Osteopenia and Osteoporosis Screening Detection: Calcaneal Quantitative Ultrasound with and without Calibration Factor Comparison to Gold Standard Dual X-ray Absorptiometry.

BACKGROUND: osteoporosis is a worldwide major health problem that normally diagnosed in advanced stages. So, an early detection at preclinical stage is now an interesting issue. A key factor to early diagnosis the disease is the used of noninvasive bone densitometry. Dual energy x-ray absorptiometry (DXA) is the gold standard techniques for the proposed. However, the high cost, non-widely available and exposed to ionizing radiation are still a drawback of the machine. Therefore, a cheaper, smaller and non-ionizing device such quantitative ultrasound (QUS) is now a favor alternative method, but the possibility of used QUS measurement instead of DXA is still limited due to their uncertainties. So, the aim of our study was to calibrated the QUS with the DXA to allowing the possible to establish a calibration factor (CF) to improve the measured value closer to the standard method. METHODOLOGY: 135 healthy men and women aged 30-88 years were recruited for lumbar spine/femoral neck DXA and calcaneal QUS scanning. The Pearson's correlation between T- and Z-score from the two systems were studied. Moreover, the sensitivity, specificity and percentage of diagnosed accuracy for both with and without CF were calculated. RESULTS: The significant correlation between the two systems showed a positive trajectory in highly correlation (r = 0.784-0.899). Analyses showed a higher sensitivity, specificity and reduced the misdiagnosed rates when applied the CF in QUS values. CONCLUSIONS: QUS results showed a significantly correlated with DXA results for both lumbar spine and femoral neck sites with some percentage differences. These differences can be reduced by applied an individual specific machine CF to improve a QUS results. As identification of high risk of osteopenia and osteoporosis to reduce the demand of DXA propose, using a QUS alternative method can be a reliable that provide a cheaper and lack of ionizing radiation.

MicroRNAs as potential biopredictors for premenopausal osteoporosis: a biochemical and molecular study.

BACKGROUND: Circulating micro-RNAs have been proposed as a new type of biomarker in several diseases, particularly those related to bone health. They have shown great potential due to their feasibility and simplicity of measurement in all body fluids, especially urine, plasma, and serum. AIM: This study aimed to evaluate the expression of a set of mRNAs, namely miR-21, miR-24, mir-100, miR-24a, miR-103-3p, and miR-142-3p. Their proposed roles in the progression of osteoporosis were identified using a real-time polymerase chain reaction (RT-PCR) analysis in premenopausal women. In addition, their correlations with osteocalcin (OC), bone-specific alkaline phosphatase (BAP), and deoxypyridinoline (DPD) bone markers were explored. METHODS: A total of 85 healthy premenopausal women aged 25-50 years old were included in this study. Based on a DXA scan (Z-score) analysis and calcaneus broadband ultrasound attenuation scores (c-BUAs), measured via quantitative ultrasound (QUS), the subjects were classified into three groups: normal group (n = 25), osteopenia (n = 30), and osteoporosis (n = 30). Real-time-PCR and immunoassay analyses were performed to determine miRNA expression levels and serum OC, s-BAP, and DPD, respectively, as biomarkers of bone health. RESULTS: Among the identified miRNAs, only miR-21, miR-24, and mir-100 were significantly upregulated and increased in the serum of patients with osteopenia and osteoporosis, and miR-24a, miR-103-3p, and miR-142-3p were downregulated and significantly decreased in osteoporosis. Both upregulated and downregulated miRNAs were significantly correlated with BMD, c-BUA, OC, s-BAP, and DPD. CONCLUSION: A group of circulating miRNAs was shown to be closely correlated with the parameters BMD, c-BUA, OC, s-BAP, and DPD, which are traditionally used for bone-health measurements. They could be identified as non-invasive biomarkers in premenopausal patients with osteoporosis. More studies with large sample sizes are recommended to estimate the mechanistic role of miRNAs in osteoporosis pathogenesis and to provide evidence for the use of these miRNAs as a non-invasive method of diagnosing clinical osteoporosis, especially in premenopausal patients.

Pulse-Echo Technique to Compensate for Laminate Membrane Transmission Loss in Phantom-Based Ultrasonic Attenuation Coefficient Measurements.

