Health Awareness Society

   Numerous papers have  been published in major medical journals attesting to the accuracy of  Electron Beam CT Coronary Artery Scanning. Perhaps the most widely quoted statistic is the approximate 95% reliability of this procedure in ruling out obstructive coronary artery disease. This means that a negative scan (no coronary calcium) indicates with 95% reliability that the patient does not have a significant coronary artery obstruction. It should be noted that the older the patient, the higher the degree of reliability of a negative scan.

  With respect to positive scans (those finding coronary calcium), it has been demonstrated in numerous studies that (1) the amount of calcium correlates very highly with the overall volume of plaque and (2) the overall plaque volume correlates very highly with event risk (heart attacks, bypass surgeries, angioplasties). In other words, the higher the calcium score, the greater the risk of an event. One of the leading researchers in this field, Alan D. Guerci, M.D., Executive Vice President and Director of Research at St. Francis Hospital (Roslyn, N.Y.), was quoted as follows in The Wall Street Journal on September 27, 1996:

   Numerous papers have  been published in major medical journals attesting to the accuracy of  Electron Beam CT Coronary Artery Scanning. Perhaps the most widely quoted statistic is the approximate 95% reliability of this procedure in ruling out obstructive coronary artery disease. This means that a negative scan (no coronary calcium) indicates with 95% reliability that the patient does not have a significant coronary artery obstruction. It should be noted that the older the patient, the higher the degree of reliability of a negative scan.

"Our data indicate that the electron beam CT-derived coronary artery calcium score predicts fatal and nonfatal heart attacks, as well as the need for coronary bypass surgery and coronary (balloon) angioplasty, with unprecedented accuracy." 

   Recently, you may have heard other imaging centers claim that they can also perform coronary artery scans. However, many of these centers use spiral (a.k.a. helical) CT scanners that are not as accurate or reliable for cardiac purposes as the Electron Beam CT Scanner used at Heart Check America affiliated centers. While in general, spiral CT is excellent imaging technology and very reputable firms manufacture the scanners these centers use, they are clearly inferior for cardiac imaging. The reason is quite simple. When you attempt to take pictures of a moving object such as the beating heart, the shutter speed of the camera becomes of paramount importance. If the camera is too slow, the images are very blurry. The acquisition time for Electron Beam CT images is 100 msec (1/10 second), whereas the acquisition time for spiral scanners typically ranges from 400 - 700 msec. The effect on the quality of images of various shutter speeds can be seen in the visual example below.