MR-IMAGING IN ACUTE INFECTIOUS CELLULITIS

PURPOSE: To describe magnetic resonance (MR) imaging findings in acute infectious cellulitis and assess its value for the diagnosis of sever e necrotizing forms. MATERIALS AND METHODS: Spin-echo (SE) T1- and T2- weighted imaging was performed in 36 patients with acute infectious ce llulitis. T1-weighted SE images obtained after injection of a paramagn etic contrast agent were also obtained when an abscess was suspected o n precontrast images, Sixteen patients underwent surgical debridement, along with fascial and muscle biopsy. RESULTS: Distinct MR imaging fe atures were found in patients with necrotizing soft-tissue infections, that is, hyperintense signal on T2-weighted images at the deep fascia e, poorly defined areas of hyperintense signal on T2-weighted images w ithin muscles, and peripheral enhancement on contrast material-enhance d T1-weighted images. In nonnecrotizing cellulitis, signal intensity a bnormalities were seen only in the subcutaneous fat. CONCLUSION: The p recise extent of acute cellulitis and the presence of necrotizing soft -tissue infections can be determined with MR imaging, particularly on T2-weighted images.