Current-induced magnetic resonance phase imaging.
Electric current-induced phase alternations have been imaged by fast magnetic resonance image (MRI) technology. We measured the magnetic resonance phase images induced by pulsed current stimulation from a phantom and detected its sensitivity. The pulsed current-induced phase image demonstrated the feasibility to detect phase changes of the proton magnetic resonance signal that could mimic neuronal firing. At the present experimental setting, a magnetic field strength change of 1.7 +/- 0.3 nT can be detected. We also calculated the averaged value of the magnetic flux density BT parallel to B0 produced by electric current I inside the voxel as a function of the wire position. The results of the calculation were consistent with our observation that for the same experimental setting the current-induced phase change could vary with location of the wire inside the voxel. We discuss our findings in terms of possible direct MRI detection of neuronal activity.
Bodurka
J
J
Biophysics Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA.
Jesmanowicz
A
A
Hyde
J S
JS
Xu
H
H
Estkowski
L
L
Li
S J
SJ
D005071:Evoked Potentials; D005240:Feasibility Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D009474:Neurons / Q000502:physiology*; D019047:Phantoms, Imaging