? This application describes research and development for in vivo imaging, as described in NIH solicitation PAR-03-125. The objective is to develop, feasibility test, and commercialize a novel technology product for detecting functional brain activation using magnetic resonance. Current fMRI measures are limited to indirect assessments of neuronal function based upon cerebral hemodynamics, including blood oxygen level difference (BOLD) signals and changes in blood flow. Indirect measurements of activation that rely upon blood flow are inherently limited by the temporal and spatial scales of hemodynamic processes. Methods using electrical measurements (EEG) or magnetic measurements (MEG) are capable of high temporal resolution, but do not allow spatial localization of current sources within the brain except through source modeling. Several groups have attempted to use imaging methods to directly measure the changes in electromagnetic fields associated with neuronal activation within the brain. However, these signals are predicted to be very small, in the picoTesla range, and at the time of writing, enabling technologies are not available. ? ? We have developed novel methods that allow extremely precise measurement of electromagnetic signals internal to the brain, with precision in the picoTesla range. Initial pilot data have verified that these methods are capable of detecting signals in this range both within a specially designed phantom, and in vivo. Additionally, early examples from our pilot data are suggestive of direct measurement of neuronal activation signals in vivo. This technology will be further developed and tested according to the following Specific Aims: ? 1) Optimize/Characterize The Method/n Vitro Using A Current-Conducting Phantom ? 2) Demonstrate Noise Level/n Vivo Appropriate to Measure Estimated Neuronal Current Signals ? 3) Demonstrate Neuronal Current Measurement in Vivo. ? ?
| deCharms, R Christopher (2008) Applications of real-time fMRI. Nat Rev Neurosci 9:720-9 |
