Page 33 - Imaging of Osteoarthritis and Rheumatoid Arthritis in Hand Joints

Systematic review of advanced hand OA imaging
Methodological quality
The results of the presented studies pose some limitations and should be interpreted with caution (see online supplementary text S2 for details). The
optimal spectrum of patients should consist of a mix of patients who are likely
to undergo imaging for diagnosis or follow-up of hand OA. However, some 2 studies only included patients with severe OA, while others added healthy
controls to the patient group. Other general limitations included insufficient description of sample size determination, and lack of information about the training and experience of the examiner.
In the validity studies, the use of only severely affected patients might have increased sensitivity, while the use of healthy volunteers as reference standard might have increased specificity or overestimated correlations.19 In the reliability studies, agreement might have been inflated in samples where results are obvious, for example in patients with extreme disease status or healthy controls.20 Examiner blinding was insufficiently described in reliability studies. As incomplete blinding may affect reliability results,20 it should be described extensively. Responsiveness studies often lacked a-priori hypotheses of the expected change, which are recommended as it is easy to retrospectively create alternative explanations for low correlations or differences between changes.21 It was also often unclear whether raters could review their prior ratings. This is important as not knowing previous results minimizes expectation bias, but gives a higher measurement error.64
Validity
Eleven US, five MRI and three scintigraphy articles examined validity (table 2). None of the studies determined criterion validity by comparing with histology or arthroscopy. Construct validity was determined by using different comparators as healthy controls, CR, joint pain, joint swelling, or MRI.
Four of 11 US studies compared hand OA patients with healthy controls and reported significant differences in JSN,42 osteophytes,42 synovitis,31, 42, 60 Power Doppler signal (PD),31, 42, 60 and joint effusion,31, 37, 60 while no significant differences were found for tendon effusion.31 Five studies compared structural US changes with CR, and US generally detected more osteophytes,41, 46, 51, 52 erosions,51, 52 and JSN.41 Only one study detected less erosions with US (sensitivity=0.72,
31