Quantitative Ultrasound Device Research Articles

大学生におけるボディ・マス・インデックスと食生活および骨量との関連性について

The relationship was investigated between the body mass index (BMI), eating habits and bone mass in male and female students. A questionnaire survey of the eating habits and eating behavior was conducted on 277 male and 317 female students. We measured the bone mass with a quantitative ultrasound device, the height, body weight, and body fat. We divided the subjects into three groups based on the BMI value: BMI<18.5 group, 18.5≤BMI<25 group, and BMI≥25 group. The percentage of female students who were actively seeking nutritional knowledge and information and who habitually assessed their own eating behavior was significantly higher in the BMI<18.5 group than in the 18.5≤BMI<25 group. However, there was no significant difference in these factors among the BMI groups for male students. The osteo sono assessment index (OSI) was significantly lower in the BMI<18.5 group than in the 18.5≤BMI<25 group of females (p<0.001). The results of this study provide useful data for the relationship between BMI, eating habits and bone mass in male and female students. The data reveal that appropriate nutritional education on bone metabolism in the BMI<18.5 group of female students was especially important for preventing osteoporosis.

Effects on Balance, Falls, and Bone Mineral Density of a Home-based Exercise Program without Home Visits in Community-Dwelling Elderly Women: a Randomized Controlled Trial

The aim of the present study was to investigate the effects of home-based exercise without home visits on physical function, falls, and bone mineral density in community-dwelling elderly women. Sixty community-dwelling, elderly (> or =65 years of age) women were recruited from a Japanese community. Subjects were randomly assigned to a home-based exercise group or a control group. The subjects assigned to the home-based exercise group performed home-based exercise without home visits 3 times per week for 6 months in their homes. Assessments of physical function and bone mineral density were carried out before and after intervention in both groups. Muscle strength, gait velocity, the timed up and go test (TUGT), single leg stance time, the bend reach performance test, and reaction time were measured to assess physical function. The patients' history of falls was also assessed before and after the 12-month follow-up. To determine bone mineral density, the speed of sound (SOS) at the right calcaneus was measured using a quantitative ultrasound device. There were no significant differences between the two groups in baseline characteristics. 82.6% of subjects completed the prescribed exercise program in the home-based exercise group. Compared to the control group, TUGT improved significantly (p<0.05) in the home-based exercise group. Home-based exercise without home visits can be adopted for community-dwelling elderly women, particularly since no specific place or instructor is needed.

QUANTITATIVE ULTRASONOGRAPHY FOR ASSESSMENT OF BONE MINERAL DENSITY IN THE CANINE RADIUS AND TIBIA

Quantitative ultrasound allows noninvasive assessment of cortical bone density. Potential applications include monitoring of fracture healing, rehabilitation, and skeletal diseases. The objectives of this study were to determine the three most accessible portals to obtain speed of sound measurements of the radius and tibia with an Omnisense multisite quantitative ultrasound device and to determine probe-dependent intra- and interoperator variability for speed of sound measurements of the radius and tibia in six healthy hounds. The radius was most accessible at the cranial proximal metaphysis, the cranial middiaphysis, and medial distal metaphysis. Speed of sound measurements were possible at these sites on the radius with acceptable intra- and interoperator variation (1.6-4.6%). Measurements differed significantly when performed with different probes at the cranial proximal radial metaphysis. The tibia was most accessible at the cranial proximal metaphysis, the medial middiaphysis, and medial distal metaphysis. The medial middiaphyseal and mediodistal tibial sites allowed measurements with lowest intra- and interoperator variation (< 3.5%). A smaller probe allowed tibial measurements with lowest interoperator variation. Measurements did not differ significantly at each tibial site when different probes were used. Measurements did not differ significantly between observers when measuring with the same probe at each specific site on radius and tibia. A medium-size probe allowed for most time-efficient measurements and the least number of failed measurements on the radius and tibia. Speed of sound can be consistently measured by different observers on the radius and tibia in healthy hounds.

