Should all patients with polymyalgia rheumatica have a vascular ultrasound assessment?

There is a growing appreciation that both giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are closely interrelated conditions that have significant overlap in aetiology, clinical characteristics and treatment regimens. Subclinical GCA in PMR is becoming increasingly recognised, and there is evolving evidence that this may be a more aggressive disease phenotype than PMR. Ultrasound (US) lends itself well as a screening tool for GCA in PMR; it is inexpensive, non-invasive, widely available, lacks ionising radiation, may be performed at the bedside and is recommended by EULAR as a first-line investigation for suspected GCA. There is insufficient evidence to currently recommend that all patients with PMR should have a US assessment for vascular involvement. However, as clinical and laboratory parameters alone do not accurately diagnose patients with subclinical GCA, we suggest that vascular US will be increasingly performed by rheumatologists in practice to identify these patients with PMR, preferably as part of larger prospective outcome studies.

[18F]FDG PET/CT for therapeutic assessment of Abatacept in early-onset polymyalgia rheumatica.

PURPOSE: Evaluate the benefit of 2-deoxy-2-[18F]-fluoro-D-glucose ([18F] FDG) positron emission tomography/computed tomography (PET/CT) for the therapeutic assessment of Abatacept (ABA) as first-line therapy in early-onset polymyalgia rheumatica (PMR) patients. METHODS: This was an ancillary study of ALORS trial (Abatacept in earLy Onset polymyalgia Rheumatica Study) assessing the ability of ABA versus placebo to achieve low disease activity (C-Reactive Protein PMR activity score (CRP PMR-AS) ≤ to 10) without glucocorticoid (GC) at week 12 in patients with early-onset PMR. The patients underwent [18F] FDG PET/CT at baseline and after 12 weeks of treatment. Responses to treatments were evaluated according to CRP PMR-AS, Erythrocyte Sedimentation Rate (ESR) PMR-AS, Clin PMR-AS, and CRP-Imputed (Imput-CRP) PMR-AS. Quantitative score by maximal standardized uptake value (SUVmax) and combined qualitative scores according to liver uptake (Leuven, Leuven/Groningen, and Besançon Scores) were used for assessment of [18F] FDG uptake in regions of interest (ROI) usually affected in PMR. Student's t-test was applied to evaluate the clinical, biological, and [18F] FDG uptake variation difference in ABA and placebo groups between W0 and W12. Subgroup analysis by GC rescue was performed. RESULTS: At W12, there was no significant difference according to SUVmax between the ABA and the placebo groups in all ROI. Subgroup analysis according to GC administration demonstrated a significant (p 0.047) decrease in SUVmax within the left sternoclavicular joint ROI in the ABA group (- 0.8) compared to the placebo group (+ 0.6) without GC rescue. Other results did not reveal any significant difference between the ABA and placebo groups. According to combined qualitative scores, there was no significant difference between ABA and placebo groups for the direct comparison analysis and subgroup analysis according to GC rescue. CONCLUSION: [18F] FDG PET/CT uptake did not decrease significantly after ABA compared to placebo in anatomical areas usually affected in PMR patients. These results are correlated with the clinical-biological therapeutic assessment. CLINICAL TRIAL REGISTRATION: The study was approved by the appropriate ethics committee (CPP Sud-Est II Ref CPP: 2018-33), and all patients gave their written informed consent before study enrollment. The protocol was registered on Clinicaltrials.gov (NCT03632187).

The effect of prednisolone and a short-term prednisolone discontinuation for the diagnostic accuracy of FDG-PET/CT in polymyalgia rheumatica-a prospective study of 101 patients.

