Factors influencing the speed of sound through the proximal phalanges

Karate Training Improves Skeletal Status Assessed by Quantitative Ultrasound in Girls and Premenopausal Women

PURPOSE

The aim of the study was to assess the influence of regular karate training on the skeletal status evaluated by quantitative ultrasound (QUS) in females.

METHODS

A group of 132 karate training girls and women at mean age 19.57 (standard deviation [SD] 7.64) yr (range 7.3-45.3 yr) and 322 age-, sex- and body size-matched controls were enrolled into the study. Mean training duration in the karate group was 7.52 (SD 5.05) yr and mean training frequency was 2.97 (SD 1.21) per wk. The QUS measurements were performed at hand proximal phalanges, using a DBM Sonic 1200 (IGEA, Carpi, Italy) sonographic device, which measures amplitude-dependent speed of sound (Ad-SoS [m/s]).

RESULTS

The results of Ad-SoS obtained in karatekas were generally higher than in controls with significant difference for prepubertal girls (1966.2 [SD 46.2] vs 1942.7 [SD 38.4]; p < 0.05) and for adult women (2124.4 [SD 48.0] vs 2105.3 [SD 54.0]; p < 0.05).

CONCLUSIONS

Regular karate training is a factor that is positively associated with results of the QUS measurements at hand phalanges in exercising females and its impact is most strongly pronounced in prepuberty and adulthood.

Imaging methods for bone mass evaluation during childhood and adolescence: an update

The objective of the work was to prepare an update on imaging methods for bone evaluation during childhood and adolescence. The text was based on original and review articles on imaging methods for clinical evaluation of bone mass in children and adolescents up to 20 years old. They were selected from BIREME and PUBMED by means of the following keywords: bone density; osteoporosis/diagnosis; densitometry; tomography; ultrasonography; magnetic resonance imaging; and radiogrammetry and published in Portuguese or English, in the last 10 years (2006-2016). The article was organized into topics with the description of peculiarities, advantages and disadvantages of each imaging method and their possible clinical applicability. Despite the emergence of new technologies, dual energy X-ray absorptiometry (DXA) remains the gold standard method for low bone mass diagnosis in all age groups. However, interpretation is complex in children and adolescents and demands skilled people. Quantitative computed tomography (QCT) [central QCT, peripheral QCT (pQCT) and high resolution-pQCT (HR-pQCT)] and magnetic resonance imaging (MRI) evaluate real bone density, but are not yet available for routine use. Quantitative bone ultrasound (QUS) shows good perspectives for its use in primary prevention actions. Automated radiogrammetry shows promise as a method able to flag individuals who might benefit from a complete bone assessment, but the clinical value of the measures still needs to be established.

Pamidronate treatment stimulates the onset of recovery phase reducing fracture rate and skeletal deformities in patients with idiopathic juvenile osteoporosis: comparison with untreated patients

Although spontaneous remission occurs in patients with idiopathic juvenile osteoporosis (IJO), permanent bone deformities may occur. The effects of long-term pamidronate treatment on clinical findings, bone mineral status, and fracture rate were evaluated. Nine patients (age 9.8 ± 1.1 years, 7 males) with IJO were randomized to intravenous pamidronate (0.8 ± 0.1 mg/kg per day for 3 days; cycles per year 2.0 ± 0.1; duration 7.3 ± 1.1 years; n = 5) or no treatment (n = 4). Fracture rate, phalangeal quantitative ultrasound, and lumbar bone mineral density (BMD) by dual energy X-ray absorptiometry at entry and during follow-up (range 6.3-9.4 years) were assessed. Bone pain improved in treated patients. Difficulty walking continued for 3-5 years in untreated patients, and vertebral collapses occurred in three of them. During follow-up, phalangeal amplitude-dependent speed of sound (AD-SoS), bone transmission time (BTT), and lumbar BMDarea and BMDvolume progressively increased in treated patients (P < 0.05-P < 0.0001). In untreated patients AD-SoS and BTT decreased during the first 2-4 years of follow-up (P < 0.05-P < 0.01); lumbar BMDarea increased after 6 years (P < 0.001) whereas BTT and lumbar BMDvolume increased after 7 years of follow-up (P < 0.05 and P < 0.001, respectively). At the end of follow-up, AD-SoS, BTT, lumbar BMDarea, and BMDvolume Z-scores were lower in untreated patients than in treated patients (-2.2 ± 0.3 and -0.5 ± 0.2; -1.9 ± 0.2 and -0.6 ± 0.2; -2.3 ± 0.3 and -0.7 ± 0.3; -2.4 ± 0.2 and -0.7 ± 0.3, P < 0.0001, respectively). Fracture rate was higher in untreated patients than in treated patients during the first 3 years of follow-up (P < 0.02). Our study showed that spontaneous recovery of bone mineral status is unsatisfactory in patients with IJO. Pamidronate treatment stimulated the onset of recovery phase reducing fracture rate and permanent disabilities without evidence of side-effects.

Impact of metabolic control on bone quality in phenylketonuria and mild hyperphenylalaninemia

OBJECTIVES

A reduction of bone mineral density of unknown etiology has been reported in phenylketonuria (PKU) by radiological techniques, whereas no data on bone density in mild hyperphenylalaninemia (HPA) are available. We aimed to assess bone condition in PKU and HPA by quantitative ultrasound (QUS), taking into account patients' clinical and biochemical features.

