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PubMed2001

[Prevalence of osteoporosis assessed by densitometry in the Spanish female population].

BACKGROUND: Osteoporotic fractures represent an important clinic and socioeconomic problem. Although it is well known the incidence of fractures in Spain, we do not know how many persons are at risk. The World Health Organization (WHO) has approved a densitometric criteria to define osteopenia (OSPE) and osteoporosis (OSP). The aim of this study has been to evaluate the prevalence of OSP and OSPE in women of the Spanish population. SUBJECTS AND METHOD: With the data of a study of bone mass in the Spanish population, stratified according to age, using dual-energy X-ray absortiometry (DXA) with a QDR/1000 Hologic device and according the WHO criteria, we have calculated the prevalence of OSP and OSPE in normal Spanish women at the lumbar spine (LS) and/or femoral neck (FN). RESULTS: The prevalence of osteoporosis at LS is: 0.34% in the group aged 20-44 years; 4.31% in the group aged 45-49 years; up to 9.09% in the group aged 50-59 years; 24.29% in the 60-69 years, and 40.0% in the group aged 70-79 years. The overall prevalence of osteoporosis is 11.13%, confidence interval (CI) 95% from 9.4 to 12.8%. The prevalence of osteoporosis at FN is: 0.17% in the group aged 20-44 years, 0% in the 45-49 years, up to 1.3% in the 50-59 years, 5.71% in the 60-69 years and 24.24% in the group aged 70-79 years. The overall prevalence of osteoporosis is 4,29% (CI 95% 3.2-5.4%). The prevalence in female older than 50 years was 22.8% at LS and 9.1% at FN. 12.73% of Spanish women population has osteoporosis at LS or FN, which represent about 1,974,400 women; 2.68% of total population has osteoporosis in both sites. CONCLUSIONS: Even we do not include in this study women with established osteoporosis (with fractures), the number of Spanish women with osteoporosis is very high.

Absorptiometry, Photon↗
PubMed2000

Detection of bone disease with ultrasound--comparison with bone densitometry.

A system for ultrasonic in-vivo examination of a heel bone (calcaneus) was developed. When operating in transmission mode, the system can measure broadband ultrasonic attenuation-BUA, speed of sound--SOS and thickness of bone. BUA and SOS are measured by comparing the pulses transmitted through the heel with the reference pulse transmitted through water. In our approach, we operate in the backscattered mode in addition to transmission. The backscattered ultrasonic technique for bone characterization is very promising because the magnitude of backscattered waves depends on the scattering cross-section of a trabecular structure that, to some extent, describes the microarchitecture of a calcaneus. Additionally, when the backscattered and transmitted signals are compared, some of the signal distortions caused by tissue and bone interfaces are reduced. A set of data representing signals transmitted through the heel and reflected inside a calcaneus for patients with osteoporosis was collected. Several signal-processing techniques were applied in order to smooth the backscattered signal and to calculate a trabecular structure cros-section (TSC) function. Results obtained by these approaches along with a spectral shift method and a standard BUA measurement are presented and compared to X-ray bone mineral density determination results.

Absorptiometry, Photon↗
PubMed2004

Computerized methods for X-ray-based small bone densitometry.

Animal models have been widely used to correlate in vivo changes in bone mineral density (BMD) with changes in disease state of bone. In small animal models, e.g. the hindlimb suspension model of bone loss, a non-invasive assessment of BMD is required. X-ray radiography has been surpassed in some cases by quantitative computed tomography (QCT) and dual X-ray absorptiometry (DEXA) quantitation. However, there are drawbacks in using the computerized methods, especially for small animals. In this paper, we present image-processing algorithms to quantitatively determine bone area and mineral density in digitized radiographs. Image calibration is based on a calibration step wedge, and the algorithm automatically detects the steps and computes the calibration data. In addition, we demonstrate how the algorithm can accurately determine the cortical outline of the bone and provide reliable data and statistics for small animal studies. A downloadable implementation example for the popular NIH Image package is provided.

Absorptiometry, Photon↗
PubMed1998

Bone densitometry: applications in sports-medicine.

Physical exercise and sports increase muscular mass and the remodelling process of bones. The increment of bone depends on the type and the quality of sport. Short-term high-performance activities such as sprint, tennis, fencing lead to increased bone mineral density as well as weight lifting or heavy athletics. Swimming, bicycling, walking are associated with good musculature conditioning without an increase of bone mass. The effects on the bone by performing endurance activities are controversially discussed. Excessive sport leads to an increase of fatigue fractures. Low bone mass may result from hormonal disregulation in female athletes.

Absorptiometry, Photon↗
PubMed1999

Application of first-derivative UV-spectrophotometry, TLC-densitometry and liquid chromatography for the simultaneous determination of mebeverine hydrochloride and sulpiride.

