Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S Kingshighway Blvd, Campus Box 8131, St Louis, MO 63110.
Radiographics. 2013 Sep-Oct;33(5):1253-73. doi: 10.1148/rg.335125178.
Juvenile idiopathic arthritis (JIA) is a heterogeneous group of diseases characterized by synovial inflammation and is the most common rheumatic complaint in children. To facilitate research and treatment, JIA has been further classified on the basis of the number of joints involved, additional symptoms, family history, and serologic findings. Imaging in patients with JIA has historically relied on radiography, which allows the accurate assessment of chronic changes of JIA, including growth disturbances, periostitis, and joint malalignment. However, radiographic findings of active inflammation are nonspecific, and, in the past, clinical evaluation has taken precedence over imaging of acute disease. Recent advances in disease-modifying therapeutic agents that can help prevent long-term disability in patients with JIA have led to greater emphasis on the detection of early joint-centered inflammation that cannot be accurately assessed radiographically and may not be evident clinically. Both contrast material-enhanced magnetic resonance (MR) imaging and Doppler ultrasonography (US) are well suited for this application and are playing an increasingly important role in diagnosis, risk stratification, treatment monitoring, and problem solving. Contrast-enhanced MR imaging is the most sensitive technique for the detection of synovitis and is the only modality that can help detect bone marrow edema, both of which indicate active inflammation. US is more sensitive than radiography for the detection of synovial proliferation and effusions and is particularly useful in the evaluation of small peripheral joints. The complexity of the temporomandibular and sacroiliac joints limits the usefulness of radiographic or US evaluation, and contrast-enhanced MR imaging is the preferred modality for evaluation of these structures.
幼年特发性关节炎（JIA）是一组以滑膜炎症为特征的异质性疾病，是儿童最常见的风湿性疾病。为了便于研究和治疗，JIA 根据受累关节数量、其他症状、家族史和血清学发现进一步分类。JIA 患者的影像学检查历史上依赖于放射摄影，这可以准确评估 JIA 的慢性变化，包括生长障碍、骨膜炎和关节对线不良。然而，活动性炎症的放射摄影表现是非特异性的，过去，临床评估优先于急性疾病的影像学检查。近年来，疾病修饰治疗药物的进步可以帮助预防 JIA 患者的长期残疾，这导致人们更加重视早期以关节为中心的炎症的检测，这些炎症在放射摄影上无法准确评估，临床上也可能不明显。对比增强磁共振成像（MR）和多普勒超声（US）都非常适合这种应用，并且在诊断、风险分层、治疗监测和解决问题方面发挥着越来越重要的作用。对比增强 MR 成像对于滑膜炎的检测最敏感，并且是唯一可以帮助检测骨髓水肿的方法，这两者都表明存在活动性炎症。US 对于滑膜炎和积液的检测比放射摄影更敏感，在评估小的外周关节方面特别有用。颞下颌关节和骶髂关节的复杂性限制了放射摄影或 US 评估的实用性，而对比增强 MR 成像则是评估这些结构的首选方法。
