Implementation of Z-scores as an age- and sex-independent parameter for estimating joint space widths in rheumatoid arthritis.

OBJECTIVE: To compare normative data of joint space distances (JSD) with the JSD of patients with rheumatoid arthritis (RA) as measured by computer-aided joint space analysis (CAJSA) at the metacarpophalangeal (MCP) articulations, and to differentiate age- and sex-related alterations from the disease-related joint space narrowing. METHODS: In total, 256 healthy subjects and 248 patients with verified RA (following revised ACR criteria) underwent computerized semiautomated measurements of JSD (CAJSA, version 1.3.6) at the MCP articulation (JSD-MCP) based on digital radiographs. The Z-score, a comparative parameter that differentiates joint space alterations caused by RA-related cartilage destruction from age- and sex-related changes, was calculated. RESULTS: Our data showed a relationship between measured joint space widths (MCP total and MCP thumb to little finger) and age for healthy subjects and also the RA group. The RA group revealed an age-related joint space narrowing that was surpassed by the RA-related narrowing of joint space widths classified by Sharp joint space narrowing score and resulting in smaller Z-scores for RA patients. CONCLUSION: The CAJSA technique seems to distinguish age-related JSD changes in healthy volunteers from RA-induced alterations. In addition the Z-score was also able to differentiate RA-dependent narrowing of JSD. Calculation of the Z-scores based on sex- and age-specific reference data may facilitate earlier identification of patients with RA, allowing initiation of a more optimal, individually adapted therapeutic strategy.

Normative reference values of joint space width estimated by computer-aided joint space analysis (CAJSA): the distal interphalangeal joint.

PURPOSE: The study introduces reference data for a computer-aided analysis. The semiautomated computer-aided diagnostic system provides the estimation of joint space width at the distal interphalangeal joints, considering gender-specific and age-related changes. PATIENTS AND METHODS: 869 subjects (351 female/518 male) with hand x-rays were included and underwent measurements of joint space distances at the distal interphalangeal articulation (JSD-DIP) of the second to the fifth finger using computer-aided joint space analysis (CAJSA). RESULTS: Data showed a notable age-related decrease of CAJSA parameters, and an accentuated age-related joint space narrowing in women. Males showed a significantly wider JSD-DIP (+ 16.7%) compared to the female cohort for all age groups. Both men and women revealed an accentuated decrease of JSD-DIP (total) in the age group from 10 to 15 years (for men -10.5% and for women -17.6%). After the age of 21 years a continuous decline of the JSD-DIP (total) is observed. CONCLUSION: Our data present gender-specific and age-related normative reference data for computer-aided joint space analysis, which provide a valid and reliable differentiation between disease-related joint space narrowing and age-related joint space narrowing, particularly in patients with osteoarthritis of the fingers.

Computer-aided joint space analysis of the metacarpal-phalangeal and proximal-interphalangeal finger joint: normative age-related and gender-specific data.

PURPOSE: The purpose of the study was to provide reference data for computer-aided joint space analysis based on a semi-automated and computer-aided diagnostic system for the measurement of metacarpal-phalangeal and proximal-interphalangeal finger joint widths; additionally, the determination of sex differences and the investigation of changes in joint width with age were evaluated. PATIENTS AND METHODS: Eighty hundred and sixty-nine patients (351 female and 518 male) received radiographs of the hand for trauma and were screened for a host of conditions known to affect the joint spaces. All participants underwent measurements of joint space distances at the metacarpal-phalangeal articulation (JSD-MCP) from the thumb to the small finger and at the proximal-interphalangeal articulation (JSD-PIP) from the index finger to the small finger using computer-aided diagnosis technology with semi-automated edge detection. RESULTS: The study revealed an annual narrowing of the JSD of 0.6% for the JSD-MCP and for the JSD-PIP. Furthermore, the data demonstrated a notable age-related decrease in JSD, including an accentuated age-related joint space narrowing in women for both articulations. Additionally, males showed a significantly wider JSD-MCP (+11.1%) and JSD-PIP (+15.4%) compared with the female cohort in all age groups. CONCLUSION: Our data presented gender-specific and age-related normative reference values for computer-aided joint space analysis of the JSD-MCP and JSD-PIP that could be used to identify disease-related joint space narrowing, particularly in patients with osteoarthritis and rheumatoid arthritis commonly involving the peripheral small hand joints.

Computer-aided joint space analysis (CAJSA) of the proximal-interphalangeal joint-normative age-related and gender specific data.

RATIONALE AND OBJECTIVES: To provide reference data for computer-aided joint space analysis (CAJSA) based on a semiautomated and computer-aided diagnostic system for the measurement of joint space widths (ie, proximal-interphalangeal joint), considering gender-specific and age-related differences. MATERIALS AND METHODS: A total of 869 subjects were enrolled (351 females/518 males) with radiographs of the hand. All participants underwent measurements of joint space distances at the proximal-interphalangeal articulation (JSD-PIP) of the second to fifth finger using CAJSA technology. RESULTS: The data verify a notable age-related decrease of CAJSA parameters, showing an accentuated age-related joint space narrowing in women. Additionally, males showed a significant wider JSD-PIP (+15.4%) compared with the female cohort for all age groups. CONCLUSIONS: Our data present gender-specific and age-related normative reference values for computer-aided joint space analysis of JSD-PIP and provide a valid and reliable quantification of disease-related joint space narrowing, particularly in patients with osteoarthritis and rheumatoid arthritis involving the peripheral small hand joints.

