Comparison between 1.5T and 3.0T MRI: both field strengths sensitively detect subclinical inflammation of hand and forefoot in patients with arthralgia.

OBJECTIVE: Magnetic resonance imaging (MRI) of small joints sensitively detects inflammation. This inflammation, and tenosynovitis in particular, has been shown to predict rheumatoid arthritis (RA) development in arthralgia patients. These data have predominantly been acquired on 1.0-1.5 T MRI. However, 3.0 T is now commonly used in practice. Evidence on the comparability of these field strengths is scarce and has never included subtle inflammation in arthralgia patients or tenosynovitis. Therefore, we assessed the comparability of 1.5 T and 3.0 T in detecting subclinical inflammation in arthralgia patients. METHOD: A total of 2968 locations (joints, bones, tendon sheaths) in the hands and forefeet of 28 patients with small-joint arthralgia, at risk for RA, were imaged on both 1.5 and 3.0 T MRI. Two blinded readers independently scored erosions, osteitis, synovitis, and tenosynovitis, in line with the Rheumatoid Arthritis Magnetic Resonance Imaging Score (RAMRIS). Features were summed into inflammation (osteitis, synovitis, tenosynovitis) and RAMRIS (inflammation and erosions). Agreement was assessed with intraclass correlation coefficients (ICCs) for continuous scores and after dichotomization into presence or absence of inflammation, on patient and location levels. RESULTS: Interreader ICCs were excellent (> 0.90). Comparing 1.5 and 3.0 T revealed an ICC of 0.90 for inflammation and RAMRIS. ICCs for individual inflammation features were: tenosynovitis 0.87 (95% confidence interval 0.74-0.94), synovitis 0.65 (0.24-0.84), and osteitis 0.96 (0.91-0.98). Agreement was 83% for inflammation and 89% for RAMRIS. Analyses on the location level showed similar results. CONCLUSION: Agreement on subclinical inflammation between 1.5 T and 3.0 T was excellent. Although synovitis scores were slightly different, synovitis often occurs simultaneously with other inflammatory signs, suggesting that scientific results on the predictive value of MRI-detected inflammation for RA, obtained on 1.5 T MRI, can be generalized to 3.0 T MRI.

Do magnetic resonance imaging-detected erosions predict progression to rheumatoid arthritis in patients presenting with clinically suspect arthralgia? A longitudinal study.

Objective: Radiographic joint erosions are a hallmark of rheumatoid arthritis (RA). Magnetic resonance imaging (MRI) is more sensitive than radiographs in detecting erosions. It is unknown whether MRI-detected erosions are predictive for RA development in patients with clinically suspect arthralgia (CSA). Therefore, we investigated the prognostic value of MRI-detected erosions, defined as any MRI erosion, or MRI erosion characteristics that were recently identified as specific for RA in patients with evident arthritis. Method: Patients presenting with CSA (n = 490) underwent contrast-enhanced 1.5 T MRI of the wrist, metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joints. MRIs were scored according to the Rheumatoid Arthritis Magnetic Resonance Imaging Scoring system (RAMRIS). Presence of any MRI erosion (present in < 5% of symptom-free controls) and RA-specific erosion characteristics as identified previously (grade ≥ 2 erosions, erosions in MTP5, erosions in MTP1 if aged < 40 years) were studied with clinically apparent inflammatory arthritis development as outcome. Analyses were corrected for age and MRI-detected subclinical inflammation. Results: Erosions were present in 20%. Presence of any MRI erosion was not associated with arthritis development [multivariable analysis hazard ratio (HR) 0.97 (95% confidence interval 0.59-1.59)]. The different RA-specific erosion characteristics were not predictive [grade ≥ 2 HR 1.05 (0.33-3.34), erosions in MTP5 HR 1.08 (0.47-2.48), and MTP1 if aged < 40 years HR 1.11 (0.26-4.70)]. Erosion scores were higher in anti-citrullinated protein antibody (ACPA)-positive than in ACPA-negative patients (median 2.0 vs 1.0, p = 0.002), and related to more subclinical inflammation. Within both subgroups, MRI erosions were not predictive. Conclusions: MRI-detected erosions in hands and feet were not predictive for inflammatory arthritis development. Therefore, evaluating MRI for erosions in addition to subclinical inflammation does not provide added clinical value in CSA.

