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Sample records for dual-energy x-ray absorptiometry

  1. Vertebral morphometry by dual-energy X-ray absorptiometry

    International Nuclear Information System (INIS)

    Boyanov, M.

    2002-01-01

    Vertebral fractures are a key feature of overt osteoporosis. Different X-ray morphometric techniques have been developed for quantification of changes in vertebral body shape. In recent years, a new method was implemented based on dual-energy X-ray absorptiometry. Morphometric X-ray absorptiometry, MXA, is a source of lower radiation and there is no image distortion. Several aspects of its application are under heavy discussion: image quality, accuracy and precision, reference databases, age changes in vertebral shape. The differential diagnosis of vertebral fracture/deformity is difficult. MXA has prove its value in large epidemiological studies on prevalence of vertebral deformities, as well in assessing the effects of different diseases and medications on vertebral body architecture. MXA is a promising method for future research and clinical work. (author)

  2. Research of age changes of bone tissue of dual-energy X-ray absorptiometry

    International Nuclear Information System (INIS)

    Rizhik, V.M.; Kmetyuk, V.M.; Fed'kyiv, S.V.

    2003-01-01

    With the help of a method dual-energy x-ray absorptiometry (DEXA) mineral density bone tissue was defined in view of age, sex and individual features. Is established, that the parameters (DEXA) have precise interrelation with age changes in bone tissue, which aris with osteoporosis and have the certain clinical value

  3. Bone age assessment by dual-energy X-ray absorptiometry in children: an alternative for X-ray?

    Science.gov (United States)

    Heppe, D H M; Taal, H R; Ernst, G D S; Van Den Akker, E L T; Lequin, M M H; Hokken-Koelega, A C S; Geelhoed, J J M; Jaddoe, V W V

    2012-02-01

    The aim of the study was to validate dual-energy X-ray absorptiometry (DXA) as a method to assess bone age in children. Paired dual-energy X-ray absorptiometry (DXA) scans and X-rays of the left hand were performed in 95 children who attended the paediatric endocrinology outpatient clinic of University Hospital Rotterdam, the Netherlands. We compared bone age assessments by DXA scan with those performed by X-ray. Bone age assessment was performed by two blinded observers according to the reference method of Greulich and Pyle. Intra-observer and interobserver reproducibility were investigated using the intraclass correlation coefficient (ICC), and agreement was tested using Bland and Altman plots. The intra-observer ICCs for both observers were 0.997 and 0.991 for X-ray and 0.993 and 0.987 for DXA assessments. The interobserver ICC was 0.993 and 0.991 for X-ray and DXA assessments, respectively. The mean difference between bone age assessed by X-ray and DXA was 0.11 years. The limits of agreement ranged from -0.82 to 1.05 years, which means that 95% of all differences between the methods were covered by this range. Results of bone age assessment by DXA scan are similar to those obtained by X-ray. The DXA method seems to be an alternative for assessing bone age in a paediatric hospital-based population.

  4. Dual-energy X-ray absorptiometry predicts bone formation in lower limb callotasis lengthening.

    OpenAIRE

    Maffulli, N.; Cheng, J. C.; Sher, A.; Lam, T. P.

    1997-01-01

    The rate of regenerate bone mineral content (BMC) acceleration was studied using dual-energy X-ray absorptiometry (DEXA) in callotasis lengthening of the lower limb. Eleven youngsters (age range 5-17 years) undergoing callotasis lengthening for congenital, post-traumatic or post-infective conditions were studied longitudinally. Patients were initially scanned once a week until completion of the lengthening phase, and at 2-week intervals thereafter until removal of the fixator. They were subse...

  5. Reference Values for Assessment of Unilateral Limb Lymphedema with Dual-Energy X-Ray Absorptiometry

    DEFF Research Database (Denmark)

    Gjorup, Caroline A; Hendel, Helle W; Klausen, Tobias W

    2018-01-01

    INTRODUCTION: The clinical assessment of unilateral limb lymphedema is commonly based on measurements of interlimb volume differences. Reference values for interlimb percentage differences of the volume, fat mass, and lean mass measured with dual-energy X-ray absorptiometry (DXA) scan are, however...... is calculated as follows: ("Limb-of-interest"-contralateral)/contralateral × 100. The interlimb percentage differences for the limb-of-interest were stratified to upper (according to handedness) and lower limbs and categorized as none/mild, moderate, or severe, respectively, based on whether the value is below...

  6. Body composition in hemodialysis patients measured by dual-energy X-ray absorptiometry

    DEFF Research Database (Denmark)

    Stenver, Doris Irene; Gotfredsen, Arne; Hilsted, J

    1995-01-01

    Dual-energy X-ray absorptiometry (DXA) measures three of the principal components of the body: fat mass, lean soft-tissue mass (comprising muscle, inner organs, and the body water), and the bone mineral content. The purpose of this study was to test the estimation capacity of DXA when it is applied...... and reduction in fat-free mass (lean soft-tissue mass plus bone mineral content) was observed by DXA. The estimation of the fat-free mass was independent of the amount of fluid loss. No significant differences in variance between the data obtained before and after the dialysis were observed. We conclude...

  7. Dual-energy X-ray absorptiometry for the simultaneous determination of Density and Moisture Content in Porous Structural Materials

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard; Jensen, Signe Kamp; Gerward, Leif

    1999-01-01

    The paper describes the dual-energy x-ray equipment, which consists of a x-ray source, filters and a detector. The x-ray beam can be moved automatically in two dimensions relative to a fixed specimen. The purpose of the equipment is to measure simultaneously the density and moisture content...... in porous materials relevant for the building industry. The theory of dual-energy x-ray absorptiometry (DEXA) is presented. DEXA results on two combinations of aluminium and acrylic plastic are compared with corresponding values calculated from the geometry of the experimental setup. The results from the x......-ray measurements show good agreement with results from the two standard materials which imitate water in a porous material. On this background the dual-energy x-ray absorptiometry measurement principle can be used on porous structural materials....

  8. Direct X-ray radiogrammetry versus dual-energy X-ray absorptiometry: assessment of bone density in children treated for acute lymphoblastic leukaemia and growth hormone deficiency

    NARCIS (Netherlands)

    van Rijn, Rick R.; Boot, Annemieke; Wittenberg, Rianne; van der Sluis, Inge M.; van den Heuvel-Eibrink, Marry M.; Lequin, Maarten H.; de MuinckKeizer-Schrama, Sabine M. P. F.; van Kuijk, Cornelis

    2006-01-01

    BACKGROUND: In recent years interest in bone densitometry in children has increased. OBJECTIVE: To evaluate the clinical application of digital X-ray radiogrammetry (DXR) and compare the results with those of dual-energy X-ray absorptiometry (DXA). MATERIALS AND METHODS: A total of 41 children with

  9. Pediatric body composition analysis with dual-energy X-ray absorptiometry

    International Nuclear Information System (INIS)

    Helba, Maura; Binkovitz, Larry A.

    2009-01-01

    Pediatric applications of body composition analysis (BCA) have become of increased interest to pediatricians and other specialists. With the increasing prevalence of morbid obesity and with an increased awareness of anorexia nervosa, pediatric specialists are utilizing BCA data to help identify, treat, and prevent these conditions. Dual-energy X-ray absorptiometry (DXA) can be used to determine the fat mass (FM) and lean tissue mass (LTM), as well as bone mineral content (BMC). Among the readily available BCA techniques, DXA is the most widely used and it has the additional benefit of precisely quantifying regional FM and LTM. This review evaluates the strengths and limitations of DXA as a pediatric BCA method and considers the utilization of DXA to identify trends and variations in FM and LTM measurements in obese and anorexic children. (orig.)

  10. Pediatric body composition analysis with dual-energy X-ray absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Helba, Maura; Binkovitz, Larry A. [Nationwide Children' s Hospital, Department of Radiology, Columbus, OH (United States)

    2009-07-15

    Pediatric applications of body composition analysis (BCA) have become of increased interest to pediatricians and other specialists. With the increasing prevalence of morbid obesity and with an increased awareness of anorexia nervosa, pediatric specialists are utilizing BCA data to help identify, treat, and prevent these conditions. Dual-energy X-ray absorptiometry (DXA) can be used to determine the fat mass (FM) and lean tissue mass (LTM), as well as bone mineral content (BMC). Among the readily available BCA techniques, DXA is the most widely used and it has the additional benefit of precisely quantifying regional FM and LTM. This review evaluates the strengths and limitations of DXA as a pediatric BCA method and considers the utilization of DXA to identify trends and variations in FM and LTM measurements in obese and anorexic children. (orig.)

  11. Dual Energy X Ray Absorptiometry for Bone Mineral Density and Body Composition Assessment

    International Nuclear Information System (INIS)

    2010-01-01

    The IAEA assists Member States in their efforts to develop effective evidence based interventions to combat malnutrition in all its forms using nuclear techniques. The unique characteristics of nuclear techniques in nutrition, in particular stable isotope techniques and dual energy X ray absorptiometry (DXA), make these methods highly suitable for development and evaluation of interventions to address the double burden of malnutrition, i.e. 'undernutrition' and 'overnutrition', globally. This publication provides information on the theoretical background and practical application of state of the art methodology for bone mineral density (BMD) measurements and body composition assessment by DXA. The IAEA has contributed to the development and transfer of technical expertise in the use of DXA in Member States through support to national and regional nutrition projects via the technical cooperation programme and coordinated research projects addressing priority areas in nutrition. This book will be an important part of the IAEA's efforts to transfer technology and to contribute to capacity building in this field

  12. A status report on dual energy x-ray absorptiometry quality control in Korea

    International Nuclear Information System (INIS)

    Kim, Jung Su; Ro, Young Hoon; Lee, In Ju; Kim, Jung Min; Kim, Sung Su; Kim, Kyoung Ah

    2016-01-01

    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

  13. Neonatal anthropometrics and body composition in obese children investigated by dual energy X-ray absorptiometry

    DEFF Research Database (Denmark)

    Lausten-Thomsen, Ulrik; Nielsen, Tenna Ruest Haarmark; Thagaard, Ida Näslund

    2014-01-01

    index (BFMI), and fat free mass index (FFMI) in obese children and the preceding in utero conditions expressed by birth weight, birth length, and birth weight for gestational age. The study cohort consisted of 776 obese Danish children (median age 11.6 years, range 3.6-17.9) with a mean Body Mass Index......UNLABELLED: Epidemiological and animal studies have suggested an effect of the intrauterine milieu upon the development of childhood obesity. This study investigates the relationship between body composition measured by dual energy X-ray absorptiometry expressed as body fat percent, body fat mass...... Standard Deviation Score (BMI SDS) of 2.86 (range 1.64-5.48) treated in our national referral centre. In a linear general regression model adjusted for age, gender, socioeconomic status, and duration of breastfeeding, we found the body fat percent, FFMI, and BFMI at the time of enrolment in childhood...

  14. A status report on dual energy x-ray absorptiometry quality control in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Su [Dept. of Radiogic Technology, Chungbuk Health and Science University, Cheongju (Korea, Republic of); Ro, Young Hoon; Lee, In Ju; Kim, Jung Min [Dept. of Bio-convergence Engineering, Korea University Graduate School, Seoul (Korea, Republic of); Kim, Sung Su [Dept. of Healthcare Management, Cheongju University, Cheongju (Korea, Republic of); Kim, Kyoung Ah [Dept. of Diagnostic Radiology, CHA Bundang Medical Center, CHA University, Sungnam (Korea, Republic of)

    2016-12-15

    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.

  15. Radiographic measurement of bone mineral: reviewing dual energy X-ray absorptiometry

    International Nuclear Information System (INIS)

    Sim, L.H.; van Doorn, T.

    1995-01-01

    Radiographic methods of bone mineral measurement have been reviewed, with particular emphasis on the methods of Dual Energy X-ray Absorptiometry (DEXA). Features of the three major brands of DEXA equipment available in Australasia have been summarised. Radiation hazard is considered to be small, with patient effective doses of the order of a few microSieverts. In vivo measurement precision of the order of 1% is achievable for PA scans of the lumbar spine. Lateral scans can achieve measurement precision of the order of 4%. Recent technological developments using X-ray fan beams and multi element detector arrays on C-arm devices have resulted in faster scan times, higher resolution images, and an ability to perform PA and lateral scanning without the need to reposition the patient. Accuracy of DEXA is dependent upon specific instrumentation and data reduction algorithms, but results generally correlate well with ashed bone measurements. Major sources of inaccuracy include inhomogeneous distributions of fat, and machine specific factors such as edge detection algorithms. Lack of absolute inter unit comparability may cause difficulties in clinical practice. 88 refs., 5 figs

  16. Assessment of body composition by dual-energy X-ray absorptiometry, bioimpedance analysis and anthropometrics in children

    DEFF Research Database (Denmark)

    Tompuri, Tuomo T; Lakka, Timo A; Hakulinen, Mikko

    2015-01-01

    We compared InBody720 segmental multifrequency bioimpedance analysis (SMF-BIA) with Lunar Prodigy Advance dual-energy X-ray absorptiometry (DXA) in assessment of body composition among 178 predominantly prepubertal children. Segmental agreement analysis of body compartments was carried out...

  17. Pediatric dual-energy X-ray absorptiometry: interpretation and clinical and research application

    Directory of Open Access Journals (Sweden)

    Jung Sub Lim

    2010-03-01

    Full Text Available 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.

  18. Fundamental evaluation of bone densitometry using dual energy X-ray absorptiometry (DEXA)

    Energy Technology Data Exchange (ETDEWEB)

    Koizumi, Kiyoshi; Uchiyama, Guio; Araki, Tsutomu (Yamanashi Medical Coll., Tamaho (Japan)) (and others)

    1990-02-01

    A newly developed instrument based on dual energy X-ray absorptiometry (DEXA), Hologic QDR-1000, was evaluated fundamentally and clinically. Image quality was quite satisfactory though radiation exposure was minimal, 780.2 nC/kg (3.024 mR) for lumbar measurement. Reproducibility of the repeated measurement of a phantom was fairly good; 0.343 CV% in a same day and 0.520 CV% in a long period. Accuracy determined by measurement of potassium phosphate solution was also satisfactory. Bone mineral densities measured by this instrument were fairly correlated with those measured by single energy quantitative CT; coefficient was 0.740 for 17 patients. Mix-DP plates of more than 10 cm thick overestimated the bone mineral densities of a phantom. Bone mineral densities of Japanese normal volunteers were in the normal range (mean {plus minus} 2SD) of the Americans though mostly lower than the mean. In patients with spondylosis deformans or prominent aortic calcification, bone mineral densities might be overestimated. Lateral view was obtainable though its reproducibility was not good. Positioning especially for measuring femoral neck was quite critical for reproducible measurement. In conclusion, this new instrument is quite accurate and satisfactory for clinical application to measuring bone mineral densities. (author).

  19. Fundamental evaluation of bone densitometry using dual energy X-ray absorptiometry (DEXA)

    International Nuclear Information System (INIS)

    Koizumi, Kiyoshi; Uchiyama, Guio; Araki, Tsutomu

    1990-01-01

    A newly developed instrument based on dual energy X-ray absorptiometry (DEXA), Hologic QDR-1000, was evaluated fundamentally and clinically. Image quality was quite satisfactory though radiation exposure was minimal, 780.2 nC/kg (3.024 mR) for lumbar measurement. Reproducibility of the repeated measurement of a phantom was fairly good; 0.343 CV% in a same day and 0.520 CV% in a long period. Accuracy determined by measurement of potassium phosphate solution was also satisfactory. Bone mineral densities measured by this instrument were fairly correlated with those measured by single energy quantitative CT; coefficient was 0.740 for 17 patients. Mix-DP plates of more than 10 cm thick overestimated the bone mineral densities of a phantom. Bone mineral densities of Japanese normal volunteers were in the normal range (mean ± 2SD) of the Americans though mostly lower than the mean. In patients with spondylosis deformans or prominent aortic calcification, bone mineral densities might be overestimated. Lateral view was obtainable though its reproducibility was not good. Positioning especially for measuring femoral neck was quite critical for reproducible measurement. In conclusion, this new instrument is quite accurate and satisfactory for clinical application to measuring bone mineral densities. (author)

  20. A study of percentage body fat in children via dual energy X-ray absorptiometry (DEXA)

    International Nuclear Information System (INIS)

    Kawano, Shoji; Yagi, Shinichi; Fujino, Mitsuyoshi; Tanaka, Hiroyuki; Morita, Tetsuro; Fukunaga, Masao

    1994-01-01

    Percentage body fat was measured using dual energy X-ray absorptiometry (DEXA), bioelectrical impedance analysis (BIA) and skin fold calipers on 26 children (nine in obesity group, 12 in healthy group and 5 in steroid treated group). Mean percent body fat did not differ significantly between methods in the whole subjects as well as the healthy group and the steroid treated group. However, the mean percent body fat using skin fold caliper was higher for the obesity group than the other two. The measurements of all cases in the obesity group by DEXA were higher than those of BIA. There were high correlations among the percent body fat obtained by each technique. According to the analysis of mean regional percent fat, the percent fat of legs was the highest in the healthy and steroid treated group, while there was no regional difference in the obesity group. It should be possible to classify each case in the obesity group into upper segment and lower segment obesity by DEXA. (author)

  1. Dual Energy X Ray Absorptiometry for Bone Mineral Density and Body Composition Assessment (Arabic Edition)

    International Nuclear Information System (INIS)

    2013-01-01

    The IAEA assists Member States in their efforts to develop effective evidence based interventions to combat malnutrition in all its forms using nuclear techniques. The unique characteristics of nuclear techniques in nutrition, in particular stable isotope techniques and dual energy X ray absorptiometry (DXA), make these methods highly suitable for development and evaluation of interventions to address the double burden of malnutrition, i.e. 'undernutrition' and 'overnutrition', globally. This publication provides information on the theoretical background and practical application of state of the art methodology for bone mineral density (BMD) measurements and body composition assessment by DXA. The IAEA has contributed to the development and transfer of technical expertise in the use of DXA in Member States through support to national and regional nutrition projects via the technical cooperation programme and coordinated research projects addressing priority areas in nutrition. This book will be an important part of the IAEA's efforts to transfer technology and to contribute to capacity building in this field. The publication was developed by an international group of experts and is intended for nutritionists, radiation technologists, researchers and health professionals using DXA for BMD measurements and body composition assessment.

  2. Clinical usefulness of calcaneal measurements using dual energy x-ray absorptiometry

    International Nuclear Information System (INIS)

    Kohno, Jun; Nakata, Tomoko; Ito, Masako

    1999-01-01

    To investigate the clinical usefulness of calcaneal measurement using dual-energy x-ray absorptiometry (DXA), the ability to detect bone loss and fracture risk were evaluated in comparison with spinal bone mineral density (BMD) measured using DXA and quantitative CT (QCT) and with calcaneal quantitative ultrasound (QUS). Furthermore, to investigate the region in calcaneus in which to detect bone change sensitively, the ability to detect bone loss and fracture risk were also evaluated using new regions of interest (ROIs) that were manually defined. The subjects were 165 healthy women, and 188 female patients with fracture, estrogen deficiency, and steroid-induced osteoporosis. Calcaneal BMD with some manually defined ROIs showed lower precision and less sensitivity in detecting bone loss than BMD measured with automatically defined ROIs. Calcaneal DXA, spinal DXA, and QCT demonstrated significant age-related bone loss, and all measurements could discriminate fracture cases from non-fracture cases. Calcaneal DXA could discriminate the bone loss associated with estrogen deficiency as well as spinal DXA. Furthermore, calcaneal measurements showed a greater ability to detect steroid-induced bone loss than spinal DXA, probably because this group included subjects of advanced age with spondylosis. In conclusion, calcaneal DXA is useful to assess BMD in subjects who are not suitable for spinal measurement, although the ability to detect age-related bone loss in calcaneal DXA is less than in spinal measurements. (author)

  3. Bone mineral analysis through dual energy X-ray absorptiometry in laboratory animals

    International Nuclear Information System (INIS)

    Tsujio, Masashi; Mizorogi, Toshihiro; Kitamura, Itsuko

    2009-01-01

    To determine how to eliminate species difference in animal bone experiment, bone mineral content (BMC) was measured using dual energy X-ray absorptiometry (DXA) on the femurs of laboratory mice (Mus musculus) and rats (Rattus norvegicus), and common marmosets (Callithrix jacchus). Measures were taken on femurs in situ, detached from the body, skinned and defleshed, or dried completely. When the BMC of the bone measured in the intact limb attached to the trunk was set at 100%, the actual BMC of the dry bone was 58.7±11.5% in mice and 103.2±3.2% in rats. Similarly, the bone area (Area) and bone mineral density (BMD) of the dried femur was significantly lower in the mouse femurs than intact limb. Thus, soft limb tissue such as skin and muscle modified the BMC, Area, and BMD only in mouse but not in those from rats or marmosets. The bone mineral ratio (BMR; BMC divided by dry bone weight) was nearest to the human bone value in the rat femurs, whereas the mouse femur BMR was the most different. The BMR was proved to be a practical index in evaluating bone characteristics in laboratory animals, but the mouse femur might not be suitable as an animal model for research into the aging of human bone. (author)

  4. The evaluation of breast tissues removed during reductive mammaplasty with dual energy X-ray absorptiometry

    International Nuclear Information System (INIS)

    De Lorenzo, Antonino; Gravante, Gianpiero; Sorge, Roberto; Nicoli, Fabio; Caruso, Riccardo; Araco, Antonino; Servidio, Michele; Orlandi, Augusto; Cervelli, Valerio

    2009-01-01

    Purpose: We conducted a case-control study in which patients were evaluated with dual energy X-ray absorptiometry (DEXA) before and after breast reduction surgery, and results were correlated with the histological examination. Our goal was to confirm the DEXA as a precise technique for the measurement of breast composition, in order to propose it for the preoperative evaluation of plastic surgery patients. Materials and methods: We prospectively recruited all women that underwent reduction mammaplasty and excluded patients with contraindications to the operation or those that previously underwent bariatric surgery to reduce their weight. Patients were evaluated with DEXA 1 week before and after surgery. Results: From February to October 2006 we recruited 25 patients. The statistical analysis found a significant reduction of weight, BMI, regional fat free mass and fat mass after the operation. The comparison between DEXA and the histological analysis produced a correlation r = 0.989 (r 2 = 0.978), with a predictivity of 98% and a percentage of error 8.3% (95% confidence intervals -252.6, 273.7; 95% limits of agreements of Bland and Altman -436.0, 457.1). Similar results were obtained with the analysis of fat. Conclusions: Our study demonstrated that conventional segmental DEXA is a very precise technique to measure the amount of tissue removed in breast reductions and could open future application in the preoperative assessment of patients undergoing such operations.

  5. Prevalence and type of errors in dual-energy X-ray absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Messina, Carmelo; Bandirali, Michele; D' Alonzo, Nathascja Katia [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milano (Italy); Sconfienza, Luca Maria; Sardanelli, Francesco [IRCCS Policlinico San Donato, Unita di Radiologia, San Donato Milanese (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, San Donato Milanese (Italy); Di Leo, Giovanni; Papini, Giacomo Davide Edoardo [IRCCS Policlinico San Donato, Unita di Radiologia, San Donato Milanese (Italy); Ulivieri, Fabio Massimo [IRCCS Fondazione Ca' Granda Ospedale Maggiore Policlinico, Mineralometria Ossea Computerizzata e Ambulatorio Malattie Metabolismo Minerale e Osseo, Servizio di Medicina Nucleare, Milano (Italy)

    2015-05-01

    Pitfalls in dual-energy x-ray absorptiometry (DXA) are common. Our aim was to assess rate and type of errors in DXA examinations/reports, evaluating a consecutive series of DXA images of patients examined elsewhere and later presenting to our institution for a follow-up DXA. After ethics committee approval, a radiologist retrospectively reviewed all DXA images provided by patients presenting at our institution for a new DXA. Errors were categorized as patient positioning (PP), data analysis (DA), artefacts and/or demographics. Of 2,476 patients, 1,198 had no previous DXA, while 793 had a previous DXA performed in our institution. The remaining 485 (20 %) patients entered the study (38 men and 447 women; mean age ± standard deviation, 68 ± 9 years). Previous DXA examinations were performed at a total of 37 centres. Of 485 reports, 451 (93 %) had at least one error out of a total of 558 errors distributed as follows: 441 (79 %) were DA, 66 (12 %) PP, 39 (7 %) artefacts and 12 (2 %) demographics. About 20 % of patients did not undergo DXA at the same institution as previously. More than 90 % of DXA presented at least one error, mainly of DA. International Society for Clinical Densitometry guidelines are very poorly adopted. (orig.)

  6. The evaluation of breast tissues removed during reductive mammaplasty with dual energy X-ray absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    De Lorenzo, Antonino [Division of Human Nutrition, University of Tor Vergata in Rome (Italy); Gravante, Gianpiero [Division of Human Nutrition, University of Tor Vergata in Rome (Italy); Department of Surgery, Whipps Cross University Hospital, London (United Kingdom)], E-mail: ggravante@hotmail.com; Sorge, Roberto [Laboratory of Biometry, University of Tor Vergata in Rome (Italy); Nicoli, Fabio; Caruso, Riccardo; Araco, Antonino [Department of Plastic Surgery, University of Tor Vergata in Rome (Italy); Servidio, Michele [Division of Human Nutrition, University of Tor Vergata in Rome (Italy); Orlandi, Augusto [Department of Biopathology, Anatomic Pathology Institute, University of Tor Vergata in Rome (Italy); Cervelli, Valerio [Department of Plastic Surgery, University of Tor Vergata in Rome (Italy)

    2009-06-15

    Purpose: We conducted a case-control study in which patients were evaluated with dual energy X-ray absorptiometry (DEXA) before and after breast reduction surgery, and results were correlated with the histological examination. Our goal was to confirm the DEXA as a precise technique for the measurement of breast composition, in order to propose it for the preoperative evaluation of plastic surgery patients. Materials and methods: We prospectively recruited all women that underwent reduction mammaplasty and excluded patients with contraindications to the operation or those that previously underwent bariatric surgery to reduce their weight. Patients were evaluated with DEXA 1 week before and after surgery. Results: From February to October 2006 we recruited 25 patients. The statistical analysis found a significant reduction of weight, BMI, regional fat free mass and fat mass after the operation. The comparison between DEXA and the histological analysis produced a correlation r = 0.989 (r{sup 2} = 0.978), with a predictivity of 98% and a percentage of error 8.3% (95% confidence intervals -252.6, 273.7; 95% limits of agreements of Bland and Altman -436.0, 457.1). Similar results were obtained with the analysis of fat. Conclusions: Our study demonstrated that conventional segmental DEXA is a very precise technique to measure the amount of tissue removed in breast reductions and could open future application in the preoperative assessment of patients undergoing such operations.

  7. Measuring body composition in overweight individuals by dual energy x-ray absorptiometry

    International Nuclear Information System (INIS)

    Brownbill, Rhonda A; Ilich, Jasminka Z

    2005-01-01

    Dual energy x-ray absorptiometry (DXA) is widely used for body composition measurements in normal-weight and overweight/obese individuals. The limitations of bone densitometers have been frequently addressed. However, the possible errors in assessing body composition in overweight individuals due to incorrect positioning or limitations of DXA to accurately assess both bone mineral density and body composition in obese individuals have not received much attention and are the focus of this report. We discuss proper ways of measuring overweight individuals and point to some studies where that might not have been the case. It appears that currently, the most prudent approach to assess body composition of large individuals who cannot fit under the scanning area would be to estimate regional fat, namely the regions of thigh and/or abdomen. Additionally, using two-half body scans, although time consuming, may provide a relatively accurate measurement of total body fat, however, more studies using this technique are needed to validate it. Researchers using bone densitometers for body composition measurements need to have an understanding of its limitations in overweight individuals and address them appropriately when interpreting their results. Studies on accuracy and precision in measurements of both bone and soft tissue composition in overweight individuals using available densitometers are needed

  8. Dual energy X-Ray absorptiometry body composition reference values from NHANES.

    Directory of Open Access Journals (Sweden)

    Thomas L Kelly

    Full Text Available In 2008 the National Center for Health Statistics released a dual energy x-ray absorptiometry (DXA whole body dataset from the NHANES population-based sample acquired with modern fan beam scanners in 15 counties across the United States from 1999 through 2004. The NHANES dataset was partitioned by gender and ethnicity and DXA whole body measures of %fat, fat mass/height(2, lean mass/height(2, appendicular lean mass/height(2, %fat trunk/%fat legs ratio, trunk/limb fat mass ratio of fat, bone mineral content (BMC and bone mineral density (BMD were analyzed to provide reference values for subjects 8 to 85 years old. DXA reference values for adults were normalized to age; reference values for children included total and sub-total whole body results and were normalized to age, height, or lean mass. We developed an obesity classification scheme by using estabbody mass index (BMI classification thresholds and prevalences in young adults to generate matching classification thresholds for Fat Mass Index (FMI; fat mass/height(2. These reference values should be helpful in the evaluation of a variety of adult and childhood abnormalities involving fat, lean, and bone, for establishing entry criteria into clinical trials, and for other medical, research, and epidemiological uses.

  9. Use of dual energy X-ray absorptiometry in pediatric patients.

    Science.gov (United States)

    Wasserman, Halley; O'Donnell, Jennifer M; Gordon, Catherine M

    2017-11-01

    Dual Energy X-ray Absorptiometry (DXA) is a vital tool for assessing bone health in patients at risk for fragility fractures. In pediatric patients, this technology is used in conjunction with clinical fracture history to diagnosis osteoporosis and monitor treatment response. Childhood and adolescence is characterized by linear growth and bone mass accrual; thus there are important differences in the interpretation of bone measurements obtained by DXA in these young patients. This review aims to explore the current indications for DXA use and interpretation of DXA in the pediatric age group using currently available reference databases. Limitations of DXA in pediatric patients, specifically in children with short stature, will be explored. We will review several pathophysiologic mechanisms that may lead to low bone density in children, discussing representative diseases and the recommendations for monitoring bone health with DXA in these conditions. Finally, we will highlight new methods by which DXA imaging can gather additional information on bone health in children and may improve our ability to predict fractures and osteoporosis. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Bone mineral density in renal osteodystrophy: Comparison of dual energy X-ray absorptiometry and quantitative computed tomography. Vergleichende Untersuchungen mit der quantitativen Computertomographie und der Dual-Energy-X-Ray-Absorptiometrie zur Knochendichte bei renaler Osteopathie

    Energy Technology Data Exchange (ETDEWEB)

    Funke, M.; Maeurer, J.; Grabbe, E. (Abt. Roentgendiagnostik, Klinikum, Goettingen Univ. (Germany)); Scheler, F. (Abt. Nephrologie und Rheumatologie, Klinikum, Goettingen Univ. (Germany))

    1992-08-01

    Measurements of bone density were carried out in 25 patients on dialysis for terminal renal insufficiency, using quantitative computed tomography (QCT) and dual energy X-ray absorptiometry (DXA). Unlike in subjects with normal kidneys, there was no significant correlation between these methods in this series. Ten patients showed an increase in bone density of the vertebral spongiosa on QCT measurements, which was interpreted as due to osteosclerotic bone changes in renal osteopathy. QCT showed advantages over DXA in demonstrating these changes. (orig.).

  11. Comparison of bioimpedance analysis and dual-energy x-ray absorptiometry in peritoneal diaysis patients according to edema

    OpenAIRE

    Seok Hui Kang; Kyu Hyang Cho; Jong Won Park; Kyung Woo Yoon; Jun Young Do

    2012-01-01

    The change in difference between bioimpedance analysis (BIA) and dual-energy X-ray absorptiometry (DEXA) according to edema is an important issue for peritoneal dialysis (PD) patients. We reviewed all adults who received PD. Patients had undergone two body composition measurements. 1108 cases were measured simultaneously by BIA and DEXA. Measurements were divided into four quartiles based on edema index. There were significant correlations and intraclass correlations between the two methods f...

  12. Bone mineral density in healthy Syrian women measured by dual energy X-ray absorptiometry

    Directory of Open Access Journals (Sweden)

    Bakir Mohamed Adel

    2018-03-01

    Full Text Available Assessment of bone mineral density (BMD using dual energy X-ray absorptiometry (DXA technique is considered as a standard technique for diagnosing osteopenia and osteoporosis and evaluating the severity of such diseases. Numerous studies have demonstrated the necessity to establish an ethnic-specific reference data for Bone mineral density measurements. Such data are lacking for the Syrian population. The objectives of this study are (1 to establish BMD reference values in a group of healthy Syrian women using DXA technique, (2 to compare with values from other populations, (3 to study the prevalence of osteopenia and osteoporosis in Syrian women using the manufacturer reference values. A total of 951 healthy Syrian women aged 20-79 years participated in this study. Weight, height, and BMI have been determined. BMD measurements were performed using Lunar Prodigy Advance System (GE. The data were compared with those from other populations. The results have demonstrated the expected decline in BMD with age after peaking at 30-39 years old group. The peak values of the lumbar spine and femur neck were 1.16 (0.12, and 0.95 (0.13 g/cm2, respectively. The results of the Syrian women were compared with those from other populations and the differences were presented. Osteopenia was diagnosed in 35.80% and 60.31% and osteoporosis in 6.23% and 2.72% in lumbar spine and femur neck, respectively, of women 50-59 years of age. These ratios increased to 36.84%, 68.42% and 23.68%, 13.10%, respectively, in the age group more than 59 years. BMD values of the Syrian women were determined for the first time. The results demonstrate the importance of establishing population-specific reference range for BMD values for an accurate assessment of Osteoporosis. High prevalence of osteopenia and osteoporosis was demonstrated in Syrian using the manufacturer reference values.

  13. Predicting skeletal muscle mass from dual-energy X-ray absorptiometry in Japanese prepubertal children.

    Science.gov (United States)

    Midorikawa, T; Ohta, M; Hikihara, Y; Torii, S; Sakamoto, S

    2017-10-01

    We aimed to develop regression-based prediction equations for estimating total and regional skeletal muscle mass (SMM) from measurements of lean soft tissue mass (LSTM) using dual-energy X-ray absorptiometry (DXA) and investigate the validity of these equations. In total, 144 healthy Japanese prepubertal children aged 6-12 years were divided into 2 groups: the model development group (62 boys and 38 girls) and the validation group (26 boys and 18 girls). Contiguous MRI images with a 1-cm slice thickness were obtained from the first cervical vertebra to the ankle joints as reference data. The SMM was calculated from the summation of the digitized cross-sectional areas. Total and regional LSTM was measured using DXA. Strong significant correlations were observed between the site-matched SMM (total, arms, trunk and legs) measured by MRI and the LSTM obtained by DXA in the model development group for both boys and girls (R 2 adj =0.86-0.97, Pprediction equations were applied to the validation group, the measured total (boys 9.47±2.21 kg; girls 8.18±2.62 kg) and regional SMM were very similar to the predicted values for both boys (total SMM 9.40±2.39 kg) and girls (total SMM 8.17±2.57 kg). The results of the Bland-Altman analysis for the validation group did not indicate any bias for either boys or girls with the exception of the arm region for the girls. These results suggest that the DXA-derived prediction equations are precise and accurate for the estimation of total and regional SMM in Japanese prepubertal boys and girls.

  14. Dual-energy X-ray absorptiometry body composition in patients with secondary osteoporosis.

    Science.gov (United States)

    Messina, Carmelo; Monaco, Cristian Giuseppe; Ulivieri, Fabio Massimo; Sardanelli, Francesco; Sconfienza, Luca Maria

    2016-08-01

    Due to the tight relationship between bone and soft tissues, there has been an increased interest in body composition assessment in patients with secondary osteoporosis as well as other pathological conditions. Dual-energy X-ray absorptiometry (DXA) is primarily devoted to the evaluation of bone mineral status, but continuous scientific advances of body composition software made DXA a rapid and easily available technique to assess body composition in terms of fat mass and lean mass. As a result, the International Society for Clinical Densitometry (ISCD) recently developed Official Positions regarding the use of this technique for body composition analysis. According to ISCD paper, indications are mainly limited to three conditions: HIV patients treated with antiretroviral agents associated with a risk of lipoatrophy; obese patients undergoing treatment for high weight loss; patients with sarcopenia or muscle weakness. Nevertheless, there are several other interesting clinical applications that were not included in the ISCD position paper, such as body composition assessment in patients undergoing organ transplantation, pulmonary disease as well as all those chronic condition that may lead to malnutrition. In conclusion, DXA body composition offers new diagnostic and research possibilities for a variety of diseases; due to its high reproducibility, DXA has also the potential to monitor body composition changes with pharmacological, nutritional or physic therapeutic interventions. ISCD addressed and recommended a list of clinical condition, but the crescent availability of DXA scans and software improvements may open the use of DXA to other indication in the next future. This article provides an overview of DXA body composition indications in the management of secondary osteoporosis and other clinical indications in adults. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Comparison of Singh index accuracy and dual energy X-ray absorptiometry bone mineral density measurement for evaluating osteoporosis

    International Nuclear Information System (INIS)

    Salamat, M. R.; Rostampour, N.; Zofaghari, Sh. J.; Hoseyni-Panah, H.; Javdan, M.

    2010-01-01

    The Singh index is an inexpensive simple method to evaluate bone density, commonly used to assess osteoporosis is based on the radiological appearance of the trabecular bone structure of the proximal femur on a plain antero-posterior radiograph. The purpose of this study was to compare between Singh index and bone mineral density measurement using dual energy X-ray absorptiometry. Materials and Methods: Three orthopedists evaluated radiographs of 72 patients suspected with osteoporosis. The inter-observer agreements of the Singh index were obtained by using kappa statistics. The bone mineral density of proximal femur was measured by dual energy X-ray absorptiometry in all patients, and then the bone mineral density results were compared with those of Singh index by using reference radiographic charts of the Singh index method. Dual-energy X-ray absorptiometry was used to measure bone mineral density. A Norland XR46 system was used for the investigations. Results: The inter-observer agreement kappa values were 0.01, 0.07 and 0.09 (mean value: 0.05) and the strength of the observer agreements was negligible. The obtained Osteoporosis prevalence among the studied patients was 38.9%. Conclusion: The inter-observer variation was large, there was no any correlation between the Singh index and bone densitometry. So, the index cannot be used; for evaluating and osteoporosis diagnosis, because of its low reliability.

  16. Detecting meaningful body composition changes in athletes using dual-energy x-ray absorptiometry

    International Nuclear Information System (INIS)

    Colyer, Steffi L; Roberts, Simon P; Thompson, Dylan; Stokes, Keith A; Bilzon, James L J; Salo, Aki I T; Robinson, Jonathan B

    2016-01-01

    Dual-energy x-ray absorptiometry (DXA) imaging is considered to provide a valid and reliable estimation of body composition when stringent scanning protocols are adopted. However, applied practitioners are not always able to achieve this level of control and the subsequent impact on measurement precision is not always taken into account when evaluating longitudinal body composition changes. The primary aim of this study was to establish the reliability of DXA in an applied elite sport setting to investigate whether real body composition changes can be detected. Additionally, the performance implications of these changes during the training year were investigated. Forty-eight well-trained athletes (from four diverse sports) underwent two DXA scans using a ‘real-world’ approach (with limited pre-scan controls), typically within 48 h, to quantify typical error of measurement (TEM). Twenty-five athletes underwent further scans, before and after specific training and competition blocks. ‘True’ body composition changes were evaluated using 2  ×  TEM thresholds. Twelve bob skeleton athletes also performed countermovement jump and leg press tests at each time point. Many ‘true’ body composition changes were detected and coincided with the primary training emphases (e.g. lean mass gains during hypertrophy-based training). Clear relationships (r  ±  90% CI) were observed between performance changes (countermovement jump and leg press) and changes in lean mass (0.53  ±  0.26 and 0.35  ±  0.28, respectively) and fat mass (−0.44  ±  0.27 and  −0.37  ±  0.28, respectively). DXA was able to detect real body composition changes without the use of stringent scanning controls. Associations between changes in body composition and performance demonstrated the potential influence of these changes on strength and power indices. (paper)

  17. Dual energy X-ray absorptiometry spine scans to determine abdominal fat in postmenopausal women.

    Science.gov (United States)

    Bea, J W; Blew, R M; Going, S B; Hsu, C-H; Lee, M C; Lee, V R; Caan, B J; Kwan, M L; Lohman, T G

    2016-11-01

    Body composition may be a better predictor of chronic disease risk than body mass index (BMI) in older populations. We sought to validate spine fat fraction (%) from dual energy X-ray absorptiometry (DXA) spine scans as a proxy for total abdominal fat. Total body DXA scan abdominal fat regions of interest (ROI) that have been previously validated by magnetic resonance imaging were assessed among healthy, postmenopausal women who also had antero-posterior spine scans (n = 103). ROIs were (1) lumbar vertebrae L2-L4 and (2) L2-Iliac Crest (L2-IC), manually selected by two independent raters, and (3) trunk, auto-selected by DXA software. Intra-class correlation coefficients evaluated intra and inter-rater reliability on a random subset (N = 25). Linear regression models, validated by bootstrapping, assessed the relationship between spine fat fraction (%) and total abdominal fat (%) ROIs. Mean age, BMI, and total body fat were 66.1 ± 4.8 y, 25.8 ± 3.8 kg/m 2 and 40.0 ± 6.6%, respectively. There were no significant differences within or between raters. Linear regression models adjusted for several participant and scan characteristics were equivalent to using only BMI and spine fat fraction. The model predicted L2-L4 (Adj. R 2 : 0.83) and L2-IC (Adj. R 2 : 0.84) abdominal fat (%) well; the adjusted R 2 for trunk fat (%) was 0.78. Model validation demonstrated minimal over-fitting (Adj. R 2 : 0.82, 0.83, and 0.77 for L2-L4, L2-IC, and trunk fat, respectively). The strong correlation between spine fat fraction and DXA abdominal fat measures make it suitable for further development in postmenopausal chronic disease risk prediction models. Am. J. Hum. Biol. 28:918-926, 2016. © 2016Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  18. [Body composition by dual-energy x-ray absorptiometry in women with fibromyalgia].

    Science.gov (United States)

    Lobo, Márcia Maria Marques Teles; Paiva, Eduardo dos Santos; Andretta, Aline; Schieferdecker, Maria Eliana Madalozzo

    2014-01-01

    To assess body composition in women with fibromyalgia (FM) comparing to the reference value for healthy women. Cross-sectional observational analytical study, with 52 women selected with Fibromyalgia, according American College of Rheumatology (ACR, 1990) criteria. The patients were selected in Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR) and divided into two groups, 28 patients with a BMI (Body Mass Index) equal or higher (≥) than 25kg/m2 and 24 patients with BMI less or equal (≤) 24.99 kg/m2, subjected to physical examination for the count of tender points (TP) and completing the fibromyalgia impact questionnaire (FIQ). The assessment of body composition was performed by the Dual-Energy X-Ray Absorptiometry (DXA). The values of the fat mass percentage (MG %) found in the two groups were compared to the average percentage of MG by age and sex, described by Heward (2004). The mean age of the study groups was 47.8 ± 8.6 years, the FIQ score was 70.5 ± 18.6 and TP 16.2 ± 2.0. The mean BMI was 26.4 ± 4.1 kg/m2, and the amount of MG was 25.2 ± 7.8 kg and 39.5 ± 6.8%, and lean mass (LM) was 37 2 ± 3.7 kg and 60.4 ± 7.3%. In the group with BMI ≤ 25 kg/m2, the MG % was 33.8% (21.5 -42.4) and in the group with BMI ≥ 25 kg/m2 of the MG was 44.4% (37.6 -56.2). Both groups women with FM eutrophic as the overweight and obese group, presented higher reference MG% levels comparing with the standard levels for healthy women. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

  19. Bone mineral density in renal osteodystrophy: Comparison of dual energy X-ray absorptiometry and quantitative computed tomography

    International Nuclear Information System (INIS)

    Funke, M.; Maeurer, J.; Grabbe, E.; Scheler, F.

    1992-01-01

    Measurements of bone density were carried out in 25 patients on dialysis for terminal renal insufficiency, using quantitative computed tomography (QCT) and dual energy X-ray absorptiometry (DXA). Unlike in subjects with normal kidneys, there was no significant correlation between these methods in this series. Ten patients showed an increase in bone density of the vertebral spongiosa on QCT measurements, which was interpreted as due to osteosclerotic bone changes in renal osteopathy. QCT showed advantages over DXA in demonstrating these changes. (orig.) [de

  20. Dual-energy X-ray absorptiometry in the lumbar spine, proximal femur and distal radius in children

    International Nuclear Information System (INIS)

    Tsukahara, H.; Sudo, M.; Umezaki, M.; Hiraoka, M.; Yamamoto, K.; Ishii, Y.; Haruki, S.

    1992-01-01

    Dual-energy X-ray absorptiometry was used to measure bone mineral density (BMD) in the lumbar spine, proximal femur and distal radius in 48 Japanese children aged 3-18 years. In the normal children (n=32), BMD increased with age in all locations, with a nearly twofold increase from preschool age to adolescence. Most of the children with chronic diseases known to affect bone metabolism (e.g., steroid osteoporosis) (n=16) had low BMD in every region, indicating that these disease states probably affect multiple sites of the skeleton in children. (orig.)

  1. The study of dual energy X-ray absorptiometry on body composition components in obesity

    International Nuclear Information System (INIS)

    Huang Zhongkui; Chen Wei; Long Liling; Li Xiaoyang

    2009-01-01

    Objective: To study the correlation of the bone mineral density (BMD) and the body composition components of body mass index (BMI), FAT and LEAN in Chinese obesity. Methods: There were 150 cases in obesity group diagnosed by BMI, including 75 males [ median age 46 years, mean weight (89.64 ± 8.33) kg] and 75 females [median age 45 years, mean weight (77.23 ± 6.85) kg]. There were 150 persons with normal BMI in the control group, including 75 males [(median age 47 years, mean weight (62.34 ± 5.72) kg] and 75 females [ median age 45 years, mean weight (50.16 ± 5.06) kg]. The body height and weight of 300 persons in two groups were measured respectively and ,simultaneously calculated the BMI. These data and the body composition parameters measured by the dual energy X-ray absorptiometry (DEXA) in these two groups were compared and analyzed. The data obtained used two-sample t-test analysis, bi-variable correlation used Pearson linear correlation analysis and multi-variable correlation used multiple linear regression analysis. Results: FAT of arms, legs trunk and total body of male cases in obesity group was (2.90 ± 0.57), (7.48 ± 1.46), (15.67 ± 3.05), (30.92 ± 5.94) kg respectively, FAT% was (30.9 ± 5.1)%, (30.6 ± 5.8)%, (37.3 ± 4.7)%, (35.1 ± 4.4)% respectively, it was significantly higher than that in control group [FAT was (1.12 ± 0.64), (3.27 ± 1.22), (6.71 ± 3.29), (11.61 ± 5.16) kg respectively, FAT% was (15.4 ± 4.8)%, (16.5 ± 5.0)%, (21.8 ± 5.8)%, (18.6 ± 5.3)% respectively], P 2 respectively, it was significantly higher than that in control group [ LEAN was (22.89 ± 1.68), (48.89 ± 3.72) kg respectively, BMD was (0.89 ± 0.07), (1.15 ± 0.06) g/cm 2 respectively], P 2 respectively, and there were no statistical significance compared with those in control group [LEAN was (5.99 ± 0.72), (16.83 ± 1.67) kg respectively, BMD was (0.90 ± 0.08), (1.29 ± 0.09) g/cm 2 respectively]. FAT of arms, legs, trunk and total body of females in

  2. Improvements in the management of rheumatic patients from vertebral image obtained through dual-energy X-ray absorptiometry

    Directory of Open Access Journals (Sweden)

    D. Gatti

    2011-09-01

    Full Text Available The diagnosis of asymptomatic vertebral fracture is clinically useful and the identification of new fractures may influences the choice of appropriate therapeutic measures. In order to identify moderate and asymptomatic vertebral deformities in an objective and reproducible manner, vertebral morphometry is performed. This method measures the vertebral body’s anterior, middle and posterior heights at the dorsal and lumbar level. Currently this technique is performed on lateral images of the spine obtained through the traditional X-ray method (radiological morphometry or morphometric X-ray radiography, MRX and, more recently from images obtained through dual-energy X-ray absorptiometry (DXA machines (visual assessment of x-ray absoptiometry scans or morphometric X-ray absorptiometry, MXA, commonly used to measure bone mineral density. The main advantage of MXA relative to MRX is the lower radiation dose to which the patient is exposed during the exam. In addition, MXA scans offers the advantage of acquiring a single image of thoracic and lumbar spine, without any distortion (e.g.: coning. The most obvious advantage of MXA is the opportunity of obtaining during the same session a bone mineral density evaluation, and digital images that are easily processable, manageable, recordable and comparable for the patient’s follow up. A limitation of the MXA technique is the inferior quality of the images, that make often impossible the detection of the vertebral edges, and the impossibility to visualize the upper thoracic vertebral bodies. MXA, despite its intrinsic limitations, when carried out by trained personnel may provide substantial improvements in the management (diagnosis and follow-up of rheumatic patients.

  3. Precision of dual energy X-ray absorptiometry for body composition measurements in cats

    International Nuclear Information System (INIS)

    Borges, N.C.; Vasconcellos, R.S.; Canola, J.C.; Carciofi, A.C.; Pereira, G.T.; Paula, F.J.A.

    2008-01-01

    A short-term precision error of the individual subject and the DEXA technique, such as the effect of the repositioning of the cat on the examination table, were established. Four neutered adult cats (BW=4342 g) and three females (BW=3459 g) were submitted to five repeated scans with and without repositioning between them. Precision was estimated from the mean of the five measurements and expressed by the individual coefficient of variation (CV). The precision error of the technique was estimated by the variance of scan pool (n=35) and expressed in CV for the technique (CVt). The degrees of freedom and confidence intervals were determined to avoid underestimation of precision errors. Bone mineral content (BMC), lean mass (LM), and fat mass (FM) averages were higher (P<0.05) when animals were repositioned. The CVt was significantly higher (P<0.05) for bone mineral density (BMD), LM, and FM when the animals were repositioned. For short-term precision measurements, the repositioning of the animal was important to establish the precision of the technique. The dual energy xray absorptiometry method provided precision for body composition measurements in adult cats. (author)

  4. Stature estimation based on vertebral morphometry by dual energy X-rays absorptiometry imaging in Italian females

    Directory of Open Access Journals (Sweden)

    Chantal Milani

    2017-02-01

    Full Text Available Anthropological profile in forensic context includes the assessment of parameters as ancestry, sex, age and stature of an individual by the analysis of skeletal remains. Stature can be estimated from decomposed and fully or partially skeletonized remains by means of anatomical or mathematical methods applied on the whole skeleton or single bones. Many authors calculated regression formulae for the living stature estimation by these methods, in particular based on a population similar to the remains recovered. Long bones are commonly used for stature estimation, but, when they are missing, methods involving different parts of the skeleton are needed. In this preliminary study we measured heights of the vertebral bodies in a female Caucasian Italian population, evaluated by images of morphometric X-ray absorptiometry based on dual-energy X-ray absorptiometry in living subjects investigated for routine diagnostic purposes. Thoracic and lumbar segments of the spine were measured and statistical analysis was performed, thus obtaining regression formulae for estimated living stature from thoraco-lumbar spine segments (T6-T12, L1-L4 and T6-L4. We propose this method for stature evaluation in physical or forensic anthropology when the spine is available and long bones are missing.

  5. Neutron activation analysis. Criterion method for evaluation of dual-energy x-ray absorptiometry measurements in infants

    International Nuclear Information System (INIS)

    Ellis, K.J.; Shypailo, R.J.; Schoknecht, P.; Pond, W.G.

    1995-01-01

    Total body neutron activation analysis (NAA) was used to examine the elemental composition of 22 piglets in the weight range 0.7 kg to 3.4 kg. The accuracy of the NAA technique, compared to direct chemical carcass analysis, established it as an equivalent chemical criterion (reference) method. The body composition of 14 human infant cadavers was also examined by NAA and by dual-energy x-ray absorptiometry (DXA). The DXA-derived lean, fat, and bone compartments were compared with an NAA chemical model of composition. Each of the three compartments was significantly correlated (r=0.85-0.95.p<0.001) for the two independent assay, although there were substantial differences for the estimated size of the compartments for individual infants. (author). 11 refs., 2 figs., 2 tabs

  6. Comparison of Dual Energy X-ray Absorptiometry and Bioimpedance in Assessing Body Composition and Nutrition in Peritoneal Dialysis Patients

    DEFF Research Database (Denmark)

    Popovic, Velena; Zerahn, Bo; Heaf, James Goya

    2017-01-01

    OBJECTIVE: Peritoneal dialysis (PD) patients are characterized by protein malnutrition and muscle wasting. Reliable, easy, and cheap methods for evaluating nutrition are desirable. Three methods are commonly available: dual-energy X-ray absorptiometry (DXA), bioimpedance (BI), and subjective global...... assessment (SGA).The objective of the study was to compare the previously mentioned methods for assessment of body composition and nutritional status in PD patients. DESIGN: The study is cross-sectional and consisted of 72 PD patients from a single center PD ambulatorium. METHODS: Participants were measured...... in this population. OH might reduce DXA accuracy in PD patients. LTI and ICW may be useful measures to supplement SGA in assessing nutrition....

  7. Volume and Tissue Composition Changes Measured with Dual-Energy X-Ray Absorptiometry in Melanoma-Related Limb Lymphedema

    DEFF Research Database (Denmark)

    Gjorup, Caroline A; Hendel, Helle W; Zerahn, Bo

    2017-01-01

    Abstracts Background: The aim of this cross-sectional study was to investigate the volume, fat mass, and lean mass in both upper and lower limbs measured with dual-energy X-ray absorptiometry (DXA) in melanoma patients with melanoma-related limb lymphedema. METHODS AND RESULTS: Four hundred thirty...... lymphedema was diagnosed on the basis of history and characteristic physical findings on the clinical examination. The inter-limb differences in volume, fat mass, and lean mass measured with DXA were categorized as none/mild, moderate, or severe according to reference values (taking handedness into account......, and the majority of lymphedemas were categorized as mild. The increase in the volume of limbs with lymphedema was primarily due to an increase in fat mass. CONCLUSION: There is a high prevalence of melanoma-related limb lymphedema. The increase in volume in the limb with lymphedema is primarily due to an increase...

  8. Assessment of adiposity in psoriatic patients by dual energy X-ray absorptiometry compared to conventional methods*

    Science.gov (United States)

    Diniz, Michelle dos Santos; Bavoso, Nádia Couto; Kakehasi, Adriana Maria; Lauria, Márcio Weissheimer; Soares, Maria Marta Sarquis; Machado-Pinto, Jackson

    2016-01-01

    BACKGROUND Obesity is considered a chronic low-grade inflammatory disease that shares mediators of inflammation with psoriasis, such as TNF-α and IL-6. The relationship between these two conditions involves factors such as predisposition and response to therapy, in addition to an association with cardiovascular disease. OBJECTIVES The aim of the present study was to investigate the prevalence of adiposity as determined by body mass index (BMI), waist circumference (WC), and dual energy X-ray absorptiometry (DXA) evaluation in patients with psoriasis. METHODS BMI, WC and body composition by DXA were measured in 42 psoriatic patients without joint complaints and in 41 control patients using standard procedures. In the comparison between cases and controls, we used Pearson’s Χ2 test or Fisher’s exact test, and the nonparametric Mann-Whitney test. The difference between the diverse classification methods for obesity was evaluated using McNemar’s test. To test the level of agreement between those variables, we used the weighted kappa coefficient. RESULTS There was no difference in the prevalence of obesity among cases and controls. Both BMI and WC had low agreement with measures of body fat evaluated by DXA. With the use of DXA scanning, prevalence of overweight and obesity in patients with psoriasis was 83.3%, which constitutes a strong evidence of the need for intervention on this metabolic parameter. CONCLUSION Dual energy X-ray absorptiometry was more capable of identifying obesity compared with BMI and WC both in psoriatic and control patients. PMID:27192512

  9. Assessment of bone mineral density with dual energy X-ray absorptiometry in pre-and post-menopausal women

    International Nuclear Information System (INIS)

    Salamat, M. R.; Rostampour, N.; Shanehsazzadeh, S.; Tavakoli, M. B.; Siavash, M.; Almasi, T.

    2008-01-01

    Osteoporosis is a chronic disease that contributes substantially to decrease physical activity and decline in the quality of life. Osteoporosis can be diagnosed easily with the use of dual-energy X-ray absorptiometry equipment. The aim of this study was to investigate the magnitude of bone loss on proximal femur and lumbar spine in pre-and post-menopausal women from Isfahan Osteoporosis Diagnosis Center since 2005. Materials and Methods: Bone mineral density measurements using dual-energy X-ray absorptiometry have been performed at Isfahan Osteoporosis Diagnosis Center. 185 pre-menopausal and 174 early post-menopausal women were selected randomly. A Norland XR46 system was used for the investigations. The student t-lest was done to find the difference between the T-scores of the femoral neck and lumbar spine in pre-and post-menopausal women. Results: Mean Bone mineral density for the femoral neck and lumbar spine in pre-menopausal women were 0.859 ± 0.136 and 1.012 ± 0.161 and in post-menopausal women were 0.816 ± 0.119 and 0.919 ± 0.140, respectively. Long-term Bone mineral density CVs of 1.0% and 1.2% for the lumbar spine and femoral neck were found, respectively. The differences between the femoral neck and lumbar spine for pre-and post-menopausal women were t = -9.02, P < 0.05 and t = -3.50, P < 0.05, respectively. Conclusion: In spite of, the reported lower Bone mineral density T-scores for the lumbar spine compared With the femoral neck for women, we found that the femoral neck had significantly lower T-score than lumbar spine for both pre-and post-menopausal women.

  10. Reference data for bone density and body composition measured with dual energy x ray absorptiometry in white children and young adults

    NARCIS (Netherlands)

    I.M. van der Sluis (Inge); M.A.J. de Ridder (Maria); A.M. Boot (Annemieke); E.P. Krenning (Eric); S.M.P.F. de Muinck Keizer-Schrama (Sabine)

    2002-01-01

    textabstractAIMS: To obtain normative data on bone mineral density and body composition measured with dual energy x ray absorptiometry (DXA) from early childhood to young adulthood. METHODS: Cross sectional results from 444 healthy white volunteers (4-20 years) in the Netherlands

  11. Fundamental Movement Skill Proficiency and Body Composition Measured by Dual Energy X-Ray Absorptiometry in Eight-Year-Old Children

    Science.gov (United States)

    Slotte, Sari; Sääkslahti, Arja; Metsämuuronen, Jari; Rintala, Pauli

    2015-01-01

    Objective: The main aim was to examine the association between fundamental movement skills (FMS) and objectively measured body composition using dual energy X-ray absorptiometry (DXA). Methods: A study of 304 eight-year-old children in Finland. FMS were assessed with the "Test of gross motor development," 2nd ed. Total body fat…

  12. Change in fat-free mass assessed by bioelectrical impedance, total body potassium and dual energy X-ray absorptiometry during prolonged weight loss

    DEFF Research Database (Denmark)

    Hendel, H W; Gotfredsen, A; Højgaard, L

    1996-01-01

    A total of 16 obese women (body mass index (BMI) 30-43 kg m(-2)) participated in a weight reduction study. Before and after a weight loss of 11.7 +/- 7.4 kg (mean +/- SD), body composition was assessed by dual energy X-ray absorptiometry (DXA), and total body potassium counting (TBK). These measu...

  13. Direct X-ray radiogrammetry versus dual-energy X-ray absorptiometry: assessment of bone density in children treated for acute lymphoblastic leukaemia and growth hormone deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Rijn, Rick R. van; Wittenberg, Rianne [Academic Medical Centre Amsterdam, Department of Radiology, Amsterdam Zuid-Oost (Netherlands); Boot, Annemieke; Sluis, Inge M. van der; MuinckKeizer-Schrama, Sabine M.P.F. de [Erasmus MC-Sophia Children' s Hospital, Department of Paediatric Endocrinology, Rotterdam (Netherlands); Heuvel-Eibrink, Marry M. van den [Erasmus MC-Sophia Children' s Hospital, Department of Paediatric Haematology/Oncology, Rotterdam (Netherlands); Lequin, Maarten H. [Erasmus MC-Sophia Children' s Hospital, Department of Paediatric Radiology, Rotterdam (Netherlands); Kuijk, Cornelis Van [University Medical Centre ' Radboud' , Department of Radiology, Nijmegen (Netherlands)

    2006-03-15

    In recent years interest in bone densitometry in children has increased. To evaluate the clinical application of digital X-ray radiogrammetry (DXR) and compare the results with those of dual-energy X-ray absorptiometry (DXA). A total of 41 children with acute lymphoblastic leukaemia (ALL) and 26 children with growth hormone deficiency (GHD) were included in this longitudinal study. Radiographs of the left hand were obtained and used for DXR. DXA of the total body and of the lumbar spine was performed. In both study populations significant correlations between DXR and DXA were found, and, with the exception of the correlation between DXR bone mineral density (DXR-BMD) and bone mineral apparent density in the GHD population, all correlations had a P-value of <0.001. During treatment a change in DXR-BMD was found in children with GHD. Our study showed that DXR in a paediatric population shows a strong correlation with DXA of the lumbar spine and total body and that it is able to detect a change in BMD during treatment. (orig.)

  14. Direct X-ray radiogrammetry versus dual-energy X-ray absorptiometry: assessment of bone density in children treated for acute lymphoblastic leukaemia and growth hormone deficiency

    International Nuclear Information System (INIS)

    Rijn, Rick R. van; Wittenberg, Rianne; Boot, Annemieke; Sluis, Inge M. van der; MuinckKeizer-Schrama, Sabine M.P.F. de; Heuvel-Eibrink, Marry M. van den; Lequin, Maarten H.; Kuijk, Cornelis Van

    2006-01-01

    In recent years interest in bone densitometry in children has increased. To evaluate the clinical application of digital X-ray radiogrammetry (DXR) and compare the results with those of dual-energy X-ray absorptiometry (DXA). A total of 41 children with acute lymphoblastic leukaemia (ALL) and 26 children with growth hormone deficiency (GHD) were included in this longitudinal study. Radiographs of the left hand were obtained and used for DXR. DXA of the total body and of the lumbar spine was performed. In both study populations significant correlations between DXR and DXA were found, and, with the exception of the correlation between DXR bone mineral density (DXR-BMD) and bone mineral apparent density in the GHD population, all correlations had a P-value of <0.001. During treatment a change in DXR-BMD was found in children with GHD. Our study showed that DXR in a paediatric population shows a strong correlation with DXA of the lumbar spine and total body and that it is able to detect a change in BMD during treatment. (orig.)

