No abstract available.
Densitometry*

The image quality management of bone mineral density (BMD) is the responsibility and duty of radio-technologists who carry out examinations. However, inaccurate conclusions due to the lack of understanding and ignorance regarding the methodology of image quality management can be a fatal error to patients. The accuracy and precision of BMD measurement must be maintained at the highest level so that actual biological changes can be detected with even slight changes in BMD. Accuracy and precision should be continuously preserved for image quality of machines. Those factors will contribute to ensure the reliability of BMD examination. The enforcement of proper quality control of radiologists performing BMD inspections which brings about the durability extensions of equipment and accurate results of calculations will help the assurance of reliable inspections.
Absorptiometry, Photon ; Bone Density ; Densitometry ; Humans ; Quality Control*

BACKGROUND: Although dual energy X-ray absorptiometry (DXA) is known to standard equipment for bone mineral density (BMD) measurements. Different results of BMD measurement using a number of different types of devices are difficult to use clinical practice. The purpose of this study was to evaluate discrepancy and standardizations of DXA devices from three manufactures using a European Spine Phantom (ESP). METHODS: We calculated the accuracy and precision of 36 DXA devices from three manufacturers (10 Hologic, 16 Lunar, and 10 Osteosys) using a ESP (semi-anthropomorphic). The ESP was measured 5 times on each equipment without repositioning. Accuracy was assessed by comparing BMD (g/cm2) values measured on each device with the actual value of the phantom. Precision was assessed by the coefficient of variation (CVsd). RESULTS: Lunar devices were, on average, 22%, 8.3%, and 5% overestimation for low (L1) BMD values, medium (L2), and high (L3) BMD values. Hologic devices were, on average, 6% overestimation for L1 BMD, and 5% and 6.2% underestimation for L2 and L3 BMD values. Osteosys devices was, on average, 12.7% (0.063 g/cm2), 6.3% (0.062 g/cm2), and 5% (0.075 g/cm2) underestimation for L1, L2, and L3, respectively. The mean CVsd for L1-L3 BMD were 0.01%, 0.78%, and 2.46% for Lunar, Hologic, and Osteosys devices respectively. CONCLUSIONS: The BMD comparison in this study demonstrates that BMD result of three different devices are significant different between three devices. Differences of BMD between three devices are necessary to BMD standardization.
Absorptiometry, Photon ; Bone Density ; Densitometry* ; Lumbar Vertebrae ; Spine*

OBJECTIVES: As clinics that treat patients with osteoporosis do not usually have central dual-energy X-ray absorptiometry (DXA), bone density is often measured with radial DXA. However, no long-term evidence exists for radius bone density outcomes following treatment with once-weekly teriparatide in actual medical treatment. METHODS: We evaluated changes in bone density at 6-, 12-, and 18-month intervals using radial DXA in patients treated with once-weekly teriparatide for more than 6 months. RESULTS: A significant increase in bone mineral density (BMD) was observed at the 1/3 and 1/10 radius sites 12 months after the initiation of once-weekly teriparatide. We also observed that the rate of change in BMD was greater at the distal 1/10 radius than at the 1/3 radius. CONCLUSIONS: Considering these points, the effect of once-weekly teriparatide therapy can be observed at the radius. In clinics that do not have central DXA, but instead have radial DXA, these findings can help to evaluate the effect of once-weekly teriparatide treatment on osteoporosis.
Absorptiometry, Photon ; Bone Density ; Densitometry ; Humans ; Osteoporosis ; Radius ; Teriparatide

OBJECTIVES: Bone densitometry is a current method for evaluating skeletal status, assessing osteoporosis, and determining fracture risk. DEXA has rapidly become a dominent method for evaluating skeletal status. But the comparison of patient data among different DEXA scanners is complicated because the instruments show differences in scanner design, bone mineral calibration, and analysis algorithms. The purpose of this study is making standardization of DEXA and comparability among different DEXA system. METHODS: Posteroanterior lumbar spine (L2-IA) measurements of healthy 83 racially homogenous Korean women, age 38-66 years (mean +/- 516, range of BMD 0.624-1.574g/cm) were obtained on a Lunar DPX-L, a Hologic QDR-2000, and a Norland XR-36. All sujects had no spinal deformities, ostophytes, fracture and scoliosis on thoracolumbar spinal X-ray. We performed the measurement of BMD in each subjects with different three scanners at the same time. RESULTS: The results of cross-calibration spinal BMD (L2-4, g/cm2) in patient study (r2=0.972-0.974); Lunar DPX-L=(1.149 X Hologic)+0.008=(1.022 X Norland)+0.137, Hologic QDR-2000=(0.847 X Lunar)+0.019= (0.876 X Norland)+0.124, and Norland XR-36=(0.954 X Lunar)-0.107=1.110 X Hologic)-0.113. The average absolute difference in patients` spinal BMD values (L2-L4) between Lunar and Hologic was 0.146g/cm2 (14%); it was 0.156g/cm2 (15%) between Lunar and Norland and 0.010g/cm2 (1%) between Hologic and Norland. CONCLUSIONS: The formula of this cross-calibration shows good correlation. We conclude that it is possible to compare the different spinal BMD values obtained on the different DEXA scanners.
Absorptiometry, Photon* ; Bone Density ; Calibration ; Congenital Abnormalities ; Densitometry ; Female ; Humans ; Osteoporosis ; Scoliosis ; Spine

