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Sample records for quantitative computed tomography

  1. Quantitative computed tomography evaluation of pulmonary disease

    DEFF Research Database (Denmark)

    Mcevoy, Fintan J; Buelund, Lene; Strathe, Anders B

    2009-01-01

    Objective assessment of pulmonary disease from computed tomography (CT) examinations is desirable but difficult. When such assessments can be made, it is important that they are related to some part of the pathophysiologic process present.......Objective assessment of pulmonary disease from computed tomography (CT) examinations is desirable but difficult. When such assessments can be made, it is important that they are related to some part of the pathophysiologic process present....

  2. Quantitative computed tomography imaging of airway remodeling in severe asthma.

    Science.gov (United States)

    Grenier, Philippe A; Fetita, Catalin I; Brillet, Pierre-Yves

    2016-02-01

    Asthma is a heterogeneous condition and approximately 5-10% of asthmatic subjects have severe disease associated with structure changes of the airways (airway remodeling) that may develop over time or shortly after onset of disease. Quantitative computed tomography (QCT) imaging of the tracheobronchial tree and lung parenchyma has improved during the last 10 years, and has enabled investigators to study the large airway architecture in detail and assess indirectly the small airway structure. In severe asthmatics, morphologic changes in large airways, quantitatively assessed using 2D-3D airway registration and recent algorithms, are characterized by airway wall thickening, luminal narrowing and bronchial stenoses. Extent of expiratory gas trapping, quantitatively assessed using lung densitometry, may be used to assess indirectly small airway remodeling. Investigators have used these quantitative imaging techniques in order to attempt severity grading of asthma, and to identify clusters of asthmatic patients that differ in morphologic and functional characteristics. Although standardization of image analysis procedures needs to be improved, the identification of remodeling pattern in various phenotypes of severe asthma and the ability to relate airway structures to important clinical outcomes should help target treatment more effectively.

  3. Quantitative analysis of cholesteatoma using high resolution computed tomography

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    Kikuchi, Shigeru; Yamasoba, Tatsuya (Kameda General Hospital, Chiba (Japan)); Iinuma, Toshitaka

    1992-05-01

    Seventy-three cases of adult cholesteatoma, including 52 cases of pars flaccida type cholesteatoma and 21 of pars tensa type cholesteatoma, were examined using high resolution computed tomography, in both axial (lateral semicircular canal plane) and coronal sections (cochlear, vestibular and antral plane). These cases were classified into two subtypes according to the presence of extension of cholesteatoma into the antrum. Sixty cases of chronic otitis media with central perforation (COM) were also examined as controls. Various locations of the middle ear cavity were measured in terms of size in comparison with pars flaccida type cholesteatoma, pars tensa type cholesteatoma and COM. The width of the attic was significantly larger in both pars flaccida type and pars tensa type cholesteatoma than in COM. With pars flaccida type cholesteatoma there was a significantly larger distance between the malleus and lateral wall of the attic than with COM. In contrast, the distance between the malleus and medial wall of the attic was significantly larger with pars tensa type cholesteatoma than with COM. With cholesteatoma extending into the antrum, regardless of the type of cholesteatoma, there were significantly larger distances than with COM at the following sites: the width and height of the aditus ad antrum, and the width, height and anterior-posterior diameter of the antrum. However, these distances were not significantly different between cholesteatoma without extension into the antrum and COM. The hitherto demonstrated qualitative impressions of bone destruction in cholesteatoma were quantitatively verified in detail using high resolution computed tomography. (author).

  4. Quantitative computed tomography measures of emphysema and airway wall thickness are related to respiratory symptoms

    DEFF Research Database (Denmark)

    Grydeland, Thomas B; Dirksen, Asger; Coxson, Harvey O

    2010-01-01

    There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness.......There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness....

  5. Quantitative computed tomography measures of emphysema and airway wall thickness are related to respiratory symptoms

    DEFF Research Database (Denmark)

    Grydeland, Thomas B; Dirksen, Asger; Coxson, Harvey O

    2010-01-01

    There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness.......There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness....

  6. Quantitative cone beam X-ray luminescence tomography/X-ray computed tomography imaging

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    Chen, Dongmei; Zhu, Shouping, E-mail: zhusp2009@gmail.com; Chen, Xueli; Chao, Tiantian; Cao, Xu; Zhao, Fengjun; Huang, Liyu; Liang, Jimin [Engineering Research Center of Molecular and Neuro Imaging of Ministry of Education and School of Life Science and Technology, Xidian University, Xi' an, Shaanxi 710071 (China)

    2014-11-10

    X-ray luminescence tomography (XLT) is an imaging technology based on X-ray-excitable materials. The main purpose of this paper is to obtain quantitative luminescence concentration using the structural information of the X-ray computed tomography (XCT) in the hybrid cone beam XLT/XCT system. A multi-wavelength luminescence cone beam XLT method with the structural a priori information is presented to relieve the severe ill-posedness problem in the cone beam XLT. The nanophosphors and phantom experiments were undertaken to access the linear relationship of the system response. Then, an in vivo mouse experiment was conducted. The in vivo experimental results show that the recovered concentration error as low as 6.67% with the location error of 0.85 mm can be achieved. The results demonstrate that the proposed method can accurately recover the nanophosphor inclusion and realize the quantitative imaging.

  7. Morphological analysis of the proximal femur using quantitative computed tomography

    Science.gov (United States)

    Jacobson, Donald; Carrera, Guilermo

    2006-01-01

    The anatomy of the proximal femur was studied in 35 specimens using quantitative computed tomography (QCT) and compared with anatomical sections studied by plane radiography and gross dissection. We found the primary supporting structure of the femoral head to be the primary compressive strut, which is a dense column of trabecular bone projecting from the pressure buttress of the medial femoral neck to the epiphyseal scar. Trabecular bone mushroomed from the epiphyseal scar and terminated at right angles to the cortex of the femoral head. We believe the primary compressive strut is the predominant load-bearing structure connecting the femoral head to the femoral neck, as many specimens lacked continuity of the head cortex to the femoral neck. Based on the CT number, the primary compressive strut had similar bone density to cortical structures such as the lesser trochanter, calcar femorale and posterior lateral femoral cortex. Ward’s triangle lacked structural integrity in many cases, and we doubt the significance of tensile trabculae for sharing load. Surgical techniques such as femoral fracture fixation, resurfacing hip arthroplasty and allograft transplantation may benefit from this knowledge. PMID:16896872

  8. Quantitative ultrasonic computed tomography using phase-insensitive pyroelectric detectors.

    Science.gov (United States)

    Zeqiri, Bajram; Baker, Christian; Alosa, Giuseppe; Wells, Peter N T; Liang, Hai-Dong

