Longitudinal relaxation rate equal to reciprocal of T1 relaxation time (R1= 1/T1).

Combidex® is the brand name (same as Sinerem®) for an ultrasmall superparamagnetic iron oxide (USPIO) in the development pipeline to detect metastatic disease in lymph nodes. Metastatic lymph nodes show less uptake of this MRI contrast agent, which results in less signal decrease and allows the differentiation of normal lymph nodes from normal-sized, metastatic nodes. Combidex® has also potential to be used as a functional molecular imaging agent.
In March 2005, AMAG Pharmaceuticals Inc received an approvable letter from the U.S. Food and Drug Administration with respect to Combidex subject to certain conditions.
See also Ferumoxtran, Drug Development and Approval Process USA, Molecular Imaging and Classifications, Characteristics, etc.

Short name: PION, generic name: Polycrystalline iron oxide nanoparticles, central moiety: Fe2+/Fe3+, relaxivity: T2*enhanced, r2//r1=4.4, r2//r1=7
A substance under development (preclin.) as an RES-directed MRI contrast agent (larger particles = DDM 128, PION-ASF) for MR lymphography and the detection of liver lesions.

Sinerem® is the brand name (same as Combidex®) for an ultrasmall superparamagnetic iron oxide (USPIO) to detect metastatic disease in lymph nodes. Metastatic nodes show less uptake of this MRI contrast agent, which results in less signal decrease and allows the differentiation of normal lymph nodes from normal-sized, metastatic nodes.
Lymph node imaging with Sinerem® is performed 24 to 36 hours after slow infusion. Normal lymph nodes turn black post contrast, namely on T2* weighted images. Metastatic lymph nodes remain unchanged in signal intensity.
Indication and Diseases: Cancer, Imaging for diagnosis, Lymphatic disorders.
See Ferumoxtran, and Classifications, Characteristics, etc.

Guerbet decided in 2007 to withdraw its Marketing Authorisation Application (MAA) for Sinerem.

Artirem®, the arthrography-specific contrast agent for MRI is a dilute form of Dotarem® with a less concentration of Gd (1:200). Artirem® has to be injected directly into the joints for better visualization and delimitation, of the ligament and tendon structures in particular.