Word: ct
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...also ideal for scanning children with congenital heart problems, since repeated radiation exposure in youngsters leads to an increased risk of developing cancer as adults. But again there are drawbacks. MRI scans are much more expensive than CT scans, and generating and interpreting them require lots of training. Furthermore, the magnet exerts a powerful attractive force on any iron-containing metals, so special precautions must be taken to prevent accidents...
Before 64-slice CT appeared on the scene, many physicians thought the future of cardiac scans belonged to a completely different technology: magnetic resonance imaging. Instead of X rays, MRI uses powerful electromagnets that are tuned to detect the hydrogen found in water--which in turn is present in most of the body's soft tissues. An MRI machine can produce astonishingly detailed images of the heart. Just as important, it can also determine how healthy the cardiac tissue is. For example, in a heart-attack patient, an MRI can pick out precisely which sections of the cardiac muscle...
Advocates of MRI admit that CT scans probably have the edge when it comes to imaging the heart's arteries, but that's about all. "Coronary arteries are only a small part of the heart," says Dr. Raymond Kim, co-director of the Duke Cardiovascular Magnetic Resonance Center. MRI is better at telling you how well the heart is pumping, how healthy its walls are and what shape the valves and chambers are in. In other words, says Dr. Edward Martin of the Oklahoma Heart Institute in Tulsa, "MRI has the potential to do everything...
...future, however, may belong to whoever can figure out how to make all these imaging technologies work together. One approach combines the anatomical accuracy of CT imaging with the functional information provided by a type of nuclear scan called positron-emission tomography (PET). Still in its early days in the clinic, PET/CT could help doctors see how much of the cardiac muscle is still alive after a heart attack and whether a bypass operation, balloon angioplasty or stent surgery would help damaged areas recover...
...increasingly clear that not all plaques that form inside a coronary artery's walls are dangerous. Some appear to be stable and don't grow much, whereas others contain an explosive combination of hardened fat and inflammatory proteins that make them likely to burst, triggering a heart attack. Neither CT nor MRI scans can reliably distinguish between the two sorts of lesions. Researchers are developing compounds that are chemically attracted to the inflammatory components of an unstable plaque with the hope of someday tagging trouble spots that need to be treated. But that could take a while...