    2013-08-07

    The principle of using ultrasonic computed tomography (UCT) clinically for mapping tissue acoustic properties was suggested almost 40 years ago. Despite strong research activity, UCT been unable to rival its x-ray counterpart in terms of the ability to distinguish tissue pathologies. Conventional piezoelectric detectors deployed in UCT are termed phase-sensitive (PS) and it is well established that this property can lead to artefacts related to refraction and phase-cancellation that mask true tissue structure, particularly for reconstructions involving attenuation. Equally, it has long been known that phase-insensitive (PI) detectors are more immune to this effect, although sufficiently sensitive devices for clinical use have not been available. This paper explores the application of novel PI detectors to UCT. Their operating principle is based on exploiting the pyroelectric properties of the piezoelectric polymer polyvinylidene difluoride. An important detector performance characteristic which makes it particularly suited to UCT, is the lack of directionality of the PI response, relative to the PS detector mode of operation. The performance of the detectors is compared to conventional PS detection methods, for quantitatively assessing the attenuation distribution within various test objects, including a two-phase polyurethane phantom. UCT images are presented for a range of single detector apertures; tomographic reconstruction images being compared with the known structure of phantoms containing inserts as small as 3 mm, which were readily imaged. For larger diameter inserts (>10 mm), the transmitter-detector combination was able to establish the attenuation coefficient of the insert to within ±10% of values determined separately from plane-wave measurements on representative material plaques. The research has demonstrated that the new PI detectors are significantly less susceptible to refraction and phase-cancellation artefacts, generating realistic images in

  9. Quantitative analysis of left ventricular strain using cardiac computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Buss, Sebastian J., E-mail: sebastian.buss@med.uni-heidelberg.de [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany); Schulz, Felix; Mereles, Derliz [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany); Hosch, Waldemar [Department of Diagnostic and Interventional Radiology, University of Heidelberg, 69120 Heidelberg (Germany); Galuschky, Christian; Schummers, Georg; Stapf, Daniel [TomTec Imaging Systems GmbH, Munich (Germany); Hofmann, Nina; Giannitsis, Evangelos; Hardt, Stefan E. [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany); Kauczor, Hans-Ulrich [Department of Diagnostic and Interventional Radiology, University of Heidelberg, 69120 Heidelberg (Germany); Katus, Hugo A.; Korosoglou, Grigorios [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany)

    2014-03-15

    Objectives: To investigate whether cardiac computed tomography (CCT) can determine left ventricular (LV) radial, circumferential and longitudinal myocardial deformation in comparison to two-dimensional echocardiography in patients with congestive heart failure. Background: Echocardiography allows for accurate assessment of strain with high temporal resolution. A reduced strain is associated with a poor prognosis in cardiomyopathies. However, strain imaging is limited in patients with poor echogenic windows, so that, in selected cases, tomographic imaging techniques may be preferable for the evaluation of myocardial deformation. Methods: Consecutive patients (n = 27) with congestive heart failure who underwent a clinically indicated ECG-gated contrast-enhanced 64-slice dual-source CCT for the evaluation of the cardiac veins prior to cardiac resynchronization therapy (CRT) were included. All patients underwent additional echocardiography. LV radial, circumferential and longitudinal strain and strain rates were analyzed in identical midventricular short axis, 4-, 2- and 3-chamber views for both modalities using the same prototype software algorithm (feature tracking). Time for analysis was assessed for both modalities. Results: Close correlations were observed for both techniques regarding global strain (r = 0.93, r = 0.87 and r = 0.84 for radial, circumferential and longitudinal strain, respectively, p < 0.001 for all). Similar trends were observed for regional radial, longitudinal and circumferential strain (r = 0.88, r = 0.84 and r = 0.94, respectively, p < 0.001 for all). The number of non-diagnostic myocardial segments was significantly higher with echocardiography than with CCT (9.6% versus 1.9%, p < 0.001). In addition, the required time for complete quantitative strain analysis was significantly shorter for CCT compared to echocardiography (877 ± 119 s per patient versus 1105 ± 258 s per patient, p < 0.001). Conclusion: Quantitative assessment of LV strain

  10. Semi-quantitative myocardial perfusion measured by computed tomography in patients with refractory angina

    DEFF Research Database (Denmark)

    Qayyum, Abbas Ali; Kühl, Jørgen Tobias; Kjaer, Andreas

    2017-01-01

    INTRODUCTION: Computed tomography (CT) is a novel method for assessment of myocardial perfusion and has not yet been compared to rubidium-82 positron emission tomography (PET). We aimed to compare CT measured semi-quantitative myocardial perfusion with absolute quantified myocardial perfusion using...

  11. Quantitative Pulmonary Imaging Using Computed Tomography and Magnetic Resonance Imaging

    Science.gov (United States)

    Washko, George R.; Parraga, Grace; Coxson, Harvey O.

    2011-01-01

    Measurements of lung function, including spirometry and body plethesmography, are easy to perform and are the current clinical standard for assessing disease severity. However, these lung functional techniques do not adequately explain the observed variability in clinical manifestations of disease and offer little insight into the relationship of lung structure and function. Lung imaging and the image based assessment of lung disease has matured to the extent that it is common for clinical, epidemiologic, and genetic investigation to have a component dedicated to image analysis. There are several exciting imaging modalities currently being used for the non-invasive study of lung anatomy and function. In this review we will focus on two of them, x-ray computed tomography and magnetic resonance imaging. Following a brief introduction of each method we detail some of the most recent work being done to characterize smoking-related lung disease and the clinical applications of such knowledge. PMID:22142490

  12. Quantitative Computed Tomography and image analysis for advanced muscle assessment

    Directory of Open Access Journals (Sweden)

    Kyle Joseph Edmunds

    2016-06-01

    Full Text Available Medical imaging is of particular interest in the field of translational myology, as extant literature describes the utilization of a wide variety of techniques to non-invasively recapitulate and quantity various internal and external tissue morphologies. In the clinical context, medical imaging remains a vital tool for diagnostics and investigative assessment. This review outlines the results from several investigations on the use of computed tomography (CT and image analysis techniques to assess muscle conditions and degenerative process due to aging or pathological conditions. Herein, we detail the acquisition of spiral CT images and the use of advanced image analysis tools to characterize muscles in 2D and 3D. Results from these studies recapitulate changes in tissue composition within muscles, as visualized by the association of tissue types to specified Hounsfield Unit (HU values for fat, loose connective tissue or atrophic muscle, and normal muscle, including fascia and tendon. We show how results from these analyses can be presented as both average HU values and compositions with respect to total muscle volumes, demonstrating the reliability of these tools to monitor, assess and characterize muscle degeneration.

