RESUMEN
Radiogrammetry remains a convenient method of bone mass measurement. It is the only objective means of quantifying metacarpal osteoporosis (OP) in rheumatoid arthritis (RA). An automated technique using a digitizer (interfaced with an IBM PC) for measurement of combined cortical width (CCW) at the mid-shaft of six metacarpals was evaluated in three groups of individuals under 50 years of age (98 normal controls, 96 RA, 63 SLE). Intra-observer, inter-observer, and inter-institution reproducibility was assessed with a 'phantom' embedded in a rectangular mould of wax. Intra-patient variation was also assessed in RA patients seen on two occasions less than a month apart. Two hundred and fifty-seven subjects were studied. The method was found to be reproducible for a single observer, among five different observers and in two separate institutions. The RA subjects seen on two occasions showed no significant differences in CCW. The technique showed significant differences of CCW in the three groups of premenopausal subjects (controls; RA; SLE) studied (p less than 0.001). The six metacarpal bone mass was calculated in less than 5 min. The technique of digitized radiogrammetry is an improvement on the Vernier caliper technique. The method is useful for epidemiological cross-sectional studies and for evaluation of long-term radiological changes in RA.
Asunto(s)
Metacarpo/diagnóstico por imagen , Osteoporosis/diagnóstico por imagen , Intensificación de Imagen Radiográfica , Adulto , Artritis Reumatoide/diagnóstico por imagen , Densidad Ósea , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Lupus Eritematoso Sistémico/diagnóstico por imagen , Masculino , Modelos Estructurales , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
A cross sectional analysis of the correlation between clinical, laboratory, and radiological markers of disease activity in 98 patients with classical rheumatoid arthritis (RA) is reported. The median age was 38 years, the median age at onset of disease 29 years, and the median duration of disease seven years. The Keitel function test (KFT) showed good correlation with the Ritchie articular index (RAI) (p less than 0.0001; r = 0.5) and the disability questionnaire (DQ) (p less than 0.0001; r = 0.6). The RAI and DQ correlated weakly with laboratory variables, while the KFT showed significant correlation with the erythrocyte sedimentation rate (ESR), C reactive protein (CRP), and plasma viscosity (PV) (p less than 0.001; r = 0.4; 0.3; 0.4). Only the KFT showed significant correlations with bone mass measurements (p less than 0.01; r = -0.3; -0.4), and the Larsen index at the right wrist (p less than 0.0001; r = 0.4). Consensus analysis suggested that the KFT is a useful single clinical test of disease activity in RA. The hand functional index (HFI), a component of the KFT, showed significant correlation with the total KFT (r = 0.9). Prospective drug trials are needed to establish the value of the HFI in the monitoring of patients with RA.