1. Molecular Imaging Program at Stanford and Bio-X Program, Department of Radiology, Stanford University School of Medicine, Palo Alto, CA 94305, USA.
2. Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
3. Penn State Cancer Institute, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
4. Department of Urology, Stanford University School of Medicine, Palo Alto, CA 94305, USA.
5. Department of Electrical Engineering, Stanford University, Palo Alto, CA 94305, USA.
6. Edward L. Ginzton Laboratory, Center for Nanoscale Science and Engineering, Stanford University, Palo Alto, CA 94305, USA.
7. Department of Bioengineering and Department of Materials Science & Engineering, Stanford University School of Medicine, Palo Alto, CA 94305, USA.