Anterior communicating artery aneurysm computed tomography

SAH in anterior communicating artery aneurysms results in blood in the anterior interhemispheric fissure in essentially all cases, and is associated with intracerebral hematoma in 63% of cases ¹⁾. Intraventricular hematoma is seen in 79 % of cases, with the blood entering the ventricles from the intracerebral hematoma in about one–third of these. Acute hydrocephalus was present in 25% of patients (late hydrocephalus, a common sequela of SAH, was not studied). Frontal lobe infarcts occur in 20%, usually several days following SAH ²⁾. One of the few causes of the rare finding of bilateral ACA distribution infarcts is vasospasm following hemorrhage from rupture of an ACoA aneurysm. This results in prefrontal lobotomy-like findings of apathy and abulia.

Weisberg reviewed the CT findings in 40 patients with ruptured aneurysms of the anterior cerebral artery or anterior communicating artery. Within 3 days of the ictus, the common patterns included blood in the pericallosal cistern and interhemispheric fissure, blood in the caval-septal region, unilateral or bilateral frontal hematoma, and diffuse symmetric intraventricular and basal cisternal blood ³⁾.

For CT classification see the Modified Fisher scale.