Premium
Saturation recovery single‐shot acquisition (SASHA) for myocardial T 1 mapping
Author(s) -
Chow Kelvin,
Flewitt Jacqueline A.,
Green Jordin D.,
Pagano Joseph J.,
Friedrich Matthias G.,
Thompson Richard B.
Publication year - 2014
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.24878
Subject(s) - imaging phantom , heart rate , heart failure , medicine , flip angle , nuclear medicine , single shot , steady state free precession imaging , biomedical engineering , reproducibility , saturation (graph theory) , cardiology , nuclear magnetic resonance , magnetic resonance imaging , blood pressure , physics , mathematics , radiology , statistics , combinatorics , optics
Purpose To validate a new saturation recovery single‐shot acquisition (SASHA) pulse sequence for T 1 mapping and to compare SASHA T 1 values in heart failure patients and healthy controls. Theory The SASHA sequence consists of 10 electrocardiogram‐triggered single‐shot balanced steady‐state free precession images in a breath‐hold. The first image is acquired without magnetization preparation and the remaining nine images follow saturation pulses with variable saturation recovery times. Methods SASHA was validated through Bloch equation simulations, Monte Carlo simulations, and phantom experiments. Pre‐ and postcontrast myocardial and blood T 1 values were measured in 29 healthy volunteers and 7 patients with heart failure. Results SASHA T 1 values had excellent agreement (bias, 5 ± 5 ms) with spin echo experiments in phantoms with a wide range of physiologic T 1 and T 2 values and its accuracy was independent of flip angle, absolute T 1 , T 2 , and heart rate. The average baseline myocardial T 1 in heart failure patients was higher than in healthy controls (1200 ± 32 vs. 1170 ± 9 ms, P < 0.05) at 1.5T, as was the calculated blood–tissue partition coefficient, λ, (0.42 ± 0.04 vs. 0.38 ± 0.02, P < 0.05), consistent with diffuse myocardial fibrosis. Conclusions The SASHA sequence is a simple and fast approach to in vivo T 1 mapping with good accuracy in simulations and phantom experiments. Magn Reson Med 71:2082–2095, 2014. © 2013 Wiley Periodicals, Inc .