Abstract
Medical imaging employs x-rays to provide crucial internal anatomical and functional information for clinical diagnosis. While x-ray imaging is invaluable, it involves ionising radiation, which can be harmful. Attenuation of x-rays passing through the anatomy results from primary radiation–anatomy interactions, often accompanied by scatter radiation. Scatter radiation, devoid of diagnostic value, can compromise image quality. Balancing scatter reduction with image quality and patient safety is a challenge.This study investigated six anti-scatter grids’ (ASG) performance across various x-ray radiography systems, revealing that grid effects on image quality differ depending on image receptors. This underscores the need for grid selection tailored to specific systems. The conventional beam stop method for grid evaluation, though widely used, is complex and impractical in clinical settings. Thus, a simpler and validated alternative method is proposed. Criteria for grid performance evaluation, encompassing basic and derived criteria, were comprehensively reviewed. Experimental setups for measuring primary, scatter and total radiation were discussed. However, the resource-intensive nature of the beam stop method emphasises the necessity of a more efficient evaluation method.
The research confirmed significant variation in ASG performance across different x-ray radiography systems, reaffirming the need for tailored grid selection. The limitations of the beam stop method were further highlighted, underscoring the urgency for a more accessible evaluation method.
A novel semicircle method was introduced, requiring only two experimental setups compared to the six required by the beam stop method. Comparative analysis of scatter-to-primary ratios between the two methods yielded insignificant differences, supporting the semicircle method’s practicality. In analysing ASG performance across various radiography systems, the semicircle method demonstrated comparable results to the beam stop method, establishing its suitability for clinicians and researchers in clinical environments.
Overall, the thesis provides an in-depth review of grid performance evaluation criteria and proposes and validates a novel semicircle method suitable for clinicians to undertake ASG performance evaluation on their imaging systems. The experimental results show that the semicircle method is a valid alternative to the beam stop method, with simpler experimental arrangements and equally accurate results. The thesis emphasises the importance of evaluating the performance of anti-scatter grids before applying them to x-ray planar radiography systems, and the proposed semicircle method provides a practical solution to this problem.
| Date of Award | 2024 |
|---|---|
| Original language | English |
| Supervisor | Rob DAVIDSON (Supervisor) & Abel Zhou (Supervisor) |