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Adiabatic Slice-Selective Excitation for Surface Coils

✍ Scribed by Jun Shen; Douglas L. Rothman

Publisher
Elsevier Science
Year
1997
Tongue
English
Weight
220 KB
Volume
124
Category
Article
ISSN
1090-7807

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✦ Synopsis

A novel RF pulse designed to perform a diabatic slice-selective excitation for surface coils (ASSESS) is proposed in which Bzero gradient is modulated in concert with RF frequency modulation. Within the selected slice, the principles of BIR4 pulses are employed to obtain well-defined, pure-phase and self-refocused spin rotation of arbitrary flip angles despite the presence of high B1 inhomogeneity produced by surface coils. Outside the slice, advantage is taken of the B1 field to dephase equilibrium magnetization to achieve slice selection or outer-volume suppression. This scheme should be useful for many localization techniques. Quaternion analysis of the overall propagator of the proposed pulse and numerical simulations using Bloch equations are performed. The pulse is tested experimentally on a phantom sample.

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