Robin Bruhn, Presenter: Nothing to Disclose

Miriam Ariens, Abstract Co-Author: Nothing to Disclose

Christian Wasiak, Abstract Co-Author: Employee, Fraunhofer-Gesellschaft

Paul Borm, Abstract Co-Author: Employee, Nano4Imaging GmbH

Matthias Von Walter, Abstract Co-Author: Empolyee, Hemoteq AG

Christiane Katharina Kuhl MD, Abstract Co-Author: Advisory Board Member, Bayer AG

Nils Andreas Kraemer, Abstract Co-Author: Nothing to Disclose

In spite of many challenges, MRI guided vascular interventions may offer advantages because they may allow the depiction of not only the target vessel, but also the surrounding anatomy of the target organ. For all types of vascular procedures, a guidewire is needed to navigate the catheter to the target vessel. In trans-arterial tumor therapies, small vessels need to be selectively engaged with microcatheters. Purpose of this research was to evaluate a new 0.018” MR-compatible guidewire (GW) in an in-vitro phantom.

We developed a MR-compatible GW consisting of a non-ferromagnetic fibre glass core and two surrounding layers of agamid fibre. Using the micropullwinding technique, stiffness and flexibility of the GW can be varied individually along the shaft. Iron oxide nanoparticles in 3 different concentrations (M1, M2, M3) applied along the tip at distances of 1 cm are used for visualization in MRI. A hydrophilic coating assures gliding of the GW (sliding friction coefficient <0.25).  Two different gradient echo sequences with a temporal resolution of 0.30 sec and 0.78 sec, respectively, were used to visualize navigation of this GW in an in-vitro vessel phantom with and without flow simulation. Visibility of the GW was assessed by measuring marker susceptibility artefacts (a total of n=56) on the MR images. To evaluate clinical GW steerability, different phantom vessels were engaged under MR guidance.

On both real-time sequences the markers attached to the GW tip allowed precise visualization. The mean diameters of the marker susceptibility artefacts in pulse sequences acquired horizontal (X) and along B0 (Y) were 5.5/8.4mm (X/Y) (standard deviation (SD) 1.1/1.2mm) for M1; 7.5/9.3mm (SD 0.8/0.8mm) for M2 and 9.4/12.1mm (SD 1.0/1.2mm) for M3. Under MRI guidance, all target vessels of the phantom could be engaged successfully in adequate time.

The new micropullwinding technique offers the opportunity to build a thin (0.018”) MR-compatible GW that appears to be useful for superselective vascular MR-guided interventions. Animal experiments are in preparation.

With the new production technique an adjustable 0.018” GW for superselective endovascular MR-guided interventions may become feasible.

Bruhn, R, Ariens, M, Wasiak, C, Borm, P, Von Walter, M, Kuhl, C, Kraemer, N, Development and Evaluation of a MR-compatible Guidewire with a Diameter of 0.018”: Preliminary Results.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13044463.html