From the Guidelines
Imaging is not required to make the diagnosis in patients with typical presentation of osteoarthritis (OA), and conventional radiography should be used before other modalities if imaging is needed. When considering osteo imaging for diagnostic purposes, it's essential to understand the recommendations for the use of imaging in the clinical management of peripheral joint osteoarthritis, as outlined in the EULAR recommendations 1. The key points to consider are:
- Imaging abnormalities of OA are commonly seen, especially with increasing age, but this does not necessarily correlate with symptoms.
- The diagnosis of OA can typically be made without imaging in patients with typical presentations, which include usage-related pain, short duration morning stiffness, age >40, and symptoms affecting one or a few joints.
- In atypical presentations, imaging is recommended to help confirm the diagnosis of OA and/or make alternative or additional diagnoses, with a level of evidence rated as IV and a mean level of agreement (LOA) of 9.6 (9.1 to 10) 1.
- Routine imaging in OA follow-up is not recommended unless there is unexpected rapid progression of symptoms or a change in clinical characteristics, suggesting that imaging should be used judiciously and based on clinical judgment.
- The choice of imaging modality is also important, with conventional radiography being the first-line choice, and other modalities like ultrasound (US) or magnetic resonance imaging (MRI) being used for additional diagnoses, particularly for soft tissue or bone assessment.
- The accuracy of intra-articular injection can be improved with imaging, especially for joints that are difficult to access, highlighting another potential use of osteo imaging in the management of OA. Considering these points, the approach to osteo imaging should be guided by the clinical presentation and the need for additional diagnostic information, with the goal of minimizing unnecessary imaging and optimizing patient outcomes.
From the Research
Osteo Imaging Techniques
- Dual-energy X-ray absorptiometry (DXA) is a widely used technique for assessing bone mineral density (BMD) and diagnosing osteoporosis 2, 3
- DXA-based Trabecular Bone Score (TBS) can provide complementary information about bone microarchitecture 4
- Computed Tomography (CT) can provide a 3-D volumetric assessment of BMD and can be used for opportunistic screening of osteoporosis 3
- Magnetic Resonance Imaging (MRI) can provide quantitative information about trabecular bone microstructure and cortical bone quantity and quality 4, 5
Comparison of Osteo Imaging Techniques
- DXA and CT have been compared in terms of their ability to assess BMD, with CT showing promise as a tool for opportunistic screening of osteoporosis 3
- MRI has been shown to be superior to DXA in predicting osteoporotic fracture risk at the proximal femur 5
- Digital X-ray radiogrammetry (DXR) has been compared to DXA and FRAX in terms of its ability to discriminate major osteoporotic fractures, with DXR showing similar performance to FRAX and DXA 6
Clinical Applications of Osteo Imaging
- Osteo imaging techniques can be used to diagnose osteoporosis, assess fracture risk, and monitor treatment response 2, 4
- Opportunistic screening of osteoporosis using CT scans can help identify individuals at risk of osteoporotic fractures 3
- MRI-based quantitative osteoporosis imaging can provide valuable information about trabecular bone microstructure and cortical bone quantity and quality, which can be used to improve fracture risk assessments 5