Comparison of contrast-enhanced MRI features of the (teno)synovium in the wrist of patients with juvenile idiopathic arthritis and pediatric controls.

To directly compare and describe the differences between juvenile idiopathic arthritis (JIA) patients and pediatric controls regarding features of the synovial and tenosynovial membrane on contrast-enhanced magnetic resonance imaging (MRI) of the wrist. T1-weighted contrast-enhanced MRI scans of 25 JIA patients with clinically active wrist arthritis and 25 children without a history of joint complaints nor any clinical signs of joint inflammation were evaluated by two readers blinded to clinical data. The synovium was scored at five anatomical sites based on thickening of the synovium (0-3 scale) and synovial enhancement (0-2 scale). Thickening and/or enhancement of the tenosynovium was scored at four anatomical sites using a 0-3 scale. Significantly higher scores for synovial thickening (median 4 vs. 1, p < 0.001) and synovial enhancement (median 4 vs. 1, p < 0.001) are found in the wrist of JIA patients as compared to controls. JIA patients experienced the highest synovial scores at the mid-/inter-carpal, 2nd -5th carpometacarpal, and radiocarpal joints. No significant difference in tenosynovial scores is found between both groups (median 0 vs. 0, p = 0.220). This study highlights the higher synovial thickening/enhancement scores on contrast-enhanced MRI of the wrist in JIA patients compared to pediatric controls. Tenosynovial thickening and/or enhancement was rarely present in both groups. In JIA patients, synovial thickening and enhancement were particularly present at three anatomical sites. These results substantially support rheumatologists and radiologists when navigating through MRI of the wrist in search for JIA disease activity.

Juvenile Idiopathic Arthritis: Diffusion-weighted MRI in the Assessment of Arthritis in the Knee.

Background Diffusion-weighted imaging (DWI) can depict the inflamed synovial membrane in arthritis. Purpose To study the diagnostic accuracy of DWI for the detection of arthritis compared with the clinical reference standard and to compare DWI to contrast material-enhanced MRI for the detection of synovial inflammation. Materials and Methods In this institutional review board-approved prospective study, 45 participants with juvenile idiopathic arthritis (JIA) or suspected of having JIA (seven boys, 38 girls; median age, 14 years [interquartile range, 12-16 years]) were included between December 2015 and December 2018. Study participants underwent pre- and postcontrast 3.0-T MRI of the knee with an additional DWI sequence. For the clinical reference standard, a multidisciplinary team determined the presence or absence of arthritis on the basis of clinical, laboratory, and imaging findings (excluding DWI). Two data sets were scored by two radiologists blinded to all clinical data; data set 1 contained pre- and postcontrast sequences (contrast-enhanced MRI), and data set 2 contained precontrast and DWI sequences (DWI). Diagnostic accuracy was determined by comparing the scores of the DWI data set to those of the clinical reference standard. Second, DWI was compared with contrast-enhanced MRI regarding detection of synovial inflammation. Results Sensitivity for detection of arthritis for DWI was 93% (13 of the 14 participants with arthritis were correctly classified with DWI; 95% confidence interval [CI]: 64%, 100%) and specificity was 81% (25 of 31 participants without arthritis were correctly classified with DWI; 95% CI: 62%, 92%). Scores for synovial inflammation at DWI and contrast-enhanced MRI agreed in 37 of 45 participants (82%), resulting in a sensitivity of 92% (12 of 13 participants; 95% CI: 62%, 100%) and specificity of 78% (25 of 32 participants; 95% CI: 60%, 90%) with DWI when contrast-enhanced MRI was considered the reference standard. Conclusion Diffusion-weighted imaging (DWI) was accurate in detecting arthritis in pediatric participants with juvenile idiopathic arthritis (JIA) or suspected of having JIA and showed agreement with contrast-enhanced MRI. The results indicate that DWI could replace contrast-enhanced MRI for imaging of synovial inflammation in this patient group. © RSNA, 2020 Online supplemental material is available for this article.

MRP8/14 and neutrophil elastase for predicting treatment response and occurrence of flare in patients with juvenile idiopathic arthritis.

