Abstract
Carotid atherosclerotic plaques have a three-dimensional shape on initial detection and progress in their contour and size in all three directions over time. To estimate the plaque volume, we measured circumferential (c(p)) and sagittal (l(p)) length, and mean of luminally protruding thickness (t(mean)) from axial and sagittal carotid duplex ultrasonography (CDU) images of the carotid plaques. Then, we calculated plaque volume using the hemi-ellipsoid volume formula (π[c(p) × l(p) × t(mean)]/6) with the three axis values. We logically validated that the hemi-ellipsoid volume formula could be applied to estimate the volume of all plaques with smooth or irregular thicknesses and involving the partial or entire axial lumen. The hemi-ellipsoid volume evaluations were a better tool to assess severity and atherosclerotic burden of carotid atherosclerotic plaques on follow-up than one-dimensional diameter ([1-{stenosis/lumen diameter}] × 100%) and two-dimensional area stenosis ([1-{stenosis/lumen area}] × 100%) evaluations. The present study showed successful implementation of the hemi-ellipsoid volume formula to logically measure plaque volume. The logical volume estimation was better for evaluating and monitoring the severity and atherosclerotic burden of carotid plaques.