Correlation of computed tomographic, angiographic, and neuropathological changes in giant cerebral aneurysms

Area of Science:

• Neuroradiology
• Cerebrovascular Imaging
• Medical Imaging Analysis

Background:

• Giant aneurysms of the circle of Willis present diagnostic challenges.
• Computed tomography (CT) is a key imaging modality for evaluating these lesions.
• Understanding CT patterns can improve characterization and management.

Purpose of the Study:

• To identify and describe distinct CT patterns of giant aneurysms involving or adjacent to the circle of Willis.
• To correlate CT findings with angiographic and neuropathological data.
• To highlight the diagnostic utility of specific CT features, such as the 'target' sign.

Main Methods:

• Retrospective analysis of CT scans (pre- and post-contrast) in patients with giant aneurysms.
• Classification of aneurysms into nonthrombotic, partially thrombotic, and completely thrombotic groups based on CT imaging.
• Correlation of CT findings with available angiography and neuropathological reports.

Main Results:

• Three CT patterns were identified: nonthrombotic, partially thrombotic, and completely thrombotic.
• Partially thrombotic aneurysms demonstrated a characteristic 'target' appearance on post-contrast CT.
• Ring calcification was frequently observed in partially and completely thrombotic aneurysms, but absent in nonthrombotic lesions.

Conclusions:

• CT imaging effectively categorizes giant aneurysms of the circle of Willis into distinct thrombotic patterns.
• The 'target' sign on CT is a specific indicator of partially thrombotic aneurysms.
• CT findings, including calcification patterns, correlate with angiographic and pathological features, aiding in aneurysm characterization.