OBJECTIVE: To study two neutrophil activation markers, myeloid-related protein (MRP) 8/14 and neutrophil elastase (NE), for their ability to predict treatment response and flare in patients with JIA. METHODS: Using samples from two cohorts (I and II), we determined MRP8/14 and NE levels of 32 (I) and 81 (II) patients with new-onset, DMARD-naïve arthritis and compared patients who responded to treatment (defined as fulfilling ≥ adjusted ACRpedi50 response and/or inactive disease) with non-responders (defined as fulfilling < adjusted ACRpedi50 response and/or active disease) at 6 and 12 months. Secondly, we compared biomarker levels of 54 (I) and 34 (II) patients with clinically inactive disease who did or did not suffer from a flare of arthritis after 6 or 12 months. Receiver operating characteristic analyses were carried out to study the predictive value of MRP8/14 and NE for treatment response and flare. RESULTS: For both cohorts, baseline MRP8/14 and NE levels for patients who did or did not respond to treatment were not different. Also, MRP8/14 and NE levels were not different in patients who did or did not flare. Receiver operating characteristic analysis of MRP8/14 and NE demonstrated areas under the curve <0.7 in both cohorts. CONCLUSION: In our cohorts, MRP8/14 and NE could not predict treatment response. Also, when patients had inactive disease, neither marker could predict flares.

Exploring contrast-enhanced MRI findings of the clinically non-inflamed symptomatic pediatric wrist.

BACKGROUND: Knowledge of the synovial and tenosynovial appearance of the clinically non-arthritic symptomatic juvenile wrist using contrast-enhanced magnetic resonance imaging (MRI) is sparse. OBJECTIVES: To analyze contrast-enhanced MRI findings of the clinically non-inflamed symptomatic pediatric wrist, focusing on the enhancing synovial and tenosynovial membrane. To evaluate the coexistent presence of (teno)synovial enhancement, joint fluid, bony depressions and medullary changes suggestive of bone marrow edema. MATERIALS AND METHODS: We included 20 children (15 girls; age range: 7.5-17.6 years) who underwent contrast-enhanced MRI of the wrist, based on initial clinical indication, and eventually turned out to be unaffected by arthritic or orthopedic disorders. Various imaging characteristics of the synovium, tenosynovium, joint fluid, bone tissue and bone marrow were evaluated using existing MRI scoring systems. RESULTS: In 3/20 (15%) children, mild or moderate-severe synovial enhancement was observed and 2/20 (10%) children showed mild tenosynovial enhancement/thickening. Joint fluid (11/20 children; 55%), bony depressions (20/20 children; 100%) and medullary changes suggestive of bone marrow edema (6/20; 30%) were found in a substantial percentage of children. The most frequently observed combination of coexisting imaging characteristics was bony depressions with ≥2 mm joint fluid, which was found in 7/20 (35%) children. Simultaneous presence of synovial and tenosynovial enhancement/thickening, bony depressions and medullary changes suggestive of bone marrow edema was observed in one child. CONCLUSION: Several juvenile idiopathic arthritis-relevant MRI characteristics can be observed in the clinically non-inflamed symptomatic pediatric wrist.

Correction to: Diffusion-weighted imaging for assessment of synovial inflammation in juvenile idiopathic arthritis: a promising imaging biomarker as an alternative to gadolinium-based contrast agents.

The original version of this article, published on 12 June 2017, unfortunately contained a mistake.

Prolonged time between intravenous contrast administration and image acquisition results in increased synovial thickness at magnetic resonance imaging in patients with juvenile idiopathic arthritis.

