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

Osteoporosis in children and adolescents: when to suspect and how to diagnose it

Early recognition of osteoporosis in children and adolescents is important in order to establish an appropriate diagnosis of the underlying condition and to initiate treatment if necessary. In this review, we present the diagnostic work-up, and its pitfalls, of pediatric patients suspected of osteoporosis including a careful collection of the medical and personal history, a complete physical examination, biochemical data, molecular genetics, and imaging techniques. The most recent and relevant literature has been reviewed to offer a broad overview on the topic. Genetic and acquired pediatric bone disorders are relatively common and cause substantial morbidity. In recent years, there has been significant progress in the understanding of the genetic and molecular mechanistic basis of bone fragility and in the identification of acquired causes of osteoporosis in children. Specifically, drugs that can negatively impact bone health (e.g. steroids) and immobilization related to acute and chronic diseases (e.g. Duchenne muscular dystrophy) represent major risk factors for the development of secondary osteoporosis and therefore an indication to screen for bone mineral density and vertebral fractures. Long-term studies in children chronically treated with steroids have resulted in the development of systematic approaches to diagnose and manage pediatric osteoporosis.

CONCLUSIONS

Osteoporosis in children requires consultation with and/or referral to a pediatric bone specialist. This is particularly relevant since children possess the unique ability for spontaneous and medication-assisted recovery, including reshaping of vertebral fractures. As such, pediatricians have an opportunity to improve bone mass accrual and musculoskeletal health in osteoporotic children.

WHAT IS KNOWN

• Both genetic and acquired pediatric disorders can compromise bone health and predispose to fractures early in life. • The identification of children at risk of osteoporosis is essential to make a timely diagnosis and start the treatment, if necessary.

WHAT IS NEW

• Pediatricians have an opportunity to improve bone mass accrual and musculoskeletal health in osteoporotic children and children at risk of osteoporosis. • We offer an extensive but concise overview about the risk factors for osteoporosis and the diagnostic work-up (and its pitfalls) of pediatric patients suspected of osteoporosis.

Metacarpal bone diameter increases constantly in adult females, but escalated resorption of the inner surface at menopause explains the observed decreased bone mineral density at digital X-ray radiogrammetry

OBJECTIVE

To assess how bone morphology and mineralization changes with age, in women by digital X-ray radiogrammetry (DXR). DXR has potential as a screening tool for osteoporosis, as it can evaluate bone mineralization similarly to dual-energy X-ray absorptiometry.

METHODS

The nondominant hand was analyzed with DXR in 13,285 women ages 40-74 years undergoing mammography. 1,556 women attended two consecutive examinations with 18 to 24 months interval. Changes in bone parameters were calculated and compared in 5-year age groups. Regression analysis and ANOVA tests were performed.

RESULTS

Univariate linear regression showed no significant difference in age or bone size between the groups with single or consecutive measurements. In the group with consecutive measurements, the average inner diameter (DXR-ID) of the metacarpals significantly increased with age from 0.38 cm in the 40-45 years age span to 0.47 cm in the 65+ age group (P < 0.001), whereas DXR bone mineral density (DXR-BMD) decreased from 0.59 g/cm2 to 0.50 g/cm2 in the same age groups (P < 0.001). Intraindividual measurements showed a fourfold increase in yearly DXR-ID increase and concurrent DXR-BMD loss between 50 and 59 years of age (P < 0.001). The outer diameter only increased significantly between the youngest and oldest age group (P < 0.001).

CONCLUSIONS

The faster decrease in DXR-BMD observed during and after menopause is caused by resorption of the inner cortical surface, not matched by outer diameter increase. We speculate that most bones in the human body grow in the same pattern as observed in the metacarpals, partly explaining decreasing BMD at DXR and dual-energy X-ray absorptiometry.

Quantifying cortical bone in fragmentary archeological second metacarpals

OBJECTIVES

Skeletal variation in cortical bone thickness is an indicator of bone quality and health in archeological populations. Second metacarpal radiogrammetry, which measures cortical thickness at the shaft midpoint, is traditionally used to evaluate bone loss in bioarcheological and some clinical contexts. However fragmentary elements are regularly omitted because the midpoint cannot be determined. This methodological limitation reduces sample sizes and biases them against individuals prone to fracture, such as older individuals with low bone mass. This study introduces a new technique for measuring cortical bone in second metacarpals, the "Region of Interest" (ROI) method, which quantifies bone in archeological remains with less-than-ideal preservation while accounting for cortical heterogeneity.

MATERIALS AND METHODS

The ROI method was adapted from digital X-ray radiogrammetry (DXR), a clinical method used to estimate bone mineral density, and tested using second metacarpals from Middenbeemster, Netherlands, a 19th century known age and sex skeletal collection. The ROI method quantifies cortical bone area within a 1.9 cm-long, mid-diaphyseal region, standardized for body size differences using total area (CAI_ROI ). CAI_ROI values were compared to traditional radiogrammetric cortical indices (CI) to assess the method's ability to identify age-related bone loss.

RESULTS

CAI_ROI values have high intra- and interobserver replicability and are strongly and significantly correlated with CI values for both males (r[n = 39] = 0.906, p = 0.000) and females (r[n = 58] = 0.925, p = 0.000).

CONCLUSION

The ROI method complements traditional radiogrammetry analyses and provides a reliable way to quantify cortical bone in incomplete second metacarpals, thereby maximizing sample sizes, allowing patterns in bone acquisition and loss to be more comprehensively depicted in archeological assemblages.

Computer-aided diagnosis systems for osteoporosis detection: a comprehensive survey

Computer-aided diagnosis (CAD) has revolutionized the field of medical diagnosis. They assist in improving the treatment potentials and intensify the survival frequency by early diagnosing the diseases in an efficient, timely, and cost-effective way. The automatic segmentation has led the radiologist to successfully segment the region of interest to improve the diagnosis of diseases from medical images which is not so efficiently possible by manual segmentation. The aim of this paper is to survey the vision-based CAD systems especially focusing on the segmentation techniques for the pathological bone disease known as osteoporosis. Osteoporosis is the state of the bones where the mineral density of bones decreases and they become porous, making the bones easily susceptible to fractures by small injury or a fall. The article covers the image acquisition techniques for acquiring the medical images for osteoporosis diagnosis. The article also discusses the advanced machine learning paradigms employed in segmentation for osteoporosis disease. Other image processing steps in osteoporosis like feature extraction and classification are also briefly described. Finally, the paper gives the future directions to improve the osteoporosis diagnosis and presents the proposed architecture. Graphical abstract.

Metacarpal Indices and Their Association with Fracture in South African Children and Adolescents

This prospective study assessed whether metacarpal indices predict fracture risk in children and adolescents. Radiogrammetry was performed at the second metacarpal midshaft on annual hand-wrist radiographs of 359 South African (SA) children aged 10-17 years. Bone length, bone width, and medullary width were measured, and the following proxies for bone strength calculated: metacarpal index (MCI), bone mineral density (BMD), section modulus (SM), stress-strain index (SSI), and slenderness index (SLI). Height and weight were measured annually. Self-reported physical activity (PA) and fracture history were obtained at ages 15 years (for the preceding 12 months) and 17 years, respectively. At 17 years, 82 (23%) participants (black, 16%; white, 42%; p < 0.001) reported a previous fracture. None of the bone measures or indices were associated with fracture in black participants. In white females, after adjusting for PA, a 1 standard deviation (SD) greater SLI doubled the fracture risk [odds ratio (OR) 2.08; 95% confidence interval (CI) 1.08, 3.98]. In white males, a 1 SD greater BMD was associated with a 2.62-fold increase in fracture risk (OR 3.62; 95% CI 1.22, 10.75), whilst a 1 SD greater SM (OR 2.29; 95% CI 1.07, 4.89) and SSI (OR 2.23; 95% CI 1.11, 4.47) were associated with a more than twofold increase in fracture risk, after height, and PA adjustment. No single index consistently predicted fracture across the four groups possibly due to ethnic and sex differences in bone geometry, muscle mass, and skeletal loading. Metacarpal radiogrammetry did not reliably predict fracture in SA children.

