Longitudinal changes in ultrasound parameters of the calcaneus

The effects of age, physical activity level, and body anthropometry on calcaneal speed of sound value in men

The influences of age, physical activity, and body anthropometry on calcaneal speed of sound are different among young adults, middle-aged, and elderly men.

INTRODUCTION

Quantitative ultrasound assessment of bone health status is much needed for developing countries in the screening of osteoporosis, but further studies on the factors that influence the quantitative ultrasound indices are required.

OBJECTIVES

The present study examined the influence of age, lifestyle factors, and body anthropometry on calcaneal speed of sound (SOS) in a group of Malaysian men of diverse age range.

SUBJECTS AND METHODS

A cross-sectional study was conducted, and data from 687 eligible males were used for analysis. They answered a detailed questionnaire on their physical activity status, and their anthropometric measurements were taken. Their calcaneal SOS values were evaluated using the CM-200 sonometer (Furuno, Nishinomiya City, Japan).

RESULTS

Subjects with higher body mass index (BMI) had higher calcaneal SOS values albeit significant difference was only found in the elderly subjects (p < 0.05). Sedentary subjects had lower calcaneal SOS values than physically active subjects, but significant difference was only found in the middle-aged subjects (p < 0.05). Calcaneal SOS was significantly (p < 0.05) correlated with age in young men; height, BMI, and physical activity score in middle-aged men; height and physical activity score in elderly men; and age and physical activity score for overall subjects. In a multivariate regression model, significant (p < 0.05) predictors for calcaneal SOS included age for young men; physical activity, BMI, body fat percentage, and height for middle-aged men; height for elderly men; and age, height, physical activity, weight, and body fat percentage for overall subjects.

CONCLUSION

Age, body anthropometry, and physical activity level have significant effects on the calcaneal SOS value in men.

Effect of community-based nutrition education intervention on calcium intake and bone mass in postmenopausal Vietnamese women

Objective

To examine the effect of community-based nutrition education intervention on calcium intake and bone mass in Vietnamese postmenopausal women.

Design

A controlled trial was conducted in two groups as intervention and control. The intervention group was given nutrition education during 18 months to improve calcium intake, while the control subjects had the usual diet. Calcium intake and bone mass were evaluated every 6 months. Bone mass was assessed by speed of sound (SOS) at calcaneus, referred to as quantitative ultrasound measurement. Anthropometric indices and serum parathyroid hormone (PTH) were determined at baseline and at the end of intervention.

Setting

Two rural communes of Hai Duong province located in the Red River Delta in Vietnam.

Subjects

A total of 140 women aged 55–65 years, who were more than 5 years postmenopausal and with low calcium intake (<400 mg/d), were recruited. After 18 months of intervention, 108 women completed the study.

Results

Calcium intake in the intervention group had increased significantly (P < 0·01) while it had no significant changes in controls. SOS values were not changed significantly in the intervention subjects while it decreased significantly by 0·5 % in the controls (P < 0·01). The intervention led to a decrease in serum PTH by 12 % (P < 0·01). In the controls, there was an increase in serum PTH by 32 % (P < 0·001).

Conclusion

Nutrition education intervention was effective in improving calcium intake and retarding bone loss in the studied subjects.

What is the role of DXA, QUS and bone markers in fracture prediction, treatment allocation and monitoring?

There is evidence that treatment can decrease the risk of fractures in osteoporotic patients, and screening of these patients is therefore relevant. Diagnosis of osteoporosis is based on the T-score calculated from bone mineral density (BMD) measurements. BMD measurements have been widely used for the management of osteoporosis, and a low BMD is a strong risk factor for fractures. But BMD measurement has several limitations in both diagnosis, prediction of fracture risk, and treatment follow-up. Quantitative ultrasound (QUS) parameters, an alternative to BMD in the assessment of bone, are independent risk factors for osteoporotic fracture. However, the use of QUS cannot be recommended for both allocation and monitoring of treatment. Biochemical markers of bone remodelling can be useful for both prediction of fracture risk and monitoring of treatment if sources of variability are controlled.

