Digital X-ray radiogrammetry: a new appendicular bone densitometric method with high precision

Osteoporosis In Turkish HIV/AIDS patients: comparative analysis by dual energy X-ray absorptiometry and digital X-ray radiogrammetry

Recently, osteoporosis has attracted concern among physicians treating patients with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS). Many confounding factors are assumed to play a role in its pathogenesis. The discussion has increased dramatically since the introduction of highly active antiretroviral therapy (HAART), and, in fact, the pertinent data have become much more contradictory. In this study, we have evaluated the BMD of our HIV/AIDS patients, comparatively by two methodologies: dual energy X-ray absorptiometry (DXA) and digital X-ray radiogrammetry (DXR). The study comprised 27 HIV/AIDS patients (15 males, 12 females). Bone mineral density measurements using DXA (Hologic QDR-4500) were performed at the lumbar spine (L1-L4), femur and distal radius. DXR evaluations were done by Pronosco X-posure system (Sectra Pronosco, Denmark) using the X-ray graphs of the patients' non-dominant hands. Nine patients (33.33%) were found to have osteoporosis. Fourteen (51.85%) had osteopenia and four (14.81%) were normal. Estimated BMD and cortical thickness measurements obtained from DXR significantly correlated with lumbar, femoral and radial DXA measurements. Whether disease-related or drug-related, the tendency to a decline in the bone mass of these patients exists, and future studies are awaited to unravel the clinical significance of osteopenia, risk of fracture and the individual differences between HAART regimens in HIV/AIDS. We also believe that launching screening and treatment guidelines for osteoporosis in these patients will then become reasonable. Last but not least, DXR appears to be a promising tool in this regard.

Age-related changes in cortical bone mass: data from a German female cohort

To describe data from digital radiogrammetry (DXR) in an unselected German female cohort over a wide age range. Using a retrospective study design we analyzed radiographs of the hand from 540 German women (aged 5-96 years) using an automated assessment of cortical thickness, metacarpal index (MCI), and estimated cortical bone mineral density (DXR-BMD) on digitized radiographs. Both hands were radiographed in 97 women. In this group DXR-BMD and cortical thickness were significantly higher in the right metacarpals while there was no significant difference in MCI. To study the association with age we differentiated young (<20 years), middle-aged (20-45 years), and an older patients (>45 years). In young women all parameters increased significantly with age in a linear fashion (r=0.8 for DXR-BMD, r=0.7 for MCI). In those aged 25-45 years DXR-BMD and MCI were highest (peak bone mass). In women aged 45 or older all parameters decreased with age in an almost linear fashion with an annual change ranging from 0.7% to 0.9%. Our results for an unselected German female cohort indicate that DXR is a reliable, widely available osteodensitometric technique based on the refinement of conventional radiogrammetry. These findings are comparable to those from other studies and represent a valid resource for clinical application and for comparisons with other ethnic groups.

Use of digital x ray radiogrammetry in the assessment of joint damage in rheumatoid arthritis

OBJECTIVE

To compare digital x ray radiogrammetry (DXR) with manual radiography for assessing bone loss in RA and examine the relationship of the scores obtained with other disease indices.

METHODS

225 consecutive consenting subjects attending the RA clinic were enrolled. An x ray examination was carried out; demographic details recorded; a self assessment questionnaire completed; blood taken for ESR measurement; and an assessment made by a trained nurse. All x ray films were scored manually using the modified Sharp technique by a single observer; 20 films were rescored by three readers. Films were assessed with the Pronosco X-Posure system, version 2.0. Analysis included chi2 tests, independent t tests, multiple linear regression, and partial correlations, as appropriate. The smallest detectable difference (SDD), coefficient of variation (CV), and coefficient of repeatability (CR) were determined from Bland and Altman plots.

RESULTS

The DXR precision varied: SDD = 0.002-0.9; CV = 0.09-5.9%; CR = 0.002-0.792, but was better than that of the intra- and interobserver Sharp scores: SDD = 73.9; CV = 27.8%; CR = 33.0-47.6. The DXR measurements, bone mineral density (R2 = 0.210), metacarpal index (R2 = 0.222), and cortical thickness (R2 = 0.215), significantly predicted Sharp scores. In women, DXR measurements significantly correlated with modified HAQ scores but with no other disease indices. Sharp scores significantly correlated with assessor's global assessment, swollen and tender joint counts, pain, HAQ, and DAS28.

