• 제목/요약/키워드: Dual energy X-ray

검색결과 309건 처리시간 0.031초

Virtual Monochromatic Image Quality from Dual-Layer Dual-Energy Computed Tomography for Detecting Brain Tumors

  • Shota Tanoue;Takeshi Nakaura;Yasunori Nagayama;Hiroyuki Uetani;Osamu Ikeda;Yasuyuki Yamashita
    • Korean Journal of Radiology
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    • 제22권6호
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    • pp.951-958
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    • 2021
  • Objective: To evaluate the usefulness of virtual monochromatic images (VMIs) obtained using dual-layer dual-energy CT (DL-DECT) for evaluating brain tumors. Materials and Methods: This retrospective study included 32 patients with brain tumors who had undergone non-contrast head CT using DL-DECT. Among them, 15 had glioblastoma (GBM), 7 had malignant lymphoma, 5 had high-grade glioma other than GBM, 3 had low-grade glioma, and 2 had metastatic tumors. Conventional polychromatic images and VMIs (40-200 keV at 10 keV intervals) were generated. We compared CT attenuation, image noise, contrast, and contrast-to-noise ratio (CNR) between tumor and white matter (WM) or grey matter (GM) between VMIs showing the highest CNR (optimized VMI) and conventional CT images using the paired t test. Two radiologists subjectively assessed the contrast, margin, noise, artifact, and diagnostic confidence of optimized VMIs and conventional images on a 4-point scale. Results: The image noise of VMIs at all energy levels tested was significantly lower than that of conventional CT images (p < 0.05). The 40-keV VMIs yielded the best CNR. Furthermore, both contrast and CNR between the tumor and WM were significantly higher in the 40 keV images than in the conventional CT images (p < 0.001); however, the contrast and CNR between tumor and GM were not significantly different (p = 0.47 and p = 0.31, respectively). The subjective scores assigned to contrast, margin, and diagnostic confidence were significantly higher for 40 keV images than for conventional CT images (p < 0.01). Conclusion: In head CT for patients with brain tumors, compared with conventional CT images, 40 keV VMIs from DL-DECT yielded superior tumor contrast and diagnostic confidence, especially for brain tumors located in the WM.

Sparse 표현을 이용한 이중 에너지 X 선 흡수 영상 잡음 제거 (Noise Reduction for Dual-energy X-ray Absorptiometry Image using Sparse Representation)

  • 김형일;엄원용;김대회;노용만
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2012년도 춘계학술발표대회
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    • pp.369-372
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    • 2012
  • 대사성 골 질환인 골다공증(Osteoporosis)의 조기 진단을 위한 골 밀도를 측정하는 방법이 최근 연구되고 있다. 골 밀도 영상은 이중 에너지 X 선 흡수법에 의해 측정되는데, 영상에 존재하는 잡음은 뼈 영역 추출과 골 밀도 계산에 어려움을 주고 있다. 따라서 본 논문에서는 최근 신호처리 분야에서 폭넓게 사용되고 있는 sparse 표현을 도입하여 X 선 영상의 잡음을 제거하는 방법을 제안한다. 실험을 통해 제안한 잡음 제거 방법의 결과가 기존의 방법에 비해 개선됨을 MSR(Mean to Standard deviation Ratio)과 CNR(Contrast to Noise Ratio)을 통해 확인하였다.

DEXA사에 의한 일부 남자농구선수들의 체구성에 관한 연구 -체지방량, 체구성, 비율, 체조직 구성 비율, 골광물질함량과 골밀도를 중심으로- (A Study on the Body Composition in Korean Basketball Players by Dual Energy X -ray Absorptiometry)

