TY - JOUR
T1 - Torque property of titanium alloy cerebral aneurysm clips in a magnetic resonance scanner
AU - Tang, Minghui
AU - Kawahira, Shingo
AU - Nomura, Naoyuki
AU - Yamamoto, Toru
N1 - Funding Information:
The authors thank Dr Daisaku Ikeda of Mizuho Corporation for providing the materials and the torque measurement apparatus. The authors are deeply appreciative of the reviewer’s constructive comments. This study was supported by Strategic Promotion of Innovative Research and Development (S-Innovation) from the Japan Agency for Medical Research and Development (AMRD).
Funding Information:
The authors thank Dr Daisaku Ikeda of Mizuho Corporation for providing the materials and the torque measurement apparatus. The authors are deeply appreciative of the reviewer?s constructive comments. This study was supported by Strategic Promotion of Innovative Research and Development (S-Innovation) from the Japan Agency for Medical Research and Development (AMRD).
Publisher Copyright:
© 2019, Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2020/1/1
Y1 - 2020/1/1
N2 - 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.].
AB - 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.].
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U2 - 10.1007/s10856-019-6329-4
DO - 10.1007/s10856-019-6329-4
M3 - Article
C2 - 31838592
AN - SCOPUS:85076478643
VL - 31
JO - Journal of Materials Science: Materials in Medicine
JF - Journal of Materials Science: Materials in Medicine
SN - 0957-4530
IS - 1
M1 - 6
ER -