Quantitative imaging techniques for the assessment of osteoporosis and sarcopenia

Bone and muscle are two deeply interconnected organs and a strong relationship between them exists in their development and maintenance. The peak of both bone and muscle mass is achieved in early adulthood, followed by a progressive decline after the age of 40. The increase in life expectancy in developed countries resulted in an increase of degenerative diseases affecting the musculoskeletal system. Osteoporosis and sarcopenia represent a major cause of morbidity and mortality in the elderly population and are associated with a significant increase in healthcare costs. Several imaging techniques are currently available for the non-invasive investigation of bone and muscle mass and quality. Conventional radiology, dual energy X-ray absorptiometry (DXA), computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound often play a complementary role in the study of osteoporosis and sarcopenia, depicting different aspects of the same pathology. This paper presents the different imaging modalities currently used for the investigation of bone and muscle mass and quality in osteoporosis and sarcopenia with special emphasis on the clinical applications and limitations of each technique and with the intent to provide interesting insights into recent advances in the field of conventional imaging, novel high-resolution techniques and fracture risk.

Decrease in bone mineral density during three months after diagnosis of early rheumatoid arthritis measured by digital X-ray radiogrammetry predicts radiographic joint damage after one year

Background

Periarticular osteopenia is an early sign of incipient joint injury in rheumatoid arthritis (RA), but cannot be accurately quantified using conventional radiography. Digital X-ray radiogrammetry (DXR) is a computerized technique to estimate bone mineral density (BMD) from hand radiographs. The aim of this study was to evaluate whether decrease in BMD of the hands (BMD loss), as determined by DXR 3 months after diagnosis, predicts radiographic joint damage after 1 and 2 years in patients with early RA.

Methods

Patients (n = 176) with early RA (<12 months after onset of symptoms) from three different Swedish rheumatology centers were consecutively included in the study, and 167 of these patients were included in the analysis. Medication was given in accordance with Swedish guidelines, and the patients were followed for 2 years. Rheumatoid factor and antibodies to cyclic citrullinated peptides (anti-CCP) were measured at baseline, and 28-joint Disease Activity Score (DAS28) was assessed at each visit. Radiographs of the hands and feet were obtained at baseline, 3 months (hands only) and 1 and 2 years. Baseline and 1-year and 2-year radiographs were evaluated by the Larsen score. Radiographic progression was defined as a difference in Larsen score above the smallest detectable change. DXR-BMD was measured at baseline and after 3 months. BMD loss was defined as moderate when the decrease in BMD was between 0.25 and 2.5 mg/cm²/month and as severe when the decrease was greater than 2.5 mg/cm²/month. Multivariate regression was applied to test the association between DXR-BMD loss and radiographic damage, including adjustments for possible confounders.

Results

DXR-BMD loss during the initial 3 months occurred in 59% of the patients (44% moderate, 15% severe): 32 patients (19%) had radiographic progression at 1 year and 45 (35%) at 2 years. In multiple regression analyses, the magnitude of DXR-BMD loss was significantly associated with increase in Larsen score between baseline and 1 year (p = 0.033, adjusted R-squared = 0.069).

Conclusion

DXR-BMD loss during the initial 3 months independently predicted radiographic joint damage at 1 year in patients with early RA. Thus, DXR-BMD may be a useful tool to detect ongoing joint damage and thereby to improve individualization of therapy in early RA.

Metacarpal bone loss in patients with rheumatoid arthritis estimated by a new Digital X-ray Radiogrammetry method - initial results

BACKGROUND

The Digital X-ray Radiogrammetry (DXR) method measures the cortical bone thickness in the shafts of the metacarpals and has demonstrated its relevance in the assessment of hand bone loss caused by rheumatoid arthritis (RA). The aim of this study was to validate a novel approach of the DXR method in comparison with the original version considering patients with RA.

METHOD

The study includes 49 patients with verified RA. The new version is an extension of the BoneXpert method commonly used in pediatrics which has these characteristics: (1) It introduces a new technique to analyze the images which automatically validates the results for most images, and (2) it defines the measurement region relative to the ends of the metacarpals. The BoneXpert method measures the Metacarpal Index (MCI) at the metacarpal bone (II to IV). Additionally, the MCI is quantified by the DXR X-posure System.

RESULTS

The new version correctly analyzed all 49 images, and 45 were automatically validated. The standard deviation between the MCI results of the two versions was 2.9% of the mean MCI. The average Larsen score was 2.6 with a standard deviation of 1.3. The correlation of MCI to Larsen score was -0.81 in both versions, and there was no significant difference in their ability to detect erosions.

CONCLUSION

The new DXR version (BoneXpert) validated 92% of the cases automatically, while the same good correlation to RA severity could be presented compared to the old version.

Digital X-ray radiogrammetry in the study of osteoporotic fractures: Comparison to dual energy X-ray absorptiometry and FRAX

Osteoporosis is often underdiagnosed and undertreated. Screening of post-menopausal women for clinical risk factors and/or low bone mineral density (BMD) has been proposed to overcome this. Digital X-ray radiogrammetry (DXR) estimates hand BMD from standard hand X-ray images and have shown to predict fractures and osteoporosis. Recently, digital radiology and the internet have opened up the possibility of conducting automated opportunistic screening with DXR in post-fracture care or in combination with mammography. This study compared the performance of DXR with FRAX® and DXA in discriminating major osteoporotic fracture (MOF) (hip, clinical spine, forearm or shoulder), hip fracture and femoral neck osteoporosis. This prospective cohort study was conducted on 5278 women 65years and older in the Study of Osteoporotic Fractures (SOF) cohort. Baseline hand X-ray images were analyzed and fractures were ascertained during 10years of follow up. Age-adjusted area under receiver operating characteristic curve (AUC) for MOF and hip fracture and for femoral neck osteoporosis (DXA FN BMD T-score ≤-2.5) was used to compare the methods. Sensitivity to femoral neck osteoporosis at equal selection rates was tabulated for FRAX and DXR. DXR-BMD, FRAX (no BMD) and lumbar spine DXA BMD were all similar in fracture discriminative performance with an AUC around 0.65 for MOF and 0.70 for hip fractures for all three methods. As expected femoral neck DXA provided fracture discrimination superior both to other BMD measurements and to FRAX. AUC for selection of patients with femoral neck osteoporosis was higher with DXR-BMD, 0.76 (0.74-0.77), than with FRAX, 0.69 (0.67-0.71), (p<0.0001). In conclusion, DXR-BMD discriminates incident fractures to a similar degree as FRAX and predicts femoral neck osteoporosis to a larger degree than FRAX. DXR shows promise as a method to automatically flag individuals who might benefit from an osteoporosis assessment.

Exploring the relationship between bone density and severity of distal radius fragility fracture in women

Background

Bone mineral density (BMD) has been shown to be a consistent and independent risk factor for distal radius fracture. Inconsistent data have been reported on the association between BMD and severity of distal radius fracture. Our primary aim was to explore if there is an association between cortical BMD at the hand and the severity of fragility distal radius fracture.

