Prodigy Densitometer Research Articles

Application of DIXON MRI sequencing in the diagnosis of changes in the spongy substance of vertebral bodies in comparison with osteodensitometry data

The aim of this study was to analyze the patterns of changes in the fat fraction of the vertebral bodies according to the modified DIXON protocol (mDixon, MRI) in patients of different age groups with densitometry data.Materials and methods. In the course of our study, a Siemens Magnetom Verio 3T tomograph was used for diagnostics, for assessing the condition of the vertebrae of the lumbosacral spine, measuring FF, a computer program was used: “RadiAnt DICOM viewer”. DIXON (two-point) parameters of TSE pulse train with T2 type of weighting: TR 4000 ms, TE 88 ms, slice thickness 4 mm, matrix 320 × 320, NEX 1, FOV 260 × 260 mm, pixel size 0.8 × 0.8 mm, bandwidth 345 Hz/pixel. Scanning time: 3 min. 50 sec. We also used a GE Lunar Prodigy densitometer. Measurement parameters: mode – standard (13–25 cm), length 19.1 cm, width 18.0 cm. Method: mDixon.Results. 71 patients were examined (average age is 57 years; average BMI (body mass index): 27.94). Osteopenia was diagnosed in 21 patients, osteoporosis – in 13. Bone mineral density (BMD) was obtained using X-ray densitometry, which served as a reference for detecting abnormal bone density and osteoporosis. A comparison was made of BMD values in patients with normal and patients with osteoporosis / osteopenia: the values in patients with normal were 21.85% higher than in patients with osteoporosis / osteopenia. We also compared the parameters of vertebral fat density (FF) in patients with normal and pathology – the values in patients with normal were 15.65% less than in patients with pathology. Correlation analysis revealed a relationship between BMD and FF parameters. According to the results of the morphometry of the vertebral bodies, wedge-shaped deformity of the vertebral bodies was revealed in 8% of patients with osteoporosis / osteopenia.Conclusions. The MRI method based on the DIXON trace is of great importance in the diagnosis of changes in the spongy substance of the vertebral bodies. In the study of correlation analysis, an inverse relationship was found between the BMD and FF parameters.

Оцінка мікроархітектури хребта за допомогою TBS допомагає розрізнити пацієнтів з основними остеопоротичними переломами та контрольну групу залежно та незалежно від МЩКТ: Східноєвропейське дослідження TBS

Метою дослідження була оцінка клінічної ефективності моделі, що поєднує показники мінеральної щільності (МЩКТ) і мікроархітектури (TBS) кісткової тканини хребта, щодо виявлення остеопоротичних переломів. Східноєвропейське багатоцентрове дослідження (Сербія, Болгарія, Румунія, Україна) оцінювало роль TBS у рутинній клінічній практиці як доповнення до МЩКТ. Усі відскановані дані були отримані на денситометрах Hologic Discovery й GE Prodigy звичайним способом, що застосовується в клінічній практиці. Клінічні значення МЩКТ хребта і TBS для всіх типів остеопоротичних переломів (All-OP Fx) додатково були проаналізовані методом двохетапного дерева класифікації (МЩКТ супроводжувалось аналізом тертилів TBS). Були визначені чутливість, специфічність і точність виявлення переломів, а також був розрахований Net Reclassification Index (NRI). Дослідження включало 1031 жінку віком 45 років і старше з різних країн Східної Європи. Клінічні центри були перехресно відкалібровані за МЩКТ і TBS. Як і очікувалось, мінеральна щільність кісткової тканини хребта і TBS корелювали помірно (r2 = 0,19). Показник поширеності для всіх типів остеопоротичних переломів (All-OP Fx) становив 26%. Пацієнти з переломами мали значимо нижчі показники TBS і МЩКТ хребта, ніж особи без переломів (p = 0,01). Показник TBS асоціювався з наявністю переломів навіть після поправки на вік і МЩКТ хребта з OR (odds ratio) 1,27 [1,07–1,51]. Показники МЩКТ хребта за Т-критерієм –2,5 і нижче та TBS нижнього тертиля були подібні з погляду чутливості (35 проти 39%), специфічності (78 проти 80%) і точності (64 проти 66%). Комбінація МЩКТ хребта і TBS приводила до значного підвищення чутливості (+28%) і точності (+17%) порівняно з використанням тільки МЩКТ хребта, у той час як специфічність покращувалась помірно (+9%). Загальний коефіцієнт ефективності комбінації, визначений за допомогою NRI, становив 36%. Поєднане застосування МЩКТ хребта і TBS істотно зменшило кількість суб’єктів, які потребують додаткової діагностики МЩКТ, із 7 до 2. Ми показали, що в східноєвропейській когорті використання TBS як доповнення до МЩКТ хребта дозволяє правильно класифікувати більше ніж третину з усіх пацієнтів. Крім того, кількість осіб, які потребують додаткової діагностики, зменшилась до 2. Щоб оцінити вигоду використання TBS для системи охорони здоров’я, необхідно провести додаткові економічні дослідження.