Vertebral fractures in patients with chronic obstructive pulmonary disease: the EOLO Study

This study aimed to evaluate the prevalence of vertebral fractures to investigate the determinants of vertebral fracture risk in patients with COPD. The risk of vertebral fractures is strictly related to the severity of the disease. The use of glucocorticoids and the presence of low values of quantitative ultrasound (QUS) may represent additional risk factors. Chronic obstructive pulmonary disease (COPD) appears to be associated with osteoporosis. Our study aimed to evaluate the prevalence of vertebral fractures and to investigate the main determinants of vertebral fracture risk in patients with COPD. In 3,030 ambulatory COPD patients (1,778 men and 1,262 women) aged 50 years or over, we evaluated: COPD severity, presence of vertebral fractures on lateral chest X-ray and bone status by using a quantitative ultrasound device. In men there was a strong association between COPD severity and fractures (p < 0.001), conversely in women the association between COPD severity and fractures was at limit (p = 0.049). In men, but not in women, glucocorticoid treatment was significantly associated with vertebral fractures. The patients with high or moderate risk of osteoporosis presented an increased risk of vertebral fracture (OR 2.71; 95% CI 2.04-3.60 and OR 1.54; 95% CI 1.26-1.88, respectively). Logistic regression analysis showed that COPD severity and glucocorticoid treatment, both inhaled and oral, were associated with increased risk of vertebral fractures. In COPD patients the risk of vertebral fractures is strictly related to the severity of the disease. The use of glucocorticoids and reduced QUS at calcaneous may represent additional risk factors.

The clinical use of quantitative ultrasound (QUS) in the detection and management of osteoporosis

For the detection and management of osteoporosis and osteoporosis-related fractures, quantitative ultrasound (QUS) is emerging as a relatively low-cost and readily accessible alternative to dual-energy X-ray absorptiometry (DXA) measurement of bone mineral density (BMD) in certain circumstances. The following is a brief, but thorough review of the existing literature with respect to the use of QUS in 6 settings: 1) assessing fragility fracture risk; 2) diagnosing osteoporosis; 3) initiating osteoporosis treatment; 4) monitoring osteoporosis treatment; 5) osteoporosis case finding; and 6) quality assurance and control. Many QUS devices exist that are quite different with respect to the parameters they measure and the strength of empirical evidence supporting their use. In general, heel QUS appears to be most tested and most effective. Overall, some, but not all, heel QUS devices are effective assessing fracture risk in some, but not all, populations, the evidence being strongest for Caucasian females over 55 years old. Otherwise, the evidence is fair with respect to certain devices allowing for the accurate diagnosis of likelihood of osteoporosis, and generally fair to poor in terms of QUS use when initiating or monitoring osteoporosis treatment. A reasonable protocol is proposed herein for case-finding purposes, which relies on a combined assessment of clinical risk factors (CR.F) and heel QUS. Finally, several recommendations are made for quality assurance and control.

A new quality of bone ultrasound research

Quantitative ultrasound (QUS) methods have strong power to predict osteoporotic fractures, but they are also very relevant for the assessment of bone quality. A representative sample of recent studies addressing these topics can be found in this special issue. Further pursuit of these methods will establish micro-QUS imaging methods as tools for measuring specific aspects of bone quality. Once this is achieved, we will be able to link such data to the clinical QUS methods used in vivo to determine which aspects of bone quality cause QUS to be a predictor of fracture risk that is independent of bone mineral density (BMD). Potentially this could lead to the development of a new generation of QUS devices for improved and expanded clinical assessment. Good quality of basic science work will thus lead to good quality of clinical patient examinations on the basis of a more detailed assessment of bone quality.