  13. Quantitative computed tomography: emphysema and airway wall thickness by sex, age and smoking

    DEFF Research Database (Denmark)

    Grydeland, T B; Dirksen, A; Coxson, H O;

    2009-01-01

    We investigated how quantitative high-resolution computed tomography (HRCT) measures of emphysema and airway wall thickness (AWT) vary with sex, age and smoking history. We included 463 chronic obstructive pulmonary disease (COPD) cases and 431 controls. All included subjects were current or ex...

  14. Quantitative computed tomography measurements of emphysema for diagnosing asthma-chronic obstructive pulmonary disease overlap syndrome

    OpenAIRE

    Xie M; Wang W; Dou S; Cui L; Xiao W

    2016-01-01

    Mengshuang Xie, Wei Wang, Shuang Dou, Liwei Cui, Wei Xiao Department of Pulmonary Medicine, Qilu Hospital, Shandong University, Jinan, People’s Republic of China Background: The diagnostic criteria of asthma–COPD overlap syndrome (ACOS) are controversial. Emphysema is characteristic of COPD and usually does not exist in typical asthma patients. Emphysema in patients with asthma suggests the coexistence of COPD. Quantitative computed tomography (CT) allows repeated evalua...

  15. Quantitative computed tomography of the liver in juvenile green sea turtles (Chelonia mydas).

    Science.gov (United States)

    Bonelli, Marília de Albuquerque; de Oliveira, Daniel Capucho; Costa, Lorena Adão Vescovi Séllos; Forattini, Jannine Garcia; Júnior, João Luiz Rossi; Leite, Flaviana Lima Guião; Costa, Fabiano Séllos

    2013-06-01

    Quantitative computed tomography (QCT) is a highly sensitive, applicable technique for determining the x-ray attenuation of organs. This technique reveals great precision in the detection of alterations in the x-ray attenuation of hepatic parenchyma, although the lack of studies establishing normal values limits its application in wild animals. The objective of this study was to establish mean hepatic attenuation values in four healthy juvenile sea turtles (Chelonia mydas) using QCT. Helical computed tomography scans were performed and regions of interest selected in the liver after multi-planar reconstruction images were obtained. The mean attenuation value for the hepatic parenchyma in these four turtles was 60.09 +/- 5.3 standard deviation Hounsfield units. Determining normal x-ray attenuation values of the liver increases knowledge of the computed tomographic anatomy of this species and may be useful in the investigation of hepatic diseases.

  16. Physical bone changes in carragheenin-induced arthritis evaluated by quantitative computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Soeballe, K.; Hansen, E.S. (Aarhus Univ. (Denmark). Biomechanics Lab. Aarhus Univ. (Denmark). Inst. of Experimental Clinical Research); Pedersen, C.M. (Aarhus Kommunehospital (Denmark). Dept. of Diagnostic Radiology); Odgaard, A.; Hvid, I.; Buenger, C. (Aarhus Univ. (Denmark). Biomechanics Lab.); Juhl, G.I. (Aarhus Univ. (Denmark). Inst. of Experimental Clinical Research); Rasmussen, H.B. (Aarhus Amtssygehus (Denmark). Inst. of Pathology)

    1991-07-01

    Repeated non-invasive measurements were performed in dogs to trabecular bone density (TBD), low density bone area (LDBA), and high density bone area (HDBA) in chronic arthritis using quantitative computed tomography (QCT). Unilateral chronic arthritis of the knee had been induced by weekly instillation of 2 ml carragheenin into the right knee joint for 12 weeks with the left knee serving as a control. CT scanning of the distal femoral condyles was performed in 12 mature dogs with chronic arthritis. Another 6 dogs underwent a longitudinal CT study starting immediately prior to induction of arthritis. Indentation test and histomorphometric analyses confirmed the bone density changes as measured by CT. (orig./GDG).

  17. Corrected coronary opacification decrease from coronary computed tomography angiography: Validation with quantitative 13N-ammonia positron emission tomography.

    Science.gov (United States)

    Benz, Dominik C; Gräni, Christoph; Ferro, Paola; Neumeier, Luis; Messerli, Michael; Possner, Mathias; Clerc, Olivier F; Gebhard, Catherine; Gaemperli, Oliver; Pazhenkottil, Aju P; Kaufmann, Philipp A; Buechel, Ronny R

    2017-07-06

    To assess the functional relevance of a coronary artery stenosis, corrected coronary opacification (CCO) decrease derived from coronary computed tomography angiography (CCTA) has been proposed. The present study aims at validating CCO decrease with quantitative 13N-ammonia positron emission tomography (PET) myocardial perfusion imaging (MPI). This retrospective study consists of 39 patients who underwent hybrid CCTA/PET-MPI. From CCTA, attenuation in the coronary lumen was measured before and after a stenosis and corrected to the aorta to calculate CCO and its decrease. Relative flow reserve (RFR) was calculated by dividing the stress myocardial blood flow (MBF) of a vessel territory subtended by a stenotic coronary by the stress MBF of the reference territories without stenoses. RFR was abnormal in 11 vessel territories (27%). CCO decrease yielded a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy for prediction of an abnormal RFR of 73%, 70%, 88%, 47%, and 70%, respectively. CCTA-derived CCO decrease has moderate diagnostic accuracy to predict an abnormal RFR in PET-MPI. However, its high negative predictive value to rule out functional relevance of a given lesion may confer clinical implications in the diagnostic work-up of patients with a coronary stenosis.

  18. Comparison of the Spine and Hip BMD Assessments Derived from Quantitative Computed Tomography

    Directory of Open Access Journals (Sweden)

    Xiao-Hui Ma

    2015-01-01

    Full Text Available Quantification of bone mineral density (BMD is being used as the main method to diagnose osteoporosis. Dual-energy X-ray absorptiometry (DXA is the most common tools for measuring BMD. Compared to DXA, quantitative computed tomography (QCT can determine in three dimensions the true volumetric BMD (vBMD at any skeletal site. In addition to the spine, the hip is an important site for axial BMD measurement. This study examines lumbar spine and hip BMD of Chinese adults by QCT. Age related changes in bone mass derived by QCT measurements were determined. The osteoporosis QCT detection rates at the spine and hip are assessed in both female and male, and agreement of skeletal status category between the spine and hip in older adults is also assessed.

  19. Changes in bone structure of Corriedale sheep with inherited rickets: a peripheral quantitative computed tomography assessment.

