What features suggest this an extradural haemorrhage?
An extradural haematoma is typically biconvex in shape and does not cross suture lines. They are commonly associated with a skull fracture.
Brain:
extradural haematoma measuring up to 30mm in depth with a marked mass effect, including midline shift and uncal herniation. Early entrapped left lateral ventricle
subarachnoid blood in the left Sylvian fissure
sulcal effacement
right temporal bone fracture extending into the mandibular fossa. Fluid in the right mastoid air cells, but no clear fracture