A 34-year-old man with a history of seizures presented after a generalised seizure. An MRI of the brain and MR angiogram of the brain (figure 1) were performed, demonstrating a partially thrombosed, giant intracranial aneurysm involving the left anterior cerebral artery (ACA). Figure 1 T2 axial MRI of the brain demonstrates a centrally located, large hypointense lesion, consistent with the giant, partially thrombosed A2 segment aneurysm. The bilateral arrows indicate flow voids, representing the channel within the aneurysm itself where blood flow is still present, while the larger red arrow indicates the significant amount of thrombus within the aneurysm. The patient …