Methods

Consecutively recruited females aged ≥50 years with fragility fracture at the distal radius (n = 110) from a county hospital were included. Cortical hand BMD was assessed by the digital X-ray radiogrammetry (DXR) method. X-rays of the fracture were scored by experienced orthopedic surgeons for fracture severity according to the Müller AO classification of long bones and radiographic parameters such as ulnar variance and dorsal angle.

Results

A weak association between lower DXR BMD and increased ulnar variance and dorsal angle was found but not with the AO scoring system for fracture type. A history of glucocorticoid (GC) use but not DXR-BMD was found to be significantly associated with the presence of having an intra- or extra-articular fracture.

Conclusion

Our data indicate that bone material properties which are impaired by GC use are more important for fracture severity than BMD.

Advances in bone imaging for osteoporosis

The diagnosis and management of osteoporosis have been improved by the development of new quantitative methods of skeletal assessment and by the availability of an increasing number of therapeutic options, respectively. A number of imaging methods exist and all have advantages and disadvantages. Dual-energy X-ray absorptiometry (DXA) is the most widely available and commonly utilized method for clinical diagnosis of osteoporosis and will remain so for the foreseeable future. The WHO 10-year fracture risk assessment tool (FRAX(®)) will improve clinical use of DXA and the cost-effectiveness of therapeutic intervention. Improved reporting of radiographic features that suggest osteoporosis and the presence of vertebral fracture, which are powerful predictors of future fractures, could increase the frequency of appropriate DXA referrals. Quantitative CT remains predominantly a research tool, but has advantages over DXA--allowing measurement of volumetric density, separate measures of cortical and trabecular bone density, and evaluation of bone shape and size. High resolution imaging, using both CT and MRI, has been introduced to measure trabecular and cortical bone microstructure. Although these methods provide detailed insights into the effects of disease and therapies on bone, they are technically challenging and not widely available, so they are unlikely to be used in clinical practice.

Digital X-ray radiogrammetry of hand or wrist radiographs can predict hip fracture risk--a study in 5,420 women and 2,837 men

OBJECTIVES

To assess whether digital X-ray radiogrammetry (DXR) analysis of standard clinical hand or wrist radiographs obtained at emergency hospitals can predict hip fracture risk.

METHODS

A total of 45,538 radiographs depicting the left hand were gathered from three emergency hospitals in Stockholm, Sweden. Radiographs with insufficiently included metacarpal bone, fractures in measurement regions, foreign material or unacceptable positioning were manually excluded. A total of 18,824 radiographs from 15,072 patients were analysed with DXR, yielding a calculated BMD equivalent (DXR-BMD). Patients were matched with the national death and inpatient registers. Inclusion criteria were age ≥ 40 years, no prior hip fracture and observation time > 7 days. Hip fractures were identified via ICD-10 codes. Age-adjusted hazard ratio per standard deviation (HR/SD) was calculated using Cox regression.

RESULTS

8,257 patients (65.6 % female, 34.4 % male) met the inclusion criteria. One hundred twenty-two patients suffered a hip fracture after their radiograph. The fracture group had a significantly lower DXR-BMD than the non-fracture group when adjusted for age. The HR/SD for hip fracture was 2.52 and 2.08 in women and men respectively. The area under the curve was 0.89 in women and 0.84 in men.

CONCLUSIONS

DXR analysis of wrist and hand radiographs obtained at emergency hospitals predicts hip fracture risk in women and men.

KEY POINTS

• Digital X-ray radiogrammetry of emergency hand/wrist radiographs predicts hip fracture risk. • Digital X-ray radiogrammetry (DXR) predicts hip fracture risk in both women and men. • Osteoporosis can potentially be identified in patients with suspected wrist fractures. • DXR can potentially be used for selective osteoporosis screening.

Does digital X-ray radiogrammetry have a role in identifying patients at increased risk for joint destruction in early rheumatoid arthritis?

INTRODUCTION

The aim of this study was to investigate the role of hand bone mineral density (BMD) loss analyzed with digital X-ray radiogrammetry (DXR) in early rheumatoid arthritis (RA) as a predictor for progression of joint damage.

METHODS

In 379 patients with early RA, baseline and one-year hand BMD was measured with DXR and the hand bone loss (HBL) was analyzed using the smallest detectable change (HBLsdc) and tertiles (HBLtertiles). Joint damage in hands and feet were scored according to the Sharp van der Heijde (SHS) method at baseline and at one, two, five and eight years. At the same time-points Disease Activity Score (DAS28) was calculated and functional disability assessed. Rheumatoid factor (RF) and antibodies against cyclic citrullinated peptides (anti-CCP) were analyzed at baseline.

RESULTS

Sixty-six percent of the patients had hand BMD loss in the first year of RA determined by HBLsdc and 65% by HBLtertiles. Radiographic progression after two, five and eight years was associated with hand bone loss defined by HBLsdc. By HBLtertiles there were significant associations at all time-points except at eight years. The change in DXR at one year (ChDXR1yr) correlated significantly and inversely with the change in SHS (ChSHS) at two, five and eight years. Multivariate analysis showed that only change in SHS during the first year and the presence of anti-CCP were independent predictors of long-term progressive joint damage. If radiographic scores were not included, DXR-BMD loss was an independent predictor. Patients with great bone loss by HBLtertiles had significantly more often high disease activity after two years. However, neither bone loss by HBLsdc or HBLtertiles nor by ChDXR1yr was an independent predictor of remission after two, five and eight years.

CONCLUSIONS

This study confirms previous reports of an association of decrease in DXR-BMD during the first disease year with progression of radiographic joint damage over an extended period of time. This association was independent in a regression model only when radiological findings were excluded suggesting a possible predictive role of DXR-BMD in clinical practice when radiographic evaluation is not available. However, further studies are required before this can be established.

Correlation between hand/wrist and panoramic radiographs in severe secondary hyperparathyroidism

OBJECTIVES

Hand/wrist and dental radiographs are important for osteoporosis analysis in secondary hyperparathyroidism (SHPT). This study evaluated whether a correlation exists between the effects of the disease on the hands and jaws, and investigated the association between osteoporosis progression in the hands and parathyroid hormone (PTH) levels in chronic kidney disease (CKD) patients.

MATERIALS AND METHODS

Four panoramic radiographic parameters (mental index, mandibular cortical index, trabecular bone pattern, and calcification/resorption) and four corresponding hand/wrist radiographic parameters (metacarpal cortical thickness, phalangeal cortical index, trabecular bone pattern, and calcification/resorption) were applied to investigate possible correlation between the effects of SHPT on the jaws and hands/wrists, by Spearman's correlation coefficient. PTH levels and the hand/wrist radiographic parameters were also tested by spearman's correlation coefficient (p < 0.05). The presence of brown tumors, vascular calcifications, and acroosteolysis on the hands was also evaluated.

RESULTS

Mandibular cortical index was strongly correlated with the phalangeal cortical index (p = 0.000). Phalangeal cortical index and trabecular bone pattern of hand/wrist correlated with PTH levels (0.002 and 0.000, respectively). Brown tumors occurred in four CKD patients, while both vascular calcifications and acroosteolysis were observed in 19 patients.

CONCLUSION

There is a significant correlation between the morphological changes caused by secondary hyperparathyroidism in hand and jaw bones. The morphological status can be assessed using the mandibular cortical index, besides the phalangeal cortical index. The latter correlates well with parathyroid hormone levels of advanced chronic kidney disease.

