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

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.

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.

The effect of including quantitative heel ultrasound in models for estimation of 10-year absolute risk of fracture

The role of quantitative ultrasound (QUS) in clinical practice is debatable. An unanswered question is that whether combining QUS and BMD measurements could improve the prediction of fracture risk. We examined this in a sample of men and women in the European Prospective Investigation into Cancer (EPIC)-Norfolk who had both heel QUS and hip DXA between 1995 and 1997 and were followed for any incident fracture up to 2007. From 1455 participants (703 men) aged 65-76 years at baseline, 79 developed a fracture over 10.3+/-1.4 years of follow-up. Two separate sex-stratified Cox proportional-hazard models were used including clinical risk factors and total hip BMD. Heel broadband ultrasound attenuation (BUA) was also included in the second model. Global measures of model fit, area under ROC curve, and the Hosmer-Lemeshow statistic showed relative superiority of the model including BUA. Using each model, we calculated 10-year absolute risk of fracture for all participants and categorized them in groups of < 5%, 5% to < 15%, and > or = 15%. Comparison of groupings showed a total re-classification of 16.6% of participants after inclusion of BUA with the greatest re-classification (30.7%) among the group with intermediate risk. Adding a QUS measurement to models based on clinical risk factors and BMD improves the predictive power of models and suggests that further attention should be paid to QUS as a clinical tool for fracture risk assessment.

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.

Calcaneus ultrasonometry and dual-energy X-ray absorptiometry for the evaluation of vertebral fracture risk

The aim of this retrospective, cross-sectional, controlled, non-population-based study was to evaluate the specificity and sensitivity of quantitative ultrasonometry (QUS) of the heel and of dual-energy X-ray absorptiometry (DXA) in the prediction of morphometric vertebral fracture in postmenopausal women and to establish whether the combination of the two devices could improve the capacity to identify the presence of vertebral fracture. Also, we tried to identify the best T-score threshold for high risk of vertebral fracture for both QUS and DXA, highlighting the discrepancies between the two methodologies and between the various sites examined with DXA. From 6,300 patients examined by DXA (total body, lumbar spine, total femur, femoral neck), QUS and DXA vertebral morphometry (MXA), we selected 764 postmenopausal women with nontraumatic vertebral fractures; 770 postmenopausal women with normal morphometry were chosen as a control group. Logistic regression analysis yielded odds ratios (ORs) for bone mineral density (BMD) measurements and QUS that were comparable: BMD-total body 4.16, BMD-lumbar spine 4.80, BMD-total femur 3.77, BMD-femoral neck 3.86, and QUS 4.41, without statistical differences even after correction for different confounding variables (menopausal years, weight, height, body mass index, and age). The ORs obtained from different combinations of QUS and DXA results did not show statistically significant differences compared to those from a single method alone. The sensitivity and specificity of all measurements were determined by area using the receiver operating characteristic curve; these were 0.94 for total body, 0.95 for lumbar spine, 0.86 for total femur, 0.89 for femoral neck, and 0.93 for QUS, without statistical difference. The areas under the curve obtained from the combination of QUS and DXA were higher but without statistical significance compared to QUS alone. In conclusion, both QUS and DXA were able to discriminate women with fracture from women without fracture and independently contributed to determining the association with fracture. The combination of QUS and BMD did not improve the diagnostic ability of either individual technique. We found different diagnostic thresholds for QUS and DXA.

