Tomography reconstructs an interior distribution from measurements along multiple lines or paths through it. A linear unattenuated model is the Radon transform; absorption changes it to an attenuated Radon transform.
Transmission measurements determine line integrals of an absorption coefficient after taking the logarithm of incident intensity divided by transmitted intensity. Under the ideal straight-ray model, these measurements are a Radon transform; filtered backprojection reconstructs a planar slice. Angular coverage, calibration and noise control matter because differentiating measured projections amplifies high frequencies. In contrast, single-photon emission computed tomography reconstructs an emitting source through a possibly attenuating medium.
A form of tomography that reconstructs an internal radioactive source from directional counts of individually emitted photons. Known spatial photon absorption gives the exponential path weight in an attenuated Radon transform. Full directed data and a suitable reconstruction formula recover the source intensity rather than a transmitted exterior-beam attenuation map.
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Tomography is an imaging technique used to create detailed internal images of an object, typically a body or an organ. It involves taking cross-sectional images, or slices, of the object from different angles. This technique allows for the visualization of internal structures without requiring invasive procedures.