  15. Comparison of bioimpedance analysis and dual-energy x-ray absorptiometry in peritoneal diaysis patients according to edema

    Directory of Open Access Journals (Sweden)

    Seok Hui Kang

    2012-06-01

    Full Text Available The change in difference between bioimpedance analysis (BIA and dual-energy X-ray absorptiometry (DEXA according to edema is an important issue for peritoneal dialysis (PD patients. We reviewed all adults who received PD. Patients had undergone two body composition measurements. 1108 cases were measured simultaneously by BIA and DEXA. Measurements were divided into four quartiles based on edema index. There were significant correlations and intraclass correlations between the two methods for lean mass (LM, fat mass (FM and bone mineral content. On a simple linear regression analysis, non-standardized-βs of total LM decreased as the grade of edema index increased (from 1.008 to 0.949. Those of total FM were increased as the grade of edema index increased (from 1.034 to 1.162. Bias for total LM changed to negative and negative bias increased as the grade of edema index increased (from 0.406 kg to –2.276 kg. There was a positive bias for total FM in first quartile and increased as the grade of edema index increased (from 0.594 kg to 2.863 kg. In conclusion, the present study demonstrates that BIA can measure normal hydrated LM in CAPD patients with edema. However, FM is overestimated in PD patients with edema. The difference between the two measurements increases as the grade of edema increases.

  16. Dual-energy X-ray absorptiometry: analysis of pediatric fat estimate errors due to tissue hydration effects.

    Science.gov (United States)

    Testolin, C G; Gore, R; Rivkin, T; Horlick, M; Arbo, J; Wang, Z; Chiumello, G; Heymsfield, S B

    2000-12-01

    Dual-energy X-ray absorptiometry (DXA) percent (%) fat estimates may be inaccurate in young children, who typically have high tissue hydration levels. This study was designed to provide a comprehensive analysis of pediatric tissue hydration effects on DXA %fat estimates. Phase 1 was experimental and included three in vitro studies to establish the physical basis of DXA %fat-estimation models. Phase 2 extended phase 1 models and consisted of theoretical calculations to estimate the %fat errors emanating from previously reported pediatric hydration effects. Phase 1 experiments supported the two-compartment DXA soft tissue model and established that pixel ratio of low to high energy (R values) are a predictable function of tissue elemental content. In phase 2, modeling of reference body composition values from birth to age 120 mo revealed that %fat errors will arise if a "constant" adult lean soft tissue R value is applied to the pediatric population; the maximum %fat error, approximately 0.8%, would be present at birth. High tissue hydration, as observed in infants and young children, leads to errors in DXA %fat estimates. The magnitude of these errors based on theoretical calculations is small and may not be of clinical or research significance.

  17. Provider Distribution Changes in Dual-Energy X-Ray Absorptiometry in the Medicare Population Over the Past Decade.

    Science.gov (United States)

    Intenzo, Charles M; Parker, Laurence; Levin, David C; Kim, Sung M; Rao, Vijay M

    2016-01-01

    Both radiologists as well as nonimaging physicians perform dual-energy X-ray absorptiometry (DXA) imaging in the United States. This study aims to compare provider distribution between these physician groups on the Medicare population, which is the predominant age group of patients evaluated by this imaging procedure. Using the 2 relevant Current Procedural Terminology, Fourth Edition codes for DXA scans, source data were obtained from the CMS Physician Supplier Procedure Summary Master Files from 2003 through 2013. DXA scan procedure volumes for radiologists and nonradiologists on Medicare patients were tabulated. Utilization rates were calculated. From 2003 to 2013, the total number of DXA scans performed on Medicare patients decreased by 2%. However, over the same period, the number of scans performed by radiologists had increased by 25% over nonimaging specialists, whose utilization had declined by approximately the same amount. From 2003 to 2013, the rate of utilization of DXA scans in the Medicare fee-for-service population declined somewhat. However, radiologists continue to gain market share from other specialists and now predominate in this type of imaging by a substantial margin. Copyright © 2016 International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  18. Dual-energy X-ray absorptiometry is a valid tool for assessing skeletal muscle mass in older women.

    Science.gov (United States)

    Chen, Zhao; Wang, ZiMian; Lohman, Timothy; Heymsfield, Steven B; Outwater, Eric; Nicholas, Jennifer S; Bassford, Tamsen; LaCroix, Andrea; Sherrill, Duane; Punyanitya, Mark; Wu, Guanglin; Going, Scott

    2007-12-01

    Assessing skeletal muscle mass (SMM) is critical in studying and detecting sarcopenia. Direct measurements by MRI or computerized tomography are expensive or high in radiation exposure. Dual-energy X-ray absorptiometry (DXA) is promising for body composition assessments, but the validity of DXA for predicting SMM in the elderly is still under investigation. The objective of this study was to assess the relationship between DXA-derived measurements of lean soft tissue mass (LSTM) and SMM in older women. Study participants were postmenopausal women (n = 101) recruited in southern Arizona. Total and regional body composition was measured using MRI and DXA (QDR4500w). The participants' mean age was 70.7 +/- 6.4 y and their mean BMI was 27.4 +/- 5.1 kg/m2. DXA-derived LSTM was highly correlated with MRI-derived SMM for the whole body (r = 0.94; P LSTM assessments for the leg region but not for the total body. In conclusion, although the relationships between DXA measures and MRI-derived SMM vary by region of interest, the overall prediction of SMM by DXA is excellent. We conclude that DXA is a reliable method for cross-sectional assessments of SMM in older women.

  19. Measuring body composition in dogs using multifrequency bioelectrical impedance analysis and dual energy X-ray absorptiometry.

    Science.gov (United States)

    Rae, L S; Vankan, D M; Rand, J S; Flickinger, E A; Ward, L C

    2016-06-01

    Thirty-five healthy, neutered, mixed breed dogs were used to determine the ability of multifrequency bioelectrical impedance analysis (MFBIA) to predict accurately fat-free mass (FFM) in dogs using dual energy X-ray absorptiometry (DXA)-measured FFM as reference. A second aim was to compare MFBIA predictions with morphometric predictions. MFBIA-based predictors provided an accurate measure of FFM, within 1.5% when compared to DXA-derived FFM, in normal weight dogs. FFM estimates were most highly correlated with DXA-measured FFM when the prediction equation included resistance quotient, bodyweight, and body condition score. At the population level, the inclusion of impedance as a predictor variable did not add substantially to the predictive power achieved with morphometric variables alone; in individual dogs, impedance predictors were more valuable than morphometric predictors. These results indicate that, following further validation, MFBIA could provide a useful tool in clinical practice to objectively measure FFM in canine patients and help improve compliance with prevention and treatment programs for obesity in dogs. Copyright © 2016. Published by Elsevier Ltd.

  20. Dual-energy X-ray absorptiometry diagnostic discordance between Z-scores and T-scores in young adults.

    LENUS (Irish Health Repository)

    Carey, John J

    2009-01-01

    Diagnostic criteria for postmenopausal osteoporosis using central dual-energy X-ray absorptiometry (DXA) T-scores have been widely accepted. The validity of these criteria for other populations, including premenopausal women and young men, has not been established. The International Society for Clinical Densitometry (ISCD) recommends using DXA Z-scores, not T-scores, for diagnosis in premenopausal women and men aged 20-49 yr, though studies supporting this position have not been published. We examined diagnostic agreement between DXA-generated T-scores and Z-scores in a cohort of men and women aged 20-49 yr, using 1994 World Health Organization and 2005 ISCD DXA criteria. Four thousand two hundred and seventy-five unique subjects were available for analysis. The agreement between DXA T-scores and Z-scores was moderate (Cohen\\'s kappa: 0.53-0.75). The use of Z-scores resulted in significantly fewer (McNemar\\'s p<0.001) subjects diagnosed with "osteopenia," "low bone mass for age," or "osteoporosis." Thirty-nine percent of Hologic (Hologic, Inc., Bedford, MA) subjects and 30% of Lunar (GE Lunar, GE Madison, WI) subjects diagnosed with "osteoporosis" by T-score were reclassified as either "normal" or "osteopenia" when their Z-score was used. Substitution of DXA Z-scores for T-scores results in significant diagnostic disagreement and significantly fewer persons being diagnosed with low bone mineral density.

  1. Age-related proximal femur bone mineral loss in South Indian women: a dual energy X-ray absorptiometry study.

    Science.gov (United States)

    Anburajan, M; Rethinasabapathi, C; Korath, M P; Ponnappa, B G; Kumar, K S; Panicker, T M; Govindan, A; Jagadeesan, G N

    2001-04-01

    i) To collect normative data for proximal femur bone mineral density (BMD) in South Indian women using dual energy X-ray absorptiometry (DXA) and ii) to study the rate and significance of hip bone mineral loss with advancing age in this population. Forty five women, whose age ranged from 16 to 84 years were studied. This sample was drawn randomly from general medical practice at KJ Hospital, Chennai, South India during November, 1997 to April, 1998. Of these 45 cases, 21 were pre-menopausal (mean +/- SD age = 30.9+/-8.8 years) and 24 post-menopausal (mean +/- SD age = 62.1+/-11.0 years). Subjects with secondary bone diseases were excluded. Also excluded were those taking any drugs known to affect calcium metabolism e.g., thiazide diuretics, oestrogen and calcium. Subjects were divided into seven decadal age groups from 15-24 years to 75-84 years. BMD of the right proximal femur was evaluated using a QDR-1000 DXA bone densitometer (Hologic Inc., Waltham, Massachusetts, USA). Data analysis was done with SPSS/PC statistical software package. Linear regression analysis showed significant (p India women have been evaluated and it may prove useful for diagnosing osteoporosis in the women of South India.

  2. Preclinical validation of automated dual-energy X-ray absorptiometry and computed tomography-based body composition measurements

    International Nuclear Information System (INIS)

    DEVRIESE, Joke; Pottel, Hans; BEELS, Laurence; VAN DE WIELE, Christophe; MAES, Alex; GHEYSENS, Olivier

    2016-01-01

    The aim of this study was to determine and validate a set of Hounsfield unit (HU) ranges to segment computed tomography (CT) images into tissue types and to test the validity of dual-energy X-ray absorptiometry (DXA) tissue segmentation on pure, unmixed porcine tissues. This preclinical prospective study was approved by the local ethical committee. Different quantities of porcine bone tissue (BT), lean tissue (LT) and adipose tissue (AT) were scanned using DXA and CT. Tissue type segmentation in DXA was performed via the standard clinical protocol and in CT through different sets of HU ranges. Percent coefficients of variation (%CV) were used to assess precision while % differences of observed masses were tested against zero using the Wilcoxon signed-rank Test. Total mass DXA measurements differ little but significantly (P=0.016) from true mass, while total mass CT measurements based on literature values show non-significant (P=0.69) differences of 1.7% and 2.0%. BT mass estimates with DXA differed more from true mass (median -78.2 to -75.8%) than other tissue types (median -11.3 to -8.1%). Tissue mass estimates with CT and literature HU ranges showed small differences from true mass for every tissue type (median -10.4 to 8.8%). The most suited method for automated tissue segmentation is CT and can become a valuable tool in quantitative nuclear medicine.

  3. Total and regional bone mineral content in healthy Spanish subjects by dual-energy X-ray absorptiometry

    International Nuclear Information System (INIS)

    Aguado Henche, S.; Rodriguez Torres, R.; Clemente de Arriba, C.; Gomez Pellico, L.

    2008-01-01

    This is an observational cross-sectional study. The aim of the present study was to describe and analyze patterns of change in total and regional bone mineral content in relation to age and gender in a sedentary Spanish sample population (from the Community of Madrid). The age range of the sample population was from birth to 80 years. One thousand one hundred twenty healthy subjects were recruited and divided into 16 groups according to age. Each subject underwent whole-body densitometry using dual-energy X-ray absorptiometry. An analysis was made of the amount of bone mineral content (BMC) in the whole body and in different regions: the head, trunk, upper limbs, and lower limbs. Gender differences in mean values for upper limbs and lower limbs are statistically significant between 16 and 70 years of age. For the head and trunk, the mean BMC values show the most significant gender differences between 16 and 25 years of age (p≤0.001). Total bone mineral content (TBMC) and TBMC-to-height ratio show significant gender differences between 16 and 70 years of age. In females, TBMC values increase up to 20 years of age and in males up to 25 years of age. We have determined an evolutionary normal pattern of bone mineral content in urban Spanish people. (orig.)

  4. Magnetic resonance imaging and dual energy X-ray absorptiometry of the lumbar spine in professional wrestlers and untrained men.

    Science.gov (United States)

    Hu, M; Sheng, J; Kang, Z; Zou, L; Guo, J; Sun, P

    2014-08-01

    The aim of this study was to examine the relation between bone marrow adipose tissue (BMAT) and bone mineral density (BMD) of lumbar spine in male professional wrestlers and healthy untrained men. A total of 14 wrestlers (22.9±3.4 years) and 11 controls (24.4±1.6 years) were studied cross-sectionally. Body composition and BMD were measured by dual-energy X-ray absorptiometry. Magnetic resonance imaging of the lumbar spine was examined in a sagittal T1-weighted (T1-w) spin-echo (SE) sequence. The averaged bone marrow signal intensity (SI) of L2-L4 was related to the signal of an adjacent nondegenerative disk. Mean SI of T1-w SE in wrestlers was lower than controls (P=0.001), indicating L2-L4 BMAT in wrestlers was lower compared to controls. L2-L4 BMD in wrestlers was higher than controls (PBMAT and BMD was confirmed in this relatively small subject sample with narrow age range, which implies that exercise training is an important determinant of this association.

  5. Dual-energy X-ray absorptiometry underestimates in vivo lumbar spine bone mineral density in overweight rats.

    Science.gov (United States)

    Cherif, Rim; Vico, Laurence; Laroche, Norbert; Sakly, Mohsen; Attia, Nebil; Lavet, Cedric

    2018-01-01

    Dual-energy X-ray absorptiometry (DXA) is currently the most widely used technique for measuring areal bone mineral density (BMD). However, several studies have shown inaccuracy, with either overestimation or underestimation of DXA BMD measurements in the case of overweight or obese individuals. We have designed an overweight rat model based on junk food to compare the effect of obesity on in vivo and ex vivo BMD and bone mineral content measurements. Thirty-eight 6-month old male rats were given a chow diet (n = 13) or a high fat and sucrose diet (n = 25), with the calorie amount being kept the same in the two groups, for 19 weeks. L1 BMD, L1 bone mineral content, amount of abdominal fat, and amount of abdominal lean were obtained from in vivo DXA scan. Ex vivo L1 BMD was also measured. A difference between in vivo and ex vivo DXA BMD measurements (P body weight, perirenal fat, abdominal fat, and abdominal lean. Multiple linear regression analysis shows that body weight, abdominal fat, and abdominal lean were independently related to ex vivo BMD. DXA underestimated lumbar in vivo BMD in overweight rats, and this measurement error is related to body weight and abdominal fat. Therefore, caution must be used when one is interpreting BMD among overweight and obese individuals.

  6. Total and regional bone mineral content in healthy Spanish subjects by dual-energy X-ray absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Aguado Henche, S.; Rodriguez Torres, R.; Clemente de Arriba, C.; Gomez Pellico, L. [Universidad de Alcala, Departamento de Anatomia y Embriologia Humana, Facultad de Medicina, Alcala de Henares, Madrid (Spain)

    2008-11-15

    This is an observational cross-sectional study. The aim of the present study was to describe and analyze patterns of change in total and regional bone mineral content in relation to age and gender in a sedentary Spanish sample population (from the Community of Madrid). The age range of the sample population was from birth to 80 years. One thousand one hundred twenty healthy subjects were recruited and divided into 16 groups according to age. Each subject underwent whole-body densitometry using dual-energy X-ray absorptiometry. An analysis was made of the amount of bone mineral content (BMC) in the whole body and in different regions: the head, trunk, upper limbs, and lower limbs. Gender differences in mean values for upper limbs and lower limbs are statistically significant between 16 and 70 years of age. For the head and trunk, the mean BMC values show the most significant gender differences between 16 and 25 years of age (p{<=}0.001). Total bone mineral content (TBMC) and TBMC-to-height ratio show significant gender differences between 16 and 70 years of age. In females, TBMC values increase up to 20 years of age and in males up to 25 years of age. We have determined an evolutionary normal pattern of bone mineral content in urban Spanish people. (orig.)

  7. A comparison of bone mineral density in osteoporotic fracture of the proximal femur using dual energy X-ray absorptiometry

    International Nuclear Information System (INIS)

    Lee, Jong Seok; Yoo, Beong Gyu; Kim, Keung Sik

    2000-01-01

    There were some controversies about direct cause of hip fracture. We attempted to look at 40 osteoporotic proximal femur fractures in women over 50 years between March in 1999 and February in 2000. The bone density of the fracture group and the healthy 85 control group was measured by Dual Energy X-ray absorptiometry (DEXA). The result was compared using age matched paired T test. The results were as follows: The femoral neck fractures were 14 cases and the trochanteric fractures were 26 cases. Mean age at a fracture was 67.1 years in neck fracture group and 76.5 years in trochanteric fracture. In the control group, the bone density of both side of the proximal femur was measured and it showed statistically no difference between both sides in same person. The bone density of neck, Ward's triangle, trochanter (P<0.05) and lumbar spine (P<0.001) was significantly reduced in the proximal femoral fracture group comparing with the control group. The bone density of neck, Ward's triangle, trochanter (P<0.05) was significantly reduced in the proximal femoral neck fracture group comparing with the control group, but there was no statistical difference in lumbar spine comparing with the control group. The bone density of neck, Ward's triangle, trochanter and lumbar spine (P<0.001) was significantly reduced in the proximal femoral neck fracture group comparing with the control group. We concluded that the bone mineral densities (BMD) of proximal femur and lumbar spine had decreased in hip fractures but that the bone mineral density and T-score % of the proximal femur were statistically lower than that of the lumbar spine. We suggest that measuring the bone mineral density of the proximal femur may reflect the weakness of the proximal femur more precisely than measuring the bone mineral density of the lumbar spine

  8. Cortical thickness estimation of the proximal femur from multi-view dual-energy X-ray absorptiometry (DXA)

    Science.gov (United States)

    Tsaousis, N.; Gee, A. H.; Treece, G. M.; Poole, K. E. S.

    2013-02-01

    Hip fracture is the leading cause of acute orthopaedic hospital admission amongst the elderly, with around a third of patients not surviving one year post-fracture. Although various preventative therapies are available, patient selection is difficult. The current state-of-the-art risk assessment tool (FRAX) ignores focal structural defects, such as cortical bone thinning, a critical component in characterizing hip fragility. Cortical thickness can be measured using CT, but this is expensive and involves a significant radiation dose. Instead, Dual-Energy X-ray Absorptiometry (DXA) is currently the preferred imaging modality for assessing hip fracture risk and is used routinely in clinical practice. Our ambition is to develop a tool to measure cortical thickness using multi-view DXA instead of CT. In this initial study, we work with digitally reconstructed radiographs (DRRs) derived from CT data as a surrogate for DXA scans: this enables us to compare directly the thickness estimates with the gold standard CT results. Our approach involves a model-based femoral shape reconstruction followed by a data-driven algorithm to extract numerous cortical thickness point estimates. In a series of experiments on the shaft and trochanteric regions of 48 proximal femurs, we validated our algorithm and established its performance limits using 20 views in the range 0°-171°: estimation errors were 0:19 +/- 0:53mm (mean +/- one standard deviation). In a more clinically viable protocol using four views in the range 0°-51°, where no other bony structures obstruct the projection of the femur, measurement errors were -0:07 +/- 0:79 mm.

  9. The reliability of dual-energy X-ray absorptiometry measurements of bone mineral density in the metatarsals

    International Nuclear Information System (INIS)

    Fuller, Joel T.; Buckley, Jonathan D.; Tsiros, Margarita D.; Thewlis, Dominic; Archer, Jane

    2016-01-01

    To investigate the reliability of a simple, efficient technique for measuring bone mineral density (BMD) in the metatarsals using dual-energy X-ray absorptiometry (DXA). BMD of the right foot of 32 trained male distance runners was measured using a DXA scanner with the foot in the plantar position. Separate regions of interest (ROI) were used to assess the BMD of each metatarsal shaft (1st-5th) for each participant. ROI analysis was repeated by the same investigator to determine within-scan intra-rater reliability and by a different investigator to determine within-scan inter-rater reliability. Repeat DXA scans were undertaken for ten participants to assess between-scan intra-rater reliability. Assessment of BMD was consistently most reliable for the first metatarsal across all domains of reliability assessed (intra-class correlation coefficient [ICC] ≥0.97; coefficient of variation [CV] ≤1.5 %; limits of agreement [LOA] ≤4.2 %). Reasonable levels of intra-rater reliability were also achieved for the second and fifth metatarsals (ICC ≥0.90; CV ≤4.2 %; LOA ≤11.9 %). Poorer levels of reliability were demonstrated for the third (ICC ≥0.64; CV ≤8.2 %; LOA ≤23.6 %) and fourth metatarsals (ICC ≥0.67; CV ≤9.6 %; LOA ≤27.5 %). BMD was greatest in the first and second metatarsals (P < 0.01). Reliable measurements of BMD were achieved for the first, second and fifth metatarsals. (orig.)

  10. Reproducibility of trabecular bone score with different scan modes using dual-energy X-ray absorptiometry: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Bandirali, Michele; Messina, Carmelo [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milano (Italy); Di Leo, Giovanni [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Pastor Lopez, Maria Juana; Ulivieri, Fabio M. [Servizio di Medicina Nucleare, Ospedale Maggiore, Mineralometria Ossea Computerizzata e Ambulatorio Malattie Metabolismo Minerale e Osseo, Milano (Italy); Mai, Alessandro [Universita degli Studi di Milano, Tecniche di Radiologia Medica, per Immagini e Radioterapia, Milano (Italy); Sardanelli, Francesco [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, San Donato Milanese (Italy)

    2014-08-12

    The trabecular bone score (TBS) accounts for the bone microarchitecture and is calculated on dual-energy X-ray absorptiometry (DXA). We estimated the reproducibility of the TBS using different scan modes compared to the reproducibility bone mineral density (BMD). A spine phantom was used with a Hologic QDR-Discovery A densitometer. For each scan mode [fast array, array, high definition (HD)], 25 scans were automatically performed without phantom repositioning; a further 25 scans were performed with phantom repositioning. For each scan, the TBS was obtained. The coefficient of variation (CoV) was calculated as the ratio between standard deviation and mean; percent least significant change (LSC%) as 2.8 x CoV; reproducibility as the complement to 100 % of LSC%. Differences among scan modes were assessed using ANOVA. Without phantom repositioning, the mean TBS (mm{sup -1}) was: 1.352 (fast array), 1.321 (array), and 1.360 (HD); with phantom repositioning, it was 1.345, 1.332, and 1.362, respectively. Reproducibility of the TBS without phantom repositioning was 97.7 % (fast array), 98.3 % (array), and 98.2 % (HD); with phantom repositioning, it was 97.9 %, 98.7 %, and 98.4 %, respectively. LSC% was ≤2.26 %. Differences among scan modes were all statistically significant (p ≤ 0.019). Reproducibility of BMD was 99.1 % with all scan modes, while LSC% was from 0.86 % to 0.91 %. Reproducibility error of the TBS was 2-3-fold higher than that of BMD. Although statistically significant, differences in TBS among scan modes were within the highest LSC%. Thus, the three scan modes can be considered interchangeable. (orig.)

  11. Dual energy X-ray absorptiometry spine scans to determine abdominal fat in post-menopausal women

    Science.gov (United States)

    Bea, J. W.; Blew, R. M.; Going, S. B.; Hsu, C-H; Lee, M. C.; Lee, V. R.; Caan, B.J.; Kwan, M.L.; Lohman, T. G.

    2016-01-01

    Body composition may be a better predictor of chronic disease risk than body mass index (BMI) in older populations. Objectives We sought to validate spine fat fraction (%) from dual energy X-ray absorptiometry (DXA) spine scans as a proxy for total abdominal fat. Methods Total body DXA scan abdominal fat regions of interest (ROI) that have been previously validated by magnetic resonance imaging were assessed among healthy, postmenopausal women who also had antero-posterior spine scans (n=103). ROIs were 1) lumbar vertebrae L2-L4 and 2) L2-Iliac Crest (L2-IC), manually selected by two independent raters, and 3) trunk, auto-selected by DXA software. Intra-class correlation coefficients evaluated intra and inter-rater reliability on a random subset (N=25). Linear regression models, validated by bootstrapping, assessed the relationship between spine fat fraction (%) and total abdominal fat (%) ROIs. Results Mean age, BMI and total body fat were: 66.1 ± 4.8y, 25.8 ± 3.8kg/m2 and 40.0 ± 6.6%, respectively. There were no significant differences within or between raters. Linear regression models adjusted for several participant and scan characteristics were equivalent to using only BMI and spine fat fraction. The model predicted L2-L4 (Adj. R2: 0.83) and L2-IC (Adj.R2:0.84) abdominal fat (%) well; the adjusted R2 for trunk fat (%) was 0.78. Model validation demonstrated minimal over-fitting (Adj. R2: 0.82, 0.83, and 0.77 for L2-L4, L2-IC, and trunk fat respectively). Conclusions The strong correlation between spine fat fraction and DXA abdominal fat measures make it suitable for further development in post-menopausal chronic disease risk prediction models. PMID:27416964

  12. A comparison of bone mineral density in osteoporotic fracture of the proximal femur using dual energy X-ray absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Seok; Yoo, Beong Gyu [Wonkwang Health Science College, Iksan (Korea, Republic of); Kim, Keung Sik [Yonsei University Yong Dong Severance Hospital, Seoul (Korea, Republic of)

    2000-04-15

    There were some controversies about direct cause of hip fracture. We attempted to look at 40 osteoporotic proximal femur fractures in women over 50 years between March in 1999 and February in 2000. The bone density of the fracture group and the healthy 85 control group was measured by Dual Energy X-ray absorptiometry (DEXA). The result was compared using age matched paired T test. The results were as follows: The femoral neck fractures were 14 cases and the trochanteric fractures were 26 cases. Mean age at a fracture was 67.1 years in neck fracture group and 76.5 years in trochanteric fracture. In the control group, the bone density of both side of the proximal femur was measured and it showed statistically no difference between both sides in same person. The bone density of neck, Ward's triangle, trochanter (P<0.05) and lumbar spine (P<0.001) was significantly reduced in the proximal femoral fracture group comparing with the control group. The bone density of neck, Ward's triangle, trochanter (P<0.05) was significantly reduced in the proximal femoral neck fracture group comparing with the control group, but there was no statistical difference in lumbar spine comparing with the control group. The bone density of neck, Ward's triangle, trochanter and lumbar spine (P<0.001) was significantly reduced in the proximal femoral neck fracture group comparing with the control group. We concluded that the bone mineral densities (BMD) of proximal femur and lumbar spine had decreased in hip fractures but that the bone mineral density and T-score % of the proximal femur were statistically lower than that of the lumbar spine. We suggest that measuring the bone mineral density of the proximal femur may reflect the weakness of the proximal femur more precisely than measuring the bone mineral density of the lumbar spine.

  13. The reliability of dual-energy X-ray absorptiometry measurements of bone mineral density in the metatarsals

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Joel T.; Buckley, Jonathan D.; Tsiros, Margarita D.; Thewlis, Dominic [University of South Australia, Alliance for Research in Exercise, Nutrition and Activity (ARENA), Sansom Institute for Health Research, GPO Box 2471, Adelaide, South Australia (Australia); Archer, Jane [University of South Australia, Medical Radiation, School of Health Sciences, Adelaide (Australia)

    2016-01-15

    To investigate the reliability of a simple, efficient technique for measuring bone mineral density (BMD) in the metatarsals using dual-energy X-ray absorptiometry (DXA). BMD of the right foot of 32 trained male distance runners was measured using a DXA scanner with the foot in the plantar position. Separate regions of interest (ROI) were used to assess the BMD of each metatarsal shaft (1st-5th) for each participant. ROI analysis was repeated by the same investigator to determine within-scan intra-rater reliability and by a different investigator to determine within-scan inter-rater reliability. Repeat DXA scans were undertaken for ten participants to assess between-scan intra-rater reliability. Assessment of BMD was consistently most reliable for the first metatarsal across all domains of reliability assessed (intra-class correlation coefficient [ICC] ≥0.97; coefficient of variation [CV] ≤1.5 %; limits of agreement [LOA] ≤4.2 %). Reasonable levels of intra-rater reliability were also achieved for the second and fifth metatarsals (ICC ≥0.90; CV ≤4.2 %; LOA ≤11.9 %). Poorer levels of reliability were demonstrated for the third (ICC ≥0.64; CV ≤8.2 %; LOA ≤23.6 %) and fourth metatarsals (ICC ≥0.67; CV ≤9.6 %; LOA ≤27.5 %). BMD was greatest in the first and second metatarsals (P < 0.01). Reliable measurements of BMD were achieved for the first, second and fifth metatarsals. (orig.)

  14. Predictive Validity of the Body Adiposity Index in Overweight and Obese Adults Using Dual-Energy X-ray Absorptiometry

    Science.gov (United States)

    Ramírez-Vélez, Robinson; Correa-Bautista, Jorge Enrique; González-Ruíz, Katherine; Vivas, Andrés; García-Hermoso, Antonio; Triana-Reina, Hector Reynaldo

    2016-01-01

    The body adiposity index (BAI) is a recent anthropometric measure proven to be valid in predicting body fat percentage (BF%) in some populations. However, the results have been inconsistent across populations. This study was designed to verify the validity of BAI in predicting BF% in a sample of overweight/obese adults, using dual-energy X-ray absorptiometry (DEXA) as the reference method. A cross-sectional study was conducted in 48 participants (54% women, mean age 41.0 ± 7.3 years old). DEXA was used as the “gold standard” to determine BF%. Pearson’s correlation coefficient was used to evaluate the association between BAI and BF%, as assessed by DEXA. A paired sample t-test was used to test differences in mean BF% obtained with BAI and DEXA methods. To evaluate the concordance between BF% as measured by DEXA and as estimated by BAI, we used Lin’s concordance correlation coefficient and Bland–Altman agreement analysis. The correlation between BF% obtained by DEXA and that estimated by BAI was r = 0.844, p < 0.001. Paired t-test showed a significant mean difference in BF% between methods (BAI = 33.3 ± 6.2 vs. DEXA 39.0 ± 6.1; p < 0.001). The bias of the BAI was −6.0 ± 3.0 BF% (95% CI = −12.0 to 1.0), indicating that the BAI method significantly underestimated the BF% compared to the reference method. Lin’s concordance correlation coefficient was considered stronger (ρc = 0.923, 95% CI = 0.862 to 0.957). In obese adults, BAI presented low agreement with BF% measured by DEXA; therefore, BAI is not recommended for BF% prediction in this overweight/obese sample studied. PMID:27916871

  15. Comparison of bioimpedance and dual-energy x-ray absorptiometry for measurement of fat mass in hemodialysis patients.

    Science.gov (United States)

    Molfino, Alessio; Don, Burl R; Kaysen, George A

    2012-01-01

    Fat mass (FM) is measured with dual-energy X-ray absorptiometry (DXA), but is expensive and not portable. Multifrequency bioimpedance spectroscopy (BIS) measures total body water (TBW), intracellular water (ICW) and extracellular water (ECW). FM is calculated by subtracting fat-free mass (FFM) from weight assuming a fractional hydration of FFM of 0.73. Hemodialysis (HD) patients, however, have nonphysiologic expansion of ECW. Our aim was to apply a model to estimate FM in HD patients and controls. We estimated the hydration of FFM in healthy subjects and HD patients with BIS (Impedimed multifrequency) assuming a hydration of 0.73 or using a model allowing ECW and ICW to vary, deriving a value for FM accounting for variances in ECW and ICW. FM was measured by DXA (Hologic Discovery W) in 25 controls and in 11 HD patients. We measured TBW, ECW and ICW with BIS and calculated FM using either weight - TBW/0.73 or with a model accounting for variations in ECW/ICW to estimate FM. ECW/ICW was greater in HD patients than in controls (0.83 ± 0.08 vs. 0.76 ± 0.04; p = 0.001). FM (kg) measured by DXA or estimated from TBW using constant hydration or accounting for variations in ECW/ICW was not significantly different in controls or in HD patients. Values obtained by all methods correlated (p measured by DXA and by BIS in both controls and HD patients combined correlated (r(2) = 0.871). Expansion of ECW in HD patients is statistically significant; however, the effect on hydration of FFM was insufficient to cause significant deviation from values derived using a hydration value of 0.73 within the range of expansion of ECW in the HD patient population studied here. Copyright © 2013 S. Karger AG, Basel.

  16. Effect of endodontic cement on bone mineral density using serial dual-energy x-ray absorptiometry.

    Science.gov (United States)

    Saghiri, Mohammad Ali; Orangi, Jafar; Tanideh, Nader; Janghorban, Kamal; Sheibani, Nader

    2014-05-01

    Materials with new compositions were tested in order to develop dental materials with better properties. Calcium silicate-based cements, including white mineral trioxide aggregate (WMTA), may improve osteopromotion because of their composition. Nano-modified cements may help researchers produce ideal root-end filling materials. Serial dual-energy x-ray absorptiometry measurement was used to evaluate the effects of particle size and the addition of tricalcium aluminate (C3A) to a type of mineral trioxide aggregate-based cement on bone mineral density and the surrounding tissues in the mandible of rabbits. Forty mature male rabbits (N = 40) were anesthetized, and a bone defect measuring 7 × 1 × 1 mm was created on the semimandible. The rabbits were divided into 2 groups, which were subdivided into 5 subgroups with 4 animals each based on the defect filled by the following: Nano-WMTA (patent application #13/211.880), WMTA (as standard), WMTA without C3A, Nano-WMTA + 2% Nano-C3A (Fujindonjnan Industrial Co, Ltd, Fujindonjnan Xiamen, China), and a control group. Twenty and forty days postoperatively, the animals were sacrificed, and the semimandibles were removed for DXA measurement. The Kruskal-Wallis test followed by the Mann-Whitney U test showed significant differences between the groups at a significance level of P density at both intervals and P20 day = .004 and P40 day = .005 for bone mineral content. This study showed that bone regeneration was enhanced by reducing the particle size (nano-modified) and C3A mixture. This may relate to the existence of an external supply of minerals and a larger surface area of nano-modified material, which may lead to faster release rate of Ca(2+), inducing bone formation. Adding Nano-C3A to Nano-WMTA may improve bone regeneration properties. Copyright © 2014 American Association of Endodontists. All rights reserved.

  17. Estimation of percentage body fat by dual-energy x-ray absorptiometry: evaluation by in vivo human elemental composition

    International Nuclear Information System (INIS)

    Wang Zimian; Pierson, Richard N; Heymsfield, Steven B; Chen Zhao; Zhu Shankuan

    2010-01-01

    Dual-energy x-ray absorptiometry (DXA) is widely applied for estimating body fat. The percentage of body mass as fat (%fat) is predicted from a DXA-estimated R ST value defined as the ratio of soft tissue attenuation at two photon energies (e.g., 40 keV and 70 keV). Theoretically, the R ST concept depends on the mass of each major element in the human body. The DXA R ST values, however, have never been fully evaluated by measured human elemental composition. The present investigation evaluated the DXA R ST value by the total body mass of 11 major elements and the DXA %fat by the five-component (5C) model, respectively. Six elements (i.e. C, N, Na, P, Cl and Ca) were measured by in vivo neutron activation analysis, and potassium (i.e. K) by whole-body 40 K counting in 27 healthy adults. Models were developed for predicting the total body mass of four additional elements (i.e. H, O, Mg and S). The elemental content of soft tissue, after correction for bone mineral elements, was used to predict the R ST values. The DXA R ST values were strongly associated with the R ST values predicted from elemental content (r = 0.976, P ST to systematically exceed the DXA-measured R ST (mean ± SD, 1.389 ± 0.024 versus 1.341 ± 0.024). DXA-estimated %fat was strongly associated with 5C %fat (24.4 ± 12.0% versus 24.9 ± 11.1%, r = 0.983, P ST is evaluated by in vivo elemental composition, and the present study supports the underlying physical concept and accuracy of the DXA method for estimating %fat.

  18. The reliability of dual-energy X-ray absorptiometry measurements of bone mineral density in the metatarsals.

    Science.gov (United States)

    Fuller, Joel T; Archer, Jane; Buckley, Jonathan D; Tsiros, Margarita D; Thewlis, Dominic

    2016-01-01

    To investigate the reliability of a simple, efficient technique for measuring bone mineral density (BMD) in the metatarsals using dual-energy X-ray absorptiometry (DXA). BMD of the right foot of 32 trained male distance runners was measured using a DXA scanner with the foot in the plantar position. Separate regions of interest (ROI) were used to assess the BMD of each metatarsal shaft (1st-5th) for each participant. ROI analysis was repeated by the same investigator to determine within-scan intra-rater reliability and by a different investigator to determine within-scan inter-rater reliability. Repeat DXA scans were undertaken for ten participants to assess between-scan intra-rater reliability. Assessment of BMD was consistently most reliable for the first metatarsal across all domains of reliability assessed (intra-class correlation coefficient [ICC] ≥0.97; coefficient of variation [CV] ≤1.5%; limits of agreement [LOA] ≤4.2%). Reasonable levels of intra-rater reliability were also achieved for the second and fifth metatarsals (ICC ≥0.90; CV ≤4.2%; LOA ≤11.9%). Poorer levels of reliability were demonstrated for the third (ICC ≥0.64; CV ≤8.2%; LOA ≤23.6%) and fourth metatarsals (ICC ≥0.67; CV ≤9.6%; LOA ≤27.5%). BMD was greatest in the first and second metatarsals (P Reliable measurements of BMD were achieved for the first, second and fifth metatarsals.

  19. Estimation of percentage body fat by dual-energy x-ray absorptiometry: evaluation by in vivo human elemental composition

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zimian; Pierson, Richard N [Obesity Research Center, St Luke' s-Roosevelt Hospital, Columbia University, College of Physicians and Surgeons, New York, NY (United States); Heymsfield, Steven B [Clinical Research, Metabolism, Merck Research Laboratories, Rahway, NJ (United States); Chen Zhao [Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ (United States); Zhu Shankuan, E-mail: zw28@columbia.ed [Obesity and Body Composition Research Center, Zhejiang University, School of Public Health, Hangzhou (China)

    2010-05-07

    Dual-energy x-ray absorptiometry (DXA) is widely applied for estimating body fat. The percentage of body mass as fat (%fat) is predicted from a DXA-estimated R{sub ST} value defined as the ratio of soft tissue attenuation at two photon energies (e.g., 40 keV and 70 keV). Theoretically, the R{sub ST} concept depends on the mass of each major element in the human body. The DXA R{sub ST} values, however, have never been fully evaluated by measured human elemental composition. The present investigation evaluated the DXA R{sub ST} value by the total body mass of 11 major elements and the DXA %fat by the five-component (5C) model, respectively. Six elements (i.e. C, N, Na, P, Cl and Ca) were measured by in vivo neutron activation analysis, and potassium (i.e. K) by whole-body {sup 40}K counting in 27 healthy adults. Models were developed for predicting the total body mass of four additional elements (i.e. H, O, Mg and S). The elemental content of soft tissue, after correction for bone mineral elements, was used to predict the R{sub ST} values. The DXA R{sub ST} values were strongly associated with the R{sub ST} values predicted from elemental content (r = 0.976, P < 0.001), although there was a tendency for the elemental-predicted R{sub ST} to systematically exceed the DXA-measured R{sub ST} (mean {+-} SD, 1.389 {+-} 0.024 versus 1.341 {+-} 0.024). DXA-estimated %fat was strongly associated with 5C %fat (24.4 {+-} 12.0% versus 24.9 {+-} 11.1%, r = 0.983, P < 0.001). DXA R{sub ST} is evaluated by in vivo elemental composition, and the present study supports the underlying physical concept and accuracy of the DXA method for estimating %fat.

  20. 'Real world' imprecision of dual-energy x-ray absorptiometry (DEXA) at L2-4 and femur neck

    International Nuclear Information System (INIS)

    Phillipov, G.; Sigalas, V.; Seaborn, C.; Phillips, P.; Rowe, C.; Kitchener, M.

    1998-01-01

    Full text: While measurement of bone density (BMD) by DEXA is routinely used to diagnose osteoporosis and estimate future fracture risk, data on what constitutes a significant change between serial BMD measurements has received much less attention. The use of repeat BMD measurements is particularly important to either assess the rate of bone loss or treatment efficacy for individual patients. However to estimate a statistically significant change between consecutive bone mineral density (BMD) measurements requires an accurate knowledge of dual-energy x-ray absorptiometry (DEXA) imprecision under actual day-to-day working conditions. DEXA imprecision, based on in vitro models, such as manufacturers' phantoms, leads to a marked under-estimation of true imprecision, since significant sources of variance (patient positioning, inter- and intra-operator variability etc) are ignored. In an attempt to provide a robust estimate of imprecision for our Lunar DPXplus, 28 females and one male(age 72.8 + 7.8 yr)were recruited to have multiple DEXA scans at approximately four week intervals. The subjects were handled using exactly the same procedure as that for our referred patients. Initial findings after each subject has had am average of 6.6 DEXA scans showed that the within subject variability (CV w ) associated with the AP lumbar spine (L2-4)and femur-neck was 1.83 and 2.24% respectively. No significant correlation was found between BMD values and CV w at either site. Since instrument variability is about 0.7% (derived from phantom studies), it is apparent that operator variation accounts for the majority of total variability. From the derived imprecision, the percentage difference for a significant change at a predefined probability limit is 5.1 and 6.2% for the spine and femur-neck sites respectively, when the probability of a false alarm is 5% (bi-directional). Knowledge of the critical difference required between successive measurements, combined with the known rate of

  1. The influence of body composition assessed by dual-energy x-ray absorptiometry on functional capacity of patients with chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Gualberto Ruas

    Full Text Available INTRODUCTION: The individual with chronic obstructive pulmonary disease (COPD can experience a significant reduction of body composition, peripheral muscle dysfunction, resulting in a negative influence on functional capacity. OBJECTIVES: To analyze the influence of body composition assessed by dual-energy x-ray absorptiometry on functional capacity of patients with chronic obstructive pulmonary disease (COPD. MATERIALS AND METHODS: Eleven male patients with COPD (COPDG, seven presenting moderate obstruction and four severe, and 11 sedentary male subjects (CG were evaluated by dual-energy x-ray absorptiometry to assess their body composition. All subjects also performed the 6-minute walk test (6MWT and Step Test (6MST to assess their functional capacity. RESULTS: No significant differences were found between groups for anthropometric data such as age, weight, height and body mass index (BMI. However, the COPDG presented Forced Vital Capacity (FVC, Forced Expiratory Volume in one second (FEV1, FEV1/FVC ratio, Maximal Voluntary Ventilation (MVV, Walked Distance (WD and Number of Steps (NS significantly lower than the CG (p < 0.05, Student's t-test. The Body Bone Mass (BBM, BBM%, Lean Mass (LM, LM%, and Right Lower Limb (RLL and Left Lower Limb (LLL were significantly lower in the COPDG when compared with the CG, presenting statistically significant positive correlations with 6MWT's WD and 6MST's NS (p < 0.05, Pearson's test. CONCLUSION: We conclude that body composition is an important prognostic factor for patients with COPD, which reinforces the importance of assessing body composition by dual-energy absorptiometry since it has demonstrated with satisfactory accuracy in clinical practice. Moreover, it is a useful parameter for evaluation and reassessment in pulmonary rehabilitation programs.

  2. Change in fat-free mass assessed by bioelectrical impedance, total body potassium and dual energy X-ray absorptiometry during prolonged weight loss

    DEFF Research Database (Denmark)

    Hendel, H W; Gotfredsen, A; Højgaard, L

    1996-01-01

    A total of 16 obese women (body mass index (BMI) 30-43 kg m(-2)) participated in a weight reduction study. Before and after a weight loss of 11.7 +/- 7.4 kg (mean +/- SD), body composition was assessed by dual energy X-ray absorptiometry (DXA), and total body potassium counting (TBK). These measu......A total of 16 obese women (body mass index (BMI) 30-43 kg m(-2)) participated in a weight reduction study. Before and after a weight loss of 11.7 +/- 7.4 kg (mean +/- SD), body composition was assessed by dual energy X-ray absorptiometry (DXA), and total body potassium counting (TBK......). These measurements were compared with bioimpedance analysis (BIA) by applying 11 predictive BIA equations published in the literature. Predictive equations for the present study population were developed, with the use of fat-free mass (FFM) as assessed by TBK and DXA as references in multiple regression analysis....... The results of the BIA equations varied widely; FFM was generally overestimated by BIA as compared with DXA and TBK before and after weight loss. During weight loss, the FFM did not change, as estimated by DXA (1.3 +/- 2.3 kg, p > 0.05) and TBK (0.9 +/- 2.9 kg, p > 0.05). The recorded change in impedance (R...

  3. Body Fat Percentages by Dual-energy X-ray Absorptiometry Corresponding to Body Mass Index Cutoffs for Overweight and Obesity in Indian Children

    Directory of Open Access Journals (Sweden)

    Deepa Pandit

    2009-01-01

    Full Text Available Background Indians are suspected to have higher body fat percent at a given body mass index (BMI than their western counterparts. Objective To estimate percent body fat in apparently healthy Indian children and adolescents by dual-energy X-ray absorptiometry (DXA and explore linkages of BMI with body fat percent for better health risk assessment. Methods Age, weight, height of 316 boys and 250 girls (6–17 years were recorded. Body composition was measured by dual-energy X-ray absorptiometry (DXA. High adiposity was defined as body fat percent (BF% > McCarthy's 85th percentile of body fat reference data. Receiver operating characteristic analysis (ROC was carried out for CDC BMI Z score for it's ability to judge excess fatness. Results High BF% was seen in 38.5% boys and 54.0% girls (p < 0.05. Percentage of obese children as defined by the BMI cutoffs of International Obesity Task Force (IOTF (2.1% for boys and 6.9% for girls was lower than that using Indian (13.7% for boys and 20.9% for girls and CDC (14.1% for boys and 20.9% for girls cutoffs. The point closest to one on the ROC curves of CDC BMI Z-scores indicated high adiposity at BMI cutoff of 22 at the age of 17 yr in both the genders. Conclusions Higher body fat percentage is associated with lower BMI values in Indian children.

  4. Bone densitometry by dual-energy X-ray absorptiometry (DXA in preterm newborns compared with full-term peers in the first six months of life

    Directory of Open Access Journals (Sweden)

    Virginia S. Quintal

    2014-12-01

    Full Text Available OBJECTIVES: To longitudinally assess bone mineral content (BMC, bone mineral density (BMD, and whole-body lean mass obtained through bone densitometry by dual-energy X-ray absorptiometry (DXA in preterm newborns (PTNs and compare them with full-term newborns (FTNs from birth to 6 months of corrected postnatal age. METHODS: A total of 28 adequate for gestational age (AGA newborns were studied: 14 preterm and 14 full-term newborns. DXA was used to determine BMC, BMD, and lean mass in three moments: 40 weeks corrected post-conceptual age, as well as 3 and 6 months of corrected postnatal age. PTNs had gestational age ≤ 32 weeks at birth and were fed their mother's own milk or milk from the human milk bank. RESULTS: All infants had an increase in BMC, BMD, and lean body mass values during the study. PTNs had lower BMC, BMD, and lean mass at 40 weeks of corrected post-conceptual age in relation to FTNs (p < 0.001, p < 0.001, p = 0.047, respectively. However, there was an acceleration in the mineralization process of PTNs, which was sufficient to achieve the normal values of FTNs at 6 months of corrected age. CONCLUSIONS: This study suggests that bone densitometry by dual-energy X-ray absorptiometry is a good method for the assessment of body composition parameters at baseline, and at the follow-up of these PTNs.

  5. Percentage body fat by dual-energy X-ray absorptiometry is associated with menstrual recovery in adolescents with anorexia nervosa.

    Science.gov (United States)

    Pitts, Sarah; Blood, Emily; Divasta, Amy; Gordon, Catherine M

    2014-06-01

    To evaluate mediators of resumption of menses (ROM) in adolescents with anorexia nervosa (AN). Anthropometrics, body composition by dual-energy X-ray absorptiometry, hormonal studies, and responses to mental health screens were obtained at 6-month intervals for 18 months in 37 adolescents with AN randomized to the placebo arm of a double-blind treatment trial. Outcomes were compared between subjects with menstrual recovery and those without. Twenty-four subjects (65%) had ROM. Higher percentage body fat was associated with ROM (odds ratio, 1.19; 95% confidence interval, 1.06, 1.33; p adolescents with AN. Copyright © 2014 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  6. Estimation of stature and length of limb segments in children and adolescents from whole-body dual-energy X-ray absorptiometry scans

    International Nuclear Information System (INIS)

    Abrahamyan, Davit O.; Gazarian, Aram; Braillon, Pierre M.

    2008-01-01

    Anthropometric standards vary among different populations, and renewal of these reference values is necessary. To produce formulae for the assessment of limb segment lengths. Whole-body dual-energy X-ray absorptiometry scans of 413 Caucasian children and adolescents (170 boys, 243 girls) aged from 6 to 18 years were retrospectively analysed. Body height and the lengths of four long bones (humerus, radius, femur and tibia) were measured. The validity (concurrent validity) and reproducibility (intraobserver reliability) of the measurement technique were tested. High linear correlations (r > 0.9) were found between the mentioned five longitudinal measures. Corresponding linear regression equations for the most important relationships were derived. The tests of validity and reproducibility revealed a good degree of precision of the applied technique. The reference formulae obtained from the analysis of whole-body DEXA scans will be useful for anthropologists, and forensic and nutrition specialists, as well as for prosthetists and paediatric orthopaedic surgeons. (orig.)

  7. Prediction of appendicular skeletal and fat mass in children: excellent concordance of dual-energy X-ray absorptiometry and magnetic resonance imaging.

    Science.gov (United States)

    Bridge, Pascale; Pocock, Nicholas A; Nguyen, Tuan; Munns, Craig; Cowell, Christopher T; Thompson, Martin W

    2009-09-01

    Body composition studies in children have great potential to help understand the aetiology and evolution of acute and chronic. diseases. To validate appendicular lean soft tissue mass (LSTM) and fat mass (FM) measured using dual energy X-ray absorptiometry (DXA), with magnetic resonance imaging (MRI) as the reference standard, in healthy peri-pubertal adolescents. Peri-pubertal Caucasian children (n = 74) aged 11-14 years were evaluated. DXA LSTM and FM of the mid third femur were measured and skeletal muscle mass (SM) and FM of the same region were measured on the same day by MRI. There was a strong correlation between MRI SM and DXA LSTM (r2 = 0.98, index of concordance [C] = 0.91). DXA estimation of LSTM exceeded MRI SM by a mean of 189 g, from 6-371 g (p LSTM measurement in children, confirming its potential in clinical and research roles in paediatric diseases affecting and related to body composition.

  8. Agreement Between Bioelectrical Impedance and Dual-Energy X-Ray Absorptiometry to Track Changes in Fat-Free Mass After Resistance Training in Older Women.

    Science.gov (United States)

    Nascimento, Matheus A; Silva, Danilo R P; Ribeiro, Alex S; Pina, Fábio L C; Gerage, Aline M; Gobbo, Luís A; Mayhew, Jerry L; Cyrino, Edilson S

    2018-05-23

    Nascimento, MA, Silva, DRP, Ribeiro, AS, Pina, FLC, Gerage, AM, Gobbo, LA, Mayhew, JL, and Cyrino, ES. Agreement between bioelectrical impedance and dual-energy x-ray absorptiometry to track changes in fat-free mass after resistance training in older women. J Strength Cond Res XX(X): 000-000, 2018-The aim of our study was to compare the agreement between bioelectrical impedance (BIA) and dual-energy X-ray absorptiometry (DXA) to track changes on fat-free mass (FFM) after a resistance training (RT) program in older women. Forty-three older women (65.2 ± 4.6 years, 59.5 ± 9.2 kg, 156.4 ± 6.0 cm, 24.3 ± 3.3 kg·m) participated in a RT intervention (12 weeks, 8 exercises, 2 sets, 10-15 repetitions, 3 nonconsecutive days per week). Fat-free mass changes were determined by a single-frequency BIA device (EQ1), 6 BIA prediction equations for older women (EQ2, EQ3, EQ4, EQ5, EQ6, and EQ7), and DXA. At pretraining, 3 equations overpredicted, and 3 underpredicted DXA FFM (F = 244.63, p FFM (F = 176.25, p FFM (0.65 ± 0.82 kg; p FFM. Low correlations between FFM and equation change values suggest that single-frequency BIA-derived equations may not provide sufficient accuracy to track changes in FFM after 12 weeks of RT in older women.

  9. Comparison of Circumference Measures and Height-Weight Tables With Dual-Energy X-Ray Absorptiometry Assessment of Body Composition in R.O.T.C. Cadets.

    Science.gov (United States)

    Mitchell, Katherine M; Pritchett, Robert C; Gee, David L; Pritchett, Kelly L

    2017-09-01

    Mitchell, KM, Pritchett, RC, Gee, DL, and Pritchett, KL. Comparison of circumference measures and height-weight tables with dual-energy X-ray absorptiometry assessment of body composition in R.O.T.C. cadets. J Strength Cond Res 31(9): 2552-2556, 2017-Height-weight tables and circumference measures are used by the U.S. Army to predict body composition because they require little equipment or expertise. However, agreement between the Army's new 2002 circumference equation and an established laboratory technique has not been determined. The purpose of this study was to quantify agreement in body fat percentages between the Army's circumference measures (taping) and dual-energy X-ray absorptiometry (DXA); second to determine categorical agreement between height-weight tables and DXA. Male Reserve Officer Training Corps (R.O.T.C.) cadets (N = 23; 20.6 ± 1.6 years, 179.1 ± 6.6 cm; 81.4 ± 10.3 kg) were taped according to Army protocol to predict body fat. The % body fat prediction was compared with DXA through a Bland-Altman Plot with ±2-4% body fat established as a zone of agreement (ZOA). Thirteen out of 23 cadets fell outside the ZOA. No cadet was over the compliance threshold (20-22% fat) using the tape method, however, with DXA, 7 out of 23 cadets were noncompliant. Height-weight tables provided a moderate level of categorical agreement with DXA. The results depict poor agreement between taping and DXA, as taping generally underestimated % body fat. Compared with taping, height-weight tables were better able to identify excess fat weight.

  10. Dual-energy X-ray absorptiometry applied to the assessment of tibial subchondral bone mineral density in osteoarthritis of the knee

    International Nuclear Information System (INIS)

    Clarke, S.; Duddy, J.; Nickols, G.; Kirwan, J.R.; Wakeley, C.; Watt, I.; Ellingham, K.; Sharif, M.; Elson, C.J.

    2004-01-01

    Plain X-ray is an imprecise tool for monitoring the subchondral bony changes associated with the development of knee osteoarthritis (OA). Our objective was to develop and validate a technique for assessing tibial subchondral bone density (BMD) in knee OA using dual energy X-ray absorptiometry (DXA). Patients with OA of at least one knee underwent DXA scanning of both knees. Regions of interest (ROI) were placed in the lateral and medial compartments of tibial subchondral bone. Weight-bearing plain X-rays and Te 99m scintiscans of both knees were obtained and scored. One hundred and twelve patients (223 knees) underwent DXA and radiography. Intra-observer CV% was 2.4% and 1.0% for the medial and lateral ROI respectively. Definite OA (Kellgren and Lawrence Grade 2, 3 or 4) was correlated with age-related preservation of subchondral BMD compared to radiographically normal knees. Raised BMD was also associated with subchondral sclerosis, and positive scintigraphy. DXA may provide a safe, rapid and reliable means of assessing knee OA. Cross-sectional age-related subchondral tibial BMD loss is attenuated by knee OA. (orig.)

  11. Lumbar spine and total-body dual-energy X-ray absorptiometry in children with severe neurological impairment and intellectual disability: a pilot study of artefacts and disrupting factors

    NARCIS (Netherlands)

    Mergler, S.; Rieken, R.; Tibboel, D.; Evenhuis, H. M.; van Rijn, R. R.; Penning, C.

    2012-01-01

    Children with severe neurological impairment and intellectual disability (ID) are susceptible for developing low bone mineral density (BMD) and fractures. BMD is generally measured with dual-energy X-ray absorptiometry (DXA). To describe the occurrence of factors that may influence the feasibility

  12. Fat-free mass prediction equations for bioelectric impedance analysis compared to dual energy X-ray absorptiometry in obese adolescents: a validation study.

    Science.gov (United States)

    Hofsteenge, Geesje H; Chinapaw, Mai J M; Weijs, Peter J M

    2015-10-15

    In clinical practice, patient friendly methods to assess body composition in obese adolescents are needed. Therefore, the bioelectrical impedance analysis (BIA) related fat-free mass (FFM) prediction equations (FFM-BIA) were evaluated in obese adolescents (age 11-18 years) compared to FFM measured by dual-energy x-ray absorptiometry (FFM-DXA) and a new population specific FFM-BIA equation is developed. After an overnight fast, the subjects attended the outpatient clinic. After measuring height and weight, a full body scan by dual-energy x-ray absorptiometry (DXA) and a BIA measurement was performed. Thirteen predictive FFM-BIA equations based on weight, height, age, resistance, reactance and/or impedance were systematically selected and compared to FFM-DXA. Accuracy of FFM-BIA equations was evaluated by the percentage adolescents predicted within 5% of FFM-DXA measured, the mean percentage difference between predicted and measured values (bias) and the Root Mean Squared prediction Error (RMSE). Multiple linear regression was conducted to develop a new BIA equation. Validation was based on 103 adolescents (60% girls), age 14.5 (sd1.7) years, weight 94.1 (sd15.6) kg and FFM-DXA of 56.1 (sd9.8) kg. The percentage accurate estimations varied between equations from 0 to 68%; bias ranged from -29.3 to +36.3% and RMSE ranged from 2.8 to 12.4 kg. An alternative prediction equation was developed: FFM = 0.527 * H(cm)(2)/Imp + 0.306 * weight - 1.862 (R(2) = 0.92, SEE = 2.85 kg). Percentage accurate prediction was 76%. Compared to DXA, the Gray equation underestimated the FFM with 0.4 kg (55.7 ± 8.3), had an RMSE of 3.2 kg, 63% accurate prediction and the smallest bias of (-0.1%). When split by sex, the Gray equation had the narrowest range in accurate predictions, bias, and RMSE. For the assessment of FFM with BIA, the Gray-FFM equation appears to be the most accurate, but 63% is still not at an acceptable accuracy level for obese adolescents. The new equation appears to

  13. Evaluation of mandibular bone mineral density using the dual-energy X-ray absorptiometry technique in edentulous subjects living in an endemic fluorosis region.

    Science.gov (United States)

    Buyukkaplan, U S; Guldag, M U

    2012-07-01

    Fluoride is one of the biological trace elements with a strong affinity for osseous, cartilaginous and dental tissue. The dental and skeletal effects of high fluoride intake have already been studied in the literature, but little is known about the effects of high fluoride intake on edentulous mandibles. The purpose of this study was to evaluate the effects of high fluoride intake on mandibular bone mineral density (BMD) measured by the dual-energy X-ray absorptiometry (DXA) technique in edentulous individuals with systemic fluorosis. 32 people who were living in an endemic fluorosis area since birth and 31 people who were living in a non-endemic fluorosis area since birth (control group) participated in this study. Systemic fluorosis was diagnosed in the patients using the sialic acid (NANA)/glycosaminoglycan (GAG) ratio. The BMDs of the mandibles were determined by the DXA technique. The serum NANA/GAG ratios in the fluorosis group were significantly lower than those in the control group (p structures of the stomatognathic system.

  14. Measurements of bone mineral density in the lumbar spine and proximal femur using lunar prodigy and the new pencil-beam dual-energy X-ray absorptiometry

    International Nuclear Information System (INIS)

    Choi, Dongil; Kim, Deog-Yoon; Han, Chung Soo; Kim, Seonwoo; Bok, Hae Sook; Huh, Wooseong; Ko, Jae-Wook; Hong, Sung Hwa

    2010-01-01

    We evaluated the correlation of the absolute bone mineral density (BMD) values of the lumbar spine and standard sites of the proximal femur obtained from a Lunar Prodigy and the newly developed pencil-beam dual-energy X-ray absorptiometry (Dexxum). Between June 2008 and December 2008, 79 Korean volunteers were enrolled. Measurements were obtained on the same day using both densitometers. The absolute BMD values (g/cm 2 ) from the two densitometers were evaluated using Pearson's correlation analysis with Bonferroni's correction for the three clinically important sites. In order to evaluate precision, we performed duplicate Dexxum measurements, and calculated the within-subject coefficient of variation (WSCV). The Pearson's correlation coefficient (r) of BMD values for the total proximal femur, femoral neck, and lumbar spine by the two densitometers were 0.926, 0.948, and 0.955 respectively, and the null hypotheses of r = 0.8 were all rejected (p < 0.001 by one-sided Z-test with Fisher's z-transformation for each site). The T-scores (r ≥ 0.842) and Z-scores (r ≥ 0.709) also showed strong positive correlations. The duplicate BMD values of Dexxum showed a high level of precision (WSCV ≤ 4.27%). Dexxum measurements of BMD, T-scores, and Z-scores showed a strong linear correlation with those measured on Lunar Prodigy. (orig.)

  15. Vertebral fractures assessed with dual-energy X-ray absorptiometry in patients with Addison's disease on glucocorticoid and mineralocorticoid replacement therapy.

    Science.gov (United States)

    Camozzi, Valentina; Betterle, Corrado; Frigo, Anna Chiara; Zaccariotto, Veronica; Zaninotto, Martina; De Caneva, Erica; Lucato, Paola; Gomiero, Walter; Garelli, Silvia; Sabbadin, Chiara; Salvà, Monica; Costa, Miriam Dalla; Boscaro, Marco; Luisetto, Giovanni

    2018-02-01

    to assess bone damage and metabolic abnormalities in patients with Addison's disease given replacement doses of glucocorticoids and mineralocorticoids. A total of 87 patients and 81 age-matched and sex-matched healthy controls were studied. The following parameters were measured: urinary cortisol, serum calcium, phosphorus, creatinine, 24-h urinary calcium excretion, bone alkaline phosphatase, parathyroid hormone, serum CrossLaps, 25 hydroxyvitamin D, and 1,25 dihydroxyvitamin D. Clear vertebral images were obtained with dual-energy X-ray absorptiometry in 61 Addison's disease patients and 47 controls and assessed using Genant's classification. Nineteen Addison's disease patients (31.1%) had at least one morphometric vertebral fracture, as opposed to six controls (12.8%, odds ratio 3.09, 95% confidence interval 1.12-8.52). There were no significant differences in bone mineral density parameters at any site between patients and controls. In Addison's disease patients, there was a positive correlation between urinary cortisol and urinary calcium excretion. Patients with fractures had a longer history of disease than those without fractures. Patients taking fludrocortisone had a higher bone mineral density than untreated patients at all sites except the lumbar spine. Addison's disease patients have more fragile bones irrespective of any decrease in bone mineral density. Supra-physiological doses of glucocorticoids and longer-standing disease (with a consequently higher glucocorticoid intake) might be the main causes behind patients' increased bone fragility. Associated mineralocorticoid treatment seems to have a protective effect on bone mineral density.

