The role of computed tomographic angiography in subarachnoid hemorrhage, and in the assessment of carotid stenosis

Introduction. A new investigative modality, computed tomographic angiography (CTA), is compared to the current standard digital subtraction angiography (DSA) for the detection of intracranial aneurysms and cerebral vasospasm following subarachnoid hemorrhage (SAH) and for the detection of carotid artery bifurcation disease.;Methods. Patients suffering SAH underwent CTA and DSA. The CTA and DSA exams were compared for the detection and characterization of cerebral aneurysms and cerebral vasospasm. Patients suffering cerebrovascular accidents underwent Doppler ultrasound, CTA, and DSA of the carotid bifurcation. These exams were compared for the detection and characterization of carotid stenosis.;Results. CTA was found to be highly sensitive (90%) and specific (100%) for aneurysm detection. CTA was able to replace DSA in 48% of patients suffering SAH. CTA was highly sensitive (95%) and specific (95%) for detecting none or severe vasospasm in proximal arterial locations. CTA was highly sensitive and specific (>90%) for detecting >50% carotid stenosis or 100% stenosis, but was less so for detecting 50--69% or 70--99% stenosis.;Conclusions. CTA is highly accurate in detecting cerebral aneurysms in the setting of SAH and at least half of patients require only CTA. CTA was accurate in detecting none or severe vasospasm in proximal arterial locations. CTA was excellent for detecting >50% or 100% carotid stenosis.