Ultrasound velocity through the cortex of phalanges, radius, and tibia in normal and osteoporotic postmenopausal women using a new multisite quantitative ultrasound device

Quantitative Ultrasound (QUS) in the Management of Osteoporosis and Assessment of Fracture Risk: An Update

Quantitative ultrasound (QUS) presents a low cost and readily available alternative to DXA measurements of bone mineral density (BMD) for osteoporotic fracture risk assessment. It is performed in a variety of skeletal sites, among which the most widely investigated and clinically used are first the calcaneus and then the radius. Nevertheless, there is still uncertainty in the incorporation of QUS in the clinical management of osteoporosis as the level of clinical validation differs substantially upon the QUS models available. In fact, results from a given QUS device can unlikely be extrapolated to another one, given the technological differences between QUS devices. The use of QUS in clinical routine to identify individuals at low or high risk of fracture could be considered primarily when central DXA is not easily available. In this later case, it is recommended that QUS bone parameters are used in combination with established clinical risk factors for fracture. Currently, stand-alone QUS is not recommended for treatment initiation decision making or follow-up. As WHO classification of osteoporosis thresholds cannot apply to QUS, thresholds specific for given QUS devices and parameters need to be determined and cross-validated widely to have a well-defined and certain use of QUS in osteoporosis clinical workflow. Despite the acknowledged current clinical limitations for QUS to be used more widely in daily routine, substantial progresses have been made and new results are promising.

Urine and Serum Electrolytes and Biochemical Values Associated with Osteoporosis in Premenopausal and Postmenopausal Women: A Longitudinal and Cross-Sectional Study Using Korean Genome and Epidemiology Study (KoGES) Cohort

Osteoporosis is a major public health concern, especially in women. This study aims to identify early biomarkers from biochemical measurements of serum and urine for recognizing the development of osteoporosis and osteopenia in premenopausal and postmenopausal women. From the Korean Genome and Epidemiology Study (KoGES) cohort, longitudinal study participants with normal bone density were enrolled and assessed for the association of baseline clinical and biochemical factors with osteoporosis development over 4 years. In addition, a cross-sectional study between normal bone density and osteopenia/osteoporosis was conducted to validate the risk factors found in the longitudinal cohort. Of the 5272 female participants in the KoGES cohort, 813 women (501 premenopausal and 312 menopausal) who had normal bone density at baseline were included in the longitudinal study. During the 4 years of follow-up, 64 patients developed osteoporosis and 354 developed osteopenia. In a multivariate logistic regression analysis, serum calcium and urine uric acid levels were significantly associated with elevated osteoporosis risk in premenopausal and postmenopausal women, respectively (risk of osteoporosis by serum calcium levels in premenopausal women: 4.03 (1.09–14.93), p = 0.037; risk of osteoporosis by urine uric acid levels in postmenopausal women: 24.08 (1.79–323.69), p = 0.016). For the cross-sectional study, serum and urine parameters were compared between women with osteopenia or osteoporosis at baseline and those with normal bone density. Urine uric acid levels were found to be significantly higher in both premenopausal and postmenopausal women with bone loss than in women with normal bone density (p < 0.001 and p = 0.004, respectively). Uric acid level in urine may be an early marker for the development of osteoporosis in women, especially after menopause.

Serum Spermidine as a Novel Potential Predictor for Fragility Fractures

CONTEXT

Metabolomics is an emerging tool that provides insights into the dynamics of phenotypic changes. It is a potential method for the discovery of novel serum markers of fracture.

OBJECTIVE

To identify metabolite parameters that can be used as a proxy for osteoporotic fracture risk.

DESIGN

Prospective study based on the Ansung cohort in Korea.

SETTING

The general community.

PARTICIPANTS

A total of 1504 participants with metabolomic analyses.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

Fragility fractures.

RESULTS

We measured 135 baseline metabolite profiles in fasting serum of the participants. The participants had a mean age of 60.2 years and were comprised of 585 (38.9%) men. During a mean 9-year follow-up, 112 osteoporotic fracture events occurred. Of all metabolites measured, only serum spermidine concentrations were positively associated with the risk of fracture (hazard ratio [HR] per 1 μM of spermidine 1.35, 95% confidence interval [CI] = 1.03-1.65, P = 0.020) after adjusting for age, sex, body mass index, diabetes, hypertension, smoking status, previous fracture history, and baseline tibial quantitative ultrasound. Participants with spermidine concentrations >1.57 μM had a 2.2-fold higher risk of fractures (95% CI 1.08-4.51, P = 0.030) compared with those with concentrations ≤1.57 μM after adjustment. In a subgroup analysis, women with baseline spermidine concentrations >1.57 μM also had a 2.4-fold higher risk of fracture than those with concentrations ≤1.57 μM (95% CI 1.02-5.48, P = 0.047).

