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The study aims to establish national diagnostic reference levels (NDRLs) for computed tomography (CT) examinations performed on adult patients based on clinical indications, patient gender, and size in the Kingdom of Bahrain. The volume CT dose index (CTDI vol) and dose length product (DLP) were collected between September 2020 and September 2021 from 63% of the total number of CT scanners in the country (five out of eight CT scanners). The data were collected from at least ten patients for eight common clinical indications in the head, abdomen-pelvis and chest-abdomen-pelvis (CAP) regions. The NDRLs were calculated for each clinical indication as the third quartile of the CT scanners' median values of CTDI vol and DLP. They were also calculated based on the patient's gender (for the head) and their size (for the abdomen-pelvis and CAP clinical indications). From 1665 CT examinations, the NDRLs in term of CTDI vol were 67, 66, 67, 13, 14, 17, 19, and 15 mGy for symptoms of headache, trauma, stroke, flank pain, renal colic, abdominal pain, diverticulitis/appendicitis and oncologic follow-up, respectively. Likewise, these were 1206, 1286, 1152, 690, 779, 972, 1061, 1073 mGy cm in terms of DLP, respectively. For large size patients, NDRLs in terms of CTDI vol were on average 1.7 times higher than those from medium size patients for all the clinical indications in the abdomen-pelvis and CAP regions. The NDRLs were established for the most common clinical indications in the Kingdom of Bahrain. They are higher than those established in the literature, thus emphasizing the urgent need of an optimization strategy for better patient radiation protection. • National diagnostic reference levels (NDRL) are established for eight common clinical indications for adults CT in Bahrain. • Bahraini NDRLs are higher than those established in the literature for the most clinical indications. • For trunk clinical indications, NDRLs for large patients are on average 1.7 times higher than medium size patients. [ABSTRACT FROM AUTHOR]

Purpose Recent reports on radiation accidents and injuries in interventional cardiology (IC) raised the issue of radiation protection, especially for pediatric patients. This work hence focused on the measurement of skin dose in diagnostic and therapeutic pediatric IC procedures and the estimation of organ doses. Methods Exposures parameters including Dose Area Product (DAP), Cumulative Dose (CD), etc. were retrospectively reviewed for 263 patients undergoing diagnostic or therapeutic IC procedures for a congenital heart disease. These were all taken from a large pediatric hospital responsible for approximately 50% of all pediatric IC activity in the country. Patient age and weight were also collected. Additionally, Peak Skin Dose (PSD) was measured using thermoluminescent dosemeters for a sample of 50 children, 7 diagnostic (DP) and 43 therapeutic procedures (TP). Finally, breasts, lungs, esophagus and thyroid doses were estimated based on DAP-to-organ doses conversion factors available in literature. Results The study included 263 patients divided into 4 groups according to weight: < 5 kg with 5 DP and 31 TP, 5–<15 kg with 40 DP and 72 TP, 15–<30 kg with 19 DP and 67 TP and 30–<55 kg with 4 DP and 25 TP. For DP, median DAP and CD values for the four groups were 0.5, 2, 4 and 20 Gy.cm 2 and 6, 28, 36 and 165 mGy respectively. Those were 1, 2, 4 and 10 Gy.cm 2 and 10, 36, 41 and 75 mGy for TP correspondingly. The mean measured PSD was 15 (1–30) and 94 (1–491) mGy for DP and TP respectively. The mean breasts, lungs, esophagus and thyroid doses for neonate (respectively infant) were 2.1, 2.8, 3.1 and 2.3 mGy (8, 12, 9 and 6 mGy) respectively for DP and 3.9, 5, 6 and 4 mGy (23, 34, 26 and 18 mGy) respectively for TP. Conclusions Exposures parameters and measured PSD values were very low excluding the risk of skin injuries. The lungs and esophagus involved highest estimated organ doses for both neonate and infant. For patients requiring repeated procedures, accumulated doses will increase the cancer risk in specific organ. [ABSTRACT FROM AUTHOR]