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SAR Distributions in the Abdomen of a Pregnant Woman Generated in a Bird Cage Coil for the MRI System
https://repo.qst.go.jp/records/61880
https://repo.qst.go.jp/records/61880e86c29e1-15be-434f-9bda-ea7c9618d075
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2006-11-07 | |||||
| タイトル | ||||||
| タイトル | SAR Distributions in the Abdomen of a Pregnant Woman Generated in a Bird Cage Coil for the MRI System | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Saito, Kazuyuki
× Saito, Kazuyuki× Ito, Koichi× Ikehira, Hiroo× et.al× 齊藤 一幸× 伊藤 公一× 池平 博夫 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | MRI (magnetic resonance imaging) is an effective method for diagnosis of diseases. The MRI system is made of some important units including RF (radio frequency) devices. The RF coil is one of the important parts in the RF unit. During the imaging, the RF coil radiates EM (electromagnetic) pulse to the human body and in response receives the NMR (nuclear magnetic resonance) signals emitted from the body. Therefore, it is necessary to estimate the SAR (specific absorption rate) in the human body due to the radiated EM energy from RF coils. Especially, in this study, the SAR distributions in the abdomen of pregnant woman are investigated by the FDTD (Finite Difference Time Domain) calculations. Here, we assumed the imaging of a pregnant woman in early period and employed a realistic women model, developed at the National Institute of Information and Communications Technology (NICT), Japan. In addition, a bird cage coil is employed as one of the typical RF coils for MRI system. The operating frequency of the coil is around 64 MHz, which is used in the 1.5 T MRI system. Before the SAR calculations, the capacitors on the bird cage coil were adjusted so that the resonance frequency of the coil might be around 64 MHz. In the SAR calculations, the realistic women model is inserted into the bird cage coil. As a result of the calculations, relatively high SAR values are observed around the skin, muscle, etc which have a high electrical conductivity and are located close to the surface of the body. Meanwhile, the SAR in the uterus and the ovary is extremely low compared with the above mentioned regions. As a further study, the SAR distributions in a 7-month pregnant woman model, which is developed by NICT, Japan and our laboratory, will be investigated. In this investigation, it is considered that the SAR of the fetus, especially around the head is important. Moreover, it is necessary to calculate the SAR by the other RF coils used in conventional MRI systems. | |||||
| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | The first European Conference on Antennas and Propagation (EuCAP 2006) | |||||
| 発表年月日 | ||||||
| 日付 | 2006-11-10 | |||||
| 日付タイプ | Issued | |||||
