A novel ultrasound methodology for estimating spine mineral density

Osteoporosis, Osteoarthritis, and Subchondral Insufficiency Fracture: Recent Insights

The increased incidence of osteoarthritis (OA), particularly knee and hip OA, and osteoporosis (OP), owing to population aging, have escalated the medical expense burden. Osteoarthritis is more prevalent in older women, and the involvement of subchondral bone fragility spotlights its association with OP. Notably, subchondral insufficiency fracture (SIF) may represent a more pronounced condition of OA pathophysiology. This review summarizes the relationship between OA and OP, incorporating recent insights into SIF. Progressive SIF leads to joint collapse and secondary OA and is associated with OP. Furthermore, the thinning and fragility of subchondral bone in early-stage OA suggest that SIF may be a subtype of OA (osteoporosis-related OA, OPOA) characterized by significant subchondral bone damage. The high bone mineral density observed in OA may be overestimated due to osteophytes and sclerosis and can potentially contribute to OPOA. The incidence of OPOA is expected to increase along with population aging. Therefore, prioritizing OP screening, early interventions for patients with early-stage OA, and fracture prevention measures such as rehabilitation, fracture liaison services, nutritional management, and medication guidance are essential.

High-sensitivity immunoassay on interdigitated electrode to detect osteoporosis biological marker

Osteoporosis is with porous bones, which refers to a decrease in the bone mineral density and weakens the bones to become brittle. Osteoporosis often progresses without any pain or symptoms until the bone fractures. Monitoring the condition of bone regularly helps to identify the bone that weakens at its earlier stages. In general, radiological techniques have been used to measure bone mineral density, are expensive, and the procedures are complicated. Therefore, researchers are focusing on the alternative method of biomarker quantification to identify bone mineral density. This research work was focused on quantifying the osteoporosis biomarker of C-terminal telopeptide of type I collagen (CTX-I) on an interdigitated electrode (IDE) sensor. Gold nanomaterial-modified anti-CTX-I antibody was attached to silica nanomaterial-decorated IDE and then identified by CTX-I interaction. Higher immobilization of antibodies was recorded on diamond-modified IDE through gold nanoparticles, and detected CTX-I as low as 0.5 pg/mL [y = 1.5507x - 0.9043 R2 = 0.9715], determined on a linear curve at the range 0.5-3.5 ng/mL. Further, specific identification of CTX-I was confirmed by control performances with osteopontin, IL-6, and anti-IgG antibody.

Bone health status evaluation in men by means of REMS technology

BACKGROUND

Osteoporosis in males is largely under-diagnosed and under-treated, with most of the diagnosis confirmed only after an osteoporotic fracture. Therefore, there is an urgent need for highly accurate and precise technologies capable of identifying osteoporosis earlier, thereby avoiding complications from fragility fractures.

AIMS

This study aimed to evaluate the diagnostic accuracy and precision of the non-ionizing technology Radiofrequency Echographic Multi Spectrometry (REMS) for the diagnosis of osteoporosis in a male population in comparison with conventional Dual-energy X-ray Absorptiometry (DXA).

METHODS

A cohort of 603 Caucasian males aged between 30 and 90 years were involved in the study. All the enrolled patients underwent lumbar and femoral scans with both DXA and REMS. The diagnostic agreement between REMS and DXA-measured BMD was expressed by Pearson correlation coefficient and Bland-Altman method. The accuracy of the diagnostic classification was evaluated by the assessment of sensitivity and specificity considering DXA as reference.

RESULTS

A significant correlation between REMS- and DXA-measured T-score values (r = 0.91, p < 0.0001) for lumbar spine and for femoral neck (r = 0.90, p < 0.0001) documented the substantial equivalence of the two measurement techniques. Bland-Altman outcomes showed that the average difference in T-score measurement is very close to zero (-0.06 ± 0.60 g/cm2 for lumbar spine and - 0.07 ± 0.44 g/cm2 for femoral neck) confirming the agreement between the two techniques. Furthermore, REMS resulted an effective technique to discriminate osteoporotic patients from the non-osteoporotic ones on both lumbar spine (sensitivity = 90.1%, specificity = 93.6%) and femoral neck (sensitivity = 90.9%, specificity = 94.6%). Precision yielded RMS-CV = 0.40% for spine and RMS-CV = 0.34% for femur.

CONCLUSION

REMS, is a reliable technology for the diagnosis of osteoporosis also in men. This evidence corroborates its high diagnostic performance already observed in previous studies involving female populations.

Radiofrequency Echographic Multispectrometry (REMS) can Overcome the Effects of Structural Internal Artifacts and Evaluate Bone Fragility Accurately

PURPOSE

This study measured bone mineral density (BMD) in a Japanese population using the novel non-ionizing system using radiofrequency echographic multispectrometry (REMS) and compared the results with those obtained using traditional dual-energy X-ray absorptiometry (DXA). We aimed to identify any discrepancies between measurements obtained using these instruments and identify the influencing factors.

METHODS

This cross-sectional study examined patients with osteoporosis treated at a single center from April to August 2023. We examined BMD assessment by DXA and REMS in lumbar spine and proximal femur. Patients were categorized into two groups: those with discrepancies between lumbar spine BMD measured by DXA and REMS, and those without. Semiquantitative evaluation of vertebral fractures and abdominal aortic calcification scoring were also performed and compared between the two groups, along with various patient characteristics.

RESULTS

A total of 70 patients (88.6% female; mean age 78.39 ± 9.50 years) undergoing osteoporosis treatment were included in the study. A significant difference was noted between DXA and REMS measurement of BMD and T-scores, with REMS recording consistently lower values. The discrepancy group exhibited a higher incidence of multiple vertebral fractures and increased vascular calcification than the non-discrepancy group. Multivariate analysis indicated that diabetes mellitus, severe vertebral fractures, and increased abdominal aortic calcification scores were significantly associated with discrepancies in lumbar spine T-scores.

CONCLUSION

This study suggests that REMS may offer a more accurate measurement of BMD, overcoming the overestimation of BMD by DXA owing to factors such as vertebral deformities, abdominal aortic calcification, and diabetes mellitus.

The Advantages of Radiofrequency Echographic MultiSpectrometry in the Evaluation of Bone Mineral Density in a Population with Osteoarthritis at the Lumbar Spine

BACKGROUND

Osteoarthritis (OA) in the lumbar spine can potentially lead to an overestimation of bone mineral density (BMD), and this can be a challenge in accurately diagnosing conditions like osteoporosis, where precise measurement of BMD is crucial. Radiofrequency Echographic Multi Spectrometry (REMS) is being recognized as an innovative diagnostic tool for assessing bone status. The purpose of this study was to evaluate whether the use of REMS may enhance the identification of osteoporosis in patients with osteoarthritis.

METHODS

A cohort of 500 patients (mean age: 63.9 ± 11.2 years) diagnosed with osteoarthritis and having a medical prescription for dual-energy X-ray absorptiometry (DXA) were recruited for the study. All patients underwent BMD measurements at lumbar spine and femoral sites by both DXA and REMS techniques.

RESULTS

The T-score values for BMD at the lumbar spine (BMD-LS) by DXA were significantly higher with respect to BMD-LS by REMS across all OA severity scores, and the differences were more pronounced in patients with a higher degree of OA severity (p < 0.001). Furthermore, the percentage of subjects classified as "osteoporotic", on the basis of BMD by REMS was markedly higher than those classified by DXA, both when considering all skeletal sites (39.4% vs. 15.1%, respectively) and the lumbar spine alone (30.5% vs. 6.0%, respectively). A similar pattern was observed when OA patients were grouped according to the Kellgren-Lawrence grading score.

CONCLUSIONS

The findings from our study indicate that, in a population with varying severity levels of osteoarthritis, REMS demonstrated a higher capability to diagnose osteoporosis compared to DXA, and this could lead to earlier intervention and improved outcomes for patients with bone fragility, reducing the likelihood of fractures and associated complications.

In Vivo Assessment of Bone Quality Without X-rays

PURPOSE OF REVIEW

This review summarizes recent advances in the assessment of bone quality using non-X-ray techniques.

