Contrast-enhanced magnetic resonance imaging (MRI) remains the most comprehensive modality to assess juvenile idiopathic arthritis (JIA)-related inflammation and osteochondral damage in the temporomandibular joints (TMJ). This study tested the reliability of a new JIA MRI scoring system for TMJ (JAMRIS-TMJ) and the impact of variations in calibration and reader specialty. Thirty-one MRI exams of bilateral TMJs were scored independently using the JAMRIS-TMJ by 20 readers consisting of radiologists and non-radiologist clinicians in three reading groups, with or without a calibrating atlas and/or tutorial. The inter-reader reliability in the multidisciplinary cohort assessed by the generalizability coefficient was 0.61–0.67 for the inflammatory and 0.66–0.74 for the damage domain. The atlas and tutorial did not improve agreement within radiologists, but improved the agreement between radiologist and non-radiologist groups. Agreements between different calibration levels were 0.02 to 0.08 lower by the generalizability coefficient compared to agreement within calibration levels; agreement between specialty groups was 0.04 to 0.10 lower than within specialty groups. Averaging two radiologists raised the reliability above 0.8 for both domains. Therefore, the reliability of JAMRIS-TMJ was moderate-to-good depending on the presence of specialty and calibration differences. The atlas and tutorial are necessary to improve reliability when the reader cohort consists of multiple specialties.

Currently there is no consensus agreement on the degree of enhancement in normal temporomandibular joints (TMJ) in children, which makes it difficult for clinicians to distinguish between the presence/absence of mild synovitis. Quantitative measurements of synovial and condylar enhancement may be useful additions to current qualitative methods on early MRI diagnosis and follow up of TMJ involvement in JIA. The purpose of the study is to establish thresholds/tendencies for quantitative measures that enable distinction between mild TMJ involvement and normal TMJ appearance based on the degree of synovial and bone marrow enhancement in JIA patients. TMJ MRI examinations in 67 children with JIA and in 24 non-rheumatologic children who underwent MRI for neurologic/orbit indications were retrospectively assessed. As a priori determined TMJs of JIA patients were categorized into three groups by experienced staff radiologists based on the degree of synovial and condylar enhancement: no active disease (rheumatologic control), mild and moderate/severe findings. The signal intensity (SI) of the synovial tissue around each condyle and of the bone marrow was measured to calculate the enhancement ratio (ER) and relative SI change. The ER was calculated using signal to noise ratios, while relative SI change was calculated using signal intensities alone. Quantitative measurements of synovial and condylar enhancement of TMJs with mild or moderate/severe findings were compared with the rheumatologic and non-rheumatologic controls. Mean ER values were significantly different between the TMJs without active disease and those with mild and moderate/severe synovial enhancement, with highest values in the moderate/severe group (P < 0.0001). Similar findings were seen for condylar enhancement with P < 0.005. Relative SI change was unable to differentiate TMJs with mild synovitis from the two controls (P > 0.10). 27/60 (45 %) TMJs without active disease had osteochondral changes. 8/40 (20 %) TMJs in the mild group did not demonstrate any synovial thickening. Quantitative signal to noise ratios of TMJ synovial and condylar enhancement generate thresholds/tendencies, which offer additional information to differentiate mild synovitis from normal TMJs in JIA patients. Osteochondral changes and synovial thickening may not be reliable indicators of active TMJ involvement and should be differentiated from synovial enhancement.

This study reports the reliability of the juvenile idiopathic arthritis magnetic resonance imaging scoring system (JAMRIS-SIJ). The study comprised of eight raters—two rheumatologists and six radiologists—and 30 coronal T1 and Short-Tau Inversion Recovery (STIR) MRI scans of patients with enthesitis-related juvenile spondylarthritis. The median age of patients was 15 years with a mean disease duration of 5 years and 22 (73.3%) of the sample were boys. The inter-rater agreement of scores for each of the JAMRIS-SIJ items was calculated using a two-way random effect, absolute agreement, and single rater intraclass correlation coefficient (ICC 2.1). The ICC was interpreted together with kurtosis, since the ICC is also affected by the distribution of scores in the sample. The eight-rater, single measure inter-rater ICC (and kurtosis) values for JAMRIS-SIJ inflammation and damage components were the following: bone marrow edema (BME), 0.76 (1.2); joint space inflammation, 0.60 (1.8); capsulitis, 0.58 (9.2); enthesitis, 0.20 (0.1); ankylosis, 0.89 (35); sclerosis, 0.53 (4.6); erosion, 0.50 (6.5); fat lesion, 0.40 (21); backfill, 0.38 (38). The inter-rater reliability for BME and ankylosis scores was good and met the a priori set ICC threshold, whereas for the other items it was variable and below the selected threshold. Future directives should focus on refinement of the scores, definitions, and methods of interpretation prior to validation of the JAMRIS-SIJ through the assessment of its measurement properties.