PATIENTS AND METHODS

Phalangeal QUS has been used for bone assessment in 78 patients affected by PKU (n = 42) or mild HPA (n = 36). For each patient, blood phenylalanine concentrations in the 2 years before the study have been recorded and related to bone assessment.

RESULTS

Overall normal bone quality has been observed in the whole study group (AD-SoS standard deviation score [SDS] 0.25 ± 1.29; BTT SDS -0.13 ± 1.08). PKU adolescents (age older than 15 years, AD-SoS SDS -0.54 ± 1.33; BTT SDS -0.85 ± 1.21) and patients with poor compliance with treatment (blood phenylalanine >10 mg/dL, AD-SoS SDS -0.47 ± 1.39; BTT SDS -0.97 ± 1.14) showed lower BTT SDS with respect to normal population (P = 0.003 and P < 0.001, respectively). Patients with PKU with good compliance with treatment (blood phenylalanine < 10 mg/dL, AD-SoS SDS 0.65 ± 1.33; BTT SDS 0.15 ± 0.94) and patients with mild HPA (AD-SoS SDS 0.44 ± 1.06 and BTT SDS 0.19 ± 0.85) showed normal bone mineral density and cortical thickness.

CONCLUSIONS

Good compliance with treatment in PKU during adolescence and adulthood is desirable because diet discontinuation is associated with bone loss. Mild HPA seems not to be complicated by bone damage.

Cortical thickness and medullary canal dimensions of the bone phalanx are predicted by quantitative ultrasound parameters

The aim of the study was to investigate the relationship between quantitative ultrasound (QUS) parameters extracted from the analysis of the ultrasound (US) signal and the geometric properties of the bones. One hundred and one subjects in the age range of 20-7 4yr (mean: 52+/-12 yr) have been measured by QUS at the phalanges for the evaluation of amplitude-dependent speed of sound (AD-SoS), bone transmission time (BTT), US peak amplitude (UPA), signal dynamic (SDY), slope, energy, and fast wave amplitude (FWA). Hand radiograph, lumbar spine dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT), and femoral neck DXA forearm peripheral QCT were performed on all patients. BTT is related to cortical thickness (CTh) (r=0.62, p<0.0001), and FWA is related to medullary canal thickness (r=-0.64, p<0.0001). Other parameters are related to both medullary canal thickness (AD-SoS: r=-0.21; UPA: r=-0.53; SDY: r=-0.56; slope: r=-0.64; energy: r=-0.44, p<0.05) and CTh (AD-SoS: r=0.54, p<0.0001; UPA: r=0.51; SDY: r=0.38; slope: r=0.32; energy: r=0.56, p<0.001). Linear multivariate models indicate that BTT, UPA, and energy measured at the phalanges carry independent information on CTh of the bone, whereas FWA, SDY, and slope are related only to medullary canal thickness.

Analysis of quantitative ultrasound graphic trace and derived variables assessed at proximal phalanges of the hand in healthy subjects and in patients with cerebral palsy or juvenile idiopathic arthritis. A pilot study

Amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT) are the quantitative ultrasound (QUS) variables usually assessed at proximal phalanges of the hand to estimate bone mineral status. The aim of the study was to provide a reference database for some additional QUS variables reflecting morphology of the ultrasound graphic trace according to gender, age, height, weight, and body mass index (BMI), and to assess their clinical usefulness. Fifty-two patients (age 3.1-20.9 years) affected by cerebral palsy with spastic tetraplegia (CPST, n=38) or polyarticular active juvenile idiopathic arthritis (JIA, n=14) were examined. In addition to AD-SoS and BTT, two QUS variables derived from the morphological analysis of ultrasound graphic trace, such as energy, extrapolated from the area under the ultrasound signal received, and weighted-slope (W-slope), derived from the angular coefficient of the regression line fitting the top point of the peaks of the ultrasound signal, were measured by phalangeal QUS (DBM Sonic, IGEA). The values of all the QUS variables measured in the patients were compared with our own sex- and age-reference values (n=1083, 587 males and 496 females, aged 3-21 years). The mean values of AD-SoS, BTT, energy, and W-slope were reduced (P<0.0001) in patients as a whole compared with normative data (-2.4+/-1.2, -2.7+/-1.5, -2.5+/-1.1, -2.5+/-1.1 Z-score, respectively). Fractured patients showed lower (P<0.001-P<0.0001) values of the QUS variables than fracture-free patients (AD-SoS, -3.3+/-1.2 and -1.8+/-0.9; BTT, -3.9+/-1.7 and -1.8+/-1.1; energy, -3.2+/-1.2 and -2.2+/-0.7; W-slope, -3.4+/-1.4 and -2.2+/-0.9 Z-score, respectively). There was no difference (P=NS) between patients with CPST and those with JIA. Age and height were positively correlated with all the QUS variables (r=0.55-0.79, P<0.01-P<0.0001). QUS variables were positively correlated among them (r=0.74-0.94, P<0.0001). Age and number of fractures were independent predictors of the QUS variables (coefficients: AD-SoS, 11.466 and -17.642; BTT, 0.049 and -0.045; energy, 1.072 and -1.303; W-slope, 0.046 and -0.067; respectively). In conclusion, measurement of QUS variables derived from the morphological analysis of the ultrasound signal could give additional information in estimating bone mineral status in children and adolescents, probably reflecting some aspect related to bone structure.