CONCLUSION

DXR measurements are more precise than Sharp scores; both are related to long term disease activity in RA. DXR is simple to use, does not require intensive training, and may identify subjects not responding to standard treatment.

Comparison of dual X-ray absorptiometry (DXA), digital X-ray radiogrammetry (DXR), and conventional radiographs in the evaluation of osteoporosis and bone erosions in patients with rheumatoid arthritis

OBJECTIVE

To compare the relationship between bone mineral density (BMD) in the metacarpal bones and forearm measured by dual X-ray absorptiometry (DXA) and digital X-ray radiogrammetry (DXR) and radiological alterations in patients with early and established rheumatoid arthritis (RA).

PATIENTS AND METHODS

In each of the three disease duration groups, 11 female RA patients were included. The patients were further divided into two groups according to bone erosions. BMD in the metacarpals was evaluated by DXA and DXR.

RESULTS

A significant relationship between DXA-BMD and DXR-BMD was observed. DXR-BMD and the individually combined cortical thickness (CT) of the metacarpo-phalangeal (MCP) joints were related to disease duration and erosions. Patients with erosive disease had lower values of age- and sex-adjusted BMD measured with DXA, but most significantly with DXR.

CONCLUSION

DXR appears to be a more sensitive method than DXA in detecting early bone loss in patients with RA. The relationship of DXR-BMD to disease duration and bone damage indicates that the DXR method may be useful in the evaluation of disease activity and progression.

Evaluation of bone-mineral density by digital X-ray radiogrammetry (DXR) in pediatric renal transplant recipients

BACKGROUND

Loss of bone mass and increased fracture risk are known complications after renal transplantation in adults. Risk factors include donor source, dialysis status prior to transplantation, aetiology of renal disease, transplant rejection and drug therapy, particularly steroids.

OBJECTIVE

In this preliminary study of quantification of bone loss in children after renal transplantion, we evaluated the applicability of digital X-ray radiogrammetry (DXR) of hand radiographs to estimate cortical bone mineral density (DXR-BMD).

MATERIALS AND METHODS

A total of 23 renal transplant recipients (9 girls, 14 boys; age 6.5-20 years, median 16.3 years) underwent DXR measurements for calculation of DXR-BMD and metacarpal index (DXR-MCI) using radiographs of the non-dominant left hand. The duration between transplantation and the DXR evaluation, the duration of dialysis and medication were considered. The results were compared to a local age-matched and gender-matched reference data base.

RESULTS

Our study revealed a significant decrease in bone mineral density compared to an age-matched and sex-matched normal population (P<0.05). In three patients the DXR-BMD was reduced more than -2.5 SD. In 12 patients the DXR-BMD was between -1 and -2.5 SD, and in 7 patients the DXR-BMD was in the normal range. In one patient, evaluation was not possible. Fractures were documented in three patients following transplantation. Reduced DXR-BMD was not significantly associated with immunosuppressive therapy or the duration of dialysis, and there was no significant correlation between DXR-BMD and the time between transplantation and DXR evaluation.

CONCLUSIONS

Paediatric renal transplant patients show reduced DXR-BMD. In this preliminary study we demonstrated that DXR-BMD seems to be a reliable technique for quantification of demineralisation following renal transplantation in children.

Calcium supplementation and bone mineral density in females from childhood to young adulthood: a randomized controlled trial

BACKGROUND

Short-term studies established that calcium influences bone accretion during growth. Whether long-term supplementation influences bone accretion in young adults is not known.

OBJECTIVE

This study evaluated the long-term effects of calcium supplementation on bone accretion among females from childhood to young adulthood.

DESIGN

A 4-y randomized clinical trial recruited 354 females in pubertal stage 2 and optionally was extended for an additional 3 y. The mean dietary calcium intake of the participants over 7 y was approximately 830 mg/d; calcium-supplemented persons received an additional approximately 670 mg/d. Primary outcome variables were distal and proximal radius bone mineral density (BMD), total-body BMD (TBBMD), and metacarpal cortical indexes.

RESULTS

Multivariate analyses of the primary outcomes indicated that calcium-supplementation effects vary over time. Follow-up univariate analyses indicated that all primary outcomes were significantly larger in the supplemented group than in the placebo group at the year 4 endpoint. However, at the year 7 endpoint, this effect vanished for TBBMD and distal radius BMD. Longitudinal models for TBBMD and proximal radius BMD, according to the time since menarche, showed a highly significant effect of supplementation during the pubertal growth spurt and a diminishing effect thereafter. Post hoc stratifications by compliance-adjusted total calcium intake and by final stature or metacarpal total cross-sectional area showed that calcium effects depend on compliance and body frame.

