Omniscan® is a nonionic chelate complex with low osmolality used as a paramagnetic MRI contrast agent. The efficacy of Omniscan® is similar to that of Gd-DTPA. Omniscan® is given intravenously to enhance images of intracranial and spinal lesions where there is abnormal vascularity or an abnormal blood brain barrier. The complex does not cross an intact blood brain barrier so Omniscan® only accumulates in lesions such as neoplasm's and abscesses.

WARNING: NEPHROGENIC SYSTEMIC FIBROSIS 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 Gadodiamide, and Classifications, Characteristics, etc.

OptiMARK® is a formulation of a nonionic gadolinium chelate of diethylenetriamine pentaacetic acid bismethoxyethylamide (gadoversetamide), for use as a paramagnetic MRI contrast agent. OptiMARK® (gadoversetamide injection) is to be administered by intravenous injection. OptiMARK® is indicated for MRI diagnostic procedures to provide increased enhancement and visualization of lesions of the brain, spine and liver, including tumors.

WARNING: NEPHROGENIC SYSTEMIC FIBROSIS 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.

Short name: Gd-DTPA, generic name: Gadopentetate dimeglumine, chemical compound: Gadolinium-diethylenetriaminepentaacetic acid
Gadopentetate dimeglumine was introduced in 1981, as the first paramagnetic MRI contrast agent (ionic). The Gd-induced dipole dipole interactions lead to shortening of T1, which results in contrast enhancement on T1 weighted images. The used metal ion Gd3+ (gadolinium) is toxic, and therefore bound in the renally excreted DTPA chelate, a very stable complex. The Gd-complex also induce susceptibility effects, as a result of the magnetic field gradient between the contrast agent in the blood vessels and the surrounding tissue, that lead to shortening of T2 or T2*.
Following intravenous administration, the compound is distributed rapidly in the extracellular space and is eliminated unchanged by glomerular filtration via the kidneys. Up to 6 hours, post injection an average of 83% of the dose is eliminated renal.

See also Magnevist®, Gadolinium and Contrast Agents.

Short name: Gd-HP-DO3A, generic name: Gadoteridol injection, chemical compound: Gd-1,4,7-tris(carbonylmethyl)-10-(2'-hydroxypropyl)-1,4,7,10-tetraazacyclododecane
(ProHance®) A nonionic MRI contrast agent with a low molecular weight complex of gadolinium (macrocyclic chelate, which tightly binds the Gd atom).
Gadoteridol does not cross the blood brain barrier. If the barrier is damaged, gadoteridol will penetrate into lesions such as tumors. It also highlights areas of increased vascularity so it has been used to improve the delimitation of lesions elsewhere in the body.
Apart from its paramagnetic effects, gadoteridol has no pharmacological activity in the body. After intravenous injection, most of the dose is excreted unchanged in the urine within 24 hours.

See also Contrast Agents and ProHance®.