CONCLUSIONS

Increased baseline spermidine concentrations were associated with a risk of osteoporotic fracture during a mean 9-year follow-up. The biological significance of the metabolites in the musculoskeletal system could be a subject for future studies.

Defining disease progression in Chinese mainland people: Association between bone mineral density and knee osteoarthritis

Objective

To evaluate change in bone mineral density (BMD) during development of knee osteoarthritis (OA) in elderly Chinese community residents. Further, to monitor disease progression by recording speed of sound (SOS), one parameter of BMD provided by quantitative ultrasound measurement.

Methods

A total of 4173 community residents of the Chinese mainland were organized to complete questionnaires and relevant measurements, including anthropometry, radiology and quantitative ultrasound (QUS). SOS measurements of the distal radius were acquired using QUS measurements. The Kellgren-Lawrence (KL) grade of knee OA was evaluated by two experienced radiographers using X-rays. Finally, a general linear models analysis was performed to determine potential relationships. Further, the area under the receiver operating characteristic curve (ROC AUC) was applied to assess the distinction model.

Results

The SOS score in the OA group was significantly lower than that in the control group (p ​< ​0.001). However, after adjustment for age and body mass index (BMI), no significant difference was observed in the male population (p ​＝ ​0.841), while a significantly lower SOS score presented in knee OA participants in the female population (p ​＝ ​0.033). A turning point in SOS scores, from increasing to decreasing trends, occurred around KL grade 2; the SOS score gradually increased with progression in participants from KL grades 0 to 2, whereas the SOS score presented a significant decrease in participants with KL grades 3 and 4. The AUC for the model to distinguish OA progression was 0.891.

Conclusion

There was a non-linear and stage-specific association between SOS score and knee OA, which presented a positive relationship in early stages, but a negative relationship in advanced stages. A decline of SOS score in knee OA patients in early stages should alert clinicians to the possibility of disease progression.

The Translational potential of this article

In the present study, the relationship between OA and BMD had established by SOS. The results suggested that close monitoring of SOS in elderly Chinese communities residents with knee OA could alert disease progression involvement by an easily accessible method, and help early referral to orthopedist consultation for further examination and treatment.

Change in Quantitative Ultrasound-assessed Speed of Sound as a Function of Age in Women and Men and Association With the Use of Antiresorptive Agents: The Canadian Multicentre Osteoporosis Study

INTRODUCTION

Five-year changes in multisite quantitative ultrasound-assessed speed of sound (SOS in m/s) were studied in a cohort of women and men. The impacts of antiresorptive therapies and menopausal status on SOS were also assessed.

METHODOLOGY

Two SOS assessments, clinical assessments, and comprehensive questionnaires were completed 5 years apart on 509 women and 211 men. Age at first assessment was grouped into: <40 yr, 40-49 yr, 50-59 yr, 60-69 yr, 70-79 yr and 80+ yr. Mean rate of change in SOS at the distal radius and tibia were calculated for each age grouping by sex. SOS changes were stratified by antiresorptive use (yes, no) or menopausal status (premenopausal, postmenopausal, or bilateral oophorectomy).

RESULTS

Mean losses in SOS occurred over the 5 years in almost all age groupings. In women, mean losses in SOS for the <40 yr, 40-49 yr, 50-59 yr, 60-69 yr, 70-79 yr, and 80+ yr age groupings were -59, -83, -107, -92, -80 and -66 (p = 0.30; differences among age groupings) at the radius and -18, -16, -54, -1, -9 and 31 at the tibia (p < 0.05), respectively. In men, mean SOS losses were -101, -56, -69, -67, -83 and -127 at the radius (p = 0.61) and -46, -61, 0, -35, -29, and -26 at the tibia (p = 0.23). At the tibia, women prescribed antiresorptives had a mean increase in SOS (8.6 m/s) whereas untreated participants had a mean loss (-23.0; p < 0.001); there was no significant impact at the distal radius. There were no significant differences in change in SOS among menopausal groups (p > 0.26).

CONCLUSIONS

Mean SOS generally declined over 5 years in all age groupings of both sexes. The consistent mean losses in SOS over the age spans investigated are coincident with increasing fracture risk. Women on antiresorptive therapy had increased mean SOS over the 5-year assessment period at the tibia, whereas untreated women had mean losses in SOS.

The relationship between platelet count and bone mineral density: results from two independent population-based studies

In two population-based study of middle-aged and older people, we investigated if platelet count was associated with bone mineral density and determined whether the association remained over time. Highest platelet counts within the normal range are significantly associated with osteopenia and osteoporosis in middle-aged and elderly people.

