Contrast is also improved by means of media including iodine and barium which facilitate differentiation between materials that absorb X-rays to a similar degree (such as soft tissues). X-rays are only weakly absorbed by photographic film, so intensifier screens (thin sheets containing phosphor) are used to further blacken the screen and at the same time reduce a patient’s exposure to ionising radiation. Conventional X-rays are well suited, for instance, to dental imaging and within trauma and orthopaedic departments to detect bone fractures.Įnhancing contrast Physicians can interpret these images and use them to produce a medical diagnosis. The X-ray image is stored as a radiograph on photographic film. Radiographers are able to select the type and intensity of X-rays to be used depending on the tissue or area of the body under examination and amount of contrast necessary. This produces the characteristic black-and-white contrast observed in X-ray images. Attenuation of X-ray photons depends on the photon energy (as different interaction processes dominate at different photon energies) and the atomic number of the elements present in the imaged materials (attenuation is stronger for higher effective atomic number).īone and calcium-dense tissues have high densities and absorb X-rays very well, whilst lower-density soft tissues (including muscle fibres) behave less so. The degree of transmission of X-rays is recorded as a shadowgraph. A detector (photographic film) captures the attenuated X-rays on the opposite side.
Under exposure x ray images generator#
It provides images of a good resolution and requires little preparation and examination time with the patient.Īn X-ray generator transmits a beam of X-rays through an object (the body part to be examined), and parts of the energy of the beam are absorbed in various amounts depending on the composition of the material they pass through.
X-ray radiography remains one of the most widely used types of imaging used for medical purposes.
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