M. Reijnierse

Using a reference when defining an abnormal MRI reduces false-positive MRI results—a longitudinal study in two cohorts at risk for rheumatoid arthritis

ObjectivesnThe use of hand and foot MRI in the diagnostic process of RA has been advocated. Recent studies showed that MRI is helpful in predicting progression from clinically suspect arthralgia (CSA) to clinical arthritis, and from undifferentiated arthritis (UA) to RA. Symptom-free persons can also show inflammation on MRI. This study aimed to evaluate if MRI findings in symptom-free volunteers are relevant when defining a positive MRI.nnnMethodsnTwo hundred and twenty-five CSA patients and two hundred and one UA patients underwent MRI of MCP, wrist and MTP joints at baseline and were followed for 1 year on progression to arthritis and RA, respectively, as reported previously. MRI was considered positive if ⩾ 1 joint showed inflammation (called uncorrected definition), or if ⩾ 1 joint had inflammation that was present in < 5% of persons of the same age category at the same location (called 5% corrected definition). Test characteristics were compared for both definitions.nnnResultsnBy using MRI data of symptom-free volunteers as reference, specificity of MRI-detected inflammation increased from 22 to 56% in CSA patients, and from 10 to 36% in UA patients. The sensitivity was not affected; it was 88 and 85% in CSA patients and 93 and 93% in UA patients. The accuracy also increased, from 32 to 60% in CSA patients and 22 to 44% in UA patients.nnnConclusionnThe use of a reference population resulted in a substantial reduction of false-positive results, without influencing the sensitivity. Although common for other tests in medicine, this phenomenon is novel for MRI in the early detection of RA.

Efficacy of MRI in primary care for patients with knee complaints due to trauma: protocol of a randomised controlled non-inferiority trial (TACKLE trial)

BackgroundPatients with traumatic knee complaints regularly consult their general practitioner (GP). MRI might be a valuable diagnostic tool to assist GPs in making appropriate treatment decisions and reducing costs. Therefore, this study will assess the cost-effectiveness of referral to MRI by GPs compared with usual care, in patients with persistent traumatic knee complaints.Design and methodsThis is a multi-centre, open-labelled randomised controlled non-inferiority trial in combination with a concurrent observational cohort study. Eligible patients (aged 18–45xa0years) have knee complaints due to trauma (or sudden onset) occurring in the preceding 6xa0months and consulting their GP. Participants are randomised to: 1) an MRI group, i.e. GP referral to MRI, or 2) a usual care group, i.e. no MRI. Primary outcomes are knee-related daily function, medical costs (healthcare use and productivity loss), and quality of life. Secondary outcomes are disability due to knee complaints, severity of knee pain, and patients’ perceived recovery and satisfaction. Outcomes are measured at baseline and at 1.5, 3, 6, 9 and 12xa0months follow-up. Also collected are data on patient demographics, GPs’ initial working diagnosis, GPs’ preferred management at baseline, and MRI findings.DiscussionIn the Netherlands, the additional diagnostic value and cost-effectiveness of direct access to knee MRI for patients presenting with traumatic knee complaints in general practice is unknown. Although GPs increasingly refer patients to MRI, the Dutch clinical guideline ‘Traumatic knee complaints’ for GPs does not recommend referral to MRI, mainly because the cost-effectiveness is still unknown.Trial registrationDutch Trial Registration: NTR3689.

Reliability of mSASSS scoring in everyday practice in DESIR-cohort study centres: cross-sectional study of agreement with trained readers.

The assessment of axial SpondyloArthritis (axSpA) lesions is important; not only to evaluate a major contributor to disease severity, but also to determine whether drugs are effective in inhibiting structural progression. In trials, assessment of axSpA lesions can be done locally in a study centre, or in a centralised manner by specifically trained readers. The potential impact of choosing one method rather than the other is unknown. In earlier work, we found the same—moderate—level of agreement between local reading (LocR) and central reading (CentR) as between the two central readers regarding radiographic sacroiliitis assessment.1 However, differences between LocR and CentR resulted in misclassification of some patients (ankylosing spondylitis (AS) or axSpA meeting Assessment of SpondyloArthritis international Society (ASAS) criteria).2 The modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) is the recommended tool to assess erosions, sclerosis, squaring and (bridging) syndesmophytes at each anterior vertebral corner of the cervical and lumbar spine.3 ,4 The objective of this study was to assess the agreement between baseline mSASSS values of patients with recent-onset inflammatory back pain (devenir des spondyloarthrites indifferenciees recentes (DESIR) …