PURPOSE: 2-[18F]Fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) has been suggested as an imaging modality to diagnose polymyalgia rheumatica (PMR). However, the applicability of FDG-PET/CT remains unclear, especially following glucocorticoid administration. This study aimed to investigate the diagnostic accuracy of FDG-PET/CT before and during prednisolone treatment, as well as following short-term prednisolone discontinuation. METHODS: Treatment naïve suspected PMR patients were clinically diagnosed at baseline and subsequently had an FDG-PET/CT performed. Patients diagnosed with PMR were administered prednisolone following the first FDG-PET/CT and had a second FDG-PET/CT performed after 8 weeks of treatment. Subsequently, prednisolone was tapered with short-term discontinuation at week 9 followed by a third FDG-PET/CT at week 10. An FDG-PET/CT classification of PMR/non-PMR was applied, utilizing both the validated Leuven score and a dichotomous PMR score. The final diagnosis was based on clinical follow-up after 1 year. RESULTS: A total of 68 and 27 patients received a final clinical diagnosis of PMR or non-PMR. A baseline FDG-PET/CT classified the patients as having PMR with a sensitivity/specificity of 86%/63% (Leuven score) and 82%/70% (dichotomous score). Comparing the subgroup of non-PMR with inflammatory diseases to the PMR group demonstrated a specificity of 39%/54% (Leuven/dichotomous score). After 8 weeks of prednisolone treatment, the sensitivity of FDG-PET/CT decreased to 36%/41% (Leuven/dichotomous score), while a short-term prednisolone discontinuation increased the sensitivity to 66%/60%. CONCLUSION: FDG-PET/CT has limited diagnostic accuracy for differentiating PMR from other inflammatory diseases. If FDG-PET/CT is intended for diagnostic purposes, prednisolone should be discontinued to enhance diagnostic accuracy. TRIAL REGISTRATION: ClinicalTrials.gov (NCT04519580). Registered 17th of August 2020.

Diagnostic value of 18F-fluorodeoxyglucose positron emission tomography and computed tomography for differentiating polymyalgia rheumatica and rheumatoid arthritis: Using classification and regression tree analysis.

OBJECTIVES: Determining which sites were important to differentiate polymyalgia rheumatica (PMR) from rheumatoid arthritis (RA) using 18F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET-CT) is challenging. METHODS: Patients with PMR or RA who were undergoing PET-CT were recruited at two mutual-aid hospitals in Japan between 2009 and 2018. Classification and regression tree (CART) analyses were performed to identify FDG uptake patterns that differentiated PMR from RA. RESULTS: We enrolled 35 patients with PMR and 46 patients with RA. Univariate CART analysis showed that FDG uptake in the shoulder joints, spinous processes of the lumbar vertebrae, pubic symphysis, sternoclavicular joints, ischial tuberosities, greater trochanters, and hip joints differentiated PMR from RA. Multivariate CART analysis revealed that FDG uptake by at least one of the ischial tuberosities had the highest diagnostic value for distinguishing PMR from RA (sensitivity, 77.1%; specificity, 82.6%). We performed the same CART analysis to patients who had not undergone treatment (PMR, n = 28; RA, n = 9). Similar results were obtained, and sensitivity and specificity were increased (sensitivity, 89.3%; specificity, 88.8%). CONCLUSIONS: In PET-CT, FDG uptake by at least one of the ischial tuberosities best discriminates between PMR and RA.

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in polymyalgia rheumatica: an observational study.

OBJECTIVES: Polymyalgia rheumatica (PMR) is an inflammatory disease with a diagnosis that is sometimes difficult to establish. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) might be helpful. We analysed the usefulness of 18F-FDG PET/CT for the diagnosis of PMR. METHODS: This was an observational retrospective study of individuals with PMR who underwent 18F-FDG PET/CT and a control group. We assessed clinical and 18F-FDG PET/CT characteristics. Sixteen sites were studied. The number of sites with significant FDG uptake, the mean maximum standardised uptake value (SUVmax) and the highest SUVmax value were assessed for each patient. RESULTS: Data for 123 patients with PMR (37 with corticosteroids [CSTs] use) were analysed; 85 had new-onset PMR. As compared with the 75 controls, patients with new-onset PMR had higher mean ± SD number of sites with significant FDG uptake (11.3 ± 3.3 vs. 0.9 ± 1.1, p<0.001) and higher SUVmax scores (p<0.001). A cut-off of 5 hypermetabolic sites provided sensitivity of 96.5% and specificity 100%. For the total SUVmax score, a cut-off of 3 had the best sensitivity (92.6%) and specificity (86.1%). As compared with PMR patients using CSTs, those who were CST-naive had significantly higher CRP level (p<0.001), number of sites with significant FDG uptake (p<0.001) and SUVmax scores (p<0.01). In contrast, large-vessel vasculitis was more frequent in patients receiving CSTs than CST-naive patients (27% vs. 8%, p<0.01). CONCLUSIONS: The number of hypermetabolic sites or SUVmax quantification might be useful for PMR diagnosis, and CSTs might affect the results of 18F-FDG PET/CT.

