Optimizing Knee X-ray Imaging: Balancing Radiation Dose and Image Quality

Background: Radiation plays a significant contributor to medical diagnostics. However, the questions about risks of repeated radiation highlight the need for the optimization of radiation doses, especially in musculoskeletal imaging like knee X-rays, to ensure safety without compromising diagnostic quality.

Objectives: The study aimed to optimize knee X-ray imaging protocols, balancing of radiation dose and image quality. Specifically, the most effective exposure factors that provide minimum radiation exposure with maximum diagnostic accuracy. This study also compared different protocols to identify the safest and most accurate technique in clinical practice.

Materials and Methods: This study was conducted at a university hospital from December 2024 to January 2025, using a Portable X-ray unit knee imaging. Three exposure protocols were used: (1) standard parameters (77.50 kV, 8 mAs), (2) the 10kV rule (73 kV, 50% reduction in mAs), and (3) a modified 10 kV rule (73 kV, 75% reduction in mAs).The Alderson Rando knee phantom was imaged in AP and LAT positions, with the radiation doses measured using OSL dosimeters. Results were analyzed using descriptive statistics, paired t-tests, and ANOVA.

Results: The standard protocol delivered the highest dose, significantly higher (p < 0.05) than the other protocols, with an average dose of 0.64 ±0.03 mGy in AP and 0.73 ± 0.07 mGy in LAT. The10 kV and modified 10 kV rules reduced doses by23.4% to 39.1% in AP and 22.2% to 42.5% in LAT. Image quality decreased with higher mAs reductions but remained clinically acceptable.

Conclusion: Optimization exposure parameters, especially using the 10 kV rule and its modification, reduced radiation doses while maintaining diagnostic accuracy. This highlights the need for a refinement of the X-ray protocols in order to minimize patient doses without compromising diagnostic value. Additional studies on the applicability of optimized protocols across different populations and imaging systems are warranted.