Automated quantitative coronary arteriography: morphologic and physiologic validation in vivo of a rapid digital angiographic method.

Quantitative coronary arteriography has been shown to be useful in assessing the extent of coronary disease, its functional significance, and its response to therapeutic interventions. Most current methods rely either on hand-drawn arterial contours or automatic edge-detection algorithms applied to 35 mm cineangiograms. To assess the performance in vivo of a new, fully automatic, rapid coronary quantitation program, dogs were instrumented with precision-drilled, plastic cylinders to create intraluminal stenoses in the left anterior descending and/or circumflex arteries, as well as with high-fidelity micromanometers and electromagnetic flow probes. Stenosis diameters ranged from 0.83 to 1.83 mm. Biplane, on-line, digital coronary angiograms and cineangiograms were recorded during standard selective coronary arteriography in the closed-chest preparation. The on-line digital images were analyzed in nonsubtracted and subtracted modes. Cineangiograms were digitized to allow coronary quantitation by the same computer program. There was an excellent correlation between known and measured minimal diameter stenoses (r = .87 to .98, SEE = 0.09 to 0.24 mm). Interobserver and intraobserver variability analysis showed high reproducibility (r = .90 to .97, SEE = 0.12 to 0.23 mm). The best results in both analyses were achieved by nonsubtracted digital imaging and the worst by cineradiography. Measures of percent diameter stenosis, percent area stenosis (geometric and videometric), and absolute minimal cross-sectional area (geometric and videometric) were all significantly correlated with independent measures of actual coronary flow reserve. This study provides direct anatomic and physiologic validation in vivo of a new and rapid coronary quantitation method suitable for analysis of both digital angiograms and cineangiograms.