Do statins decrease vascular inflammation in patients at risk for large-vessel vasculitis? A retrospective observational study with FDG-PET/CT in polymyalgia rheumatica, giant cell arteritis and fever of unknown origin.

OBJECTIVES: [18F] Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) can detect the presence of large-vessel vasculitis (LVV) in patients with polymyalgia rheumatica (PMR), giant cell arteritis (GCA) and fever of unknown origin (FUO). The aim of this study was to evaluate whether statins could reduce FDG-PET/CT-assessed vascular inflammation in this group of patients. METHODS: Clinical, demographic, laboratory data, current pharmacological treatments, and cardiovascular risk factors of patients with PMR, GCA and FUO, who underwent FDG-PET/CT, were recorded. FDG uptake was measured at prespecified arterial sites with the mean standardised uptake value (SUV), and with a qualitative visual score, summed up to obtain a total vascular score (TVS). LVV was diagnosed if arterial FDG visual uptake was equal or higher of liver uptake. RESULTS: 129 patients were included (96 with PMR, 16 with GCA, 13 with both PMR and GCA, and 4 with FUO), of whom 75 (58.1%) showed LVV. Twenty out of 129 (15.5%) patients were taking statins. TVS was significantly lower in patients treated with statins (p=0.02), especially in the aorta (p=0.023) and femoral arteries (p=0.027). CONCLUSIONS: Our preliminary results suggest that statins may exert a potential protective role on vascular inflammation in patients with PMR and GCA. Statin use could spuriously decrease FDG uptake of the vessel walls.

Assessing the feasibility of SUVindex (a metric derived from FDG PET/CT) for the diagnosis of polymyalgia rheumatica.

AIM: To evaluate the feasibility of standard uptake value (SUV) index (ratio lesional maximum SUV [SUVmax] to liver mean SUV [SUVmean]) as a metabolic parameter for diagnosing polymyalgia rheumatica (PMR). MATERIALS AND METHODS: A retrospective group of patients with PMR and controls with symptoms similar to PMR but diagnosed with other diseases. Semiquantitative and qualitative analysis of 2-[18F]-fluoro-2-deoxy-d-glucose (18F-FDG) uptake at 18 sites was undertaken for all patients. The diagnostic value of positron-emission tomography/computed tomography (PET/CT) for PMR was assessed by R software using logistic regression and a generalised additive model (GAM). All images were examined independently by two nuclear medicine physicians with extensive work experience. RESULTS: The characteristic sites of PMR were the ischial tuberosity, interspinous bursa, periarticular hip, and symphysis pubis enthesis. The area under the curve (AUC) of the characteristic site SUV index was 0.930, and the best cut-off value was 1.685 with a sensitivity of 84.6% and a specificity of 92.6%. After adjusting for potential confounders, the probability of PMR diagnosis increased as the characteristic site SUV index increased and there was a nonlinear correlation between the two. When the characteristic site SUV index was ≥2.56, the probability of PMR gradually reached the threshold effect, which was as high as 90% or more. CONCLUSION: The characteristic site SUV index is an independent factor for diagnosing PMR, and PMR should be highly suspected when it is ≥ 1.685. Nonetheless, it is important to note that these findings are based on an initial retrospective single-centre study and require external validation and further prospective evaluation before being translated into clinical practice.

Usefulness of ultrasound as a predictor of elderly-onset rheumatoid arthritis with polymyalgia rheumatica-like onset.

