摘要：A review is presented which covers the basic theory of nuclear magnetic resonance (NMR) with regard to angular momentum, magnetic moments, and the classical mechanical description of the NMR experiment. Longitudinal (T,) and Transverse (T2) relaxation times are defined as well as the basic pulse sequences used for their measurement. In particular, the 180°-t-90° and the Hahn Spin Echo pulse sequences are described in detail. Basic Magnetic Resonance Imaging (MRI) theory is discussed with regard to slice selection, frequency encoding, and phase encoding to define the imaged volume element. The equations defining the amount of Tt , T2 , and proton density which contribute to the images are discussed. Common MRI pulsing sequences are described in detail as well as the imaging time equation. Recent in-vivo magnetic resonance studies involving the use of contrast agents, and the use of localized spectroscopy, specifically 13C, 19F, MNa and 39K, are discussed.
