Evaluation of the performance of digital x-ray systems in pelvis radiography.

The aim of this study was to investigate the performance of eight digital radiography systems and to optimise the dose-image quality relationship for digital pelvis radiography. The study involved eight digital radiography systems used for general examinations at Vilnius University Hospital Santaros Klinikos. An anthropomorphic pelvic phantom (CIRS, US) was used to simulate a patient undergoing clinical pelvis radiography. Dose quantities entrance surface dose, dose area product (DAP) and exposure parameters (kVp, mA, mAs) were measured and the effects on the images were evaluated, considering physical contrast to noise ratio (CNR) and observer-based evaluations as image quality metrics. Increasing the tube voltage by 5 kVp from standard protocol led to a reduction in radiation dose (DAP) by 12%-20% with a slight impact on image quality (CNR decreases by 2%-10%). There was an inter-observer variability in image rating across different equipment (kappa value between 0 and 0.3); however, both observers agreed that increasing kVp up to 85-90 kV had no effect on perceived image quality. The results indicate that optimisation strategies should be tailored specifically for each x-ray system since significant performance differences and wide variations in radiation dose exist across various digital radiography systems used in clinical settings. The use of high kVp can be used for dose optimisation in digital pelvis radiography without compromising image diagnostic accuracy.

Demographics of the members of the special interest group for early career medical physicists: A statistical analysis of survey results.

INTRODUCTION: The Early Career Medical Physicists Special Interest Group (SIG_FREC) that operates within EFOMP aims to represent individuals with less than 10 years of experience working as medical physics professionals. The purpose of this survey was to better understand the specific needs and expectations of early-career medical physicists across Europe. The aim of this study was to allow these early-career professionals to voice their ideas within EFOMP and provide insights into their challenges and opportunities while also providing them with the possibility of making suggestions for the growth of the SIG. Doing this, the members can be better equipped to be future leaders of the Medical Physics profession in their own country and in Europe. METHODS: The Steering Committee of SIG_FREC developed a questionnaire and distributed it to its members. RESULTS: Out of the total number of members of the SIG_FREC at the time of the questionnaire (97 members), 42 of them responded to the survey yielding a response rate of 43%. These provided valuable insights based on their experiences about medical physics in their country. CONCLUSION: The responses to the questionnaire provided a snapshot of the opinion of early-career medical physicists, representing a wide geographical distribution across Europe. The feedback from SIG_FREC members highlighted potential future operations within EFOMP.

Modification of 3D Printable Polymer Filaments for Radiation Shielding Applications.

There is a growing need to develop lead-free shielding materials that are safe, low weight, durable, environmentally friendly, chemically and mechanically stable and customizable for specific applications. Fused deposition modeling (FDM), an additive manufacturing technique based on the extrusion of a thermoplastic filament into a 3D printed object one layer at a time, could be employed well in applications involving ionizing radiation due to its relatively low cost, design flexibility and high manufacturing precision. This study aimed at developing 3D printing composites that contain Titanium dioxide as a filler agent for shielding in a medical radiation environment. First, the effect of low-dose ionizing radiation (up to 15 Gy) on the mechanical properties of common 3D printing polymers, ABS, ULTRAT, PLA, NYLON, ASA and PETG, was investigated. Since ABS experienced the lowest variation in its ultimate tensile strength (±5%) and Young's modulus (-5%/+11%), it was chosen as a matrix for a new extruded 3D filament containing TiO2 at 1 wt.%, 3 wt.%, and 5 wt.%. With the incorporation of TiO2 at different filler contents, the UTS of the ABS composites varied between 24.1 MPa and 28.4 MPa, with the highest value recorded for 3 wt.% TiO2. Young's modulus values were dependent on both the TiO2 concentration and on the irradiation dose. In addition, the ABS/TiO2 composites with a higher filler content (3 wt.% and 5 wt.%) maintained their attenuation ability even after exposure to a radiation dose of 100 Gy as opposed to pure ABS, which exhibited a ~2.5% reduction in its mass attenuation coefficient after exposure to the same dose of radiation. The pilot investigation performed demonstrated that the newly developed ABS/TiO2 composite containing 5 wt.% of filler can be successfully employed to shield electronic devices operating in a radiotherapy room.