1. Department of Biomedical Engineering, Vanderbilt University , Nashville, TN 37232 , USA
2. Institute of Imaging Science, Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center , Nashville, TN 37232 , USA
3. Department of Neurological Surgery, Vanderbilt University Medical Center , Nashville, TN 37232 , USA
4. Department of Electrical and Computer Engineering, Vanderbilt University , Nashville, TN 37212 , USA