• Investigative Magnetic Resonance Imaging
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• v.16 no.1
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• pp.16-24
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• 2012

Purpose : The purpose of this study was to determine whether there is a significant correlation between vertebral marrow fat fraction measured using Dixon quantitative chemical shift MRI (QCSI) and BMD on dual-energy X-ray absorptiometry (DXA). Materials and Methods: This retrospective study included 68 healthy individuals [mean age, 50.7 years; range, 25-76; male/female (M/F) = 36/32] who underwent DXA of the L-spine and whole body MRI including QCSI of the L-spine and chemical shift MRI of the liver. The enrolled individuals were divided into subgroups according to sex and T-score [i.e., normal bone density (M/F=27/23) and osteopenia (M/F=9/9)]. Vertebral marrow (Dixon QCSI, TR/TE 10.2/4.8 ms) and hepatic fat fractions (chemical shift technique, TR/TE 110/4.9 and 2.2 ms) were calculated on MRI. We evaluated whether there were significant differences in age, body mass index (BMI), vertebral marrow fat fraction, or hepatic fat fraction among the subgroups. Whether or not the participant had reached menopause was also evaluated in females. The correlations among variables (i.e., age, BMI, vertebral marrow and hepatic fat fractions, BMD) were evaluated using Spearman's correlation method. Results: There were no significant differences in age, BMI, or vertebral marrow and hepatic fat fractions between the two male subgroups (normal bone density vs. osteopenia). In female subjects, mean age in the osteopenic subgroup was greater than that in the normal subgroup (p=0.01). Presence of menopause was more common in the osteopenic subgroup [77.8% (7/9)] than the normal subgroup [26.1% (6/23), p<0.05]. The other variables showed no significant difference between female subgroups. The only significant correlation with marrow fat fraction after partial correlation analysis was that with age in the female subjects (r=0.43, p<0.05). Conclusion: The vertebral marrow fat fraction calculated using the Dixon QCSI does not precisely reflect the mild decrease in BMD for either sex.

• Journal of the Korean Society of Radiology
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• v.13 no.2
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• pp.185-192
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• 2019

DXA is the most commonly used BMD examination equipment with the best performance on reflecting the biological alteration with tiny change of bone density. In spite of the importance of the quality control to maintain the accuracy and precision of the examination, considerable number of hospitals are not conducting QC due to the difficulty and high cost of the phantom product. This study develops the cross revision phantom with 3D printer and the change of the degree of infilling filaments which can be readily secured, and provides the usefulness assessment of the developed phantom by comparing with existing products. The Hounsfield Units of ABS, TPU, PLA, 30% Cu-PLA, and 30% Al-PLA are assessed. The Hounsfield Units result at infilling rate 100% was $-149.74{\pm}2.36$, $-55.62{\pm}7.14$, $-7.68{\pm}3.82$, $87.53{\pm}1.07$, and $1795.20{\pm}16.15$. The L1, L2, L3 BMD of 3D printing phantom with linear regression model were $0.620{\pm}0.010g/cm^2$, $1.092{\pm}0.025g/cm^2$, $1.554{\pm}0.026g/cm^2$ which are statistically relevant to the existing phantom products. This result provides the base line data for various medical phantom produce and capability of proper quality control of DXA equipment.

• Journal of the Korean Orthopaedic Association
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• v.56 no.6
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• pp.491-497
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• 2021