SAT0041 The Course of Bone Marrow Edema in Early Undifferentiated and Rheumatoid Arthritis; A Longitudinal MRI Study on Bone Level

Background In rheumatoid arthritis (RA) patients, bone marrow edema (BME)-scores are associated with development of erosions. However, little is known on the course and outcome of BME at bone level. Therefore this study determined the association of BME and MRI-synovitis in the same bone longitudinally. Objectives This study was aimed to determine the course of BME and MRI-synovitis at bone level. Furthermore the association between the course of BME and local synovitis and the development of erosions in the same bone was studied. Methods 1,947 bones of MCP, wrist and MTP-joints of 59 patients presenting with rheumatoid or undifferentiated arthritis were studied using 1.5T MRI at baseline, after four and twelve months. Scanning and scoring of BME, synovitis and erosions were performed according to RAMRIS. The relation of the course of BME and synovitis to erosive progression at bone level during 1-year was evaluated. Results Of the bones showing BME at baseline (n=203), BME persisted in 56%, disappeared in 39%, and disappeared-reappeared seldom (5%). Stratified analyses at baseline revealed that BME was associated with erosive progression, in presence and in absence of local synovitis (ORs 7.5 95%CI 3.8-14.9 and 6.9 95%CI 1.9-25.6). Local synovitis, however, was not associated with erosive progression (OR 2.0 95%CI 0.6-7.0 in presence of BME and 1.9 95%CI 0.8-4.1 in the absence of BME). In multivariable GEE-analyses, persistent BME was strongly associated with erosive progression (OR 60 95%CI 17-318), in contrast to persistent synovitis (OR 1.4 95%CI 0.4-5.3). Conclusions BME frequently persists during the first year. Persistent BME was strongly associated with erosive progression in the same bone, independent of local synovitis. No independent association was observed for persistent synovitis. These findings are relevant for the comprehension on the development of erosions in RA. Disclosure of Interest None declared

THU0032 Diagnostic Accuracy of Hand and Foot MRI for Early Rheumatoid Arthritis

Background Early diagnosis and treatment of rheumatoid arthritis (RA) is advocated. However, in part of the RA-patients a classifiable diagnosis cannot be made at first presentation; these patients present with unclassified arthritis (UA). The use of MRI for early diagnosis of RA is recommended, yet the evidence is limited. Objectives To assess the performance of hand and foot MRI for early diagnosis of RA. Methods Unilateral contrast-enhanced 1.5T MRI of the hand and foot was performed in 589 early arthritis patients included in the Leiden Early Arthritis Clinic, of whom 229 presented with RA, 159 with other arthritides and 201 with UA. MRI-findings observed in symptom-free controls served as reference to define an abnormal MRI. In preliminary investigations, patients that presented with RA were compared with symptom-free controls and with patients that presented with other arthritides. Thereafter, the accuracy of MRI was determined in UA-patients that were followed for 1-year on fulfilling the 1987-RA-criteria (primary outcome); the secondary outcome was start of disease-modifying drugs. Results The results of the preliminary investigations were promising and showed that MRI-detected tenosynovitis was more discriminative than other types of MRI-inflammation. Of all UA-patients, 29 (14%) developed RA and 75 (37%) started disease-modifying treatment. MRI-detected tenosynovitis was associated with RA-development independent of other types of MRI-inflammation (odds ratio (OR) 7.5 95%CI 2.4–23) and also independent of age and commonly used measures of inflammation (number of swollen joints and C-reactive protein) (OR 4.2 95%CI 1.4–12.9). Within UA-patients, the negative predictive value (NPV) of abnormal tenosynovitis was 95% and the positive predictive value (PPV) 25%. The performance was best in the subgroup UA-patients presenting with oligo-arthritis (18% developed RA): PPV was 36%, NPV 98%, sensitivity 93%, and specificity 63%. Decision curve analysis revealed a higher net benefit for a model including MRI-detected tenosynovitis. Conclusions MRI-detected inflammation, MRI-detected tenosynovitis in particular, contributes to identification of the UA-patient that will develop RA. Disclosure of Interest None declared

