| A man in his 40s, complaining of chest pain, goes to his | | | | radiation exposure. |
| primary care physician. He has no known heart | | | | Coronary CT angiography uses a CAT scanner, |
| disease; he is a few pounds overweight and sits | | | | combined with iodine-based contrast agents, to |
| behind a desk all day. How likely is he to die from a | | | | generate cross sectional views of the heart and |
| coronary event within the next 10 years? Coronary | | | | coronary arteries. An advanced 3D workstation is |
| CT angiography (CCTA), a new, noninvasive test, | | | | used to process the images obtained, to depict cardiac |
| offers a fast and reliable means of ruling out the | | | | and vascular anatomy. A radiologist or cardiologist |
| presence of relevant coronary artery stenoses. | | | | evaluates the rendered images and reports his or her |
| "5.5% (9 million) of Americans aged 20-79 years are at | | | | findings. |
| intermediate risk of cardiac death or nonfatal | | | | But not all patients with chest pain have coronary |
| myocardial infarction within the next 10 years, using the | | | | artery disease. |
| standard NCEP definition of intermediate risk-two or | | | | In an article published in Radiology Today, Dr. David |
| more risk factors plus a Framingham score of | | | | Dowe, MD and COO of Atlantic Medical Imaging, |
| 10%-20%," according to Jon G. Keevil, M.D., of the | | | | stated, "... primary care doctors love that the exam |
| department of medicine at the University of Wisconsin, | | | | (CCTA) tells them exactly where the patient stands |
| Madison. "And using the most liberal definition of all-not | | | | with coronary artery disease. It basically answers the |
| even bothering to count risk factors, and instead | | | | question, does this patient have coronary heart |
| labeling everyone with a Framingham score of | | | | disease or not? Many times patients have been cycled |
| 6%-20% as intermediate-risk-then 16.2% qualify," says | | | | through cardiology when in fact they should have gone |
| Dr. Keevil. | | | | right to a gastroenterologist because their chest pain is |
| Identifying and treating coronary artery disease (CAD) | | | | esophageal in origin." |
| in its early stages has a positive affect on patients' | | | | Coronary CTA helps the primary care doctor place |
| health and is much less expensive than treating | | | | patients into the proper specialist's hands without the |
| far-advanced cardiovascular disease. | | | | patient having to see a cardiologist, pulmonologist, and |
| One traditional test for determining the presence and | | | | gastroenterologist. The advantage to the patient is the |
| severity of CAD is myocardial perfusion imaging (MPI), | | | | avoidance of unnecessary and potentially risky tests |
| that indirectly assesses arterial blockage. This test is | | | | and their related costs and inconveniences. |
| done with a nuclear camera over a period of up to | | | | Finally, with CT's ability to image the heart as part of a |
| several hours. Another traditional test is the invasive | | | | larger scan, the CCTA doubles as a generalized chest |
| coronary catheterization angiogram. A conventional | | | | scan where tumors, aneurysms, embolisms, and other |
| angiogram is an expensive procedure with a small but | | | | non-cardiac anomalies may be identified. |
| definite risk of complications, and that requires either a | | | | ## |
| brief hospitalization or a period of observation for | | | | 1-National Cholesterol Education Program. |
| several hours after the procedure. According to Dr. | | | | 2-A simple coronary disease prediction algorithm using |
| Armin Zadeh, Director of Cardiac CT at Johns Hopkins | | | | categorical variables, used to predict multivariate |
| School of Medicine, "The complication statistically at | | | | coronary heart disease risk in patients without overt |
| least of dying with a diagnostic cardiac catheterization | | | | coronary heart disease. Developed at the Framingham |
| is 1 in 1,000. There's still 1 in 500 of having strokes. The | | | | Heart Study, National Heart, Lung, and Blood Institute, |
| vascular complication rate is really quite drastic...." | | | | Framingham, Mass. |
| A 20-minute CCTA presents less risk to the patient | | | | 3-2005 annual meeting of the American College of |
| than invasive angiography; can reliably rule out the | | | | Cardiology, as reported in the April 15, 2005 edition of |
| presence of significant CAD in patients with a low to | | | | OB/GYN News article by Bruce Jancin. |
| intermediate probability of having CAD; and can reliably | | | | 4-Interview was conducted in November 2006 by Burt |
| achieve the high degree of diagnostic accuracy and | | | | Cohen of Angioplasty.Org and posted on their website. |
| technical performance necessary to replace | | | | 5-Radiology Today Interview: David A. Dowe, MD - |
| conventional angiography. Coronary CT angiography is | | | | Putting Cardiac CT Angiography Into Practice |
| also considered a more efficient and definitive | | | | Radiology Today Vol. 7 No. 4 P. |
| alternative to MPI, at approximately the same level of | | | | |