BACKGROUND: Post-contrast synovial thickness measurement is necessary for scoring disease activity in juvenile idiopathic arthritis (JIA). However, the timing of post-contrast sequences varies widely among institutions. This variation in timing could influence thickness measurements. OBJECTIVE: To measure thickness of the synovial membrane on early and late post-contrast knee magnetic resonance (MR) images of patients with JIA. MATERIALS AND METHODS: Dynamic contrast-enhanced T1-weighted knee MR images of 53 children with JIA with current or past knee arthritis were used to study synovial thickness at time point 1 (about 1 min) and time point 2 (about 5 min after contrast administration). Two experienced readers, who were blinded for the time point, independently measured synovial thickness at a predefined, marked location in the patellofemoral compartment on randomized images. Synovial thickness at the two time points was compared using the Wilcoxon signed rank test. Repeatibility of the synovial thickness measurements was studied using intraclass correlation coefficients and Bland-Altman plots. RESULTS: Median synovial thickness of the 53 patients (median age: 13.5 years, 59% female) increased with prolonged post-contrast interval with a synovial thickness of 1.4 mm at time point 1 and a synovial thickness of 1.5 mm at time point 2 (P<0.001). Repeated synovial thickness measurements showed an intraclass correlation coefficient (ICC) of 0.75, P<0.05 for time point 1 and an ICC of 0.91, P<0.05 for time point 2. CONCLUSION: Post-contrast synovial membrane thickness measurements are time-dependent. Therefore, standardization of post-contrast image acquisition timing is important to achieve consistent grading of synovial inflammation.

Contrast-enhanced MRI findings of the knee in healthy children; establishing normal values.

OBJECTIVES: To define normative standards for the knee in healthy children using contrast-enhanced MRI, focusing on normal synovial membrane thickness. Secondly, presence of joint fluid and bone marrow oedema was evaluated. METHODS: For this study, children without disorders potentially resulting in (accompanying) arthritis were included. Patients underwent clinical assessments, followed by contrast-enhanced MRI. MRI features were evaluated in consensus using the Juvenile Arthritis MRI Scoring (JAMRIS) system. Additionally, the presence of joint fluid was evaluated. No cartilage lesions or bone abnormalities were observed. RESULTS: We included 57 healthy children. The overall mean thickness of the normal synovial membrane was 0.4 mm (min-max; 0.0-1.8mm). The synovium was thickest around the cruciate ligaments and retropatellar and suprapatellar regions. The mean overall diameter of the largest pocket of joint fluid was 2.8 mm (min-max; 0.9-8.0mm). Bone marrow changes were observed in three children (all in the apex patellae). CONCLUSIONS: The normal synovial membrane was maximally 1.8 mm thick, indicating that the JAMRIS cut-off value of 2 mm can be considered a valid measure for evaluating synovial hypertrophy. Some joint fluid and bone marrow changes suggestive of bone marrow oedema in the apex patellae can be seen in healthy children. KEY POINTS: • Knowledge on the normal synovial appearance using contrast-enhanced MR is lacking. • In healthy children, normal synovial membrane is maximally 1.8 mm thick. • Normal synovium is thickest around the cruciate ligaments, retropatellar and suprapatellar. • Bone marrow oedema in the apex patellae is seen in healthy children.

Juvenile idiopathic arthritis: magnetic resonance imaging of the clinically unaffected knee.

BACKGROUND: Synovial thickening detected on magnetic resonance imaging (MRI) is present in a significant number of children with clinically inactive juvenile idiopathic arthritis (JIA). OBJECTIVE: To evaluate patient characteristics and disease activity parameters in a cohort of children with clinically inactive JIA, both with and without synovial thickening, in order to clarify the observed discrepancy between clinical and MRI assessments. MATERIALS AND METHODS: We prospectively enrolled 52 clinically inactive JIA patients (median age 13.3 years, 63.5% girls) who underwent MRI of the knee as major target joint in JIA. Children were divided into two groups based on MRI outcome: group 1, with synovial thickening on MRI; and group 2, with no synovial thickening on MRI. We used the Juvenile Arthritis MRI Scoring system to evaluate synovial thickness. We compared patient characteristics and disease activity parameters between the groups. RESULTS: Synovial thickening on MRI was present in 18 clinically inactive patients (group 1, 34.6%). The age was significantly lower for the patients in group 1 (median 10.7 versus 14.4, P=0.008). No significant differences were observed in any of the other patient characteristics nor the disease activity parameters tested. CONCLUSION: Synovial thickening on MRI was present in nearly 35% of the children with clinically inactive JIA. Children with synovial thickening on MRI were significantly younger than those without. This might indicate that younger patients are at risk of subclinical disease activity and under-treatment, although the exact clinical relevance of synovial thickening on MRI has not been determined.

