Objective: Magnetic resonance angiography (MRA) can be used to identify cerebral aneurysms. In this report, techniques for the diagnosis of giant cerebral aneurysm using MRA are discussed. Pitfalls in the diagnosis are presented.
Background: Giant cerebral aneurysms, which can be partially or totally thrombosed, or may have slow flow, can be confusing and difficult to diagnose. Giant cerebral aneurysms with thrombus formation, produce an artifact in time-of-flight MRA in which the thrombus simulates flowing blood.
Method: Five consecutive patients with the suspected diagnosis of giant cerebral aneurysm by MRA were analyzed. Neuroradiological studies were reviewed.
Results: In 20% of the cases, the correct diagnosis was made using MRA; in 60% of the cases, a correct diagnosis was made, but the size or the presence of flow was not correctly identified; in 20% of the cases, the diagnosis was incorrect. Four patients with giant cerebral aneurysms who presented a diagnostic and a therapeutic challenge are discussed.
Conclusion: Unless MRA findings are combined with computed tomography scan and magnetic resonance imaging findings, the exact nature of the sac contents of giant cerebral aneurysms cannot be identified.