Paediatric National Diagnostic Reference Levels of Computed Tomography Examination in Ghana

Introduction: The aim of the study was to establish and propose the utilisation of National Diagnostic Reference Levels (DRLs) for DLP (dose length product) and CTDIvol (volume weighted computed tomography dose index) for routine computed tomography (CT) for paediatric examinations. Additionally, the study estimated signal-to-noise ratio and lifetime attributable radiation risk. The materials used include multi-detector computed tomography machine, quality control equipment, Head and Body phantoms and MeVisLab workstation. Methods: The methodology involved estimation of CTDIVOL, DLP, using a minimum of 20 patients per CT facility, imaging parameters for the head, chest, and abdomen-pelvis CT examinations. In all 300 images of randomly selected paediatric patients undergoing CT scans of head, chest, and abdomen-Pelvis from five centres. 200 images which met the selection criterion were used for the analysis. Results: The measured median and upper quartile CTDIvol for head were 6.86 and 7.33 mGy, chest was 6.98 and 6.70 mGy, abdomen-pelvis were 4.71 and 5.28 mGy respectively. While DLP for head was 1103.00 and 1249.58 mGy-cm, chest was 978.86 and 1250.42 mGy-cm, abdomen-pelvis were 565.85 and 787.05 mGy-cm. Conclusion: The results of the CTDI and DLP values were comparable to international standard values. It also recommends the use of the established CTDI and DLP as reference values for future intercomparison of data from similar studies.