Coronary luminal morphology: Reconstruction from digital angiograms
Academic Article
Overview
abstract
Morphological features of coronary artery luminal anatomy may reflect lesion hemodynamics, composition, and stability. Therefore, a method of reconstructing arterial cross-sectional luminal shape from biplane digital cineangiograms was developed and applied to contrast-filled plexiglass models of coronary arteries with circular, crescentic, and double-luminal cross-sectional shapes. The extent to which cross-sectional shape could be reconstructed using only two orthogonal digital angiographic views was assessed using a reconstruction error (RE, % pixels incorrectly determined to contain contrast) and two quantitative descriptors of shape morphology-a measure of roundedness (RND, ratio of minimum to maximum second moment of the cross-sectional shape) and a descriptor of shape topology, the Euler number (Eu, number of solid regions in the shape minus the number of holes in the shape). Single-luminal cross-sectional shapes were reconstructed from biplane digital angiograms with a mean reconstruction error, RE, of 13.0% ± 2.0% (n = 16) for circular and 16.3% ± 1.5% (n = 32) for crescentic lumens. The mean roundedness was within 4.4% ± 0.9% (n = 16) and 11.2% ± 1.4% (n = 32) of the expected roundedness for circular and crescent luminal cross-sections, respectively. Shape topology was reconstructed accurately (true Eu = 1) independent of viewing angle for the single-luminal circular (Eu = 1.00 ± 0.00, n = 16) and crescentic (Eu = 1.03 ± 0.07, n = 32) cross-sections. Double-luminal cross-sections, which possess an inherent ambiguity when viewed at oblique angles, were detectable by Euler numbers of 2, 3, or 4. Thus, luminal morphology can be reasonably reconstructed from orthogonal images when circular or crescentic lesions are present; when complex double-luminal lesions exist, some ambiguity in reconstructed shape can be expected.