CLINICAL RELEVANCE

Panoramic images reveal morphological changes in the jaw bone, indicating likewise changes in the hand/wrist in severe secondary hyperparathyroidism. The severity of the bone changes may be a reflection of the parathyroid hormone levels in advanced chronic kidney disease.

Growth hormone effects on cortical bone dimensions in young adults with childhood-onset growth hormone deficiency

Growth hormone (GH) treatment in young adults with childhood-onset GH deficiency has beneficial effects on bone mass. The present study shows that cortical bone dimensions also benefit from GH treatment, with endosteal expansion and increased cortical thickness leading to improved bone strength.

INTRODUCTION

In young adults with childhood-onset growth hormone deficiency (CO GHD), GH treatment after final height is reached has been shown to have beneficial effects on spine and hip bone mineral density. The objective of the study was to evaluate the influence of GH on cortical bone dimensions.

METHODS

Patients (n = 160; mean age, 21.2 years; 63% males) with CO GHD were randomised 2:1 to GH or no treatment for 24 months. Cortical bone dimensions were evaluated by digital x-ray radiogrammetry of the metacarpal bones every 6 months.

RESULTS

After 24 months, cortical thickness was increased compared with the controls (6.43%, CI 3.34 to 9.61%; p = 0.0001) and metacarpal index (MCI) (6.14%, CI 3.95 to 8.38%; p < 0.0001), while the endosteal diameter decreased (-4.64%, CI -7.15 to -2.05; p < 0.001). Total bone width did not change significantly (0.68%, CI -1.17 to 2.57%; not significant (NS)). A gender effect was seen on bone width (p < 0.0001), endosteal diameter (p < 0.01) and cortical thickness (p < 0.01), but not with MCI (NS).

CONCLUSIONS

Cortical bone reacts promptly to reinstitution of GH beyond the attainment of final height by increasing the cortical thickness through endosteal bone growth. This leads to a higher peak bone mass and may reduce the risk of cortical bone fragility later in life.

Comparison between amputation-induced demineralization and age-related bone loss using digital X-ray radiogrammetry

Digital X-ray radiogrammetry (DXR) is a computer-assisted automatic osteodensitometric tool. This study was performed to compare DXR measurements between bone changes following amputation trauma and age-related bone loss. Thirty-five men, who had undergone finger amputations, received a baseline examination and 2--3 serial measurements. As a second group, 215 males older than 70yr were enrolled. All patients obtained standardized hand radiographs. The following DXR parameters evaluating metacarpals were considered: cortical bone mineral density (DXR-BMD), cortical thickness (DXR-CT), metacarpal index (DXR-MCI), outer bone diameter (width; DXR-W), and inner medullary diameter (DXR-MD). In the amputation group, the DXR parameters showed an accentuated initial decrease between first and second measurements (DRX-BMD--12.7%, DXR-CT--14.2%, DXR-W--8.6%, DXR-MCI--6.1%; p<0.001) followed by a less pronounced reduction between second and third radiographs (DRX-BMD--0.5%, DXR-CT--1.5%, DXR-W--0.1%, DXR-MCI--1.3%). DXR-MD revealed a reduction of--3.6% (p<0.05) between first and second estimates and a non-significant increase (+1.1%) between second and third measurements. When compared with the second and third estimates in the amputation group, men older than 70yr presented lower DXR-BMD, DXR-CT, and DXR-MCI values (p<0.001), but larger metacarpal outer and inner bone diameters (DXR-W and DXR-MD; p<0.001). DXR-MD of the elderly men group was also more extended when compared with the baseline measurements of the amputation cohort (p<0.001). The early accentuated cortical bone loss and particularly the pronounced decrease of the outer bone width seem to be characteristic for amputation-induced osteoporosis, suggesting that this might be a distinct secondary osteoporosis entity. When compared with amputation-associated osteoporosis, where the bone loss occurs to a higher extent in the outer bone diameter than in the medullary cavity, the age-related bone changes lead more to an increase of the medullary diameter than of the outer bone width.

Long-term in-vitro precision of direct digital X-ray radiogrammetry

OBJECTIVE

Digital X-ray radiogrammetry (DXR) calculates peripheral bone mineral density (BMD) from hand radiographs. The short-term precision for direct DXR has been reported to be highly satisfactory. However, long-term precision for this method has not been examined. Thus, the aim of this study was to examine the long-term in-vitro precision for the new direct digital version of DXR.

MATERIALS AND METHODS

The in-vitro precision for direct DXR was tested with cadaver phantoms on four different X-ray systems at baseline, 3 months, 6 months, and in one machine also at 12 months. At each time point, 31 measurements were performed.

RESULTS

The in-vitro longitudinal precision for the four radiographic systems ranged from 0.22 to 0.43% expressed as coefficient of variation (CV%). The smallest detectable difference (SDD) ranged from 0.0034 to 0.0054 g/cm(2).

CONCLUSIONS

The in vitro long-term precision for direct DXR was comparable to the previous reported short-term in-vitro precision for all tested X-ray systems. These data show that DXR is a stable method for detecting small changes in bone density during 6-12 months of follow-up.

Low bone mineral density in Indian patients with fragility fractures

OBJECTIVE

Low bone mineral density (BMD) is a major risk factor for fragility fractures in osteoporosis. In recent studies, its use with clinical risk factors has been shown to enhance prediction of fragility fractures. The present study was done to assess BMD in Indian patients with fragility fractures using digital X-ray radiogrammetry (DXR-BMD).

METHODS

A total of 228 patients (64 male and 164 female) admitted to an Orthopedic Hospital for management of fragility fracture were recruited. For each patient, DXR-BMD was obtained from an anteroposterior radiograph of the non-dominant hand.

RESULTS

The number of subjects with hip fracture was 104 (40 male, 64 female). Vertebral fractures were seen in 67 patients (11 male, 56 female) and distal radial fracture in 57 patients (13 male, 44 female). The DXR-BMD (g/cm(2)) was significantly lower in subjects with any fragility fracture (0.51 vs. 0.58 in men and 0.41 vs. 0.54 in women). When compared to the age-matched normative reference data by decade, all subjects with fragility fracture had significantly lower DXR-BMD except male subjects in the age decade of 40-49 years.

CONCLUSION

This study confirms lower DXR-BMD in Indian subjects with fragility fractures. This may have a potential role in fracture prediction when used with clinical risk factors in the Indian population.

Bone mineral density by digital X-ray radiogrammetry is strongly decreased and associated with joint destruction in long-standing rheumatoid arthritis: a cross-sectional study

BACKGROUND

The aims were to explore bone mineral density (BMD) by digital X-ray radiogrammetry (DXR) in postmenopausal women with long-lasting rheumatoid arthritis (RA) in relation to dual x-ray absorptiometry (DXA)-BMD, joint destruction by conventional radiographs and disease related variables in a cross-sectional study.

METHODS

Seventy-five postmenopausal women with RA were examined by DXA measuring DXA-BMD of the forearm, total hip and lumbar spine, by scoring joint destruction on plain radiographs by the method of Larsen and by DXR-BMD in metacarpals two to four. The DXR-BMD results of the RA women were compared with an age and sex-matched reference database. A function of DXR-BMD in relation to age and disease duration was created. Associations were investigated by bivariate and multiple linear regression analyses.

