Assessment of radiation dose from abdominal computed tomography at Maharat Nakhon Ratchasima Hospital

Abstract

Background: Abdominal computed tomography (CT) plays a crucial role in a diagnosis of disease and continually increases. However, X-ray radiation is harmful and requires a careful monitoring of patient radiation dose obtained from this procedure. Objectives: This study aimed to determine patient radiation dose from upper abdomen CT, lower abdomen CT and whole abdomen CT at Maharat Nakhon Ratchasima Hospital and compare this data with national diagnostic reference levels (NDRLs). Moreover, the evaluation of entrance surface air kerma (ESAK) of abdomen, eyes, and thyroid were performed. Methods: Patients who had undergone upper abdomen CT, lower abdomen CT, and whole abdomen CT (30 patients for each examination) between February and April 2023, and met the inclusion criteria, were recruited. The nanoDot optically stimulated luminescence dosimeters (OSLDs) were placed on patient’s skin at the eyes, thyroid, and abdomen to measure the ESAK. The radiation dose parameters including volumetric CT dose index (CTDI_vol), dose length product (DLP), total DLP were recorded. Furthermore, an effective dose was calculated. Results: The highest values of CTDI_vol (13.45 mGy), DLP (714.19 mGy.cm), total DLP (2575.20 mGy.cm), and effective dose (38.50 mSv) were obtained from the whole abdomen CT examination. However, CTDI_vol and DLP values for upper abdomen CT and whole abdomen CT were lower than the NDRLs. The highest ESAK values were consequently observed for the eyes (0.88 ± 0.19 mGy), thyroid (1.28 ± 0.23 mGy), and abdomen (36.98 ± 1.54 mGy) for the whole abdomen CT examination. Conclusion: The CTDI_vol and DLP values obtained from abdominal CT at Maharat Nakhon Ratchasima Hospital were within the NDRLs, indicating that our abdominal CT protocols for both upper abdomen and whole abdomen can be used to examine patients appropriately.