Aims Examination of the indications for and yield of medical CT scans in a tertiary paediatric emergency department.
Review of current literature on the radiation burden and long term sequelae of these scans.
Methods One year of ED CT requests in a paediatric hospital were identified using the electronic request system. The electronic records were examined. Children with a medical indication had their notes pulled and interrogated with a survey questionnaire. Current literature was reviewed.
Results 137 scans performed.
87 had a surgical presentation, 52 were medically indicated.
Of the medical scans, 27 were girls and 25 boys.
There were 20 (39%) positive CTs, 17 (33%) relevant to the clinical presentation.
Mean age 6 years 9/12, median 7, range 1/12 to 18 years.
The majority presented with more than one symptom or sign.
6 scans were performed under GA, with one intubated for the purpose of the scan.
25 of the 52 had subsequent MRI scans.
Discussion CTs account for 9% of radiological investigations in the general population, but 47% of medical radiation dose. 11% of scans are performed in children and the use of scans is growing year on year. Awareness of the radiation burden is variable among clinicians but there is consensus that there is no such thing as harmless radiation. Children's developing organs and longer life expectancy render them particularly vulnerable to long term sequelae.
Reviewing medical CTs outcome data helps us to minimise exposure, eg in the above data in generalised seizures there were no positive findings. SIGN 81 re diagnosis and management of childhood epilepsies suggests elective MRI, with no discussion of emergency CTs. 50% of those with suspected papilloedema had optic drusen, identifiable using USS.
The heterogeneous nature of medical presentations precludes formal guidelines. While the importance of a negative scan in some management decisions is recognised, the very low yield for some presentations emphasises that the most appropriate imaging modality requires careful consideration.