RECENT FINDINGS

Quantitative ultrasound (QUS) provides multiple measurements of bone characteristics based on the propagation of sound through bone, the attenuation of that sound, and different processing techniques. QUS parameters and model predictions based on backscattered signals can discriminate non-fracture from fracture cases with accuracy comparable to standard bone mineral density (BMD). With advances in magnetic resonance imaging (MRI), bound water and pore water, or a porosity index, can be quantified in several long bones in vivo. Since such imaging-derived measurements correlate with the fracture resistance of bone, they potentially provide new BMD-independent predictors of fracture risk. While numerous measurements of mineral, organic matrix, and bound water by Raman spectroscopy correlate with the strength and toughness of cortical bone, the clinical assessment of person's bone quality using spatially offset Raman spectroscopy (SORS) requires advanced spectral processing techniques that minimize contaminating signals from fat, skin, and blood. Limiting exposure of patients to ionizing radiation, QUS, MRI, and SORS has the potential to improve the assessment of fracture risk and track changes of new therapies that target bone matrix and micro-structure.

Radiofrequency Echographic Multispectrometry (REMS): A New Option in the Assessment Bone Status in Adults with Osteogenesis Imperfecta

This study aimed to estimate the utility of the Radiofrequency Echographic Multispectrometry (REMS) approach in the assessment of bone mineral density (BMD) in subjects with osteogenesis imperfecta (OI). In 41 subjects (40.5 ± 18.7 years) with OI and in 36 healthy controls, we measured BMD at the lumbar spine (LS-BMD), femoral neck (FN-BMD) and total hip (TH-BMD), employing a dual-energy X-ray absorptiometry tool. Additionally, REMS scans were also performed at the lumbar and femoral sites. The presence and number of reported fractures were assessed in the study population. Patients characterized by a history of fragility fractures represented 84.5% of the study population. OI subjects showed significantly reduced BMD values both at the level of the lumbar spine and the femoral subregions (p < 0.01) compared to healthy controls when performed using both the DXA and the REMS method. Dividing OI patients on the basis of the Sillence classification, no differences were found between the LS-BMD values carried out using the DXA technique between the OI type I group and OI Type III and IV groups. On the contrary, the OI Type III and IV groups presented significantly lower values of both Trabecular Bone Score (TBS) and LS-BMD through REMS with respect to OI type I patients (p < 0.05). Based on the data of this study, it is possible to conclude that even the new REMS assessment, which does not use ionizing radiation, represents an excellent method for studying the bone status in subjects affected by OI.

Prenatal and Neonatal Bone Health: Updated Review on Early Identification of Newborns at High Risk for Osteopenia

Bone health starts with maternal health and nutrition, which influences bone mass and density already in utero. The mechanisms underlying the effect of the intrauterine environment on bone health are partly unknown but certainly include the 'foetal programming' of oxidative stress and endocrine systems, which influence later skeletal growth and development. With this narrative review, we describe the current evidence for identifying patients with risk factors for developing osteopenia, today's management of these populations, and screening and prevention programs based on gestational age, weight, and morbidity. Challenges for bone health prevention include the need for new technologies that are specific and applicable to pregnant women, the foetus, and, later, the newborn. Radiofrequency ultrasound spectrometry (REMS) has proven to be a useful tool in the assessment of bone mineral density (BMD) in pregnant women. Few studies have reported that transmission ultrasound can also be used to assess BMD in newborns. The advantages of this technology in the foetus and newborn are the absence of ionising radiation, ease of use, and, above all, the possibility of performing longitudinal studies from intrauterine to extrauterine life. The use of these technologies already in the intrauterine period could help prevent associated diseases, such as osteoporosis and osteopenia, which are characterised by a reduction in bone mass and degeneration of bone structure and lead to an increased risk of fractures in adulthood with considerable social repercussions for the related direct and indirect costs.

Short-Term Precision and Repeatability of Radiofrequency Echographic Multi Spectrometry (REMS) on Lumbar Spine and Proximal Femur: An In Vivo Study

To determine the short-term intra-operator precision and inter-operator repeatability of radiofrequency echographic multi-spectrometry (REMS) at the lumbar spine (LS) and proximal femur (FEM). All patients underwent an ultrasound scan of the LS and FEM. Both precision and repeatability, expressed as root-mean-square coefficient of variation (RMS-CV) and least significant change (LSC) were obtained using data from two consecutive REMS acquisitions by the same operator or two different operators, respectively. The precision was also assessed in the cohort stratified according to BMI classification. The mean (±SD) age of our subjects was 48.9 ± 6.8 for LS and 48.3 ± 6.1 for FEM. Precision was assessed on 42 subjects at LS and 37 subjects on FEM. Mean (±SD) BMI was 24.71 ± 4.2 for LS and 25.0 ± 4.84 for FEM. Respectively, the intra-operator precision error (RMS-CV) and LSC resulted in 0.47% and 1.29% at the spine and 0.32% and 0.89% at the proximal femur evaluation. The inter-operator variability investigated at the LS yielded an RMS-CV error of 0.55% and LSC of 1.52%, whereas for the FEM, the RMS-CV was 0.51% and the LSC was 1.40%. Similar values were found when subjects were divided into BMI subgroups. REMS technique provides a precise estimation of the US-BMD independent of subjects' BMI differences.

Radiofrequency Echographic Multi Spectrometry (R.E.M.S.): New Frontiers for Ultrasound Use in the Assessment of Bone Status-A Current Picture

Osteoporosis is a frequently occurring skeletal disease, and osteoporosis-related fractures represent a significant burden for healthcare systems. Dual-Energy X-ray Absorptiometry (DXA) is the most commonly used method for assessing bone mineral density (BMD). Today, particular attention is being directed towards new technologies, especially those that do not use radiation, for the early diagnosis of altered bone status. Radiofrequency Echographic Multi Spectrometry (REMS) is a non-ionizing technology that evaluates the bone status at axial skeletal sites by analyzing raw ultrasound signals. In this review, we evaluated the data on the REMS technique present in the literature. The literature data confirmed diagnostic concordance between BMD values obtained using DXA and REMS. Furthermore, REMS has adequate precision and repeatability characteristics, is able to predict the risk of fragility fractures, and may be able to overcome some of the limitations of DXA. In conclusion, REMS could become the method of choice for the assessment of bone status in children, in women of childbearing age or who are pregnant, and in several secondary osteoporosis conditions due to its good precision and replicability, its transportability, and the absence of ionizing radiation. Finally, REMS may allow qualitative and not just quantitative assessments of bone status.

Fragility Score: a REMS-based indicator for the prediction of incident fragility fractures at 5 years

BACKGROUND

Accurate estimation of the imminent fragility fracture risk currently represents a challenging task. The novel Fragility Score (FS) parameter, obtained during a Radiofrequency Echographic Multi Spectrometry (REMS) scan of lumbar or femoral regions, has been developed for the non-ionizing estimation of skeletal fragility.

AIMS

The aim of this study was to assess the performance of FS in the early identification of patients at risk for incident fragility fractures with respect to bone mineral density (BMD) measurements.

METHODS

Data from 1989 Caucasians of both genders were analysed and the incidence of fractures was assessed during a follow-up period up to 5 years. The diagnostic performance of FS to discriminate between patients with and without incident fragility fracture in comparison to that of the BMD T-scores measured by both Dual X-ray Absorptiometry (DXA) and REMS was assessed through ROC analysis.

RESULTS

Concerning the prediction of generic osteoporotic fractures, FS provided AUC = 0.811 for women and AUC = 0.780 for men, which resulted in AUC = 0.715 and AUC = 0.758, respectively, when adjusted for age and body mass index (BMI). For the prediction of hip fractures, the corresponding values were AUC = 0.780 for women and AUC = 0.809 for men, which became AUC = 0.735 and AUC = 0.758, respectively, after age- and BMI-adjustment. Overall, FS showed the highest prediction ability for any considered fracture type in both genders, resulting always being significantly higher than either T-scores, whose AUC values were in the range 0.472-0.709.

CONCLUSION

FS displayed a superior performance in fracture prediction, representing a valuable diagnostic tool to accurately detect a short-term fracture risk.

