Cardiovascular MR imaging includes the complete anatomical display of the heart with CINE imaging of all phases of the heartbeat. Ultrafast techniques make breath hold three-dimensional coverage of the heart in different cardiac axes feasible. Cardiac MRI provides reliable anatomical and functional assessment of the heart and evaluation of myocardial viability and coronary artery disease by a noninvasive diagnostic imaging technique.
Cardiovascular MRI offers potential advantages over radioisotopic techniques because it provides superior spatial resolution, does not use ionizing radiation, has no imaging orientations constraints and contrast resolution better than echocardiography. It also offers direct visualization and characterization of atherosclerotic plaques and diseased vessel walls and surrounding tissues in cardiovascular research.
MRI perfusion approaches measure the alteration of regional myocardial magnetic properties after the intravenous injection of contrast agents and assess the extent of injury after a myocardial infarction and the presence of myocardial viability with a technique based on late enhancement. Extracellular MRI contrast agents, like Gd-DTPA, accumulate only in irreversibly damaged myocardium after a time period of at least 10 minutes.
This type of patients may also have an implanted cardiac stent, bypass or a cardiac pacemaker and special caution should be observed on the MRI safety and the contraindications. While a number of coronary stents have been tested and reported to be MRI compatible, coronary stents must be assessed on an individual basis, with the medical team weighing the risks and benefits of the MRI procedure.

Cardiac MRI overview:

Cardiovascular MRI has become one of the most effective noninvasive imaging techniques for almost all groups of heart and vascular disease.

Possible MR guided interventions are breast MRI, liver and bone biopsies. Open MRI is advantageous to guide interventional procedures because this type of MRI scanner provides a better patient access.
Before the MRI guided biopsy is started, all the necessary precautions ensuring normal sterile and safe conditions for an intervention have to be performed. This includes the special safety issues concerning MRI surroundings and special equipment, like non-magnetic biopsy needles, localization tools (e.g. wires to mark lesions prior to surgery with breast MRI guidance) etc.

See also 5 Gauss Line, Contraindications, Low Field MRI, MR Compatibility, Magnetic Resonance Guided Focused Ultrasound and Computer Aided Detection.

The subacute risks and side effects of magnetic and RF fields (for patients and staff) have been intensively examined for a long time, but there have been no long-term studies following persons who have been exposed to the static magnetic fields used in MRI. However, no permanent hazardous effects of a static magnetic field exposure upon human beings have yet been demonstrated.
Temporary possible side effects of high magnetic and RF fields:
The results of some animal and cellular studies suggest the possibility that electromagnetic fields may act as co-carcinogens or tumor promoters, but the data are inconclusive. Up to 45 tesla, no important effects on enzyme systems have been observed. Neither changes in enzyme kinetics, nor orientation changes in macromolecules have been conclusively demonstrated.
There are some publications associating an increase in the incidence of leukemia with the location of buildings close to high-current power lines with extremely low-frequency (ELF) electromagnetic radiation of 50-60 Hz, and industrial exposure to electric and magnetic fields but a transposition of such effects to MRI or MRS seems unlikely.
Under consideration of the MRI safety guidelines, real dangers or risks of an exposure with common MRI field strengths up to 3 tesla as well as the RF exposure during the MRI scan, are not to be expected.

For more MRI safety information see also Nerve Conductivity, Contraindications, Pregnancy and Specific Absorption Rate.

See also the related poll result: 'In 2010 your scanner will probably work with a field strength of'

(NSF) Nephrogenic systemic fibrosis is a rare and highly debilitating disorder that involves extensive thickening and hardening of the skin with fibrotic nodules and plaques.
MRI contrast media have very low side effects, but accumulating data indicate that gadolinium-based contrast agents increase the risk for the development of NSF among patients with severe renal insufficiency or renal dysfunction due to the hepato-renal syndrome or in the perioperative liver transplantation period.
Due to this reason, gadolinium contrast agents are now considered contraindicated in patients with an estimated glomerular filtration rate fewer than 30 mL/min/1.73m². In these patients, avoid use of gadolinium-based contrast agents unless the diagnostic information is essential and not available with non-contrast enhanced magnetic resonance imaging (MRI).

Recognized or possibly associated factors for NSF:
When administering a gadolinium-based contrast agent, do not exceed the recommended dose and allow a sufficient period of time for elimination of the contrast medium from the body prior to any readminstration. Screen all patients for renal dysfunction by obtaining a history and/or laboratory tests.

See also Contrast Medium, Adverse Reaction, MRI Risks, MRI Safety, Ionic Intravenous Contrast Agents, Nonionic Intravenous Contrast Agents, and Contraindications.