The Evaluation of Benign Acute Childhood Myositis by Ultrasound Elastography

Abstract

Objective: Herein, we aimed to determine the diagnostic contribution of ultrasound elastography (UE) technique to the assessment of muscle stiffness in pediatric patients with myositis.
 Material and Methods: This study enrolled 16 patients who presented to our hospital’s Pediatric Neurology Outpatient Clinic with the complaint of inability to walk and who had a clinical presentation of benign acute childhood myositis (BACM). The patients were referred to the Radiology Department to undergo muscle ultrasonography (USG), where they underwent UE of the gastrocnemius muscle (GCM).
 Results: Children with myositis and healthy children are similar age (7.06 ± 1.52 year (5–11) vs. 7.00 ± 1.59 year (5–11) year) (P: 0.908) and body mass index (BMI) (20.04 ± 1.58 (18.6–24.2) vs. 22.08 ± 1.43 (19.9–24.4) (P: 0.946). The mean serum creatine kinase (CK) was measured as 1520.3 ± 1163.6 U/L (min: 456, max:4100) in children with myositis. In the children with myositis, the thickness of the medial and lateral GCM increased compared with that in control group (medial; 18.15 ± 3.02 mm vs 13.10 ± 2.26 mm, p<0.001, lateral; 13.51 ± 3.07 mm vs 9.34 ± 1.86 mm, p<0.001). The medial and lateral GCM ratio in group 1 was slight bigger than that in group 2 (medial; 1.10 ± 0.37 vs 1.00 ± 0.34, p: 0.274, lateral; 1.22 ± 0.44 vs 1.10 ± 0.29, p: 0.243). GCM strain values were mildly elevated in patients with myositis compared to controls.
 Conclusion: In the children with myositis, the thickness of the medial and lateral GCM increased compared with that in control group. GCM strain ratio values were slightly higher in myositis patients compared to the control group. We think that the increase in muscle thickness values is mainly secondary to the edema seen in myositis. In addition, UE is a clinically applicable quantitative analysis for changes in myositis.