  High-temperature superconductivity has a significant opportunity to improve
the performance of nuclear magnetic resonance (NMR) spectroscopy and magnetic
resonance imaging (MRI) systems. The low rf losses and low operating
temperatures of superconducting coils allow them to improve the signal-to-noise
ratio in applications where the system noise dominates that of the sample under
study. These improvements translate into new capabilities and shorter
measurement times for NMR and MRI systems. In this pedagogical paper, we
discuss the implementation and impact of high-T$_c$ superconducting thin films
in rf coils for NMR and MRI applications.