Appropriateness of internal digital phantoms for monitoring the stability of the UBIS 5000 quantitative ultrasound device in clinical trials

In bone status assessment, proper quality assurance/quality control is crucial since changes due to disease or therapeutic treatment are very small, in the order of 2-5%. Unlike for dual X-ray absorptiometry, quality control procedures have not been extensively developed and validated for quantitative ultrasound technology, limiting its use in longitudinal monitoring. While the challenge of developing an ideal anthropometric phantom is still open, some manufacturers use the concept of the internal digital phantom mimicking human characteristics to check the stability of their device. The objective of the study was to develop a sensitive model of quality control suitable for the correction of QUS patient data. In order to achieve this goal, we simulated a longitudinal device lifetime with both correct and malfunctioning behaviors. Then, we verified the efficiency of digital phantoms in detecting those changes and subsequently established the in vitro/in vivo relationship. This is the first time that an attempt to validate an internal digital phantom has made, and that this type of validation approach is used. The digital phantom (DP) was designed to mimic normal bone (BUAP2) and osteoporotic bone (BUAP1) properties. The DP was studied using the UBIS 5000 ultrasound device (DMS, France). Diverse malfunctions of the UBIS-5000 were simulated. Several series of measurements were performed on both BUAP1 and 2 and on 12 volunteers at each grade of malfunction. The effect of each simulated malfunction on in vivo and in vitro results was presented graphically by plotting the average BUA values against the percentage change from baseline. The change from baseline in BUA was modeled using linear regression, and the in vivo/in vitro ratio was obtained from the model. All experimentations influenced the measure of BUAP1 and 2 as well as the measure of our 12 volunteers. However, the degree of significance varied as a function of the severity of the malfunction, and the results also differed substantially in magnitude between in vivo and in vitro. Indeed, the DP was about 10 times more sensitive to variations of the transfer function than was the in vivo measurement, which is very reassuring. The sensitivity of the digital phantoms was reliable in the determination of simulated malfunctions of the UBIS-5000. The digital phantoms provided an accurate evaluation of the acoustic performance of the scanner, including the fidelity of transducers. In light of these results, the QC approach of the UBIS-5000 will be extremely simple to implement compared with other devices. Indeed, since the digital phantom was automatically measured during every patient measurement, the QC approach could be built on an individual level basis rather than on an average basis.

Influence of age and osteoporosis on calcaneus trabecular bone structure: a preliminary in vivo MRI study by quantitative texture analysis

Recent developments in high-resolution MR imaging techniques have opened up new perspectives for structural characterization of trabecular bone by non-invasive methods. In this study, 3-D MR imaging was performed on 17 healthy volunteers and 6 osteoporotic patients. Two different MR sequences were used to evaluate the impact on MR acquisition on texture analysis results. Images were analyzed with four automated methods of texture analysis (grey level histogram, cooccurrence, runlength and gradient matrices) enabling quantitative analysis of grey level intensity and distribution within three different regions of interest (ROI). Texture analysis is not very frequently used since the interpretation of the large number of calculated parameters is difficult. We applied multiparametric data analyses such as principal component analysis (CFA) and hierarchical ascending classification (HAC) to determine the relevant parameters to differentiate between three sets of images (healthy young volunteers, healthy postmenopaused and osteoporotic patients). The results suggest that relevant texture information (depending on the ROI localization in the calcaneus) can be extracted from calcaneus MR images to evaluate osteoporosis and age effects on trabecular bone structure if strictly the same acquisition sequences are used for all patients' examination.

Biochemical and ultrasound tests for early diagnosis of active neuro-osteoarthropathy (NOA) of the diabetic foot

OBJECTIVES

To test the effectiveness of a combined approach to an early diagnosis of neuro-osteoarthropathy (NOA) of the diabetic foot, we studied a group of outpatients with active NOA, presenting for the first time to our Diabetic Foot Clinic in 1998, by means of an integrated approach designed to assess bone turnover.

PATIENTS AND METHODS

Fifteen consecutive diabetic patients (five Type 1 and ten Type 2 diabetic individuals, age 61.9+/-12.2 years, diabetes duration 18.7+/-8.9 years, HbA(1c) 8.4+/-1.5%) with active NOA (Group 1) were compared to nine diabetic patients with chronic stable NOA (Group 2), 14 neuropathic diabetic patients without NOA (Group 3), 13 non-neuropathic diabetic patients (Group 4) and 15 healthy controls (Group 5). Determination of serum carboxy-terminal collagen telopeptide (ICTP), bone alkaline phosphatase isoenzyme (B-ALP), osteocalcin (BGP) concentrations, as well as urinary excretion of deoxypyridinoline (DPD) were obtained in all individuals for assessment of bone reabsorption and new bone formation. Moreover in all individuals quantitative ultrasound (QUS) of the calcaneal bone was performed and mass density of lumbar spine and femur bone was determined by dual-energy X-ray absorptiometry (DEXA).

