<title>Pulmonary arterial remodeling revealed by microfocal x-ray tomography</title>

Abstract

Animal models and micro-CT imaging are useful for understanding the functional consequences of, and identifying the genes involved in, the remodeling of vascular structures that accompanies pulmonary vascular disease. Using a micro-CT scanner to image contrast-ennanced arteries in excised lungs from fawn hooded rats (a strain genetically susceptible to hyPoxia induced pulmonary hypertension), we found that portions of tne_pulmonary arterial tree downstream from a given diameter were morphometrically indistinguishable. This "self-consistency" propertY provided a means for summarizing the pulmonary arterial tree architecture and mechanical properties using a parameter vector obtained from measurements of the contiguous set of vessel segments comprising the longest (principal) pathway and its branches over a range of vascular pressures. This parameter vector was used to characterize the pulmonary vascular remodeling that o<;curred in rats exposed to a hypoxic (11.5% oxygen) environment and provided the input to a hemodynamic model relating structure to function. The major effect of the remodeling was a longitudinally (pulmonary artery to arterioles) uniform decrease in vessel , distensibility that resulted in a 90% increase in arterial resistance. Despite the almost uniform change in vessel distensibility, over 50% of the resistance increase was attributable to vessels. with unstressed diameters less than 125 microns.

Microfocal X-ray CT imaging and pulmonary arterial distensibility in excised rat lungs

“…) and is being used increasingly for physiological genomics in general (14,15,23,41,46) and for physiological genomics of the pulmonary vasculature in particular (21,26,29,42,47). Thus the objective of this study was to develop an approach for X-ray micro-CT measurement of pulmonary arterial diameters and their three-dimensional locations within the intact rat lung.…”

System for the analysis and visualization of large 3D anatomical trees

“…Rudimentary automated techniques for the definition of the vascular and hepatic trees have been previously suggested [4,[8][9][10][12][13][14][15]. Also, partly in recognition of the great complexity of vascular trees depicted in large 3D images, some automated analysis work has only focused on a principal pathway, where a principal pathway is designated as one selected path from the beginning of the tree (the "root") to the end of one terminating branch [16][17][18]. A few recent efforts have proposed rudimentary interactive "point and click" editing for deleting unwanted *Corresponding author.…”