Phalangeal quantitative ultrasound and bone mineral density in evaluating cortical bone loss: a study in postmenopausal women with primary hyperparathyroidism and subclinical iatrogenic hyperthyroidism

Twenty-five postmenopausal women with primary hyperparathyroidism (PHPT) and 30 age-matched women with subclinical hyperthyroidism (sHTH) were studied to assess cortical bone loss. One hundred two healthy women were also recruited. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry at lumbar spine (LS), femoral neck (FN) and femoral total (FT), and at one-third of the radius (R). Amplitude-dependent speed of sound (ADSoS) and Ultrasound Bone Profile Index (UBPI) were also evaluated using phalangeal quantitative ultrasound (QUS). A significant correlation was found between QUS and BMD at LS (ADSoS, p < 0.05) and R (ADSoS and UBPI, p < 0.001) in controls. QUS significantly correlated with BMD at LS, FN (p < 0.01), and FT (p < 0.001) in sHTH. No correlations were found in the PHPT group. Mean T-score values of all parameters were significantly lower in patients compared with controls (p < 0.001); however, they did not differ between PHPT and sHTH patients. T-score of R, ADSoS, and UBPI was reduced compared with other sites (p < 0.001) in both diseases. In postmenopausal women with PHPT and sHTH, bone loss is mainly detectable at cortical level. However, qualitative and/or structural changes of bone could account for the lack of correlations between these 2 techniques at cortical sites.

Osteoprotegerin and Bone Mineral Density in Hemodiafiltration Patients

A newly identified cytokine, osteoprotegerin (OPG) appears to be involved in the regulation of bone remodeling. In vitro studies suggest that OPG, a soluble member of the TNF receptor family of proteins, inhibits osteoclastogenesis by interrupting the intercellular signaling between osteoblastic stromal cells and osteoclast progenitors. As patients with chronic renal failure (CRF) often have renal osteodystrophy (ROD), we investigated the role of osteoprotegerin (OPG) in ROD, and investigated whether there was any relationship between serum OPG, intact parathyroid (PTH) (iPTH), vitamin D, and trabecular bone. Serum OPG combined with iPTH might be a useful tool in the noninvasive diagnosis of ROD, at least in cases in which the range of PTH values compromises reliable diagnosis. Thirty-six patients on maintenance hemodiafiltration (HDF) and a control group of 36 age and sex matched healthy subjects with no known metabolic bone disease were studied. The following assays were made on serum: iPTH, osteocalcin (BGP), bone alkaline phosphatase, 25(OH)-cholecalciferol, calcium, phosphate, OPG, IGF-1, estradiol, and free testosterone. Serum Ca++, P, B-ALP, BGP, IGF-1, iPTH, and OPG levels were significantly higher in HDF patients than in controls, while DXA measurements and quantitative ultrasound (QUS) parameters were significantly lower. On grouping patients according to their mean OPG levels, we observed significantly lower serum IGF-1, vitamin D3 concentrations, and lumbar spine and hip bone mineral density in the high OPG groups. No correlation was found between OPG and bone turnover markers, whereas a negative correlation was found between serum OPG and IGF-1 levels (r=-0.64, p=0.032). Serum iPTH concentrations were positively correlated with bone alkaline phosphatase (B-ALP) (r=0.69, p=0.038) and BGP (r=0.92, p<0.001). The findings made suggest that an increase in OPG levels may be a compensatory response to elevated bone loss. The low bone mineral density (BMD) levels found in the high OPG group might have been due to the significant decrease in serum IGF-1 and vitamin D3 observed. In conclusion, the findings made in the present study demonstrate that increased OPG in hemodiafiltration patients is only partly due to decreased renal clearance. As it may partly reflect a compensatory response to increased bone loss, this parameter might be helpful in the identification of patients with a marked reduction in trabecular BMD.

Bone quantity and quality in Brazilian female schoolchildren and adolescents

The aim of the present study was to evaluate quantitative ultrasound parameters of the finger phalanges bones (AD-SoS, amplitude-dependent speed of sound, and BTT, bone transmission time) of schoolchildren, using a DBM Sonic device (IGEA, Carpi, Italy), to obtain normative values for the Brazilian population. The sample consisted of 1,775 healthy schoolchildren, all females, aged 8-17 years. We observed a progressive increase for the variables of weight, height, body mass index (BMI), AD-SoS, and BTT with advancing age. Results for AD-SoS showed increasing and significant variation from 8 to 17 years old (1,938-2,103 m/s, an increase of 8.52%, P < 0.0001), and also for BTT (0.84-1.45 micros, an increase of 72.6%, P < 0.0001). A gradual increase in the values of AD-SoS and BTT was observed with advances in pubertal stages. There was an interaction between the variables of age, height, and pubertal stages, predicting AD-SoS (R (2) = 0.49) and BTT (R (2) = 0.53). The study showed that AD-SoS and BTT, evaluated by means of bone ultrasonometry of the phalanges in females, increase gradually with age, being more evident during puberty, probably as a reflex of the structural organization of bone growth and development, or changes in the content of the bone tissue.

