• 제목/요약/키워드: Absorptiometry, Dual-Energy X-Ray

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Dual Energy X-ray 흡수 영상의 분해를 통한 뼈 영역 추출 (Bone Region Extraction by Dual Energy X-ray Absorbtion Image Decomposition)

  • 권주원;조선일;안영복;노용만
    • 한국멀티미디어학회논문지
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    • 제12권9호
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    • pp.1233-1241
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    • 2009
  • 골다공증은 45세 이상의 여성 50% 이상이 갖고 있는 질환이다. 더욱이 질병의 증상을 환자가 느끼지 못하여 병을 심화시키기 때문에 조기 진단으로 골다공증을 예방하는 것이 중요하다. 이를 위해 골밀도(Bone Mineral Density)의 효과적인 측정을 위한 다양한 연구가 국내외적으로 수행되고 있다. 골밀도 측정을 위해서는 X-선 영상이 활용되고 있으며, 이 중에서 이중 에너지 X 선 흡수법(DEXA)을 이용하여 골밀도를 측정하는 방법은 많은 관심을 받고 있는 분야이다. DEXA 영상은 서로 다른 두 에너지준위의 X선으로부터 영상을 획득함으로써 생체조직의 중첩에 의한 잡음을 효과적으로 줄여 진단효과를 높이는데 유용하다. 하지만, DEXA 영상에서 골영역을 추출하기 위해서는 실험적으로 계수를 결정해야 하는 문제점이 있다. 본 논문에서는 두 에너지 흡수 영상에서 골영역을 추출하기 위해 실험적으로 결정하는 변수를 X-선 영상의 물리적 의미와 각 에너지에 반응하는 생체조직들의 감쇠상수 특성을 기반으로 분석하여 골영역을 효과적으로 검출하는 방법을 제안한다. 더불어 다양한 영상을 적용한 실험으로 제안한 알고리즘의 효율성을 확인하였다.

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Application of an Energy Sensitive CZT Detector to a DXA Type of Bone Densitometer

  • Yoon, Je-Woong;Lee, Hyung-Koo;Lee, Heung-Kyu
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.422-424
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    • 2002
  • The accuracy of DXA(Dual Energy X-ray Absorptiometry) highly depends on the detection and separation capability of dual energy X-ray X-ray photons. In addition both of scan time and patient exposure are affected by detection efficiency. A CZT detector with a good energy resolution and high detection efficiency was evaluated for the application of bone densitometry. Its performance was compared to a photomultiplier tube with a NaI(T1) scintillator in terms of energy resolution, detection efficiency and the accuracy of bone mineral density measurement. The comparison study was performed with CZT detector and PM tube using DXA equipments(OSTEO Plus, OSTEO Prima, ISOL Technology). The energy spectrum was acquired using MCA(Multi-Channel Analyzer). The used X-ray energy ranged from 20keV to 86keV. The MCA result of the CZT detector showed a slightly sharper energy spectrum than that of NaI(T1). Detection efficiency of the CZT detector at 59.5keV was 1.4 times better. Remarkably the final results of bone mineral density measurements demonstrate only less than 1% difference. The CZT detector appears to have many benefits for the application of bone densitometry. Its excellent energy resolution can enhance the counting accuracy of dual energy X-ray spectrum. Furthermore its compactness in physical dimension and no cooling requirement will be additional benefits for a more compact and accurate bone densitometer.

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국산 이중에너지 방사선흡수 골밀도 장치와 GE Lunar Prodigy의 교차분석 식 도출에 관한 연구 (Cross-Calibration of Domestic Devices and GE Lunar Prodigy Advance Dual-Energy X-Ray Densitometer Devices for Bone Mineral Measurements)

  • 김정수;노영훈;이인주;김경아;이인자;김정민
    • 방사선산업학회지
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    • 제11권1호
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    • pp.27-31
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    • 2017
  • Reliable follow-up of bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA) is essential in clinical practice. When there is a difference in the BMD values from DXA systems in the same patient, cross calibration equation is required for the reliable follow-up. Unfortunately, no equation is existed in BMD measure between GE Lunar Prodigy Advance (US, GE Healthcare; LPA) and Osteosys Dexxum T (Korea, Osteosys; ODT) DXA systems. In this study, we evaluate the agreement of BMD values between LPA and ODT and suggest the cross calibration equation using European spine phantom (ESP) with two systems. We performed BMD measurements using ten scans with ESP in each DXA systems. We compared BMD values and calculated cross calibration equation by linear regression analysis. The comparison between the LPA and ODT bone densitometers used the ESP. Compared to the ESP BMD values, ODT underestimated 14.36% and LPA overestimated 12.96%. The average of total BMD measurement values acquired with ODT were 21.44% lower than those from LPA. Cross-calibration equation for LPA and ODT was derived from ESP. We calculated simple cross calibration equation for LPA and ODT DXA systems. Cross-calibration equation is necessary for the reliable follow-up of BMD values in two different systems.

