• 제목/요약/키워드: Dual-Energy

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Characteristics of 15 MV Photon Beam from a Varian Clinac 1800 Dual Energy Linear Accelerator (CLINAC 1800 선형가속기의 15 MV X-선의 특성)

  • Kim, Kye-Jun;Lee, Jong-Young;Park, Kyung-Ran
    • Radiation Oncology Journal
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    • v.9 no.1
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    • pp.131-141
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    • 1991
  • A comprehensive set of dosimetric measurements has been made on the Varian Clinac 1800 15 MV photon beam. Beam quality, percentage depth dose, dose in the build up region, output, symmetry and flatness, transmission through iead (Cerrobend), tray attenuation, isodose curves for the open and wedged fields were measured using 3 dimensional water phantom dosimetry system (including film densitometer system) and polystyrene phantoms. These dosimetric measurements sufficiently characterized the beam to permit clinical use. The depth dose characteristics of photon beam is $d_{max}$ of 3.0 cm and percentage depth dose of $76.8\%$ at 10 cm,100 cm source-surface distance, field size of $10\times10\;cm^2$ for 15 MV X-ray beam. The Output factors ranged 0.927 for $4\times4\;cm^2$ field to 1,087 for $35\times35\;cm^2$ field. The build-up level of maximum dose was at 3.0 cm and surface dose was approximately $15.5\%$ for a field size $10\times10\;cm^2$ The stability of output is $within\pm1\%$ and flatness and symmetry are $within\pm3\%$. The half value thickness (HVL) of lead is 13 mm, which corresponds to an attenuation coefficient of $0.053\;mm^{-1}$. These figures compare facorably with the manufacturesr`s specifications.

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Association of Bone Mineral Density with Physiological Characteristics and Lifestyles in Premenopausal Working Women (폐경전 성인직장여성의 골밀도와 생리적 특성 및 생활습관과의 관련성)

  • 임화재
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.2
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    • pp.339-348
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    • 2004
  • This study was peformed to assess the relationships among bone mineral density (BMD), Physiological characteristics and lifestyle factors in 61 premenopausal working women aged 30∼49 y in Busan. The BMDs of the lumbar spines (Ll∼L4), femoral necks (FN), ward's triangles (WT) and trochanters (TC) were measured by dual energy X-ray absorptiometry. Data for physiological characteristics and physical activity was assessed by questionnaire and usual intakes of coffee, green tea, alcohol, Coca cola by food frequency questionnaire. The BMDs of L14, FN, WT and TC were 1.02 g/$\textrm{cm}^2$, 0.76 g/$\textrm{cm}^2$,0.69 g/$\textrm{cm}^2$ and 0.66 g/$\textrm{cm}^2$respectively The BMD of FN was assessed as osteopenia by T-score. The BMD of WT was positively correlated with age of monarch (p<0.05) and the BMD of Ll4 was positively correlated with delivery number (p<0.05). The BMD of Ll4 was positively correlated with hours of outdoor activity per weekend and week (p<0.05, p<0.05). The BMDs of FN and WT (p<0.05, p<0.05) were positively correlated with intake of green tea per month and the BMD of FN (p<0.05) was positively correlated with intake of wine per month. But the BMD of Ll (p<0.05) was negatively correlated with intake of Coca cola per month. So nutritional education for increasing hours of outdoor activity and decreasing intake frequency of beverage contributing to diminishment of bone mineral density is needed for premenopausal working women to prevent osteoporosis.

