Document Type

Article

Language

eng

Format of Original

14 p.

Publication Date

8-2005

Publisher

Elsevier Inc.

Source Publication

Computer Methods and Programs in Biomedicine

Source ISSN

0169-2607

Original Item ID

DOI: 10.1016/j.cmpb.2005.03.005

Abstract

Restenosis caused by neointimal hyperplasia (NH) remains an important clinical problem after stent implantation. Restenosis varies with stent geometry, and idealized computational fluid dynamics (CFD) models have indicated that geometric properties of the implanted stent may differentially influence NH. However, 3D studies capturing the in vivo flow domain within stented vessels have not been conducted at a resolution sufficient to detect subtle alterations in vascular geometry caused by the stent and the subsequent temporal development of NH. We present the details and limitations of a series of post-processing operations used in conjunction with microfocal X-ray CT imaging and reconstruction to generate geometrically accurate flow domains within the localized region of a stent several weeks after implantation. Microfocal X-ray CT reconstruction volumes were subjected to an automated program to perform arterial thresholding, spatial orientation, and surface smoothing of stented and unstented rabbit iliac arteries several weeks after antegrade implantation. A transfer function was obtained for the current post-processing methodology containing reconstructed 16 mm stents implanted into rabbit iliac arteries for up to 21 days after implantation and resolved at circumferential and axial resolutions of 32 and 50 μm, respectively. The results indicate that the techniques presented are sufficient to resolve distributions of WSS with 80% accuracy in segments containing 16 surface perturbations over a 16 mm stented region. These methods will be used to test the hypothesis that reductions in normalized wall shear stress (WSS) and increases in the spatial disparity of WSS immediately after stent implantation may spatially correlate with the temporal development of NH within the stented region.

Comments

Accepted version. Computer Methods and Programs in Biomedicine, Vol. 79, No. 2 (August 2005): 121-134. DOI. © 2005 Elsevier Ireland Ltd. Used with permission.

John F. LaDisa, Jr. was also affiliated with the Departments of Anesthesiology, Medical College of Wisconsin and the Clement J. Zablocki Veterans Affairs Medical Center at time of publication.

Robert C. Molthen was also affiliated with the Department of Pulmonary and Critical Care Medicine, Medical College of Wisconsin and the Clement J. Zablocki Veterans Affairs Medical Center at time of publication.

David C. Warltier was also affiliated with the Departments of Anesthesiology, Medical College of Wisconsin, Department of Pulmonary and Critical Care Medicine, Medical College of Wisconsin Department of Medicine, Division of Cardiovascular Diseases, Medical College of Wisconsin and the Clement J. Zablocki Veterans Affairs Medical Center at time of publication.

Paul S. Pagel was also affiliated with the Departments of Anesthesiology, Medical College of Wisconsin and the Clement J. Zablocki Veterans Affairs Medical Center at time of publication.

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