Quantitative ultrasound and dual-energy X-ray absorptiometry in the prediction of fragility fracture in men

Fragility fractures in men represent a major health problem, and this prompts a necessity for reliable tools for the identification of men at risk of fracture. In order to assess the ability of dual-energy X-ray absorptiometry (DXA) and quantitative ultrasound (QUS) in the prediction of fracture risk in men and whether their combination might be useful in a clinical setting, we studied 401 men (age range 45-82 years, mean 60.3+/-12.5), of whom 133 had osteoporotic fractures and 268 did not. In all subjects we measured bone mineral density at the lumbar spine (BMD-LS) and at the femur, calculating thereafter the standard femoral subregions: neck (BMD-FN), total hip (BMD-T), trochanter (BMD-TR), intertrochanter (BMD-ITR), and Ward's triangle (BMD-W), by DXA. We also performed ultrasound parameters at the calcaneus: speed of sound (SOS), broadband ultrasound attenuation (BUA) and Stiffness, by Achilles plus, and at the phalanxes: amplitude dependent speed of sound (AD-SoS) and the parameters of the graphic trace: bone transmission time (BTT), fast wave amplitude (FWA), signal dynamic (SDy) and ultrasound bone profile index (UBPI), by Bone Profiler. All DXA and QUS parameters, apart from FWA, were significantly (P<0.001) lower in patients with a history of fracture. BMD at the proximal femur showed the best ability in discriminating men with or without fractures. QUS at the heel showed discriminatory ability significantly better than QUS at the fingers. By logistic regression analysis, adjusted for age and BMI, BMD-T showed the best association with fragility fracture [odds ratio (OR)=3.43, 95% confidence interval (CI)=2.47-4.77]. Among QUS parameters, the highest value of the OR was shown by stiffness (OR=3.18, CI=2.27-4.48). FWA and SDy were not associated with fragility fractures in men. If DXA and QUS were combined, the prediction of the OR of fragility fracture events in men increases; in fact Stiffness was able to increase the OR when added to BMD-LS (OR=5.44, CI=3.16-10.13) and BMD-T (OR=6.08, CI=2.63-14.27). SOS and BUA showed a similar pattern. AD-SoS improved the prediction of fracture only when combined with BMD-LS (OR=4.36, CI=1.99-9.57). If BMD-LS and BMD-FN or BMD-T were combined, the value of the OR increases (OR=4.59, CI=2.27-9.25 and OR=4.68, CI=2.24-9.76), respectively. Our study supports the effectiveness of QUS in the identification of osteoporotic fractures in men. QUS seems to play an independent and complementary role, with respect to DXA, in order to enhance the power for predicting osteoporotic fractures in men.

Osteoporosis Screening and Education in Community Pharmacies Using a Team Approach

STUDY OBJECTIVES

To develop a model for osteoporosis screening and education in community pharmacies using a team approach, compare bone mineral density T-scores between quantitative ultrasound (QUS) and dual-energy x-ray absorptiometry (DXA), and determine patient satisfaction with this pharmacist-provided osteoporosis screening and education program.

DESIGN

Prospective, cross-sectional study.

SETTING

Community pharmacies and outpatient family medicine, internal medicine, and obstetrics and gynecology clinics in Amarillo, Texas.

PATIENTS

Women aged 55 years or older with no previous diagnosis of osteoporosis or osteopenia who had at least one additional risk factor for osteoporosis and had not been screened in the previous 3 years.

INTERVENTION

Patients were referred from family medicine, internal medicine, and obstetrics and gynecology clinics to a community pharmacy. Osteoporosis screening using heel QUS and education regarding disease prevention and treatment were provided by pharmacists. Screening results, recommendations for confirmatory DXA, and potential treatments options were provided to the referring physicians.

MEASUREMENTS AND MAIN RESULTS

A total of 100 patients (mean age 66.2+/-7.9 yrs) were enrolled in the study; three were subsequently excluded. Of the 97 study patients who were screened using QUS, 45 (46%) patients were at moderate risk (T-score<-1 to>-2.5) and nine (9%) were at high risk (T-score<or=-2.5). Of 54 patients recommended for DXA referral, 20 (37%) completed the scan. All 20 were diagnosed with either osteopenia (9 patients [45%]) or osteoporosis (11 patients [55%]). Correlation was moderate between T-scores obtained by QUS and DXA of lumbar vertebrae 1-4 (r=0.45, p=0.026). Counseling regarding risk factors, screening results, smoking cessation, calcium intake, exercise, and caffeine intake was perceived by patients as valuable or highly valuable (medians for all items ranged from 4-5 on a 5-point Likert scale). Of 84 patients assessed (13 were lost to follow-up), 81 (96%) said they would recommend this service to others.

