CTA in SAH is of great value in demonstrating vascular anatomy and the exact size of an aneurysm. However, IA-DSA is still needed for diagnostic evaluation in aneurysms smaller than 5 mm in diameter, especially in those located near bony structures.

Subarachnoid hemorrhage following severe trauma to the head is relatively common. In most cases the bleed originates from superficial veins and occasionally from arteries. Following the replacement of cerebral angiography with CT in the diagnostic evaluation of head traumas fewer traumatic aneurysms have been observed. This may indicate that some traumatic aneurysms are missed if angiographic procedures are not performed in patients with severe head injury. Trauma patients admitted to our institution are submitted to CT including a bone algorithm. In case of subarachnoid hemorrhage, especially in the basal cisterns, CT- angiography is performed. Digital subtraction angiography is performed as well in cases with uncertain interpretations. During one year 81 patients were admitted with subarachnoid hemorrhage following head trauma. Thirteen (16%) of them underwent CT-angiography and in five (6.2%) with SAH in the basal cistern traumatic aneurysms were found. Four of these cases had a skull base fracture including fractures through the clivus. Four cases were embolized and one very small extradural aneurysm is still not treated. One small pericallosal aneurysm was operated. A traumatic aneurysm should always be suspected n patients with skull base fractures and subarachnoid hemorrhage in the basal cisterns.

CTA in SAH is of great value in demonstrating vascular anatomy and the exact size of an aneurysm. However, IA-DSA is still needed for diagnostic evaluation in aneurysms smaller than 5 mm in diameter, especially in those located near bony structures.