Частота і локалізація остеопоротичних переломів залежно від віку, мінеральної щільності та якості кісткової тканини в українських жінок у постменопаузальному періоді

Актуальність. Низькотравматичні переломи є важливими ускладненнями системного остеопорозу, що призводять до зниження якості життя, збільшення захворюваності, інвалідності та смертності. У наш час мінеральна щільність кісткової тканини (МЩКТ) і трабекулярний кістковий індекс (ТКI), що визначаються за допомогою двохенергетичної рентгенівської абсорбцiометрiї, є двома основними параметрами міцності кістки. Вони широко використовуються при діагностиці остеопорозу. Метою дослідження було вивчення частоти і локалізації різних остеопоротичних переломів у жінок в постменопаузальному періоді залежно від віку, МЩКТ і ТКI. Матеріали та методи. Проведено одномоментне дослідження і проаналізовані дані 1369 жінок у постменопаузальному періоді (вік 45–89 років). Пацієнтки були розділені на групи залежно від МЩКТ згідно з критеріями Всесвітньої організації охорони здоров’я: нормальний стан кісткової тканини (T-індекс > –1,0 стандартного відхилення (СВ)), остеопенія (≤ –1,0 T-індекс > –2,5 СВ), остео­пороз (T-індекс ≤ –2,5 СВ), і в залежності від квартилів (груп) ТКI (L1-L4): QI — найнижча квартиль (0,36–1,08); QII — нижня квартиль (1,08–1,20); QIII — верхня квартиль (1,20–1,32); QIV — найвища квартиль (1,32–1,79). МЩКТ і ТКI поперекового відділу хребта (L1-L4) вимірювали за допомогою денситометра Prodigy (GE Medical systems, Lunar, модель 8743, 2005). ТКI визначали з використанням програмного забезпечення TBS Insight (Med-Imaps, Bordeaux, France, 2006). Результати. Встановлено, що ризик усіх типів остеопоротичних переломів у жінок достовірно збільшується з віком (вертебральних переломів — у 1,97–4,26 раза, невертебральних — у 1,96–5,45, комбінованих — у 1,54—3,14 раза). Крім того, ми ви­явили, що остеопоротичні переломи присутні у всіх групах жінок iз різною МЩКТ: при остеопорозі (45,5 %), остеопенiї (26,9 %) та за нормального стану кісткової тканини (18,1 %). Найбільшою частота остеопоротичних переломів була при остеопорозі (46,5 %), переважно в жінок iз хребцевими і комбінованими переломами. Тільки в 25,5 % пацієнток iз невертебральними переломами спостерігається остеопороз. Низький ТКI відзначався в 50,8 % жінок iз вертебральними, 43,7 % — невертебральними і в 32,8 % — iз комбінованими (хребцевими і невертебральними) остеопоротичними переломами. Висновки. Остеопоротичні переломи частково пов’язані з віком, МЩКТ і ТКI. Однак існують й інші важливі чинники, що впливають на ризик переломів, і їх поєднання вимагає подальшого вивчення.

Cross-calibration of GE Lunar iDXA and Prodigy Densitometer for measurement of bone mineral density in young adults

The assessment of bone mineral density (BMD) is essential to skeletal health, and dual-energy x-ray absorptiometry (DXA) is a type of bone densitometer that is extensively used in both clinical and research settings. When changing a DXA system during longitudinal monitoring or multicenter studies, it is important to conduct cross-calibration between the new and reference scanners to ensure that BMD values measured by the two systems are as close as possible. Purpose: To properly cross calibrate between the GE Lunar iDXA and Prodigy in healthy young adults. Methods: Thirty college students, ten males and twenty females, participated in the study. The BMD at the lumbar spine and dual femurs were measured using the GE iDXA and Prodigy by the same licensed technician on the same day. A paired sample t-test and linear regression analysis were utilized to compare the BMD values between the two systems. Limits of agreement were obtained by Bland-Altman analyses. Results: Although strong correlations were found between the two systems (r = 0.985 – 0.998), the iDXA had significantly higher lumbar spine (1.54%) and dual femur (1.28 - 1.56%) BMD values compared to the Prodigy. Conclusion: Our results suggest that calibration equations should be considered to examine data across densitometers to reduce system differences in the young adult population.

Quantification of Scan Analysis Errors in GE Lunar DXA Visceral Adiposity in Adults

