Consensus-driven conceptual development of a standardized whole body-MRI scoring system for assessment of disease activity in juvenile idiopathic arthritis: MRI in JIA OMERACT working group.

OBJECTIVES: Whole body-MRI is helpful in directing diagnostic and treatment approaches, and as a research outcome measure. We describe our initial consensus-driven phase towards developing a whole body-MRI scoring system for juvenile idiopathic arthritis. METHODS: An iterative approach using three rounds of anonymous Delphi surveys followed by a consensus meeting was used to draft the structure of the whole body-MRI scoring system, including the relevant anatomic joints and entheses for assessment, diagnostic item selection, definition and grading, and selection of appropriate MRI planes and sequences. The surveys were completed independently by an international expert group consisting of pediatric radiologists and rheumatologists. RESULTS: Twenty-two experts participated in at least one of three rounds of Delphi surveys and a concluding consensus meeting. A first iteration scoring system was developed which ultimately included the assessment of 100 peripheral, 23 chest, and 76 axial joints, and 64 entheses, with 2-4 diagnostic items graded in each of the items, using binary (presence/absence) and 2-3-level ordinal scores. Recommendations on anatomic MRI planes and sequences were specified as the minimally necessary imaging protocol for the scoring system. CONCLUSION: A novel whole body-MRI scoring system for juvenile idiopathic arthritis was developed by consensus among members of MRI in JIA OMERACT working group. Further iterative refinements, reliability testing, and responsiveness are warranted in upcoming studies.

Broadening the spectrum of neonatal hemochromatosis.

Neonatal hemochromatosis (NH) has been defined as neonatal liver disorder accompanied by extrahepatic siderosis, and gestational alloimmune liver disease (GALD) is the main cause of NH. We report an atypical case of NH that may have gone underdiagnosed. A male infant was born at term after an uneventful antenatal period. At 7 h of life, he was noted to be tachypneic. Chest X-ray was normal and capillary blood gas analysis showed severe lactic acidosis. An extended blood test showed elevated levels of tyrosine and methionine that, after excluding an inborn error of metabolism, led to the diagnosis of acute liver failure. Hyperferritinemia and elevated transferrin saturation were suggestive of NH. Extrahepatic siderosis on MRI confirmed the diagnosis of NH, so even though the infant was in good general condition, a dose of intravenous immunoglobulin was administered and double volume exchange transfusion was performed. Treatment of a suspected case of GALD and prevention in subsequent gestations is imperative.

MR Imaging of the Temporomandibular Joint in Juvenile Idiopathic Arthritis: Technique and Findings.

The term juvenile idiopathic arthritis (JIA) encompasses a group of arthritides of unknown cause that begin before 16 years of age and last for at least 6 weeks. Temporomandibular joint (TMJ) involvement has been described in up to 87% of children with JIA and has been associated with all JIA subtypes. TMJ involvement is difficult to detect clinically. In one study, 71% of JIA patients with active TMJ synovitis were asymptomatic and 63% had normal physical examination results. Moreover, the main growth center of the mandible is located in the condyle, separated from the joint space by only a thin layer of fibrocartilage. This makes mandibular growth vulnerable to arthritic changes, eventually resulting in facial asymmetry and retrognathia. Therefore, early detection and treatment of TMJ arthritis are paramount to preserving motility and preventing deformity. As clinical symptoms and physical examination results are not good markers of TMJ involvement, imaging plays a key role in diagnosis and treatment monitoring. Magnetic resonance imaging is the technique of choice for the study of TMJ arthritis. It has the advantages of displaying both soft tissue and bone, is the most sensitive technique for detecting acute synovitis, and is the only one able to demonstrate bone marrow edema. In addition, it allows the assessment of changes to the joint over time and evaluation of the effectiveness of therapeutic interventions. ©RSNA, 2017.