Normative data for digital X-ray radiogrammetry from a female and male German cohort.

This study presents German reference data for digital X-ray radiogrammetry (DXR) differentiated by males as well as females, and quantifies for gender-specific and age-related differences including all DXR parameters. This study also documents the effects of different X-ray settings (e.g., radiographs of the wrist or the hand) on DXR measurements. There were 2085 patients who were prospectively enrolled (954 females and 1131 males) from a data pool of 11,915 patients with radiographs of the nondominant hand or wrist. All patients underwent measurements of bone mineral density (BMD), cortical thickness, bone width, and the metacarpal index (MCI) using DXR technology. These data showed a continuous age-related increase of the DXR parameters to the point of peak bone mass, then a continuous decline beyond the peak bone mass with accentuated age-related cortical bone loss in women. Peak bone mass is reached at approximately 30-34 yr for women and 45-49 yr for men. In addition, men had a significantly higher DXR BMD (mean: +12.8%) compared with woman in all age groups. Regarding the impact of various X-ray settings (e.g., X-ray(wrist) vs. X-ray(hand)), no significant difference was observed between both groups, men as well as women. The development of digital imaging technology has enabled more precise measurements of several radio-geometric features. The present study estimated normative reference values for DXR in German Caucasian women and men. Based on this reference data, a valid and reliable quantification of disease-related demineralization based on measurements of DXR BMD and MCI is now available for the Caucasian ethnic group.

Computerized digital imaging techniques provided by digital X-ray radiogrammetry as new diagnostic tool in rheumatoid arthritis.

PURPOSE: Our study evaluates digital x-ray radiogrammetry (DXR) and Radiogrammetry Kit (RK) as a new diagnostic method for the measurement of disease-related osteoporosis including quantification of joint space narrowing dependent on the severity of rheumatoid arthritis (RA). MATERIALS AND METHODS: A total of 172 unselected patients with RA underwent computerized measurements of bone mineral density (BMD) and metacarpal index (MCI) by DXR, as well as a semiautomated measurement of joint space distances at the metacarpal-phalangeal articulation (JSD-MCP 2-5), both were analyzed from plain radiographs of the nondominant hand. RESULTS: Correlations between DXR-BMD and DXR-MCI vs. parameters of RK were all significant (0.34 < R < 0.61; p < 0.01). An expected negative association was observed between RK parameters and the different scoring methods (-0.27 < R < -0.59). The maximum relative decrease in BMD vs. MCI as measured by DXR between the highest and lowest RA severity group was -27.7% vs. -27.5% (p < 0.01) for the modified Larsen Score, whereas the minimal value of relative DXR-BMD and DXR-MCI reduction could be documented for the Sharp Erosion Score (-20.8% vs. -26.8%; p < 0.01). The relative reduction of mean JSD-MCP using RK significantly varied from -25.0% (Sharp Erosion Score) to -41.2% (modified Larsen Score). In addition, an excellent reproducibility of DXR and RK could be verified. CONCLUSION: DXR in combination with RK could be a promising, widely available diagnostic tool to supplement the different scoring methods of RA with quantitative data, allowing an earlier and improved diagnosis and more precision in determining disease progression.

Computerized quantification of joint space narrowing and periarticular demineralization in patients with rheumatoid arthritis based on digital x-ray radiogrammetry.

OBJECTIVES: The aim of our work was to evaluate digital x-ray radiogrammetry (DXR) for the quantification of disease-related periarticular demineralization and computerized analysis of joint space distances (JSDA) for the measurement of joint space narrowing as a new diagnostic method for the early detection of joint-associated alterations and for monitoring disease progression in patients with rheumatoid arthritis (RA). MATERIALS AND METHODS: Digital radiographs in 313 patients with varying severity of RA were performed annually and assessed by 2 radiologists using modified Larsen and also the Sharp scores within an observation period of 3 years. The hand radiographs underwent measurements of bone mineral density (BMD) and metacarpal index (MCI) by DXR, as well as computerized JSDA at the metacarpal-phalangeal articulation (JSD-MCP) for a cross-sectional and longitudinal study design. RESULTS: Both DXR-BMD (-29.6%; P < 0.01) and DXR-MCI (-31.0%; P < 0.01) revealed a notable reduction dependent on the severity of RA (from grade 1 to grade 5 of the modified Larsen score); the severity dependent decrease of mean JSD-MCP ranged from -31.9% (P < 0.01; Sharp erosion part) to -39.1% (P < 0.01) for the modified Larsen score. Over an observation period of 3 years, a significant decrease of DXR-BMD (-22.3%) and DXR-MCI (-23.3%) as well as JSD-MCP mean (-17.5%) was observed (P < 0.05), whereas an accentuated decline of DXR and JSDA parameters was verified for patients without disease-modifying antirheumatic drugs or methotrexate therapy. CONCLUSION: Computerized analysis of hand radiographs by DXR and JSDA is a promising approach to assess the severity and to monitor the progression of RA because DXR and JSDA are timely able to measure periarticular demineralization and also narrowing of JSD-MCP dependent on the severity, the medical treatment and the course of RA.