Purpose: To investigate the prevalence of osteoporosis or osteopenia via dual-energy X-ray absorptiometry bone mineral density (DEXA BMD) in adult males who showed radiolucent lumbar vertebra on the plain radiographs. Materials and Methods: The DEXA BMD values of 98 adult males, who showed radiolucent vertebrae on plain X-rays, were compared with those of the control group (n=168) and osteoporosis-related fracture group (n=113) by statistical analysis. The World Health Organization (WHO) method (lower value between the mean lumbar and femur neck) and the Hansen's method (lowest lumbar vertebra) were used to determine osteoporosis. Results: The mean and standard deviation of the BMD value of each group was -1.4 (±1.2) in the suspicious group, -0.8 (±1.1) in the control group, and -2.4 (±1.0) in the fracture group, respectively; the difference was statistically significant. Using the WHO method, the prevalence ratio of osteoporosis was 17.3% in the suspicious group, 8.3% in the control group, and 45.1% in the fracture group, respectively. Osteopenia was observed in 40.8% of the suspicious group. Hansen's method (lowest lumbar vertebra) revealed the prevalence of osteoporosis in 30.6% of the suspicious group, 17.9% of the control group, and 62.0% of the fracture group. Conclusion: Approximately 17.3% of the suspicious group was diagnosed with osteoporosis, and 40.8% were osteopenic by a confirmative BMD study (WHO criteria) among the adult males showing apparent radiolucency on plain X-rays. The control group also showed an 8% prevalence of osteoporosis. These results suggest that males also are vulnerable to osteoporosis. Therefore, a BMD study should also be used for males, especially for the people showing lumbar vertebrae with radiolucent features.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.43-48
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• 2017

Measurement of bone marrow measurements may occur if bone marrow examination performed with bone marrow examination (bone marrow examination) and bone density (bone scan) are performed together recently. Thus, it was examined in clinical aspects that $^{99m}Tc-MDP$ compounds were affected by bone mineral density measurements. The average age of the participants in the experiment was $35.17{\pm}9.45$ and the patient fractures of the lumbar vertebrae that could affect the metabolic disease and bone density measurements affecting the metabolic disease of the 17 subjects. 6 patients with normal bone mineral density T-scores>-1.0 in 12 patients were analyzed before and after the administration of $^{99m}Tc-MDP$. In the lumbar spine, the average of $0.975{\pm}0.084g/cm^2$ and $0.966{\pm}0.078g/cm^2$ were increased by $0.009g/cm^2$. respectively In the right proximal femur, mean values were $0.909{\pm}0.078g/cm^2$ and $0.913{\pm}0.086g/cm^2$. In the right proximal thigh, mean values were $0.909{\pm}0.078g/cm^2$ and $0.913{\pm}0.08 g/cm^2$, respectively, which decreased by $0.004g/cm^2$. In the left side proximal femur, mean $0.887{\pm}0.099g/cm^2$ and $0.881{\pm}0.103g/cm^2$, respectively, increased by $0.007g/cm^2$. Therefore, the BMD changes in the lumbar region were larger than that in the proximal thigh. In addition, $^{99m}Tc-MDP$ did not affect the BMD. And a bone scan test using a technetium-labeled compound emitting a gamma-ray energy of 140 keV did not significantly affect bone density measurements. However, if the nuclear medical examination and the osteoporosis test are to be performed together, the examination should be carried out at intervals considering the exposures of the patient.

• Journal of radiological science and technology
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• v.39 no.2
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• pp.263-271
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• 2016

The market size of the bone absorptiometric X-ray system and the number of its approval by Ministry of Food and Drug Safety (MFDS) has annually increased, with a trend of increasing aging population and osteoporosis patients. For approval of manufactured or imported medical devices in Republic of Korea, it is required to submit its technical document. Therefore, it is need to develop the technical document guideline for the bone absorptiometric X-ray system for manufacturers, importers and reviewers. First of all, the technical documents which were already approved were examined and analyzed through MFDS approval administration system. Second, safety and performance test standards and methods that match international standards were drawn after conducting survey of the market status and the technology development trend for it, with examination and analysis of applicable domestic and overseas standards. Third, by operating industry-research-government cooperation, the guideline draft on writing technical document for the bone absorptiometric X-ray system was discussed, collecting their opinion. As a result, it is suitable to international and domestic condition, includes test evaluation methods and offer various information with appropriate examples to civil petitioner, when they write the technical documents.

