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Journal ArticleDOI

Measurement of Bone Mineral in vivo: An Improved Method

11 Oct 1963-Science (American Association for the Advancement of Science)-Vol. 142, Iss: 3589, pp 230-232
TL;DR: The mineral content of bone can be determined by measuring the absorption by bone of a monochromatic, low-energy photon beam which originates in a radioactive source and is measured by counting with a scintillation detector.
Abstract: The mineral content of bone can be determined by measuring the absorption by bone of a monochromatic, low-energy photon beam which originates in a radioactive source (iodine-125 at 27.3 kev or americium 241 at 59.6 kev). The intensity of the beam transmitted by the bone is measured by counting with a scintillation detector. Since the photon source and detector are well collimated, errors resulting from scattered radiation are reduced. From measurements of the intensity of the transmitted beam, made at intervals across the bone, the total mineral content of the bone can be determined. The results are accurate and reproducible to within about 3 percent.
Citations
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Journal ArticleDOI
TL;DR: Bone mineral density was measured in vivo at the lumbar spine (predominantly trabecular bone) by dual photon absorptiometry and at the midradius (greater than 95% cortical bone) and distal radius (75% cortical and 25% trabECular bone), by single photon absorptioniometry as mentioned in this paper.
Abstract: Patterns of bone loss in the axial and the appendicular skeleton were studied in 185 normal volunteers (105 women and 82 men; age range, 20--89 yr) and in 76 women and 9 men with vertebral fractures due to osteoporosis. Bone mineral density was measured in vivo at the lumbar spine (predominantly trabecular bone) by dual photon absorptiometry and at the midradius (greater than 95% cortical bone) and distal radius (75% cortical and 25% trabecular bone) by single photon absorptiometry. In normal women, bone diminution from the vertebrae began in young adulthood and was linear. In the appendicular skeleton, bone diminution did not occur until age 50 yr, was accelerated from aged 51 to 65 yr, and then decelerated somewhat after age 65 yr. Overall bone diminution throughout life was 47% for the vertebrae, 30% for the midradius, and 39% for the distal radius. In normal men, vertebral and appendicular bone diminution with aging was minimal or insignificant. Mean bone mineral density was lower in patients with osteoporosis than in age- and sex-matched normal subjects at all three scanning sites, although spinal measurements discriminated best; however, there was considerable overlap. By age 65 yr, half of the normal women (and by age 85 yr, virtually all of them) had vertebral bone mineral density values below the 90th percentile of women with vertebral fractures and, thus, might be considered to have asymptomatic osteoporosis. For men, the degree of overlap was less. The data suggest that disproportionate loss of trabecular bone from the axial skeleton is a distinguishing characteristic of spinal osteoporosis.

1,167 citations


Cites methods from "Measurement of Bone Mineral in vivo..."

  • ...Measurements of bone density were also made at the midradius and at the distal radius with use of the single photon absorptiometric technique, as described by Cameron and Sorenson (11)....

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  • ...BMDof the midradius (>90% cortical bone) and the distal radius (75% cortical and 25% trabecular bone) was measured by single photon absorptiometry (7, 11)....

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Journal ArticleDOI
TL;DR: New analysis methods to reduce the confounding effect of bone size are described, and a parameter, bone mineral apparent density (BMAD, g/cm3), is introduced that better reflects bone apparent density.
Abstract: Bone densitometry using dual-photon absorptiometry (DPA) or dual-energy x-ray absorptiometry (DXA) has become a standard method for assessing bone mineral content in the spine and other skeletal regions. A projected areal density, referred to as bone mineral density (BMD,g/cm2), is normally calculated to assess regional bone density and strength. We demonstrate that this measure can be misleading when used to compare bones of different sizes due to inherent biases caused by bone thickness differences. For example, assuming that volumetric bone density remains constant and bony linear dimensions are proportional to height, a 20% increase in height would result in a 20% increase in both the thickness and the BMD of any bone. We describe new analysis methods to reduce the confounding effect of bone size, and we introduce a parameter, bone mineral apparent density (BMAD, g/cm3), that better reflects bone apparent density. Using this parameter, we calculate a quantity that serves as an index of bone strength (IBS, g2/cm4) for whole vertebral bodies. These analyses were applied to lumbar spine (L2-4) DXA measurements in a population of women 17-40 years old and appear to offer advantages to conventional techniques.