OBJECTIVES: Accurately measuring the attenuation coefficient (AC) of reference phantoms is critical in clinical applications of quantitative ultrasound. Phantom AC measurement requires proper compensation of membrane transmission loss. Conventional methods require separate membrane samples to obtain membrane transmission loss. Unfortunately, separate membrane samples are often unavailable. A pulse-echo approach is proposed herein to compensate for membrane transmission loss without requiring separate membrane samples. METHODS: The proposed method consists of the following steps. First, the insertion loss, caused by phantom attenuation and membrane transmission loss, is measured. Second, the membrane reflection coefficient is measured. Third, the unknown acoustic parameters of the membrane and phantom material are estimated by fitting theoretical reflection coefficient to the measured one. Finally, the fitted parameters are used to estimate membrane transmission loss and phantom AC. The proposed method was validated through k-Wave simulations and phantom experiments. Experimental AC measurements were repeated on 5 distinct phantoms by 2 operators to assess the repeatability and reproducibility of the proposed method. Five transducers were used to cover a broad bandwidth (0.7-16 MHz). RESULTS: The acquired AC in the simulations had a maximum error of 0.06 dB/cm-MHz for simulated phantom AC values ranging from 0.5 to 1 dB/cm-MHz. The acquired AC in the experiments had a maximum error of 0.045 dB/cm-MHz for phantom AC values ranging from 0.28 to 1.48 dB/cm-MHz. Good repeatability and cross-operator reproducibility were observed with a mean coefficient of variation below 0.054. CONCLUSION: The proposed method simplifies phantom AC measurement while providing satisfactory accuracy and precision.

Review of Envelope Statistics Models for Quantitative Ultrasound Imaging and Tissue Characterization.

The homodyned K-distribution and the K-distribution, viewed as a special case, as well as the Rayleigh and the Rice distributions, viewed as limit cases, are discussed in the context of quantitative ultrasound (QUS) imaging. The Nakagami distribution is presented as an approximation of the homodyned K-distribution. The main assumptions made are (1) the absence of log-compression or application of nonlinear filtering on the echo envelope of the radiofrequency signal and (2) the randomness and independence of the diffuse scatterers. We explain why other available models are less amenable to a physical interpretation of their parameters. We also present the main methods for the estimation of the statistical parameters of these distributions. We explain why we advocate the methods based on the X-statistics for the Rice and the Nakagami distributions and the K-distribution. The limitations of the proposed models are presented. Several new results are included in the discussion sections, with proofs in the appendix.

Dietary Saturated Fat and Bone Health in Young Adults: The Young Finns Cohort.

Previous studies suggest that saturated fat (SFA) intake may negatively impact on bone. However, few human studies on the topic exist. Women and men aged 31-46 years from the Cardiovascular Risk in Young Finns study attended the peripheral quantitative computed tomography and ultrasound bone measurements in 2008 (n = 1884-1953, ~ 56% women). In addition, fracture diagnoses in 1980-2018 were searched for the national health care registers and 431 participants had at least one fracture. Food consumption was gathered with the 48-h dietary recall interviews and food frequency questionnaire in 1980-2007. In the present study, radial, tibial, and calcaneal bone traits, and fractures were examined relative to the long-term intake of SFA. No consistent associations were seen between bone outcomes and SFA intake that would have replicated in both women and men. The only evidence for differential distributions was seen in cortical density and cortical-to-total area ratio at the radial shaft, and speed of sound at the calcaneus, which were 0.1-0.4% higher in women in the lowest tertile of SFA intake compared with the highest tertile. In addition, among men, the odds ratio (OR) of fractures was greater in the second (OR 1.86, 95% confidence interval (CI) 1.03-3.33) and third tertile of SFA intake (OR 2.45, 95% CI 1.38-4.36) compared with the lowest tertile, independently of many risk factors of osteoporosis. In this observational study, we found no robust evidence of the associations of dietary long-term SFA intake with bone outcomes. Therefore, additional studies are needed to confirm the association of dietary SFA with bone health in humans.

Relationships between QUS and HR-pQCT, DXA, and bone turnover markers.

