MR evaluation of stent patency - In vitro tests of 22 metallic stents and the possibility of determining their patency by MR angiography

Citation
Jma. Meyer et al., MR evaluation of stent patency - In vitro tests of 22 metallic stents and the possibility of determining their patency by MR angiography, INV RADIOL, 35(12), 2000, pp. 739-746
Citations number
23
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Medical Research Diagnosis & Treatment
Journal title
INVESTIGATIVE RADIOLOGY
ISSN journal
00209996 → ACNP
Volume
35
Issue
12
Year of publication
2000
Pages
739 - 746
Database
ISI
SICI code
0020-9996(200012)35:12<739:MEOSP->2.0.ZU;2-2
Abstract
RATIONALE AND OBJECTIVES. To determine the extent to which visualization of intrastent anatomy in stents of different composition and design is possib le by using contrast-enhanced MR angiography. METHODS. Twenty-two MR-compatible stents, most of which had a diameter of 8 mm, were positioned in a phantom filled with aqueous gadolinium solution. Coronal and axial spoiled three-dimensional gradient-echo sequences were pe rformed. Images were acquired with stents positioned at varying angulations to the main magnetic field B-0. Profiles orthogonal to the stent axis allo wed measurement of artifact sizes independent of window width and center. RESULTS. Oriented along B-0, the Cragg, Corvita, Passager, Wallstent, Strec ker, Impag, Perflex, and ZA stents allowed visualization of more than 48% o f the lumen. The Memotherm, Smart, and Jostent SelfX stents showed a promin ent reduction of the inner lumen to below 41%. The lumina of the covered Jo stent, Palmaz, Sinus, and Symphony stents were completely obscured. The Imp ag, Perflex, and Strecker tantalum stents shelved growing artifact sizes an d a lumen reduction of at least 40% with increasing angulation to B-0. CONCLUSIONS. Evaluation of the inner stent lumen by applying contrast-enhan ced, three-dimensional gradient-echo sequences is not possible for the majo rity of stents because of their large artifacts. These depend on the stent type and orientation to B-0. Even stents made of nitinol and cobalt alloys only allow qualitative patency assessment but no quantification of stenosis .