OBJECTIVES: Differentiation between polymyalgia rheumatica (PMR) and elderly-onset rheumatoid arthritis (EORA), especially in elderly patients, is often difficult due to similarities in symptoms and serological kinetics. In this study, we aimed to analyse the predictors of EORA with PMR-like onset. METHODS: Seventy-two patients diagnosed with PMR, who attended our hospital for routine care and underwent musculoskeletal ultrasonography at that time were evaluated. Synovitis was evaluated semi-quantitatively (0-3) by grey scale (GS) and power Doppler (PD) in 24 joints [both hands (wrist, metacarpophalageal, and proximal interphalangeal joints) and both shoulder joints]. RESULTS: Overall, 18 patients had rheumatoid arthritis (25.0%); the mean age was 75.0 years, and 34.7% and 65.3% were male and female, respectively. In PMR and PMR/EORA groups, multivariate logistic analysis showed that rheumatoid factor positivity, GS ≥2 of hand joints, and PD ≥1 of hand joints were independent factors with significant differences. At least one of the three factors had a sensitivity of 88.9% and specificity of 92.6%. CONCLUSIONS: The presence of at least one of the criteria: rheumatoid factor positivity, GS ≥ 2, and PD ≥ 1 of hand joints, suggested the possibility of developing EORA within 1 year of PMR diagnosis.

Comparison and validation of FDG-PET/CT scores for polymyalgia rheumatica.

OBJECTIVES: To compare and validate the diagnostic accuracy of fluorodeoxyglucose (FDG)-PET/CT scores for PMR; and to explore their association with clinical factors. METHODS: This retrospective study included 39 consecutive patients diagnosed with PMR and 19 PMR comparators. The final clinical diagnosis was established after 6 months follow-up. Patients underwent FDG-PET/CT prior to glucocorticoid treatment. Visual grading of FDG uptake was performed at 30 anatomic sites. Three FDG-PET/CT scores (the Leuven Score, two Besançon Scores) and two algorithms (the Saint-Etienne and Heidelberg Algorithms) were investigated. Receiver operating characteristic (ROC) analysis with area under the curve (AUC) was performed. Diagnostic accuracy was assessed at predefined cut-off points. RESULTS: All three FDG-PET/CT scores showed high diagnostic accuracy for a clinical diagnosis of PMR in the ROC analysis (AUC 0.889-0.914). The Leuven Score provided a sensitivity of 89.7% and specificity of 84.2% at its predefined cut-off point. A simplified Leuven Score showed similar diagnostic accuracy to that of the original score. The Besançon Scores showed limited specificity at their predefined cut-off points (i.e. 47.4% and 63.2%), while ROC analysis suggested that substantially higher cut-off points are needed for these scores. The Heidelberg and Saint-Etienne Algorithms demonstrated high sensitivity, but lower specificity (i.e. 78.9% and 42.1%, respectively) for PMR. Female sex and presence of large-vessel vasculitis were associated with lower FDG-PET/CT scores in patients with PMR. CONCLUSION: The Leuven Score showed the highest diagnostic utility for PMR. A modified, concise version of the Leuven Score provided similar diagnostic accuracy to that of the original score.

Ultrasound of shoulder and knee improves the accuracy of the 2012 EULAR/ACR provisional classification criteria for polymyalgia rheumatica.

OBJECTIVE: Recent studies suggest that the knee is frequently involved in PMR. In this study, we aimed to determine whether the US assessment of the shoulder and knee discriminates between PMR and other differential diagnoses and improves the accuracy of the 2012 EULAR/ACR provisional classification criteria for PMR. METHODS: We consecutively enrolled 81 untreated patients who received a diagnosis of PMR. These patients were divided into two groups based on the final diagnosis made at 1-year follow-up: PMR-definite group (n = 60) and PMR-mimic group (n = 21). We also enrolled age/sex-matched untreated RA patients with shoulder pain from an independent cohort (RA group, n = 60). All patients underwent comprehensive US assessment of the shoulder and knee for synovitis, bursitis, tenosynovitis, tendinitis and ligament inflammation at baseline. RESULTS: US scores for tenosynovitis, tendinitis and ligament inflammation better discriminated the PMR-definite group from the PMR-mimic and RA groups than do those for synovitis or bursitis. Among logistic regression models to identify US variables that were associated with the PMR-definite group, the best fitted model included two US variables: the bilateral involvement of the shoulder (long head of biceps, supraspinatus or subscapularis tendon) and the bilateral involvement of the knee (popliteus tendon or medial or lateral collateral ligament). Incorporating these two items into the 2012 EULAR/ACR provisional classification criteria numerically increased the accuracy to classify the PMR-definite group. CONCLUSION: US assessment of the tendon/ligament-related lesions in the shoulder and knee may improve the accuracy of the 2012 EULAR/ACR provisional classification criteria for PMR.

