Imaging Inflamed Synovial Joints

Correlating SPECT-CT activity in cervical facet joints with positive response to cervical medial branch blocks

Introduction

Cervical facet arthritis is a significant source of neck pain and impaired function that is amenable to treatment with medial branch radiofrequency neurotomy (RFN). Identifying appropriate patients for this treatment requires integration of information from the history, physical exam and diagnostic imaging, but the current diagnostic standard for facet-mediated pain is positive comparative medial branch blockade (MBB). SPECT-CT has recently been evaluated as a potential predictor of positive medial branch blocks with mixed results. The purpose of this retrospective analysis was to determine if a relationship exists between increased uptake on SPECT-CT of a given cervical facet joint and a positive MBB.

Methods

A retrospective review was performed to identify all patients undergoing cervical MBB within 12 months after having a cervical SPECT-CT. Each procedure was categorized as either Concordant (all facet joints demonstrating increased 99mTc uptake on SPECT-CT were blocked) or Discordant (at least one facet joint demonstrating increased 99mTc uptake on SPECT-CT was not blocked or block was performed in a patient that had no increased uptake on SPECT-CT). Statistical analysis was performed to determine if concordance between facet joints demonstrating increased uptake on SPECT-CT and those undergoing MBB was associated with a positive block using cutoffs of 50% and 80% pain relief.

Results

A total of 43 procedures were analyzed (25% Concordant, 75% Discordant) and both groups demonstrated improvement in pain Numeric Rating Scale (NRS) scores. No significant association between concordance and positive MBB was identified at thresholds of 50% (p = .481) and 80% (p = 1.000) pain relief.

Conclusion

SPECT-CT findings do not accurately predict positive cervical MBB but may provide valuable information that can be considered with other factors when deciding which joints to treat.

Correlating SPECT-CT activity in lumbar facet joints with response to lumbar medial branch and L5 dorsal ramus blocks

Introduction

Lumbar facet arthritis is a significant source of back pain and impaired function that is amenable to treatment with medial branch radiofrequency neurotomy (RFN). Identifying appropriate patients for this treatment requires integration of information from the history, physical exam, and diagnostic imaging, but the current diagnostic standard for facet-mediated pain is positive comparative medial branch blocks (MBBs). Lumbar SPECT-CT has recently been evaluated as a potential predictor of positive MBBs with mixed results. The purpose of this retrospective analysis was to determine if the level of concordance between SPECT-CT uptake and facet joints targeted with MBB was associated with a positive block.

Methods

A retrospective review was performed to identify all patients undergoing lumbar MBB within 12 months after having a lumbar SPECT-CT. Each procedure was classified into one of four categories based on the level of concordance between facet joints demonstrating increased 99mTc uptake on SPECT-CT and those being blocked: 1) Complete Concordance (all joints demonstrating increased uptake were blocked and no additional joints blocked); 2) Partial Concordance (all joints demonstrating increased uptake were blocked, with at least one joint not demonstrating increased uptake blocked); 3) Partial Discordance (at least one but not all joints demonstrating increased uptake were blocked); 4) Complete Discordance (all blocks performed at joints not demonstrating increased uptake). Statistical analysis was performed to determine if the level of concordance between increased uptake on SPECT-CT and joints undergoing MBB was associated with a positive block using cutoffs of 50 % and 80 % pain relief.

Results

A total of 180 procedures were analyzed (23 % Complete Concordance, 22 % Partial Concordance, 31 % Partial Discordance, 24 % Complete Discordance) and all groups demonstrated improvement in pain Numeric Rating Scale (NRS) scores. There was no significant association between level of concordance and having a positive block using thresholds of 50 % pain relief, χ 2(3, N = 180) = 4.880, p = .181; or 80 % pain relief, χ 2(3, N = 180) = 1.272, p = .736.

Conclusion

SPECT-CT findings do not accurately predict positive lumbar MBB but may provide valuable information that can be considered with other factors when deciding which joints to treat.

Imaging of non-osteochondral tissues in osteoarthritis

OBJECTIVE

The aim of this review is to describe imaging techniques for evaluation of non-osteochondral structures such as the synovium, menisci in the knee, labrum in the hip, ligaments and muscles and to review the literature from recent clinical and epidemiological studies of OA.

METHODS

This is a non-systematic narrative review of published literature on imaging of non-osteochondral tissues in OA. PubMed and MEDLINE search for articles published up to 2014, using the keywords osteoarthritis, synovitis, meniscus, labrum, ligaments, plica, muscles, magnetic resonance imaging (MRI), ultrasound, computed tomography (CT), scintigraphy, and positron emission tomography (PET).

RESULTS

Published literature showed imaging of non-osteochondral tissues in OA relies primarily on MRI and ultrasound. The use of semiquantitative and quantitative imaging biomarkers of non-osteochondral tissues in clinical and epidemiological OA studies is reported. We highlight studies that have compared both imaging methodologies directly, and those that have established a relationship between imaging biomarkers and clinical outcomes. We provide recommendations as to which imaging protocols should be used to assess disease-specific changes regarding synovium, meniscus in the knee, labrum in the hip, and ligaments, and highlight potential pitfalls in their usage.

CONCLUSION

MRI and ultrasound are currently the most useful imaging modalities for evaluation of non-osteochondral tissues in OA. MRI evaluation of any tissue needs to be performed using appropriate MR pulse sequences. Ultrasound may be particularly useful for evaluation of small joints of the hand. Nuclear medicine and CT play a limited role in imaging of non-osteochondral tissues in OA.

Imaging of synovitis in osteoarthritis: current status and outlook

OBJECTIVES

This review article provides an overview of the current state of imaging of synovitis in osteoarthritis (OA), looking at recent advances and controversies and focusing particularly on the application of ultrasound and magnetic resonance imaging (MRI) in the assessment of the hand and knee joint. Computed tomography and nuclear medicine including positron emission tomography are also briefly discussed.

METHODS

PubMed and MEDLINE search for articles published up to 2010, using the keywords synovitis, osteoarthritis, rheumatoid arthritis, pathogenesis, imaging, radiography, computed tomography, nuclear medicine, magnetic resonance imaging, ultrasound, and pain.

RESULTS

Synovitis is defined as inflammation of the synovial membrane. Modern imaging techniques have demonstrated that synovial pathology is common in the early and late stages of OA and may be associated with pain. The current standard for OA imaging in clinical practice is conventional radiography but it does not allow direct visualization of synovitis. MRI without contrast administration, although widely used in clinical studies, cannot assess synovitis directly. Contrast-enhanced MRI and ultrasound, however, both allow direct visualization of synovitis including early inflammatory changes. They are regularly used to image synovitis in rheumatoid arthritis and increasingly in OA.

CONCLUSIONS

Synovitis is increasingly recognized as an important feature of the pathophysiology of OA, although there is conflicting evidence with respect to its association with disease severity and clinical parameters. Contrast-enhanced MRI and ultrasound are the most important methods for assessing synovitis associated with OA.