REPRODUCIBILITY OF QUANTITATIVE ARTERIOGRAPHIC ASSESSMENT OF ATHEROSCLEROSIS IN THE FEMORAL-ARTERY

Results from computer-analysed angiograms in the Probucol Quantitative Regression Swedish Trial (PQRST) were analysed to determine the repro ducibility of the method and any drift in the analysing system. The pr ecision index (P(mu)) for 2 angiography series, made at 10 min interva ls, of the femoral artery in 276 patients was 10.5 for lumen volume an d 21.9 for roughness (edge irregularity). No difference in reproducibi lity was found between patients with and without symptoms of periphera l atherosclerosis or when looking at the reproducibility over years. A drift of 0.67% per year in the radiographic equipment (but not in the analysis system) was found, confirmed by use of phantoms. Computer-ba sed analysis of femoral atherosclerosis is a reliable method for follo w-up trials, giving high reproducibility even if the trial spans over several years and involves different centres. The use of phantoms is e ssential for checking the method over time.