Mri contrast agents endowed with concentration independent responsiveness
AssigneeBracco Imaging Folli S.p.A.
InventorsSilvio Aime, Enzo Terreno
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Abstract
The present invention relates to a method for the in vivo, ex vivo, or in vitro determination of physical or chemical parameters of diagnostic interest by use of a slow tumbling paramagnetic agent that is responsive to changes of said physical or chemical parameter through changes in the R2p/R1p ratio allowing the determination of the said parameter in a manner that is independent on the actual agent concentration.
Claims20
A method for the in vivo determination, by use of the MRI technique, of a physical or chemical parameter of diagnostic interest in a human or animal body organ, fluid or tissue, said method comprising:
- administering to said human or animal a diagnostically effective amount of a slow tumbling paramagnetic agent that is responsive to microenvironmental changes of said parameter through changes in the R2p/R1p ratio;
- recording a MRI;
- and
- calculating the R2p/R1p ratio responsive for said parameter.
A diagnostic composition comprising at least one slow tumbling paramagnetic agent endowed with a τR value from 1 to 10 ns and a τM value from 0.01 to 1 μs and for which the rotational mobility τR and/or the mean residence lifetime τM of the mobile protons dipolarly coupled to their metal center and/or the longitudinal electronic relaxation time τ1S are dependent on the physical or chemical parameter of diagnostic interest, for use in determining the said parameter in a human or animal body organ or tissue, by use of MR Imaging.
A slow tumbling paramagnetic agent responsive to changes of a given physical or chemical parameter of diagnostic interest through changes in R2p/R1p ratio for use in the determination of the said parameter in a human or animal body organ, fluid or tissue, by use of the MRI, in a manner which is independent on the absolute concentration of said administered agent.
A compound selected from the following:
- the (Gd-1)4/Avidin adduct wherein Gd-1 has the following structure
- the macromolecular adduct Gd-II.
Dependencies are inferred from the claim text.