Utilization of dual-energy X-ray absorptiometry is increasing in clinical settings and the fitness industry as a viable tool to assess total and regional body composition, including visceral adiposity. Previous research using small samples (<50) has described several pitfalls in patient positioning, scan acquisition, and/or analysis that alter regional body composition values. Our aim was to quantify the largest probable error in measures of total, android, gynoid, and visceral fat caused by incorrect placement of the head cut-line, in a large sample of adults. Total body images (N = 436) from 196 women and 67 men (20–85 years) scanned on a GE Lunar Prodigy densitometer were analyzed using enCORE software in 2 ways: (1) placing the head cut-line just beneath the bony protuberance of the chin according to manufacturer recommendation (correct method); (2) placing the head cut-line at the lowest point below the chin and just above the soft tissue at the shoulders (incorrect method). All other cut-lines were fixed. Mean differences in adiposity were examined using Lin's concordance correlation coefficient; equality of means and variances were evaluated using Bradley-Blackwood F-tests. The limits of agreement were displayed as Bland-Altman plots and calculated as the mean difference ±1.96 times the standard deviation of the difference. Correlation coefficients for paired comparisons of adiposity for correct vs incorrect cut-line placement ranged from 0.983–0.999 for all variables (all p < 0.001). Significant mean differences were 172 ± 130, 201 ± 168, 65 ± 122, and −143 ± 336 g for android, gynoid, visceral, and total fat mass, respectively (all p < 0.0001). These differences exceeded our site's least significant change in 66%, 37%, 29%, and 4% of participant scans for android, gynoid, visceral, and total fat mass, respectively. Our findings underscore the importance of careful review of the manufacturer's auto analysis and consistency in conducting serial scans to ensure accurate and precise measures of regional body fat.

“Effect of very dense artifacts on Hologic and general electric bone densitometry results”

Very dense objects, such as lead bullets are described as "black hole" artifacts on Hologic densitometers. Whether similar results occur on GE scanners is not reported. We hypothesized that dense artifacts confound both brands of densitometers. Three lead bullets of varying size were placed overlying or adjacent to L3 on anthropomorphic and encapsulated aluminum spine phantoms. Three scans were acquired with and without projectiles on a Hologic Discovery W, GE iDXA, and Prodigy densitometer. Lead bullets are measured as having high bone mineral content (BMC); they appear black in dual-energy mode on Hologic scanners and are colored blue on GE scanners. On Hologic scanners, BMC of a dense artifact over bone is excluded, but the bone area is not altered. Consequently, bone mineral density (BMD) of the affected vertebra, and of L1-4, is decreased. For example, a .45 caliber bullet over L3 decreased BMD (p < 0.05) by 48.3% and L1-4 by 9.1%. GE scanners excluded associated BMC and area covered by the artifact, thereby minimizing impact on BMD. Dense artifacts over soft tissue on a phantom do not substantially affect BMD on either manufacturer's densitometer when scanned. Densitometer manufacturers handle very dense artifacts differently. GE software removes artifact BMC and area with resultant minimal impact on BMD, Hologic removes only BMC, not area, thereby decreasing BMD. Regardless of this difference, when dense artifacts overlay the spine, it is best to exclude the affected vertebral body. Finally, the BMD stability observed with artifacts over soft tissue may not be replicated in humans.

PB1995 THE EFFECTS OF ANTITUMOR THERAPY ON BONE REMODELING IN PATIENTS WITH HODGKIN'S LYMPHOMA

Background:Cures have been achieved in a significant proportion of patients with Hodgkin lymphoma (HL) for many years. Treatment for HL has been associated with adverse late effects. One of those consequences of antitumor therapy may be a change in bone mineral density (BMD). Hemoblastosis is considered as a strong risk factor for secondary osteoporosis and major low‐energy fractures. The decrease in BMD can be associated with polychemotherapy, including various combinations of cytostatic drugs and glucocorticoids, as well as with hypogonadism caused by toxic effects of radiotherapy and chemotherapy, tumor process, low physical activity and other factors.Aims:To assess the bone mineral density (BMD) in patients with HL.Methods:The study included 103 patients with HL from the City Hematology Center of Novosibirsk, from 19 to 72 years of age (median 49 years [33;55]). The disease was staged according to the Ann Arbor staging system: 55 patients had early stage disease and 48 patients had advanced stage disease (stage III to IV). All subjects received first‐line regimens (ABVD, BEACOPP‐14, et al.). Eighteen patients with advanced stages and unfavorable prognosis obtained second‐line regimens (DHAP, ESHAP). Radiotherapy was performed in 57 (55,3%) individuals. Complete remission was achieved in 60 of 103 patients (58,2%), and partial remission was recorded in 32 ones (31%). The BMD was assessed by dual‐energy X‐ray absorptiometry with GE Lunar Prodigy densitometer (USA). The assessed variables were BMD and T‐ or Z‐criterion (when appropriate) at the lumbar spine (L1–L4), proximal femur, femoral neck and forearm of a non‐dominant arm. Fracture Risk Assessment Tool (WHO FRAX, web version 3.8, adjusted for Russia) was used to determine the risk of major osteoporotic fractures.Results:The decreased BMD was revealed in 47 observed HL subjects (45,6%), 30 of them diagnosed osteoporosis. The decline in BMD was more frequent in patients aged ≥50 years as compared to younger ones (χ2 = 5,75; p = 0,02). More patients with radiotherapy in anamnesis had decreased BMD compared to patients who received chemotherapy only (χ2 = 8,82; p = 0,003) More than half of the patients (60 %) receiving regimens containing glucocorticosteroids had BMD decrease. Based on FRAX assessment, the 10‐year risk of major low‐energy fractures and the hip fractures was expectedly higher in patients with osteoporosis and osteopenia as compared to subjects with normal BMD (p &lt; 0,05). A comparative analysis revealed that patients younger than 50 years old had more often lower values of BMD and Z‐score of the lumbar spine. In turn, the femoral neck was the most frequent localization of osteoporosis in patients older 50 years and postmenopausal women.Summary/Conclusion:The study demonstrates high prevalence of decreased BMD in patients with HL. The decrease in BMD is associated with radiotherapy and chemotherapy with glucocorticoids.