  16. Accuracy of lateral dual energy X-ray absorptiometry for the determination of bone mineral content in the thoracic and lumbar spine: an in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Edmondston, S.J. (Curtin Univ., Perth (Australia). Dept. of Physiotherapy); Singer, K.P. (Royal Perth Hospital, WA (Australia) Curtin Univ., Perth (Australia). Dept. of Physiotherapy); Price, R.I. (Sir Charles Gairdner Hospital, Perth (Australia)); Breidahl, P.D. (Royal Perth Hospital, WA (Australia))

    1993-04-01

    Lateral scanning with dual energy X-ray absorptiometry (DXA) was undertaken on 153 thoracic and lumbar vertebral bodies from nine individuals (mean age 67; range 34-92 years) to establish their bone mineral content (BMC). All specimens were subsequently de-fatted and ashed to compare ash weight with BMC of the T1 to L5 segments. Linear regression analysis indicated a higher correlation between BMC and measured ash weights for each vertebral column (range: r = 0.97-0.99), with error analysis for all vertebrae tested showing a standard error of 0.40 g, or 10.8%. For the L2-4 segments the accuracy error was 0.50 g or 7.9%. In both cases there was a mean trend towards underestimation of ash weight. Mean BMC values of the T1 to T5 segments were similar before a progressive increase caudally. These data affirm the utility of DXA for determining bone mineral content in the vertebral column across wide ranges of age, and segmental and bone density. (Author).

  17. Accuracy of lateral dual energy X-ray absorptiometry for the determination of bone mineral content in the thoracic and lumbar spine: an in vitro study

    International Nuclear Information System (INIS)

    Edmondston, S.J.; Breidahl, P.D.

    1993-01-01

    Lateral scanning with dual energy X-ray absorptiometry (DXA) was undertaken on 153 thoracic and lumbar vertebral bodies from nine individuals (mean age 67; range 34-92 years) to establish their bone mineral content (BMC). All specimens were subsequently de-fatted and ashed to compare ash weight with BMC of the T1 to L5 segments. Linear regression analysis indicated a higher correlation between BMC and measured ash weights for each vertebral column (range: r = 0.97-0.99), with error analysis for all vertebrae tested showing a standard error of 0.40 g, or 10.8%. For the L2-4 segments the accuracy error was 0.50 g or 7.9%. In both cases there was a mean trend towards underestimation of ash weight. Mean BMC values of the T1 to T5 segments were similar before a progressive increase caudally. These data affirm the utility of DXA for determining bone mineral content in the vertebral column across wide ranges of age, and segmental and bone density. (Author)

  18. Dual-energy X-ray absorptiometry and force-plate analysis of gait in dogs with healed femora after leg-lengthening plate fixation

    International Nuclear Information System (INIS)

    Muir, P.; Markel, M.D.; Bogdanske, J.J.; Johnson, K.A.

    1995-01-01

    Dual-energy x-ray absorptiometry was used to measure bone mineral density of four regions in healed femora of nine dogs after fracture fixation with a leg-lengthening plate. Six to 85 months (mean, 46 months) after surgery, the bone mineral density of healed femora was not significantly different from the contralateral uninjured femora (P > .05; power = 0.8 at delta = 15%). Radiolucencies around the proximal screws, apparently associated with screw loosening, were seen on radiographic views of the healed femora of three dogs. In one of these dogs, one screw in the proximal metaphysis had broken. Force-plate analysis of gait was also performed on dogs at the time of bone mineral density measurement. Peak vertical force was decreased in the pelvic limb with the healed fracture compared with the contralateral unoperated limb (P < 0.05). Clinically apparent lameness in three dogs did not appear to be associated with altered bone mineral density and may have been caused by hip osteoarthritis, a nondisplaced hairline diaphyseal fracture, and screw loosening in conjunction with extensive post-traumatic soft tissue injury

  19. Evaluation of femur of orchiectomized Guinea pigs by bone densitometry using dual-energy X-ray absorptiometry (DXA) and mechanical testing

    Energy Technology Data Exchange (ETDEWEB)

    Estanislau, Cristiane de Abreu; Rahal, Sheila Canavese; Araujo, Fabio Andre Pinheiro de, E-mail: crisestanislau@hotmail.co, E-mail: sheilacr@fmvz.unesp.b, E-mail: fabioandre@fmvz.unesp.b [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil). Faculdade de Medicina, Veterinaria e Zootecnia. Dept. de Cirurgia e Anestesiologia Veterinaria; Sergio Swain Muller, E-mail: diretoria@fmb.unesp.b [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil). Faculdade de Medicina, Veterinaria e Zootecnia. Dept. de Cirurgia e Ortopedia; Louzada, Mario Jefferson Quirino, E-mail: louzada@fmva.unesp.b [Universidade Estadual Paulista (UNESP), Aracatuba, SP (Brazil). Faculdade de Medicina Veterinaria; Estanislau, Caroline de Abreu, E-mail: caestanis@hotmail.co

    2010-03-15

    The aim of this study was to evaluate the effects of castration on bones in the male guinea pigs and to observe whether mechanical testing correlates with dual-energy X-ray absorptiometry (DXA). Twelve male guinea pigs (Cavia porcellus), aged 21-27 days, and with average initial weight of 279 grams were used. The animals were equally allocated to two groups: GI - orchiectomized animals and GII - intact control animals. They underwent euthanasia at seven months following surgery. DXA measurement was performed at the mid third of the right femoral diaphysis in the cortical region and at the left femoral neck in order to verify its correlation with results of mechanical testing. Three-point bending test of right femur and axial compression test of left femur were performed. Bone mineral density of GI was significantly lower only at femoral neck. No differences were observed in the maximum load values between GI and GII for both bending and axial compression tests. The bending test revealed lower bone stiffness in GI compared to GII, but in the axial compression test no differences between groups were observed. Only left femur showed positive correlation coefficient between maximum load and bone mineral density according to Pearson's correlation coefficient. The results suggest that hormonal deprivation in guinea pigs induces reduction of bone mineral density, especially in the femoral neck area and reduction of bone stiffness in the mid-femoral diaphysis. (author)

  20. Impact of hydration status on body composition as measured by dual energy X-ray absorptiometry in normal volunteers and patients on haemodialysis

    International Nuclear Information System (INIS)

    Horber, F.F.; Thomi, F.; Casez, J.P.; Fonteille, J.; Jaeger, Ph.

    1992-01-01

    To evaluate the influence of hydration status on the estimation of body composition using dual-energy X-ray absorptiometry (DXA), six normal volunteers and seven patients on maintenance haemodialysis were investigated using two different DXA machines (Lunar DPX, Hologic QDR 1000/W). Normal volunteers were studied (Hologic QDR 1000/W) before and 1 h after ingestion of breakfast, lunch and dinner (drinking various amounts of liquids at each meal, 0.5-2.4 kg). Whereas bone mineral content and body fat mass did not change, lean body mass of the trunk increased as a consequence of the meals. Conversely in patients on haemodialysis (Lunar DPX), lean body mass decreased in all segments of the body as a consequence of removal of 0.9-4.4 kg of salt-containing fluid by haemodialysis (trunk 61%, legs 30%, arms 5.5% and rest of the body 3.5%), whereas bone mineral content and body fat mass remained unchanged. (author)

  1. Dual Energy X-Ray Absorptiometry Compared with Anthropometry in Relation to Cardio-Metabolic Risk Factors in a Young Adult Population: Is the 'Gold Standard' Tarnished?

    Science.gov (United States)

    Demmer, Denise L; Beilin, Lawrence J; Hands, Beth; Burrows, Sally; Pennell, Craig E; Lye, Stephen J; Mountain, Jennifer A; Mori, Trevor A

    2016-01-01

    Assessment of adiposity using dual energy x-ray absorptiometry (DXA) has been considered more advantageous in comparison to anthropometry for predicting cardio-metabolic risk in the older population, by virtue of its ability to distinguish total and regional fat. Nonetheless, there is increasing uncertainty regarding the relative superiority of DXA and little comparative data exist in young adults. This study aimed to identify which measure of adiposity determined by either DXA or anthropometry is optimal within a range of cardio-metabolic risk factors in young adults. 1138 adults aged 20 years were assessed by DXA and standard anthropometry from the Western Australian Pregnancy Cohort (Raine) Study. Cross-sectional linear regression analyses were performed. Waist to height ratio was superior to any DXA measure with HDL-C. BMI was the superior model in relation to blood pressure than any DXA measure. Midriff fat mass (DXA) and waist circumference were comparable in relation to glucose. For all the other cardio-metabolic variables, anthropometric and DXA measures were comparable. DXA midriff fat mass compared with BMI or waist hip ratio was the superior measure for triglycerides, insulin and HOMA-IR. Although midriff fat mass (measured by DXA) was the superior measure with insulin sensitivity and triglycerides, the anthropometric measures were better or equal with various DXA measures for majority of the cardio-metabolic risk factors. Our findings suggest, clinical anthropometry is generally as useful as DXA in the evaluation of the individual cardio-metabolic risk factors in young adults.

  2. Characterization of changes in total body composition for patients with head and neck cancer undergoing chemoradiotherapy using dual-energy x-ray absorptiometry.

    Science.gov (United States)

    Jackson, William; Alexander, Neil; Schipper, Matthew; Fig, Lorraine; Feng, Felix; Jolly, Shruti

    2014-09-01

    Patients with head and neck cancer experience significant weight loss secondary to concurrent chemoradiotherapy (CCRT). Using dual-energy X-ray absorptiometry (DEXA) scans, we characterize total body composition changes during and after CCRT in order to develop novel clinical care models that will improve the patient's quality of life (QOL). Sixty DEXA scans were obtained from 12 patients undergoing CCRT for locally advanced squamous cell head and neck cancer. DEXAs were performed at baseline, during treatment, completion of CCRT, and then 1 and 2 months posttreatment. Mean weight loss by treatment end was 9.5 kg (10.2%; p = .0002). On average, lean body mass (LBM) decreased 10.2% (p = .001), and fat body mass (FBM) decreased 11.1% (p = .001) during CCRT. LBM began to normalize after completion of treatment, whereas FBM continued to decline. Substantial loss of muscle and FBM occurs in patients undergoing CCRT for head and neck cancer. To prevent long-term disability and QOL decline after curative CCRT, clinical care interventions incorporating aggressive nutrition/exercise counseling are needed. Copyright © 2013 Wiley Periodicals, Inc.

  3. Impact of beverage consumption, age, and site dependency on dual energy X-ray absorptiometry (DEXA) measurements in perimenopausal women: a prospective study.

    Science.gov (United States)

    Lo, Huan-Chu; Kuo, Duen-Pang; Chen, Yen-Lin

    2017-08-01

    The aim of this study was to determine the best site for bone mineral density (BMD) measurements based on T -scores, age, and beverage consumption. In this prospective study, 271 women stratified by age (average age: 61.9 years) underwent dual energy X-ray absorptiometry (DEXA) scanning of their lumbar spine, hips, and forearms. Osteoporosis was defined as a BMD of 2.5 standard deviations or more below the mean peak bone mass based on a reference population of adult women (translated as a T -score ≤ -2.5), as measured by DEXA. Participants were also evaluated regarding alcohol and caffeine consumption by a semiquantitative questionnaire. A significant discrepancy was observed in the classification of osteoporosis at different locations, with hip and forearm showing the best correlation (Pearson's r = 0.627, p consumption. In the group ≤ 50 years of age, lumbar spine and forearm T -scores were only associated with alcohol consumption. In the group over 50 years of age, hip and forearm T -scores were only associated with caffeine consumption. Bone mineral density measurements at the hip and forearm correlated with caffeine consumption in elderly Taiwanese women. This is an important finding since age and caffeine consumption are known risk factors for osteoporosis.

  4. Single- and multi-frequency bioelectrical impedance analyses to analyse body composition in maintenance haemodialysis patients: comparison with dual-energy x-ray absorptiometry

    International Nuclear Information System (INIS)

    Donadio, C; Halim, A Ben; Caprio, F; Grassi, G; Khedr, B; Mazzantini, M

    2008-01-01

    The aim of this study was to evaluate the adequacy of single-frequency (sf-BIA) and multi-frequency bioelectrical impedance analyses (mf-BIA), in comparison with dual-energy x-ray absorptiometry (DXA), to evaluate body composition in maintenance haemodialysis (MHD) patients. Body composition of 27 adult MHD patients (9 f, 18 m), BMI 17.5–34.4 kg m −2 , was examined with DXA and BIA, with two different sf-BIA and 1 mf-BIA analysers. Biochemical markers of nutritional status and adequacy of dialytic treatment were also determined. Fat mass (FM) estimated by the different BIA analysers was found to be slightly but significantly higher than FM measured by DXA. In contrast, fat-free mass (FFM) obtained with BIA was found to be slightly but significantly lower than FFM DXA. No significant differences were found between LBM-DXA (that is FFM-DXA minus bone mass) and the different FFM BIA. The lowest mean prediction error versus DXA values was found with sf1BIA. In any case, a close correlation was found between all BIA values and DXA values, particularly for FFM. Furthermore, FFM and LBM results were significantly correlated with serum creatinine, which in MHD patients is an indicator of muscle mass. These results indicate that BIA can be used to evaluate body composition in MHD patients

  5. Preoperative and postoperative agreement in fat free mass (FFM) between bioelectrical impedance spectroscopy (BIS) and dual-energy X-ray absorptiometry (DXA) in patients undergoing cardiac surgery.

    Science.gov (United States)

    van Venrooij, Lenny M W; Verberne, Hein J; de Vos, Rien; Borgmeijer-Hoelen, Mieke M M J; van Leeuwen, Paul A M; de Mol, Bas A J M

    2010-12-01

    To measure undernutrition in terms of fat free mass (FFM), there are several options. The aim of this study was to assess agreement in FFM between the portable, bedside bioelectrical impedance spectrometry (BIS) and relatively expensive, non-portable dual-energy X-ray absorptiometry (DXA) in patients undergoing cardiac surgery. In a prospective study, body composition measurements by BIS and DXA were performed two weeks prior and two months after cardiac surgery. Preoperative and postoperative agreement in FFM between BIS and DXA were analyzed with Bland and Altman plots. Twenty-six patients were analyzed. BIS overestimated preoperative and postoperative FFM by 2 kg compared to DXA (2.3 kg (95%CI: -3.5-8.1 kg) and 2.1 kg (95%CI: -4.5-8.7 kg), respectively). BIS underestimated FFM change by -0.5% (95%CI: -8.4-7.5%). There is a large inter-individual variation between BIS and DXA. This hinders the interchange-ability of BIS and DXA in routine clinical practice and may lead to misclassifications and thereby inappropriate nutritional treatment and possible postoperative complications. To evaluate nutritional therapy in patients undergoing cardiac surgery, we advocate the use of DXA assessed FFM in parallel to BIS assessed extracellular and intracellular water and FFM. Copyright © 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  6. Effect of ¹⁸F-FDG administration on measurements of bone mineral density and body composition by dual-energy X-ray absorptiometry.

    Science.gov (United States)

    Kim, Dae-Weung; Kim, Woo Hyoung; Kim, Myoung Hyoun; Kim, Seong Su; Mo, Eun Hee; Lee, Chun Ho; Kim, Chang Guhn

    2013-01-01

    The purpose of this study was to determine whether antecedent administration of ¹⁸F-fluorodeoxyglucose (FDG) used in positron emission tomography (PET) scanning results in corruption of bone mineral density (BMD) and body composition measured by dual-energy X-ray absorptiometry (DXA) system. DXA measurements of BMD and body composition had been performed twice, before and after ¹⁸F-FDG PET scan in 30 patients. The comparison of pre-values and post-values of all BMD values showed a decrease after the injection. However, only the decrease of whole-body BMD (WB-BMD) was statistically significant (p < 0.05). Whole-body fat mass had increased and whole-body lean body mass had decreased after the injection of ¹⁸F-FDG, and these were statistically significant (p < 0.05). There is statistically significant correlation between the injected ¹⁸F-FDG dose and a decrease of WB-BMD (r = -0.405; p < 0.05). The findings of this study suggest that when both ¹⁸F-FDG PET and DXA measurements for whole-body composition are performed in close-time proximity, ¹⁸F-FDG PET scans should follow the DXA measurement. Otherwise, BMD measurements of total femur or lumbar spine could be followed by ¹⁸F-FDG PET in close-time proximity. Copyright © 2013 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  7. Precision of dual-energy X-ray absorptiometry of the knee and heel: methodology and implications for research to reduce bone mineral loss after spinal cord injury.

    Science.gov (United States)

    Peppler, W T; Kim, W J; Ethans, K; Cowley, K C

    2017-05-01

    Methodological validation of dual-energy x-ray absorptiometry (DXA)-based measures of leg bone mineral density (BMD) based on the guidelines of the International Society for Clinical Densitometry. The primary objective of this study was to determine the precision of BMD estimates at the knee and heel using the manufacturer provided DXA acquisition algorithm. The secondary objective was to determine the smallest change in DXA-based measurement of BMD that should be surpassed (least significant change (LSC)) before suggesting that a biological change has occurred in the distal femur, proximal tibia and calcaneus. Academic Research Centre, Canada. Ten people with motor-complete SCI of at least 2 years duration and 10 people from the general population volunteered to have four DXA-based measurements taken of their femur, tibia and calcaneus. BMDs for seven regions of interest (RIs) were calculated, as were short-term precision (root-mean-square (RMS) standard deviation (g cm -2 ), RMS-coefficient of variation (RMS-CV, %)) and LSC. Overall, RMS-CV values were similar between SCI (3.63-10.20%, mean=5.3%) and able-bodied (1.85-5.73%, mean=4%) cohorts, despite lower absolute BMD values at each RIs in those with SCI (35%, heel to 54%, knee; P10% are needed to detect differences between treated and untreated groups in studies aimed at reducing bone mineral loss after SCI.

  8. Evaluation of femur of orchiectomized Guinea pigs by bone densitometry using dual-energy X-ray absorptiometry (DXA) and mechanical testing

    International Nuclear Information System (INIS)

    Estanislau, Cristiane de Abreu; Rahal, Sheila Canavese; Araujo, Fabio Andre Pinheiro de; Sergio Swain Muller; Louzada, Mario Jefferson Quirino; Estanislau, Caroline de Abreu

    2010-01-01

    The aim of this study was to evaluate the effects of castration on bones in the male guinea pigs and to observe whether mechanical testing correlates with dual-energy X-ray absorptiometry (DXA). Twelve male guinea pigs (Cavia porcellus), aged 21-27 days, and with average initial weight of 279 grams were used. The animals were equally allocated to two groups: GI - orchiectomized animals and GII - intact control animals. They underwent euthanasia at seven months following surgery. DXA measurement was performed at the mid third of the right femoral diaphysis in the cortical region and at the left femoral neck in order to verify its correlation with results of mechanical testing. Three-point bending test of right femur and axial compression test of left femur were performed. Bone mineral density of GI was significantly lower only at femoral neck. No differences were observed in the maximum load values between GI and GII for both bending and axial compression tests. The bending test revealed lower bone stiffness in GI compared to GII, but in the axial compression test no differences between groups were observed. Only left femur showed positive correlation coefficient between maximum load and bone mineral density according to Pearson's correlation coefficient. The results suggest that hormonal deprivation in guinea pigs induces reduction of bone mineral density, especially in the femoral neck area and reduction of bone stiffness in the mid-femoral diaphysis. (author)

  9. Application of dual-energy X-ray absorptiometry to measure the changes of bone mineral density in 131 healthy women

    International Nuclear Information System (INIS)

    Sang Shibiao; Wang Dongliang; Wu Yiwei

    2002-01-01

    131 healthy women aged 31-72 years participated in the study, include 64 sexual maturity women aged 31-52 were enrolled in four groups based on age, and 67 postmenopausal women, the years of menopause from 1 month to 23 years, were also enrolled in four groups based on duration of menopause. The bone mineral density of the lumbar-spine and femur were measured using dual-energy X-rays absorptiometry. At the same time, the serum E 2 , FSH, BGP were detected by radioimmunoassay; the serum AKP, calcium, phosphate were detected using automatic biochemistry instrument. The results were: the BMD of lumbar-spine and right femur were decreased, and associated with increasing age and the duration of menopause, especially after menopause. Significant positive correlation was noted between BMD and E 2 . Serum AKP and BGP levels were higher in postmenopausal women than those of sexual maturity women. The serum calcium level was increased significantly soon after menopause, then decreased to normal level, and maintained in this level. The serum phosphate level had no difference in these groups. Therefore BMD, serum E 2 , BGP and AKP determination have some value for the early diagnosis of postmenopausal osteoporosis and prediction of bone fracture also

  10. Relationship between Weight, Body Mass Index, and Bone Mineral Density in Men Referred for Dual-Energy X-Ray Absorptiometry Scan in Isfahan, Iran.

    Science.gov (United States)

    Salamat, Mohammad Reza; Salamat, Amir Hossein; Abedi, Iraj; Janghorbani, Mohsen

    2013-01-01

    Objective. Although several studies have investigated the association between body mass index (BMI) and bone mineral density (BMD), the results are inconsistent. The aim of this study was to further investigate the relation between BMI, weight and BMD in an Iranian men population. Methods. A total of 230 men 50-79 years old were examined. All men underwent a standard BMD scans of hip (total hip, femoral neck, trochanter, and femoral shaft) and lumbar vertebrae (L2-L4) using a Dual-Energy X-ray Absorptiometry (DXA) scan and examination of body size. Participants were categorised in two BMI group: normal weight obese, BMI ≥ 25 kg/m(2). Results. Compared to men with BMI ≥ 25, the age-adjusted odds ratio of osteopenia was 2.2 (95% CI 0.85, 5.93) and for osteoporosis was 4.4 (1.51, 12.87) for men with BMI osteoporosis. Conclusions. These data indicate that both BMI and weight are associated with BMD of hip and vertebrae and overweight and obesity decreased the risk for osteoporosis. The results of this study highlight the need for osteoporosis prevention strategies in elderly men as well as postmenopausal women.

  11. Relationship between Weight, Body Mass Index, and Bone Mineral Density in Men Referred for Dual-Energy X-Ray Absorptiometry Scan in Isfahan, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Salamat

    2013-01-01

    Full Text Available Objective. Although several studies have investigated the association between body mass index (BMI and bone mineral density (BMD, the results are inconsistent. The aim of this study was to further investigate the relation between BMI, weight and BMD in an Iranian men population. Methods. A total of 230 men 50-79 years old were examined. All men underwent a standard BMD scans of hip (total hip, femoral neck, trochanter, and femoral shaft and lumbar vertebrae (L2-L4 using a Dual-Energy X-ray Absorptiometry (DXA scan and examination of body size. Participants were categorised in two BMI group: normal weight <25.0 kg/m2 and overweight and obese, BMI ≥ 25 kg/m2. Results. Compared to men with BMI ≥ 25, the age-adjusted odds ratio of osteopenia was 2.2 (95% CI 0.85, 5.93 and for osteoporosis was 4.4 (1.51, 12.87 for men with BMI < 25. It was noted that BMI and weight was associated with a high BMD, compatible with a diagnosis of osteoporosis. Conclusions. These data indicate that both BMI and weight are associated with BMD of hip and vertebrae and overweight and obesity decreased the risk for osteoporosis. The results of this study highlight the need for osteoporosis prevention strategies in elderly men as well as postmenopausal women.

  12. The Influence of Magnetic Resonance Imaging Findings of Degenerative Disease on Dual-Energy X-ray Absorptiometry Measurements in Middle-Aged Men

    International Nuclear Information System (INIS)

    Donescu, O.S.; Battie, M.C.; Videman, T.

    2007-01-01

    Purpose: To examine degenerative features based on magnetic resonance imaging (MRI) measurements at the lumbar spine in relation to dual-energy X-ray absorptiometry (DXA), and to investigate whether bone mineral density (BMD) is reflected in the substitution of bone trabecular structure by fat at the vertebral body level indicated by MRI T1 relaxation time, endplate concavity, and hypertrophic (osteophytes and endplate sclerosis) MRI findings. Material and Methods: The sample for this cross-sectional study was composed of 102 subjects, 35-70 years old, from a population-based cohort. Data collection included DXA in the anterior-posterior projection at the L1-L4 vertebrae and right femoral neck, and MRI of the lumbar spine in the midsagittal plane. Results: Age, vertebral signal intensity, osteophytes, and endplate concavity collectively explained 20% of the variance in spine BMD. Conclusion: The study findings suggest that degenerative findings based on MRI measurements at the lumbar spine have an influence on bone assessment using DXA. Therefore, an overall bone assessment such as DXA might not offer an accurate measure of BMD

  13. Is whole body bone mineral density measured by the dual energy X-ray absorptiometry applied to evaluate risk of osteoporosis among Japanese adult females?

    International Nuclear Information System (INIS)

    Sakai, Yumiko; Koike, George; Numata, Makoto; Taneda, Kiyoshi; Jingu, Sumie

    2010-01-01

    The purpose of this study is to measure whole body fat accurately, the dual energy X-ray absorptiometry (DXA) is widely utilized. Simultaneously, bone mineral density (BMD) of the whole body can also be measured. BMD is one of important information to diagnose osteoporosis. However, it is not established to use whole body BMD for this diagnosis. It is recommended that lumbar and/or hip BMD should be used for diagnosing osteoporosis by the guideline for prevention and treatment of osteoporosis. Although it is possible to measure whole body BMD and lumbar and/or hip BMD separately at the same visit, it is inevitable to expose patients to more X-ray. Therefore, an aim of this study is to elucidate the relationship between whole body BMD and lumbar BMD to find the cut off point of whole body BMD for screening of osteoporosis. Two hundred and thirty six Japanese adult females were ascertained to this study. Whole body BMD and lumbar BMD of each subject were measured with the use of Delphi W (Hologic, USA). One hundred and sixty five subjects were judged as possible osteoporosis (less than 80% of young adult mean (YAM) of lumbar BMD and/or definite fracture of lumbar vertebras). The cut off point of whole body BMD for screening possible osteoporosis was estimated by receiver operated characteristic (ROC) analysis. The cut off point of whole body BMD was 84% of YAM, equivalent to 80% of YAM of lumbar BMD, with the following sensitivity and specificity (0.84 and 0.79, respectively), indicating that whole body BMD could be used for screening osteoporosis. (author)

  14. Dual energy x-ray absorptiometry (DEXA) in the assessment of liver iron in patients with beta thalassaemia major

    International Nuclear Information System (INIS)

    Chatterton, B.E.; Thomas, C.M.; Schultz, C.G.

    2000-01-01

    Full text: Beta thalassaemia major is a condition in which anaemia from abnormal haemoglobin production causes bone marrow expansion and frequently reduced bone mineral density. These patients have a chronic requirement for transfusion which results in tissue iron overload which may cause organ damage. Increased X-ray attenuation in the liver was noted in patients undergoing whole body DEXA for the assessment of bone density and it was assumed that this was related to liver iron stores. The aim of this study was to determine if useful information about liver iron could be obtained from these studies. Method: Using a Lunar DPXL, whole body scanning was performed in 16 patients (eight male) age 19-32 with Beta Thalassaemia. As well as calculating indices of total body composition, regions of interest were placed over the visualised liver. The 'bone mineral content' (BMC),g and bone mineral density (BMD),g/cm 2 were calculated over the liver regions, with the assumption that the calculation related to mineral in the region of interest. The results were compared with the serum ferritin as an indirect measure of body iron stores. Results showed a highly significant correlation (r=0.85) between 'BMD' in the liver region and ferritin. Conclusion: Despite the known difficulties with equating iron stores and ferritin, and possible confounders on liver density, such as fibrosis, the high correlation suggests that DEXA may have a place in the assessment of iron deposition, and be more cost effective than other technologies such as MRI and CT. Prospective studies with invasive measurements of liver iron will be needed to determine this. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  15. Preoperative and postoperative agreement in fat free mass (FFM) between bioelectrical impedance spectroscopy (BIS) and dual-energy X-ray absorptiometry (DXA) in patients undergoing cardiac surgery

    NARCIS (Netherlands)

    van Venrooij, Lenny M. W.; Verberne, Hein J.; de Vos, Rien; Borgmeijer-Hoelen, Mieke M. M. J.; van Leeuwen, Paul A. M.; de Mol, Bas A. J. M.

    2010-01-01

    Background & aims: To measure undernutrition in terms of fat free mass (FFM), there are several options. The aim of this study was to assess agreement in FFM between the portable, bedside bioelectrical impedance spectrometry (BIS) and relatively expensive, non-portable dual-energy X-ray

  16. Use of dual energy X-ray absorptiometry, the trabecular bone score and quantitative computed tomography in the evaluation of chronic kidney disease-mineral and bone disorders.

    Science.gov (United States)

    Pocock, Nicholas

    2017-03-01

    In subjects with chronic kidney disease (CKD) who suffer a minimal trauma fracture, the problem is to differentiate between osteoporosis and the various forms of renal bone disease associated with CKD-mineral and bone disorder. This problem is exacerbated by the fact that renal osteodystrophy may coexist with osteoporosis. The World Health Organization's bone mineral density (BMD) criteria for osteopenia ( -2.5 < T-score < -1.0) and osteoporosis (a T-score ≤ -2.5) may be used in patients with CKD stages 1-3. In CKD stages 4-5, BMD by dual-energy X-ray absorptiometry (DXA) is less predictive and may underestimate fracture risk. The development of absolute fracture risk (AFR) algorithms, such as FRAX® and the Garvan absolute fracture risk calculator, to predict risk of fracture over a given time (usually 10 years) aims to incorporate non-BMD risk factors into the clinical assessment. FRAX® has been shown to be useful to assess fracture risk in CKD but may underestimate fracture risk in advanced CKD. The trabecular bone score is a measure of grey scale homogeneity obtained from spine DXA, which correlates to trabecular microarchitecture and is an independent risk factor for fracture. Recent data demonstrate the potential utility of the trabecular bone score adjustment of AFR through the FRAX® algorithm in subjects with CKD. Parameters of bone microarchitecture using peripheral quantitative computed tomography (pQCT) or high-resolution pQCT are also able to discriminate fracture status in subjects with CKD. However, there are at present no convincing data that the addition of pQCT or high-resolution pQCT parameters to DXA BMD improves fracture discrimination. More advanced estimates of bone strength derived from measurements of micro-architecture, by QCT-derived finite element analysis may be incorporated into AFR algorithms in the future. © 2017 Asian Pacific Society of Nephrology.

  17. Human immunodeficiency virus-associated lipodystrophy: an objective definition based on dual-energy x-ray absorptiometry-derived regional fat ratios in a South Asian population.

    Science.gov (United States)

    Asha, Hesarghatta Shyamasunder; Seshadri, Mandalam Subramaniam; Paul, Thomas Vizhalil; Abraham, Ooriapadickal Cherian; Rupali, Priscilla; Thomas, Nihal

    2012-01-01

    To develop an objective definition of human immunodeficiency virus (HIV)-associated lipodystrophy by using regional fat mass ratios and to assess the utility of anthropometric and skinfold measurements in the initial screening for lipodystrophy. Male patients between 25 and 50 years old with proven HIV infection (highly active antiretroviral therapy [HAART]-naïve subjects and those receiving successful HAART) were studied and compared with body mass index (BMI)-matched HIV-negative control subjects. Anthropometric variables, body composition, dual-energy x-ray absorptiometry findings, and metabolic variables were compared among the 3 study groups and between those patients with and those without lipodystrophy. Trunk fat/lower limb fat mass ratio >2.28 identified 54.3% of patients with HIV receiving HAART as having lipodystrophy and had the highest odds ratio for predicting metabolic syndrome. The "clinical diagnosis of lipodystrophy" and the "clinical scoring system" had too many false-positive and false-negative results. Triceps skinfold thickness (SFT)/BMI ratio ≤0.49 and abdominal SFT/triceps SFT ratio >1.385 have good sensitivity but poor specificity in identifying lipodystrophy. In comparison with HAART-naïve patients with HIV, those receiving HAART had significantly higher insulin resistance, and a significantly greater proportion had impaired glucose tolerance and dyslipidemia. Among patients receiving HAART, those with lipodystrophy had a greater degree of insulin resistance, higher triglyceride levels, and lower levels of high-density lipoprotein cholesterol. The trunk fat/lower limb fat mass ratio in BMI-matched normal subjects can be used to derive cutoff values to define lipodystrophy objectively in HIV-infected patients. Defining lipodystrophy in this way is better than other methods of identifying those patients with increased cardiovascular risk. Triceps SFT/BMI and abdominal SFT/triceps SFT ratios may be useful as screening tools in resource

  18. Assess the discrimination of Achilles InSight calcaneus quantitative ultrasound device for osteoporosis in Chinese women: Compared with dual energy X-ray absorptiometry measurements

    Energy Technology Data Exchange (ETDEWEB)

    Jin Ningning, E-mail: ningning_jin@163.com [Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100032 (China); Lin Shouqing, E-mail: Shouqing_Lin2003@yahoo.com.cn [Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100032 (China); Zhang Ying, E-mail: steel_lee@sina.com.cn [Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100032 (China); Chen Fengling, E-mail: bjzqk@126.com [Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100032 (China)

    2010-11-15

    Since the implementation of quantitative ultrasound (QUS) technology may become a part of future clinical decision making to identify osteoporosis and prevent fractures, this study was initiated to evaluate the correlations of QUS parameters and axial bone mineral density (BMD) using dual energy X-ray absorptiometry (DXA) and to assess the discrimination of QUS measurements for osteoporosis and osteopenia defined by WHO criteria. 106 native Chinese women (aged 50.2 {+-} 10.9 SD, 21-74 years) were involved. Each subject received both QUS measurements at left calcaneus with Achilles InSight and DXA measurements with DPX-L at lumbar spine (L{sub 2-4}), total hip and femoral neck. Achilles InSight provided the stiffness index (SI) which derived from Broadband Ultrasound Attenuation (BUA) and Speed of Sound (SOS), and the T-scores of SI were calculated. We found that the QUS parameter SI was statistically significant but medium correlated (r = 0.458-0.587) with DXA at the lumbar spine, total hip and femoral neck (P < 0.0001 for all correlations). With ROC analysis, the area under the ROC curve of diagnosis of osteoporosis and osteopenia were 0.933 and 0.796, respectively. To identify osteoporosis, when the T-score threshold of SI was defined as -1.4, the sensitivity was 100%, and the specificity was 73.7%. Our study confirmed that QUS measurements performed with Achilles InSight were capable to identify osteoporosis defined by axial BMD using DXA in Chinese women.

  19. Assess the discrimination of Achilles InSight calcaneus quantitative ultrasound device for osteoporosis in Chinese women: Compared with dual energy X-ray absorptiometry measurements

    International Nuclear Information System (INIS)

    Jin Ningning; Lin Shouqing; Zhang Ying; Chen Fengling

    2010-01-01

    Since the implementation of quantitative ultrasound (QUS) technology may become a part of future clinical decision making to identify osteoporosis and prevent fractures, this study was initiated to evaluate the correlations of QUS parameters and axial bone mineral density (BMD) using dual energy X-ray absorptiometry (DXA) and to assess the discrimination of QUS measurements for osteoporosis and osteopenia defined by WHO criteria. 106 native Chinese women (aged 50.2 ± 10.9 SD, 21-74 years) were involved. Each subject received both QUS measurements at left calcaneus with Achilles InSight and DXA measurements with DPX-L at lumbar spine (L 2-4 ), total hip and femoral neck. Achilles InSight provided the stiffness index (SI) which derived from Broadband Ultrasound Attenuation (BUA) and Speed of Sound (SOS), and the T-scores of SI were calculated. We found that the QUS parameter SI was statistically significant but medium correlated (r = 0.458-0.587) with DXA at the lumbar spine, total hip and femoral neck (P < 0.0001 for all correlations). With ROC analysis, the area under the ROC curve of diagnosis of osteoporosis and osteopenia were 0.933 and 0.796, respectively. To identify osteoporosis, when the T-score threshold of SI was defined as -1.4, the sensitivity was 100%, and the specificity was 73.7%. Our study confirmed that QUS measurements performed with Achilles InSight were capable to identify osteoporosis defined by axial BMD using DXA in Chinese women.

  20. [Comparison BMC assessed by dual-energy X-ray absorptiometry and multi-frequency bioelectrical impedance in Chinese overweight and obesity adults].

    Science.gov (United States)

    Wang, Zhenghe; Fu, Lianguo; Yang, Yide; Wang, Shuo; Ma, Jun

    2016-05-01

    To compare consistency of Body Mineral Content (BMC, kg) assessed by Multi-frequency Bioelectrical Impedance Analysis ( MF-BIA) and Dual Energy X-ray Absorptiometry (DXA) measurement, providing evidence for MF-BIA accurate application in Chinese overweight/obese adults. A total of 1323 overweight/obesity adults aged 22-55 years were recruited voluntarily. All the subjects received the measurement of BMC both using MF-BIA and DXA. To evaluate the agreement of BMC measured by MF-BIA and DXA using interclass correlation coefficients (ICC), then establish correction prediction models. The mean difference of BMC between two methods was significant different with 0, overweight male subgroup was 0.28 kg, and 0.38 kg for obesity male, 0.24 kg for overweight female and 0.36 kg for obesity female, respectively (P BMC between MF-BIA and DXA measurement were statistically significant in all subgroups (P BMC (DXA method) = -0.297 + 1.005 x BMC (MF-BIA method). Obese male population: BMC (DXA method) =0.302 + 0.799 x BMC (MF-BIA method). Overweight female groups: BMC (DXA method) = 0.780 + 0.598 x BMC (MF-BIA method). Obese female group: BMC (DXA method) = 0.755 + 0.597 x BMC (MF-BIA method). Upon examination, correction prediction models were better. Co The correlation and agreement of BMC measured by BIA and DXA are weak in Chinese overweight/obese adults. Therefore, consideration should be given to BMC measured by BIA method in Chinese overweight/obese adults. It should be corrected or adjusted to reduce errors compared with DXA method.

  1. Concurrent agreement between an anthropometric model to predict thigh volume and dual-energy X-Ray absorptiometry assessment in female volleyball players aged 14-18 years.

    Science.gov (United States)

    Tavares, Óscar M; Valente-Dos-Santos, João; Duarte, João P; Póvoas, Susana C; Gobbo, Luís A; Fernandes, Rômulo A; Marinho, Daniel A; Casanova, José M; Sherar, Lauren B; Courteix, Daniel; Coelho-E-Silva, Manuel J

    2016-11-24

    A variety of performance outputs are strongly determined by lower limbs volume and composition in children and adolescents. The current study aimed to examine the validity of thigh volume (TV) estimated by anthropometry in late adolescent female volleyball players. Dual-energy X-ray absorptiometry (DXA) measures were used as the reference method. Total and regional body composition was assessed with a Lunar DPX NT/Pro/MD+/Duo/Bravo scanner in a cross-sectional sample of 42 Portuguese female volleyball players aged 14-18 years (165.2 ± 0.9 cm; 61.1 ± 1.4 kg). TV was estimated with the reference method (TV-DXA) and with the anthropometric method (TV-ANTH). Agreement between procedures was assessed with Deming regression. The analysis also considered a calibration of the anthropometric approach. The equation that best predicted TV-DXA was: -0.899 + 0.876 × log 10 (body mass) + 0.113 × log 10 (TV-ANTH). This new model (NM) was validated using the predicted residual sum of squares (PRESS) method (R 2 PRESS  = 0.838). Correlation between the reference method and the NM was 0.934 (95%CI: 0.880-0.964, S y∙x  = 0.325 L). A new and accurate anthropometric method to estimate TV in adolescent female volleyball players was obtained from the equation of Jones and Pearson alongside with adjustments for body mass.

  2. Lower Lean Mass Measured by Dual-Energy X-ray Absorptiometry (DXA) is Not Associated with Increased Risk of Hip Fracture in Women: The Framingham Osteoporosis Study.

    Science.gov (United States)

    McLean, Robert R; Kiel, Douglas P; Berry, Sarah D; Broe, Kerry E; Zhang, Xiaochun; Cupples, L Adrienne; Hannan, Marian T

    2018-01-05

    Although muscle mass influences strength in older adults, it is unclear whether low lean mass measured by dual-energy X-ray absorptiometry (DXA) is an independent risk factor for hip fracture. Our objective was to determine the association between DXA lean mass and incident hip fracture risk among 1978 women aged 50 years and older participating in the Framingham Study Original and Offspring cohorts. Leg and total body lean mass (kg) were assessed from whole-body DXA scans collected in 1992-2001. Hip fracture follow-up extended from DXA assessment to the occurrence of fracture, death, drop-out, or end of follow-up in 2007. Cox proportional hazards regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) estimating the relative risk of hip fracture associated with a 1-kg increase in baseline lean mass. Mean age was 66 years (range 50-93). Over a median of 8 years of follow-up, 99 hip fractures occurred. In models adjusted for age, height, study cohort, and percent total body fat, neither leg (HR 1.11; 95% CI 0.94, 1.31) nor total body (HR 1.06; 95% CI 0.99, 1.13) lean mass were associated with hip fracture. After further adjustment for femoral neck bone mineral density, leg lean mass results were similar (HR 1.10; 95% CI 0.93, 1.30). In contrast, 1 kg greater total body lean mass was associated with 9% higher hip fracture risk (HR 1.09; 95% CI 1.02, 1.18). Our findings suggest that in women, lower lean mass measured by DXA is not associated with increased risk of hip fracture.

  3. Dual Energy X-Ray Absorptiometry Compared with Anthropometry in Relation to Cardio-Metabolic Risk Factors in a Young Adult Population: Is the 'Gold Standard' Tarnished?

    Directory of Open Access Journals (Sweden)

    Denise L Demmer

    Full Text Available Assessment of adiposity using dual energy x-ray absorptiometry (DXA has been considered more advantageous in comparison to anthropometry for predicting cardio-metabolic risk in the older population, by virtue of its ability to distinguish total and regional fat. Nonetheless, there is increasing uncertainty regarding the relative superiority of DXA and little comparative data exist in young adults. This study aimed to identify which measure of adiposity determined by either DXA or anthropometry is optimal within a range of cardio-metabolic risk factors in young adults.1138 adults aged 20 years were assessed by DXA and standard anthropometry from the Western Australian Pregnancy Cohort (Raine Study. Cross-sectional linear regression analyses were performed. Waist to height ratio was superior to any DXA measure with HDL-C. BMI was the superior model in relation to blood pressure than any DXA measure. Midriff fat mass (DXA and waist circumference were comparable in relation to glucose. For all the other cardio-metabolic variables, anthropometric and DXA measures were comparable. DXA midriff fat mass compared with BMI or waist hip ratio was the superior measure for triglycerides, insulin and HOMA-IR.Although midriff fat mass (measured by DXA was the superior measure with insulin sensitivity and triglycerides, the anthropometric measures were better or equal with various DXA measures for majority of the cardio-metabolic risk factors. Our findings suggest, clinical anthropometry is generally as useful as DXA in the evaluation of the individual cardio-metabolic risk factors in young adults.

  4. Sex- and age-specific percentiles of body composition indices for Chinese adults using dual-energy X-ray absorptiometry.

    Science.gov (United States)

    Xiao, Zeyu; Guo, Bin; Gong, Jian; Tang, Yongjin; Shang, Jingjie; Cheng, Yong; Xu, Hao

    2017-10-01

    The aims of the study were to develop sex- and age-specific percentiles for lean mass index (LMI), appendicular LMI (aLMI), fat mass index (FMI), and body fat distribution indices in Chinese adults using dual-energy X-ray absorptiometry (DXA), and to compare those indices with those of other ethnicities using the US NHANES data. Whole-body and regional lean mass and fat mass (FM) were measured using DXA in 5688 healthy males (n = 1693) and females (n = 3995) aged 20-90 years. Body fat distribution indices were expressed as % fat trunk/% fat legs, trunk/appendicular FM ratio (FMR), and android/gynoid FMR. Percentile curves of LMI, aLMI, FMI, and body fat distribution indices were obtained by the Lambda-Mu-Sigma method. The aLMI and LMI were negatively associated with age, decreasing from the fifth decade for males, but were not associated with age in females. Females had more total FM than males, whereas males had greater central adiposity (% fat trunk/% fat legs ratio, trunk/appendicular FMR, and android/gynoid FMR) than females. Moreover, FMI and body fat distribution indices consistently increased with age in both sexes, especially in women. In comparison with white, black, and Mexican populations in the USA, Chinese adults had lower total FM, but had greater central adiposity (% fat trunk/% fat legs ratio and trunk/appendicular FMR). Additionally, older white and Mexican populations showed greater decreases for aLMI and LMI than their Chinese counterparts. We present the sex- and age-specific percentiles for aLMI, LMI, FMI, and body fat distribution indices by DXA in Chinese adults, which may refine the individual assessment of the nutritional status of Chinese adults.

  5. ADRB2 gene variants, dual-energy x-ray absorptiometry body composition, and hypertension in Tobago men of African descent.

    Science.gov (United States)

    Beason, Tracey Samantha; Bunker, Clareann H; Zmuda, Joseph M; Wilson, John W; Patrick, Alan L; Wheeler, Victor W; Weissfeld, Joel L

    2011-05-01

    Classic tissue effects of β(2)-adrenergic receptor activation include skeletal muscle glycogenolysis and vascular smooth muscle relaxation, factors relevant to obesity and hypertension, respectively. In a population-based study, we examined 2 common amino acid substitutions in the β(2)-adrenergic receptor gene (ADRB2) in relation to body composition and blood pressure. A cross-sectional analysis of 1893 African-descent men living in Tobago and participating in a prostate cancer screening study was performed. Body mass index, waist circumference, blood pressure, dual-energy x-ray absorptiometry body composition, and ADRB2 (Arg16Gly; Gln27Glu) genotype were determined. Twenty-six percent were obese (body mass index ≥30 kg/m(2)), and 50% were hypertensive. ADRB2 Arg16Gly and Gln27Glu alleles were in linkage disequilibrium (D' = 0.96, r(2) = 0.15). ADRB2 16Gly-containing and 27Glu-containing genotypes were equally frequent in low, medium, and high tertiles of percentage of body fat mass (16Gly-containing genotypes: 73.4%, 74.4%, and 74.5%, P(trend) = .66; 27Glu-containing genotypes: 27.6%, 23.8%, and 25.4%, P(trend) = .39) and in normal blood pressure, prehypertensive, and hypertensive men (16Gly-containing genotypes: 73.4%, 72.8%, and 74.4%, P(trend) = .61; 27Glu-containing genotypes: 25.6%, 24.1%, and 26.7%, P(trend) = .50). In a high-obesity and high-hypertension risk population with ancestry in common with African Americans, genetic variation defined by 2 common ADRB2 amino acid substitutions was not associated with body composition or hypertension. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Are adult patients with Laron syndrome osteopenic? A comparison between dual-energy X-ray absorptiometry and volumetric bone densities.

    Science.gov (United States)

    Benbassat, Carlos A; Eshed, Varda; Kamjin, Moshe; Laron, Zvi

    2003-10-01

    Severe short stature resulting from a deficiency in IGF-I is a prominent feature of Laron syndrome (LS). Although low bone mineral density (BMD) has been noted in LS patients examined by dual energy x-ray absorptiometry (DEXA), this technique does not take volume into account and may therefore underestimate the true bone density in patients with small bones. The aim of the present study was to evaluate the BMD yielded by DEXA in our LS patients using estimated volumetric values. Volumetric density was calculated with the following formulas: bone mineral apparent density (BMAD) = bone mineral content (BMC)/(area)(3/2) for the lumbar spine and BMAD = BMC/area(2) for the femoral neck. The study sample included 12 patients (mean age, 43.9 yr; mean height, 123.7 cm). Findings were compared with 10 osteopenic subjects without developmental abnormalities (mean age, 56 yr; mean height, 164.8 cm) and 10 healthy control subjects matched for sex and age to the LS patients (mean height, 165.5 cm). BMAD in the LS group was 0.201 +/- 0.02 g/cm(3) at the lumbar spine and 0.201 +/- 0.04 g/cm(3) at the femoral neck; corresponding values for the osteopenic group were 0.130 +/- 0.01 and 0.140 +/- 0.01 g/cm(3), and for the controls, 0.178 +/- 0.03 and 0.192 +/- 0.02 g/cm(3). Although areal BMD was significantly lower in the LS and osteopenic subjects compared with controls (P < 0.02) at both the lumbar spine and femoral neck, BMAD was low (P < 0.01) in the osteopenic group only. In conclusion, DEXA does not seem to be a reliable measure of osteoporosis in patients with LS.

  7. Dual-energy X-ray absorptiometry, skinfold thickness and waist circumference for assessing body composition in ambulant and non-ambulant wheelchair games players

    Directory of Open Access Journals (Sweden)

    Annika eWillems

    2015-11-01

    Full Text Available Field-based assessments provide a cost–effective and accessible alternative to dual-energy X-ray absorptiometry (DXA for practitioners determining body composition in athletic populations. It remains unclear how the range of physical impairments classifiable in wheelchair sports may affect the utility of field-based body composition techniques. The present study assessed body composition using DXA in 14 wheelchair games players who were either wheelchair dependent (non-walkers; n =7 or relied on a wheelchair for sports participation only (walkers; n =7. Anthropometric measurements were used to predict body fat percentage with existing regression equations established for able-bodied persons by Sloan & Weir, Durnin & Womersley, Lean et al, Gallagher et al and Pongchaiyakul et al. In addition, linear regression analysis was performed to calculate the association between body fat percentage and BMI, waist circumference, sum of 6 skinfold thicknesses and sum of 8 skinfold thicknesses. Results showed that non-walkers had significantly lower total lean tissue mass (46.2±=6.6 kg vs. 59.4±8.2 kg, P =.006 and total body mass (65.8 ±4.2 kg vs. 79.4 ±14.9 kg; P =0.05 than walkers. Body fat percentage calculated from most existing regression equations was significantly lower than that from DXA, by 2 to 9% in walkers and 8 to14% in non-walkers. Of the anthropometric measurements, the sum of 8 skinfold thicknesses had the lowest standard error of estimation in predicting body fat content. In conclusion, existing anthropometric equations developed in able-bodied populations substantially underestimated body fat content in wheelchair athletes, particularly non-walkers. Impairment specific equations may be needed in wheelchair athletes.

  8. Quantification of trunk and android lean mass using dual energy x-ray absorptiometry compared to magnetic resonance imaging after spinal cord injury.

    Science.gov (United States)

    Rankin, Kathleen C; O'Brien, Laura C; Gorgey, Ashraf S

    2018-02-20

    To determine whether dual energy x-ray absorptiometry (DXA) compared to magnetic resonance imaging (MRI) may accurately quantify trunk lean mass (LM) after chronic spinal cord injury (SCI) and to investigate the relationships between trunk LM, visceral adiposity, trunk fat mass and basal metabolic rate (BMR). Cross-sectional design and correlational analysis. Research setting in a medical center. Twenty-two men with motor complete paraplegia (n = 14; T4-T11) and tetraplegia (n = 8; C5-C7) were recruited as part of a clinical trial. Not applicable. Trunk and android LM were measured using DXA. The volume of six trunk muscle groups were then measured using MRI to quantify trunk LM-MRI. Subcutaneous and visceral adipose tissue (VAT) cross-sectional areas were also measured using MRI. After overnight fast, BMR was evaluated using indirect calorimetry. Trunk LM-DXA (24 ± 3.3 kg) and android LM-DXA (3.6 ± 0.7 kg) overestimated (P android LM-DXA + 0.126; r 2 =0.26, SEE= 0.21 kg, P = 0.018. Percentage trunk LM-MRI was inversely related to VAT (r=-0.79, P android LM-DXA overestimated trunk LM-MRI. Percentage trunk LM-MRI, but not LM-DXA, was inversely related to trunk central adiposity. The findings highlight the importance of exercising trunk LM to attenuate cardio-metabolic disorders after SCI.

  9. Prediction of Android and Gynoid Body Adiposity via a Three-dimensional Stereovision Body Imaging System and Dual-Energy X-ray Absorptiometry.

    Science.gov (United States)

    Lee, Jane J; Freeland-Graves, Jeanne H; Pepper, M Reese; Stanforth, Philip R; Xu, Bugao

    2015-01-01

    Current methods for measuring regional body fat are expensive and inconvenient compared to the relative cost-effectiveness and ease of use of a stereovision body imaging (SBI) system. The primary goal of this research is to develop prediction models for android and gynoid fat by body measurements assessed via SBI and dual-energy x-ray absorptiometry (DXA). Subsequently, mathematical equations for prediction of total and regional (trunk, leg) body adiposity were established via parameters measured by SBI and DXA. A total of 121 participants were randomly assigned into primary and cross-validation groups. Body measurements were obtained via traditional anthropometrics, SBI, and DXA. Multiple regression analysis was conducted to develop mathematical equations by demographics and SBI assessed body measurements as independent variables and body adiposity (fat mass and percentage fat) as dependent variables. The validity of the prediction models was evaluated by a split sample method and Bland-Altman analysis. The R(2) of the prediction equations for fat mass and percentage body fat were 93.2% and 76.4% for android and 91.4% and 66.5% for gynoid, respectively. The limits of agreement for the fat mass and percentage fat were -0.06 ± 0.87 kg and -0.11% ± 1.97% for android and -0.04 ± 1.58 kg and -0.19% ± 4.27% for gynoid. Prediction values for fat mass and percentage fat were 94.6% and 88.9% for total body, 93.9% and 71.0% for trunk, and 92.4% and 64.1% for leg, respectively. The three-dimensional (3D) SBI produces reliable parameters that can predict android and gynoid as well as total and regional (trunk, leg) fat mass.

  10. A comparative study on BMD of lumbar spine and proximal femur in post-menopausal women using dual energy X-ray absorptiometry

    International Nuclear Information System (INIS)

    Yoon, Han Sik; Mo, Eun Hee

    1999-01-01

    Osteoporosis, which causes mainly fracture of the spine, proximal femur and distal radius by minimal trauma, is a major public health problem and its prevalence is steadily increasing in Korea according to the development of public health care. There are reliable methods for diagnosis based on bone densitometry. Early detection and intervention are important for reducing the incidence of fractures. A consensus definition of osteoporosis, based on bone density measurement, has been developed by the World Health Organization(WHO). In this study, bone mineral density(BMD) was measured by dual energy x-ray absorptiometry(DEXA) at the proximal femur and lumbar spine in 132 post-menopausal women. The purpose of this study is to find influential factors on the BMD of the proximal femur and the lumbar spine and to analyze correlation between BMD and the problematic factors. We obtained the following results : 1. Mean BMD score, T-score and Z-score of the proximal femur were 0.81(g/cm 2 ), -2.45(S.D.) and -2.09(S.D.) respectively and in the lumber spine were 0.83(g/cm 2 ), -2.02(S.D.), -2.43(S.D.) respectively. 2. In correlation analysis between BMD and many factors, correlation coefficients were -0.467, 0.212, -0.321 and 0.241 in age, height, duration after menopause respectively. BMI and the residuals were comparatively small. 3. Correlation coefficients to age matched BMD, in height and body weight were 0.222 and 0.241, in age and duration after menopause were -0.268, -0.282. 4. The fracture threshold of proximal femur BMD to the 90th percentile was 0.845(g/cm 2 ). 5. At the result of multiple regression analysis, age, body weight, BMI(kg/m 2 ) and duration after menopause described as significant variables

  11. A comparative study on BMD of lumbar spine and proximal femur in post-menopausal women using dual energy X-ray absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Han Sik [Wonkwang Health Science College, Iksan (Korea, Republic of); Mo, Eun Hee [College of Medicine, Wonkwang Univ., Iksan (Korea, Republic of)

    1999-04-01

    Osteoporosis, which causes mainly fracture of the spine, proximal femur and distal radius by minimal trauma, is a major public health problem and its prevalence is steadily increasing in Korea according to the development of public health care. There are reliable methods for diagnosis based on bone densitometry. Early detection and intervention are important for reducing the incidence of fractures. A consensus definition of osteoporosis, based on bone density measurement, has been developed by the World Health Organization(WHO). In this study, bone mineral density(BMD) was measured by dual energy x-ray absorptiometry(DEXA) at the proximal femur and lumbar spine in 132 post-menopausal women. The purpose of this study is to find influential factors on the BMD of the proximal femur and the lumbar spine and to analyze correlation between BMD and the problematic factors. We obtained the following results : 1. Mean BMD score, T-score and Z-score of the proximal femur were 0.81(g/cm{sup 2}), -2.45(S.D.) and -2.09(S.D.) respectively and in the lumber spine were 0.83(g/cm{sup 2}), -2.02(S.D.), -2.43(S.D.) respectively. 2. In correlation analysis between BMD and many factors, correlation coefficients were -0.467, 0.212, -0.321 and 0.241 in age, height, duration after menopause respectively. BMI and the residuals were comparatively small. 3. Correlation coefficients to age matched BMD, in height and body weight were 0.222 and 0.241, in age and duration after menopause were -0.268, -0.282. 4. The fracture threshold of proximal femur BMD to the 90th percentile was 0.845(g/cm{sup 2}). 5. At the result of multiple regression analysis, age, body weight, BMI(kg/m{sup 2}) and duration after menopause described as significant variables.

  12. Comparison of dual-energy X-ray absorptiometry and magnetic resonance imaging-measured adipose tissue depots in HIV-infected and control subjects.

    Science.gov (United States)

    Scherzer, Rebecca; Shen, Wei; Bacchetti, Peter; Kotler, Donald; Lewis, Cora E; Shlipak, Michael G; Punyanitya, Mark; Heymsfield, Steven B; Grunfeld, Carl

    2008-10-01

    Studies in persons without HIV infection have compared adipose tissue measured by dual-energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI), but no such study has been conducted in HIV-infected (HIV+) subjects, who have a high prevalence of regional fat loss. We compared DXA- with MRI-measured trunk, leg, arm, and total fat in HIV+ and control subjects. A cross-sectional analysis was conducted in 877 HIV+ subjects and 260 control subjects in FRAM (Study of Fat Redistribution and Metabolic Change in HIV Infection), stratified by sex and HIV status. Univariate associations of DXA with MRI were strongest for total and trunk fat (r > or = 0.92) and slightly weaker for leg (r > or = 0.87) and arm (r > or = 0.71) fat. The average estimated limb fat was substantially greater for DXA than for MRI for HIV+ and control men and women (all P < 0.0001). Less of a difference was observed in trunk fat measured by DXA and MRI, but the difference was still statistically significant (P < 0.0001). Bland-Altman plots showed increasing differences and variability. Greater average limb fat in control and HIV+ subjects (both P < 0.0001) was associated with greater differences between DXA and MRI measurements. Because the control subjects had more limb fat than did the HIV+ subjects, greater amounts of fat were measured by DXA than by MRI when control subjects were compared with HIV+ subjects. More HIV+ subjects had leg fat in the bottom decile of the control subjects by DXA than by MRI (P < 0.0001). Although DXA- and MRI-measured adipose tissue depots correlate strongly in HIV+ and control subjects, differences increase as average fat increases, particularly for limb fat. DXA may estimate a higher prevalence of peripheral lipoatrophy than does MRI in HIV+ subjects.

  13. The Study on Bone Mineral Density Measurement Error in Accordance with Change in ROI by Utilizing Dual Energy X-ray Absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yun Hong [Dept. of Diagnostic Radiology, Korea University Guro Hospital, Seoul (Korea, Republic of); Lee, In Ja [Dept. of Radiological Technology, Dongnam Health College, Suwon (Korea, Republic of); Yong, Hyung Jin [Dept. of Medicine Physics, The Graduate School of Biomedical Science Korea University, Seoul (Korea, Republic of)

    2012-03-15

    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.

  14. Use of dual-energy X-ray absorptiometry (DXA) for diagnosis and fracture risk assessment; WHO-criteria, T- and Z-score, and reference databases.

    Science.gov (United States)

    Dimai, Hans P

    2017-11-01

    Dual-energy X-ray absorptiometry (DXA) is a two-dimensional imaging technology developed to assess bone mineral density (BMD) of the entire human skeleton and also specifically of skeletal sites known to be most vulnerable to fracture. In order to simplify interpretation of BMD measurement results and allow comparability among different DXA-devices, the T-score concept was introduced. This concept involves an individual's BMD which is then compared with the mean value of a young healthy reference population, with the difference expressed as a standard deviation (SD). Since the early nineties of the past century, the diagnostic categories "normal, osteopenia, and osteoporosis", as recommended by a WHO working Group, are based on this concept. Thus, DXA is still the globally accepted "gold-standard" method for the noninvasive diagnosis of osteoporosis. Another score obtained from DXA measurement, termed Z-score, describes the number of SDs by which the BMD in an individual differs from the mean value expected for age and sex. Although not intended for diagnosis of osteoporosis in adults, it nevertheless provides information about an individual's fracture risk compared to peers. DXA measurement can either be used as a "stand-alone" means in the assessment of an individual's fracture risk, or incorporated into one of the available fracture risk assessment tools such as FRAX® or Garvan, thus improving the predictive power of such tools. The issue which reference databases should be used by DXA-device manufacturers for T-score reference standards has been recently addressed by an expert group, who recommended use National Health and Nutrition Examination Survey III (NHANES III) databases for the hip reference standard but own databases for the lumbar spine. Furthermore, in men it is recommended use female reference databases for calculation of the T-score and use male reference databases for calculation of Z-score. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. DUAL-ENERGY X-RAY ABSORPTIOMETRY AND CALCULATED FRAX RISK SCORES MAY UNDERESTIMATE OSTEOPOROTIC FRACTURE RISK IN VITAMIN D-DEFICIENT VETERANS WITH HIV INFECTION.

    Science.gov (United States)

    Stephens, Kelly I; Rubinsztain, Leon; Payan, John; Rentsch, Chris; Rimland, David; Tangpricha, Vin

    2016-04-01

    We evaluated the utility of the World Health Organization (WHO) Fracture Risk Assessment Tool (FRAX) in assessing fracture risk in patients with human immunodeficiency virus (HIV) and vitamin D deficiency. This was a retrospective study of HIV-infected patients with co-existing vitamin D deficiency at the Atlanta Veterans Affairs Medical Center. Bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry (DEXA), and the 10-year fracture risk was calculated by the WHO FRAX algorithm. Two independent radiologists reviewed lateral chest radiographs for the presence of subclinical vertebral fractures. We identified 232 patients with HIV and vitamin D deficiency. Overall, 15.5% of patients met diagnostic criteria for osteoporosis on DEXA, and 58% had low BMD (T-score between -1 and -2.5). The median risk of any major osteoporotic and hip fracture by FRAX score was 1.45 and 0.10%, respectively. Subclinical vertebral fractures were detected in 46.6% of patients. Compared to those without fractures, those with fractures had similar prevalence of osteoporosis (15.3% versus 15.7%; P>.999), low BMD (53.2% versus 59.3%; P = .419), and similar FRAX hip scores (0.10% versus 0.10%; P = .412). While the FRAX major score was lower in the nonfracture group versus fracture group (1.30% versus 1.60%; P = .025), this was not clinically significant. We found a high prevalence of subclinical vertebral fractures among vitamin D-deficient HIV patients; however, DEXA and FRAX failed to predict those with fractures. Our results suggest that traditional screening tools for fragility fractures may not be applicable to this high-risk patient population.