Diffusion-weighted imaging for assessment of synovial inflammation in juvenile idiopathic arthritis: a promising imaging biomarker as an alternative to gadolinium-based contrast agents.

OBJECTIVES: To compare dynamic-contrast-enhanced MRI (DCE) and diffusion-weighted imaging (DWI) in quantifying synovial inflammation in juvenile idiopathic arthritis (JIA). METHODS: Regions of interest (ROI) were drawn in the synovium of JIA patients on T1 DCE and T2 DWI, followed by extraction of the maximum enhancement (ME), maximum initial slope (MIS), time to peak (TTP), % of different time intensity curve shapes (TIC) and apparent diffusion coefficient (ADC) of the ROIs. Mann-Whitney-U test was used for comparing parameters between MRI-active and -inactive patients (defined by the juvenile arthritis MRI scoring system). Spearman's rank was used to analyse the correlation between DCE and DWI. RESULTS: Thirty-five JIA patients (18 MRI active and 17 MRI inactive) were included. Median age was 13.1 years and 71% were female. ME, MIS, TTP, % TIC 5 and ADC were significantly different in MRI-active versus MRI-inactive JIA with median ADC 1.49 × 10-3mm2/s in MRI-active and 1.25 × 10-3mm2/s in MRI-inactive JIA, p = 0.001, 95% confidence interval of difference in medians =0.11-0.53 × 10-3mm2/s. ADC correlated to ME, MIS and TIC 5 shapes (r = 0.62, r = 0.45, r = -0.51, respectively, all p < 0.05). CONCLUSIONS: Similar to DCE parameters, DWI-derived ADC is significantly different in MRI-active JIA as compared to MRI-inactive JIA. The non-invasiveness of DWI combined with its possibility to detect synovial inflammation shows the potential of DWI. KEY POINTS: • MRI can quantify: dynamic contrast-enhanced and diffusion-weighted MRI can quantify synovitis • Both DWI and DCE can differentiate active from inactive JIA • The DWI-derived apparent diffusion coefficient (ADC) is higher in active JIA • DWI is non-invasive and thus safer and more patient-friendly • DWI is a potentially powerful and non-invasive imaging biomarker for JIA.

Use of antidepressants during pregnancy in the Netherlands: observational study into postpartum interventions.

BACKGROUND: Psychiatric disorders and use of selective antidepressants during pregnancy can have negative effects on mother and infant postpartum. This study aimed to provide evidence-based recommendations on observation of antidepressant-exposed mother-infant dyads. METHODS: In this observational study, mother-infant dyads were observed for possible consequences of either the maternal psychiatric disorder or fetal exposure to selective antidepressants during pregnancy. These possible complications can lead to medical interventions, including 1. adjustment of antidepressants 2. admission to the psychiatric department 3. additional investigations due to indistinctness about the origin of neonatal symptoms 4. treatment of poor neonatal adaptation and 5. consultation of an external organization for additional care. The type, number and time to medical interventions were analyzed. RESULTS: In 61% of the 324 included mother-infant dyads one or more intrventions were performed. Adjustment of antidepressants and treatment of poor neonatal adaptation were most prevalent. In 75% of dyads the final intervention was performed within 48 h. CONCLUSIONS: The high prevalence and type of medical interventions requires professional observation of all mother-infant dyads exposed to selective antidepressants. In the absence of specialized home care, hospital admission is indicated whereby an observational period of 48 h seems sufficient for most dyads.

Dynamic contrast-enhanced magnetic resonance imaging of the wrist in children with juvenile idiopathic arthritis.

