NZ 598540 The disclosure relates to a diagnostic composition comprising Compound I, a pharmaceutically acceptable carrier； and dissolved therein a sodium compound and a calcium compound providing a sodium ion concentration of 40-50 mM and a calcium ion concentration of 0.1-0.7 mM. The disclosure also relates to the use of said diagnostic composition for in vivo imaging detection method, wherein the in vivo imaging detection method comprises: (i) detecting signals emitted by a distributed form of the Compound I in the diagnostic composition, wherein the composition has been administered to a human or animal body, and (ii) generating an image representative of the location and/or amount of said signal.