    Science.gov (United States)

    Dittmer, Keren E; Firth, Elwyn C; Thompson, Keith G; Marshall, Jonathan C; Blair, Hugh T

    2011-03-01

    An inherited skeletal disease with gross and microscopic features of rickets has been diagnosed in Corriedale sheep in New Zealand. The aim of this study was to quantify the changes present in tibia from sheep with inherited rickets using peripheral quantitative computed tomography. In affected sheep, scans in the proximal tibia, where metaphysis becomes diaphysis, showed significantly greater trabecular bone mineral content (BMC) and bone mineral density (BMD). The sheep with inherited rickets had significantly greater BMC and bone area in the mid-diaphysis of the proximal tibia compared to control sheep. However, BMD in the mid-diaphysis was significantly less in affected sheep than in controls, due to the greater cortical area and lower voxel density values in affected sheep. From this it was concluded that the increased strain on under-mineralised bone in sheep with inherited rickets led to increased bone mass in an attempt to improve bone strength.

  20. Single- versus dual-energy quantitative computed tomography for spinal densitometry in patients with rheumatoid arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Laan, R.F.J.M.; Erning, L.J.Th.O. van; Lemmens, J.A.M.; Putte, L.B.A. van de; Ruijs, S.H.J.; Riel, P.L.C.M. van (University Hospital, Nijmegen (Netherlands))

    1992-10-01

    Lumbar bone mineral density was measured by both single- and dual-energy quantitative computed tomography in 109 patients with rheumatoid arthritis. The results were corrected for the age-related increase in vertebral fat content by converting them to percentages of expected densities, using sex and energy-level specific regression equations obtained in a normal reference population. The percentages of expected density are approximately 10% lower in the single- than in the dual-energy mode, both in the patients with and without prednisone therapy. This difference is statistically highly significant, and is positively correlated with the duration of the disease and with the degree of radiological joint destruction. The data suggest that the vertebral fat content may be increased in patients with rheumatoid arthritis, as a consequence of disease-dependent mechanisms. (Author).

  1. Finite element analysis of the hip and spine based on quantitative computed tomography.

    Science.gov (United States)

    Carpenter, R Dana

    2013-06-01

    Quantitative computed tomography (QCT) provides three-dimensional information about bone geometry and the spatial distribution of bone mineral. Images obtained with QCT can be used to create finite element models, which offer the ability to analyze bone strength and the distribution of mechanical stress and physical deformation. This approach can be used to investigate different mechanical loading scenarios (stance and fall configurations at the hip, for example) and to estimate whole bone strength and the relative mechanical contributions of the cortical and trabecular bone compartments. Finite element analyses based on QCT images of the hip and spine have been used to provide important insights into the biomechanical effects of factors such as age, sex, bone loss, pharmaceuticals, and mechanical loading at sites of high clinical importance. Thus, this analysis approach has become an important tool in the study of the etiology and treatment of osteoporosis at the hip and spine.

  2. Mapping Bone Mineral Density Obtained by Quantitative Computed Tomography to Bone Volume Fraction

    Science.gov (United States)

    Pennline, James A.; Mulugeta, Lealem

    2017-01-01

    Methods for relating or mapping estimates of volumetric Bone Mineral Density (vBMD) obtained by Quantitative Computed Tomography to Bone Volume Fraction (BVF) are outlined mathematically. The methods are based on definitions of bone properties, cited experimental studies and regression relations derived from them for trabecular bone in the proximal femur. Using an experimental range of values in the intertrochanteric region obtained from male and female human subjects, age 18 to 49, the BVF values calculated from four different methods were compared to the experimental average and numerical range. The BVF values computed from the conversion method used data from two sources. One source provided pre bed rest vBMD values in the intertrochanteric region from 24 bed rest subject who participated in a 70 day study. Another source contained preflight vBMD values from 18 astronauts who spent 4 to 6 months on the ISS. To aid the use of a mapping from BMD to BVF, the discussion includes how to formulate them for purpose of computational modeling. An application of the conversions would be used to aid in modeling of time varying changes in vBMD as it relates to changes in BVF via bone remodeling and/or modeling.

  3. Quantitative study of undersampled recoverability for sparse images in computed tomography

    DEFF Research Database (Denmark)

    Jørgensen, Jakob Heide; Sidky, Emil Y.; Hansen, Per Christian

    2012-01-01

    Image reconstruction methods based on exploiting image sparsity, motivated by compressed sensing (CS), allow reconstruction from a significantly reduced number of projections in X-ray computed tomography (CT). However, CS provides neither theoretical guarantees of accurate CT reconstruction, nor...

  4. Computed-tomography-guided anatomic standardization for quantitative assessment of dopamine transporter SPECT

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    Yokoyama, Kota [National Center of Neurology and Psychiatry, Department of Radiology, Tokyo (Japan); National Center of Neurology and Psychiatry, Integrative Brain Imaging Center, Tokyo (Japan); Imabayashi, Etsuko; Matsuda, Hiroshi [National Center of Neurology and Psychiatry, Integrative Brain Imaging Center, Tokyo (Japan); Sumida, Kaoru; Sone, Daichi; Kimura, Yukio; Sato, Noriko [National Center of Neurology and Psychiatry, Department of Radiology, Tokyo (Japan); Mukai, Youhei; Murata, Miho [National Center of Neurology and Psychiatry, Department of Neurology, Tokyo (Japan)

    2017-03-15

    For the quantitative assessment of dopamine transporter (DAT) using [{sup 123}I]FP-CIT single-photon emission computed tomography (SPECT) (DaTscan), anatomic standardization is preferable for achieving objective and user-independent quantification of striatal binding using a volume-of-interest (VOI) template. However, low accumulation of DAT in Parkinson's disease (PD) would lead to a deformation error when using a DaTscan-specific template without any structural information. To avoid this deformation error, we applied computed tomography (CT) data obtained using SPECT/CT equipment to anatomic standardization. We retrospectively analyzed DaTscan images of 130 patients with parkinsonian syndromes (PS), including 80 PD and 50 non-PD patients. First we segmented gray matter from CT images using statistical parametric mapping 12 (SPM12). These gray-matter images were then anatomically standardized using the diffeomorphic anatomical registration using exponentiated Lie algebra (DARTEL) algorithm. Next, DaTscan images were warped with the same parameters used in the CT anatomic standardization. The target striatal VOIs for decreased DAT in PD were generated from the SPM12 group comparison of 20 DaTscan images from each group. We applied these VOIs to DaTscan images of the remaining patients in both groups and calculated the specific binding ratios (SBRs) using nonspecific counts in a reference area. In terms of the differential diagnosis of PD and non-PD groups using SBR, we compared the present method with two other methods, DaTQUANT and DaTView, which have already been released as software programs for the quantitative assessment of DaTscan images. The SPM12 group comparison showed a significant DAT decrease in PD patients in the bilateral whole striatum. Of the three methods assessed, the present CT-guided method showed the greatest power for discriminating PD and non-PD groups, as it completely separated the two groups. CT-guided anatomic standardization using