RESULTS

DXR-BMD was strongly decreased in RA patients compared to the reference database (p < 0.001). Calculations showed that DXR-BMD was not markedly influenced the first years after diagnosis of RA, but between approximately 5-10 years of disease there was a steep decline in DXR-BMD which subsequently levelled off. In multiple regression analyses disease duration, CRP and DXR-BMD were independent variables associated with Larsen score (R2= 0.64). Larsen score and BMD forearm were independent determinants of DXR-BMD (R2 = 0.79).

CONCLUSIONS

DXR-BMD was strongly reduced and associated with both Larsen score and DXA-BMD forearm in these postmenopausal women with RA implying that DXR-BMD is a technique that reflects both the erosive process and bone loss adjacent to affected joints.

Early changes in bone mineral density measured by digital X-ray radiogrammetry predict up to 20 years radiological outcome in rheumatoid arthritis

INTRODUCTION

Changes in bone mineral density (BMD) in the hand as evaluated by digital X-ray radiogrammetry (DXR) of the second to fourth metacarpal bones has been suggested to predict future joint damage in patients with rheumatoid arthritis (RA). This study's objective was to investigate whether DXR-BMD loss early in the course of the disease predicts the development of joint damage in RA patients followed for up to 20 years.

METHODS

A total of 183 patients (115 women and 68 men) with early RA (mean disease duration, 11 months) included from 1985 to 1989 were followed prospectively (the Lund early RA cohort). Clinical and functional measures were assessed yearly. Joint damage was evaluated according to the Larsen score on radiographs of the hands and feet obtained in years 0 to 5 and years 10, 15 and 20. These radiographs were digitized, and BMD of the second to fourth metacarpal bones was evaluated by DXR. Early DXR-BMD change rate (that is, bone loss) per year calculated from the first two radiographs obtained on average 9 months apart (SD ± 4.8) were available for 135 patients. Mean values of the right and left hand were used.

RESULTS

Mean early DXR-BMD loss during the first year calculated was -0.023 g/cm2 (SD ± 0.025). Patients with marked bone loss, that is, early DXR-BMD loss above the median for the group, had significantly worse progression of joint damage at all examinations during the 20-year period.

CONCLUSIONS

Early DXR-BMD progression rate predicted the development of joint damage evaluated according to Larsen score at year 1 and for up to 20 years in this cohort of early RA patients.

Radiogrammetry and radiographic absorptiometry

Metacarpal morphometry and radiogrammetry are the oldest methods for quantitative assessment of the skeleton. The historical aspects of these measurements are reviewed. Although they were inexpensive and widely available and provided useful research and epidemiologic information, they were labor intensive and imprecise. They were replaced with the current established methods of bone mineral densitometry. With the application of modern computer vision techniques, metacarpal morphometric analysis has been rejuvenated, with improvement in precision and evidence that the method can be applied to studies in adults and children. Evidence for limited normal reference data and the ability to predict future fractures in osteoporosis and reflect activity and predict outcomes in rheumatoid arthritis are presented.

Disease activity and severity in early inflammatory arthritis predict hand cortical bone loss

Objectives. To determine the influence of disease-related variables on hand cortical bone loss in women with early inflammatory arthritis (IA), and whether hand cortical bone mass predicts subsequent joint damage.

Method. Adults aged ≥16 years with recent onset of IA were recruited to the Norfolk Arthritis Register between 1990 and 1998, and followed prospectively. At baseline, patients had their joints examined for swelling and tenderness and had CRP and disease activity 28-joint assessment score (DAS-28) measured. Radiographs of the hands were performed in a subgroup of patients at Year 1 and at follow-up, which were assessed using digital X-ray radiogrammetry (DXR). They were also evaluated for the presence of erosions using Larsen’s method. Linear mixed models were used to investigate whether disease-related factors predicted change in DXR–areal bone mineral density (BMD_a). We also evaluated whether DXR–BMD_a predicted the subsequent occurrence of erosive disease.

Results. Two hundred and four women, mean (s.d.) age 55.1 (14.0) years, were included. Median follow-up between radiographs was 4 years. The mean within-subject change in BMD_a was 0.024 g/cm² equivalent to 1% decline per year. After adjustment for age, height and weight, compared with those within the lower tertile for CRP, those in the upper tertile had greater subsequent loss of bone. This was true also for DAS-28 and Larsen score. Among those without erosions on the initial radiograph (121), DXR–BMD_a at baseline did not predict the new occurrence of erosions.

Conclusion. Increased disease activity and severity are associated with accelerated bone loss. However, lower BMD_a did not predict the new occurrence of erosive disease.

Using hand bone mass measurements to assess progression of rheumatoid arthritis

In rheumatoid arthritis (RA) bone involvement presents as joint erosions in addition to generalized and periarticular osteoporosis. Joint erosions on radiographs of the hands and feet are considered to be the gold standard to evaluate progression of bone and joint damage in RA, even though erosions on radiographs are not used as a marker of early bone involvement. Periarticular bone loss seen on radiographs may be the first sign of bone involvement in RA. Over the last decade there has been an increased awareness of the importance of early aggressive treatment in RA, leading to a need for methods which can identify bone involvement in the early stages of RA. As inflammatory bone loss, especially at the hand, has been shown to occur early in RA, quantitative measures of hand bone loss have been proposed as an outcome measure for the detection of bone involvement. In this review article we present data supporting the hypothesis that both erosions and osteoporosis in RA occur as a result of the same pathophysiological mechanisms activating the osteoclast. Furthermore the role of hand bone loss as an early marker of inflammatory bone involvement, a predictor of subsequent radiographic joint damage and a response variable to anti-inflammatory treatment is discussed.

Hand bone mineral density is associated with both total hip and lumbar spine bone mineral density in post-menopausal women with RA

OBJECTIVE

RA is associated with localized bone loss in the hands, as well as generalized osteoporosis. We evaluated the relationship between hand digital X-ray radiogrammetry BMD (DXR-BMD) and total hip and lumbar spine BMD.

METHODS

We conducted a cross-sectional study of 138 post-menopausal women with RA. The DXR-BMD was calculated based on digitized hand radiographs. Measurements of the total hip and lumbar spine BMD were performed by a DXA-BMD (BMDa) scan. Patient and physician questionnaires and laboratory samples supplied information on relevant covariates. Separate multivariate linear regression models were constructed to determine the cross-sectional relationship between hand DXR-BMD (independent variable) and total hip or lumbar spine BMD (dependent variables).

RESULTS

The cohort comprised women with a median age of 61 years and RA disease duration of 13 years. Seventy-six per cent were either RF and/or anti-cyclic citrullinated peptide (anti-CCP) positive and most had moderate disease activity [median disease activity score-28 joint count (DAS28) 3.7]. Hand DXR-BMD was significantly associated with total hip BMD (beta = 0.61; P < 0.0001) and lumbar spine BMD (beta = 0.62; P < 0.0008) in adjusted models.

CONCLUSIONS

This study suggests that hand DXR-BMD is associated with both the total hip and lumbar spine BMD among post-menopausal women with RA. The relationship between bone loss in the hands and generalized osteoporosis should be further explored in longitudinal studies of patients with RA.

Antibodies to cyclic citrullinated protein and erythrocyte sedimentation rate predict hand bone loss in patients with rheumatoid arthritis of short duration: a longitudinal study

Introduction

Radiographic progression in rheumatoid arthritis (RA) has in several studies been shown to be predicted by serological markers widely used in daily clinical practice. The objective of this longitudinal study was to examine if these serological markers also predict hand bone mineral density (BMD) loss in patients with RA of short disease duration.

