischemia in diabetic retinopathy (DR) but is limited by its wide variability even in healthy individuals. We hypothesized that FAZ enlargement, which we defined as the difference between the functional FAZ (on optical coherence tomography angiography; OCTA) and structural FAZ (en face OCT), may be a more accurate metric of macular ischemia. In this study, we test the hypothesis that FAZ enlargement is associated with decreased best-corrected visual acuity (BCVA) and low luminance visual acuity (LLVA) and performs better than the functional FAZ as a marker of vision loss.
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