CONCLUSION

Osteoporosis screening and education in community pharmacies are effective in detecting undiagnosed disease and are perceived by patients as highly useful.

Diagnostic performance of quantitative ultrasound calcaneus measurement in case finding for osteoporosis in Thai postmenopausal women

AIM

Dual-energy X-ray absorptiometry (DXA) is currently considered the gold standard for the diagnosis of osteoporosis. Quantitative ultrasound (QUS) can be an alternative method that is less expensive, portable, and can be used at a primary care level to indicate osteoporosis in women. The present study aimed to assess the diagnostic performance of QUS calcaneus measurement in a case finding for osteoporosis in Thai postmenopausal women using DXA as a gold standard.

METHODS

Three hundred postmenopausal women, who had not menstruated normally for at least 1 year, were included in the study. To determine the accuracy and reliability of QUS of the calcaneus, calcaneus bone density measurement was carried out using the QUS and left femoral neck bone density was measured using DXA. Bone mass density (BMD) was interpreted as osteoporotic or normal using WHO criteria for determining the performance of QUS. Optimal cut-off values were determined using a receiver operating characteristic (ROC) curve for diagnosing the osteoporosis cases.

RESULTS

The number of osteoporosis cases in this study was 107 (35.67%). The sensitivity, specificity, positive and negative predictive values were 39.25%, 91.71%, 72.41%, 73.14%, respectively, when using the T-score of the WHO criteria as a reference. The positive and negative likelihood ratios were 4.73 and 0.66. When using the ROC curve to determine the optimal cut-off values, using the stiffness index of the QUS and categorizing age (<65 years and >or=65 years) before conducting the test, sensitivity and specificity were 77.6% and 59.6%, respectively.

CONCLUSIONS

Bone mass density measurement for predicting osteoporosis using QUS had a very low sensitivity and was not good enough to replace the standard tool (DXA).

Discrimination of osteoporotic patients with quantitative ultrasound using imaging or non-imaging device

OBJECTIVES

Quantitative ultrasound (QUS) has emerged as a new tool in the assessment of fracture risk. The aim of this study was to compare the clinical utility of QUS parameters measured using imaging and non-imaging devices in the discrimination of osteoporotic patients.

METHODS

QUS (Broadband Ultrasound Attenuation, BUA dB/MHz, and Speed of Sound, SOS m/s) were measured and then statistical analyses were performed.

RESULTS

The 106 women included were 65 +/- 8 years aged. Using DXA, T score was < or = -2.5 at either lumbar spine or hip in 59% of patients, and 25% had osteoporotic fractures. QUS results were different among devices, and these differences were highly dependent on the measured value. There was a similar effect of age and duration of menopause for all parameters. To obtain 90% of sensitivity for the diagnosis of osteoporosis, the thresholds were 50.80 and 71.70 dB/MHz for BUA and 1544.80 and 1551.50 m/s for SOS, using imaging and non-imaging devices, respectively. Belonging to the highest tertile of QUS had a negative predictive value for osteoporosis ranging from 59% to 65%. In the lowest tertile of QUS, the proportion of osteoporotic women was between 73% and 80%. All QUS parameters, except BUA measured with the non-imaging device, were able to discriminate post-menopausal women with fractures after adjustment for age and hip BMD.

CONCLUSIONS

Our data suggest that an imaging system improves the utility of BUA measurement, but not SOS, for post-menopausal osteoporosis assessment.

