Giant intracranial aneurysm

Case contributed by Emmanouil Kalioras
Diagnosis almost certain


Treated ACom aneurysm 9 years ago, headache

Patient Data

Age: 70 years
Gender: Male

Large lobulated extra-axial lesion in the anterior and middle cranial fossa with peripheral T1 hyper- and T2 hypointense signals and T1 iso- to hypo- and T2 hyperintense signal in the center. The lesion shows blooming artifact on SWI, suggesting the presence of thrombus.

White matter buckling sign in the left frontal lobe. 

Leptomeningeal blooming artifact on SWI images around the frontal lobes bilaterally (superficial siderosis).

Confluent T2/FLAIR white matter hyperintensities adjacent to the lesion, sparing the cortex, in keeping with vasogenic edema.

Distension of Meckel's cave bilaterally suggesting raised intracranial pressure.

Intraparenchymal lesion with T2 hypointense hemosiderin ring located in the posterior limb of the left internal capsule extending into the left cerebral peduncle, indicative of cavernoma.

Gliosis and encephalomalacia in the anterior part of left frontal lobe, associated with ex vacuo dilatation of frontal horn of the left lateral ventricle.

Small area of extravasating gadolinium out of the anterior communicating artery into the lesion is seen, supporting the case of intracranial aneurysm with active bleeding.

Case Discussion

Intracranial aneurysms that exceed 25 mm in diameter are defined as giant aneurysms and have a high mortality rate. Anterior communicating artery aneurysms have a high prevalence of reoccurrence 1.

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