  • 박경래;강동원;최중명;박순영
    • 보건교육건강증진학회지
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    • 제15권1호
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    • pp.179-194
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    • 1998
  • This study focused on the body composition of Korean Basketball Players in Dual X -ray Absorptiometry. The principal subjects of this study were 10 Basketball Players who participated in the process of Dual Energy X -ray Absorptiometry at K.H. University Hospital for 8 months from Sept. 1. 1996 to April, 30. 1997. On the basis of the these measurements, the authors calculated physical indices and total fat percent. On the results of bone densitometry, the author analyzed body fat weight, body composition according to body position, bone mineral density and discerned the difference between the fatness which was calculated indirectly and which gained from the bone densitometry. 1. General Characteristics The mean age of the subjects was 20.4$\times$1.35 year. 2. Physical. Measurement The mean physical growth and development of the subjects were superior to standard value of the average Koreans 3. Body Fat by Physical Measurement Body surface area was 2.019$\times$0.111$m^2$, body volume was 74.4$\times$7.2$\ell$, body density was 1.041$\times$0.007$\ell$/kg, and body fat percent was 24.9$\times$2.9%. 4. Body Fat by Bone Densitometry Total body fat percent was 15.17$\times$2.19% and according to body position that of upper limb was 1.62%, that of lower limb was 5.55%, that of trunk was 7.06% and that of head was 1.05%. There was significant difference between the amounts of body fat from the methods used in this study; that from physical measurements and from bone densitometry method could be said most desirable. 5. Body composition According to Body Position Trunk was highest at 46.7%, lower limb was 36.0%, upper limb was 10.6%, and head was 6.7% in order. 6. Bone Mineral Content and Bone Density In bone mineral amount by body position, that of upper limb was 466.9$\times$46.4g, that of lower limb was 1,424.1$\times$154.0g, that of trunk was 1,343.0$\times$150.3g, and total bone mineral content was 3,786.8$\times$348.4g(4.78$\times$0.13%). Bone mineral density by body position, that of upper limb was 0.758$\times$0.072g/$\textrm{cm}^2$, that of lower limb was 1,342$\times$0.095g/$\textrm{cm}^2$, that of trunk was 1,169$\textrm{cm}^2$0.082g/$\textrm{cm}^2$, that of head was 1,742$\times$0.154g/$\textrm{cm}^2$ and total bone mineral density was 1,204$\times$0.077g/$\textrm{cm}^2$.

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건강한 성인 남녀의 골밀도와 골다공증 위험요인 (Bone Mineral Density and Risk Factors of Osteoporosis in Healthy Men and Women)

  • Shin, Su-Jin;Shin, Kyung-Rim;Shin, Chol;Park, Sun-Young
    • 보건교육건강증진학회지
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    • 제25권5호
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    • pp.53-64
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    • 2008
  • 목적. 본 연구의 목적은 골다공증의 유병률을 확인하고 건강증진 프로그램의 우선적 대상을 확인하고자 실시되었다. 방법. 연구대상자는 Ansan Health Study센터를 방문한 18-84세의 성인 남녀 1,269명이었다. 위험요인을 평가하기 위한 질문지를 이용하였고 DEXA(Dual Energy X-ray Absorptiometry)를 이용하여 2번 요추와 대퇴의 골밀도를 측정하였다. 수집된 자료는 SPSS12.0프로그램을 이용하여 분석하였다. 결과. 골밀도는 50대와 60대 여성에게서 급격히 감소하였으며, 골다공증 유병률은 대퇴와 요추를 기준으로 남성은 각각 0.8%, 6.3%, 여성은 0.9%와 7.1%로 나타났다. 골다공증 지식 정도는 골밀도와 유의한 순상관관계가 있는 것으로 나타났다. 결론. 본 연구의 결과는 골다공증 예방 프로그램을 위한 효과적이고 실제적인 중재전략을 위한 기초자료를 제공하였다.

방사선 촬영 기법을 이용한 양서류 신체상태 평가: 골밀도와 먹이 자원 가용성 간의 상관 관계 (Assessment of Body Condition in Amphibians Using Radiography: Relationship between Bone Mineral Density and Food Resource Availability)

  • 박준규;도윤호
    • 생태와환경
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    • 제52권4호
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    • pp.358-365
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    • 2019
  • 본 연구에서는 방사선 촬영 기법을 사용하여 국내에 서식하는 무미양서류인 청개구리 (Hyla japonica), 옴개구리(Glandirana rugosa), 참개구리(Pelophylax nigromaculatus), 황소개구리(Lithobates catesbeianus)의 체성분과 골밀도를 분석하였다. 이중 엑스선 촬영 장치(Dual-energy X-ray absorptiometry)를 사용하여 체성분과 골밀도를 측정하였으며 암수 간 차이와 종 간 차이를 파악하였다. 또한 방사선 촬영 기법을 사용한 신체 상태 평가 방법의 효용성을 확인하기 위해 무미양서류 4종의 먹이자원 가용성을 파악하고 신체상태와의 관계를 확인하였다. 신체를 구성하는 성분인 골, 지방, 제지방 비율과 골밀도는 암수 간 차이가 없었지만 무미양서류 4종 간 차이는 있었다. 골밀도와 먹이자원 가용성은 황소개구리가 가장 높았으며 청개구리가 가장 낮았다. 옴개구리와 참개구리의 먹이자원 가용성은 차이는 없었다. 골밀도와 먹이자원 가용성은 유의미한 상관관계를 가졌으며 먹이 상태를 나타내는 질소 안정동위원소비는 골밀도에 의해서만 변화하는 것을 확인하였다. 기회적 포식자인 무미양서류의 먹이 상태 혹은 자원 가용성이 체성분은 물론 골밀도에 영향을 미칠 수 있다. 개체의 신체 상태를 나타내는 체성분과 골밀도는 무미양서류에서 서식지의 안정성을 평가하는 생태지표로서 사용이 가능할 것으로 보인다.

