Similar to a CT scan of the body, iodinated contrast is injected through a vein in the arm. However, because of the rapid rate of the heart, examination of the heart and coronary arteries is challenging. With the introduction of a 64 slice CT scanner, we are now able to “freeze” the motion of the heart to image the coronary arteries with a high resolution. Coronary CT angiography has become quite useful in ruling out significant coronary artery disease in individuals with a low to moderate cardiac risk. Coronary CT angiography allows a less invasive, quicker and safer alternative to traditional angiography.
Computed Tomographic Scan combines a series of X-Ray views taken from many different angles to produce “cross-sectional” images of the body system, such as the brain, the heart and the bones. Each picture is of an area, or 'slice' of the body, similar to the slices of a loaf of bread. The imaging speed of CT scan is usually very fast (though extra time is needed for preparation to ensure best quality result). The CT scan generally obtains many “thin slices” of the body organ system and enables the ordering and the interpretating physicians to view the data in a 3-dimensional format in special workstations.
The CT images are obtained using X-Rays (a form of radiation). In certain cases, an iodinated contrast will also be used, in order to provide better information of the body organs and the blood vessels. In certain situations that patient cannot undergo Magnetic Resonance Imaging (MRI), e.g. pacemaker insertion or claustrophobia, CT can also provide very useful information.
At Baylor St. Luke’s Medical Center, the CT department provides a large volume of CT scans to both our in- and out-patients with state-of-the-art CT scanners. Our clinicians aim to obtain the best quality images with the lowest radiation dose. By fall 2011, we will be finished installing the first premium multi-slice CT scanner in the Texas Medical Center that will provide further comprehensive and advanced imaging of the CV system. In addition, the new premium scanner will offer further radiation dose reduction techniques.
Tests offered at the Baylor St. Luke's Medical Center CVCT department include the following:
Not every clinical condition is appropriate for CT and there are certain clinical situations when CT should not be performed. Your ordering physician would ensure that you can receive iodine contrast (including a stable kidney function). Your doctor should already have discussed the risk and benefit of the CT scan and determined the benefit of receiving x-rays (and therefore the information CT will provide to make further clinician decisions) would outweigh any theoretical risk.
The CVCT service at the Baylor St. Luke’s Medical Center is staffed by dedicated clinicians with advanced and specialized training in CV imaging. The majority of the reports will be completed within 24 hours of examination and be sent directly to the ordering physicians.
Watch a video of a 3D CT of the heart and pulmonary vessels.
CT Calcium Score
A cardiac CT scan for coronary calcium is a non-invasive way of obtaining information about the presence, location and extent of calcified plaque in the coronary arteries—the vessels that supply oxygen-containing blood to the heart muscle. Calcified plaque results when there is a build-up of fat and other substances under the inner layer of the artery. This material can calcify which signals the presence of atherosclerosis, a disease of the vessel wall, also called coronary artery disease (CAD). People with this disease have an increased risk for heart attacks. In addition, over time, progression of plaque build up (CAD) can narrow the arteries or even close off blood flow to the heart. The result may be chest pain, sometimes called "angina," or a heart attack.
Because calcium is a marker of CAD, the amount of calcium detected on a cardiac CT scan is a helpful prognostic tool. The findings on cardiac CT are expressed as a calcium score. Another name for this test is coronary artery calcium scoring.
Women should inform their physician if they are pregnant, or if there is any possibility they may be pregnant.
Radiation Dose: Special care is taken during X-Ray examinations to use of the lowest radiation dose possible while producing the best images for evaluation.