  16. Precision of high-resolution dual energy x-ray absorptiometry of bone mineral status and body composition in small animal models

    Directory of Open Access Journals (Sweden)

    Lochmüller E. M.

    2001-01-01

    Full Text Available The purpose of this study was to analyze the in situ precision (reproducibility of bone mineral and body composition measurements in mice of different body weights and rats, using a high-resolution DXA (dual energy X-ray absorptiometry scanner. We examined 48 NMRI mice weighing approximately 10 to 60 g, and 10 rats weighing approximately 140 g. Four repeated measurements were obtained on different days. In mice, the standard deviations of repeated measurements ranged from 2.5 to 242 mg for bone mineral content (BMC, from 0.16 to 3.74 g for fat, and from 0.40 to 4.21 g for lean mass. The coefficient of variation in percent (CV% for BMC/BMD (bone mineral density was highest in the 10 g mice (12.8% / 4.9% and lowest in the 40 g mice (3.5% /1.7%. In rats, it was 2.5 /1.2% in the lower extremity, 7.1/3.0 % in the spine, 5.7/2.0 % in the femur, and 3.6%/2.1% in the tibia. The CV% for fat and lean mass in mice was higher than for BMC. The study demonstrates good precision of bone mineral and moderate precision of body composition measure-ments in small animals, using a high-resolution DXA system. The technique can be used for testing the efficacy of drugs in small animal models, for muta-genesis screens, and for the phenotypic characterization of transgenic mice.

  17. Point-of-Care Phalangeal Bone Mineral Density Measurement Can Reduce the Need of Dual-Energy X-Ray Absorptiometry Scanning in Danish Women at Risk of Fracture

    DEFF Research Database (Denmark)

    Holmberg, Teresa; Bech, Mickael; Gram, Jeppe

    2016-01-01

    Identifying persons with a high risk of osteoporotic fractures remains a challenge. DXA uptake in women with elevated risk of osteoporosis seems to be depending on distance to scanning facilities. This study aimed to investigate the ability of a small portable scanner in identifying women...... with reduced bone mineral density (BMD), and to define triage thresholds for pre-selection. Total hip and lumbar spine BMD was measured by dual-energy X-ray absorptiometry and phalangeal BMD by radiographic absorptiometry in 121 Danish women with intermediate or high 10-year fracture probability (aged 61...... and only 6 % of women in the low-risk group would be false negatives....

  18. Sarcopenic obesity assessed using dual energy X-ray absorptiometry (DXA) can predict cardiovascular disease in patients with type 2 diabetes: a retrospective observational study.

    Science.gov (United States)

    Fukuda, Tatsuya; Bouchi, Ryotaro; Takeuchi, Takato; Tsujimoto, Kazutaka; Minami, Isao; Yoshimoto, Takanobu; Ogawa, Yoshihiro

    2018-04-10

    Sarcopenic obesity, defined as reduced skeletal muscle mass and power with increased adiposity, was reported to be associated with cardiovascular disease risks in previous cross-sectional studies. Whole body dual-energy X-ray absorptiometry (DXA) can simultaneously evaluate both fat and muscle mass, therefore, whole body DXA may be suitable for the diagnosis of sarcopenic obesity. However, little is known regarding whether sarcopenic obesity determined using whole body DXA could predict incident cardiovascular disease (CVD). The aim of this study was to investigate the impact of sarcopenic obesity on incident CVD in patients with type 2 diabetes. A total of 716 Japanese patients (mean age 65 ± 13 years; 47.0% female) were enrolled. Android fat mass (kg), gynoid fat mass (kg), and skeletal muscle index (SMI) calculated as appendicular non-fat mass (kg) divided by height squared (m 2 ), were measured using whole body DXA. Sarcopenic obesity was defined as the coexistence of low SMI and obesity determined by four patterns of obesity as follows: android to gynoid ratio (A/G ratio), android fat mass or percentage of body fat (%BF) was higher than the sex-specific median, or body mass index (BMI) was equal to or greater than 25 kg/m 2 . The study endpoint was the first occurrence or recurrence of CVD. Over a median follow up of 2.6 years (IQR 2.1-3.2 years), 53 patients reached the endpoint. Sarcopenic obesity was significantly associated with incident CVD even after adjustment for the confounding variables, when using A/G ratio [hazard ratio (HR) 2.63, 95% CI 1.10-6.28, p = 0.030] and android fat mass (HR 2.57, 95% CI 1.01-6.54, p = 0.048) to define obesity, but not %BF (HR 1.67, 95% CI 0.69-4.02, p = 0.252), and BMI (HR 1.55, 95% CI 0.44-5.49, p = 0.496). The present data suggest that the whole body DXA is valuable in the diagnosis of sarcopenic obesity (high A/G ratio or android fat mass with low SMI) to determine the risk of CVD events in

  19. Use of dual-energy X-ray absorptiometry in obese individuals: The possibility to estimate whole body composition from DXA half-body scans

    International Nuclear Information System (INIS)

    Lundqvist, K.; Neovius, M.; Grigorenko, A.; Nordenstroem, J.; Roessner, S.

    2009-01-01

    Background: Because of its high accuracy, dual-energy X-ray absorptiometry (DXA) has become one of the most frequently used methods for estimating human body composition. One limiting factor concerning measuring obese people with the DXA technique is the size of the scanning area. Objective: To explore the possibility of estimating whole body composition from half-body scans before and after weight reduction, and compare the results with densitometry measurements. Design: Intervention study of 15 obese adults (age 47.2 ± 13.4; BMI 35.9 ± 3.1) who were measured with full- and half-body DXA scans before and after a 7-week weight loss program. On both occasions, body composition was also assessed with air-displacement plethysmography (ADP). Results: The mean weight loss at follow-up was 14.9 ± 4.1 kg (5.0 kg/m 2 ), corresponding to a 14% decrease in body weight. When comparing the results from full- and half-body DXA, between 96% and 98% of the variance was explained. At baseline, %Body Fat (%BF) did not differ significantly between full and half-body measurements (0.6, -0.1-1.3), but the half-body method overestimated it by 1.0% (0.2-1.8) at follow-up. On the contrary, the difference between DXA and ADP in the assessment of %BF was both significant and of large magnitude (5.2; 2.4-8.0) at baseline, while non-significant and near zero (0.4; -1.3-2.2) at follow-up when the subjects had lost a significant amount of weight. Conclusion: The results obtained from half-body DXA scans can accurately predict whole body composition, as measured by full-body DXA, before and after significant weight reduction, in obese patients who barely fit into the scanning area. However, increasing discordance between DXA and ADP with increasing adiposity was seen, indicating that the measurements might not be as reliable on extreme obese subjects as on normal and overweight ditto

  20. National Health and Nutrition Examination Survey whole-body dual-energy X-ray absorptiometry reference data for GE Lunar systems.

    Science.gov (United States)

    Fan, Bo; Shepherd, John A; Levine, Michael A; Steinberg, Dee; Wacker, Wynn; Barden, Howard S; Ergun, David; Wu, Xin P

    2014-01-01

    The National Health and Nutrition Examination Survey (NHANES 1999-2004) includes adult and pediatric comparisons for total body bone and body composition results. Because dual-energy x-ray absorptiometry (DXA) measurements from different manufacturers are not standardized, NHANES reference values currently are applicable only to a single make and model of Hologic DXA system. The purpose of this study was to derive body composition reference curves for GE Healthcare Lunar DXA systems. Published values from the NHANES 1999-2004 survey were acquired from the Centers for Disease Control and Prevention website. Using previously reported cross-calibration equations between Hologic and GE-Lunar, we converted the total body and regional bone and soft-tissue measurements from NHANES 1999-2004 to GE-Lunar values. The LMS (LmsChartMaker Pro Version 3.5) curve fitting method was used to generate GE-Lunar reference curves. Separate curves were generated for each sex and ethnicity. The reference curves were also divided into pediatric (≤20 years old) and adult (>20 years old) groups. Adult reference curves were derived as a function of age. Additional relationships of pediatric DXA values were derived as a function of height, lean mass, and bone area. Robustness was tested between Hologic and GE-Lunar Z-score values. The NHANES 1999-2004 survey included a sample of 20,672 participants' (9630 female) DXA scans. A total of 8056 participants were younger than 20 yr and were included in the pediatric reference data set. Participants enrolled in the study who weighed more than 136 kg (over scanner table limit) were excluded. The average Z-scores comparing the new GE-Lunar reference curves are close to zero, and the standard deviation of the Z-scores are close to one for all variables. As expected, all measurements on the GE-Lunar reference curves for participants younger than 20 yr increase monotonically with age. In the adult population, most of the curves are constant at younger

  1. Cross-mode bioelectrical impedance analysis in a standing position for estimating fat-free mass validated against dual-energy x-ray absorptiometry.

    Science.gov (United States)

    Huang, Ai-Chun; Chen, Yu-Yawn; Chuang, Chih-Lin; Chiang, Li-Ming; Lu, Hsueh-Kuan; Lin, Hung-Chi; Chen, Kuen-Tsann; Hsiao, An-Chi; Hsieh, Kuen-Chang

    2015-11-01

    Bioelectrical impedance analysis (BIA) is commonly used to assess body composition. Cross-mode (left hand to right foot, Z(CR)) BIA presumably uses the longest current path in the human body, which may generate better results when estimating fat-free mass (FFM). We compared the cross-mode with the hand-to-foot mode (right hand to right foot, Z(HF)) using dual-energy x-ray absorptiometry (DXA) as the reference. We hypothesized that when comparing anthropometric parameters using stepwise regression analysis, the impedance value from the cross-mode analysis would have better prediction accuracy than that from the hand-to-foot mode analysis. We studied 264 men and 232 women (mean ages, 32.19 ± 14.95 and 34.51 ± 14.96 years, respectively; mean body mass indexes, 24.54 ± 3.74 and 23.44 ± 4.61 kg/m2, respectively). The DXA-measured FFMs in men and women were 58.85 ± 8.15 and 40.48 ± 5.64 kg, respectively. Multiple stepwise linear regression analyses were performed to construct sex-specific FFM equations. The correlations of FFM measured by DXA vs. FFM from hand-to-foot mode and estimated FFM by cross-mode were 0.85 and 0.86 in women, with standard errors of estimate of 2.96 and 2.92 kg, respectively. In men, they were 0.91 and 0.91, with standard errors of the estimates of 3.34 and 3.48 kg, respectively. Bland-Altman plots showed limits of agreement of -6.78 to 6.78 kg for FFM from hand-to-foot mode and -7.06 to 7.06 kg for estimated FFM by cross-mode for men, and -5.91 to 5.91 and -5.84 to 5.84 kg, respectively, for women. Paired t tests showed no significant differences between the 2 modes (P > .05). Hence, cross-mode BIA appears to represent a reasonable and practical application for assessing FFM in Chinese populations. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Use of dual-energy X-ray absorptiometry in obese individuals: The possibility to estimate whole body composition from DXA half-body scans

    Energy Technology Data Exchange (ETDEWEB)

    Lundqvist, K. [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, SE-171 76 Stockholm (Sweden)], E-mail: kent.lundqvist@karolinska.se; Neovius, M. [Obesity Unit, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, SE-141 86 Stockholm (Sweden); Grigorenko, A. [Research and Development Unit, YLab Wellcare Institute, SE-113 60 Stockholm (Sweden); Nordenstroem, J. [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, SE-171 76 Stockholm (Sweden); Roessner, S. [Obesity Unit, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, SE-141 86 Stockholm (Sweden)

    2009-02-15

    Background: Because of its high accuracy, dual-energy X-ray absorptiometry (DXA) has become one of the most frequently used methods for estimating human body composition. One limiting factor concerning measuring obese people with the DXA technique is the size of the scanning area. Objective: To explore the possibility of estimating whole body composition from half-body scans before and after weight reduction, and compare the results with densitometry measurements. Design: Intervention study of 15 obese adults (age 47.2 {+-} 13.4; BMI 35.9 {+-} 3.1) who were measured with full- and half-body DXA scans before and after a 7-week weight loss program. On both occasions, body composition was also assessed with air-displacement plethysmography (ADP). Results: The mean weight loss at follow-up was 14.9 {+-} 4.1 kg (5.0 kg/m{sup 2}), corresponding to a 14% decrease in body weight. When comparing the results from full- and half-body DXA, between 96% and 98% of the variance was explained. At baseline, %Body Fat (%BF) did not differ significantly between full and half-body measurements (0.6, -0.1-1.3), but the half-body method overestimated it by 1.0% (0.2-1.8) at follow-up. On the contrary, the difference between DXA and ADP in the assessment of %BF was both significant and of large magnitude (5.2; 2.4-8.0) at baseline, while non-significant and near zero (0.4; -1.3-2.2) at follow-up when the subjects had lost a significant amount of weight. Conclusion: The results obtained from half-body DXA scans can accurately predict whole body composition, as measured by full-body DXA, before and after significant weight reduction, in obese patients who barely fit into the scanning area. However, increasing discordance between DXA and ADP with increasing adiposity was seen, indicating that the measurements might not be as reliable on extreme obese subjects as on normal and overweight ditto.

  3. Associations Between Sedentary Time, Physical Activity, and Dual-Energy X-ray Absorptiometry Measures of Total Body, Android, and Gynoid Fat Mass in Children.

    Science.gov (United States)

    McCormack, Lacey; Meendering, Jessica; Specker, Bonny; Binkley, Teresa

    2016-01-01

    Negative health outcomes are associated with excess body fat, low levels of physical activity (PA), and high sedentary time (ST). Relationships between PA, ST, and body fat distribution, including android and gynoid fat, assessed using dual-energy X-ray absorptiometry (DXA) have not been measured in children. The purpose of this study was to test associations between levels of activity and body composition in children and to evaluate if levels of activity predict body composition by DXA and by body mass index percentile in a similar manner. PA, ST, and body composition from 87 children (8.8-11.8 yr, grades 3-5, 44 boys) were used to test the association among study variables. Accelerometers measured PA and ST. Body composition measured by DXA included bone mineral content (BMC) and fat and lean mass of the total body (TB, less head), android, and gynoid regions. ST (range: 409-685 min/wk) was positively associated with TB percent fat (0.03, 95% confidence interval [CI]: 0.00-0.05) and android fat mass (1.5 g, 95% CI: 0.4-3.0), and inversely associated with the lean mass of the TB (-10.7 g, 95% CI: -20.8 to -0.63) and gynoid regions (-2.2 g, 95% CI: -4.3 to -0.2), and with BMC (-0.43 g, 95% CI: 0.77-0.09). Moderate-to-vigorous PA was associated with lower TB (-53 g, 95% CI: -87 to -18), android (-5 g, 95% CI: -8 to -2]), and gynoid fat (-6 g, 95% CI: -11 to -0.5). Vigorous activity results were similar. Light PA was associated with increased TB (17.1 g, 95% CI: 3.0-31.3) and gynoid lean mass (3.9 g, 95% CI: 1.0-6.8) and BMC (0.59 g, 95% CI: 0.10-1.07). In boys, there were significant associations between activity and DXA percent body fat measures that were not found with the body mass index percentile. Objective measures of PA were inversely associated with TB, android, and gynoid fat, whereas ST was directly associated with TB percent fat and, in particular, android fat. Activity levels predict body composition measures by DXA and, in

  4. Male Osteoporosis Awareness in the Elderly: an Analysis of Dual-Energy X-Ray Absorptiometry Use in Australia Between 1995 and 2015.

    Science.gov (United States)

    Chen, Weiwen; Pocock, Nicholas

    Osteoporosis is commonly perceived to be a disease confined to aging females, despite ongoing educational interventions. There are few data on the temporal change of dual-energy X-ray absorptiometry (DXA) use in aging males compared to females. Australian Medicare DXA claims between 1995 and 2015 were analyzed to investigate gender differences and temporal change of DXA use in males and females aged 45-85 yr. In females aged 45-54 and 55-64 yr, there was a progressive increase in DXA claims per capita between 1995 until 2002, with little subsequent change from 2002 to 2015 in the younger group, but a slow subsequent increase in females aged 55-64 yr. In males aged 45-54 and 55-64 yr, there was a progressive increase in DXA claims per capita between 1995 and 2002 with an ongoing slow increase from 2002 to 2015. In older females and males aged 65-74, 75-84, or ≥85 yr, there was a progressive increase in DXA claims per capita between 1995 and 2002, with a slow increase thereafter until 2007. After 2007, following the introduction of Medicare eligibility for age over 70, claims per capita increased sharply in all 3 age groups, with a subsequent ongoing increase. The male : female claim ratio in all groups demonstrates low relative male DXA use, with the ratio consistently below 1.0. Following the 2007 Medicare change, the male : female ratio improved in the 65-74, 75-84, and ≥85 age groups. The rate of increase in the male : female ratio in subjects ≥85 yr was significantly greater than that in the 65-74 (p < 0.001) and 75-84 (p < 0.001) age groups. DXA use in males is consistently lower than that in females. Government funding intervention appears to have been most effective in relation to very elderly males over 85 yr but less so in relation to the age group 65-84. There is a need for improved education of health professionals about the risk of osteoporosis in males aged 65-84 yr. Copyright © 2016 International Society for

  5. Small animals bone density and morphometry analysis with a dual energy X-rays absorptiometry bone densitometer using a 2D digital radiographic detector

    International Nuclear Information System (INIS)

    Boudousq, V.; Bordy, T.; Gonon, G.; Dinten, J.M.

    2004-01-01

    LEXXOS (DMS, Montpellier, France) is the first axial and total body cone beam bone densitometer using a 2D digital radiographic detector. In previous papers, technical principles and patients' Bone Mineral Density (BMD) measurement performances were presented. Bone densitometers are also used on small animals for drug development. In this presentation, we show how LEXXOS can be adapted for small animals' examinations and evaluate its performances. At first, in order to take advantage of the whole area of the 20 x 20 cm 2 digital radiographic detector, it has been made profit of X-Rays magnification by adapting the geometrical configuration. Secondly, as small animals present low BMD, a specific dual energy calibration has been defined. This adapted system has then been evaluated on two sets of mice: six reference mice and six ovariectomized mice. Each month, these two populations have been examined and the averaged total body BMD has been measured. This evaluation shows that the right order of BMD magnitude is obtained and, as expected, BMD increases on two sets until a period around puberty and the ovariectomized set presents a significant decrease after. Moreover, the bone image obtained by dual energy processing on LEXXOS presents a radiographic image quality providing useful complementary information on bone morphometry and architecture. This study shows that LEXXOS cone beam bone densitometer provides simultaneously useful quantitative and qualitative information for analysis of bone evolution on small animals. In the future, same system architecture and processing methodology can be used with higher resolution detectors in order to refine information on bone architecture. (authors)

  6. The relation between dual energy X-ray absorptiometry measurements of body fat composition and plasma ghrelin in patients with end-stage renal disease

    International Nuclear Information System (INIS)

    Elsayed, Naglaa M.; Hamed, Soha T.; El-Khatib, Mohamed M.; El-Shehaby, Amal M.

    2009-01-01

    Objective was to clarify the role of ghrelin in malnutrition in uremia and its relationship to fat composition using dual x-ray absorptiometry (DXA). This is a cohort study including Group I: 60 patients with end stage renal disease (30 on hemodialysis [group IA] and 30 pre-dialysis [group IB]) and Group II: 20 controls. This study was carried out in Cairo University Hospital, Kasr Al-Aini, Cairo, Egypt in 2007. Body fat composition (total, differential and lean body mass) was assessed using DXA and plasma ghrelin was measured. Ghrelin was significantly higher in hemodialysis and pre-dialysis groups compared to the control group and higher in hemodialysis group compared to the pre-dialysis group. In hemodialysis, ghrelin was negatively correlated with weight, body mass index (BMI), and truncal fat mass, and positively correlated with serum creatinine, lean body mass. In control, plasma ghrelin showed negative correlation with weight, BMI, truncal fat mass and positive correlation with lean body mass. Ghrelin was markedly elevated in renal failure due to its decrease in excretion. Negative correlation between ghrelin and fat mass composition was detected in dialysis patients. Serial evaluation of body fat mass composition using DXA is recommended for assessment of nutritional status of those patients. (author)

  7. Measurement of bone mineral density in the tunnel regions for anterior cruciate ligament reconstruction by dual-energy X-ray absorptiometry, computed tomography scan, and the immersion technique based on Archimedes' principle.

    Science.gov (United States)

    Tie, Kai; Wang, Hua; Wang, Xin; Chen, Liaobin

    2012-10-01

    To determine, for anterior cruciate ligament (ACL) reconstruction, whether the bone mineral density (BMD) of the femoral tunnel was higher than that of the tibial tunnel, to provide objective evidence for choosing the appropriate diameter of interference screws. Two groups were enrolled. One group comprised 30 normal volunteers, and the other comprised 9 patients with ACL rupture. Dual-energy X-ray absorptiometry was used to measure the BMD of the femoral and tibial tunnel regions of the volunteers' right knees by choosing a circular area covering the screw fixation region. The knees were also scanned by spiral computed tomography (CT), and the 3-dimensional reconstruction technique was used to determine the circular sections passing through the longitudinal axis of the femoral and tibial tunnels. Grayscale CT values of the cross-sectional area were measured. Cylindrical cancellous bone blocks were removed from the femoral and tibial tunnels during the ACL reconstruction for the patients. The volumetric BMD of the bone blocks was measured using a standardized immersion technique according to Archimedes' principle. As measured by dual-energy X-ray absorptiometry, the BMD of the femoral and tibial tunnel regions was 1.162 ± 0.034 g/cm(2) and 0.814 ± 0.038 g/cm(2), respectively (P difference in both femoral and tibial tunnel regions. For ACL reconstruction, the BMD of the femoral tunnel is higher than that of the tibial tunnel. This implies that a proportionally larger-diameter interference screw should be used for fixation in the proximal tibia than that used for fixation in the distal femur. Level IV, therapeutic case series. Copyright © 2012 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  8. Dual-energy x-ray absorptiometry to measure the effects of a thirteen-week moderate to vigorous aquatic exercise and nutritional education intervention on percent body fat in adults with intellectual disabilities from group home settings.

    Science.gov (United States)

    Casey, Amanda; Boyd, Colin; Mackenzie, Sasho; Rasmussen, Roy

    2012-05-01

    People with intellectual disability are more likely to be obese and extremely obese than people without intellectual disability with rates remaining elevated among adults, women and individuals living in community settings. Dual-energy X-ray absorptiometry measured the effects of a 13-week aquatic exercise and nutrition intervention on percent body fat in eight adults with intellectual disabilities (aged 41.0 ± 13.7 yrs) of varying fat levels (15%-39%) from two group homes. A moderate to vigorous aquatic exercise program lasted for the duration of 13 weeks with three, one-hour sessions held at a 25m pool each week. Nutritional assistants educated participants as to the importance of food choice and portion size. A two-tailed Wilcoxon matched-pairs signed-ranks test determined the impact of the combined intervention on body fat percentage and BMI at pre and post test. Median body fat percentage (0.8 %) and BMI (0.3 kg/m(2)) decreased following the exercise intervention, but neither were statistically significant, p = .11 and p = .55, respectively. The combined intervention was ineffective at reducing percent body fat in adults with intellectual disability according to dual-energy X-ray absorptiometry. These results are in agreement with findings from exercise alone interventions and suggest that more stringent nutritional guidelines are needed for this population and especially for individuals living in group home settings. The study did show that adults with intellectual disability may participate in moderate to vigorous physical activity when given the opportunity.

  9. Relationship between Weight, Body Mass Index, and Bone Mineral Density in Men Referred for Dual-Energy X-Ray Absorptiometry Scan in Isfahan, Iran

    OpenAIRE

    Salamat, Mohammad Reza; Salamat, Amir Hossein; Abedi, Iraj; Janghorbani, Mohsen

    2013-01-01

    Objective. Although several studies have investigated the association between body mass index (BMI) and bone mineral density (BMD), the results are inconsistent. The aim of this study was to further investigate the relation between BMI, weight and BMD in an Iranian men population. Methods. A total of 230 men 50-79 years old were examined. All men underwent a standard BMD scans of hip (total hip, femoral neck, trochanter, and femoral shaft) and lumbar vertebrae (L2-L4) using a Dual-Energy X-ra...

  10. Lumbar spine and total-body dual-energy X-ray absorptiometry in children with severe neurological impairment and intellectual disability: a pilot study of artefacts and disrupting factors

    Energy Technology Data Exchange (ETDEWEB)

    Mergler, S.; Rieken, R.; Evenhuis, H.M.; Penning, C. [Erasmus University Medical Centre, Intellectual Disability Medicine, Department of General Practice, PO Box 2040, CA, Rotterdam (Netherlands); Tibboel, D. [Erasmus University Medical Centre, Department of Pediatric Surgery, Rotterdam (Netherlands); Rijn, R.R. van [Academic Medical Centre, Department of Radiology, Amsterdam (Netherlands)

    2012-05-15

    Children with severe neurological impairment and intellectual disability (ID) are susceptible for developing low bone mineral density (BMD) and fractures. BMD is generally measured with dual-energy X-ray absorptiometry (DXA). To describe the occurrence of factors that may influence the feasibility of DXA and the accuracy of DXA outcome in children with severe neurological impairment and ID. Based on literature and expert opinion, a list of disrupting factors was developed. Occurrence of these factors was assessed in 27 children who underwent DXA measurement. Disrupting factors that occurred most frequently were movement during measurement (82%), aberrant body composition (67%), small length for age (56%) and scoliosis (37%). The number of disrupting factors per child was mean 5.3 (range 1-8). No correlation was found between DXA outcomes and the number of disrupting factors. Factors that may negatively influence the accuracy of DXA outcome are frequently present in children with severe neurological impairment and ID. No systematic deviation of DXA outcome in coherence with the amount of disrupting factors was found, but physicians should be aware of the possible influence of disrupting factors on the accuracy of DXA. (orig.)

  11. Short-term precision assessment of trabecular bone score and bone mineral density using dual-energy X-ray absorptiometry with different scan modes: an in vivo study

    Energy Technology Data Exchange (ETDEWEB)

    Bandirali, Michele; Poloni, Alessandro; Messina, Carmelo; Petrini, Marcello [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milano (Italy); Sconfienza, Luca Maria; Sardanelli, Francesco [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, San Donato Milanese (Italy); Papini, Giacomo Davide Edoardo; Di Leo, Giovanni [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Ulivieri, Fabio Massimo [IRCCS Fondazione Ca' Granda Ospedale Maggiore Policlinico, Mineralometria Ossea Computerizzata e Ambulatorio Malattie Metabolismo Minerale e Osseo, Servizio di Medicina Nucleare, Milano (Italy)

    2015-07-15

    We estimated the in vivo reproducibility of trabecular bone score (TBS) from dual-energy X-ray absorptiometry (DXA) using different imaging modes to be compared to that of bone mineral density (BMD). We enrolled 30 patients for each imaging mode: fast-array, array, high definition. Each patient underwent two DXA examinations with in-between repositioning. BMD and TBS were obtained according to the International Society for Clinical Densitometry guidelines. The coefficient of variation (CoV) was calculated as the ratio between root mean square standard deviation and mean, percent least significant change (LSC) as 2.77 x CoV, reproducibility as the complement to 100 % LSC. Fast-array imaging mode resulted in 0.8 % CoV and 2.1 % LSC for BMD, 1.9 % and 5.3 % for TBS, respectively; array imaging mode resulted in 0.7 % and 2.0 % for BMD, 1.9 % and 5.2 %, for TBS; high-definition imaging mode resulted in 0.7 % and 2.0 %, for BMD; 2.0 % and 5.4 % for TBS, respectively. Reproducibility of TBS (95 %) was significantly lower than that of BMD (98 %) (p < 0.012). Difference in reproducibility among the imaging modes was not significant for either BMD or TBS (p = 0.942). While TBS reproducibility was significantly lower than that of BMD, differences among imaging modes were not significant for both TBS and BMD. (orig.)

  12. Whole-body bone mineral content, lean body mass, and fat mass measured by dual-energy x-ray absorptiometry in a population of normal Canadian children and adolescents

    Energy Technology Data Exchange (ETDEWEB)

    Sala, A. [McMaster Children' s Hospital, Hamilton, Ontario (Canada); McMaster Univ., Dept. of Pediatrics, Hamilton, Ontario (Canada); Univ. of Milan-Bicocca, Monza (Italy); Webber, C.E. [Hamilton Health Sciences, Dept. of Nuclear Medicine, Hamilton, Ontario (Canada); McMaster Univ., Dept. of Radiology, Hamilton, Ontario (Canada)]. E-mail: webber@hhsc.ca; Morrison, J. [McMaster Children' s Hospital, Hamilton, Ontario (Canada); Beaumont, L.F. [Hamilton Health Sciences, Dept. of Nuclear Medicine, Hamilton, Ontario (Canada); Barr, R.D. [McMaster Children' s Hospital, Hamilton, Ontario (Canada); McMaster Univ., Dept. of Pediatrics, Hamilton, Ontario (Canada)

    2007-02-15

    Measurements of body composition have evident value in evaluating growing children and adolescents, and dual-energy X-ray absorptiometry (DXA) is a tool that provides accurate measurements of whole-body bone mineral content (WBBMC), lean body mass (LBM), and fat mass (FM). To interpret such measurements in the context of ill health, normative values must be available. Such information could be expected to be regionally specific because of differences in ethnic, dietary, and physical activity determinants. In this study, DXA was performed with Hologic densitometers in normal girls (n = 91) and boys (n 88) between 3 and 18 years of age. The derivation of normal ranges is presented for boys and girls. The correlation of the sum of WBBMC, LBM, and FM with directly measured body weight was almost perfect (r > 0.997). As expected, FM and body mass index correlated strongly. The normal values for WBBMC, LBM, and FM from this study are compared with other Canadian data and with published normative data from Argentina and the Netherlands, all of which use different densitometers. The results of this study allow the calculation of z scores for each facet of body composition and facilitate the use of DXA to report routine evaluations of body composition in children and adolescents. (author)

  13. Whole-body bone mineral content, lean body mass, and fat mass measured by dual-energy x-ray absorptiometry in a population of normal Canadian children and adolescents

    International Nuclear Information System (INIS)

    Sala, A.; Webber, C.E.; Morrison, J.; Beaumont, L.F.; Barr, R.D.

    2007-01-01

    Measurements of body composition have evident value in evaluating growing children and adolescents, and dual-energy X-ray absorptiometry (DXA) is a tool that provides accurate measurements of whole-body bone mineral content (WBBMC), lean body mass (LBM), and fat mass (FM). To interpret such measurements in the context of ill health, normative values must be available. Such information could be expected to be regionally specific because of differences in ethnic, dietary, and physical activity determinants. In this study, DXA was performed with Hologic densitometers in normal girls (n = 91) and boys (n 88) between 3 and 18 years of age. The derivation of normal ranges is presented for boys and girls. The correlation of the sum of WBBMC, LBM, and FM with directly measured body weight was almost perfect (r > 0.997). As expected, FM and body mass index correlated strongly. The normal values for WBBMC, LBM, and FM from this study are compared with other Canadian data and with published normative data from Argentina and the Netherlands, all of which use different densitometers. The results of this study allow the calculation of z scores for each facet of body composition and facilitate the use of DXA to report routine evaluations of body composition in children and adolescents. (author)

  14. Reduction of misclassification rates of obesity by body mass index using dual-energy X-ray absorptiometry scans to improve subsequent prediction of per cent fat mass in a Caucasian population

    DEFF Research Database (Denmark)

    Pedersen, Susie Dawn; Astrup, Arne; Skovgaard, Ib

    2011-01-01

    Recognition is increasing for the errors of body mass index (BMI) in classification of excess body fat. Dual-energy X-ray absorptiometry (DXA) is accurate to assess body fat mass per cent (%FM), but is underutilized clinically. We examined the prevalence of obesity misclassification by BMI....... The majority of men with BMI 25–27 kg m-2 and women with BMI 24–26 kg m-2 were misclassified. Using multiple scan data (189 men, 311 women) and calculating the patient-specific constant C = (1 - %FM/100)3/2 ¥ BMI from baseline BMI and %FM, misclassification rates were halved for both genders when a personal...... threshold, BMIT, was used ([BMIT = C/(0.75)3/2] for men and [BMIT = C/(0.65)3/2] for women). We conclude that simple formulae allow evaluation of fatness of individual patients more accurately than BMI, with the use of one baseline DXA scan, and enable the establishment of patient-specific obesity treatment...

  15. Lumbar spine and total-body dual-energy X-ray absorptiometry in children with severe neurological impairment and intellectual disability: a pilot study of artefacts and disrupting factors

    International Nuclear Information System (INIS)

    Mergler, S.; Rieken, R.; Evenhuis, H.M.; Penning, C.; Tibboel, D.; Rijn, R.R. van

    2012-01-01

    Children with severe neurological impairment and intellectual disability (ID) are susceptible for developing low bone mineral density (BMD) and fractures. BMD is generally measured with dual-energy X-ray absorptiometry (DXA). To describe the occurrence of factors that may influence the feasibility of DXA and the accuracy of DXA outcome in children with severe neurological impairment and ID. Based on literature and expert opinion, a list of disrupting factors was developed. Occurrence of these factors was assessed in 27 children who underwent DXA measurement. Disrupting factors that occurred most frequently were movement during measurement (82%), aberrant body composition (67%), small length for age (56%) and scoliosis (37%). The number of disrupting factors per child was mean 5.3 (range 1-8). No correlation was found between DXA outcomes and the number of disrupting factors. Factors that may negatively influence the accuracy of DXA outcome are frequently present in children with severe neurological impairment and ID. No systematic deviation of DXA outcome in coherence with the amount of disrupting factors was found, but physicians should be aware of the possible influence of disrupting factors on the accuracy of DXA. (orig.)

  16. Dual-energy x-ray absorptiometry to measure the influence of a 16-week community-based swim training program on body fat in children and adolescents with intellectual disabilities.

    Science.gov (United States)

    Casey, Amanda Faith; Rasmussen, Roy; Mackenzie, Sasho J; Glenn, Jillian

    2010-07-01

    To use dual-energy x-ray absorptiometry (DXA) to measure the effects of a 16-week community-based swim training program on percent body fat in children and adolescents with intellectual disability (ID). Convenience sample. University sport complex and exercise science laboratory. Children and adolescents (n=8; mean age +/- SD, 13.1 +/- 3.4 y), 2 girls and 6 boys with ID, of varying fat levels (11%-35%). A swim training program lasting for the duration of 16 weeks with three 1-hour sessions held at a 25-m pool each week. Assessing percent body fat at pretest and posttest through the use of DXA. After the 16-week exercise training program, we observed a 1.2% median increase in body fat percentage with a range from -0.3% to 4.5%. Wilcoxon matched-pairs signed-ranks tests suggest that these results are statistically significant (P=.039; exact). Exercise training alone proved ineffectual in reducing percent body fat in 8 children and adolescents with ID. Further research should consider implementing a combined diet and exercise program. To gauge the effectiveness of intervention programs, valid methods and complex measurement tools such as DXA should be used to assess changes in percent body fat in such a heterogeneous population. Copyright 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  17. Non-invasive methods for the determination of body and carcass composition in livestock: dual-energy X-ray absorptiometry, computed tomography, magnetic resonance imaging and ultrasound: invited review.

    Science.gov (United States)

    Scholz, A M; Bünger, L; Kongsro, J; Baulain, U; Mitchell, A D

    2015-07-01

    The ability to accurately measure body or carcass composition is important for performance testing, grading and finally selection or payment of meat-producing animals. Advances especially in non-invasive techniques are mainly based on the development of electronic and computer-driven methods in order to provide objective phenotypic data. The preference for a specific technique depends on the target animal species or carcass, combined with technical and practical aspects such as accuracy, reliability, cost, portability, speed, ease of use, safety and for in vivo measurements the need for fixation or sedation. The techniques rely on specific device-driven signals, which interact with tissues in the body or carcass at the atomic or molecular level, resulting in secondary or attenuated signals detected by the instruments and analyzed quantitatively. The electromagnetic signal produced by the instrument may originate from mechanical energy such as sound waves (ultrasound - US), 'photon' radiation (X-ray-computed tomography - CT, dual-energy X-ray absorptiometry - DXA) or radio frequency waves (magnetic resonance imaging - MRI). The signals detected by the corresponding instruments are processed to measure, for example, tissue depths, areas, volumes or distributions of fat, muscle (water, protein) and partly bone or bone mineral. Among the above techniques, CT is the most accurate one followed by MRI and DXA, whereas US can be used for all sizes of farm animal species even under field conditions. CT, MRI and US can provide volume data, whereas only DXA delivers immediate whole-body composition results without (2D) image manipulation. A combination of simple US and more expensive CT, MRI or DXA might be applied for farm animal selection programs in a stepwise approach.

  18. Dual Energy X-Ray Absorptiometry Compared with Anthropometry in Relation to Cardio-Metabolic Risk Factors in a Young Adult Population: Is the ‘Gold Standard’ Tarnished?

    Science.gov (United States)

    Hands, Beth; Pennell, Craig E.; Lye, Stephen J.; Mountain, Jennifer A.

    2016-01-01

    Background and Aims Assessment of adiposity using dual energy x-ray absorptiometry (DXA) has been considered more advantageous in comparison to anthropometry for predicting cardio-metabolic risk in the older population, by virtue of its ability to distinguish total and regional fat. Nonetheless, there is increasing uncertainty regarding the relative superiority of DXA and little comparative data exist in young adults. This study aimed to identify which measure of adiposity determined by either DXA or anthropometry is optimal within a range of cardio-metabolic risk factors in young adults. Methods and Results 1138 adults aged 20 years were assessed by DXA and standard anthropometry from the Western Australian Pregnancy Cohort (Raine) Study. Cross-sectional linear regression analyses were performed. Waist to height ratio was superior to any DXA measure with HDL-C. BMI was the superior model in relation to blood pressure than any DXA measure. Midriff fat mass (DXA) and waist circumference were comparable in relation to glucose. For all the other cardio-metabolic variables, anthropometric and DXA measures were comparable. DXA midriff fat mass compared with BMI or waist hip ratio was the superior measure for triglycerides, insulin and HOMA-IR. Conclusion Although midriff fat mass (measured by DXA) was the superior measure with insulin sensitivity and triglycerides, the anthropometric measures were better or equal with various DXA measures for majority of the cardio-metabolic risk factors. Our findings suggest, clinical anthropometry is generally as useful as DXA in the evaluation of the individual cardio-metabolic risk factors in young adults. PMID:27622523

  19. A comparison of dual-energy X-ray absorptiometry, air displacement plethysmography and A-mode ultrasound to assess body composition in college-age adults.

    Science.gov (United States)

    Johnson, Kelly E; Miller, Brian; Gibson, Ann L; McLain, Trisha A; Juvancic-Heltzel, Judith A; Kappler, Rachele M; Otterstetter, Ronald

    2017-11-01

    There is currently a dearth of scientific literature exploring the agreement of A-mode ultrasound (US) body composition analysis with dual-energy X-ray absorptiometry (DXA) and air displacement plethysmography (ADP). To investigate the agreement of US with DXA and ADP for estimating fat mass (FM) and fat-free mass (FFM). College-age men (n = 33) and women (n = 41) volunteered to participate in this study. Participants were instructed to adhere to the following pretest protocol: refrain from food and drink 12 h prior to testing and wear tight fitting clothing. Body composition (BCA) was assessed using US, DXA and ADP in accordance with the respective manufacturer's guidelines. Two-way mixed-model AVOVA and Bland and Altman techniques were applied to explore agreement for FM and FFM among the three methods: US, ADP and DXA and by sex. There was no statistically significant effect by sex for either FM or FFM across all BCA comparisons (P = 0·504 and 0·510, respectively). US was not statistically different from ADP for FM and FFM (P ≈ 1·00). However, for FM and FFM, there were significant differences between DXA and both US and ADP (P≤0·001). The Bland and Altman analyses revealed large individual differences for all BCA. There was statistical agreement between US and ADP for FM and FFM but lack of agreement for US and ADP when compared to DXA. However, the large limits of agreement between methods warrant caution in generalizing these findings. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  20. An evaluation of the EagleTM FA DEXA (Dual-energy X-ray Absorptiometry) scanner as a method of estimating the chemical lean in cartons of boneless beef

    International Nuclear Information System (INIS)

    Purchas, R.W.; Archibald, R.; West, J.G.; Bartle, C.M.

    2007-01-01

    The accuracy with which the Eagle TM FA DEXA (dual-energy X-ray absorptiometry) scanner measured the chemical lean percentage (CL) of boneless beef in 27.2 kg cartons was evaluated under actual production operating conditions in a commercial meat plant. Forty cartons of boneless beef (CL range 60 to 98) were scanned in triplicate (Scan CL), and the results obtained were compared with chemically determined estimates of CL from three laboratories (Lab CL) performed in triplicate on each of three samples taken from the minced and blended contents of each carton. Differences between CL estimates from the different laboratories and from the different sub-samples were small and not statistically significant. The relationship between Scan CL and the Lab CL had an R 2 value of 99.6% and a residual standard deviation (RSD) of 0.79. When estimates of errors associated with sampling and laboratory analysis (RSDs of 0.4 to 0.6) were taken into account, the Scan CL RSD was estimated to be between 0.6 and 0.7. The mean difference between Scan CL and Lab CL was 0.28. Thus the measures of accuracy were within the specifications for the scanner, which are stated as being an RSD of less than 1 and an average difference between Scan CL and actual CL of less than 1 percentage point. Estimates of CL obtained by analysing cores (about 1.5% of the total carton) taken from the cartons, were not closely related to Scan CL with an RSD of 2.00 for this relationship. Small but statistically significant differences were found between the CL groups (65, 80, 90, and 95%) in the deviations between Lab CL and Scan CL. It is concluded that the Eagle TM FA on-line DEXA scanner provides a rapid on-line means of accurately estimating the CL content of boneless beef in standard cartons. (author). 11 refs., 2 figs., 4 tabs

  1. Fat to muscle ratio measurements with dual energy x-ray absorbtiometry

    Energy Technology Data Exchange (ETDEWEB)

    Chen, A. [Shenzhen College of International Education, 1st HuangGang Park St., Shenzhen, GuangDong (China); Luo, J. [Department of Biomedical Engineering, University at Buffalo, 332 Bonner Hall, Buffalo, NY 14260-1920 (United States); Wang, A. [Department of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Broadbent, C. [School of Engineering, Columbia University, 1130 Amsterdam Av., New York, NY 10027 (United States); Zhong, J. [Department of English, Dartmouth College, 6032 Sanborn House, Hanover, NH 03755 (United States); Dilmanian, F.A. [Departments of Radiation Oncology, Neurology, and Radiology, Stony Brook University, Stony Brook, NY 11794 (United States); Zafonte, F.; Zhong, Z. [National Synchrotron Light Source II, Brookhaven National Laboratory, Bldg. 743, Upton, NY 11973 (United States)

    2015-07-11

    Accurate measurement of the fat-to-muscle ratio in animal model is important for obesity research. An efficient way to measure the fat to muscle ratio in animal model using dual-energy absorptiometry is presented in this paper. A radioactive source exciting x-ray fluorescence from a target material is used to provide the two x-ray energies needed. The x-rays, after transmitting through the sample, are measured with an energy-sensitive Ge detector. Phantoms and specimens were measured. The results showed that the method was sensitive to the fat to muscle ratios with good linearity. A standard deviation of a few percent in the fat to muscle ratio could be observed with the x-ray dose of 0.001 mGy.

  2. Preliminary research on dual-energy X-ray phase-contrast imaging

    Science.gov (United States)

    Han, Hua-Jie; Wang, Sheng-Hao; Gao, Kun; Wang, Zhi-Li; Zhang, Can; Yang, Meng; Zhang, Kai; Zhu, Pei-Ping

    2016-04-01

    Dual-energy X-ray absorptiometry (DEXA) has been widely applied to measure the bone mineral density (BMD) and soft-tissue composition of the human body. However, the use of DEXA is greatly limited for low-Z materials such as soft tissues due to their weak absorption, while X-ray phase-contrast imaging (XPCI) shows significantly improved contrast in comparison with the conventional standard absorption-based X-ray imaging for soft tissues. In this paper, we propose a novel X-ray phase-contrast method to measure the area density of low-Z materials, including a single-energy method and a dual-energy method. The single-energy method is for the area density calculation of one low-Z material, while the dual-energy method aims to calculate the area densities of two low-Z materials simultaneously. Comparing the experimental and simulation results with the theoretical ones, the new method proves to have the potential to replace DEXA in area density measurement. The new method sets the prerequisites for a future precise and low-dose area density calculation method for low-Z materials. Supported by Major State Basic Research Development Program (2012CB825800), Science Fund for Creative Research Groups (11321503) and National Natural Science Foundation of China (11179004, 10979055, 11205189, 11205157)

  3. The cut-off point of dual energy X-ray and laser of calcaneus osteoporosis diagnosis in postmenopausal women

    International Nuclear Information System (INIS)

    Salimzadeh, A.; Forough, B.; Olia, B.; Alishiri, G. H.; Ghasemzadeh, A.

    2005-01-01

    Dual X-Ray Absorptiometry is a method which can extensively be used for bone mineral densitometry . Another more recent method is dual energy X-ray and laser, which associate with dual X ray absorptiometry, assisted by laser measure heel thickness. In this study the cut off points for dual energy X-ray and laser of calcaneus in the diagnosis of osteoporosis in different bone regions in postmenopausal women had been determined. Materials and Methods: In 268 postmenopausal women, BMD of the spinal and femoral regions was measured by DM, and the value for the calcaneous was measured by dual energy X-ray and laser. The agreement of the two methods in the diagnosis of osteoporosis and optimal cut-off point for dual energy X-ray and laser in defining osteoporosis was obtained. What obtained was the agreement of the two methods in the diagnosis of osteoporosis, as well as the optimal cut-off point for dual energy X-ray and laser in defining osteoporosis. Results: Dual X-Ray Absorptiometry showed osteoporosis in 40.7% of cases with 35.2% in L2-L4, 16.2% in the femoral neck, and 11.7% for the femoral total region. The dual energy X-ray and laser found osteoporosis, considering -2.5 SD as a threshold, in 26.1% of cases. Agreement of the two methods in the diagnosis of osteoporosis (Kappa score) was 0.443 for the lumbar region, 0.464 for the neck, and, 0.421 for total femur regions (all P values were significant). Using Receiver Operating Characteristic curves, it was found that a T-score of -2.1, -2.6 and -2.4 as the optimal cut-off point of dual energy X-ray and laser in the diagnosis of osteoporosis in the lumbar spine, the neck and total region of femur, respectively. Conclusion: The results of this study showed a moderate agreement between the two methods in the diagnosis of osteoporosis. It seems that the dual energy X-ray and laser cannot be used as a substitute for the DM method, but it can be used as a screening method to find (to diagnose) osteoporosis

  4. Reproducibility of morphometric X-ray absorptiometry

    International Nuclear Information System (INIS)

    Culton, N.; Pocock, N.

    1999-01-01

    Full text: Morphometric X-ray absorptiometry (MXA) using DXA is potentially a useful clinical tool which may provide additional vertebral fracture information with low radiation exposure. While morphometric analysis is semi-automated, operator intervention is crucial for the accurate positioning of the six data points quantifying the vertebral heights at the anterior, middle and posterior positions. Our study evaluated intra-operator reproducibility of MXA in an elderly patient population and assessed the effect of training and experience on vertebral height precision. Ten patients, with a mean lumbar T score of - 2.07, were studied. Images were processed by a trained operator who had initially only limited morphometric experience. The analysis of the data files were repeated at 2 and 6 weeks, during which time the operator had obtained further experience and training. The intra-operator precision of vertebral height measurements was calculated using the three separate combinations of paired analyses, and expressed as the coefficient of variation. This study confirms the importance of adequate training and attention to detail in MXA analysis. The data indicate that the precision of MXA is adequate for its use in the diagnosis of vertebral fractures, based on a 20% deformity criteria. Use of MXA for monitoring would require approximately an 8% change in vertebral heights to achieve statistical significance

  5. Precision of dual energy X-ray absorptiometry for body composition measurements in cats; Precisao da tecnica de absorciometria de raios-X de dupla energia na determinacao da composicao corporal em gatos

    Energy Technology Data Exchange (ETDEWEB)

    Borges, N.C. [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Escola de Veterinaria]. E-mail: naida@vet.ufg.br; Vasconcellos, R.S.; Canola, J.C.; Carciofi, A.C.; Pereira, G.T. [UNESP, Jaboticabal, SP (Brazil). Faculdade de Ciencias Agrarias e Veterinarias; Paula, F.J.A. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina

    2008-07-01

    A short-term precision error of the individual subject and the DEXA technique, such as the effect of the repositioning of the cat on the examination table, were established. Four neutered adult cats (BW=4342 g) and three females (BW=3459 g) were submitted to five repeated scans with and without repositioning between them. Precision was estimated from the mean of the five measurements and expressed by the individual coefficient of variation (CV). The precision error of the technique was estimated by the variance of scan pool (n=35) and expressed in CV for the technique (CVt). The degrees of freedom and confidence intervals were determined to avoid underestimation of precision errors. Bone mineral content (BMC), lean mass (LM), and fat mass (FM) averages were higher (P<0.05) when animals were repositioned. The CVt was significantly higher (P<0.05) for bone mineral density (BMD), LM, and FM when the animals were repositioned. For short-term precision measurements, the repositioning of the animal was important to establish the precision of the technique. The dual energy xray absorptiometry method provided precision for body composition measurements in adult cats. (author)

  6. Measurement of vertebral bone marrow lipid profile at 1.5-T proton magnetic resonance spectroscopy and bone mineral density at dual-energy X-ray absorptiometry: correlation in a swine model

    Energy Technology Data Exchange (ETDEWEB)

    Di Leo, Giovanni; Fina, Laura [IRCCS Policlinico San Donato, Unita di Radiologia, San Donato Milanese (Italy); Bandirali, Michele; Messina, Carmelo [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milan (Italy); Sardanelli, Francesco [IRCCS Policlinico San Donato, Unita di Radiologia, San Donato Milanese (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, San Donato Milanese (Italy)

    2014-08-15

    Bone marrow is mainly composed of red (hematopoietic) and yellow (fatty) components. Soon after the birth there is a physiological conversion of the bone marrow from red to yellow, so that the percentage of hematopoietic cells and adipocytes changes with aging. Although bone marrow adipogenesis is a physiologic process involving all mammals, recent studies showed an accelerated marrow adipogenesis associated with several chronic conditions, including osteoporosis [4] and diabetes mellitus. Moreover, this increased marrow fat is accompanied by a decrease in bone density. Marrow fat is therefore increasingly believed to influence the bone microenvironment. Diagnostic tools for quantitative measurement of bone marrow fat and bone mineral density (BMD) include proton magnetic resonance spectroscopy (MRS) and dual-energy Xray absorptiometry (DXA), respectively. Using MRS, an inverse relationship between vertebral bone marrow fat content and lumbar BMD has been demonstrated in patients affected with osteoporosis or with diabetes mellitus. In most studies, a quite standard MRS sequence has been used, with short echo times (TE) for the measurement of the bulk methylene. In this study we sought to optimize the MRS sequence in order to try to measure other fat components of the vertebral bone marrow at 1.5 T. For this purpose, we used an animal model that allowed long acquisition times and repeated measures. Moreover, we aimed at estimating in this model the relationship between vertebral bone marrow fat content at proton MRS and BMD at DXA.

  7. Measurement of vertebral bone marrow lipid profile at 1.5-T proton magnetic resonance spectroscopy and bone mineral density at dual-energy X-ray absorptiometry: correlation in a swine model

    International Nuclear Information System (INIS)

    Di Leo, Giovanni; Fina, Laura; Bandirali, Michele; Messina, Carmelo; Sardanelli, Francesco

    2014-01-01

    Bone marrow is mainly composed of red (hematopoietic) and yellow (fatty) components. Soon after the birth there is a physiological conversion of the bone marrow from red to yellow, so that the percentage of hematopoietic cells and adipocytes changes with aging. Although bone marrow adipogenesis is a physiologic process involving all mammals, recent studies showed an accelerated marrow adipogenesis associated with several chronic conditions, including osteoporosis [4] and diabetes mellitus. Moreover, this increased marrow fat is accompanied by a decrease in bone density. Marrow fat is therefore increasingly believed to influence the bone microenvironment. Diagnostic tools for quantitative measurement of bone marrow fat and bone mineral density (BMD) include proton magnetic resonance spectroscopy (MRS) and dual-energy Xray absorptiometry (DXA), respectively. Using MRS, an inverse relationship between vertebral bone marrow fat content and lumbar BMD has been demonstrated in patients affected with osteoporosis or with diabetes mellitus. In most studies, a quite standard MRS sequence has been used, with short echo times (TE) for the measurement of the bulk methylene. In this study we sought to optimize the MRS sequence in order to try to measure other fat components of the vertebral bone marrow at 1.5 T. For this purpose, we used an animal model that allowed long acquisition times and repeated measures. Moreover, we aimed at estimating in this model the relationship between vertebral bone marrow fat content at proton MRS and BMD at DXA.

  8. Comparison of dual photon and dual energy X-ray bone densitometers in a clinic setting

    International Nuclear Information System (INIS)

    Nelson, D.A.; Shaffer, S.; Brown, E.B.; Flynn, M.J.; Cody, D.D.

    1991-01-01

    Two separate studies were conducted. We evaluated the relationships between results of lumbar spine measurements using two dual photon absorptiometry (DPA1 and DPA2) instruments and one dual energy X-ray (DXA) instrument with the same subject (49 volunteers), and also in 65 patients who were measured on the DPA1 and DXA machines. Second, we measured the lumbar spine and the proximal femur in three groups of 12 female volunteers three times on one instrument within 1 week. We purposely simulated a busy clinic setting with different technologists, older radioactive sources, and a heterogeneous patient group. The comparison study indicated a significant difference between the mean bone density values reported by the machines, but the results were highly correlated (R 2 = 0.89-0.96). This study emphasizes the differences between instruments, the potential for greater error in busy clinic environments, and the apparent superiority of dual energy X-ray absorptiometry under these less than ideal conditions. (orig./GDG)

  9. Design of parallel dual-energy X-ray beam and its performance for security radiography

    International Nuclear Information System (INIS)

    Kim, Kwang Hyun; Myoung, Sung Min; Chung, Yong Hyun

    2011-01-01

    A new concept of dual-energy X-ray beam generation and acquisition of dual-energy security radiography is proposed. Erbium (Er) and rhodium (Rh) with a copper filter were positioned in front of X-ray tube to generate low- and high-energy X-ray spectra. Low- and high-energy X-rays were guided to separately enter into two parallel detectors. Monte Carlo code of MCNPX was used to derive an optimum thickness of each filter for improved dual X-ray image quality. It was desired to provide separation ability between organic and inorganic matters for the condition of 140 kVp/0.8 mA as used in the security application. Acquired dual-energy X-ray beams were evaluated by the dual-energy Z-map yielding enhanced performance compared with a commercial dual-energy detector. A collimator for the parallel dual-energy X-ray beam was designed to minimize X-ray beam interference between low- and high-energy parallel beams for 500 mm source-to-detector distance.

  10. Simultaneous dual-energy X-ray stereo imaging

    Czech Academy of Sciences Publication Activity Database

    Mokso, R.; Oberta, Peter

    2015-01-01

    Roč. 22, Jul (2015), 1078-1082 ISSN 0909-0495 Institutional support: RVO:68378271 Keywords : optics * crystal * imaging * dual-energy Subject RIV: BH - Optics , Masers, Lasers Impact factor: 2.736, year: 2014

  11. Dual-energy X-ray radiography for automatic high-Z material detection

    International Nuclear Information System (INIS)

    Chen Gongyin; Bennett, Gordon; Perticone, David

    2007-01-01

    There is an urgent need for high-Z material detection in cargo. Materials with Z > 74 can indicate the presence of fissile materials or radiation shielding. Dual (high) energy X-ray material discrimination is based on the fact that different materials have different energy dependence in X-ray attenuation coefficients. This paper introduces the basic physics and analyzes the factors that affect dual-energy material discrimination performance. A detection algorithm is also discussed

  12. Anthropometrics and body composition by dual energy X-ray in children of obese women

    DEFF Research Database (Denmark)

    Tanvig, Mette; Vinter, Christina A; Jørgensen, Jan S

    2014-01-01

    of the RCT mothers and in 97 reference group children with Body Mass Index (BMI) Z-score as a primary outcome. Body composition was estimated by Dual Energy X-ray (DEXA) in 123 successful scans out of 147 (84%). RESULTS: No differences between randomized groups were seen in mean (95% C.I.) BMI Z...

  13. Dual-energy x-ray image decomposition by independent component analysis

    Science.gov (United States)

    Jiang, Yifeng; Jiang, Dazong; Zhang, Feng; Zhang, Dengfu; Lin, Gang

    2001-09-01

    The spatial distributions of bone and soft tissue in human body are separated by independent component analysis (ICA) of dual-energy x-ray images. It is because of the dual energy imaging modelí-s conformity to the ICA model that we can apply this method: (1) the absorption in body is mainly caused by photoelectric absorption and Compton scattering; (2) they take place simultaneously but are mutually independent; and (3) for monochromatic x-ray sources the total attenuation is achieved by linear combination of these two absorption. Compared with the conventional method, the proposed one needs no priori information about the accurate x-ray energy magnitude for imaging, while the results of the separation agree well with the conventional one.

  14. Errors in dual x-ray beam differential absorptiometry

    International Nuclear Information System (INIS)

    Bolin, F.; Preuss, L.; Gilbert, K.; Bugenis, C.

    1977-01-01

    Errors pertinent to the dual beam absorptiometry system have been studied and five areas are given in detail: (1) scattering, in which a computer analysis of multiple scattering shows little error due to this effect; (2) geometrical configuration effects, in which the slope of the sample is shown to influence the accuracy of the measurement; (3) Poisson variations, wherein it is shown that a simultaneous reduction can be obtained in both dosage and statistical error; (4) absorption coefficients, in which the effect of variation in absorption coefficient compilations is shown to have a critical effect on the interpretations of experimental data; and (5) filtering, wherein is shown the need for filters on dual beam systems using a characteristic x-ray output. A zero filter system is outlined

  15. Bone X-ray absorptiometry using two energies

    International Nuclear Information System (INIS)

    Laval-Jeantet, A.M.; Laval-Jeantet, M.; Bloch, J.

    1979-01-01

    A method of X-ray absorptiometry using two energies (28 and 36 keV) as a means of determining mineralisation of a bone specimen is described. The ratio of coefficients determined at the different energies varies according to the total mineralisation of the bone studied. A model, representing a serie of bone specimens constructed to study this relationship is described. The coefficients of attenuation for a given wavelength were measured. The relation between the coefficients found at two energies for a given specimen of known mineral content was found to vary as a function of the mineralisation. It is possible to determine the coefficient of attenuation characteristic of a bone and hence its mineralisation and thickness by measurements at two different wavelengths using this function. Experimental results show this potential of the method, but also its high sensitivity to small measurements errors [fr

  16. Radiation Detection and Dual-Energy X-Ray Imaging for Port Security

    Energy Technology Data Exchange (ETDEWEB)

    Pashby, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glenn, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Divin, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Martz, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-08-09

    Millions of cargo containers are transported across the United States border annually and are inspected for illicit radioactive material and contraband using a combination of passive radiation portal monitors (RPM) and high energy X-ray non-intrusive inspection (NII) systems. As detection performance is expected to vary with the material composition of cargo, characterizing the types of material present in cargo is important to national security. This work analyzes the passive radiation and dual energy radiography signatures from on RPM and two NII system, respectively. First, the cargos were analyzed to determine their ability to attenuate emissions from an embedded radioactive source. Secondly, dual-energy X-ray discrimination was used to determine the material composition and density of the cargos.

  17. Spectral and dual-energy X-ray imaging for medical applications

    Science.gov (United States)

    Fredenberg, Erik

    2018-01-01

    Spectral imaging is an umbrella term for energy-resolved X-ray imaging in medicine. The technique makes use of the energy dependence of X-ray attenuation to either increase the contrast-to-noise ratio, or to provide quantitative image data and reduce image artefacts by so-called material decomposition. Spectral imaging is not new, but has gained interest in recent years because of rapidly increasing availability of spectral and dual-energy CT and the dawn of energy-resolved photon-counting detectors. This review examines the current technological status of spectral and dual-energy imaging and a number of practical applications of the technology in medicine.

  18. Grating Oriented Line-Wise Filtration (GOLF) for Dual-Energy X-ray CT

    Science.gov (United States)

    Xi, Yan; Cong, Wenxiang; Harrison, Daniel; Wang, Ge

    2017-12-01

    In medical X-ray Computed Tomography (CT), the use of two distinct X-ray source spectra (energies) allows dose-reduction and material discrimination relative to that achieved with only one source spectrum. Existing dual-energy CT methods include source kVp-switching, double-layer detection, dual-source gantry, and two-pass scanning. Each method suffers either from strong spectral correlation or patient-motion artifacts. To simultaneously address these problems, we propose to improve CT data acquisition with the Grating Oriented Line-wise Filtration (GOLF) method, a novel X-ray filter that is placed between the source and patient. GOLF uses a combination of absorption and filtering gratings that are moved relative to each other and in synchronization with the X-ray tube kVp-switching process and/or the detector view-sampling process. Simulation results show that GOLF can improve the spectral performance of kVp-switching to match that of dual-source CT while avoiding patient motion artifacts and dual imaging chains. Although significant flux is absorbed by this pre-patient filter, the proposed GOLF method is a novel path for cost-effectively extracting dual-energy or multi-energy data and reducing radiation dose with or without kVp switching.

  19. Design of dual energy x-ray detector for conveyor belt with steel wire ropes

    Science.gov (United States)

    Dai, Yue; Miao, Changyun; Rong, Feng

    2009-07-01

    A dual energy X-ray detector for conveyor belt with steel wire ropes is researched in the paper. Conveyor belt with steel wire ropes is one of primary transfer equipments in modern production. The traditional test methods like electromagnetic induction principle could not display inner image of steel wire ropes directly. So X-ray detection technology has used to detect the conveyor belt. However the image was not so clear by the interference of the rubber belt. Therefore, the dualenergy X-ray detection technology with subtraction method is developed to numerically remove the rubber belt from radiograph, thus improving the definition of the ropes image. The purpose of this research is to design a dual energy Xray detector that could make the operator easier to found the faulty of the belt. This detection system is composed of Xray source, detector controlled by FPGA chip, PC for running image processing system and so on. With the result of the simulating, this design really improved the capability of the staff to test the conveyor belt.

  20. Metacarpal index by digital X-ray radiogrammetry: normative reference values and comparison with dual X-ray absorptiometry

    DEFF Research Database (Denmark)

    Hyldstrup, Lars; Nielsen, S P

    2001-01-01

    Metacarpal index (MCI), the combined cortical midmetacarpal thickness divided by the outer mid-metacarpal diameter, fell into oblivion when dual photon absorptiometry was introduced a quarter of a century ago. Modern PC-based digital X-ray diameter measurements offers a unique opportunity...