Simulation and modeling of a new quantitative ultrasound imaging device using cylindrical crossed beam forming arrays

Real‐time quantitative ultrasound imaging (QUI) produces images of bone properties with the advantages of being non‐ionizing, portable and repeatable. A real‐time QUI technique has been proposed, based on two 2‐D arrays (24x24 transducer elements) to produce a confocal spherical focusing in transmit and receive modes. However, the electronics to manage beam scanning and focusing is complex and remains expensive. To overcome these disadvantages, a new device has been developed, based on two 1‐D transducer arrays (72x1 transducer elements) and confocal cylindrical crossed‐beam forming. The intersection of two orthogonal cylindrical focus lines replaces the spherical focused beams. Initial results obtained with this approach showed a distortion and a shift of the spectrum in the low frequency range compared to the reference confocal spherical focusing technique. The aim of the study was to explain the observed differences between spherical and cylindrical focusing techniques using numerical simulations of elementary impulse responses calculated in the confocal and reception planes. The orthogonal configuration of the transmit and receive focusing line results in orthogonal curvatures of the transmitted wavefront and receiving aperture, with summation by the receiving aperture of an out‐of‐phase wavefront. We show that this effect is the major source for the frequency response artifacts.

Prospective evaluation of risk of vertebral fractures using quantitative ultrasound measurements and bone mineral density in a population-based sample of postmenopausal women: results of the Basel Osteoporosis Study

Objective:Prospective studies have shown that quantitative ultrasound (QUS) techniques predict the risk of fracture of the proximal femur with similar standardised risk ratios to dual-energy x-ray absorptiometry (DXA). Few studies...

Quantitative ultrasound (QUS) measurements in small versus appropriate birth weight for gestation neonates

Background: Small for gestation (SGA) neonates have lower birth weight (&lt;10th percentile) and lower bone mass compared to those born with appropriate birth weights (AGA, 10th to 90th percentile). QUS measurements are thought to reflect multiple parameters in addition to bone mass which contributed to bone strength and there are limited data on QUS measurements in SGA infants.Hypothesis: SGA infants will have lower QUS measurements compared to AGA neonates.Methods: Speed of sound (SOS) measurements were obtained at left tibia with a commercial axial transmission QUS device using manufacturer (Sunlight Omnisense 7000S Bone Sonometer) supplied neonatal software and CR and/or CS probes. CV of duplicate measurement was 0.6% of mean. None of the SGA infants had any known intrauterine infectious or genetic disorders. All measurements were performed within a few days after birth. Based on the expected lower birth weight and bone mass of SGA infants, this study was powered to detect a 10% difference in SOS between AGA and SGA neonates.Results:Conclusion: There were no significant differences in QUS SOS measurements between SGA and AGA neonates.

In Vivo Measurements of Ultrasound Transmission Through the Human Proximal Femur

Quantitative ultrasound (QUS) measurements can be used to estimate osteoporotic fracture risk. The commonly used variables are the speed of sound (SOS) and the frequency dependent sound attenuation (broadband ultrasound attenuation, [BUA]) of a wave propagating through the bone, preferably the calcaneus. The technology, so far, is less suitable for direct measurement in vivo at the spine or the femur for prediction of bone mineral density (BMD) or fracture risk at the main osteoporotic fracture sites. To improve the clinical performance of QUS, we built a device for direct QUS measurements at the human femur in vivo. In vivo images of ultrasound transmission at one of the main fracture sites, the proximal femur, could be acquired. The estimated precision of SOS measurements of 0.5% achieved at the femur is comparable with the precision of peripheral QUS devices. (E-mail: barkmann@rad.uni-kiel.de)

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.

Wavelet-Based Signal Processing of In Vitro Ultrasonic Measurements at the Proximal Femur

To estimate osteoporotic fracture risk, several techniques for quantitative ultrasound (QUS) measurements at peripheral sites have been developed. As these techniques are limited in the prediction of fracture risk of the central skeleton, such as the hip, we are developing a QUS device for direct measurements at the femur. In doing so, we noticed the necessity to improve the conventional signal processing because it failed in a considerable number of measurements due to multipath transmission. Two sets of excised human femurs ( n = 6 + 34) were scanned in transmission mode. Instead of using the conventional methods, the radio-frequency signals were processed with the continuous wavelet transform to detect their time-of-flights for the calculation of speed-of-sound (SOS) in bone. The SOS-values were averaged over a region similar to the total hip region of dual X-ray absorptiometry (DXA) measurements and compared with bone mineral density (BMD) measured with DXA. Testing six standard wavelets, this algorithm failed for only 0% to 6% of scan in test set 1 compared with 29% when using conventional algorithms. For test set 2, it failed for 2% to 12% compared with approximately 40%. SOS and BMD correlated significantly in both test sets (test set 1: r 2 = 0.87 to 0.92, p < 0.007; test set 2: r 2 = 0.68 to 0.79, p < 0.0001). The correlations are comparable with correlations recently reported. However, the number of evaluable signals could be substantially increased, which improves the perspectives of the in vivo measurements. (E-mail: dencks@rad.uni-kiel.de)