SAT0084 Evaluation of Functional Disability in Patients with Clinically Suspect Arthralgia

Background A phase of arthralgia precedes the emergence of rheumatoid arthritis (RA). This phase is not yet well characterized. The presence of MRI-detected subclinical inflammation has been identified in this phase and is correlated with RA development. However, it is unknown if patients with arthralgia at risk for RA (with and without subclinical inflammation) have functional limitations. Objectives This study assessed functional disability in patients with clinically suspect arthralgia (CSA) and the associations with MRI-detected inflammation and progression to clinical arthritis. Methods Between April 2012 and April 2015 patients were included in the CSA cohort. Patients with CSA were defined as having no clinical arthritis, with symptoms of hands or feet for <1 year and were considered to be at risk for RA by their rheumatologists based on their clinical presentation. At baseline, functional disability was assessed using HAQ scores and unilateral 1.5 T extremity MRIs of wrist, MCP and MTP joints were made. MRIs were scored on synovitis, tenosynovitis and bone marrow edema (BME) by two independent readers. The sum of these features yielded the total MRI-inflammation score. Pearson correlation coefficients, linear regression models, paired t-tests and Cox proportional hazards regression analyses were used. Results Of the 255 patients included, 77% were female and the mean age was 44.2 years. Median HAQ score was 0.50 at baseline and median duration of follow-up was 61 weeks. In univariable linear regression, a higher total inflammation score was significantly associated with a higher HAQ score (β=0.01, p=0.019). Of the individual types of inflammation, tenosynovitis showed the strongest correlation (β=0.04, p=0.003). When evaluating subclinical inflammation at specific hand joints in relation to HAQ-questions measuring hand function, significant correlations were observed. For instance, difficulties with opening previously opened jars was associated with MRI-inflammation score at the wrists (Pearson r=0.18, p=0.011). Patients that progressed to clinical arthritis had higher HAQ scores at presentation, than CSA-patients that did not progress (median HAQ scores 0.90 and 0.50 respectively). HAQ scores above 0.90 in particular were associated with arthritis development (HR=2.62, 95% CI: 1.06–6.47, p=0.036) as shown in the Kaplan-Meier plot (figure 1). An analysis of the patients that did develop arthritis revealed that median HAQ-scores were the same both at initial presentation with CSA and at conversion to clinical arthritis (median HAQ scores 0.90 and 0.68 respectively, paired t-test p-value = 0.751). Conclusions CSA-patients already have functional limitations. The severity of functional disability is associated with the severity of local subclinical inflammation. CSA-patients that progressed to clinical arthritis had high HAQ scores at baseline and these HAQ scores did not increase when arthritis became clinically evident. Disclosure of Interest None declared

Does MRI add value in general practice for patients with traumatic knee complaints? A 1-year randomised controlled trial

Objective To determine whether referral to MRI by the general practitioner (GP) is non-inferior to usual care (no access to MRI by GPs) in patients with traumatic knee complaints regarding knee-related daily function. Methods This was a multicentre, non-inferiority randomised controlled trial with 1-year follow-up. GPs invited eligible patients during or after their consultation. Eligible patients (18–45 years) consulted a GP with knee complaints due to a trauma during the previous 6 months. Patients allocated to the MRI group received an MRI at (median) 7 (IQR 1–33) days after the baseline questionnaire. Patients in the usual care group received information on the course of knee complaints, and a referral to a physiotherapist or orthopaedic surgeon when indicated. The primary outcome measure was knee-related daily function measured with the Lysholm scale (0 to 100; 100=excellentu2009function) over 1u2009year, with a non-inferiority margin of 6 points. Results A total of 356 patients were included and randomised to MRI (n=179) or usual care (n=177) from November 2012 to December 2015. MRI was non-inferior to usual care concerning knee-related daily function during 1-year follow-up, for the intention-to-treat (overall adjusted estimate: 0.33; 95%u2009CI −1.73 to 2.39) and per-protocol (overall adjusted estimate: 0.06; 95%u2009CI −2.08 to 2.19) analysis. There were no differences between both groups in the amount of patients visiting other healthcare providers. Conclusion MRI in general practice in patients with traumatic knee complaints was non-inferior to usual care regarding knee-related daily function during 1-year follow-up. Trial registration number NTR3689.