Cost-minimization analysis to support the HTA of Radiofrequency Echographic Multi Spectrometry (REMS) in the diagnosis of osteoporosis

Introduction

A timely diagnosis of osteoporosis is key to reducing its growing clinical and economic burden. Radiofrequency Echographic Multi Spectrometry (REMS), a new diagnostic technology using an ultrasound approach, has been recognized by scientific associations as a facilitator of patients' care pathway. We aimed at evaluating the costs of REMS vs. the conventional ionizing technology (dual-energy X-ray absorptiometry, DXA) for the diagnosis of osteoporosis from the perspective of the Italian National Health Service (NHS) using a cost-minimization analysis (CMA).

Methods

We carried out structured qualitative interviews and a structured expert elicitation exercise to estimate healthcare resource consumption with a purposeful sample of clinical experts. For the elicitation exercise, an Excel tool was developed and, for each parameter, experts were asked to provide the lowest, highest and most likely value. Estimates provided by experts were averaged with equal weights. Unit costs were retrieved using different public sources.

Results

Considering the base-case scenario (most likely value), the cost of professionals amounts to €31.9 for REMS and €48.8 for DXA, the cost of instrumental examinations and laboratory tests to €45.1 for REMS and €68.2 for DXA. Overall, in terms of current costs, REMS is associated with a mean saving for the NHS of €40.0 (range: €27.6-71.5) for each patient.

Conclusions

REMS is associated with lower direct healthcare costs with respect to DXA. These results may inform policy-makers on the value of the REMS technology in the earlier diagnosis for osteoporosis, and support their decision regarding the reimbursement and diffusion of the technology in the Italian NHS.

Advancement in the Treatment of Osteoporosis and the Effects on Bone Healing

Osteoporosis (OP) is a major global health concern, with aging being one of the most important risk factors. Osteoarthritis (OA) is also an age-related disorder. Patients with OP and/or OA may be treated surgically for fractures or when their quality of life is impaired. Poor bone quality due to OP can seriously complicate the stability of a bone fixation construct and/or surgical fracture treatment. This review summarizes the current knowledge on the pathophysiology of normal and osteoporotic bone healing, the effect of a bone fracture on bone turnover markers, the diagnosis of a low bone mineral density (BMD) before surgical intervention, and the effect of available anti-osteoporosis treatment. Interventions that improve bone health may enhance the probability of favorable surgical outcomes. Fracture healing and the treatment of atypical femoral fractures are also discussed.

Radiofrequency echographic multispectrometry (REMS): an innovative technique for the assessment of bone status in young women with anorexia nervosa

PURPOSE

Reduced bone mineral density (BMD) and increase risk of fragility fracture are common complication of anorexia nervosa (AN). BMD by dual-energy X-ray absorptiometry (DXA) present several limits in subjects with AN. This study aimed to evaluate the usefulness of the new Radiofrequency echographic multispectrometry (REMS) technique in the assessment of bone status in young women with AN.

METHODS

In a cohort of 50 subjects with restrictive AN and in 30 healthy controls, we measured BMD at the lumbar spine (LS-BMD), at femoral neck (FN-BMD) and total hip (TH-BMD) using both DXA and REMS technique.

RESULTS

BMD evaluated by DXA and REMS technique at all measurement sites were all significantly (p < 0.01) lower in subjects suffering from AN subjects than in controls. Good correlations were detected between BMD by DXA and BMD by REMS measurements at LS (r = 0.64, p < 0.01) at FN (r = 0.86, p < 0.01) and at TH (r = 0.84, p < 0.01) in subjects suffering from AN. Moreover, Bland-Altman analysis confirmed the good agreement between the two techniques. The subjects suffering from AN with previous vertebral fragility fractures presented lower values of both BMD-LS and BMD-TH by DXA and by REMS with respect to those without fractures; however, the difference was significant only for BMD-TH by REMS (p < 0.05).

CONCLUSIONS

Our data suggest that REMS technique due to its characteristic of precision and reproducibility may represent an important tool for the evaluation of the changes in bone status in AN young women, especially during the fertile age and in case of pregnancy and breastfeeding.

LEVEL OF EVIDENCE

Level of evidence: level III cohort study.

Predicting Lumbar Vertebral Osteopenia Using LvOPI Scores and Logistic Regression Models in an Exploratory Study of Premenopausal Taiwanese Women

Purpose

To propose hybrid predicting models integrating clinical and magnetic resonance imaging (MRI) features to diagnose lumbar vertebral osteopenia (LvOPI) in premenopausal women.

Methods

This prospective study enrolled 101 Taiwanese women, including 53 before and 48 women after menopause. Clinical information, including age, body height, body weight and body mass index (BMI), were recorded. Bone mineral density (BMD) was measured by the dual-energy X-ray absorptiometry. Lumbar vertebral fat fraction (LvFF) was measured by MRI. LvOPI scores (LvOPISs) comprising different clinical features and LvFF were constructed to diagnose LvOPI. Statistical analyses included normality tests, linear regression analyses, logistic regression analyses, group comparisons, and diagnostic performance. A P value less than 0.05 was considered as statistically significant.

Results

The post-menopausal women had higher age, body weight, BMI, LvFF and lower BMD than the pre-menopausal women (all P < 0.05). The lumbar vertebral osteoporosis group had significantly higher age, longer MMI, and higher LvFF than the LvOPI group (all P < 0.05) and normal group (all P < 0.005). LvOPISs (AUC, 0.843 to 0.864) outperformed body weight (0.747; P = 0.0566), BMI (0.737; P < 0.05), age (0.649; P < 0.05), and body height (0.5; P < 0.05) in diagnosing LvOPI in the premenopausal women. Hybrid predicting models using logistic regression analysis (0.894 to 0.9) further outperformed all single predictors in diagnosing LvOPI in the premenopausal women (P < 0.05).

Conclusion

The diagnostic accuracy of the LvOPI can be improved by using our proposed hybrid predicting models in Taiwanese premenopausal women.

Osteoporosis Diagnostic Model Using a Multichannel Convolutional Neural Network Based on Quantitative Ultrasound Radiofrequency Signal

Quantitative ultrasound (QUS) is a promising screening method for osteoporosis. In this study, a new method to improve the diagnostic accuracy of QUS was established in which a multichannel convolutional neural network (MCNN) processes the raw radiofrequency (RF) signal of QUS. The improvement in the diagnostic accuracy of osteoporosis using this new method was evaluated by comparison with the conventional speed of sound (SOS) method. Dual-energy X-ray absorptiometry was used as the diagnostic standard. After being trained, validated and tested in a data set consisting of 274 participants, the MCNN model could significantly raise the accuracy of osteoporosis diagnosis compared with the SOS method. The adjusted MCNN model performed even better when adjusted by age, height and weight data. The sensitivity, specificity and accuracy of the adjusted MCNN method for osteoporosis diagnosis were 80.86%, 84.23% and 83.05%, respectively; the corresponding values for SOS were 50.60%, 73.68% and 66.67%. The area under the receiver operating characteristic curve of the adjusted MCNN method was also higher than that of SOS (0.846 vs. 0.679). In conclusion, our study indicates that the MCNN method may be more accurate than the conventional SOS method. The MCNN tool and ultrasound RF signal analysis are promising future developmental directions for QUS in screening for osteoporosis.

Reproducibility and Accuracy of the Radiofrequency Echographic Multi-Spectrometry for Femoral Mineral Density Estimation and Discriminative Power of the Femoral Fragility Score in Patients with Primary and Disuse-Related Osteoporosis

We aimed to investigate the reproducibility and accuracy of Radiofrequency Echographic Multi-Spectrometry (REMS) for femoral BMD estimation and the reproducibility and discriminative power of the REMS-derived femoral fragility score. 175 patients with primary and disuse-related osteoporosis were recruited: one femoral Dual-energy X-ray Absorptiometry (DXA) scan and two femoral REMS scans were acquired. No significant test—retest differences were observed for all REMS-derived variables. The diagnostic concordance between DXA and REMS was 63% (Cohen’s kappa = 0.31) in patients with primary osteoporosis and 13% (Cohen’s kappa: −0.04) in patients with disuse-related osteoporosis. No significant difference was observed between REMS and DXA for either femoral neck BMD (mean difference between REMS and DXA: −0.015 g/cm²) or total femur BMD (mean difference: −0.004 g/cm²) in patients with primary osteoporosis. Significant differences between the two techniques were observed in patients with disuse-related osteoporosis (femoral neck BMD difference: 0.136 g/cm²; total femur BMD difference: 0.236 g/cm²). Statistically significant differences in the fragility score were obtained between the fractured and non-fractured patients for both populations. In conclusion, REMS showed excellent test-retest reproducibility, but the diagnostic concordance between DXA and REMS was between minimal and poor. Further studies are required to improve the REMS—derived estimation of femoral BMD.

