Described are amphiphilic polymers that are provided with chelating moieties. The amphiphilic polymers are block copolymers comprising a hydrophilic block and a hydrophobic block, with the chelating moieties linked to the end-group of the hydrophilic block. The disclosed polymers are capable of self-assembly into structures such as micelles and polymersomes. With suitable metals present in the form of coordination complexes with the chelating moieties, the chelating amphiphilic polymers of the invention are suitable for use in various imaging techniques requiring metal labeling, such as MRI (T1/T2 weighted contrast agents or CEST contrast agents) SPECT, PET or Spectral CT.