RESULTS

QUS was significantly lower in the active NOA patients as compared with other groups (P<0.01), while ICTP was higher in both NOA groups (P<0.01). Urinary DPD was higher in the neuropathic non-NOA group (P<0.01) than the other groups, and osteocalcin was higher in healthy controls compared to diabetic patients without NOA. QUS and ICTP were inversely correlated (r=0.44, P=0.000). QUS in the active NOA group was significantly (P<0.01) lower in the affected compared to the unaffected foot.

CONCLUSION

Our results indicate a possible role for an integrated approach to the diagnosis and monitoring of NOA involving the diabetic foot. DPD may identify patients at-risk for NOA, ICTP could be tested as a marker for NOA in asymptomatic cases. Finally, QUS of the calcaneal bone may be useful in discriminating active versus quiescent phases.

Ultrasound of the skeleton: review of its clinical applications and pitfalls

Quantitative ultrasound (QUS) is receiving considerable attention in the assessment of osteoporosis because of its ease of use, lack of radiation exposure, region of interest, and relatively low costs. These features have made the technique appealing for screening adult and pediatric patients. This article discusses some of the clinical applications, limitations, and strengths of QUS.

Quality controls for two heel bone ultrasounds used in the Swiss Evaluation of the Methods of Measurement of Osteoporotic Fracture Risk Study

Because of the important morbidity and mortality associated with osteoporosis, it is essential to detect subjects at risk by screening methods, such as bone quantitative ultrasounds (QUSs). Several studies showed that QUS could predict fractures. None, however, compared prospectively different QUS devices, and few data of quality controls (QCs) have been published. The Swiss Evaluation of the Methods of Measurement of Osteoporotic Fracture Risk is a prospective multicenter study that compared three QUSs for the assessment of hip fracture risk in a population of 7609 women age >/=70 yr. Because the inclusion phase lasted 20 mo, and because 10 centers participated in this study, QC became a major issue. We therefore developed a QC procedure to assess the stability and precision of the devices, and for their cross-calibration. Our study focuses on the two heel QUSs. The water bath system (Achilles+) had a higher precision than the dry system (Sahara). The QC results were highly dependent on temperature. QUS stability was acceptable, but Sahara must be calibrated regularly. A sufficient homogeneity among all the Sahara devices could be demonstrated, whereas significant differences were found among the Achilles+ devices. For speed of sound, 52% of the differences among the Achilles+ was explained by the water s temperature. However, for broadband ultrasound attenuation, a maximal difference of 23% persisted after adjustment for temperature. Because such differences could influence measurements in vivo, it is crucial to develop standardized phantoms to be used in prospective multicenter studies.

Quantitative ultrasound in postmenopausal osteoporosis

Ultrasound has been proposed as a low-cost, radiation-free method for osteoporosis assessment in postmenopausal women. Large prospective studies have shown that ultrasound parameters can be used for fracture risk estimate in this population, providing that adequate quality control is performed. The places of both ultrasound and the current gold standard method for bone assessment, dual energy x-ray absorptiometry, are still to be determined. Further studies are needed on the diagnosis of osteoporosis using ultrasound, because current diagnostic thresholds, designed by the World Health Organization, do not apply to this-new technology. Monitoring of skeletal changes and treatment effects by ultrasound cannot be recommended.

