北京生物醫(yī)學工程

一種基于光抽運效應的磁共振信號檢測方法

A Novel MR Signal Detection Method Based on Optical Pumping

作者：王慧賢趙武貽楊文暉胡麗麗王錚

單位：中國科學院電工研究所(北京100190)

分類號：

出版年·卷·期（頁碼）：2010·29·4（349-352）

摘要：

與常規(guī)磁共振成像相比，超低場磁共振成像技術所需的成像磁體可降至mT級甚至μT級，不僅大大降低了設備的成本和體積，還能夠獲得普通高場磁共振成像設備無法得到的特殊圖像，具有非常廣闊的應用前景。本文介紹了一種基于光抽運現(xiàn)象的磁共振信號檢測方法，該方法根據(jù)外加磁場會影響堿金屬原子對特定波長光吸收的原理，通過檢測透射光強的變化檢測磁共振信號。文章最后利用線圈產(chǎn)生模擬磁共振信號，給出了一維及二維磁共振成像的實驗結(jié)果，結(jié)果表明該方法對于磁共振信號有良好的頻率分辨率及相位控制的穩(wěn)定性。由于該方法具有高靈敏度、低成本以及在信號檢測時需要很弱背景場等特點，因此特別適用于超低場磁共振信號的檢測。

Compared with conventional magnetic resonance imaging (MRI) system，the main magnetic field of ultralow field MRI system could be reduced to mT level or even μT level，which not only reduces the cost and size of the equipment, but also makes it possible to obtain special images which would be impossibly obtained by ordinary high field MRI equipments. The paper proposes a new magnetic resonance signals detection method based on optical pumping, which uses the principles that an external magnetic field affects the alkali metal atoms on the absorption of specific wavelengths of light, and magnetic resonance signals can be measured by detecting the transmitted light intensity. Finally, the paper presents the experiment results of simulated one dimensional and two dimensional MRI signals generated via a coil. The results show that the method has a good frequency resolution and stability of phase control for magnetic resonance signals detection. Since the method has high sensitivity, low cost and the need for very weak background field in signal detection, it is especially suitable for ultralow field magnetic resonance signal detection.

參考文獻：

［1］Zotev VS,Matlashov AN,Volegov PL, et al.SQUIDbased instrumentation for ultralowfield MRI. Superconductor Science and Technology, 2007, 20(11): 367-373.
［2］Daniel Raftery.MRI without the magnet. Proceedings of the National Sciences, 2006,103(34):12657-12658.
［3］CohenTannoudji C, DuPontRoc J, Haroche S,et al.Detection of the Static Magnetic Field Produced by the Oriented Nuclei of Optically Pumped 3He Gas.Physical Review Letters, 1969, 22(15):758-760.
［4］張昌達.量子磁力儀研究和開發(fā)近況.物探與化探，2005, 29(4):283-287.
［5］張昌達，董浩斌.量子磁力儀評說.工程地球物理學報， 2004, 1(6):499-507.
［6］Xu SJ,Yashchuk VV,Donaldson MH,et al.Magnetic resonance imaging with an optical atomic magnetometer.Proceedings of the National Academy of Sciences,2006, 103(34): 12668-12671.
［7］吳思誠，王祖銓.近代物理實驗.第2版.北京：北京大學出版社，1995.
［8］Ito T,Kondo K,Hashi T,Rb Optical Pumping in a Very Weak Magnetic Field.Japanese Journal of Applied Physics, 1968,7: 565-566.
［9］Haacke E,Brown R,Thompson M,et al.Magnetic resonance imaging: physical principles and sequence design.New York:WileyLiss,1999.

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