Table of Contents
Computed Tomography (CT) is a medical imaging technique that uses X-ray measurements taken from different angles to create detailed cross-sectional images of the body. Understanding the physics behind CT involves grasping the key calculations that enable accurate image reconstruction.
Basic Principles of CT Physics
CT imaging relies on the attenuation of X-ray beams as they pass through tissues. The degree of attenuation varies with tissue density and composition. Detectors measure the transmitted X-ray intensities, which are then used to reconstruct images.
Key Calculations in Image Reconstruction
The primary mathematical process in CT is the Radon transform, which converts the measured projections into a form suitable for image reconstruction. The inverse Radon transform, often implemented via filtered back projection, is used to generate the cross-sectional images.
Important Parameters and Formulas
Some critical calculations include:
- Attenuation coefficient (μ): Determines how much X-ray intensity decreases as it passes through tissue.
- Line integral: The total attenuation along a specific path, calculated as the sum of μ over the path length.
- Filtered back projection: Combines the projection data with a filter to reduce artifacts and improve image clarity.