Patient Dose Optimisation of Abdominopelvic Protocols During X-Ray Imaging.

Abstract

Introduction: Abdominopelvic radiography is commonly performed in both supine and erect positions, raising concerns about radiation dose exposure. In Ghana, there is limited data on organ dose evaluation in these examinations, particularly regarding patient positioning for dose optimisation. Additionally, the risk of dose creep in Digital Radiography (DR) due to its wide dynamic range further complicates dose management. This study aimed to estimate organ doses for patients undergoing abdominopelvic radiography in both positions and to develop an optimisation strategy that minimises radiation exposure while maintaining image quality.

Methods: Organ doses were estimated using CalDose X 5.0 for 112 patients across two facilities in both erect and supine positions. Image quality was assessed using signal-to-noise ratio (SNR) values for five specific organs, with the kidney, the liver, and the prostate selected for dose and image quality optimisation. Additionally, 34 exposures were performed on an anthropomorphic phantom using varying exposure parameters and focus-to-detector distances (FDD), with thermoluminescence dosimeters (TLDs) employed for dose optimisation measurement.

Results: An average of 39.9% and 52.9% of radiographs had optimal and high SNR values respectively. After the optimisation procedure, the recommended exposure parameters were 70 kVp, 10 mAs, and 110 cm FDD for both positions. In the supine position, organ doses reduced with a percentage difference of 50.0, 65.22 and 19.21, and 23.03, 28.97 and 30.98 for SNR for the kidney, the liver and the prostate respectively. In the erect position, organ doses reduced with a percentage difference of 72.34, 72 and 4.55, and SNR percentage difference of 10.69, 9.39 and 32.83 for the kidney, the liver and the prostate respectively.

Conclusion: Abdominopelvic organ doses vary based on patient demographics and exposure settings. The optimisation strategy significantly reduced radiation doses while preserving image quality. These findings emphasise the importance of standardised imaging protocols to enhance patient safety and radiation protection in clinical practice.