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PubMed1990

The relationship between densitometry of the radius and vertebral fractures.

In 105 postmenopausal women with clinical suspicion of osteoporosis single photon absorptiometry (SPA) of the forearm and fracture percentage of the thoracic and lumbar spine were estimated. SPA was performed on the commonly used mid-radius site as well as on a modified distal radius site where radius and ulna are separated by five mm. Spine fracture percentage was inversely correlated with mid-radius SPA (r = -0.49) but more closely with distal radius SPA (r = -0.61). With bone mineral density values above 0.400 g/cm2 on the distal radius, no fractures were found. Between 0.325 and 0.400 g/cm2, 35% of the patients showed vertebral fractures but only up to a maximum of 30%. Below 0.325 g/cm2, 89% of the women had crushed vertebrae, often more than 30% of those measured. In conclusion, these results indicate that modified distal radius densitometry is superior to the commonly used mid-radius measurement and has some predictive value for the presence of vertebral fractures.

Absorptiometry, Photon↗

PubMed1990

A porcelain gallbladder affecting the assessment of bone mineral content.

Dual-photon absorptiometry is a reliable method for the assessment of bone mineral content (BMC). The presence of focal bone disease, degenerative joint disease, or aortic calcifications may complicate the evaluation of BMC and may lead to erroneous findings. The misleading effect of a porcelain gallbladder is described.

Absorptiometry, Photon↗

PubMed1990

Importance of measurement of bone density in the management of osteoporosis.

Bone mass is the primary, although not the only, determinant of fracture. Over the past few years a number of noninvasive techniques have been developed to more sensitively quantitate bone mass. These include radiogrammetry (RG) and radiographic photodensitometry (RD), single and dual photon absorptiometry (SPA and DPA), quantitative computed tomography (QCT), and single and dual-energy X-ray absorptiometry (SEXA and DEXA). These techniques provide bone mass quantitation at the spine, wrist, hip and total body skeletal sites that are the principal areas usually involved in osteoporosis. The evaluation of the aetiology, progression, and treatment of osteoporosis has been clearly improved with the use of these methods. It is the intent of this review to discuss the pros and cons of these techniques, in particular their applications to the detection and management of osteoporosis.

Absorptiometry, Photon↗

PubMed1990

[Bone mineral density of the lumbar spine and proximal femur of normal females in Buenos Aires].

The bone mineral density (BMD) of the lumbar spine and proximal femur was determined in 170 and 131 respectively normal females from 20 to 79 years of age. The BMD was determined by dual photon absorptiometry with a Lunar DP3 equipment. The results per decade of age are shown on table 2. The percentage fall between the 3rd and 8th decades of age at different skeletal sites is summarized on table 3. Meanwhile the bone loss at the lumbar spine and mid-radius from a previous study was approximately 3% before the menopause, the BMD of proximal femur diminished approximately 14% over the neck and 19% at the Ward's triangle during the same period. From age 50 to 80 the average bone loss was similar at the spine and femoral neck (approximately 15%) but it was more severe at the Ward's triangle (approximately 24%). The results obtained in the Buenos Aires females were compared to the values observed in studies performed in United States and Australia using the same equipment. No differences were found among the three populations using the Bonferroni's analysis for multiple comparisons. The BMD appears to be similar in different caucasian populations when the same type of equipment is used, but the values cannot be compared with the results obtained with other equipment. A sustained diminution of the proximal femur BMD was observed from age 20 to 80, whereas over the spine a distinct difference before and after the menopause was found.

Absorptiometry, Photon↗

PubMed1990

[Bone mineral density in climacteric. Identification of patients with risk of developing osteoporosis].

The bone mineral density (BMD) of the lumbar spine was determined by dual photon absorptiometry in 98 normal females: 26 premenopausal between 40 and 48 years of age and 72 unselected women 1 to 20 years after the onset of menopause, all of them attending the Menopause Clinic of the Hospital. The results were as follows: Premenopause 1.20 +/- 0.09; Postmenopause: 1.8 years: 1.16 +/- 0.10; 5.3 years: 1.10 +/- 0.12; 9.0 years: 1.06 +/- 0.12; 15.1 years: 1.01 +/- 0.11 g/cm2. The total bone loss during the period of observation was 16%. The cross-sectional data appears to fit an exponential curve with approximate diminution of 2.0%/year at the onset and 1%/year 10 years after the menopause. The individual values obtained in 45 females between 1 and 10 years postmenopause are plotted in Figure 2. Two patients with BMD below 0.9 g/cm2 were specially studied. One of them had asymptomatic primary hyperparathyroidism and the other overt osteoporosis with a crush fracture of a dorsal vertebra. Following the average bone loss of the group and assuming that the BMD should not fall at age 65 below the theoretical threshold for spine fractures (0.98 g/cm2) a risk curve was designed: 58% of the women were above and 42% below. This percentage is similar to the number of females who suffer osteoporotic fractures at age 70. Considering the Quetelet index (weight in kg/height in m2) the females were divided in 3 groups: above 30, between 30 and 23 and below 23.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1990

