About Dr. Krongrad: Publications
Krongrad A: A method for increasing nuclear magnetic resonance signals in living biological tissue using zinc. U.S. patent 5,250,284, Oct.5, 1993
The invention comprises a method for detection, spectra analysis and imaging the concentration and characteristics of magnetic nuclei in living biological tissue [eg. prostate cancer]. Magnetic isotopes are administered to living biological tissue in a chemical form in which it is bioavailable and at concentration levels greater than naturally occurring concentration levels, i.e. at which the magnetic isotope has been enriched. The magnetic isotope administered is selected from isotopes of elements which are metabolized by the living biological tissue. The tissue is allowed to absorb and metabolize the isotope [one example is zinc and the prostate, where it is highly concentrated]. The tissue is then, for example, subjected to a magnetic field which will orient all nuclei with nonzero spin and generate a net magnetic moment M, aligned parallel to the field, within the tissue. When the excitation magnetic pulse is interrupted, the nuclei return to their original equilibrium with characteristic resonance. In the process the nuclei emit radiation in the radio frequency region of the electromagnetic spectrum. This radiation is detected and converted into spectra or images which reflect the concentration and chemical characteristics of the nuclei. These spectra or images are then used to study the normal physiology of the isotope and following this to detect abnormal biology.
The invention provides a new method for studying normal biology and detecting aberrations in that biology. It relies on some of the existing MRS and MRI technology, but differs significantly in its method of signal enhancement. In previously described signal enhancement, "contrast" agents are not directly measurable and are not the source of signal. In contradistinction, this invention describes the augmentation of signal by increasing the concentration of physiologically relevant magnetic nuclei by exogenous administration. The administered nuclei are thus very directly and advantageously the source of signal.
This inventive concept and method where the magnetic resonant signal itself is increased has many advantages over prior methodology both with and without the use of signal enhancement though the application of contrast agent particles. The previous focus on ferromagnetic, paramagnetic and diamagnetic enhancers is further evidence of the novelty of the methodology of directly increasing the quantity of resonance signal through the application of increased concentrations of magnetic isotopes to study absorption or metabolization in living biological tissue. Such a technique has long been needed.