Electric Current Density Imaging of Pedunculate Oak(Quercus RoburL.) Twigs by Magnetic Resonance Imaging

The use of Electric Current Density Imaging (CDI) technique to map spatial distribution of induced electric currents through two years old twigs of pedunculate oak (Quercus robur L.) is presented. Specifically, this magnetic resonance technique was implemented to image conductivity contrast in different tree tissues. Imaged electric conductivity distributions of pith, wood, and phloem together with cambial zone and undifferentiated xylem were compared with flame atomic absorption spectrometry measurements of potassium. Good correlation was observed. The undifferentiated xylem + cambial zone + complete phloem showed higher electrical conductivity and normalized potassium values than both differentiated xylem and pith. By a novel magnetic resonance imaging technique it is demonstrated that the path of least resistance to an electric current was along tissues of maximum free potassium concentration.