investigating the association between muscular ultrasonographic alterations and clinical symptoms in patients with inflammatory myopathy

Introduction: muscle biopsy is commonly used to diagnose inflammatory myopathies. we evaluated the ability of muscle ultrasound, a non-invasive and simple tool, to distinguish between healthy subjects and patients with inflammatory myopathy.methods: this study was conducted on 17 patients recently diagnosed with biopsy inflammatory myopathies (12 dermatomyositis, 5 polymyositis) compared with 17 age- and gender-matched healthy control adults. all patients underwent clinical assessments, including manual muscle testing, hand-held dynamometry, and muscle ultrasound evaluations, including thickness and echo intensity in predefined muscle groups. results: the disease duration was seven months (interquartile range: 3 to 11 months). except for the biceps and gastrocnemius, patients’ muscles had significantly higher echo intensity and lower thickness than the control group. the echo intensity sum-score manifested the highest area under the curve compared to the sum-scores of other variables (echo intensity vs manual muscle testing: area under curves-difference=0.18, p<0.01; echo intensity vs dynamometry: area under curves-difference=0.14, p=0.02; echo intensity vs thickness: area under curves-differences-difference=0.25, p<0.01). conclusion: the echo intensity of muscles differed significantly between healthy individuals and patients with inflammatory myopathies and may serve as a useful diagnostic biomarker.