1 / 10

OCT history and background…

OCT history and background…. OCT History. Invented by Fujimoto, Puliafito and coworkers in 1991 Commercialized by Humphrey Zeiss More than 2000 systems in use worldwide A broad based tool for comprehensive ophthalmologists. Optical Coherence Tomography. Background:.

haile
Download Presentation

OCT history and background…

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. OCT history and background…

  2. OCT History • Invented by Fujimoto, Puliafito and coworkers in 1991 • Commercialized by Humphrey Zeiss • More than 2000 systems in use worldwide • A broad based tool for comprehensive ophthalmologists

  3. Optical Coherence Tomography Background: • OCT: a non-invasive technique for forming high spatial resolution, cross-sectional images of biological tissues • Principle of OCT: the longitudinal location of tissue structures are determined by measuring the time-of-flight delays of light backscattered from these structures. The optical delays are measured by low coherence interferometry • Technique facts: Penetration depth: 1.5 – 3 mm Spatial resolution: 10 – 15 µm

  4. What do you see in OCT images? • OCT is a map of the reflectivity of the sample. Reflections are generated at index of refraction mismatches. In most tissues, main sources of reflection are collagen fiber bundles, cell walls, and cell nuclei. Dark areas on the image represent homogeneous material with low reflectivity, such as air or clear fluids. • The imaging light is attenuated in the sample, so there is an exponential decrease in the intensity of the image with depth. Blood attenuates the signal faster than collagenous tissues, fat and fluids attenuate the signal the least.

  5. Information on lateral position is provided by transverse scanning of the probe-beam

  6. Normal Macular Histology vs. StratusOCT Stratus OCT (OCT-3 Histology

  7. OCT2 (2000) OCT3 (2002) Commercial OCT Systems Zeiss Humphrey Ophthalmic Systems OCT1 (1996)

  8. Problems and needs…

  9. Problems Speckle Noise: It is a natural consequence of the limited spatial-frequency bandwidth of the interference signals. Erroneous boundary detection on diseased retina with the commercially available algorithm. The current commercial OCT system only reports thickness and volume measurements of the macular region, but no quantitative information is reported about fluid-filled regions and internal reflectivity of the retinal structure.

  10. Needs • Speckle noise reduction and edge enhancement of OCT images • Better quantitative methods to potentially yield more accurate description of the local changes of the retina1 • Detect very early morphologic and functional deficits related to later visual outcome • Quantitative imaging assessment of drug response • Image guidance software for interventions 1Delineating Fluid-filled Region Boundaries in Optical Coherence Tomography Images of the Retina. Cabrera Fernández, D.IEEE Transaction on Medical Imaging, 2005 Aug; 24(8): 929-45

More Related