FRI0465 Angles of sacrum inclination effect on radiologic imaging reading in spondyloarthritis (the antelope-desir study)

Objectives To assess the impact of spinal angles on clinical and imaging features of suspicion of axial spondyloarthritis (axSpA). Methods The DESIR cohort is a prospective longitudinal cohort study of adults aged 18–50 with inflammatory back pain (IBP) ≥3 months, ≤3 years. Baseline lateral lumbar radiography of patients included in DESIR cohort were read by two central blinded fellow readers (and a rheumatologist spine specialist in case of discrepancy) for Sacral Horizontal Angle (SHA), Lumbosacral angle (LSA) and total Lordotic Angle (TLA) measures. On the basis of literature, patients were classified depending on whether they had TLA more or less than 50°, SHA more or less than 40° or LSA more or less than 15°. Associations between angles and baseline clinical variables, presence of X-Rays (New York) and MRI (ASAS and MORPHO proposal definition) sacroiliitis, presence of spinal signs of spondyloarthritis (mSASSS, BASRI-total, SPARCC scores), presence of spinal degenerative MRI signs on X-rays (yes or no) and MRI (presence of Modic abnormalities, Pfirrmann score, Canal stenosis, Extrusion, High intensity zone Facet osteoarthritis) according to central reading (two readers) and axSpA diagnostic confidence (according to local clinicians confidence on a 0–10 visual analog scale) were assessed by univariate analysis using the chi-square test (or Fishers exact test where appropriate) and the Mann-Whitney test. Adjustment for multiple testing was performed according to Bonferroni method. Results Of 708 patients, data were available for 677, 675 and 672 for SHA, LSA and TLA, measures with a mean value of 39.2°, 14.5° and 51.5° respectively. Clinical features and diagnostic confidence did not differ between the SHA, LSA and TLA groups. More sacroiliitis imaging, according to ASAS (41.4% versus 32.0%) and MORPHO definition (48.6% versus 39.3%), were reported in TLA<50° group but the differences did not reach statistical significance. Radiological scores were low with a mean value of 0.49 (±1.83), 0.30 (±0.78) and 4.9 (±9.0) for mSASSS, BASRI-total and SPARCC score, respectively, and no inter-group difference was found. In L5S1, more grade 3 and 4 Pfirrmann class and MODIC discopathy (types 1 and 2) were observed for SHA <40°, and TLA <50° (p<0.001) whereas the difference did not reach the significance level for LSA<15° (p=0.05) (table). Conclusions Lumbar spine morphology is not associated with any clinical variable, presence on X-Rays or MRI of spinal signs of spondyloarthritis or sacroiliitis. At the L5S1 level, a more horizontal SHA and a reduction of TLA is associated with more degenerative radiological lumbar spine manifestations. Disclosure of Interest None declared

SAT0511 Thumb base osteoarthritis: associations between synovitis on ultrasound and pain