In Vivo Comparison of Backscatter Techniques for Ultrasonic Bone Assessment at the Femoral Neck

Ultrasonic techniques are being developed to detect changes in cancellous bone caused by osteoporosis. The goal of this study was to test the relative in vivo performance of eight backscatter parameters developed over the last several years for ultrasonic bone assessment: apparent integrated backscatter (AIB), frequency slope of apparent backscatter (FSAB), frequency intercept of apparent backscatter (FIAB), normalized mean of the backscatter difference (nMBD), normalized slope of the backscatter difference (nSBD), normalized intercept of the backscatter difference (nIBD), normalized backscatter amplitude ratio (nBAR) and backscatter amplitude decay constant (BADC). Backscatter measurements were performed on the left and right femoral necks of 80 adult volunteers (age = 25 ± 11 y) using an imaging system equipped with a convex array transducer. For comparison, additional ultrasonic measurements were performed at the left and right heel using a commercially available heel-bone ultrasonometer that measured the stiffness index. Six of the eight backscatter parameters (all but nSBD and nIBD) exhibited similar and highly significant (p < 0.000001) left-right correlations (0.51 ≤ R ≤ 0.68), indicating sensitivity to naturally occurring variations in bone tissue. Left-right correlations for the stiffness index measured at the heel (R = 0.75) were not significantly better than those produced by AIB, FSAB and FIAB. The short-term precisions of AIB, nMBD, nBAR and BADC (7.8%-11.7%) were comparable to that of the stiffness index measured with the heel-bone ultrasonometer (7.5%).

Could radiofrequency echographic multispectrometry (REMS) overcome the overestimation in BMD by dual-energy X-ray absorptiometry (DXA) at the lumbar spine?

BACKGROUND

Osteoarthritis (OA) and vertebral fractures at the lumbar spine lead to an overestimation of bone mineral density (BMD). Recently, a new approach for osteoporosis diagnosis, defined as radiofrequency echographic multi-spectrometry (REMS), represents an innovative diagnostic tool that seems to be able to investigate bone quality and provide an estimation of fracture risk independent of BMD. The aim of this paper was to evaluate whether the use of REMS technology can favor the diagnosis of osteoporosis in subjects with an apparent increase in BMD.

METHODS

In a cohort of 159 postmenopausal (66.2 ± 11.6 yrs) women with overestimated BMD by DXA at the lumbar spine, we performed an echographic scan with the REMS technique.

RESULTS

The mean values of BMD at different skeletal sites obtained by the DXA and REMS techniques showed that the BMD T-scores by REMS were significantly lower than those obtained by the DXA technique both at the lumbar spine (p < 0.01) and at all femoral subregions (p < 0.05). In OA subjects, the percentage of women classified as "osteoporotic" on the basis of BMD by REMS was markedly higher with respect to those classified by DXA (35.1% vs 9.3%, respectively). Similarly, the REMS allows a greater number of fractured patients to be classified as osteoporotic than DXA (58.7% vs 23.3%, respectively).

CONCLUSIONS

REMS technology by the analysis of native raw unfiltered ultrasound signals appears to be able to overcome the most common artifacts, such as OA and vertebral fracture of the lumbar spine, which affect the value of BMD by DXA.

Assessing Bone Quality of the Spine in Children with Scoliosis Using the Ultrasound Reflection Frequency Amplitude Index Method: A Preliminary Study

Osteopenia is considered a common phenomenon in patients who have scoliosis. Quantitative ultrasound has been used to assess skeletal status for decades, and recently ultrasound imaging using reflection signals from vertebrae were as well applied to measure spinal curvatures in children with scoliosis. The objectives of this study were to develop a new method that can robustly extract a parameter from ultrasound spinal data for estimating bone quality of scoliotic patients and to investigate the potential of the parameter in predicting curve progression. The frequency amplitude index (FAI) was calculated based on the spectrum of the original radiofrequency signals reflected from the tissue-vertebra interface. The correlation between FAI and reflection coefficient was validated using decalcified bovine bone samples in vitro, and the FAIs of scoliotic subjects were investigated in vivo with reference to body mass index, Cobb angles and curve progression status. The results revealed that the intra-rater measures were highly reliable between different trials (intra-class correlation coefficient = 0.997). The FAI value was strongly correlated with the reflection coefficient of bone tissue (R² = 0.824), and the lower FAI indicated the higher risk of curve progression for the non-mild scoliosis cases. This preliminary study found that the FAI method can provide a feasible and robust approach to assessment of the bone quality of spine and may be a promising factor in monitoring curve progression of patients who have adolescent idiopathic scoliosis.

Ability of radiofrequency echographic multispectrometry to identify osteoporosis status in elderly women with type 2 diabetes

BACKGROUND

Patients with type 2 diabetes (T2DM) have an increased or normal BMD; however fragility fractures represent one of the most important complications of T2DM.

AIMS

This study aimed to evaluate whether the use of the Radiofrequency Echographic multi spectrometry (REMS) technique may improve the identification of osteoporosis in T2DM patients.

METHODS

In a cohort of 90 consecutive postmenopausal elderly (70.5 ± 7.6 years) women with T2DM and in 90 healthy controls we measured BMD at the lumbar spine (LS-BMD), at femoral neck (FN-BMD) and total hip (TH-BMD) using a dual-energy X-ray absorptiometry device; moreover, REMS scans were also carried out at the same axial sites.

RESULTS

DXA measurements were all higher in T2DM than in non-T2DM women; instead, all REMS measurements were lower in T2DM than in non T2DM women. Moreover, the percentage of T2DM women classified as "osteoporotic", on the basis of BMD by REMS was markedly higher with respect to those classified by DXA (47.0% vs 28.0%, respectively). On the contrary, the percentage of T2DM women classified as osteopenic or normal by DXA was higher with respect to that by REMS (48.8% and 23.2% vs 38.6% and 14.5%, respectively). T2DM women with fragility fractures presented lower values of both BMD-LS by DXA and BMD-LS by REMS with respect to those without fractures; however, the difference was significant only for BMD-LS by REMS (p < 0.05).

CONCLUSIONS

Our data suggest that REMS technology may represent a useful approach to enhance the diagnosis of osteoporosis in patients with T2DM.

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.

Could Radiofrequency Echographic Multi-Spectrometry (REMS) Overcome the Limitations of BMD by DXA Related to Artifacts? A Series of 3 Cases

Dual-energy X-ray absorptiometry (DXA) is considered the gold standard in the evaluation of bone mineral density (BMD) and in the diagnosis of osteoporosis.The diagnostic sensitivity of BMD at lumbar spine is frequently reduced by the presence of artifacts. This study aimed to show the usefulness of radiofrequency echographic multi-spectrometry (REMS) in determining lumbar BMD in the presence of artifacts with DXA measurements. We present 3 cases in which REMS technology, by the analysis of native raw unfiltered ultrasound signals, appears to be able to recognize and overcome the most common artifacts that affect the value of the BMD by DXA, thus allowing a better assessment of fracture risk.

New technology REMS for bone evaluation compared to DXA in adult women for the osteoporosis diagnosis: a real-life experience

Osteoporosis is a prevalent skeletal disorder in postmenopausal women. REMS represents a potential technology for osteoporosis diagnosis in clinical practice.

OBJECTIVE

To assess the accuracy of Radiofrequency Echographic Multi Spectrometry (REMS) technology in diagnosing osteoporosis in comparison with dual X-ray absorptiometry (DXA) on a population of Brazilian women.

