Evaluation of SNR/Resolution Tradeoffs Using the Theoretical Information Content

Introduction: In magnetic resonance imaging a tradeoff exists between resolution and the signal to noise ratio (SNR). With any imaging protocol, different fractions of the available scan time could be used to acquire data at higher spatial frequencies (achieving higher resolution) and to perform signal averaging (obtaining greater SNR). A potential way to establish the optimal balance between resolution and SNR is to determine the solution which provides the maximum information content. First defined by Shannon (1) in the context of communication theory, the theoretical information content has since been used as a measure of image quality in the fields of photography and medical imaging (CT and MRI) (2,3). In this study, the information content of a variety of MR images, which corresponded to different SNR/resolution tradeoffs for a range of scan durations, was determined.