ABSTRACT: Computer-based methods to measure radiographic joint space width (JSW) have the potential to improve the longitudinal assessment of rheumatoid arthritis (RA). The purpose of this report was to measure the long-term patient repositioning reproducibility of software-measured radiographic JSW.
Patients underwent baseline and followup hand radiography examinations with a followup time of ≤3 years. To eliminate any JSW change due to real disease progression, the evaluation was performed on "unaffected" joints, defined as having JSW and erosion Sharp scores of 0 at both baseline and followup. The root mean square SD (RMSSD) and coefficient of variation (CV) were used as the reproducibility metrics.
The RMSSD was 0.14 mm (CV 10.5%) for all joints, 0.18 mm (CV 10.9%) for the metacarpophalangeal (MCP) joints, and 0.08 mm (CV 8.3%) for the proximal interphalangeal (PIP) joints. The distribution of JSW change was asymmetric, suggesting that narrowing due to RA progression occurred for several joints. A second analysis was performed, excluding joints where the loss of JSW was greater than 3 SDs. For this analysis, the RMSSD was 0.10 mm (CV 7.5%) for all joints, 0.12 mm (CV 7.3%) for the MCP joints, and 0.07 mm (CV 7.1%) for the PIP joints.
Repositioning reproducibility is very good but is likely to be a dominating factor compared to reader and software reproducibility. Additionally, further evidence is given that a software method is able to detect changes in some joints for which the Sharp score is insensitive.
Arthritis care & research. 10/2010; 63(2):203-7.
ABSTRACT: Magnetic resonance imaging (MRI) and radiography are established imaging modalities for the assessment of knee osteoarthritis (OA). The objective of our study was to compare the responsiveness of radiographic joint space width (JSW) with MRI-derived measures of cartilage morphometry for OA progression in participants from the Osteoarthritis Initiative (OAI).
This study examined the baseline and 12-month visits of a subset of 150 subjects from the OAI. Measurement of radiographic JSW was facilitated by the use of automated software that delineated the femoral and tibial margins of the joint. Measures of medial compartment minimum JSW and JSW at fixed locations were compared with cartilage morphometry measures derived from MRI. The results were stratified by Kellgren/Lawrence (K/L) scale grade and by tibiofemoral anatomic axis angle. In order to examine the relative responsiveness of various techniques, we calculated the standardized response mean (SRM) between the 2 visits.
The SRM for radiographic JSW measured at the optimal location was -0.32 compared with -0.39 for the most responsive MRI measure. For the subgroup with a K/L scale grade of 2 or 3, the most responsive SRM values were -0.34 for radiographic JSW and -0.42 for MRI.
Our study demonstrates that new measures using a software analysis of digital knee radiographic images are comparable with MRI in detecting OA progression, and potentially superior when considering the cost-effectiveness of the 2 imaging modalities.
Arthritis care & research. 07/2010; 62(7):932-7.
ABSTRACT: To determine the radiographic joint space width (JSW) in undamaged metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints of patients with early rheumatoid arthritis (RA) and to identify important clinical determinants of JSW.
Radiographs of patients with RA of <1 year's duration, from an early arthritis cohort at a tertiary care rheumatology clinic, were obtained. JSW was analyzed by joint, finger, age, sex, height, and a number of other clinically relevant variables. Multivariate analysis was also performed, to account for possible confounding between variables.
Thirty-eight patients were included in the study. We found that JSW was greater in the MCP joint than the PIP joint (P < 0.0001). JSW was significantly greater in men (P < 0.0001) and increased with increasing height (P < 0.003), but was not associated with age (P < 0.21). In multivariate analyses, sex was shown to be the most important predictor of JSW.
In patients with early RA, MCP and PIP JSW is significantly associated with sex and height. In studies of RA in which JSW measurements are included as an outcome, these differences may need to be accounted for in the analysis.
Arthritis & Rheumatism 06/2006; 54(5):1440-3. · 7.87 Impact Factor
ABSTRACT: To compare the diagnostic performance of a computer-based method for measuring joint space width with the Sharp joint space narrowing (JSN) scoring method in patients with rheumatoid arthritis (RA).
A random sample of patients with early RA, for whom sequential hand radiographs and Sharp scores were available, was selected from the National Data Bank for Rheumatic Diseases. Hand joint space width was measured using an automated, computer-based method in random order and with blinding for clinical information. We constructed a receiver operating characteristic curve and compared the diagnostic performance of the computer-based and Sharp methods based on the areas under the curve.
One hundred twenty-nine patients with early RA who underwent serial radiography were included. Changes in the computer-based and Sharp methods were highly correlated (r = 0.75, P < 0.001). The computer-based method was significantly more discriminant than the Sharp JSN subscale. The area under the curve of the computer-based method was 0.96 (95% confidence interval [95% CI] 0.94, 0.99) compared with 0.93 (95% CI 0.89, 0.96) for the Sharp subscale (P = 0.024). At the most discriminant cutoff, specificity of the computer-based method was 88.4% compared with 81.4% for the Sharp subscale (P = 0.11); sensitivity was 87.6% for the computer-based method compared with 82.2% for Sharp subscale (P = 0.19). The signal-to-noise ratio for the computer-based method was 83% compared with 70% for the Sharp subscale (P = 0.013).
The computer-based method for measuring joint space width is more discriminant than the semiquantitative Sharp JSN subscale.
Arthritis & Rheumatism 06/2006; 54(5):1444-50. · 7.87 Impact Factor
ABSTRACT: To compare the effectiveness of 3 therapeutic strategies in preventing progressive joint damage, in a population-based cohort. The 3 strategies were infliximab with concomitant disease-modifying antirheumatic drugs (DMARDs), etanercept with concomitant DMARDs, and etanercept alone.
We used sequential radiographs to assess all patients who were treated with infliximab or etanercept for >10 months. The rates of erosion progression and joint space narrowing (JSN) were analyzed using multivariate regression models for longitudinal data, with adjustment for potential confounders.
A total of 372 patients treated with anti-tumor necrosis factor (TNF) therapies met the inclusion criteria. The baseline characteristics of the patients assigned to the 3 strategies were not significantly different, except that, as expected, more patients were receiving combination therapy with infliximab. The combination of infliximab plus DMARDs was significantly more effective than etanercept alone for controlling erosion progression (P < 0.001), but the effectiveness of the 2 combination-treatment strategies was similar (P = 0.07). The combination of infliximab plus DMARDs was also more effective at controlling progressive JSN compared with etanercept alone (P = 0.04) or etanercept plus DMARDs (P = 0.02). Treatment with anti-TNF agents (infliximab or etanercept) plus concomitant DMARDs was more effective than treatment with etanercept alone for controlling erosion progression (P = 0.045).
When combined with traditional DMARDs, both etanercept and infliximab appear to offer similar protection against progressive structural joint damage, and combination therapy with either of these agents appears to be more effective than treatment with etanercept alone.
Arthritis & Rheumatism 01/2006; 54(1):54-9. · 7.87 Impact Factor