SEVERITY ASSESSMENT OF ACUTE PULMONARY-EMBOLISM WITH SPIRAL CT - EVALUATION OF 2 MODIFIED ANGIOGRAPHIC SCORES AND COMPARISON WITH CLINICAL-DATA

Spiral computed tomography (CT) has shown promising results in the det ection of acute pulmonary embolism. The aim of this study was to inves tigate whether the severity of acute pulmonary embolism could be quant itatively assessed with spiral CT examinations and to test the potenti al clinical impact of this information. In a consecutive series of 123 patients screened with spiral CT for suspected acute pulmonary emboli sm, 31 patients (25%) had evidence of emboli. The severity of pulmonar y arterial obstruction in those 31 spiral CT examinations was evaluate d by two independent observers using angiographic scores previously de scribed by Walsh (29) and Miller (30), adapted to the needs of spiral CT. Clinical patient subgroups were defined according to oxygen satura tion, heart rate, and echocardiographic signs of right ventricular str ain. CT severity scores were then correlated to each other and to clin ical parameters using the Spearman rank test. Interobserver agreement was calculated using the analysis of variance. Both modified Walsh and Miller scores were readily reproducible and showed interobserver agre ements of 0.85 and 0.96, respectively (p = 0.001). Patients with mild and marked clinical abnormalities showed statistically significant dif ferences between CT severity scores. Differences between severity scor es of patients with moderate and marked clinical abnormalities were so mewhat significant. No significant mean severity score differences wer e seen between patients with mild and moderate clinical abnormalities. Although correlations of severity scores and detailed clinical parame ters within the defined subgroups were moderate to poor, threshold sco res greater than 10 (Miller) and greater than 11 (Walsh) always indica ted marked clinical abnormalities. The modified scores presented in th is study constitute a readily reproducible method for the quantitative assessment of acute pulmonary embolism severity on spiral CT examinat ions.