Your browser doesn't support javascript.
loading
An advanced phantom study assessing the feasibility of neuronal current imaging by ultra-low-field NMR.
Körber, Rainer; Nieminen, Jaakko O; Höfner, Nora; Jazbinsek, Vojko; Scheer, Hans-Jürgen; Kim, Kiwoong; Burghoff, Martin.
Afiliación
  • Körber R; Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany. Electronic address: rainer.koerber@ptb.de.
  • Nieminen JO; Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany; Department of Biomedical Engineering and Computational Science, Aalto University School of Science, P.O. Box 12200, FI-00076 AALTO, Finland.
  • Höfner N; Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany.
  • Jazbinsek V; Institute of Mathematics, Physics and Mechanics, Jadranska 19, 1000 Ljubljana, Slovenia.
  • Scheer HJ; Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany.
  • Kim K; Korea Research Institute of Standards and Science, Daejeon 305-340, South Korea.
  • Burghoff M; Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany.
J Magn Reson ; 237: 182-190, 2013 Dec.
Article en En | MEDLINE | ID: mdl-24252245
In ultra-low-field (ULF) NMR/MRI, a common scheme is to magnetize the sample by a polarizing field of up to hundreds of mT, after which the NMR signal, precessing in a field on the order of several µT, is detected with superconducting quantum interference devices (SQUIDs). In our ULF-NMR system, we polarize with up to 50mT and deploy a single-stage DC-SQUID current sensor with an integrated input coil which is connected to a wire-wound Nb gradiometer. We developed this system (white noise 0.50fT/√Hz) for assessing the feasibility of imaging neuronal currents by detecting their effect on the ULF-NMR signal. Magnetoencephalography investigations of evoked brain activity showed neuronal dipole moments below 50nAm. With our instrumentation, we have studied two different approaches for neuronal current imaging. In the so-called DC effect, long-lived neuronal activity shifts the Larmor frequency of the surrounding protons. An alternative strategy is to exploit fast neuronal activity as a tipping pulse. This so-called AC effect requires the proton Larmor frequency to match the frequency of the neuronal activity, which ranges from near-DC to ∼kHz. We emulated neuronal activity by means of a single dipolar source in a physical phantom, consisting of a hollow sphere filled with an aqueous solution of CuSO4 and NaCl. In these phantom studies, with physiologically relevant dipole depths, we determined resolution limits for our set-up for the AC and the DC effect of ∼10µAm and ∼50nAm, respectively. Hence, the DC effect appears to be detectable in vivo by current ULF-NMR technology.
Asunto(s)
Palabras clave
Texto completo
Añadir a Mi BVS
Imprimir
XML
PubMed Links
Buscar en Google

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Imagen por Resonancia Magnética / Fantasmas de Imagen / Neuronas Tipo de estudio: Risk_factors_studies Límite: Adult / Humans / Male Idioma: En Revista: J Magn Reson Asunto de la revista: DIAGNOSTICO POR IMAGEM Año: 2013 Tipo del documento: Article Pais de publicación: Estados Unidos
Texto completo
Añadir a Mi BVS
Imprimir
XML
PubMed Links
Buscar en Google

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Imagen por Resonancia Magnética / Fantasmas de Imagen / Neuronas Tipo de estudio: Risk_factors_studies Límite: Adult / Humans / Male Idioma: En Revista: J Magn Reson Asunto de la revista: DIAGNOSTICO POR IMAGEM Año: 2013 Tipo del documento: Article Pais de publicación: Estados Unidos