Temporal stability of dysmorphic fusiform aneurysms of the intracranial internal carotid artery.

PURPOSE

Estimation of the stability of dysmorphic fusiform aneurysms of the intracranial internal carotid artery requires precise monitoring of their volumes. This report describes a method of magnetic resonance (MR) imaging and three-dimensional postprocessing to study the evolution of these aneurysms in a prospective cohort of patients not immediately suitable for surgery or endovascular treatment.

MATERIALS AND METHODS

Ten patients with fusiform aneurysms of the intracranial internal carotid artery underwent serial MR studies. Five patients were studied at two time points and the remainder at multiple time points (mean delay between studies, 12.6 mo ± 3.8). For each patient, studies from all time points were coregistered. The volumes of each vessel component were calculated.

RESULTS

Mean aneurysm volume was 833 mm(3) ± 878. Mean annual rate of volume progression was 1.37% ± 2.09. All aneurysms were thrombus-free.

CONCLUSIONS

This study indicates that, given the relatively low rate of progression of dysplastic fusiform aneurysms and the complexity of their shape, three-dimensional quantitative volumetric methods can be helpful in monitoring whether any growth has occurred.