Precision of regional bone mineral measurements obtained from total-body scans.

Newer bone densitometers using dual-photon absorptiometry (DPA) or dual energy x-ray absorptiometry (DEXA) are capable of measuring the total-body bone mineral; regional analysis of these scans would have significant utility if adequate precision were possible. This study investigated short term precision by weekly scanning (three to five times) normal subjects (total 48 scans) and long term precision by scanning a whole-body phantom 30 times over 15 mo. For the 30 phantom scans, a coefficient of variation (CV) of bone mineral content (BMC) and bone mineral density (BMD) was calculated for each region. Nonrandom changes were analyzed by plotting the phantom data with time and testing the slope of the fitted line for significance. Similarly for the subjects, a CV for each region and the mean value for all subjects was obtained. From this study we conclude (a) BMD is more precise than BMC, (b) long-term precision was poorer than short term, (c) long-term regional BMD precision (%) was: head, 3.2; arms, 2.8; legs, 1.6; ribs, 2.6; pelvis, 3.8; thoracic spine, 3.8; lumbar spine, 7.1; total spine, 2.4; trunk, 2.2; total body, 1.2.

Absorptiometry, Photon↗

PubMed1990

Bone mineral density in adult celiac patients and the effect of gluten-free diet from childhood.

Peripheral single photon absorptiometry was used to measure forearm bone mineral density in 22 celiacs on gluten-free diet from childhood (male 14, female 8, age 13-20) and 29 untreated adult celiacs at diagnosis (male 5, female 24, age 18-56, 14 with subclinical disease), compared with healthy sex- and age-matched controls. Bone mineral density was similar in patients treated from childhood and their controls [(668.4 +/- 65.3 vs. 654.9 +/- 69.6 mg/cm2, (mean +/- SD)], but significantly lower in untreated patients than in their controls (598.3 +/- 83.1 vs 673.2 +/- 42.7 mg/cm2, p less than 0.001). It was also significantly lower in the 12 younger untreated celiacs (18-28 yr) versus controls (619.4 +/- 68.5 vs 669.1 +/- 39.3 mg/cm2, p less than 0.01). In the untreated women, but not their controls, a negative correlation (p less than 0.05) was observed between bone mineral density and age. Bone mineral density did not correlate with severity of clinical or biochemical abnormalities. These results suggest that bone derangements are common in celiacs diagnosed in adulthood, even if they never presented evident malabsorption symptoms, and emphasize the importance of early diagnosis and treatment.

Absorptiometry, Photon↗

PubMed1990

Effects of age and sex on bone density at the hip and spine in a normal Caucasian New Zealand population.

We have studied a normal adult caucasian population (462 females, 264 males age range 20-84) using dual photon absorptiometry to establish patterns of bone reduction at the spine and hip. Subjects were either randomly selected from the electoral roll or volunteers. Bone mineral density reduction at the lumbar spine in females appeared to increase at 40 years and was sustained until 60 years. In males bone mineral density at the spine was preserved. The density at the hip in females decreased throughout adult life beginning before the menopause. In males bone density was preserved at the femoral neck and trochanteric region but not at Wards triangle where reduction occurred throughout life. When compared with other normal populations there was higher bone mineral density at the spine in postmenopausal New Zealand females but no significant difference at the hip.

Absorptiometry, Photon↗

PubMed1990

Bone mineral density after bicycle ergometry training.