  1. Detection and quantification of coronary calcium from dual energy chest x-rays: Phantom feasibility study.

    Science.gov (United States)

    Zhou, Bo; Wen, Di; Nye, Katelyn; Gilkeson, Robert C; Eck, Brendan; Jordan, David; Wilson, David L

    2017-10-01

    We have demonstrated the ability to identify coronary calcium, a reliable biomarker of coronary artery disease, using nongated, 2-shot, dual energy (DE) chest x-ray imaging. Here we will use digital simulations, backed up by measurements, to characterize DE calcium signals and the role of potential confounds such as beam hardening, x-ray scatter, cardiac motion, and pulmonary artery pulsation. For the DE calcium signal, we will consider quantification, as compared to CT calcium score, and visualization. We created stylized and anatomical digital 3D phantoms including heart, lung, coronary calcium, spine, ribs, pulmonary artery, and adipose. We simulated high and low kVp x-ray acquisitions with x-ray spectra, energy dependent attenuation, scatter, ideal detector, and automatic exposure control (AEC). Phantoms allowed us to vary adipose thickness, cardiac motion, etc. We used specialized dual energy coronary calcium (DECC) processing that includes corrections for scatter and beam hardening. Beam hardening over a wide range of adipose thickness (0-30 cm) reduced the change in intensity of a coronary artery calcification (ΔI CAC ) by calcium signal (ΔI CAC ) in DECC images ±9%. If a simulated pulmonary artery fills with blood between exposures, it can give rise to a residual signal in DECC images, explaining pulmonary artery visibility in some clinical images. Residual misregistration can be mostly compensated by integrating signals in an enlarged region encompassing registration artifacts. DECC calcium score compared favorably to CT mass and volume scores over a number of phantom perturbations. Simulations indicate that proper DECC processing can faithfully recover coronary calcium signals. Beam hardening, errors in scatter estimation, cardiac motion, calcium residual misregistration etc., are all manageable. Simulations are valuable as we continue to optimize DE coronary calcium image processing and quantitative analysis. © 2017 American Association of Physicists

  2. Automated materials discrimination using 3D dual energy X ray images

    International Nuclear Information System (INIS)

    Wang, Ta Wee

    2002-01-01

    The ability of a human observer to identify an explosive device concealed in complex arrangements of objects routinely encountered in the 2D x-ray screening of passenger baggage at airports is often problematic. Standard dual-energy x-ray techniques enable colour encoding of the resultant images in terms of organic, inorganic and metal substances. This transmission imaging technique produces colour information computed from a high-energy x-ray signal and a low energy x-ray signal (80keV eff ≤ 13) to be automatically discriminated from many layers of overlapping substances. This is achieved by applying a basis materials subtraction technique to the data provided by a wavelet image segmentation algorithm. This imaging technique is reliant upon the image data for the masking substances to be discriminated independently of the target material. Further work investigated the extraction of depth data from stereoscopic images to estimate the mass density of the target material. A binocular stereoscopic dual-energy x-ray machine previously developed by the Vision Systems Group at The Nottingham Trent University in collaboration with The Home Office Science and Technology Group provided the image data for the empirical investigation. This machine utilises a novel linear castellated dual-energy x-ray detector recently developed by the Vision Systems Group. This detector array employs half the number of scintillator-photodiode sensors in comparison to a conventional linear dual-energy sensor. The castellated sensor required the development of an image enhancement algorithm to remove the spatial interlace effect in the resultant images prior to the calibration of the system for materials discrimination. To automate the basis materials subtraction technique a wavelet image segmentation and classification algorithm was developed. This enabled overlapping image structures in the x-rayed baggage to be partitioned. A series of experiments was conducted to investigate the

  3. Small animals bone density and morphometry analysis with a dual energy X-rays absorptiometry bone densitometer using a 2D digital radiographic detector; Analyse de la densite osseuse et de la morphometrie de petits animaux avec un osteodensitometre bi-energie utilisant un capteur 2D de radiographie numerique

    Energy Technology Data Exchange (ETDEWEB)

    Boudousq, V. [Centre Hospitalier Universitaire de Nimes, 30 (France); Bordy, T.; Gonon, G.; Dinten, J.M. [CEA Grenoble (DTBS/STD), Lab. d' Electronique et de Technologie de l' Informatique, LETI, 38 (France)

    2004-07-01

    LEXXOS (DMS, Montpellier, France) is the first axial and total body cone beam bone densitometer using a 2D digital radiographic detector. In previous papers, technical principles and patients' Bone Mineral Density (BMD) measurement performances were presented. Bone densitometers are also used on small animals for drug development. In this presentation, we show how LEXXOS can be adapted for small animals' examinations and evaluate its performances. At first, in order to take advantage of the whole area of the 20 x 20 cm{sup 2} digital radiographic detector, it has been made profit of X-Rays magnification by adapting the geometrical configuration. Secondly, as small animals present low BMD, a specific dual energy calibration has been defined. This adapted system has then been evaluated on two sets of mice: six reference mice and six ovariectomized mice. Each month, these two populations have been examined and the averaged total body BMD has been measured. This evaluation shows that the right order of BMD magnitude is obtained and, as expected, BMD increases on two sets until a period around puberty and the ovariectomized set presents a significant decrease after. Moreover, the bone image obtained by dual energy processing on LEXXOS presents a radiographic image quality providing useful complementary information on bone morphometry and architecture. This study shows that LEXXOS cone beam bone densitometer provides simultaneously useful quantitative and qualitative information for analysis of bone evolution on small animals. In the future, same system architecture and processing methodology can be used with higher resolution detectors in order to refine information on bone architecture. (authors)

  4. Optimum filter selection for Dual Energy X-ray Applications through Analytical Modeling

    International Nuclear Information System (INIS)

    Koukou, V; Martini, N; Sotiropoulou, P; Nikiforidis, G; Michail, C; Kalyvas, N; Kandarakis, I; Fountos, G

    2015-01-01

    In this simulation study, an analytical model was used in order to determine the optimal acquisition parameters for a dual energy breast imaging system. The modeled detector system, consisted of a 33.91mg/cm 2 Gd 2 O 2 S:Tb scintillator screen, placed in direct contact with a high resolution CMOS sensor. Tungsten anode X-ray spectra, filtered with various filter materials and filter thicknesses were examined for both the low- and high-energy beams, resulting in 3375 combinations. The selection of these filters was based on their K absorption edge (K-edge filtering). The calcification signal-to-noise ratio (SNR tc ) and the mean glandular dose (MGD) were calculated. The total mean glandular dose was constrained to be within acceptable levels. Optimization was based on the maximization of the SNR tc /MGD ratio. The results showed that the optimum spectral combination was 40kVp with added beam filtration of 100 μm Ag and 70kVp Cu filtered spectrum of 1000 μm for the low- and high-energy, respectively. The minimum detectable calcification size was 150 μm. Simulations demonstrate that this dual energy X-ray technique could enhance breast calcification detection. (paper)

  5. X-ray dual energy spectral parameter optimization for bone Calcium/Phosphorus mass ratio estimation

    International Nuclear Information System (INIS)

    Sotiropoulou, P I; Martini, N D; Koukou, V N; Nikiforidis, G C; Fountos, G P; Michail, C M; Valais, I G; Kandarakis, I S

    2015-01-01

    Calcium (Ca) and Phosphorus (P) bone mass ratio has been identified as an important, yet underutilized, risk factor in osteoporosis diagnosis. The purpose of this simulation study is to investigate the use of effective or mean mass attenuation coefficient in Ca/P mass ratio estimation with the use of a dual-energy method. The investigation was based on the minimization of the accuracy of Ca/P ratio, with respect to the Coefficient of Variation of the ratio. Different set-ups were examined, based on the K-edge filtering technique and single X-ray exposure. The modified X-ray output was attenuated by various Ca/P mass ratios resulting in nine calibration points, while keeping constant the total bone thickness. The simulated data were obtained considering a photon counting energy discriminating detector. The standard deviation of the residuals was used to compare and evaluate the accuracy between the different dual energy set-ups. The optimum mass attenuation coefficient for the Ca/P mass ratio estimation was the effective coefficient in all the examined set-ups. The variation of the residuals between the different set-ups was not significant. (paper)

  6. Optimal design of detector thickness for dual-energy x-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Woon; Kim, Ho Kyung [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The projection of three-dimensional (3D) human body on a two-dimensional (2D) radiograph results in the superimposition of normal tissue that can obscure abnormalities and in some common cases be misread as abnormalities. To reduce or eliminate this effect, 3D depth-discrimination techniques such as computed tomography can be used. Another method for improving conspicuity of abnormalities is an energy discrimination technique such as dual-energy imaging (DEI). The DEI discriminates, or enhances, material content (e.g. bone or soft tissue) within a 2D radiograph by combining images obtained at separte low and high energies. A commercial DEI system uses the fast kilovoltage (kVp) switching technique, which acquires low and highkVp projections in successive x-ray exposure. To obtain better quality in DE images, a large energy separation between the low and high-kVp setups is typically used for chest (e.g. 60/120 kVp). The optimal CsI thickness for dual-energy chest imaging has been theoretically investigated by evaluating prewhitening observer model detectability indexes. To evaluate the PW and PWE detectability indexes, dual-energy fluence and MTF have reviewed compared to the conventional descriptions.

  7. Whole body dual X-ray absorptiometry for bone mineral density and body composition using a flat panel detector

    International Nuclear Information System (INIS)

    Dinten, J.M.; Robert-Coutant, C.; Gonon, G.; Bordy, T.

    2003-01-01

    Whole-body dual-energy X-ray absorptiometry (DXA) systems are used for the determination of bone mineral density (BMD) but also for body composition estimates (lean mass and fat mass). The calculation is based on the difference in attenuation of body tissues for a low-energy of about 50 KeV and a high-energy of about 80-100 KeV. The measurement of dual-energy projections allows first to compute to the body composition in the non-bone area, and then to extrapolate the fat / lean ratio of soft tissue into the bone area in order to compute the BMD. Since detectors have limited area, a whole body examination requires a scan of the patient and a reconstruction process in order to build up a large field image from smaller radiographs. This reconstruction process must keep the quantitative value of the radiographs, and avoid any distortion which could be a consequence of the conic acquisition geometry. The cone angle is low (6 at maximum) and the large overlap between radiographs helps to reconstruct an image equivalent with a parallel-beam geometry. Scatter is corrected from the radiographs before reconstruction, as described in a previous paper ('Dual-energy X-rays absorptiometry using a 2D digital radiography detector. Application to bone densitometry', SPIE Medical Imaging 2001, Medical Physics). We have developed an original reconstruction method dedicated to whole-body examinations which will be described. Thanks to the quasi-radiologic quality of the detector, reconstructed images are of very good quality and this makes the measurement of BMD and fat / lean masses easier. (author)

  8. Errors in dual-energy X-ray scanning of the hip because of nonuniform fat distribution.

    Science.gov (United States)

    Tothill, Peter; Weir, Nicholas; Loveland, John

    2014-01-01

    The variable proportion of fat in overlying soft tissue is a potential source of error in dual-energy X-ray absorptiometry (DXA) measurements of bone mineral. The effect on spine scanning has previously been assessed from cadaver studies and from computed tomography (CT) scans of soft tissue distribution. We have now applied the latter technique to DXA hip scanning. The CT scans performed for clinical purposes were used to derive mean adipose tissue thicknesses over bone and background areas for total hip and femoral neck. The former was always lower. More importantly, the fat thickness differences varied among subjects. Errors because of bone marrow fat were deduced from CT measurements of marrow thickness and assumed fat proportions of marrow. The effect of these differences on measured bone mineral density was deduced from phantom measurements of the bone equivalence of fat. Uncertainties of around 0.06g/cm(2) are similar to those previously reported for spine scanning and the results from cadaver measurements. They should be considered in assessing the diagnostic accuracy of DXA scanning. Copyright © 2014 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  9. Optimizing detector thickness in dual-shot dual-energy x-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Woon; Kam, Soohwa; Youn, Hanbean; Kim, Ho Kyung [Pusan National University, Busan (Korea, Republic of)

    2015-05-15

    As a result, there exist apparent limitations in the conventional two-dimensional (2D) radiography: One is that the contrast between the structure of interest and the background in a radiograph is much less than the intrinsic subject contrast (i.e. the difference between their attenuation coefficients; Another is that the superimposed anatomical structures in the 2D radiograph results in an anatomical background clutter that may decrease the conspicuity of subtle underlying features. These limitations in spatial and material discrimination are important motivations for the recent development of 3D (e.g. tomosynthesis) and dual energy imaging (DEI) systems. DEI technique uses a combination of two images obtained at two different energies in successive x-ray exposures by rapidly switching the kilovolage (kV) applied to the x-ray tube. Commercial DEI systems usually employ a 'single' of flat-panel detector (FPD) to obtain two different kV images. However, we have a doubt in the use of the same detector for acquiring two different projections for the low- and high-kV setups because it is typically known that there exists an optimal detector thickness regarding specific imaging tasks or energies used.

  10. Morphometric X-ray Absorptiometry: Reference Data for Vertebral Dimensions in a Population-based Sample of Young Danish Men

    International Nuclear Information System (INIS)

    Wulff, R.; Koch Holst, A.; Nielsen, T.L.; Andersen, M.; Hagen, C.; Brixen, K.

    2004-01-01

    Purpose: To determine reference values for vertebral heights in healthy young Danish males using morphometric X-ray absorptiometry (MXA). Material and Methods: A population-based study group of 487 males aged between 20 and 30 years (mean 25 years) from the county of Funen, Denmark, were recruited. Using a Hologic QDR 4500 (dual energy X-ray absorptiometry) DXA-scanner, MXA scans covering the vertebrae from T4 to L4 were acquired for each subject. Anterior (Ha), middle (Hm), and posterior (Hp) heights of the thoracic (T4-T12) and lumbar (L1-L4) vertebral bodies were measured. Moreover, wedge, mid-wedge, crush I, and crush II ratios were calculated. Results: No correlation between vertebral dimensions and crush indices on the one hand and age or weight on the other were found. Body height, however, correlated significantly with the cumulated vertebral heights. Reference data for vertebral dimensions, wedge, mid-wedge, crush I, and crush II are tabulated. Conclusion: The anterior, middle, and posterior heights of the vertebral bodies of T4 to L4 can be measured reproducible with MXA. In young men, the cumulative vertebral heights correlated with body height but not with age. Moreover, the wedge and crush indices were unrelated of both age and height

  11. Quantitative analysis of bone mineral measurements in different types of dual-energy absorptiometry systems: Comparison of CT vs DEXA

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myeong Seong [Dept. of Radiology, National Cancer Center, Goyang (Korea, Republic of)

    2017-06-15

    Generally assessing bone mineral density (BMD) were performed on dual energy X-ray absorptiometry (DEXA) the same as dual energy CT (DECT) with a rapid-kVp switching. The purpose of this study is to compare the different of BMD value between DEXA and DECT method, and evaluate usefulness of DECT method. Using scanner for BMD measurements were GE, Healthcare Discovery 750 HD for DECT and Hologic QDR 4500W for DEXA. For compare BMD value in each method, scanned lumbar spine phantom and subjects visiting Korean National Cancer Center from April 2015 to December 2015, records of 50 patients. This study was approved by the Institutional Review Board. The mean BMD value measures for spine phantom and for subjects in each scanners presented strong correlation (r=0.948 with p<0.05 for phantom; r=0.635 with p<0.05 and Kendall's tau (τ)=0.46 with p<0.05 for subjects) and linear relationship between DECT and conventional DEXA. DECT technique for BMD measurement will provide a very useful methodology without additional radiation dose.

  12. Energy spectrum analysis between single and dual energy source x-ray imaging for PCB non-destructive test

    International Nuclear Information System (INIS)

    Park, Kyeong Jin; Kim, Myung Soo; Lee, Min Ju; Kang, Dong Uk; Lee, Dae Hee; Kim, Ye Won; Kim, Chan Kyu; Kim, Hyoung Taek; Kim, Gi Yoon; Cho, Gyu Seong

    2015-01-01

    Reliability of printed circuit board (PCB), which is based on high integrated circuit technology, is having been important because of development of electric and self-driving car. In order to answer these demand, automated X-ray inspection (AXI) is best solution for PCB nondestructive test. PCB is consist of plastic, copper, and, lead, which have low to high Z-number materials. By using dual energy X-ray imaging, these materials can be inspected accurately and efficiently. Dual energy X-ray imaging, that have the advantage of separating materials, however, need some solution such as energy separation method and enhancing efficiency because PCB has materials that has wide range of Z-number. In this work, we found out several things by analysis of X-ray energy spectrum. Separating between lead and combination of plastic and copper is only possible with energy range not dose. On the other hand, separating between plastic and copper is only with dose not energy range. Moreover the copper filter of high energy part of dual X-ray imaging and 50 kVp of low energy part of dual X-ray imaging is best for efficiency

  13. Energy spectrum analysis between single and dual energy source x-ray imaging for PCB non-destructive test

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyeong Jin; Kim, Myung Soo; Lee, Min Ju; Kang, Dong Uk; Lee, Dae Hee; Kim, Ye Won; Kim, Chan Kyu; Kim, Hyoung Taek; Kim, Gi Yoon; Cho, Gyu Seong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-08-15

    Reliability of printed circuit board (PCB), which is based on high integrated circuit technology, is having been important because of development of electric and self-driving car. In order to answer these demand, automated X-ray inspection (AXI) is best solution for PCB nondestructive test. PCB is consist of plastic, copper, and, lead, which have low to high Z-number materials. By using dual energy X-ray imaging, these materials can be inspected accurately and efficiently. Dual energy X-ray imaging, that have the advantage of separating materials, however, need some solution such as energy separation method and enhancing efficiency because PCB has materials that has wide range of Z-number. In this work, we found out several things by analysis of X-ray energy spectrum. Separating between lead and combination of plastic and copper is only possible with energy range not dose. On the other hand, separating between plastic and copper is only with dose not energy range. Moreover the copper filter of high energy part of dual X-ray imaging and 50 kVp of low energy part of dual X-ray imaging is best for efficiency.

  14. A new method of explosive detection based on dual-energy X-ray technology and forward-scattering

    International Nuclear Information System (INIS)

    Zhao Kun; Li Jianmin

    2004-01-01

    Based on dual-energy X-ray technology combined with forward-scattering, a brand new explosive detection method is presented. Dual-energy technology can give the information on the effective atomic number (Z eff ) of an irradiated component, while the intensity of the forward scattered photons can reveal the density information according to our research. Therefore, the existence of the explosive can be effectively identified by combining these two characteristic quantities. Compared with the earlier inspection approaches, the new one has a series of particular advantages, such as high detection rate, low false alarm rate, automatic alarm and so forth. The project is ongoing. (authors)

  15. Development of a dual-energy silicon X-ray diode and its application to gadolinium imaging

    International Nuclear Information System (INIS)

    Sato, Yuichi; Sato, Eiichi; Ehara, Shigeru; Oda, Yasuyuki; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Enomoto, Toshiyuki; Watanabe, Manabu; Kusachi, Shinya

    2015-01-01

    To perform dual-energy X-ray imaging, we developed a dual-energy silicon X-ray diode (DE-Si-XD) consisting of two ceramic-substrate silicon X-ray diodes (Si-XD) and a 0.2-mm-thick copper filter. The Si-XD is a high-sensitivity Si photodiode selected for detecting X-rays. In the front Si-XD, X-ray photons from an X-ray tube are directly detected. Because low-energy photons are absorbed by the front Si-XD and the filter, the average photon energy increases when the back Si-XD is used. In the front Si-XD, the photocurrents flowing through the Si-XD are converted into voltages and amplified using current–voltage and voltage–voltage (V–V) amplifiers. The output from the V–V amplifier is input to an analog-digital converter through an integrator for smoothing the voltage. The same amplification method is also used in the back Si-XD. Dual-energy computed tomography (DE–CT) is accomplished by repeated linear scans and rotations of the object, and two projection curves of the object are obtained simultaneously by linear scanning at a tube voltage of 90 kV and a current of 1.0 mA. In the DE–CT, the exposure time for obtaining a tomogram is 10 min with scan steps of 0.5 mm and rotation steps of 1.0°. Using gadolinium-based contrast media, energy subtraction was performed. - Highlights: • Dual-energy X-ray diode consists of two Si diodes and a Cu filter. • Low and high-energy X-rays are detected using front and back diodes. • Two-different-energy tomograms were easily obtained simultaneously. • Gd-K-edge CT was accomplished using the back diode. • Energy subtraction was performed easily to image a target object

  16. Concept of effective atomic number and effective mass density in dual-energy X-ray computed tomography

    International Nuclear Information System (INIS)

    Bonnin, Anne; Duvauchelle, Philippe; Kaftandjian, Valérie; Ponard, Pascal

    2014-01-01

    This paper focuses on dual-energy X-ray computed tomography and especially the decomposition of the measured attenuation coefficient in a mass density and atomic number basis. In particular, the concept of effective atomic number is discussed. Although the atomic number is well defined for chemical elements, the definition of an effective atomic number for any compound is not an easy task. After reviewing different definitions available in literature, a definition related to the method of measurement and X-ray energy, is suggested. A new concept of effective mass density is then introduced in order to characterize material from dual-energy computed tomography. Finally, this new concept and definition are applied on a simulated case, focusing on explosives identification in luggage

  17. Determination of liquid's molecular interference function based on X-ray diffraction and dual-energy CT in security screening

    International Nuclear Information System (INIS)

    Zhang, Li; YangDai, Tianyi

    2016-01-01

    A method for deriving the molecular interference function (MIF) of an unknown liquid for security screening is presented. Based on the effective atomic number reconstructed from dual-energy computed tomography (CT), equivalent molecular formula of the liquid is estimated. After a series of optimizations, the MIF and a new effective atomic number are finally obtained from the X-ray diffraction (XRD) profile. The proposed method generates more accurate results with less sensitivity to the noise and data deficiency of the XRD profile. - Highlights: • EDXRD combined with dual-energy CT has been utilized for deriving the molecular interference function of an unknown liquid. • The liquid's equivalent molecular formula is estimated based on the effective atomic number reconstructed from dual-energy CT. • The proposed method provides two ways to estimate the molecular interference function: the simplified way and accurate way. • A new effective atomic number of the liquid could be obtained.

  18. Dual-energy radiographic absorptiometry of the lumbar spine and proximal femur

    International Nuclear Information System (INIS)

    Moscona, A.; Gundry, C.; Sartoris, D.J.; Barrett-Connor, E.; Stein, J.A.; Resnick, D.

    1988-01-01

    Dual-energy radiographic absorptiometry (DRA), dual-photon absorptiometry (DPA), and single-photon absorptiometry (SPA) were used for comprehensive densitometry of 500 men and women aged 65-100 years, within an epidemiologic study of osteoporosis risk factors. DRA and DPA of the lumbar spine (L1-L4) and proximal femur were performed with a Hologic QDR-100 system and a Lunar DP3 system, respectively, and SPA of the 33% shaft and ultradistal forearm sites was performed with a Lunar SP2 system. DRA and DPA results showed high correlation at both sites (tau=.9,P<.001); data conversion factors were derived. SPA results for the ultradistal site correlated better with vertebral and femoral density (tau=.6,P<.1) than did those for the shaft site (tau=.4,P<.5) but neither forearm measurement was reliable predictive of axial mineral status. The various measurements displayed an age-dependent interrelationship. The DRA method offers the advantage of short examination times (about 5 minutes per site) and high precision (about 1%)

  19. Impact of polychromatic x-ray sources on helical, cone-beam computed tomography and dual-energy methods

    International Nuclear Information System (INIS)

    Sidky, Emil Y; Zou Yu; Pan Xiaochuan

    2004-01-01

    Recently, there has been much work devoted to developing accurate and efficient algorithms for image reconstruction in helical, cone-beam computed tomography (CT). Little attention, however, has been directed to the effect of physical factors on helical, cone-beam CT image reconstruction. This work investigates the effect of polychromatic x-rays on image reconstruction in helical, cone-beam computed tomography. A pre-reconstruction dual-energy technique is developed to reduce beam-hardening artefacts and enhance contrast in soft tissue

  20. Research on multi-spectrum detector in high-energy dual-energy X-ray imaging system

    International Nuclear Information System (INIS)

    Li Qinghua; Wang Xuewu; Li Jianmin; Kang Kejun; Li Yuanjing; Zhong Huaqiang

    2008-01-01

    The high-energy dual-energy X-ray imaging system can discriminate the material of the objects inspected, but when the objects are too thin, the discrimination becomes very difficult. This paper proposes the use of multi-spectrum detector to improve the ability to discriminate thin material, and a series of simulation were done with the Monte Carlo method. Firstly the X-ray depositions in the detectors with different thickness were calculated, and then the discrimination effects with different detector structure and parameters were calculated. The simulation results validated that using appropriate multi-spectrum detector can improve the discrimination accuracy of thin material, particularly thin high-Z material. (authors)

  1. Linear iterative near-field phase retrieval (LIPR) for dual-energy x-ray imaging and material discrimination.

    Science.gov (United States)

    Li, Heyang Thomas; Kingston, Andrew M; Myers, Glenn R; Beeching, Levi; Sheppard, Adrian P

    2018-01-01

    Near-field x-ray refraction (phase) contrast is unavoidable in many lab-based micro-CT imaging systems. Quantitative analysis of x-ray refraction (a.k.a. phase retrieval) is in general an under-constrained problem. Regularizing assumptions may not hold true for interesting samples; popular single-material methods are inappropriate for heterogeneous samples, leading to undesired blurring and/or over-sharpening. In this paper, we constrain and solve the phase-retrieval problem for heterogeneous objects, using the Alvarez-Macovski model for x-ray attenuation. Under this assumption we neglect Rayleigh scattering and pair production, considering only Compton scattering and the photoelectric effect. We formulate and test the resulting method to extract the material properties of density and atomic number from single-distance, dual-energy imaging of both strongly and weakly attenuating multi-material objects with polychromatic x-ray spectra. Simulation and experimental data are used to compare our proposed method with the Paganin single-material phase-retrieval algorithm, and an innovative interpretation of the data-constrained modeling phase-retrieval technique.

  2. A phantom test of proton-induced dual-energy X-ray angiography using iodinated contrast media

    International Nuclear Information System (INIS)

    Oguri, Y.; Hasegawa, J.; Ogawa, M.; Kaneko, J.; Sasa, K.

    2007-01-01

    Characteristic-line radiation from heavy metal targets bombarded by MeV proton beams has been tested as an X-ray source for dual-energy K-edge subtraction imaging for human angiography (blood vessel imaging) based on iodinated contrast media. To utilize the strong absorption by iodine (Z=53) at its K-absorption edge (33.2 keV), we used K α -line of La (lanthanum, Z=57) at 33.4 keV. As a reference, also K α X emission of Sn (tin, Z=50) at 25.2 keV was employed. Metallic plates of La and Sn were irradiated by 7-MeV protons to produce these characteristic X-rays. Energy-subtraction method was tested using Lucite phantoms which contain aqueous solutions of KI (potassium iodide) with different concentrations. Also Ca(H 2 PO 4 ) 2 powder was stuffed in these phantoms to simulate bones. The transmission images of the phantoms were recorded on imaging plates. During the exposure, the energy spectra of the X-rays were monitored by a CdTe detector. We found that the contrast of images of iodide solutions taken with La X-rays was higher than that with Sn X-rays. Also the energy subtraction procedure was successfully applied to reduce the graphical noise due to the bones and inhomogeneity of the soft tissue. However, to apply the present method to actual clinical use, the X-ray intensity must be increased by several orders of magnitude. Also the transmission of the 'lower-energy' photons has to be a few orders higher for imaging of objects as thick as human chest. (author)

  3. Abdominal fat indicators: anthropometry vs dual energy x-ray absortometry

    Directory of Open Access Journals (Sweden)

    Maria Fátima Glaner

    2008-06-01

    Full Text Available Excessive abdominal fat contributes to the development of chronic nontransmissible diseases. Dual emission X Ray absorptiometry (DXA is a simple to administer technique that allows abdominal fat percentage (%abdominalFDXA to be determined. Anthropometric measurements, which have been validated and are of low cost, such as the abdominal circumferences 2.5cm above the umbilical scar (ABC2,5 and level with the umbilical scar (ABCum, are used as indicators of abdominal fat. Skin folds (SF are little used for this purpose. The objective of this study was to verify which of these anthropometric indicators best correlates with and best explains abdominalFDXA. The sample was made up of 22 women (43.9±11.6 years; 34.7±8.3 %G totalDXA and 18 men (31.9±11.6 years; 19.0±8.0 %G totalDXA who were measured for ABC2.5, ABCum, suprailiac SF (SI, midaxillary SF (AM and abdominal SF (AB, while abdominalF (L1-L4 was measured by DXA. Pearson’s correlation and multivariate linear regression (“enter” method were employed to verify the anthropometric measurements’ correlations and percentage of explanation with relation to abdominalFDXA. Strong correlations and significant levels of explanation (pResumoO excesso de gordura abdominal contribui no desenvolvimento de doenças crônicas não-transmissíveis. A absortometria de raio-X de dupla energia (AXDE é uma técnica de simples aplicação, que permite a mensuração do percentual de gordura abdominal (%G abdominalAXDE. As medidas antropométricas, validadas e de baixo custo, como os perímetros abdominal 2,5cm acima da cicatriz umbilical (PAB2,5 e ao nível da cicatriz umbilical (PABum, são empregadas como indicadores de gordura abdominal. As dobras cutâneas (DC são pouco estudadas nesse sentido. Assim, o objetivo desse estudo foi verificar quais destes indicadores antropométricos mais se correlacionam e explicam o %G abdominalAXDE. A amostra foi composta por 22 mulheres (43,9±11,6 anos; 34,7±8,3 %G

  4. Optimization of breast cancer detection in Dual Energy X-ray Mammography using a CMOS imaging detector

    International Nuclear Information System (INIS)

    Koukou, V; Martini, N; Sotiropoulou, P; Nikiforidis, G; Fountos, G; Michail, C; Kalyvas, N; Valais, I; Kandarakis, I; Bakas, A; Kounadi, E

    2015-01-01

    Dual energy mammography has the ability to improve the detection of microcalcifications leading to early diagnosis of breast cancer. In this simulation study, a prototype dual energy mammography system, using a CMOS based imaging detector with different X-ray spectra, was modeled. The device consists of a 33.91 mg/cm 2 Gd 2 O 2 S:Tb scintillator screen, placed in direct contact with the sensor, with a pixel size of 22.5 μm. Various filter materials and tube voltages of a Tungsten (W) anode for both the low and high energy were examined. The selection of the filters applied to W spectra was based on their K- edges (K-edge filtering). Hydroxyapatite (HAp) was used to simulate microcalcifications. Calcification signal-to-noise ratio (SNR tc ) was calculated for entrance surface dose within the acceptable levels of conventional mammography. Optimization was based on the maximization of SNR tc while minimizing the entrance dose. The best compromise between SNR tc value and dose was provided by a 35kVp X-ray spectrum with added beam filtration of 100μm Pd and a 70kVp Yb filtered spectrum of 800 μm for the low and high energy, respectively. Computer simulation results show that a SNR tc value of 3.6 can be achieved for a calcification size of 200 μm. Compared with previous studies, this method can improve detectability of microcalcifications

  5. Estimating the Absorbed Dose to Critical Organs During Dual X-ray Absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari-Dizaji, M.; Sharafi, A. A.; Larijani, B.; Mokhlesian, N.; Hasanzadeh, H. [Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

    2008-04-15

    Objective : The purpose of this study is to estimate a patient's organ dose (effective dose) during performance of dual X-ray absorptiometry by using the correlations derived from the surface dose and the depth doses in an anthropomorphic phantom. Materials and Methods : An anthropomorphic phantom was designed and TLDs (Thermoluminescent Dosimeters) were placed at the surface and these were also inserted at different depths of the thyroid and uterus of the anthropomorphic phantom. The absorbed doses were measured on the phantom for the spine and femur scan modes. The correlation coefficients and regression functions between the absorbed surface dose and the depth dose were determined. The derived correlation was then applied for 40 women patients to estimate the depth doses to the thyroid and uterus. Result : There was a correlation between the surface dose and depth dose of the thyroid and uterus in both scan modes. For the women's dosimetry, the average surface doses of the thyroid and uterus were 1.88 {mu}Gy and 1.81 Gy, respectively. Also, the scan center dose in the women was 5.70 Gy. There was correlation between the thyroid and uterus surface doses, and the scan center dose. Conclusion : We concluded that the effective dose to the patient's critical organs during dual X-ray absorptiometry can be estimated by the correlation derived from phantom dosimetry.

  6. Estimating the Absorbed Dose to Critical Organs During Dual X-ray Absorptiometry

    International Nuclear Information System (INIS)

    Mokhtari-Dizaji, M.; Sharafi, A. A.; Larijani, B.; Mokhlesian, N.; Hasanzadeh, H.

    2008-01-01

    Objective : The purpose of this study is to estimate a patient's organ dose (effective dose) during performance of dual X-ray absorptiometry by using the correlations derived from the surface dose and the depth doses in an anthropomorphic phantom. Materials and Methods : An anthropomorphic phantom was designed and TLDs (Thermoluminescent Dosimeters) were placed at the surface and these were also inserted at different depths of the thyroid and uterus of the anthropomorphic phantom. The absorbed doses were measured on the phantom for the spine and femur scan modes. The correlation coefficients and regression functions between the absorbed surface dose and the depth dose were determined. The derived correlation was then applied for 40 women patients to estimate the depth doses to the thyroid and uterus. Result : There was a correlation between the surface dose and depth dose of the thyroid and uterus in both scan modes. For the women's dosimetry, the average surface doses of the thyroid and uterus were 1.88 μGy and 1.81 Gy, respectively. Also, the scan center dose in the women was 5.70 Gy. There was correlation between the thyroid and uterus surface doses, and the scan center dose. Conclusion : We concluded that the effective dose to the patient's critical organs during dual X-ray absorptiometry can be estimated by the correlation derived from phantom dosimetry

  7. [Particle size determination by radioisotope x-ray absorptiometry with sedimentation method].

    Science.gov (United States)

    Matsui, Y; Furuta, T; Miyagawa, S

    1976-09-01

    The possibility of radioisotope X-ray absorptiometry to determine the particle size of powder in conjunction with sedimentation was investigated. The experimental accuracy was primarily determined by Cow and X-ray intensity. where Co'=weight concentration of the particle in the suspension w'=(micron/rho)l/(mu/rho)s-rhol/rhos rho; density micron/rho; mass absorption coefficient, suffix l and s indicate dispersion and particle, respectively. The radiosiotopes, Fe-55, Pu-238 and Cd-109 have high w-values over the wide range of the atomic number. However, a source of high micron value such as Fe-55 is not suitable because the optimal X-ray transmission length, Lopt is decided by the expression, micronlLopt approximately 2/(1+C'ow') by using Cd-109 AgKX-ray source, the weight size distribution of particles from the heavy elements such as PbO2 to light elements such as Al2O3 or flyash was determined.

  8. A deep learning framework for the automated inspection of complex dual-energy x-ray cargo imagery

    Science.gov (United States)

    Rogers, Thomas W.; Jaccard, Nicolas; Griffin, Lewis D.

    2017-05-01

    Previously, we investigated the use of Convolutional Neural Networks (CNNs) to detect so-called Small Metallic Threats (SMTs) hidden amongst legitimate goods inside a cargo container. We trained a CNN from scratch on data produced by a Threat Image Projection (TIP) framework that generates images with realistic variation to robustify performance. The system achieved 90% detection of containers that contained a single SMT, while raising 6% false positives on benign containers. The best CNN architecture used the raw high energy image (single-energy) and its logarithm as input channels. Use of the logarithm improved performance, thus echoing studies on human operator performance. However, it is an unexpected result with CNNs. In this work, we (i) investigate methods to exploit material information captured in dual-energy images, and (ii) introduce a new CNN training scheme that generates `spot-the-difference' benign and threat pairs on-the-fly. To the best of our knowledge, this is the first time that CNNs have been applied directly to raw dual-energy X-ray imagery, in any field. To exploit dual-energy, we experiment with adapting several physics-derived approaches to material discrimination from the cargo literature, and introduce three novel variants. We hypothesise that CNNs can implicitly learn about the material characteristics of objects from the raw dual-energy images, and use this to suppress false positives. The best performing method is able to detect 95% of containers containing a single SMT, while raising 0.4% false positives on benign containers. This is a step change improvement in performance over our prior work

  9. Dual-energy X-ray micro-CT imaging of hybrid Ni/Al open-cell foam

    International Nuclear Information System (INIS)

    Fíla, T.; Koudelka, P.; Zlámal, P.; Jiroušek, O.; Kumpová, I.; Vavřík, D.; Jung, A.

    2016-01-01

    In this paper, we employ dual-energy X-ray microfocus tomography (DECT) measurement to develop high-resolution finite element (FE) models that can be used for the numerical assessment of the deformation behaviour of hybrid Ni/Al foam subjected to both quasi-static and dynamic compressive loading. Cubic samples of hybrid Ni/Al open-cell foam with an edge length of [15]mm were investigated by the DECT measurement. The material was prepared using AlSi 7 Mg 0.3 aluminium foam with a mean pore size of [0.85]mm, coated with nanocrystalline nickel (crystallite size of approx. [50]nm) to form a surface layer with a theoretical thickness of [0.075]mm. CT imaging was carried out using state-of-the-art DSCT/DECT X-ray scanner developed at Centre of Excellence Telč. The device consists of a modular orthogonal assembly of two tube-detector imaging pairs, with an independent geometry setting and shared rotational stage mounted on a complex 16-axis CNC positioning system to enable unprecedented measurement variability for highly-detailed tomographical measurements. A sample of the metal foam was simultaneously irradiated using an XWT-240-SE reflection type X-ray tube and an XWT-160-TCHR transmission type X-ray tube. An enhanced dual-source sampling strategy was used for data acquisition. X-ray images were taken using XRD1622 large area GOS scintillator flat panel detectors with an active area of [410 × 410]mm and resolution [2048 × 2048]pixels. Tomographic scanning was performed in 1,200 projections with a 0.3 degree angular step to improve the accuracy of the generated models due to the very complex microstructure and high attenuation of the investigated material. Reconstructed data was processed using a dual-energy algorithm, and was used for the development of a 3D model and voxel model of the foam. The selected parameters of the models were compared with nominal parameters of the actual foam and showed good correlation

  10. Dual energy x-ray microtomography for development and inspection of advanced aerospace materials

    International Nuclear Information System (INIS)

    Alvarez, R.E.; Cao, Q.

    1990-01-01

    A key step in development of advanced composite materials is to characterize their internal structure and composition in a quantitative manner. In this paper, the authors describe a technique and an instrument that allows the measurements of the interior volume of the material. It has several key advantages over conventional computed tomography. The technique quantitatively measures the mass density and effective atomic number throughout the volume. Further, these measurements are made with microscopic (20 micrometer or better) spatial resolution. The technique is based on ARACOR's Tomoscope computed tomography instrument and on dual energy computed tomography. The authors describe the theory of the technique and show experimental measurements of metal matrix composite materials

  11. A dual-energy medical instrument for measurement of x-ray source voltage and dose rate

    Science.gov (United States)

    Ryzhikov, V. D.; Naydenov, S. V.; Volkov, V. G.; Opolonin, O. D.; Makhota, S.; Pochet, T.; Smith, C. F.

    2016-03-01

    An original dual-energy detector and medical instrument have been developed to measure the output voltages and dose rates of X-ray sources. Theoretical and experimental studies were carried out to characterize the parameters of a new scintillator-photodiode sandwich-detector based on specially-prepared zinc selenide crystals in which the low-energy detector (LED) works both as the detector of the low-energy radiation and as an absorption filter allowing the highenergy fraction of the radiation to pass through to the high-energy detector (HED). The use of the LED as a low-energy filter in combination with a separate HED opens broad possibilities for such sandwich structures. In particular, it becomes possible to analyze and process the sum, difference and ratio of signals coming from these detectors, ensuring a broad (up to 106) measurement range of X-ray intensity from the source and a leveling of the energy dependence. We have chosen an optimum design of the detector and the geometry of the component LED and HED parts that allow energy-dependence leveling to within specified limits. The deviation in energy dependence of the detector does not exceed about 5% in the energy range from 30 to 120 keV. The developed detector and instrument allow contactless measurement of the anode voltage of an X-ray emitter from 40 to 140 kV with an error no greater than 3%. The dose rate measurement range is from 1 to 200 R/min. An original medical instrument has passed clinical testing and was recommended for use in medical institutions for X-ray diagnostics.

  12. Cross-calibration of domestic devices and GE lunar prodigy advance dual-energy X-ray densitometer devices for bone mineral measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Su [Chungbuk Health and Science University, Cheongju (Korea, Republic of); Rho, Young Hoon; Lee, In Ju; Kim, Jung Min [Korea University Graduate School, Seoul (Korea, Republic of); Kim, Kyoung A [CHA Bundang Medical Center, CHA University, Seongnam (Korea, Republic of); Lee, In Ja [Dongnam Health University, Suwon (Korea, Republic of)

    2017-03-15

    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.

  13. A Study of Equipment Accuracy and Test Precision in Dual Energy X-ray Absorptiometry

    International Nuclear Information System (INIS)

    Dong, Kyung Rae; Kim, Ho Sung; Jung, Woon Kwan

    2008-01-01

    Because there is a difference depending on the environment as for an inspection equipment the important part of bone density scan and the precision/accuracy of a tester, the management of quality must be made systematically. The equipment failure caused by overload effect due to the aged equipment and the increase of a patient was made frequently. Thus, the replacement of equipment and additional purchases of new bone density equipment caused a compatibility problem in tracking patients. This study wants to know whether the clinical changes of patient's bone density can be accurately and precisely reflected when used it compatibility like the existing equipment after equipment replacement and expansion. Two equipment of GE Lunar Prodigy Advance(P1 and P2) and the Phantom HOLOGIC Spine Road(HSP) were used to measure equipment precision. Each device scans 20 times so that precision data was acquired from the phantom(Group 1). The precision of a tester was measured by shooting twice the same patient, every 15 members from each of the target equipment in 120 women(average age 48.78, 20-60 years old)(Group 2). In addition, the measurement of the precision of a tester and the cross-calibration data were made by scanning 20 times in each of the equipment using HSP, based on the data obtained from the management of quality using phantom(ASP) every morning (Group 3). The same patient was shot only once in one equipment alternately to make the measurement of the precision of a tester and the cross-calibration data in 120 women(average age 48.78, 20-60 years old)(Group 4). It is steady equipment according to daily Q.C Data with 0.996 g/cm 2 , change value(%CV) 0.08. The meanSD and a %CV price are ALP in Group 1(P1 : , , P2 : , %CV=0.192). The mean±SD and a %CV price are P1 : 1.064±0.002 g/cm 2 , %CV=0.190 g/cm 2 , P2 : 1.061±0.003 g/cm 3 , %CV=0.163 in Group 2. The average error±2SD and %CV are P1 - (spine: 0.001±0.013 g/cm 2 , %CV=0.94, Femur: 0.001±0.019 g/cm 2 , %CV=0.96), P2 - (spine: 0.002±0.018 g/cm 2 , %CV=0.55, Femur: 0.001±0.013 g/cm 2 , %CV=0.48) in Group 3. The average error±2SD, %CV, and r value was spine : 0.006±0.024 g/cm 2 , %CV=0.86, r=0.995, Femur: 0±0.014 g/cm 2 , %CV=0.54, r=0.998 in Group 4. Both LUNAR ASP CV% and HOLOGIC Spine Phantom are included in the normal range of error of ±2% defined in ISCD. BMD measurement keeps a relatively constant value, so showing excellent repeatability. The Phantom has homogeneous characteristics, but it has limitations to reflect the clinical part including variations in patient's body weight or body fat. As a result, it is believed that quality control using Phantom will be useful to check mis-calibration of the equipment used. A value measured a patient two times with one equipment, and that of double-crossed two equipment are all included within 2SD Value in the Bland - Altman Graph compared results of Group 3 with Group 4. The r value of 0.99 or higher in Linear regression analysis(Regression Analysis) indicated high precision and correlation. Therefore, it revealed that two compatible equipment did not affect in tracking the patients. Regular testing equipment and capabilities of a tester, then appropriate calibration will have to be achieved in order to calculate confidential BMD.

  14. Relationship between bone strength and dual-energy X-ray absorptiometry measurements in pigs

    DEFF Research Database (Denmark)

    Nielsen, Dorte Hald; McEvoy, Fintan; Madsen, M.T.

    2007-01-01

    BMD (1.4 g/cm2, respectively). The results showed a difference in the maximum load, in the stress at maximum load, and stiffness among each BMD group (P ... and extrinsic measures of bone strength and BMD was thus demonstrated. The projected change in each of the variables reported, for a 0.1 /cm2 alteration in BMD (within the BMD range evaluated in this study), is as follows: maximum load, 708 N; stress at maximum load, 50 N/mm2; stiffness, 391.6 N/mm; and elastic...... modulus, 108 N/mm2 (P relationship between BMD and bone strength and indicate that BMD screening can be used in fracture risk assessments in production pigs....

  15. Dual energy X-ray absorptiometry for the measurement of bone mineral density in Shanghai residents

    International Nuclear Information System (INIS)

    Zhang Yuanxun; Li Deyi; Ma Jixiao; Huang Qiren

    1996-01-01

    In recent years, the rapid development of bone mineral density determination technique provides a powerful research tool to diagnose osteoporosis and prevent fracture. Since the beginning of 1995, the research group incooperation with Shanghai 6th people's hospital is carrying on bone density measurements as a part of Co-ordinated Research Programme (CRP) organized by International Atomic Energy Agency (IAEA). The purpose of this study is to determine the age of peak bone mass in each study group of Shanghai residents and to quantify differences in bone density as functions of the age and sex of persons in the study groups. At the same time the authors should get the normal human BMD (Bone Mineral Density) reference database specially for Shanghai residents, China. The roles of various life styles, exercise, diet and so on are also investigated

  16. Global variations in peak bone mass as studied by dual-energy X-ray absorptiometry

    International Nuclear Information System (INIS)

    McCloskey, E.V.; Dey, A.; Bostock, J.; Parr, R.M.; Aras, N.; Balogh, A.; Borelli, A.; Krishnan, S.; Lobo, G.; Qin, L.L.

    2004-01-01

    In 1994, the International Atomic Energy Agency (IAEA) initiated a 5-year Co-ordinated Research Project (CRP) to determine geographical and racial differences in peak bone mineral density (BMD) in men and women aged 15-49 years. Distinct global differences in BMD were demonstrated at the hip and spine in both men and women approximating to one population standard deviation between populations with the highest and lowest BMD. These differences persist following adjustments for age, sex and body size. Such information is valuable in understanding the reasons for global differences in fracture rate and predicting future trends in fracture incidence. (author)

  17. Evaluation of osteoporosis using conventional radiographic methods and dual energy x-ray absorptiometry

    International Nuclear Information System (INIS)

    Anburajan, M.

    2001-01-01

    In India, conventional radiographs play a major part in evaluating osteoporosis since advanced bone densitometers are expensive and not widely available. Our aim in this study was to investigate the usefulness of conventional radiographic methods, viz., clavicle and metacarpal radiogrammetry, quantitative vertebral morphometry, Singh's index, hip geometry compared to a sophisticated method, viz., DXA for studying osteoporosis in south Indian men (n=663) and women (n=741). This study provides data on BMD of the proximal femur in normal south Indian females. In women, aged above 65 years, BMD of femoral neck, trochanter, and Ward's triangle decreased by 0.90%, 0.84%, and 1.66% per annum, respectively. In 45 pre- and post-menopausal women without fractures, total hip BMD correlated significantly ( p 2 =0.47), medial cortical thickness of the femoral shaft (r 2 =0.38) and neck (r 2 =0.29), combined cortical thickness (CCT) and %CCT of the clavicle (r 2 =0.54 each), and the second metacarpal (r 2 =0.51 and r 2 =0.53, respectively). On comparing variables studied for osteoporotic women with corresponding values in the premenopausal group, the average difference in SD from the mean was greatest for clavicle radiogrammetry (-3.7 SD for %CCT of the clavicle). An empirical formula for predicting total hip BMD with good sensitivity was derived from a multiple linear regression equation involving three independent variables, viz., CCT, %CCT of the clavicle (measured from the chest radiograph) and the patient's age. This author's equation, with modified weightings, has 82% sensitivity and 94% specificity and a positive and negative predictive value of 88% and 91% respectively. A chest radiograph in combination with the formula would serve as a readily available, inexpensive tool for assessing post-menopausal osteoporosis, especially in developing countries

  18. Segmental Musculoskeletal Examinations using Dual-Energy X-Ray Absorptiometry (DXA: Positioning and Analysis Considerations

    Directory of Open Access Journals (Sweden)

    Nicolas H. Hart, Sophia Nimphius, Tania Spiteri, Jodie L. Cochrane, Robert U. Newton

    2015-09-01

    Full Text Available Musculoskeletal examinations provide informative and valuable quantitative insight into muscle and bone health. DXA is one mainstream tool used to accurately and reliably determine body composition components and bone mass characteristics in-vivo. Presently, whole body scan models separate the body into axial and appendicular regions, however there is a need for localised appendicular segmentation models to further examine regions of interest within the upper and lower extremities. Similarly, inconsistencies pertaining to patient positioning exist in the literature which influence measurement precision and analysis outcomes highlighting a need for standardised procedure. This paper provides standardised and reproducible: 1 positioning and analysis procedures using DXA and 2 reliable segmental examinations through descriptive appendicular boundaries. Whole-body scans were performed on forty-six (n = 46 football athletes (age: 22.9 ± 4.3 yrs; height: 1.85 ± 0.07 cm; weight: 87.4 ± 10.3 kg; body fat: 11.4 ± 4.5 % using DXA. All segments across all scans were analysed three times by the main investigator on three separate days, and by three independent investigators a week following the original analysis. To examine intra-rater and inter-rater, between day and researcher reliability, coefficients of variation (CV and intraclass correlation coefficients (ICC were determined. Positioning and segmental analysis procedures presented in this study produced very high, nearly perfect intra-tester (CV ≤ 2.0%; ICC ≥ 0.988 and inter-tester (CV ≤ 2.4%; ICC ≥ 0.980 reliability, demonstrating excellent reproducibility within and between practitioners. Standardised examinations of axial and appendicular segments are necessary. Future studies aiming to quantify and report segmental analyses of the upper- and lower-body musculoskeletal properties using whole-body DXA scans are encouraged to use the patient positioning and image analysis procedures outlined in this paper.

  19. A Study of Equipment Accuracy and Test Precision in Dual Energy X-ray Absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Kyung Rae [Dept. of Radiological Technology, Gwangju Health College, Gwangju (Korea, Republic of); Kim, Ho Sung [Dept. of Nuclear Medicine, Asan Medical Center, Seoul (Korea, Republic of); Jung, Woon Kwan [Dept. of Nuclear Energy Technology, Chosun University, Gwangju (Korea, Republic of)

    2008-03-15

    Because there is a difference depending on the environment as for an inspection equipment the important part of bone density scan and the precision/accuracy of a tester, the management of quality must be made systematically. The equipment failure caused by overload effect due to the aged equipment and the increase of a patient was made frequently. Thus, the replacement of equipment and additional purchases of new bone density equipment caused a compatibility problem in tracking patients. This study wants to know whether the clinical changes of patient's bone density can be accurately and precisely reflected when used it compatibility like the existing equipment after equipment replacement and expansion. Two equipment of GE Lunar Prodigy Advance(P1 and P2) and the Phantom HOLOGIC Spine Road(HSP) were used to measure equipment precision. Each device scans 20 times so that precision data was acquired from the phantom(Group 1). The precision of a tester was measured by shooting twice the same patient, every 15 members from each of the target equipment in 120 women(average age 48.78, 20-60 years old)(Group 2). In addition, the measurement of the precision of a tester and the cross-calibration data were made by scanning 20 times in each of the equipment using HSP, based on the data obtained from the management of quality using phantom(ASP) every morning (Group 3). The same patient was shot only once in one equipment alternately to make the measurement of the precision of a tester and the cross-calibration data in 120 women(average age 48.78, 20-60 years old)(Group 4). It is steady equipment according to daily Q.C Data with 0.996 g/cm{sup 2}, change value(%CV) 0.08. The meanSD and a %CV price are ALP in Group 1(P1 : , , P2 : , %CV=0.192). The mean{+-}SD and a %CV price are P1 : 1.064{+-}0.002 g/cm{sup 2}, %CV=0.190 g/cm{sup 2}, P2 : 1.061{+-}0.003 g/cm{sup 3}, %CV=0.163 in Group 2. The average error{+-}2SD and %CV are P1 - (spine: 0.001{+-}0.013 g/cm{sup 2}, %CV=0.94, Femur: 0.001{+-}0.019 g/cm{sup 2}, %CV=0.96), P2 - (spine: 0.002{+-}0.018 g/cm{sup 2}, %CV=0.55, Femur: 0.001{+-}0.013 g/cm{sup 2}, %CV=0.48) in Group 3. The average error{+-}2SD, %CV, and r value was spine : 0.006{+-}0.024 g/cm{sup 2}, %CV=0.86, r=0.995, Femur: 0{+-}0.014 g/cm{sup 2}, %CV=0.54, r=0.998 in Group 4. Both LUNAR ASP CV% and HOLOGIC Spine Phantom are included in the normal range of error of {+-}2% defined in ISCD. BMD measurement keeps a relatively constant value, so showing excellent repeatability. The Phantom has homogeneous characteristics, but it has limitations to reflect the clinical part including variations in patient's body weight or body fat. As a result, it is believed that quality control using Phantom will be useful to check mis-calibration of the equipment used. A value measured a patient two times with one equipment, and that of double-crossed two equipment are all included within 2SD Value in the Bland - Altman Graph compared results of Group 3 with Group 4. The r value of 0.99 or higher in Linear regression analysis(Regression Analysis) indicated high precision and correlation. Therefore, it revealed that two compatible equipment did not affect in tracking the patients. Regular testing equipment and capabilities of a tester, then appropriate calibration will have to be achieved in order to calculate confidential BMD.

  20. Measurement of body composition in cats using computed tomography and dual energy X-ray absorptiometry

    DEFF Research Database (Denmark)

    Buelund, Lene E; Nielsen, Dorte H; McEvoy, Fintan

    2011-01-01

    compared CT and DEXA data from 73 healthy adult neutered domestic cats. Three approaches for measuring adipose tissue percentage from full-body CT scans were explored. By examining the frequency distribution of voxels by Hounsfield unit (HU) value, it is possible to calculate a fat index (Fat...

  1. Segmental Musculoskeletal Examinations using Dual-Energy X-Ray Absorptiometry (DXA): Positioning and Analysis Considerations.

    Science.gov (United States)

    Hart, Nicolas H; Nimphius, Sophia; Spiteri, Tania; Cochrane, Jodie L; Newton, Robert U

    2015-09-01

    Musculoskeletal examinations provide informative and valuable quantitative insight into muscle and bone health. DXA is one mainstream tool used to accurately and reliably determine body composition components and bone mass characteristics in-vivo. Presently, whole body scan models separate the body into axial and appendicular regions, however there is a need for localised appendicular segmentation models to further examine regions of interest within the upper and lower extremities. Similarly, inconsistencies pertaining to patient positioning exist in the literature which influence measurement precision and analysis outcomes highlighting a need for standardised procedure. This paper provides standardised and reproducible: 1) positioning and analysis procedures using DXA and 2) reliable segmental examinations through descriptive appendicular boundaries. Whole-body scans were performed on forty-six (n = 46) football athletes (age: 22.9 ± 4.3 yrs; height: 1.85 ± 0.07 cm; weight: 87.4 ± 10.3 kg; body fat: 11.4 ± 4.5 %) using DXA. All segments across all scans were analysed three times by the main investigator on three separate days, and by three independent investigators a week following the original analysis. To examine intra-rater and inter-rater, between day and researcher reliability, coefficients of variation (CV) and intraclass correlation coefficients (ICC) were determined. Positioning and segmental analysis procedures presented in this study produced very high, nearly perfect intra-tester (CV ≤ 2.0%; ICC ≥ 0.988) and inter-tester (CV ≤ 2.4%; ICC ≥ 0.980) reliability, demonstrating excellent reproducibility within and between practitioners. Standardised examinations of axial and appendicular segments are necessary. Future studies aiming to quantify and report segmental analyses of the upper- and lower-body musculoskeletal properties using whole-body DXA scans are encouraged to use the patient positioning and image analysis procedures outlined in this paper. Key pointsMusculoskeletal examinations using DXA technology require highly standardised and reproducible patient positioning and image analysis procedures to accurately measure and monitor axial, appendicular and segmental regions of interest.Internal rotation and fixation of the lower-limbs is strongly recommended during whole-body DXA scans to prevent undesired movement, improve frontal mass accessibility and enhance ankle joint visibility during scan performance and analysis.Appendicular segmental analyses using whole-body DXA scans are highly reliable for all regional upper-body and lower-body segmentations, with hard-tissue (CV ≤ 1.5%; R ≥ 0.990) achieving greater reliability and lower error than soft-tissue (CV ≤ 2.4%; R ≥ 0.980) masses when using our appendicular segmental boundaries.

  2. Validity of dual X-ray absorptiometry scanning for determination of body composition in IDDM patients

    DEFF Research Database (Denmark)

    Rosenfalck, A M; Almdal, T; Gotfredsen, A

    1995-01-01

    Data on body composition in patients with insulin-dependent diabetes mellitus (IDDM) are scarce. Dual X-ray absorptiometry (DXA) scanning has proved useful for this purpose in other groups of patients. We tested the validity of the DXA scanner for the determination of fat-free mass (FFM) and fat......, 5 males and 8 females, aged 34.2 years +/- SD 10.4, and 11 IDDM patients, 5 males, 6 females, aged 28.1 years +/- 7.3, diabetes duration 4.2 +/- 2.9 (1.0-9.9), were examined. The patients had no long-term diabetic complications and they had normal ophthalmoscopy and urine albumin excretion...

  3. Validity of dual X-ray absorptiometry scanning for determination of body composition in IDDM patients

    DEFF Research Database (Denmark)

    Rosenfalck, A M; Almdal, Thomas Peter; Gotfredsen, A

    1995-01-01

    Data on body composition in patients with insulin-dependent diabetes mellitus (IDDM) are scarce. Dual X-ray absorptiometry (DXA) scanning has proved useful for this purpose in other groups of patients. We tested the validity of the DXA scanner for the determination of fat-free mass (FFM) and fat....... The agreement between FFM estimated by DXA and the other methods, expressed as mean difference +/- 2 SD was; for DXA vs. TBK, 0.09 +/- 6.26 and 0.50 +/- 5.26 kg for controls and IDDM patients respectively; DXA vs. TBW, -2.07 +/- 2.56 and -1.07 +/- 4.58 kg; DXA vs. Ucrea, -2.62 +/- 8.02 and 2.00 +/- 10.0 kg; DXA...

  4. Measurement of bone mineral using multiple-energy x-ray absorptiometry

    International Nuclear Information System (INIS)

    Swanpalmer, Janos; Kullenberg, Ragnar; Hansson, Tommy

    1998-01-01

    Our laboratory has previously reported a method of determining the amount of bone mineral using triple-energy absorptiometry with a continuous x-ray spectrum. In the present study, the experimental properties of the technique were examined. The accuracy, the influence of fat content and body thickness and the in vitro and in vivo precision were analysed. The results found in this investigation showed that despite the complexity of the technique, the amount of bone mineral can be accurately determined. The in vivo precision was determined to be 3.4%, expressed as the coefficient of variation (CV), for different skeletal parts. The in vitro precision was found to be 2.1% (CV). Neither the fat content nor the body thickness had any effect on the measured bone mineral values. Excellent linearity and a close correlation were found between the true and the measured bone mineral values. (author)

  5. Mass thickness measurement of dual-sample by dual-energy X-rays

    International Nuclear Information System (INIS)

    Chen Mincong; Li Hongmei; Chen Ziyu; Shen Ji

    2008-01-01

    X-ray equivalent energy can be used to measure mass thicknesses of materials. Based on this, a method of mass thickness measurement of dual-sample was discussed. It was found that in the range of sample mass thickness under investigation, the equivalent mass attenuation coefficient of a component could be used to compute mass thicknesses of a dual-sample, with relative errors of less than 5%. Mass thickness measurement of a fish sample was performed, and the fish bone and flesh could be displayed separately and clearly by their own mass thicknesses. This indicates that the method is effective in mass thickness measurement of dual-sample of suitable thicknesses. (authors)

  6. Measurements of moisture content in wood fuels with dual energy x-ray; Maetning av fukt i biobraenslen med dubbelenergiroentgen

    Energy Technology Data Exchange (ETDEWEB)

    Nordell, Anders [Industriellt Utvecklingscentrum i Karlskoga, Karlskoga (Sweden); Vikterloef, K J [Oerebro Radiofysik AB, Oerebro (Sweden)

    2000-04-01

    Good methods enabling quick determination of moisture in wood fuels are lacking. A standardized method generally used by the biofuel industry means drying samples in furnaces during at least 16 hours. The idea of this work has been to investigate if x-ray technique can offer a superior alternative for fast moisture determination. Analysis with x-ray has many advantages. The x-rays go completely through the whole test specimen. Large samples or many sequential samples can rapidly be measured. The penetration is extraordinary good; all parts of the tested mass will be analyzed. The measurement relies on the absorption of gamma photons in the tested mass. The x-ray absorption is carried out deep down in the atoms and therefore is independent of the materials equation of state as temperature, grain size or molecule binding. The disadvantages of the method are the general anxiety which can be for gamma rays, the relative high cost for equipment and the fact that an x-ray tube will wear with time and needs replacement. The method used here for moisture measurement is known as dual energy x-ray. The test sample is simultaneously exposed to transmission of two separate x-ray energies. The two energies are absorbed differently by the sample. The ratio of the absorption in the two respective energies is calculated and from that conclusions on the composition of the material can be drawn. The equipment used in this test is a standard medical apparatus adapted for the study of human body composition. When instead used for measurements of moisture in wood material the discrimination signal is about half of that achieved in the normal medical case. Despite that, the signal has been good enough for giving satisfactory accuracy in the moisture estimation. A little more than sixty approved results are presented in the report comprehending ten different fuel types. The results are grouped into three main categories depending on fuel type, wood fuels, peat fuels and salix including

  7. Multiscale deformable registration for dual-energy x-ray imaging

    International Nuclear Information System (INIS)

    Gang, G. J.; Varon, C. A.; Kashani, H.; Richard, S.; Paul, N. S.; Van Metter, R.; Yorkston, J.; Siewerdsen, J. H.