Apparent Young's modulus of human radius using inverse finite-element method

The ability to assess the elastic and failure properties of cortical bone at the radial diaphysis has a clinical importance. A new generation of quantitative ultrasound (QUS) devices and peripheral quantitative computed tomography (p-QCT) has been developed to assess non-invasively bone material and structural properties at the distal radius. This anatomical site is characterized by a thin cortical thickness that complicates traditional mechanical testing methods on specimens. Until now, mechanical properties of cortical bone at distal radius (e.g., elastic modulus, yield stress and strain) remain rarely studied probably due to experimental difficulties. The present study introduces an inverse finite-element method strategy to measure the elastic modulus and yield properties of human cortical specimens of the radial diaphysis. Twenty millimeter-thick portions of diaphysis were cut from 40 human radii (ages 45–90) for biomechanical test. Subsequently the same portion was modeled in order to obtain a specimen-specific three dimensional finite-element model (3D-FEM). Longitudinal elastic constants at the apparent level and stress characterizations were performed by coupling mechanical parameters with isotropic linear-elastic simulations. The results indicated that the mean apparent Young's modulus for radial cortical bone was 16 GPa (SD 1.8) and the yield stress was 153 MPa (SD 33). Breaking load was 12,946 N (SD 3644), cortical thickness 2.9 mm (SD 0.6), structural effective strain at the yield ( ε y = 0.0097 ) and failure ( ε u = 0.0154 ) load were also calculated. The 3D-FEM strategy described here may help to investigate bone mechanical properties when some difficulties arise from machining mechanical sample.

Bone Metabolism Changes During Anti‐TNF‐α Therapy in Patients with Active Rheumatoid Arthritis

