Diagnostic reference level for computed tomography abdominal examinations: A multicentre study

Computed tomography (CT) represents one of the largest sources of medical diagnostic ionizing radiation exposures to patients. As with other radiological imaging procedures, optimization leading to adoption of diagnostic reference levels (DRL) is recommended, mitigating unnecessary exposure. Present study has made evaluation of patient exposures, seeking a national DRL in Sudan for several abdominal CT techniques. In a study involving 16 radiology departments, data were obtained in imaging of a total of 321 patients examined for issues associated wtith the abdomen and pelvis. Patient weight and age ranges were 65-75 kg and 18-70 years respectively. Observed have been abdomen and abdomen-pelvis dose length products (DLP) in the range 1331 mGy cm to 3172 mGy cm and 370 mGy cm to 1687 mGy cm, respectively. The mean and range of CTDIvol (in mGy) for the abdomen and abdomen-pelvis respectively were found to be 28.2 (3.0-13.0) and 26.0 (4.0-80.0). Patient doses were observed to vary both between departments and within the same department, wide variation in technical settings suggesting need for staff training in CT dose optimization techniques. The patient doses are found to be greater than those typically observed in other studies elsewhere. DRLs are proposed for all of the investigated CT procedures.