• Nuclear Engineering and Technology
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• v.52 no.10
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• pp.2346-2352
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• 2020

Dual-energy x-ray absorptiometry (DXA) is the noninvasive method to diagnose osteoporosis disease characterized by low bone mass and deterioration of bone tissue. Many global companies and research groups have developed the various DXA detectors using a direct photon-counting detector such as a cadmium zinc telluride (CZT) sensor. However, this approach using CZT sensor has some drawback such as the limitation of scalability by high cost and the loss of efficiency due to the requirement of a thin detector. In this study, a SiPM based DXA system was developed and its performance evaluated experimentally. The DXA detector was composed of a SiPM sensor coupled with a single LYSO scintillation crystal (3 × 3 × 2 ㎣). The prototype DXA detector was mounted on the dedicated front-end circuit consisting of a voltage-sensitive preamplifier, pulse shaping amplifier and constant fraction discriminator (CFD) circuit. The SiPM based DXA detector showed the 34% (at 59 keV) energy resolution with good BMD accuracy. The proposed SiPM based DXA detector showed the performance comparable to the conventional DXA detector based on CZT.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.286-293
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• 2010

Peak bone mass is established predominately during childhood and adolescence. It is an important determinant of future resistance to osteoporosis and fractures to gain bone mass during growth. The issue of low bone density in children and adolescents has recently attracted much attention and the use of pediatric dual-energy X-ray absorptiometry (DXA) is increasing. The process of interpretation of pediatric DXA results is different from that of adults because normal bone mineral density (BMD) of children varies by age, body size, pubertal stage, skeletal maturation, sex, and ethnicity. Thus, an appropriate normal BMD Z-score reference value with Z-score should be used to detect and manage low BMD. Z-scores below -2.0 are generally considered a low BMD to pediatrician even though diagnoses of osteoporosis in children and adolescents are usually only made in the presence of at least one fragility fracture. This article will review the basic knowledge and practical guidelines on pediatric DXA based on the International Society for Clinical Densitometry (ISCD) Pediatric Official Positions. Also discussed are the characteristics of normal Korean children and adolescents with respect to BMD development. The objective of this review is to help pediatricians to understand when DXA will be useful and how to interpret pediatric DXA reports in the clinical practice for management of children with the potential to develop osteoporosis in adulthood.

• Journal of radiological science and technology
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• v.41 no.1
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• pp.47-51
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• 2018

To evaluate the applicability of osteoporosis management by statistical analysis of the correlation between bone mineral density (BMD) changes after menopause by dividing the T-score of bone mineral density measured by dual energy X-ray absorptiometry do. Between January 1, 2016 and July 31, 2017, women who visited the medical center of W Medical Center were enrolled in this study. The postmenopausal period was divided into 5 groups, There were 18 patients within 5 years, 44 patients in 6~10 years, 134 patients in 11~15 years, 109 patients in 16~20 years and 21 patients in 21 years or older. And postmenopausal women. Bone mineral density (BMD) of the lumbar spine and femur was measured using a dual energy X-ray absorptiometry. The lowest value among lumbar spine 1, 2, 3 and 4 and the lowest value among the femoral neck, greater trochanter, total femur, and ward Values were measured. The statistical significance was analyzed by using bivariate correlation coefficient method and one - way ANOVA. In 326 patients who underwent BMD, the correlation between bone mineral density and postmenopausal BMD showed a negative correlation (-.159, p<.01) with BMD of femur and BMD of lumbar spine The correlation between the menopausal period and negative (-.208, p<.01) was shown. There was a significant difference (p<.012) between the postmenopausal femur bone density and the mean value of the lumbar spine BMD (p<.000). The relationship between bone mineral density (BMD) and postmenopausal women's postmenopausal status can be estimated by estimating the bone mineral density and using it as a basic data for osteoporosis management.

• Journal of the Korean Society of Radiology
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• v.12 no.7
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• pp.833-844
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• 2018

Dual energy X-ray absorptiometry is mainly used as an X-ray test method. For equipment manufactured GE and Hologic, cross-calibration analyses (CCA) of machines from the same manufacturer and between units from different manufacturers have been conducted, but the CCA of equipment manufactured in Korea are inadequate. Through CCA, we present a formula of the intersections between the Korean medical equipment company (KEC) with GE and Hologic manufactured DXA, and among the KEC DXA. The CCA was conducted for the European Spine Phantom on DXA from four KEC and three global medical equipment company (GEC) manufacturers. We compared bone mineral density (BMD) values and calculated the CCA equation by linear regression analysis. The standard-deviations (SD) of the BMD values were highest for the Dexxum T for the low, medium, and high spine, which were 0.030, 0.029, and 0.037, respectively. The smallest SD in the low and medium vertebrae were 0.005 and 0.004 for the Horizon Ci, respectively, and 0.005 for the Osteo Pro Max in the high vertebrae. Based on the intersection equations of the KEC DXA established in this study, CCA of various KEC DXA should be established for more accurate follow-up of BMD tests in clinical environments.

• Imaging Science in Dentistry
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• v.30 no.4
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• pp.235-242
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• 2000

Purpose: To evaluate the effect of the systemic osteoporosis on radiographic density of alveolar bone and cortical thickness of mandible. Materials and Methods: The bone mineral density values of lumbar and femur were measured by dual-energy X-ray absorptiometry and T scores of lumbar, femur were obtained respectively. Radiographic densities of alveolar bones and panorama mandibular index (PMI, represents as cortical thickness) were analysed statistically according to age and T score variables. Results: The radiographic density of alveolar bone of maxillary molar showed significant difference by age and femur T group. That of mandibular molar showed significant difference between femur T group. Panorama mandibular index showed significant difference between age groups. Conclusion: The radiographic density of alvealar bones was more dependent on age and femur T than lumbar T. Cortical thickness of mandible was correlated with increasing age.