Quantitative ultrasound in the management of osteoporosis: the 2007 ISCD Official Positions

Dual-energy X-ray absorptiometry (DXA) is commonly used in the care of patients for diagnostic classification of osteoporosis, low bone mass (osteopenia), or normal bone density; assessment of fracture risk; and monitoring changes in bone density over time. The development of other technologies for the evaluation of skeletal health has been associated with uncertainties regarding their applications in clinical practice. Quantitative ultrasound (QUS), a technology for measuring properties of bone at peripheral skeletal sites, is more portable and less expensive than DXA, without the use of ionizing radiation. The proliferation of QUS devices that are technologically diverse, measuring and reporting variable bone parameters in different ways, examining different skeletal sites, and having differing levels of validating data for association with DXA-measured bone density and fracture risk, has created many challenges in applying QUS for use in clinical practice. The International Society for Clinical Densitometry (ISCD) 2007 Position Development Conference (PDC) addressed clinical applications of QUS for fracture risk assessment, diagnosis of osteoporosis, treatment initiation, monitoring of treatment, and quality assurance/quality control. The ISCD Official Positions on QUS resulting from this PDC, the rationale for their establishment, and recommendations for further study are presented here.

Quantitative ultrasound detects bone impairment after bone marrow transplantation in children and adolescents affected by hematological diseases

PURPOSE

Bone marrow transplantation (BMT) recipients are at risk of bone mass impairment and skeletal morbidity. We investigated bone status with quantitative ultrasound (QUS) technique in children and adolescents with hematological diseases before and after BMT.

METHODS

Phalangeal QUS measures for amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT) were obtained in 144 hematological patients (81M, 63F; 11.6+/-5.2 years); forty two were evaluated before BMT and 102 after allogeneic or autologous BMT. Bone parameters were expressed as Z-scores based on age-sex-matched normal controls.

RESULTS

Mean BTT Z-score was reduced in subjects after BMT compared to patients before BMT (M, -0.35+/-1.04 vs. 0.70+/-1.11, P<0.001; F, -0.60+/-1.23 vs. 0.23+/-1.17, P<0.05). Females and males with hormone deficiencies showed reduced BTT Z-scores when compared with subjects without hormone defects (M, -0.52+/-1.0 vs. 0.05+/-1.17, P<0.05; F, -0.50+/-1.27 vs. -0.19+/-1.26; P=0.06). AD-SoS and BTT Z-scores were reduced in 15 subjects with fractures and/or avascular osteonecrosis compared to patients without bone events (-1.52+/-1.7 vs. -0.41+/-1.32 and -0.85+/-1.19 vs. -0.10+/-1.18; both Ps<0.05). Bone event cumulative incidence was 4 times greater in subjects who suffered from chronic GVHD.

CONCLUSIONS

Assessment of phalangeal QUS in young BMT survivors points towards impairment of bone status and endocrine dysfunction and chronic GVHD as risk factors of adverse bone events.

The clinical use of quantitative ultrasound (QUS) in the detection and management of osteoporosis

For the detection and management of osteoporosis and osteoporosis-related fractures, quantitative ultrasound (QUS) is emerging as a relatively low-cost and readily accessible alternative to dual-energy X-ray absorptiometry (DXA) measurement of bone mineral density (BMD) in certain circumstances. The following is a brief, but thorough review of the existing literature with respect to the use of QUS in 6 settings: 1) assessing fragility fracture risk; 2) diagnosing osteoporosis; 3) initiating osteoporosis treatment; 4) monitoring osteoporosis treatment; 5) osteoporosis case finding; and 6) quality assurance and control. Many QUS devices exist that are quite different with respect to the parameters they measure and the strength of empirical evidence supporting their use. In general, heel QUS appears to be most tested and most effective. Overall, some, but not all, heel QUS devices are effective assessing fracture risk in some, but not all, populations, the evidence being strongest for Caucasian females over 55 years old. Otherwise, the evidence is fair with respect to certain devices allowing for the accurate diagnosis of likelihood of osteoporosis, and generally fair to poor in terms of QUS use when initiating or monitoring osteoporosis treatment. A reasonable protocol is proposed herein for case-finding purposes, which relies on a combined assessment of clinical risk factors (CR.F) and heel QUS. Finally, several recommendations are made for quality assurance and control.

Assessing bone mass in children and adolescents

Growing awareness that osteoporosis may have its antecedents in childhood has led to increasing interest in assessing bone mass in children and adolescents. Several noninvasive imaging techniques are currently available to measure properties of the growing skeleton, including bone mass, density, cross-sectional area, and microarchitecture. Dual-energy x-ray absorptiometry (DXA) is the most widely used technique, but it has several major limitations associated with its dependence on two-dimensional projections. Quantitative CT and peripheral quantitative CT allow three-dimensional imaging but are more costly and have higher radiation exposure. Quantitative ultrasound is simple and inexpensive but can measure bone "quality" only at a single peripheral site. MRI techniques for measuring bone are still under development and not yet ready for clinical use. For all of these techniques, clinical interpretation of the bone measures obtained remains a significant challenge. Further research is needed to relate these measures to osteoporosis in the elderly and to short-term and long-term fracture risk.

