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PubMed1991

[Mean value of bone mineral content in Hungary measured by dual-photon absorptiometry].

Bone mineral content and density of the lumbar spine and femoral neck was measured by dual energy X-ray absorptiometry in normal volunteers (89 women, 77 men) in different age groups. Peak values in both sexes occurred in the 3rd decade and are about 25% higher in men than those in women. In women the bone loss begins around 40 years at lumbar spine and also at the femoral neck. The rate of bone loss in the 6th decade--according to the menopause--significantly accelerates. The diminution in the 8th decade is higher again. In men the decrease of the lumbar spine density is also significant in connection with the ageing process, but the rate of the bone loss is slower, than in women. The femoral neck density and mineral content values begin to decrease at the 4th decade. The decrease of bone mineral content and density of femoral neck are equivalent in both sexes but some difference exists in the velocity. The data were compared with West-european values. The values of the femoral neck are lower, while those of the lumbar spine in the 5th decade in the female are higher in the Hungarian population. The reason of this difference may be the consequence of the obesity of the Hungarian female population.

Absorptiometry, Photon↗
PubMedDate not supplied

[Dual-photon absorptiometry of the calcaneum in osteoporosis. Preliminary results].

Anteroposterior views of the lumbar spine are commonly used for the measurement of bone mineral density (BMD) by diphoton absorptiometry (DPA). Values in lumbar vertebral BMD can be increased by the existence of a compression fracture, osteoarthrosis, scoliosis or aortic calcifications. Evaluation of bone loss at a peripheral site, such as the calcaneum (essentially trabecular site), could compensate for the principal causes of error associated with vertebral measurement. Calcaneal BMD in 195 control women was used to establish reference values closely correlated with lumbar BMD (p less than 0.001). The same study was undertaken in osteoporotic women. Preliminary results based upon 38 cases are reported here. Measurement of BMD of the calcaneum was correlated with vertebral trabecular bone density measured by double energy CT scan, indicating that this peripheral site offers a good reflection of what is happening at vertebral trabecular level. In contrast, calcaneal BMD was not correlated with spinal BMD, except if patients with osteoarthrosis and/or scoliosis were eliminated. Measurement of the BMD of the calcaneum by DPA is thus a simple, rapid and reproducible method for evaluation of a trabecular bone site which could be complementary to the measurement of lumbar BMD when the latter is falsified by artefacts.

Absorptiometry, Photon↗
PubMed1990

[Dual photon absorptiometry].

BMC and BMD of the total body bone and lumbar spine were measured in normal control and patients with metabolic bone diseases by DPA (Dichromatic Bone Densitometer Model 2600, Norland corporation). Also, total body fat mass was measured in patients with obesity. We discussed basic technical problems and showed some data to assess patients with metabolic diseases known to affect the skeleton such as primary and secondary hyperparathyroidism. DPA is useful technique to assess patients with metabolic bone diseases and to monitor the efficacy of treatments.

Absorptiometry, Photon↗
PubMed1990

[Postmenopausal osteoporosis: early detection of subjects at risk using spinal dual photon absorptiometry].

With quantification techniques of the spinal bone condition, especially with spinal biphotonic absorptiometry, early screening of patients risking subsequent development of osteoporosis complicated with vertebral compression is possible. An investigation was conducted in Lower Normandy, in 386 women who had undergone menopause or an ovariectomy, with ages ranging between 40 and 56 years; 274 were in a peri-menopausal state. We had previously established a curve of the bone mineral content according to age. From this curve, in semilogarhythmic representation, we assessed each patient's risk. This risk is considered as high in 30 p. cent of the patients, non existent in 52 p. cent and 18 p. cent are borderline. The percentage of high risk patients increases with the number of years since menopause. It is hoped that the incidence of osteoporosis will decrease with early screening and preventive therapeutic measures.

Absorptiometry, Photon↗
PubMed1990

[Double photon absorptiometry in renal osteodystrophy].

Bone mineral content (BMC) of the lumbar spine (L2-L4), femoral neck, Ward's triangle and the trochanteric region was measured in 52 consecutive patients on maintenance haemodialysis. In the whole group the median BMC value as percentage of sex- and age-matched normal means was significantly decreased only in Ward's triangle (91.7%; p less than 0.02). In patients with chronic interstitial nephritis there was a significant decrease in bone density in Ward's triangle and the trochanteric region (p less than 0.02). There was no correlation between BMC and time on dialysis or intact parathormone. BMC value did not predict the type of renal osteodystrophy, according to Delling. 17 patients underwent a second investigation after one year. There was a slight fall in mean BMC of the lumbar spine (-0.9%) and Ward's triangle (-1.1%). The fall in mean BMC of the trochanteric region was pronounced (-3.2%). We believe that the observed low demineralisation, which was more pronounced in patients with interstitial nephritis, may be attributable to early and carefully monitored therapy with vitamin D metabolites.

Absorptiometry, Photon↗
PubMed1989

[Linear bone densitometry by monochromatic photon absorptiometry. A study of a normal population in Apulia].

An epidemiological survey was conducted on a group of Apulian residents in order to compare the densitometric data obtained with those produced by other European and North American authors. The results confirm the need for personal data on our own population given the often significant differences in order to avoid errors in monitoring patients who may require even long-term treatment.

Absorptiometry, Photon↗
PubMed1988

Measurement of bone by dual-photon absorptiometry (DPA) and dual-energy X-ray absorptiometry (DEXA).

Bone densitometry is essential for (a) confirming a diagnosis of osteoporosis, (b) determining the degree of osteopenia and risk of fracture, and (c) monitoring the response of bone to therapeutic agents. Fracture risk at specific axial fracture sites (spine, proximal femur), is associated directly with bone mineral density (BMD) at these sites. ROC analysis demonstrates that the diagnostic sensitivity of spine and femur BMD for spine and/or femur fracture is substantially superior to BMD of appendicular sites in the immediate postmenopausal period. Femoral neck BMD affords high diagnostic sensitivity for proximal femur fracture even in the elderly. Recent prospective studies have shown that bone densitometry can predict future fractures in postmenopausal women. Conventional DPA with 153Gd provides high accuracy for total body, spine, and femur BMD with adequate clinical precision of 1%, 2% and 3%, respectively. Dual-energy x-ray absorptiometry (DEXA), using either switched kVp or by k-edge filtering, offers better precision; typically the precision error is halved. The higher flux available from x-ray sources provides other advantages over DPA, including: improved spatial resolution (2 vs 4 mm), reduced radiation exposure (1 vs 2 mrem), and decreased scan times (3 to 10X). Improved DPA systems, with automatic gain stabilization to minimize drift, could offer clinical precision comparable to DEXA but the scan time and spatial resolution remain as before. Both DPA and DEXA allow detection of therapeutic efficacy in individual patients over the first year or two of therapy.

Absorptiometry, Photon↗