INTRODUCTION: Relationship of quantitative ultrasound (QUS) with high-resolution peripheral quantitative computed tomography (HR-pQCT), dual-energy X-ray absorptiometry (DXA), and bone-related biochemical markers was analyzed. MATERIALS AND METHODS: The subjects were 480 individuals. Speed of sound (SOS) was measured by calcaneal QUS. Volumetric bone mineral density (vBMD) and microarchitecture of trabecular and cortical bone in the distal radius and tibia were assessed by HR-pQCT. Areal bone mineral density (aBMD) in the lumbar spine and proximal femur were measured by DXA. TRACP-5b, P1NP, 25 (OH) vitamin D, and pentosidine were evaluated by biochemical tests. The correlation of each parameter was analyzed for all subjects and by sex and age group. RESULTS: QUS was moderately correlated with Tb.vBMD and Tb.BV/TV in the radius and tibia. No correlation was seen with Ct.vBMD or cortical porosity (Ct.Po). Although a correlation was seen with cortical thickness (Ct.Th) in the tibia in all subjects, no correlation was seen in women aged ≥ 60 years. QUS showed moderate correlations with aBMD in the proximal femur. Although moderate correlation was seen with aBMD in the lumbar spine in all subjects, no correlation was seen in subjects aged ≥ 60 years. No significant correlations were seen between QUS and biochemical markers. CONCLUSIONS: Moderate correlations were seen between QUS and Tb.vBMD and microarchitecture in the radius and tibia and aBMD of the proximal femur. On the other hand, practically no correlations were seen with Ct.vBMD or Ct.Po and the bone-related biochemical markers. Only in middle age, moderate correlations were seen with Ct.Th in the tibia and with aBMD of the lumbar spine.

Development of a QUS Device to Evaluate Deterioration of Cortical Bone: Verification by HR-pQCT and Measurements in Healthy Individuals and Dialysis Patients.

INTRODUCTION: The objectives of this study were to identify what is reflected in cortical speed of sound (cSOS) measured by a cortical quantitative ultrasound (cortical QUS) device we have developed, and to investigate cSOS measurements in healthy individuals and dialysis patients. METHODS: The cSOS and the SOS were measured by cortical QUS and conventional QUS in 20 volunteers, and the correlations between these measurements and areal bone mineral density measured by dual-energy X-ray absorptiometry and bone microstructural parameters on high-resolution peripheral quantitative computed tomography were analyzed. The cSOS and the SOS were measured in 91 young adults (47 men, 44 women), 64 elderly people (30 men, 33 women), and 64 dialysis patients (33 men, 31 women). The period of hemodialysis and intact parathyroid hormoneevels were also investigated in the dialysis patients. RESULTS: cSOS was correlated with cortical tissue mineral density (tibia: r = 0.74, radius: r = 0.72) on high-resolution peripheral quantitative computed tomography, reflecting the degree of minaralization and microporosity of cortical bone. There was no correlation with the thickness of cortical bone, suggesting that it measured the bone quality rather than bone mass. Elderly women had lower cSOS than young adults (3865 ± 74 vs 3971 ± 63 m/s, p < 0.01). Many of dialysis patients showed very low cSOS and it was related to higher intact parathyroid hormone levels (male: ß = -0.67, female: ß = -0.60). CONCLUSIONS: Our cortical QUS device is capable of evaluating the qualitative degradation of cortical bone, which cannot be assessed by conventional QUS, and its use in combination with conventional QUS may provide a better understanding of fracture risk.

Bone strength of the proximal femur in healthy subjects with ossification of the posterior longitudinal ligament.

We compared the bone strength measured via quantitative computed tomography-based finite element method (QCT/FEM) between healthy adults with and without ossification of the posterior longitudinal ligament (OPLL). No statistically significant difference was observed in the bone strength between healthy adults with and without OPLL. Hyperostosis of the posterior longitudinal ligament in OPLL may not be associated with the systemic bone strength. INTRODUCTION: Although patients with OPLL have been reportedly associated with increased level of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA), little is known about the bone strength in OPLL subjects. The aim of this study is to investigate the bone strength measured via QCT/FEM in healthy subjects with OPLL using the medical check-up data, including whole-body CT scans. METHODS: We examined 796 participants (529 men and 267 women) who underwent CT scans in a single health center between January 2008 and May 2009. We identified OPLL in whole spine and divided the subjects into two groups: non-OPLL and OPLL groups. We calculated the predicted bone strength (PBS) of the proximal femur using QCT/FEM and examined the bone mineral status of the calcaneus using quantitative ultrasound (QUS). We compared the PBS and the QUS parameters between the non-OPLL and OPLL groups. RESULTS: Seventy-four subjects (9.3%; 57 men and 17 women) were diagnosed with OPLL in the whole spine. The OPLL group was significantly older than the non-OPLL group. No statistically significant difference was observed in the PBS and the QUS parameters between the non-OPLL and OPLL groups in both sexes. Furthermore, no statistically significant difference was noted in the PBS and the QUS parameters between two groups in age- and gender-matched analysis. CONCLUSIONS: Our results suggest that hyperostosis of the posterior longitudinal ligament in OPLL may not be associated with bone strength and bone mineral status at the extremities.

