Interventional MR: vascular applications

Abstract

Three strategies for visualisation of MR-dedicated guidewires and catheters have been proposed, namely active tracking, the technique of locally induced field inhomogeneity and passive susceptibility-based tracking. In this article the pros and cons of these techniques are discussed, including the development of MR-dedicated guidewires and catheters, scan techniques, post-processing tools, and display facilities for MR tracking. Finally, some of the results obtained with MR tracking are discussed.

MRA of hemodialysis access grafts and fistulae using selective contrast injection and flow interruption

“…Techniques for MR-guided endovascular interventions still have to be developed further to provide a clinically attractive alternative (19). In addition, a complete angiographic evaluation of the graft or fistula on DSA includes visualization of the run-off vessels to the superior vena cava (8).…”

Improved Delineation of Ventricular Shunt Catheters Using Fast Steady-State Gradient Recalled-Echo Sequences in a Rapid Brain MR Imaging Protocol in Nonsedated Pediatric Patients

“…15 The increased conspicuity of the intracranial shunts and catheters is likely due to a combination of the susceptibility effects of the intrinsic catheter components and by intravoxel phase dispersion caused by the local magnetic field gradients of the internal tubing structure. [17][18][19] Most intracranial shunts and catheters are composed of a hardened silicone elastomer and are impregnated with barium. Briefly, the silicones are synthetic polymers composed of a repeating silicone-oxygen (siloxane) backbone with organic groups attached through silicone-carbon bonds.…”

MR-guided endovascular interventions: a comprehensive review on techniques and applications

“…However, a major and crucial advantage is that, unlike the active tracking techniques in use, passive tracking techniques are much more simple to use and more robust, thereby fulfilling key features for interventional procedures [6].…”

“…These strategies can be subdivided into a "passive" and an "active" visualization approach, each having its specific advantages and limitations (Fig. 5) [6,38].…”

“…Concerning the "passive" approach susceptibility markers (negative markers) for guidewires or signal enhancing markers (positive markers) for guidewires and catheters are linked to the device, thereby gaining detectability as a key feature without using further hardware [6,7].…”