BACKGROUND: Dynamic contrast-enhanced MRI provides information on the heterogeneity of the synovium, the primary target of disease in children with juvenile idiopathic arthritis (JIA). OBJECTIVE: To evaluate the feasibility of dynamic contrast-enhanced MRI in the wrist of children with JIA using conventional descriptive measures and time-intensity-curve shape analysis. To explore the association between enhancement characteristics and clinical disease status. MATERIALS AND METHODS: Thirty-two children with JIA and wrist involvement underwent dynamic contrast-enhanced MRI with movement-registration and were classified using validated criteria as clinically active (n = 27) or inactive (n = 5). Outcome measures included descriptive parameters and the classification into time-intensity-curve shapes, which represent the patterns of signal intensity change over time. Differences in dynamic contrast-enhanced MRI outcome measures between clinically active and clinically inactive disease were analyzed and correlation with the Juvenile Arthritis Disease Activity Score was determined. RESULTS: Comprehensive evaluation of disease status was technically feasible and the quality of the dynamic dataset was improved by movement registration. The conventional descriptive measure maximum enhancement differed significantly between clinically active and inactive disease (P = 0.019), whereas time-intensity-curve shape analysis showed no differences. Juvenile Arthritis Disease Activity Score correlated moderately with enhancing volume (P = 0.484). CONCLUSION: Dynamic contrast-enhanced MRI is a promising biomarker for evaluating disease status in children with JIA and wrist involvement. Conventional descriptive dynamic contrast-enhanced MRI measures are better associated with clinically active disease than time-intensity-curve shape analysis.

Trends in prescription of biological agents and outcomes of juvenile idiopathic arthritis: results of the Dutch national Arthritis and Biologics in Children Register.

BACKGROUND: Treatment of juvenile idiopathic arthritis (JIA) has changed dramatically since the introduction of biological agents in 1999. OBJECTIVE: To evaluate trends in prescription patterns of biological agents and the subsequent outcome of JIA. METHODS: The Arthritis and Biologics in Children register (multicentre prospective observational study) aimed to include all consecutive patients with JIA in the Netherlands who had started biological agents since 1999. Patients were divided according to year of introduction of first biological agent. Patient characteristics at introduction of the first biological agent and its effectiveness were analysed over 12 years. RESULTS: 335 patients with non-systemic JIA and 86 patients with systemic JIA started a biological agent between 1999 and 2010. Etanercept remained the most often prescribed biological agent for non-systemic JIA; anakinra became first choice for systemic JIA. The use of systemic glucocorticoids and synthetic disease-modifying antirheumatic drugs before biological agents decreased. During these 12 years of observation, biological agents were prescribed earlier in the disease course and to patients with lower baseline JADAS (Juvenile Arthritis Disease Activity Score) disease activity. All baseline disease activity parameters were lowered in patients with non-systemic JIA. In systemic JIA, prescription patterns changed towards very early introduction of biological agents (median 0.4 years of disease duration) in patients with a low number of joints with active arthritis and high erythrocyte sedimentation rates. These changes for both systemic and non-systemic JIA resulted in more patients with inactive disease after 3 and 15 months of treatment. CONCLUSIONS: Biological agents are increasingly prescribed, earlier in the disease and in patients with JIA with lower disease activity. These changes are accompanied by better short-term disease outcomes.

Mirtazapine in pregnancy and lactation: data from a case series.

Depression is a common disorder in pregnancy and associated with adverse effects for both mother and neonate. Pharmacological treatment and prevention options include mirtazapine. In a series of 56 cases, we investigated neonatal outcome after intrauterine exposure to mirtazapine and exposure through lactation in the first days postpartum.No increase in any neonatal complication was observed. None of the infants exposed to mirtazapine in the first trimester were born with a major malformation. Of the 54 infants exposed to mirtazapine in the third trimester, 14 were diagnosed with poor neonatal adaptation syndrome (PNAS). This incidence (25.9%) is similar to the incidence of PNAS after intrauterine exposure to other antidepressants. The incidence of PNAS after exposure to mirtazapine was significantly diminished in children who were partially or fully breastfed (18.6% versus 54.5%, P = 0.024).

Contrast-enhanced MRI features in the early diagnosis of Juvenile Idiopathic Arthritis.

