Abstract: For constructing an asymmetric RF pulse for an MRI system, a first RF amplitude for a first part of a time interval is determined and an RF amplitude curve, which depends on at least one RF curve parameter is received. A combined RF amplitude curve for the time interval is determined by combining the first RF amplitude for the first part of the time interval and the RF amplitude curve for a second part of the time interval, which succeeds the first part of the time interval. The combined RF amplitude curve is optimized using a loss function, which comprises an energy loss term, which depends on a pulse energy of the combined RF amplitude curve, and using the at least one RF curve parameter as at least one optimization variable. A combined amplitude of the asymmetric RF pulse is given by the optimized combined RF amplitude curve.