Image-based Hemodynamics and Wall Enhancement in a Superior Basilar Aneurysm: Growth to Rupture

Abstract

Background: High-resolution magnetic resonance imaging (HR-MRI) could be used to evaluate the inflammatory process of tissue remodeling via aneurysm wall enhancement (AWE), however, due to the lack of longitudinal evidence, its relationship to the flow pattern has not been fully understood. In this study, HR-MRI and computational hemodynamics were synchronously analyzed on a longitudinal case, from growth to rupture, to reveal the biomechanical and pathological development of intracranial aneurysm (IA).Methods: One patient with superior basilar aneurysm was strictly examined. The growing process and the rupture event of the IA was captured via longitudinal HR-MRI examinations. The signal intensity, thickness of enhancement region, and spatial growth of IA were quantified. In addition, computational fluidic analysis was applied on the patient-specific model at each time points. Precise voxel-based comparison was conducted among the morphological, hemodynamic and enhancement data. Results: There was a significant difference in the flow pattern between enhancement and non-enhancement areas. The time-averaged wall shear stress was negatively correlated with the radial growth of IA (r=-0.413). Enhancement areas were found consistent to the presentations of low flow velocity. Peak signal intensity occurred in the area where displacement index or its rate were in positive values.Conclusions: Based on this growth to rupture longitudinal study, the relationship between hemodynamic patterns to AWE features was confirmed. The rupture site of IA was likely to occur in the junction between the growing and the non-growing interface of the aneurysm wall.