Introduction The number of CT examinations increases every year, due to its strong diagnostic performance. Thus, radiation dose optimization in CT is especially important in paediatric patients, due to their long life expectancy and greater radiosensitivity. In fact, Directive Euratom 2013/59 considers CT procedures as high-dose practices, which require especial attention in radiation protection optimization. Diagnostic reference levels (DRLs) are a key tool in CT dose optimization, particularly on paediatric patients. Therefore, member states shall ensure the establishment, regular review and use of diagnostic reference...

Material and methods The study has been performed at a Philips Brilliance CT unit (64 detector rows), installed at a paediatric Hospital after implementation of iterative reconstruction (IR) technique iDose4. The examinations considered in the study are the most frequently performed: spiral chest and head CT. Until implementation of IR, head studies for patients over 1 year were performed mainly sequential. Now, every head CT is performed as helical scan. Dosimetric quantities evaluated are Dose Length Product (DLP) and volumetric Computed Tomography Dose Index (CTDIvol),...

The implementation of new paediatric protocols based on iterative reconstruction, has led to a significant optimization of paediatric patient doses in CT, while maintaining or even improving image quality. New reference levels have been established and will be often revised in further optimization procedures.

Mrs. Paula García Castañón Medical Physicist Medical Physics and Radiation Protection Department University Hospital La Princesa C/ Diego de León, 62 28006- Madrid SPAIN e-mail: [email protected] Tlf: +34 626612619

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