Околонедельные колебания проекционной минеральной плотности в зонах Груена после тотальной артропластики тазобедренного сустава (случай из практики и краткий обзор литературы)

Introduction Dual-energy X-ray absorptiometry (DEXA) provides a quantitative estimation of the projectional bone mineral density (PBMD) with minor radiation exposure and in a cost-effective way. It is one of the ways for a dynamic control of stem integration into the host bone after total hip arthroplasty (THA). Osteocytes are considered to play the key role in the regulation of implant integration process. Hence, DEXA could be used for estimation of functional activity and directions for regulation of osteocytes activities in the periprosthetic area. Purpose Current study presents the results of chronologic and biological PBMD in the periprosthetic zone after THA in two patients with a perspective for a future use of such an approach to reveal a local response of tissue to the implant. Material and methods PBMD was studied daily for 10 days with PRODIGY densitometer after THA in a 54-year old patient with posttraumatic right hip osteoarthrosis and a 59-year old patient with right femoral neck fracture nonunion. Cementless ZIMMER implants were used. Results In the first patient, oscillatory BMD alterations in the Gruen zones ranged from 2.4 to 11.6 % with an average wavelength of 4.6 days. In the second patient, the alterations were within the range of 2.3–8.7 % with an average wavelength of 4.5 days. PBMD changes in the adjacent Gruen zones occurred asymmetrically with some oscillational phase lagging relative to each other. After approximation of the results by linear trend, PBMD increased by 1.7 % on average in all Gruen zones in the first patient, except zones 2 and 3, and its mean growth was 1.7 %. On the contrary, PBMD decreased in all the zones in the second patient, except zones 4 and 7. Mean decrease was 1.7 %. Conclusion Chronobiological approach opens up possibilities for evaluation of structural and functional skeleton reorganization in the periprosthetic zone after THA. Further research is needed for a deeper insight into this complex issue.

Do Textiles Impact DXA Bone Density or Body Composition Results?

External artifacts can confound dual-energy X-ray absorptiometry (DXA) measurements. It is often accepted that garments free of metal do not affect DXA results; however, little data exist in this regard. It is plausible that some textiles absorb radiation and thereby alter DXA results. We hypothesized that some dense or synthetic textiles, for example, reflective materials, might alter DXA-measured bone and soft tissue mass. Hologic and GE Lunar spine phantoms and a Bioclinica prototype total body phantom were imaged on a GE Lunar iDXA and Prodigy densitometer. Each phantom was scanned 10 times to establish mean values. Subsequently, 2 layers of various fabrics were placed over the entire top surface of the phantom, and 10 scans were performed without repositioning. Samples of natural, synthetic, or embellished fabric (including those with reflective material) and of varying thickness were used. Wilcoxon signed rank tests were used to compare the means between bare phantom and textile-covered phantom. Significant differences were demonstrated often, depending on the scanner, phantom, and textile used. A polyester fabric with reflective strip consistently altered measurements. For example, this fabric increased measured mean lumbar spine bone mineral density and total body bone mineral content by 0.008 g/cm2 and 3.6 g, respectively (p < 0.01). Similarly, mean total body fat decreased (−173 g) and lean mass increased (+213 g; p < 0.01). Fat and lean mass were also affected by metallic thread, wool, blend denim, and shiny polyester (p < 0.05), and lean mass was affected by cotton denim and sweatshirt material (p < 0.0003). In conclusion, textiles can affect DXA-measured bone mineral density and body composition results. Even small amounts of reflective material could alter mass measurements by ~25% of the least significant change. Clothing made of dense textiles (e.g., wool and denim) or those with reflective material and metallic thread should be avoided during DXA scanning.

An Investigation Into the Differences in Bone Density and Body Composition Measurements Between 2 GE Lunar Densitometers and Their Comparison to a 4-Component Model