Longitudinal assessment of bone quality by quantitative ultrasonography in children and adolescents

Among the techniques available to assess bone quality, quantitative ultrasonography of the proximal phalanges of the hand (QUS) has emerged as particularly attractive. In this study, amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT) were obtained by the sonographic device DBM Sonic BP IGEA in two sessions at two years' interval, in a school-age population (589 subjects, 290 mol/L and 299F, aged 3 to 16 y) with the aim to determine accuracy of QUS measurements, evaluate QUS variable changes during growth, relate these values with age and growth variables. Mean AD-SoS and BTT at age classes from 5 to 12 y as determined at the first and second measurement sessions were not significantly different. A significant increment (p < 0.0001) between the first and the second measurement was observed for both QUS variables. AD-SoS and BTT showed significantly different variations in the various age groups (ANOVA). Correlations were found of AD-SoS and BTT increments with age, height, weight, pubertal stage and with height growth velocity (p < 0.05). AD-SoS and BTT increment curves presented a very similar trend decreasing from 4 to 7 y of age. Thereafter a plateau was reached up to the age of 10 to 11 y in girls and 11 to 12 y in boys, when an increase was observed corresponding to pubertal growth rate acceleration. In conclusion, the present study would confirm that QUS measurements are accurate. Ad-SoS and BTT increment models are similar to most growth velocity curves and follow a strongly age- and growth-dependent pattern.

Cross-sectional reference data for phalangeal quantitative ultrasound from early childhood to young-adulthood according to gender, age, skeletal growth, and pubertal development

Bone mineral status by phalangeal quantitative ultrasound (QUS, DBM Sonic, IGEA, Carpi, Modena, Italy) was examined in 3044 (1513 males and 1531 females) healthy subjects, aged 2-21 years. The aim of the study was to provide a reference database for phalangeal QUS parameters, amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT), both expressed as centiles and Z score, according to gender, age, height, weight, body mass index (BMI), and pubertal stage to be used for estimating bone mineral status in patients with disorders of growth or of bone and mineral metabolism. In both sexes, AD-SoS and BTT increased significantly (P<0.0001) according to all the anthropometric variables. Females showed higher values than males in the age groups 9-14 for AD-SoS (P<0.04-P<0.0001) and in the age groups 11-13 for BTT (P<0.02). Males had higher BTT values than females in the age groups 6-8 and 15-21 (P<0.04-P<0.0001). AD-SoS was higher (P<0.02-P<0.0001) in females than in males at pubertal stages 2, 3, and 4, but it was higher (P=0.001) in males compared with females at pubertal stage 5. BTT was higher in males than females at pubertal stages 1 (P<0.0001), 2 (P<0.01), and 5 (P<0.0001). In both sexes, AD-SoS and BTT were significantly correlated between them (r=0.92, P<0.0001) and with all the anthropometric variables (r=0.53-r=0.85, P<0.0001). Age, weight, BMI, and pubertal stage were independent predictors of AD-SoS in males; age and pubertal stage were independent predictors of AD-SoS in females. In both sexes, height and pubertal stage, and also age only in females, were independent predictors of BTT. In conclusion, our data show that gender, age, height, and timing of sexual maturation are main determinants of bone structure and geometry, and that both these two processes may be captured by phalangeal QUS. It may be a useful tool to assess bone mineral status from early childhood to young-adulthood with a very small confounding effect related to bone sizes and without exposing the subjects to a source of radiation.

Quantitative ultrasound at the hand phalanges in patients with acromegaly

The aim of this study was assessment of skeletal status using quantitative ultrasound (QUS) at hand phalanges in patients with acromegaly. A group of 38 patients with acromegaly (27 women and 11 men) with a mean age of 57.21 +/- 9.85 years was compared with a control group of 44 men and 108 women matched for gender, age and body size. Amplitude-dependent speed of sound (Ad-SoS) at hand phalanges had lower values in patients with acromegaly than in controls, both in the entire group and in men and women, respectively. The positive correlation between Ad-SoS and height and the negative one between Ad-SoS and age was found in the entire group of patients with acromegaly. No correlations between Ad-SoS and time from diagnosis or duration of the symptoms were found. Age affected Ad-SoS significantly less in the entire patient group than in controls. Similarly, in women, age and body mass affected Ad-SoS less than in controls. A stepwise multiple regression analysis carried out in the patient group identified age as the only factor significantly influencing negatively the Ad-SoS value (regression equation: Ad-SoS (m/s) = 2124 m/s - 3.26 x age (years) [r2= 0.26, standard error of estimate = 55.1, p < 0.01]). In conclusion, our data demonstrate that, in patients with acromegaly, skeletal status assessed by QUS was affected. This could reflect the worsening of the mechanical properties of bones studied and the increased risk of fractures in other sites of the skeleton. The changes observed were not related to acromegaly-associated hypogonadism. Further studies to assess the role of QUS in acromegaly are necessary and fracture prevalence and risk ought to be established.