PURPOSE

Recently, platelets were found to play a role in bone remodeling. However, data on the association between platelet count and osteoporosis are lacking. Our study aimed to investigate the association between platelet counts, osteopenia, and osteoporosis in middle-aged and elderly Koreans.

METHODS

We analyzed cross-sectional data from 5181 adults (postmenopausal women and men over 50 years of age) in the 2008-2011 Korea National Health and Nutrition Examination Survey (KNHANES) and longitudinal prospective data from 3312 adults over 50 years of age in the Korean Genome and Epidemiology Study (KoGES). Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry in the KNHANES and quantitative ultrasound in the KoGES. The platelet counts were categorized into quintiles within normal ranges (150-450 × 10³ μL). The associations between platelet counts, osteopenia, and osteoporosis were estimated using a multinomial logistic model.

RESULTS

BMD of the femur neck, total femur, and lumbar spine all decreased with increasing platelet counts. The cut-off points of the platelet counts to differentiate normal BMD from osteopenia and osteopenia from osteoporosis were 217 × 10³/μL and 269 × 10³/μL, respectively. The odds ratios (95% confidence intervals) in the highest platelet quartile were 1.39 (1.03-1.88) for osteopenia and 1.60 (1.07-2.37) for osteoporosis after adjusting for confounding factors. The distal radius T-score was significantly decreased in the highest platelet tertile group at a follow-up of 10 years.

CONCLUSION

Highest platelet counts within the normal range are significantly associated with osteopenia and osteoporosis in middle-aged and elderly people.

High dairy products intake reduces osteoporosis risk in Korean postmenopausal women: A 4 year follow-up study

BACKGROUND/OBJECTIVES

The aim of this study was to identify the effect of dairy products, milk and yogurt on osteoporosis incidence among Korean postmenopausal women using prospective cohort data.

MATERIALS/METHODS

Between 2001 and 2003, 10,038 participants were recruited in rural and urban areas for a baseline examination of a community-based cohort study. Of those, 1,573 postmenopausal women (aged 40–69 years at baseline) were eligible for the present study. Intakes of dairy products, milk, and yogurt were assessed using a validated semi-quantitative food frequency questionnaire. The speed of sound at the radius and tibia were measured using a quantitative ultrasound device and osteoporosis was defined based on the WHO criteria (T-score ≤ −2.5).

RESULTS

During the 4-years follow-up study, the cumulative incidence of osteoporosis was 18.4% (273 cases) in the radius and 33.6% (407 cases) in the tibia. The subjects with higher frequency of dairy product consumption showed a decreased risk of radius osteoporosis after adjusting for potential confounders [hazard ratio (HR) = 0.51, 95% confidence interval (CI): 0.33–0.80 for >1 time/day vs. non consumer; P for trend = 0.0027]. Similarly, high frequency of milk and yogurt consumption had a protective effect on radius osteoporosis risk [milk: HR = 0.60, 95% CI: 0.42–0.87 for > 5–6 times/week vs. non consumer (P for trend = 0.0130), yogurt: HR = 0.51, 95% CI: 0.30–0.85 for > 5–6 times/week vs. non consumer (P for trend = 0.0167)]. However, high dairy products consumption was not related with tibia osteoporosis.

CONCLUSIONS

This study suggests that daily intake of dairy products could potentially reduce radius osteoporosis incidence among Korean postmenopausal women.

Quantitative Ultrasound (QUS) in the Management of Osteoporosis and Assessment of Fracture Risk

The use of quantitative ultrasound (QUS) for a variety of skeletal sites, associated with the absence of technology-specific guidelines, has created uncertainty with respect to the application of QUS results to the management of individual patients in clinical practice. However, when prospectively validated (this is not the case for all QUS devices and skeletal sites), QUS is a proven, low-cost, and readily accessible alternative to dual-energy X-ray absorptiometry (DXA) measurements of bone mineral density (BMD) for the assessment of fracture risk. Indeed, the clinical use of QUS to identify subjects at low or high risk of osteoporotic fracture should be considered when central DXA is unavailable. Furthermore, the use of QUS in conjunction with clinical risk factors (CRF),allows for the identification of subjects who have a low and high probability of osteoporotic fracture. Device- and parameter-specific thresholds should be developed and cross-validated to confirm the concurrent use of QUS and CRF for the institution of pharmacological therapy and monitoring therapy.

