title: Heating and safety of a new MR-compatible guidewire prototype versus a standard nitinol guidewire.
abstract: Our purpose in this study was to examine heating of nitinol and polyetheretherketone (PEEK) guidewires during near-real-time MR imaging in an artificial vascular model an "aorta phantom". The first 100 cm of the nitinol- and PEEK-based guidewires both 145 × 0.08 cm were immersed in a saline-filled aorta phantom. The probes of a fiber-optic thermometer were positioned at the tips of both wires. Balanced steady-state free precession (bSSFP) [TE 1.6 ms; TR 3.5 ms; flip angle (FA) 60°; field of view (FOV) 40 cm; matrix 256 × 256; specific absorption rate (SAR); 1.15 Watt (W)/kg] and spoiled gradient-echo (SPGR) (TE 1.8 ms; TR 60 ms; FA 60°; FOV 40 cm; matrix 256 × 256; SAR 1.15 W/kg) pulse sequences were acquired in a 1.5-T MR scanner with use of an 8-channel array coil. Temperatures were recorded while the phantom was placed centrally in the bore of a MR scanner and in an off-center position (x = 24 cm, y = -5 cm, z = -10/10 cm). The temperature of the nitinol guidewire increased by 0.3 °C (center) and 1.1 °C (off-center position) with use of the bSSFP and by 9.6 and 13 °C (off-center position) with use of the SPGR sequence. Only minor temperature changes up to a maximum of 0.4 °C were observed with the MR-compatible PEEK guidewire when any position or sequence was applied. The PEEK guidewire showed substantially lower heating as compared to the nitinol guidewire in near-real-time imaging sequences in a phantom.
authors.affiliation: Clinic of Diagnostic and Interventional Neuroradiology, Saarland Medical Center, Homburg, Germany, m.wolska-krawczyk@uks.eu.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Wolska-Krawczyk
authors.forename: Martin A
authors.initials: MA
authors.lastname: Rube
authors.forename: Erwin
authors.initials: E
authors.lastname: Immel
authors.forename: Andreas
authors.initials: A
authors.lastname: Melzer
authors.forename: Arno
authors.initials: A
authors.lastname: Buecker
mesh_terms: D000042:Absorption; D000497:Alloys / Q000737:chemistry*; D001011:Aorta / Q000473:pathology; D001577:Benzophenones; D004867:Equipment Design; D005290:Ferric Compounds / Q000737:chemistry; D006361:Heating; D006801:Humans; D007659:Ketones / Q000737:chemistry; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008953:Models, Anatomic; D055100:Optical Fibers; D019047:Phantoms, Imaging; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D015642:Radiology, Interventional; D015203:Reproducibility of Results; D013696:Temperature
chemical_list: D000497:Alloys; D001577:Benzophenones; D005290:Ferric Compounds; D007659:Ketones; D011108:Polymers; C000499:ferric oxide; C013616:nitinol; C063834:polyetheretherketone; D011092:Polyethylene Glycols