Optical coherence tomography is a low-loss, high-resolution, non-invasive medical imaging technology developed in the early 1990s. It combines optical technology with ultrasensitive detectors. Using modern computer image processing, OCT fills the gap in resolution and imaging depth between microscopes and ultrasound imaging. The imaging resolution of OCT is about 10~15 μm, which is clearer than that of intravascular ultrasound (IVUS), but OCT cannot image through blood. Compared with IVUS, its tissue penetration ability is lower, and the imaging depth is limited to 1-2mm.
Using the different reflectivity of different tissues in the eye to light (using 830nm near-infrared light), the delay time and reflection intensity of the reflected light wave and the reference light wave are compared through a low-coherence optical interferometer, and the structure and distance of different tissues are analyzed. The images are processed by computer and the cross-sectional structure of the tissue is displayed in pseudo-color. The rapid development of artificial intelligence technology in recent years can realize automated diagnosis and triage faster, handle referrals faster, and provide the best accuracy and wider applicability anywhere. AI has great application potential in the medical field. It can reduce repetitive work and save costs in image recognition, data mining, information extraction, etc., and can play an important role in improving the efficiency and accuracy of medical behaviors such as disease screening, diagnosis, efficacy evaluation, prediction, and health management.
OCT and artificial intelligence have expanded from the early ophthalmology field to many fields
Ophthalmology field
The first clinical application field of OCT technology is the ophthalmology field, which can perform non-contact tomographic imaging of the microstructure of living eye tissue. This high-resolution imaging technology can instantly obtain retinal tomographic images, better display the changes in the subtle structure of the retina, and provide a new way to observe lesions in vivo.
With the improvement of OCT performance, it can be predicted that OCT will have a more profound impact on ophthalmology, thereby improving the sensitivity and specificity of early diagnosis of diseases and changing the ability to monitor disease progression. At present, OCT is mainly used in clinical practice for early diagnosis and postoperative follow-up of glaucoma, macular degeneration, vitreoretinal diseases, and subretinal neovascularization.