Comparison of Speed of Sound Measures Assessed by Multisite Quantitative Ultrasound to Bone Mineral Density Measures Assessed by Dual-Energy X-Ray Absorptiometry in a Large Canadian Cohort: the Canadian Multicentre Osteoporosis Study (CaMos)

Dual-energy X-ray absorptiometry (DXA) is an important tool for the estimate of fracture risk through the measurement of bone mineral density (BMD). Similarly, multisite quantitate ultrasound can prospectively predict future fracture through the measurement of speed of sound (SOS). This investigation compared BMD (at the femoral neck, total hip, and lumbar spine) and SOS measures (at the distal radius, tibia, and phalanx sites) in a large sample of randomly-selected and community-based individuals from the Canadian Multicentre Osteoporosis Study. Furthermore, mass, height, and age were also compared with both measures. There were 4123 patients included with an age range of 30-96.8 yr. Pearson product moment correlations between BMD and SOS measures were low (0.21-0.29; all p<0.001), irrespective of site. Mass was moderately correlated with BMD measures (0.40-0.58; p<0.001), but lowly correlated with SOS measures (0.03-0.13; p<0.05). BMD and SOS were negatively correlated to age (-0.17 to -0.44; p<0.001). When regression analyses were performed to predict SOS measures at the 3 sites, the models predicted 20%-23% of the variance, leaving 77%-80% unaccounted for. The SOS measures in this study were found to be largely independent from BMD measures. In areas with no or limited access to DXA, the multisite quantitative ultrasound may act as a valuable tool to assess fracture risk. In locales with liberal access to DXA, the addition of SOS to BMD and other clinical risk factors may improve the identification of those patients at high risk for future fracture.

Normative data for multisite quantitative ultrasound: the Canadian Multicenter Osteoporosis Study

Multisite quantitative ultrasound (mQUS) machines are attractive tools for assessing fragility fracture risk as they are often portable, comparatively inexpensive, require little training for their use, and emit no ionizing radiation. The primary objective of this investigation was to generate an mQUS normative database of speed of sound (SOS, in m/s) measures from a large sample of randomly selected community-based individuals. mQUS (BeamMed Omnisense MultiSite Quantitative Ultrasound 7000 S) measurements were obtained and assessed at the distal radius, tibia, and phalanx. All analyses were made separately for men and women and for each anatomical site. Scatterplots (SOS vs age) identified 30-39 yr of age as periods of both maximal SOS and of relative stability for all 3 sites over the age span investigated (30-96 yr of age; 2948 women and 1176 men) and, thus, was used as the "reference" population. For cross-sectional comparison of trends over aging, a number of age groupings were created: 30-39, 40-49, 50-59, 60-69, 70-79, and 80+ yr. In general, there were decreases in SOS over increasing age groupings. The normative data generated can be used to compare a given patient's mQUS measurement with reference to a young, healthy population, assigning them a gender-appropriate T-score.

Association between low-frequency ultrasound and hip fractures -- comparison with DXA-based BMD

BACKGROUND

New methods for diagnosing osteoporosis and evaluating fracture risk are being developed. We aim to study the association between low-frequency (LF) axial transmission ultrasound and hip fracture risk in a population-based sample of older women.

METHODS

The study population consisted of 490 community-dwelling women (78-82 years). Ultrasound velocity (V(LF)) at mid-tibia was measured in 2006 using a low-frequency scanning axial transmission device. Bone mineral density (BMD) at proximal femur measured using dual-energy x-ray absorptiometry (DXA) was used as the reference method. The fracture history of the participants was collected from December 1997 until the end of 2010. Lifestyle-related risk factors and mobility were assessed at 1997.

RESULTS

During the total follow-up period (1997-2010), 130 women had one or more fractures, and 20 of them had a hip fracture. Low V(LF) (the lowest quartile) was associated with increased hip fracture risk when compared with V(LF) in the normal range (Odds ratio, OR = 3.3, 95% confidence interval (CI) 1.3-8.4). However, V(LF) was not related to fracture risk when all bone sites were considered. Osteoporotic femoral neck BMD was associated with higher risk of a hip fracture (OR = 4.1, 95% CI 1.6-10.5) and higher risk of any fracture (OR = 2.4, 95% CI 1.6-3.8) compared to the non-osteoporotic femoral neck BMD. Decreased VLF remained a significant risk factor for hip fracture when combined with lifestyle-related risk factors (OR = 3.3, 95% CI 1.2-9.0).

CONCLUSION

Low V(LF) was associated with hip fracture risk in older women even when combined with lifestyle-related risk factors. Further development of the method is needed to improve the measurement precision and to confirm the results.