Clinical and FDG-PET/CT correlates in patients with polymyalgia rheumatica.

OBJECTIVES: We aimed to evaluate joint and vessel uptake in patients with polymyalgia rheumatica (PMR) by FDG-PET and correlate it with clinical findings. METHODS: Consecutive PMR patients, without clinical signs of giant cell arteritis, underwent a standardised clinical examination and FDG-PET/CT. Controls were consecutive subjects undergoing FDG-PET for the suspicion of neoplasm not confirmed by the examination. Uptake was evaluated by a qualitative visual score, using the liver uptake as reference and by the semi-quantitative mean standardised uptake value (SUV) and target-to-background ratio (TBR) methods. RESULTS: Eighty-four patients and 84 controls (55 women, median age 73 years, range 50-92 years in both groups) were studied. Sixteen patients were taking glucocorticoids (GC). PMR patients showed a higher articular uptake than controls. GC-treated patients showed uptake lower than GC-naïve patients, but still higher than controls. PMR patients showed a higher vascular uptake than controls in all districts except in the carotid arteries, when evaluated by the visual score. Conversely, the semi-quantitative approach yielded no significant differences. Forty-two patients (50%) showed PET evidence of large-vessel vasculitis (LVV), defined as uptake ≥ than that of the liver, and 11.9% showed LVV with vascular uptake higher than that of the liver. The correlation between clinical findings and uptake was scarce. Neither clinical nor laboratory findings could predict the presence of LVV. CONCLUSIONS: Patients with PMR show a typical joint pattern at FDG-PET. There are no clinical or laboratory predictors of LVV. Imaging appears to be the only tool to assess LVV in these patients.

New insights into the role of imaging in polymyalgia rheumatica.

PMR is an inflammatory rheumatic disease of elderly people characterized by pain and stiffness in the neck, shoulder and pelvic girdles. No specific diagnostic confirmatory tests exist and clinical symptoms, as well as increased acute phase reactants, are unspecific. The diagnostic value of imaging including ultrasound, MRI and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) with/without CT for PMR is increasingly studied. These techniques, particularly FDG-PET/CT, may help to detect underlying GCA in PMR patients with an incomplete response to glucocorticoids and/or recurrent relapses. Recent imaging studies provide novel insights into the anatomical basis of inflammation in PMR, particularly at hip and spine, which may help to distinguish this disease from other mimicking conditions. In this review, we discuss novel insights into the pathoanatomy of PMR, compare the diagnostic values of different imaging techniques and summarize current data on the role of imaging for monitoring and outcome prediction.

Diagnostic value of [18F]FDG-PET/CT in polymyalgia rheumatica: a systematic review and meta-analysis.

