Estimating the Volume of Cerebral Aneurysms: Method Error versus Volume Variation over Time

摘要

To the Editor:The theoretical volumetric filling of a cerebral aneurysm after endovascular coiling ("packing density") has been considered an indicator of long-term aneurysm occlusion. The volumetric filling is the volume of all coils implanted expressed as a percentage of the aneurysm volume. While the volumes of the coils are easily and precisely calculated using the cylindrical volume equation (assigning outer coil diameters and lengths according to product specification), the method error in estimating aneurysm volume has been a matter of concern. The recent article by Hanley et Al.1 brings another contribution to this question. In this study, the volumes of silicone models of cerebral aneurysms were accurately measured, and compared to volume estimates obtained by DSA, CTA and MRA as interpreted by four independent observers.