What will we do if or when CT heart scans become outdated and something better comes along?
Heart scans are, after all, our principal tool for detection and precise quantification of coronary atherosclerotic plaque. They provide the basis for the Track Your Plaque program: serial heart scans to track progression or regression of coronary plaque.
So what the heck will we do if heart scans become obsolete, if some other technology proves superior for precise lengthwise quantification of coronary plaque ?
Simple: Then we will convert to that measure.
Say, for instance, that in 5 years, MRI advances to the point where it is quick and precise, despite the rapid motion of the heart that has, in past, caused this technology to stumble for plaque quantification. Instead of obtaining a heart scan score of, say, 350, instead an MRI might yield information like:
Calcium volume: 350 cubic mm
Soft plaque elements: 200 cubic mm
Fibrous tissue: 700 cubic mm
In other words, while a CT heart scan provides a calcium score that serves as a surrogate measure of total plaque volume, perhaps the next wave of technology will directly measure total plaque volume.
Don't CT coronary angiograms already measure total plaque volume?
No, they definitely do not. At present, the best they can do is visualize the non-calcific elements and suggest the diameter reduction created by plaque at a specific point. Thus, results like "50% blockage in the mid-left anterior descending." What they do not provide is a lengthwise total volume of plaque and all its elements. Perhaps some software manipulation in future will yield such information (and I think it will, though I personally have been unable to accomplish it).
So neither the Track Your Plaque program nor the Heart Scan Blog are necessarily bound to heart scans. But heart scans, in 2008, remain the number one best tool for plaque quantification that is easy, precise, available, and inexpensive. For those reasons, CT heart scans continue to serve as the basis for these programs, and not CT angiograms, MRI, or other non-quantitative technology.