• Journal of the Korean Society of Radiology
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• v.82 no.1
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• pp.173-181
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• 2021

Purpose To evaluate the ability of the Hounsfield unit (HU) measurement of the femoral neck during multidetector computed tomography (MDCT) for assessing osteoporosis compared with dual-energy X-ray absorptiometry (DXA). Materials and Methods Forty-two patients with femoral neck fractures who underwent MDCT and DXA from July to December 2016 were included in this study. HU measurements were made of the cancellous portions of the normal contralateral femoral neck on MDCT. Bone mineral density (BMD) and T-scores were obtained at the femur DXA. Correlations of HU values with BMD and T-scores were analyzed using Spearman's correlation test. Results The mean BMD and T-score of the femoral neck were 0.650 g/cm² and -2.4, respectively. The mean HU values for the normal, osteopenia, and osteoporosis groups were 131.9, 98.9, and 41.3, respectively. HU values at the femoral neck were positively correlated with BMD (r² = 0.670; p < 0.001) and T-scores (r² = 0.676; p < 0.001). Conclusion The HU values of the femoral neck on MDCT are significantly correlated with BMD and T-scores of femur DXA. The HU values may serve as a diagnostic tool for the screening of regional bone quality when MDCT is performed for other reasons.

• Journal of radiological science and technology
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• v.41 no.4
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• pp.351-360
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• 2018

In recent years, demand for examination of bone mineral density (BMD) is increasing in Korea according aging society. Therefore, it is required to develop an efficient management program that can increase the safety and reliability of Dual Energy X-ray Absorptiometry (DXA) that can be applied to the criteria of the World Health Organization. It is necessary to develop a management program that can design a program to improve the accuracy and precision of the results of the analysis and to improve the accuracy of diagnosis of osteoporosis by development a high quality DXA report. It is recommended to prepare the examination manuals and to establish procedures of standard operating including the program to prevent the pitfalls during the examination, the compatibility evaluation of the examination data, and the contents of the radiation safety. In addition, relevant regulations on the production of high-quality DXA reports are required and government and related agencies should introduce individual and facility recognition programs through DXA measurement and education programs and training. It is considered that efforts should be made to prepare high quality DXA report by guidelines on all aspects of BMD for preparation about aging society.

• Journal of radiological science and technology
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• v.39 no.4
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• pp.527-534
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• 2016

Dual-energy X-ray absorptiometry (DEXA) is the most widely used technical instrument for evaluating bone mineral content (BMC) and density (BMD) in patients of all ages. In 2016, DEXA devices operating is 5617 in Korea. In this study we investigated the quality of management practices survey for DEXA equipment and we analyzed it. We got a survey response rate of 12.6%. Accurate bone densitometry test is used data for estimation a patient's risk of fracture. However, improper bone densitometry will increase the possibility of causing a false positive. Therefore. it is essential to use the proper aids accurate bone densitomenty to be performed, and the quality control of the device to reduce the error factor of the tester through the training to reduce error for the device and the attitude.

• Imaging Science in Dentistry
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• v.47 no.4
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• pp.247-254
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• 2017

Purpose: Dual-energy X-ray imaging is widely used today in various areas of medicine and in other applications. However, no similar technique exists for dental applications. In this study, we propose a dual-energy technique for dental diagnoses based on voltage-switching. Materials and Methods: The method presented in this study allowed different groups of materials to be classified based on atomic number, thereby enabling two-dimensional images to be colorized. Computer simulations showed the feasibility of this approach. Using a number of different samples with typical biologic and synthetic dental materials, the technique was applied to radiographs acquired with a commercially available dental X-ray unit. Results: This technique provided a novel visual representation of the intraoral environment in three colors, and is of diagnostic value when compared to state-of-the-art grayscale images, since the oral cavity often contains multiple permanent foreign materials. Conclusion: This work developed a technique for two-dimensional dual-energy imaging in the context of dental applications and showed its feasibility with a commercial dental X-ray unit in simulation and experimental studies.

• Journal of Yeungnam Medical Science
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• v.10 no.2
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• pp.369-379
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• 1993

The bone mineral density(BMD) of the lumbar spine (L2-L4) was measured by using dual energy x-ray absorptiometry(Norland XR26 DEXA) in 80 children aged between 2months and 15years (group 1 : 2month-1years, group 2 : 1year-5years, group 3 : 6years-10years, group 4 : 11years-15years). The correlation coefficient of BMD with age, body weight, height and Tanner stage were 0.696, 0.693, 0.717 and 0.636 respectively. There were significant difference in BMD($g/cm^2$) between group 1(BMD : $0.335{\pm}0.175$) and group 2(BMD : $0.627{\pm}0.200$). and group 3(BMD : $0.714{\pm}0.189$) and group 4(BMD : $0.873{\pm}0.163$)(P<0.05). There was no significant difference of BMD between boys and girls(P<0.05). BMD also increased significantly with development of Tanner stages(Tanner stage 1 : $0.547{\pm}0.234$, Tanner stage 2 : $0.783{\pm}0.136$, Tanner stage 3 : $0.998{\pm}0.080$ )(P<0.05). These data indicate that the BMD was correlated with age, body weight, height and Tanner stage significantly and BMD increased significantly during growth spurt occured in 1 to 4years of age and puberty.