이중에너지 방사선 흡수계측법(DEXA)을 이용한 성인들의 체구성과 골밀도 분석 (The analysis of body composition and bone mineral density in adult by using dual energy X-ray absorptiometry)

  • 이중철;한상완
    • The Journal of Korean Physical Therapy
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    • 제15권4호
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    • pp.466-478
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    • 2003
  • This study was to evaluate the body composition and bone mineral density according to aging in adult and investigated the relationship between various parameters such as body mass index(BMI), bone mineral density(BMD), bone mineral content(BMC), lean body mass(LBM), fat mass(FM) and the value obtained from dual energy X-ray absorptiometry(DEXA). The subjects were composed of healthy adult male and female who were $20^{\sim}73$ years old and they were divided three group according to age (A group : 20-39 yrs., B group : 40-59 yrs., C group : more than 60 yrs.). The conclusion derived from statistical analysis was as follows : 1. Bone mineral content and density were significantly affected by lean body mass(relatively, R=0.85 - 0.63). 2. There was significant difference among age groups in total bone mineral density. 3. There was significant difference among age groups in bone mineral content of male and female. 4. Lean body mass is diminished according to age, but there was not significant difference among age groups. 5. Fat mass of A group in male had the highest mass and followed by C group and B group. In female groups, fat mass of A group had the highest mass and followed by B group and C group. Abdominal fat mass is increased according to age. This result suggest that aging was closely relation with loss of muscle mass, bone mineral density and bone mineral content.

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이중에너지엑스선흡수기(Dual energy X-ray Absorptiometry: DXA)를 이용한 골밀도검사 결과분석에서 수동분석법의 유용성 평가 (Usefulness of Manual Analysis of Bone Mineral Density Using Dual Energy X-ray Absorptiometry)

  • 김은혜;곽종길;김호성
    • 방사선산업학회지
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    • 제12권4호
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    • pp.317-324
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    • 2018
  • The results of bone mineral density analysis using DXA were compared between automatic and manual methods. The purpose of this paper is to verify the range of errors of each analysis method in the same patient and select a proper method to minimize errors. Comparisons between automatic and manual analysis methods were made using BMD, BMC and AREA. Basal and follow up examinations were performed with the patients of normal, osteopenia and osteoporosis. In the basal examinations, the precision errors between automatic and manual method showed 1.9% in normal, 3.1% in osteopenia and 3.8% in osteoporosis. In case of follow up studies, the precision errors between automatic and manual method showed 2.3% in normal, 3.2% in osteopenia and 3.5% in osteoporosis. BMC and AREA also showed a tendency to increase precision errors on osteopenia and osteoporosis. Therefore, a manual method would be a better option to minimize errors in patients with osteopenia and osteoporosis.

이중에너지 X선 흡수계측법을 이용한 대퇴골 근위부의 형태학적 측정에 따른 골절 위험도의 예측 (Predict of Fracture Risk Rate According to Morphological Measuring of Proximal Femoral Part Using Dual Energy X-ray Absoptiometry)

  • 윤한식
    • 대한방사선기술학회지:방사선기술과학
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    • 제25권1호
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    • pp.49-53
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    • 2002
  • The femoral fracture is the most serious problem of old ages haying osteoporotic fractures. First of all, prevention to reduce the incidence of hip fracture and to identify the risk factor is essential subject. The purpose of this study is to investigate which geometric parameters of proximal femur are related to the hip fracture risk in old ages. Author analyzed the bone density and bone content of over 60 years old women who had suffered hip fracture (n=60) and non fracture groups (n=60). Author concluded that geometric measurements of proximal femoral part made on dual energy x-ray absorptiometry can predict hip fracture independently of bone mineral density.

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Does Simultaneous Computed Tomography and Quantitative Computed Tomography Show Better Prescription Rate than Dual-energy X-ray Absorptiometry for Osteoporotic Hip Fracture?