Methods

163 patients with RA of short disease duration (2.4 years) were included and followed longitudinally. Antibodies to cyclic citrullinated protein (anti-CCP), rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were analysed from baseline blood-samples. Hand BMD was measured by digital X-ray radiogrammetry (DXR) based on hand and wrist radiographs obtained at baseline and 1, 2 and 5-year follow-up.

Results

During the study period, DXR-BMD decreased by median (inter quartile range) 1.7% (4.1 to 0.4), 2.8% (5.3 to 0.9) and 5.6% (11.7 to 2.3) after 1, 2 and 5 years, respectively. Elevated baseline anti-CCP, RF, ESR and CRP levels were in univariate linear regression analyses consistently associated with DXR-BMD change at all time-points. Anti-CCP and ESR were independently associated with hand DXR-BMD in multivariate linear regression analyses. Elevated anti-CCP levels were consistent and independent predictors of loss in cortical hand bone during the study period, with the odds ratios (95% confidence interval) 2.2 (1.0 to 4.5), 2.6 (1.1 to 6.2) and 4.9 (1.4 to 16.7) for the 1, 2, and 5-year follow-up periods, respectively.

Conclusions

Anti-CCP and ESR were found to be independent predictors of early localised BMD loss. This finding adds to the understanding of anti-CCP and ESR as important predictors of bone involvement in RA.

Adalimumab therapy reduces hand bone loss in early rheumatoid arthritis: explorative analyses from the PREMIER study

OBJECTIVE

The effect of adalimumab on hand osteoporosis was examined and related to radiographic joint damage in the three treatment arms of the PREMIER study: adalimumab plus methotrexate, adalimumab and methotrexate monotherapy. Predictors of hand bone loss were also searched for.

METHODS

768 patients (537 fulfilled 2 years) with rheumatoid arthritis (RA) for less than 3 years, never treated with methotrexate, were included. Hand bone loss was assessed by digital x ray radiogrammetry (DXR) on the same hand radiographs scored with modified Sharp score at baseline, 26, 52 and 104 weeks. For DXR, metacarpal cortical index (MCI) was the primary bone measure.

RESULTS

At all time points the rate of percentage DXR-MCI loss was lowest in the combination group (-1.15; -2.16; -3.03) and greatest in the methotrexate monotherapy group (-1.42; -2.87; -4.62), with figures in between for the adalimumab monotherapy group (-1.33; -2.45; -4.03). Significant differences between the combination group and the methotrexate group were seen at 52 (p = 0.009) and 104 weeks (p<0.001). The order of hand bone loss across the three treatment arms was similar to the order of radiographic progression. Older age, elevated C-reactive protein and non-use of adalimumab were predictors of hand bone loss.

CONCLUSION

This study supports a similar pathogenic mechanism for hand bone loss and erosions in RA. The combination of adalimumab and methotrexate seems to arrest hand bone loss less effectively than radiographic joint damage. Quantitative measures of osteoporosis may thus be a more sensitive tool for assessment of inflammatory bone involvement in RA.

Imaging of metabolic bone diseases

Bone scintigraphy and X-ray are complementary in the assessment of Paget's disease. Whereas bone scintigraphy allows visualization of the whole skeleton and 'hot spots', X-ray enables visualization of more detailed images of the pagetic bone lesion. X-ray may be invaluable in the diagnosis of osteomalacia, especially in children. As osteomalacia is characterized by impaired bone mineralization, the use of bone density measures may lead to misinterpretation of the condition as osteoporosis. Dual-energy X-ray absorptiometry at the femoral neck is the 'gold standard' for the assessment of osteoporosis. However, all devices are useful to predict the risk of fracture. In the future, high-resolution computer tomography and magnetic resonance imaging may become valuable clinical tools, capturing the architectural aspect of bone strength and improving fracture prediction models.

Short-time in vitro and in vivo precision of direct digital X-ray radiogrammetry

Digital X-ray radiogrammetry (DXR) calculates peripheral bone mineral density (BMD) from hand radiographs. The aim of this study was to examine in vitro and in vivo precision for the new direct digital version of DXR, a development of the conventional DXR. The in vitro precision for direct DXR was tested on 4 different X-ray equipment, based on 31 radiographs of the same phantom. The in vivo precision was based on duplicate hand radiographs from both hands in 39 individuals. For the 4 X-ray equipment, in vitro precision ranged from 0.14% to 0.30%, expressed as coefficient of variations (CV%) and from 0.0012 to 0.0028 g/cm2, expressed as smallest detectable difference (SDD). The precision was correlated to the resolution of the radiographic equipment (r=0.95, p=0.05). The corresponding values for the in vivo precision for mean values of both hands were: CV%=0.46%; SDD=0.0046 g/cm2, and least significant change (LSC%)=1.28%. The DXR-BMD for 1 of the X-ray equipment differed 1.1% from the overall mean. The precision for direct DXR was highly satisfactory both in vitro and in vivo. DXR-BMD values may differ between the radiographic equipment, and follow-up measurements should be performed with the same X-ray equipment.

Hand bone loss as an outcome measure in established rheumatoid arthritis: 2-year observational study comparing cortical and total bone loss

The aim of this 2-year longitudinal observational study was to explore hand bone loss as a disease outcome measure in established rheumatoid arthritis (RA). A cohort of 215 patients with RA (170 women and 45 men, aged 20-70 years) were recruited from the Oslo RA registry and studied for changes in hand bone mass during a 2-year follow-up. Digital X-ray radiogrammetry (DXR) was used to measure cortical hand bone mineral density (BMD) and metacarpal cortical index, whereas dual-energy X-ray absorptiometry (DXA) was used to assess whole hand BMD, which measures total cortical and trabecular bone. DXA-BMD total hip and spine and informative data for disease and therapy were also collected. Hand bone loss could be revealed over a 2-year follow-up measured by DXR-BMD (-0.90%, P < 0.01), but not by DXA-BMD (0.00%, P = 0.87). DXA-BMD hand bone loss was only observed in patients with disease duration < or = 3 years and not in patients with longer disease duration (-0.96% versus 0.24%, P < 0.01), whereas loss of DXR-BMD was independent of disease duration. Disease activity (measured by the disease activity score including 28 joints) independently predicted loss of DXR-BMD but not changes in the DXA-BMD hand in the multivariate analysis. The change in DXR metacarpal cortical index was highly correlated to DXR-BMD (r = 0.94, P < 0.001). These data suggest that DXR-BMD may be a more appropriate technique to identify RA-related bone involvement in hands compared with DXA-BMD measurement, but further studies are needed to explore this hypothesis.

Low bone mineral density is associated with reduced hip joint space width in women: results from the Copenhagen Osteoarthritis Study

OBJECTIVE

Since estrogen receptors (ER-alpha/ER-beta) were identified in human chondrocytes, animal and experimental studies have demonstrated the importance of continued estrogen production for the integrity of articular cartilage. However, human epidemiological support of the hypothesis has been inconclusive. The present cross-sectional study investigated the relationship between reduced bone mineral density (BMD), as a surrogate parameter of endogenous estrogen status assessed by digital x-ray radiogrammetry, and reduced minimum hip joint space width (JSW).

DESIGN

Standardized hand radiographs of the Copenhagen Osteoarthritis Study cohort of 3,913 adults (1,470 male/2,443 female) with a mean age of 60 years (range, 18-92) were analyzed using X-Posure digital software, version 2.0 (Sectra-Pronosco). The system is operator independent. From 1,200 individual measurements per radiograph, mean BMD was calculated. Minimum hip JSW was assessed on standardized pelvic radiographs.