We describe a study to assess the precision of the GE Lunar iDXA and the agreement between the iDXA and GE Lunar Prodigy densitometers for the measurement of regional- and total-body bone and body composition in normal to obese healthy adults. We compare the whole-body fat mass by dual-energy X-ray absorptiometry (DXA) to measurements by a 4-component (4-C) model. Sixty-nine participants, aged 37 ± 12 yr, with a body mass index of 26.2 ± 5.1 kg/cm2, were measured once on the Prodigy and twice on the iDXA. The 4-C model estimated fat mass from body mass, total body water by deuterium dilution, body volume by air displacement plethysmography, and bone mass by DXA. Agreements between measurements made on the 2 instruments and by the 4-C model were analyzed by Bland-Altman and linear regression analyses. Where appropriate, translational cross-calibration equations were derived. Differences between DXA software versions were investigated. iDXA precision was less than 2% of the measured value for all regional- and whole-body bone and body composition measurements with the exception of arm fat mass (2.28%). We found significant differences between iDXA and Prodigy (p < 0.05) whole-body and regional bone, fat mass (FM), and lean mass, with the exception of hip bone mass, area and density, and spine area. Compared to iDXA, Prodigy overestimated FM and underestimated lean mass. However, compared to 4-C, iDXA showed a smaller bias and narrower limits of agreement than Prodigy. No significant differences between software versions in FM estimations existed. Our results demonstrate excellent iDXA precision. However, significant differences exist between the 2 GE Lunar instruments, Prodigy and iDXA measurement values. A divergence from the reference 4-C observations remains in FM estimations made by DXA even following the recent advances in technology. Further studies are particularly warranted in individuals with large FM contents.

Visceral fat reference values derived from healthy European men and women aged 20-30 years using GE Healthcare dual-energy x-ray absorptiometry.

Dual energy X-ray absorptiometry (DXA) is an established technique used in clinical and research settings to evaluate total and regional fat. Additionally, recently developed software allow to quantify visceral adipose tissue (VAT). Currently, there are no reference values available for GE Healthcare DXA systems for VAT. The aim of this study was to develop reference values for VAT in healthy European adults aged 20–30 years using a GE Healthcare Prodigy densitometer along with the dedicated CoreScan application. We also assessed the associations of VAT with traditional cardiometabolic risk factors. In 421 participants (207 men; 214 women), we performed DXA whole-body scans and calculated total body fat (BF) and VAT (in gender-specific percentiles). We also measured blood pressure and fasting glucose, insulin, and blood lipids. Males, in comparison with females, had 2-fold greater VAT both in units of mass (542 ± 451 g; 95% CI: 479.6‒605.1 g vs. 258 ± 226 g; 95% CI: 226.9‒288.6 g) and volume (570 ± 468 cm3; 95% CI: 505.1‒635.2 cm3 vs. 273 ± 237 cm3; 95% CI: 240.6‒305.3 cm3). They also had significantly higher the VAT/BF ratio. VAT showed a stronger positive correlation than BF with blood pressure, triglycerides, LDL-cholesterol, glucose, insulin, and homeostasis model assessment-insulin resistance index and a stronger negative correlation with HDL-cholesterol. Among these variables, VAT had the highest area under the curve for triglycerides ≥150 mg/dL (0.727 in males and 0.712 in females). In conclusion, we provide reference values for VAT obtained from healthy adults using the GE Healthcare DXA. These values may be useful in the diagnosis of visceral obesity, for identifying subjects with high obesity-related risks, in epidemiological studies, as a target for therapies, and in physically trained individuals. In both genders, VAT was associated with traditional cardiometabolic risk factors, particularly hypertriglyceridemia.

Vitamin D status and abdominal aortic calcification in postmenopausal women.

Vitamin D has an important role in bone metabolism and may be involved in the process of vascular calcification. The objective of this study was to evaluate the effect of vitamin D status on the presence of abdominal aortic calcification (AAC). We enrolled, in a cross-sectional study, 429 postmenopausal women [mean age, weight, and BMI of 59.5±8.3 (50-83) years, 75.8±13.3 (35-165) kg, and 29.9±5.2 (14.6-50.8) kg/m2, respectively]. Lateral vertebral fracture assessment (VFA) images and scans of the lumbar spine and proximal femur were obtained using a Lunar Prodigy densitometer. Vertebral fractures (VFs) were defined using the Genant semiquantitative (SQ) approach. We used the Kauppila score to assess AAC extension. Clinical risk factors of osteoporosis were collected, and 25-hydroxy vitamin D was measured using electrochemiluminescence (Roche). Prevalence of osteoporosis and hypovitaminosis D (<20ng/ml) was 21.0% and 78.1%, respectively. VFs grade 2/3 were identified in 76 patients (17.7%). Two thirds of the evaluable participants did not have any detectable AAC. The prevalence of significant atherosclerotic burden, defined as a radiographic 24-point AAC score of 5 or higher, was 7.9%. The group of women with extended AAC were older and had a statistically significant higher menopause duration and more prevalent grade 2/3 VFs. Compared to women with normal values of vitamin D, women with vitamin D insufficiency (<20ng/ml) and deficiency (<10ng/ml) had a lower BMD and more prevalent VFs. No difference was noted with regard to AAC among the three groups. Multiple stepwise conditional logistic regression analysis showed that the presence of AAC was associated significantly with age and the presence of VFs. Extended aortic calcifications are independently associated with prevalent VFA-identified VFs but not with serum vitamin D levels in postmenopausal women. VFA imaging using DXA may detect at the same time prevalent VFs and AAC, an important cardiovascular disease risk factor.

Influence of obesity on vertebral fracture prevalence and vitamin D status in postmenopausal women.