    2009-01-01

    Dual-energy (DE) imaging of the chest improves the conspicuity of subtle lung nodules through the removal of overlying anatomical noise. Recent work has shown double-shot DE imaging (i.e., successive acquisition of low- and high-energy projections) to provide detective quantum efficiency, spectral separation (and therefore contrast), and radiation dose superior to single-shot DE imaging configurations (e.g., with a CR cassette). However, the temporal separation between high-energy (HE) and low-energy (LE) image acquisition can result in motion artifacts in the DE images, reducing image quality and diminishing diagnostic performance. This has motivated the development of a deformable registration technique that aligns the HE image onto the LE image before DE decomposition. The algorithm reported here operates in multiple passes at progressively smaller scales and increasing resolution. The first pass addresses large-scale motion by means of mutual information optimization, while successive passes (2-4) correct misregistration at finer scales by means of normalized cross correlation. Evaluation of registration performance in 129 patients imaged using an experimental DE imaging prototype demonstrated a statistically significant improvement in image alignment. Specific to the cardiac region, the registration algorithm was found to outperform a simple cardiac-gating system designed to trigger both HE and LE exposures during diastole. Modulation transfer function (MTF) analysis reveals additional advantages in DE image quality in terms of noise reduction and edge enhancement. This algorithm could offer an important tool in enhancing DE image quality and potentially improving diagnostic performance.

  8. Fourier Analysis of Single-Shot Dual-Energy X-ray Imaging Characteristics

    International Nuclear Information System (INIS)

    Kim, Jun Woo; Kim, Dong Woon; Kim, Ho Kyung

    2016-01-01

    The sandwich detector was realized by stacking two scintillator-based flat-panel detectors (FPDs) between which an intermediate copper (Cu) filter layer was placed to further enhance spectral energy separation. As a result, the proper selection of filter material and its thickness could be a trade-off between the extent of energy separation (hence, DE image quality) and image noise due to reduction in the number of x-ray quanta reaching the rear FPD. Although the conventional kVp-switching dual-shot method showed better image qualities than the single-shot method because of larger spectral energy separation, the motion-artifact-free DE image with reasonably good image quality was a potential prospect of the single-shot method. For the reliable and better use of the sandwich detector for specific imaging applications, the sandwich detector should be optimally designed with a proper selection of scintillator material and thickness in each detector layer (i.e. the front and rear detectors), and aforementioned intermediate filter material and thickness. It is noted that glue is used to adhere the fragile photodiode array onto the ceramic substrate and these glue patterns are apparent in the rear and DE images. The glue pattern in the rear image comes from the front FPD. Unlike the conventional ESF as shown in Fig. 3(a), the ESF obtained from the subtracted image showed an enhancement as shown in Fig. 3(b). Consequently, the MTF obtained from the subtraction ESF showed a bandpass filter characteristic, as shown in Fig. 3(c), unlike the conventional low-pass filter characteristic (i.e., monotonic decrease of MTF value with increasing the spatial frequency). This MTF characteristic is due to the subtraction of two images with different spatial resolving powers (i.e., different thicknesses of phosphors between the front and rear detectors) as can be seen in unsharp masking digital image processing, which subtracts Gaussian-blurred image from the original image

  9. Fourier Analysis of Single-Shot Dual-Energy X-ray Imaging Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jun Woo; Kim, Dong Woon; Kim, Ho Kyung [Pusan National University, Busan (Korea, Republic of)

    2016-05-15

    The sandwich detector was realized by stacking two scintillator-based flat-panel detectors (FPDs) between which an intermediate copper (Cu) filter layer was placed to further enhance spectral energy separation. As a result, the proper selection of filter material and its thickness could be a trade-off between the extent of energy separation (hence, DE image quality) and image noise due to reduction in the number of x-ray quanta reaching the rear FPD. Although the conventional kVp-switching dual-shot method showed better image qualities than the single-shot method because of larger spectral energy separation, the motion-artifact-free DE image with reasonably good image quality was a potential prospect of the single-shot method. For the reliable and better use of the sandwich detector for specific imaging applications, the sandwich detector should be optimally designed with a proper selection of scintillator material and thickness in each detector layer (i.e. the front and rear detectors), and aforementioned intermediate filter material and thickness. It is noted that glue is used to adhere the fragile photodiode array onto the ceramic substrate and these glue patterns are apparent in the rear and DE images. The glue pattern in the rear image comes from the front FPD. Unlike the conventional ESF as shown in Fig. 3(a), the ESF obtained from the subtracted image showed an enhancement as shown in Fig. 3(b). Consequently, the MTF obtained from the subtraction ESF showed a bandpass filter characteristic, as shown in Fig. 3(c), unlike the conventional low-pass filter characteristic (i.e., monotonic decrease of MTF value with increasing the spatial frequency). This MTF characteristic is due to the subtraction of two images with different spatial resolving powers (i.e., different thicknesses of phosphors between the front and rear detectors) as can be seen in unsharp masking digital image processing, which subtracts Gaussian-blurred image from the original image.

  10. Quantitative morphologic assessment of thoracolumbar vertebrae in Korean women by morphometric x-ray absorptiometry

    International Nuclear Information System (INIS)

    Cheon, Bong Jin; Huh, Jin Do; Kim, Sung Min; Oh, Kyong Seung; Kim, Jong Min; Jung, Gyoo Sik; Joh, Young Duk

    1999-01-01

    To compare the accuracy of lateral radiography of the spine with that of morphometric X-ray absorptiometry(MXA) in vertebral morphometry, and to evaluate normal vertebral morphometry using MXA in Korean women. A spine phantom was constructed using copper pipe. Its anterior and posterior heights were measured directly, with lateral radiographs and with MXA, and the values thus obtained were compared. Inter- and intra-observer variations were evaluated by three radiologists. The vertebral morphometry of 30 young women volunteers were imaged using thoracic and lumbar lateral radiographs and MXA, and analysis included the measurement of anterior and posterior heights from T4 to L4. We also obtained the vertebral morphometry of 200 normal Korean women who underwent MXA between March 1995 and February 1996, though those with osteoporosis and other spinal lesions were excluded from this study. Thoracolumbar vertebral indexes were statistically correlated with age, height and bone mineral density. There were no statistically significant differences in the heights of spine phantom measured by MXA compared with actual size (mean difference=0.28mm). Simple radiographs were magnified by 23.7% at a phantom-table distance of 15cm, and distortion ranged from 0.5% to 22.5%, depending on phantom level and phantom-table distance. In the study of volunteers, the magnification rate between a simple radiograph and MXA was about 26.6%. Anterior height increased progressively from the thoracic to the lumbar spine, though posterior height peaked at L2, and L4 was less than anterior height. In Korean women, indices of vertebral morphometry decreased significantly with aging, with the most prominent decrease occurring during the seventh decade. The mineral density of spinal bone decreased markedly after the sixth decade. Radiographs showed more magnification and distortion than did MXA, though between morphometric X-ray absorptiometry (MXA) and actual size, there was no significant

  11. Validity of dual X-ray absorptiometry scanning for determination of body composition in IDDM patients

    DEFF Research Database (Denmark)

    Rosenfalck, A M; Almdal, Thomas Peter; Gotfredsen, A

    1995-01-01

    Data on body composition in patients with insulin-dependent diabetes mellitus (IDDM) are scarce. Dual X-ray absorptiometry (DXA) scanning has proved useful for this purpose in other groups of patients. We tested the validity of the DXA scanner for the determination of fat-free mass (FFM) and fat...... mass in IDDM patients and control subjects, as compared to other reference methods, i.e. total body potassium by 40K whole body counting (TBK), total body water by tritiated water (TBW), bioelectrical impedance analysis (BIA) and 24-h urinary creatinine excretion (Ucrea). A total of 13 healthy controls....... The agreement between FFM estimated by DXA and the other methods, expressed as mean difference +/- 2 SD was; for DXA vs. TBK, 0.09 +/- 6.26 and 0.50 +/- 5.26 kg for controls and IDDM patients respectively; DXA vs. TBW, -2.07 +/- 2.56 and -1.07 +/- 4.58 kg; DXA vs. Ucrea, -2.62 +/- 8.02 and 2.00 +/- 10.0 kg; DXA...

  12. Photon absorptiometry

    International Nuclear Information System (INIS)

    Valkema, R.; Blokland, J.A.K.; Papapoulos, S.E.; Bijvoet, O.L.M.; Pauwels, E.K.J.

    1989-01-01

    Osteoporosis is a significant health problem in the western world, with important medical, social and economical consequences. Prevention and treatment require reliable methods for in vivo monitoring of the bone mineral content (BMC) and its change in time. This paper presents an overview of currently used radiological methods, based on photon absorptiometry, and their clinical applications. With recent methods based on dual energy X-ray absorptiometry accurate and precise measurements of axial BMC can be obtained. Whether this improvements allows reliable detection of small changes in BMC remains to be investigated. (Author). 95 refs.; 1 tab

  13. The use of dual X-ray absorptiometry for the determination of skeletal calcium accretion

    International Nuclear Information System (INIS)

    Ilich, J.Z.; Skugor, M.; Matkovic, V.

    1994-01-01

    The neutron activation analysis is considered the 'gold standard' method for the measurement of total body calcium (TBCa). The disadvantage of this method is that there are only a few centers that can perform the measurements with good precision, accuracy and relatively low radiation exposure. The measurement of TBCa gives the information about Ca skeletal accretion which is important for the determination of Ca requirements. The purpose of our study was to measure TBCa in adolescent females during different time periods. The TBCa was measured by the use of dual X-ray absorptiometry (DXA), on Lunar DPX-L densitometer (LUNAR Corp., Madison WI). The in-vivo precision of the instrument for TBCa measurements was 0.93%. The study population included 364 healthy, Caucasian females. An average age at baseline was 10.8±0.8 years (mean±SD) and 11.9±0.8 years after 1 year. The subjects underwent pubertal stage (PS) changes of PS 2 to PS 3 in their sexual development. The TBCa was 506±91 g (mean±SD) at baseline and 614±122 g after 1 year, with 21.3% change. Assuming that Ca comprises ∼ 38%% of bone mineral, there was ∼ 108 g of Ca accumulated in 1 year or ∼ 296 mg Ca/day. In addition, we compared Ca accretion measured by DXA (over the 6 months period) and 2 weeks Ca balance study on a subsample of 26 girls. The accumulation of Ca by DXA method was 52g/6 months and the one estimated from balance study was 50g. We conclude that DXA is a suitable noninvasive method for the measurement of TBCa accretion during rapid growth and for clinical intervention trials in adults. (author)

  14. Manipulation of Muscle Creatine and Glycogen Changes Dual X-ray Absorptiometry Estimates of Body Composition.

    Science.gov (United States)

    Bone, Julia L; Ross, Megan L; Tomcik, Kristyen A; Jeacocke, Nikki A; Hopkins, Will G; Burke, Louise M

    2017-05-01

    Standardizing a dual x-ray absorptiometry (DXA) protocol is thought to provide a reliable measurement of body composition. We investigated the effects of manipulating muscle glycogen and creatine content independently and additively on DXA estimates of lean mass. Eighteen well-trained male cyclists undertook a parallel group application of creatine loading (n = 9) (20 g·d for 5 d loading; 3 g·d maintenance) or placebo (n = 9) with crossover application of glycogen loading (12 v 6 g·kg BM per day for 48 h) as part of a larger study involving a glycogen-depleting exercise protocol. Body composition, total body water, muscle glycogen and creatine content were assessed via DXA, bioelectrical impedance spectroscopy and standard biopsy techniques. Changes in the mean were assessed using the following effect-size scale: >0.2 small, >0.6, moderate, >1.2 large and compared with the threshold for the smallest worthwhile effect of the treatment. Glycogen loading, both with and without creatine loading, resulted in substantial increases in estimates of lean body mass (mean ± SD; 3.0% ± 0.7% and 2.0% ± 0.9%) and leg lean mass (3.1% ± 1.8% and 2.6% ± 1.0%) respectively. A substantial decrease in leg lean mass was observed after the glycogen depleting condition (-1.4% ± 1.6%). Total body water showed substantial increases after glycogen loading (2.3% ± 2.3%), creatine loading (1.4% ± 1.9%) and the combined treatment (2.3% ± 1.1%). Changes in muscle metabolites and water content alter DXA estimates of lean mass during periods in which minimal change in muscle protein mass is likely. This information needs to be considered in interpreting the results of DXA-derived estimates of body composition in athletes.

  15. Measurements of bone mineral density of the proximal femur by two commercially available dual energy X-ray absorptiometric systems

    International Nuclear Information System (INIS)

    Svendsen, O.L.; Marslew, U.; Hassager, C.; Christiansen, C.

    1992-01-01

    Two dual energy X-ray absorptiometric (DXA) instruments have recently become commercially available for local bone densitometry: the QDR-1000 (Hologic Inc.) and the DPX (Lunar Radiation Corp.). We report the precision, influence of femoral, rotation, correlation and agreement of bone mineral measurements of the proximal fermur by these two instruments. In vitro (femur phantom) short-term precision was 1.1%-3.5%, and the long-term precision was 1.2%-3.8%. In vivo (groups of 10 premenopausal and 10 postmenopausal women) short-term precision of duplicate measurements was 1.6%-4.7%, and long-term precision was 1.9%-5.5%. Overall, the precision for Ward's triangle was over 3% and that for the femoral neck and trochanter, 2%-3%. Rotation of the femur phantom produced a statistically significant change in the bone mineral density (BMD) of the femoral neck. Within a clinically relevant range of femoral rotation (20deg inward rotation ±5deg) the coefficient of variation (CV%) increased by a mean factor of 1.1-1.4. Although the correlation (r<0.9) between BMD measurements of the proximal femur by the DPX and QDR-1000 in 30 postmenopausal women was high, there was lack of agreement between the two instruments. We found no statistically significant differences between the right and left femur in 30 postmenopausal women. A bilateral femur scan took a mean total time of about 22 min. We conclude that with the introduction of DXA instruments, the precision of bone mineral measurments of the proximal femur has improved. However, for comparability between commercially available DXA instruments, it might be advantageous if units were standardized. (orig.)

  16. An experimental implementation of the 90 .deg. compton scattering inspection method for identifying explosive materials using dual energy x-ray

    International Nuclear Information System (INIS)

    Park, Ji Sung

    2012-02-01

    In order to obtain the physical properties of an inspection object using an X-ray source, the energy-resolving X-ray method, reflecting the characteristic of continuous energy, is a very useful tool. In this study, the effective atomic number (Z eff ) and normal density (ρ) obtained by the source weighting method on a dual energy X-ray inspection system are presented and demonstrated by experimental implementation. Two X-ray beams of the suggested method were designed using the XCOMP5r code. The filter design of a high energy X-ray source was fixed as 3.5 mm Sn at 150 kVp tube voltage, and the new high energy X-ray beam was named as IN150. The filter design of a low energy X-ray source was also fixed as 0.5 mm Sn at 90 kVp tube voltage, and the new beam was named as IN90. Benchmark calculations by MCNP simulation experiments were performed using four different materials, i.e., Polyethylene, Acetal, Urethane, and TNT. The results of the benchmark calculation showed that the new method can estimate the effective atomic number and the normal density of a scattered object accurately, even when the object was arbitrarily located in samples. Finally to verify the proposed new method, scattering experiments using various polymerized compounds were carried out. The effective attenuation coefficients (μ 1 , μ 2 ) of the experiment objects at the source energies E 1 and E 2 , were calculated using scattered spectra. The effective atomic number and the normal density were then calculated by using the ratio of μ 1 to μ 2 . As a result in case of all sample geometries, the relative differences between the calculation value and the reference value for the effective atomic numbers of each material were within 14 %, and the relative differences for the normal densities were within 12 %. This observation led us to the conclusion that the new 90 .deg. Compton scattering method for identifying explosive materials using a dual-energy X-ray is valid for calculating effective

  17. Errors due to non-uniform distribution of fat in dual X-ray absorptiometry of the lumbar spine

    International Nuclear Information System (INIS)

    Tothill, P.; Pye, D.W.

    1992-01-01

    Errors in spinal dual X-ray absorptiometry (DXA) were studied by analysing X-ray CT scans taken for diagnostic purposes on 20 patients representing a wide range of fat content. The mean difference between the fat thickness over the vertebral bodies and that over a background area in antero-posterior (AP) scanning was 6.7 ± 8.1 mm for men and 13.4 ± 4.7 mm for women. For AP scanning a non-uniform fat distribution leads to a mean overestimate of 0.029 g/cm 2 for men and 0.057 g/cm 2 for women. The error exceeded 0.1 g/cm 2 in 10% of slices. For lateral scanning the error exceeded 0.1 g/cm 2 (about 15% of normal) in a quarter of slices. (author)

  18. Bone loss in unclassified polyarthritis and early rheumatoid arthritis is better detected by digital x ray radiogrammetry than dual x ray absorptiometry: relationship with disease activity and radiographic outcome

    DEFF Research Database (Denmark)

    Jensen, T; Klarlund, Mette; Hansen, M

    2004-01-01

    OBJECTIVE: To compare changes in regional bone mineral density (BMD) of the metacarpal joints measured by dual x ray absorptiometry (DXA) and digital x ray radiogrammetry (DXR) in relation to disease activity and radiographic outcome in a two year follow up study of patients with early RA...... polyarthritis. The patients with RA were divided into groups according to mean disease activity, average glucocorticoid dose, and MRI and x ray detected bone erosions in the hands. Clinical and biochemical measurements were made every month and an x ray examination of the hands and BMD of the metacarpal joints...

  19. Using dual-energy x-ray imaging to enhance automated lung tumor tracking during real-time adaptive radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Menten, Martin J., E-mail: martin.menten@icr.ac.uk; Fast, Martin F.; Nill, Simeon; Oelfke, Uwe, E-mail: uwe.oelfke@icr.ac.uk [Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London SM2 5NG (United Kingdom)

    2015-12-15

    Purpose: Real-time, markerless localization of lung tumors with kV imaging is often inhibited by ribs obscuring the tumor and poor soft-tissue contrast. This study investigates the use of dual-energy imaging, which can generate radiographs with reduced bone visibility, to enhance automated lung tumor tracking for real-time adaptive radiotherapy. Methods: kV images of an anthropomorphic breathing chest phantom were experimentally acquired and radiographs of actual lung cancer patients were Monte-Carlo-simulated at three imaging settings: low-energy (70 kVp, 1.5 mAs), high-energy (140 kVp, 2.5 mAs, 1 mm additional tin filtration), and clinical (120 kVp, 0.25 mAs). Regular dual-energy images were calculated by weighted logarithmic subtraction of high- and low-energy images and filter-free dual-energy images were generated from clinical and low-energy radiographs. The weighting factor to calculate the dual-energy images was determined by means of a novel objective score. The usefulness of dual-energy imaging for real-time tracking with an automated template matching algorithm was investigated. Results: Regular dual-energy imaging was able to increase tracking accuracy in left–right images of the anthropomorphic phantom as well as in 7 out of 24 investigated patient cases. Tracking accuracy remained comparable in three cases and decreased in five cases. Filter-free dual-energy imaging was only able to increase accuracy in 2 out of 24 cases. In four cases no change in accuracy was observed and tracking accuracy worsened in nine cases. In 9 out of 24 cases, it was not possible to define a tracking template due to poor soft-tissue contrast regardless of input images. The mean localization errors using clinical, regular dual-energy, and filter-free dual-energy radiographs were 3.85, 3.32, and 5.24 mm, respectively. Tracking success was dependent on tumor position, tumor size, imaging beam angle, and patient size. Conclusions: This study has highlighted the influence of

  20. Using dual-energy x-ray imaging to enhance automated lung tumor tracking during real-time adaptive radiotherapy

    International Nuclear Information System (INIS)

    Menten, Martin J.; Fast, Martin F.; Nill, Simeon; Oelfke, Uwe

    2015-01-01

    Purpose: Real-time, markerless localization of lung tumors with kV imaging is often inhibited by ribs obscuring the tumor and poor soft-tissue contrast. This study investigates the use of dual-energy imaging, which can generate radiographs with reduced bone visibility, to enhance automated lung tumor tracking for real-time adaptive radiotherapy. Methods: kV images of an anthropomorphic breathing chest phantom were experimentally acquired and radiographs of actual lung cancer patients were Monte-Carlo-simulated at three imaging settings: low-energy (70 kVp, 1.5 mAs), high-energy (140 kVp, 2.5 mAs, 1 mm additional tin filtration), and clinical (120 kVp, 0.25 mAs). Regular dual-energy images were calculated by weighted logarithmic subtraction of high- and low-energy images and filter-free dual-energy images were generated from clinical and low-energy radiographs. The weighting factor to calculate the dual-energy images was determined by means of a novel objective score. The usefulness of dual-energy imaging for real-time tracking with an automated template matching algorithm was investigated. Results: Regular dual-energy imaging was able to increase tracking accuracy in left–right images of the anthropomorphic phantom as well as in 7 out of 24 investigated patient cases. Tracking accuracy remained comparable in three cases and decreased in five cases. Filter-free dual-energy imaging was only able to increase accuracy in 2 out of 24 cases. In four cases no change in accuracy was observed and tracking accuracy worsened in nine cases. In 9 out of 24 cases, it was not possible to define a tracking template due to poor soft-tissue contrast regardless of input images. The mean localization errors using clinical, regular dual-energy, and filter-free dual-energy radiographs were 3.85, 3.32, and 5.24 mm, respectively. Tracking success was dependent on tumor position, tumor size, imaging beam angle, and patient size. Conclusions: This study has highlighted the influence of

  1. Using dual-energy x-ray imaging to enhance automated lung tumor tracking during real-time adaptive radiotherapy.

    Science.gov (United States)

    Menten, Martin J; Fast, Martin F; Nill, Simeon; Oelfke, Uwe

    2015-12-01

    Real-time, markerless localization of lung tumors with kV imaging is often inhibited by ribs obscuring the tumor and poor soft-tissue contrast. This study investigates the use of dual-energy imaging, which can generate radiographs with reduced bone visibility, to enhance automated lung tumor tracking for real-time adaptive radiotherapy. kV images of an anthropomorphic breathing chest phantom were experimentally acquired and radiographs of actual lung cancer patients were Monte-Carlo-simulated at three imaging settings: low-energy (70 kVp, 1.5 mAs), high-energy (140 kVp, 2.5 mAs, 1 mm additional tin filtration), and clinical (120 kVp, 0.25 mAs). Regular dual-energy images were calculated by weighted logarithmic subtraction of high- and low-energy images and filter-free dual-energy images were generated from clinical and low-energy radiographs. The weighting factor to calculate the dual-energy images was determined by means of a novel objective score. The usefulness of dual-energy imaging for real-time tracking with an automated template matching algorithm was investigated. Regular dual-energy imaging was able to increase tracking accuracy in left-right images of the anthropomorphic phantom as well as in 7 out of 24 investigated patient cases. Tracking accuracy remained comparable in three cases and decreased in five cases. Filter-free dual-energy imaging was only able to increase accuracy in 2 out of 24 cases. In four cases no change in accuracy was observed and tracking accuracy worsened in nine cases. In 9 out of 24 cases, it was not possible to define a tracking template due to poor soft-tissue contrast regardless of input images. The mean localization errors using clinical, regular dual-energy, and filter-free dual-energy radiographs were 3.85, 3.32, and 5.24 mm, respectively. Tracking success was dependent on tumor position, tumor size, imaging beam angle, and patient size. This study has highlighted the influence of patient anatomy on the success rate of real

  2. A digital x-ray imaging MWPC detector system for precision absorptiometry

    International Nuclear Information System (INIS)

    Batemen, J.E.; Connolly, J.F.; Glasgow, W.

    1977-11-01

    An X-ray absorptiometric imaging system (based on a xenon-filled multiwire proportional counter) has been developed with high counting rate capability, good spatial resolution and linear mass response, aimed at permitting bone mass measurements to be made in the peripheral skeleton with precision approaching 1%. The system is described and preliminary results on test phantoms are presented. (author)

  3. Dual-energy X-ray micro-CT imaging of hybrid Ni/Al open-cell foam

    Czech Academy of Sciences Publication Activity Database

    Fíla, T.; Kumpová, Ivana; Koudelka_ml., P.; Zlámal, P.; Vavřík, Daniel; Jiroušek, O.; Jung, A.

    2016-01-01

    Roč. 11, č. 1 (2016), C01005 ISSN 1748-0221. [International Workshop on Radiation Imaging Detectors (IWORID2015) /17./. Hamburg, 28.06.2015-02.07.2015] Institutional support: RVO:68378297 Keywords : computerized tomography (CT) * computed radiography (CR) * X-ray radiography and digital radiography (DR) * inspection with x-rays Subject RIV: JJ - Other Materials Impact factor: 1.220, year: 2016 http://iopscience.iop.org/article/10.1088/1748-0221/11/01/C01005/pdf

  4. Pre-reconstruction dual-energy, X-ray computerized tomography (CT): theory, implementation, results, and clinical use

    International Nuclear Information System (INIS)

    Oravez, W.T.

    1986-01-01

    For the task of bone mineral measurement, single-energy quantitative CT has demonstrated its worth in terms of precision for most longitudinal clinical studies. However, for cross-sectional clinical studies, known inaccuracy exists due to less than robust beam-hardening corrections, and negatively biased bone mineral measurement, due to the effect of unknown variable concentration of bone marrow fat within the metabolically active trabecular bone space. A dual-energy measurement technique provides a solution to these deficiencies of single-energy measurements. The fundamental theory of dual-energy measurement techniques is based on a Compton-photoelectric approximation and the mixture rule for the total attenuation coefficient. Resolution of atomic composition and electron density components of attenuation should then be possible. To take full advantage of these principles, the raw dual-energy projection values are operated on before reconstruction. This method beam-hardening and composition-selective imaging. Rapid kilovoltage switching between projection measurements, rather than serial measurements, assures the best measurement quality

  5. Usefulness of calcaneal quantitative ultrasound stiffness for the evaluation of bone health in HIV-1-infected subjects: comparison with dual X-ray absorptiometry.

    Science.gov (United States)

    Fantauzzi, Alessandra; Floridia, Marco; Ceci, Fabrizio; Cacciatore, Francesco; Vullo, Vincenzo; Mezzaroma, Ivano

    2016-01-01

    With the development of effective treatments and the resulting increase in life expectancy, bone mineral density (BMD) alteration has emerged as an important comorbidity in human immunodeficiency virus type-1 (HIV-1)-infected individuals. The potential contributors to the pathogenesis of osteopenia/osteoporosis include a higher prevalence of risk factors, combined antiretroviral therapy (cART)-exposure, HIV-1 itself and chronic immune activation/inflammation. Dual-energy X-ray absorptiometry (DXA) is the "gold standard" technique for assessing bone status in HIV-1 population. We conducted a cross-sectional study to investigate bone mineral status in a group of 158 HIV-1-infected subjects. The primary endpoint was the feasibility of calcaneal quantitative ultrasound (QUS) as a screening tool for BMD. All subjects were receiving stable cART and were virologically suppressed (HIV-RNA HIV-1-specific characteristics, also including cART strategies. In the univariate analyses BMD, QUS indexes, and Fracture Risk Assessment Tool scores conversely showed significant associations with one or more demographic or HIV-1-related variables. Moreover, a significant relationship between calcaneal quantitative ultrasound index/stiffness and femoral/lumbar BMD values from DXA was described. The multivariate analysis showed an independent association between calcaneal quantitative ultrasound index/stiffness and body mass index, higher CD4+ T-cell numbers and low 25-OH D2/D3 vitamin D levels HIV-1-infected patients for assessing bone health impairment. In fact, the results obtained confirm that calcaneal QUS may be useful for monitoring bone status, being a noninvasive and inexpensive technique, especially in those subjects with the classical traditional risk factors for bone damage that were observed earlier in HIV-1 population.

  6. Role of clinical indications of bone mass measurement with bi-photonic X-ray absorptiometry. Interet et indications cliniques des mesures de masse osseuse par absorptiometrie biphotonique a rayons X

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    Bone densitometry by precise, reliable and non-traumatic methods such as X-ray bi-phonon absorptiometry, is the only way to predict osteoporosis fractures risks. The whole epidemiological studies establish that bone mass loss and osteoporosis risk are directly linked. The measurement of the bone mass is the basis of osteoporosis prevention for elderly women, and of other clinical situations. This paper gives, by a critical analysis of available data, advantages and limits of bone mass measurements by X-ray bi-phonon absorptiometry, and essential clinical indications. (A.B.). 181 refs.

  7. Simultaneous Reduction in Noise and Cross-Contamination Artifacts for Dual-Energy X-Ray CT

    Directory of Open Access Journals (Sweden)

    Baojun Li

    2013-01-01

    Full Text Available Purpose. Dual-energy CT imaging tends to suffer from much lower signal-to-noise ratio than single-energy CT. In this paper, we propose an improved anticorrelated noise reduction (ACNR method without causing cross-contamination artifacts. Methods. The proposed algorithm diffuses both basis material density images (e.g., water and iodine at the same time using a novel correlated diffusion algorithm. The algorithm has been compared to the original ACNR algorithm in a contrast-enhanced, IRB-approved patient study. Material density accuracy and noise reduction are quantitatively evaluated by the percent density error and the percent noise reduction. Results. Both algorithms have significantly reduced the noises of basis material density images in all cases. The average percent noise reduction is 69.3% and 66.5% with the ACNR algorithm and the proposed algorithm, respectively. However, the ACNR algorithm alters the original material density by an average of 13% (or 2.18 mg/cc with a maximum of 58.7% (or 8.97 mg/cc in this study. This is evident in the water density images as massive cross-contaminations are seen in all five clinical cases. On the contrary, the proposed algorithm only changes the mean density by 2.4% (or 0.69 mg/cc with a maximum of 7.6% (or 1.31 mg/cc. The cross-contamination artifacts are significantly minimized or absent with the proposed algorithm. Conclusion. The proposed algorithm can significantly reduce image noise present in basis material density images from dual-energy CT imaging, with minimized cross-contaminations compared to the ACNR algorithm.

  8. Dual energy X-ray absorptiometry analysis of peri-prosthetic stress shielding in the Birmingham resurfacing hip replacement.

    LENUS (Irish Health Repository)

    Harty, J A

    2012-02-03

    INTRODUCTION: Numerous reports in the literature refer to the femoral neck fracture rate in hip resurfacing. The aim of this study was to determine the bone mineral density and evidence of stress shielding around the femoral component of the Birmingham resurfacing prosthesis. MATERIAL AND METHODS: Twenty-eight patients with primary unilateral osteoarthritis had a Birmingham resurfacing prosthesis. DEXA analysis of the proximal femur and femoral neck was performed and compared with the opposite unaffected side. RESULTS: Total periprosthetic bone mineral density was 0.49% greater than the control, but this did not achieve statistical significance. Although the BMD of the femoral neck was slightly increased on the prosthetic side (1.002 g\\/cm2) as opposed to the control side, this difference did not reach statistical significance. CONCLUSION: The Birmingham resurfacing prosthesis does not appear to reduce femoral neck bone mineral density in comparison to the normal femoral neck bone density. We conclude that femoral neck fractures are unlikely to be due to stress shielding related to the prosthesis.

  9. New dual-energy X-ray absorptiometry equipment in the assessment of vertebral fractures: technical limits and software accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Bazzocchi, Alberto; Diano, Danila; Battista, Giuseppe [University of Bologna, Sant' Orsola - Malpighi Hospital, Imaging Division, Clinical Department of Radiological and Histocytopathological Sciences, Bologna (Italy); Albisinni, Ugo [Rizzoli Orthopaedic Institute, Department of Radiology, Bologna (Italy); Rossi, Cristina [University of Parma, Section of Radiological Sciences, Department of Clinic Sciences, Parma (Italy); Guglielmi, Giuseppe [University of Foggia, Department of Radiology, Foggia (Italy); Department of Radiology, Scientific Institute Hospital ' ' Casa Sollievo della Sofferenza' ' , San Giovanni Rotondo (Italy)

    2012-07-15

    The aim of this study was to investigate software accuracy and influence of body mass index on image quality of Lunar iDXA (Lunar, Madison, WI, USA; software enCORE 12.0) in vertebral fracture (VFs) assessment. We enrolled 65 normal or overweight patients (group 1) and 64 obese patients (group 2) with indication for morphometric evaluation of the spine. Patients underwent iDXA, with scans performed in the standard manner by an expert technologist. Lateral images of the spine were subsequently evaluated by a musculoskeletal radiologist as the gold standard. Our analysis considered five points: vertebral bodies missed or not assessable or wrongly labeled on T4-L4 segment, diagnostic performance of the automatic morphometric point-positioning system in the detection of VFs, upgrading and downgrading of fractures, radiologist intervention rate, and BMI influence. In group 1, 57/845 (6.7%) vertebral bodies and 34/832 (4.1%) in group 2 were not assessable - the upper thoracic spine. enCORE failed to recognize vertebral levels in 5.4% of the patients (7.7% in group 1 vs. 3.1% in group 2). On a lesion-based analysis sensitivity, specificity and accuracy of the software were 81.4, 93.8, and 93.1% in group 1 and 69.1, 88.3, and 86.7% in group 2, respectively. For 52.7% of the vertebrae in group 1 (51/8 upgraded/downgraded) and 70.0% in group 2 (96/26 upgraded/downgraded), a point correction was necessary and this changed the diagnosis respectively in 29.2 and 50.0% of the patients. Differences in diagnostic performance and point correction rate were significantly different between the two groups; however, BMI did not significantly affect vertebral level labeling and was correlated with a better visualization of the whole T4-L4 spine segment. This study provides new and interesting information about the accuracy, reliability, and imaging quality provided by iDXA in the assessment of VFs. (orig.)

  10. Bone mineral density of the spine using dual energy X-ray absorptiometry for atomic bomb survivors in Nagasaki. 2

    International Nuclear Information System (INIS)

    Tagawa, Masuko; Kohno, Tsuneaki; Morikawa, Akira; Mine, Mariko; Honda, Sumihisa.

    1996-01-01

    Bone mineral density, a risk factor for osteoporosis, of the spine of 3,414 survivors was measured using Hologic QDR2000 DEXA apparatus. Decrease of the density was shown correlated with age and was statistically significant in forties and fifties as compared with other ages. No significance was seen between the density and the distance of irradiation. Menopause, fracture, experience for osteoporosis examination and that for its treatment were significantly correlated with the density decrease. No significance was observed in meals, exercise and sunlight exposure. High significance (p<0.01) was detected in coffee and alcohol intakes. In groups having twice examinations, no significance was seen between changes in the density and in the meals, exercise and go-out period. (H.O.)

  11. Repeatability of Volume and Regional Body Composition Measurements of the Lower Limb Using Dual-energy X-ray Absorptiometry

    DEFF Research Database (Denmark)

    Gjorup, Caroline A; Zerahn, Bo; Juul, Sarah

    2017-01-01

    was calculated using the density of bone mineral content, fat, and lean mass. The repeatability of the volume of the lower limb and regional thigh and lower leg tissue composition (bone mineral content, fat, and lean mass) was good with intraclass correlation coefficient values of 0.97 to 0.99, and narrow limits...

  12. Bone mineral density of the spine using dual energy X-ray absorptiometry for atomic bomb survivors in Nagasaki. 2

    Energy Technology Data Exchange (ETDEWEB)

    Tagawa, Masuko; Kohno, Tsuneaki; Morikawa, Akira [Nagasaki Atomic Bomb Casualty Council (Japan); Mine, Mariko; Honda, Sumihisa

    1996-03-01

    Bone mineral density, a risk factor for osteoporosis, of the spine of 3,414 survivors was measured using Hologic QDR2000 DEXA apparatus. Decrease of the density was shown correlated with age and was statistically significant in forties and fifties as compared with other ages. No significance was seen between the density and the distance of irradiation. Menopause, fracture, experience for osteoporosis examination and that for its treatment were significantly correlated with the density decrease. No significance was observed in meals, exercise and sunlight exposure. High significance (p<0.01) was detected in coffee and alcohol intakes. In groups having twice examinations, no significance was seen between changes in the density and in the meals, exercise and go-out period. (H.O.)

  13. Single x-ray absorptiometry method for the quantitative mammographic measure of fibroglandular tissue volume

    International Nuclear Information System (INIS)

    Malkov, Serghei; Wang, Jeff; Kerlikowske, Karla; Cummings, Steven R.; Shepherd, John A.

    2009-01-01

    Purpose: This study describes the design and characteristics of a highly accurate, precise, and automated single-energy method to quantify percent fibroglandular tissue volume (%FGV) and fibroglandular tissue volume (FGV) using digital screening mammography. Methods: The method uses a breast tissue-equivalent phantom in the unused portion of the mammogram as a reference to estimate breast composition. The phantom is used to calculate breast thickness and composition for each image regardless of x-ray technique or the presence of paddle tilt. The phantom adheres to the top of the mammographic compression paddle and stays in place for both craniocaudal and mediolateral oblique screening views. We describe the automated method to identify the phantom and paddle orientation with a three-dimensional reconstruction least-squares technique. A series of test phantoms, with a breast thickness range of 0.5-8 cm and a %FGV of 0%-100%, were made to test the accuracy and precision of the technique. Results: Using test phantoms, the estimated repeatability standard deviation equaled 2%, with a ±2% accuracy for the entire thickness and density ranges. Without correction, paddle tilt was found to create large errors in the measured density values of up to 7%/mm difference from actual breast thickness. This new density measurement is stable over time, with no significant drifts in calibration noted during a four-month period. Comparisons of %FGV to mammographic percent density and left to right breast %FGV were highly correlated (r=0.83 and 0.94, respectively). Conclusions: An automated method for quantifying fibroglandular tissue volume has been developed. It exhibited good accuracy and precision for a broad range of breast thicknesses, paddle tilt angles, and %FGV values. Clinical testing showed high correlation to mammographic density and between left and right breasts.

  14. Comparison of model and human observer performance for detection and discrimination tasks using dual-energy x-ray images

    International Nuclear Information System (INIS)

    Richard, Samuel; Siewerdsen, Jeffrey H.

    2008-01-01

    Model observer performance, computed theoretically using cascaded systems analysis (CSA), was compared to the performance of human observers in detection and discrimination tasks. Dual-energy (DE) imaging provided a wide range of acquisition and decomposition parameters for which observer performance could be predicted and measured. This work combined previously derived observer models (e.g., Fisher-Hotelling and non-prewhitening) with CSA modeling of the DE image noise-equivalent quanta (NEQ) and imaging task (e.g., sphere detection, shape discrimination, and texture discrimination) to yield theoretical predictions of detectability index (d ' ) and area under the receiver operating characteristic (A Z ). Theoretical predictions were compared to human observer performance assessed using 9-alternative forced-choice tests to yield measurement of A Z as a function of DE image acquisition parameters (viz., allocation of dose between the low- and high-energy images) and decomposition technique [viz., three DE image decomposition algorithms: standard log subtraction (SLS), simple-smoothing of the high-energy image (SSH), and anti-correlated noise reduction (ACNR)]. Results showed good agreement between theory and measurements over a broad range of imaging conditions. The incorporation of an eye filter and internal noise in the observer models demonstrated improved correspondence with human observer performance. Optimal acquisition and decomposition parameters were shown to depend on the imaging task; for example, ACNR and SSH yielded the greatest performance in the detection of soft-tissue and bony lesions, respectively. This study provides encouraging evidence that Fourier-based modeling of NEQ computed via CSA and imaging task provides a good approximation to human observer performance for simple imaging tasks, helping to bridge the gap between Fourier metrics of detector performance (e.g., NEQ) and human observer performance.

  15. Discrimination of hip fractures by quantitative ultrasound of the phalanges and the calcaneus and dual X-ray absorptiometry

    International Nuclear Information System (INIS)

    Damilakis, John; Papadokostakis, George; Perisinakis, Kostas; Maris, Thomas; Dimitriou, P.; Hadjipavlou, Alexander; Gourtsoyiannis, Nicholas

    2004-01-01

    The aim of the current study was to evaluate the ability of different techniques used for the assessment of bone status to discriminate between postmenopausal women with and without hip fracture. Fifty-one postmenopausal women (mean age 64.5±6.5) who had sustained a low energy hip fracture and 51 age-matched controls (mean age 64.6±6.0) were studied. Quantitative ultrasound (QUS) assessment was carried out using the Ubis 3000 device capable of measuring broadband ultrasound attenuation (BUA) and speed of sound at the calcaneus (SOS C ) and the Sunlight Omnisense device capable of estimating speed of sound at the phalanges (SOS P ). Femoral neck bone mineral density (BMD) was assessed using dual X-ray absorptiometry. Correlations between QUS variables ranged from r=0.35 to 0.72 and between QUS variables and BMD from r=0.30 to 0.36. BMD was the best discriminator of hip fractures (odds ratio = 3.61, area under curve = 0.824). All QUS variables were significant discriminators of hip fractures with odds ratios ranging from 1.88 to 2.63 and areas under the ROC curves ranging from 0.663 to 0.740. Among the QUS variables, the SOS P showed the best odds ratio and area under curve. Comparison between the areas under the ROC curve did not show any significant difference between SOS P , BUA and BMD. On the contrary, the difference between SOS C and BMD was significant (P P , although the difference did not reach statistical significance

  16. Sci-Thur AM: YIS – 07: Optimizing dual-energy x-ray parameters using a single filter for both high and low-energy images to enhance soft-tissue imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, Wesley; Sattarivand, Mike [Department of Radiation Oncology, Dalhousie University at Nova Scotia Health Authority, Department of Radiation Oncology, Dalhousie University at Nova Scotia Health Authority (Canada)

    2016-08-15

    Objective: To optimize dual-energy parameters of ExacTrac stereoscopic x-ray imaging system for lung SBRT patients Methods: Simulated spectra and a lung phantom were used to optimize filter material, thickness, kVps, and weighting factors to obtain bone subtracted dual-energy images. Spektr simulations were used to identify material in the atomic number (Z) range [3–83] based on a metric defined to separate spectrums of high and low energies. Both energies used the same filter due to time constraints of image acquisition in lung SBRT imaging. A lung phantom containing bone, soft tissue, and a tumor mimicking material was imaged with filter thicknesses range [0–1] mm and kVp range [60–140]. A cost function based on contrast-to-noise-ratio of bone, soft tissue, and tumor, as well as image noise content, was defined to optimize filter thickness and kVp. Using the optimized parameters, dual-energy images of anthropomorphic Rando phantom were acquired and evaluated for bone subtraction. Imaging dose was measured with dual-energy technique using tin filtering. Results: Tin was the material of choice providing the best energy separation, non-toxicity, and non-reactiveness. The best soft-tissue-only image in the lung phantom was obtained using 0.3 mm tin and [140, 80] kVp pair. Dual-energy images of the Rando phantom had noticeable bone elimination when compared to no filtration. Dose was lower with tin filtering compared to no filtration. Conclusions: Dual-energy soft-tissue imaging is feasible using ExacTrac stereoscopic imaging system utilizing a single tin filter for both high and low energies and optimized acquisition parameters.

  17. Sci-Thur AM: YIS – 07: Optimizing dual-energy x-ray parameters using a single filter for both high and low-energy images to enhance soft-tissue imaging

    International Nuclear Information System (INIS)

    Bowman, Wesley; Sattarivand, Mike

    2016-01-01

    Objective: To optimize dual-energy parameters of ExacTrac stereoscopic x-ray imaging system for lung SBRT patients Methods: Simulated spectra and a lung phantom were used to optimize filter material, thickness, kVps, and weighting factors to obtain bone subtracted dual-energy images. Spektr simulations were used to identify material in the atomic number (Z) range [3–83] based on a metric defined to separate spectrums of high and low energies. Both energies used the same filter due to time constraints of image acquisition in lung SBRT imaging. A lung phantom containing bone, soft tissue, and a tumor mimicking material was imaged with filter thicknesses range [0–1] mm and kVp range [60–140]. A cost function based on contrast-to-noise-ratio of bone, soft tissue, and tumor, as well as image noise content, was defined to optimize filter thickness and kVp. Using the optimized parameters, dual-energy images of anthropomorphic Rando phantom were acquired and evaluated for bone subtraction. Imaging dose was measured with dual-energy technique using tin filtering. Results: Tin was the material of choice providing the best energy separation, non-toxicity, and non-reactiveness. The best soft-tissue-only image in the lung phantom was obtained using 0.3 mm tin and [140, 80] kVp pair. Dual-energy images of the Rando phantom had noticeable bone elimination when compared to no filtration. Dose was lower with tin filtering compared to no filtration. Conclusions: Dual-energy soft-tissue imaging is feasible using ExacTrac stereoscopic imaging system utilizing a single tin filter for both high and low energies and optimized acquisition parameters.

  18. Osteopoikilosis: A Cause of Elevated Bone Mineral Density on Dual X-Ray Absorptiometry Measurement in a Young Woman: Case Report

    Directory of Open Access Journals (Sweden)

    Asylbek Kaparov

    2010-04-01

    Full Text Available Osteopoikilosis (OPK is an asymptomatic, rare bone dysplasia. It causes an increase in bone density. The etiology and pathogenesis is unknown. OPK is generally diagnosed incidentally on plain radiographies which were performed for other locomotor system symptoms. Diagnostic lesions of OPK are typically diffuse, round, symmetrically shaped sclerotic bone areas. Laboratory findings and bone scintigraphy are usually normal. OPK should be considered in the differential diagnosis of osteoblastic bone disorders. OPK is a benign disease and invasive diagnostic procedures as well as aggressive treatment modalities should be avoided. In young individuals who have elevated scores on dual-energy X-Ray absoptiometry measurement, OPK as well as other sclerosing bone disorders would be considered. (From the World of Osteoporosis 2010;16:25-8

  19. Performance of X-ray absorptiometry in post-menopausal vertebral osteoporosis. Discriminant value of vertebral and femoral measurements, fracture threshold, reproducibility. Performances de l'absorptiometrie a rayons X dans l'osteoporose vertebrale post-menopausique

    Energy Technology Data Exchange (ETDEWEB)

    Pouilles, J.M.; Tremollieres, F.; Ribot, C. (Hopital Purpan, 31 - Toulouse (FR))

    1990-12-01

    The aim of this study was to assess the performance of a new bone densitometry technique, X-ray absorptiometry, in vertebral osteoporosis with fracture(s). Vertebral and femoral (neck, Ward's triangle and trochanter) bone density was measured in 60 women with at least one vertebral compression fracture of osteoporotic origin (mean age: 61), 100 controls of the same age and in 40 young adults (mean age: 30). Osteoporosis patients had significantly (p<0.0005) low bone density values in comparison with the young adults. Measurements using the spine and Ward's triangle had the best discriminant values assessed by the ROC (Receiver Operating Characteristics) technique (areas under the curve: 95% and 84% respectively). The fracture threshold was fixed at a vertebral bone density of 0.78 g/cm{sup 2}, this value giving the best compromise between sensitivity (83%) and specificity (95%) with 91% of subjects appropriately classifed. Reproducibility was assessed in the short term in 9 osteoporosis patients. The mean standard deviation of measurements was 0.017 g/cm{sup 2} (coefficient of variation: 2.6%) as compared with 0.010 g/cm{sup 2} (coefficient of variation: 0.8%) in the young adult. These results emphasise the true advance represented by X-ray absorptiometry in the area of bone densitometry, notably in the assessment and monitoring of demineralisation disorders.

  20. How does quantitative ultrasound compare to dual X-ray absorptiometry at various skeletal sites in relation to the WHO diagnosis categories?

    DEFF Research Database (Denmark)

    Jørgensen, H L; Warming, L; Bjarnason, N H

    2001-01-01

    group by the investigated parameters is large ranging from 25.9% of the women being diagnosed as osteopenic by BUA at the heel to 43.0% by BMD at the femoral neck. For men, the same range is from 20.5% by BUA to 44.1% by BMD at the femoral neck. For the classification into the osteoporotic group...... with this classification is assessed in terms of sensitivity and specificity. We conclude that there are significant differences in the classification of osteoporosis/osteopenia depending on the site measured and the technique used for the bone mass assessment. Furthermore, we suggest that development of technique...... as either osteopenic or osteoporotic according to these guidelines using dual X-ray absorptiometry (DXA), at the hip, at the spine and at the lower forearm and quantitative ultrasound (QUS), at the heel. A total of 247 men, 209 postmenopausal women and 195 premenopausal women were included in the study...

  1. Body composition and bone mineral mass in normal and obese female population using dual X-ray absorptiometry

    International Nuclear Information System (INIS)

    Massardo, T.; Gonzalez, P.; Coll, C.; Rodriguez, J.L.; Solis, I.; Oviedo, S.

    2002-01-01

    It has been observed that a greater percentage of body fat is associated with augmented bone mineral mass. Objective: The goal of this work was to assess the relationship between bone mineral density (BMD in g/cm 2 ) and content (BMC in g) and soft tissue components, fat and lean mass (in g) in whole body of adult female population in Chile. Method: We studied 185 volunteers, asymptomatic, excluding those using estrogens, regular medication, tobacco (>10 cigarettes/day), excessive alcohol intake or with prior oophorectomy. They were separated in 111 pre and 74 post menopausal and according to body mass index (BMI) they were 37 women > 30 kg/m 2 and 148 2 . A Lunar Dual X-Ray absorptiometer was used to determine whole BMD and BMC. Results: Post menopausal women were older and smaller [p:0.0001], with higher body mass index [p:0.0007] and with lower BMD and BMC and higher fat mass than the pre menopausal group; In the whole group, women with BMI ≥ 30 (obese) were compared with normal weight observing no difference in BMD. The fat mass incremented significantly with age. Obese women > 50 years presented greater BMC than the non-obese. The percentage of fat corresponded to 48% in the obese group and to 39% in the non-obese [p<0.0001]. Conclusion: Fat mass somehow protect bone mineral loss in older normal population, probably associated to multifactorial causes including extra ovaric estrogen production. Postmenopausal women presented lower mineral content than premenopausal, as it was expected

  2. Total and Segmental Body Composition Examination in Collegiate Football Players Using Multifrequency Bioelectrical Impedance Analysis and Dual X-ray Absorptiometry.

    Science.gov (United States)

    Raymond, Christiana J; Dengel, Donald R; Bosch, Tyler A

    2018-03-01

    Raymond, CJ, Dengel, DR, and Bosch, TA. Total and segmental body composition examination in collegiate football players using multifrequency bioelectrical impedance analysis and dual X-ray absorptiometry. J Strength Cond Res 32(3): 772-782, 2018-The current study examined the influence of player position on the agreement between multifrequency bioelectrical impedance analysis (MfBIA) and dual X-ray absorptiometry (DXA) when assessing total and segmental percent body fat (BF%), fat mass (FM), and fat-free mass (FFM) in National Collegiate Athletic Association Division I collegiate football athletes. Forty-four male collegiate athletes (age = 19 ± 1 year; height = 1.9 ± 1.0 m; and body mass = 106.4 ± 18.8 kg) participated. Player positions included: offensive linemen (OL; n = 7), tight ends (TE; n = 4), wide receivers (WR; n = 9), defensive linemen (DL; n = 6), defensive backs (DB; n = 8), linebackers (LB; n = 6), and running backs (RB; n = 4). Total and segmental body composition measured using MfBIA were compared with values obtained using DXA. Compared with DXA, MfBIA underestimated BF% (3.0 ± 3.8%), total FM (2.5 ± 4.3 kg), arm FM (0.4 ± 0.8 kg), arm FFM (1.4 ± 0.9 kg), leg FM (2.8 ± 2.0 kg), and leg FFM (5.4 ± 2.4 kg) (all p FFM (-2.4 ± 4.5 kg) (p FFM), ±3.83 kg (leg FM), ±4.62 kg (leg FFM), and ±8.83 kg (total FFM). No significant differences were observed between devices for trunk FM (-0.3 ± 3.0 kg; p = 0.565) and trunk FFM (0.4 ± 2.4 kg; p = 0.278), with LOAs of ±5.92 and ±4.69 kg, respectively. Player position significantly affected all between-device mean body composition measurement differences (adjusted p ≤ 0.05), with OL demonstrating the greatest effect on each variable. Therefore, MfBIA does not seem accurate in examining between-player body composition in college football players.

  3. TRABECULAR BONE SCORE – A NON-INVASIVE ANALYTICAL METHOD TO EVALUATE BONE QUALITY BASED ON ROUTINE DUAL-ENERGY ABSORPTIOMETRY. PERSPECTIVES OF ITS USE IN CLINICAL PRACTICE

    Directory of Open Access Journals (Sweden)

    T. T. Tsoriev

    2016-01-01

    Full Text Available Two-dimensional dual-energy X-ray absorptiometry (DXA, osteodensitometry is currently considered as the gold standard for diagnosis of osteoporosis. However, despite good operational characteristics, this type of investigation cannot help to assess bone microarchitecture and the degree of its derangement in osteoporosis. Therefore, trabecular bone score (TBS has been developed as a  non-invasive method of indirect description of bone microarchitecture based on data derived from a  standard DXA of the lumbar spine. Not being a direct mapping of the physical measurements of trabecular microarchitecture, TBS nevertheless shows a positive correlation with quantitative values obtained from micro-computed tomography and high resolution peripheral quantitative computed tomography, i.e. with the bone volume fraction, junction density, trabecular numbers and their disintegration. There is also an association between the ability of the bone tissue to resist stress in experimental studies ex vivo and TBS measurement. Due to TBS, there is a possibility to detect bone microarchitecture impairment even in individuals with normal bone mineral density (BMD, i.e. higher TBS values correlate with improved bone microstructure, whereas a  reduced TBS shows its deterioration. Limitation of TBS use are primarily related to the DXA image quality: image faults caused either by technical reasons or by too low or too high body mass index can lead to an overestimation/underestimation of the index. Assessment of the lumbar TBS has been repeatedly performed in cross-sectional and prospective studies in representative patient samples (mainly postmenopausal women and significant numbers of healthy subjects, and proved to be a predictor (independent of BMD of fracture risk. An evaluation of the possibility to use TBS for early diagnosis of secondary osteoporosis (related to various endocrine disorders  would be of great interest, as BMD, as known from clinical

  4. Correlation between bone mineral density of jaws and skeletal sites in an Iranian population using dual X-ray energy absorptiometry.

    Science.gov (United States)

    Esfahanizadeh, Nasrin; Davaie, Sotoudeh; Rokn, A R; Daneshparvar, Hamid Reza; Bayat, Noushin; Khondi, Nasrin; Ajvadi, Sara; Ghandi, Mostafa

    2013-07-01

    The aim of the present study was to evaluate the relationship between the bone density of various regions of jaws and skeletal bones. A total of 110 patients with a mean age of 55.01 ± 10.77 years were selected for the purpose of the present descriptive study. Dual X-ray Energy Absorptiometry (DXA) was carried out to determine bone mineral density (BMD) of the femur and lumbar vertebrae. Then all the subjects underwent DXA of the jaw bones and BMD values were determined at four jaw regions. Data were analyzed by SPSS 16 statistical software, and the correlation between the various BMD values was determined by Pearson's correlation coefficient. The results showed that 42.7% of females had normal BMD values in the femur, and in vertebrae, 20% were osteopenic and 37.3% suffered from osteoporosis, with statistically significant differences in the BMD values of the jaws between the three above-mentioned groups (P < 0.001). There was an increasing tendency toward osteopenia and osteoporosis with age. There was a positive correlation between BMD values of the femur and lumbar vertebrae and those of all the jaw regions under study (P < 0.005). There was a negative correlation (P < 0.01) between age and the BMD values of the femur, lumbar vertebrae and anterior maxilla. The bone density of the maxilla and mandible and presence of osteoporosis or osteopenia in these bones might reflect the same problem in skeletal bones.

  5. Feasibility of cone beam computed tomography radiomorphometric analysis and fractal dimension in assessment of postmenopausal osteoporosis in correlation with dual X-ray absorptiometry.

    Science.gov (United States)

    Mostafa, Raghdaa A; Arnout, Eman A; Abo El-Fotouh, Mona M

    The aim of the present study was to assess the feasibility of using mandibular CBCT radiomorphometric indices and box-counting fractal dimension (FD) to detect osteoporosis in post-menopausal females, compare them with the healthy control group and to correlate the findings with the bone mineral density measured by dual X-ray absorptiometry (DXA). This study consisted of 50 post-menopausal females, with age ranging from 55 to 70 years. Based on their DXA results, they were classified into osteoporotic and control groups. Mandibular CBCT radiomorphomertic indices and FD analysis were measured. Significant differences were found for the CT cortical index scores (CTCI), CT mental index (CTMI) and CT mandibular index (CTI) between the control and osteoporotic groups. The control group showed higher mean values than the osteoporotic group. For FD values, no significant differences were found between the two groups. CBCT radiomorphometric indices could be used as an adjuvant tool to refer patients at risk of osteoporosis for further assessment.

  6. The Effect of (99m)Tc on Dual-Energy X-Ray Absorptiometry Measurement of Body Composition and Bone Mineral Density

    DEFF Research Database (Denmark)

    Fosbøl, Marie Øbro; Dupont, Anders; Alslev, Louise

    2012-01-01

    the administration of a tracer marked with (99m)Tc were included. The patients underwent a whole-body DXA scan before and within 2h after tracer injection using a GE/Lunar Prodigy scanner. Control scans were performed on 40 volunteers, who had not received any radioactive tracer. In both phantom and patient...

  7. Periprosthetic bone density changes after MiniHipTM cementless femoral short stem: one-year results of dual-energy X-ray absorptiometry study

    Directory of Open Access Journals (Sweden)

    Ercan Ahmet

    2016-01-01

    Full Text Available Introduction: The purpose of the current study was to investigate the reaction of the femur to the implantation of the MiniHipTM in terms of: (1 bone density change during one year; (2 correlations between stem length, CCD (caput-collum-diaphyseal, femoral offset, T-value, and bone density; (3 other co-variables that influence the change of bone density. Patients and methods: MiniHipTM implant was performed for 62 patients. The age range of the patients who underwent treatment was 25–78 years. Periprothestic bone density was determined within two weeks postoperatively, after three, six, and twelve months utilizing the DEXA scan. Results: The highest change was observed in the first three months post-implantation, while significant decrease in density was recorded at proximal Gruen zones 1, 2, and 7, and at distal Gruen zone 4. The decrease in density reached a plateau between the third and sixth months after operation. Afterwards, bone density recovered up to the 12th postoperative month. The correlation analysis showed significant difference between Gruen zone 1 and stem size and CCD. The same significant trend was not reached for Gruen zone 7. Femoral offset showed no correlation. Covariance analysis was unable to establish connection of the results with diagnosis, pairings, or gender. Discussion: MiniHipTM densitometric results are promising and comparable to good results of the other representatives of the femoral neck partially-sustaining short stem prostheses with a lower proximal bone density reduction. Periprosthetic bone resorption is a multifactorial process where stem size, CCD angle, and patient-specific variables such as T-value have an impact on the periprosthetic bone remodeling. In particular, this applies to Gruen zone 1.

  8. The effect of position on the precision of dual-energy X-ray absorptiometry and correlation with body condition score in dogs and cats

    DEFF Research Database (Denmark)

    Bjørnvad, Charlotte R.; Nielsen, Mie E.; Hansen, Susanna E.M.

    2017-01-01

    during DEXA scanning influences results. Dogs and cats that were brought to the University Hospital for Companion Animals for euthanasia during the period 15 September–6 November 2015 were consecutively recruited if owners signed a written consent. Following euthanasia and before rigor mortis...

  9. Nutritional secondary hyperparathyroidism in two cats: evaluation of bone mineral density with dual-energy X-ray absorptiometry and computed tomography

    DEFF Research Database (Denmark)

    Dimopoulou, M.; Kirpensteijn, J; Nielsen, D. H.

    2010-01-01

    Two three-month-old, intact female Abyssinian cats were presented with a history of lameness, constipation and ataxia. The cats had been fed a diet composed almost exclusively of meat. Both showed severe osteopenia and multiple pathological fractures on radiography. Following euthanasia of the more...

  10. Change in fat-free mass assessed by bioelectrical impedance, total body potassium and dual energy X-ray absorptiometry during prolonged weight loss

    DEFF Research Database (Denmark)

    Hendel, H W; Gotfredsen, A; Højgaard, L

    1996-01-01

    ). These measurements were compared with bioimpedance analysis (BIA) by applying 11 predictive BIA equations published in the literature. Predictive equations for the present study population were developed, with the use of fat-free mass (FFM) as assessed by TBK and DXA as references in multiple regression analysis....... The results of the BIA equations varied widely; FFM was generally overestimated by BIA as compared with DXA and TBK before and after weight loss. During weight loss, the FFM did not change, as estimated by DXA (1.3 +/- 2.3 kg, p > 0.05) and TBK (0.9 +/- 2.9 kg, p > 0.05). The recorded change in impedance (R......) was also insignificant. Three BIA equations from the literature, which were not specific for the degree of obesity in the present study group, predicted changes in FFM (from 0.5 + 3.6 to 2.4 +/- 4.4kg, p > 0.05) that were comparable with those estimated by the reference methods. Eight equations from...

  11. Body composition during weight loss in obese patients estimated by dual energy X-ray absorptiometry and by total body potassium

    DEFF Research Database (Denmark)

    Hendel, H W; Gotfredsen, A; Andersen, T

    1996-01-01

    for FFM were strong (r = 0.92 and 0.93). Bland and Altman plots showed limits of agreement of +/-9 kg before and after weight loss; DXA underestimated FFM in women and overestimated FFM in men. DXA accounted for 80% of the lost body weight. The composition of the lost body mass did not differ from...... that estimated by TBK (7.6% FFM and 92.4% FM by TBK; 11% FFM and 89% FM by DXA). CONCLUSION: DXA estimates accurately the body composition and the composition of weight loss in groups of obese subjects. However, the scan table may be too small for patients weighing more than 95 kg....

  12. Fat-free mass prediction equations for bioelectric impedance analysis compared to dual energy X-ray absorptiometry in obese adolescents: a validation study

    NARCIS (Netherlands)

    Hofsteenge, G.H.; Chin A Paw, M.J.M.; Weijs, P.J.M.

    2015-01-01

    Background: In clinical practice, patient friendly methods to assess body composition in obese adolescents are needed. Therefore, the bioelectrical impedance analysis (BIA) related fat-free mass (FFM) prediction equations (FFM-BIA) were evaluated in obese adolescents (age 11-18 years) compared to

  13. Effect of degenerative change of lumbar spine on lateral bone mineral density measurement using dual energy x-ray absorptiometry: usefulness of measurement in the supine lateral projection

    International Nuclear Information System (INIS)

    Seo, Ja Young; Jo, Jin Man; Choi, Yun Young; Cho, Suk Shin; Cho, Su Hyeon

    1998-01-01

    To evaluate the usefulness of supine lateral bone mineral density (BMD) measurement using DXA by comparing AP and lateral spine BMD in patients with degenerative change Six hundred and seventy-two women underwnet AP and lateral BMD measurement of L-spine, using DXA. Spur changes and end-plate sclerosis were considered as degenerative change, and osteoporosis was defined according to WHO criteria. The ratio of mid-lateral BMD to AP BMD was calculated and the differences in ratio were analyzed in the degenerative group and controls, according to aging and osteoporosis, using the t test and ANOVA. The correlation coefficiency between aging and AP BMD and lateral BMD, respectively, was calculated. The mLat/AP ratio in the control and degenerative group was 0.710±0.005/0.622±0.028(p=3D0.003) in the 40-49-year-old group, 0.663±0.006/0.612±0.016 (p=3D0.002) in the 50-59-year-old group. 0.626±0.015/0.552±0.023 (p+0.007) in the 60-69-year-old group, and 0.717±0.028/0.600±0.045 (p=3D0.076) in those aged over 70. The ratio was 0.656±0.015/0.598±0.038(p=3D0.099) in osteoporosis, 0.684±0.008/0.596±0.016 (p=3D0.000) in osteopenia, and 0.688±0.005/0.583±0.019 (p=3D0.000) in normal subjects, showing that lateral BMD is more sensitive than AP BMD, espectially in the degenerative group. There was negative correlation between aging and AP BMD(r=3D-0.545), lateral BMD(r=3D0.571), and mid-lateral BMD(r=3D-0.583). In a selective group of patients with degenerative change, supine lateral BMD measurement of L-spine is useful

  14. A prospective dual-energy X-ray absorptiometry study of bone remodeling after implantation of the Nanos short-stemmed prosthesis.

