Abstract: To evaluate the reliability of geometry-based computer-aided detection and quantification for emboli morphology and embolism severity of acute pulmonary embolism. Thirty patients suspected acute PE were analyzed by manual and computer-aided interpretation of vascular obstruction index and computer-aided measurements of emboli quantitative indicators, respectively. The reliabilities of Qanadli and Mastora scores using computer-aided and manual interpretation were analyzed. The time costs of manual and computer-aided interpretation were statistically different(Q:(185.83 ±71.23) s vs.(169.97 ±69.16) s; M:(374.90 ±150.16) s vs.(121.07 ±51.76) s,all P < 0.001). The difference between computer-aided and manual interpretation of Qanadli score was 1.83 ±2.19; 97.5%(39/40) of the measurements were within 95% confidence interval(ICC=0.998). The difference between computer-aided and manual interpretation of Mastora score was 1.46 ±1.62; 97.5%(39/40) of the measurements were within 95% confidence interval(ICC=0.997). The emboli quantitative indicators were moderately correlated with Qanadli and Mastora scores(all P < 0.001). Computer-aided detection and quantification could help to improve the timeliness and reliability of vascular obstruction index, and provide additional and significant quantitative indicators for disease assessment.