Radiation Dose Distribution for Patients Undergoing Routine Radiological Scans for Kidney Stone Diagnosis at the University Hospital of the West Indies

Abstract

Objectives: To investigate the radiation dose received by patients undergoing routine plain x-ray and computed tomography scans for kidney stone studies. Methods: For x-ray scans two sets of experiments were performed. ThermoLuminescence Dosimeters were used to determine the distribution of radiation dose across the abdominal surface and an acrylic water phantom equipped with a Farmer ionization chamber was used to measure the radiation dose as x-ray photons travel through the abdomen. For CT scans, the Dose Length Product (DLP) over 3 months for abdominal studies was recorded. Calculations were done to convert the DLP to effective dose using k factor values from the International Commission on Radiological Protection (ICRP) report 103. The results were then mapped and analysed using Microsoft excel and Wolfram Mathematical software. Results: Skin dose was greatest at the centre of the abdomen. Radiation equivalent dose to the skin for a plain abdominal x-ray ranged from 2.38mSv for patients with a sthenic body habitus to 5.45mSv for hypersthenic patients. For CT scans, effective dose was found to range between 6.72mSv and 24.27mSv. Conclusion: All radiation dose measured were found to be within recommended ICRP operational limits. The developed procedure could be implemented in other radiology departments in Jamaica as a part of their quality assurance program.