Assessment Of Mineral Density Research Articles

9 Operator Radiation Exposure from the GE-Lunar Prodigy

Dual Energy X-Ray Absorptiometry (DXA) is the most commonly used method for Bone Mineral Density (BMD) assessment and is an important component in osteoporosis diagnosis and management. DXA systems require ionising radiation to perform this measurement.DXA technologists generally remain within the room while scanning and consequently are exposed to low dose radiation. The use of DXA is increasing in both clinical and research facilities. Additionally, newer systems with higher resolution and faster scan times are becoming available, which is usually achieved with increases in photon flux as well as improvements in detectors. As a result of the increased photon flux, there has been an increased concern for the level of radiation exposure to operators. Previous research has shown radiation dose to technologists performing DXA scanning to be low

Serum 1-84 and 7-84 parathyroid hormone concentrations and bone in patients with primary hyperparathyroidism

Parathyroid hormone (PTH) acts on bone as both anabolic and catabolic factor. It includes two fractions: 1-84 (cyclase activating PTH, CAP) which increases bone turnover and serum calcium, and 7-84 (cyclase inactivating PTH, CIP) acting the opposite way. The aim of this study was to establish whether bone mineral density (BMD) and turnover in patients' primary hyperparathyroidism (HPT) are dependent on CAP and CIP concentrations. Thirty-one patients with HPT and 29 appropriately matched controls were examined. Parameters of calcium-phosphate homeostasis and BMD were estimated. BMD of radius shaft was lower in patients with HPT as compared with controls, whereas BMD of spine and ultradistal radius were similar. Serum calcium, bone alkaline phosphatase, total PTH, 1-84 PTH, and 7-84 PTH were higher in HPT patients, whereas serum phosphate was lower and beta cross-laps similar. Both total PTH and CAP correlated significantly with BMD of radius shaft and serum calcium concentration, but not with other examined parameters. Total and 1-84 PTH are similarly associated with examined parameters in patients with HPT. Thus, determination of serum CAP concentration does not seem to have advantages over total PTH with regard to bone mineral density and bone turnover assessment in those patients.

Well-nourished cystic fibrosis patients have normal mineral density, but reduced cortical thickness at the forearm

Our goal was to assess mineral density and geometry of the cortex at the level of the forearm in adolescents and young adults with cystic fibrosis, using peripheral quantitative computed tomography. We found that density was normal, but cortical thickness significantly reduced, as well in males as in females. Our goal was to measure bone mineral density as a volumetric density, as well as total cross-sectional area, cortical area and cortical thickness, using peripheral quantitative computed tomography (pQCT) at the forearm in adolescents and young adults with cystic fibrosis. We evaluated relationships between forearm bone measurements and body composition assessed using dual energy X-ray absorptiometry (DXA). An XCT 2000 pQCT (Stratec, Pforzheim, Germany) and a QDR 4500 A-upgraded to Discovery DXA device (Hologic, Waltham, MA, USA) were used. Forty-eight patients (31 males,17 females, mean+/-SD 20+/5 years) were studied. Anthropometric features were: height 169+/- 10 cm, SDS 0.05+/-0.12, body mass index 19.8+/- 2.5 kg/m(2), SDS -0.56+/-0.14. Bone mineral density and total cross-sectional area of the forearm and body composition were normal, whereas cortical thickness was significantly reduced in males (mean Z-score - 1.22, p < 0.05), and in females (mean Z-score - 1.61, p < 0.05). Total body lean mass correlated more strongly with cortical thickness (r = 0.72, p < 0.001) than with total bone mineral density at the proximal radius (r = 0.39, p < 0.05). Adolescents and young adults with cystic fibrosis, presenting with only a slight degree of underweight, have at the radius a preserved bone mineral density but a reduced cortical thickness.

Bone mineral density (BMD) assessment using the EOS® low-dose X-ray device: A feasibility study

Bone mineral density (BMD) assessment using the EOS® low-dose X-ray device: A feasibility study

Bone safety of aromatase inhibitors versus tamoxifen

Bone loss may be a potential side effect of implementing aromatase inhibitors in the adjuvant setting. Current evidence suggests a minor bone loss during treatment with the steroidal aromatase inhibitor exemestane compared to placebo and a nonsignificant increase in fracture rate during treatment with exemestane when compared to tamoxifen. Such a difference could be due to the bone-sparing effects of tamoxifen. For the nonsteroidal inhibitors letrozole and anastrozole, the MA17 study revealed a nonsignificant increase in fracture rate for letrozole compared to placebo. In contrast, both anastrozole and letrozole were found to significantly increase fracture rate compared to tamoxifen when administered as monotherapy or given sequentially. While an increased fracture rate may have detrimental effects, evidence suggests that enhanced bone loss may be preventable through careful bone mineral density (BMD) assessment and treatment with bisphosphonates.

