Ultrasonography as a useful modality for documenting sacroiliitis in radiographically negative inflammatory back pain: a comparative evaluation with MRI

Doppler and Spectral Ultrasound of Sacroiliac Joints in Pediatric Patients with Suspected Juvenile Spondyloarthritis

Background: Power Doppler ultrasound (PDUS) with spectral wave analysis (SWA) has been compared with magnetic resonance imaging (MRI) in documenting active sacroiliitis in early spondyloarthritis (SpA) but, to date, PDUS/SWA has not been yet applied to the study of sacroiliac joints (SIJs) in children. Methods: A group of 20 children (13 F/7 M, mean age 14.2 y) with suspected juvenile SpA (jSpA) underwent PDUS/SWA and, subsequently, MRI of the SIJs. SIJs PDUS scoring and resistance index (RI) of the SIJs flows were recorded. The accuracy of PDUS/SWA for the diagnosis of active sacroiliitis was evaluated, with MRI as the gold standard. Results: PDUS signals were detected in 19 patients and 30 SIJs. Bone marrow edema (BME) lesions on MRI were detected in 12 patients (diagnosed as jSpA) and 22 SIJs. PDUS scoring on SIJs were higher in patients with a final diagnosis of jSpA (p = 0.003). On SWA, the mean RIs in patients with or without final diagnosis of active sacroiliitis were, respectively, 0.604 and 0.767 (p = 0.005) at joint level. A RI < 0.55 and PDUS > 1 showed the higher specificity for sacroiliitis (AUROC curve 0.854 for PDUS and 0.920 for RI). SIJs PDUS/SWA showed an overall concordance of 82.35%, with substantial agreement (k = 0.627) with MRI on the diagnosis of sacroiliitis. Conclusions: In children with sacroiliitis, PDUS demonstrates a rich vascularization into SIJs and low RIs (<0.55) have high specificity for this condition. SIJs PDUS/SWA could be useful as a screening method in children with suspected jSpA.

ACR Appropriateness Criteria® Inflammatory Back Pain: Known or Suspected Axial Spondyloarthritis: 2021 Update

Inflammatory back pain is a hallmark feature of axial spondyloarthritis, a heterogeneous group of inflammatory disorders which affects the sacroiliac joints and spine. Imaging plays a key role in diagnosis of this disease and in facilitating appropriate treatment. This document provides evidence-based recommendations on the appropriate use of imaging studies during multiple stages of the clinical evaluation of patients with suspected or known axial spondyloarthritis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Power and spectral Doppler ultrasound in suspected active sacroiliitis: a comparison with magnetic resonance imaging as gold standard

OBJECTIVES

The objectives of this study were to study with Power Doppler US (PDUS) the SI joints (SIJs) of patients with suspected active sacroiliitis, to describe SIJ flows with spectral wave analysis (SWA) on Doppler US, and to correlate US data with both clinical characteristics and presence of SIJ bone marrow oedema (BME) in subsequent MRI.

METHODS

A total of 42 patients (32 females and 10 males, mean age 46.8 years) with recent onset of inflammatory back pain (IBP) were included. Every patient underwent US examination with a convex 1-8 MHz probe [scoring PDUS signals with a three-point scale and describing flows in SWA calculating the mean Resistive Index (RI)] and subsequent MRI of the SIJs.

RESULTS

PDUS signals were detected in 34 patients and 62 SIJs. In 29 patients and 56 SIJs, MRI revealed BME. A definite diagnosis of SpA was made in 32 patients. PDUS signals were more frequent (P < 0.0001) in patients with a final diagnosis of SpA, yielding a higher PDUS score (P = 0.0304). PDUS grading correlated with both BME grading (r = 0.740, P = 0.0001) and AS DAS (ASDAS) (r = 0.6257, P = 0.0004), but not with inflammatory reactants nor anthropometric data. Mean RI were, respectively, 0.60 and 0.73 (P < 0.0001) in patients with or without diagnosis of active sacroiliitis. The most inclusive RI cut-off resulted <0.70 [positive predictive value (PPV) 94%, accuracy 90%, P = 0.0001]. The best Likelihood Ratio (5.471) for RI to detect pathologic cases was obtained with a cut-off of <0.60 (PPV 96%).

CONCLUSIONS

PDUS and SWA of SIJs demonstrate good diagnostic accuracy for active sacroiliitis compared with MRI.

Value of Color Doppler Ultrasound Assessment of Sacroiliac Joints in Patients with Inflammatory Low Back Pain

OBJECTIVE

To evaluate the diagnostic value of color Doppler ultrasound (CDUS) for the detection of sacroiliitis, in patients with inflammatory back pain (IBP).

METHODS

Consecutive patients with IBP and suspected axial spondyloarthritis (SpA), but without a definitive diagnosis, were included. Consecutive patients with defined SpA and axial involvement were included as a control group. All patients underwent clinical evaluation, magnetic resonance imaging (MRI), and CDUS of sacroiliac joints (SIJ) within the same week. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the diagnosis of sacroiliitis by CDUS were calculated, using MRI as the gold standard.