CONCLUSIONS

Calcium supplementation significantly influenced bone accretion in young females during the pubertal growth spurt. By young adulthood, significant effects remained at metacarpals and at the forearm of tall persons, which indicated that the calcium requirement for growth is associated with skeletal size. These results may be important for both primary prevention of osteoporosis and prevention of bone fragility fractures during growth.

Influence of image-capturing parameters on digital X-ray radiogrammetry

The purpose of this study was to evaluate the importance of different image-capturing conditions, which might influence the characteristics of radiographs and, consequently, impact calculations of bone mineral density (BMD) and Metacarpal Index (MCI) using digital X-ray radiogrammetry (DXR). Radiographs of the left hand of deceased males were acquired three times using systematically varied parameters: 4-8 miliamp seconds (mA); 40-52 kV; film-focus distance (FFD); 90-130 cm; film sensitivity, 200/400; and different image modalities (conventional vs original digital radiographs as well as digital printouts). Furthermore, the interradiograph reproducibility using both conventional equipment and printouts vs originals of digital images and the intraradiograph reproducibility (either conventional or digital printouts) were evaluated. All BMD and MCI measurements were obtained with the DXR technology. The interradiograph reproducibility of DXR-BMD using conventional images under standardized conditions (6 mAs; 42 kV; 1 m FFD; film sensitivity of 200) was calculated to be coefficient of variation (CV) = 0.49% for Agfa Curix film and CV = 0.33% for Kodak T-MAT-Plus film, whereas reproducibility error using digital images ranged from CV = 0.57% (digital printouts; Philips) to CV = 1.50% (original digital images; Siemens). The intraradiograph reproducibility error was observed to be CV = 0.13% (conventional; Kodak film) vs CV = 0.27% (digital printouts; Philips). The BMD calculation was not noticeably affected by changes of FFD, exposure level, or film sensitivity/film brand, but was influenced by tube voltage (CV = 0.99% for Kodak film to CV = 2.05% for Siemens digital printouts). No significant differences were observed between the BMD and MCI data. DXR provides measurements of MCI and BMD with high precision and reproducibility. The measurements are unaffected by all tested image-capturing conditions, with the exception of tube voltage. In addition, different digital image devices clearly have an effect on DXR reproducibility.

Digital x-ray radiogrammetry combined with semiautomated analysis of joint space widths as a new diagnostic approach in rheumatoid arthritis: A cross-sectional and longitudinal study

OBJECTIVE

To evaluate digital x-ray radiogrammetry (DXR) and the Radiogrammetry Kit program as new diagnostic tools for quantifying disease-related periarticular osteoporosis and for measuring joint space narrowing according to the severity and duration of rheumatoid arthritis (RA).

METHODS

Using DXR, we performed computerized calculations of bone mineral density (BMD) and the metacarpal index (MCI) in 258 patients with active RA. Using the Radiogrammetry Kit program, we also performed semiautomated measurements of joint space width (JSW) at the second through the fifth metacarpophalangeal (MCP) joints in these patients.

RESULTS

All correlations between the different parameters of both techniques (BMD and the MCI as measured by DXR and MCP JSW as measured by the Radiogrammetry Kit) were significant (0.36 < or = R < or = 0.63; P < 0.01). As expected, a significant negative association was shown between the different MCP JSW results and the results of all scoring methods (-0.67 < or = R < or = -0.29). The BMD and the MCI measured by DXR both decreased significantly between Steinbrocker stage I and stage IV (by 32.7% and 36.6%, respectively; both P < 0.01). Reductions in the overall (mean) MCP JSW varied from 35.3% (Larsen score) to 52.9% (Steinbrocker stage). Over a period of 6 years, we observed relative decreases in BMD and the MCI as measured by DXR (32.1% and 33.3%, respectively), as well as in the overall (mean) MCP JSW (23.5%), and these were pronounced in early RA (duration <1 year). In addition, excellent reproducibility of DXR and Radiogrammetry Kit parameters was verified (coefficients of variation <1%).

CONCLUSION

DXR with the integrated Radiogrammetry Kit program could be a promising, widely available diagnostic tool for supplementing the different RA scoring methods with quantitative data, thus allowing an earlier and improved diagnosis of RA and more precision in determining disease progression.

