====== Anterior communicating artery aneurysm computed tomography ======

[[SAH]] in [[anterior communicating artery aneurysm]]s results in blood in the anterior [[interhemispheric fissure]] in essentially all cases, and is associated with [[intracerebral hematoma]] in 63% of cases
((Yock DH, Larson DA.CT of Hemorrhage from Anterior Communicating Artery Aneurysms, with Angiographic Correlation. Radiology. 1980; 134:399–407)).
[[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
((Yock DH, Larson DA.CT of Hemorrhage from Anterior Communicating Artery Aneurysms, with Angiographic Correlation. Radiology. 1980; 134:399–407)).
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]].
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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
((Weisberg LA. Ruptured aneurysms of anterior cerebral or anterior communicating
arteries: CT patterns. Neurology. 1985 Nov;35(11):1562-6. PubMed PMID: 4058745.)).

{{::aneurysmalsubarachnoidhemorrhageanteriorcommunicatingarteryaneurysm.jpg?200|}}

===== Classification =====

For CT classification see the [[Modified Fisher scale]].