Evaluation of error bounds on calcaneal speed of sound caused by surrounding soft tissue

For absorptiometry measurements, soft tissue may have an impact on quantitative ultrasound (QUS) measurements. In the present study, we focused primarily on the quantification of measurement error on speed of sound (SOS) caused by surrounding soft tissue. The relevant soft tissue parameters affecting the inherent SOS inaccuracies are thickness and sound velocity. To meet our goal, SOS measurements were taken at the right heel using a QUS imaging device in 21 healthy subjects. Site-matched measurements of soft tissue thickness (STT) and bone width were performed using magnetic resonance imaging of the heel. Several bone velocities were calculated either by accounting for bone width (SOSBW) only or by taking into account the exact path lengths of all major components traversed by ultrasound &lapr;V(b)). Given that soft tissue composition is difficult to determine in vivo, we chose to estimate lower and upper error bounds on bone velocity (V(b lower) and V(b upper)) by spanning the full range of available values in the literature. The mean BW was 30.7 +/- 2.7 mm and the mean medial and external STTs were 8.8 +/- 1.7 and 8.5 +/- 1.5 mm, respectively. Accounting for true BW only resulted in no significant difference between SOS (1533 +/- 37) and SOSBW (1531 +/- 33). By contrast, accounting for both true BW and surrounding soft tissue resulted in an increase in the calculated bone velocity and statistically significant differences between SOS and V(b upper) (1568 +/- 36) and V(b lower) (1542 +/- 34). Root mean square errors between SOS and the calculated velocities were 0.34, 2. 32, and 0.70% for SOSBW, V(b upper), and V(b lower), respectively. We report here measurement errors caused by soft tissue to be 3 to 20 times higher than the SOS short-term precision (SOS coefficient of variation of 0.1%). Our results suggest that inaccuracies in SOS measurement caused by overlying soft tissue cannot be neglected. Overlying soft tissues may influence outcomes of longitudinal studies, especially if variations in tissue thickness and composition occur during the longitudinal follow-up. A practical way of minimizing the measurement error could be to perform an adequate correction for the overlying soft tissue. However, ideally, this should require knowing both the thickness and sound velocity in soft tissue. One might preferably conduct experimental investigations that directly control soft tissue thickness and composition to resolve this problem.

Correlation of quantitative ultrasound of bone with biochemical markers of bone resorption in women with osteoporotic fractures

The purpose of this study was to examine the correlation of parameters of bone quality assessed by quantitative ultrasound (QUS) with biochemical indexes of bone resorption. QUS of the calcaneus and the hand phalanges, and biochemical parameters (urinary excretion of pyridinoline [Pyr] and deoxypyridinoline [D-Pyr]) were measured in a group of 30 well-characterized postmenopausal women with established osteoporosis and fragility fractures. All patients were treatment free. QUS data significantly correlated with both urinary Pyr and D-Pyr (p < 0.001 for speed of sound [SOS], broadband ultrasound attenuation [BUA], and stiffness at the heel; p < 0.001 for amplitude-dependent SOS at the proximal phalanges of the nondominant hand). No significant correlation was observed between spine and femoral bone mineral density and the urinary excretion of Pyr and D-Pyr. Results of this study suggest that QUS of bone evaluates characteristics of bone influenced by the bone resorption rate.

Evaluation of quantitative ultrasound and dual X-Ray absorptiometry measurements in women with and without fractures

Dual X-ray absorptiometry (DXA) is considered a gold standard for bone measurements in the assessment of osteoporosis. Other techniques such as quantitative ultrasound (QUS) are promising to detect patients with osteoporosis-related fractures and to predict fracture risk. In this cross-sectional retrospective study, we analyzed the behavior of QUS and DXA measurements alone and in combination with regard to the presence of fractures in 320 women, 147 with nontraumatic fractures. Speed of sound (SOS), broadband ultrasound attenuation (BUA), and a third parameter derived from SOS and BUA called stiffness were measured at the calcaneus using an Achilles device (Lunar, Madison, WI). Lumbar (BMDL) and hip (BMDH( bone mineral density were measured by DXA (Hologic QDR 1000, Waltham, MA). Mean SOS, BUA, stiffness, and BMDL and BMDH were significantly lower in women with fractures compared with women without fractures. Logistic regression adjusted for age identified stiffness as the parameter most strongly associated with the presence of fracture: its sensitivity was 54% and specificity 70%. Hip BMD was second, with a sensitivity of 54% and a specificity of 69%. Combining QUS and DXA measurements did not improve the specificity nor the sensitivity. There was no difference in the odds ratios with regard to the technique that was chosen for bone assessment. In conclusion, these results suggest that low QUS measurements are associated with the presence of fractures in a way similar to DXA. In our study, the combination of QUS and DXA did not improve the discrimination of women with fractures.