This project is to develop an instrument to measure the polarization of a hyperpolarized noble gas, Helium- 3 and Xenon-129, for enhanced lung MRIs in a clinical environment. It is essential to have some means of measuring polarization at various stages in the handling of these gases, e.g. at production, storage, transport and administration to a patient. The instrument we propose will be portable, compact (about 6 in. cube), self contained and versatile, able to operate in several modes and in various environments, yet capable of being integrated in a larger system. Unlike presently used methods of measuring polarization, this is a direct measure of nuclear polarization that does not destroy any of the polarization of the sample being measured. It operates on the principle that two coupled resonant systems, in this case an electronic L-C circuit and the magnetically resonating nuclei, oscillate in unison in either of two frequencies, neither of which is the same as the magnetic resonant frequency of the nuclei. The system is made to oscillate at a very low amplitude, and polarization is derived from measurements of frequency. Since the magnetic field probing the nuclei is not much stronger than thermal noise, and at a frequency different from their resonant frequency, the nuclei are not disturbed. The program is to investigate different modes of exploiting this phenomenon (the splitting of the resonance), to devise protocols for efficient implementation, and to develop software to enable the instrument to operate automatically and in an intelligent user friendly manner; to design plug in modules to enable the instrument to work in a variety of environments; to calibrate the instrument to give a direct output of the polarization at the instant when it is measured for 3He and 129Xe, to package, test, and arrange the manufacture of a final model. MR imaging of the lungs and airways using hyperpolarized noble gases (3He and 129Xe) is particularly useful in the early diagnosis and management of, e.g. emphysema, asthma, cystic fibrosis, COPD etc., as it reveals, with zero radiation dose, information about morphology and functioning of the lungs, circulation and soft tissues, not available with other techniques.
