Diagnostic agreement of two calcaneal ultrasound devices: the Sahara bone sonometer and the Achilles+

The correlation between calcaneus stiffness index calculated by QUS and total body BMD assessed by DXA in Chinese children and adolescents

Few studies have shown comparison data between calcaneus stiffness index (SI) calculated by quantitative ultrasound (QUS) and bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) in the Chinese population. This study was aimed to examine the correlations between calcaneus SI calculated by QUS and total body BMD and bone mineral content (BMC) measured by DXA in Chinese children and adolescents. We measured the total body BMD and BMC using Lunar Prodigy (GE Healthcare), and speed of sound (SOS), broadband ultrasound attenuation (BUA), and a calculated SI of the left os calcis using Lunar Achilles Express (GE Healthcare) in 392 healthy Chinese schoolchildren and adolescents aged 5-19 years. The short-term precision for DXA was 0.5 % for total body BMD. The precision for QUS was 1.8 % for SI, 2.9 % for BUA, and 0.4 % for SOS. Pearson's correlation coefficients (r) were calculated to assess the possible correlations between the total body BMC by DXA and SI calculated by QUS. There were significantly positive correlations between SI of the left os calcis and total body BMD (r = 0.693, p < 0.001, n = 392) and BMC (r = 0.690, p < 0.001, n = 392). For all the subjects, significant positive correlations were observed between the calcaneal SI and the age, weight, height, BMI, total body BMD, total body BMC, total body lean mass, and total body fat mass, with r ranging from 0.310 (total body fat mass) to 0.693 (total body BMD) (p < 0.001, n = 392). In conclusion, QUS bone densitometry is a useful measuring method showing the physiological bone development in childhood and adolescence.

Normative calcaneal quantitative ultrasound data for the indigenous Shuar and non-Shuar Colonos of the Ecuadorian Amazon

Minimal data on bone mineral density changes are available from populations in developing countries. Using calcaneal quantitative ultrasound (QUS) techniques, the current study contributes to remedying this gap in the literature by establishing a normative data set on the indigenous Shuar and non-Shuar Colonos of the Ecuadorian Amazon.

PURPOSE

The paucity of bone mineral density (BMD) data from populations in developing countries partially reflects the lack of diagnostic resources in these areas. Portable QUS techniques now enable researchers to collect bone health data in remote field-based settings and to contribute normative data from developing regions. The main objective of this study is to establish normative QUS data for two Ecuadorian Amazonian populations-the indigenous Shuar and non-Shuar Colonos. The effects of ethnic group, sex, age, and body size on QUS parameters are also considered.

METHODS

A study cohort consisting of 227 Shuar and 261 Colonos (15-91 years old) were recruited from several small rural Ecuadorian communities in the Upano River Valley. Calcaneal QUS parameters were collected on the right heel of each participant using a Sahara bone sonometer. Three ultrasound generated parameters were employed: broadband ultrasound attenuation (BUA), speed of sound (SOS), and calculated heel BMD (hBMD).

RESULTS

In both populations and sexes, all QUS values were progressively lower with advancing age. Shuar have significantly higher QUS values than Colonos, with most pronounced differences found between pre-menopausal Shuar and Colono females. Multiple regression analyses show that age is a key predictor of QUS while weight alone is a less consistent determinant. Both Shuar males and females display comparatively greater QUS parameters than other reference populations.

CONCLUSIONS

These normative data for three calcaneal QUS parameters will be useful for predicting fracture risk and determining diagnostic QUS criteria of osteoporosis in non-industrialized populations in South America and elsewhere.

Precision of Lunar Achilles+ bone quality measurements: time dependency and multiple machine use in field studies

Qualitative ultrasound (QUS) is a portable, safe and relatively inexpensive technique used to obtain information on bone mineral quality in adults and children. QUS measures bone stiffness index (SI) through the incorporation of speed of sound (SOS) and broadband ultrasound attenuation (BUA). QUS technology may prove to be extremely useful in field research where more than one machine is used over different periods of time. 13 adults (27.6+/-4.6 years old) were recruited to determine the internal stability of two Lunar Achilles+ QUS machines (Lunar1, Lunar2), as well as the repeatability in bone stiffness measures between the two machines over time. Triplicate measurements of the calcaneus were taken within the same day (n = 258) and at 1 week (n = 120), 6 months (n = 54) and 1 year (n = 18) apart to determine the time-dependent repeatability. Using paired t-tests and separate mixed effects models, there were no differences reported in SI, SOS or BUA values within one machine, or between two machines over these short- and long-term time-frames. These results indicate that QUS machines are internally consistent and different machines may be used over time to provide reliable measurements of changes in bone quality.

Comparisons of bone mass measurements on various skeletal sites including quantitative ultrasonography of the calcaneus for assessing age-related losses, their correlations, and diagnostic agreement using the Japanese and WHO criteria for osteoporosis

PURPOSE

The aim of this study was to compare age-related bone losses and correlations among several bone mass measurements and to evaluate diagnostic agreement among them using the Japanese and WHO criteria for osteoporosis.

MATERIALS AND METHODS

A total of 846 women (mean +/- SD: age 54 +/- 9 years) were evaluated. Bone mineral densities of the lumbar spine, femoral neck, and calcaneus were measured by dual X-ray absorptiometry and distal radius by peripheral computed tomography. Quantitative ultrasonography (QUS) parameters of the calcaneus were also measured. The age-related bone losses after 50 years of age and correlations among bone mass results were evaluated using linear regression analysis. Diagnostic agreement was evaluated by kappa statistics.

RESULTS

The annual losses ranged from 1.0% to 1.6%. The correlation coefficients ranged from 0.54 to 0.78. The kappa scores ranged from 0.52 to 0.30 for all subjects using the Japanese criteria and from 0.38 to 0.15 using the WHO criteria.

CONCLUSION

Bone mass measurements including QUS on various skeletal sites documented age-related changes similarly, and their bone masses correlated moderately. The diagnostic agreements among them were fair to poor. To screen out women with a risk of osteoporosis, it is important to choose which technique to use and which skeletal site to measure.

Osteoporosis: Point-of-Care Testing

OBJECTIVE

To review the literature concerning the utility of point-of-care (POC) testing devices for the diagnosis and management of osteoporosis.

DATA SOURCES

Articles were identified from a MEDLINE search (1993–June 2003). Additional references were obtained from cross-referencing the bibliographies of selected articles.

STUDY SELECTION AND DATA EXTRACTION

After evaluation of clinical trials and select review articles, articles comparing peripheral dual-energy absorptiometry (pDXA) or quantitative ultrasound (QUS) with central DXA (cDXA) measurements were emphasized in this analysis.

DATA SYNTHESIS

Sensitivity for detecting osteoporosis by QUS or pDXA varies widely (range 35–75%). Using adjusted T-score cutoffs increases sensitivity to 85–95%, at the price of reducing device specificity to 23–49%. Many states require a radiology technician to perform pDXA tests.

CONCLUSIONS

POC testing with peripheral devices should only be considered in areas with limited access to cDXA or for women who initially refuse cDXA testing. T scores of −1.0 or less with POC testing typically require further evaluation via cDXA. Many states require pDXAs to be performed by certified radiology technologists, making QUS use more feasible for pharmacists. POC testing should not be used for assessing response to osteoporosis therapy.