Three Cases of Tiny Intracranial Aneurysm Identified to be Ruptured by Site of Remaining Clot in Follow-up Computed Tomography and Subsequent Angiogram

Introduction: The authors report three patients with tiny aneurysms for whom coil embolization was performed, evaluating them as the source of hemorrhage on subsequent angiogram based on follow-up CT findings of residual hematomas although each aneurysm was not recognized as the site of rupture on imaging early after the onset of subarachnoid hemorrhage.Case Presentations: Case 1: A 44-year-old female with a basilar-superior cerebellar artery aneurysm. The presence of an aneurysm was suspected, but it was very small, and it could not be concluded as the source of hemorrhage. Case 2: A 66-year-old male with an internal carotid artery aneurysm. A tiny aneurysm was detected, but it could not be concluded as the source of hemorrhage based on the distribution of hemorrhage. Case 3: A 58-year-old female with a basilar artery aneurysm. Initially, imaging did not reveal this aneurysm, and other aneurysms were treated. In all patients, these were evaluated as ruptured aneurysms during the course based on changes in CT and angiography findings, and coil embolization was performed. There has been no recurrence.Conclusion: Angiography based on CT findings of residual hematomas is useful for estimating the rupture of tiny aneurysms.