Cerebral (aneurysm) clips are at first contraindicated for MRI examinations unless specifically approved.
Other type of clips: Examinations may be done a few weeks after an operation. Movement of clips or staples placed in a body cavity can present a hazard, but this is often reduced due to the formation of fibrosis around the clips.

Short name: CMC 001, central moiety: Mn2+
CMC 001 is an orally administered MRI contrast agent in development for enhancement of the liver, bile ducts and gastrointestinal tract. Applications are screening of liver tumors/metastases, imaging of the biliary tract and it could be suitable for liver function studies by following the metabolism and excretion of manganese in the liver cells. Several advantages like better images, higher safety, lower costs and less inconvenience for the patient can be expected.
Animal experiments and clinical studies in humans Phase I and Phase II A, have shown excellent contrast enhancing properties with only minimal adverse effects. CMC 001 is under development by the Medicon Valley based CMC Contrast AB to receive a cost effective, safe and highly diagnostic MR contrast medium for abdominal MR imaging. Clinical studies in Phase III are started.

'CMC Contrast AB (Copenhagen Malmø Contrast AB) was established in April 2000. CMC Contrast AB was founded by professor Henrik Thomsen and the two main owners Malmøhus Invest AB and Öresund - Healthcare Capital KS.'
'The purpose of CMC Contrast AB is to develop the product CMC 001 to a registered medicinal product with market authorisation in the international pharmaceutical markets. CMC Contrast AB holds all the rights to CMC 001, and the company aims to develop CMC 001 to a registered medicinal product on a worldwide basis.'

Not necessarily a contraindication, but the examination may damage or impair it. Interference in electronic cochlear implants and ferromagnetic mechanical stapedial replacements has been reported.

Short name: Code 7228, generic name: Ferumoxytol, central moiety: Fe
Code 7228 is the code name for a substance in the development pipeline (AMAG Pharmaceuticals, Inc.) for use as a contrast agent in magnetic resonance angiography (MRA). Ferumoxytol, as a true blood pool agent, resides in the vascular space for an extended period of time and does not leak out into adjacent tissues like currently used gadolinium-based contrast agents. The product is being evaluated in MRA applications for the detection of blood flow in the heart muscle, in exploratory studies for the diagnosis of vulnerable plaque and as a next generation lymph node agent.
Code 7228 is currently in approval phase for use as an iron replacement therapeutic in chronic kidney disease patients receiving erythropoetin.
It is presently contemplated that Ferumoxytol will compete with the contrast agents Vasovist™ from EPIX Pharmaceuticals, Inc. and NC100150 Injection from Nycomed Amersham.