METHODS

A population of women age ranged between 30 and 80 was recruited at DXA Service of São Paulo School-Hospital, Brazil. They underwent REMS and DXA scans at the axial sites. The REMS accuracy for the osteoporosis diagnosis was evaluated in comparison with DXA on both sites. The intra-operator and inter-operator coefficient of variation (CV) was also calculated.

RESULTS

A total of 343 patients were enrolled in the study. Erroneous scans due to poor quality acquisitions with both methods or to other technical reasons were excluded; 227 lumbar spine exams and 238 hip exams were acceptable for comparison analysis. The comparison between REMS and DXA outcomes showed that the average difference in BMD (expressed as bias±1.96 SD) was -0.026±0.179g/cm² for the spine and -0.027±0.156g/cm² for the femoral neck. When accepted 0.3 tolerance on T-score, there were no cases diagnosed as osteoporosis by DXA that were defined as normal by REMS. The REMS intra-operator CV was 0.51% for the lumbar spine and 1.08% for the femoral neck. The REMS inter-operator CV was 1.43% for the lumbar spine and 1.93% for the femoral neck.

CONCLUSION

The REMS approach had high accuracy for the diagnosis of osteoporosis in comparison with DXA in adult women. According to our results, this new technology has shown to be a promising alternative for populations without access to DXA densitometry.

Ultrasonic Bone Assessment: Ability of Apparent Backscatter Techniques to Detect Changes in the Microstructure of Human Cancellous Bone

Ultrasonic backscatter techniques may offer a useful approach for detecting changes in bone caused by osteoporosis. The goal of this study was to investigate how bone mineral density (BMD) and the microstructure of human cancellous bone affect three ultrasonic backscatter parameters that have been identified as potentially useful for ultrasonic bone assessment purposes: the apparent integrated backscatter (AIB), the frequency slope of apparent backscatter (FSAB), and the frequency intercept of apparent backscatter (FIAB). Ultrasonic measurements were performed with a 3.5-MHz broadband transducer on 54 specimens of human cancellous bone prepared from the proximal femur. Microstructural parameters and BMD were measured using X-ray microcomputed tomography (micro-CT). Relationships between AIB, FSAB, FIAB, and the micro-CT parameters were investigated using univariate and multivariate statistical analysis techniques. Moderate-to-strong univariate correlations were observed between the backscatter parameters and microstructure and BMD in many cases. The partial correlation analysis indicated that the backscatter parameters are dependent on microstructure independently of BMD in some cases. Multiple stepwise linear regression analysis used to generate multivariate models found that microstructure was a significant predictor of the backscatter parameters in most cases.

[The relevance of the diagnosis, treatment and prevention of osteoporosis for the clinical practice of doctors working in the field of rehabilitation and spa medicine]

There is a high prevalence of osteoporosis (OP) among patients of the older age undergoing rehabilitation. Therefore, it is obvious that physicians working in the field of physical and rehabilitative medicine should be well oriented in this medical problem.

OBJECTIVE

To study the relevance of the OP problem for physicians working in the field of physical and rehabilitation medicine, their awareness of the main methods of diagnosis, treatment and prevention of OP, as well as the frequency of using these methods in daily clinical practice.

MATERIAL AND METHODS

A cross-type study was carried out using a questionnaire survey. The study included 157 doctors (male 34, female 123) of 8 medical specialties working in 27 specialized medical institutions on the profile of «medical rehabilitation» or «spa treatment». The questionnaire for doctors consisted of 21 items of special questions.

RESULTS

90.45% of doctors considered the problem of OP is relevant for their clinical activities, 100% of respondents indicated that the presence of OP significantly affects the rehabilitation prognosis, 95.54% - the effectiveness of medical rehabilitation. According to the respondents the patients with OP cover 30.0% of total patients flow on average. 145 (92.36%) doctors noted that they know the OP risk factors, 155 (98.73%) - methods for OP diagnosing, 108 (68.79%) - methods for OP treatment, 126 (80, 25%) - methods for OP prevention, 74 (47.13%) - FRAX. 55 (35.01%) respondents identified their level of awareness on the OP problem as sufficient for managing patients with this pathology. Diagnostic procedures for OP were recommended by all interviewed endocrinologists (100%), most of traumatologists-orthopedists (72.73%), obstetricians-gynecologists (66.67%) and cardiologists (64.28%), as well as on average 1/2 (50%) neurologists and therapists. OP treatment was mainly performed by endocrinologists (100%), obstetricians-gynecologists (66.67%) and therapists (60%). 32.48% of physicians in the study sample have ever referred their patients to a densitometry and the diagnosis of OP was established in 80.25% of cases on the basis of bone densitometry data.

CONCLUSION

The problem of OP is relevant for the clinical practice of doctors working in the field of rehabilitation and balneology medicine; the presence of OP significantly affects the prognosis and effectiveness of medical rehabilitation. The results of the study demonstrated the need to expand the availability of OP diagnostics methods in rehabilitation and balneology organizations, as well as the need to raise awareness of the OP problem among specialists working in this area.

Drug Repurposing: An Emerging Tool for Drug Reuse, Recycling and Discovery

Drug repositioning or repurposing is a revolutionary breakthrough in drug development that focuses on rediscovering new uses for old therapeutic agents. Drug repositioning can be defined more precisely as the process of exploring new indications for an already approved drug while drug repurposing includes overall re-development approaches grounded in the identical chemical structure of the active drug moiety as in the original product. The repositioning approach accelerates the drug development process, curtails the cost and risk inherent to drug development. The strategy focuses on the polypharmacology of drugs to unlocks novel opportunities for logically designing more efficient therapeutic agents for unmet medical disorders. Drug repositioning also expresses certain regulatory challenges that hamper its further utilization. The review outlines the eminent role of drug repositioning in new drug discovery, methods to predict the molecular targets of a drug molecule, advantages that the strategy offers to the pharmaceutical industries, explaining how the industrial collaborations with academics can assist in the discovering more repositioning opportunities. The focus of the review is to highlight the latest applications of drug repositioning in various disorders. The review also includes a comparison of old and new therapeutic uses of repurposed drugs, assessing their novel mechanisms of action and pharmacological effects in the management of various disorders. Various restrictions and challenges that repurposed drugs come across during their development and regulatory phases are also highlighted.

Radiofrequency Echographic Multi Spectrometry (REMS) for the diagnosis of osteoporosis in a European multicenter clinical context

BACKGROUND

Radiofrequency Echographic Multi Spectrometry (REMS) is a non-ionizing technology for the densitometric assessment of osteoporosis. It has already been validated in Italian women with respect to the current clinical reference technology, Dual-energy X-ray Absorptiometry (DXA).

PURPOSE

Aim of the current study was to assess the diagnostic accuracy of REMS technology with respect to DXA in a wider European clinical context.

METHODS

A total of 4307 female Caucasian patients aged between 30 and 90 years underwent DXA and REMS scans at femoral neck and/or lumbar spine (the site depending on the medical prescription). The acquired data underwent a rigorous quality check in order to exclude the erroneous DXA and REMS reports. The diagnostic agreement between the two technologies was assessed, also stratifying for patients' age groups. The ability to recognise previously fractured patients was also investigated.

RESULTS

Overall, 4245 lumbar spine scans and 4271 femoral neck scans were performed. The ability to discriminate patients with and without osteoporosis by femoral neck investigation resulted in sensitivity and specificity of 90.4% and 95.5%, respectively. For lumbar spine scans, a sensitivity of 90.9% and a specificity of 95.1% were obtained. The areas under the curve (AUCs) of the Receiver Operating Characteristic (ROC) curve evaluating the ability to discriminate groups of patients with previous osteoporotic fracture using DXA and REMS T-score values were 0.631 and 0.683 (p < 0.0001), respectively, for femoral neck scans, whereas 0.603 and 0.640 (p = 0.0002), respectively, for lumbar spine scans.

CONCLUSION

The diagnostic effectiveness of REMS technology at reference anatomical sites for the assessment of osteoporosis has been confirmed in a large series of female patients, spanning from younger and pre-menopausal to elderly women up to 90 years, in a multicenter European clinical context.