  5. Evaluation of static and dynamic perfusion cardiac computed tomography for quantitation and classification tasks.

    Science.gov (United States)

    Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R; La Riviere, Patrick J; Alessio, Adam M

    2016-04-01

    Cardiac computed tomography (CT) acquisitions for perfusion assessment can be performed in a dynamic or static mode. Either method may be used for a variety of clinical tasks, including (1) stratifying patients into categories of ischemia and (2) using a quantitative myocardial blood flow (MBF) estimate to evaluate disease severity. In this simulation study, we compare method performance on these classification and quantification tasks for matched radiation dose levels and for different flow states, patient sizes, and injected contrast levels. Under conditions simulated, the dynamic method has low bias in MBF estimates (0 to [Formula: see text]) compared to linearly interpreted static assessment (0.45 to [Formula: see text]), making it more suitable for quantitative estimation. At matched radiation dose levels, receiver operating characteristic analysis demonstrated that the static method, with its high bias but generally lower variance, had superior performance ([Formula: see text]) in stratifying patients, especially for larger patients and lower contrast doses [area under the curve [Formula: see text] to 96 versus 0.86]. We also demonstrate that static assessment with a correctly tuned exponential relationship between the apparent CT number and MBF has superior quantification performance to static assessment with a linear relationship and to dynamic assessment. However, tuning the exponential relationship to the patient and scan characteristics will likely prove challenging. This study demonstrates that the selection and optimization of static or dynamic acquisition modes should depend on the specific clinical task.

  6. Bone densitometry in healthy cats by quantitative computed tomography; Densitometria ossea em gatos higidos por tomografia computadorizada quantitativa

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, D.C. [Universidade Federal do Parana - Curitiba, PR (Brazil); Costa, L.A.V.S.; Teixeira, M.W.; Costa, F.S. [Universidade Federal Rural de Pernambuco - Recife, PE (Brazil); Cardoso, M.J.L. [Universidade Estadual do Norte do Parana - Campus Luiz Meneghel - Bandeirantes, PR (Brazil)

    2012-06-15

    The radiodensity of the trabecular bone of the lumbar vertebrae in 16 healthy adult cats was studied using quantitative computed tomography (QCT). The average radiodensity of the trabecular bone of the second lumbar vertebra was 436.1 +- 42.1 Hounsfield units. However, there was a nonhomogeneous radiodensity distribution of the vertebral body. (author)

  7. Novel application of quantitative single-photon emission computed-tomography/computed tomography to predict early response to methimazole in Graves' disease

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Joo; Bang, Ji In; Kim, Ji Young; Moon, Jae Hoon [Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam (Korea, Republic of); So, Young [Dept. of Nuclear Medicine, Konkuk University Medical Center, Seoul (Korea, Republic of); Lee, Won Woo [Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul (Korea, Republic of)

    2017-06-15

    Since Graves' disease (GD) is resistant to antithyroid drugs (ATDs), an accurate quantitative thyroid function measurement is required for the prediction of early responses to ATD. Quantitative parameters derived from the novel technology, single-photon emission computed tomography/computed tomography (SPECT/CT), were investigated for the prediction of achievement of euthyroidism after methimazole (MMI) treatment in GD. A total of 36 GD patients (10 males, 26 females; mean age, 45.3 ± 13.8 years) were enrolled for this study, from April 2015 to January 2016. They underwent quantitative thyroid SPECT/CT 20 minutes post-injection of {sup 99m}Tc-pertechnetate (5 mCi). Association between the time to biochemical euthyroidism after MMI treatment and uptake, standardized uptake value (SUV), functional thyroid mass (SUVmean × thyroid volume) from the SPECT/CT, and clinical/biochemical variables, were investigated. GD patients had a significantly greater %uptake (6.9 ± 6.4%) than historical control euthyroid patients (n = 20, 0.8 ± 0.5%, p < 0.001) from the same quantitative SPECT/CT protocol. Euthyroidism was achieved in 14 patients at 156 ± 62 days post-MMI treatment, but 22 patients had still not achieved euthyroidism by the last follow-up time-point (208 ± 80 days). In the univariate Cox regression analysis, the initial MMI dose (p = 0.014), %uptake (p = 0.015), and functional thyroid mass (p = 0.016) were significant predictors of euthyroidism in response to MMI treatment. However, only uptake remained significant in a multivariate Cox regression analysis (p = 0.034). A uptake cutoff of 5.0% dichotomized the faster responding versus the slower responding GD patients (p = 0.006). A novel parameter of thyroid uptake from quantitative SPECT/CT is a predictive indicator of an early response to MMI in GD patients.

  8. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special ... the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT ...

  9. Automated quantitative coronary computed tomography correlates of myocardial ischaemia on gated myocardial perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Graaf, Michiel A. de; Boogers, Mark J.; Veltman, Caroline E. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); The Interuniversity Cardiology Institute of The Netherlands, Utrecht (Netherlands); El-Naggar, Heba M.; Bax, Jeroen J.; Delgado, Victoria [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Broersen, Alexander; Kitslaar, Pieter H.; Dijkstra, Jouke [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Kroft, Lucia J. [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Younis, Imad Al [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands); Reiber, Johan H. [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Medis medical imaging systems B.V., Leiden (Netherlands); Scholte, Arthur J. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands)

    2013-08-15

    Automated software tools have permitted more comprehensive, robust and reproducible quantification of coronary stenosis, plaque burden and plaque location of coronary computed tomography angiography (CTA) data. The association between these quantitative CTA (QCT) parameters and the presence of myocardial ischaemia has not been explored. The aim of the present investigation was to evaluate the association between QCT parameters of coronary artery lesions and the presence of myocardial ischaemia on gated myocardial perfusion single-photon emission CT (SPECT). Included in the study were 40 patients (mean age 58.2 {+-} 10.9 years, 27 men) with known or suspected coronary artery disease (CAD) who had undergone multidetector row CTA and gated myocardial perfusion SPECT within 6 months. From the CTA datasets, vessel-based and lesion-based visual analyses were performed. Consecutively, lesion-based QCT was performed to assess plaque length, plaque burden, percentage lumen area stenosis and remodelling index. Subsequently, the presence of myocardial ischaemia was assessed using the summed difference score (SDS {>=}2) on gated myocardial perfusion SPECT. Myocardial ischaemia was seen in 25 patients (62.5 %) in 37 vascular territories. Quantitatively assessed significant stenosis and quantitatively assessed lesion length were independently associated with myocardial ischaemia (OR 7.72, 95 % CI 2.41-24.7, p < 0.001, and OR 1.07, 95 % CI 1.00-1.45, p = 0.032, respectively) after correcting for clinical variables and visually assessed significant stenosis. The addition of quantitatively assessed significant stenosis ({chi} {sup 2} = 20.7) and lesion length ({chi} {sup 2} = 26.0) to the clinical variables and the visual assessment ({chi} {sup 2} = 5.9) had incremental value in the association with myocardial ischaemia. Coronary lesion length and quantitatively assessed significant stenosis were independently associated with myocardial ischaemia. Both quantitative parameters have

  10. In vitro atherosclerotic plaque and calcium quantitation by intravascular ultrasound and electron-beam computed tomography.

