Squid system for meg and low field magnetic resonance

• Autorzy: Burghoff M. , Albrecht H. H. , Hartwig S. , Hilschenz I. , Körber R. , Sander Thömmes T. , Scheer H. J. , Voigt J. , Trahms L.
• Języki publikacji: EN

Abstrakty

EN

A SQUID magnetometer system was developed for measuring sustained brain activity by magnetoencephalography (DC-MEG) and to record the free precession decay of protons (FPD) of the human brain at very low fields. The SQUID system has a white noise level of about 4 fT/√Hz. To generate the MR signal, two magnetic fields are used: a static polarisation field of a few mT and a static detection field of a few microtesla. To test the spectral resolution of the system, we measured the FPD of protons in distilled water having a spectral line width of about 156 mHz with an instrumental resolution of 2 mHz. The proton resonance line width of the human brain was found to be about 3.0 Hz. Using the same SQUID system we recorded a DC-MEG signal with an amplitude of about 1.5 pT upon motor stimulation. On the basis of these data, we discuss the possibility of detecting a shift of the resonance line due to the superposition of the neuromagnetic field generated by sustained brain activity.

Słowa kluczowe

EN

SQUID; MEG; low-field MR; neuronal currents

• Wydawca: Komitet Metrologii i Aparatury Naukowej PAN
• Czasopismo: Metrology and Measurement Systems
• Rocznik: 2009
• Tom: Vol. 16, nr 3
• Strony: 371--375
• Opis fizyczny: Bibliogr. 7 poz., rys., wykr.

Twórcy

autor

Burghoff M.

autor

Albrecht H. H.

autor

Hartwig S.

autor

Hilschenz I.

autor

Körber R.

autor

Sander Thömmes T.

autor

Scheer H. J.

autor

Voigt J.

autor

Trahms L.

• Physikalisch-Technische Bundesanstalt, Biosignals, Abbestrasse 2-12, D-10587 Berlin, Germany,

Bibliografia

• [1] Ya.S. Greenberg: “Application of superconducting quantum interference devices to nuclear magnetic resonance”. Rev. Mod. Phys., no. 70, 1998, pp. 175-222.
• [2] R. McDermott, A.H. Trabesinger, M. Mück, E.L. Hahn, A. Pines, J. Clarke: “Liquid state NMR and scalar couplings in microtesla magnetic fields”. Science, no. 295, 2002, pp. 2247-2249.
• [3] V.S. Zotev, A.N. Matlashov, P.L. Volegov, I.M. Savukov, M.E. Espy, J.C. Mosher, J.J. Gomez, R.H. Kraus Jr.: „Microtesla MRI of the human brain combined with MEG”. J. Magn. Reson., vol. 194, no. 1, 2008, pp. 115-120.
• [4] A.M. Cassarà, B. Maraviglia, S. Hartwig, L. Trahms, M. Burghoff: “Neuronal current detection with lowfield magnetic resonance: simulations and methods”. J. Magn. Reson., 2009, doi:10.1016/j.mri.01.015.
• [5] D. Drung: “High-Tc and low-Tc dc SQUID electronics”. Supercond. Sci. Technol., vol. 16, no. 12, 2003, pp. 1320-1336.
• [6] M. Burghoff, T.H. Sander, A. Schnabel, D. Drung, L. Trahms, G. Curio, B.M. Mackert: “dc Megnetoencephalography: Direct measurements in a magnetically extremely-well shielded room”. Appl. Phys. Lett., vol. 85, no. 25, 2004, pp. 6278-6280.
• [7] M. Burghoff, S. Hartwig, L. Trahms, J. Bernarding: “Nuclear magnetic resonance in the nanoTesla range”. Appl. Phys. Lett., vol. 87, no. 5, 2005, pp. 054103.