Bone quality in perinatally HIV-infected children: role of age, sex, growth, HIV infection, and antiretroviral therapy

Appropriate supportive care and identification of long-term sequels of therapy are of paramount importance in HIV-infected pediatric patients. As low bone mineral quality (BMQ) in patients can be considered a marker of possible degeneration in osteopenia and osteoporosis in adulthood, we evaluated bone features in a pediatric population. Forty-four patients (23 females, 21 males; aged 3-17 years) were compared with a control population (1227 healthy children: 568 females, 641 males; aged 3-18 years). Seven patients were CDC stage C, 18 B, and 18 A. All patients were vertically infected; four were naive to any antiretroviral treatment, seven were taking two NRTIs, and 32 were on HAART. BMQ was assessed by a quantitative ultrasound (QUS) technique. It measures the amplitude-dependent speed of sound (AD-SoS, m/sec) and the bone transmission time (BTT, microsec). QUS values were significantly lower in cases than in controls, even after adjustment for age and body size (AD-SoS: 1924.7 +/- 64.9 and BTT: 0.97 +/- 0.3 in controls; AD-SoS: 1879.7 +/- 57.2 and BTT: 0.80 +/- 0.32 in cases; p < or = 0.001). The associations of AD-SoS and BTT with gender, type of therapy, and CDC stages were not significant. AD-SoS and BTT were significantly associated with age (r = 0.59, p < 0.0001), skeletal age SDS (r = 0.46, p = 0.002), height (r = 0.66, p < 0.0001), and therapy duration (r = 0.31, p = 0.04). Both AD-SoS and BTT values in patients fell below mean values of controls. Follow-up of bone mineral density is important in patients to prevent long-term problems of skeletal status.

Use of multiple acoustic wave modes for assessment of long bones: model study

Multiple acoustic wave mode method has been proposed as a new modality in axial bone QUS. The new method is based on measurement of ultrasound velocity at different ratio of wavelength to the bone thickness, and taking into account both bulk and guided waves. It allows assessment of changes in both the material properties related to porosity and mineralization as well as the cortical thickness influenced by resorption from inner layers, which are equally important in diagnostics of osteoporosis and other bone osteopenia. Developed method was validated in model studies using a dual-frequency (100 and 500 kHz) ultrasound device. Three types of bone phantoms for long bones were developed and tested: (1) tubular specimens from polymer materials to model combined changes of material stiffness and cortical wall thickness; (2) layered specimens to model porosity in compact bone progressing from endosteum towards periosteum; (3) animal bone specimens with both cortical and trabecular components. Observed changes of the ultrasound velocity of guided waves at 100 kHz followed gradual changes in the thickness of the intact cortical layer. On the other hand, the bulk velocity at 500 kHz remained nearly constant at the different cortical layer thickness but was affected by the material stiffness. Similar trends were observed in phantoms and in fragments of animal bones.

Assessment of skeletal development in preterm and term infants by quantitative ultrasound

Assessment of skeletal development using a nonionizing method would be desirable in critically ill preterm infants. We investigated the second metacarpus by quantitative ultrasound (QUS). Cross-sectional data were collected in 132 preterm or term infants measured within 24 h from birth and in 142 term infants up to the age of 18 mo. Longitudinal data were collected in 150 preterm infants up to the age of 14 mo. Cross-sectional data were used to devise reference curves for metacarpal speed of sound (mcSOS) and metacarpal bone transmission time (mcBTT). Both parameters increase during the last trimester of gestation. After birth, mcSOS declines up to the 6 mo and then increases up to 18 mo of life. McBTT values remain stable after birth. At birth, QUS values of preterm infants are lower than those observed at birth in term infants. In the longitudinal study, mcSOS showed a trend similar to that observed among term infants, nevertheless, values are lower up to 4-6 mo of life. Among preterm infants, mcBTT increases until it reaches values observed in term infants. Preterm infants in their first months of life have lower QUS values compared with term infants of same weight or length. This study demonstrates that it is possible to follow skeletal development and maturation by QUS in preterm infants. More specifically, the mcBTT values may provide information on bone tissue that is independent of length and weight of the preterm infant. The method here described is safe, repeatable, and reliable.

Impact of anthropometric, lifestyle, and body composition variables on ultrasound measurements in school children

Quantitative ultrasound (QUS) measurement at hand phalanges was demonstrated to be a reliable method to assess skeletal maturation during childhood and adolescence. The aim of the study was to evaluate the influence of age, gender, puberty, lifestyle factors, and body composition on QUS parameters and to provide a normative database for QUS in school children in Lebanon. Measurements of phalangeal osteosonography were examined in 256 healthy subjects (132 boys and 124 girls) aged 11-18 years using an ultrasound device. In both genders, amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT) increased significantly with age and pubertal stages. Girls had higher AD-SoS values than boys between 11 and 15 years of age and at Tanner stages III and IV; however, no differences were detected in the older age groups. AD-SoS and BTT showed a significant positive correlation with age and height in both genders (R = 0.41-0.66, P < 0.01). There was no correlation between physical activity, calcium intake, sun exposure, and any of the QUS parameters in either gender. Weight showed moderate positive correlation with AD-SoS in boys and with BTT in both genders (R = 0.31-0.47, P < 0.01). Lean mass showed significant positive correlation with AD-SoS and BTT (R = 0.2-0.68, P < 0.01) in both genders. Percentage body fat showed significant negative correlation with BTT and AD-SoS in boys (R = -0.25 to -0.37, P < 0.01). In the linear regression analyses, there was a significant negative correlation between percentage fat mass and both AD-SoS and BTT in both genders. In conclusion, QUS parameters of the phalanges in Lebanese children are related to growth variables such as height, age, and puberty in healthy children. The impact and magnitude of body composition variables and lifestyle factors on ultrasonometry derived variables differ from their effect on dual energy X-ray absorptiometry derived parameters.