The effect of functional electrical stimulation (FES) cycle ergometry on bone mineral density (BMD) was investigated in six spinal cord injury (SCI) quadriplegic men. Each subject trained three days a week for six months on an FES cycle ergometer. Pretraining and posttraining BMD measurements of the proximal femur were performed using dual photon absorptiometry. Mean pretraining BMD (percent norm) for the femoral neck, Ward triangle, and trochanter were 66.65, 57.43, and 57.67, respectively. After six months of FES cycle ergometry, mean BMD measurements were 66.15, 57.07, and 55.13, respectively. There was no statistically significant difference between the pretraining and posttraining BMD measurements. All subjects were found to have osteoporotic proximal femurs when BMD was expressed as a percent of their age-matched controls. Bone mineral density measurements were subsequently performed on three additional men with SCI who had exercised for three years with the FES cycle ergometry modality. Their mean BMDs were not significantly different from the experimental group. This study demonstrated that six months of FES cycle ergometry did not produce an increase in BMD.

Absorptiometry, Photon↗

PubMed1990

Regional bone mineral measurements.

Total body dual-photon transmission scanning was performed in 9 control persons, 15 athletes and in 5 patients with eating disorders. Total body bone mineral mass was measured, with a reproducibility of 2%; for regional bone mineral mass the reproducibility was 4%. The fraction of total bone mineral in the spines and heads of women is greater than in men. Patients with eating disorders have a smaller fraction of total body mineral in the pelvis than female controls. Weight lifters have a significantly greater mineral mass in the trunk region than other athletes and male controls. These and other differences are consistent with the conclusion that total body dual-photon absorptiometry allows quantitation of the distribution of mineral within the skeleton.

Absorptiometry, Photon↗

PubMed1990

Decreased bone density in adolescent girls with anorexia nervosa.

Osteoporosis develops in women with chronic anorexia nervosa. To determine whether bone mass is reduced in younger patients as well, bone density was studied in a group of adolescent patients with anorexia nervosa. With single- and dual-photon absorptiometry, a comparison was made of bone mineral density of midradius, lumbar spine, and whole body in 18 girls (12 to 20 years of age) with anorexia nervosa and 25 healthy control subjects of comparable age. Patients had significantly lower lumbar vertebral bone density than did control subjects (0.830 +/- 0.140 vs 1.054 +/- 0.139 g/cm2) and significantly lower whole body bone mass (0.700 +/- 0.130 vs 0.955 +/- 0.130 g/cm2). Midradius bone density was not significantly reduced. Of 18 patients, 12 had bone density greater than 2 standard deviations less than normal values for age. The diagnosis of anorexia nervosa had been made less than 1 year earlier for half of these girls. Body mass index correlated significantly with bone mass in girls who were not anorexic (P less than .05, .005, and .0001 for lumbar, radius, and whole body, respectively). Bone mineral correlated significantly with body mass index in patients with anorexia nervosa as well. In addition, age at onset and duration of anorexia nervosa, but not calcium intake, activity level, or duration of amenorrhea correlated significantly with bone mineral density. It was concluded that important deficits of bone mass occur as a frequent and often early complication of anorexia nervosa in adolescence. Whole body is considerably more sensitive than midradius bone density as a measure of cortical bone loss in this illness.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMedDate not supplied

Bone mass measurement, fracture risk, and screening for osteoporosis.

There is a positive relationship between bone mass and resistance to breaking. Measurements of the spine made by quantitative computed tomography (QCT) and dual photon absorptiometry (DPA) appear to allow a determination of the risk of vertebral compression fracture, although some important confirmatory studies remain to be done. Measurements made in the extremities generally do not allow prediction of vertebral fracture risk. Prediction of hip fracture risk is difficult because of the complex geometry of the femur. The few data which are available suggest that DPA may be useful to predict the risk of femoral neck fracture. If these data can be confirmed, cost-benefit analysis indicates that mass screening for osteoporosis may be a viable strategy. Physicians and patients using bone mass measurement techniques should be aware that these tests can be misleading, and that scrupulous attention to detail is required. Close supervision of the tests by a physician is necessary to ensure that meaningful data are obtained.

Absorptiometry, Photon↗

PubMed1989

Structural and compositional changes in aging bone: osteopenia in lumbar vertebrae of Wistar female rats.

