Abstract
Most magnetic resonance (MR) imaging systems were originally designed with analog spectrometers, since that was the βstate of the artβ in the late 1970s, when they were developed. Advances in technology have allowed the design of radioβfrequency electronics with a much larger percentage of digital components while the cost of such components has decreased. This has given manufacturers the incentive to develop new spectrometers that incorporate these electronics for cost reduction and potentially better performance. Upgrades and new models of MR units have become available with these soβcalled βdigital spectrometers.β Because of the interest in the new systems, the Instrumentation Subcommittee of the Basic Science Council of the Society for Magnetic Resonance Imaging has produced this report to review the basic features of analog and digital spectrometers to help the MR imaging community better understand the similarities and differences of these systems. Some details of actual commercial implementations were left out to focus on the basic features. Regardless, the authors hope they have provided a readable introduction to this important topic.