BackgroundIt is well established that weight is an important determinant of bone health. Whereas obesity is associated with increased mortality and morbidity from diabetes and cardiovascular diseases, high body weight is widely believed to be associated to hypovitaminosis D and protective against the development of osteoporosis and fracture risk. The objective of the study was to evaluate the effect of BMI on vitamin D status and on densitometric vertebral fractures (VFs) in a large series of asymptomatic women aged over 50 who had a VFA examination during their bone mineral density (BMD) testing.MethodsWe enrolled 429 postmenopausal women (mean age, weight and BMI of 59.5 ± 8.3 (50 to 83) years, 75.8 ± 13.3 (35 to 165) kgs and 29.9 ± 5.2 (14.6 to 50.8) kg/m2, respectively. Lateral VFA images and scans of the lumbar spine and proximal femur were obtained using a Lunar Prodigy densitometer. VFs were defined using the Genant semiquantitative (SQ) approach. Clinical risk factors of osteoporosis were collected and 25-hydroxivitamin D was measured using electrochimiluminescence (Roche).ResultsPrevalence of osteoporosis and hypovitaminosis D (<20 ng/ml) was 21.0 % and 78.1 % respectively. VFs grade 2/3were identified in 76 (17.7 %). Comparison between women according to their BMI showed that obese women had a higher BMD and less proportion of women with osteoporosis and VFs grade 2/3 than lean and overweight women. The prevalence of VFs globally increased with age and as BMI and BMD declined. Stepwise regression analysis showed that the presence of osteoporosis was independently related to BMI and history of fractures while the presence of grade 2/3 VFs was independently related to age, hypovitaminosis D and years of menopause.ConclusionObese women had a higher BMD and lower prevalence of VFs. VFs were significantly related to age, hypovitaminosis D and years since menopause. However, among obese women, prevalence of VFs was increased in osteoporotic women.

Relationships between vertebral fractures, sex hormones and vitamin D in Moroccan postmenopausal women: a cross sectional study.

BackgroundVertebral Fractures (VFs) are associated with bone loss that occurs before menopause but is accelerated at menopause as a result of sex hormone deficiency.To determine the association of sex hormones, bone remodeling markers and vitamin D levels with bone mineral density (BMD) and asymptomatic VFs prevalence using vertebral fracture assessment (VFA) in a cohort of Moroccan menopausal women.MethodsThis was a cross-sectional study conducted from October 2012 to April 2013 with menopausal women aged 50 years old and over. A total of 207 women who had no previous diagnosis of osteoporosis were enrolled in this cross-sectional study. Women were recruited prospectively from our laboratory department. VFA images and scans of the lumbar spine and proximal femur were obtained using a GE Healthcare Lunar Prodigy densitometer. VFs were defined using a combination of Genant semiquantitative approach and morphometry. Serum levels of estradiol, dehydroepiandrosterone sulfate, Sex hormone binding globulin, vitamin D, Osteocalcin, Crosslaps, intact parathormone were measured by Electrochemiluminescent immunoassay technique.ResultsAmong the 207 women, 18.3 % (n = 38) had densitometric osteoporosis. On VFA, VFs were detected in 134 (62.3 %), including 96 (44.6 %) grade 1 and 38 (17.6 %) grade 2/3. There was no difference in the plasma levels of sex steroids, bone remodeling markers and vitamin D in the group of women with VFs (grade 1 and grade 2/3) and without VFs. The combination of variables that best predicted grade 2/3 VFs included the number of years since menopause and the lumbar spine T-score.ConclusionThese data confirm the importance of postmenopausal estrogen and SHBG concentrations in the bone loss and the pathogenesis of osteoporosis in elderly women, but not in the occurrence of the VFs.

Osteoporosis, vertebral fractures and metabolic syndrome in postmenopausal women.

BackgroundThe combined effect of the metabolic syndrome (MS) risk factors on bone health has led to controversial results and it is still not clear whether this effect is protective or detrimental. The study aimed to examine the association between MS and bone mineral density (BMD), osteoporosis, and vertebral fractures (VFs) among ambulatory older postmenopausal women.Methods270 post-menopausal women with a mean age of 61.0 years ± 7.8 (50 to 90) with no prior known diagnosis of osteoporosis were recruited. BMD and Lateral vertebral fracture assessment (VFA) images were obtained using a GE Healthcare Lunar Prodigy densitometer. VFs were defined using a combination of Genant semiquantitative approach and morphometry.ResultsThe MS as defined by the NCEP-ATP III was present in 62 women (23.0%). According to the WHO classification, 82 had osteoporosis at any site (30.4%). VFs were identified in 116 (43.0%): 80 (29.6%) had grade 1 and 36 (13.3%) had grade 2 or 3. Women with MS had a significantly higher BMD and lower prevalence of osteoporosis (17.7% vs. 34.1%) than those without MS. No significant statistical difference was noted in prevalence of VFs (14.5 vs. 13.0%). There were significantly less women with MS among the group of osteoporotic women (13% vs. 27%; p = 0.018). Conditional regression binary analysis assessing the presence of osteoporosis as the dependent variable showed that women with a MS had a significant 71% decrease in the odds of being osteoporotic by BMD compared with women who had not MS accounting for age, BMI, number of parities and years since menopause.ConclusionWomen with MS had higher BMD at the hip and spine, suggesting a protective effect of MS on bone. However, the prevalence of VFs was similar between women with or without MS.