RESULTS

There were 198 SIJ evaluated in 99 patients (36 with previous SpA). There were 61 men (61.6%), with a mean age of 39.8 years (SD 11.3) and median disease duration of 24 months (IQR 12-84). At the patient level, CDUS had a sensitivity of 63% (95% CI 48.7-75.7%) and a specificity of 89% (95% CI 76-96%). The PPV was 87.2% (95% CI 72.6-95.7%) and the NPV was 66.7% (95% CI 53.3-78.3%). At joint level, CDUS had a sensitivity of 60% (95% CI 49-70%) and a specificity of 93% (95% CI 88-98%). The PPV was 83% (95% CI 78-95%) and the NPV was 43% (95% CI 33-56%). The sensitivity of CDUS for the diagnosis of axial SpA was 54% (95% CI 36.6-71.2%), specificity was 82% (95% CI 63.1-93.9%), PPV was 79% (95% CI 57.8-92.9%), and NPV was 59% (95% CI 42.1-74.4%).

CONCLUSION

CDUS showed adequate diagnostic properties for detection of sacroiliitis and is a useful tool in patients with IBP.

Spectral Doppler and automated software-guided ultrasound assessment of bilateral common carotid intima-media thickness in spondyloarthritis: is there a correlation with clinical findings?

Background and aim

Limited information is currently available about whether carotid intima-media thickness (IMT) correlates with the degree of disease activity in spondyloarthritis. The objective of this study was to evaluate the correlation between articular and carotid ultrasound data and laboratory and clinical variables in patients with spondyloarthritis.

Methods

Twenty-two patients with spondyloarthritis, recruited consecutively via the spondyloarthritis service of the Universidade Pontifícia Católica de Campinas, São Paulo, Brazil, were assessed using carotid artery ultrasound (radiofrequency quality intima-media thickness, RF-QIMT), joint ultrasound, clinical evaluation, and laboratory tests.

Results

Mean (standard deviation, SD) carotid RF-QIMT was 0.643 (0.16) mm. Mean (SD) resistive index (RI) values for the right and left carotid arteries were 0.67 (0.12) and 0.82 (0.38), respectively. Mean (SD) RI values for the right and left sacroiliac joints were 1.10 (0.97) and 0.94 (0.13), respectively. Several significant correlations were detected between ultrasound, clinical, and laboratory variables. Notably, there were correlations between sacroiliac RI and erythrocyte sedimentation rate (p=0.027) and RF-QIMT (p=0.037); between RF-QIMT and Framingham score (p=0.012) and metabolic parameters, including abdominal waist measurement, body mass index (BMI) (p=0.032 to p=0.044).

Conclusions

In patients with spondyloarthritis, RF-QIMT detected atherosclerotic changes in the carotid artery wall, and spectral Doppler detected inflammatory activity in sacroiliac joints. Positive correlations were observed between these ultrasound findings and parameters reflecting patients’ metabolic profile and alterations in inflammatory markers.

Ultrasound of sacroiliac joints in spondyloarthritis: a systematic review

Ultrasound (US) is an accessible imaging technique with a possible role to diagnose active sacroiliitis, so this technique is projected as a promising diagnostic tool for the diagnosis of SpA. We analyse the available evidence about the use of US as a diagnostic tool in sacroiliitis in patients with SpA, by a systemic review of the literature fulfilling OMERACT criteria. A systematic literature search for original articles was carried out using four databases (Medline, Embase, Scopus and Web of Science). Data from studies were included only if participants had SpA and a US examination of sacroiliac joint (SIJ) was performed. The methodological quality of the studies was assessed using QUADAS-2 tool. Thirteen studies were included. All studies were observational, prospective and cross-sectional. In most articles (76.9%), the main US finding compatible with sacroiliitis evaluated was the presence of vascularisation (Doppler signals) with measurements of the resistive index (RI). The sensitivity and specificity analysis were performed in seven studies (58.8%) and were good, with a median of 90 and 89.2%, respectively. The studies showed a positive to moderate a strong correlation between the US and the gold standard but this was optimal only in four studies. In general, the agreement was good in all studies (≥ 0.80). The methods of evaluation of sacroiliitis vary between the studies included. To date, there is not enough evidence to support the use of ultrasound as a diagnostic method for sacroiliitis but it has potential to identify structural lesions at SIJ's level.

Recommendations for the Use of Ultrasound and Magnetic Resonance in Patients With Spondyloarthritis, Including Psoriatic Arthritis, and Patients With Juvenile Idiopathic Arthritis

OBJECTIVE

To develop evidence-based recommendations on the use of ultrasound (US) and magnetic resonance imaging in patients with spondyloarthritis, including psoriatic arthritis, and juvenile idiopathic arthritis.

METHODS

Recommendations were generated following a nominal group technique. A panel of experts (15 rheumatologists and 3 radiologists) was established in the first panel meeting to define the scope and purpose of the consensus document, as well as chapters, potential recommendations and systematic literature reviews (we used and updated those from previous EULAR documents). A first draft of recommendations and text was generated. Then, an electronic Delphi process (2 rounds) was carried out. Recommendations were voted from 1 (total disagreement) to 10 (total agreement). We defined agreement if at least 70% of participants voted≥7. The level of evidence and grade or recommendation was assessed using the Oxford Centre for Evidence Based Medicine levels of evidence. The full text was circulated and reviewed by the panel. The consensus was coordinated by an expert methodologist.

RESULTS

A total of 12 recommendations were proposed for each disease. They include, along with explanations of the validity of US and magnetic resonance imaging regarding inflammation and damage detection, diagnosis, prediction (structural damage progression, flare, treatment response, etc.), monitoring and the use of US guided injections/biopsies.

CONCLUSIONS

These recommendations will help clinicians use US and magnetic resonance imaging in patients with spondyloarthritis and juvenile idiopathic arthritis.