DEVELOPMENT OF NATIONAL DIAGNOSTIC REFERENCE LEVELS FOR HEAD CT EXAMINATIONS IN MOROCCO: A CLINICAL INDICATION-BASED APPROACH TO OPTIMIZE RADIATION DOSE AND ENHANCE PATIENT SAFETY

This study investigates dosimetric data and technical parameters from 1,299 head CT examinations conducted across 20 hospitals, including 5 university, 8 provincial, and 7 private hospitals, using CT scanners from manufacturers such as Canon, General Electric, Siemens, and Hitachi.Various CT scanner configurations were employed, with technical parameters including kVp values ranging from 80 to 140, mAs between 100 and 300, and scan lengths varying from 6 cm to 28 cm.The dosimetric analysis revealed significant differences in radiation doses across clinical protocols.For stroke evaluation (364 patients) underwent non-contrast scans yielding a mean CTDIvol of 58.71 3.20 mGy and a median effective dose of 12.33 0.99 mSv.Acute brain protocols (272 patients) using similar scan parameters showed a mean CTDIvol of 55.66 4.00 mGy and an effective dose of 11.69 1.19 mSv.Post-contrast non-vascular brain scans (156 patients) resulted in a CTDIvol of 61.48 4.50 mGy and an effective dose of 12.91 1.33 mSv.Contrast-enhanced angiographic imaging (156 patients) with double-phase protocols recorded a mean CTDIvol of 57.60 4.00 mGy and an effective dose of 12.09 1.19 mSv.Oncology simulation scans (117 patients) required the highest doses, with a CTDIvol of 74.74 15.69 mGy and an effective dose of 25.13 1.80 mSv.In contrast,sinus protocols (130 patients) showed a lower mean CTDIvol of 50.08 3.00 mGy and an effective dose of 9.82 0.64 mSv, reflecting the reduced scan range.Temporal bone imaging (104 patients) employed a limited scan length, resulting in a lower CTDIvol of 49.71 2.80 mGy and an effective dose of 5.57 0.28 mSv.The study revealed significant variations in DRLs driven by clinical requirements and regional disparities in healthcare infrastructure.These findings highlight the balance between diagnostic accuracy and radiation dose optimization across different clinical indications, contributing to improved patient safety while maintaining clinical efficacy.