Nanodiamond imaging: a new molecular imaging approach.

A new molecular imaging approach is proposed that combines optical detection and magnetic field gradients to achieve high sensitivity and high spatial resolution. Called Nanodiamond Imaging, this new modality images the location of nanodiamonds within a living organism. Since nanodiamonds can be tagged with biologically active molecules and are nontoxic, Nanodiamond Imaging may become an important biomedical research tool with possible clinical application. A Nanodiamond Imaging system actually senses a particular type of defect in the nanodiamond called the nitrogen-vacancy center. A prototype system has been built that was tested by imaging an artificial target within a volume of chicken breast. The resolving power should be <100 µm with modest improvements, significantly finer than PET, SPECT, and in-vivo optical imaging. The sensitivity of the imaging system, taking into account foreseen improvements, should be better than a 10 nanomolar concentration of carbon atoms, referenced to a 1 mm(3) voxel volume and one second of measurement time (10 nM·mm(3)·Hz(-1/2))--a similar sensitivity to the other molecular imaging techniques, but with a stable, non-radioactive tracer.