Myositis
School ager
with left calf pain and eosinophillia. Axial STIR MRI of the calves (above) shows diffusely bright signal in the expanded and edematous muscles in the posterior compartment of the left calf. Sagittal STIR MRI of the left calf (below) shows the length of involvement throughout the entire posterior compartment of the left calf.The diagnosis was myositis most likely due to a parasitic infection.
Myositis is the subset of myopathy characterized by inflammation of skeletal muscle.
Pathology
Etiology
Myositides can be generally categorized by etiology as follows :
- inflammatory myositis
- dermatomyositis
- polymyositis
- antisynthetase syndrome
- immune-mediated necrotizing myopathy
- inclusion body myositis
- proliferative myositis
- eosinophilic myositis
- granulomatous myositis
- infectious myositis
- bacterial myositis (pyomyositis)
- viral myositis
- influenza myositis
- coxsackievirus B virus-related pleurodynia (Bornholm disease)
- virus-associated rhabdomyolysis
- parasitic myositis (a cause of eosinophilic myositis)
- cysticercosis
- trichinosis
- fungal myositis (rare)
- drug-related myositis
- statin-related myositis
- trauma or iatrogenic myositis
- myositis ossificans
- radiation-induced myositis
Radiographic features
MRI is the gold standard modality for noninvasive evaluation of myositis, which shows classic edema signal pattern (high T2WI and STIR signal) in affected muscles. Inflamed muscles demonstrate contrast enhancement.
If chronic, T1WI will show high muscle signal indicating fat replacement and atrophy.
Siehe auch:
- Myositis ossificans
- Dermatomyositis
- infektiöse Myositis
- Polymyositis
- orbital myositis
- interstitielle Myositis
und weiter:
Assoziationen und Differentialdiagnosen zu Myositis:
