Role of nuclear magnetic resonance relaxation times in medical imaging

The purpose of this paper is to provide an overview of the physical foundations and applications of NMR imaging--a method of obtaining images of biological systems by nuclear magnetic resonance. We begin by briefly exploring the history of nuclear magnetic resonance and that of NMR imaging. We then move into the basic theory of the magnetic resonance phenomenon and are introduced to NMR relaxation times, Tl and T2, and how these relaxation times apply to biomedical imaging. We continue our investigation by looking at some of the instrumentation necessary for an NMR imaging system and conclude by exploring one of the many important application of NMR imaging, that of fetal monitoring and obstetric diagnosis.