Assessing bone status beyond BMD: evaluation of bone geometry and porosity by quantitative ultrasound of human finger phalanges

In an in vitro study, we found significant associations between QUS variables and properties and geometrical parameters of the compact bone of human finger phalanges. QUS variables were not only related to BMD but also to other skeletal properties, which explained 70% of the variability of speed of sound.

INTRODUCTION

Transverse transmission quantitative ultrasound (QUS) measurements at the finger phalanges are known to be correlated with BMD and to predict osteoporotic fractures. To determine which other skeletal properties are affected by ultrasound, we investigated the impact of density, geometry, and porosity on QUS variables in vitro.

MATERIALS AND METHODS

Ultrasound variables were correlated with density, porosity, and geometrical characteristics of cortical bone. Additionally, we tested which combinations of geometry and bone properties best predicted the ultrasound results observed. Forty-four proximal phalanges from the middle finger were investigated at their distal metaphysis, similar to the typical clinical measurement procedure. Donor age ranged from 52 to 98 years (15 males and 29 females; mean age, 80.9 +/- 9.4 years). QUS variables were measured on the metaphysis of the phalanges using the DBMSonic 1200. Quantitative CT was used for the measurement of BMD, and high-resolution MRI was used for the measurement of porosity and geometrical variables.

RESULTS

Speed of sound (SOS) and the clinically used variable AD-SOS correlated significantly with area, relative area, density, and porosity of the compact bone (R2 = 0.28-0.58, p < 0.0001). Signal amplitude correlated significantly only with relative area of the compact bone and area of the medullary canal (R2 = 0.18-0.20, p < 0.01). The combination of cortical area, density, and porosity improved the determination of SOS to R2 = 0.70, with a residual unexplained variability of 54 m/s (3.2%).

CONCLUSIONS

These results clarify the impact of skeletal properties on QUS variables. SOS is affected by cortical area, cortical bone density, and cortical porosity, whereas attenuation only depends on geometry of the medulla. AD-SOS, the variable routinely measured in clinical practice, is primarily affected by cortical area. QUS of the finger phalanges is not only related to BMD but also to other skeletal properties.

Bone imaging: traditional techniques and their interpretation

Patients with osteoporosis have to be diagnosed at an early stage to prevent fractures, the worst complication of this disease. Currently, measurements of bone mineral density (BMD) are used most frequently in the diagnosis of osteoporosis. According to the World Health Organization, osteoporosis is defined on the basis of BMD measurements that are compared with those of a healthy, young, female population. The best established techniques to measure BMD are dual x-ray absorptiometry of the lumbar spine and proximal femur and quantitative computed tomography of the lumbar spine. Conventional radiographs are not suited to assess bone mass, but they are important in the diagnosis and differential diagnosis of osteoporotic fractures. Quantitative ultrasound and structure analysis, based on high-resolution magnetic resonance imaging and computed tomography, are newer techniques in the diagnosis of osteoporosis that also focus on the assessment of bone structure.

Assessment of bone quality by quantitative ultrasound of proximal phalanges of the hand and fracture rate in children and adolescents with bone and mineral disorders

Bone quality by quantitative ultrasound and fracture rate were assessed in 135 (64 males) children and adolescents aged 3-21 y with bone and mineral disorders such as chronic anticonvulsants or glucocorticoids treatment, juvenile rheumatoid arthritis, celiac disease, paucity of intrahepatic bile ducts, autoimmune hepatitis, genetic diseases, idiopathic juvenile osteoporosis, disuse osteoporosis, beta-thalassemia major, survivors of acute lymphoblastic leukemia, liver transplantation, calcium deficiency, and nutritional or X-linked hypophosphatemic rickets. Amplitude-dependent speed of sound through the distal end of the first phalangeal diaphysis of the last four fingers of the hand was measured by an ultrasound device. In the majority of patients cortical area to total area ratio by metacarpal radiogrammetry (n = 120) and lumbar bone mineral density (BMD) by dual-energy x-ray absorptiometry (n = 99) were also assessed. In patients with X-linked hypophosphatemic rickets radial BMD by single-photon absorptiometry instead of lumbar BMD was measured. Mean values of amplitude-dependent speed of sound, cortical area to total area ratio, lumbar BMDarea, or lumbar BMD corrected for bone sizes estimated by a mathematical model (BMDvolume), as well as mean values of radial BMD in patients with X-linked hypophosphatemic rickets, expressed as z score, were significantly reduced (p < 0.0001) in comparison with their reference values (-1.7 +/- 1.0, -2.0 +/- 0.9, -3.0 +/- 1.3, -1.9 +/- 1.0, -2.7 +/- 0.7, respectively). A positive relationship was found between amplitude-dependent speed of sound and cortical area to total area ratio (r = 0.90, p < 0.0001), lumbar BMDarea (r = 0.62, p < 0.0001), or lumbar BMDvolume (r = 0.66, p < 0.0001). Fifty-two patients (38.5%) had suffered fractures in the 6 mo preceding the bone measurements, the radial distal metaphysis being the most frequent fracture site (28.8%). Mean values of amplitude-dependent speed of sound, cortical area to total area ratio, lumbar BMDarea, or lumbar BMDvolume, expressed as z score, of fractured patients were significantly lower (p < 0.0001) than those of fracture-free patients (-2.2 +/- 1.0 and -1.4 +/- 0.8, -2.6 +/- 0.9 and -1.7 +/- 0.7, -3.5 +/- 1.2 and -2.5 +/- 1.0, -2.5 +/- 1.0 and -1.3 +/- 0.7, respectively). Phalangeal quantitative ultrasound may be a useful method to assess bone quality and fracture risk in children and adolescents with bone and mineral disorders.

