MRI in Juvenile Idiopathic Arthritis and Juvenile Dermatomyositis

Abstract

The use of MRI in the assessment of the musculoskeletal system in children has important differences from its use in adults. Growth in children has significant impact on the epiphysis and growth plate, which are important structures in the growing child, and there are radiological features that differ from those in adults: disease may alter structures during a period of growth; the pathologies themselves are a distinct group of diseases at variance with adult arthritis and myositis, with a different spectrum of differential diagnoses; and many technical issues are different when imaging a child. These are important considerations in choosing the appropriate imaging. MRI is a powerful and valuable imaging technique in pediatric musculoskeletal pathologies, with considerable potential for future developments to enhance its role in diagnosis, management, and therapeutic intervention for these children.

MRI guided wire localization muscle biopsy in a child with juvenile dermatomyositis

“…Though a rare disease, it is the most common inflammatory myopathy in children with an incidence of 2–3 cases per million children per year [1,4]. Skin rashes and proximal muscle weakness are the most common symptoms, typically consisting of a heliotrope rash involving the eyelids, erythematous rash on the extensor surfaces (Gottron’s papules), and proximal muscle weakness [1,2]. Gastrointestinal, pulmonary, cardiac, and joint involvement, as well as other organ system involvement can also be seen, but is less common [5].…”

“…Imaging findings are not included in the criteria for diagnosis of JDM; however, many clinicians have been using imaging as a tool for diagnosis and monitoring of disease activity [2]. Ultrasound may demonstrate edema and swollen muscle fibers in the affected muscles [9].…”

“…Ultrasound may demonstrate edema and swollen muscle fibers in the affected muscles [9]. MRI findings of symmetric muscular edema are typical of JDM, however the intramuscular edema may be patchy [2,10,11]. Fatty infiltration and muscle atrophy may be evident on T1 MRI images in chronically affected muscles [2,3,10].…”

“…Dermatologic and muscle manifestations are most common, typically consisting of a heliotrope rash involving the eyelids, erythematous rash on the extensor surfaces (Gottron’s papules), and proximal muscle weakness [1,2]. Surgical muscle biopsy is diagnostic for cases in which the clinical presentation may not be clear.…”

Arthrites juvéniles idiopathiques

“…ostéoïde, ostéochondrite, chondrolyse idiopathique de la hanche, hémarthrose, leucémie[31,47,75] . Les « arthrites » leucémiques sont le plus souvent pauciarticulaires, asymétriques, sans raideur ; l'épanchement est généralement absent ou peu abondant .…”