Association between frailty and bone loss in patients undergoing maintenance hemodialysis.

Frailty is significantly associated with bone loss in the general population. However, it is unclear whether this association also exists in patients undergoing hemodialysis who have chronic kidney disease-mineral and bone disorder (CKD-MBD). This study aimed to assess the association between frailty and bone loss in patients undergoing hemodialysis. This cross-sectional study included 214 (90 women, 124 men) Japanese outpatients undergoing maintenance hemodialysis three times per week, with a mean age of 67.1 years (women) and 66.8 years (men). Frailty was defined based on criteria set forth by the Cardiovascular Health Study (CHS)-19 (21.1%) women and 47 (37.9%) men were robust, 41 (45.6%) women and 43 (34.7%) men were pre-frail, and 30 (33.3%) women and 34 (27.4%) men were frail. For bone mass, quantitative ultrasound (QUS) parameters (speed of sound, broadband ultrasound attenuation, stiffness index) of the calcaneus were measured. The association between frailty and QUS parameters was determined separately for women and men using multivariate analysis of covariance (ANCOVA), with adjustments for clinical characteristics including age, body mass index, hemodialysis vintage, diabetes, current smoking, serum albumin, phosphate, corrected calcium, intact parathyroid hormone, and medication for CKD-MBD (vitamin D receptor activator, calcimimetics). ANCOVA revealed that all QUS parameters declined significantly with increasing levels of frailty in both sexes (P < 0.05). In conclusion, frailty (as defined by CHS criteria) should be considered a risk factor for bone loss in patients undergoing hemodialysis.

Relationship between bone turnover markers and the heel stiffness index measured by quantitative ultrasound in post-menopausal Japanese women.

Background: Osteoporosis in women is a serious health problem. The relationships between biochemical markers of bone turnover and bone mineral density (BMD) in women have been reported, but no study has examined relationships between tartrate-resistant acid phosphatase-5b (TRACP-5b) or bone-specific alkaline phosphatase (BAP) and bone mass measured by quantitative ultrasound (QUS) in Japanese post-menopausal women. Aim: To investigate the serum TRACP-5b and BAP levels and to determine their associations with the heel stiffness index measured by QUS in post-menopausal women. Subjects and methods: The subjects were 510 post-menopausal women who were invited to participate in periodic health examinations in 2011-2013 (the Unzen Study). The heel stiffness index (bone mass) was measured by QUS. Serum samples were collected and TRACP-5b and BAP levels were measured. Results: Multiple regression analysis showed that a higher log (TRACP-5b) was correlated with a lower stiffness index (p = 0.014) and log (BAP) was not correlated with stiffness index after adjusting for covariates (p = 0.136). Conclusion: Higher rates of bone resorption are associated with a lower stiffness index in Japanese post-menopausal women. These results may indicate that high bone resorption affects bone mass more than bone formation, resulting in a low bone mass.

Use of quantitative ultrasound as bone mineral density evaluation in an Italian female population living with HIV: A real-life experience.

This is a multicenter cross-sectional study where we aimed to detect the rate of osteopenia/osteoporosis in an HIV female population (WLWHIV) by means of "heel quantitative ultrasound" (QUS) measurement. We enrolled 273 patients, mean age 48.1 years, 36% menopausal, 96% on combination antiretroviral therapy (cART). Calcaneal measure of bone mass index by QUS revealed osteopenia and osteoporosis in 76 (27.8%) and 16 (5.9%) WLWHIV. Our data underline the correlation between low QUS parameters and traditional risk factors for osteoporosis rather than with cART exposure, thus suggesting the crucial importance of detection and correction of traditional risk factors for osteoporosis in WLWHIV.

Usefulness of circuit training at home for improving bone mass and muscle mass while losing fat mass in undergraduate female students.