Versuch der Differenzierung zwischen kortikoidinduzierter Osteopenie und periartikul�rer Demineralisation mit Hilfe der Digitalen Radiogrammetrie (DXR) bei Patienten mit rheumatoider Arthritis

PURPOSE

To investigate a new bone densitometric technology based on digital radiogrammetry (DXR) with respect to its ability to measure severity-dependent variations of bone mineral density (BMD) in patients with rheumatoid arthritis and to differentiate between corticoid-induced and periarticular bone mineral density loss.

PATIENTS AND METHODS

A total of 153 randomly selected patients suffering from verified rheumatoid arthritis underwent digitally performed plain radiographs of the non-dominant hand and also measurements of dual-energy X-ray absorptiometry (DXA) regarding total femur and lumbar spine in 102 patients and peripheral quantitative computed tomography (pQCT) regarding the distal radius in 51 patients. Using DXR the radiographs of the non-dominant hand were analyzed for cortical bone mineral density calculation. The severity was classified in the DXA group using the Ratingen score. Furthermore, both study populations were divided into patients with and without corticoid therapy.

RESULTS

Correlations between BMD determined by DXR and by DXA (R=0.44 for lumbar spine and R=0.61 for total femur) versus pQCT (0.46<R<0.59) were all significant. An appropriate association was confirmed between pQCT and DXA (R=0.61 for total femur and 0.73 for LWS). In the subgroup of patients with corticoid therapy (mean dose: 5 mg/d for a period of more than 6 month), our data showed-similar to the collective of all patients-significant correlations (0.34<R<0.59) between DXR and the other methods. In contrast to pQCT (0.37<R<0.59) the study revealed a poor association between DXR- and DXA-parameters in the subgroup of patients without corticoid therapy; only the correlation between DXA-BMD of total femur and DXR-BMD achieved a significant level (R=0.38, p<0.05). The mean value of BMD measured by DXR decreased severity dependently from 0.59 g/cm(2) (Stage 1) to 0.46 g/cm(2) (Stage 5). Similar results were verified for the metacarpal index (DXR). The relative decrease of BMD between the highest and lowest score was 21% (p<0.05). Otherwise the reduction of bone mineral density using DXA revealed no significant results.

CONCLUSION

The DXR-based BMD calculation can distinguish severity and progress of disease-related periarticular demineralization in contrast to those of DXA. In this context, DXA primarily measures the systemic (corticoid-induced) osteoporosis and pQCT partially estimates disease-related bone mineral density loss, whereas DXR can predominantly analyze and quantify the periarticular demineralization, which often shows a manifestation at an early stage of rheumatoid arthritis. Therefore DXR seems to be a diagnostic tool in the course of rheumatoid arthritis.

Bone loss in unclassified polyarthritis and early rheumatoid arthritis is better detected by digital x ray radiogrammetry than dual x ray absorptiometry: relationship with disease activity and radiographic outcome

OBJECTIVE

To compare changes in regional bone mineral density (BMD) of the metacarpal joints measured by dual x ray absorptiometry (DXA) and digital x ray radiogrammetry (DXR) in relation to disease activity and radiographic outcome in a two year follow up study of patients with early RA and unclassified polyarthritis.

PATIENTS AND METHODS

72 patients with symmetrically swollen and tender second and third metacarpophalangeal or proximal interphalangeal joints for at least four weeks and less than two years were included. 51 patients fulfilled the ACR criteria for RA. 21 patients had unclassified polyarthritis. The patients with RA were divided into groups according to mean disease activity, average glucocorticoid dose, and MRI and x ray detected bone erosions in the hands. Clinical and biochemical measurements were made every month and an x ray examination of the hands and BMD of the metacarpal joints every six months.

RESULTS

DXR BMD decreased significantly only in patients with RA from month 6 and was associated with the mean disease activity. Patients with RA and erosive as well as non-erosive disease showed a significant decrease in the rate of bone loss, greatest in those with erosive disease. No changes in BMD measured by DXA were seen in any patient group.

CONCLUSION

DXR is a useful measure of the destructive disease activity in patients with RA and unclassified polyarthritis, providing valuable information about bone changes associated with disease activity and erosive disease in early RA. DXR is better than DXA for detecting and monitoring periarticular osteoporosis of the metacarpal bone.