Discriminative capacity of calcaneal quantitative ultrasound and of osteoporosis and fracture risk factors in postmenopausal women with osteoporotic fractures

Bone fragility fractures constitute the principal complication of osteoporosis. The identification of individuals at high risk of sustaining osteoporotic fractures is important for implementing preventive measures. The purpose of this study is to analyze the discriminative capacity of a series of osteoporosis and fracture risk factors, and of calcaneal quantitative ultrasound (QUS), in a population of postmenopausal women with a history of osteoporotic fracture. A cross-sectional analysis was made of a cohort of 5195 women aged 65 or older (mean +/- SD: 72.3 +/- 5.4 years) seen in 58 primary care centers in Spain. A total of 1042 women (20.1%) presented with a history of osteoporotic fracture. Most fractures (93%) were non-vertebral. Age-adjusted odds ratios corresponding to each decrease in one standard deviation of the different QUS parameters ranged from 1.47 to 1.55 (P < 0.001) for fractures. The age-adjusted multivariate analysis yielded the following risk factors independently associated with a history of osteoporotic fracture: number of fertile years, a family history of fracture, falls in the previous year, a history of chronic obstructive airway disease, the use of antiarrhythmic drugs, and a low value for any of the QUS parameters. The area under the receiver operating characteristic curve of the best model was 0.656. In summary, a series of easily assessable osteoporotic fracture risk factors has been identified. QUS was shown to discriminate between women with and without a history of fracture, and constitutes a useful tool for assessing fracture risk. Various of the vertebral and hip fracture risk factors frequently cited in North American and British populations showed no discriminative capacity in our series--thus suggesting that such factors may not be fully applicable to our population and/or to the predominant type of fractures included in the present study.

Discriminatory ability of quantitative ultrasound parameters and bone mineral density in a population-based sample of postmenopausal women with vertebral fractures: results of the Basel Osteoporosis Study

The discriminatory potential to classify subjects with or without vertebral fractures was tested cross-sectionally with different methods for the measurement of bone status in a population-based sample of postmenopausal women. Quantitative ultrasound (QUS) measurement at the calcaneus (Lunar Achilles, Hologic Sahara), the proximal phalanges (Igea Bone Profiler), and measurement of bone mineral density (BMD) with dual-energy X-ray absorptiometry (DXA; Lunar Expert) at several anatomic sites was performed in 500 postmenopausal women (aged 65-75 years) randomly selected from the population. In addition, 50 young female subjects (20-40 years old) had QUS measurements and served as controls to express QUS results as T-score values. Radiographs of the lumbar and thoracic spine were performed in the elderly women. Two independent radiologists reviewed the X-rays for the presence of vertebral fractures. Of 486 eligible study participants, no fracture was seen in 396 participants. Single vertebral fractures were observed in 71 subjects; 19 individuals presented multiple fractures. The overall prevalence of vertebral fractures was 18.5%. Participants without vertebral fractures were compared with subjects with vertebral fractures. Normal statistical distributions were found for all bone measurement results. Risk of vertebral fracture in subjects with no and multiple vertebral fracture was estimated using age adjusted odds ratios (ORs) for QUS and dual-energy X-ray absorptiometry (DXA) values. Each SD decrease in bone measurement increased the risk of multiple vertebral fracture by 3.0 (95% CI, 1.6-5.6) for the Achilles stiffness, by 3.8 (95% CI, 1.8-8.2) for the Sahara QUI, 2.1 (95% CI, 1.3-3.4) for the Bone Profiler amplitude-dependent speed of sound (AD-SOS), and 2.1 (95% CI, 1.2-3.9) and 2.4 (95% CI, 1.3-4.3) for DXA lumbar spine and for DXA total hip, respectively. Results of a discriminant analysis showed sensitivities between 84% and 58% and specificities between 72% and 58% for the respective DXA and QUS parameters. Optimum fracture thresholds for QUS measurements derived from this analysis were calculated also. Optimum T-score threshold values for QUS measurements tended to be higher than those for DXA measurements. However, the performance of QUS measurements is at least comparable with DXA measurements in identifying subjects with multiple vertebral fractures randomly selected from the population.

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.