1,020 citations

Journal ArticleDOI
04 Nov 1992-JAMA
TL;DR: Gain in bone mass occurs in healthy young women during the third decade of life and physical activity and dietary calcium intake both exert a positive effect on this bone gain, and use of oral contraceptives exerts a further independent positive effect.
Abstract: Objective. —To test whether bone mass increases in healthy nonpregnant white women during early adult life after cessation of linear growth; and to test whether various self-chosen levels of physical activity and nutrient intake or use of oral contraceptives influences this increase in bone mass. Design. —Longitudinal prospective study of up to 5 years of 156 healthy college-aged women full-time students attending professional schools in universities in the Omaha, Neb, area. Setting. —University medical center. Participants. —A convenience sample of healthy women students from Omahaarea professional schools. Any candidate with an illness, condition, or medication (except oral contraceptives) thought to affect general health or bone mass was excluded. Interventions. —None. Outcome Measures. —Clinical and family histories of disease, particularly osteoporosis; oral contraceptive use; bone mineral densities of the spine, forearm, and total body by dual- and single-photon absorptiometry; estimates of nutrient intake by repeated 7-day diet diaries; and measures of physical activity using a physical activity monitor. Results. —The median gain in bone mass for the third decade of life, expressed as a percentage per decade, was 4.8% for the forearm, 5.9% for lumbar bone mineral content, 6.8% for lumbar bone mineral density, and 12.5% for total body bone mass (P Conclusions. —Gain in bone mass occurs in healthy young women during the third decade of life. Physical activity and dietary calcium intake both exert a positive effect on this bone gain. Use of oral contraceptives exerts a further independent positive effect. Changes in life-style among college-aged women, involving relatively modest increases in physical activity and calcium intake, may significantly reduce the risk of osteoporosis late in life. (JAMA. 1992;268:2403-2408)

781 citations

Journal ArticleDOI
TL;DR: It is concluded that testosterone therapy given to adult men with acquired hypogonadism decreases sc fat and increases lean muscle mass and testosterone therapy reduces bone remodeling and increases trabecular bone density.
Abstract: Acquired hypogonadism is being increasingly recognized in adult men. However, the effects of long term testosterone replacement on bone density and body composition are largely unknown. We investigated 36 adult men with acquired hypogonadism (age, 22-69 yr; median, 58 yr), including 29 men with central hypogonadism and 7 men with primary hypogonadism, and 44 age-matched eugonadal controls. Baseline evaluation included body composition analysis by bioimpedance, determination of site-specific adipose area by dual energy quantitative computed tomography scan (QCT) of the lumbar spine, and measurements of spinal bone mineral density (BMD) using dual energy x-ray absortiometry, spinal trabecular BMD with QCT, and radial BMD with single photon absorptiometry. Percent body fat was significantly greater in the hypogonadal men compared to eugonadal men (mean +/- SEM, 26.4 +/- 1.1% vs. 19.2 +/- 0.8%; P < 0.01). The mean trabecular BMD determined by QCT for the hypogonadal men was 115 +/- 6 mg K2HPO4/cc. Spinal BMD was significantly lower than that in eugonadal controls (1.006 +/- 0.024 vs. 1.109 +/- 0.028 g/cm2; P = 0.02, respectively). Radial BMD was similar in both groups. Testosterone enanthate therapy was initiated in 29 hypogonadal men at a dose of 100 mg/week, and the subjects were evaluated at 6-month intervals for 18 months. During testosterone therapy, the percent body fat decreased 14 +/- 4% (P < 0.001). There was a 13 +/- 4% decrease in subcutaneous fat (P < 0.01) and a 7 +/- 2% increase in lean muscle mass (P = 0.01) during testosterone therapy. Spinal BMD and trabecular BMD increased by 5 +/- 1% (P < 0.001) and 14 +/- 3% (P < 0.001), respectively. Radial BMD did not change. Serum bone-specific alkaline phosphatase and urinary deoxypyridinoline excretion, markers of bone formation and resorption, respectively, decreased significantly over the 18 months (P = 0.003 and P = 0.04, respectively). We conclude that testosterone therapy given to adult men with acquired hypogonadism decreases sc fat and increases lean muscle mass. In addition, testosterone therapy reduces bone remodeling and increases trabecular bone density. The beneficial effects of androgen administration on body composition and bone density may provide additional indications for testosterone therapy in hypogonadal men.

767 citations

References
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Journal ArticleDOI
TL;DR: In this article, an empirical method of calculating mass absorption coefficients is given for all elements and for wave lengths less than the K critical absorption wave length, and partial tables give constants for wave length between the L 1 and M 1 critical wave lengths.
Abstract: An empirical method of calculating mass absorption coefficients is given. Complete tables of constants are presented for calculating μ/ρ for all elements and for wave‐lengths less than the K critical absorption wave‐length. Partial tables give constants for wave‐lengths between the L1 and M1 critical wave‐lengths.Calculated mass absorption coefficients are given for the common elements.

156 citations

Journal ArticleDOI
05 Oct 1962-Science
TL;DR: The theory underlying the method is presented with data comparing values obtained by different methods, and standard techniques between laboratories and confusion in terminology are highlighted.
Abstract: Measurements in vivo are complicated by physical and physiological problems. Lack of standard techniques between laboratories and confusion in terminology have prompted this report. The theory underlying the method is presented with data comparing values obtained by different methods.

17 citations

Journal ArticleDOI
TL;DR: Since the scintillation counter technique eliminates the filing as a source of error and can reduce scattering error by means of a collimated beam, it is possible that this technique may be made more accurate than the filing technique.
Abstract: The use of a scintillation counter as an x-ray detector for bone density measurement was investigated experimentally. It was shown that the accuracy of bone density measurement attainable with the scintillation counter technique is as good as that attainable with the older x-ray film technique. Since the scintillation counter technique eliminates the filing as a source of error and can reduce scattering error by means of a collimated beam, it is possible that this technique may be made more accurate than the filing technique. X-ray film, on the other hand, has the advantage of providing a more permanent record of the bone and clearly shows the points on the bone where the trace path is located.

8 citations