Infected versus sterile abdominal fluid collections in postoperative CT: a scoring system based on clinical and imaging findings.

PURPOSE Characterization of intraabdominal fluid collections as postoperative complication is a challenging task. The aim was to develop and validate a new score to differentiate infected from sterile postoperative abdominal fluid collections and to compare it with a published score. MATERIALS AND METHODS From May to November 2015, all patients with postoperative CT and C-reactive protein (CRP) 24 hours before CT-guided drainage were retrospectively included (Group A). HU, gas entrapment and wall enhancement of fluid collections were evaluated in the CT. All parameters were correlated with microbiology. To validate the score and to compare it with a published score, a second patient cohort was retrospectively recruited (Group B; January 2013-April 2015; December 2015-September 2016). RESULTS In Group A (50 patients), univariate analysis confirmed that the four parameters were significantly associated with infected fluid collections. Based on binary logistic regression analysis, a score from 0 to 11 was developed (CRP