The Influence of mAs on Effective Dose and Image Quality in Chest CT scans Using RANDO Phantom

Abstract

Balancing radiation dose and image quality in chest CT scans is critical for patient safety and diagnostic accuracy. This study investigates the impact of milliampere-seconds (mAs) on effective radiation dose and image quality using a RANDO phantom. By systematically varying mAs settings (180–480 mAs) while maintaining constant tube voltage (kVp), radiation dose metrics (CTDIvol and dose-length product [DLP]) and image quality parameters (signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]) were measured. Results demonstrated a linear increase in radiation dose with higher mAs, while improvements in SNR and CNR plateaued beyond 230 mAs. These findings highlight the importance of optimizing mAs settings to minimize radiation exposure while preserving diagnostic image quality, suggesting that dose reductions are achievable without compromising clinical utility.