OBJECTIVES: To determine whether clinical, laboratory or Magnetic Resonance Imaging (MRI) measures differentiate Juvenile Idiopathic Arthritis (JIA) from other forms of active childhood arthritis. MATERIALS AND METHODS: We prospectively collected data of 80 treatment-naïve patients clinically suspected of JIA with active non-infectious arthritis of (at least) one knee for <12 months duration. Upon presentation patients underwent clinical and laboratory assessments and contrast-enhanced MRI. MRI was not used as a diagnostic criterion. RESULTS: Forty-four (55%) patients were clinically diagnosed with JIA, whereas in 36 (45%) patients the diagnosis of JIA was discarded on clinical or laboratory findings. MRI-based synovitis was present in 27 (61.4%) JIA patients and in 7 (19.4%) non-JIA patients (P < 0.001). Five factors (male gender, physician's global assessment of overall disease activity, joints with limited range of motion, HLA-B27, MRI-based synovitis) were associated with the onset of JIA. In multivariate analysis MRI-based synovitis proved to be independently associated with JIA (OR 6.58, 95% CI 2.36-18.33). In patients with MRI-based synovitis, the RR of having JIA was 3.16 (95% CI 1.6-6.4). CONCLUSIONS: The presence of MRI-based synovitis is associated with the clinical onset of JIA. Physical examination could be supported by MRI, particularly to contribute in the early differentiation of different forms of non-infectious childhood arthritis. KEY POINTS: • Juvenile Idiopathic Arthritis (JIA) is a diagnosis of exclusion. • Differentiating JIA and other forms of childhood arthritis can be difficult. • MRI-techniques have substantially improved evaluation of joint abnormalities in JIA patients. • MRI-based synovitis is significantly associated with the clinical onset of JIA. • MRI could support physical examination in the early differentiation of childhood arthritis.

Risk factors for poor neonatal adaptation after exposure to antidepressants in utero.

AIM: Infants exposed to antidepressants in utero are at risk of developing poor neonatal adaptation (PNA). This study identified risk factors for PNA. METHODS: In this cohort study, data on mothers and infants admitted to the maternity ward of a general hospital between 2007 and 2012 were analysed. All infants were exposed to an antidepressant during the last trimester of foetal life. The main outcome measure was PNA, defined as at least one Finnegan scores of four or more during admission. Risk factors analysed for their possible association with PNA included type of feeding, type and dosage of antidepressant, prematurity and maternal smoking, anxiety and depression. RESULTS: We included 247 infants in the study and 157 (64%) developed PNA. Formula feeding was associated with an increased risk of PNA compared to breastfeeding or mixed feeding (OR 3.16 95% CI 1.40-7.13 p = 0.003). Selective serotonin reuptake inhibitors (SSRIs) were associated with an increased risk of PNA compared to serotonin and noradrenaline reuptake inhibitors (OR 2.52 95% CI 1.07-5.95 p = 0.04). Dosage did not influence the risk of PNA (OR 1.50 95% CI 0.89-2.52 p = 0.13). CONCLUSION: Formula feeding and exposure to SSRIs were associated with development of PNA, but dosage was not.

Contrast-enhanced MRI compared with the physical examination in the evaluation of disease activity in juvenile idiopathic arthritis.