PURPOSE: Polymyalgia rheumatica (PMR) can be difficult to diagnose. Whole-body [18F]FDG-PET/CT allows for a comprehensive evaluation of all relevant articular and extra-articular structures affected by PMR. We aimed to summarize current evidence on the diagnostic value of [18F]FDG-PET/CT for a diagnosis of PMR. METHODS: PubMed/MEDLINE and the Cochrane Library database were searched from inception through May 31, 2020. Studies containing patients with PMR who underwent [18F]FDG-PET/CT were included. Screening and full-text review were performed by 3 investigators and data extraction by 2 investigators. Risk of bias was examined with the QUADAS-2 tool. Diagnostic test meta-analysis was performed with a bivariate model. RESULTS: Twenty studies were included in the systematic review, of which 9 studies (n = 636 patients) were eligible for meta-analysis. [18F]FDG positivity at the following sites was associated with a diagnosis of PMR: interspinous bursae (positive likelihood ratio (LR+) 4.00; 95% CI 1.84-8.71), hips (LR+ 2.91; 95% CI 2.09-4.05), ischial tuberosities (LR+ 2.86; 95% CI 1.91-4.28), shoulders (LR+ 2.57; 95% CI 1.24-5.32) and sternoclavicular joints (LR+ 2.31; 95% CI 1.33-4.02). Negative likelihood ratios (LR-) for these sites, as well as the greater trochanters, were all less than 0.50. Composite [18F]FDG-PET/CT scores, as reported in 3 studies, provided a pooled LR+ of 3.91 (95% CI 2.42-6.32) and LR- of 0.19 (95% CI 0.10-0.36). Moderate to high heterogeneity was observed across the studies, mainly due to differences in patient selection, scanning procedures and/or interpretation criteria. CONCLUSION: Significant [18F]FDG uptake at a combination of anatomic sites is informative for a diagnosis of PMR. [18F]FDG-PET/CT might be an important diagnostic tool in patients with suspected PMR. This study also highlights the need for adherence to published procedural recommendations and standardized interpretation criteria for the use of [18F]FDG-PET/CT in PMR.

Gadolinium-enhanced magnetic resonance imaging in shoulders contributes accurate diagnosis and predicting recurrence to patients with polymyalgia rheumatica.

OBJECTIVES: We aimed to evaluate whether gadolinium-enhanced magnetic resonance imaging (MRI) in shoulders can contribute to more accurate diagnosis and prediction of recurrence in patients with polymyalgia rheumatica (PMR). METHODS: Gadolinium-enhanced MRI and ultrasonography (US) in shoulders were performed in the patients who had bilateral shoulders pain and fulfilled the Bird's Classification Criteria between June 2012 and June 2018. PMR was clinically diagnosed by at least two rheumatologists. MRI and US findings assessed by independent radiologists were compared between the PMR or non-PMR patients. PMR patients were treated with 20 mg/day of prednisolone and were followed-up until June 2019 to determine any recurrences of the disease. RESULTS: PMR was diagnosed in 58 of 137 patients received gadolinium-enhanced MRI and US examinations. Enhancement of joint capsule, enhancement of rotator cuff tendon and focal bone oedema in humerus heads were frequently found in the PMR patients. If the three findings were used in combination to diagnose PMR, MRI had 76% sensitivity and 85% specificity, higher compared to US findings, which had 50% sensitivity and 72% specificity. During follow-up, PMR recurred in 24 patients. Patients with recurrent PMR were younger in age, had less enhancement of rotator cuff tendon and more synovial hypertrophy findings on their MRI. CONCLUSIONS: Gadolinium-enhanced MRI could display capsulitis, rotator cuff tendonitis and focal bone oedema in humerus heads that was sensitive and specific to patients with PMR, improving diagnostic accuracy in PMR. Rotator cuff tendonitis and synovial hypertrophy on MRI could help predict recurrence in PMR.

Imaging in polymyalgia rheumatica: which technique to use?

Polymyalgia rheumatica (PM) is an inflammatory rheumatic disorder characterised by pain and stiffness, mainly in the neck, shoulders, and pelvic girdle and possible association with giant cell arteritis. Currently, there is no diagnostic gold standard for PM, however, an extensive assessment of patients' inflammatory status aided by imaging evaluation is crucial for disease stratification. Many imaging techniques study PM features and their possible complications or associations with giant cell arteritis: radiography, ultrasound, scintigraphy, magnetic resonance imaging, and positron emission tomography/computed tomography. Each one has different advantages and disadvantages. The aim of this review is to clarify the current uses of imaging in PM for diagnosis and follow-up through a literature review of the last 10 years.

Diagnostic capability of contrast-enhanced pelvic girdle magnetic resonance imaging in polymyalgia rheumatica.

