Fluid-based augmentation of magnetic resonance visualization of interventional devices

To evaluate the transient artifact augmentation of microtubes in magnetic resonance imaging by fluid injection.

Twenty-one fluorinated ethylene propylene catheters (inner diameter 760 μm) were filled with three different contrast media at various concentrations (Ferucarbotran, Resovist®, Bayer Schering Pharma; Manganese dichloride, MnCl2, Sigma-Aldrich; Gadobutrol, Gadovist®, Bayer Schering Pharma). Artifact appearance was determined in an ex vivo phantom at 1.5 T using three different sequences: T1-weighted three-dimensional volume interpolated breath-hold examination, T2-weighted turbo spin echo, and T1-weighted fast low angle shot. Catheter angulation to the main magnetic field (B0) was varied. Influence of parameters on artifact diameters was assessed with a multiple linear regression similar to an analysis of variance.

Artifact diameter was significantly influenced by the contrast agent (p < 0.001), concentration of the contrast agent (p < 0.001), angulation of the phantom to B0 with the largest artifact at 90° (p < 0.001), and encoding direction with a larger diameter in phase encoding direction (PED, p < 0.001). Mean artifact diameters at 90° angulation to B0 in PED were 18.5 ± 5.4 mm in 0.5 mmol/ml Ferucarbotran, 8.7 ± 2.5 mm in 1 mmol/ml Gadobutrol, and 11.6 ± 4.6 mm in 5 mmol/ml MnCl₂ .

Fluid-based contrast agents might be applied to interventional devices and thus temporarily augment the artifact ensuring both visibility and safe navigation.