Three methods are described for the simultaneous determination of mebeverine hydrochloride (MB) and sulpiride (SU) in combined pharmaceutical tablets. The first method depends on first-derivative ultraviolet spectrophotometry, with zero-crossing measurement method. The first derivative amplitudes at 214.2 and 221.6 nm were selected for the assay of MB and SU, respectively. Calibration graphs follow Beer's law in the range of 10-30 and 2-8 microg/ml(-1), and the linearity was satisfactory (r = 0.9999), for MB and SU, respectively. The second method was based on the application of the thin layer chromatographic separation of both drugs followed by the densitometric measurements of their spot areas. After separation on silica gel GF254 plates, using ethanol: diethyl ether: triethylamine (70:30:1 v/v) as the mobile phase, the chromatographic zones corresponding to the spots of MB and SU were scanned at 262 and 240 nm, respectively. The calibration function was established in the ranges of 4-12 microg for MB and 2-8 microg for SU. The third method was an internal standard procedure based on high performance liquid chromatographic separation of the two drugs on a reversed-phase, Bondapak CN column. The detection was done at 243 nm using buclizine hydrochloride as internal standard. All chromatographic methods showed good linearity, precision and reproducibility. No spectral or chromatographic interference from the tablet excipients were found. The proposed methods were successfully applied to the assay of commercial tablets and content uniformity test. The procedures were rapid, simple and suitable for quality control application.

Anticonvulsants↗
PubMed2005

Failure to recognize and act on abnormal test results: the case of screening bone densitometry.

BACKGROUND: Failure to follow up on abnormal test results is common. A model was developed to capture the reasons why providers did not take action on abnormal test results. METHODS: A systematic review of the medical literature was conducted to identify why providers did not follow up on test results. The reasons were then synthesized to develop an operational model. The model was tested by reviewing electronic medical records of consecutive patients diagnosed with osteoporosis through a dual-energy x-ray absorptiometry (DXA) scan to determine whether: (1) the scan results had been reeviewed; (2) therapy was recommended; (3) the scan results were not reviewed and why this occurred. RESULTS: Of the 48 newly diagnosed osteoporosis patients, 16 did not receive a recommendation to begin treatment. There was no evidence that the scan results wrere reviewed in 11 of the 16 cases (23% of all abnormal scans); the scan results of an additional 5 patients were reviewed but no treatment was recommended. DISCUSSION AND CONCLUSIONS: A clinically significant ercentage of DXA scan results went unrecognized. As a long-term solution, direct patient notification could theoretically reduce the burden on providers, activate and empower patients, and create a back-up system for ensuring that patients are notified of their test results.

Absorptiometry, Photon↗
PubMed1999

Central region-of-interest analysis of lumbar spine densitometry demonstrates lower bone mass in older rhesus monkeys.

Osteoarthritis (OA) spuriously elevates spine bone mineral density (BMD) as measured by dual-energy X-ray absorptiometry (DXA). This study documents spinal OA prevalence in adult female rhesus monkeys, and evaluates a custom central region-of-interest (CROI) analysis technique designed to minimize OA effects on BMD measurement. Lumbar spine radiographs were obtained on 71 animals, age 10-37 years. OA degree was blindly scored as none, minimal, or moderate/severe. Moderate/severe OA was not observed before age 19, but was present in 66% of older animals. Subsequently, lumbar spine (L2-4) BMD was determined by standard DXA analysis and manual placement of 0.92 cm2 CROIs in two groups of female rhesus monkeys. One group (eight control, eight postovariectomy, ages 10-19 years) was assessed longitudinally, the second (n = 90, ages 10-37) cross-sectionally. Measured bone loss following ovariectomy (8.1% standard analysis, 11.5 % CROI) was comparable with both techniques. By contrast, CROI demonstrated lower bone mass with age (p < 0.0001), whereas only a trend (p = 0.06) was observed with standard analysis. When World Health Organization criteria were applied, 42% of animals > or = age 19 years were classified as osteopenic/osteoporotic by standard analysis compared with 67% by CROI. All "normal" animals reclassified as osteopenic/osteoporotic by CROI had OA. In conclusion, female rhesus monkeys often develop spinal OA with advancing age. CROI analysis demonstrated lower bone density in older monkeys and was as sensitive to estrogen-depletion bone loss as standard methodology. This suggests that alternative analysis techniques, such as CROI, may be more appropriate to evaluate bone density in nonhuman primates, and potentially in people.

Absorptiometry, Photon↗
PubMed1999

Use of peripheral quantitative computed tomography for densitometry of the femoral neck and spine in cynomolgus monkeys (Macaca fascicularis).

Quantitative computed tomography (QCT) allows for the separate densitometric examination of cortical and cancellous bone in vivo. With the new peripheral QCT (pQCT) instrument (the Norland/Stratec XCT-3000A), we evaluated the clinically relevant axial sites of spine and femoral neck in nonhuman primates in vivo. The reproducibility was good (coefficient of variation [CV] <3% at both sites for cortical, trabecular, and total bone mineral density [BMD]; CV 3%-7% for bone mineral content [BMC] and cross-sectional bone area). One hundred sixty intact female cynomolgus monkeys (M. fascicularis) were scanned at the femoral neck. There was less variability among monkeys in cortical BMD (mean 802 mg/mL, CV 6%) as opposed to trabecular BMD (mean 334 mg/mL, CV 28%) or transition zone BMD (mean 457 mg/mL, CV 12%). Scans were performed on lumbar vertebrae (L-4, L-5, and L-6) from five monkeys in vivo and ex vivo. Removal of soft tissue increased measured BMD. Decreasing voxel size from 0.4 mm to 0.2 mm increased measured BMD by diminishing the partial volume effect. Factor analysis demonstrated the expected relationships between pQCT parameters and physical measurement of bone mass and volume ex vivo. Preliminary results in eight ovariectomized and eight reproductively intact monkeys revealed a lower transition zone BMD at the femoral neck, and lower total BMD of the vertebral body in estrogen-deficient animals.

Absorptiometry, Photon↗