The discriminative ability of FRAX, the WHO algorithm, to identify women with prevalent asymptomatic vertebral fractures: a cross-sectional study.

BackgroundA Moroccan model for the FRAX tool to determine the absolute risk of osteoporotic fracture at 10 years has been established recently. The study aimed to assess the discriminative capacity of FRAX in identifying women with prevalent asymptomatic vertebral fractures (VFs).MethodsWe enrolled in this cross-sectional study 908 post-menopausal women with a mean age of 60.9 years ±7.7 (50 to 91) with no prior known diagnosis of osteoporosis. Subjects were recruited from asymptomatic women selected from the general population. Lateral VFA images and scans of the lumbar spine and proximal femur were obtained using a GE Healthcare Lunar Prodigy densitometer. VFs were defined using a combination of Genantsemiquantitative (SQ) approach and morphometry. We calculated the absolute risk of major fracture and hip fracture with and without bone mineral density (BMD)using the FRAX website.The overall discriminative value of the different risk scores was assessed by calculating the areas under the ROC curve (AUC).ResultsVFA images showed that 179 of the participants (19.7%) had at least one grade 2/3 VF. The group of women with VFs had a statistically significant higher FRAX scores for major and hip fractures with and without BMD, and lower weight, height, and lumbar spine and hip BMD and T-scores than those without a VFA-identified VF. The AUC ROC of FRAX for major fracture without BMD was 0.757 (CI 95%; 0.718-0.797) and 0.736 (CI 95%; 0.695-0.777) with BMD, being 0.756 (CI 95%; 0.716-0.796) and 0.747 (CI 95%; 0.709-0.785), respectively for FRAX hip fracture without and with BMD. The AUC ROC of lumbar spine T-score and femoral neck T-score were 0.660 (CI 95%; 0.611-0.708) and 0.707 (CI 95%; 0.664-0.751) respectively.ConclusionIn asymptomatic post-menopausal women, the FRAX risk for major fracture without BMD had a better discriminative capacity in identifying the women with prevalent VFs than lumbar spine and femoral neck T-scores suggesting its usefulness in identifying women in whom VFA could be indicated.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2474-15-365) contains supplementary material, which is available to authorized users.

Vertebral microarchitecture and fragility fracture in men: A TBS study

IntroductionAlthough osteoporosis is considered a disease of women, 25% of the individuals with osteoporosis are men. BMD measurement by DXA is the gold standard used to diagnose osteoporosis and assess fracture risk. Nevertheless, BMD does not take into account alterations of microarchitecture. TBS is an index of bone microarchitecture extracted from the spine DXA. Previous studies have reported the ability of the spine TBS to predict osteoporotic fractures in women. This is the first case-controlled study in men to evaluate the potential diagnostic value of TBS as a complement to bone mineral density (BMD), by comparing men with and without fractures. MethodsTo be eligible for this study, subjects had to be non-Hispanic US white men aged 40 and older. Furthermore, subjects were excluded if they have or have had previously any treatment or illness that may influence bone metabolism. Fractured subjects were included if the presence of at least one fracture was confirmed. Cases were matched for age (±3years) and BMD (±0.04g/cm2) with three controls. BMD and TBS were first retrospectively evaluated at AP spine (L1–L4) with a Prodigy densitometer (GE-Lunar, Madison, USA) and TBS iNsight® (Med-Imaps, France) in Lausanne University Hospital blinded from clinical outcome. Inter-group comparisons were undertaken using Student's t-tests or Wilcoxon signed rank tests. Odds ratios were calculated per one standard deviation decrease as well as areas under the receiver operating curve (AUC). ResultsAfter applying inclusion/exclusion criteria, a group of 180 male subjects was obtained. This group consists of 45 fractured subjects (age=63.3±12.6years, BMI=27.1±4.2kg/m2) and 135 control subjects (age=62.9±11.9years, BMI=26.7±3.9kg/m2) matched for age (p=0.86) and BMD (p=0.20). A weak correlation was obtained between TBS and BMD and between TBS and BMI (r=0.27 and r=−0.28, respectively, p<0.01). Subjects with fracture have a significant lower TBS compared to control subjects (p=0.013), whereas no differences were obtained for BMI, height and weight (p>0.10). TBS OR per standard deviation is 1.55 [1.09–2.20] for all fracture type. When considering vertebral fracture only TBS OR reached 2.07 [1.14–3.74]. ConclusionThis study showed the potential use of TBS in men. TBS revealed a significant difference between fractured and age- and spine BMD-matched nonfractured subjects. These results are consistent with those previously reported on for men of other nationalities.