Fractures in adolescents: authors’ reply to Pluskiewicz and Halaba

We thank Dr. Pluskiewicz and Dr. Halaba for their interest in this population survey of fractures. The following diseases (number of cases) were recorded: juvenile euthyreotic goiter (110), asthma (five), follow-up of treated Hodgkin’s disease (one), chronic hepatitis B (one), and juvenile arthritis (one). One-hundred seventy respondents reported no milk consumption; some may have had cow’s milk allergy. This was presented and discussed in the manuscript. Some respondents may have had osteogenesis imperfecta or silent celiac disease, but those reporting seven to 10 fractures reported neither illness nor drug therapy. Hospitalizations occurred in 27 (7.2%) of 377 subjects with fractures and in 79 (9.1%) subjects without fractures (not significant). Bone mineral density and personality assessments were not done. General terms were used in the questionnaire to achieve clarity and high response rates. Fractures occurred during school and leisure time activities, including sport. We did not record specified circumstances or mechanisms of injury or falls.

Bone Mineral Density (BMD) Assessment of Central Skeletal Sites From Peripheral BMD and Ultrasonographic Measurements: An Improved Solution Employing Age and Weight in Type 3 Regression

The objective of this study was to develop a method whereby bone mineral density measurements of the heel and finger, as well as ultrasonographic measurements of calcaneal sound transmission, could identify individuals with a diagnosis of osteoporosis or osteopenia by the World Health Organization criteria for these diagnoses in the central skeleton (i.e., the lumbar spine (LS) and hip [femoral neck] [FN]). Two hundred and forty-four women in a university hospital laboratory setting had dual-energy X-ray absorptiometry measurements of bone mineral density (BMD) in the calcaneus, finger, hip, and spine, and quantitative ultrasound of the calcaneus. Regression equations were developed to predict central bone mineral T-scores from T-scores of peripheral measurements, adjusted by age and weight. Equations were validated by predicting the cut point for osteopenia at the lumbar spine and hip (T-score=-1.0). Ninety-five percent confidence intervals of the mean predicted LS or FN T-score from each peripheral site included -1.0. We conclude that our derived regression equations (taking into account interaction of peripheral BMD with patient age and weight) are useful for predicting T-scores in the central skeleton. This approach reduces the potential for misdiagnosis, which can result if one uses unadjusted peripheral T-scores, which are only moderately correlated with the central measurements of BMD.

Bone Mineral Density Referral for Dual-Energy X-Ray Absorptiometry Using Quantitative Ultrasound as a Prescreening Tool in Postmenopausal Women from the General Population: A Cost-Effectiveness Analysis

The aim of our study was to assess, from the perspective of the National Health Services in Spain, the cost-effectiveness of quantitative ultrasound (QUS) as a prescreen referral method for bone mineral density (BMD) assessment by dual-energy X-ray absorptiometry (DXA) in postmenopausal women of the general population. Using femoral neck DXA and heel QUS. We evaluated 267 consecutive postmenopausal women 65 years and older and attending primary care physician offices for any medical reason. Subjects were classified as osteoporotic or nonosteoporotic (normal or osteopenic) using the WHO definition for DXA. Effectiveness was assessed in terms of the sensitivity and specificity of the referral decisions based on the QUS measurement. Local costs were estimated from health services and actual resource used. Cost-effectiveness was evaluated in terms of the expected cost per true positive osteoporotic case detected. Baseline prevalence of osteoporosis evaluated by DXA was 55.8%. The sensitivity and specificity for the diagnosis of osteoporosis by QUS using the optimal cutoff thresholds for the estimated heel BMD T-score were 97% and 94%, respectively. The average cost per osteoporotic case detected based on DXA measurement alone was 23.85 euros. The average cost per osteoporotic case detected using QUS as a prescreen was 22.00 euros. The incremental cost-effectiveness of DXA versus QUS was 114.00 euros per true positive case detected. Our results suggest that screening for osteoporosis with QUS while applying strict cufoff values in postmenopausal women of the general population is not substantially more cost-effective than DXA alone for the diagnosis of osteoporosis. However, the screening strategy with QUS may be an option in those circumstances where the diagnosis of osteoporosis is deficient because of the difficulty in accessing DXA equipment.

