8/8/2023 0 Comments Scatter radiationThis means that the first layer encountered by the radiation beam attenuates many more photons than the succeeding layers. The nature of the exponential relationship is that each thickness of material attenuates the same fraction of photons entering it. The relationship between the number of photons reaching a specific point and the thickness of the material to that point is exponential. If we count the number of photons penetrating through each thickness of material, we begin to see a fundamental characteristic of photon penetration. Some of the photons travel a relatively short distance before interacting, whereas others pass through or penetrate the object. Let us consider a group of mono-energetic photons entering an object, as shownīelow. In fact, there is no way to predict the range of a specific photon. This distance can be considered the range of the individual photons.Ī characteristic of radiation is that all photons do not have the same range, even when they have the same energy. When photons enter an object, they travel some distance before interacting. It might be helpful in understanding the characteristics of radiation penetration to first consider the range, or distance, traveled by the individual photons before they are absorbed or scattered. Penetrating than low-energy photons, although there are limits and exceptions to this, which we discuss later. Increasing photon energy generallyĭecreases the probability of interactions (attenuation) and, The probability of photons interacting, especially with the photoelectric effect, is related to their energy. The amount of penetration depends on the energy of the individual photons and the atomic number, density, and thickness of the object, as illustratedįactors That Affect the Penetration of Radiation through a Specific Object Penetration is the inverse of attenuation. The penetration can be expressed as the fraction of radiation passing through the object. When they are directed into an object, some of the photons are absorbed or scattered, whereas others completely penetrate the object. Portable X-ray machine dose exposure ionization chamber dosimeter.One of the characteristics of x- and gamma radiations that makes them useful for medical imaging is their penetrating ability. Accordingly, teaching materials on radiation safety for radiological interns and clinical technicians were formulated. ![]() The radiologist without a lead shield should stand at point B of patient's feet. When the PX and the C-arm machine were used, the radiation doses at a distance of 2 m were attenuated to the background radiation level. The maximum dose in five directions was nine times to the minimum dose. Only taking the vertical projection into account, the radiation doses at point B was the lowest (0.52 μGy), and the radiation doses at point E was the highest (4 μGy).The PA projection radiation at point B was the lowest (0.36 μGy) and the radiation doses at point E was the highest(2.77 μGy), occupying 10-32% of the maximum doses. The AP projection radiation doses at point B was the lowest (0.07☐.03 μGy) and the radiation doses at point D was the highest (0.26☐.08 μGy). The Fluke biomedical model 660-5DE (400 cc) and 660-3DE (4 cc) ion chambers were used to detect air dose at a distance of approximately two meters from the central point. The radiation dose measured at point B was the lowest, and the scattered radiation dose absorbed by the prosthesis from the X-ray's vertical projection was 0.07 ☐.03 μGy, which was less than the background radiation levels. Assuming that the central point of the X-ray was located at the belly button, five detection points were distributed in the operation room at 1 m above the ground and 1-2 m from the central point horizontally. With the adoption of the Rando Phantom, several frequently X-rayed body parts were exposed to X-ray radiation, and the scattered radiation doses were measured by ionization chamber dosimeters at various angles from the patient. This work aimed to investigate the spatial distribution of scattered radiation doses induced by exposure to the portable X-ray, the C-arm machine, and to simulate the radiologist without a shield of lead clothing, radiation doses absorbed by medical staff at 2 m from the central exposure point.
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