Potential clinical relevance of digital radiogrammetry for quantification of periarticular bone demineralization in patients suffering from rheumatoid arthritis depending on severity and compared with DXA

The aim of this study was to investigate a new bone densitometric technology based on digital radiogrammetry (DXR) with respect to its ability to measure severity-dependent variations of bone mineralization in patients with rheumatoid arthritis. One hundred six randomly selected patients suffering from verified rheumatoid arthritis underwent digitally performed plain radiographs of the non-dominant hand and measurements of dual-energy X-ray absorptiometry (DXA) regarding total femur and lumbar spine. Using DXR the radiographs were analyzed retrospectively for bone mineral density (BMD) calculation. The severity was classified using Larsen score and Steinbroker stage blinded by two radiologists. A third radiologist reviewed the incongruently scored cases. Mean values of calculated parameters changed as follows from Larsen 1 to Larsen 5: Bone mineral density (DXR-BMD) decreased from 0.55 to 0.44 g/cm2 (p=0.000), DXR-MCI decreased from 0.44 to 0.33 (p=0.001), DXA-BMD (total femur) decreased from 0.92 to 0.78 g/cm2 (p=0.090) and DXA-BMD (lumbar spine) decreased from 0.91 to 0.84 g/cm2 (p=0.595). Similar results were verified for the Steinbroker stage. The relative decrease of BMD measured by DXR between the highest and lowest score was 20% for Steinbroker stage and Larsen score (p<0.05). The relative decrease of BMD using DXA revealed not such a significant result. Similar results were verified for metacarpal index (estimated by DXR). Correlations between BMD determined by DXR and by DXA were all significant (R=0.45 for lumbar spine and R=0.59 for total femur). Consequently, less than 35% of the DXR-BMD value is explainable by corresponding DXA values. The DXR-based BMD calculation seems to be able to distinguish severity and progress of the disease in contrast to those of DXA at lumbar spine and total femur.

Semi-automated evaluation of the cortico-medullar index on radius radiographs: a study in prepubertal girls

The aim of the study was to validate a non-invasive method allowing a semi-automatic cortico-medullar index (CMI) computation from standard radiographs. Fifty-five radiographs of the non-dominant radius of prepubertal girls (aged 10.12+/-1.47 years) were scanned (100 microm scanning resolution) by the same observer. To detect the grey level peaks, we used the Deriche's recursive filter applied to the grey level gradients and we defined the cortical areas by thresholding (iterative contour detection). The CMI was calculated as cortical areas divided by the total bone area. The reproducibility was tested through the analysis of ten radiographs scanned twice, on 5, 10, 15, 20, 30 and 40 lines at each side of a reference line located at the distal third part of the radius. We used the root mean square coefficient of variation (RMS-CV) as verification. Dual-Energy X-ray (DXA) was used for densitometry measurements of the whole body, and non dominant radius (mid-, distal third and ultra distal). The result attaining the best reproducibility concerned the 15-line position (Mean CMI=0.58+/-0.005 with a 1.36% RMS-CV). CMI correlated significantly with Bone Mineral Density (BMD) (r=0.40, 0.33 and 0.50, P<0.01, respectively, at the whole body, mid- and third distal of the radius), Bone Mineral Content (BMC) (r=0.32, 0.36, 0.34 and 0.35, respectively, at the whole body (P=0.01), mid- (P=0.007), third distal (P=0.01) and ultra distal of the radius (P=0.01)) but not with BMD at the ultra distal of the radius (r=-0.01, P=0.9). This semi-automated new method has been easily implemented, reproducible, and therefore, could be useful tool for the bone CMI computation.

