A radiopharmaceutical composition comprising: (i) a compound of the formula I: ** Formula ** wherein: Z is S, NR ', O, or C (R') 2 wherein each R 'is independently H or alkyl C1-6, such that the tautomeric form of the heterocyclic ring when Z is C (R ') 2 is an indole: ** Formula ** Y is hydrogen, C1-6 alkyl, halo, OR' or SR ', in where R 'is H or C1-6 alkyl, or Y is -NR1R2； R1-10 is each independently selected from the group consisting of hydrogen, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 alkoxy, C4-6 cycloalkyl, hydroxy, C1-6 hydroxyalkyl, C2- hydroxyalkenyl 6, C2-6 hydroxyalkynyl, thiol, C1-6 thioalkyl, C2-6 thioalkenyl, C2-6 thioalkynyl, C1-6 thioalkoxy, halo, C1-6 haloalkyl, C2-6 haloalkenyl, C2-6 haloalkynyl, C1-6 haloalkoxy , amino, C1-6 aminoalkyl, C2-6 aminoalkenyl, C2-6 aminoalkynyl, C1-6 aminoalkoxy, cyano, C1-6 cyanoalkyl, C2-6 cyanoalkenyl, C2-6 cyanoalkynyl, and C1-6 cyanoalkoxy； nitro, C1-6 nitroalkyl, C2-6 nitroalkenyl, C2-6 nitroalkynyl, and C1-6 nitroalkoxy； and, wherein at least one atom of said compound of the formula I is a radioactive isotope suitable for in vivo image acquisition； (ii) a biocompatible vehicle that is 5-10% aqueous ethanol (v / v)； and, (iii) 0.05-5.0% w / v polysorbate； at a pH of 4.0 to 10.5.Una composición radiofarmacéutica que comprende: (i) un compuesto de la fórmula I:**Fórmula** en donde: Z es S, NR', O, o C(R')2 en donde cada R' es independientemente H o alquilo C1-6, de tal modo que la forma tautómera del anillo heterocíclico cuando Z es C(R')2 es un indol:**Fórmula** Y es hidrógeno, alquilo C1-6, halo, OR' o SR', en donde R' es H o alquilo C1-6, o Y es -NR1R2； R1-10 se selecciona cada uno independientemente del grupo que consiste en hidrógeno, alquilo C1-6, alquenilo C2-6, alquinilo C2-6, alcoxi C1-6, cicloalquilo C4-6, hidroxilo, hidroxialquilo C1-6, hidroxialquenilo C2-6, hidroxialquinilo C2-6, tiol, tioalquilo C1-6, tioalquenilo C2-6, tioalquinilo C2-6, tioalcoxi C1-6, halo, haloalquilo C1-6, haloalquenilo C2-6
