Method and compositions for orally administered contrast agents for MR imaging
Disclosed is CT or MR contrast agent which comprises a base or carrier scaffold formed of a polyhydroxol compound having a linker to which a Gd-DOTA is covalently bonded. Also disclosed is a method of screening a patient for colon cancer using a CT or MR contrast, which method comprises administering to a patient undergoing screening a compound as above described.
1. A method of screening a patient for colon cancer using a computed tomographic (CT) or magnetic resonance (MR) colonography, said method comprising:
dissolving a water soluble CT or MR contrast agent in an aqueous solution to produce an aqueous solution of colonography contrast agent;
administering to a patient said aqueous solution of colonography contrast agent; and
screening the patient for colon cancer using a computed tomographic colonography (CT-C) or a magnetic resonance colonography (MR-C), wherein the water soluble CT or MR contrast agent comprises a base or carrier scaffold formed of a polyhydroxol compound having a plurality of polyhydroxol functional groups, wherein each of said polyhydroxol functional group is linked to a moiety of the formula:
and wherein R comprises straight chain polyethylene glycol linker having on its terminal end a Gd-chelated DOTA moiety of the formula:
2. The method of claim 1 , wherein the polyhydroxol compound comprises a disaccharide.
3. The method of claim 2 , wherein the polyhydroxol compound comprises sucrose.
4. The method of claim 2 , wherein the average number of Gd-DOTA chelates bonded to the sucrose is 8.
5. The method of claim 1 , wherein the linker incorporates one or more straight chain hydrocarbon segments.
6. The method of claim 1 , wherein the linker incorporates one or more branch chain hydrocarbon segments.
7. The method of claim 1 , wherein colorectal cancer (CRC) cells are screened for.
8. The method of claim 1 , wherein the molar relaxivity (R 1 ) of said water soluble CT or MR contrast agent is 213±1.7 mM s −1 .