Cardiac MRI is a relatively new method of imaging the heart and blood vessels that is non-invasive and does not use radiation (like X-rays). Instead, a powerful magnetic field is briefly created to cause hydrogen ions within cells to move from their normal position. When the field is turned off the hydrogen ions move back to their original positions, and the energy they release is detected by the machine and interpreted to create an image.
Cardiac MRI is safe and no long-term ill effects have been demonstrated, although claustrophobia may be a problem in a few patients. One of the most important safety issues for MRI is to keep metals that are attracted to the magnet (steel, for example) away from the scanner. This means that patients with cerebrovascular clips, pacemakers and other electronic implants are usually not able to undergo cardiac MRI scanning. Hip prostheses, prosthetic heart valves, coronary stents and sternal sutures, however, are not attracted to the magnet so patients can safely undergo MRI scanning.
Indications for Adult Cardiac MRI
- Adult Congenital Heart Disease- Initial evaluation and follow-up of adult congenital heart disease.
- Acquired diseases of the major blood vessels- eg aorta, renal arteries
- Coronary artery disease- coronary anomalies
- Overall heart size and function cardiomyopathies, myocardial infiltrative disorders, etc.
- Assessment of pericardium and constrictive pericarditis.
- Assessment of cardiac valve function
- Assessment and characterisation of cardiac tumours.