Radiation Dose Optimization and Dose Deviation Index Analysis in Portable Chest X-ray Examinations for Newborns in Intensive Care Unit

Abstract

Purposes: To study radiation doses received by newborns from portable chest X-ray examinations, analyze dose deviation indicators, and evaluate relationships between various factors affecting radiation dose.

Study design: Cross-sectional descriptive study

Materials and Methods: A comparative study was conducted before and after implementing improved portable chest X-ray techniques in 58 newborns in each group at the neonatal intensive care unit. The relationship between entrance surface air kerma (ESAK) and various parameters including tube current-time product (mAs), peak kilovoltage (kVp), chest thickness, radiation field size, and birth weight was analyzed.

Main findings: Before optimization, the mean ESAK was 1.36 ± 0.05 mGy, which significantly decreased to 0.06 ± 0.01 mGy after optimization (95.58% reduction, p < 0.001). mAs showed the strongest correlation with ESAK (r = 0.991), followed by kVp (r = 0.885) and chest thickness (r = 0.421), whereas beam size and weight showed no significant correlation. The proportion of images within the acceptable DI range (±3) increased from 55.17% to 94.83%, while overexposed images decreased from 44.83% to 5.17%. Post-optimization radiation dose levels complied with Thailand’s national reference levels (≤ 0.06 mGy).

Conclusion and recommendations: Optimized portable chest X-ray techniques significantly reduced radiation doses to newborns while maintaining diagnostic image quality within acceptable standards. mAs and kVp were the primary factors controlling radiation dose.