Computer‐based methods for measuring joint space and estimating erosion volume in the finger and wrist joints of patients with rheumatoid arthritis

Abstract

Objective. This study was conducted 1) to determine the feasibility of using computer programs to measure radiographic joint space width and estimate erosion volume in the hands of patients with rheumatoid arthritis (RA), and 2) to compare the new computer-based methods with established scoring methods. Methods. To measure the joint space width in the finger and wrist joints of RA patients, hand and wrist radiographic films were scanned using a tabletop scanner and analyzed with programs written using the "macro" capabilities of NIH Image software. Estimation of erosion volume was determined by utilizing gray-scale intensity to calibrate bone density units per mm 3 , which made possible comparisons between the erosions and noneroded, anatomically similar sites. Results. In 3 sets of duplicate measurements of joint space width on 79, 48, and 48 finger and wrist joints, the mean absolute deviation from the mean of the 2 measurements was 0.036 mm (SD 0.034), 0.032 mm (SD 0.049), and 0.021 mm (SD 0.016), respectively. Joint space measurements and scoring of joint space narrowing both demonstrated a difference between active treatment and placebo in an old trial set on gold therapy (P 0.03 and P 0.01, respectively). Two repeated measurements of bone density units in the bones of 3 different hands differed from the mean of the measurement by 2.29-4.04%. In 2 experiments, estimates of erosion volume showed a greater difference between gold therapy and placebo than did erosion scores in the trial set (P 0.049 and P 0.016 versus P 0.27). Conclusion. Computer-based methods for measuring finger and wrist joint spaces and estimating erosion volume in patients with RA agree with the results of radiographic scoring of erosions and joint space narrowing.

Computerized Digital Imaging Techniques Provided by Digital X-ray Radiogrammetry as New Diagnostic Tool in Rheumatoid Arthritis

“…Previous techniques used for joint space analysis have not been able to provide consistently accurate estimates for affected finger joints caused by distinctive disease-related abnormalities. 9 Furthermore, the proximal interphalangeal joint should be not considered, because these joints show a bicompartmental configuration resulting in a varied width of each compartment dependent on minor rotation of the hand. Therefore establishing normative data and estimating minimal diseaserelated changes is limited in this articulation.…”

“…Therefore establishing normative data and estimating minimal diseaserelated changes is limited in this articulation. 9 Using digital hand radiographs, this study evaluated the ability of making precise measurements of the radiographic visible joint space distances of the metacarpalYphalangeal articulation in any grade of RA via the Radiogrammetry Kit, and of quantifying the periarticular demineralization via DXR in the course of RA. Our technique should help to identify those patients with RA who are going to develop joint damage before major erosions occur and to consecutively optimize the individual therapeutic strategies.…”

“…The usual disadvantages of joint space measurements using serial filming, such as different position of the hands during imaging, variation in x-ray beam angle, and disease-related limitations (in particular, destruction and subluxation of articulations), can be avoided by sampling a large portion of each joint space, which was done in our new technique as recommended by Sharp et al 9 To achieve reliable data, our study uses the metacarpalYphalangeal articulation for joint space calculation, which facilitates the edge detection via more effective visualization of the ridge of the joint margin by the computerized program and which shows the most inflammatory alterations caused by RA. 5 Finally, this computerized, operator-independent calculation of the four JSD-MCP, DXR-MCI, and DXR-BMD for one hand requires only up to 4 min, thereby using less time compared to the scoring methods.…”

Bildgebende Verfahren in der Rheumatologie: Scoring-Methoden bei der rheumatoiden Arthritis

“…Hauptaufgabe des Scorens ist demnach die Quantifizierung der Destruktion. Versuche mittels Computertechnik die Destruktionen zu messen waren bisher wenig erfolgreich (2). Die semi-quantitativen ScoringMethoden erfassen insbesondere die erosiven Verän-derungen.…”

Feasibility study of semi-automated measurements of finger joint space widths

“…New advances in computer-aided diagnosis (CAD) have led to signiWcant improvements in the Weld of radiogeometrical analysis of joint space widths [7], in particular for the Wnger joint space widths in patients with osteoarthritis and rheumatoid arthritis [8][9][10][11][12][13][14][15][16][17]. The computer-aided joint space analysis (CAJSA) is a recently developed CAD-technique for semiautomated measurements of joint space widths at the Wnger articulations [18].…”