Establishment of Diagnostic Reference Levels for Computed Tomography Scanning in Hamadan

Background: New advancements have increased the capabilities of computed tomography as a sectional medical imaging modality. An important note is assessing absorbed dose to patients and minimizing it when performing computed tomography examinations. One approach to control dose is to establish diagnostic reference levels. Objective: This study aimed to investigate diagnostic reference levels of computed tomography in Hamadan. Material and Methods: This work was conducted as an experimental study. Computed tomography dose index (CTDI) was measured using a Piranha quality control kit, head and body CTDI phantoms for brain, lung, abdomen-pelvic and coronary CT angiography examinations. Volume Computed Tomography Dose Index (CTDIvol) was calculated from obtained data and 3rd quartile of that was determined as diagnostic reference levels. Results: Diagnostic reference levels (DRLs) in terms of CTDIvol for brain, lung, abdomen-pelvic and coronary CT angiography were 50/25, 6/73, 22/01 and 32/06 mGy respectively in Hamadan. Difference between displayed CTDIvol and measured CTDIvol is not significance for all examinations (p>0.05). Conclusion: DRLs depend on to many dose affecting parameters in CT. DRL for brain CT is greater than other scan regions. Application of DRLs which resulted from this study can help to optimize radiation dose to the patients while maintaining acceptable diagnostic images quality.