Computed Tomography Imaging Characteristics in the Diagnosis and Assessment of Cellulitis in Patients with Leg Swelling

<i>Background and Objectives:</i> This study aimed to evaluate the imaging characteristics of computed tomography (CT) for diagnosing and assessing cellulitis in patients with leg swelling. <i>Materials and Methods:</i> Overall, 1545 patients who underwent CT for leg swelling were retrospectively analyzed. Among them, 174 were diagnosed with cellulitis based on clinical findings, laboratory tests indicating inflammation, and their response to antibiotics. Patients with previous follow-up CT scans, negative CT findings, or alternative diagnoses were excluded (<i>n</i> = 1123). Two radiologists independently assessed the CT images while blinded to other clinical data, resolving discrepancies through consensus. <i>Results:</i> Among 174 patients with cellulitis, 112 were men, and 62 were women, with a mean age of 64.1 ± 15.8 years. The patients were categorized into two groups based on the affected region: Group I (thigh or lower leg, <i>n</i> = 130) and Group II (foot involvement only, <i>n</i> = 44). The qualitative CT features analyzed included skin thickening (83.9%), subcutaneous edema (94.8%), early venous return (82.8%), lymph node pathological findings (72.4%), and prominent lymph node enhancement (79.3%). Group I demonstrated significantly higher rates of skin thickening, subcutaneous edema, and early venous return than Group II. Pairwise analysis of CT findings revealed significant associations between skin thickening and subcutaneous edema, skin thickening and early venous return on MIP, and early venous return on MIP and lymph node pathology. <i>Conclusions:</i> CT provides valuable diagnostic features of cellulitis in patients with leg swelling. Skin thickening, subcutaneous edema, early venous return, and lymph node abnormalities are key findings in the diagnosis of cellulitis.