Calcium density score
The calcium density score is referred to as a measure to quantify coronary artery calcium.
Measurement
Calcium density itself describes the concentration of calcium in a specific atherosclerotic plaque . Calcium density can be calculated by dividing the Agatston score by the total area of calcium. The latter is retrieved by dividing the calcium volume score by the slice thickness. So if both the Agatston score and calcium volume score are known, the average calcium density score can be calculated .
Interpretation
Coronary artery calcium density is positively correlated with age, but inversely correlated with other cardiovascular risk factors and in asymptomatic individuals higher coronary artery calcium density seems to be inversely correlated with coronary heart disease and cardiovascular disease at any level of calcium volume . In other words, coronary artery disease is positively associated with plaque volume and many of them are calcified but soft or mixed atherosclerotic plaques are more likely to rupture than densely calcified plaques. The latter is more likely older and prone to lead to stable angina, which then gets revascularized .
In symptomatic individuals, however, the calcium density score seems to be a significant and independent as well as superior predictor of incidental major cardiovascular events (MACE) within a two years period than the Agatston score or calcium volume score .