Evaluating spine micro-architectural texture (via TBS) discriminates major osteoporotic fractures from controls both as well as and independent of site matched BMD: the Eastern European TBS study

The aim of the study was to assess the clinical performance of the model combining areal bone mineral density (aBMD) at spine and microarchitecural texture (TBS) for the detection of the osteoporotic fracture. The Eastern European Study is a multicenter study (Serbia, Bulgaria, Romania and Ukraine) evaluating the role of TBS in routine clinical practice as a complement to aBMD. All scans were acquired on Hologic Discovery and GE Prodigy densitometers in a routine clinical manner. The additional clinical values of aBMD and TBS were analyzed using a two steps classification tree approach (aBMD followed by TBS tertiles) for all type of osteoporotic fracture (All-OP Fx). Sensitivity, specificity and accuracy of fracture detection as well as the Net Reclassification Index (NRI) were calculated. This study involves 1031 women subjects aged 45 and older recruited in east European countries. Clinical centers were cross-calibrated in terms of BMD and TBS. As expected, areal BMD (aBMD) at spine and TBS were only moderately correlated (r (2) = 0.19). Prevalence rate for All-OP Fx was 26 %. Subjects with fracture have significant lower TBS and aBMD than subjects without fracture (p < 0.01). TBS remains associated with the fracture even after adjustment for age and aBMD with an OR of 1.27 [1.07-1.51]. When using aBMD T-score of -2.5 and the lowest TBS tertile thresholds, both BMD and TBS were similar in terms of sensitivity (35 vs. 39 %), specificity (78 vs. 80 %) and accuracy (64 vs. 66 %). aBMD and TBS combination, induced a significant improvement in sensitivity (+28 %) and accuracy (+17 %) compared to aBMD alone whereas a moderate improvement was observed in terms of specificity (+9 %). The overall combination gain was 36 % as expressed using the NRI. aBMD and TBS combination decrease significantly the number of subjects needed to diagnose from 7 for aBMD alone to 2. In a multi-centre Eastern European cohort, we have shown that the use of TBS in addition to the aBMD permit to reclassified correctly more than one-third of the overall subjects. Furthermore, the number of subjects needed to diagnose fell to 2 subjects. Economical studies have to be performed to evaluate the gain induced by the use of TBS for the healthcare system.

A Cross-Calibration Study of the GE-Lunar iDXA and Prodigy for the Assessment of Lumbar Spine and Total Hip Bone Parameters via Three Statistical Methods

This study assessed agreement between the GE Lunar iDXA and Prodigy densitometers for bone measurements and used 3 statistical methods to derive cross-calibration equations: linear regression, the Deming method, and multivariate analysis. Compatibility of machines for the measurements of bone mineral density, bone mineral content, and bone area also was explored. Eighty-five adults, age: 45.5 (SD 12.8) years; body mass index: 25.6 (SD 3.7) kg.m−2 were measured once at the lumbar spine: L1–L4 and total hip on each densitometer, within 24 hours. Both linear regression and Deming analysis indicated that cross-calibration equations were required at the lumbar spine and total hip but not at the femoral neck. Multivariate analysis identified femur thickness and femur percent fat as predictive variables at the femoral neck and total hip. Bland Altman analysis (Prodigy–iDXA) indicated significant positive bone mineral density bias at the lumbar spine and femoral neck. Significant bone mineral content biases were observed at all 3 sites and bone area biases at both hip sites. These initial results suggest there are small significant differences in the bone parameters and that all 3 bone parameters should be evaluated when comparing densitometers, especially when there are differences in pixel size between the densitometers.

Vertebral fractures and abdominal aortic calcification in postmenopausal women. A cohort study

IntroductionVertebral fracture assessment (VFA) imaging with a bone densitometer can simultaneously detect prevalent vertebral fractures (VFs) and abdominal aortic calcification (AAC). ObjectiveTo study the relation between the prevalence of VFs using VFA in asymptomatic women and the prevalence and severity of AAC. DesignThis is a cross-sectional study. SettingsSubjects were recruited in a third care center from asymptomatic women selected from the general population. ParticipantsWe enrolled 908 post-menopausal women with a mean age of 60.9years±7.7 (50 to 91) with no prior known diagnosis of osteoporosis or taking medication interfering with bone metabolism. Primary and secondary outcome measuresLateral VFA images and scans of the lumbar spine and proximal femur were obtained using a GE Healthcare Lunar Prodigy densitometer. VFs were defined using a combination of Genant semiquantitative (SQ) approach and morphometry. VFA images were scored for AAC using a validated 24 point scale. ResultsVFA images showed that 179 of the participants (19.7%) had at least one grade 2/3 VF, 81% did not have any detectable AAC whereas the prevalence of significant atherosclerotic burden, defined as AAC score of 5 or higher, was 12%. The group of women with 2/3 VFs had a statistically significant higher AAC score and higher proportion of subjects with extended AAC, and lower weight, height, and lumbar spine and hip BMD and T-scores than those without VFA-identified VFs. Multiple regression analysis showed that the presence of grade 2/3 VFs was significantly associated with age, BMI, history of peripheral fracture, AAC score≥5 and densitometric osteoporosis. ConclusionIn post-menopausal women, extended AAC is independently associated with prevalent VFs regardless of age, BMI, history of fractures, and BMD.