Figure 6.

Segmentation and 3-D rendering of dye-injected vessels (the injected dye is white in the tomograms and orange in the 3-D renderings) to illustrate the four types of plexiform lesions. Insets show 2-D cross sections of the same lesions. Black asterisk, plexiform lesion; PA, pulmonary artery. A: type 1 lesion. The black arrowhead marks the monopodial branch connecting the PA to the lesion, and white asterisks connections to the vasa vasorum. White arrowheads mark the adventitia. B: type 2 lesion. The white asterisk marks the intrapulmonary bronchopulmonary anastomoses (IBA), proximal to the occlusion of the PA. The lesion connects with the peribronchiolar vascular network surrounding the airway (3-D reconstructed in blue). White arrowheads mark collateral flow to the poorly perfused area distal to the obstruction. C: type 3 lesion. The white asterisk shows a pulmonary vein that connects with the lesion. D: type 4 lesion within the PA. The cross section shown in the inset is captured approximately where the black asterisk is positioned, to illustrate how it would look in a 2 D histological slide. Supplemental Videos S6–S9 show the same lesions as in A–D. As images A through D are 2-D images of 3-D projections, regular scale bars are inapplicable. For reference, the lumen diameter of parent vessels are indicated by dashed lines: A = 359 µm; B = 228 µm; C = 137 µm; D = 251 µm. 2-D, two-dimensional; 3-D; three-dimensional.