Because the coronary arteries supplying blood to the cardiac muscle are in constant motion as the heart beats, obtaining X-ray images of the vessels was difficult until the new superfast machines were built. Angiography involves sliding a catheter through the circulatory system until it reaches a coronary artery. A special dye is injected through the catheter into the vessel while X-ray photos are taken. Over one million diagnostic cardiac catheterizations are performed each year, the AHA estimates. An ultrafast CT exam takes only a few minutes and does not require the presence of a physician.
Plaques are deposits of cholesterol, other fats and substances such as calcium.
Ultrafast CT scans take pictures of the calcium, a mineral that tends to be found in larger amounts in older plaques, says Brundage. For that reason, ultrafast CT may not be as useful in patients under age 45. The average age of the 456 men and 254 women in the study was 56. To further determine the diagnostic accuracy of ultrafast CT scanning, the scientists also studied the 283 patients with angiograms showing no significant coronary disease. I think that's the important breakthrough.