Examination of parameters influencing the image quality and patients' doses during computer tomography imaging method and determination of diagnostic reference levels

The Diagnostic Reference Level (DRL), is an important tool for dose monitoring and optimizing diagnostic imaging modalities, such as Computed Tomography (CT). Image quality gained by CT scan correlates with the patient's effective dose. The purpose of this study was: to determine DRLs; research the potential of optimization in the acquisition protocols and diagnostic quality of images. This research is conducted in three hospitals across North Macedonia in period 2016-2021, all using GE Bright Speed CT scanner with AEC system. Clinical protocols for abdominal regions and head were considered. A total of 287 CT scans were analyzed. Results have shown that: there are differences in the number of series and acquisition parameters, particularly in the abdominal studies. Variations in the average CTDIvol values were noticed in similar patients (by size). In addition, no correlation between scan range and patient height compromised the assessment of the DLP value per type of examination. A difference in DLP greater than 25% was evident for similar patients in height, especially among the contrast phases. Finally, the same image quality was provided in examinations differing by even double value in the CTDIvol. Therefore, the clinical protocol for abdominal scans needs to be standardized and optimized according to the clinical indication. (author)