Role of Ultrasound in Diagnosis of Muscle Diseases

Many muscle diseases share common clinical features that render arriving at appropriate diagnoses difficult. The combination of muscle imaging with clinical can limit the differential diagnosis and yield the most probable one and can direct genetic testing as the only method to arrive at a definite diagnosis.

In recent years, the use of high-resolution ultrasound had become an important tool in diagnosis and in the monitoring of disease progression and treatment of both hereditary and acquired myopathies. Additionally, it entails a safe, accessible, low-cost, and no ionizing radiation tool which renders the technique extremely suitable for paediatric patients and patients who cannot lie still without sedation. therefore, it can be used as a complementary tool to electro-diagnosis.

Ultrasound permits to evaluate echo intensity, muscle perfusion, transverse and longitudinal sections of the muscle and its thickness at rest and during maximal voluntary contractions, overlying subcutaneous fat, cross-sectional area, and angled fibers of pennate muscles.

The use of sonographically guided biopsy is an easy, safe, and reliable method for attaining tissue for histologic diagnosis in neuromuscular disease.

In most myopathies, either acute or chronic, muscle tissue undergoes morphological changes giving rise to replacement of muscle by connective tissue and/or fat. Pattern recognition on muscle imaging might be helpful in distinguishing between different disease entities.

Inclusion criteria

• Males and females.
• 2-60 years old.
• For patients with acute inflammatory myositis: patients presenting with characteristic picture of acute inflammatory myositis according to the myositis association 2019.
• For patients with acute inflammatory myositis: newly diagnosed patients within one month from onset of disease.
• All patients not received any previous specific treatment for myopathy.

Exclusion criteria

• Patients with clinically or electrophysiologically suspected other neuromuscular conditions that mimic myopathy such as motor neuron disease, neuromuscular junction disorders.
• Patients with secondary causes of myopathies; as drug induced, endocrinal disorders like diabetes mellitus and hypothyroidism or metabolic myopathy.
• Patients who received any previous specific treatment for myopathy