title: Flat pancake distant dipolar fields for enhancement of intermolecular multiple-quantum coherence signals.
abstract: Intermolecular multiple-quantum coherences (iMQCs) originated from distant dipolar field (DDF) possess some appealing unique properties for magnetic resonance imaging (MRI). DDF is usually induced with continuous wave (i.e., sine- or square-wave) magnetization modulation in the whole sample. In this article, a spatially localized and enhanced DDF was optimally tailored in a thin slice with an adiabatic inversion pulse. Evidence was provided to show that careful tailoring of the spatially localized DDF can generate highly efficient iMQC signals, with more than two-fold enhancement compared to the conventional sine-wave magnetization modulation method, and 1.5 times of that with the square-wave modulation under the similar condition. Theoretical predictions, simulation results, and experimental verifications agree well with each other. Practical implementation of this approach for efficient iMQC MRI was explored.
authors.affiliation: Department of Electronic Science and Communication Engineering, Fujian Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen 361005, China.
authors.forename: Congbo
authors.initials: C
authors.lastname: Cai
authors.forename: Yulan
authors.initials: Y
authors.lastname: Lin
authors.forename: Shuhui
authors.initials: S
authors.lastname: Cai
authors.forename: Huijun
authors.initials: H
authors.lastname: Sun
authors.forename: Jianhui
authors.initials: J
authors.lastname: Zhong
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000818:Animals; D008279:Magnetic Resonance Imaging; D051379:Mice; D008962:Models, Theoretical; D011789:Quantum Theory