Osteoporosis (OP) occurs more frequently in patients with rheumatoid arthritis (RA) than in healthy individuals. Specific treatments of RA may increase susceptibility to OP, but at the same time decrease inflammatory activity, which is associated with accelerated bone loss. Treatment with TNF-alpha blockers might influence bone metabolism and prevent structural bone damage in RA, in particular at the periarticular level. Our aim was to assess the influence of anti-TNF-alpha therapy on bone metabolism in RA patients. To that end we evaluated a group of 30 RA patients [mean age 50.6 +/- 6.8 years; median disease duration 82 +/- 38 months; median disease activity score (DAS-28) 5.8 +/- 1.2: 70% of whom were positive for the rheumatoid factor IgM (>40 IU/mL)]. Patients were treated with stable therapy of prednisone (7.5 mg/day) and methotrexate (MTX = 10 mg/week). Eleven of these RA patients further received etanercept (25 mg, twice/weekly) and 10 infliximab (3 mg/kg on 0, 2, 6, and every 8 weeks thereafter). A control group included 10 RA patients with stable therapy (prednisone and MTX) and without anti-TNF-alpha therapy. All the patients fulfilled the ACR criteria for the diagnosis of adult RA and were treated for 6 months. Quantitative ultrasound (QUS) bone densitometry was performed at the metaphyses of the proximal phalanges of both hands with a DBM Sonic 1200 QUS device (IGEA, Carpi, Italy). Amplitude-dependent speed of sound (AD-SoS) was evaluated at base line and at 3 and 6 months. Bone mineral density (BMD) of the hip and lumbar spine (L1-L4) was determined by a densitometer (GE Lunar Prodigy, USA) at base line at after 6 months. Soluble bone turnover markers [osteocalcin (BGP) and deoxypyridinoline/creatinine (Dpd/Cr) ratio] were measured in all patients at the same times, using enzyme-linked immunosorbent assay tests. All data were compared using Wilcoxon signed rank test. Results were as follows: AD-SoS values were found increased by 1.3% after 6 months of treatment in the RA patients treated with anti-TNF-alpha therapy. On the contrary, the Ad-SoS levels decreased by 4.6% during the same period in the untreated RA group. BMD increased by 0.2% at lumbar spine and 0.1% at the hip in TNF-alpha-blocker-treated patients and decreased by 0.8% and 0.6% (at lumbar spine and at the hip, respectively) in RA patients without anti-TNF-alpha therapy. However, BMD variations were not significant. In RA patients treated with TNF-alpha blockers, BGP levels were found significantly increased (14.8 +/- 3.8 mg/mL vs. 22.4 +/- 4.2 mg/mL; P < 0.01) and Dpd/Cr levels were found significantly decreased (8.2 +/- 2.1 nM vs. 4.6 +/- 1.8 nM; P < 0.01) at 6 months when compared to base line values. On the contrary, there were no significant differences in the untreated RA patients concerning these latter parameters (BGP = 12.2 +/- 3.1 mg/mL vs. 10.8 +/- 2.8 mg/mL and Dpd/Cr = 8.9 +/- 2.4 nM vs. 10.2 +/- 1.8 nM, respectively). In conclusion, during 6 months of treatment of RA patients with TNF blockers, bone formation seems increased while bone resorption seems decreased. The reduced rate of OP appears to be supported by the same mechanisms involved in the decreased bone joint resorption during anti-TNF-alpha therapy, that is, the marked decrease of the proinflammatory (i.e., TNF-alpha) cytokine effects on bone metabolism.

Comparison of the Achilles Express Ultrasonometer with Central Dual-Energy X-Ray Absorptiometry

Quantitative ultrasound (QUS) devices provide portable, easy-to-operate, low-cost options for point-of-care screening of bone mineral density (BMD). Community pharmacists should be aware of the precision, sensitivity, and specificity of these devices prior to their purchase. To determine the precision, sensitivity, and specificity of the Achilles Express ultrasonometer compared with central dual-energy X-ray absorptiometry (cDXA) as well as its utility as a bone density screening device in the community pharmacy setting. A prospective study in a community pharmacy and outpatient ambulatory clinic was conducted with 2 groups of white women. Group 1 participants were 25-35 years of age (young, healthy), and those in Group 2 were 45 years of age or older (postmenopausal). BMD assessments of the spine and the nondominant wrist and hip were performed using cDXA. Assessments of the heel were performed using the Achilles Express, a QUS device. The main outcome measures were correlation of t-scores between cDXA and QUS measurements using the Pearson correlation test. Twenty-two (30 +/- 4 years of age) and 31 (55 +/- 17 years of age) women were enrolled into Groups 1 and 2, respectively. Significant correlations between QUS and hip and spine cDXA t-scores were found in both groups. Correlation coefficients for QUS versus hip cDXA were 0.51 (95% CI 0.11 to 0.77) and 0.70 (95% CI 0.46 to 0.85) in Groups 1 and 2, respectively. Correlation coefficients for the QUS versus spine cDXA were 0.64 (95% CI 0.31 to 0.84) and 0.60 (95% CI 0.31 to 0.79) in Groups 1 and 2, respectively. The QUS device has a sensitivity level of 88% and specificity of 71% to detect a hip cDXA t-score of less than-1. The Achilles Express ultrasonometer is a reasonable screening tool to detect low BMD in postmenopausal women.

