Background A range of sacroiliac joint (SIJ) MRI protocols are used in clinical practice but not all were specifically designed for diagnostic ascertainment. This can be confusing and no standard diagnostic SIJ MRI protocol is currently accepted worldwide. Objective To develop a standardised MRI image acquisition protocol (IAP) for diagnostic ascertainment of sacroiliitis. Methods 13 radiologist members of Assessment of SpondyloArthritis International Society (ASAS) and the SpondyloArthritis Research and Treatment Network (SPARTAN) plus two rheumatologists participated in a consensus exercise. A draft IAP was circulated with background information and online examples. Feedback on all issues was tabulated and recirculated. The remaining points of contention were resolved and the revised IAP was presented to the entire ASAS membership. Results A minimum four-sequence IAP is recommended for diagnostic ascertainment of sacroiliitis and its differential diagnoses meeting the following requirements. Three semicoronal sequences, parallel to the dorsal cortex of the S2 vertebral body, should include sequences sensitive for detection of (1) changes in fat signal and structural damage with T1-weighting; (2) active inflammation, being T2-weighted with fat suppression; (3) bone erosion optimally depicting the bone–cartilage interface of the articular surface and (4) a semiaxial sequence sensitive for detection of inflammation. The IAP was approved at the 2022 ASAS annual meeting with 91% of the membership in favour. Conclusion A standardised IAP for SIJ MRI for diagnostic ascertainment of sacroiliitis is recommended and should be composed of at least four sequences that include imaging in two planes and optimally visualise inflammation, structural damage and the bone–cartilage interface.

Objectives Knowledge on the epidemiology and long-term course of rotator cuff calcific tendinitis (RCCT) is scarce. We assessed demographics, radiological characteristics, and their association with long-term outcomes in a large patient group. Methods Baseline demographics, radiological characteristics and treatment were recorded in 342 patients. Interobserver agreement of radiological measures was analyzed. Long-term outcome was evaluated with questionnaires (WORC, DASH). The association of baseline characteristics with outcome was assessed. Results Mean age was 49.0 (SD = 10.0), and 59.5 % were female. The dominant arm was affected in 66.0 %, and 21.3 % had bilateral disease. Calcifications were on average 18.7 mm (SD = 10.1, ICC = 0.84 (p < 0.001)) and located 10.1 mm (SD = 11.8) medially to the acromion (ICC = 0.77 (p < 0.001)). Gärtner type I calcifications were found in 32.1 % (Kappa = 0.47 (p < 0.001)). After 14 years (SD = 7.1) of follow-up, median WORC was 72.5 (range, 3.0-100.0; WORC < 60 in 42 %) and median DASH 17.0 (range, 0.0-82.0). Female gender, dominant arm involvement, bilateral disease, longer duration of symptoms, and multiple calcifications were associated with inferior WORC. DASH results were similar. Conclusions Many subjects have persisting shoulder complaints years after diagnosis, regardless of treatment. Female gender, dominant arm involvement, bilateral disease, longer duration of symptoms, and multiple calcifications were associated with inferior outcome. Radiological measures had moderate-to-good reliability and no prognostic value. Key Points • Most RCCT studies report on short-term outcome and/or small patients groups. • In this large, long-term observational study, RCCT appeared to not be self-limiting in many subjects. • Negative prognostic factors included female gender, more calcifications, dominant arm affected, and longer duration of symptoms. • Interobserver agreement of general radiological RCCT measures is moderate to good. • More rigorous diagnostics and treatment might be needed in specific RCCT cases.

The consensus recommendations by the Assessment of SpondyloArthritis International Society provide a structured approach for effective communication from radiologists to rheumatologists for sacroiliac joint imaging of suspected or known axial spondyloarthritis, emphasizing the importance of detailed reporting, consideration of differential diagnoses, and expert collaboration.

Introduction: It is known that anticitrullinated peptide antibody (ACPA)–positive rheumatoid arthritis (RA) has a preclinical phase. Whether this phase is also present in ACPA-negative RA is unknown. To determine this, we studied ACPA-negative arthralgia patients who were considered prone to progress to RA for local subclinical inflammation observed on hand and foot magnetic resonance imaging (MRI) scans. Methods: We studied a total of 64 ACPA-negative patients without clinically detectable arthritis and with arthralgia of the small joints within the previous 1 year. Because of the character of the patients’ symptoms, the rheumatologists considered these patients to be prone to progress to RA. For comparisons, we evaluated 19 healthy, symptom-free controls and 20 ACPA-negative RA patients, who were identified according to the 1987 American Rheumatism Association criteria. All participants underwent MRI of unilateral wrist, metacarpophalangeal and metatarsophalangeal joints. Synovitis and bone marrow oedema (BME) were scored according to the OMERACT rheumatoid arthritis magnetic resonance imaging scoring system, and the scores were summed to yield the ‘MRI inflammation score’. Scores were compared between groups. Among the ACPA-negative arthralgia patients, MRI inflammation scores were related to C-reactive protein (CRP) levels and the tenderness of scanned joints. Results: MRI inflammation scores increased progressively among the groups of controls and ACPA-negative arthralgia and RA patients (median scores = 0, 1 and 10, respectively; P < 0.001). The MRI inflammation scores of ACPA-negative arthralgia patients were significantly higher than those of controls (P = 0.018). In particular, the synovitis scores were higher in ACPA-negative arthralgia patients (P = 0.046). Among the ACPA-negative arthralgia patients, inflammation was observed predominantly in the wrist (53%). The synovitis scores were associated with CRP levels (P = 0.007) and joint tenderness (P = 0.026). Despite the limited follow-up duration, five patients developed clinically detectable arthritis. These five patients had higher scores for MRI inflammation (P = 0.001), synovitis (P = 0.002) and BME (P = 0.003) compared to the other patients. Conclusion: Subclinical synovitis was observed in the small joints of ACPA-negative arthralgia patients, and especially in patients whose conditions progressed to clinically detectable arthritis. This finding suggests the presence of a preclinical phase in ACPA-negative RA. Further longitudinal studies of these lesions and patients are required to confirm this hypothesis.