Necrotizing fasciitis: CT characteristics.

Abstract

To establish computed tomographic (CT) criteria for the diagnosis of necrotizing fasciitis. Twenty CT scans in 20 patients with pathologically proved necrotizing fasciitis were reviewed retrospectively for fascial thickening, fat infiltration, focal fluid collection, soft-tissue gas, muscle involvement, and intra-abdominal extension; the findings were correlated with clinical factors, including associated illnesses, disease site, treatment, and outcome. Average patient age was 57.8 years; there were 13 men and seven women. Four patients (20%) died. Asymmetric fascial thickening and fat stranding were seen in 16 patients (80%). Gas tracking along fascial planes was present in 11 patients (55%), and abscesses were found in seven patients (35%). Infection sites were scrotum (n = 6), a lower extremity (n = 4), perineum (n = 4), neck (n = 2), back (n = 2), arm (n = 1), and abdomen (n = 1). Underlying illness (n = 17) was diabetes in 10 patients (50%), alcoholism in three (15%), chronic renal failure in two (10%), and drug abuse in two (10%). CT criteria of asymmetric fascial thickening and gas are valuable in assessing suspected necrotizing fasciitis. CT also can provide information on coexistent deep collections.