Relationship between risk factors and QUS in a European Population: The OPUS study

There are many risk factors associated with low bone mineral density. Quantitative ultrasound (QUS) is a generally accepted method for measurement of bone and has been shown to be strongly associated with future fracture risk. The Osteoporosis and Ultrasound Study (OPUS) is a multi-centre European wide study examining 5 different QUS scanners (4 calcaneal, 1 finger device). The aim of this paper was to examine the relationship between risk factors (as assessed by questionnaire) and QUS measurements. 449 younger women (aged 20 to 39 years) and 2283 older women (aged 55 to 79 years) were included in this analysis. As expected, those with a self-reported previous fracture had lower QUS measurements than those without ( P < 0.001). However, no significant difference was seen between those reporting a maternal hip fracture and those who did not report such an event. Differences were found for smokers vs. non-smokers for SOS but not for BUA measurements. Weight was positively correlated with all BUA variables but only with some SOS variables. We determined which risk factors were most strongly associated with QUS measurements by using step-wise multiple regression. Models for each QUS measurement were calculated, and the R 2 values ranged from 0.18 to 0.28 for SOS, 0.27 to 0.32 for BUA and 0.31 to 0.42 for the finger QUS device. The most common risk factors across all models were age, use of hormone replacement therapy, self-reported previous fracture, self-reported diagnosis of osteoporosis, current weight, pulse rate and self-reported estimated height at age 20 years. We analysed relationships across the 5 centres and detected some geographical differences in the prevalence of the risk factors. In conclusion, similar relationships are seen with QUS measurements as are found for bone mineral density. However, the strength of the association is dependent on the type of QUS device and variable measured.

Lifelong risk factors for osteoporosis and fractures in elderly women with low body mass index—A population-based study

Low body weight is associated with an increased risk for osteoporosis and fractures, but the contribution of other lifestyle related factors have not been previously studied within lean elderly women. The present study evaluated the association between lifelong lifestyle factors and bone density, falls and postmenopausal fractures in elderly women with low body mass index (BMI). A population-based sample of 1222 women aged 70 to 73 years was stratified by BMI tertiles, and all 407 women in the lowest tertile participated. Data on falls and postmenopausal fractures, physical activity, functional capacity, calcium intake, smoking, alcohol intake and medical factors at different ages were obtained by a questionnaire. Calcaneum bone mass as broadband ultrasound attenuation (BUA) was assessed with a quantitative ultrasound (QUS) device, and bone mineral density (BMD) at the distal radius was measured with a dual-energy X-ray absorptiometry (DXA). Low current physical activity was associated with lower calcaneum BUA and factors associated with higher BUA were body weight, low lifetime occupational physical activity, hormone replacement and type 2 diabetes. Weight, type 2 diabetes and thiatzide use were associated with higher radius BMD. The final multivariate model consisted of four independent factors associated with fractures: low lifetime habitual physical activity (OR 3.7, 95% CI 1.9–7.1), diabetes (OR 0.2, 95% CI 0.1–1.0), living alone (OR 1.7, 95% CI 1.0–3.0) and calcaneum BUA (1.8, 95% CI 1.3–2.4). Poor functional ability and symptoms of depression were associated with recent falling. In elderly women with low BMI, lifelong physical activity may protect from fractures, while low calcaneum bone mass and living unpartnered appear to be associated with an increased risk for fractures. Poor functional ability and presence of depression may be associated with risk of falling. Type 2 diabetes may modify the risk of low bone mass and low-trauma postmenopausal fractures. Albeit that the results of this study need to be confirmed in prospective follow-up studies, multifactorial program with the emphasis on physical and social activation in the primary care setting for preventing falls and fractures in lean elderly women is recommended.

Calcaneal Quantitative Ultrasound Measurements in Young Male and Female Professional Dancers

