Utilization of computed tomography for extremity cellulitis: a retrospective single-center analysis

Abstract

PurposeRoutine imaging of soft tissue infection is not recommended and represents a potential area of computed tomography (CT) overuse. The utility of CT in patients with superficial soft tissue infection of the extremities is unknown. The purpose of this study is to evaluate the utilization and clinical impact of CT ordered in the setting of extremity cellulitis. MethodsWe retrospectively analyzed patients with extremity cellulitis examined with CT between 2012-2021 at a single center. We collected patient history, diagnostic imaging characteristics, and subsequent surgery decision. We hypothesized that yield of CT for deep infection was significantly lower than 10% and that yield was decreasing over time. These hypotheses were evaluated with Rao-Scott Chi-Square tests and repeated measures logistic regression. ResultsThere were 496 eligible encounters among 463 patients. Yield of positive CT among lower extremity patients was 5.5% (95%CI 3.33-7.75), significantly less than our hypothesis of 10% (p=0.003). In 71.8% of encounters, patients underwent diagnostic imaging studies in addition to CT. Utilization rose from 0.08% per hospital visit in 2012-2013 to 0.14% in 2020-2021, with differences in yield between time periods not reaching statistical significance (p=0.059). Among 496 encounters, 62 received surgery (12.1%), with 21 of these cases preceded by a positive CT for deep infection. ConclusionsOur 10-year single-center analysis of CT use for extremity cellulitis demonstrated a low yield of positive CT findings for deep infection and limited impact of CT on surgical management. A high incidence of patients undergoing multiple radiologic exams suggests uncertainty in selecting appropriate imaging modalities in this clinical scenario.