Patent ID: 7524483

Claim:
A method for the determination, by use of the CEST MRI technique, of a physical or chemical parameter selected from temperature, pH, metabolite concentration, O 2 or CO 2 partial pressure and enzymatic activity in a human or animal body organ, fluid or tissue, wherein: a responsive paramagnetic CEST contrast agent is administered comprising at least one exchangeable proton whose saturation capability is correlated to the physical or chemical parameter of interest, and a CEST MR image responsive for said parameter is generated, the employed CEST contrast agent comprising a paramagnetic chelate compound in which the chelating ligand is a compound of formula (I) where: Ligand A R = R′ = R″ = R′″ = —CH 2 —CONH—CH 2 COOH Ligand B R = R′ = R″ = R′″ = —CH 2 —CONHNH 2 Ligand C R = R′ = R″ = —CH 2 —CONH 2 Ligand D R = R′ = R″ = —CH 2 —CONH 2 Ligand E R = R′ = R″ = —CH 2 —CONH 2 Ligand F R = R′ = R″ = —CH 2 —CONH—CH 2 —COOBu Ligand G R = R′ = R″ = —CH 2 —CONH 2 Ligand H R = R′ = R″ = —CH 2 —CONH 2 Ligand L R = R′ = R″ = —CH 2 —CONH—CH 2 COOH and the paramagnetic ion is selected from the group consisting of iron (II) (high spin), iron (III), cobalt (II), copper (II), nickel (II), praseodymium (III), neodymium (III), dysprosium (III), erbium (III), terbium (III), holmium (III), thulium (III), ytterbium (III), and europium (III), or a physiological acceptable salt thereof.