OBJECTIVE: There is currently no diagnostic test for PMR. A characteristic pattern of extracapsular inflammation as assessed by contrast-enhanced MRI (ceMRI) has recently been described in the pelvis of patients with PMR. We aimed to evaluate the performance of inflammatory ceMRI signals at predefined pelvic sites as a diagnostic test for PMR. METHODS: Pelvic MRI scans of patients with pelvic girdle pain (n = 120), including 40 patients with an expert diagnosis of PMR and 80 controls with other reasons for pelvic pain were scored by three blinded radiologists, who evaluated the degree of contrast enhancement at 19 predefined tendinous and capsular pelvic structures. Different patterns of involvement were analysed statistically. RESULTS: The frequency of bilateral peritendinitis and pericapsulitis including less common sites, such as the proximal origins of the m. rectus femoris and m. adductor longus, differed significantly between PMR cases and controls: 13.4 ± 2.7 vs 4.0 ± 2.3. A cut-off of ≥10 inflamed sites discriminated well between groups (sensitivity 95.8%, specificity 97.1%). Bilateral inflammation of the insertion of the proximal m. rectus femoris or adductor longus tendons together with ≥3 other bilaterally inflamed sites performed even better (sensitivity 100%, specificity 97.5%). CONCLUSION: This study confirms that a distinctive MRI pattern of pelvic inflammation (bilateral peritendinitis and pericapsulitis and the proximal origins of the m. rectus femoris and m. adductor longus) is characteristic for PMR. The high sensitivity and specificity of the set of anatomical sites evaluated suggests their clinical usefulness as a confirmatory diagnostic test.

Abnormalities at three musculoskeletal sites on whole-body positron emission tomography/computed tomography can diagnose polymyalgia rheumatica with high sensitivity and specificity.

PURPOSE: To evaluate the sensitivity and specificity of PET/CT findings in PMR and generate a diagnostic algorithm utilizing a minimum number of musculoskeletal sites. METHODS: Steroid-naïve patients with newly diagnosed PMR (2012 EULAR/ACR classification criteria) were prospectively recruited to undergo whole-body 18F-FDG PET/CT. Each PMR case was age- and sex-matched to four PET/CT controls. Control scan indication, diagnosis and medical history were extracted from the clinical record. Qualitative and semi-quantitative scoring (maximum standardized uptake value [SUVmax]) of abnormal 18F-FDG uptake at 21 musculoskeletal sites was undertaken for cases and controls. Results informed the development of a novel PET/CT diagnostic algorithm using a classification and regression trees (CART) method. RESULTS: Thirty-three cases met the inclusion criteria and were matched to 132 controls. Mean age was 68.6 ± 7.4 years for cases compared with 68.2 ± 7.3 for controls, and 54.5% were male. Median CRP was 49 mg/L (32-65) and ESR 41.5 mm/h (24.6-64.4) in the PMR group. The predominant control indication for PET/CT was malignancy (63.6%). Individual musculoskeletal sites proved insufficient for diagnostic purposes. A novel algorithm comprising 18F-FDG uptake ≥ 2 adjacent to the ischial tuberosities in combination with either abnormalities at the peri-articular shoulder or interspinous bursa achieved a sensitivity of 90.9% and specificity of 92.4% for diagnosing PMR. CONCLUSIONS: The presence of abnormal 18F-FDG uptake adjacent to the ischial tuberosities together with findings at the peri-articular shoulder or interspinous bursa on whole-body PET/CT is highly sensitive and specific for a diagnosis of PMR. TRIAL REGISTRATION: Clinical Trial Registration: Australian New Zealand Clinical Trials Registry, http://www.anzctr.org.au , ACTRN1261400696695.

Ultrasound shoulder assessment of calcium pyrophosphate disease with suspected polymyalgia rheumatica.

