Interactive 3D segmentation by tubular envelope model for the aorta treatment

Abstract

We propose a novel interactive 3D segmentation approach and geometric model definition called tubular envelope model. It is conceived to express the shape of tubular objects. The main challenges we have achieved are the speed and interactivity of the construction. A computer program designed for this task gives the user full control of the shape and precision, with no significant computational errors. Six CT (computed tomography) aortic dissection images have been used for the tubular envelopes construction. Hence, we have proposed a generic parametric model of the aorta for its interactive construction. It leads us to rapid visualization and navigation inside the artery (rough virtual angioscopy). The low complexity of the model and the ease of interactive design makes the tubular envelope suitable for aorta segmentation in comparison to the other segmentation methods. The model accuracy is adjustable by the user according to his requirements; the time of construction is approved by clinicians. More generally, the tubular envelope could be used in other applications, e.g. to define a region of interest for more precise segmentation or feature extraction inside, to develop a parametric model with deformation capabilities.

Interventional planning and assistance for ascending aorta dissections

“…Then, we construct aparametric model I 3 of the aorta. That model is a 3D mesh interactively built [6]by delineating the outer aortic wall into I 2 .…”

“…Otherwise, starting with a roughly computed initializationT 0 , we perform a sampling overthe selected orientations range,choosing the best parameters from a similarity measure (Dice coefficient) issued from the projections for each sample. The optimal 3D orientationT~is chosen for the sample with maximum similarity measure.The resultingcoarse transformation parameters are given after carrying out the final 3D/2D ITD algorithm for the best volume orientation (see [6] for further details).…”