Detection and visualization of endoleaks in CT data for monitoring of thoracic and abdominal aortic aneurysm stents

In this paper we present an efficient algorithm for the segmentation of the inner and outer boundary of thoratic and abdominal aortic aneurysms (TAA & AAA) in computed tomography angiography (CTA) acquisitions. The aneurysm segmentation includes two steps: first, the inner boundary is segmented based on a grey level model with two thresholds; then, an adapted active contour model approach is applied to the more complicated outer boundary segmentation, with its initialization based on the available inner boundary segmentation. An opacity image, which aims at enhancing important features while reducing spurious structures, is calculated from the CTA images and employed to guide the deformation of the model. In addition, the active contour model is extended by a constraint force that prevents intersections of the inner and outer boundary and keeps the outer boundary at a distance, given by the thrombus thickness, to the inner boundary. Based upon the segmentation results, we can measure the aneurysm size at each centerline point on the centerline orthogonal multiplanar reformatting (MPR) plane. Furthermore, a 3D TAA or AAA model is reconstructed from the set of segmented contours, and the presence of endoleaks is detected and highlighted. The implemented method has been evaluated on nine clinical CTA data sets with variations in anatomy and location of the pathology and has shown promising results.

[1]  Marcel Breeuwer,et al.  Myocardial boundary extraction using coupled active contours , 2003, Computers in Cardiology, 2003.

[2]  Bernd Freisleben,et al.  A Fast Vessel Centerline Extraction Algorithm for Catheter Simulation , 2007, Twentieth IEEE International Symposium on Computer-Based Medical Systems (CBMS'07).

[3]  T. Boskamp,et al.  New vessel analysis tool for morphometric quantification and visualization of vessels in CT and MR imaging data sets. , 2004, Radiographics : a review publication of the Radiological Society of North America, Inc.

[4]  Bernd Freisleben,et al.  Simulation of bifurcated stent grafts to treat abdominal aortic aneurysms (AAA) , 2007, SPIE Medical Imaging.

[5]  Marc Levoy,et al.  Display of surfaces from volume data , 1988, IEEE Computer Graphics and Applications.

[6]  Bernd Freisleben,et al.  PREOPERATIVE MEASUREMENT OF ANEURYSMS AND STENOSIS AND STENTSIMULATION FOR ENDOVASCULAR TREATMENT , 2007, 2007 4th IEEE International Symposium on Biomedical Imaging: From Nano to Macro.

[7]  Erik Buskens,et al.  Two-year outcomes after conventional or endovascular repair of abdominal aortic aneurysms. , 2005, The New England journal of medicine.

[8]  Marleen de Bruijne,et al.  Adapting Active Shape Models for 3D Segmentation of Tubular Structures in Medical Images , 2003, IPMI.

[9]  M. Schocke,et al.  Serial CT Volume Measurements after Endovascular Aortic Aneurysm Repair , 2001, Journal of endovascular therapy : an official journal of the International Society of Endovascular Specialists.