1. A method of imaging at least two chemical species using magnetic resonance imaging with signal separation for two chemical species resulting in separate signal datasets for these two chemical species, the method comprising: acquiring first and second echo data at two different echo times using a two-point method resulting in a first and second acquired complex datasets, modelling the first and second acquired complex datasets by multi-peak model of at least one of the chemical species said modelling resulting in a first and second modelled complex dataset, said first and second modelled complex datasets comprising a first and second phasor and separate signal complex datasets for the two chemical species, the modelling of the first and second complex datasets employing a linear combination of the separate signal complex datasets for the two chemical species, multiplied by the first and second phasor, weights for the linear combination being derived from the spectral signal model of at least one of the chemical species; determining the magnitude of the first and second acquired complex datasets and retrieving an initial estimate of the separate signal datasets for the two chemical species based on the first and second modelled complex datasets, deriving from the first and second acquired complex datasets and the initial estimate of the separate signal datasets for the two chemical species at least one solution for the first and second phasors based on the first and second modelled complex datasets, determining from the first and second acquired complex datasets and one solution for the first and second phasors a final estimate of the separate signal complex datasets for the two chemical species by minimizing a residuum between the first and second acquired complex datasets and the first and second modelled complex datasets, reconstructing at least one of the first and second species datasets into an image, and, displaying at least one of the images on a display device.