Contribution of tenosynovitis of small joints to the symptom morning stiffness in patients presenting with undifferentiated and rheumatoid arthritis.

Objective: Morning stiffness (MS) is characteristic of rheumatoid arthritis (RA). Despite its association with functional disability, the extent to which local inflammatory processes contribute to this symptom is unknown. Magnetic resonance imaging (MRI)-detected tenosynovitis of small joints is recognized as an early feature of RA, which is also associated with functional impairments. It has been proposed that tenosynovitis contributes to MS. Therefore, we assessed the relationship between MS and MRI-detected inflammation, in particular tenosynovitis.Method: In total, 286 consecutive patients newly presenting with undifferentiated arthritis and RA underwent contrast-enhanced 1.5 T MRI of (2-5) metacarpophalangeal, wrist, and (1-5) metatarsophalangeal joints. Scans were scored for tenosynovitis according to Haavardsholm, and for synovitis by Rheumatoid Arthritis Magnetic Resonance Imaging Scoring (RAMRIS). MS was dichotomized as ≥ 60 min or not. Associations between MS and tenosynovitis/synovitis were tested with logistic regression, data were categorized (solitary or simultaneous presence of synovitis/tenosynovitis), and the presence of an additive interaction was assessed.Results: MS was present in 40% of patients. Tenosynovitis was more often present in patients with MS than without MS [80% vs 65%, odds ratio (OR) 2.11, 95% confidence interval (1.21;3.69)]. Synovitis was more often present in patients with MS [58% vs 44%, OR 1.79 (1.11;2.91)]. In categorized analyses, concurrent synovitis and tenosynovitis had the largest association [OR 2.43 (1.30;4.54)], in contrast to solitary synovitis [OR 0.85 (0.21;3.47)]. The additive interaction was non-significant. The variance explained in all analyses was small (range 4-5%).Conclusion: Tenosynovitis, combined with synovitis, at small joints is associated with MS and contributes to the pathophysiology of MS.

Bone mineral density loss in clinically suspect arthralgia is associated with subclinical inflammation and progression to clinical arthritis.

OBJECTIVE: Peripheral bone mineral density (BMD) may be decreased in early rheumatoid arthritis (RA) but it is unknown whether BMD loss emerges before arthritis is clinically apparent. We aimed to study whether BMD loss occurs in patients with clinically suspect arthralgia (CSA), and whether it is associated with progression to clinical arthritis and magnetic resonance imaging (MRI)-detected subclinical inflammation. METHOD: Patients with CSA had arthralgia for <1 year and were at risk of progressing to RA according to their rheumatologists. At baseline, a 1.5 T MRI was performed of unilateral metacarpophalangeal, wrist, and metatarsophalangeal joints, and scored on synovitis, bone marrow oedema, and tenosynovitis;. summing these features yielded the total MRI inflammation score. Digital X-ray radiogrammetry (DXR) was used to estimate BMD on two sequential conventional hand radiographs (mean interval between radiographs 4.4 months). The change in BMD was studied; BMD loss was defined as a decrease of ≥2.5 mg/cm2/month. Patients were followed for arthritis development for a median of 18.4 months. RESULTS: In CSA patients (n = 108), change in BMD was negatively associated with age (ß = -0.03, p = 0.007). BMD loss in CSA patients was associated with arthritis development [adjusted for age hazard ratio (HR) = 6.1, 95% confidence interval (CI) 1.7 to 21.4] and was most frequently estimated in the months before clinical arthritis development. The total MRI inflammation scores were associated with the change in BMD (adjusted for age ß = -0.05, p = 0.047). The total MRI inflammation score and BMD loss were both independently associated with arthritis development (HR = 1.1, 95% CI 1.1 to 1.2, and HR = 4.6, 95% CI 1.2 to 17.2, respectively). CONCLUSION: In CSA patients, severe BMD loss is associated with MRI-detectable subclinical inflammation and with progression to clinical arthritis.