Tomographic imaging was electrocardiographically
triggered at 60% or 80% of the R-R interval
(according to each individual imaging center’s protocol) and
proceeded from the level of the carina to the diaphragm.
Thus, this imaging protocol prevented the visualization of a
portion of the aortic arch. All areas of calcification with a
minimal density of 130 Hounsfield units within the borders
of the coronary arteries, aorta, mitral and aortic valves were
computed. A calcified plaque was considered present if at
least three contiguous pixels with a density of 130
Hounsfield units were measured (an area equivalent to
1.03 mm2). The radiation exposure from one EBT scan is
approximately 1 rem.