BACKGROUND: The purpose of this study was to determine whether or not circuit training at home affects the calcaneus quantitative ultrasound status as well as other indices of body composition among undergraduate female students. METHODS: Forty-one adolescents were recruited (18.5 ± 0.6 years old). The stiffness index of the calcaneus, broadband ultrasound attenuation of the calcaneus, speed of sound of the calcaneus, and body frame index. This was a three-month intervention study, so the measurements were conducted at baseline, 2 months later, and 3 months later while the subjects underwent circuit training at home. The subjects were divided into two groups: namely, the exercising group and non-exercising group. RESULTS: In the exercising group, broadband ultrasound attenuation of the calcaneus was higher 2 months later (p = 0.033) as well as 3 months later (p = 0.036), and the speed of sound of the calcaneus was higher 3 months later (p = 0.018). In addition, the muscle mass was strongly positively correlated with the calcaneus QUS-SOS (p = 0.004), while the body fat percentage was a strongly negatively correlated with the calcaneus QUS-BUA (p = 0.043). In the non-exercising group, the stiffness index of the calcaneus was higher 2 months later (p = 0.002) as well as 3 months later (p = 0.002). Furthermore, the body percentage was strongly positively correlated with the calcaneus QUS-SI (p = 0.009). CONCLUSIONS: These findings suggest that the calcaneus quantitative ultrasound status and muscle mass while losing fat mass may be improved by means of a simple exercise regimen within a short period among undergraduate female students.

Agreement Between Dual-Energy X-Ray Absorptiometry and Quantitative Ultrasound to Evaluate Bone Health in Adolescents: The PRO-BONE Study.

PURPOSE: The present study aims to investigate the association between dual-energy X-ray absorptiometry (DXA) and quantitative ultrasound (QUS) parameters and the intermethods agreement in active males. METHODS: In this cross-sectional study, bone health (by DXA and calcaneal QUS), physical activity (by accelerometers), and anthropometrics measurements were assessed in 117 active adolescents (12-14 y old). Bivariate correlation coefficients were calculated to assess the relationships between DXA standard regions of interest and QUS parameters. Intraclass correlation coefficients and Bland-Altman plots were used to assess the level of agreement between bone mineral content regions derived from DXA and stiffness index. The measurements were z score transformed for comparison. RESULTS: Most QUS parameters were positive and significantly correlated with DXA outcomes (stiffness index: r = .43-.52; broadband ultrasound attenuation: r = .50-.58; speed of sound: r = .25-.27) with the hip showing the highest correlations. Moreover, the present study found fair to good intraclass correlation coefficients of agreement (.60-.68) between DXA and QUS to assess bone health. The Bland-Altman analysis showed a limited percentage of outliers (3.2%-8.6%). CONCLUSION: QUS device could represent an acceptable alternative method to assess bone health in active adolescent males.

Analysis of Two Quantitative Ultrasound Approaches.

There are two well-known ultrasonic approaches to extract sets of quantitative parameters: Lizzi-Feleppa (LF) parameters: slope, intercept, and midband; and quantitative ultrasound (QUS)-derived parameters: effective scatterer diameter (ESD) and effective acoustic concentration (EAC). In this study, the relation between the LF and QUS-derived parameters is studied theoretically and experimentally on ex vivo mouse livers. As expected from the theory, LF slope is correlated to ESD ([Formula: see text]), and from experimental data, LF midband is correlated to EAC ([Formula: see text]). However, LF intercept is not correlated to ESD ([Formula: see text]) nor EAC ([Formula: see text]). The unexpected correlation observed between LF slope and EAC ([Formula: see text]) results likely from the high correlation between ESD and EAC due to the inversion process. For a liver fat percentage estimation, an important potential medical application, the parameters presenting the better correlation are EAC ([Formula: see text]) and LF midband ([Formula: see text]).

Preliminary results demonstrating the impact of Mediterranean diet on bone health.

