Some dyamides are under preclinical development as intravascular MRI contrast agents for blood flow perfusion.

Short name: Dy-DTPA-BMA, generic name: Sprodyamide, central moiety: Dy2+, contrast effect: T2*enhanced, relaxivity: r1=3.4, r2=3.8, B0=0.47,

Short name: Dy-DTPA, central moiety: Dy2+, contrast effect: T2*enhanced,

Short name: Albumin-(Dy-DTPA)x, central moiety: Dy2+, contrast effect: T2*enhanced.

Eovist® (other brand name Primovist™) is a organ specific MRI contrast agent for the imaging, detection and characterization of liver conditions, including liver tumors, cysts, as well as other malignant and benign lesions. It is a water-soluble ethoxybenzyl derivative of Gd-DTPA. This compound is taken up by the hepatocytes (approximately 30% of the dose goes to the hepatocytes) and is equally excreted renal and biliary in humans. Excretion of Gd-EOB-DTPA in the bile may also permit visualization of both the gall bladder and the bile ducts.
Eovist® brightens the signal of T1 weighted MR images immediately after contrast administration. Dynamic and accumulation phase imaging can also be performed after bolus injection of Eovist®. The hepatocytes uptake will increase the signal intensity of normal liver parenchyma at 10 to 20 minutes after injection. This results in improved lesion-to-liver contrast because malignant tumors (metastases, the majority of hepatocellular carcinomas) do not contain either hepatocytes or their functioning is hampered.

WARNING: Gadolinium-based contrast agents increase the risk for nephrogenic systemic fibrosis (NSF) in patients with acute or chronic severe renal insufficiency (glomerular filtration rate less than 30 mL/min/1.73m²), or acute renal insufficiency of any severity due to the hepato-renal syndrome or in the perioperative liver transplantation period.

See also Drug Development and Approval Process USA, Contrast Medium, Hepatobiliary Contrast Agents, Tumor Specific Agents and Molecular Imaging.

Short name: GN-1140, chemical compound: Gd-DTPA-DeA, central moiety: Gd, phase: II
Gd-DTPA-DeA [Welfide Corp., Osaka, Japan], a paramagnetic MR contrast agent with hepatobiliary excretion is under development for liver imaging. This hydrophilic gadolinium chelate is a derivative of Gd-DTPA.

Paramagnetic substances, for example Gd-DTPA solutions, are used as MRI oral contrast agents in gastrointestinal imaging to depict the lumen of the digestive organs. Different Gd-DTPA solutions or zeolites containing gadolinium can be used e.g., for diagnosis of delayed gastric emptying, diagnosis of Crohn's disease etc.
Low concentrations of gastrointestinal paramagnetic contrast agents cause a reduction in T1 relaxation time; consequently, these agents act on T1 weighted images by increasing the signal intensity of the bowel lumen. High concentrations cause T2 shortening by decreasing the signal, similar to superparamagnetic iron oxide. Gd-DTPA chelates are unstable at the low pH in the stomach, therefore buffering is necessary for oral use.

See also Gadopentetate Gastrointestinal, Gadolinium Zeolite, Negative Oral Contrast Agents, Gastrointestinal Superparamagnetic Contrast Agents, and Ferric ammonium citrate.

Short name: Gd-DTPA-BMA, generic name: Gadodiamide, chemical compound: Gd-diethylenetriaminepentaacetate-bis(methylamide), central moiety: Gd
A paramagnetic MRI contrast agent (nonionic) with a small molecular weight linear chelate. Due to the linkage of two DTPA molecules through amide bonds the molecule is uncharged and has a low osmolality. The substance is excreted almost exclusively by the kidneys.

See also Nonionic Intravenous Contrast Agents and Omniscan®.