    Science.gov (United States)

    Zeh, Alexander; Pankow, Franziska; Röllinhoff, Marc; Delank, Stefan; Wohlrab, David

    2013-04-01

    The aim of this study was to analyze the bone remodeling around the Nanos stem (Smith & Nephew, Marl, Germany) after primary total hip arthroplasty for coxarthrosis. In 25 patients (15 male, 10 female, mean age 59.9 years) with the diagnosis of coxarthrosis, a DEXA scan was performed immediately after surgery, 97 days (SD 6.1 days) and 368 days (SD 6.2 days) after implantation of a Nanos prosthesis. Plain radiographs were analyzed digitally for radiolucent lines, varus-valgus femoral stem alignment, measurement of stem migration and changes in varus-valgus femoral stem alignment. The position of the center of rotation (COR) and the offset were assessed pre- and postoperatively. Harris Hip Score was used to evaluate the clinical outcome. The DEXA scan showed a significant and relevant increase in BMD (Bone Mineral Density) in Gruen-Zone 6 (12%) and a decrease in Zone 1 (15%), 2 (5%) and 7 (12%), which was interpreted as reflecting a distal load transfer in the metaphysis of the femur. There was no clinically relevant migration or tilting of the Nanos stem. Radiolucent lines were noted in 12 cases, mainly at the polished tip area of the prosthesis; this was not regarded as a sign of impaired osseointegration. There was no significant difference between the position of the COR and the pre- and postoperative offset. The absence of stem migration, angulation, or relevant radiolucent lines is seen as evidence for an unimpaired osseointegration of the Nanos stem approximately 12 months after implantation. It is concluded that the Nanos prosthesis can reduce loss of BMD of the proximal femur composed with conventional stems or other short-stemmed implants.

  15. Normative values for CT-based texture analysis of vertebral bodies in dual X-ray absorptiometry-confirmed, normally mineralized subjects

    International Nuclear Information System (INIS)

    Mannil, Manoj; Eberhard, Matthias; Becker, Anton S.; Alkadhi, Hatem; Guggenberger, Roman; Schoenenberg, Denise; Osterhoff, Georg; Frey, Diana P.; Konukoglu, Ender

    2017-01-01

    To develop age-, gender-, and regional-specific normative values for texture analysis (TA) of spinal computed tomography (CT) in subjects with normal bone mineral density (BMD), as defined by dual X-ray absorptiometry (DXA), and to determine age-, gender-, and regional-specific differences. In this retrospective, IRB-approved study, TA was performed on sagittal CT bone images of the thoracic and lumbar spine using dedicated software (MaZda) in 141 individuals with normal DXA BMD findings. Numbers of female and male subjects were balanced in each of six age decades. Three hundred and five TA features were analyzed in thoracic and lumbar vertebrae using free-hand regions-of-interest. Intraclass correlation (ICC) coefficients were calculated for determining intra- and inter-observer agreement of each feature. Further dimension reduction was performed with correlation analyses. The TA features with an ICC 0.8 with other features were excluded from further analysis for dimension reduction. From the remaining 31 texture features, a significant correlation with age was found for the features mean (r = -0.489, p < 0.001), variance (r = -0.681, p < 0.001), kurtosis (r = 0.273, p < 0.001), and WavEnLL_s4 (r = 0.273, p < 0.001). Significant differences were found between genders for various higher-level texture features (p < 0.001). Regional differences among the thoracic spine, thoracic-lumbar junction, and lumbar spine were found for most TA features (p < 0.021). This study established normative values of TA features on CT images of the spine and showed age-, gender-, and regional-specific differences in individuals with normal BMD as defined by DXA. (orig.)

  16. Correlation between bone mineral density of jaws and skeletal sites in an Iranian population using dual X-ray energy absorptiometry

    Directory of Open Access Journals (Sweden)

    Nasrin Esfahanizadeh

    2013-01-01

    Full Text Available Background: The aim of the present study was to evaluate the relationship between the bone density of various regions of jaws and skeletal bones. Materials and Methods: A total of 110 patients with a mean age of 55.01 ± 10.77 years were selected for the purpose of the present descriptive study. Dual X-ray Energy Absorptiometry (DXA was carried out to determine bone mineral density (BMD of the femur and lumbar vertebrae. Then all the subjects underwent DXA of the jaw bones and BMD values were determined at four jaw regions. Data were analyzed by SPSS 16 statistical software, and the correlation between the various BMD values was determined by Pearson′s correlation coefficient. Results: The results showed that 42.7% of females had normal BMD values in the femur, and in vertebrae, 20% were osteopenic and 37.3% suffered from osteoporosis, with statistically significant differences in the BMD values of the jaws between the three above-mentioned groups (P < 0.001. There was an increasing tendency toward osteopenia and osteoporosis with age. There was a positive correlation between BMD values of the femur and lumbar vertebrae and those of all the jaw regions under study (P < 0.005. There was a negative correlation (P < 0.01 between age and the BMD values of the femur, lumbar vertebrae and anterior maxilla. Conclusion: The bone density of the maxilla and mandible and presence of osteoporosis or osteopenia in these bones might reflect the same problem in skeletal bones.

  17. Normative values for CT-based texture analysis of vertebral bodies in dual X-ray absorptiometry-confirmed, normally mineralized subjects.

    Science.gov (United States)

    Mannil, Manoj; Eberhard, Matthias; Becker, Anton S; Schönenberg, Denise; Osterhoff, Georg; Frey, Diana P; Konukoglu, Ender; Alkadhi, Hatem; Guggenberger, Roman

    2017-11-01

    To develop age-, gender-, and regional-specific normative values for texture analysis (TA) of spinal computed tomography (CT) in subjects with normal bone mineral density (BMD), as defined by dual X-ray absorptiometry (DXA), and to determine age-, gender-, and regional-specific differences. In this retrospective, IRB-approved study, TA was performed on sagittal CT bone images of the thoracic and lumbar spine using dedicated software (MaZda) in 141 individuals with normal DXA BMD findings. Numbers of female and male subjects were balanced in each of six age decades. Three hundred and five TA features were analyzed in thoracic and lumbar vertebrae using free-hand regions-of-interest. Intraclass correlation (ICC) coefficients were calculated for determining intra- and inter-observer agreement of each feature. Further dimension reduction was performed with correlation analyses. The TA features with an ICC  0.8 with other features were excluded from further analysis for dimension reduction. From the remaining 31 texture features, a significant correlation with age was found for the features mean (r = -0.489, p < 0.001), variance (r = -0.681, p < 0.001), kurtosis (r = 0.273, p < 0.001), and WavEnLL_s4 (r = 0.273, p < 0.001). Significant differences were found between genders for various higher-level texture features (p < 0.001). Regional differences among the thoracic spine, thoracic-lumbar junction, and lumbar spine were found for most TA features (p < 0.021). This study established normative values of TA features on CT images of the spine and showed age-, gender-, and regional-specific differences in individuals with normal BMD as defined by DXA.

  18. Normative values for CT-based texture analysis of vertebral bodies in dual X-ray absorptiometry-confirmed, normally mineralized subjects

    Energy Technology Data Exchange (ETDEWEB)

    Mannil, Manoj; Eberhard, Matthias; Becker, Anton S.; Alkadhi, Hatem; Guggenberger, Roman [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Schoenenberg, Denise; Osterhoff, Georg [University Hospital Zurich, Division of Trauma Surgery, Zurich (Switzerland); Frey, Diana P. [University Hospital Zurich, Department of Rheumatology, Zurich (Switzerland); Konukoglu, Ender [Computer Vision Laboratory, Department of Information Technology and Electrical Engineering, Zurich (Switzerland)

    2017-11-15

    To develop age-, gender-, and regional-specific normative values for texture analysis (TA) of spinal computed tomography (CT) in subjects with normal bone mineral density (BMD), as defined by dual X-ray absorptiometry (DXA), and to determine age-, gender-, and regional-specific differences. In this retrospective, IRB-approved study, TA was performed on sagittal CT bone images of the thoracic and lumbar spine using dedicated software (MaZda) in 141 individuals with normal DXA BMD findings. Numbers of female and male subjects were balanced in each of six age decades. Three hundred and five TA features were analyzed in thoracic and lumbar vertebrae using free-hand regions-of-interest. Intraclass correlation (ICC) coefficients were calculated for determining intra- and inter-observer agreement of each feature. Further dimension reduction was performed with correlation analyses. The TA features with an ICC < 0.81 indicating compromised intra- and inter-observer agreement and with Pearson correlation scores r > 0.8 with other features were excluded from further analysis for dimension reduction. From the remaining 31 texture features, a significant correlation with age was found for the features mean (r = -0.489, p < 0.001), variance (r = -0.681, p < 0.001), kurtosis (r = 0.273, p < 0.001), and WavEnLL{sub s}4 (r = 0.273, p < 0.001). Significant differences were found between genders for various higher-level texture features (p < 0.001). Regional differences among the thoracic spine, thoracic-lumbar junction, and lumbar spine were found for most TA features (p < 0.021). This study established normative values of TA features on CT images of the spine and showed age-, gender-, and regional-specific differences in individuals with normal BMD as defined by DXA. (orig.)

  19. Depth dose of critical organs of phantom based on surface dose exposed with Dual X-ray absorptiometry: pencil beam using TLD dosimetry

    Directory of Open Access Journals (Sweden)

    Ali Akbar Sharafi

    2009-02-01

    Full Text Available Introduction: Dual X-ray absorptiometry (DXA is one of the most widely used techniques fornon-invasive assessment of bone status. Radiation dosimetry is well established technique for pencilbeam and fan beam DXA system, for the assessment of the surface absorbed dose. No publishedassessment of the absorbed dose for the various depths of the critical organs such as the thyroid anduterus was found. Therefore, in this study, we measured the surface dose and depth dose of criticalorgans to determine the correlation between the depth dose and the surface dose.Materials and Methods: A Lunar DPX-MD (pencil beam system was used in this study. Ananthropomorphic phantom was designed. AP spine and femur scan modes were used to measure thesurface and depth doses of the thyroid left and right lobes and uterus in various deeps and scan centers.TLDs-400 were placed at the surface, near the source and also inserted at different depths in thyroidand uterus of the anthropomorphic phantom. Absorbed doses were measured on the phantom for APspine and femur scans. The correlation between the absorbed dose and the depth was found using thelinear regression analysis.Results: There was no significant correlation between the depth dose and the scan center doseexcept in the femur scan. AP spine effective dose were calculated as 0.064, 0.059, 0.061 and 0.242μSv for thyroid left, right lobes, uterus and ovary, respectively.Conclusion: It is concluded that there is significant correlation between the surface and the doseof various depths of the scanned sections.

  20. Dual-energy X-ray analysis using synchrotron computed tomography at 35 and 60 keV for the estimation of photon interaction coefficients describing attenuation and energy absorption.

    Science.gov (United States)

    Midgley, Stewart; Schleich, Nanette

    2015-05-01

    A novel method for dual-energy X-ray analysis (DEXA) is tested using measurements of the X-ray linear attenuation coefficient μ. The key is a mathematical model that describes elemental cross sections using a polynomial in atomic number. The model is combined with the mixture rule to describe μ for materials, using the same polynomial coefficients. Materials are characterized by their electron density Ne and statistical moments Rk describing their distribution of elements, analogous to the concept of effective atomic number. In an experiment with materials of known density and composition, measurements of μ are written as a system of linear simultaneous equations, which is solved for the polynomial coefficients. DEXA itself involves computed tomography (CT) scans at two energies to provide a system of non-linear simultaneous equations that are solved for Ne and the fourth statistical moment R4. Results are presented for phantoms containing dilute salt solutions and for a biological specimen. The experiment identifies 1% systematic errors in the CT measurements, arising from third-harmonic radiation, and 20-30% noise, which is reduced to 3-5% by pre-processing with the median filter and careful choice of reconstruction parameters. DEXA accuracy is quantified for the phantom as the mean absolute differences for Ne and R4: 0.8% and 1.0% for soft tissue and 1.2% and 0.8% for bone-like samples, respectively. The DEXA results for the biological specimen are combined with model coefficients obtained from the tabulations to predict μ and the mass energy absorption coefficient at energies of 10 keV to 20 MeV.

  1. Dual energy cardiac CT.

    Science.gov (United States)

    Carrascosa, Patricia; Deviggiano, Alejandro; Rodriguez-Granillo, Gastón

    2017-06-01

    Conventional single energy CT suffers from technical limitations related to the polychromatic nature of X-rays. Dual energy cardiac CT (DECT) shows promise to attenuate and even overcome some of these limitations, and might broaden the scope of patients eligible for cardiac CT towards the inclusion of higher risk patients. This might be achieved as a result of both safety (contrast reduction) and physiopathological (myocardial perfusion and characterization) issues. In this article, we will review the main clinical cardiac applications of DECT, that can be summarized in two core aspects: coronary artery evaluation, and myocardial evaluation.

  2. Aging and bone. X-ray bone densitometry

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Rikushi (Shiga Univ. of Medical Sciences, Otsu (Japan))

    1994-01-01

    Bone mass at all ages of the individuals is the integration of genetic factors, nutrition, physical exercise, hormonal environments, and other factors influencing the bone. It is also a measurable risk factor for osteoporosis which may subsequently cause bone fractures. Thus measuring bone mass is required to predict the probability of developing bone fractures subsequent to osteoporosis, and to diagnose osteoporosis, and to manage the osteoporosis patient. This paper discusses bone mineral measurements according to their characteristics and clinical application. Methodology for measuring bone mass has rapidly progressed during the past 15 years, which covers photodensitometry, photon absorptiometry (single energy X-ray absorptiometry and dual energy X-ray absorptiometry), quantitative CT, and ultrasound. These techniques have allowed noninvasive measurement of bone mineral density in any site of the skeleton with high accuracy and precision, although a single use of the technique cannot satisfy the complete clinical requirements. Thus the most appropriate method for measuring bone mineral density is important to monitor bone mass change and according to the specific site. (N.K.).

  3. Aging and bone. X-ray bone densitometry

    International Nuclear Information System (INIS)

    Morita, Rikushi

    1994-01-01

    Bone mass at all ages of the individuals is the integration of genetic factors, nutrition, physical exercise, hormonal environments, and other factors influencing the bone. It is also a measurable risk factor for osteoporosis which may subsequently cause bone fractures. Thus measuring bone mass is required to predict the probability of developing bone fractures subsequent to osteoporosis, and to diagnose osteoporosis, and to manage the osteoporosis patient. This paper discusses bone mineral measurements according to their characteristics and clinical application. Methodology for measuring bone mass has rapidly progressed during the past 15 years, which covers photodensitometry, photon absorptiometry (single energy X-ray absorptiometry and dual energy X-ray absorptiometry), quantitative CT, and ultrasound. These techniques have allowed noninvasive measurement of bone mineral density in any site of the skeleton with high accuracy and precision, although a single use of the technique cannot satisfy the complete clinical requirements. Thus the most appropriate method for measuring bone mineral density is important to monitor bone mass change and according to the specific site. (N.K.)

  4. Multiple energy computed tomography with monochromatic x rays from the NSLS

    International Nuclear Information System (INIS)

    Dilmanian, F.A.; Nachaliel, E.; Garrett, R.F.; Thomlinson, W.C.; Chapman, L.D.; Moulin, H.R.; Oversluizen, T.; Rarback, H.M.; Rivers, M.; Spanne, P.; Thompson, A.C.; Zeman, H.D.

    1991-01-01

    We used monochromatic x rays from the X17 superconducting wiggler beamline at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory, for dual-energy quantitative computed tomography (CT) of a 27 mm-diameter phantom containing solutions of different KOH concentrations in cylindrical holes of 5-mm diameter. The CT configuration was a fixed horizontal fan-shaped beam of 1.5 mm height and 30 mm width, and a subject rotating around a vertical axis. The transmitted x rays were detected by a linear-array Si(Li) detector with 120 elements of 0.25 mm width each. We used a two-crystal Bragg-Bragg fixed-exit monochromator with Si crystals. Dual photon absorptiometry (DPA) CT data were taken at 20 and 38 keV. The reconstructed phantom images show the potential of the system for quantitative CT

  5. Myocardial perfusion imaging with dual energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); De Cecco, Carlo N. [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncology and Pathology, University of Rome “Sapienza”, Rome (Italy); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Spandorfer, Adam; Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States)

    2016-10-15

    Highlights: • Stress dual-energy sCTMPI offers the possibility to directly detect the presence of myocardial perfusion defects. • Stress dual-energy sCTMPI allows differentiating between reversible and fixed myocardial perfusion defects. • The combination of coronary CT angiography and dual-energy sCTMPI can improve the ability of CT to detect hemodynamically relevant coronary artery disease. - Abstract: Dual-energy CT (DECT) enables simultaneous use of two different tube voltages, thus different x-ray absorption characteristics are acquired in the same anatomic location with two different X-ray spectra. The various DECT techniques allow material decomposition and mapping of the iodine distribution within the myocardium. Static dual-energy myocardial perfusion imaging (sCTMPI) using pharmacological stress agents demonstrate myocardial ischemia by single snapshot images of myocardial iodine distribution. sCTMPI gives incremental values to coronary artery stenosis detected on coronary CT angiography (CCTA) by showing consequent reversible or fixed myocardial perfusion defects. The comprehensive acquisition of CCTA and sCTMPI offers extensive morphological and functional evaluation of coronary artery disease. Recent studies have revealed that dual-energy sCTMPI shows promising diagnostic accuracy for the detection of hemodynamically significant coronary artery disease compared to single-photon emission computed tomography, invasive coronary angiography, and cardiac MRI. The aim of this review is to present currently available DECT techniques for static myocardial perfusion imaging and recent clinical applications and ongoing investigations.

  6. Bone mineral content (BMC) of the lumbar vertebrae (L2-L4) measured by quantitative computed tomography (QCT) and dual energy X-ray absorptiometry (DXA) in 21 hemodialysis (HD) patients

    International Nuclear Information System (INIS)

    Takahashi, Nobuyoshi; Suzuki, Tadashi; Sato, Motoaki; Oh, Songchol; Sato, Atsushi; Saito, Hisao; Funyu, Tomihisa.

    1996-01-01

    BMC of lumbar vertebrae (L2-L4) was measured by QCT and DXA in 21 HD patients. The effect of sex, aging, HD duration, postmenopausal years and various blood parameters of bone metabolism on BMC was assessed statistically. BMC showed a good positive correlation not only with DXA and QCT (trabecular and cortical bone), but with QCT (trabecular bone) and QCT (cortical bone). A significant age-related decrease in BMC, particularly by QCT (trabecular bone), was found in both sexes. BMC measured by QCT (trabecular bone) increased with the duration of HD in male patients. A negative relationship between postmenopausal years and BMC measured by QCT (trabecular and cortical bone) was prominent. BMC was not found to be correlated with various blood parameters of bone metabolism. Thus, measurement of BMC (L2-L4) by QCT has the advantage of allowing more precise examination of changes in cortical and trabecular bone. (author)

  7. Skull x-ray

    Science.gov (United States)

    X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  8. Neck x-ray

    Science.gov (United States)

    X-ray - neck; Cervical spine x-ray; Lateral neck x-ray ... There is low radiation exposure. X-rays are monitored so that the lowest amount of radiation is used to produce the image. Pregnant women and ...

  9. Evaluating fracture healing using digital x-ray image analysis

    African Journals Online (AJOL)

    2011-03-02

    Mar 2, 2011 ... with intensive imaging and modelling.6 dual energy X-ray ... techniques due to their high-quality digital output in ... the bone in the loaded X-ray is at an angular offset due to .... The research described in this article was carried ...

  10. Dual-energy digital radiography for the assessment of bone mineral density

    Energy Technology Data Exchange (ETDEWEB)

    Tahvanainen, Paeivi S.; Lammentausta, Eveliina; Tervonen, Osmo; Jaemsae, Timo; Nieminen, Miika T. (Dept. of Diagnostic Radiology, Univ. of Oulu, Oulu (Finland)), e-mail: paivi.tahvanainen@oulu.fi; Pulkkinen, Pasi (Dept. of Medical Technology, Univ. of Oulu, Oulu (Finland))

    2010-06-15

    Background: Bone mineral density (BMD) is usually determined by dual-energy X-ray absorptiometry (DXA). Digital radiography (DR) has enabled the application of dual-energy techniques for separating bone and soft tissue, but it is not clear yet whether BMD information can reliably be obtained using DR. Purpose: To determine the ability of dual-energy digital radiography (DEDR) to predict BMD as determined by DXA. Material and Methods: Reindeer femora (n=15) were imaged in a water bath at a typical clinical imaging voltage of 79 kVp and additionally at 100 kVp on a DR system. BMD was determined in four segmented regions (femoral neck, trochanter, inter-trochanter, Ward's triangle) from these images using the DXA calculation principle. BMD results as determined by DEDR were compared with BMD values as determined by DXA. Results: Significant moderate to high linear correlations (0.66-0.76) were observed at the femoral neck, Ward's triangle, and trochanter between BMD values as determined by the two techniques. The coefficient of variation (CVRMS) ranged between 2.2 and 4.7% and 0.2 and 1.8% for DEDR and DXA analyses, respectively. Conclusion: DXA-based BMD information can be obtained with moderate precision and accuracy using DEDR. In future, combining BMD measurements using DEDR with structural and geometrical information available on digital radiographs could enable a more comprehensive assessment of bone . Keywords: BMD, DXA, bone assessment

  11. Qualitative Evaluation of Digital Hand X-rays is Not a Reliable Method to Assess Bone Mineral Density

    Directory of Open Access Journals (Sweden)

    AndrewJ. Miller

    2017-01-01

    Full Text Available Object: The gold standard for evaluating bone mineral density is dual energy x-ray absorptiometry (DEXA.  Prior studies have shown poor reliability using analog wrist X-rays in diagnosing osteoporosis. Our goal was to investigate if there was improved diagnostic value to visual assessment of digital hand X-rays in osteoporosis screening. We hypothesized that similar to analog counterparts, digital hand X-rays have poor correlation and reliability in determining bone mineral density (BMD relative to DEXA.Methods: We prospectively evaluated female patients older than 65 years who presented to our hand clinic with digital hand and wrist X-rays as part of their evaluation over six months. Patients who had a fracture and were without DEXA scans within the past two years were excluded. Five fellowship-trained hand surgeons, blinded to DEXA T-scores, evaluated the x-rays over two assessments separated by four weeks and classified them as osteoporotic, osteopenic, or normal BMD.  Accuracy relative to DEXA T-score, interobserver and intraobserver rates were calculated.Results: Thirty four patients met the inclusion criteria and a total of 340 x-rays reviews were performed.  The assessments were correct in 169 cases (49% as compared to the DEXA T-scores. A mean weighted kappa coefficient of agreement between observers was 0.29 (range 0.02-0.41 reflecting a fair agreement. The first and second assessment for all five physicians was 0.46 (range 0.19-0.78 reflecting a moderate agreement.  Grouping osteoporosis and osteopenia together compared to normal, the accuracy, interobserver and intraobserver rates increased to 63%, 0.42 and 0.54 respectively.Conclusion: Abnormally low BMD is a common occurrence in patients treated for upper extremity disorders. There is poor accuracy relative to DEXA scan and only fair agreement in diagnosing osteoporosis using visual assessments of digital x-rays.

  12. X-Ray

    Science.gov (United States)

    ... enema. What you can expect During the X-ray X-rays are performed at doctors' offices, dentists' offices, ... as those using a contrast medium. Your child's X-ray Restraints or other techniques may be used to ...

  13. Abdominal x-ray

    Science.gov (United States)

    Abdominal film; X-ray - abdomen; Flat plate; KUB x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  14. Chest X-Ray

    Medline Plus

    Full Text Available ... talk with you about chest radiography also known as chest x-rays. Chest x-rays are the ... treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray ...

  15. X-ray astronomy

    International Nuclear Information System (INIS)

    Giacconi, R.; Gursky, H.

    1974-01-01

    This text contains ten chapters and three appendices. Following an introduction, chapters two through five deal with observational techniques, mechanisms for the production of x rays in a cosmic setting, the x-ray sky and solar x-ray emission. Chapters six through ten include compact x-ray sources, supernova remnants, the interstellar medium, extragalactic x-ray sources and the cosmic x-ray background. Interactions of x rays with matter, units and conversion factors and a catalog of x-ray sources comprise the three appendices. (U.S.)

  16. X-ray Digital Linear Tomosynthesis Imaging for Artificial Pulmonary Nodule Detection

    Directory of Open Access Journals (Sweden)

    Tsutomu Gomi

    2011-01-01

    Full Text Available The purpose of this paper is to identify indications for volumetric X-ray digital linear tomosynthesis (DLT with single- and dual-energy subtraction techniques for artificial pulmonary nodule detection and compare X-ray DLT, X-ray digital radiography, and computed tomography.

  17. Chest X-Ray

    Medline Plus

    Full Text Available ... about chest radiography also known as chest x-rays. Chest x-rays are the most commonly performed x-ray exams and use a very small dose of ... of the inside of the chest. A chest x-ray is used to evaluate the lungs, heart and ...

  18. Dual energy scanning beam laminographic x-radiography

    Science.gov (United States)

    Majewski, S.; Wojcik, R.F.

    1998-04-21

    A multiple x-ray energy level imaging system includes a scanning x-ray beam and two detector design having a first low x-ray energy sensitive detector and a second high x-ray energy sensitive detector. The low x-ray energy detector is placed next to or in front of the high x-ray energy detector. The low energy sensitive detector has small stopping power for x-rays. The lower energy x-rays are absorbed and converted into electrical signals while the majority of the higher energy x-rays pass through undetected. The high energy sensitive detector has a large stopping power for x-rays as well as it having a filter placed between it and the object to absorb the lower energy x-rays. In a second embodiment; a single energy sensitive detector is provided which provides an output signal proportional to the amount of energy in each individual x-ray it absorbed. It can then have an electronic threshold or thresholds set to select two or more energy ranges for the images. By having multiple detectors located at different positions, a dual energy laminography system is possible. 6 figs.

  19. X-ray sky

    International Nuclear Information System (INIS)

    Gruen, M.; Koubsky, P.

    1977-01-01

    The history is described of the discoveries of X-ray sources in the sky. The individual X-ray detectors are described in more detail, i.e., gas counters, scintillation detectors, semiconductor detectors, and the principles of X-ray spectrometry and of radiation collimation aimed at increased resolution are discussed. Currently, over 200 celestial X-ray sources are known. Some were identified as nebulae, in some pulsations were found or the source was identified as a binary star. X-ray bursts of novae were also observed. The X-ray radiation is briefly mentioned of spherical star clusters and of extragalactic X-ray sources. (Oy)

  20. Dual energy CT

    DEFF Research Database (Denmark)

    Al-Najami, Issam; Drue, Henrik Christian; Steele, Robert

    2017-01-01

    and inaccurate with existing methods. Dual Energy Computed Tomography (DECT) enables qualitative tissue differentiation by simultaneous scanning with different levels of energy. We aimed to assess the feasibility of DECT in quantifying tumor response to neoadjuvant therapy in loco-advanced rectal cancer. METHODS...... to determine the average quantitative parameters; effective-Z, water- and iodine-concentration, Dual Energy Index (DEI), and Dual Energy Ratio (DER). These parameters were compared to the regression in the resection specimen as measured by the pathologist. RESULTS: Changes in the quantitative parameters...

  1. Chest X-Ray

    Medline Plus

    Full Text Available ... some concerns about chest x-rays. However, it’s important to consider the likelihood of benefit to your health. While a chest x-ray use a ... posted: How to Obtain and Share ...

  2. Chest X-Ray

    Medline Plus

    Full Text Available ... X-ray Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey Rubin, a radiologist ... about chest x-rays, visit Radiology Info dot org. Thank you for your time! Spotlight Recently posted: ...

  3. X-ray apparatus

    International Nuclear Information System (INIS)

    Sell, L.J.

    1981-01-01

    A diagnostic x-ray device, readily convertible between conventional radiographic and tomographic operating modes, is described. An improved drive system interconnects and drives the x-ray source and the imaging device through coordinated movements for tomography

  4. X-ray - skeleton

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003381.htm X-ray - skeleton To use the sharing features on this ... Degenerative bone conditions Osteomyelitis Risks There is low radiation exposure. X-rays machines are set to provide the smallest ...

  5. Chest X-Ray

    Medline Plus

    Full Text Available ... I’d like to talk with you about chest radiography also known as chest x-rays. Chest x-rays are the most ... far outweighs any risk. For more information about chest x-rays, visit Radiology Info dot org. Thank you for your time! ...

  6. Chest X-Ray

    Medline Plus

    Full Text Available ... by Image/Video Gallery Your Radiologist Explains Chest X-ray Transcript Welcome to Radiology Info dot org! Hello, ... you about chest radiography also known as chest x-rays. Chest x-rays are the most commonly performed ...

  7. Flash X-ray

    International Nuclear Information System (INIS)

    Sato, Eiichi

    2003-01-01

    Generation of quasi-monochromatic X-ray by production of weakly ionized line plasma (flash X-ray), high-speed imaging by the X-ray and high-contrast imaging by the characteristic X-ray absorption are described. The equipment for the X-ray is consisted from the high-voltage power supply and condenser, turbo molecular pump, and plasma X-ray tube. The tube has a long linear anticathode to produce the line plasma and flash X-ray at 20 kA current at maximum. X-ray spectrum is measured by the imaging plate equipped in the computed radiography system after diffracted by a LiF single crystal bender. Cu anticathode generates sharp peaks of K X-ray series. The tissue images are presented for vertebra, rabbit ear and heart, and dog heart by X-ray fluoroscopy with Ce anticathode. Generation of K-orbit characteristic X-ray with extremely low bremsstrahung is to be attempted for medical use. (N.I.)

  8. X-ray astronomy

    International Nuclear Information System (INIS)

    Culhane, J.L.; Sanford, P.W.

    1981-01-01

    X-ray astronomy has been established as a powerful means of observing matter in its most extreme form. The energy liberated by sources discovered in our Galaxy has confirmed that collapsed stars of great density, and with intense gravitational fields, can be studied by making observations in the X-ray part of the electromagnetic spectrum. The astronomical objects which emit detectable X-rays include our own Sun and extend to quasars at the edge of the Universe. This book describes the history, techniques and results obtained in the first twenty-five years of exploration. Space rockets and satellites are essential for carrying the instruments above the Earth's atmosphere where it becomes possible to view the X-rays from stars and nebulae. The subject is covered in chapters, entitled: the birth of X-ray astronomy; the nature of X-radiation; X-rays from the Sun; solar-flare X-rays; X-rays from beyond the solar system; supernovae and their remnants; X-rays from binary stars; white dwarfs and neutron stars; black holes; X-rays from galaxies and quasars; clusters of galaxies; the observatories of the future. (author)

  9. X-ray holography

    International Nuclear Information System (INIS)

    Faigel, G.; Tegze, M.; Belakhovsky, M.; Marchesini, S.; Bortel, G.

    2003-01-01

    In the last decade holographic methods using hard X-rays were developed. They are able to resolve atomic distances, and can give the 3D arrangement of atoms around a selected element. Therefore, hard X-ray holography has potential applications in chemistry, biology and physics. In this article we give a general description of these methods and discuss the developments in the experimental technique. The capabilities of hard X-ray holography are demonstrated by examples

  10. Dual energy radiography using active detector technology

    International Nuclear Information System (INIS)

    Seibert, J.A.; Poage, T.F.; Alvarez, R.E.

    1996-01-01

    A new technology has been implemented using an open-quotes active-detectorclose quotes comprised of two computed radiography (CR) imaging plates in a sandwich geometry for dual-energy radiography. This detector allows excellent energy separation, short exposure time, and high signal to noise ratio (SNR) for clinically robust open-quotes bone-onlyclose quotes and open-quotes soft-tissue onlyclose quotes images with minimum patient motion. Energy separation is achieved by two separate exposures at widely different kVp's: the high energy (120 kVp + 1.5 mm Cu filter) exposure is initiated first, followed by a short burst of intense light to erase the latent image on the front plate, and then a 50 kVp (low energy) exposure. A personal computer interfaced to the x-ray generator, filter wheel, and active detector system orchestrates the acquisition sequence within a time period of 150 msec. The front and back plates are processed using a CR readout algorithm with fixed speed and wide dynamic range. open-quotes Bone-onlyclose quotes and open-quotes soft-tissue onlyclose quotes images are calculated by geometric alignment of the two images and application of dual energy decomposition algorithms on a pixel by pixel basis. Resultant images of a calibration phantom demonstrate an increase of SNR 2 / dose by ∼73 times when compared to a single exposure open-quotes passive-detectorclose quotes comprised of CR imaging plates, and an ∼8 fold increase compared to a screen-film dual-energy cassette comprised of different phosphor compounds. In conclusion, dual energy imaging with open-quotes active detectorclose quotes technology is clinically feasible and can provide substantial improvements over conventional methods for dual-energy radiography

  11. Providing x-rays

    International Nuclear Information System (INIS)

    Mallozzi, P.J.; Epstein, H.M.

    1985-01-01

    This invention provides an apparatus for providing x-rays to an object that may be in an ordinary environment such as air at approximately atmospheric pressure. The apparatus comprises: means (typically a laser beam) for directing energy onto a target to produce x-rays of a selected spectrum and intensity at the target; a fluid-tight enclosure around the target; means for maintaining the pressure in the first enclosure substantially below atmospheric pressure; a fluid-tight second enclosure adjoining the first enclosure, the common wall portion having an opening large enough to permit x-rays to pass through but small enough to allow the pressure reducing means to evacuate gas from the first enclosure at least as fast as it enters through the opening; the second enclosure filled with a gas that is highly transparent to x-rays; the wall of the second enclosure to which the x-rays travel having a portion that is highly transparent to x-rays (usually a beryllium or plastic foil), so that the object to which the x-rays are to be provided may be located outside the second enclosure and adjacent thereto and thus receive the x-rays substantially unimpeded by air or other intervening matter. The apparatus is particularly suited to obtaining EXAFS (extended x-ray fine structure spectroscopy) data on a material

  12. X-ray interferometers

    International Nuclear Information System (INIS)

    Franks, A.

    1980-01-01

    An improved type of amplitude-division x-ray interferometer is described. The wavelength at which the interferometer can operate is variable, allowing the instrument to be used to measure x-ray wavelength, and the angle of inclination is variable for sample investigation. (U.K.)

  13. Extremity x-ray

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003461.htm Extremity x-ray To use the sharing features on this page, ... in the body Risks There is low-level radiation exposure. X-rays are monitored and regulated to provide the ...

  14. X-rays utilization

    International Nuclear Information System (INIS)

    Rebigan, F.

    1979-03-01

    The modality of X-ray utilization in different activities and economy is given. One presents firstly quantities and units used in radiation dosimetry and other fields. One gives the generation of X-rays, their properties as well as the elements of radiation protection. The utilization characteristics of these radiations in different fields are finally given. (author)

  15. Chest X-Ray

    Medline Plus

    Full Text Available ... by Image/Video Gallery Your Radiologist Explains Chest X-ray Transcript Welcome to Radiology Info dot org! Hello, ... d like to talk with you about chest radiography also known as chest x-rays. Chest x- ...

  16. X-ray crystallography

    Science.gov (United States)

    2001-01-01

    X-rays diffracted from a well-ordered protein crystal create sharp patterns of scattered light on film. A computer can use these patterns to generate a model of a protein molecule. To analyze the selected crystal, an X-ray crystallographer shines X-rays through the crystal. Unlike a single dental X-ray, which produces a shadow image of a tooth, these X-rays have to be taken many times from different angles to produce a pattern from the scattered light, a map of the intensity of the X-rays after they diffract through the crystal. The X-rays bounce off the electron clouds that form the outer structure of each atom. A flawed crystal will yield a blurry pattern; a well-ordered protein crystal yields a series of sharp diffraction patterns. From these patterns, researchers build an electron density map. With powerful computers and a lot of calculations, scientists can use the electron density patterns to determine the structure of the protein and make a computer-generated model of the structure. The models let researchers improve their understanding of how the protein functions. They also allow scientists to look for receptor sites and active areas that control a protein's function and role in the progress of diseases. From there, pharmaceutical researchers can design molecules that fit the active site, much like a key and lock, so that the protein is locked without affecting the rest of the body. This is called structure-based drug design.

  17. A dynamic material discrimination algorithm for dual MV energy X-ray digital radiography

    International Nuclear Information System (INIS)

    Li, Liang; Li, Ruizhe; Zhang, Siyuan; Zhao, Tiao; Chen, Zhiqiang

    2016-01-01

    Dual-energy X-ray radiography has become a well-established technique in medical, industrial, and security applications, because of its material or tissue discrimination capability. The main difficulty of this technique is dealing with the materials overlapping problem. When there are two or more materials along the X-ray beam path, its material discrimination performance will be affected. In order to solve this problem, a new dynamic material discrimination algorithm is proposed for dual-energy X-ray digital radiography, which can also be extended to multi-energy X-ray situations. The algorithm has three steps: α-curve-based pre-classification, decomposition of overlapped materials, and the final material recognition. The key of the algorithm is to establish a dual-energy radiograph database of both pure basis materials and pair combinations of them. After the pre-classification results, original dual-energy projections of overlapped materials can be dynamically decomposed into two sets of dual-energy radiographs of each pure material by the algorithm. Thus, more accurate discrimination results can be provided even with the existence of the overlapping problem. Both numerical and experimental results that prove the validity and effectiveness of the algorithm are presented. - Highlights: • A material discrimination algorithm for dual MV energy X-ray digital radiography is proposed. • To solve the materials overlapping problem of the current dual energy algorithm. • The experimental results with the 4/7 MV container inspection system are shown.

  18. X-ray lasers

    CERN Document Server

    Elton, Raymond C

    2012-01-01

    The first in its field, this book is both an introduction to x-ray lasers and a how-to guide for specialists. It provides new entrants and others interested in the field with a comprehensive overview and describes useful examples of analysis and experiments as background and guidance for researchers undertaking new laser designs. In one succinct volume, X-Ray Lasers collects the knowledge and experience gained in two decades of x-ray laser development and conveys the exciting challenges and possibilities still to come._Add on for longer version of blurb_M>The reader is first introduced

  19. X-ray apparatus

    International Nuclear Information System (INIS)

    Bernstein, S.; Stagg, L.; Lambert, T.W.; Griswa, P.J.

    1976-01-01

    A patient support system for X-ray equipment in arteriographic studies of the heart is described in detail. The support system has been designed to overcome many of the practical problems encountered in using previous types of arteriographic X-ray equipment. The support system is capable of horizontal movement and, by a series of shafts attached to the main support system, the X-ray source and image intensifier or detector may be rotated through the same angle. The system is highly flexible and details are given of several possible operational modes. (U.K.)

  20. X-ray detector

    International Nuclear Information System (INIS)

    Whetten, N.R.; Houston, J.M.

    1977-01-01

    An ionization chamber for use in determining the spatial distribution of x-ray photons in tomography systems comprises a plurality of substantially parallel, planar anodes separated by parallel, planar cathodes and enclosed in a gas of high atomic weight at a pressure from approximately 10 atmospheres to approximately 50 atmospheres. The cathode and anode structures comprise metals which are substantially opaque to x-ray radiation and thereby tend to reduce the resolution limiting effects of x-ray fluoresence in the gas. In another embodiment of the invention the anodes comprise parallel conductive bars disposed between two planar cathodes. Guard rings eliminate surface leakage currents between adjacent electrodes. 8 figures

  1. X-ray apparatus

    International Nuclear Information System (INIS)

    Grady, J.K.

    1985-01-01

    X-ray apparatus is described which has a shutter between the X-ray source and the patient. The shutter controls the level of radiation to which the patient is exposed instead of merely discontinuing the electric power supplied to the source. When the shutter is opened a radiation sensor senses the level of X-radiation. When a preset quantity of X-radiation has been measured an exposure control closes the shutter. Instead of using the radiation sensor, the integrated power supplied to the anode of the X-ray source may be measured. (author)

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive medical ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small dose ... limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is ...

  4. X-ray examination apparatus

    NARCIS (Netherlands)

    2000-01-01

    The invention relates to an X-ray apparatus which includes an adjustable X-ray filter. In order to adjust an intensity profile of the X-ray beam, an X-ray absorbing liquid is transported to filter elements of the X-ray filter. Such transport is susceptible to gravitational forces which lead to an

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  6. Bone X-Ray (Radiography)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  8. Abdomen X-Ray (Radiography)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Abdomen Abdominal x-ray uses a very small ... of an abdominal x-ray? What is abdominal x-ray? An x-ray (radiograph) is a noninvasive medical ...

  9. Chest X-Ray

    Medline Plus

    Full Text Available ... Disorders Video: The Basketball Game: An MRI Story Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Chest X-ray Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey ...

  10. Chest X-Ray

    Medline Plus

    Full Text Available ... also be useful to help diagnose and monitor treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  11. X-ray tubes

    International Nuclear Information System (INIS)

    Young, R.W.

    1979-01-01

    A form of x-ray tube is described which provides satisfactory focussing of the electron beam when the beam extends for several feet from gun to target. Such a tube can be used for computerised tomographic scanning. (UK)

  12. Chest X-Ray

    Medline Plus

    Full Text Available ... breath, persistent cough, fever, chest pain or injury. It may also be useful to help diagnose and ... have some concerns about chest x-rays. However, it’s important to consider the likelihood of benefit to ...

  13. Chest X-Ray

    Medline Plus

    Full Text Available ... An MRI Story Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Chest X-ray ... posted: How to Obtain and Share Your Medical Images Movement Disorders Video: The Basketball Game: An MRI ...

  14. Chest X-Ray

    Medline Plus

    Full Text Available ... accurate diagnosis far outweighs any risk. For more information about chest x-rays, visit Radiology Info dot ... Inc. (RSNA). To help ensure current and accurate information, we do not permit copying but encourage linking ...

  15. Chest X-Ray

    Medline Plus

    Full Text Available ... Site Index A-Z Spotlight Recently posted: Pancreatic Cancer The Limitations of Online Dose Calculators Video: The ... of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  16. Chest X-Ray

    Medline Plus

    Full Text Available ... exams and use a very small dose of ionizing radiation to produce pictures of the inside of the ... chest x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs ...

  17. Chest X-Ray

    Medline Plus

    Full Text Available ... However, it’s important to consider the likelihood of benefit to your health. While a chest x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs any risk. ...

  18. Chest X-Ray

    Medline Plus

    Full Text Available ... June is Men's Health Month Recently posted: Pancreatic Cancer The Limitations of Online Dose Calculators Video: The ... of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  19. X-ray sources

    International Nuclear Information System (INIS)

    Masswig, I.

    1986-01-01

    The tkb market survey comparatively evaluates the X-ray sources and replacement tubes for stationary equipment currently available on the German market. It lists the equipment parameters of 235 commercially available X-ray sources and their replacement tubes and gives the criteria for purchase decisions. The survey has been completed with December 1985, and offers good information concerning medical and technical aspects as well as those of safety and maintenance. (orig.) [de

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of knee x-rays. A portable x-ray machine is a compact apparatus that can be taken ... of the body being examined, an x-ray machine produces a small burst of radiation that passes ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... that might interfere with the x-ray images. Women should always inform their physician and x-ray ... Safety page for more information about radiation dose. Women should always inform their physician or x-ray ...

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... ray examination. X-rays usually have no side effects in the typical diagnostic range for this exam. ... x-rays. A Word About Minimizing Radiation Exposure Special care is taken during x-ray examinations to ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... drawer under the table holds the x-ray film or image recording plate . Sometimes the x-ray ... extended over the patient while an x-ray film holder or image recording plate is placed beneath ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... are the limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray ( ... leg (shin), ankle or foot. top of page What are some common uses of the procedure? A ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ...

  6. SpineAnalyzer™ is an accurate and precise method of vertebral fracture detection and classification on dual-energy lateral vertebral assessment scans

    International Nuclear Information System (INIS)

    Birch, C.; Knapp, K.; Hopkins, S.; Gallimore, S.; Rock, B.

    2015-01-01

    Osteoporotic fractures of the spine are associated with significant morbidity, are highly predictive of hip fractures, but frequently do not present clinically. When there is a low to moderate clinical suspicion of vertebral fracture, which would not justify acquisition of a radiograph, vertebral fracture assessment (VFA) using Dual-energy X-ray Absorptiometry (DXA) offers a low-dose opportunity for diagnosis. Different approaches to the classification of vertebral fractures have been documented. The aim of this study was to measure the precision and accuracy of SpineAnalyzer™, a quantitative morphometry software program. Lateral vertebral assessment images of 64 men were analysed using SpineAnalyzer™ and standard GE Lunar software. The images were also analysed by two expert readers using a semi-quantitative approach. Agreement between groups ranged from 95.99% to 98.60%. The intra-rater precision for the application of SpineAnalyzer™ to vertebrae was poor in the upper thoracic regions, but good elsewhere. SpineAnalyzer™ is a reproducible and accurate method for measuring vertebral height and quantifying vertebral fractures from VFA scans. - Highlights: • Vertebral fracture assessment (VFA) using Dual-energy X-ray Absorptiometry (DXA) offers a low-dose opportunity for diagnosis. • Agreement between VFA software (SpineAnalyzer™) and expert readers is high. • Intra-rater precision of SpineAnalyzer™ applied to upper thoracic vertebrae is poor, but good elsewhere. • SpineAnalyzer™ is reproducible and accurate for vertebral height measurement and fracture quantification from VFA scans

  7. X-Ray Absorption with Transmission X-Ray Microscopes

    NARCIS (Netherlands)

    de Groot, F.M.F.

    2016-01-01

    In this section we focus on the use of transmission X-ray microscopy (TXM) to measure the XAS spectra. In the last decade a range of soft X-ray and hard X-ray TXM microscopes have been developed, allowing the measurement of XAS spectra with 10–100 nm resolution. In the hard X-ray range the TXM

  8. Comparison study of noise reduction algorithms in dual energy chest digital tomosynthesis

    Science.gov (United States)

    Lee, D.; Kim, Y.-S.; Choi, S.; Lee, H.; Choi, S.; Kim, H.-J.

    2018-04-01

    Dual energy chest digital tomosynthesis (CDT) is a recently developed medical technique that takes advantage of both tomosynthesis and dual energy X-ray images. However, quantum noise, which occurs in dual energy X-ray images, strongly interferes with diagnosis in various clinical situations. Therefore, noise reduction is necessary in dual energy CDT. In this study, noise-compensating algorithms, including a simple smoothing of high-energy images (SSH) and anti-correlated noise reduction (ACNR), were evaluated in a CDT system. We used a newly developed prototype CDT system and anthropomorphic chest phantom for experimental studies. The resulting images demonstrated that dual energy CDT can selectively image anatomical structures, such as bone and soft tissue. Among the resulting images, those acquired with ACNR showed the best image quality. Both coefficient of variation and contrast to noise ratio (CNR) were the highest in ACNR among the three different dual energy techniques, and the CNR of bone was significantly improved compared to the reconstructed images acquired at a single energy. This study demonstrated the clinical value of dual energy CDT and quantitatively showed that ACNR is the most suitable among the three developed dual energy techniques, including standard log subtraction, SSH, and ACNR.

  9. Phantom-less bone mineral density (BMD) measurement using dual energy computed tomography-based 3-material decomposition

    Science.gov (United States)

    Hofmann, Philipp; Sedlmair, Martin; Krauss, Bernhard; Wichmann, Julian L.; Bauer, Ralf W.; Flohr, Thomas G.; Mahnken, Andreas H.

    2016-03-01

    Osteoporosis is a degenerative bone disease usually diagnosed at the manifestation of fragility fractures, which severely endanger the health of especially the elderly. To ensure timely therapeutic countermeasures, noninvasive and widely applicable diagnostic methods are required. Currently the primary quantifiable indicator for bone stability, bone mineral density (BMD), is obtained either by DEXA (Dual-energy X-ray absorptiometry) or qCT (quantitative CT). Both have respective advantages and disadvantages, with DEXA being considered as gold standard. For timely diagnosis of osteoporosis, another CT-based method is presented. A Dual Energy CT reconstruction workflow is being developed to evaluate BMD by evaluating lumbar spine (L1-L4) DE-CT images. The workflow is ROI-based and automated for practical use. A dual energy 3-material decomposition algorithm is used to differentiate bone from soft tissue and fat attenuation. The algorithm uses material attenuation coefficients on different beam energy levels. The bone fraction of the three different tissues is used to calculate the amount of hydroxylapatite in the trabecular bone of the corpus vertebrae inside a predefined ROI. Calibrations have been performed to obtain volumetric bone mineral density (vBMD) without having to add a calibration phantom or to use special scan protocols or hardware. Accuracy and precision are dependent on image noise and comparable to qCT images. Clinical indications are in accordance with the DEXA gold standard. The decomposition-based workflow shows bone degradation effects normally not visible on standard CT images which would induce errors in normal qCT results.

  10. X-ray tube

    International Nuclear Information System (INIS)

    Webley, R.S.

    1975-01-01

    The object of the invention described is to provide an X-ray tube providing a scanned X-ray output which does not require a scanned electron beam. This is obtained by an X-ray tube including an anode which is rotatable about an axis, and a source of a beam of energy, for example an electron beam, arranged to impinge on a surface of the anode to generate X-radiation substantially at the region of incidence on the anode surface. The anode is rotatable about the axis to move the region of incidence over the surface. The anode is so shaped that the rotation causes the region of incidence to move in a predetermined manner relative to fixed parts of the tube so that the generated X-radiation is scanned in a predetermined manner relative to the tube. (UK)

  11. X-ray astronomy

    International Nuclear Information System (INIS)

    Giacconi, R.; Setti, G.

    1980-01-01

    This book contains the lectures, and the most important seminars held at the NATO meeting on X-Ray astronomy in Erice, July 1979. The meeting was an opportune forum to discuss the results of the first 8-months of operation of the X-ray satellite, HEAO-2 (Einstein Observatory) which was launched at the end of 1978. Besides surveying these results, the meeting covered extragalactic astronomy, including the relevant observations obtained in other portions of the electromagnetic spectrum (ultra-violet, optical, infrared and radio). The discussion on galactic X-ray sources essentially covered classical binaries, globular clusters and bursters and its significance to extragalactic sources and to high energy astrophysics was borne in mind. (orig.)

  12. Flash x-ray

    International Nuclear Information System (INIS)

    Johnson, Q.; Pellinen, D.

    1976-01-01

    The complementary techniques of flash x-ray radiography (FXR) and flash x-ray diffraction (FXD) provide access to a unique domain in nondestructive materials testing. FXR is useful in studies of macroscopic properties during extremely short time intervals, and FXD, the newer technique, is used in studies of microscopic properties. Although these techniques are similar in many respects, there are some substantial differences. FXD generally requires low-voltage, line-radiation sources and extremely accurate timing; FXR is usually less demanding. Phenomena which can be profitably studied by FXR often can also be studied by FXD to permit a complete materials characterization

  13. X-ray astronomy

    International Nuclear Information System (INIS)

    Narayanan, M.S.

    1976-01-01

    The deployment of detectors outside the deleterious effects of the atmosphere by sending them in space vehicles, has been explained. This has thrown open the entire spectrum of the electromagnetic and particle radiation to direct observations, thus enlarging the vistas of the field of astronomy and astrophysics. The discovery of strong emitters of X-rays such as SCO X-1, NorX-2, transient sources such as Cen X-2, Cen X-4, Cen X-1, Supernova remnants Tan X-1, etc., are reported. The background of the X-ray spectrum as measured during two rocket flights over Thumba, India is presented. (K.B.)

  14. X-ray masks

    International Nuclear Information System (INIS)

    Greenwood, J.C.; Satchell, D.W.

    1984-01-01

    In semiconductor manufacture, where X-ray irradiation is used, a thin silicon membrane can be used as an X-ray mask. This membrane has areas on which are patterns to define the regions to be irradiated. These regions are of antireflection material. With the thin, in the order of 3 microns, membranes used, fragility is a problem. Hence a number of ribs of silicon are formed integral with the membrane, and which are relatively thick, 5 to 10 microns. The ribs may be formed by localised deeper boron deposition followed by a selective etch. (author)

  15. X-ray detector

    International Nuclear Information System (INIS)

    Houston, J.M.; Whetten, N.R.

    1981-01-01

    An ionization chamber for use in determining the spatial distribution of x-ray photons in tomography systems comprises a plurality of substantially parallel, planar anodes separated by parallel, planar cathodes and enclosed in a gas of high atomic weight at a pressure from approximately 10 atmospheres to approximately 50 atmospheres. The cathode and anode structures comprise metals which are substantially opaque to x-ray radiation and thereby tend to reduce the resolution limiting effects of xray fluoresence in the gas. In another embodiment of the invention the anodes comprise parallel conductive bars disposed between two planar cathodes. Guard rings eliminate surface leakage currents between adjacent electrodes

  16. Panoramic Dental X-Ray

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a very small dose of ... x-ray , is a two-dimensional (2-D) dental x-ray examination that captures the entire mouth ...

  17. Subluminous X-ray binaries

    NARCIS (Netherlands)

    Armas Padilla, M.

    2013-01-01

    The discovery of the first X-ray binary, Scorpius X-1, by Giacconi et al. (1962), marked the birth of X-ray astronomy. Following that discovery, many additional X-ray sources where found with the first generation of X-ray rockets and observatories (e.g., UHURU and Einstein). The short-timescale

  18. X-Ray Exam: Pelvis

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Pelvis KidsHealth / For Parents / X-Ray Exam: ... Ray Exam: Hip Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  19. X-Ray Exam: Forearm

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Forearm KidsHealth / For Parents / X-Ray Exam: ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  20. X-Ray Exam: Foot

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Foot KidsHealth / For Parents / X-Ray Exam: ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  1. X-Ray Exam: Wrist

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Wrist KidsHealth / For Parents / X-Ray Exam: ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  2. Thoracic spine x-ray

    Science.gov (United States)

    Vertebral radiography; X-ray - spine; Thoracic x-ray; Spine x-ray; Thoracic spine films; Back films ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  3. X-Ray Exam: Finger

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Finger KidsHealth / For Parents / X-Ray Exam: ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  4. CRL X-ray tube

    International Nuclear Information System (INIS)

    Kolchevsky, N.N.; Petrov, P.V.

    2015-01-01

    A novel types of X-ray tubes with refractive lenses are proposed. CRL-R X-ray tube consists of Compound Refractive Lens- CRL and Reflection X-ray tube. CRL acts as X-ray window. CRL-T X-ray consists of CRL and Transmission X-ray tube. CRL acts as target for electron beam. CRL refractive lens acts as filter, collimator, waveguide and focusing lens. Properties and construction of the CRL X-ray tube are discussed. (authors)

  5. X rays and condensed matter

    International Nuclear Information System (INIS)

    Daillant, J.

    1997-01-01

    After a historical review of the discovery and study of X rays, the various interaction processes between X rays and matter are described: Thomson scattering, Compton scattering, X-photon absorption through photoelectric effect, and magnetic scattering. X ray sources such as the European Synchrotron Radiation Facility (ESRF) are described. The various X-ray applications are presented: imagery such as X tomography, X microscopy, phase contrast; X-ray photoelectron spectroscopy and X-ray absorption spectroscopy; X-ray scattering and diffraction techniques

  6. Digital X-ray radiogrammetry better identifies osteoarthritis patients with a low bone mineral density than quantitative ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Goerres, Gerhard W. [University Hospital Zurich, Institute of Diagnostic Radiology, Department of Medical Radiology, Zurich (Switzerland); University Hospital Zurich, Osteoporosis Center, Zurich (Switzerland); Frey, Diana; Studer, Annina; Hauser, Dagmar; Zilic, Nathalie [University Hospital Zurich, Osteoporosis Center, Zurich (Switzerland); Hany, Thomas F. [University Hospital Zurich, Institute of Nuclear Medicine, Department of Medical Radiology, Zurich (Switzerland); Seifert, Burkhardt [University of Zurich, Department of Biostatistics, Zurich (Switzerland); Haeuselmann, Hans J. [Center for Rheumatology and Bone Disease, Klinik im Park, Zurich (Switzerland); Michel, Beat A.; Uebelhart, Daniel [University Hospital Zurich, Osteoporosis Center, Zurich (Switzerland); University Hospital Zurich, Department of Rheumatology and Institute of Physical Medicine, Zurich (Switzerland); Hans, Didier [University Hospital Geneva, Division of Nuclear Medicine, Geneva (Switzerland)

    2007-04-15

    This study assessed the ability of quantitative ultrasound (QUS) and digital X-ray radiogrammetry (DXR) to identify osteopenia and osteoporosis in patients with knee osteoarthritis (OA). One hundred and sixty-one patients with painful knee OA (81 men, 80 women; age 62.6{+-}9.2 years, range 40-82 years) were included in this cross-sectional study and underwent dual-energy X-ray absorptiometry (DXA) of both hips and the lumbar spine, QUS of the phalanges and calcanei of both hands and heels, and DXR using radiographs of both hands. Unpaired t-test, Mann-Whitney U test, ROC analysis and Spearman's rank correlation were used for comparisons and correlation of methods. Using DXA as the reference standard, we defined a low bone mineral density (BMD) as a T-score {<=}-1.0 at the lumbar spine or proximal femur. In contrast to phalangeal or calcaneal QUS, DXR was able to discriminate patients with a low BMD at the lumbar spine (p<0.0001) or hips (p<0.0001). ROC analysis showed that DXR had an acceptable predictive power in identifying OA patients a low hip BMD (sensitivity 70%, specificity 71%). Therefore, DXR used as a screening tool could help in identifying patients with knee OA for DXA. (orig.)

  7. X-ray beam generator

    International Nuclear Information System (INIS)

    Koller, T.J.; Randmer, J.A.

    1977-01-01

    A method of minimizing the preferential angular absorption of the divergent beam from an X-ray generator is described. The generator consists of an X-ray shielded housing with an X-ray transmissive window symmetrically placed in radial alignment with a focal spot area on a sloped target surface of an X-ray tube in the housing. The X-ray tube may be of the stationary anode type or of the rotating anode type. (U.K.)

  8. Dual Energy Tomosynthesis breast phantom imaging

    Science.gov (United States)

    Koukou, V.; Martini, N.; Fountos, G.; Messaris, G.; Michail, C.; Kandarakis, I.; Nikiforidis, G.

    2017-12-01

    Dual energy (DE) imaging technique has been applied to many theoretical and experimental studies. The aim of the current study is to evaluate dual energy in breast tomosynthesis using commercial tomosynthesis system in terms of its potential to better visualize microcalcifications (μCs). The system uses a tungsten target X-ray tube and a selenium direct conversion detector. Low-energy (LE) images were acquired at different tube voltages (28, 30, 32 kV), while high-energy images at 49 kV. Fifteen projections, for the low- and high-energy respectively, were acquired without grid while tube scanned continuously. Log-subtraction algorithm was used in order to obtain the DE images with the weighting factor, w, derived empirically. The subtraction was applied to each pair of LE and HE slices after reconstruction. The TORMAM phantom was imaged with the different settings. Four regions-of-interest including μCs were identified in the inhomogeneous part of the phantom. The μCs in DE images were more clearly visible compared to the low-energy images. Initial results showed that DE tomosynthesis imaging is a promising modality, however more work is required.

  9. Chest X-Ray

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos ... x-ray is used to evaluate the lungs, heart and chest wall and may be used to ...

  10. X-ray sources

    International Nuclear Information System (INIS)

    Bonse, U.

    1979-11-01

    The author describes several possibilities for the production of X-radiation. Especially he discusses the use of bremsstrahlung at electron impact on solid targets and the synchrotron radiation. He presents some equations for the calculation of X-ray intensities. Especially the X-radiation from the DORIS storage ring is discussed. (HSI)

  11. Medical x-ray

    International Nuclear Information System (INIS)

    Abd Aziz Mhd Ramli; Gui Ah Auu; Husaini Salleh; Idris Besar; Mohd Ashhar Khalid; Muhammad Jamal Md Isa; Shaharuddin Mohd; Siti Najila Mohd Janib; Mohamed Ali Abdul Khader; Mahalatchimi Dave; Mohd Fazly Abdul Rahim; Ng Chee Moon; Ram Piari; Teoh Hoon Heng; Lee Peter

    2004-01-01

    This book describes the fundamental subject about medical radiography. It is a multidisciplinary field that requires cross professional input from scientists, engineers and medical doctors. However, it is presented in simple language to suit different levels of readers from x-ray operators and radiographers to physists, general practitioners and radiology specialists.The book is written in accordance to the requirements of the standard syllabus approved by the Ministry of Health Malaysia for the training of medical x-ray operator and general practitioners. In general, the content is not only designed to provide relevant and essential subject for related professionals in medical radiological services such as x-ray operator, radiographer and radiologists, but also to address those in associated radiological services including nurses, medical technologists and physicists.The book is organized and arranged sequentially into 3 parts for easy reference: Radiation safety; X-ray equipment and associated facilities; Radiography practices. With proper grasping of all these parts, the radiological services could be provided with confident and the highest professional standard. Thus, medical imaging with highest quality that can provide useful diagnostic information at minimum doses and at cost effective could be assured

  12. Chest X-Ray

    Medline Plus

    Full Text Available ... change into a gown. You may have some concerns about chest x-rays. However, it’s important to ... You Sponsored by About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2018 ...

  13. How well does dual photon absorptiometry predict osteoporosis

    International Nuclear Information System (INIS)

    Harrison, J.E.; Krishnan, S.S.; Muller, C.; Strauss, A.; Mukherjee, S.; Sturtridge, W.C.

    1993-01-01

    The accuracy of dual energy X-ray absorptiometry (DEXA) for measurement of bone mass carried out by quantitative digital radiography (Hologic Inc.) was compared to results with neutron activation analysis (NAA) on 106 subjects. The accuracy with DEXA was further investigated by measurements on aluminium samples of known composition. DEXA measured 4 lumbar vertebrae by spine scan. The central third of the skeleton also was measured by whole body scan to obtain data on the same large part of the skeleton as measured by NAA. Results suggested that DEXA spine scans were more reliable than whole body scans. In addition, the measurement of total mineral content (BMC) was more reliable than the normalization of BMC to bone surface area (BMC/Area) or bone mineral density (BDM). Since the proportion of bone below detection would increase with development of osteoporosis, with osteoporosis the BMC would be increasingly underestimated, but to only a small extent, while the BMD would be more significantly overestimated. (author) 4 refs.; 5 figs.; 2 tabs

  14. Theory and applications of the dual energy technique

    International Nuclear Information System (INIS)

    Chuang, K.S.K.