OBJECTIVES: To assess the value of magnetic resonance imaging (MRI) in discriminating between active and inactive juvenile idiopathic arthritis (JIA) patients and to compare physical examination outcomes with MRI outcomes in the assessment of disease status in JIA patients. METHODS: Consecutive JIA patients with knee involvement were prospectively studied using an open-bore MRI. Imaging findings from 146 JIA patients were analysed (59.6% female; mean age, 12.9 years). Patients were classified as clinically active or inactive. MRI features were evaluated using the JAMRIS system, comprising validated scores for synovial hypertrophy, bone marrow oedema, cartilage lesions and bone erosions. RESULTS: Inter-reader reliability was good for all MRI features (intra-class correlation coefficient [ICC] = 0.87-0.94). No differences were found between the two groups regarding MRI scores of bone marrow oedema, cartilage lesions or bone erosions. Synovial hypertrophy scores differed significantly between groups (P = 0.016). Nonetheless, synovial hypertrophy was also present in 14 JIA patients (35.9%) with clinically inactive disease. Of JIA patients considered clinically active, 48.6% showed no signs of MRI-based synovitis. CONCLUSIONS: MRI can discriminate between clinically active and inactive JIA patients. However, physical examination is neither very sensitive nor specific in evaluating JIA disease activity compared with MRI. Subclinical synovitis was present in >35% of presumed clinically inactive patients. KEY POINTS: • MRI is sensitive for evaluating juvenile idiopathic arthritis (JIA) disease activity. • Contrast-enhanced MRI can distinguish clinically active and inactive JIA patients. • Subclinical synovitis is present in 35.9 % of presumed clinically inactive patients. • Physical examination is neither sensitive nor specific in evaluating JIA disease activity.

Pixel-by-pixel analysis of DCE-MRI curve shape patterns in knees of active and inactive juvenile idiopathic arthritis patients.

OBJECTIVES: To compare DCE-MRI parameters and the relative number of time-intensity curve (TIC) shapes as derived from pixel-by-pixel DCE-MRI TIC shape analysis between knees of clinically active and inactive juvenile idiopathic arthritis (JIA) patients. METHODS: DCE-MRI data sets were prospectively obtained. Patients were classified into two clinical groups: active disease (n = 43) and inactive disease (n = 34). Parametric maps, showing seven different TIC shape types, were created per slice. Statistical measures of different TIC shapes, maximal enhancement (ME), maximal initial slope (MIS), initial area under the curve (iAUC), time-to-peak (TTP), enhancing volume (EV), volume transfer constant (K(trans)), extravascular space fractional volume (V(e)) and reverse volume transfer constant (k(ep)) of each voxel were calculated in a three-dimensional volume-of-interest of the synovial membrane. RESULTS: Imaging findings from 77 JIA patients were analysed. Significantly higher numbers of TIC shape 4 (P = 0.008), median ME (P = 0.015), MIS (P = 0.001) and iAUC (P = 0.002) were observed in clinically active compared with inactive patients. TIC shape 5 showed higher presence in the clinically inactive patients (P = 0.036). CONCLUSIONS: The pixel-by-pixel DCE-MRI TIC shape analysis method proved capable of differentiating clinically active from inactive JIA patients by the difference in the number of TIC shapes, as well as the descriptive parameters ME, MIS and iAUC. KEY POINTS: • The pixel-by-pixel TIC shape method differentiates clinically active and inactive JIA patients • Significantly higher numbers of TIC shape 4 were observed in clinically active patients • DCE-MRI parameters ME, MIS and iAUC differ between active and inactive patients • The pixel-by-pixel analysis method allows direct visualization of the heterogeneously distributed disease • The DCE-MRI TIC shape method may serve as a quantitative outcome measure.

Distribution pattern of MRI abnormalities within the knee and wrist of juvenile idiopathic arthritis patients: signature of disease activity.

OBJECTIVE: The aim of this study in clinically active juvenile idiopathic arthritis (JIA) was to assess the frequency and distribution pattern of synovitis as hallmark of disease and additional soft-tissue and bony abnormalities on MRI in the knee and wrist as two target joints. MATERIALS AND METHODS: MRI datasets of 153 clinically active JIA patients (110 with knee and 43 with wrist involvement) were evaluated independently by two readers for the presence of literature-based imaging features: "synovial hypertrophy," "bone marrow changes," "bone erosions," "tenosynovitis" (only in the wrist), and "cartilage lesions" (only in the knee) in accordance with validated definitions and scoring locations. RESULTS: Synovial hypertrophy was most frequently observed--both in the knee and in the wrist (61.8-65.1% of cases). For the knee, the most frequently involved locations were the cruciate ligaments (46/183 locations [25.1%] affected with synovial hypertrophy) and medial patella (18/62 locations [29.0%] with bone marrow changes). Cartilage lesions and bone erosions were rare (5.5-7.3% of cases). For the wrist, most frequently involved were the radiocarpal joint (21/64 locations [32.8%] with synovial hypertrophy), lunate (7/46 locations [15.2%] with bone marrow changes), and capitate or triquetrum (6/28 locations [21.4%] with bone erosions). Tenosynovitis was a common wrist-specific feature (46.5% of cases). MRI showed no abnormalities in a subgroup of patients with clinically active knee (23.6%) and wrist (16.3%) involvement. CONCLUSION: The distribution pattern of MRI abnormalities in the knee and wrist of active JIA patients provides a practical tool to detect a signature of JIA disease activity in target joints.

