Establishment of Diagnostic Reference Levels for Childhood Head CT in the District of Abidjan in C？te d’Ivoire

Computed tomography is an indispensable X-ray imaging modality used to diagnose numerous pathologies, but it can also involve the delivery of high ionizing radiation doses harmful to the health of patients. This study aims to survey the level of radiation doses delivered to child patients during head exams in CT imaging to set up the Dosimetric Reference Levels (DRLs), a routine dose optimization tool, based on data acquired at the University Hospital of Angré (UHA), the University Hospital of Treichville (UHT) and the Polyclinic Hospital Farah (Farah) for optimizing procedures in Ivorian hospitals. Prospectively performed on 334 CT images of 186 child patients, this study was carried out on CT systems such as Hitachi Scenaria, Sinovision Insitum, and Philips Incisive used respectively at UHA, UHT and Farah. Children’s scan data were classified into four age bands: <1.5 years, 1.5 - 5.5 years, 5.5 - 10.5 years, and 10.5 - 16 years. Each yielded dose index (volume CT dose index as CTDI_vol or dose-length product as DLP) value, whatever the hospital, increases with respect to the age of child patients. Based on the 75th percentile of the whole dose distributions, the DRLs of the CTDI_vol is 54.37 mGy whatever the age groups and those of the DLP with respect to age bands are 1224.55 mGy？cm, 1414.06 mGy？cm, 1632.24 mGy.cm and 1544.57 mGy？cm, respectively. The averaged values of CTDI_vol and DLP smaller than the corresponding DRLs values suggest that practices in our three facilities are optimized. However, comparing our results with those from different international studies, we see that the CTDI_vol and DLP values obtained in the present work are higher. These results suggest additional surveys to ensure our DRLs values and efforts from radiologists, imaging technicians and medical physicists to strengthen clinical procedures for the radiation protection of children undergoing CT scans in C？te d’Ivoire.