Prediction of trabecular bone qualitative properties using scanning quantitative ultrasound

Microgravity induced bone loss represents a critical health problem in astronauts, particularly occurred in weight-supporting skeleton, which leads to osteopenia and increase of fracture risk. Lack of suitable evaluation modality makes it difficult for monitoring skeletal status in long term space mission and increases potential risk of complication. Such disuse osteopenia and osteoporosis compromise trabecular bone density, and architectural and mechanical properties. While X-ray based imaging would not be practical in space, quantitative ultrasound may provide advantages to characterize bone density and strength through wave propagation in complex trabecular structure. This study used a scanning confocal acoustic diagnostic and navigation system (SCAN) to evaluate trabecular bone quality in 60 cubic trabecular samples harvested from adult sheep. Ultrasound image based SCAN measurements in structural and strength properties were validated by μCT and compressive mechanical testing. This result indicated a moderately strong negative correlations observed between broadband ultrasonic attenuation (BUA) and μCT-determined bone volume fraction (BV/TV, R²=0.53). Strong correlations were observed between ultrasound velocity (UV) and bone's mechanical strength and structural parameters, i.e., bulk Young's modulus (R²=0.67) and BV/TV (R²=0.85). The predictions for bone density and mechanical strength were significantly improved by using a linear combination of both BUA and UV, yielding R²=0.92 for BV/TV and R²=0.71 for bulk Young's modulus. These results imply that quantitative ultrasound can characterize trabecular structural and mechanical properties through measurements of particular ultrasound parameters, and potentially provide an excellent estimation for bone's structural integrity.

Multisite quantitative ultrasound for the prediction of fractures over 5 years of follow-up: the Canadian Multicentre Osteoporosis Study

This study assessed the ability of multisite quantitative ultrasound (mQUS) to predict fracture over a 5-year follow-up. Participants were a subset of the Canadian Multicentre Osteoporosis Study. mQUS-assessed speed of sound (SOS in m/s) at three sites (distal radius, tibia, and phalanx) and extensive questionnaires were completed, after which participants were followed for 5 years and incident fractures recorded. Two survival analyses were completed for each site--a univariate analysis and an adjusted multivariate analysis controlling for age, antiresorptive use, femoral neck bone mineral density, number of diseases, previous fractures, body mass index (BMI), parental history of hip fracture, current smoking, current alcoholic drinks >3 per day, current use of glucocorticoids, and rheumatoid arthritis diagnosis (variables from the FRAX 10-year fracture risk assessment tool). The unit of change for regression analyses was one standard deviation for all measurement sites, specific to site and sex. Separate analyses were completed for all clinical fractures, nonvertebral fractures, and hip fractures by sex. There were 2633 women and 1108 men included, and they experienced 204 incident fractures over 5 years (5.5% fractured). Univariate models revealed statistically significant (p < 0.05) predictive ability of mQUS for all three measurement sites for women alone for all three fracture types (one standard deviation decrease in SOS was associated with a 52% to 130% increase in the risk of fracture), but not for the men's group. The adjusted model found that measures at the distal radius and tibia in the women's group could significantly (p < 0.05) predict all clinical fractures and nonvertebral fractures within the next 5 years (one standard deviation decrease in SOS was associated with a 25% to 31% increase in the risk of fracture). mQUS provided significant 5-year clinical fracture prediction in women, independent of bone mineral density and other significant risk factors for fracture, when measured at the distal radius and tibia sites.

Prevalence of low bone mineral density in inpatients with traumatic brain injury receiving neurobehavioural rehabilitation: a postoperative, observational study

BACKGROUND

Osteoporosis is characterised by low bone mineral density (BMD) leading to an increased risk of fracture. Patients who have sustained a significant traumatic brain injury may have an increased risk of secondary reduced BMD as a result of immobility and other factors.

OBJECTIVES

To describe BMD in a cohort of patients recovering from traumatic brain injury, and to discuss the implications of the findings for physiotherapy practice.

DESIGN

Prospective, observational.

SETTING

Specialist, residential unit providing care for individuals with brain injury, many with a history of severe challenging behaviour.

PARTICIPANTS

Current inpatients (n=51, 80% male) with the capacity to provide consent, as judged by their responsible clinician. The median age was 41 years (range 20 to 60 years), and the median time since the brain injury was sustained was 22 years (range 4 to 54 years).

METHODS

Participants' BMD was measured at the radius and tibia using quantitative ultrasound. Various clinical and demographic details were collected.

RESULTS

Participants had suboptimal BMD measurements that were generally low for their age and gender. Nine (18%) participants met the criteria for osteopenia measured at the radius, and 26 (51%) participants met criteria for osteoporosis or osteopenia measured at the tibia.

CONCLUSIONS

Some participants had reduced BMD, putting them at risk of fracture or of developing such risk in the future. This group is at particular risk because they frequently display challenging aggressive behaviours that may be met with responses including proportionate use of manual restraint. Physiotherapists should bear this increased risk in mind when devising exercise programmes assessing risk in neurobehavioural rehabilitation settings.

Ultrasound bone mass in schizophrenic patients on antipsychotic therapy

OBJECTIVE

To determine bone mass using quantitative phalangeal bone ultrasound in institutionalized schizophrenic patients under chronic treatment with antipsychotic drugs.

