Optimization of Radiation Exposure Parameters for CT Chest in Obese Patients

Abstract

Background: Computed Tomography (CT) is one of the most widely used diagnostic tools in modern radiology; however, its use of ionizing radiation presents significant safety concerns, especially in obese patients who require higher exposure levels to achieve diagnostic image quality. This study aims to optimize radiation exposure parameters for CT chest examinations in obese patients by modifying technical settings while adhering to the ALARA (As Low As Reasonably Achievable) principle. Methods: A cross-sectional study was conducted on 341 obese adults aged 18–70 years undergoing CT chest scans. Data were collected for patient demographics, BMI, CT parameters (kVp, mAs, slice thickness), and dose indices (CTDIvol and DLP). Statistical analysis was used to identify correlations between patient body habitus and radiation dose, while maintaining diagnostic image quality. Results: The average BMI was 25.9 kg/m². Dose indices (CTDIvol and DLP) showed direct proportionality with BMI and body weight. Iterative Reconstruction (IR) combined with Automatic Exposure Control (AEC) reduced the mean effective dose by 28–30% without loss of image clarity. Optimization of tube current (200–250 mA) and voltage (100–120 kVp) maintained image contrast while reducing noise. CTDIvol correlated strongly with BMI (r=0.62). Results confirmed that weight-specific protocols can reduce exposure substantially. Conclusion: The study demonstrates that radiation dose can be safely reduced in obese patients through size based protocols, AEC, and iterative reconstruction algorithms. Tailored CT chest scanning protocols maintain diagnostic efficacy while minimizing radiation exposure.