Cardiac Imaging

Technological advancements in the field of medicine have provided physicians with a plethora of techniques, instruments and machines with which to accurately diagnose and treat disease. One particular area of medicine that has experienced explosive growth in the past 25 years or so is diagnostic imaging, medical tests that provide pictures of the body for the purpose of diagnosing disease.

Diagnostic Imaging

• A variety of different techniques and pieces of equipment are available for producing images of the body’s organs and tissues. X-rays represent a form of diagnostic imaging that has been in existence since the early 1900s. More recent diagnostic imaging procedures include ultrasound, computed tomography (CT) scanning, nuclear imaging, magnetic resonance imaging (MRI) and positron emission photography (PET) scanning. Many of these techniques are used to produce images of the heart and its structures, tests referred to as cardiac imaging. Common cardiac imaging procedures include cardiac CT angiography, cardiac MRI, echocardiography and nuclear cardiology.

CT Angiography

• Cardiac CT angiography is a noninvasive imaging technique used to provide a three-dimensional picture of the heart and its surrounding blood vessels. It literally allows physicians to look inside the heart without having to perform surgery. It aids cardiologists in diagnosing coronary artery disease, disorders of the aorta and other structural abnormalities of the heart. The test is often used to evaluate patients with inconclusive stress tests. This procedure is not recommended for routine cardiac screening as it does expose the patient to radiation.

Cardiac MRI

• The cardiac MRI is a particularly valuable noninvasive procedure because it provides live images that allow doctors to visualize the heart while it is beating. According to the University of Chicago Medical Center, the test is the “gold standard” for assessing heart function. Evaluation of the heart muscle’s structure and function can demonstrate causes of heart failure and the amount of muscle damage caused by a heart attack. Images are created using a large magnet, radio waves and a computer rather than radiation.

Echocardiography

• An echocardiogram is a noninvasive procedure that utilizes sound waves to demonstrate the heart’s structure, function and blood flow. It is particularly useful for examining the valves in the heart. Echocardiography can be used in a variety of ways and for different purposes. Sometimes it is used in conjunction with stress testing, providing images of the heart’s response to physically or chemically induced exercise. It can also be used along with invasive procedures that require the doctor to explore the inside of the heart. In such cases, echocardiography aids in guiding the physician’s movements, allowing him to see what he normally would not without cutting the patient.

Nuclear Cardiac Imaging

• Under normal circumstances, blood flow throughout the body can not be seen without the aid of special dyes. Nuclear cardiac imaging uses radionuclide dyes to demonstrate blood circulation to the heart muscle. The minimally invasive procedure is performed by first injecting a small amount of dye into a patient’s vein. A special camera is then used to detect the dye-containing blood and trace it as it flows through the different areas of the heart. Areas lacking dye represent those tissues not receiving sufficient blood supply. The procedure is beneficial for detecting the presence of blockages in coronary arteries.