METHODS

A total of 73 patients with schizophrenia (25 women, mean age 59.84 +/- 17.01 years; 48 men, mean age 61.89 +/- 12.95 years) and 73 healthy subjects (25 women, mean age 60.37 +/- 17.16 years; 48 men, mean age 61.24 +/- 13.09 years) participated in the study. Bone status was assessed using an ultrasound device that measures the amplitude-dependent speed of sound (Ad-SoS) in metres per second. Measurements were made on the phalanges (II-V) of the non-dominant hand, and the mean value was computed.

RESULTS

The schizophrenic women had higher levels of prolactin (PRL), parathyroid hormone (PTH), alkaline phosphatase (AlPh), and tartrate-resistant acid phosphatase (TRAP) (all p < 0.0001), and lower 25-hydroxyvitamin D(25(OH)D3) levels (p < 0.0001) and Ad-SoS values (p < 0.05) than controls. Ad-SoS was higher in schizophrenic men (p < 0.05).

CONCLUSIONS

Schizophrenic women in treatment with antipsychotic drugs had a loss of phalangeal bone mass that was associated with the levels of vitamin D or PTH, and increased bone turnover.

Bone mass and architecture determination: state of the art

Bone fracture occurs when the bone strength (i.e. the ability of the bone to resist a force) is less than the force applied to the bone. In the elderly, falls represent the more severe forces applied to bone. Bone density is a good marker of bone strength, and has been used widely in this respect. Nevertheless, many aspects of bone strength cannot be explained by bone density alone. For this reason there has been increasing interest in studying architectural parameters of bone, beyond bone density, which may affect bone strength. Macro-architectural parameters include e.g. bone size and geometry assessed with techniques such as radiography, dual-energy x-ray absorptiometry (DXA), peripheral quantitative computed tomography (QCT), computed tomography (CT) and magnetic resonance imaging (MRI). Micro-architectural parameters include fine cortical and trabecular structural detail which can be evaluated using high-resolution imaging techniques such as multidetector CT, MRI, and high-resolution peripheral QCT. These techniques are providing a great deal of new information on the physiological architectural responses of bone to aging, weightlessness, and treatment. This will ultimately lead to the prediction of fracture risk being improved through a combined assessment of bone density and architectural parameters.

Quantitative ultrasound in the management of osteoporosis: the 2007 ISCD Official Positions

Dual-energy X-ray absorptiometry (DXA) is commonly used in the care of patients for diagnostic classification of osteoporosis, low bone mass (osteopenia), or normal bone density; assessment of fracture risk; and monitoring changes in bone density over time. The development of other technologies for the evaluation of skeletal health has been associated with uncertainties regarding their applications in clinical practice. Quantitative ultrasound (QUS), a technology for measuring properties of bone at peripheral skeletal sites, is more portable and less expensive than DXA, without the use of ionizing radiation. The proliferation of QUS devices that are technologically diverse, measuring and reporting variable bone parameters in different ways, examining different skeletal sites, and having differing levels of validating data for association with DXA-measured bone density and fracture risk, has created many challenges in applying QUS for use in clinical practice. The International Society for Clinical Densitometry (ISCD) 2007 Position Development Conference (PDC) addressed clinical applications of QUS for fracture risk assessment, diagnosis of osteoporosis, treatment initiation, monitoring of treatment, and quality assurance/quality control. The ISCD Official Positions on QUS resulting from this PDC, the rationale for their establishment, and recommendations for further study are presented here.

An update on the assessment of osteoporosis using radiologic techniques

In this article, the currently available radiologic techniques for assessing osteoporosis are reviewed. Density measurements of the skeleton using dual X-ray absorptiometry (DXA) are clinically indicated for the assessment of osteoporosis and for the evaluation of therapies. DXA is the most widely used technique for identifying patients with osteoporosis. Quantitative computed tomography (QCT) is the only method, which provides a volumetric density. Unlike DXA, QCT allows for selective trabecular measurement and is less sensitive to degenerative diseases of the spine. The analysis of bone structure in conjunction with bone density is an exciting new field in the assessment of osteoporosis. High-resolution multi-slice CT and micro-CT are useful tools for the assessment of bone microarchitecture. A growing literature indicates that quantitative ultrasound (QUS) techniques are capable of assessing fracture risk. Although the ease of use and the absence of ionizing radiation make QUS attractive, the specific role of QUS techniques in clinical practice needs further determination. Considerable progress has been made in the development of MR techniques for assessing osteoporosis during the last few years. In addition to relaxometry techniques, high-resolution MR imaging, diffusion MR imaging and in-vivo MR spectroscopy may be used to quantify trabecular bone architecture and mineral composition.

