Phase-sensitive cardiac tagging--REALTAG.
Fully inverting spins, instead of merely saturating them, provides superior contrast for tagging procedures. The resulting improvement in tag contrast-to-noise ratio (CNR) yields higher-precision tag detection. Also, thinner slices and hence reduced tag separations can be employed, providing displacement and strain measurements with better spatial resolution. Alternatively, the improved tag contrast can be used to obtain cine images covering a greater portion of the cardiac cycle. The use of standard magnitude reconstruction for images of these inversion tags causes rectification of the negative-valued signals from the tags, confounding the image interpretation. Therefore, a phase-sensitive reconstruction scheme of the inverted tags must be employed. Here we demonstrate the implementation of inverted tags with phase-sensitive reconstruction in a ramped-flip-angle, steady-state free precession (SSFP) sequence.
Derbyshire
J Andrew
JA
Laboratory of Cardiac Energetics, National Heart Lung and Blood Institute, National Institutes of Health, DHHS, Bethesda, Maryland, USA.
Sampath
Smita
S
Laboratory of Cardiac Energetics, National Heart Lung and Blood Institute, National Institutes of Health, DHHS, Bethesda, Maryland, USA.
McVeigh
Elliot R
ER
Laboratory of Cardiac Energetics, National Heart Lung and Blood Institute, National Institutes of Health, DHHS, Bethesda, Maryland, USA.
D003198:Computer Simulation; D006321:Heart / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*