    Science.gov (United States)

    Gutfinger, D E; Leung, C Y; Hiro, T; Maheswaran, B; Nakamura, S; Detrano, R; Kang, X; Tang, W; Tobis, J M

    1996-05-01

    The purpose of this investigation was to compare the accuracy of intravascular ultrasound (IVUS) and electron-beam computed tomography (EBCT) in quantitating human atherosclerotic plaque and calcium. In experiment 1, 12 human atherosclerotic arterial segments were obtained at autopsy and imaged by using IVUS and EBCT. The plaque from each arterial segment was dissected and a volume measurement of the dissected plaque was obtained by water displacement. The plaque from each arterial segment was ashed at 700 degrees F, and the weight of the remaining ashes was used as an estimate of the calcium mass. In experiment II, 11 calcified arterial segments were obtained at autopsy and imaged by using IVUS at one site along the artery. A corresponding histologic cross section stained with Masson's trichrome was prepared. In experiment I, the mean plaque volume measured by water displacement was 165.3 +/- 118.4 microliters. The mean plaque volume calculated by IVUS was 166.1 +/- 114.4 microliters and correlated closely with that by water displacement (r = 0.98, p volume by IVUS was 18.6 +/- 11.2 microliters and correlated linearly with the calcium mass by ashing (r = 0.87, p volume as well as the cross-sectional area and volume of intralesional calcium, especially if the calcium is localized at the base of the plaque. IVUS underestimates the amount of calcium present because of signal drop-off when the calcium is too thick for the ultrasound to completely penetrate. In comparison, EBCT accurately quantitates calcium mass regardless of the intralesional calcium morphologic characteristics; however, EBCT does not accurately quantitate plaque volume and will miss noncalcified atherosclerotic lesions.

  11. Quantitative analysis of the right auricle with 256-slice computed tomography.

    Science.gov (United States)

    Li, Cai-Ying; Gao, Bu-Lang; Pan, Tong; Xiang, Cheng; Zhang, Xue-Jing; Liu, Xiao-Wei; Fan, Qiong-Ying

    2017-04-01

    To quantitatively measure the morphology parameters of the right auricle with 256-slice multidetector computed tomography angiography (MDCTA) in healthy people. A retrospective analysis of 200 patients who had undergone coronary MDCTA with negative findings was performed. The raw imaging data were reconstructed and the right auricular volume, right atrial volume, right auricle height, base long and short axes, base perimeter and area, normal angle, and distance were quantitatively measured. Men had significantly (P right auricular volume (13.3 ± 4.0 vs. 11.7 ± 3.7 mL) and height (33.0 ± 5.0 vs. 30.5 ± 5.2 mm), the base long axis (34.4 ± 4.1 vs. 33.2 ± 3.9 mm), area (787.6 ± 177.6 vs. 771.0 ± 143.2 mm(2)) and perimeter (119.2 ± 17.5 vs. 115.0 ± 13.0), and the normal distance (22.4 ± 6.6 vs. 20.2 ± 6.7 mm). The normal 95 % reference range for the right auricular parameters was put forward. The right auricular parameters had a good correlation with the right atrium volume, aortic diameter, the body weight, height, and body surface area but a bad correlation with the vertebral body height. Significantly (P  0.05) difference existed in the other right auricular parameters. Quantitative measurements of the right auricle can help us get a good understanding of the right auricular morphology and its relationship with surrounding structures and are helpful for cardiac interventions of electrophysiology and radiofrequency ablation.

  12. Micro/nano-computed tomography technology for quantitative dynamic, multi-scale imaging of morphogenesis.

    Science.gov (United States)

    Gregg, Chelsea L; Recknagel, Andrew K; Butcher, Jonathan T

    2015-01-01

    Tissue morphogenesis and embryonic development are dynamic events challenging to quantify, especially considering the intricate events that happen simultaneously in different locations and time. Micro- and more recently nano-computed tomography (micro/nanoCT) has been used for the past 15 years to characterize large 3D fields of tortuous geometries at high spatial resolution. We and others have advanced micro/nanoCT imaging strategies for quantifying tissue- and organ-level fate changes throughout morphogenesis. Exogenous soft tissue contrast media enables visualization of vascular lumens and tissues via extravasation. Furthermore, the emergence of antigen-specific tissue contrast enables direct quantitative visualization of protein and mRNA expression. Micro-CT X-ray doses appear to be non-embryotoxic, enabling longitudinal imaging studies in live embryos. In this chapter we present established soft tissue contrast protocols for obtaining high-quality micro/nanoCT images and the image processing techniques useful for quantifying anatomical and physiological information from the data sets.

  13. Role of peripheral quantitative computed tomography in identifying disuse osteoporosis in paraplegia

    Energy Technology Data Exchange (ETDEWEB)

    Coupaud, Sylvie [University of Glasgow, Centre for Rehabilitation Engineering, Department of Mechanical Engineering, Glasgow (United Kingdom); Southern General Hospital, Queen Elizabeth National Spinal Injuries Unit, Glasgow (United Kingdom); McLean, Alan N.; Allan, David B. [Southern General Hospital, Queen Elizabeth National Spinal Injuries Unit, Glasgow (United Kingdom)

    2009-10-15

    Disuse osteoporosis is a major long-term health consequence of spinal cord injury (SCI) that still needs to be addressed. Its management in SCI should begin with accurate diagnosis, followed by targeted treatments in the most vulnerable subgroups. We present data quantifying disuse osteoporosis in a cross-section of the Scottish paraplegic population to identify subgroups with lowest bone mineral density (BMD). Forty-seven people with chronic SCI at levels T2-L2 were scanned using peripheral quantitative computed tomography at four tibial sites and two femoral sites, at the Queen Elizabeth National Spinal Injuries Unit, Glasgow (UK). At the distal epiphyses, trabecular BMD (BMDtrab), total BMD, total bone cross-sectional area (CSA) and bone mineral content (BMC) were determined. In the diaphyses, cortical BMD, total bone CSA, cortical CSA and BMC were calculated. Bone, muscle and fat CSAs were estimated in the lower leg and thigh. BMDtrab decreased exponentially with time since injury at different rates in the tibia and femur. At most sites, female paraplegics had significantly lower BMC, total bone CSA and muscle CSA than male paraplegics. Subjects with lumbar SCI tended to have lower bone values and smaller muscle CSAs than in thoracic SCI. At the distal epiphyses of the tibia and femur, there is generally a rapid and extensive reduction in BMDtrab after SCI. Female subjects, and those with lumbar SCI, tend to have lower bone values than males or those with thoracic SCI, respectively. (orig.)