Predicting the failure load of the distal radius

The distal radius is an important site for the early detection of patients at risk for fracture. Since measuring bone strength in vivo is not possible, we evaluated which bone assessment method of the forearm would best predict failure load of the distal radius and computed a factor of risk for wrist fracture (Phi wrist). Thirty-eight cadaveric forearm specimens were measured by five different techniques to assess bone density, bone mineral content, geometry and trabecular structure at the distal forearm. The bone assessment techniques included dual-energy X-ray absorptiometry (DXA) of the radius, peripheral quantitative computed tomography (pQCT) of the 4% and 20% distal sites of the radius, DXA of the phalanges, digital X-ray radiogrammetry of the forearm (DXR-BMD), and quantitative ultrasound of the radius. The failure load of each excised radius was determined by simulating a fall on an outstretched hand. The pQCT measurements of polar stress-strain index and cortical content explained the greatest portion of variance in failure load (r2=0.82-0.85). Bone mineral content measures were generally better predictors of failure load (r2=0.53-0.85) than the corresponding volumetric or areal bone mineral density values (r2=0.22-0.69) measured by either pQCT or DXA. Multiple regression analysis showed that the addition of a bone geometry measure improved the ability of a bone density measure alone to predict failure load. There was high variability in the ability of different techniques and different variables within a given technique to predict failure load. Estimates of the factor of risk for wrist fracture (Phi wrist) revealed that the women in this study would have been likely to fracture their distal radius upon falling from a standing height (Phi wrist= 1.04), whereas the men would have likely withstood the impact without fracturing their wrist (Phi wrist= 0.79).

A new rapid radiological procedure for routine teratological use in bone ossification assessment: a supplement for staining methods

BACKGROUND

Presently, bone ossification is assessed by the study of single-stained fetal bones (alizarin red-S) or double-stained bones and cartilaginous structures (alcian blue followed by alizarin red-S). Both methods, especially double-staining, are labor-intensive, time-consuming, and provide qualitative information regarding skeleton ossification. Quantitative evaluation of ossification is more difficult and is usually based on determination of calcium and other minerals in the bone by means of atomic absorption spectrometry. Here we introduce a simple new method that allows quantitative determination of skeleton ossification before routine staining examination.

METHODS

Fetuses delivered by laparotomy on the 16th and 21st day of gestation as well as 1-day-old rat pups were examined. The fetuses and pups were prenatally subcutaneously exposed to sodium valproate or to physiological saline. Lateral, prone, and supine digital radiograms of each fetus were taken using the Digora-Soredex digital radiography system and the Planmeca Intra intraoral X-ray machine. According to the best visualization, the data concerning vertebra were analyzed. All the fetuses were then routinely double-stained using alcian blue and alizarin red-S.

RESULTS

Malformations of axial skeleton (rib, sternum, and thoracic and sacral vertebra) were found in valproate-treated groups. Unlike cartilage malformations, the bone changes were detected in similar frequency in radiological and staining methods. Differences in densities according to the degree of ossification in the vertebral arches and bodies at different levels of the vertebral column, between drug-treated and negative control groups were noted.

CONCLUSIONS

The preliminary results suggest that digital radiography examination is a useful method in determining delaying of skeleton ossification not detectable by other methods. It balances qualitative and quantitative aspects of the presently used methods and is also simple, objective, fast, and relatively inexpensive.

Assessing periarticular bone mineral density in patients with early psoriatic arthritis or rheumatoid arthritis

BACKGROUND

Periarticular osteoporosis is an early finding in the hands of patients with rheumatoid arthritis (RA), due to release of bone resorbing cytokines from the inflamed synovium. There has been disagreement as to whether periarticular bone loss occurs in psoriatic arthritis (PsA). Bone mineral density (BMD) can now be measured accurately using dual energy x ray absorptiometry (DEXA). Recently, DEXA has been used to measure periarticular BMD at predefined regions of interest (ROIs) around the joints.

OBJECTIVES

Firstly, to compare periarticular BMD around the finger joints of patients with early RA or PsA. Secondly, to determine whether periarticular bone loss is related to joint inflammation and radiological erosions in RA and PsA.

METHODS

Seventeen patients with RA and 15 with PsA were recruited, all with disease duration of less than five years. All finger joints were examined by one person for swelling, or tenderness, or both. Hand radiographs were scored for the presence of erosions. Periarticular BMD was measured at 10 predetermined ROIs using a Hologic QDA-4500A fan-beam densitometer.

RESULTS

Patients with PsA were less likely to be positive for rheumatoid factor (RF) (13% v 94%) and more likely to be men (60% v 23%) than patients with RA. There were no other clinical differences between patients with RA or PsA. Patients with RA had significantly lower BMD at each of the ROIs than those with PsA (p<0.05). However, these differences disappeared after adjusting for age and sex. Among patients with RA, those with a higher total number of swollen and/or tender hand joints had significantly lower periarticular BMD at the metocarpophalangeal (MCP) and proximal interphalangeal (PIP) joints. No such association was found for patients with PsA.