• Journal of radiological science and technology
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• v.32 no.4
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• pp.361-370
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• 2009

The image quality management of bone mineral density is the responsibility and duty of radiologists who carry out examinations. However, inaccurate conclusions due to lack of understanding and ignorance regarding the methodology of image quality management can be a fatal error to the patient. Therefore, objective of this paper is to understand proper image quality management and enumerate methods for examiners and patients, thereby ensuring the reliability of bone mineral density exams. The accuracy and precision of bone mineral density measurements must be at the highest level so that actual biological changes can be detected with even slight changes in bone mineral density. Accuracy and precision should be continuously preserved for image quality of machines. Those factors will contribute to ensure the reliability in bone mineral density exams. Proper equipment management or control methods are set with correcting equipment each morning and after image quality management, a phantom, recommended from the manufacturer, is used for ten to twenty-five measurements in search of a mean value with a permissible range of ${\pm}1.5%$ set as standard. There needs to be daily measurement inspections on the phantom or at least inspections three times a week in order to confirm the existence or nonexistence of changes in values in actual bone mineral density. in addition, bone mineral density measurements were evaluated and recorded following the rules of Shewhart control chart. This type of management has to be conducted for the installation and movement of equipment. For the management methods of inspectors, evaluation of the measurement precision was conducted by testing the reproducibility of the exact same figures without any real biological changes occurring during reinspection. Bone mineral density inspection was applied as the measurement method for patients either taking two measurements thirty times or three measurements fifteen times. An important point when taking measurements was after a measurement whether it was the second or third examination, it was required to descend from the table and then reascend. With a 95% confidence level, the precision error produced from the measurement bone mineral figures came to 2.77 times the minimum of the biological bone mineral density change. The value produced can be stated as the least significant change (LSC) and in the case the value is greater, it can be stated as a section of genuine biological change. From the initial inspection to equipment moving and shifter, management must be carried out and continued in order to achieve the effects. The enforcement of proper quality control of radiologists performing bone mineral density inspections which brings about the durability extensions of equipment and accurate results of calculations will help the assurance of reliable inspections.

• Journal of radiological science and technology
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• v.35 no.1
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• pp.1-7
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• 2012

Dual Energy X-ray Absorptiometry(DEXA) is commonly used to diagnose Osteoporosis. The errors of DEXA bone density operation are caused by operator, bone mineral density meter, blood testing, patient. We focus on operator error then study about how much influence operator's region of intest(ROI) in bone testing result. During from March to July in 2011. 50 patients ware selected respectively from 30, 40, 50, 60, and 70 age groups who came to Korea University Medical Center(KUMC) for their Osteoporosis treatment. A-test was performed with usually ROI and B-test was performed with most widely ROI. Then, We compare A-test and B-test for find maximum difference of T-score error which occurred operator ROI controlling. Standard deviation of T-score of B-test showed 0.1 higher then A-test in femur neck. Standard deviation of B-test showed 0.2 higher then A-test in Ward's area which in Greater trocanter and Inter trocanter. Standard deviation of B-test showed 0,1 lower then A-test in L-1. Bone density testing about Two hundred patients results are as follow. When operator ROI was changed wider than normal ROI, bone density of femur was measured more higher but bone density of L-spine was measured more lower then normal bone density. That means, sometime DEXA bone density testing result is dependent by operator ROI controlling. This is relevant with the patient's medicine and health insurance, thus, tester always keep the size of ROI for to prevent any problem in the patient.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.271-276
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• 2009

