Over the past decade or so, MRI has proven to be a very valuable tool in diagnosing various cardiac diseases such as ischemia, cardiomyopathy, cardiac tumors, aortic dissection and congenital heart disease. And hopefully, it would also become inexpensive.
What Is MRI
So what exactly is MRI? MRI stands for Magnetic Resonance Imaging. The MRI technique makes use of the characteristics of the single proton (it constitutes the nucleus of a hydrogen atom) to vibrate or resonate when it is exposed to bursts of magnetic energy. When the hydrogen nuclei resonates in response to the changes in the magnetic field, the MRI machine picks up this emitted energy and converts it into an image.
Basically, MRI uses radio frequency pulses, powerful magnetic field and a computer to generate detailed images of your organs, soft tissues, bone, heart and almost all the internal body structures. MRI produces very detailed and precise images. The current MRI machines are, in fact, able to generate 3-D images. These 3-D images can be sliced and examined in great details by your doctor.
Latest Advancements
With improvements in MRI technology, it has further become a very useful tool in detecting various heart conditions. Recently, MRI has been used in research settings to diagnose heart attacks in patients experiencing chest pain. Sometimes, when patients come to the emergency room complaining of chest pain, they might not show the typical ECG changes as seen with heart attacks. Moreover, the results of cardiac enzyme take more than one or two hours. This often leads to loss of critical time. On the other hand, MRI can detect a heart attack right away.
MRI is also being used to distinguish between stable plaques (atherosclerotic) and vulnerable plaques. Vulnerable plaques are prone to rupture and lead to a heart attack. If vulnerable plaques can be identified, they can be subjected to treatment such as angioplasty, stents, or bypass surgery.
Uses
Today MRI is used to detect and evaluate the following cardiac conditions:
• It helps to evaluate the structures and functions of the heart, valves, major vessels, and the surrounding structures such as the pericardium.
• It helps detect coronary artery disease.
• It helps to assess a patient’s recovery after treatment.
• Physicians use MRI to examine the size and thickness of the heart’s chambers.
• Helps examine the extent of damage caused to the heart muscle due to a heart attack or progressive heart disease.
• Helps detect plaque buildup in the arteries.
Advantages
There are many advantages associated with cardiac MRI. Such as-
• MRI in the future will replace the four other cardiac tests: thallium scan, diagnostic cardiac catheterization, echocardiogram, and the MUGA scan.
• Images generated by MRI are very precise and detailed, thereby helping physicians get the true picture.
• This technology does not expose the patients to ionizing radiation, which could be harmful for some patients.
Guidelines
MRI testing takes around 30 to 75 minutes. There are certain guidelines that you need to follow if you are going in for MRI testing.
• You might be administered a mild sedative if you are claustrophobic. If you have to take a sedative, then you should not eat any solid food six hours prior to the testing.
• You should be free of any magnetic and metallic items such as belt, credit cards, watches, metal zippers, etc.
• If you have gone for any metallic implants, you should tell the doctor. However, metallic implants like sternal wires and clips used in heart surgery do not cause any problems.
• Wear clothes that can be easily removed.
There are certain conditions in which a MRI cannot be performed. Patients with an implanted pacemaker or defibrillator cannot have a MRI scan. Pregnant women also are advised against MRI. Patients who have a cochlear (ear) implant, metal eye socket, implanted insulin pump, cerebral aneurysm clip or older model Starr-Edwards heart valve implant are advised against MRI.
However, on the whole, MRI has benefited millions of heart patients around the world. In the near future, patients can expect MRI to provide accurate diagnosis of heart disease.