RESULTS

Digital x-ray radiogrammetry BMD decreased in both men and women after the age of 45 years, progressively more so in women. Although minimum hip JSW in men remained relatively unaltered throughout life, a marked decline in female minimum hip JSW after age 45 years was observed. We found moderate but highly significant relationships between reduced BMD and reduced hip JSW in women (P < 0.0001), adjusted for age and dysplastic joint incongruity.

CONCLUSION

We believe that the present study supports the hypothetical relationship between reduced estrogen levels and hip JSW reduction in women.

Reproducibility of metacarpophalangeal bone mass measurements obtained by dual-energy X-ray absorptiometry in healthy volunteers and patients with early arthritis

The prognostic value of measuring hand bone mineral density (BMD) in patients with early arthritis (EA) has been recently assessed. In this work, we evaluate the reproducibility of measuring juxta-articular BMD by dual-energy X-ray absorptiometry (DXA) at the second to fifth metacarpophalangeal (MCP) joints. We obtained whole hand (WH) and MCP joint BMD measurements from 16 healthy subjects and from 22 patients with EA. The coefficient of variation, intraclass correlation coefficient (ICC), and smallest detectable difference (SDD) were calculated. The coefficient of variation ranged from 1.3% to 0.7% at MCP joints and from 1.4% to 0.9% in the WH measurements, respectively. The intra- and interobserver ICC for both WH and MCP joints ranged from 0.97 to 0.99. The SDD at the different anatomical locations analyzed ranged from 0.006 to 0.022 g/cm2 in healthy controls and from 0.005 to 0.010 g/cm2 in EA. Interestingly, patients who fulfilled rheumatoid arthritis criteria showed a lower bone mass than those with undifferentiated arthritis. Therefore, BMD measurements obtained by DXA at MCP joints were reproducible and it might be useful in the study of patients with EA.

Digital X-ray radiogrammetry better identifies osteoarthritis patients with a low bone mineral density than quantitative ultrasound

This study assessed the ability of quantitative ultrasound (QUS) and digital X-ray radiogrammetry (DXR) to identify osteopenia and osteoporosis in patients with knee osteoarthritis (OA). One hundred and sixty-one patients with painful knee OA (81 men, 80 women; age 62.6+/-9.2 years, range 40-82 years) were included in this cross-sectional study and underwent dual-energy X-ray absorptiometry (DXA) of both hips and the lumbar spine, QUS of the phalanges and calcanei of both hands and heels, and DXR using radiographs of both hands. Unpaired t-test, Mann-Whitney U test, ROC analysis and Spearman's rank correlation were used for comparisons and correlation of methods. Using DXA as the reference standard, we defined a low bone mineral density (BMD) as a T-score < or =-1.0 at the lumbar spine or proximal femur. In contrast to phalangeal or calcaneal QUS, DXR was able to discriminate patients with a low BMD at the lumbar spine (p<0.0001) or hips (p<0.0001). ROC analysis showed that DXR had an acceptable predictive power in identifying OA patients a low hip BMD (sensitivity 70%, specificity 71%). Therefore, DXR used as a screening tool could help in identifying patients with knee OA for DXA.

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.

Digital x-ray radiogrammetry identifies women at risk of osteoporotic fracture: results from a prospective study

Using digital X-ray radiogrammetry (DXR) on hand radiographs from a large population-based study, 1,370 postmenopausal women were evaluated in a prospective fashion; fracture occurrence was compared with DXR measurements of historic radiographs. Further, the aim of the study was to evaluate factors affecting DXR bone mineral density (BMD) in this cohort. The study is based on data from a subgroup of women participating in the third Copenhagen City Heart Study and additional data from a questionnaire obtained in 1999. The mean follow-up time was 6.1 years. During the observation period, 245 women suffered a fracture. Odds ratios (ORs) per 1 standard deviation decline in DXR-BMD were statistically significant for fracture in the groups of wrist fractures, proximal humerus fractures, vertebral fractures, and other fractures as well as in the total fracture group. In the hip fracture group, the P value almost reached significance (0.052). The highest ORs (2.4) were found in the group with proximal humerus fractures and in the vertebral fracture group (2.0). In the wrist fracture and hip fracture groups, ORs were 1.7 and 1.4, respectively. The group with other fractures had an OR of 1.7, and the OR in the entire fracture group was 1.6. Age, fracture, and smoking were negatively correlated with DXR-BMD, whereas BMI, age at menopause, hormone replacement therapy, and physical fitness and muscle strength were positively correlated with DXR-BMD. In conclusion, BMD estimated by DXR of the metacarpals predicts later osteoporotic fracture and seems to provide meaningful information on bone mass in epidemiological studies, where DXA measurements are not available.

The potential of digital X-ray radiogrammetry (DXR) in the assessment of osteopenia in children with chronic inflammatory bowel disease

BACKGROUND

Loss of bone mass is a known complication of chronic inflammatory bowel disease (IBD) in children. The gold standard in the evaluation of bone mineral density (BMD) is dual energy X-ray absorptiometry (DXA).

OBJECTIVE

In this preliminary study we evaluated digital X-ray radiogrammetry (DXR) which estimates BMD (DXR-BMD) from hand radiographs in children with IBD.

MATERIALS AND METHODS

A total of 26 children with IBD (10 girls, 16 boys; age range 10-18 years) underwent DXR for the calculation of DXR-BMD and metacarpal index (DXR-MCI) using the Pronosco X-posure system. The results were compared with a local reference database and correlated with the results of DXA.

RESULTS

DXR-BMD was 0.36-0.56 g/cm(2) (median 0.46 g/cm(2)) in Crohn disease patients and 0.38-0.63 g/cm(2) (median 0.48 g/cm(2)) in ulcerative colitis patients. DXR-MCI was 0.29-0.49 in Crohn disease patients and 0.28-0.53 in ulcerative colitis patients. The Z-scores were reduced to <-1 SD in five Crohn disease patients and in six ulcerative colitis patients. The coefficients (r) for the correlations between DXR-BMD and DXA-BMD were 0.78 for the lumbar spine and 0.61 for the proximal femur (P<0.01), and between DXR-MCI and DXA-BMD were 0.78 for the lumbar spine and 0.51 for the proximal femur (P<0.01).

CONCLUSIONS

DXR seems to be able to estimate cortical osteopenia in children with chronic IBD. The DXR results showed a positive correlation with DXA results.

Evaluation of bone mineral density, bone metabolism, osteoprotegerin and receptor activator of the NFkappaB ligand serum levels during treatment with infliximab in patients with rheumatoid arthritis

OBJECTIVES

To examine whether treatment with anti-tumour necrosis factor (TNF) alpha prevents loss of bone mineral density (BMD) at the spine and hip (generalised) and in the hands (local) of patients with rheumatoid arthritis, and to study the changes in markers of bone metabolism, including receptor activator of the NFkappaB ligand (RANKL) and osteoprotegerin (OPG), during anti-TNF treatment.

PATIENTS AND METHODS

102 patients with active rheumatoid arthritis, who were treated with infliximab during 1 year, were included in this open cohort study. The BMD of the spine and hip (dual x ray absorptiometry) and hands dual x ray radiogrammetry was measured before the start of treatment and after 1 year. Changes in osteocalcin formation, beta-isomerised carboxy terminal telopeptide of type 1 collagen (beta-CTx, resorption), RANKL and OPG were determined at 0, 14, 30 and 46 weeks.