The Comparison of Glomerular Filteration Rate by Kidney Depth in Dynamic kidney Scan (동적신장검사에서 신장깊이에 따른 사구체여과율 비교)

  • Hwang, Ju-Won;Lim, Young-Hyen;Yun, Jong-Jun;Lee, Hwa-Jin;Lee, Mu-Seok;Jung, Ji-Uk;Park, Se-Yun
    • The Korean Journal of Nuclear Medicine Technology
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    • v.18 no.2
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    • pp.73-77
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    • 2014
  • Purpose Find out about the significance of the GFR values calculated by the kidney depth is measured by comparing the values obtained for kidney depth was measured GFR in the CT image kidney depth and is calculated by Tonnesen law in $^{99m}Tc$-DTPA dynamic kidney scan with each applies. Materials and Methods Among patients with normal value (75~120 mL/min) computed GFR conducted of dynamic renal scan to visit from February 2013 to February 2014 and donor GFR values in patients with normal value. The mean age was 46.9 years with 14 men 13 females. We used abdomen CT image which checked before conducting dynamic Kidney scan for measuring the depth of kidney. We only used CT image that contains renal hilum and measured outermost front of the kidney from the skin surface (a) and the final surface (b) caculated the average depth of [(a + b) / 2] respectively. Using the same ROI in order to limit the change in GFR values by the other additional element was set before and after the depth value was excluded from the GFR falls kidney disease. Results Using Tonnesen law the average value was caculated 5.94 cm from the right kidney 5.90 cm from the left kidney. It was 6.83 cm, 8.71 cm in the left kidney and the right kidney average value of the depth measured on the basis of the CT image. The respective increase in left kidney 0.93 cm and right kidney 2.77 cm calculated on the basis of CT image actually measured values. GFR was calculated as the average depth of the subject calculated by the method Tonnesen $83.3{\pm}9.79mL/min$. $98.6{\pm}14.07mL/min$ GFR was applied to calculate the average depth of the subjects using the CT image, is the difference appears 15.26 mL/min was increased after seting up depth value, P value was less than 0.01 which is significant. Conclusion The difference between GFR before-after setting up depth value cause that the different of depth value. Is a measured depth of the extension value of the calculated estimates Whereas Tonnesen kidney depth method is to use in calculating the value of GFR in a typical dynamic elongation test depth derived using the CT image depth. Is thought to be able to calculate more accurately the GFR value by the distance to the center of kidney more accurately measured in the skin thereby.

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Osteoporosis in Chronic Obstructive Pulmonary Disease (만성폐쇄성폐질환에서의 골다공증에 관한 연구)

  • Kim, Seong-Ja;Lee, Young-Hyun
    • Tuberculosis and Respiratory Diseases
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    • v.47 no.1
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    • pp.90-96
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    • 1999
  • Background : Osteoporosis has been reported in patients with chronic obstructive pulmonary disease, but this association is not well established. This study was undertaken to determine whether the prevalence of osteoporosis was increased in patients with chronic obstructive pulmonary disease and we examined the relationship of corticosteroid administration with osteoporosis. Method: Subjects were 23 patients with chronic obstructive pulmonary disease and 20 control patients. We reviewed hospital records and measured bone mineral density using dual-energy x-ray absorptiometry(Lunar. USA). Results: Mean bone mineral density(BMD) of spine in COPD group was $0.683{\pm}0.154 g/cm^2$ and $0.971{\pm}0.212g/cm^2$ in controls(p<0.01). But there was no significant difference in femoral neck BMD. There were seventeen cases of osteoporosis and six cases of osteopenia in COPD group and three patients of osteoporosis and one case of osteopenia in controls. But, there was no significant correlation between disease duration of COPD and spinal T score(r=-0.395, p>0.05). Ten patients were received corticosteroid in COPD group. Spinal T score in steroid receiving patients were $-3.82{\pm}0.94(SD)$ and $-2.82{\pm}0.97(SD)$ in not having steroid patients(p<0.01). Cumulative dose of corticosteroid was associated with spinal T score(r=-0.424, p<0.05) and duration of corticosteroid administration also associated with spinal T score(r=-0.457. p<0.05). Spinal BMD of patients not having corticosteroid in COPD group(n=13) were significantly lower than that of controls($0.71{\pm}0.13 g/cm^2$ and $0.97{\pm}0.21 g/cm^2$, p<0.01). Conclusion : Prevalence of osteoporosis is increased in patients with chronic obstructive pulmonary disease. Especially patients who are receiving corticosteroid have high risk of osteoporosis or osteopenia and need for preventive management.