Objective: We examined the interobserver reliability of local progressive disease (L-PD) determination using two major radiological response evaluation criteria systems (Response evaluation Criteria in Solid Tumors (RECIST) and the European and American Osteosarcoma Study (EURAMOS)) in patients diagnosed with localized osteosarcoma (OS). Additionally, we describe the outcomes of patients determined to experience L-PD. Materials and Methods: Forty-seven patients diagnosed with localized OS between 2000 and 2012 at our institution were identified. Paired magnetic resonance imaging of the primary tumor from diagnosis and post-neoadjuvant chemotherapy were blindly assessed by two experienced radiologists and determined L-PD as per RECIST and EURAMOS radiological criteria. Interobserver reliability was measured using the kappa statistic (κ). The Kaplan Meier method and log-rank test was used to assess differences between groups. Results: Of 47 patients (median age at diagnosis 12.9 years), 16 (34%) had L-PD (by RECIST or EURAMOS radiological definition). There was less agreement between the radiologists using EURAMOS radiological criteria for L-PD (80.9%, κ = 0.48) than with RECIST criteria (97.9%, κ = 0.87). Patients with radiologically defined L-PD had a 5-year progression-free survival (PFS) of 55.6%, compared to a 5 year-PFS of 82.7% in the group of patients without L-PD (n = 31) (Log rank p = 0.0185). Conclusions: The interobserver reliability of L-PD determination is higher using RECIST than EURAMOS. RECIST can be considered for response assessment in OS clinical trials. The presence of L-PD was associated with worse outcomes.

Familial digital arthropathy-brachydactyly (FDAB) and Thiemann disease are non-inflammatory digital arthropathies with many phenotypic similarities. Thirty-three cases of Thiemann disease have been described so far (Mangat et al, Ann Rheum Dis 64:11-2, 2005; Ha et al, Thiemann's disease: a case Report, 2017) but no gene variants have been identified as causative to date. FDAB is reported in only a few patients and has been associated with three heterozygous missense variants in the Transient receptor potential vanilloid 4 (TRPV4) gene. We report a TRPV4 variant in a father and son referred with a diagnosis of Thiemann disease and compare the clinical and radiological features of Thiemann disease with Familial digital arthropathy-brachydactyly (FDAB). We hypothesize that these two entities may be one and the same. We describe a father and son referred with a diagnosis of Thiemann disease who were subsequently identified with a heterozygous variant (c.809G > T) in TRPV4. The identical genetic variant was previously reported to cause FDAB. A PUBMED® database search was conducted to retrieve articles related to Thiemann disease and FDAB. We were able to review the clinical and radiological findings of nineteen individuals affected by Thiemann disease and compare them with three families affected by FDAB. Thiemann disease initially affects the proximal interphalangeal joints and primarily the middle phalangeal bases. In FDAB, the distal phalangeal joints are first affected with the middle phalangeal heads being the primary site of changes. Radial deviation has only been described in FDAB. Our analysis determined that 5 of 20 individuals affected by Thiemann disease have clinical and radiological findings that also fit well with FDAB. FDAB and Thiemann disease are non-inflammatory digital arthropathies with phenotypic overlap. Although more extensive joint involvement, a distal hand joint preponderance and brachydactyly are expected in FDAB, there are striking clinical and radiological similarities between the two entities. Our analysis suggests that these two phenotypes may represent phenotypic variability of the same entity. Despite many attempts to identify other reported patients affected by Thiemann disease, we were not able to procure DNA from any of the cases to verify our findings. Genetic testing of an affected individual will be crucial in order to provide accurate reproductive genetic counselling about the autosomal dominant nature of this condition.