Background Hand osteoarthritis (OA) affects the interphalangeal (IP) joints but also the first carpometacarpal (CMC1) joint in the thumb base. Previous ultrasonography (US) studies of the IP joints have shown that inflammatory and structural features are frequently present and associated with clinical signs and symptoms. Until now, US studies specifically assessing the CMC1 joint have not been performed. Objectives To investigate associations between inflammatory features, structural damage and pain in CMC1 OA. Methods Cross-sectional data of 87 hand OA patients participating in the EChography in Hand OA (n=63) and the Etanercept in Hand OA (n=24) study at the Leiden University Medical Center were used in this analysis. Both CMC1 joints were assessed with US for synovial thickening, effusion and power Doppler signal (PDS) on a 0–3 scale by experienced ultrasonographers. Presence of pain upon palpation of the thumb base was assessed by trained research nurses on the same day as the US. Hand radiographs were scored blinded for clinical and US features, according to the Osteoarthritis Research Society International atlas for osteophytes (0–3), joint space narrowing (JSN, 0–3), sclerosis (0–1) and malalignment (0–1) in the CMC1 joint. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated using generalized estimating equations to investigate associations between US or radiographic features and thumb base pain on joint level. Results Of 87 patients (mean age 60.3 years, 82% women, mean BMI 27.2 kg/m2) 174 CMC1 joints were assessed, of which 54 (31%) were painful. The US features synovial thickening, effusion and PDS were found in 26%, 33% and 25% of the joints, respectively. Radiographic features were present in 55% (osteophytes), 79% (JSN), 20% (sclerosis) and 12% (malalignment) of the joints. No associations were seen between inflammatory US features and pain upon palpation of the thumb base (Table). However, osteophytes and sclerosis were associated with more pain (RR 2.5 [95% CI 1.4 to 4.6] for osteophytes grade 3 versus no osteophytes, and RR 2.0 [95% CI 1.3 to 3.2] for presence of sclerosis). Other radiographic features (JSN, malalignment) showed a trend for increased risk of pain on palpation, and for osteophytes and JSN a dose-response relation was apparent. Conclusions Radiographic features, especially osteophytes and JSN, were prevalent and more frequently present than US inflammatory features in the CMC1 joints of hand OA patients. In contrast to what is known from studies in IP joints, the presence of inflammatory US features was not associated with pain in the thumb base, but structural damage was. These results suggest differences in etiology of pain in thumb base compared to IP OA, with a larger role for structural damage in thumb base OA. Disclosure of Interest None declared

THU0704 Evaluation of the accuracy of hand and foot mri in the early identification of ra: using the prevalence of low-graded inflammation in the symptom-free population as reference reduces false-positive mri results

Background Early identification of rheumatoid arthritis (RA) is important, because it allows early treatment initiation and is associated with better disease outcomes. In this perspective, the use of hand and foot MRI in the diagnostic process of rheumatoid arthritis (RA) has been advocated. Recent studies showed that MRI is helpful in predicting progression from clinically suspect arthralgia (CSA) to clinical arthritis, and from undifferentiated arthritis (UA) to RA. However, the diagnostic value of MRI is still undetermined. Most studies focussed on the sensitivity rather than the specificity of inflammation detected on MRI. It is known that symptom-free persons can also show inflammation on MRI. Consequently, it has been questioned if MRI-findings in symptom-free volunteers are relevant to consider as a reference when defining a “positive MRI”. Objectives To determine the value of considering MRI-findings in a control group for the predictive accuracy of MRI when defining a positive MRI. Methods 225 patients with CSA and 201 patients with UA underwent MRI of MCP-, wrist- and MTP-joints at baseline and were followed for 1 year on progression to arthritis and RA respectively. MRI was considered positive either if ≥1 joint showed inflammation (called “uncorrected definition”), or if ≥1 joint had inflammation that was present in <5% of persons of the same age-category at the same location in a symptom free reference population (called “5% corrected definition”). MRI scans were scored according to RAMRIS method. Test characteristics were compared for both definitions, hence with and without the incorporation of a reference population when defining a “positive MRI”. Results By using MRI-data of symptom-free volunteers as reference, the specificity of MRI-detected inflammation increased from 22% to 56% in CSA-patients, and from 10% to 36% in UA-patients. The sensitivity was not affected; it was 88% and 85% in CSA-patients and 93% and 93% in UA-patients. The accuracy also increased, from 32% to 60% in CSA-patients and 22% to 44% in UA-patients. Conclusions The use of a reference population resulted in a substantial reduction of false-positive results, without affecting the sensitivity. This is of high importance because of the potential risks of false-positive MRI-results, for example in the setting of UA as a positive MRI-result may influence the decision to initiate disease modifying medication. Although a reference population is generally used in medicine for other tests to derive a definition of a positive test result, this is the first study demonstrating the value of a reference population to define a “positive MRI”. Disclosure of Interest None declared