  • Ko, Jae Han;Lim, Suhan;Lee, Young Han;Yang, Ick Hwan;Kam, Jin Hwa;Park, Kwan Kyu
    • Hip & pelvis
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    • 제30권4호
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    • pp.233-240
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    • 2018
  • Purpose: This study aimed to evaluate the efficacy of simultaneous computed tomography (CT) and quantitative CT (QCT) in patients with osteoporotic hip fracture (OHF) by analyzing the osteoporosis detection rate and physician prescription rate in comparison with those of conventional dual-energy X-ray absorptiometry (DXA). Materials and Methods: This study included consecutive patients older than 65 years who underwent internal fixation or hip arthroplasty for OHF between February and May 2015. The patients were assigned to either the QCT (47 patients) or DXA group (51 patients). The patients in the QCT group underwent QCT with hip CT, whereas those in the DXA group underwent DXA after surgery, before discharge, or in the outpatient clinic. In both groups, the patients received osteoporosis medication according to their QCT or DXA results. The osteoporosis evaluation rate and prescription rate were determined at discharge, postoperative (PO) day 2, PO day 6, and PO week 12 during an outpatient clinic visit. Results: The osteoporosis evaluation rate at PO week 12 was 70.6% (36 of 51 patients) in the DXA group and 100% in the QCT group (P<0.01). The prescription rates of osteoporosis medication at discharge were 70.2% and 29.4% (P<0.001) and the cumulative prescription rates at PO week 12 were 87.2% and 60.8% (P=0.003) in the QCT and DXA groups, respectively. Conclusion: Simultaneous CT and QCT significantly increased the evaluation and prescription rates in patients with OHF and may enable appropriate and consistent prescription of osteoporosis medication, which may eventually lead to patients' medication compliance.

Use of Dual-Energy X-ray Absorptiometry in Children with Inflammatory Bowel Disease: A Large Single Centre Study

  • Jois, Asha;Perera, Sajini;Simm, Peter;Alex, George
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제25권6호
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    • pp.473-480
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    • 2022
  • Purpose: Low bone mineral density (BMD) is a complication in children with inflammatory bowel disease (IBD). There are limited data evaluating dual-energy x-ray absorptiometry (DXA) as a screening tool for low BMD in children with IBD. We performed a single site retrospective analysis of DXA use. Methods: Children aged 5-18 years with IBD diagnosed between 2013 to 2017 at the Royal Children's Hospital, Australia, were included. Patient demographics, measures of disease activity, DXA scores, and factors related to BMD were collected. Results: Over a median follow up of 5.1 (4-6.4) years, 72/239 (30.1%) children underwent DXA, and 28/239 (11.7%) children had a second DXA. Our DXA practice differed to consensus guidelines regarding initial screening based on height and/or body mass index (BMI) z-score (8/17 [47.1%]), and repeat surveillance (13/42 [31.0%]). Children had a median lumbar spine (LS) z-score -0.80 (-1.65-0.075). Children with LS z-score≤-2.0 (n=14) had lower weight (6.57 [1.78-23.7] vs. 51.1 [26.5-68.7], p=0.0002) and height centiles (3.62 [1.17-17.1] vs. 42 [16.9-67.1], p=0.0001), and higher faecal calprotectin (FCP) (3041 [1182-4192] vs. 585 [139-2419], p=0.009) compared to children with LS z-score>-2.0. No fractures were reported. Of 28 children who underwent a second DXA 1.6 (1.1-2.2) years following initial DXA, no significant change in z-scores occurred. Conclusion: Children with IBD had low BMD. In addition to height centile and weight centile, FCP was associated with lower BMD, and should be considered in DXA screening guidelines. Greater clinician awareness of DXA consensus guidelines is required. Future prospective studies are required.

모녀간의 골밀도 : 신체 측정치 및 체조성, 골지표, 영양소 섭취량 및 에너지 소비량과의 관계 (Bone Mineral Density of Korean Mother-daughter Pairs : Relations to Anthropometric Measurement, Body Composition, Bone Markers, Nutrient Intakes and Energy Expenditure)

  • 이희자
    • Journal of Nutrition and Health
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    • 제29권9호
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    • pp.991-1002
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    • 1996
  • The objectives of this study were to obtain normative data for 45 mother-daughter pairs on spine, femur(neck, ward's triangle, trochanter) and total body BMD (bone mineral density) measured by dual energy X-ray absorptiometry, anthropometric measurement, body composition, biochemical markers, nutrient intakes and energy expenditure, to determin the interrelations of these factors within each group, to measure familial resemblance for each variable. We observed significantly positive correlations between height, weight, head, hip and calf circumferences, tricep, femur and calf skinfold thickness, total lean body mass(=weight-total fat body mass-bone mineral content), protein and fat intakes, Ca index, serum total protein and albumin of monter-daughter pairs(p<.05-p<.001). Among mothers, age, osteocalcin, higher, weight, Ca and energy intakes were predictors of BMDs. Among daughters, weight and energy intake were predictors of BMDs. The BMD in lumbar spine(r=.48, p<.01), femoral neck(r=.38, p<.05), ward's triangle(r=.36, p<.05) of the mothers were significantly correlated with those of the daughters, after adjustment for mother's age, hight, weight, osteocalcin, Ca and energy intakes and daughter's weight, energy intake. In regression analyses, mother's BMD also were positively associated with daughter's BMD in lumbar spine, femoral neck, ward's triangle. Our findings support that mothers with low BMD tended to have daughters with low BMD. In the age groups studied, as well genetic factors as environmental factors may have an important role in determining BMD. This study suggests that women may successfully enhance their genetically determined BMD through adequate nutrient intakes and weight bearing exercise.

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