Rapid 3D Segmentation of the Carotid Bifurcation from Serial MR Images

The current trend in computational hemodynamics is to employ realistic models derived from ex vivo or in vivo imaging. Such studies typically produce a series of images from which the lumen boundaries must first be individually extracted (i.e. 2D segmentation), and then seriallyreconstructed to produce the three-dimensional lumen surface geometry. In this paper, we present a rapid 3D segmentation technique that combines these two steps, based on the idea of an expanding virtual balloon. This 3D technique is demonstrated in application to finite element meshing and CFD modeling of flow in the carotid bifurcation of a normal volunteer imaged with black blood MRI. Wall shear stress patterns computed using a mesh generated with the 3D technique agree well with those computed using a mesh generated from conventional 2D segmentation and serial-reconstruction. In addition to reducing the time required to extract the lumen surface from hours to minutes, our approach is easy to learn and use and requires minimal user intervention, which can potentially increase the accuracy and precision of quantitative and longitudinal studies of hemodynamics and vascular disease.