MRI Findings in Hip in Juvenile Idiopathic Arthritis

Abstract

The aim of this study was to evaluate if magnetic resonance imaging allows hip arthritis in JIA to be differentiated from hip arthralgia of unknown etiology in juveniles clinically suspected for hip arthritis. This was a retrospective observational study which included 97 children with clinically suspected hip arthritis. Each hip was assessed and scored in MRI for signs of active and destructive inflammatory lesions and developmental lesions. MRI findings between JIA-confirmed patients and without final diagnosis of JIA were compared and the MRI summarized score was calculated, as the sum of scorings of all 24 hip lesions in an individual patient (i.a., effusion, synovitis, bone marrow edema, enthesitis). MRI showed at least one lesion in the majority of patients (95 patients; 98%). Effusion was the most common feature, followed by bone marrow oedema and synovitis. All lesions were more common in patients with a final diagnosis of JIA, especially synovitis and enthesitis (p = 0.037 and p = 0.047). The MRI summarized score was significantly higher in the JIA group than the non-JIA group: 3 (2–5) vs. 2 (2–2), respectively, p = 0.002. Using a cut-off score of 6, the MRI summarized score showed 25% sensitivity and 100% specificity indicating a good ability in discriminating hip arthritis during JIA from non-JIA patients. MRI allows hip arthritis in JIA to be differentiated from hip arthralgia of unknown etiology with good specificity, thus, may be helpful in confirming the diagnosis of JIA.

Advances in Musculoskeletal Imaging in Juvenile Idiopathic Arthritis

“…Magnetic resonance imaging (MRI) is a valuable technique for the assessment of pediatric musculoskeletal pathologies and is the most validated technique in JIA [ 45 ]. It is the most suitable technique for detecting synovial hypertrophy and bone marrow edema (BME) [ 1 ]. Compared with US, MRI has the advantages of allowing the three-dimensional evaluation of the peripheral and axial joints and the detection of inflammatory osteitis that cannot be visualized with radiography and US [ 46 , 47 , 48 ].…”

“…Ostrowska at al. [ 1 ] proposed a comprehensive scoring system for hip arthritis, including 24 active, chronic, and developmental hip lesions, and proposed the MRI summarized score, a sum of the scores of these lesions in an individual patient that showed 25% sensitivity and 100% specificity in discriminating hip arthritis from hip pain in juveniles without JIA ( Figure 4 ).…”

“…Concurrent with the existence of multiple studies corroborating the value of contrast-enhanced MRI, there are multiple publications on the accumulation of gadolinium contrast agent in the kidneys and brain (mostly in the basal ganglia), even after a prolonged period after contrast administration [ 81 , 82 ]. As JIA often involves numerous joints, the repetitive intravenous administration of gadolinium-based contrast agents can significantly burden the patient’s body [ 1 ]. Nusman et al identified postgadolinium synovial enhancement in 52% of the knees of healthy children [ 83 ]; thus, a question remains regarding the value of injecting contrast in children.…”

“…Juvenile idiopathic arthritis (JIA) is the most common form of childhood arthritis [ 1 , 2 , 3 , 4 , 5 , 6 ]. It is a systemic disease in which the musculoskeletal system (MSK) is the most commonly affected.…”

“…The clinical examination of joints is challenging in many cases, especially in the early stages of inflammation, and laboratory tests are not specific in the diagnostic process. Thus, there is increasing demand for novel imaging techniques to provide objective and accurate measures of inflammatory changes to monitor disease and treatment responses [ 1 , 8 ].…”