  14. Quantitative computed tomography of humpback whale (Megaptera novaeangliae) mandibles: mechanical implications for rorqual lunge-feeding.

    Science.gov (United States)

    Field, Daniel J; Campbell-Malone, Regina; Goldbogen, Jeremy A; Shadwick, Robert E

    2010-07-01

    Rorqual whales (Balaenopteridae) lunge at high speed with mouth open to nearly 90 degrees to engulf large volumes of prey-laden water. This feeding process is enabled by extremely large skulls and mandibles that increase mouth area, thereby facilitating the flux of water into the mouth. When these mandibles are lowered during lunge-feeding, they are exposed to high drag, and therefore, may be subject to significant bending forces. We hypothesized that these mandibles exhibited a mechanical design (shape and density distribution) that enables these bones to accommodate high loads during lunge-feeding without exceeding their breaking strength. We used quantitative computed tomography (QCT) to determine the three-dimensional geometry and density distribution of a pair of subadult humpback whale (Megaptera novaeangliae) mandibles (length = 2.10 m). QCT data indicated highest bone density and cross-sectional area, and therefore, high resistance to bending and deflection, from the coronoid process to the middle of the dentary, which then decreased towards the anterior end of the mandible. These results differ from the caudorostral trends of increasing mandibular bone density in mammals, such as humans and the right whale, Eubalaena glacialis, indicating that adaptive bone remodeling is a significant contributing factor in establishing mandibular bone density distributions in rorquals.

  15. Characterizing trabecular bone structure for assessing vertebral fracture risk on volumetric quantitative computed tomography

    Science.gov (United States)

    Nagarajan, Mahesh B.; Checefsky, Walter A.; Abidin, Anas Z.; Tsai, Halley; Wang, Xixi; Hobbs, Susan K.; Bauer, Jan S.; Baum, Thomas; Wismüller, Axel

    2015-03-01

    While the proximal femur is preferred for measuring bone mineral density (BMD) in fracture risk estimation, the introduction of volumetric quantitative computed tomography has revealed stronger associations between BMD and spinal fracture status. In this study, we propose to capture properties of trabecular bone structure in spinal vertebrae with advanced second-order statistical features for purposes of fracture risk assessment. For this purpose, axial multi-detector CT (MDCT) images were acquired from 28 spinal vertebrae specimens using a whole-body 256-row CT scanner with a dedicated calibration phantom. A semi-automated method was used to annotate the trabecular compartment in the central vertebral slice with a circular region of interest (ROI) to exclude cortical bone; pixels within were converted to values indicative of BMD. Six second-order statistical features derived from gray-level co-occurrence matrices (GLCM) and the mean BMD within the ROI were then extracted and used in conjunction with a generalized radial basis functions (GRBF) neural network to predict the failure load of the specimens; true failure load was measured through biomechanical testing. Prediction performance was evaluated with a root-mean-square error (RMSE) metric. The best prediction performance was observed with GLCM feature `correlation' (RMSE = 1.02 ± 0.18), which significantly outperformed all other GLCM features (p GLCM feature correlation also significantly outperformed MDCTmeasured mean BMD (RMSE = 1.11 ± 0.17) (pGLCM-derived texture features.

  16. In Vivo Assessment of Elasticity of Child Rib Cortical Bone Using Quantitative Computed Tomography

    Directory of Open Access Journals (Sweden)

    Y. Zhu

    2017-01-01

    Full Text Available Elasticity of the child rib cortical bone is poorly known due to the difficulties in obtaining specimens to perform conventional tests. It was shown on the femoral cortical bone that elasticity is strongly correlated with density for both children and adults through a unique relationship. Thus, it is assumed that the relationships between the elasticity and density of adult rib cortical bones could be expanded to include that of children. This study estimated in vivo the elasticity of the child rib cortical bone using quantitative computed tomography (QCT. Twenty-eight children (from 1 to 18 y.o. were considered. Calibrated QCT images were prescribed for various thoracic pathologies. The Hounsfield units were converted to bone mineral density (BMD. A relationship between the BMD and the elasticity of the rib cortical bone was applied to estimate the elasticity of children’s ribs in vivo. The estimated elasticity increases with growth (7.1 ± 2.5 GPa at 1 y.o. up to 11.6 ± 1.9 GPa at 18 y.o.. This data is in agreement with the few previous values obtained using direct measurements. This methodology paves the way for in vivo assessment of the elasticity of the child cortical bone based on calibrated QCT images.

  17. Peripheral quantitative computed tomography in children and adolescents: the 2007 ISCD Pediatric Official Positions.

    Science.gov (United States)

    Zemel, Babette; Bass, Shona; Binkley, Teresa; Ducher, Gaele; Macdonald, Heather; McKay, Heather; Moyer-Mileur, Laurie; Shepherd, John; Specker, Bonny; Ward, Kate; Hans, Didier

    2008-01-01

    Peripheral quantitative computed tomography (pQCT) has mainly been used as a research tool in children. To evaluate the clinical utility of pQCT and formulate recommendations for its use in children, the International Society of Clinical Densitometry (ISCD) convened a task force to review the literature and propose areas of consensus and future research. The types of pQCT technology available, the clinical application of pQCT for bone health assessment in children, the important elements to be included in a pQCT report, and quality control monitoring techniques were evaluated. The review revealed a lack of standardization of pQCT techniques, and a paucity of data regarding differences between pQCT manufacturers, models and software versions and their impact in pediatric assessment. Measurement sites varied across studies. Adequate reference data, a critical element for interpretation of pQCT results, were entirely lacking, although some comparative data on healthy children were available. The elements of the pQCT clinical report and quality control procedures are similar to those recommended for dual-energy X-ray absorptiometry. Future research is needed to establish evidence-based criteria for the selection of the measurement site, scan acquisition and analysis parameters, and outcome measures. Reference data that sufficiently characterize the normal range of variability in the population also need to be established.