RESULTS

The BMD of the spine and hip was unchanged during treatment with infliximab, whereas BMD of the hand decreased significantly by 0.8% (p<0.01). The BMD of the hip in patients with a good European League Against Rheumatism response showed a favourable change compared with patients not achieving such a response. Serum beta-CTx and RANKL were both considerably decreased compared with baseline at all time points. The decrease in beta-CTx was associated with the decrease in Disease Activity Score of 28 joints and C reactive protein during the 0-14 weeks interval.

CONCLUSION

In patients with rheumatoid arthritis treated with infliximab, spine and hip bone loss is arrested, whereas metacarpal cortical hand bone loss is not stopped. The outcome of the study also supports a relationship between clinical response, in terms of reduced inflammatory activity, and changes in bone loss of the spine, hip and hands.

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.

Value of dual-energy x-ray absorptiometry as a diagnostic and assessment tool in early rheumatoid arthritis

New research has revealed common pathophysiologic and cellular mechanisms behind the development of osteoporosis and joint damage in rheumatoid arthritis (RA). Because osteoporosis is a direct consequence of the inflammatory disease process, bone mass measurements in principle could be an outcome marker of inflammation, of damage, and of response to therapeutic intervention. Several devices have been developed for quantitative bone mass assessment including dual energy x-ray absorptiometry (DXA), which is considered the reference standard. This article based on current data and understanding discusses the use of DXA as a diagnostic and assessment tool especially in early RA.

CAD for mammography: the technique, results, current role and further developments

CAD systems, developed to assist the radiologist in the detection of suspicious lesions on mammograms, are currently controversially discussed. The highly sensitive detection of malignant structures including priors by CAD is linked with a low specific performance and a high rate of falsely positive markings. This causes controversial results regarding the effect of CAD systems for the diagnosing radiologist. This review aims to give an overview of the current literature, to state the currently discussed controversial results of CAD and to give an outlook on the next developments, which are not limited to senology, but include many other applications of CAD systems in radiology.

Peripheral bone status in rheumatoid arthritis evaluated by digital X-ray radiogrammetry and compared with multisite quantitative ultrasound

The development of secondary osteoporosis in rheumatoid arthritis (RA) has recently become well recognized, characterized by demineralization at axial and in particular periarticular peripheral bone sites. Our aim was to evaluate multisite quantitative ultrasound (QUS) compared to digital X-ray radiogrammetry (DXR) by the quantification of cortical bone loss dependent on the severity of RA. Fifty-three patients with verified RA underwent QUS measurements (Sunlight Omnisense 7000) with estimation of the speed of sound (QUS-SOS) at the distal radius and at the phalanx of the third digit. Also, bone mineral density (DXR-BMD) and metacarpal index (DXR-MCI) were estimated on metacarpals II-IV using DXR technology. Additionally, Larsen score and Steinbroker stage were assessed. Disease activity of RA was estimated by disease activity score 28 (DAS 28). For the group with minor disease activity (3.2 <or= DAS <or= 5.1), QUS-SOS (phalanx) showed a significant association to DXR-BMD (R = 0.66) and DXR-MCI (R = 0.52). In the case of accentuated disease activity (DAS > 5.1), QUS-SOS of the radius revealed a significant correlation to DXR-BMD (R = 0.71) and DXR-MCI (R = 0.84), whereas for QUS-SOS (phalanx) no significant association to the DXR parameters was shown. The DXR parameters and, to a lesser extent, the QUS data also demonstrated pronounced declines in the case of accentuated disease activity (DAS > 5.1). Both DXR-BMD (-25.9 %, P < 0.01) and DXR-MCI (-38.6 %, P < 0.01) revealed a notable reduction dependent on the severity of RA. Otherwise, QUS-SOS marginally decreased, with -2.6% (radius) and -3.9% (phalanx). DXR revealed a significant reduction of DXR-BMD as well as DXR-MCI dependent on the severity of RA and surpassed multisite QUS as a promising diagnostic tool.

Anti-resorptive therapy for the prevention of postmenopausal osteoporosis : when should treatment begin?

Osteoporosis is a condition associated with decreased bone strength and an increased fracture risk. It may be defined based on bone mineral density (BMD) with a T-score at the hip or spine of less than -2.5 standard deviations in young healthy individuals or from an osteoporotic fracture (i.e. a fracture occurring after low-energy trauma or no apparent trauma). Risk factors predisposing to fractures include: increasing age; female gender; low BMD; a prior fragility fracture; a family history of fragility fractures; low bodyweight; lack of estrogen in women (i.e. post menopause); corticosteroid use; smoking; a number of diseases; deficiency in calcium and vitamin D; an increased risk of falls (i.e. impaired vision); immobilization; and Caucasian race. The more risk factors that are present the higher the risk of fractures over the following 10 years. The need to initiate preventive therapy with anti-osteoporotic treatment increases steeply with the absolute fracture risk. Indications for referral for dual energy x-ray absorptiometry measurement of BMD include: age >65 years; age <65 years in postmenopausal women with any of the risk factors already mentioned; premature menopause (<45 years); prolonged amenorrhea (>1 year) in younger women; fragility fractures; and diseases or conditions known to lead to osteoporosis.Anti-resorptive therapies include calcium plus vitamin D, bisphosphonates (alendronate, etidronate, risedronate, ibandronate), selective estrogen receptor modulators (raloxifene), hormone replacement therapy, and calcitonin. Guidelines from several countries on when to initiate anti-resorptive therapy state that therapy may be started in patients with a prior fragility fracture (some guidelines state that in this situation no BMD measurements are necessary) or in patients with a T-score of less than -2.5 (some guidelines state that additional risk factors need to be present in this situation). Some guidelines state that anti-resorptive therapy may be initiated in patients with a T-score in the osteopenic range (from -1 to -2.5, i.e. not frank osteoporosis) in the presence of other risk factors. The cost effectiveness of anti-resorptive therapy increases with the absolute fracture risk. In some scenarios, treatment with bisphosphonates may be cost effective in a 50-year-old woman with an absolute hip fracture risk of >or=1.1% over the next 10 years.

Metacarpal index and bone mineral density in healthy African-American women

Bone mineral density (BMD) reference data of non-Caucasian women is scarce but greatly needed for African-American women. The objective of this study was to establish a metacarpal normative reference database for African-American women using digital X-ray radiogrammetry (DXR) and hand radiographs and compare these values to existing Caucasian data. Two hundred and fifty healthy African-American women between the ages of 20 and 79 years old, 14 of whom were excluded, were recruited to participate from four different clinical sites. The study population was recruited in approximately equal number into the following groups: 20-29, 30-39, 40-49, 50-59, 60-69 and 70-79 years of age. A radiograph was acquired of each subject's non-dominant hand. The radiographs were scanned and analyzed using radiogrammetric techniques, and the BMD, MCI (Metacarpal Index), bone width and cortical thickness were calculated. The regression curve that best fit the data was a second order polynomial. The BMD and MCI of young adult women (20-40 years of age) were used to calculate T-score parameters. The young reference BMD and MCI with their associated standard deviations were found to be 0.6045 g/cm2+/-0.0529 g/cm2 and 0.5096 and 0.0792, respectively. However, the MCI was found to be approximately 2.5% lower (-0.0118) compared to Caucasian women. The African-American metacarpal BMD was found to be 3.5% (0.0207 g/cm2) higher across all ages when compared to existing Caucasian reference data acquired in a similar way. The differences were found to be entirely due to larger bone size, cortical diameter and bone width in the African-American women.

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.