These are indicative of the severity of the injury, and uncomplicated fractures are not of great significance otherwise, except that temporal bone fractures may predispose to extradural haematoma.
These may require surgery to elevate the bone fragment. These are well demonstrated on CT.
Comminuted depressed fracture of the left parietal bone by more than the thickness of the calvarium itself. Associated with underlying haemorrhagic contusion and air.
These are not always visible, but blood in the sinus cavities (eg sphenoid sinus) suggests their presence. This is important as such patients are prone to developing meningitis and require antibiotic prophylaxis. If the patient has clinical evidence of skull base fracture (eg CSF rhinorrhoea or bleeding from the external auditory meatus) a normal CT does not exclude such a fracture.
On the first iimage, there is a fracture through the left occipital bone. On the second image, a haemorrhagic contusion is seen in the cerebellum. On the third, the same image on bone window settings, there is just visible a fracture overlying the contusion (It it is not as clear here as on the original, sadly), but also a fluid level in the sphenoid sinus.
This indicates an open head injury, such as due to a basal fracture communicating with sinuses or a penetrating injury to the vault (eg a bullet wound). Again it indicates the need for antibiotics.
Note the presence of extensive intracranial air anteriorly. The sulcal pattern anteriorly is outlined in white, indicating the presence of fresh subarachnoid bleeding also.
Intracranial air over frontal lobes, in suprasellar region and over left temporal lobe. Left temporal haematoma and air in soft tissue over left temporal area.
Petrous temporal bone fractures can be divided into transverse and longitudinal. They may be associated with post traumatic deafness; the transverse fracture is the more severe in this respect.
Note the longitudinal petrous bone fracture. The peripheral fracture margins are arrowed. Note also the blood in the sphenoid sinuses, consistent with a basal skull fracture. This is the same patient with intracranial air and subarachnoid bleeding.
Facial plain radiographs may be suspicious for disruption of the orbital floor. CT is an excellent tool for assessing this region, when performed in the coronal plane.
This image confirms a blowout fracture of the floor of the left orbit, with herniation of orbital fat through the defect. The inferior rectus is not directly involved. Note also the blood (air/fluid level) in the maxillary antrum.
A few images to puzzle over to finish...
This patient had suffered a fall a week or two earlier, but had recovered well. He now presents with a decreasing concious level, and has been brought to the Casualty Department by his concerned wife. What does the CT show?
See below for answers to Case 1
What abnormalities are shown on these images?
What is the sequence of events that accounts for these appearances? The second scan was obtained one month after the first, as a follow up. There was no history of accidental trauma, although the patient had a long history of unsteadiness and confusion.
Scan obtained in August.
Follow up scan obtained in September.
See the Answer Page.
Dr A C Downie
Victoria Infirmary, Glasgow
andrew@radiology.co.uk
Additional images courtesy of Dr Li Foong Foo