The aim of this study was to assess the bone status of dancers using calcaneal quantitative ultrasound (QUS). Twenty-four male and 26 female dancers (aged 19-36 years) and 100 age- and sex-matched nonathletic controls were included in this study. QUS parameters (broadband ultrasound attenuation [BUA], speed of sound [SOS], quantitative ultrasound index [QUI], and estimated heel bone mineral density [eBMD]) were obtained for both heels in all subjects using a gel-coupled QUS device. Two-way analysis of variance, including the factors of dancing status and gender, revealed significant differences in all QUS parameters between the dancers and the controls (p < 0.001 for all), without a significant interaction with gender status. For each heel (right versus left), the mean QUI, BUA, SOS, and eBMD values of the male and female dancers were 22.0% vs. 20.9% and 16.6% vs. 16.0%; 21.6% vs. 24.1% and 13.2% vs. 14.3%; 2.3% vs. 2.0% and 1.7% vs. 1.7%; and 25.0% vs. 23.9% and 19.0% vs. 18.6% higher than those of the male and female controls, respectively. Analysis of covariance still revealed significant differences between the dancers and the controls after controlling for the influence of body mass index (p < 0.001). Furthermore, the finding that significant bilateral differences in BUA did exist in the controls but not in the dancers demonstrated site-specific effects of exercise on bone, indicating that it is the dance that improved bone properties. Calcaneal QUS, with a strong discriminative ability between those involved in professional dance and normally active individuals, emerges as an attractive technology for exploring the benefits of exercise on bone, which might be a challenge for those in the conditioning field, who need to identify those who need intervention in terms of bone status and promote participation in high-impact physical activity, such as dance, to enhance bone quality.

Effect of Temperature on the Longitudinal Variability of Quantitative Ultrasound Variables

It is unclear whether longitudinal change in phantom measurements bears any relation to the long-term in vivo instrument performance of quantitative ultrasound devices. Longitudinal quantitative ultrasound phantom data were obtained by measuring the manufacturer-provided phantom at ambient temperature and two different sets of Leeds phantoms at either ambient temperature or following a phantom temperature-control protocol. Measurements were performed using the Achilles Plus bone densitometer. Changes in longitudinal phantom data were compared to in vivo quantitative ultrasound data obtained from seven healthy, young volunteers. A cosinor model with linear trend and Hotelling's T2-test were used to quantify seasonal rhythms and long-term drift in quantitative ultrasound variables. Temperature effects and marked seasonal rhythms on quantitative ultrasound phantom measurements were evident but were far less apparent in vivo. Longitudinal precision of quantitative ultrasound variables was poorer for the manufacturer-provided phantom than for phantoms that were subjected to a temperature-control protocol or for healthy volunteers. This study has shown that longitudinal precision and longitudinal change differs between in vivo and phantom data. Longitudinal quantitative ultrasound measurements for monitoring change in skeletal status cannot, as yet, be properly controlled.

In Vivo Performance Evaluation of the Achilles Insight QUS Device

Achilles plus (GE, Lunar) has been widely used worldwide for more than a decade, and for its precision, ability to predict fragility fractures and comparability to central DXA, it can be considered a reference standard among quantitative ultrasound devices. As a water-bath system, Achilles plus has obvious practical drawbacks. Achilles Insight is a new-generation device that gives ultrasound parameters in less than 1 min, providing real-time imaging of the os calcis. The aim of this study was to evaluate the in vivo performance of Achilles Insight in comparison to Achilles plus. The precision showed a coefficient of variation (CV) of 0.5 and 0.4%, 4.1 and 3.0%, 2.7 and 2.1%, respectively, for speed of sound (SOS), broadband ultrasound attenuation (BUA), and Stiffness obtained with Achilles plus and Achilles Insight. We also studied 117 postmenopausal women (mean age: 67.1+/-8.8 yr), 47 with and 70 without fragility fractures. Ultrasound parameters obtained by the two devices significantly (p<0.001) correlated and resulted in agreement according to the Bland and Altman method. Achilles plus and Achilles Insight showed similar values of areas under receiver operating characteristics (ROC) curves in discriminating patients with or without fractures (0.884, 0.82, and 0.879 for SOS, BUA, and Stiffness, respectively, with Achilles plus, and 0.882, 0.828, and 0.889, respectively, for Achilles Insight). In conclusion, the better precision of the Achilles Insight with respect to Achilles plus could be explained by the fact that the measurement with Achilles Insight needs less time and gives a consequent reduction in motion artifacts. The high correlation and the similar ability to identify postmenopausal women with vertebral fracture suggest the possibility of using the database of Achilles plus for Achilles Insight.