Comparison of questionnaire and quantitative ultrasound techniques as screening tools for DXA

The aim of the study is to assess the sensitivity and specificity of different techniques and their ability to act as screening tools in relation to dual energy X-ray absorptiometry (DXA) in a group of 208 postmenopausal women. In this study we examined eight screening systems for the diagnosis of osteoporosis, the osteoporosis self-assessment tool (OST), the osteoporosis risk assessment instrument (ORAI), the osteoporosis index of risk (OSIRIS), a risk index derived using data from the study of osteoporotic fractures (SOFSURF), the simple calculated osteoporosis risk estimation (SCORE), patient body weight (pBW), along with two ultrasound based systems, the Sunlight Omnisense (Sunlight Medical, Rehovot, Israel) and the CUBA Clinical (McCue plc, Winchester, UK). The sensitivity and specificity of the different techniques in relation to DXA were plotted as receiver-operating characteristic (ROC) curves at three different levels (DXA T-score -2.5 osteoporosis, -2 and -1 osteopenia). The areas under the curves (AUC) were calculated and showed broadband ultrasound attenuation (BUA) at the calcaneus to provide consistently the highest AUC (0.77-0.81). The velocity of sound (VOS) of the calcaneus (AUC=0.72-0.76) was equally good, but was out-performed by some of the questionnaire systems (AUC=0.66-0.79). Both the questionnaire systems and the CUBA Clinical out-perform the Sunlight Omnisense (AUC=0.58-0.7), which showed comparable performance with body weight (AUC=0.66-0.69). The results show that QUS is capable of selecting patients with low bone density as measured by DXA. A patient displaying a low QUS value should be followed up with a DXA scan to confirm the diagnosis.

The ability of peripheral quantitative ultrasound to identify patients with low bone mineral density in the hip or spine

This study aims to assess the sensitivity and specificity of two commercially available quantitative ultrasound (QUS) scanners (CUBA Clinical, Sunlight Omnisense), to differentiate patients with osteoporosis (OP) or osteopenia at the spine and hip confirmed by dual-energy x-ray absorptiometry (DXA) and to investigate the optimum cut-off values to maximize the effectiveness of the screening technique. Participants (n = 268) received DXA scans on their lumbar spine (L1-L4) and hip, with paired QUS scans on their distal radius, proximal phalanx, midshaft tibia and calcaneus. Scanners were evaluated by using receiver-operating characteristics curves and their area under the curve (AUC) values. Measurement of the calcaneus by the CUBA Clinical showed a superior ability to predict DXA, with AUC values between 0.75 to 0.83 in comparison with AUC values of 0.60 to 0.70 for the Sunlight Omnisense. Cut-off values varied according to the technique used and the accuracy of the screening required. Assessment of the calcaneus was the best QUS technique for the prediction of low bone density at the axial skeleton as diagnosed by DXA.

Relationship among MRTA, DXA, and QUS revisited

Inexpensive, commercially produced devices that directly measure bone strength in vivo are not currently available. Mechanical response tissue analysis (MRTA), a unique prototype device, is an in vivo vibrational test that measures transverse bending stiffness (a measure of whole bone strength expressed as the product of estimated Young's modulus of elasticity and cross-sectional moment of inertia, EI, Nm2) at ulna midshaft. We compared speed of sound (SOS; [m/s]) in ulna cortical bone using a commercially available axial transmission quantitative ultrasound (QUS) device with EI using MRTA. Dual-energy X-ray absorptiometry (DXA) was used to provide an estimate of ulna size (cm2), bone mineral content (BMC; [g/cm]) and areal bone mineral density (BMD; [g/cm2]). The objective of the study was to determine if ulna SOS--alone or in combination with BMD from DXA--was correlated with ulna EI, thus becoming a surrogate measure of transverse bending stiffness, and thus whole bone strength. Data were collected from 138 female volunteers (18-86 yr). EI and SOS were significantly correlated, r = +0.218, p = 0.01, but r2 was very low, 4.8%. SOS and total ulna BMD were combined to estimate elastic modulus, which correlated with EI, r = +0.377, p < 0.0001; however, the correlation was not significantly better than with SOS alone. We conclude that axial transmission QUS is not a strong surrogate in vivo technique for estimating transverse bending stiffness.

Limited diagnostic agreement of quantitative sonography of the radius and phalanges with dual-energy x-ray absorptiometry of the spine, femur, and radius for diagnosis of osteoporosis

OBJECTIVE

The aim of our study was to evaluate the diagnostic agreement of quantitative sonography of the radius and proximal phalanx and dual-energy X-ray absorptiometry (DXA) of the radius, lumbar spine, and femoral neck for the detection of osteoporosis.

