Note that ##\dot \varphi_0## is defined to be the fluence rate at the position of the graphite cylinder, which is at a distance ##l_1 = l_2## from the source. Thus, what would be the fluence rate at a distance of ##l_3## from the source, expressed in terms of ##\dot \varphi_0##, ##l_2##, and ##l_3##, assuming no lead shield?Graham87 said:
Scattered photons are those that have changed direction after interacting with tissue or other materials, while transmitted photons are those that have passed through the body without interacting. In medical imaging, scattered photons can cause noise and decrease image quality, while transmitted photons are used to create the image.
The more scattered photons present, the lower the image quality will be due to increased noise. The amount of transmitted photons, on the other hand, directly correlates to the image quality - the more transmitted photons, the clearer and more detailed the image will be.
The amount of scattered and transmitted photons is influenced by the type of imaging technique used, the energy of the x-ray beam, the density and composition of the tissue being imaged, and the thickness of the tissue.
Medical physicists use techniques such as collimation, grids, and post-processing algorithms to reduce the amount of scattered photons in imaging. These methods help to improve image quality and decrease radiation dose to the patient.
Yes, scattered photons can be useful in certain types of imaging, such as computed tomography (CT), where they can provide additional information about the tissue being imaged. However, in most cases, medical physicists aim to minimize the amount of scattered photons to improve image quality.