Cardiac Cycle-Related Volume Change in Unruptured Cerebral Aneurysms

Abstract

Background and Purpose-The hemodynamic factors of aneurysms were recently evaluated using computational fluid dynamics in a static vessel model in an effort to understand the mechanisms of initiation and rupture of aneurysms. However, few reports have evaluated the dynamic wall motion of aneurysms due to the cardiac cycle. The objective of this study was to quantify cardiac cycle-related volume changes in aneurysms using 4-dimensional CT angiography. Methods-Four-dimensional CT angiography was performed in 18 patients. Image data of 1 cardiac cycle were divided into 10 phases and the volume of the aneurysm was then quantified in each phase. These data were also compared with intracranial vessels of normal appearance. Results-The observed cardiac cycle-related volume changes were in good agreement with the sizes of the aneurysms and normal vessels. The cardiac cycle-related volume changes of the intracranial aneurysms and intracranial normal arteries were 5.40%Ϯ4.17% and 4.20Ϯ2.04%, respectively, but these did not differ statistically (Pϭ0.12). Conclusions-We successfully quantified the volume change in intracranial aneurysms and intracranial normal arteries in human subjects. The data may indicate that cardiac cycle-related volume changes do not differ between unruptured aneurysms and normal intracranial arteries, suggesting that the global integrity of an unruptured aneurysmal wall is not different from that of normal intracranial arteries. (Stroke. 2012;43:61-66.)

Feasibility of Quantification of Intracranial Aneurysm Pulsation with 4D CTA with Manual and Computer-Aided Post-Processing

“…The analysis of the pulsation of cerebral aneurysms is a technique, which has been studied mostly visually-qualitatively. There are only few reports on the quantification of the aneurysm pulsation and this technique might give important objective and comparable information[5–7]. Conclusions regarding the composition and stability of the aneurysm wall might be drawn from the pulsations.…”

“…The prediction of a future rupture might be improved and new insights given into the pathophysiologic processes involved in the aneurysm rupture [2]. The analysis is based on an ECG gated four-dimensional CT angiography (4DCTA) with high spatial resolution and a temporal resolution of 10 images in the cardiac cycle [5,7–12]. Volume changes of the cerebral vasculature and aneurysms within the cardiac cycle are very small.…”

Cerebral Aneurysm Pulsation: Do Iterative Reconstruction Methods Improve Measurement Accuracy In Vivo?

“…Previous studies found volume changes of cerebral aneurysms within the cardiac cycle of approximately 5%. 1 These pulsations did not differ significantly from those of normal cerebral arteries but showed a tendency toward larger values. Due to the small excursions of the aneurysm wall, pulsation analysis is technically challenging and improving its accuracy is demanding.…”

“…The technique is limited by the small pulsational excursions of cerebral aneurysms. If one considers a volume change of 5% within the cardiac cycle, the change in diameter of a spherical aneurysm of 5 mm diameter is on the order of 0.1 mm, 1,2 which is below the resolution of CTA. Exact segmentation of the aneurysm is, therefore, critical and of the utmost importance for the correct analysis of pulsations.…”

“…[1][2][3][4][5][6][7] Insight into aneurysm pathophysiology and improvement of risk prediction of incidental cerebral aneurysms can be expected. The technique is limited by the small pulsational excursions of cerebral aneurysms.…”