Role of CT Perfusion in Predicting Poor Outcome After Subarachnoid Hemorrhage

Role of Computed Tomography Perfusion in Detection of Patients at Risk for Delayed Cerebral Ischemia After Subarachnoid Hemorrhage

Prospective evaluation of patients with subarachnoid hemorrhage (SAH) will be done by computed tomography angiography (CTA) and perfusion imaging (CTP) for any correlation between degree of vasospasm and perfusion deficit as well as evaluating the ability of CTP to predict delayed cerebral ischemia.

Cerebral vasospasm is a serious complication of subarachnoid haemorrhage . In the first 2 weeks of SAH, angiographic vasospasm is seen up to 40-70% of patients and causes ischemic deficits in 15-36% of patients.

The best clinical indicator of significantly reduced brain perfusion (cerebral blood flow (CBF)<20 ml per 100 g/min) is the presence of new neurologic deficits. However, clinical symptoms may be vague and mimic other conditions in patients with SAH.

CT Perfusion can be used in the evaluation of patients with possible vasospasm after subarachnoid hemorrhage (SAH). It can thus be used to assess cerebral ischemia and infarction as a result of vasospasm after SAH.

The presence of cerebral vasospasm identified with transcranial Doppler, digital subtraction angiography, or CT angiography (CTA) is frequently used to confirm DCI. Presence of vasospasm, however, does not prove the presence of ischemia and absence of vasospasm does not rule out. Better diagnostic tests in the acute stage of deterioration, possibly caused by DCI, are therefore needed. In patients with SAH, CTP has recently been shown to be promising for detection of early ischemia.

Inclusion Criteria:

• All patients presented with subarachnoid haemorrhage

Exclusion Criteria:

• Patients with abnormal renal functions with creatinine ≥ 2 mg/dl/
• Patients with hypersensitivity to contrast media.
• Contraindication to radiation as pregnancy.