Postcontrast computed tomography in subarachnoid hemorrhage from ruptured aneurysms

Area of Science:

• Neuroradiology
• Neurosurgery
• Diagnostic Imaging

Background:

• Subarachnoid hemorrhage (SAH) is a critical condition often caused by ruptured cerebral aneurysms.
• Early and accurate diagnosis of SAH is crucial for timely intervention and improved patient outcomes.
• Computed tomography (CT) is a primary imaging modality for diagnosing SAH.

Purpose of the Study:

• To evaluate the diagnostic performance of CT in detecting subarachnoid blood.
• To assess the ability of CT to predict the location of ruptured aneurysms based on blood distribution.
• To determine the added value of postcontrast CT studies in diagnosing SAH.

Main Methods:

• Retrospective review of CT scans from 49 patients diagnosed with SAH secondary to ruptured aneurysms.
• Analysis of subarachnoid blood detection rates based on timing of CT scan post-hemorrhage.
• Evaluation of aneurysm site prediction accuracy based on cisternal blood patterns.
• Assessment of findings from postcontrast CT studies, including direct aneurysm visualization and subarachnoid enhancement.

Main Results:

• Subarachnoid blood was detected in 95% of patients when CT was performed within 5 days of bleeding.
• Prediction accuracy for aneurysm site varied: anterior cerebral artery (92%), middle cerebral artery (70%), and internal carotid artery (47%).
• Postcontrast CT visualized aneurysms directly in 8 cases and showed subarachnoid enhancement in 21 cases.
• Subarachnoid enhancement on postcontrast CT facilitated SAH diagnosis in 3 patients lacking precontrast cisternal blood evidence.

Conclusions:

• CT is highly sensitive for detecting SAH within 5 days of rupture.
• The distribution of cisternal blood on CT can help predict the location of the ruptured aneurysm, though accuracy varies by vessel.
• Postcontrast CT enhances diagnostic capabilities, aiding in direct aneurysm visualization and identifying SAH even when initial precontrast CT is equivocal.