One key process associated with subarachnoid hemorrhage is vasospasm. Blood is an irritant and causes the muscles surrounding the walls of the blood vessels to go into spasm. The contractions of the vessels cause vascoconstriction that produces inadequate blood flow to certain areas of the brain leading to tissue death. Although variations occur, cerebral vasospasm typically appears 4-10 days after the development of a subarachnoid hemorrhage.
The management of patients with ruptured cerebral aneurysms and vasospasm require a multi-disciplinary medical team in a closely monitored intensive-care setting. Detailed vascular imaging is required in conjunction with prompt surgical treatment (neurosurgical or endovascular intervention) and aggressive management of the vasospasm and associated medical issues.
It is vital to be able to examine the degree of brain injury and status of the cerebral vessels to determine the appropriate treatment. On many occasions, non-invasive imaging is used initially with CT or MRI to evaluate the brain, followed by CT-angiography or MR-angiography to examine the vascular status and anatomy. Ultimately, the gold-standard for the evaluation of the cerebral aneurysm and surrounding vasculature is a conventional cerebral angiogram. A cerebral angiogram is performed in a sterile environment where a catheter (wire) is inserted into the body through a blood vessel (usually in the groin) and navigated to the area of interest. Contrast dye is injected through the catheter while x-ray technology is used to provide a roadmap of the blood vessels. The cerebral angiogram is able to provide a detailed picture of the features of the aneurysm and surrounding blood vessels.