Effectiveness and safety of a second and third biological agent after failing etanercept in juvenile idiopathic arthritis: results from the Dutch National ABC Register.

OBJECTIVE: To evaluate the effectiveness and safety of switching to a second or third biological agent in juvenile idiopathic arthritis (JIA) after etanercept failure. METHODS: The Arthritis and Biologicals in Children Register aims to include all Dutch JIA patients who have used biological agents. Data on the disease course were used to estimate drug survival with Kaplan-Meier and calculate adverse event (AE) rates. RESULTS: Of 307 biologically naive JIA patients who started etanercept, 80 (26%) switched to a second and 22 (7%) to a third biological agent. During 1030 patient-years of follow-up after the introduction of etanercept, 49 switches to adalimumab, 28 infliximab, 17 anakinra, four abatacept and four trial drugs were evaluated. 84% (95% CI 80% to 88%) of patients who started etanercept as a first biological agent were, after 12 months, still on the drug, compared with 47% (95% CI 35% to 60%) who started a second and 51% (95% CI 26% to 76%) who started a third biological agent. Patients who switched because of primary ineffectiveness continued the second agent less often (32%, 95% CI 12% to 53%). After etanercept failure, drug continuation of adalimumab was similar to infliximab for patients with non-systemic JIA; anakinra was superior to a second TNF-blocker for systemic JIA. AE rates within first 12 months after initiation were comparable for each course and each biological agent. CONCLUSIONS: Switching to another biological agent is common, especially for systemic JIA patients. A second (and third) agent was less effective than the first. The choice of second biological agent by the physician mainly depends on availability and JIA category.

Tumour necrosis factor-blocking agents in persistent oligoarticular juvenile idiopathic arthritis: results from the Dutch Arthritis and Biologicals in Children Register.

OBJECTIVE: Because TNF inhibitors are not approved for persistent oligoarticular JIA (oJIA), although they are used off-label, we evaluated their effectiveness in patients in this category. METHODS: Persistent oJIA patients were selected from the Dutch Arthritis and Biologicals in Children (ABC) register, an ongoing multicentre prospective study that aims to include all Dutch children with JIA using biologic agents. Response was assessed by the JIA core-set disease activity variables and modified Wallace criteria for inactive disease. RESULTS: Until February 2011, 16 persistent oJIA patients (68.8% females) had been included in the register. Median age of onset was 8.4 years [interquartile range (IQR) 2.1-13.5 years]; history of uveitis in 18.8%; ANA-positive 56.3%. All had previously used MTX, and 81.3% had used IA CSs. Median follow-up after the introduction of biologic treatment was 13.7 months (IQR 8.3-16.7 months). Fourteen patients started etanercept and two patients who had active arthritis as well as uveitis started adalimumab. Although patients with persistent oJIA had few affected joints [median of two active joints at the start of biologic (IQR 1-3)], the patient/parent assessments of pain [median visual analogue score (VAS) 51 (IQR 1-64)] and well-being [median VAS 44 (IQR 6-66)] were high. Additionally, their physician evaluated the disease activity as moderately high [median VAS 36 (IQR 4-65)]. After 3 months this decreased to 0 (IQR 0-30) and 63% achieved inactive disease. After 15 months the disease was inactive in 9/10 observed patients. TNF inhibitors were tolerated well. CONCLUSION: TNF blocking agents seem an effective and justifiable option in persistent oJIA when treatment with IA CS injections and MTX has failed.