Role of magnetic resonance imaging in the diagnosis of dermatomyositis with normal serum creatine kinase

الملخص EN

Aim of Work: To assess the diagnostic role of magnetic resonance imaging (MRI) in dermatomyositis (DM) with normal serum creatine kinase level.

Materials & Methods: Seven DM patients and ten healthy volunteers were included in this study.

They were selected from the Rheumatology & Rehabilitation and Dermatology & Venereology Departments of Zagazig University Hospitals.

They were subjected to full history taking, full neurological examination, estimation of serum creatine kinase level, Electromyography (EMG) and MRI.

Results: Only three out of seven patients had positive muscle biopsies findings of myositis and EMG changes.

MRI showed positive findings in such patients and in three out of the remaining four patients.

The detected inflammatory changes strongly support the contention that patients with presumed DM sin myositis can actually have occult myositis.

It also confirms that MRI can be used to identify muscle inflammation and to classify patients with normal enzyme concentration.

Conclusion: MRI is an effective non-invasive modality that may be used to evaluate the presence of muscle inflammation in patients presenting with cutaneous eruption of DM without muscle weakness, normal enzyme level and normal EMG findings.

MRI may be useful in making the decision to start immuno-suppresive therapy in such patients.