3-D image analysis of abdominal aortic aneurysm.
Stud Health Technol Inform, (2000)Abstract
In this paper we propose a technique for 3-D segmentation of abdominal
aortic aneurysm (AAA) from computed tomography (CT) angiography images.
Output data form the proposed method can be used for measurement
of aortic shape and dimensions. Knowledge of aortic shape and size
is very important for selection of appropriate stent graft device
for treatment of AAA. The technique is based on a 3-D deformable
model and utilizes the level-set algorithm for implementation of
the method. The method performs 3-D segmentation of CT images and
extracts a 3-D model of aortic wall. Once the 3-D model of aortic
wall is available it is easy to perform all required measurements
for appropriate stent graft selection. The method proposed in this
paper uses the level-set algorithm instead of the classical active
contour algorithm developed by Kass et al. The main advantage of
the level set algorithm is that it enables easy segmentation surpassing
most of the drawbacks of the classical approach. In the level-set
approach for shape modeling, a 3-D surface is represented by a real
3-D function or equivalent 4-D surface. The 4-D surface is then evolved
through an iterative process of solving the differential equation
of surface motion. Surface motion is defined by velocity at each
point. The velocity is a sum of constant velocity and curvature-dependent
velocity. The stopping criterion is calculated based on image gradient.
The algorithm has been implemented in MATLAB and C languages. Experiments
have been performed using real patient CT angiography images and
have shown good results.