Evaluation of RF heating on nonmagnetic leads during MR procedures and comparisons with electoromagnetic simulation

2016 Fiscal Year Final Research Report

• Project/Area Number: 26460731
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Medical Physics and Radiological Technology
• Research Institution: Tsukuba International University
• Principal Investigator: Muranaka Hiroyuki つくば国際大学, 医療保健学部, 教授(移行) (20608468)
• Research Collaborator: YABE Hitoshi 埼玉県立リハビリテーションセンター
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: MRI Safety / RF heating / Non-magnetic Leads / Simulation

Outline of Final Research Achievements

This study is the evaluation of RF heating by the arrangement of two kinds of nonmagnetic lead wires during MRI examination. Imaging conditions were changed based on the actual placement of DBS leads and RF heating was measured with a fluorescent optical fiber thermometer using the ASTM phantom (F2182-02a). Although the risk of RF heating is small under the specified conditions, it was confirmed that the risk of RF heating is large under excessive RF irradiation. We compared SAR which is the RF heating index with B1 + rms. SAR increase is proportional to the RF heating at the lead tip, B1 + rms is proportional to the square. In the electromagnetic field analysis results, when the lead is placed on the right side of the phantom, the RF irradiation is the counterclockwise (CCW) is larger than when the RF irradiation is clockwise (CW). The special attention is required for B1 + rms which is RF heating index of the implant when there is excessive RF irradiation compared to SAR.

Free Research Field

医歯薬学