Changes in vertebral bone mineral content and density during aging were quantified in female Wistar rats. This study represents a longitudinal follow up utilizing single photon absorptiometry for the measurement of bone mineral content (BMC), quantitative computed tomography (QCT) for the measurement of bone mineral density (BMD), and image analysis histomorphometry for the measurement of trabecular bone volume (TBV) and bone cortical area (BCA). The above measurements were accompanied by biochemical assays of calcium concentrations in the respective bones. All aging animals experienced significant decreases in BMC, BMD, TBV, BCA and in the calcium content of their bones. The above features have been further emphasized through the use of scanning electron micrographs showing the age-related structural changes in a three-dimensional fashion. New, advanced technologies will enable the quantitation of 3-dimensional images that are currently obtained from the scanning electron micrograph; thus will provide new consideration as related to trabecular bone compactness (density). Energy dispersive x-ray spectroscopy indicated that the nature of crystals in aging bones does not differ markedly from that encountered in young specimens. Data are also provided with regard to the health of the animals, and it became apparent that aging rats undergo changes in their kidneys yet do not show any significant change in renal functional parameters as measured in both the serum and the urine. Hence, new noninvasive methodologies are currently available for longitudinal studies related to the skeleton in laboratory animals enabling reliable monitoring of age-related and hormonally induced changes in bones (spine and hip) of well defined experimental models.

Absorptiometry, Photon↗

PubMed1988

Quantitative computed tomography at peripheral measuring sites.

Three most frequently used noninvasive procedures for bone quantitations are dual photon absorptiometry [DPA, DPX] and quantitative computed tomography [QCT]. The peripheral QCT allows trabecular and cortical bone to quantitated separately, radiation dose is very low and precision very high.

Absorptiometry, Photon↗

PubMed1988

Values of noninvasive techniques in predicting bone histology.

These studies investigate the predictive value of the newer, noninvasive techniques (i.e. CT scans, measurement of bone mineral density by photon absorptiometry, and recent serum biochemical tests such as bone Gla-protein and specific bone alkaline phosphatase) by comparing these results to those of histomorphometry after bone biopsy. Results reveal interesting correlations and lack of correlations between bone parameters and biochemical measurements and indicate that bone biopsies along with newer noninvasive techniques represent the optimal approach to patients with metabolic bone diseases.

Absorptiometry, Photon↗

PubMed1988

[Osteoporotic changes in rheumatoid arthritis--longitudinal bone mass study and effect of 1 alpha-hydroxyvitamin D3].

Serial measurements of bone mass were carried out by single photon absorptiometry and/or X-ray microdensitometry of the second metacarpus in 29 rheumatoid arthritis patients not treated by corticosteroids. The effect of 1 alpha-hydroxyvitamin D3 on rheumatoid arthritis was also investigated by longitudinal bone mass study. In premenopausal females and also males, the rate of radial diaphyseal bone loss was less than 1%/year and bone loss was seen only in the periarticular region of affected joints. On the other hand, bone loss was much more rapid in both the periarticular and diaphyseal regions in postmenopausal patients. 1 alpha-hydroxyvitamin D3 administration for more than 1 year produced no significant change of blood biochemical examination and Lansbury's index, but resulted in a significant attenuation of bone loss rate.

Absorptiometry, Photon↗

PubMed1978

Radiological determination of changes in bone mineral content.

It is possible to obtain reliable data of changes in bone mineral content using simple radiographic techniques. Methods available include morphometry and densitometry. Of these morphometry of the third metacarpal is most accurate in our hands and cortical width is the most reliable of such morphometric data. Densitometry produces more variable results and shows no advantage over straight measurement of cortical width. The only acceptable alternative method of obtaining information about bone status is photon absorptiometry. Results of these methods are shown in a trial of oestrogen therapy for the prevention of post-menopausal osteoporosis. The data suggest that oestrogens prevent post menopausal bone loss when this is estimated by measurement of cortical width or photonabsorptiometry.

Absorptiometry, Photon↗

PubMed1983

Role of exercise in prevention of involutional bone loss.

Physical inactivity has been cited as a possible cause of osteoporosis. Because involutional bone loss in the female can begin as early as age 40, the purpose of this investigation was to compare the skeletal status of two groups of premenopausal middle-aged (30-49 yr) women of diverse physical activity levels. Bone mineralization was determined by x-ray densitometry (middle phalanx of fifth finger and os calcis) and photon absorptiometry (distal and midshaft radius) in 42 marathon runners and 38 sedentary females. Mean values for bone mineral content (BMC) and bone density were greater in the marathon runners at the midshaft radius (P less than 0.05) and at the middle phalanx of the fifth digit (P less than 0.001). Mean density of the os calcis was higher in the physically inactive women (P less than 0.001). Following normalization of the data for differences in age and body size, regression analysis suggests that the runners maintain their bone mass longer at the distal radius, a site frequently fractured in women after midlife.

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