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Relationships of Changing Social Atmosphere, Lifestyle and Bone Mineral Density in College Students (대학생의 골밀도와 사회분위기 및 생활습관과의 관계)

  • Lee, In-Ja;Ko, Yo-Han;Kim, Chung-Kyung;Kim, Hee-Sol;Park, Da-Jeong;Yoon, Hyeo-Min;Jeong, Yu-Jin
    • Journal of radiological science and technology
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    • v.36 no.4
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    • pp.263-271
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    • 2013
  • The decrease of bone mineral density gives rise to the outbreak of osteopenia and makes the possibility of a bone fracture. It makes health problems in society. It's very important to prevent osteopenia in advance. Also it's critical to prevent and take care of it in adolescent because it's the most developing period comparing to middle ages because that bone mineral density decreases. There are genetic, physical and enviromental factors that affect bone mineral density. Recently, a lifestyle and eating habits are also changing as the society atmosphere is gradually doing. This study have shown that 134 women and 75 men was chosen and responded to the survey of measuring bone mineral density and investigating a lifestyle. The measure of bone mineral density is to use Dual energy X-ray absorptiometry(DEXA) and check femoral neck and lumbar spine. Also questionaries was required to pre-made survey about their lifestyles. Analysis of data was done with SPSS program. Multiple regression analysis was used for the relation of bone mineral density, the heigths and BMI. The sample of Groups are checked for drinking, smoking or excercising about differences by t-test. The results of the experiments were; first, there is statistically significant differences in the comparisons between BMD and BMD. But there isn't any special correlation between drinking, smoking and BMD. Secondly, bone mineral density becomes low related to an intake of caffeine. Particularly, this is statically significant on women. Also there is statically significant correlation between femoral neck and quantity of motion for both men and women. Third, there is significant relation between eating habits and bone mineral density on women's lumbar spine. However, there is no significant relation between men's lumbar spine and women's one. Therefore, to prevent osteopenia, it's good to abstain from intaking caffeine within an hour after a meal. In addition, it's helpful to walk or run regularly and have a balanced meal.

Bone Mineral Density and Bone Markers in the Children with Epilepsy Taking on Chronic Anticonvulsants (장기간 항경련제를 복용하고 있는 소아 간질 환아들의 골밀도 및 골대사 지표들)

  • Lee, Soon Bum;Kang, So Young;Yu, Jeesuk
    • Clinical and Experimental Pediatrics
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    • v.48 no.5
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    • pp.527-533
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    • 2005
  • Purpose : Long-term administration of anticonvulsants in children with epilepsy may cause short stature, hypocalcemia and low bone mineral density. This study was performed for the early detection of abnormal bone metabolism in children with epilepsy on taking anticonvulsants. Methods : Thirty children aged 5 to 16 years who were diagnosed with epilepsy were enrolled in this study. All had taken anticonvulsants for more than one year. Bone mineral density of lumbar vertebra was measured by dual-energy X-ray absorptiometry. Serum calcium, phosphorous, alkaline phosphatase, 25-hydroxycholecalciferol[$25(OH)D_3$], parathyroid hormone, and urine deoxypyridinoline were measured as biochemical bone markers. Bone age and body mass index were also calculated. Results : Bone minreal density, body mass index, bone age, and height were significantly decreased in two female patients who had taken two antiepileptic drugs for more than four years and they also had chronic diseases such as cerebral palsy with microcephaly, encephalomalacia, and microcephaly with atrial septal defect. Bone mineral density had significant positive correlations with body mass index(P<0.01) and bone age(P<0.01). Conclusion : This study showed chronic medication of anticonvulsants in children may cause low bone mineral density and short stature. Bone age and body mass index could be the important surrogate markers to find the population at risk. More studies, including a large study population and long term cohort study, will be required.

