Rupture-associated changes of cerebral aneurysm geometry: high-resolution 3D imaging before and after rupture

Area of Science:

• Neurosurgery
• Radiology
• Medical Imaging

Background:

• Ruptured aneurysms rarely have prior imaging, limiting studies on geometric changes associated with rupture.
• Previous imaging allows for direct comparison of aneurysm geometry before and after rupture.

Purpose of the Study:

• To evaluate geometric differences between pre-rupture and post-rupture imaging of ruptured intracranial aneurysms.
• To identify potential risk factors for aneurysm rupture through geometric analysis.

Main Methods:

• Generated 3D geometric models from high-quality 3D image data before and after rupture.
• Compared models for changes in aneurysm volume and displacement.
• Qualitatively assessed aneurysm shape, hematoma presence, and mass effect.

Main Results:

• Aneurysm volume increased significantly post-rupture in 7 of 9 cases (median 38%, average 137%).
• New lobulations developed in 3 aneurysms.
• Displacement (up to 5 mm) and geometric changes occurred due to perianeurysmal hematoma.

Conclusions:

• Intracranial aneurysms undergo substantial geometric changes post-rupture, including volume increase, lobulation, and displacement.
• Caution is advised when interpreting geometric and hemodynamic comparisons of ruptured vs. unruptured aneurysms for rupture risk factors.