Optical coherence tomography (OCT) is a non-invasive imaging technique used in medical and scientific fields to capture high-resolution, cross-sectional images of biological tissues. It provides detailed, real-time, and three-dimensional visualization of tissue structures at the micrometer scale. OCT is particularly valuable in ophthalmology, cardiology, dermatology, and various other medical specialties.
Here are the key features and components of optical coherence tomography:
Principle of interferometry: OCT relies on the principles of low-coherence interferometry. A light source, often a near-infrared laser, is used to emit low-coherence light, which is split into a reference beam and a sample beam. The interference between these beams provides information about the depth of structures within the sample.
Depth-resolved imaging: By analyzing the interference pattern of backscattered light from the sample and the reference beam, OCT can generate depth-resolved images. This allows for the visualization of internal tissue structures in a non-invasive manner.
Cross-sectional imaging: OCT produces cross-sectional images, also known as tomograms or B-scans, which represent a two-dimensional slice of the imaged tissue. Multiple B-scans can be combined to create three-dimensional reconstructions.
High resolution: OCT provides high axial resolution, enabling the differentiation of fine structures within tissues, such as layers in the retina or coronary artery walls.
Applications:
Ophthalmology: In ophthalmic OCT, it is widely used for imaging the retina, optic nerve head, and cornea. It assists in the diagnosis and monitoring of conditions like macular degeneration, diabetic retinopathy, and glaucoma.
Cardiology: Intravascular OCT is employed for imaging blood vessels, aiding in the diagnosis and treatment of cardiovascular diseases.
Dermatology: Dermatological OCT is used for imaging skin structures, helping in the diagnosis of skin diseases and monitoring treatment responses.
Neurology: OCT is applied to study neurological tissues, including imaging the layers of the cerebral cortex.
Advancements: Advances in OCT technology include enhanced imaging speed, spectral-domain OCT (SD-OCT), and swept-source OCT (SS-OCT), which improve image quality, acquisition speed, and depth penetration.