A PET probe comprising a compound according to formula IA and / or IB ** Formula ** wherein A is ** Formula ** and R1 is OH or F, R2 is H or F, R3 is F, R4 is H, F, Cl, Br, CH3, or C2H5, R6 is H, and at least one of R1 and R3 is 18F.Una sonda para PET que comprende un compuesto de acuerdo con la fórmula IA y/o IB**Fórmula** en donde A es**Fórmula** y R1 es OH o F, R2 es H o F, R3 es F, R4 es H, F, Cl, Br, CH3, o C2H5, R6 es H, y Al menos uno de R1 y R3 es 18F.