Comparison of Radiation Doses of Computed Tomography Brain and Pulmonary Angiography with International Commission on Radiological Protection Guidelines: A Descriptive Study

Abstract

Introduction: Computed Tomography Angiography (CTA) is useful for evaluating and diagnosing conditions related to blood vessels, such as aneurysms, stenosis (narrowing of vessels), vascular malformations, and blockages. It provides valuable information for planning and guiding interventions or surgeries. It is also important to measure patient doses during CTA operations to evaluate and optimise the technique and balance the benefits compared to radiation hazards. Aim: To calculate the CT Dose Index (CTDI), Dose Length Product (DLP), and effective dose for CT brain angiography and CT pulmonary angiography, and also to compare whether the measured values are within the International Commission on Radiological Protection (ICRP) recommended levels. Materials and Methods: A retrospective descriptive study was conducted in the Department of Radiodiagnosis at Yenepoya Medical College Hospital Mangaluru, Karnataka, India, from September 2022 to September 2023. A total of 52 data points were collected for CT brain and CT pulmonary angiography examinations, which were acquired before October 2022. Information on CTDI and DLP was collected, and the effective dose was calculated using the conversion factor. The values were then compared with the ICRP reference level. Descriptive statistics, mean, and standard deviation for continuous variables, and frequency and percentage for categorical variables were used. Results: There was a significantly lower value of CTDI, DLP, and effective dose for CT brain angiography and CT pulmonary angiography compared to the ICRP recommended reference levels. The mean CTDI and DLP for CT brain angiography were 111.56 mGy and 1153.31 mGy·cm, and the mean CTDI and DLP for CT pulmonary angiography were 24.56 mGy and 713.74 mGy·cm, respectively. The mean effective dose for CT brain and CT pulmonary angiography was 2.46 mSv and 9.94 mSv, respectively. Conclusion: The measured values were within the recommended values of ICRP regulations. It is recommended that CT brain angiography and CT pulmonary angiography examinations are safer for diagnostic purposes. Optimising scanning protocols, utilising low-dose techniques, and implementing dose monitoring and control are important clinical aspects. Compliance with the guidelines helps to enhance patient care and reduce the risk of radiation-related complications.