Compared with the earlier technique of dual photon absorptiometry (DPA) using 153Gd radionuclide source, dual energy X-ray absorptiometry (DXA) has advantages of higher precision, accuracy and shorter scanning time. Despite the change from DPA to DPX, the nuclear medicine physicians has remained one of major suplier of this service due to long-standing use of DPA. Among many kinds of bone densitometries, DXA is the "gold standard" for the noninvasive diagnosis of osteoporosis. Especially there is no role for peripheral devices in the monitoring of patients on therapy. But, there are some areas of controversy related to the application of DXA, such as proper site of measurement, accurate interpretation, appropriate use of T-score, and the reference population young database. And the accuracy, precision, and quality control issues relating to bone density measurement are important subjects. To address these issues, the International Society for Clinical Densitometry (ISCD) has convened two Position Development Conferences and addressed official positions. This review deals the key elements of ISCD position paper and other important issues on the management of bone densitometry.
Absorptiometry, Photon ; Bone Density* ; Congresses as Topic ; Densitometry ; Diagnosis ; Humans ; Nuclear Medicine ; Osteoporosis ; Quality Control

The bone scan in patients with prostate cancer remains to be the most sensitive method to assess the bone metastasis. But it is nonspecific and shows similar finding in either benign or malignant disease. Bone mineral densitometry allows for the quantification of total body bone mass. So we evaluated the efficacy of the measurement of the bone mineral density with dual-energy X-ray absorptiometry in patients with prostate cancer who had showed hot spot on the bone scan. Of the 15 patients 7 cases( 47% ) showed increased bone mineral density. To evaluate the efficacy of bone mineral densitometry, we analyze the 11 patients whose bone scan show hot spot on lumbar spine. Among them 2 cases( 18%) show osteoblastic finding on the bone x-ray, but 5 cases(45%) show increased density and 2 cases show decreased density on the bone mineral densitometry. These results show that the bone mineral densitometry is more valuable than bone x-ray in the detection of abnormal bone density. Therefore we suggest that bone mineral densitometry can be used as a helpful method of bone scan to detect the metastatic bone lesion in the advanced prostatic cancer.
Absorptiometry, Photon ; Bone Density ; Densitometry* ; Humans ; Neoplasm Metastasis ; Osteoblasts ; Prostatic Neoplasms* ; Spine

Significant improvements in dual-energy X-ray absorptiometry (DXA) concerning quality, image resolution and image acquisition time have allowed the development of various functions. DXA can evaluate bone quality by indirect analysis of micro- and macro-architecture of the bone, which and improve the prediction of fracture risk. DXA can also detect existing fractures, such as vertebral fractures or atypical femur fractures, without additional radiologic imaging and radiation exposure. Moreover, it can assess the metabolic status by the measurement of body composition parameters like muscle mass and visceral fat. Although more studies are required to validate and clinically use these parameters, it is clear that DXA is not just for bone mineral densitometry.
Absorptiometry, Photon* ; Body Composition ; Bone Density* ; Densitometry ; Femur ; Intra-Abdominal Fat ; Sarcopenia

Osteoporosis is defined as a skeletal disorder characterized by compromised bone strength, predisposing an individual to increased fracture risk. Many factors can lead to the development of osteoporosis. It is usually asymptomatic unless osteoporotic fracture and secondary changes of bone structure occur. Early radiographs show normal findings; however, osteopenic appearance, fracture, cortical bone thinning, and roughening of bone trabeculae can be found according to severity of osteoporosis. These symptoms are most frequently found in the spine and proximal femur. Bone mineral density (BMD) is the standard method used to diagnose osteoporosis, and dual energy X-ray absorptiometry (DXA), one of the measurement tools for BMD, is particularly regarded as the appropriate tool applicable to WHO criteria, which defines osteoporosis as a T-score of less than 2.5 SDs below the mean of young adult women. Peripheral densitometry is less useful in predicting the risk of fractures of the spine and proximal femur, and it is not enough to diagnose and treat osteoporosis. Biochemical bone markers have demonstrated utility in clinical research and trials; however, they cannot replace BMD as a diagnostic tool. WHO recently developed FRAX, a novel method we can use to more conveniently evaluate osteoporotic fracture risk.
Absorptiometry, Photon ; Bone Density ; Densitometry ; Female ; Femur ; Humans ; Osteoporosis ; Osteoporotic Fractures ; Spine ; Young Adult

Rheumatoid arthritis is considered to be a collagen disease which mainly involves articular structures, sometimes has extraarticular manifestations. It is generally accepted now that periarticular osteoporosis develops in early phase of rheumatoid arthritis and generalized osteoporosis in late period. Of several methods of non-invasive measurement of bone mass, single photon absorptiometry was introduced by Cameron and Sorenson(1963) and it has been used for measuring bone mass by many authors with its precision, reproducibility and objective quantification. We tried to observe the quantitative changes of bone mass in rheumatoid arthritis patients with single photon absorptiometry technique. Through the study of bone densitometry in 30 rheumatoid arthritic women compared with age-matched 60 healthy controls, we obtained follow results. 1. Bone mineral density of the rheumatoid arthritis group was lower than that of the control group, but had no significant statistical difference. 2. Bone mineral density of the 40–49-year-old group and 50–59-year-old group was considerablely different in the rheumatoid arthritis group and control group. 3. Bone mineral density of the group whose rheumatoid arthritis history was over 2 year was lower than that of the group below 2 year.
Absorptiometry, Photon ; Arthritis, Rheumatoid ; Bone Density ; Collagen Diseases ; Densitometry ; Female ; Humans ; Osteoporosis