![]() ![]() John Tyndall, a pioneer in light scattering research, noted the connection between light scattering and acoustic scattering in the 1870s. As more "ray"-like phenomena were discovered, the idea of scattering was extended to them, so that William Herschel could refer to the scattering of "heat rays" (not then recognized as electromagnetic in nature) in 1800. Originally, the term was confined to light scattering (going back at least as far as Isaac Newton in the 17th century ). Reflections of radiation that undergo scattering are often called diffuse reflections and unscattered reflections are called specular (mirror-like) reflections. In conventional use, this also includes deviation of reflected radiation from the angle predicted by the law of reflection. Medical Laboratory and Measurements Technologies Biophysics Other Medical Engineering Identifiers URN: urn:nbn:se:liu:diva-119694 OAI: oai:DiVA.Scattering is a term used in physics to describe a wide range of physical processes where moving particles or radiation of some form, such as light or sound, are forced to deviate from a straight trajectory by localized non-uniformities (including particles and radiation) in the medium through which they pass. Medical staff, personnel, practitioner, staff exposure, physician, operator, occupational exposure, radiation protection, protection in medical x-ray imaging, x-ray exposure, radiation dose, radiation scatter, fluoroscopy, interventional x-ray procedures, interventional radiology, angiography, fluoroscopically guided procedures, interventional radiology dosimetry, interventional cardiology dosimetry, catheterization interventions National Category Place, publisher, year, edition, pages2015. This work completes the effect of scatter radiation distribution around the patient table, which is not yet evaluated as thoroughly by other authors. Additional measurements are needed to ensure the reliability of the model. The staff position in relation to the x-ray source and the patient size have a significant correlation to the dose rate. A model that delivers relative dose is an intuitive approach in education for interventional x-ray radiation safety. Six out of eight modelled doses deviated +/- 26.6 % from the validation cases. It was possible to create a 3D model from interpolated measurement data that can generate dose rate with promising results. In the typical operator position, the effect of craniocaudal projection angle, patient size, field size, image detector height and pulse rate on scatter radiation dose was also investigated. For five lateral C-arm projections, 68 - 80 data points each were used to measure scatter dose distribution around the patient. The aims of this thesis were to create a 3D model for representation of real-time exposure and accumulated scatter radiation to staff performing interventional x-ray procedures and identify parameters that affect the scatter radiation.Įxtensive measurements were made with real time dosimeters while irradiating an anthropomorphic phantom. Initiative to train a dose reducing behavior by education and awareness are key documents within the European Union’s guidelines on Radiation protection. There is a need to increase the awareness about scatter radiation and radiation protection efforts are gaining momentum. Although x-ray imaging is required in interventional procedures endeavors of reducing radiation exposure to staff is of high interest. The x-ray equipment and surgical techniques are constantly evolving and the interventions become more complex which may increase the x-ray dose. Lead aprons, collars and shieldings are safety precautions to protect the team in the operating room. Therefore, it is mandatory to reduce the radiation dose in medicine, a principle known as ALARA (as low as Reasonably Achievable). Studies have suggested an increase in the prevalence of eye lens cataract, thyroid cancer and left sided brain tumors in doctors. Ionizing radiation for medical purpose is potentially dangerous and can cause malignancy, skin damage and more. 2015 (English) Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits Student thesis Abstract ĭuring catheterized x-ray interventions the patient and medical staff is exposed to scatter radiation, as a consequence of tissue interactions. ![]()
0 Comments
Leave a Reply. |