Using CT scans to see plaque in coronary arteries (USA)

"The test, called, coronary artery calcium scoring, is meant to reveal patients at risk for heart attack but may prompt some to get unnecessary surgery. It seems like the pinnacle of medical science: For just a few hundred dollars, you can walk into just about any hospital in Southern California and ask a doctor to check your arteries for buildup of heart-attack-inducing calcium plaque. Most of the time, what goes on inside our bodies is a mystery, but there's something satisfying in the thought that a sophisticated piece of equipment can measure just how clogged our arteries really are (and how much more junk food we can afford, or not afford, to eat). To obtain your calcium score, a radiologist will use a CT scanner to produce images of the plaque in the coronary arteries and then estimate how much it is obstructing the flow of blood to the heart (a test known as coronary artery calcium scoring using cardiac CT). This score ranges from 0 in patients with no visible calcium to more than 400 for people who have chest pains related to blockages. In general, calcium scores of more than 100 represent people who are at increased risk of a heart attack. However, not all doctors agree that calcium scoring should be used to screen men and women who show no signs of heart disease - and they feel that advertising the procedure can lead to abuses in its application. For one thing, they say, even patients with high calcium scores may not exhibit any health problems, but the test results will increase the likelihood that patients will undergo unnecessary and dangerous surgeries" - Chicago Tribune