Iodinated aromatic choline analogs of general formula I wherein - the ring containing Z atoms is selected from benzene ring and thiophene ring; - R are independently selected from the group consisting of H; 123 I; 124 I; 125 I; 127 I; 131 I; C 1 to C 14 alkyl; C 2 to C 14 alkenyl; C 2 to C 14 alkynyl; C 6 to C 10 aryl; C 3 to C 6 heteroaryl comprising at least one heteroatom selected from O, S, N; C 3 to C 6 heterocyclyl comprising one to two heteroatoms selected from O, S, N; C 1 to C 14 alkoxy; C 6 to C 10 aryloxy; C 3 to C 6 heteroaryloxy comprising at least one heteroatom selected from O, S, N; C 3 to C 6 heterocyclyloxy comprising one to two heteroatoms selected from O, S, N; benzyloxy; C 1 to C 14 alkylthio; halogen; OH; SH; NH 2; C 1 to C 14 alkylamino; C 6 to C 10 arylamino; C 1 to C 14 acylamino; di(C 1 to C 14 alkyl)amino, wherein the alkyls are the same or different; di(C 6 to C 10 aryl)amino, wherein the aryls are the same or different; di(C 1 to C 14 acyl)amino, wherein the acyls are the same or different; CN; nitro and COOR n, wherein R n is H or C 1 to C 14 alkyl or aryl; - whereas at least one of the substituents R is 123 I; 124 I; 125 I or 131 I, - R 6 is 2-hydroxyethyl, 3-hydroxypropyl, or 4-hydroxybutyl; - R 7 and R 8 are independently selected from the group consisting of C 1 to C 6 alkyl; C 2 to C 6 alkenyl; C 2 to C 6 alkynyl; C 3 to C 8 cycloalkyl; C 3 to C 8 cycloalkenyl; C 6 to C 10 aryl; C 3 to C 6 heteroaryl comprising at least one heteroatom selected from O, S, N; C 3 to C 6 heterocyclyl comprising one or two heteroatoms selected from O, S, N; whereas R 7 and R 8 can optionally be substituted by OH group or C 1 -C 4 hydroxy alkyl group; or - R 7 and R 8 together with the nitrogen atom form a four- to seven-membered ring, optionally comprising at least one further heteroatom selected from O, S, N, a optionally substituted by OH group or C 1 -C 4 hydroxy alkyl group; - whereas at least one, preferably exactly one, of substituents R 6, R 7 and R 8 is substituted by OH group or by C 1 -C 4 hydroxy alkyl group; - Y is a linker formed by a linear or branched hydrocarbon chain having 1 to 10 carbon atoms, whereas optionally 1 to 2 carbon atoms can be replaced by oxygen and/or sulfur atoms; and - X - is a pharmaceutically acceptable anion; with the proviso that: - when exactly one of the substituents R is 123 I; 124 I; 125 I or 131 I, and is in the ortho position, and all other substituents R are hydrogen atoms, Y is ―CH 2 -, R 6 is 2-hydroxyethyl, then NR 7 R 8 is not dimethylamino or pyrrolidino group, - when exactly one of the substituents R is 123 I; 124 I; 125 I or 131 I and is in the ortho position, and all other substituents R are hydrogen atoms, Y is ―CH 2 -, R 6 is 2-hydroxyethyl, R 7 is ethyl or 2-hydroxyethyl, then R 8 is not methyl. - the ring containing Z atoms is selected from benzene ring and thiophene ring; - R are independently selected from the group consisting of H; 123 I; 124 I; 125 I; 127 I; 131 I; C 1 to C 14 alkyl; C 2 to C 14 alkenyl; C 2 to C 14 alkynyl; C 6 to C 10 aryl; C 3 to C 6 heteroaryl comprising at least one heteroatom selected from O, S, N; C 3 to C 6 heterocyclyl comprising one to two heteroatoms selected from O, S, N; C 1 to C 14 alkoxy; C 6 to C 10 aryloxy; C 3 to C 6 heteroaryloxy comprising at least one heteroatom selected from O, S, N; C 3 to C 6 heterocyclyloxy comprising one to two heteroatoms selected from O, S, N; benzyloxy; C 1 to C 14 alkylthio; halogen; OH; SH; NH 2; C 1 to C 14 alkylamino; C 6 to C 10 arylamino; C 1 to C 14 acylamino; di(C 1 to C 14 alkyl)amino, wherein the alkyls are the same or different; di(C 6 to C 10 aryl)amino, wherein the aryls are the same or different; di(C 1 to C 14 acyl)amino, wherein the acyls are the same or different; CN; nitro and COOR n, wherein R n is H or C 1 to C 14 alkyl or aryl; - whereas at least one of the substituents R is 123 I; 124 I; 125 I or 131 I, - R 6 is 2-hydroxyethyl, 3-hydroxypropyl, or 4-hydroxybutyl; - R 7 and R 8 are independently selected from the group consisting of C 1 to C 6 alkyl; C 2 to C 6 alkenyl; C 2 to C 6 alkynyl; C 3 to C 8 cycloalkyl; C 3 to C 8 cycloalkenyl; C 6 to C 10 aryl; C 3 to C 6 heteroaryl comprising at least one heteroatom selected from O, S, N; C 3 to C 6 heterocyclyl comprising one or two heteroatoms selected from O, S, N; whereas R 7 and R 8 can optionally be substituted by OH group or C 1 -C 4 hydroxy alkyl group; or - R 7 and R 8 together with the nitrogen atom form a four- to seven-membered ring, optionally comprising at least one further heteroatom selected from O, S, N, a optionally substituted by OH group or C 1 -C 4 hydroxy alkyl group; - whereas at least one, preferably exactly one, of substituents R 6, R 7 and R 8 is substituted by OH group or by C 1 -C 4 hydroxy alkyl group; - Y is a linker formed by a linear or branched hydrocarbon chain having 1 to 10 carbon atoms, whereas optionally 1 to 2 carbon atoms can be replaced by oxygen and/or sulfur atoms; and - X - is a pharmaceutically acceptable anion; - when exactly one of the substituents R is 123 I; 124 I; 125 I or 131 I, and is in the ortho position, and all other substituents R are hydrogen atoms, Y is ―CH 2 -, R 6 is 2-hydroxyethyl, then NR 7 R 8 is not dimethylamino or pyrrolidino group, - when exactly one of the substituents R is 123 I; 124 I; 125 I or 131 I and is in the ortho position, and all other substituents R are hydrogen atoms, Y is ―CH 2 -, R 6 is 2-hydroxyethyl, R 7 is ethyl or 2-hydroxyethyl, then R 8 is not methyl.