Compounds binding to neuropathological aggregates

A method of imaging a patient, the method comprising administering to the patient an amount of a compound of the following formula (I) or a pharmaceutically acceptable salt thereof

• wherein:
• X1 and X4 are independently selected from CH and N;
• X2 and X3 are independently selected from CH2, S and O;
• R1 and R2 are independently selected from F, I, Br, and At, m and n are integers independently selected from 0 or 1;
• Ar1 and Ar2 are independently aryl, heteroaryl, or a substituted version of either of these groups, wherein one or more hydrogen atom is replaced independently for each occurrence with a halogen, hydroxy, nitro, cyano, alkyl, haloalkyl, alkenyl, alkynyl, amino, alkylaryl, alkylamino, alkylamine, alkoxy, aryloxy;
• —(O—CH2—CH2)o—R10, wherein R10 is selected from —H, —OH, —OSO2alkyl, —OSO2aryl, and —F, and o is an integer from 1 to 4;
• —NR11COOalkyl, —NR11COOarylCOalkyl, —NR11COaryl;
• —COOalkyl, —COOaryl, —COalkyl, —COaryl, aryl, cycloalkyl;
• cycloalkylamino-, -cycloalkylamine, heterocycle, a fluorescent label;
• or —Z—R12 substitutions wherein Z is selected from O, NR13, NH and S;
• and wherein R11, R12 and R13 are independently selected from H, CnH2n+1, CnH2n-hal, with n being an integer of 1 to 3, —CH2—CH═CH-hal, and —[CH2—CH2—O]p—[CH2—CH2]q-hal, wherein hal is selected from F, Cl, I, Br, and At, p is an integer of 1 to 3 and q is 1 or 2;
• wherein suitable pairs of substituents attached to adjacent ring members of Ar1 or Ar2,
• respectively, can be combined to form a ring fused with Ar1 or Ar2;
• wherein the compound of formula (I) or the pharmaceutically acceptable salt thereof is a radiolabeled compound, wherein one or more groups selected from R1, R2, a substituent attached to Ar1 and a substituent attached to Ar2 contain a radioisotope of an element which is present therein.