BACKGROUND: Nutrition is an environmental factor affecting bone health. Nutrition is considered essential to achieve and maintain optimal bone mass. Mediterranean diet (MD) has shown to prevent bone disease. Aim of this study is to investigate the relationship between bone health status and adherence the MD. METHODS: Four-hundred eighteen healthy people (105 males and 313 females, age 50 ± 14 years) were recruited in the outdoor hospital of the "Campus Salute Onlus" held in Piazza del Plebiscito in Naples, October 17-20th 2013 and 09-11th October 2014. All subjects underwent clinical assessment, calcaneal quantitative ultrasound (QUS) scanner and PREvención con DIeta MEDiterránea (PREDIMED) questionnaire. RESULTS: Globally, prevalence of osteoporosis and osteopenia were 7.7 and 46.0%, respectively. The majority of subjects (60.5%) had an average score (score 6-9) of adherence to MD. The T-score showed positive correlation with PREDIMED score (r = 0.250, p < 0.001). The higher T-scores were positively associated with a higher consumption of extra-virgin olive oil (EVOO), vegetables, fruits, legumes, and fish and negatively associated with consumption of red meat. The higher T-scores were positively associated with the highest odds of PREDIMED scores (higher adherence) (OR 6.91, IC 6.27-7.61, p < 0.001). Multiple regression analysis models indicated that, among the single food items investigated, high T-score can be predicted by consumption of EVOO (p < 0.001), fish (p < 0.001) and fruit (p = 0.002) intake. A PREDIMED score of 3 was found to be predictive for a low T-score (α = 0.05, R-squared index = 0.417). CONCLUSIONS: The results demonstrate a positive correlation between bone health status and adherence to MD, suggesting that a high adherence to MD promotes bone health. The observations here reported confirmed that a specific dietary approach, such as MD, can represent a modifiable environmental factor for osteoporosis' prevention.

Constitutional bone impairment in Noonan syndrome.

Noonan syndrome (NS) is an autosomal dominant trait characterized by genotypic and phenotypic variability. It belongs to the Ras/MAPK pathway disorders collectively named Rasopathies or neurocardiofaciocutaneous syndromes. Phenotype is characterized by short stature, congenital heart defects, facial dysmorphisms, skeletal and ectodermal anomalies, cryptorchidism, mild to moderate developmental delay/learning disability, and tumor predisposition. Short stature and skeletal dysmorphisms are almost constant and several studies hypothesized a role for the RAS pathway in regulating bone metabolism. In this study, we investigated the bone quality assessed by phalangeal quantitative ultrasound (QUS) and the metabolic bone profiling in a group of patients with NS, to determine whether low bone mineralization is primary or secondary to NS characteristics. Thirty-five patients were enrolled, including 20 males (55.6%) and 15 females (44.5%) aged 1.0-17.8 years (mean 6.4 ± 4.5, median 4.9 years). Each patients was submitted to clinical examination, estimation of the bone age, laboratory assays, and QUS assessment. Twenty-five percent of the cohort shows reduced QUS values for their age based on bone transmission time. Bone measurement were adjusted for multiple factors frequently observed in NS patients, such as growth retardation, delayed bone age, retarded puberty, and reduced body mass index, potentially affecting bone quality or its appraisal. In spite of the correction attempts, QUS measurement indicates that bone impairment persists in nearly 15% of the cohort studied. Our results indicate that bone impairment in NS is likely primary and not secondary to any of the phenotypic traits of NS, nor consistent with metabolic disturbances. © 2017 Wiley Periodicals, Inc.

Bone mineral density in people living with HIV: a narrative review of the literature.

Bone health status is largely absent in South Africa, the main reasons being the absence and cost-effectiveness of specific screening equipment for assessing bone mineral density (BMD). Various risk factors seem to play a role, some of which can be modified to change bone health status. Urbanisation is also a public health concern. Changing nutritional, as well as social behaviour, play integral roles in the prevalence and incidence of decreased BMD. Furthermore, human immunodeficiency virus (HIV) specifically, has a negative impact on BMD and although highly active antiretroviral therapy increases the prognosis for HIV-infected individuals, BMD still seem to decrease further. Dual energy X-ray absorptiometry is considered the gold standard for BMD assessment; however, recent developments have provided more cost-effective screening methods, among which heel quantitative ultrasound appears to be the most widely used in resource limited countries such as South Africa.

Three-dimensional Simulation of Quantitative Ultrasound in Cancellous Bone Using the Echographic Response of a Metallic Pin.

Degenerative discopathy is a common pathology that may require spine surgery. A metallic cylindrical pin is inserted into the vertebral body to maintain soft tissues and may be used as a reflector of ultrasonic wave to estimate bone density. The first aim of this paper is to validate a three-dimensional (3-D) model to simulate the ultrasonic propagation in a trabecular bone sample in which a metallic pin has been inserted. We also aim at determining the effect of changes of bone volume fraction (BV/TV) and of positioning errors on the quantitative ultrasound (QUS) parameters in this specific configuration. The approach consists in coupling finite-difference time-domain simulation with X-ray microcomputed tomography. The correlation coefficient between experimental and simulated speed of sound (SOS)-respectively, broadband ultrasonic attenuation (BUA)-was equal to 0.90 (respectively, 0.55). The results show a significant correlation of SOS with BV/TV ( R = 0.82), while BUA values exhibit a nonlinear behavior versus BV/TV. The orientation of the pin should be controlled with an accuracy of around 1° to obtain accurate results. The results indicate that using the ultrasonic wave reflected by a pin has a potential to estimate the bone density. SOS is more reliable than BUA due to its lower sensitivity to the tilt angle.

