Establishment of local diagnostic reference level for computed tomography angiography in Morocco

Objective: To establish local diagnostic reference levels (LDRLs) for computed tomography angiography (CTA) examinations in Morocco. Methods: Data were collected from 2283 adult patients undergoing CTA scans across four hospitals in Morocco, covering examinations of the upper limb, brain, carotid arteries, pulmonary arteries, abdominal aorta, total aorta, and lower limb. CTDIvol and DLP were recorded and analyzed. The 75th percentile values were determined as local DRLs. Results: For Hospital A, the LDRLs (CTDIvol and DLP) for upper limb, brain CTA, carotids, pulmonary arteries, abdominal aorta, total aorta, and lower limb were 16.05 mGy and 1059.81 mGy × cm, 26.1 mGy and 1370.48 mGy × cm, 13.95 mGy and 1303.85 mGy × cm, 3.18 mGy and 321.38 mGy × cm, 9.69 mGy and 1453.79 mGy × cm, 5.12 mGy and 1346.47 mGy × cm, and 7.49 mGy and 600.3 mGy × cm, respectively. Hospital B had higher DRLs due to more scan phases. Hospital C’s LDRLs for carotids, pulmonary arteries, abdominal aorta, total aorta, and lower limb were 9.07 mGy and 819.49 mGy × cm, 11.52 mGy and 487.56 mGy × cm, 9.41 mGy and 1018.17 mGy × cm, 10.74 mGy and 1860.74 mGy × cm, and 9.4 mGy and 860.98 mGy × cm, respectively. Hospital D, the LDRLs for carotids, pulmonary arteries, and lower limb were 5.98 mGy and 596 mGy x cm, 3.87 mGy and 357 mGy × cm, and 6.53 mGy and 724 mGy × cm, respectively. Conclusion: Moroccan LDRLs generally have lower CTDIvol but higher DLP values, primarily due to more scan phases used. More efforts are needed to optimize radiation dose during vascular CT examinations.