Ultrasonic Bone Assessment Using the Backscatter Amplitude Decay Constant

Ultrasonic backscatter techniques are being developed to detect changes in bone caused by osteoporosis. The present study introduces a new technique that measures the exponential decay in the amplitude of the backscatter signal quantified by a parameter called the backscatter amplitude decay constant (BADC). Measurements were performed on 54 specimens of cancellous bone from 14 human femurs using a 3.5-MHz transducer. Six methods were tested to determine BADC. The recommended method measures the time slope of the natural log of the rectified signal. Measured values of BADC ranged from approximately 0.1 μs^-1 to 0.6 μs^-1. Moderate to strong correlations (Spearman's ρ >0.7) were found between BADC and the density and microstructural characteristics of the specimens determined using X-ray microcomputed tomography. The results of this study suggest that BADC may be able to detect changes in the density and microstructure of cancellous bone caused by osteoporosis and other diseases.

Radiofrequency echographic multi spectrometry for the prediction of incident fragility fractures: A 5-year follow-up study

PURPOSE

To investigate the effectiveness of the T-score values provided by Radiofrequency Echographic Multi Spectrometry (REMS) in the identification of patients at risk for incident osteoporotic fractures.

METHODS

A population of Caucasian women (30-90 years), enrolled from 2013 to 2016, underwent dual X-ray absorptiometry (DXA) and REMS scans at axial sites. The incidence of fragility fractures was assessed during a follow-up period up to 5 years. Afterwards, patients with and without incident fractures were stratified in two age-matched groups with a 1: 2 proportion (Group F' and Group NF', respectively). The performance of REMS T-score in discriminating between the two groups was quantitatively assessed and compared with DXA.

RESULTS

1516 patients were enrolled and 1370 completed the follow-up (mean ± SD: 3.7 ± 0.8 years; range: 1.9-5.0 years). Fracture incidence was 14.0%. Age-matched groups included 175 fractured patients and 350 non-fractured ones, respectively (median age 70.2 [interquartile range: 61.0-73.3] and 67.3 [65.4-69.8] years, p-value ns). The groups resulted also balanced for height, weight and BMI (p-values ns). As expected, the differences in REMS T-score (for vertebral site, -2.9 [-3.6 to -1.9] in Group F', -2.2 [-2.9 to -1.2] in Group NF') and DXA T-score (-2.8 [-3.3 to -1.9] in Group F', -2.2 [-2.9 to -1.4] in Group NF') were statistically significant (p-value <0.001). Analogous results were obtained for femoral neck. Considering the T-score cut-off of -2.5, REMS identified Group F' patients with a sensitivity of 65.1% and specificity of 57.7% of (OR = 2.6, 95%CI: 1.77-3.76, p < 0.001), whereas DXA showed a sensitivity of 57.1% and a specificity of 56.3% (OR = 1.7, 95%CI: 1.20-2.51, p-value = 0.0032). For femoral neck, REMS sensitivity and specificity were 40.2% and 79.9%, respectively, with an OR of 2.81 (95%CI: 1.80-4.39, p < 0.001). DXA, instead, showed a sensitivity and specificity of 42.3% and 79.3%, respectively, with an OR of 2.68 (95%CI: 1.71-4.21, p < 0.001).

CONCLUSIONS

REMS T-score resulted an effective predictor for the risk of incident fragility fractures in a population-based sample of female subjects, representing a promising parameter to enhance osteoporosis diagnosis in the clinical routine.

Spinal Cord Segmentation in Ultrasound Medical Imagery

In this paper, we study and evaluate the task of semantic segmentation of the spinal cord in ultrasound medical imagery. This task is useful for neurosurgeons to analyze the spinal cord movement during and after the laminectomy surgical operation. Laminectomy is performed on patients that suffer from an abnormal pressure made on the spinal cord. The surgeon operates by cutting the bones of the laminae and the intervening ligaments to relieve this pressure. During the surgery, ultrasound waves can pass through the laminectomy area to give real-time exploitable images of the spinal cord. The surgeon uses them to confirm spinal cord decompression or, occasionally, to assess a tumor adjacent to the spinal cord. The Freely pulsating spinal cord is a sign of adequate decompression. To evaluate the semantic segmentation approaches chosen in this study, we constructed two datasets using images collected from 10 different patients performing the laminectomy surgery. We found that the best solution for this task is Fully Convolutional DenseNets if the spinal cord is already in the train set. If the spinal cord does not exist in the train set, U-Net is the best. We also studied the effect of integrating inside both models some deep learning components like Atrous Spatial Pyramid Pooling (ASPP) and Depthwise Separable Convolution (DSC). We added a post-processing step and detailed the configurations to set for both models.

Ultrasonic Backscatter Difference Measurement of Bone Health in Preterm and Term Newborns

Metabolic bone disease of prematurity remains a significant problem for preterm infants. Quantitative ultrasound (QUS) has potential as a non-invasive tool for assessing bone health of newborns. The aim of this study was to assess bone health in preterm and term newborns using ultrasonic backscatter difference measurement. This study analyzed a total of 493 neonates, including 239 full-term infants (gestational age [GA] >37 wk), 201 preterm I infants (GA: 32-37 wk) and 53 extreme preterm II infants (GA <32 wk). Ultrasonic backscatter measurements were performed on the calcaneus of infants at birth, and the normalized mean of the backscatter difference spectrum (nMBD) was calculated as an ultrasonic index of neonatal bone status. Simple and multiple linear regressions were performed to determine the association of ultrasonic nMBD with GA, anthropometric characteristics and biochemical markers. Statistically significant differences in GA, anthropometric characteristics (birth weight, birth length [BL], birth head circumference and body mass index [BMI]) and biochemical markers (alkaline phosphatase, serum calcium and serum phosphate) were observed among preterm and term infants. The nMBD for term infants (median = 3.72 dB/μs, interquartile range [IR] = 1.95 dB/μs) was significantly higher than that for preterm I infants (median = 1.95 dB/μs, IR = 3.12 dB/μs), which was, in turn, significantly higher than that for preterm II infants (median = 0.19 dB/μs, IR = 3.50 dB/μs). The nMBD yielded moderate correlations (ρ = 0.57-0.62, p < 0.001) with GA and anthropometric characteristics and weak correlations (|ρ| = 0.08-0.21, p < 0.001 or not significant) with biochemical markers. Multivariate regressions revealed that only BL (p = 0.002) and BMI (p = 0.032) yielded significantly independent contributions to the nMBD measurement, and combinations of BL and BMI could explain up to 42% of the variation of nMBD in newborn infants. This study found that ultrasonic backscatter difference measurement might be helpful in bone health evaluation in preterm and term newborns. The utility of ultrasonic backscatter measurement in diagnosis of metabolic bone disease in infants should be investigated further.

Radiofrequency echographic multi-spectrometry for the in-vivo assessment of bone strength: state of the art-outcomes of an expert consensus meeting organized by the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO)

PURPOSE

The purpose of this paper was to review the available approaches for bone strength assessment, osteoporosis diagnosis and fracture risk prediction, and to provide insights into radiofrequency echographic multi spectrometry (REMS), a non-ionizing axial skeleton technique.

METHODS

A working group convened by the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis met to review the current image-based methods for bone strength assessment and fracture risk estimation, and to discuss the clinical perspectives of REMS.

RESULTS

Areal bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) is the consolidated indicator for osteoporosis diagnosis and fracture risk assessment. A more reliable fracture risk estimation would actually require an improved assessment of bone strength, integrating also bone quality information. Several different approaches have been proposed, including additional DXA-based parameters, quantitative computed tomography, and quantitative ultrasound. Although each of them showed a somewhat improved clinical performance, none satisfied all the requirements for a widespread routine employment, which was typically hindered by unclear clinical usefulness, radiation doses, limited accessibility, or inapplicability to spine and hip, therefore leaving several clinical needs still unmet. REMS is a clinically available technology for osteoporosis diagnosis and fracture risk assessment through the estimation of BMD on the axial skeleton reference sites. Its automatic processing of unfiltered ultrasound signals provides accurate BMD values in view of fracture risk assessment.

CONCLUSIONS

New approaches for improved bone strength and fracture risk estimations are needed for a better management of osteoporotic patients. In this context, REMS represents a valuable approach for osteoporosis diagnosis and fracture risk prediction.

