ii ACKNOWLEDGMENTS I extend my thanks to my committee chair, Dr. Polad Shikhaliev, for all his advice and help in research and preparation of this thesis and to all of the members of my supervisory committee: for their assistance and taking time to serve on my supervisory committee. I also thank Shannon Fritz for her selfless help with every aspect of the research project. When it came to the p...

Introduction: The dosimetric characteristics of patch sources including 32P, 90Y, 188Re and 166Ho, which are employed for radionuclide skin therapy, have been evaluated in current study Materials and Methods: The patch sources understudy were modeled by MCNPX Monte Carlo code and corresponding depth dose distribution, transverse dose profile and isodose curves...

background uterine artery embolization (uae) is a minimally invasive procedure performed under fluoroscopy for the treatment of uterine fibroids and accompanied by radiation exposure. objectives to compare ovarian radiation doses during uterine artery embolization (uae) in patients using conventional digital subtraction angiography (dsa) with those using digital flat-panel technology. patients ...

BACKGROUND The Local Diagnostic Reference Levels (LDRLs) form an efficient, concise and powerful standard for optimizing the radiation protection of a patient. OBJECTIVES To calculate the Entrance Surface Doses (ESDs) received by patients undergoing PA chest X-ray examinations in major public hospitals in Addis Ababa, thereby to establish the first Ethiopian LDRLs as part of ongoing dose redu...

Skin injury is a deterministic effect of radiation. Once a threshold dose has been exceeded, the severity of the radiation effect at any point on the skin increases with increasing dose. Peak skin dose is defined as the highest dose delivered to any portion of the patient's skin. Reducing peak skin dose can reduce the likelihood and type of skin injury. Unfortunately, peak skin dose is difficul...

Mean glandular dose (MGD) is the main dosimetric quantity in mammography. MGD evaluation is obtained by multiplying the entrance skin air kerma (ESAK) by normalized glandular dose (DgN) coefficients. While ESAK is an empirical quantity, DgN coefficients can only be estimated with Monte Carlo (MC) methods. Thus, a MC parameters benchmark is needed for effectively evaluating DgN coefficients. GEA...

Radiological imaging is an important part of today’s overall healthcare practicum, Imaging can begin as early as the first day of life but as children are more sensitive to radiation than adults special care should be in place. The main aim of the current study was to determine Entrance Surface Dose (ESD) to pediatric patients as the result of imaging procedure, in main pediatric hospital in Ta...

INTRODUCTION With the steady increase in public and professional concern regarding the biological effects of ionising radiation, there is a need for both the Chiropractic and Radiography professions to improve imaging techniques for the lowering of patient radiation doses. Lumbar radiographs are essential in chiropractic general practice for biomechanical diagnosis and postural analysis. Detail...

Silicon diode dosimeters have been used routinely for in-vivo dosimetry. Despite their popularity, an appropriate implementation of an in-vivo dosimetry program using diode detectors remains a challenge for clinical physicists. One common approach is to relate the diode readout to the entrance dose, that is, dose to the reference depth of maximum dose such as d(max) for the 10x10 cm(2) field. V...

We report here the results of a dose evaluation based on information obtained in a 2011 questionnaire as compared with an investigation made in 2007. Briefly, in general radiography, the dose used in most examinations in 2011 was lower than in 2007. However, since the entrance surface dose for chest X-rays showed an increase, there is a need to standardize the taking of digital images to be abl...