What type of radiation is referred to as 'remnant radiation'?

'Remnant radiation' refers specifically to the radiation that passes through a patient and contributes to the formation of the radiographic image. When x-rays are generated and directed towards a patient, some of these rays are absorbed by the tissues, while others pass through without being absorbed. The radiation that exits the patient and reaches the image receptor is what is referred to as remnant radiation.

This remnant radiation is crucial because it contains the information needed to create an image. It interacts with the image receptor, either directly on film or on digital detectors, to produce the radiographic image that is used for diagnostic purposes. The quality and contrast of this image depend significantly on the amount of remnant radiation captured.

Understanding remnant radiation is essential for interpreting images correctly, as well as recognizing factors that may affect image quality, such as patient thickness and tissue density.