Osteoporosis imaging

Because osteoporotic fractures may be prevented, diagnostic techniques are essential in the assessment of osteoporosis. Conventional radiographs of the spine are not suited for diagnosing early osteoporosis, but they show fractures that may have no clinical symptoms. The radiologist should be aware of the enormous significance of these fractures for future osteoporotic fractures. Bone mass measurements are standard techniques in the diagnosis of osteoporosis, which are the basis of the WHO definition of osteoporosis. In this article the authors presented these standard techniques and newer diagnostic techniques that provide insights in the structure of trabecular bone.

Quantitative ultrasound evaluation of the hand: side dominance or overuse?

Mechanical loading is considered a very important factor affecting bone mass. To investigate the effect of heavy hand use on bone status in the dominant and nondominant hands, 17 ironers and a control group were evaluated with a new quantitative ultrasound system measuring the speed of sound (SOS). Both the dominant and nondominant hands were measured in all subjects, at both the proximal III phalanx and distal one-third radius. The ironers had significantly (p = 0.001) higher SOS values at the proximal III phalanx of the dominant hand than at the nondominant hand, whereas no difference was found between the hands in this group when measured at the distal one-third radius. There was no significant difference in SOS values as related to hand dominance in the control group. In conclusion, the SOS differences of the hands seems to be related to overuse rather than to side dominance.

Bone quality assessment by quantitative ultrasound of proximal phalanxes of the hand in healthy subjects aged 3--21 years

Bone quality by quantitative ultrasound was assessed in 1083 (587 males) healthy white subjects aged 3--21 y. Amplitude-dependent speed of sound (AD-SoS) through the distal end of the first phalanx diaphysis of the last four fingers of the hand was measured by an ultrasound device (DBM Sonic 1200, IGEA, Carpi, Italy). Mean AD-SoS values increased progressively from 3 to 21 y (males, 1845.9--2119.1 m/s, p < 0.0001; females, 1842.3--2098.8 m/s, p < 0.0001). They did not differ (p = NS) between sexes up to age 11, but females showed higher (p < 0.05 - p < 0.0001) AD-SoS values than males in age groups 12, 13, and 14 y. There was no difference (p = NS) of AD-SoS values between sexes in pubertal stages 1, 2, and 5, but females had higher mean AD-SoS values than males in stages 3 (p < 0.01) and 4 (p < 0.001). Independent predictors of AD-SoS were weight, body mass index, pubertal stage, and mean width of fingers in males, and age, pubertal stage, and mean width of fingers in females (p < 0.01 - p < 0.0001). However, 7.8% in males and 3.6% in females of the increment of AD-SoS values can be related to the finger anatomy alone. AD-SoS values probably reflect the architectural organization of growing bone or changes in bone elasticity. Increased bone density and size may be additional factors influencing AD-SOS: Measurement of AD-SoS at the hand phalanxes may be a simple, noninvasive, and radiation-free technique to assess bone quality in children.

Estimation of wrist fracture load using phalangeal speed of sound: an in vitro study

This study aimed to evaluate the ability of speed of sound (SOS) measured at the phalanges to estimate simulated wrist fracture load and stress. SOS was measured along the proximal phalanges of the second, third and fourth fingers using an ultrasound (US) system operating in axial transmission mode. The bone mineral density (BMD) of the radius and the phalanges was also measured with quantitative computed tomography (QCT) and dual x-ray absorptiometry (DXA), and the combined cortical thickness (CCT) of the phalanges was measured from hand radiographs. After the measurements were completed, the radius was excised from the cadaver, embedded in polymethylmethacrylate and tested to failure on a servohydraulic testing machine. The configuration of the radius was chosen to simulate a fall onto the hand. Linear regression analysis showed a highly significant correlation between SOS (r = 0.76-0.94, p < 0.001), CCT (r = 0.86-0.90, p < 0.001) and BMD (r = 0.92-0.96, p < 0.0001) in the three proximal phalanges measured. SOS, BMD and CCT were significant predictors of fracture load (r = 0.60-0.69, p < 0.03) and stress (r = 0.65-0.77, p < 0.02). Cortical area and bone mineral content (BMC) of the radius were consistently higher predictors of fracture load (r = 0.76-0.82, p < 0.01 for area and r = 0.78-0.88, p < 0.01 for BMC) than BMD. The correlation of BMC and area was poorer with fracture stress. In a step-wise regression analysis using both phalangeal BMD and SOS, only SOS remained a significant predictor of fracture stress. In forward stepwise regression analysis, both cortical area and SOS were entered into the regression model to estimate fracture load. Only SOS remained significant in the model for estimating fracture stress. Phalangeal BMD was only entered in the combined model with the cortical area at the 4% site (r = 0.84, p = 0.002). Phalangeal SOS is a useful parameter in the assessment of bone status of the radius.