National survey on medical exposure to patients undergoing diagnostic radiology examinations: An initial overview on CT doses at UAE hospitals

The IAEA — UAE Project on Patient Radiation Protection aimed at evaluating radiation dose levels received by patients during radiological examinations. In this paper, we are presenting the preliminary results of patient doses in Computed Tomography (CT) examinations at 4 UAE hospitals (3 major governmental hospitals and 1 private). Five Multi-slice CT (MSCT) systems (4S, 16S and 64S) were included in this study. All these systems are enrolled in quality control program. CT dose levels were evaluated through either thermoluminescent detectors (TLD-100) or by using Head (16-cm Diameter) and Body (32-cm Diameter) cylindrical CTDI PMMA phantom fitted with a 10 cm pencil ionization chamber. Adult and pediatric patient CT doses were collected from common CT examinations of the Head, Chest and Abdomen & Pelvis. The CT Dose Index (CTDIvol), Dose Length Product (DLP) and Effective Doses (E) were the main CT dosimetry parameters evaluated in this project. The CTDIvol results of all CT systems showed acceptable compliance with those reported by professional organizations. The range of 3rd quartile of adult DLP values for CT Head examinations among the 4 hospitals was 384.106–5031.92 mGy.cm. The adult CT Chest examinations demonstrated the range of the 3rd quartile DLP values between 122.035–1423.06 mGy.cm while the Abdomen & Pelvis examinations showed a range of 258.446–1701.135 mGy.cm. Hospitals DD3, AA13 and ANM14 are within the UAE initial adapted local Dose Reference Levels (DRLs) and are comparable to the European guidelines while hospitals TA1 and TA2 are higher. The CT effective doses of almost all the examination types were within the level mentioned by international organizations such as the ICRP (Report 102, 2007) with the exception of CT examinations performed at TA1 & TA2. Further work is developed to reduce patient radiation doses of the common CT examinations of the Head, Chest and Abdomen & Pelvis. Adult and pediatric patient data collection and analysis of CT doses from other hospitals at the UAE are in progress.