Feature 0410 - CT coronary angiography
(click images to enlarge)
Coronary artery disease is one of the biggest sources of mortality
and morbidity in the Unites States. The disease is often silent
until late stages when it can lead to a sudden heart attack, angina
pectoris or heat failure. The early detection of coronary artery
disease is, therefore a desirable project.
In attempting to detect and diagnose coronary
artery disease, many indirect and direct tests have been developed.
Indirect tests include risk factor assessment, serum cholesterol and
triglyceride measurements, coronary calcium scoring and stress EKG.
More direct evaluation of the coronary arteries, has, to date
required more invasive tests such as catheter coronary angiography
(heart catheterization). Although considered to be the most
accurate method for detecting coronary artery disease, heart
catheterization carries a small associated risk of complications or
death of ~ 2%. This is an acceptable risk in patients who are at
high risk of a coronary artery event, however in the screening of
lower risk patients, less invasive alternative is desired. Over 1
million coronary artery catheterizations are performed in the U.S.
every year. About 30% of these are either normal, or have
insignificant abnormalities.
With the recent advent of newer generations of
multi-slice detector CT, direct visualization of the coronary
arteries with CT has been made possible. The test is minimally
invasive requiring the intravenous injection of iodine containing
contrast during a rapid computed tomographic acquisition though the
heart. The actual scan takes only a few seconds. The rapid
acquisition time and advanced software virtually freeze heart
motion, thus allowing the generation of very sharp images of the
coronary arteries. The examination requires the administration of a
short acting beta-blocker intravenously in order to temporarily slow
cardiac motion to 50 to 60 beats per minute.
The exam is intended to assess the main
coronary arteries, although second and third level branches can
often be visualized and evaluated. Additionally the resulting, high
quality, 3-dimensional images of the heart provide detailed views of
internal cardiac chamber anatomy, the pulmonary arteries and veins
and the coronary veins. In many cases this information can be quite
useful to the cardiologist for planning and treatment. Patients who
should be considered for this exam include the following:
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Individuals with chest pain or angina.
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Patients who have undergone a bypass or stent revascularization
procedure and need to be evaluated for graft or stent patency.
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Patients with unexplained cardiomyopathy.
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For procedural planning and coronary sinus localization prior to
pacemaker placement.
-
For procedural planning prior to ablation treatment.
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Patients with multiple high risk factors such as a strong family
history of heart disease, smoking and elevated cholesterol.
The patient should count on a 30 to 45 minute
stay in the radiology department for I.V. access, set-up time and
monitoring.
Radiology Associates of North Idaho, in
conjunction with Kootenai MRI and KMC, was the first to bring
this technology to our region and continues to provide cutting edge
services in imaging. We have two, state-of –the art Siemens
Sensation 16 scanners, sophisticated workstations and highly trained
personnel capable of performing these very specialized tests.
Author:
Albert J. Martinez M.D.
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