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Dynamical O-17 imaging in tumor bearing mice at 7T
https://repo.qst.go.jp/records/62126
https://repo.qst.go.jp/records/621267b4441e2-47e7-4a9f-8f93-53d9c7d21892
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2007-06-20 | |||||
| タイトル | ||||||
| タイトル | Dynamical O-17 imaging in tumor bearing mice at 7T | |||||
| 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 |
Narazaki, Michiko
× Narazaki, Michiko× Kanazawa, Yoko× Koike, Sachiko× Ando, Koichi× Ikehira, Hiroo× 楢崎 美智子× 金沢 洋子× 小池 幸子× 安藤 興一× 池平 博夫 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Introduction: Oxygen consumption rate and blood flow are important parameters for the physiological and pathological evaluation of brain, myocardium and tumors1,2, where 15O PET has been utilized. 17O MRI will be another tool for the direct observation of tumor oxygenation. Measurements of the blood flow and oxygen consumption rate by in vivo 17O NMR has been reported recently3,4. We have developed 17O imaging by FISP and succeeded in the visualization of natural abundance H217O distribution in the mouse with 10 min data acquisition5. In this study, we will report the dynamical study of 17O imaging using 17O enriched saline in the tumor bearing mice. Phantom experiments demonstrated the feature of 17O in vivo NMR signals. Methods: MRS/MRI was performed on 7T/400mm/SS system (NIRS/KOBELCO/Bruker) with 40 mm 1H/17O Litz coil (Doty Scientific Inc.). Water, ethanol or 25-100 % ethyleneglycol -water was used in phantom experiments. 17O images of healthy and tumor bearing C3H/He mice (20 . 25 g) were obtained under Ketamine:Xylazine anesthesia by true FISP with a TR/TE = 4.3/2.15 ms. A saline (0.5ml) containing 5% 17O prepared from 10% 17O water (Cambridge Isotope Laboratories, Inc) was i.v. injected to tumor bearing mice. After imaging experiment, organs were excised for 17O spectral measurements. Results: Phantom studies: The 17O signal of ethyleneglycol or water in 25% ethyleneglycol-water phantom was detected by fid acquisition mode but not by echo mode within our experimental condition. Animal studies: The S/N in the 17O images of a mouse obtained by FISP with 10 min data acquisition was dramatically improved from 3.8 to 13.4 after the injection of a saline containing 5% 17O. The result of 10 sec dynamical imaging of H217O with under the spatial resolution of 2.5 mm without slicing was shown in Fig.1. The process of initial accumulation of the injected H217O in the heart and re-distribution to whole body was demonstrated. Spatial resolution of 1.25 mm was attained with the 10 min data acquisition. Discussion: The dynamical study of H217O was achieved in the tumor bearing mice with a temporal resolution of 10 sec. The temporal and spatial resolutions attained in this study will lead this imaging method to the evaluation of blood flow or oxygen consumption rate using 17O gas and water. FISP is shown to be an effective method for imaging in vivo 17O signals from free water. The phantom experiments with ethyleneglycol-water strongly suggest that the in vivo 17O images obtained here is from the mobile H217O and not from other molecular species or immobilized water. The echo image of 17O detecting solely the signal from free water, not from the body constituents contributing as background should have an advantage over the other NMR method with FID detection in the 17O2 gas study. Reference: (1) Secomb TW. et al, 34 :313 (1995), (2) Ando K, et al, Int J Radiat Biol 75 :505 (1999), (3) Zhu XH. et al, MRM 45:543 (2001), (4) Fiat D. et al, Neurol Res 26:803 (2004), (5) Narazaki M. et al, 14th ISMRM 3113 (2006) |
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| 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 | Joint Annual Meeting ISMRM-ESMRMB 2007 | |||||
| 発表年月日 | ||||||
| 日付 | 2007-05-25 | |||||
| 日付タイプ | Issued | |||||
