title: Increasing the signal-to-noise ratio in DENSE MRI by combining displacement-encoded echoes.
abstract: A new technique was developed to increase the signal-to-noise ratio (SNR) in displacement encoding with stimulated echoes (DENSE) MRI. This signal-averaged DENSE (sav-DENSE) technique is based on the SNR advantage of extracting a pair of DENSE images with uncorrelated noise from the complex complementary spatial modulation of the magnetization image, and combining them during image reconstruction. Eleven healthy volunteers were imaged at three short-axis locations with the use of sav-DENSE, cine DENSE, and myocardial tagging pulse sequences. In this study, sav-DENSE increased the SNR by 15-34% as compared to cine DENSE. Circumferential strain values measured by sav-DENSE and myocardial tagging were strongly correlated (slope = 0.95, intercept = -0.02, R = 0.92) and within the 95% limits of agreement. The breath-hold sav-DENSE technique yielded relatively accurate and precise quantification of 2D intramyocardial function, with a 40.2-ms temporal resolution and a 3.5 x 3.5 mm2 spatial resolution.
authors.affiliation: Department of Radiology, New York University, New York, New York 10016, USA. kimd10@med.nyu.edu
authors.forename: Daniel
authors.initials: D
authors.lastname: Kim
authors.forename: Frederick H
authors.initials: FH
authors.lastname: Epstein
authors.forename: Wesley D
authors.initials: WD
authors.lastname: Gilson
authors.forename: Leon
authors.initials: L
authors.lastname: Axel
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology*; D019047:Phantoms, Imaging