In vivo evaluation of intravascular stents at three-dimensional MR angiography

The aim of this study was to assess in vivo patency of seven commonly used non-ferromagnetic plain stents as regards demonstration of the contained lumen at 3D gadolinium-enhanced MRA in a 0.5-T MR environment. Twenty-one patients with 22 stents (1 aortic, 18 iliac, 3 popliteal) were imaged with MRA. Stent-related artefacts were evaluated. Images were assessed for the presence and size of stent artefacts, luminal patency, and were correlated with stent metal mass, composition, configuration and angulation with respect to the magnetic field. Four different types of stent (Symphony, Wallstent, Memotherm, SMART) showed major artefacts preventing assessment of intradevice luminal patency or restenosis, in two stents (ZAV stent, Intracoil) minor artefacts allowed assessment of high-degree stenosis, and only one type of stent (Strecker) was perfectly imaged. Based on our limited experience, Gd-MRA appears well suited for the evaluation of only a minority of MR-compatible stents.