The aim of this study was to evaluate the effect of Bone Mineral Density(BMD) at mandible. So, we studied how to measure the BMD at mandible using DEXA(Dual energy X-ray absorptiometry, DEXA) by Horner er al (1996) and knew reproducibility of the measurements. Thirty-five patients (13 men, 22 women, mean age : 25.4 years) were examined using the GE Lunar Prodigy Advance(LUNAR Corporation, madison, USA). They were examined in Semiprone position of their body and true lateral position of their mandible selected the Lumbar lateral mode. We used the custom mode in analysis when ROI (area $30{\times}2.5\;mm^2$). Three ROIs ($30{\times}2.5\;mm^2$, $50{\times}2.5\;mm^2$, $20{\times}2.5\;mm^2$) were located each at the two different sites of the mandible (angle of mandible and mental symphysis) and BMD was measured. Differences in BMD measurement was statistically compared according to the size and location of ROI. BMD was $1.320{\pm}0.358g/cm^3$ in men and was $1.152{\pm}0.340g/cm^3$ in women. BMD at the angle of mandible was $1.201{\pm}0.361g/cm^3$ in men and was $1.025{\pm}0.377g/cm^3$ in women. BMD of men at the mental symphysis was $1.434{\pm}0.341g/cm^3$ and that of women was $1.19{\pm}0.358g/cm^3$. With the ROI of $20{\times}2.5\;mm^2$, BMD was $1.262{\pm}0.384g/cm^3$ in men and was $1.113{\pm}0.357g/cm^3$ in women. With the ROI of $50{\times}2.5\;mm^2$, BMD of men was $1.320{\pm}0.358g/cm^3$ and that of women was $1.129{\pm}0.340g/cm^3$. There was a statistically significant difference of BMD according to the size and location of ROI. When measuring mandible BMD, there are good for increasing ROI and locate between ramus and mental symphysis. Especially following exam, refer to same size and location with fore exam. According to study which measure mandible BMD, It's correct to measure better a portion of mandible then whole of BMD. Using DEXA protocol is studied good for the additional study to compare the BMD at mandible. Later date, It will be good for measurement value in implant and bone graft quantitatively. Using DEXA method gain BMD threshold value in korean.

• The Journal of the Korea Contents Association
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• v.9 no.4
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• pp.228-235
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• 2009

As we recognize the health care, test of BMD is increased. There are various methods in BMD, Dual Energy X-ray absorptiometry (DEXA) which has high precision and accuracy, and low medical exposure dose has been widely used. To measure the changes of BMD, the test must be done as same posture at first and follow up study performed a year. we analyze the difference in the hour taken before and after the examination by radiologic technologist, frequency of scout scan, and the amount of the radiation exposure. The hour of the examination and frequency of the scout scan were shorten and the dose of the radiation exposure is reduced. As the numerical value of total subjects is converted into that of one person, the duration for the test was 52 seconds, the frequency for the scout scan 0.79 time, and the dose for the radiation exposure $13{\mu}Sv$. When the health care provider perform the precise and easy methods to minimize changes of posture and the skillful ability to manage the test, useless radiation is decreased.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.3
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• pp.265-273
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• 2000

Purpose : The aim of this study was to evaluate the bone mineral density of iliac and tibial bone which are frequently selected as autogenic bone graft donor sites, and to evaluate the efficiency of this method as a guideline for the selection of bone graft donor site. Materials and Methods : In this study 61 male and 70 female volunteers at Chungbuk National University Hospital were involved between Jan. 1998 to Sept. 1999. We measured bone mineral density of the iliac and the tibial bone using dual energy X-ray absorptiometry. We evaluated the data using the SAS system for Windows and bone mineral density of the lumbar was used for control. Results : Age showed the highest correlation in correlation matrix between physical and bone variables. Height and weight showed lower correlation of linear increment. In man, the change of bone density according to age demonstrated linear decrease irrespective of the lumbar, ilium, and tibia. In woman, the change of bone density according to age showed cubic form, which increased in the third and forth decade. So it had a peak bone mass on about 35 year-old, thereafter, the change of bone density slowly decreased until 50 year-old, but it rapidly decreased after 50 year-old and it slowly decreased again after 65 year-old. Both in all subjects and subject with osteoporosis, the change of bone mineral density according to age showed statistically significant decrease in lumbar and tibia, but ilium was irrespective. Conclusion : In patients of aged or with osteoporosis, ilium demonstrated less tendency of decrease in bone mineral density than tibia. So this preliminary study suggested that ilium seemed better donor site for autogenic bone graft than tibia.