MR tagging from a signal processing perspective

Although magnetic resonance (MR) tagging has been shown to be a useful tool in myocardial motion quantification, its clinical utilization is limited as current available methods generally either lack computational speed or require extensive user intervention. Recently, the harmonic phase imaging (HARP) technique has been proposed to look at the phase information of the tagged images. HARP imaging promises to overcome the limitations of existing methods in terms of both computational speed and automation. Motivated by this work, we present mathematical analysis providing a signal processing perspective on the HARP technique. This new perspective provides a clearer understanding of how tags can be accurately tracked using highly-filtered data.