Magnetic resonance imaging of diabetic muscle infarction: report of two cases.

Diabetic muscle infarction (DMI) occurs as a rare complication of long standing or severe diabetes mellitus. The condition usually occurs spontaneously and patients usually present with acute pain and swelling of affected muscles which persists for weeks, and resolves spontaneously without intervention. Magnetic resonance (MR) imaging is the modality of choice in patients with suspected DMI based on appropriate clinical setting and plays a major role in the diagnosis, assessing the extent of involvement and differentiating DMI from other conditions. The DMI affected muscles are bulky and appear heterogeneous with hyperintense signals on T2-weighted and STIR sequences, hypo or isointense on T1-weighted images with loss of normal fatty intramuscular septae. Subcutaneous and perifascial edema can be present. On postgadolinium scans, there is diffuse heterogeneous enhancement with non-enhancing foci, which may represent areas of necrosis. Biopsy can be avoided as MR findings are highly sensitive and specific. Treatment is usually conservative. Surgical intervention is required only in patients who do not respond to conservative management. The common differential diagnosis includes cellulitis, abscess, necrotizing fasciitis and polymyositis. We present two cases below to highlight the clinical, MR imaging findings and differential diagnosis of DMI.