Table 1: Comparisons of Imaging Techniques in for the Detection of Coronary Calcium.

Technique	Advantages	Disadvantages
Coronary CT	Non-invasive technique Calcium score in asymptomatic individuals Prognostic role of calcium score Calcium location along coronary vessels detected Spotty calcifications are detected	Contrast medium
Coronary angiography	Calcium location along coronary vessel detected	Invasive technique Contrast medium Low sensitivity Only qualitative grading of calcium Moderate calcifications are detected only during the cardiac cycle
Intravascular ultrasound	No contrast medium Superficial and deep calcium is detected Semiquantitative grading of calcium: distribution, localisation, length, arc	Invasive technique Deep calcium is hidden by acoustic shadow Microcalcifications are not detected Unable to assess calcium thickness
Optical coherence tomography	Very high resolution Calcium thickness can be measured Quantitative grading of calcium: distribution, localisation, thickness, area, volume Microcalcifications are detected	Invasive technique Contrast medium Limited depth penetration