A voxel-map quantitative analysis approach for atherosclerotic noncalcified plaques of the coronary artery tree

Abstract

Noncalcified plaques (NCPs) are associated with the presence of lipid-core plaques that are prone to rupture. Thus, it is important to detect and monitor the development of NCPs. Contrast-enhanced coronary Computed Tomography Angiography (CTA) is a potential imaging technique to identify atherosclerotic plaques in the whole coronary tree, but it fails to provide information about vessel walls. In order to overcome the limitations of coronary CTA and provide more meaningful quantitative information for percutaneous coronary intervention (PCI), we proposed a Voxel-Map based on mathematical morphology to quantitatively analyze the noncalcified plaques on a three-dimensional coronary artery wall model (3D-CAWM). This approach is a combination of Voxel-Map analysis techniques, plaque locating, and anatomical location related labeling, which show more detailed and comprehensive coronary tree wall visualization.

Figure 1

3D-CTM reconstruction and creating Voxel-Map. The reconstruction of 3D-CTM (a); the horizontal plane in the position of 3D-CTM where lined in panel a (b) and a local region of the horizontal plane (c); more detailed values of pixels are shown in Figure 1(d). Positive and negative signs represent dilation and erosion, respectively, and the values represent the distance off lumen.

Figure 2

The blue and red lines represent the mean CT attenuation values of inner lumen and the border of lumen nearby wall, respectively. The y-axis is the range of CT attenuation values; the x-axis is slice number of CTA images.

Figure 3

The mean CT attenuation values of various layer on wall are gradient decreased from inside to outside. The y-axis is the range of CT attenuation values; the x-axis is slice number of CTA images.

Figure 4

Centerline extraction (a) and anatomical labeling (b).

Figure 5

The three-dimensional coronary tree model (3D-CTM) and coronary artery wall model (3D-CAWM). The original 3D-CTM (a); the 3D-CAWM (b); the top view of 3D-CAWM (c); the stenosis of coronary tree in 3D-CTM (d) and 3D-CAWM (e).

Figure 6

Quantitative analysis of 3D-CAWM. The left column shows that the original CTA images, A1, B1, C1, are horizontal plane, sagittal plane, and coronal plane, respectively. The middle column figures of A2, B2, and C2 show the corresponding planes in 3D-CAWM, and A3, B3, and C3 show the corresponding quantitative results based on Voxel-Map.

Figure 7

Plaques visualization. The reconstruction of coronary tree and NCPs (a); the transparent coronary tree to observe plaques (b); the analysis results in horizontal plane (c). The different colors represent different severities.

Figure 8

CMPR vessel representation (by AW Volume Share 4 software, GE, America). Longitudinal straightened views (a); the left rotated 284 degree views (b) and the left rotated 295 degree views (c).