Preclinical Evaluation of a Novel Fiber Compound MR Guidewire In Vivo

Krämer, Nils; Krüger, Sascha; Schmitz, Sebastian; Linssen, Marita; Schade, Heinz; Weiß, Steffen; Spüntrup, Elmar; Günther, Rolf W.; Bücker, Arno; Krombach, Gabriele A.

doi:10.1097/rli.0b013e3181a66ab5

Cited by 24 publications

(11 citation statements)

References 21 publications

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“…At the same time, artifacts were small enough to allow depiction of smaller-sized vessels (eg, subsegmental renal arteries). The distal end of the MR imaging guidewire is embedded with tungsten particles for x-ray visibility as a back-up function when MR imaging guidance does not allow completion of an interventional procedure (eg, in emergency cases) (15). However, evaluation of the MR imaging guidewires for x-ray-based conventional angiography was not a target of this study.…”

Section: Mr Imaging Guidewire Visualizationmentioning

confidence: 99%

Glass-Fiber–based MR-safe Guidewire for MR Imaging–guided Endovascular Interventions: In Vitro and Preclinical in Vivo Feasibility Study

2017

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Purpose To evaluate glass-fiber-based guidewires that are safe for magnetic resonance (MR) imaging-guided endovascular interventions by using a phantom and an in vivo swine model. Materials and Methods MR imaging-safe guidewires were made from micropultruded glass and/or aramid fibers and epoxy resin with diameters of 0.89 mm (0.035 inch) for standard and stiff guidewires and 0.36 mm (0.014 inch) for micro guidewires. MR imaging visibility and mechanical properties were assessed in a pulsatile flow model. After approval was obtained from the institutional animal care and use committee, MR imaging guidewires were evaluated for standard endovascular procedures in nine pigs. Real-time steady-state free-precession sequences were used for MR imaging-guided catheterization, balloon dilation, and stent implantation into aorto-iliac/visceral arteries and the vena cava (temporal resolution, five images per second; and spatial resolution, 150-mm field of view, and 128 × 128 matrix) with a 1.5-T clinical imager. Visualization with the guidewires was rated on a four-point scale, handling was rated on a three-point scale, and catheterization times for different vessel regions were determined by two interventional radiologists. Afterward, handling ratings and catheterization times were obtained for standard nitinol guidewires during x-ray-based fluoroscopy. Cannulation times, signal intensity in each vessel region, and visualization and handling ratings were measured for the MR imaging guidewires. Bland-Altman analysis was performed for inter- and intraobserver variability of cannulation time. Spearman rank correlation was used to compare handling of MR imaging guidewires and standard nitinol guidewires. Results MR imaging guidewires were characterized by good to excellent visibility, with a continuous artifact of 2 mm in diameter and 4 × 8-mm ball-shaped tip marker. Stiffness, flexibility, and guidance reflected comparable times for all in vitro and in vivo procedures with both the MR imaging and standard nitinol guidewires. Standard and micro MR imaging guidewires were most suitable for the iliac crossover maneuver. Phantom visceral artery cannulation was easier with standard and micro MR imaging guidewires. The stiff MR imaging guidewire provided the best support for cannulation of the swine aorta and vena cava. All interventional procedures were performed successfully without complications. Conclusion Preliminary results showed that the use of glass-fiber-based guidewires for evaluation of MR imaging-guided endovascular interventions is technically feasible and safe in a swine model, and potentially, in humans. RSNA, 2017 Online supplemental material is available for this article.

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Section: Mr Imaging Guidewire Visualizationmentioning

confidence: 99%

Glass-Fiber–based MR-safe Guidewire for MR Imaging–guided Endovascular Interventions: In Vitro and Preclinical in Vivo Feasibility Study

2017

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“…Unlike X-ray images, MRI has an excellent soft-tissue contrast [12][13][14][15][16][17]. MRI Table 1 Design requirements for the multi-selective catheter and evaluation of the assembled prototype.…”

Section: Introductionmentioning

confidence: 99%

Multi-selective catheter for MR-guided endovascular interventions

Clogenson

Lith

Dankelman

et al. 2015

Medical Engineering & Physics

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“…Numerous investigators have proposed CMR-safe guidewire designs [ 4 , 5 , 7 , 8 ], some of which have even been tested in patients [ 9 , 10 ]. Active designs are conspicuous because they incorporate antenna receiver elements, and they attempt to reduce heating by incorporating RF chokes or transformers along the shaft.…”

Section: Introductionmentioning

confidence: 99%

Segmented nitinol guidewires with stiffness-matched connectors for cardiovascular magnetic resonance catheterization: preserved mechanical performance and freedom from heating

Basar

Rogers

Ratnayaka

et al. 2015

Journal of Cardiovascular Magnetic Resonance

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BackgroundConventional guidewires are not suitable for use during cardiovascular magnetic resonance (CMR) catheterization. They employ metallic shafts for mechanical performance, but which are conductors subject to radiofrequency (RF) induced heating. To date, non-metallic CMR guidewire designs have provided inadequate mechanical support, trackability, and torquability. We propose a metallic guidewire for CMR that is by design intrinsically safe and that retains mechanical performance of commercial guidewires.MethodsThe NHLBI passive guidewire is a 0.035” CMR-safe, segmented-core nitinol device constructed using short nitinol rod segments. The electrical length of each segment is less than one-quarter wavelength at 1.5 Tesla, which eliminates standing wave formation, and which therefore eliminates RF heating along the shaft. Each of the electrically insulated segments is connected with nitinol tubes for stiffness matching to assure uniform flexion. Iron oxide markers on the distal shaft impart conspicuity.Mechanical integrity was tested according to International Organization for Standardization (ISO) standards. CMR RF heating safety was tested in vitro in a phantom according to American Society for Testing and Materials (ASTM) F-2182 standard, and in vivo in seven swine. Results were compared with a high-performance commercial nitinol guidewire.ResultsThe NHLBI passive guidewire exhibited similar mechanical behavior to the commercial comparator. RF heating was reduced from 13 °C in the commercial guidewire to 1.2 °C in the NHLBI passive guidewire in vitro, using a flip angle of 75°. The maximum temperature increase was 1.1 ± 0.3 °C in vivo, using a flip angle of 45°. The guidewire was conspicuous during left heart catheterization in swine.ConclusionsWe describe a simple and intrinsically safe design of a metallic guidewire for CMR cardiovascular catheterization. The guidewire exhibits negligible heating at high flip angles in conformance with regulatory guidelines, yet mechanically resembles a high-performance commercial guidewire. Iron oxide markers along the length of the guidewire impart passive visibility during real-time CMR. Clinical translation is imminent.

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Preclinical Evaluation of a Novel Fiber Compound MR Guidewire In Vivo

Abstract: With the aid of the GW, different fully real-time MR-guided endovascular interventions become feasible.

Cited by 24 publications

References 21 publications

Glass-Fiber–based MR-safe Guidewire for MR Imaging–guided Endovascular Interventions: In Vitro and Preclinical in Vivo Feasibility Study

Glass-Fiber–based MR-safe Guidewire for MR Imaging–guided Endovascular Interventions: In Vitro and Preclinical in Vivo Feasibility Study

Multi-selective catheter for MR-guided endovascular interventions

Segmented nitinol guidewires with stiffness-matched connectors for cardiovascular magnetic resonance catheterization: preserved mechanical performance and freedom from heating

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