Local diagnostic reference levels in children’s CT examinations according to the new european guidelines

Abstract

Introduction The determination of paediatric DRLs is a difficult task mostly due to the large variation in children’s somatometric characteristics. In children until now the DRLs were expressed as a function of patient age. The newest EU Guidelines on paediatric DRLs recommend that the grouping parameters should be patient weight for all body examinations and patient age for all head examinations. Purpose This study intends to express the local DRLs for CT examinations in accordance to new EU recommendations for patient grouping parameters: age and weight. Materials and methods Exposure parameters and dosimetric data such as CTDIvol and DLP values, were recorded from system’s console for 396 routine Head CT, 162 Thorax CT and 92 Abdomen CT examinations, along with data concerning children’s age and somatometric characteristics. Two parameters for the data grouping were applied: age, and weight. The DRLs were calculated for the considered examinations, for five age groups (0–1 month, 1–12 months, 1–5, 5–10 and 10–15 years) and five weight groups (<5, 5–15, 15–30, 30–50, 50–80 kg). Results The relationship of paediatric dose with age and somatometric characteristics was studied in detail. Dosimetric data were found to vary significantly among age and weight groups for the same type of examination. Both CTDIvol and the DLP values increase with age and weight. DLP seems to represent a better index of patient dose. Conclusion Patient dose levels may vary considerably as a function of age, size or weight and therefore DRLs for several ages, size or weight groups need to be defined. Disclosure None. The determination of paediatric DRLs is a difficult task mostly due to the large variation in children’s somatometric characteristics. In children until now the DRLs were expressed as a function of patient age. The newest EU Guidelines on paediatric DRLs recommend that the grouping parameters should be patient weight for all body examinations and patient age for all head examinations. This study intends to express the local DRLs for CT examinations in accordance to new EU recommendations for patient grouping parameters: age and weight. Exposure parameters and dosimetric data such as CTDIvol and DLP values, were recorded from system’s console for 396 routine Head CT, 162 Thorax CT and 92 Abdomen CT examinations, along with data concerning children’s age and somatometric characteristics. Two parameters for the data grouping were applied: age, and weight. The DRLs were calculated for the considered examinations, for five age groups (0–1 month, 1–12 months, 1–5, 5–10 and 10–15 years) and five weight groups (<5, 5–15, 15–30, 30–50, 50–80 kg). The relationship of paediatric dose with age and somatometric characteristics was studied in detail. Dosimetric data were found to vary significantly among age and weight groups for the same type of examination. Both CTDIvol and the DLP values increase with age and weight. DLP seems to represent a better index of patient dose. Patient dose levels may vary considerably as a function of age, size or weight and therefore DRLs for several ages, size or weight groups need to be defined.