Patent ID: 7118730

Claim:
A compound, or salts or solvates thereof, represented by the formula I(a) or I(b): wherein, R 1 , R 2 , and R 3 independently are hydrogen, halogen, OH, COOH, SO 3 H, NH 2 , NO 2 , CO—NH—NH 2 , alkyl having 1 to 4 carbons (hereinafter, referred to as C 1-4 alkyl), or O—C 1-4 alkyl, wherein two R 1 s, together, may form a benzene ring; R 4 and R 5 independently are hydrogen or C 1-4 alkyl; and m and n independently are an integer of 0 to 4; and wherein said compound is labeled with a radionuclide.