MATERIALS AND METHODS

In 95 women (mean age, 53 +/- 13 years) and 26 men (mean age, 53 +/- 13 years), DXA measurements of the lumbar spine (posterior-anterior, L1-L4) and the femoral neck, as well as quantitative sonography of the radius and proximal phalanx of the third finger were obtained. The percentage of patients below a given threshold was calculated for each imaging technique. A T score of less than -2.5 indicated presence of osteoporosis. Diagnostic agreement in identifying individuals with osteoporosis was assessed using kappa scores.

RESULTS

Between 14% and 22% of the patients were classified as osteoporotic after DXA of the various regions of interest of the radius, 31% after DXA of the spine, 43% after DXA of the femoral neck, 32% after quantitative sonography of the distal radius, and 34% after quantitative sonography of the phalanx of the third finger. Correlation coefficients between T values for quantitative sonography and those for DXA varied between not significant and 0.54 at the different regions. Kappa analysis showed the diagnostic agreement among quantitative sonography and DXA to be fair to moderate (kappa = 0.38-0.48). The highest agreement was between quantitative sonography of the proximal phalanx of the third finger and DXA of the total radius (kappa 0.48; p < 0.05).

CONCLUSION

Considerable diagnostic disagreement exists between quantitative sonography and DXA of the forearm, as is true for most quantitative techniques in the assessment of skeletal status. The lack of correlation makes quantitative sonography impractical for routine diagnostic use but might characterize different parameters related to bone quality.

Discrimination of hip fractures by quantitative ultrasound of the phalanges and the calcaneus and dual X-ray absorptiometry

The aim of the current study was to evaluate the ability of different techniques used for the assessment of bone status to discriminate between postmenopausal women with and without hip fracture. Fifty-one postmenopausal women (mean age 64.5 +/- 6.5) who had sustained a low energy hip fracture and 51 age-matched controls (mean age 64.6 +/- 6.0) were studied. Quantitative ultrasound (QUS) assessment was carried out using the Ubis 3000 device capable of measuring broadband ultrasound attenuation (BUA) and speed of sound at the calcaneus (SOSC) and the Sunlight Omnisense device capable of estimating speed of sound at the phalanges (SOSP). Femoral neck bone mineral density (BMD) was assessed using dual X-ray absorptiometry. Correlations between QUS variables ranged from r = 0.35 to 0.72 and between QUS variables and BMD from r = 0.30 to 0.36. BMD was the best discriminator of hip fractures (odds ratio = 3.61, area under curve = 0.824). All QUS variables were significant discriminators of hip fractures with odds ratios ranging from 1.88 to 2.63 and areas under the ROC curves ranging from 0.663 to 0.740. Among the QUS variables, the SOSP showed the best odds ratio and area under curve. Comparison between the areas under the ROC curve did not show any significant difference between SOSP, BUA and BMD. On the contrary, the difference between SOSC and BMD was significant (P < 0.05). In conclusion, BMD and QUS variables investigated in the current study were significant discriminators of hip fractures. The differentiation of the hip fractures by BMD was significantly better than that of BUA measured at the calcaneus. Moreover, BMD discriminated fractured patients better than BUA and SOS(P), although the difference did not reach statistical significance.

Can radial bone mineral density and quantitative ultrasound measurements reduce the number of women who need axial density skeletal assessment?

The purpose of this study was to investigate the clinical usefulness of forearm bone mineral density (BMD) and speed of sound (SOS) at the phalanx and radius as pre-selection tests to identify women with low BMD at the axial skeleton. BMD was measured by dual-energy X-ray absorptiometry (DXA) in the forearm, lumbar spine and femoral neck. SOS at the radius and phalanx was measured using a multisite quantitative ultrasound (QUS) device. Measurements were performed on 524 consecutive women referred for the assessment of BMD. Women with a T-score <-1 and T-score < or =-2.5 at either spine or femoral neck were identified, and T-score cut-off values for the forearm DXA and QUS variables were determined. Cut-off values for the forearm BMD estimated to detect normal women and those with T-score <-1 at the axial skeleton identified a total of 82% of subjects with 91% certainty. Cut-off values for the forearm BMD determined to detect women with T-score >-2.5 and those with osteoporosis allowed the identification of 62% of the study population with 90% certainty. Cut-off values for the phalangeal and radial SOS estimated to detect normal women and those with T-score <-1 at the axial skeleton identified a total of 49% and 1% of subjects, respectively. Cut-off values estimated for QUS variables to detect women with T-score >-2.5 and those with osteoporosis at the axial skeleton either failed to detect subjects with sufficient certainty (phalangeal SOS) or detected a negligible percentage of patients (radial SOS). In conclusion, forearm BMD may be used as a pre-selection test to identify women with low BMD at the axial skeleton, thus enabling reduction of the number of women who need axial BMD assessment. SOS of the phalanges and radius appears to have less value in the detection of the women with low axial BMD.