Patients with an Abdominal Aortic Aneurysm have a high risk of dying due to the rupture of a dilated aorta. Endovascular aneurysm repair is a technique to threat AAA, by which a stent graft prosthesis is implanted in the aorta of the patient. Due to its minimal invasive character, this intervention has smaller risks for the patient compared to the conventional approach. Unfortunately, due to effects such as metal fatigue, leakage and stent migration, this technique is less successful on the long term. These problems are caused by the forces applied by the pressure waves of the blood flow. It is therefore important to understand the motion behavior of the stent graft inside the human body. The technique of ECG-gated CT can be used to obtain multiple 3D images of the patient. Each of these images corresponds to a different phase of the heart cycle. Given these images, the goal is to measure the motions of the stent graft. This is done in two steps. The first is segmentation: detecting where the stent is located and subsequently creating a geometric model of the stent. This geometric model is represented as a graph consisting of nodes that are connected by edges. The nodes represent the corners and crossings in the stent’s frame, and the edges represent the wires in between. The second step is registration, by which the deformation between the different images is calculated. The motion of the stent is determined from the deformation fields and incorporated in the geometric stent model. The obtained dynamic model can be used for visualization of the motion of the stent, as well as for performing further calculations such as estimating the forces in the stent.
|Award date||22 Nov 2011|
|Place of Publication||Enschede|
|Publication status||Published - 22 Nov 2011|
- Image Processing
- stent grafts
- computed tomography