Computed tomography (CT) is optimally suited to the assessment of soft tissue and muscle inflammation. Its ability to detect subtle changes in tissue attenuation, distortion of fat/tissue planes, and the presence of fluid or gas collections has been well described [1]. The superior cross-sectional anatomic detail provided by CT allows localization of the inflammatory process to specific tissue compartments. Appropriate clinical management strategies can then be formulated on the basis of the scan findings.This essay presents a systematic approach to the evaluation of soft tissue and muscle infection by defining the various pathologic processes and then illustrating them through a series of CT studies with corresponding schematic diagrams. The specific processes discussed are cellulitis, lymphangitis/lymphedema, necrotizing fascitis, myositis/myonecrosis, and abscess. Key points in the differential diagnosis of these entities are discussed and illustrated. The clinical management of the specific pathologic processes is also discussed. Scanning techniqueA successful examination requires a careful understanding of the clinical problems to be solved and the questions to be answered. Lack of attention to detail can result in a suboptimal examination, thereby delaying correct therapy. The patient should be positioned comfortably in the scanner in such a way as to allow the use of the unaffected extremity for comparison. Depending on the length of the area to be scanned (e.g., from pelvis to knee, vs foot only) individual scan parameters will vary from the standard. Eight-millimeter collimation at 10-mm intervals is used routinely, with 4-mm collimation at 4-mm intervals used for smaller areas or for delayed scans. Spiral CT with volume data acquisition and the Correspondence to: