Imaging Characteristics of Soft Tissue Infections

Abstract

The topic of imaging of soft tissue infections and their mimics will be presented in two parts: Part I (Volume 38, Number 15) and Part II (Volume 38, Number 16). Soft tissue infections are a common reason for patients to seek medical care. Most soft tissue infections are benign and do not require diagnostic imaging. However, evaluation of soft tissue infection complications (abscess, necrosis, fasciitis, and myositis) covered in Part I;1–6 and mimics of necrotizing soft tissue fasciitis (nonnecrotizing fasciitis, vasculitides, inflammatory myositis, and graft-versus-host diseases) covered in Part II may warrant radiologic imaging. Imaging can provide valuable information regarding the extent of pathology, treatment planning (medical and/or surgical), and the detection of complications such as soft tissue necrosis, abscess, septic arthritis, osteomyelitis, and thrombophlebitis. This article discusses the clinical presentation, pathophysiology, treatment, and prognosis of soft tissue infections, with emphasis on distinguishing clinical and radiologic features that help discriminate between benign nonnecrotizing infections from the potentially lethal necrotizing processes. In addition, key imaging findings seen with soft tissue infections are compared and contrasted with those seen in the differential diagnosis.