Ruptured aneurysm with extravasation observed in four-dimensional computed tomography angiography.

We report a case of subarachnoid hemorrhage with a ruptured aneurysm in the anterior communicating artery. On multiphase dynamic contrast-enhanced four-dimensional computed tomography angiography (4D CTA), we observed active bleeding from the aneurysm that manifested over time with a corkscrew-like, spindle-like, and lobulated appearance and nebulous enhancement, characteristics reported only individually previously. The volume data for 4D CTA is easy to obtain with newly developed multidetector-row computed tomography, and 4D CTA can be used for evaluating anatomical aspects, hemodynamics, and treatment selection in cases of a ruptured cerebral aneurysm.