In this thesis, we used the technique of Spin-Exchange Optical Pumping (SEOP) to produce hyperpolarized noble gases. We studied the pressure and temperature dependence of 129 Xe polarization by making a series of cells with different gas compositions and measuring the Xe polarization over a large temperature range.We constructed a low field MRI scanner for hyperpolarized noble gases. Our scanner was built with off-the-shelf electronics and co-axial circular coils.We imaged both 3 He and 129 Xe samples. Using a fully phase encoded pulse sequence and with some auxiliary measurements, we acquired a high quality image with 129 Xe at low field (∼2 mT).We developed genuinely new techniques of Polarized Nuclear Imaging (PNI) and Polarized Nuclear Detection (PND), which make use of the asymmetric radioactive emissions of certain polarized radioactive nuclei. In these techniques, the nuclear spins are manipulated using conventional Nuclear Magnetic Resonance (NMR) methods. However, instead of detecting radiofrequency electromagnetic waves, single photons (or other types of radioactive emissions) are detected. As a result, the signal detection sensitivity is greatly enhanced. We also developed the novel Cates-Miller-Zheng (CMZ) pulse sequence class that is specially suited for PNI, and successfully acquired a preliminary image of a 131m Xe sample.To Yishen, for your love, support, and understanding