Quantitative Assessment of Radiation Dose Reduction Using Aluminum and Copper Beam Filtration in Pediatric Chest Radiography Phantom Study

Abstract

Children are more radiosensitive than adults, making radiation dose optimization a priority in pediatric radiography. In chest imaging, low-energy photons contribute substantially to patient dose without significantly improving diagnostic information. Additional beam filtration using aluminum (Al) and copper (Cu) can reduce radiation exposure by selectively attenuating low-energy photons; however, standardized comparative data in pediatric chest radiography remain limited.

This article quantitatively evaluates radiation dose reduction achieved with aluminum and copper beam filtration during simulated pediatric chest radiography using a phantom-based experimental model.

This cross-sectional experimental study was conducted using a 7-cm polymethyl methacrylate phantom representing a pediatric chest. Imaging was performed at 70 kVp and 100 cm source-to-image distance using automatic exposure control. Four filtration conditions were assessed: no additional filtration, 1.0 mm aluminum, 0.1 mm copper, and 0.2 mm copper. Dose area product (DAP) was measured using a calibrated DAP meter. Seven repeated exposures were acquired per condition (total n = 28). Mean DAP and standard deviation were calculated. Statistical analysis was performed using one-way analysis of variance with Tukey's post-hoc testing.

The highest mean DAP was observed without additional filtration (0.628 ± 0.005 Gy·cm2). Aluminum filtration (1.0 mm) reduced DAP by 27.2% (0.457 ± 0.008 Gy·cm2). Greater reductions were achieved with copper filtration: 0.1 mm Cu resulted in a 42.5% reduction (0.361 ± 0.005 Gy·cm2), while 0.2 mm Cu produced the greatest reduction of 54.9% (0.283 ± 0.006 Gy·cm2). Differences between groups were statistically significant (p < 0.05).

Additional beam filtration significantly reduces radiation dose in simulated pediatric chest radiography, with copper filtration demonstrating superior performance compared to aluminum.

Incorporating thin copper filtration, particularly 0.2 mm Cu, into pediatric chest radiography protocols may substantially reduce patient radiation exposure while maintaining standardized detector exposure. These findings support beam filtration as a practical optimization strategy in accordance with the ALARA (as low as reasonably achievable) principles. Clinical implementation should be accompanied by objective image quality evaluation and protocol validation across different pediatric age groups.