Types of Selective RF Pulses

The constant amplitude pulses are usually easier to implement and they do not require special hardware. A typical example and also the most frequently used kind of constant amplitude, frequency selective pulse is the DANTE pulse train [4]. In the simplest case it consists of a sequence of square pulses interleaved with periods of free precession. Unfortimately, the excitation profile of the DANTE sequence has extensive sidelobes. It also produces sidebands at frequencies  

Edited by M. Gielen, R. Willem and B. Wrackraeyer 01996 John Wiley Sons Ltd 

The excitation band can be shifted off-resonance by applying a constant phase increment to the DANTE pulses [5,6]. The frequency shift Av is given by  

Multiple site excitation can be achieved by interleaving several frequency shifted DANTE sequences [5-7]. 

A somewhat better excitation profile can be obtained using so-called binomial pulses [8-10]. These pulses are similar to the DANTE pulses, except their number and length are given by binomial coefficients  

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