CONCLUSIONS

In early disease, periarticular bone loss occurred both in patients with RA and those with PsA. Among patients with RA, periarticular osteoporosis was related to measures of joint inflammation. There was no association between joint inflammation and periarticular bone loss in patients with PsA, which lends support to the hypothesis that the primary site of inflammation in PsA is extrasynovial.

Assessment of phalangeal bone loss in patients with rheumatoid arthritis by quantitative ultrasound

OBJECTIVE

Periarticular osteopenia is an early radiological sign of rheumatoid arthritis (RA). Quantitative ultrasound (QUS) devices have recently been shown to be useful for assessing osteoporosis. In this study the capability of a transportable and easy to use QUS device to detect skeletal impairment of the finger phalanges in patients with RA was investigated.

METHODS

In a cross sectional study 83 women (30 controls, 29 with glucocorticosteroid (GC) treated RA, and 24 with GC treated vasculitis) were examined. QUS measurements were obtained at the metaphyses of the proximal phalanges II-V and directly at the proximal interphalangeal joints II-IV with a DBM Sonic 1200 (IGEA, Italy) QUS device. Amplitude dependent speed of sound (AD-SoS) was evaluated. In 23 of the patients with RA, hand radiographs were evaluated.

RESULTS

Significant differences between patients with RA and the other groups were found for AD-SoS at both measurement sites. Compared with age matched controls, the AD-SoS of patients with RA was lowered by two and three standard deviations at the metaphysis and joint, respectively. Fingers of patients with RA without erosions (Larsen score 0-I) already had significantly decreased QUS values, which deteriorated further with the development of erosions (Larsen II-V).

CONCLUSION

This study indicates that QUS is sensitive to phalangeal periarticular bone loss in RA. QUS is a quick, simple, and inexpensive method free of ionising radiation that appears to be suited to detection of early stages of periarticular bone loss. Its clinical use in the assessment of early RA should be further evaluated in prospective studies.

A normative reference database study for Pronosco X-posure System

Cortical width from radiographs has been used for more than 40 yr as a means of estimating bone strength. In the last 5-10 yr, increased availability of computers and the development of automated algorithms for image assessment have led to an increased interest in radiogrammetry. In this study, we examined a new radiogrammetry device, the Pronosco X-posure System, which estimates bone mineral density (BMD) from forearm/hand radiographs. We obtained hand and forearm radiographs and performed dual X-ray absorptiometry (DXA) at the wrist and hip on 832 women ages 20-79 at four clinical centers across the United States. We then used the X-posure System to estimate BMD (DXR-BMD). The goal of the study was to establish reference ranges for the method and to compare the measurement to DXA measurements of BMD at the wrist and hip. Using statistical models, we estimated that the peak value for DXR-BMD occurred at age 38 (mean = 0.598 g/cm2, standard deviation = 0.034 g/cm2). The correlation between DXR-BMD and DXA was 0.90 at the wrist and 0.61 at the hip. The relationship of DXR-BMD to reported history of fracture was of similar magnitude to that for DXA at the wrist and hip. The strong correlation of DXR-BMD from the X-posure System with DXA at the wrist from the Hologic machine suggests that the X-posure System may be an alternative to DXA at the wrist for the assessment of osteoporosis.

Metacarpal index by digital X-ray radiogrammetry: normative reference values and comparison with dual X-ray absorptiometry

Metacarpal index (MCI), the combined cortical midmetacarpal thickness divided by the outer mid-metacarpal diameter, fell into oblivion when dual photon absorptiometry was introduced a quarter of a century ago. Modern PC-based digital X-ray diameter measurements offers a unique opportunity for precise and accurate measurements of MCI (DXR-MCI). We hypothesized that DXR-MCI in contrast to projected areal bone mineral density (BMD) (DXA-BMD) is independent of bone size and studied 384 normal women by measuring DXR-MCI and DXA-BMD of the lumbar spine, hip, and distal radius. A normative MCI database for women is presented. It has its maximum in the third decade, and a moderate biologic variation that seems to decline with age. It was found that DXR-MCI was independent of body weight and body surface area, whereas all DXA-BMD values were significantly dependent on them. Body height was significantly correlated with DXA-BMD at all sites, but less so with DXR-MCI. The latter was correlated with metacarpal bone length. It is suggested that the moderate correlation between MCI and body height would be abolished if the region of interest used for calculation of MCI be adjusted according to individual metacarpal bone length. DXR-MCI correlated significantly with DXA-BMD at the sites measured, and particularly well with that of the distal radius (r = 0.67; p < 0.0001).