title: Low-power slice selective imaging of broad signals.
abstract: One of the major challenges in using magnetic resonance imaging (MRI) to study immobile samples, such as solid materials or rigid tissues like bone or ligaments, is that the images appear dark due to these samples' short-lived signals. Although it is well known that narrowband signals can be excited in inhomogeneously-broadened lines, it is less well known that similar effects can be observed in dipolar-broadened systems. These long-lived signals have not been used much, mainly because their description frequently does not match intuition. While 3D imaging with these signals has previously been reported, here we focus on the demonstration of faster, 2D slice-selective imaging. The faster imaging provides more flexibility for visualizing these rigid objects. We also focus on the frequently-encountered regime wherein the maximum power achievable for rf pulses is significantly weaker than the linewidth. This regime is typically encountered in clinical MRI scans or large volume setups. When compared to UTE and conventional slice-selective spin echo methods, this technique provides better representations of the sample considered here (an eraser sample), and higher signal-to-noise ratios than spin-echo techniques in both the high and low power regimes.
authors.affiliation: Department of Chemistry, New York University, New York, NY, United States.
authors.forename: Weiqi
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Chemistry, New York University, New York, NY, United States; Department of Radiology, New York University Langone Medical Center, New York, NY, United States.
authors.forename: Jae-Seung
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Chemistry, New York University, New York, NY, United States.
authors.forename: Boris
authors.initials: B
authors.lastname: Kharkov
authors.affiliation: Department of Chemistry, New York University, New York, NY, United States.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Ilott
authors.affiliation: Department of Chemistry, New York University, New York, NY, United States. Electronic address: alexej.jerschow@nyu.edu.
authors.forename: Alexej
authors.initials: A
authors.lastname: Jerschow
mesh_terms: D007089:Image Enhancement; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D059629:Signal-To-Noise Ratio
keywords: Long-lived signal; Low power; MRI; Semi-solids; Slice selective imaging