The present disclosure relates to a compound comprising an oxygen-15 and a process for preparation thereof. It also relates to the use of the compound in positron and/or other nuclide imaging and use of the compound in obtaining a perfusion and/or metabolic image in an animal and/or human body. A process for preparing the compound comprises irradiating a compound comprising oxygen via irradiation energy in the range of 10 MeV to 430 MeV. The oxygen atom in the compound may then be allowed to be converted to an oxygen-15 positron nuclide through a photonuclear reaction. Provided that the molecular structure of the irradiated compound is not disrupted, a compound comprising an oxygen-15 is prepared.