A Comparative Study of Bone Mineral Density and Urinary Bone Metabolic Makers according to the Nutrients Intake Levels in Postmenopausal Women (일부 폐경 후 여성의 영양소 섭취수준에 따른 골밀도와 소변 중 골대사 지표 비교연구)

  • Kim, Mi-Hyun;Lee, Da-Hong
    • Journal of Nutrition and Health
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    • v.40 no.8
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    • pp.719-727
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    • 2007
  • To elucidate the relationship among the levels of nutrients intake, bone mineral density(BMD) and the urinary biochemical markers of bone metabolism, this survey is conducted with 225 postmenopausal women over 50 years of age. The urinary biochemical markers including deoxypyridinoline(DPD) and Ca excretion were measured. Bone mineral densities of lumbar spine(L2-L4), femoral neck, ward's triangle and trochanter were measured with dual-energy X-ray absorptiometry and the nutrient intake data obtained by 24 hr recall method. Mean age of all subjects was 64.8 years old, and the BMDs of the subjects were $0.86g/cm^2$(lumbar spine), $0.60g/cm^2$(femoral neck), $0.49g/cm^2$(trochanter), and $0.41g/cm^2$(ward's triangle). The results were compared among 3 groups with different nutrient intake levels classified by the percentage of Dietary Reference Intakes(DRIs) for Koreans as follows: low < 75% DRIs, 75% DRI $\leq$ adequate < 125% DRIs, high $\geq$ 125% DRIs. Bone mineral density of adequate protein intake group was significantly higher than those of low and high protein intake groups(p<0.05). Urinary DPD excretion was lowest in protein and calcium adequate intake groups(p<0.05, p<0.05), respectively. In relation to urinary Ca excretion, it is revealed to be considerably lower in the groups taking protein and vitamin C adequate intake(p<0.05, p<0.05). The percent DRI of protein and calcium were positively correlated with the BMD of the femoral neck after adjusted age(p<0.05, p<0.05). These results showed that there are probably some relationships between nutrient intake levels and urinary biochemical markers. For postmenopausal women with adequate nutrition expecially protein, calcium and vitamin C, has an important role to postpone bone resorption and to prevent the decrease of bone density.

Effects of Physiological Factors and Lifestyles on Bone Mineral Density in Postmenopausal Women (생리적 요인과 생활습관이 폐경 후 여성의 골밀도에 미치는 영향)

  • Sung, Chung-Ja;Choi, Yun-Hee
    • Journal of Nutrition and Health
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    • v.40 no.6
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    • pp.517-525
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    • 2007
  • This study was performed to assess the effects of physiological factors and lifestyles on bone mineral density (BMD) in 64 postmenopausal women. Sixty four subjects were selected out of 223 postmenopausal women in Seoul and Kyunggido. The BMD of the lumbar spine (L2 ${\rightarrow}$ L4) and femoral neck were measured dual energy X-ray absorptiometry (DEXA). Subjects were assigned to one of three groups such as normal (T-score > -1, n = 20), osteopenia (-2.5 < Tscore ${\leq}$ -1, n = 24), and osteoporosis (T-score ${\leq}$ -2.5, n = 20). Anthropometric measurements and questionares were administered to these women. The mean age, height, weight and BMI were 62.09 yrs, 153.78 cm, 56.09 kg and 23.70 $kg/m^2$ respectively. The BMDs of lumbar spines (L2 ${\rightarrow}$ L4), femoral neck were 0.84 $g/cm^2$, 0.71 $g/cm^2$ respectively. Years after menopause and age of last delivery of the osteoporosis and osteopenia group were significantly longer than the normal group (p < 0.05). The hours of exercise and outdoor activity of the normal group were longer than the osteoporosis and osteopenia group, but there were no significant differences among the three groups. The BMDs of these two sites were positively correlated with weight, BMI, hip and body fat and negatively correlated with LBM, TBW. These results show there are no consistent effects on bone mineral density, adjusting for age and BMI, of physiological factors and lifestyles in postmenopausal women. Therefore. this study confirmed that one of the most effective ways to minimize bone loss in postmenopausal women would be to maintain an adequate body weight.