A novel quantitative method for estimating bone mineral density using B-mode ultrasound and radiofrequency signals-a pilot study on patients with rheumatoid arthritis

The objective of the present study was to evaluate whether an innovative quantitative ultrasound (QUS) technique, Radiofrequency Echographic Multi Spectromety, which combines B-mode ultrasound and radiofrequency signals, is reliable in typical Romanian patients compared to previous results obtained using dual-energy X-ray absorptiometry (DXA). The study prospectively included previously unscreened post-menopausal females with rheumatoid arthritis (RA) and age-matched healthy controls. Bone mineral density (BMD) measurements were performed with an EchoS machine (Echolight^®), which combines B-mode ultrasound and radiofrequency signals. The study included 106 RA patients, with a median disease duration of 3.2 (0.5–22) years and 119 controls. RA patients had a significantly lower body weight, body mass index (BMI) and basal metabolic rate (BMR) than the controls, while the prevalence of obesity and body fat differed insignificantly. RA patients had a significantly lower spine and hip BMD, higher fracture risk and higher prevalence of osteoporosis. Compared to RA patients without osteoporosis, those with osteoporosis were significantly older and had a longer menopause duration, but they had a significantly lower BMI, body fat, BMR and prevalence of obesity. Among the controls and RA patients, the median spine and hip BMD became significantly higher as the BMI increased from underweight to obesity. In conclusion, osteoporosis is prevalent among RA patients, as a part of a complex transformation of body mass composition, involving BMI and fat mass. The novel QUS scanning technique was able to replicate the results of the established DXA measurement of BMD and is potentially suitable for screening wide populations for osteoporosis.

A semi-automatic 3D ultrasound reconstruction method to assess the true severity of adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is a three-dimensional (3D) spinal deformity. Current practice uses the Cobb method to measure spinal severity on postero-anterior (PA) radiographs. This method may underestimate spinal deformity and exposes patients to ionizing radiation, increasing the risk of cancer. This paper reports a new 3D ultrasound method using the voxel-based reconstruction technique with bilinear interpolation to reconstruct a 3D spinal image and measure true spinal curvature on the plane of maximal curvature (PMC). Axial vertebral rotation (AVR) was measured on the 3D image and utilized to estimate the PMC. In vitro phantom experiments and in vivo clinical study were conducted to evaluate reconstruction accuracy and measurement reliability. The in vitro study showed a high accuracy of the reconstruction of vertebrae with the mean absolute difference (MAD) < 3 mm. The in vitro and in vivo measurements of AVR were reliable (> 0.90). The in vivo study also showed high intra- and inter-rater reliabilities of the PA and PMC Cobb angle measurements with ICC values > 0.90 and MADs within the clinical accepted tolerances. The PMC Cobb angles were up to 7° greater than their corresponding PA Cobb angles. This method demonstrated a non-ionizing radiation method to assess the actual severity of AIS. Graphical abstract Adolescent idiopathic scoliosis (AIS) is a lateral curvature of spine with vertebral rotation. Using the Cobb method to measure spinal severity on postero-anterior (PA) radiographs may under estimate its severity.

Correlations of the frequency dependence of the ultrasonic backscatter coefficient with the bone volume fraction and the trabecular thickness in bovine trabecular bone: Application of the binary mixture model

The ultrasonic backscatter coefficient and the exponent n (frequency dependence of the backscatter coefficient) were measured in 24 bovine femoral trabecular bone samples. The binary mixture model for ultrasonic scattering from trabecular bone was applied to predict the variations of the ultrasound parameters with the bone volume fraction (BV/TV) and the trabecular thickness (Tb.Th) in trabecular bone. The backscatter coefficient exhibited significant, positive correlations with the BV/TV (R = 0.82) and the Tb.Th (R = 0.79). In contrast, the exponent n was found to be significantly, negatively correlated with the BV/TV (R = -0.77) and the Tb.Th, (R = -0.71).

Can low-frequency guided waves at the tibia paired with machine learning differentiate between healthy and osteopenic/osteoporotic subjects? A pilot study

PURPOSE

Axial transmission quantitative acoustics (ax-QA) has shown to be a promising tool for assessing bone health and properties in a safe, inexpensive, and portable manner. This study investigated the efficacy of low-frequency ax-QA measured at the tibia, paired with a support vector machine (SVM) approach for combining multiple acoustic indicators, to diagnose osteoporosis as defined by bone mineral density.

METHODS

This pilot study measured 41 female subjects using ax-QA (flexural mode, 3 kHz) at the tibia and using dual X-ray absorptiometry (DXA) at the lumbar spine, femoral neck, and distal radius. For each location, a threshold classifier and SVM were trained to differentiate between healthy and non-healthy subjects based on the phase velocity at different frequencies. Receiver Operating Characteristics and area under curve values (AUC) were used to assess the classifiers' performances for various thresholds and class-weights.

RESULTS

The SVM outperformed the threshold classifier for all three bone locations at low false positive rates. While differentiation between healthy and non-healthy bone states was poor for the spine (AUC: 0.56 ± 0.04), good to moderate performances were observed for the radius (AUC: 0.83 ± 0.03) and hip (AUC: 0.71 ± 0.04).

CONCLUSIONS

Low-frequency ax-QA has demonstrated potential for complementing DXA in screening for osteoporosis at the radius and hip. Through further addition of acoustic indicators ax-QA could provide a diagnostic alternative in third-world countries, and bring bone health screening and monitoring into the hands of clinicians and general health practitioners everywhere.

Radiofrequency echographic multispectrometry compared with dual X-ray absorptiometry for osteoporosis diagnosis on lumbar spine and femoral neck

An innovative, non-ionizing technique to diagnose osteoporosis on lumbar spine and femoral neck was evaluated through a multicenter study involving 1914 women. The proposed method showed significant agreement with reference gold standard method and, therefore, a potential for early osteoporosis diagnoses and possibly improved patient management.

INTRODUCTION

To assess precision (i.e., short term intra-operator precision) and diagnostic accuracy of an innovative non-ionizing technique, REMS (Radiofrequency Echographic Multi Spectrometry), in comparison with the clinical gold standard reference DXA (dual X-ray absorptiometry), through an observational multicenter clinical study.

METHODS

In a multicenter cross-sectional observational study, a total of 1914 postmenopausal women (51-70 years) underwent spinal (n = 1553) and/or femoral (n = 1637) DXA, according to their medical prescription, and echographic scan of the same anatomical sites performed with the REMS approach. All the medical reports (DXA and REMS) were carefully checked to identify possible errors that could have caused inaccurate measurements: erroneous REMS reports were excluded, whereas erroneous DXA reports were re-analyzed where possible and otherwise excluded before assessing REMS accuracy. REMS precision was independently assessed.

RESULTS

In the spinal group, quality assessment on medical reports produced the exclusion of 280 patients because of REMS errors and 78 patients because of DXA errors, whereas 296 DXA reports were re-analyzed and corrected. Analogously, in the femoral group there were 205 exclusions for REMS errors, 59 exclusions for DXA errors, and 217 re-analyzed DXA reports. In the resulting dataset (n = 1195 for spine, n = 1373 for femur) REMS outcome showed a good agreement with DXA: the average difference in bone mineral density (BMD, bias ± 2SD) was -0.004 ± 0.088 g/cm² for spine and - 0.006 ± 0.076 g/cm² for femur. Linear regression showed also that the two methods were well correlated: standard error of the estimate (SEE) was 5.3% for spine and 5.8% for femur. REMS precision, expressed as RMS-CV, was 0.38% for spine and 0.32% for femur.

CONCLUSIONS

The REMS approach can be used for non-ionizing osteoporosis diagnosis directly on lumbar spine and femoral neck with a good level of accuracy and precision. However, a more rigorous operator training is needed to limit the erroneous acquisitions and to ensure the full clinical practicability.

Global research trends in spinal ultrasound: a systematic bibliometric analysis

BACKGROUND

In recent years, there has been increased interest in the use of ultrasound technology in the evaluation of spinal and paraspinal regions.

OBJECTIVE

This study aimed to investigate trends in spinal ultrasound research from 1994 to 2015 and compare the contributions of such research from different countries and authors.

STUDY DESIGN

Bibliometric analysis.

