Doctors depend on cardiac imaging when they have patients suffering from chest pain or other risk symptoms of heart problems. This imaging procedure helps doctors in finding out whether there is an evidence of heart disease, such as blockages in the coronary arteries or reduced blood flow to the heart.
There are two main techniques of cardiac imaging, Cardiac Magnetic Resonance Imaging (MRI) and Cardiac Computed Tomography (CT). Both procedures are allowing doctors to take a closer look at the heart and great vessels of a patient. MRI uses huge magnets and radio-frequency waves to promote high-quality still and moving images of the body’s internal structures; no X-ray exposure is included. However, MRI has disadvantages; people with peacemakers cannot undergo MRIs. Also some people who are morbidly obese cannot fit in into an MRI system. MRI scans require patients to hold still for extended periods of time. MRI exams can range in length from 20 minutes to 90 minutes or more. Even a slight movement of the part being scanned can cause distorted images which means the scanning will need to be repeated. On the other hand, CT scan is an x-ray procedure which combines many x-ray images with the aid of a computer to generate cross-sectional views of the body. Cardiac CT uses advanced CT technology with or without intravenous iodine-based contrast to visualize cardiac anatomy, including the coronary arteries and great arteries and veins. CT scan has also disadvantages: Lack of IV access makes the CT procedure difficult to interpret, CTA is unsuitable when there is a large amount of existing coronary artery calcification
However, some patients still have fears that cardiac imaging procedures, such as cardiac CT, as it possess a threat to them as the technique includes delivering high doses of radiation. But doctors are currently developing new protocols and guidelines to ensure the maximum use of cardiac CT with lowest level of radiation exposure. MRI and CT provide no risk to the average patient if appropriate safety guidelines are followed, MR imaging can be safely performed in patients with implanted pacemakers in carefully selected clinical circumstances when appropriate strategies are used. Despite the overall acceptance of magnetic resonance (MR) imaging as an important diagnostic tool, the current policies of most radiologic institutions and professional organizations regard the presence of a cardiac pacemaker as a definite contraindication. Potential problems concerning the interactions between MR imaging and cardiac pacemakers are motion, dislocation, and a pacemaker leads in the static magnetic field; changes to the pacemaker program and damage to the pacemaker components that may be caused by static or pulsed magnetic fields; interference of the time-varying gradient magnetic fields with pacemaker function voltages and currents in pacemaker leads induced by pulsed gradient magnetic fields and/or pulsed radio-frequency and heating in pacemaker leads due to the electromagnetic RF field. Cardiac imaging includes other types such as cardiac Ultrasound , echocardiography.