[Inflammatory muscle diseases (myositis)].

CLINICAL ISSUE: Inflammatory muscle diseases are quite heterogeneous and frequently a specific diagnosis is not easy.

STANDARD RADIOLOGICAL METHODS: Magnetic resonance imaging (MRI) is best suited to demonstrate pattern and size of inflamed muscles.

PERFORMANCE: Sensitivity of MRI in showing inflamed muscles is nearly 100%. Specificity, however, is much lower.

PRACTICAL RECOMMENDATIONS: In cases of suspected bacterial myositis, sonography may be used to exclude abscess formation prior to MRI for more precise information about inflamed muscles.