Radiography forms an image from spatially resolved transmission of X-rays or other penetrating radiation. A source illuminates the object, and a detector on the other side records how much radiation reaches each position. Variations in attenuation make internal differences observable without cutting the object.
A thicker region and a more strongly absorbing material can give similar transmission, so one projection does not uniquely determine composition or three-dimensional shape. Unwanted scattering reduces image contrast by adding radiation that did not follow the intended straight path. A reference exposure measures source and detector nonuniformity; multiple viewing directions provide additional geometric information.
A chest radiograph is an X-ray transmission image through the chest. Different paths encounter different compositions and thicknesses, producing different detected intensities through attenuation. The detector records a projection through the body rather than a physically isolated slice.
For a narrow monochromatic beam, a spatially varying linear attenuation coefficient gives . Real sources emit an electromagnetic spectrum of photon energies, and scattered radiation contributes additional signal. Overlapping structures can therefore be ambiguous in a single projection; detector display brightness also depends on processing and must not be confused directly with one local material density.
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Radiography is a medical imaging technique that uses X-rays or other forms of radiation to create images of the internal structures of an object or body. It is commonly used in medicine to visualize bones, organs, and other tissues in order to diagnose and monitor various medical conditions. The process involves exposing a photographic film or a digital detector to radiation, which passes through the body and captures the resulting image. Different tissues absorb radiation to varying degrees, allowing for the differentiation between structures.