Objective This study aimed to assess the utility of dual energy CT (DECT) for diagnosing gout. Methods A systematic literature search was performed in PubMed, EMBASE and Cochrane Library. Studies evaluating the utility of DECT for diagnosing gout were included. Reference standards were detection of monosodium urate crystals at SF assessment or a validated set of criteria. The methodological quality of studies was evaluated according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 criteria. Data from person-based and joint-/localization-based evaluations were pooled separately, and subgroup analyses for disease stage/duration and reference standard were performed. Results Ten studies were included; in person-based evaluations, the pooled (95% CI) sensitivity and specificity were 0.81 (0.77, 0.86) and 0.91 (0.85, 0.95), respectively. In joint-based evaluations, they were 0.83 (0.79, 0.86) and 0.88 (0.83, 0.92), respectively. At short disease duration (⩽6 weeks), the pooled (95% CI) sensitivity and specificity at the joint level were 0.55 (0.46, 0.64) and 0.89 (0.84, 0.94), respectively. Conclusion DECT has a high diagnostic accuracy in established gout, but its diagnostic sensitivity is low in subjects with recent onset gout.

A substantial proportion of seemingly healthy first-degree relatives of HLA-B27-positive AS patients have clinical and/or imaging abnormalities suggestive of SpA. Thirty-three percent could be classified as having SpA. Further follow-up will show which first-degree relatives will develop clinically manifest SpA.

To establish whether dual-energy CT (DECT) is a diagnostic tool, i.e., associated with initiation or discontinuation of a urate lowering drug (ULD). Secondly, to determine whether DECT results (gout deposition y/n) can be predicted by clinical and laboratory variables. Digital medical records of 147 consecutive patients with clinical suspicion of gout were analyzed retrospectively. Clinical data including medication before and after DECT, lab results, and results from diagnostic joint aspiration and DECT were collected. The relationship between DECT results and clinical and laboratory results was evaluated by univariate regression analyses; predictors showing a p < 0.10 were entered in a multivariate logistic regression model with the DECT result as outcome variable. A backward stepwise technique was applied. After the DECT, 104 of these patients had a clinical diagnosis of gout based on the clinical judgment of the rheumatologist, and in 84 of these patients, the diagnosis was confirmed by demonstration of monosodium urate (MSU) crystals in synovial fluid (SF) or by positive DECT. After DECT, the current ULD was modified in 33 (22.4%) of patients; in 29 of them, ULD was started and in 1 it was intensified. Following DECT, the current ULD was stopped in three patients. In the multivariable regression model, cardiovascular disease (OR 3.07, 95% CI 1.26–7.47), disease duration (OR 1.008, 95% CI 1.001–1.016), frequency of attack (OR 1.23, 95% CI 1.07–1.42), and creatinine clearance (OR 2.03, 95% CI 0.91–1.00) were independently associated with positive DECT results. We found that the DECT result increases the confidence of the prescribers in their decision to initiation or discontinuation of urate lowering therapy regimen in of mono- or oligoarthritis. It may be a useful imaging tool for patients who cannot undergo joint aspiration because of contraindications or with difficult to aspirate joints, or those who refuse joint aspiration. We also suggest the use of DECT in cases where a definitive diagnosis cannot be made from signs, symptoms, and MSU analysis alone.

Objective To establish the performance of (subsets of) the 2015 ACR/EULAR gout classification criteria in patients with unclassified arthritis, and to determine the value of dual-energy CT (DECT) herein. Reference was the MSU crystal detection result in SF at polarization microscopy. Methods We included subjects with acute, unclassified mono or oligoarthritis, who underwent SF analysis and DECT. Performance was assessed by calculating area under the receiver operating characteristic curve of (i) the clinical criteria subset, (ii) the clinical+serum urate subset and (iii) the full set (including DECT). Results Of the 89 subjects enrolled, 40 met the clinical+serum urate subset criteria, and 49 (55%) subjects did not. Of these 49, 30 had a negative microscopy result, of whom 15 had positive DECT; of these 15, 14 met the full set criteria only after adding the positive DECT result. For the clinical-only subset, the areas under the curves (AUCs) were 0.68 and 0.69 without and with DECT result, respectively, and for the clinical+serum urate subset without and with DECT, AUCs were 0.81 and 0.81, respectively (results not significant). Conclusion Adding the serum urate results to the clinical subset improves the performance, but adding the DECT result does not, neither does adding the DECT results to the clinical+serum urate subset. However, DECT seems to have an additive value in gout classification, especially when microscopy of SF is negative; 14/89 of patients (16%) only met the classification criteria with the use of DECT. Trial registration ClinicalTrials.gov, http://clinicaltrials.gov, NCT03038386.