OBJECTIVES: Polymyalgia rheumatica (PMR) is characterised by inflammatory pain of shoulders and the pelvic girdle that affects older people. Conditions that can mimic PMR include rheumatoid arthritis (RA), spondyloarthritis (SpA) and calcium pyrophosphate disease (CPPD). In this study, we aimed to define the prevalence of CPPD among patients with polymyalgic syndrome with suspected PMR according to recent ACR/EULAR criteria. METHODS: This was an observational study in which we included patients with polymyalgic syndrome (inflammatory pain of shoulders, elevated C-reactive protein (CRP) level, and age >50 years). All patients were tested for RA antibodies and underwent ultrasonography (US) of shoulders [gleno-humeral effusion, biceps tenosynovitis, sub-acromiodeltoid (SAD) bursitis, synovitis and CPPD of the acromio-clavicular (AC) joint and humeral bone erosion]. RESULTS: We included 94 patients with polymyalgic syndrome (mean age 69.4±11.3 years, 67% female); 27 had a diagnosis of RA and 14 SpA. The remaining 52 were considered to have PMR according to ACR/EULAR criteria for PMR; 25 had a diagnosis of CPPD. As compared with PMR patients without CPPD, those with CPPD more frequently had humeral bone erosion (p=0.003), synovitis and CPPD of the AC joint (p<0.0001 for both) and less frequently SAD bursitis (p=0.0098). For PMR diagnosis, the most sensitive US features were SAD bursitis (96.3%) and biceps tenosynovitis (85.2%), despite low specificity. For CPPD diagnosis, CPPD of the AC joint had the best ratio of sensitivity to specificity (sensitivity: 85.2%; specificity: 97.1%). CONCLUSIONS: Detection of CPPD is relatively frequent with suspected PMR. Adding US assessment of the AC joint to usual US screening might help the clinician better distinguish PMR from other conditions, notably CPPD.

Shoulder ultrasound and serum lactate dehydrogenase predict inadequate response to glucocorticoid treatment in patients with polymyalgia rheumatica.

We aimed to identify predictors of inadequate response to glucocorticoid (GC) treatment in patients with polymyalgia rheumatica (PMR). We retrospectively studied 32 patients as a derivation cohort and 24 patients as a validation cohort. The patients were divided into two groups according to the response to GC treatment: GC-responders and GC-inadequate responders (GC-IRs). We compared laboratory data and bilateral shoulder ultrasound findings between the groups. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cutoff value of candidate predictors of treatment response; the predictors were examined using multivariate logistic analysis. Gray-scale ultrasound findings of long head of the biceps (LHB) tenosynovitis and subacromial/subdeltoid (SAD) bursitis were scored semiquantitatively (0-3). A total gray-scale score (TGSS) was calculated as the sum of the gray-scale scores. In the derivation cohort, serum lactate dehydrogenase (LDH) levels and TGSS were significantly higher in GC-IRs than in GC-responders. On ROC analysis, the cutoff values of serum LDH levels ≥ 175 IU/ml and TGSS ≥ 5 were found to be the candidate predictors. Multivariate logistic analysis revealed an independent association of both the predictors with inadequate response to GC treatment. In the validation cohort, patients with one or both predictors exhibited a higher incidence of inadequate response to GC treatment. These findings indicate that the severities of LHB tenosynovitis and SAD bursitis evaluated using ultrasound and serum LDH levels are independent predictors of inadequate response to GC treatment in patients with PMR. Treatment adjustment based on prediction model may allow precise treatment of patients with PMR.

Differences of articular and extra-articular involvement in polymyalgia rheumatica: A comparison by whole-body FDG-PET/CT.

Objectives: To clarify differences in incidences of articular and extra-articular involvement in patients with polymyalgia rheumatica (PMR) using FDG-PET/CT.Methods: Twenty PMR patients were enrolled in this retrospective study. We compared frequency, degree, and patterns (diffuse or non-diffuse) of abnormal FDG accumulation in the proximal and distal articular structures (PAS, DAS), and extra-articular synovial structures (ESS). Regional analyses were performed for the large joints (shoulder, hip, and knee).Results: The incidences of positive FDG accumulation were significantly higher in the PAS (96.7%) and ESS (91.4%) than in the DAS (31.8%, p < .0001), although, the incidence in the knees (96.2%) was exceptionally high. PAS (2.79 ± 0.61) and ESS (2.52 ± 0.85) had significantly higher visual scores than DAS (0.89 ± 1.33, p < .0001). Shoulder, hip, and knee joints each had a different accumulation pattern. Strong FDG accumulation was frequently observed in the medial-to-subscapular part of the shoulder joints, the lateral part of the hip joints, and the medial part of the knee joints.Conclusion: ESS were found to be the main affected areas in PMR patients as well as PAS. DAS involvement occurred with low frequency except in the knee joints. Each large joint showed a different accumulation pattern and its own characteristically strongly affected areas.