Page 21 - Imaging of Osteoarthritis and Rheumatoid Arthritis in Hand Joints

For this thesis, we performed multiple imaging studies in hand OA with
methods other than CR. While CT is a more accurate imaging method than CR, 1 it usually results in little additional relevant clinical information when imaging
finger joints with OA. In complex anatomical areas like the wrist, CT may have
additional value, especially if the small anatomical details are relevant for
treatment options, like surgery. In chapter 3 we therefore compared CT with
CR to detect osteoarthritis in the CMC1 and STT joint in possible pre-operative
patients.
MRI is the only imaging method capable of imaging all the joint structures. Current MRI studies in hand OA are good in visualizing synovitis and bone lesions, but cartilage is not assessed directly. Joint space narrowing is used as a surrogate marker for cartilage damage, because the thin cartilage layer is hard to visualize. It is expected that direct visualization of cartilage will allow visualization of smaller cartilage defects, and improve sensitivity to change for cartilage damage. This may help further understand OA, and improve clinical trials for OA drug development. In chapter 4 and 5 we therefore asses high- resolution MRI for direct cartilage imaging in hand osteoarthritis. In chapter 4 we first assess the validity of high resolution cartilage MRI to detect cartilage damage in a small hand joint, specifically the thumb base of pre-surgical patients to compare with histological cartilage specimens of the same joint. In chapter 5 we continue with high resolution MRI to asses patients with variable stages of OA and healthy controls, and investigate if high resolution MRI detects any additional damaged joints in comparison with currently used JSN measurements in MRI.
Current role of imaging for RA
Current ACR/EULAR guidelines for classification of RA15 are mainly based on the presence of the serological markers anti-cyclic citrullinated protein antibody (ACPA) and rheumatoid factor (RF), and on the number of involved swollen or tender joints. While these criteria do not require medical imaging for classification, MRI and US detected joint swelling and synovial hypertrophy can be used to determine joint involvement. In longstanding suspected RA patients who do not meet the criteria, it is advised to make a conventional radiograph. Typical erosions as seen in progressive RA on a radiograph then also allow classification of RA. For clinical diagnosis and management of RA, imaging can be used as a problem solver. Recent EULAR recommendations
General introduction
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