Establishment of diagnostic reference level of abdominopelvic CT procedure of university hospital center Mohammed VI, Oujda

Abstract

Background: Everyday, physicians daily use different X- ray's technologies to diagnose cancer in order to save thousands of lives. The use of CT in medical diagnosis, administers radiation doses to patients that are higher than those from other radiological procedures. It has been estimated that Computed Tomography examinations make up around 20% of radiologic procedures and contribute by approximately 80% to the radiation medical exposure doses. Purpose: The goal of this study is to estimate the doses delivered during abdominopelvic Computed Tomography (CT) procedures in order to establish local diagnostic reference level (DRL) of University Hospital Center Mohamed VI of Oujda. Materials and methods: All CT examinations are performed with a scanner GENERAL ELECTRIC (GE) Optima CT 540. A total of 30 patients were examined in emergency radiology department. The data was collected from Abdomen- pelvic examinations. For each examination, CT acquisition parameters were reported, including number of series, use of contrast medium, tube kV, tube current and rotation time, slice thickness, the displayed CT dose index (CTDIvol) and the Dose Length Product (DLP). Effective dose and DRL were estimated using the International Commission on Radiological Protection conversion factors (ICRP 2007). Results: The average weight and age of patients who have benefited from the abdominopelvic CT scan are equal respectively to (59.27 ± 10.21) Kg and (25.10 ± 4.75) years. Tube voltage (kV), tube current and rotation time were 120 (kV), 275 (mA) and 1,75 (s) respectively. The average displayed CT dose index CTDIvol were (8.37± 2.52) mGy. The average dose length product (DLP) was (416.48 ± 153.53) mGy cm. The average effective dose received by patient during an abdominopelvic CT scan was (6.41 ± 2.36) mSv. Conclusion: The dose values of this study were comparable to the international reference levels of this CT examination. CT dose Optimization protocol is not implemented in the Moroccan hospitals. These values could be used as our hospital's Dose Reference Levels (DRL) until a more extensive detailed study survey is organized in Morocco for the establishment of the country's reference level.