The use of routine imaging data in diagnosis of cerebral pseudoaneurysm prior to angiography.

Purpose: A false aneurysm is rare and underdiagnosed complication of intracranial hemorrhage. Objective of the study was to point out diagnostic imaging signs of false aneurysm and to determine frequency and diagnostic significance of these signs.

Materials And Methods: Cerebral arteriography performed in our center from November 2007 to September 2010 revealed the false aneurysm in 8 patients (4 male, 4 female, mean age was 38 years). During the same angiographic procedure 6 patients were treated by endovascular embolization using coils, mixture of Histoacryl and Lipiodol or Onyx (liquid embolic material). Authors retrospectively analyzed preprocedural studies (computed tomography, magnetic resonance imaging) and angiographic findings to identify signs specific to false aneurysm.

Results: Computed tomographic findings that are not specific but should raise suspicion of the false aneurysm include: enlargement of parenchymal hematoma dimensions, unusual or delayed evolution of hematoma and spot sign associated with acute hematoma expansion. More specific signs can be revealed in digital subtraction angiography that shows a globular shaped neckless aneurysmal sac, delayed filling and emptying of contrast agent and stagnation of contrast with regard to the head position.

Conclusion: Although preangiographic imaging studies findings in patients with false aneurysms are not specific, they should lead to angiographic validation, especially enlarging parenchymal hematoma and atypical hematoma evolution. Digital subtraction angiography makes it possible to diagnose the lesion and to use endovascular embolization techniques, which are currently the method of choice for treatment of pseudoaneurysms.