The Effects of $1{\alpha}-(OH)D_3$ and Pamidronate on Steroid Induced Osteoporosis (SIO) in Children with Nephrotic Syndrome (NS) (신증후군 환아에서 스테로이드에 의한 골다공증 치료에 $1{\alpha}-(OH)D_3$와 Pamidronate의 효과)

  • Kim Sung-Do;Jhon Hye-One;Cho Byoung-Soo
    • Childhood Kidney Diseases
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    • v.6 no.2
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    • pp.209-217
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    • 2002
  • Purpose : Corticosteroid has been used as the mainstay therapy of childhood NS. But SIO is one of the serious complications of long-term steroid therapy, especially in growing children. Recently calcium, calcitonin, PTH, vitamin D and bisphosphonate has been used to treat or prevent SIO in adult, which is rare in children with NS. We studied the effect of $1{\alpha}-(OH)D_3$ and Pamidronate on SIO using dual energy X-ray absorptiometry (DEXA). Patients and methods : We studied thirty patients who admitted in the Dept. of Pediatrics of Kyung Hee Medical Hospital with NS. All patients was received longterm steroid therapy. There was no history of bone, liver, or endocrine disease. The samples, serum protein, albumin, BUN, creatinine, calcium, phosphorus, and BMD were obtained before and the six months after the dose of $1{\alpha}-(OH)D_3$ and Pamidronate, respectively Results : The mean age was $6.9{\pm}3.3\;and\;6.5{\pm}2.5$ years old. The mean duration of steroid therapy was $28.8{\pm}1.8\;and\;27.6{\pm}1.0$ months. The changes of serum protein, albumin, BUN, creatinine, calcium and phosphorus level between pre-treatment and post-treatment did not show statistical significance in both $1{\alpha}-(OH)D_3$ and Pamidronate treatment group. However, BMD was increased in both from $0.472{\pm}0.12\;and\;0.457{\pm}0.10\;g/cm^2\;to\;0.533{\pm}0.12$ and $0.529{\pm}0.09\;g/cm^2$ after treatment. (P<0.05) Conclusion : Both $1{\alpha}-(OH)D_3$ and Pamidronate appears to be effective in treating and preventing SIO in children with nephrotic syndrome requiring long-term steroid therapy.

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A Study of both Femurs Bone Densitometry's Difference for Exercise (운동유무에 따른 양측 대퇴골 골밀도 차이에 관한 연구)

  • Jang, Eun-Ju;Kim, Eun-Hye;Kim, Ho-Sung;Shin, Sang-Ki
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.1
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    • pp.73-76
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    • 2009
  • Purpose: Bone mineral densitometry test region advised by ISCD (International Society for Clinical Densitometry) is both site in case of femur, whereas our medical center measures left femur except for few extraordinary cases. It is said that right-handers had higher mean femur BMD in the left side than in the right side, but the factor influence the femur BMD is unknown. Thus, we investigate whether testing left femur only is a adequate clinical diagnosis. Materials and Methods: Subjects were 209 right-handers and 20 left-handers patient in Asan Medical Center from July to August, 30 to 70 years of age ($51{\pm}6.7$). Subjects fill out the questionnaire on hand preference and taking regular exercise. Total BMDs of bilateral femur were measured with GE Lunar Prodigy advance densitometer, and the statistical soft ware SPSS 12.0 for windows was used for statistical analysis. Results: In the total sample of the exercise group (n=127), the difference of both femur mean BMDs are $0.001{\pm}0.127\;g/cm^2$ and the non-exercise group's (n=102) both femur difference is $0.002{\pm}0.126\;g/cm^2$, there is no significant difference. And in exercise group, classified according to hand preference, each t-value is shown at right handers (n=114) are 0.65, left handers (n=13) are -0.39. Also, In non-exercise group, right handers (n=95) are -0.78, left handers (n=7) are -0.64. In the 95% confidence limit, there was no statistically significant difference (p>0.05). Conclusions: In recently researchs, there have been differences between both femurs according to hand preference. However, Our study have no significant difference both femurs BMDs. Therefore we suggest that BMD measurement of femur has no problem only one side, except for particular case like femur operation.

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