    1986-01-01

    Three important principles in the dual energy technique applied to radiography are studied in this dissertation: the decomposition method, x-ray scatter consideration, and the selection of an optimal energy pair. First, two new methods namely, iso-transmission lines and sub-region direct approximation methods, are proposed for dual energy decomposition calculation. These two methods are compared with two other conventional techniques, i.e. nonlinear equations and direct approximation. The accuracy, efficiency, and smoothness are used as indices for comparison. The authors conclude that the two new proposed methods, iso-transmission lines and sub-region, are superior than the nonlinear equations and direct approximation methods. In this dissertation, a method to perform scatter correction based on the knowledge of scatter primary ratio is presented. First, the relation between scatter primary ratio and attenuation coefficient is determined by a Monte Carlo simulation. The selection of an optimal energy pair for a dual energy system is described in this dissertation. The selection is based on the calculation of an optimum factor which takes into consideration of the noise in the high and low energy images, the radiation dose to the patient, as well as the error produced during the dual energy decomposition process. The calculation of this optimum factor is obtained using monoenergetic radiation sources on various sizes of water phantom. In addition to these three aspects, this dissertation also addresses some clinical applications of the dual energy techniques and shows some of the results

  15. Dual-energy subtraction radiography of the breast

    International Nuclear Information System (INIS)

    Asaga, Taro; Masuzawa, Chihiro; Kawahara, Satoru; Motohashi, Hisahiko; Okamoto, Takashi; Tamura, Nobuo

    1988-01-01

    Dual-energy projection radiography was applied to breast examination. To perform the dual-energy subtraction radiography using a digital radiography unit, high and low-energy exposures were made at an appropriate time interval under differing X-ray exposure conditions. Dual-energy subtraction radiography was performed in 41 cancer patients in whom the tumor shadow was equivocal or the border of cancer infiltration was not clearly demonstrated by compression mammography, and 15 patients with benign diseases such as fibrocystic disease, cyst and fibroadenoma. In 21 cases out of the 41 cancer patients, the dual-energy subtraction radiography clearly visualized the malignant tumor shadows and the border of cancer infiltration and the daughter nodules by removing the shadows of normal mammary gland. On the other hand, beign diseases such as fibrocystic disease and cyst could be diagnosed as such, because the tumor shadow and the irregularly concentrated image of mammary gland disappeared by the dual-energy subtraction. These results suggest that this new technique will be useful in examination of breast masses. (author)

  16. Dual-energy subtraction radiography of the breast

    Energy Technology Data Exchange (ETDEWEB)

    Asaga, Taro; Masuzawa, Chihiro; Kawahara, Satoru; Motohashi, Hisahiko; Okamoto, Takashi; Tamura, Nobuo

    1988-06-01

    Dual-energy projection radiography was applied to breast examination. To perform the dual-energy subtraction radiography using a digital radiography unit, high and low-energy exposures were made at an appropriate time interval under differing X-ray exposure conditions. Dual-energy subtraction radiography was performed in 41 cancer patients in whom the tumor shadow was equivocal or the border of cancer infiltration was not clearly demonstrated by compression mammography, and 15 patients with benign diseases such as fibrocystic disease, cyst and fibroadenoma. In 21 cases out of the 41 cancer patients, the dual-energy subtraction radiography clearly visualized the malignant tumor shadows and the border of cancer infiltration and the daughter nodules by removing the shadows of normal mammary gland. On the other hand, beign diseases such as fibrocystic disease and cyst could be diagnosed as such, because the tumor shadow and the irregularly concentrated image of mammary gland disappeared by the dual-energy subtraction. These results suggest that this new technique will be useful in examination of breast masses.

  17. X ray Production. Chapter 5

    Energy Technology Data Exchange (ETDEWEB)

    Nowotny, R. [Medical University of Vienna, Vienna (Austria)

    2014-09-15

    The differential absorption of X rays in tissues and organs, owing to their atomic composition, is the basis for the various imaging methods used in diagnostic radiology. The principles in the production of X rays have remained the same since their discovery. However, much refinement has gone into the design of X ray tubes to achieve the performance required for today’s radiological examinations. In this chapter, an outline of the principles of X ray production and a characterization of the radiation output of X ray tubes will be given. The basic processes producing X rays are dealt with in Section 1.4.

  18. X-ray filter for x-ray powder diffraction

    Science.gov (United States)

    Sinsheimer, John Jay; Conley, Raymond P.; Bouet, Nathalie C. D.; Dooryhee, Eric; Ghose, Sanjit

    2018-01-23

    Technologies are described for apparatus, methods and systems effective for filtering. The filters may comprise a first plate. The first plate may include an x-ray absorbing material and walls defining first slits. The first slits may include arc shaped openings through the first plate. The walls of the first plate may be configured to absorb at least some of first x-rays when the first x-rays are incident on the x-ray absorbing material, and to output second x-rays. The filters may comprise a second plate spaced from the first plate. The second plate may include the x-ray absorbing material and walls defining second slits. The second slits may include arc shaped openings through the second plate. The walls of the second plate may be configured to absorb at least some of second x-rays and to output third x-rays.

  19. Temporal subtraction of dual-energy chest radiographs

    International Nuclear Information System (INIS)

    Armato, Samuel G. III; Doshi, Devang J.; Engelmann, Roger; Caligiuri, Philip; MacMahon, Heber

    2006-01-01

    Temporal subtraction and dual-energy imaging are two enhanced radiography techniques that are receiving increased attention in chest radiography. Temporal subtraction is an image processing technique that facilitates the visualization of pathologic change across serial chest radiographic images acquired from the same patient; dual-energy imaging exploits the differential relative attenuation of x-ray photons exhibited by soft-tissue and bony structures at different x-ray energies to generate a pair of images that accentuate those structures. Although temporal subtraction images provide a powerful mechanism for enhancing visualization of subtle change, misregistration artifacts in these images can mimic or obscure abnormalities. The purpose of this study was to evaluate whether dual-energy imaging could improve the quality of temporal subtraction images. Temporal subtraction images were generated from 100 pairs of temporally sequential standard radiographic chest images and from the corresponding 100 pairs of dual-energy, soft-tissue radiographic images. The registration accuracy demonstrated in the resulting temporal subtraction images was evaluated subjectively by two radiologists. The registration accuracy of the soft-tissue-based temporal subtraction images was rated superior to that of the conventional temporal subtraction images. Registration accuracy also was evaluated objectively through an automated method, which achieved an area-under-the-ROC-curve value of 0.92 in the distinction between temporal subtraction images that demonstrated clinically acceptable and clinically unacceptable registration accuracy. By combining dual-energy soft-tissue images with temporal subtraction, misregistration artifacts can be reduced and superior image quality can be obtained

  20. X-ray refractometer

    International Nuclear Information System (INIS)

    Tur'yanskij, A.G.; Pirshin, I.V.

    2001-01-01

    Paper introduces a new circuit of X-ray refractometer to study angular and spectral features of refracted radiation within hard X-ray range. Refractometer incorporates two goniometers, two crystal-analyzers and three radiation detectors. The maximum distance between radiation source focal point and a receiving slit of the second goniometer is equal to 1.4 m. For the first time one obtained refraction patterns of fine-film specimens including C/Si stressed structure. Paper describes a new technique of refractometry via specimen oscillation at fixed position of a detecting device. Paper presents the measurement results of oscillation refraction patterns for specimens of melted quartz and ZnSe single crystal [ru

  1. X-ray radiotherapy

    International Nuclear Information System (INIS)

    Tronc, D.

    1995-01-01

    Full text: The most common form of radio therapy is X-ray therapy, where a beam of photons or their parent electrons break down hydrogen bonds within the body's cells and remove certain DNA information necessary for cell multiplication. This process can eradicate malignant cells leading to complete recovery, to the remission of some cancers, or at least to a degree of pain relief. The radiotherapy instrument is usually an electron linac, and the electrons are used either directly in 'electrotherapy' for some 10% of patients, or the electrons bombard a conversion target creating a broad beam of high energy photons or 'penetration X-rays'. The simplest machine consists of several accelerating sections at around 3 GHz, accelerating electrons to 6 MeV; a cooled tungsten target is used to produce a 4 Gray/min X-ray field which can be collimated into a rectangular shape at the patient position. This tiny linac is mounted inside a rotating isocentric gantry above the patient who must remain perfectly still. Several convergent beams can also be used to increase the delivered dose. More sophisticated accelerators operate at up to 18 MeV to increase penetration depths and decrease skin exposure. Alternatively, electrotherapy can be used with different energies for lower and variable penetration depths - approximately 0.5 cm per MeV. In this way surface tissue may be treated without affecting deeper and more critical anatomical regions. This type of linac, 1 to 2 metres long, is mounted parallel to the patient with a bending magnet to direct the beam to the radiotherapy system, which includes the target, thick movable collimator jaws, a beam field equalizer, dose rate and optical field simulation and energy controls. There are over 2000 acceleratorbased X-ray treatment units worldwide. Western countries have up to two units per million population, whereas in developing countries such as Bangladesh, the density is only one per 100 million. Several

  2. X-ray generator

    Energy Technology Data Exchange (ETDEWEB)

    Zucarias, A; Shepherd, J W

    1982-09-08

    An X-ray tube has a tubular envelope with a cathode for directing an electron beam onto a focal spot area of a spaced anode target to generate X-rays. The target is mounted for axial rotation on one end of a rotor disposed in an end portion of the envelope and encircled by a stator of an alternating current induction motor. An annular shield of high permeability magnetic material extends transversely between the electron beam and the stator of the induction motor for shunting stray or fringe electromagnetic fields established by the stator away from the electron beam to avoid consequent lateral deflections of the electron and corresponding lateral movements of the focal spot area.

  3. X-ray microtomography

    International Nuclear Information System (INIS)

    Dunsmuir, J.H.; Ferguson, S.R.; D'Amico, K.L.; Stokes, J.P.

    1991-01-01

    In this paper the authors describe the application of a new high-resolution X-ray tomographic microscope to the study of porous media. The microscope was designed to exploit the properties of a synchrotron X-ray source to perform three dimensional tomography on millimeter sized objects with micron resolution and has been used in materials science studies with both synchrotron and conventional and synchrotron sources will be compared. In this work the authors have applied the microscope to measure the three dimensional structure of fused bead packs and berea sandstones with micron resolution and have performed preliminary studies of flow in these media with the microscope operated in a digital subtraction radiography mode. Computer graphics techniques have been applied to the data to visually display the structure of the pore body system. Tomographic imaging after flow experiments should detect the structure of the oil-water interface in the pore network and this work is ongoing

  4. X-ray diffraction

    International Nuclear Information System (INIS)

    Einstein, J.R.; Wei, C.H.

    1982-01-01

    We have been interested in structural elucidation by x-ray diffraction of compounds of biological interest. Understanding exactly how atoms are arranged in three-dimensional arrays as molecules can help explain the relationship between structure and functions. The species investigated may vary in size and shape; our recent studies included such diverse substances as antischistosomal drugs, a complex of cadmium with nucleic acid base, nitrate salts of adenine, and proteins

  5. X-ray apparatus

    International Nuclear Information System (INIS)

    Tomita, Chuji.

    1980-01-01

    A principal object of the present invention is to provide an X-ray apparatus which is such that the distance between the surface of the patient's table and the floor on which the apparatus is installed is sufficiently small in the horizontal position of the patient's table of the roentgenographical pedestal and that the rotation of the pedestal from the horizontal position to a tilted position and further to the vertical position of the table can be carried out smoothly. (auth)

  6. X-ray Ordinance

    International Nuclear Information System (INIS)

    Kramer, R.; Zerlett, G.

    1983-01-01

    This commentary, presented as volume 2 of the Deutsches Strahlenschutzrecht (German legislation on radiation protection) deals with the legal provisions of the ordinance on the protection against harmful effects of X-radiation (X-ray Ordinance - RoeV), of March 1, 1973 (announced in BGBl.I, page 173), as amended by the ordinance on the protection against harmful effects of ionizing radiation, of October 13, 1976 (announced in BGBl. I, page 2905). Thus volume 2 completes the task started with volume 1, namely to present a comprehensive view and account of the body of laws governing radiation protection, a task which was thought useful as developments in the FRG led to regulations being split up into the X-ray Ordinance, and the Radiation Protection Ordinance. In order to present a well-balanced commentary on the X-ray Ordinance, it was necessary to discuss the provisions both from the legal and the medical point of view. This edition takes into account the Fourth Public Notice of the BMA (Fed. Min. of Labour and Social Affairs) concerning the implementation of the X-ray Ordinance of January 4, 1982, as well as court decisions and literature published in this field, until September 1982. In addition, the judgment of the Federal Constitutional Court, dated October 19, 1982, concerning the voidness of the law on government liability, and two decisions by the Federal High Court, dated November 23, 1982, concerning the right to have insight into medical reports - of great significance in practice - have been considered. This commentary therefore is up to date with current developments. (orig.) [de

  7. Producing x-rays

    International Nuclear Information System (INIS)

    Mallozzi, P.J.; Epstein, H.M.; Jung, R.G.; Applebaum, D.C.; Fairand, B.P.; Gallagher, W.J.

    1977-01-01

    A method of producing x-rays by directing radiant energy from a laser onto a target is described. Conversion efficiency of at least about 3 percent is obtained by providing the radiant energy in a low-power precursor pulse of approximately uniform effective intensity focused onto the surface of the target for about 1 to 30 nanoseconds so as to generate an expanding unconfined coronal plasma having less than normal solid density throughout and comprising a low-density (underdense) region wherein the plasma frequency is less than the laser radiation frequency and a higher-density (overdense) region wherein the plasma frequency is greater than the laser radiation frequency and, about 1 to 30 nanoseconds after the precursor pulse strikes the target, a higher-power main pulse focused onto the plasma for about 10 -3 to 30 nanoseconds and having such power density and total energy that the radiant energy is absorbed in the underdense region and conducted into the overdense region to heat it and thus to produce x-rays therefrom with the plasma remaining substantially below normal solid density and thus facilitating the substantial emission of x-rays in the form of spectral lines arising from nonequilibrium ionization states

  8. Bone fragility induced by X-ray irradiation in relation to cortical bone-mineral content

    International Nuclear Information System (INIS)

    Nyaruba, M.M.; Yamamoto, I.; Morita, R.; Kimura, H.

    1998-01-01

    The purpose of this study was to investigate the effects of fractional irradiation on the biomechanical properties of bone in the rat in relation to the cortical bone-mineral content (BMC), and to compare these effects with those brought about by single-dose irradiation. Seventy-five veteran female Wistar rats were divided into 4 groups. Group 1 was the control group. The left tibiae of the remaining rats were exposed to irradiation. Group 2 received one single dose of X-rays at 10-60 Gy. Groups 3 and 4 received fractional irradiation up to different cumulative doses (10-60 Gy): group 3 received 2.5 Gy once a day; group 4 received 1.25 Gy twice a day. Twenty-four weeks after irradiation, the rats were killed and the BMC in each tibial diaphysis was determined by dual-energy X-ray absorptiometry (DXA). The bones were then loaded to failure in a three-point bending test. The control group showed no difference (p>0.05) between left and right tibiae, neither in BMC nor in the maximum load at fracture. Single-dose irradiation caused a 16% (p=0.0366) decrease in the maximum load at 40 Gy, and a 19% (p=0.008) decrease at 60 Gy. The once-daily fractional dose of irradiation caused a 10% (p=0.0022) decrease in the maximum load of the irradiated tibiae at 60 Gy when compared to the intact contralateral tibiae. The twice-daily fractional dose of irradiation had no observable effect on the maximum load of the irradiated tibiae. Neither fractional irradiation modality had an effect on BMC. (orig./MG)

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the body. X-rays are the oldest and most frequently used form of medical imaging. A bone ... bones. top of page How should I prepare? Most bone x-rays require no special preparation. You ...

  10. Bone X-Ray (Radiography)

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    Full Text Available ... evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ...

  11. Bone X-Ray (Radiography)

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    Full Text Available ... can be taken to the patient in a hospital bed or the emergency room. The x-ray ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  12. Bone X-Ray (Radiography)

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    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  13. X-ray detector array

    International Nuclear Information System (INIS)

    Houston, J.M.

    1980-01-01

    The object of the invention (an ionization chamber X-ray detector array for use with high speed computerised tomographic imaging apparatus) is to reduce the time required to produce a tomographic image. The detector array described determines the distribution of X-ray intensities in one or more flat, coplanar X-ray beams. It comprises three flat anode sheets parallel to the X-ray beam, a plurality of rod-like cathodes between the anodes, a detector gas between the electrodes and a means for applying a potential between the electrodes. Each of the X-ray sources is collimated to give a narrow, planar section of X-ray photons. Sets of X-ray sources in the array are pulsed simultaneously to obtain X-ray transmission data for tomographic image reconstruction. (U.K.)

  14. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... tissue shows up in shades of gray and air appears black. Until recently, x-ray images were ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  15. Bone X-Ray (Radiography)

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    Full Text Available ... changes seen in metabolic conditions. assist in the detection and diagnosis of bone cancer . locate foreign objects ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ...

  16. Bone X-Ray (Radiography)

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    Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that ...

  17. Bone X-Ray (Radiography)

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    Full Text Available ... up in shades of gray and air appears black. Until recently, x-ray images were maintained on ... Safety page for more information about radiation dose. Women should always inform their physician or x-ray ...

  18. Bone X-Ray (Radiography)

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    Full Text Available ... wrist, arm, elbow, shoulder, spine, pelvis, hip, thigh, knee, leg (shin), ankle or foot. top of page ... the patient standing upright, as in cases of knee x-rays. A portable x-ray machine is ...

  19. Bone X-Ray (Radiography)

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    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

  20. Bone X-Ray (Radiography)

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    Full Text Available ... conditions. Imaging with x-rays involves exposing a part of the body to a small dose of ... body. Once it is carefully aimed at the part of the body being examined, an x-ray ...

  1. Radiographic absorptiometry of the phalanges as a screening instrument to detect osteoporosis of the hip

    International Nuclear Information System (INIS)

    Versluis, R.G.J.A.; Springer, M.P.; Petri, H.; Ven, C.M. van de

    1999-01-01

    Objective: To determine the validity of radiographic absorptiometry (RA) of the phalanges in detecting osteoporosis of the femoral neck, measured by dual energy X-ray absorptiometry (DXA). Material and methods: In a group practice, 494 Causasian women aged 55 to 84 years were recruited. Hand radiography and DXA measurements of the hip were performed in 449 women. 409 (91.1%) hand radiographs had sufficient quality for analysis by RA. Change of bone mass by age was obtained by using linear regression. Correlations between RA and DXA were calculated. Sensitivity and specificity of RA were calculated for several RA cut-off levels. Results: The mean bone mineral density at the femoral neck was 0.866 g/cm 2 and 92.57 arbitrary units at the phalanges. A moderate correlation of 0.53 (p<0.01) was found between RA and DXA. Depending on the cut-off level used, the sensitivity and specificity of RA in detecting osteoporosis at the femoral neck was 0.84-0.55 and 0.61-0.88, respectively. Conclusion: RA may be used as a screening technique to detect osteoporosis, but confirmation is necessary in the subgroup with a positive outcome on RA. (orig.)

  2. X-Ray Exam: Hip

    Science.gov (United States)

    ... for Educators Search English Español X-Ray Exam: Hip KidsHealth / For Parents / X-Ray Exam: Hip What's in this article? What It Is Why ... You Have Questions Print What It Is A hip X-ray is a safe and painless test ...

  3. Bone X-Ray (Radiography)

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    Full Text Available ... X-rays are a form of radiation like light or radio waves. X-rays pass through most objects, including the body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small ...

  4. Bone X-Ray (Radiography)

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    Full Text Available ... x-rays. top of page What does the equipment look like? The equipment typically used for bone x-rays consists of ... and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely available in emergency ...

  5. Bone X-Ray (Radiography)

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    Full Text Available ... The x-ray tube is connected to a flexible arm that is extended over the patient while an x-ray film holder or image recording plate is placed beneath the patient. top of page How does the procedure work? X-rays are a form of radiation like ...

  6. X-Ray Exam: Ankle

    Science.gov (United States)

    ... for Educators Search English Español X-Ray Exam: Ankle KidsHealth / For Parents / X-Ray Exam: Ankle What's in this article? What It Is Why ... You Have Questions Print What It Is An ankle X-ray is a safe and painless test ...

  7. Use of silicon microstrip detectors in medical diagnostic x-rays

    International Nuclear Information System (INIS)

    Cabal Rodriguez, Ana Ester

    2004-11-01

    This work presents the development and characterization of a single photon counting system based on silicon microstrip detectors, used in High Energy Physics experiments, and on low noise multichannel readout electronics. The thesis evaluates the feasibility of dual energy X-ray imaging with silicon microstrip detectors to be applied on medical diagnosis. Dual energy mammographic and angiographic experimental tests have been performed using the developed counting systems proto types, properly phantoms and quasi-monochromatic X ray beams, obtained on a compact dichromatic source based on a conventional X-ray tube and a mosaic crystal. A Monte Carlo simulation of the performance of the experimental setup for dual X-ray imaging has also been carried out using MCNP-4C transport code. We obtained good agreement between MCNP results and the experimental data. (Author)

  8. SMM x ray polychromator

    Science.gov (United States)

    Saba, J. L. R.

    1993-01-01

    The objective of the X-ray Polychromator (XRP) experiment was to study the physical properties of solar flare plasma and its relation to the parent active region to understand better the flare mechanism and related solar activity. Observations were made to determine the temperature, density, and dynamic structure of the pre-flare and flare plasma as a function of wavelength, space and time, the extent to which the flare plasma departs from thermal equilibrium, and the variation of this departure with time. The experiment also determines the temperature and density structure of active regions and flare-induced changes in the regions.

  9. Obstetric X-rays

    International Nuclear Information System (INIS)

    Mwachi, M.K.

    2006-01-01

    Radiography of the pelvis should never be taken to diagnose early pregnancy, because of potential hazards of radiation damage to the growing foetus. the only indication occurs in the last week of pregnancy (37 weeks). Obstetric X-ray will help you answer like confirmation of malposition,multiple pregnancies; fetal abnormalities e.g. hydrocephalus, foetal disposition. The choice of radiographic projection will help give foetal presentation, disposition as well as foetal maturity. The search pattern helps you determine maternal and spine deformity, foetal spine and head , foetal presentation and any other anomalies

  10. X-ray film

    International Nuclear Information System (INIS)

    Arndt, U.W.; Gilmore, D.J.; Wonacott, A.J.

    1977-01-01

    The performance of film as an X-ray detector is discussed and its behaviour is compared with that of a perfect Poissonian detector. The efficiency of microdensitometry as a method of extracting the information recorded on the film is discussed. More emphasis is placed in the precision of microdensitometric measurements than on the more obvious characteristic of film speed. The effects of chemical fog and background on the precision of the measurements is considered and it is concluded that the final limit to precision is set by the chemical fog. (B.D.)

  11. X-ray diffraction

    International Nuclear Information System (INIS)

    Vries, J.L. de.

    1976-01-01

    The seventh edition of Philips' Review of literature on X-ray diffraction begins with a list of conference proceedings on the subject, organised by the Philips' organisation at regular intervals in various European countries. This is followed by a list of bulletins. The bibliography is divided according to the equipment (cameras, diffractometers, monochromators) and its applications. The applications are subdivided into sections for high/low temperature and pressure, effects due to the equipment, small angle scattering and a part for stress, texture and phase analyses of metals and quantitative analysis of minerals

  12. Soft x-ray lasers

    International Nuclear Information System (INIS)

    Matthews, D.L.; Rosen, M.D.

    1988-01-01

    One of the elusive dreams of laser physicists has been the development of an x-ray laser. After 25 years of waiting, the x-ray laser has at last entered the scientific scene, although those now in operation are still laboratory prototypes. They produce soft x rays down to about five nanometers. X-ray lasers retain the usual characteristics of their optical counterparts: a very tight beam, spatial and temporal coherence, and extreme brightness. Present x-ray lasers are nearly 100 times brighter that the next most powerful x-ray source in the world: the electron synchrotron. Although Lawrence Livermore National Laboratory (LLNL) is widely known for its hard-x-ray laser program which has potential applications in the Strategic Defense Initiative, the soft x-ray lasers have no direct military applications. These lasers, and the scientific tools that result from their development, may one day have a place in the design and diagnosis of both laser fusion and hard x-ray lasers. The soft x-ray lasers now in operation at the LLNL have shown great promise but are still in the primitive state. Once x-ray lasers become reliable, efficient, and economical, they will have several important applications. Chief among them might be the creation of holograms of microscopic biological structures too small to be investigated with visible light. 5 figs

  13. X-ray spectrometry

    International Nuclear Information System (INIS)

    Markowicz, A.A.; Van Grieken, R.E.

    1986-01-01

    In the period under review, i.e, through 1984 and 1985, some 600 articles on XRS (X-ray spectrometry) were published; most of these have been scanned and the most fundamental ones are discussed. All references will refer to English-language articles, unless states otherwise. Also general books have appeared on quantitative EPXMA (electron-probe X-ray microanalysis) and analytical electron microscopy (AEM) as well as an extensive review on the application of XRS to trace analysis of environmental samples. In the period under review no radically new developments have been seen in XRS. However, significant improvements have been made. Gain in intensities has been achieved by more efficient excitation, higher reflectivity of dispersing media, and better geometry. Better understanding of the physical process of photon- and electron-specimen interactions led to complex but more accurate equations for correction of various interelement effects. Extensive use of micro- and minicomputers now enables fully automatic operation, including qualitative analysis. However, sample preparation and presentation still put a limit to further progress. Although some authors find XRS in the phase of stabilization or even stagnation, further gradual developments are expected, particularly toward more dedicated equipment, advanced automation, and image analysis systems. Ways are outlined in which XRS has been improved in the 2 last years by excitation, detection, instrumental, methodological, and theoretical advances. 340 references

  14. X-ray imaging for security applications

    Science.gov (United States)

    Evans, J. Paul

    2004-01-01

    The X-ray screening of luggage by aviation security personnel may be badly hindered by the lack of visual cues to depth in an image that has been produced by transmitted radiation. Two-dimensional "shadowgraphs" with "organic" and "metallic" objects encoded using two different colors (usually orange and blue) are still in common use. In the context of luggage screening there are no reliable cues to depth present in individual shadowgraph X-ray images. Therefore, the screener is required to convert the 'zero depth resolution' shadowgraph into a three-dimensional mental picture to be able to interpret the relative spatial relationship of the objects under inspection. Consequently, additional cognitive processing is required e.g. integration, inference and memory. However, these processes can lead to serious misinterpretations of the actual physical structure being examined. This paper describes the development of a stereoscopic imaging technique enabling the screener to utilise binocular stereopsis and kinetic depth to enhance their interpretation of the actual nature of the objects under examination. Further work has led to the development of a technique to combine parallax data (to calculate the thickness of a target material) with the results of a basis material subtraction technique to approximate the target's effective atomic number and density. This has been achieved in preliminary experiments with a novel spatially interleaved dual-energy sensor which reduces the number of scintillation elements required by 50% in comparison to conventional sensor configurations.

  15. X-ray table

    International Nuclear Information System (INIS)

    Craig, J.R.; Otto, G.W.

    1980-01-01

    An X-ray radiographic or fluoroscopic table is described which includes a film holder with a frame attached to a cable running over end pulleys for positioning the holder longitudinally as desired under the table top. The holder has a front opening to receive a cassette-supporting tray which can be slid out on tracks to change the cassette. A reed switch on the frame is opened by a permanent magnet on the tray only when the tray is half-way out. When the switch is closed, an electromagnet locks the pulley and the holder in place. The holder is thus automatically locked in place not only during exposure (tray in) but when the tray is out for changing the cassette. To re-position the holder, the operator pulls the tray half-out and, using the tray itself, pushes the holder along the table, the holder being counterbalanced by a weight. (author)

  16. X-ray equipment

    International Nuclear Information System (INIS)

    Redmayne, I.G.B.

    1988-01-01

    The patent concerns a warning and protection system for mobile x-ray equipment used for 'on site' radiography, so that workers in the vicinity of such a working unit can be alerted to its presence. The invention is a local repeater warning system which gives a preliminary warning that energisation of the tubehead is imminent, as well as a switch near the tubehead to abort or inhibit energisation. The latter switch allows personnel caught in the vicinity of the tubehead to prevent energisation. The preliminary warning may be flashing lamps or by a klaxon. The control unit for the equipment may include a monitoring circuit to detect failure of the warning light or klaxon. (U.K.)

  17. X-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Redmayne, I.G.B.

    1988-01-06

    The patent concerns a warning and protection system for mobile x-ray equipment used for 'on site' radiography, so that workers in the vicinity of such a working unit can be alerted to its presence. The invention is a local repeater warning system which gives a preliminary warning that energisation of the tubehead is imminent, as well as a switch near the tubehead to abort or inhibit energisation. The latter switch allows personnel caught in the vicinity of the tubehead to prevent energisation. The preliminary warning may be flashing lamps or by a klaxon. The control unit for the equipment may include a monitoring circuit to detect failure of the warning light or klaxon. (U.K.).

  18. Some practical aspects of dual-energy CT scanning

    International Nuclear Information System (INIS)

    Dunscombe, P.B.; Katz, D.E.; Stacey, A.J.

    1984-01-01

    Using the dual-energy scanning method developed by Brooks (1977), and making slow x-ray scans at 100 kVp, 35 mA and 140 kVp, 20 mA, measurements were made of electron density and effective atomic number in the lumbar spines of 36 patients aged from 22 to 87 years, and not known to be suffering from conditions which result in osteoporosis or osteomalacia. The authors discuss in detail the sources of experimental error which contributed to the large measured spread of normal values of electron density and effective atomic number. (U.K.)

  19. Some practical aspects of dual-energy CT scanning

    Energy Technology Data Exchange (ETDEWEB)

    Dunscombe, P.B.; Katz, D.E.; Stacey, A.J. (Charing Cross Group of Hospitals, London (UK))

    1984-01-01

    Using the dual-energy scanning method developed by Brooks (1977), and making slow x-ray scans at 100 kVp, 35 mA and 140 kVp, 20 mA, measurements were made of electron density and effective atomic number in the lumbar spines of 36 patients aged from 22 to 87 years, and not known to be suffering from conditions which result in osteoporosis or osteomalacia. The authors discuss in detail the sources of experimental error which contributed to the large measured spread of normal values of electron density and effective atomic number.

  20. X-Ray Lasers 2016

    CERN Document Server

    Bulanov, Sergei; Daido, Hiroyuki; Kato, Yoshiaki

    2018-01-01

    These proceedings comprise a selection of invited and contributed papers presented at the 15th International Conference on X-Ray Lasers (ICXRL 2016), held at the Nara Kasugano International Forum, Japan, from May 22 to 27, 2016. This conference was part of an ongoing series dedicated to recent developments in the science and technology of x-ray lasers and other coherent x-ray sources with additional focus on supporting technologies, instrumentation and applications.   The book showcases recent advances in the generation of intense, coherent x-rays, the development of practical devices and their applications across a wide variety of fields. It also discusses emerging topics such as plasma-based x-ray lasers, 4th generation accelerator-based sources and higher harmonic generations, as well as other x-ray generation schemes.

  1. X-ray instrumentation in astronomy

    International Nuclear Information System (INIS)

    Cuhlane, J.L.

    1985-01-01

    This book presents the proceedings of a conference devoted to x-ray instrumentation in astronomy. Special sections are: AXAF X-Ray Optical Systems; Specialized X-Ray Systems; X-Ray Optical Systems I; X-Ray Optical Systems II; Gas Filled X-Ray Detectors II; The NASA Advanced X-Ray Astrophysics Facility; X-Ray and EUV Spectrometers; Microchannel Plates; and Solid State Detectors

  2. Topological X-Rays Revisited

    Science.gov (United States)

    Lynch, Mark

    2012-01-01

    We continue our study of topological X-rays begun in Lynch ["Topological X-rays and MRI's," iJMEST 33(3) (2002), pp. 389-392]. We modify our definition of a topological magnetic resonance imaging and give an affirmative answer to the question posed there: Can we identify a closed set in a box by defining X-rays to probe the interior and without…

  3. X-ray and neutron interrogation of air cargo for mobile applications

    Energy Technology Data Exchange (ETDEWEB)

    Van Liew, Seth

    2015-06-01

    A system for scanning break-bulk cargo for mobile applications is presented. This combines a 140 kV multi-view, multi-energy X-ray system with 2.5 MeV neutrons. The system uses dual energy X-ray radiography with neutron radiography. The X-ray and neutron systems were designed to be collocated in a mobile environment. Various materials were interrogated with the intent of distinguishing threat materials such as explosives from similar benign materials. In particular, the identification of threats and bengins with nearly identical effective atomic numbers has been demonstrated.

  4. X-ray and neutron interrogation of air cargo for mobile applications

    International Nuclear Information System (INIS)

    Van Liew, Seth

    2015-01-01

    A system for scanning break-bulk cargo for mobile applications is presented. This combines a 140 kV multi-view, multi-energy X-ray system with 2.5 MeV neutrons. The system uses dual energy X-ray radiography with neutron radiography. The X-ray and neutron systems were designed to be collocated in a mobile environment. Various materials were interrogated with the intent of distinguishing threat materials such as explosives from similar benign materials. In particular, the identification of threats and bengins with nearly identical effective atomic numbers has been demonstrated

  5. The X-ray crystal bichromator – possible modifications and applications

    Energy Technology Data Exchange (ETDEWEB)

    Hrdý, Jaromír, E-mail: hrdy@fzu.cz

    2017-05-11

    The X-ray crystal bichromator is a device which delivers two arbitrarily chosen wavelengths in one beam. The principle and alignment was described in our previous work (Hrdý et al., 2016). With some modifications this device may be used for time-resolved experiments and dual energy imaging.

  6. Spectral correction algorithm for multispectral CdTe x-ray detectors

    DEFF Research Database (Denmark)

    Christensen, Erik D.; Kehres, Jan; Gu, Yun

    2017-01-01

    Compared to the dual energy scintillator detectors widely used today, pixelated multispectral X-ray detectors show the potential to improve material identification in various radiography and tomography applications used for industrial and security purposes. However, detector effects, such as charge...

  7. X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

    This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

  8. X-ray filtration apparatus

    International Nuclear Information System (INIS)

    Thompson, G.

    1992-01-01

    This invention relates to an X-ray shielding support device. In spite of considerable development in X-ray taking techniques, a need still exists for effective shielding, inter alia, to compensate for variations in the thickness, density and the absorption properties of the object being studied. By appropriate shielding, the X-ray image produced is of sufficient detail, contrast and intensity over its entire area to constitute a useful diagnostic aid. It is also desirable to subject the patient to the smallest possible X-ray dosage. 4 figs

  9. X-ray emission spectroscopy. X-ray fluorescence

    International Nuclear Information System (INIS)

    Despujols, J.

    1992-01-01

    Principles of X-ray emission spectrometry are first recalled, then wave-length dispersive and energy dispersive X-ray fluorescence spectrometer are described. They are essentially designed for qualitative and quantitative analysis of elements (Z>10). Sample preparation, calibration, corrections, interferences, accuracy are reviewed. Examples of use in different industries are given. (71 refs.)

  10. Dual-energy mammography: simulation studies

    International Nuclear Information System (INIS)

    Bliznakova, K; Kolitsi, Z; Pallikarakis, N

    2006-01-01

    This paper presents a mammography simulator and demonstrates its applicability in feasibility studies in dual-energy (DE) subtraction mammography. This mammography simulator is an evolution of a previously presented x-ray imaging simulation system, which has been extended with new functionalities that are specific for DE simulations. The new features include incident exposure and dose calculations, the implementation of a DE subtraction algorithm as well as amendments to the detector and source modelling. The system was then verified by simulating experiments and comparing their results against published data. The simulator was used to carry out a feasibility study of the applicability of DE techniques in mammography, and more precisely to examine whether this modality could result in better visualization and detection of microcalcifications. Investigations were carried out using a 3D breast software phantom of average thickness, monoenergetic and polyenergetic beam spectra and various detector configurations. Dual-shot techniques were simulated. Results showed the advantage of using monoenergetic in comparison with polyenergetic beams. Optimization studies with monochromatic sources were carried out to obtain the optimal low and high incident energies, based on the assessment of the figure of merit of the simulated microcalcifications in the subtracted images. The results of the simulation study with the optimal energies demonstrated that the use of the DE technique can improve visualization and increase detectability, allowing identification of microcalcifications of sizes as small as 200 μm. The quantitative results are also verified by means of a visual inspection of the synthetic images

  11. Development of a 3-D X-ray system

    Science.gov (United States)

    Evans, James Paul Owain

    The interpretation of standard two-dimensional x-ray images by humans is often very difficult. This is due to the lack of visual cues to depth in an image which has been produced by transmitted radiation. The solution put forward in this research is to introduce binocular parallax, a powerful physiological depth cue, into the resultant shadowgraph x-ray image. This has been achieved by developing a binocular stereoscopic x-ray imaging technique, which can be used for both visual inspection by human observers and also for the extraction of three-dimensional co-ordinate information. The technique is implemented in the design and development of two experimental x-ray systems and also the development of measurement algorithms. The first experimental machine is based on standard linear x-ray detector arrays and was designed as an optimum configuration for visual inspection by human observers. However, it was felt that a combination of the 3-D visual inspection capability together with a measurement facility would enhance the usefulness of the technique. Therefore, both a theoretical and an empirical analysis of the co-ordinate measurement capability of the machine has been carried out. The measurement is based on close-range photogrammetric techniques. The accuracy of the measurement has been found to be of the order of 4mm in x, 3mm in y and 6mm in z. A second experimental machine was developed and based on the same technique as that used for the first machine. However, a major departure has been the introduction of a dual energy linear x-ray detector array which will allow, in general, the discrimination between organic and inorganic substances. The second design is a compromise between ease of visual inspection for human observers and optimum three-dimensional co-ordinate measurement capability. The system is part of an on going research programme into the possibility of introducing psychological depth cues into the resultant x-ray images. The research presented in

  12. X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Attekum, P.M.T.M. van.

    1979-01-01

    The methods and results of X-ray photoelectron spectroscopy in the study of plasmons, alloys and gold compounds are discussed. After a comprehensive introduction, seven papers by the author, previously published elsewhere, are reprinted and these cover a wide range of the uses of X-ray photoelectron spectroscopy. (W.D.L.)

  13. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Weiss, M.E.

    1980-01-01

    Intra-oral dental X-ray apparatus for panoramic radiography is described in detail. It comprises a tubular target carrier supporting at its distal end a target with an inclined forward face. Image definition is improved by positioning in the path of the X-rays a window of X-ray transmitting ceramic material, e.g. 90% oxide of Be, or Al, 7% Si0 2 . The target carrier forms a probe which can be positioned in the patient's mouth. X-rays are directed forwardly and laterally of the target to an X-ray film positioned externally. The probe is provided with a detachable sleeve having V-form arms of X-ray opaque material which serve to depress the tongue out of the radiation path and also shield the roof of the mouth and other regions of the head from the X-ray pattern. A cylindrical lead shield defines the X-ray beam angle. (author)

  14. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and easiest ... bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that those parts of a patient's body not being imaged receive minimal radiation exposure. top of page What are the limitations of Bone X-ray (Radiography)? ...

  16. Traditional x-ray imaging

    International Nuclear Information System (INIS)

    Hay, G.A.

    1982-01-01

    Methods of imaging x-rays, with particular reference to medicine, are reviewed. The history and nature of x-rays, their production and spectra, contrast, shapes and fine structure, image transducers, including fluorescent screens, radiography, fluoroscopy, and image intensifiers, image detection, perception and enhancement and clinical applications are considered. (U.K.)

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that those parts of a patient's body not being imaged receive minimal radiation exposure. ...

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety How to Read Your Radiology Report ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... are a form of radiation like light or radio waves. X-rays pass through most objects, including the body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small burst of radiation that passes through the body, recording ...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different parts of the body absorb the x-rays in ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... clothing that might interfere with the x-ray images. Women should always inform their physician and x-ray ... lowest radiation dose possible while producing the best images for ... organizations continually review and update the technique standards used ...

  2. X-ray imaging system

    International Nuclear Information System (INIS)

    Houston, J.M.

    1980-01-01

    A novel, high-speed apparatus for use in X-ray computerised tomography is described in detail. It consists of a semi-circular array of X-ray sources, collimators and an ion chamber array for detection of the X-rays. The X-ray sources may be pulsed in salvos such that the corresponding detectors in the array are only illuminated by one source. The use of computer controlled salvos speeds up the image processing by at least a factor of two. The ion chamber array is designed to have a constant detection efficiency for varying angles of X-ray incidence. A detailed description of the detector construction and suggested gaseous fillings are given. It is claimed that the present tomographic system allows fast and accurate imaging of internal body organs and is insensitive to the blurring effects which motion of these organs tends to produce. (UK)

  3. X-ray diagnostics for TFTR

    International Nuclear Information System (INIS)

    von Goeler, S.; Hill, K.W.; Bitter, M.

    1982-12-01

    A short description of the x-ray diagnostic preparation for the TFTR tokamak is given. The x-ray equipment consists of the limiter x-ray monitoring system, the soft x-ray pulse-height-analysis-system, the soft x-ray imaging system and the x-ray crystal spectrometer. Particular attention is given to the radiation protection of the x-ray systems from the neutron environment

  4. X-ray filter for chest X-rays

    International Nuclear Information System (INIS)

    Ferlic, D.J.

    1984-01-01

    A description is given of an X-ray filter comprised of a sheet of radiation absorbing material with an opening corresponding to the spine and central portion of the heart. The upper portion of the filter exhibits a relatively narrow opening which becomes gradually wider toward the lower portion of the filter. This filter will permit an acceptable density level of x-ray exposure for the lungs while allowing a higher level of x-ray exposure for the mediastinum areas of the body. (author)

  5. X-ray filter for chest x-rays

    International Nuclear Information System (INIS)

    Ferlic, D.J.

    1984-01-01

    Filter for use in medical x-ray apparatus to permit higher intensity x-ray exposure in the heart and mediastinum area while maintaining a normal level of x-ray exposure in other areas of the body, particlarly in the lung area. The filter comprises a sheet of radiation absorbing material having an opening therein, said opening corresponding to the spine and central portion of the heart. Accordingly, the upper portion of the filter exhibits a relatively narrow opening which becomes gradually wider toward the lower portion of the filter

  6. The value of calcaneal bone mass measurement using a dual X-ray laser calscan device in risk screening for osteoporosis

    Directory of Open Access Journals (Sweden)

    Gulseren Kayalar

    2009-01-01

    Full Text Available OBJECTIVE: To evaluate how bone mineral density in the calcaneus measured by a dual energy X-ray laser (DXL correlates with bone mineral density in the spine and hip in Turkish women over 40 years of age and to determine whether calcaneal dual energy X-ray laser variables are associated with clinical risk factors to the same extent as axial bone mineral density measurements obtained using dual energy x-ray absorbtiometry (DXA. MATERIALS AND METHODS: A total of 2,884 Turkish women, aged 40-90 years, living in Ankara were randomly selected. Calcaneal bone mineral density was evaluated using a dual energy X-ray laser Calscan device. Subjects exhibiting a calcaneal dual energy X-ray laser T- score <-2.5 received a referral for DXA of the spine and hip. Besides dual energy X-ray laser measurements, all subjects were questioned about their medical history and the most relevant risk factors for osteoporosis. RESULTS: Using a T-score threshold of -2.5, which is recommended by the World Health Organization (WHO, dual energy X-ray laser calcaneal measurements showed that 13% of the subjects had osteoporosis, while another 56% had osteopenia. The mean calcaneal dual energy X-ray laser T-score of postmenopausal subjects who were smokers with a positive history of fracture, hormone replacement therapy (HRT, covered dressing style, lower educational level, no regular exercise habits, and low tea consumption was significantly lower than that obtained for the other group (p<0.05. A significant correlation was observed between the calcaneal dual energy X-ray laser T-score and age (r=-0.465, p=0.001, body mass index (BMI (r=0.223, p=0.001, number of live births (r=-0.229, p=0.001, breast feeding time (r=-0.064, p=0.001, and age at menarche (r=-0.050, p=0.008. The correlations between calcaneal DXL and DXA T-scores (r=0.340, p=0.001 and calcaneal DXL and DXA Z-scores (r=0.360, p=0.001 at the spine, and calcaneal DXL and DXA T- scores (r=0.28, p=0.001 and calcaneal

  7. Dual energy computer tomography. Objectve dosimetry, image quality and dose efficiency; Dual Energy Computertomographie. Objektive Dosimetrie, Bildqualitaet und Dosiseffizienz

    Energy Technology Data Exchange (ETDEWEB)

    Schenzle, Jan Christian

    2012-05-24

    The aim of the present studies was an objective reflection of newly developed methods of modern imaging techniques concerning radiation exposure to the human body. Dual Source computed tomography has opened up a broad variety of new diagnostic possibilities. Using two X-ray sources with an angular offset of about 90 in a single gantry, images with a high spatiotemporal resolution can be achieved, for example in patients suffering acute chest pain. The Dual Energy Mode is based on the acquisition of two data sets with two different X-ray spectra which make it possible to identify certain substances with different spectral properties like bone, iodine or other organic material. [6-17] There is no doubt that this technical innovation will make an essential contribution to clinical diagnostics, but it remained to be proven that there is no additional dose. An anthropomorphic Phantom and thermoluminiscent detectors were used to objectively quantify the radiation dose resulting from the different examination protocols. For Dual Energy CT examinations, it was possible to verify dose neutrality in combination with comparable image quality and even improved contrast to noise ratio. Nowadays, this protocol is used in clinical routine examinations, e.g. for the evaluation of pulmonary embolism. A milestone in dose reduction was reached with modern triple rule out protocols. Causes of acute chest pain such as heart attack, pulmonary embolism or aortic rupture can be differentiated in a single examination with a high precision and a fractional amount of dose compared to conventional methods.

  8. Semiconductor X-ray detectors

    CERN Document Server

    Lowe, Barrie Glyn

    2014-01-01

    Identifying and measuring the elemental x-rays released when materials are examined with particles (electrons, protons, alpha particles, etc.) or photons (x-rays and gamma rays) is still considered to be the primary analytical technique for routine and non-destructive materials analysis. The Lithium Drifted Silicon (Si(Li)) X-Ray Detector, with its good resolution and peak to background, pioneered this type of analysis on electron microscopes, x-ray fluorescence instruments, and radioactive source- and accelerator-based excitation systems. Although rapid progress in Silicon Drift Detectors (SDDs), Charge Coupled Devices (CCDs), and Compound Semiconductor Detectors, including renewed interest in alternative materials such as CdZnTe and diamond, has made the Si(Li) X-Ray Detector nearly obsolete, the device serves as a useful benchmark and still is used in special instances where its large, sensitive depth is essential. Semiconductor X-Ray Detectors focuses on the history and development of Si(Li) X-Ray Detect...

  9. X-ray, CT and DXA study of bone loss on medieval remains from North-West Italy.

    Science.gov (United States)

    Borrè, Alda; Boano, Rosa; Di Stefano, Marco; Castiglione, Anna; Ciccone, Giovannino; Isaia, Giovanni Carlo; Panattoni, Gian Luigi; Faletti, Carlo

    2015-07-01

    The aim of this study was to investigate whether the population differences in osteoporosis observed nowadays is a reflection of the times and modern lifestyle factors, or whether they were also present in the past. The study was performed on the skeletal remains of medieval and post-medieval populations from a burial ground in the North-West of Italy. Some individuals had been buried inside the church (privileged subjects), others outside in the parvis (members of rural population), and others still to the north of the church. X-ray, computed tomography and dual-energy X-ray absorptiometry studies were carried out on the lumbar spines and/or femurs of 27 male and 28 female individuals to determine any associations between cortical index, bone mineral density (BMD), gender, age and social status. No statistically significant differences were observed in cortical index values according to gender, age or place of burial. Conversely, statistically significant differences in average BMD values were observed according to place of burial; in particular, among those buried inside the church, a lower BMD was observed compared to the parvis group (1.09 vs. 1.42, p < 0.001) and the north group (1.09 vs. 1.49, p < 0.001). The differences observed in the BMD values may be related to the different lifestyle of the rural population, i.e. more dietary calcium intake, more sun exposure and vigorous physical activity, compared to that of the privileged individuals.

  10. X-ray film calibration

    International Nuclear Information System (INIS)

    Stone, G.F.; Dittmore, C.H.; Henke, B.L.

    1986-01-01

    This paper discusses the use of silver halide x-ray films for imaging and spectroscopy which is limited by the range of intensities that can be recorded and densitometered. Using the manufacturers processing techniques can result in 10 2-3 range in intensity recorded over 0-5 density range. By modifying the chemistry and processing times, ranges of 10 5-6 can be recorded in the same density range. The authors report on x-ray film calibration work and dynamic range improvements. Changes to the processing chemistry and the resulting changes in dynamic range and x-ray sensitivity are discussed

  11. Women and x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Dunkley, P A; Stewart, J H

    1976-01-01

    When a woman comes to an X-Ray Department it is usually necessary to know the present stage of her menstrual cycle. X-Rays may have an adverse effect on the embryo, especially in early pregnancy. However, exposure to X-Rays at any stage may be associated with a slightly increased incidence of malignant disease in childhood. The International Commission on Radiological Protection recommends that in women of child-bearing age (in some cases as young as 11 years), non-urgent diagnostic radiography be confined to the preovulatory phase of the menstrual cycle: that is, 14 days following the first day of the last menstrual period.

  12. Upsurge of X-ray astronomy 230-

    International Nuclear Information System (INIS)

    Hudec, D.R.

    1978-01-01

    Instruments are described used for X-ray astronomy, namely X-ray detectors and X-ray telescopes. Unlike telescopes, the detectors do not comprise X-ray optics. A survey is given of the results obtained in solar and stellar X-ray astronomy and hypotheses are submitted on the origin of X radiation in the interstellar space. (J.B.)

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... more information about pregnancy and x-rays. A Word About Minimizing Radiation Exposure Special care is taken ... and/or your insurance provider to get a better understanding of the possible charges you will incur. ...

  14. Bone X-Ray (Radiography)

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    Full Text Available ... is repeated. Two or three images (from different angles) will typically be taken. An x-ray may ... RadiologyInfo.org is not a medical facility. Please contact your physician with specific medical questions or for ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... no special preparation. Tell your doctor and the technologist if there is any possibility you are pregnant. ... should always inform their physician and x-ray technologist if there is any possibility that they are ...

  16. X-ray guided biopsy

    International Nuclear Information System (INIS)

    Casanova, R.; Lezana, A.H.; Pedrosa, C.S.

    1980-01-01

    Fine needle aspiration biopsy (FNAB) is now a routine procedure in many X-ray Departments. This paper presents the authors' experience with this technique in chest, abdominal and skeletal lesions. (Auth.)

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Radiography) - Bone Bone x-ray uses a very small dose of ionizing radiation to produce pictures of ... exposing a part of the body to a small dose of ionizing radiation to produce pictures of ...

  18. Bone X-Ray (Radiography)

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    Full Text Available ... replacement and fracture reductions. look for injury, infection, arthritis , abnormal bone growths and bony changes seen in ... injuries, including fractures, and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely ...

  19. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Weiss, M.E.

    1980-01-01

    Intra-oral dental X-ray apparatus for panoramic dental radiography is described in detail. It comprises an electron gun having an elongated tubular target carrier extending into the patient's mouth. The carrier supports an inclined target for direction of an X-ray pattern towards a film positioned externally of the patient's mouth. Image definition is improved by a focusing anode which focuses the electron beam into a sharp spot (0.05 to 0.10 mm diameter) on the target. The potential on the focusing anode is adjustable to vary the size of the spot. An X-ray transmitting ceramic (oxides of Be, Al and Si) window is positioned adjacent to the front face of the target. The electron beam can be magnetically deflected to change the X-ray beam direction. (author)

  20. Bone X-Ray (Radiography)

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    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... procedure varies. See the Safety page for more information about radiation dose. Women should always inform their ...

  1. X-Ray Assembler Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Federal regulations require that an assembler who installs one or more certified components of a diagnostic x-ray system submit a report of assembly. This database...

  2. Bone X-Ray (Radiography)

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    Full Text Available ... technologist, an individual specially trained to perform radiology examinations, positions the patient on the x-ray table ... bone is forming), for comparison purposes. When the examination is complete, you may be asked to wait ...

  3. Bone X-Ray (Radiography)

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    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... in a known abnormality can be monitored over time. Follow-up examinations are sometimes the best way ...

  4. Bone X-Ray (Radiography)

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    Full Text Available ... the radiation while soft tissue, such as muscle, fat and organs, allow more of the x-rays ... taken of the unaffected limb, or of a child's growth plate (where new bone is forming), for ...

  5. Bone X-Ray (Radiography)

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    Full Text Available ... the radiation while soft tissue, such as muscle, fat and organs, allow more of the x-rays ... information you were looking for? Yes No Please type your comment or suggestion into the following text ...

  6. Bone X-Ray (Radiography)

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    Full Text Available ... pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to ... See the Safety page for more information about pregnancy and x-rays. top of page What does ...

  7. Bone X-Ray (Radiography)

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    Full Text Available ... a large photographic negative). Today, most images are digital files that are stored electronically. These stored images ... and places the x-ray film holder or digital recording plate under the table in the area ...

  8. Bone X-Ray (Radiography)

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    Full Text Available ... in metabolic conditions. assist in the detection and diagnosis of bone cancer . locate foreign objects in soft ... frequently compared to current x-ray images for diagnosis and disease management. top of page How is ...

  9. Bone X-Ray (Radiography)

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    Full Text Available ... of any bone in the body, including the hand, wrist, arm, elbow, shoulder, spine, pelvis, hip, thigh, knee, leg ( ... Image Gallery Radiological technologist preparing to take an arm x-ray on a ... Images related ...

  10. Bone X-Ray (Radiography)

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    Full Text Available ... care is taken during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection organizations continually review ...

  11. Bone X-Ray (Radiography)

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    Full Text Available ... very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that ... radiation oncology provider in your community, you can search the ACR-accredited facilities database . This website does ...

  12. Bone X-Ray (Radiography)

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    Full Text Available ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different parts of the body absorb the x-rays in varying degrees. Dense ...

  13. Bone X-Ray (Radiography)

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    Full Text Available ... x-ray machine is a compact apparatus that can be taken to the patient in a hospital ... so that any change in a known abnormality can be monitored over time. Follow-up examinations are ...

  14. Bone X-Ray (Radiography)

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    Full Text Available ... of page What will I experience during and after the procedure? A bone x-ray examination itself ... available in emergency rooms, physician offices, ambulatory care centers, nursing homes and other locations, making it convenient ...

  15. Bone X-Ray (Radiography)

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    Full Text Available ... will analyze the images and send a signed report to your primary care or referring physician , who ... Medicine Radiation Safety How to Read Your Radiology Report Images related to X-ray (Radiography) - Bone Sponsored ...

  16. Bone X-Ray (Radiography)

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    Full Text Available ... bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams ... the web pages found at these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | ...

  17. Bone X-Ray (Radiography)

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    Full Text Available ... to produce pictures of any bone in the body. It is commonly used to diagnose fractured bones ... x-rays involves exposing a part of the body to a small dose of ionizing radiation to ...

  18. Bone X-Ray (Radiography)

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    Full Text Available ... to X-ray (Radiography) - Bone Sponsored by Please note RadiologyInfo.org is not a medical facility. Please ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  19. Bone X-Ray (Radiography)

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    Full Text Available ... the baby. See the Safety page for more information about pregnancy and x-rays. top of page ... procedure varies. See the Safety page for more information about radiation dose. Women should always inform their ...

  20. Bone X-Ray (Radiography)

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    Full Text Available ... and fracture reductions. look for injury, infection, arthritis , abnormal bone growths and bony changes seen in metabolic ... to current x-ray images for diagnosis and disease management. top of page How is the procedure ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... imaged. When necessary, sandbags, pillows or other positioning devices will be used to help you maintain the ... here Images × Image Gallery Radiological technologist preparing to take an arm x-ray on a patient. View ...

  2. Bone X-Ray (Radiography)

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    Full Text Available ... foot. top of page What are some common uses of the procedure? A bone x-ray is ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  3. Bone X-Ray (Radiography)

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    Full Text Available ... patient. top of page How does the procedure work? X-rays are a form of radiation like ... taken of the unaffected limb, or of a child's growth plate (where new bone is forming), for ...

  4. Flash x-ray cinematography

    International Nuclear Information System (INIS)

    Stein, W.E.

    1976-01-01

    Experiments intended to provide an overview of the potential capabilities and limitations of flash x-ray cinematography as a diagnostic technique for a Fast Reactor Safety Test Facility are described. The results provide estimates of the x-ray pulse intensity required to obtain adequate radiographs of an array of fuel pins in a typical reactor configuration. An estimate of the upper limit on the pulse duration imposed by the reactor background radiation was also determined. X-ray cinematography has been demonstrated at a repetition rate limited only by the recording equipment on hand at the time of these measurements. These preliminary results indicate that flash x-ray cinematography of the motion of fuel in a Fast Reactor Test Facility is technically feasible

  5. X-ray screening materials

    International Nuclear Information System (INIS)

    Wardley, R.B.

    1981-01-01

    This invention relates to x-ray screening materials and especially to materials in sheet form for use in the production of, for example, protective clothing such as aprons and lower back shields, curtains, mobile screens and suspended shields. The invention is based on the observation that x-ray screening materials in sheet form having greater flexiblity than the hitherto known x-ray screening materials of the same x-ray absorber content can be produced if, instead of using a single sheet of filled sheet material of increased thickness, one uses a plurality of sheets of lesser thickness together forming a laminar material of the desired thickness and one bonds the individual sheets together at their edges and, optionally, at other spaced apart points away from the edges thereby allowing one sheet to move relative to another. (U.K.)

  6. X-ray luminescent glasses

    International Nuclear Information System (INIS)

    Takahashi, T.; Yamada, O.

    1981-01-01

    X-ray luminescent glasses comprising a divalent cation such as an alkaline earth metal or other divalent cations such as pb, cd, or zn, and certain rare earth metaphosphates are suitable as vitreous, x-ray phosphors or x-ray luminescent glass fibers in an x-ray intensifying screen. The glasses have the composition n(Mo X p2o5)((1-y)tb2o3 X yce2o3 X 3p2o5) wherein N is greater than zero but less than or equal to 16, M is an alkaline earth metal or other divalent cation such as pb, cd, or zn, and Y is greater than or equal to zero but less than one

  7. Bone X-Ray (Radiography)

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    Full Text Available ... x-ray uses a very small dose of ionizing radiation to produce pictures of any bone in the ... of the body to a small dose of ionizing radiation to produce pictures of the inside of the ...

  8. Bone X-Ray (Radiography)

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    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... examination may also be necessary so that any change in a known abnormality can be monitored over ...

  9. Miniature x-ray source

    Science.gov (United States)

    Trebes, James E.; Bell, Perry M.; Robinson, Ronald B.

    2000-01-01

    A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

  10. Duodenal X-ray diagnostics

    International Nuclear Information System (INIS)

    Scheppach, W.

    1982-01-01

    The publication provides an overview of duodenal X-ray diagnostics with the aid of barium meals in 1362 patients. The introducing paragraphs deal with the topographic anatomy of the region and the methodics of X-ray investigation. The chapter entitled ''processes at the duodenum itself'' describes mainly ulcers, diverticula, congenital anomalies, tumors and inflammations. The neighbourhood processes comprise in the first place diseases having their origin at the pancreas and bile ducts. As a conclusion, endoscopic rectograde cholangio-pancreaticography and percutaneous transhepatic cholangiography are pointed out as advanced X-ray investigation methods. In the annex of X-ray images some of the described phenomena are shown in exemplary manner. (orig./MG) [de

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and ... in the typical diagnostic range for this exam. Risks There is always a slight chance of cancer ...

  13. Bone X-Ray (Radiography)

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    Full Text Available ... fracture. guide orthopedic surgery, such as spine repair/fusion, joint replacement and fracture reductions. look for injury, ... CT Exams Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety How to Read Your Radiology ...

  14. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the oldest and most frequently used form of medical imaging. A bone x-ray makes images of any ... a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... carefully aimed at the part of the body being examined, an x-ray machine produces a small ... the table in the area of the body being imaged. When necessary, sandbags, pillows or other positioning ...

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... ray examination. X-rays usually have no side effects in the typical diagnostic range for this exam. ... minimize stray (scatter) radiation. This ensures that those parts of a patient's body not being imaged receive ...

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown. ... appliances, eye glasses and any metal objects or clothing that might interfere with the x-ray images. ...

  18. Magnetic x-ray microdiffraction

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Paul G [Computer-Aided Engineering Center, University of Wisconsin, Madison, WI 53706 (United States); Isaacs, Eric D [Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2006-08-07

    Magnetic x-ray microdiffraction uses the structural specificity of x-ray diffraction to probe complex magnetic structures at the length scales relevant to physical phenomena including domain dynamics and phase transitions. Conventional magnetic crystallography techniques such as neutron or x-ray diffraction lack this spatial resolution. The combination of both reciprocal space and real space resolution with a rich magnetic cross section allows new microscopy techniques to be developed and applied to magnetism at the scale of single domains. Potential applications include a wide range of magnetic problems in nanomagnetism, the interaction of strain, polarization and magnetization in complex oxides and spatially resolved studies of magnetic phase transitions. We present the physical basis for x-ray microdiffraction and magnetic scattering processes, review microdiffraction domain imaging techniques in antiferromagnetic and ferromagnetic materials and discuss potential directions for studies. (topical review)

  19. Electromechanical x-ray generator

    Science.gov (United States)

    Watson, Scott A; Platts, David; Sorensen, Eric B

    2016-05-03

    An electro-mechanical x-ray generator configured to obtain high-energy operation with favorable energy-weight scaling. The electro-mechanical x-ray generator may include a pair of capacitor plates. The capacitor plates may be charged to a predefined voltage and may be separated to generate higher voltages on the order of hundreds of kV in the AK gap. The high voltage may be generated in a vacuum tube.

  20. Accelerator x-ray sources

    CERN Document Server

    Talman, Richard

    2007-01-01

    This first book to cover in-depth the generation of x-rays in particle accelerators focuses on electron beams produced by means of the novel Energy Recovery Linac (ERL) technology. The resulting highly brilliant x-rays are at the centre of this monograph, which continues where other books on the market stop. Written primarily for general, high energy and radiation physicists, the systematic treatment adopted by the work makes it equally suitable as an advanced textbook for young researchers.