Artifact quantification of venous stents in the MRI environment: Differences between braided and laser-cut designs.

• MRI in novel venous stents is not impaired by susceptibility-induced artifacts. • RF-induces artifacts are more complex in braided compared to laser-cut stents. • Braided stents can enhance the intraluminal signal due to B 1 amplification. To quantify B 0 - and B 1 -induced imaging artifacts of braided venous stents and to compare the artifacts to a set of laser-cut stents used in venous interventions. Three prototypes of braided venous stents with different geometries were tested in vitro. B 0 field distortion maps were measured via the frequency shift Δ f using multi-echo imaging. B 1 distortions were quantified using the double angle method. The relative amplitudes B 1 rel were calculated to compare the intraluminal alteration of B 1. Measurements were repeated with the stents in three different orientations: parallel, diagonal and orthogonal to B 0. At 1.5 T, the braided stents induced a maximum frequency shift of Δ f x < 100 H z. Signal voids were limited to a distance of 2 mm to the stent walls at an echo time of 3 ms. No substantial difference in the B 0 field distortions was seen between laser-cut and braided venous stents. B 1 rel maps showed strongly varying distortion patterns in the braided stents with the mean intraluminal B 1 rel ranging from 63 ± 18 % in prototype 1 to 98 ± 38 % in prototype 2. Compared to laser-cut stents the braided stents showed a 5 to 9 times higher coefficient of variation of the intraluminal B 1 rel . Braided venous stent prototypes allow for MR imaging of the intraluminal area without substantial signal voids due to B 0 -induced artifacts. Whereas B 1 is attenuated homogeneously in laser-cut stents, the B 1 distortion in braided stents is more inhomogeneous and shows areas with enhanced amplitude. This could potentially be used in braided stent designs for intraluminal signal amplification. [ABSTRACT FROM AUTHOR]