Marked recovery from axial osteopenia in children with liver transplantation

locations of cancellous bones than in those of cortical bones. This explains why the ratio of cortical bone mineral content to cancellous bone mineral content may indicate that estrogen deficiency has taken place in the past. In this study, we sought to establish normal Im values in Mexican women. For this purpose, 465 healthy Mexican women with no conditions known to affect bone metabolism were studied by bone densitometry (DXA) in multiple centers using Lunar DPX equipment. In all cases, bone mineral density (BMD) assessment of the spine and femoral neck was carried out. The Im was calculated using Lunar reference values from the normal Hispanic population with the following formula: Im 5 Z value of Lmin 2 Z value from femoral neck, where Lmin is the Z value of the vertebrae with the lowest value. Three groups of patients were investigated: (1) 148 premenopausal women; (2) 233 postmenopausal women without hormone replacement therapy (HRT); and (3) 84 postmenopausal women with HRT from the first year of menopause. Significant differences were found between the average of Im in postmenopausal women (21.137) vs. premonopausal women (20.286) (p , 0.0001) and vs. postmenopausal women with HRT (20.213) (p , 0.0001). With the increase in the number of years since onset of menopause, Im of postmenopausal women has been shown to decrease linearly. Calculation of Im in other locations, such as the trochanter or the femoral neck, is not a good indicator of postmenopausal bone loss. Onset and degree of postmenopausal bone loss may be determined by the difference between Z of Lmin and the femoral neck during the first densitometric assessment. In healthy perimenopausal women, an Im of ,20.3 indicates onset of menopausal bone loss. The degree of bone loss caused by estrogen deficit in the past may be determined for each woman by comparing her index to the average Im of postmenopausal women up to 65 years of age. This new index provides a dynamic evaluation of BMD and is an aid in the differential diagnosis. It also represents an advancement in the treatment of osteoporosis and estrogen deficiency.

Assessment of mineral density and atomic content of fracture callus by quantitative computerized tomography

The mineral density and atomic numbers of elements in the periosteal callus and the cortex area of a healing fracture were measured by quantitative computerized tomography (QCT) to obtain accurate information on the mineralization process in rabbit tibia. The mineral density of the periosteal callus was highest on day 15 and decreased gradually throughout the experiment. This was initially detected by QCT, but not with conventional radiography. An apparent decrease in cortical bone density on days 28 and 42 after fracture was observed. Atomic numbers of elements in the cortex remained stable, indicating a possible homeostatic mechanism of mineral preservation at the fracture callus and involved cortical area. QCT may predict density alterations in the fracture callus more accurately than conventional X-ray. Further studies are essential to predict a relationship between mineral density, atomic numbers, and mechanical stability.

Spinal bone mineral density by quantitative CT in a normal Italian population

The purpose of this study was to describe the normal cross-sectional pattern of spinal bone loss associated with aging in an Italian population and to compare these values to the American normative database. A group of 472 healthy subjects (382 females and 90 males) were recruited for bone mineral density (BMD) assessment by quantitative computed tomography (QCT). To eliminate technique-related differences in a comparison of Italian and American normal values obtained with two different scanners we performed a cross-calibration analysis scanning the same computerized imaging reference system (CIRS) phantom at both centers. The results of the cross-calibration study using the CIRS phantom were used to compare regression slopes of BMD with age and age-adjusted mean BMD of American men and women vs cross-calibrated Italian men and women. American men and women decrease more rapidly vs Italian men and women, and Italian men have significantly lower age-adjusted mean BMD than American men. For these reasons we recommend normal values to be locally obtained for an Italian population.

Bone mineral density (BMD) assessment in pediatric patients with inflammatory bowel disease (IBD)

Bone mineral density (BMD) assessment in pediatric patients with inflammatory bowel disease (IBD)

Bone mineral density and bone histomorphometric assessments of postpregnancy osteoporosis: A report of five patients

Reports of five young women who developed vertebral fractures associated with pregnancy and lactation are presented (Fig. 1). Ages ranged from 24 to 37 (mean 30) years. All five patients have osteoporosis with two to nine vertebral fractures at presentation postpartum. Bone mineral density (BMD) was measured by single-photon absorptiometry, quantitative computer tomography, and dual-energy X-ray absorptiometry. BMD of the trabecular bone was less than normal values and it remained apparently low even several years after pregnancy. Histological findings of bone biopsy identified the bone loss with increasing bone resorption. Our present findings suggest that postpregnancy osteoporosis affects mainly the trabecular bone site, and the patients might have low peak bone mass and poor reversibility probably due to a low rate of remodeling.

Non-invasive quantitative estimation of bone density in rats throughout the life cycle and in arthritic osteopenia: preliminary results.

A longitudinal bone survey was conducted in 86 female Wistar rats in order to assess mineral density kinetics from young age (5 weeks: 115 g) till late adulthood (64 weeks: 586 g). In vivo quantitative radiographic scanning was performed on the caudal vertebrae, taking trabecular mass as the parameter. Measurements were expressed as Relative Optical Density (ROD) units by means of a high resolution densitometric device. Results showed a progressive increase in mineral density throughout the life cycle, with a tendency to level in the higher weight range, indicating that progressive mineral aposition occurs in rats in dependency of age. This phenomenon, however, should be always considered within the context of continuous skeletal growth and related changes typical of this species. Twelve different animals were also examined following induction of articular inflammation with Freund's adjuvant in six of them. Bone survey conducted 12 to 18 days after inoculation revealed a significant (P less than 0.01) reduction in trabecular bone mass of scanned vertebrae in comparison with the weight-matched untreated controls. It is concluded that the in vivo quantitative assessment of bone density illustrated in this report represents a sensitive and useful tool for the long-term survey of naturally occurring or experimentally induced bone changes. Scanning of the same part of the skeleton can be repeated, thereby avoiding sacrifice of the animal and time-consuming preparation of post-mortem material.