Two-dimensional quantitative coronary angiographic models for bifurcation segmental analysis: in vitro validation of CAAS against precision manufactured plexiglas phantoms.

摘要

BACKGROUND: Quantitative coronary angiography (QCA) analysis for bifurcation lesions needs to be standardized. Objectives: In vitro validation of two models for bifurcation QCA segmental analysis. Methods: In the latest edition of the Cardiovascular angiography analysis system (CAAS 5v8, Pie Medical Imaging, Maastricht, The Netherlands) a 6-segment model for two-dimensional coronary bifurcation analysis was implemented next to the currently available 11-segment model. Both models were validated against 6 precision manufactured plexiglas phantoms, each of them mimicking a vessel with three successive bifurcation lesions with variable anatomy and Medina class. The phantoms were filled with 100% contrast agent and imaged with a biplane gantry. Images acquired in antero-posterior (AP) direction by either C-arm and at 30 degrees right and left anterior oblique angulation were analyzed by two independent analysts, blinded to the actual dimensions. Manual correction of the contours was not allowed. Measurements for minimal lumen diameter (MLD), reference vessel diameter (RVD), percent diameter stenosis (DS) and bifurcation angle (BA) were compared with the true phantom dimensions. Results: In AP views the accuracy and precision (mean difference +/- SD) of 11- and 6-segment model for MLD, RVD, and DS were 0.065 +/- 0.128 mm vs. 0.058 +/- 0.142 mm, -0.021 +/- 0.032 mm vs. -0.022 +/- 0.030 mm, and -2.45% +/- 5.07% vs. -2.28% +/- 5.29%, respectively. Phantom MLD values 0.7 mm in excellent agreement with the true dimensions.