Chelating compounds and their use.

摘要

A polyaminedithiol compound of the formula: <CHEM> wherein R1, R2, R11 and R12 are each a lower alkyl group, R21 is a hydrogen atom or a lower alkyl group, and R3 and R13 are each a hydrogen atom or a nitrogen-containing organic group, provided that at least one of R3 and R13 is a nitrogen-containing organic group, which is used for imaging of the regional cerebral blood flow.