Torque property of titanium alloy cerebral aneurysm clips in a magnetic resonance scanner

Minghui Tang, Shingo Kawahira, Naoyuki Nomura, Toru Yamamoto

研究成果: Article査読

1 被引用数 (Scopus)


Titanium (Ti) alloys have been introduced in magnetic resonance (MR) safe implantable medical devices because the susceptibility of Ti is approximately 1/10 that of the Co-Cr-Ni alloy (Elgiloy), which was the previously preferred MR-safe material. The torque applied to metallic materials in an MR imaging (MRI) scanner is commonly believed to increase with the susceptibility of the material. However, a visual inspection showed that the torque applied to Ti alloy cerebral aneurysm clips is comparable with that in the case of those of Elgiloy. In this study, we measured the torque applied to the small test pieces of rods and aneurysm clips quantitatively in a 3-T MRI using an accurate self-developed torque measurement apparatus. The maximum torques of Ti alloy and Elgiloy rod test pieces were comparable as 1.1 and 1.2 µN·m, respectively. The values for Ti alloy aneurysm clips were distinctly higher than the values for those of Elgiloy. These contradictory results of a larger torque for smaller-susceptibility products could be explained by our new theory, which takes into account the crystal susceptibility anisotropy in addition to the conventional torque due to the shape anisotropy. [Figure not available: see fulltext.].

ジャーナルJournal of Materials Science: Materials in Medicine
出版ステータスPublished - 2020 1 1

ASJC Scopus subject areas

  • 生物理学
  • バイオエンジニアリング
  • 生体材料
  • 生体医工学


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