We propose a new type of adiabatic pulses for uniform inversion of the magnetization in magnetic resonance imaging. We produced these pulses with an evolution strategy optimization, by which the search of the "best solution" has been made more efficient than by deterministic algorithms. The pulse parametrization takes into account an "Offset-independent adiabaticity condition," which guarantees insensitivity to RF inhomogeneities. The RF pulse power (both peak and mean) contributes to the cost to be minimized, as well as the error function does: in this way we obtain solutions that require lower energy than the well-known hyperbolic-secant pulse, with no loss of quality in the response profile.
Evolution strategy optimization for adiabatic pulses in MRI
MARZOLA, Pasquina;SBARBATI, Andrea
1999-01-01
Abstract
We propose a new type of adiabatic pulses for uniform inversion of the magnetization in magnetic resonance imaging. We produced these pulses with an evolution strategy optimization, by which the search of the "best solution" has been made more efficient than by deterministic algorithms. The pulse parametrization takes into account an "Offset-independent adiabaticity condition," which guarantees insensitivity to RF inhomogeneities. The RF pulse power (both peak and mean) contributes to the cost to be minimized, as well as the error function does: in this way we obtain solutions that require lower energy than the well-known hyperbolic-secant pulse, with no loss of quality in the response profile.
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