SETTING

Publications related to spinal ultrasound from 1994 to 2015 were retrieved from the Web of Science database.

METHODS

Excel 2013, GraphPad Prism 5, and VOSviewer were used to summarise bibliometric features, including the number of publications, citation frequency, H-index, and country contributions and hotspots (keywords of popular scientific fields).

RESULTS

A total of 3859 papers were included. The global inflection point (the point in time when the publication growth rate moved from positive to negative) came in 2010. The United States contributed the largest percentage of articles (1041; 26.9%), with the most citations (19 848) and the highest H-index (61). The journals Osteoporosis International and Spine had the highest publication number. The University of Toronto and the University of California, San Francisco were the most contributive institutions. Studies could be divided into three clusters: surgery, osteoporosis, and others. The keywords 'adolescent idiopathic scoliosis' and 'anaesthesia' were the latest hotspots, appearing around 2012.

CONCLUSION

Spinal ultrasound literature has grown continuously over the last 22 years, with the rate slowing down after 2010. The United States was the largest contributor in this field. Recent studies on topics related to 'adolescent idiopathic scoliosis' and 'anaesthesia' were relatively new and should be closely followed in spinal ultrasound research.

Effect of gate choice on backscatter difference measurements of cancellous bone

A variety of ultrasonic techniques have been developed to detect changes in bone caused by osteoporosis. One approach, called the backscatter difference technique, analyzes the power difference between two different portions of a backscatter signal. Analysis gates with a certain delay τ_d, width τ_w, and separation τ_s are used to define portions of the backscatter signal for analysis. The goal of the present study was to investigate how different choices of τ_d, τ_w, and τ_s affect four backscatter difference parameters: the normalized mean of the backscatter difference (nMBD), the normalized slope of the backscatter difference (nSBD), the normalized intercept of the backscatter difference (nIBD), and the normalized backscatter amplitude ratio (nBAR). Backscatter measurements were performed on 54 cube shaped specimens of human cancellous bone. nMBD, nSBD, nIBD, and nBAR were determined for 34 different combinations of τ_d, τ_w, and τ_s for each specimen. nMBD and nBAR demonstrated the strongest correlations with apparent bone density (0.48 ≤ R_s ≤ 0.90). Generally, the correlations were found to improve as τ_w + τ_s was increased and as τ_d was decreased. Among the four backscatter difference parameters, the measured values of nMBD were least sensitive to gate choice (<16%).

Bone biomarker for the clinical assessment of osteoporosis: recent developments and future perspectives

Bone biomarkers included formation, resorption and regulator are released during the bone remodeling processes. These bone biomarkers have attracted much attention in the clinical assessment of osteoporosis treatment in the past decade. Combination with the measurement of bone mineral density, the clinical applications of bone biomarkers have provided comprehensive information for diagnosis of osteoporosis. However, the analytical approaches of the bone biomarkers are still the challenge for further clinical trials. In this mini-review, we have introduced the functions of bone biomarkers and then recently developed techniques for bone biomarker measurements have been systematically integrated to discuss the possibility for osteoporosis assessment in the early stage.

Correlation between ultrasonic power spectrum and bone density on the heel

The purposes of this paper were to evaluate the correlation between ultrasonic power spectrum and bone density and to extract the effectiveness of parameters from power spectrum for evaluating bone density. A total of 50 persons 24-72years of age were recruited. All study participants underwent bone mineral density (BMD) measurements of the lumbar spine (vertebral levels L1-L4). The participants also underwent calcaneal measurements to determine ultrasonic power spectrum with central frequencies of 0.5MHz. Three parameters from normalized power spectrum, called principle frequency (PF), frequency band (FB), and amplitude for principle frequency (APF), were chosen and be evaluated the correlation with the lumbar spine BMD. The correlation coefficient of PF, FB and APF with BMD was r=-0.48 (p<0.001), r=0.48 (p<0.001), and r=-0.71 (p<0.001), respectively. The results showed that the correlation between APF and BMD was better than the correlation among PF, FB and BMD, and APF have a significant correlation with BMD. In conclusion, the correlations among the parameters of ultrasonic power spectrum and BMD are significant, and especially APF performs better than PF and FB in evaluating bone density of participants. These results suggest that ultrasonic power spectrum may contain substantial information not already contained in BUA and SOS. A multiple regression model including all three QUS variables was somewhat more predictive of BMD than a model including only BUA and SOS.

Backscatter-difference Measurements of Cancellous Bone Using an Ultrasonic Imaging System

Backscatter-difference measurements may be used to detect changes in bone caused by osteoporosis. The backscatter-difference technique measures the power difference between two portions of an ultrasonic backscatter signal. The goal of this study is to evaluate the feasibility of using an ultrasonic imaging system to perform backscatter-difference measurements of bone. Ultrasonic images and backscatter signals were acquired from 24 specimens of human cancellous bone. The signals were analyzed in the frequency domain to determine the normalized mean backscatter-difference (nMBD) and in the time domain to determine the normalized backscatter amplitude ratio (nBAR). The images were analyzed to determine the normalized pixel value difference (nPVD), which measures the difference in average pixel brightness between regions of interest placed at two different depths in the image. All three parameters were found to increase with bone mineral density. The signal-based parameters, nMBD and nBAR, correlated well with bone mineral density, yielding linear correlation coefficients that ranged from 0.74 to 0.87. The image based parameter, nPVD, performed somewhat less well, yielding correlation coefficients that ranged from 0.42 to 0.81. These results suggest that ultrasonic imaging systems may be used to perform backscatter-difference measurements for the purpose of ultrasonic bone assessment.

An Advanced Quantitative Echosound Methodology for Femoral Neck Densitometry

The aim of this paper was to investigate the clinical feasibility and the accuracy in femoral neck densitometry of the Osteoporosis Score (O.S.), an ultrasound (US) parameter for osteoporosis diagnosis that has been recently introduced for lumbar spine applications. A total of 377 female patients (aged 61-70 y) underwent both a femoral dual X-ray absorptiometry (DXA) and an echographic scan of the proximal femur. Recruited patients were sub-divided into a reference database used for ultrasound spectral model construction and a study population for repeatability assessments and accuracy evaluations. Echographic images and radiofrequency signals were analyzed through a fully automatic algorithm that performed a series of combined spectral and statistical analyses, providing as a final output the O.S. value of the femoral neck. Assuming DXA as a gold standard reference, the accuracy of O.S.-based diagnoses resulted 94.7%, with k = 0.898 (p < 0.0001). Significant correlations were also found between O.S.-estimated bone mineral density and corresponding DXA values, with r(2) up to 0.79 and root mean square error = 5.9-7.4%. The reported accuracy levels, combined with the proven ease of use and very good measurement repeatability, provide the adopted method with a potential for clinical routine application in osteoporosis diagnosis.

Major osteoporotic fragility fractures: Risk factor updates and societal impact

Osteoporosis is a silent disease without any evidence of disease until a fracture occurs. Approximately 200 million people in the world are affected by osteoporosis and 8.9 million fractures occur each year worldwide. Fractures of the hip are a major public health burden, by means of both social cost and health condition of the elderly because these fractures are one of the main causes of morbidity, impairment, decreased quality of life and mortality in women and men. The aim of this review is to analyze the most important factors related to the enormous impact of osteoporotic fractures on population. Among the most common risk factors, low body mass index; history of fragility fracture, environmental risk, early menopause, smoking, lack of vitamin D, endocrine disorders (for example insulin-dependent diabetes mellitus), use of glucocorticoids, excessive alcohol intake, immobility and others represented the main clinical risk factors associated with augmented risk of fragility fracture. The increasing trend of osteoporosis is accompanied by an underutilization of the available preventive strategies and only a small number of patients at high fracture risk are recognized and successively referred for therapy. This report provides analytic evidences to assess the best practices in osteoporosis management and indications for the adoption of a correct healthcare strategy to significantly reduce the osteoporosis burden. Early diagnosis is the key to resize the impact of osteoporosis on healthcare system. In this context, attention must be focused on the identification of high fracture risk among osteoporotic patients. It is necessary to increase national awareness campaigns across countries in order to reduce the osteoporotic fractures incidence.