Computerised tomography (CT) scans are increasingly available in provincial hospitals, and it is important that paediatric trainees understand the basics of CT scanning and how to interpret them. This teaching session covers the principles of interpreting brain and head CT scans, many of these principles are common to scans of other organs (chest, abdomen, etc). We will discuss normal CT head scans, the implications of different densities, what Hounsfield units are, brain oedema, blood of different ages, masses, contrast enhancement and what it means, and cerebral inflammation (meningitis, encephalitis, tuberculosis). This year we also had a lecture on paediatric x-ray interpretation, and this builds on that.