Computer-assisted, operator-interactive technique for calculating pulmonary arterial taper.
We have developed a computer-assisted, operator-interactive technique which performs fast, precise computations of pulmonary artery taper. Individual 35-mm cineframes from balloon-occlusion pulmonary arteriograms are digitized into a 640 X 480 matrix in 8-bit depth and loaded into a VAX 11/780 computer for analysis. After operator identification of the arterial segment, an automated process of caliber analysis is initiated. By fitting a cubic spline function to the densitometric profiles extracted from the arterial segment, serial arterial cross-sectional diameters are calculated from the mathematically-derived points along the fitted curves. Spurious profiles, caused by sectioning at bifurcations, can be overridden by an operator-interactive subroutine. Taper is derived from the slope of the least-squares fit of vessel caliber with respect to its distance along the arterial segment. Results obtained by calculations from the computer-assisted caliber measurements were compared with those obtained by hand-tracing the same vessel segments. Correlation between computer-traced inflection points and hand-traced taper was very significant (r = .96, n = 13, P less than 0.001).
D002675:Child, Preschool; D003201:Computers; D006345:Heart Septal Defects, Ventricular / Q000150:complications; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging*; D007223:Infant; D007231:Infant, Newborn; D008722:Methods; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011859:Radiography