Heel quantitative ultrasound in HIV-infected patients: a cross-sectional study.

PURPOSE: HIV infection has been associated with increased risk of osteoporosis and fragility fractures. Dual-energy X-ray absorptiometry (DXA) is the reference standard to assess bone mineral density (BMD); however, it is not easily accessible in several settings. Heel Quantitative ultrasound (QUS) is a radiation-free, easy-to-perform technique, which may help reducing the need for DXA. METHODS: In this cross-sectional study, we used heel QUS (Hologic Sahara(®)) to assess bone status in a cohort of HIV-infected patients. A QUS stiffness index (QUI) threshold >83 was used to identify patients with a low likelihood of osteoporosis. Moreover, we compared QUS results with those of 36 sex- and age-matched HIV-negative controls. RESULTS: 244 HIV-positive patients were enrolled. Median heel QUI value was 83 (73-96) vs. 93 (IQR 84-104) in the control group (p = 0.04). 110 patients (45 %) had a QUI value ≤83. Risk factors for low QUI values were age (OR 1.04 per year, 95 % CI 1.01-1.07, p = 0.004), current use of protease inhibitors (OR 1.85, CI 1.03-3.35, p = 0.039), current use of tenofovir (OR 2.28, CI 1.22-4.27, p = 0.009) and the number of risk factors for secondary osteoporosis (OR 1.46, CI 1.09-1.95, p = 0.01). Of note, QUI values were significantly correlated with FRAX score (r = -0.22, p = 0.004). According to EACS guidelines, 45 % of patients had risk factors for osteoporosis which make them eligible for DXA. By using QUS, we may avoid DXA in around half of them. CONCLUSIONS: As HIV-positive patients are living longer, the prevalence of osteoporosis is expected to increase over time. Appropriate screening, prevention and treatment are crucial to preserve bone health in this population. The use of screening techniques, such as heel QUS, may help reducing the need for DXA. Further studies are needed to define the diagnostic accuracy of this promising technique in the setting of HIV.

A non-invasive prevention program model for the assessment of osteoporosis in the early postmenopausal period: a pilot study on FRAX(®) and QUS tools advantages.

OBJECTIVE: The study analyses the performances of FRAX algorithm and quantitative ultrasound (QUS) tool in relationship to the dual-energy X-ray absorptiometry (DXA) categorization to identify patients at risk of osteoporosis during menopause and to reach new thresholds for recommending the first DXA examination. DESIGN: Retrospective cohort study. PATIENTS AND MEASUREMENTS: Two hundred eighty-two postmenopausal patients filled out a questionnaire which determined their FRAX index and performed a bone evaluation by QUS of the calcaneus to determine their stiffness index (SI). Thereafter, they underwent assessments by the gold-standard DXA bone examination. RESULTS: Statistically significant correlations were observed between FRAX (calculated without BMD) and both QUS and DXA diagnosis. FRAX mean indices of risk corresponding to the diagnosis of osteoporosis by QUS and DXA were similar. Receiver operating characteristic (ROC) curve analysis showed that both FRAX and QUS tests were sufficiently accurate in predicting the alteration of bone mineral composition. The ROC curves of QUS allowed us to identify, in our population, SI cutoff for normal patients (SI > 90.5) and for patients having osteoporosis (SI < 78.5). We selected a cutoff screening value from FRAX ROC curve for major clinical fracture (2.94). The following diagnostic algorithm demonstrated that the use of FRAX test alone has a sensitivity of 85.3 % and a specificity of 33.8 % while the use of QUS exam alone showed a sensitivity of 81.3 % and a specificity of 45.1 %. When considering the capacity of QUS exam in combination with FRAX test, the final algorithm showed a sensitivity of 69.4 % and a specificity of 57.7 %. CONCLUSIONS: The use of QUS test with adjusted cutoffs offers a similar performance to the FRAX test alone in terms of sensitivity. The combined use of the tests reduces the sensibility but increases the specificity and adds clinical information related to the bone status of the patient.