제2형 당뇨환자와 정상성인의 골밀도 비교 (Comparison of Bone Mineral Density in Type II Diabetic Patient's and Healthy Elderly Individuals)

  • 윤세원;최석주;정대인;박래준;김한수;김계엽;김태열
    • The Journal of Korean Physical Therapy
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    • 제18권2호
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    • pp.17-24
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    • 2006
  • Purpose: This study was aimed for service to clinical data of physical therapy necessity of bone complication through analysis method of BMD (bone mineral density) used DEXA (dual energy X-ray absorptiometry) to their skeletal system for physical therapy assesement and intervention program in type II diabetic patients. Methods: Experimental group of 75 subjects and comparison group of 62 subjects were participated in type II diabetic patients(40-80 ages). BMD was measured by DEXA. BMD change of BMI score and BMD comparison of age and sex would be known. Results: This study was found that decreased BMD and increased osteopenea in type II diabetes. In particular, women were lower BMD and higher incidence of osteopenea than men. Men showed significant difference in normal group. Influence of type II diabetes was great on change of BMD in men. however, it showed no significant difference from normal group. Conclusion: it was found that skeletal system complication by type II diabetes had some relations. Because reduction of BMD had a great danger to induce trauma by fall or degenerative disease of system, evaluation of proper physical therapy for its prevention and improvement and intervention program are needed. In addition, it would be important to divide type II diabetic patients into osteopenea and osteoporosis changes of skeletal system at comprehensive aspect of physical therapy.

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Cissus quadrangularis Extracts Decreases Body Fat Through Regulation of Fatty acid Synthesis in High-fat Diet-induced Obese Mice

  • Lee, Hae Jin;Lee, Dong-Ryung;Choi, Bong-Keun;Park, Sung-Bum;Jin, Ying-Yu;Yang, Seung Hwan;Suh, Joo-Won
    • Journal of Applied Biological Chemistry
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    • 제59권1호
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    • pp.49-56
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    • 2016
  • The current study investigated the anti-obesity effect of Cissus quadrangularsis extracts (CQR-300) and its molecular action mechanism on obese mice induced high-fat diet (HFD). To induce the obesity, mice were fed a HFD for 6 weeks and then fed HFD only or HFD with CQR-300 at 50 and 200 mg/kg. Then, body weight gain and white adipose tissue weights were measured. We investigated the reduction in body fat and the regulation of fatty acid synthesis was measured by dual energy X-ray absorptiometry and real-time PCR with Western blot, respectively. In vitro study, CQR-300 inhibited pancreatic lipase activity. The CQR-300 treatment was significantly decreased the body weight gain and adipocytes size as well as white adipose tissues weights in HFD-induced obese mice. Furthermore, CQR-300 reduced the body fat and fat mass with regulating of adipose tissue hormones as leptin. Treatment with 50 mg/kg CQR-300 showed effectively lower expression levels of adipogenesis/lipogenesis related genes and proteins such as CCAAT/enhancer binding protein ${\alpha}$ ($C/EBP{\alpha}$), peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$), Sterol regulatory element binding protein-1c (SREBP-1c), and fatty acid synthase (FAS) in white adipose tissue (WAT) as compared with the HFD fed only mice. These results suggest that the CQR-300 has an anti-obesity effect via inhibition of lipase activity, decrease the body fat mass by regulating the adipogenesis and lipogenesis related genes and proteins in epididymal adipose tissue with evaluate body fat reduce in the HFD-induced obese mice.