  18. Quantitative Assessment of Cervical Vertebral Maturation Using Cone Beam Computed Tomography in Korean Girls

    Directory of Open Access Journals (Sweden)

    Bo-Ram Byun

    2015-01-01

    Full Text Available This study was aimed to examine the correlation between skeletal maturation status and parameters from the odontoid process/body of the second vertebra and the bodies of third and fourth cervical vertebrae and simultaneously build multiple regression models to be able to estimate skeletal maturation status in Korean girls. Hand-wrist radiographs and cone beam computed tomography (CBCT images were obtained from 74 Korean girls (6–18 years of age. CBCT-generated cervical vertebral maturation (CVM was used to demarcate the odontoid process and the body of the second cervical vertebra, based on the dentocentral synchondrosis. Correlation coefficient analysis and multiple linear regression analysis were used for each parameter of the cervical vertebrae (P<0.05. Forty-seven of 64 parameters from CBCT-generated CVM (independent variables exhibited statistically significant correlations (P<0.05. The multiple regression model with the greatest R2 had six parameters (PH2/W2, UW2/W2, (OH+AH2/LW2, UW3/LW3, D3, and H4/W4 as independent variables with a variance inflation factor (VIF of <2. CBCT-generated CVM was able to include parameters from the second cervical vertebral body and odontoid process, respectively, for the multiple regression models. This suggests that quantitative analysis might be used to estimate skeletal maturation status.

  19. Quantitative assessment of early experimental diabetes in rats using dynamic contrast-enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Murase, Kenya [Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871 (Japan)], E-mail: murase@sahs.med.osaka-u.ac.jp; Kitamura, Akihiro; Tachibana, Atsushi; Kusakabe, Yoshinori; Matsuura, Risa; Miyazaki, Shohei [Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2010-04-15

    Purpose: To quantitatively assess the time course of changes of the renal volume and function in the early phase of streptozotocin (STZ)-induced diabetes in rats using dynamic contrast-enhanced computed tomography (DCE-CT). Methods: The DCE-CT studies were performed in 24 male Sprague-Dawley rats (n = 6 for control and n = 18 for STZ-treated group) on days 0, 4, 7, 11, and 14 using a multi-detector row CT. The rats of an STZ-treated group were given intraperitoneally 65 mg/kg body weight of STZ on day 0, and were divided into two groups based on the blood glucose concentration on day 4 being less than 300 mg/dL [STZ-treated group (L), n = 8] or greater than 300 mg/dL [STZ-treated group (G), n = 10]. The contrast clearance per unit renal volume (K{sub 1}) was estimated from the DCE-CT data using the Patlak model. The renal volume (V{sub CT}) was calculated by manually delineating the kidney on the contrast-enhanced CT image. The contrast clearance of the entire kidney (K) was obtained by K{sub 1} x V{sub CT}. Results: V{sub CT} in the STZ-treated group was significantly enlarged on day 4 compared to that on day 0 and continued until day 14. Although there were no significant changes in the time course of K{sub 1} in all groups, K in the STZ-treated groups (L) and (G) significantly increased on days 7 and 4, respectively, and continued until day 14, suggesting that hyperfiltration occurs in parallel with renal volume enlargement. Conclusion: The present method appears useful for quantitatively evaluating the time course of STZ-induced diabetes in rats, because it allows repeated and simultaneous evaluation of renal morphology and function.

  20. Quantitative computed tomography measurements of emphysema for diagnosing asthma-chronic obstructive pulmonary disease overlap syndrome

    Directory of Open Access Journals (Sweden)

    Xie M

    2016-05-01

    Full Text Available Mengshuang Xie, Wei Wang, Shuang Dou, Liwei Cui, Wei Xiao Department of Pulmonary Medicine, Qilu Hospital, Shandong University, Jinan, People’s Republic of China Background: The diagnostic criteria of asthma–COPD overlap syndrome (ACOS are controversial. Emphysema is characteristic of COPD and usually does not exist in typical asthma patients. Emphysema in patients with asthma suggests the coexistence of COPD. Quantitative computed tomography (CT allows repeated evaluation of emphysema noninvasively. We investigated the value of quantitative CT measurements of emphysema in the diagnosis of ACOS.Methods: This study included 404 participants; 151 asthma patients, 125 COPD patients, and 128 normal control subjects. All the participants underwent pulmonary function tests and a high-resolution CT scan. Emphysema measurements were taken with an Airway Inspector software. The asthma patients were divided into high and low emphysema index (EI groups based on the percentage of low attenuation areas less than −950 Hounsfield units. The characteristics of asthma patients with high EI were compared with those having low EI or COPD.Results: The normal value of percentage of low attenuation areas less than −950 Hounsfield units in Chinese aged >40 years was 2.79%±2.37%. COPD patients indicated more severe emphysema and more upper-zone-predominant distribution of emphysema than asthma patients or controls. Thirty-two (21.2% of the 151 asthma patients had high EI. Compared with asthma patients with low EI, those with high EI were significantly older, more likely to be male, had more pack-years of smoking, had more upper-zone-predominant distribution of emphysema, and had greater airflow limitation. There were no significant differences in sex ratios, pack-years of smoking, airflow limitation, or emphysema distribution between asthma patients with high EI and COPD patients. A greater number of acute exacerbations were seen in asthma patients with high

  1. Iterative reconstruction for quantitative computed tomography analysis of emphysema: consistent results using different tube currents

    Directory of Open Access Journals (Sweden)

    Yamashiro T

    2015-02-01

    Full Text Available Tsuneo Yamashiro,1 Tetsuhiro Miyara,1 Osamu Honda,2 Noriyuki Tomiyama,2 Yoshiharu Ohno,3 Satoshi Noma,4 Sadayuki Murayama1 On behalf of the ACTIve Study Group 1Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa, Japan; 2Department of Radiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan; 3Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; 4Department of Radiology, Tenri Hospital, Tenri, Nara, Japan Purpose: To assess the advantages of iterative reconstruction for quantitative computed tomography (CT analysis of pulmonary emphysema. Materials and methods: Twenty-two patients with pulmonary emphysema underwent chest CT imaging using identical scanners with three different tube currents: 240, 120, and 60 mA. Scan data were converted to CT images using Adaptive Iterative Dose Reduction using Three Dimensional Processing (AIDR3D and a conventional filtered-back projection mode. Thus, six scans with and without AIDR3D were generated per patient. All other scanning and reconstruction settings were fixed. The percent low attenuation area (LAA%; < -950 Hounsfield units and the lung density 15th percentile were automatically measured using a commercial workstation. Comparisons of LAA% and 15th percentile results between scans with and without using AIDR3D were made by Wilcoxon signed-rank tests. Associations between body weight and measurement errors among these scans were evaluated by Spearman rank correlation analysis. Results: Overall, scan series without AIDR3D had higher LAA% and lower 15th percentile values than those with AIDR3D at each tube current (P<0.0001. For scan series without AIDR3D, lower tube currents resulted in higher LAA% values and lower 15th percentiles. The extent of emphysema was significantly different between each pair among scans when not using AIDR3D (LAA%, P<0.0001; 15th percentile, P<0.01, but was not

  2. Quantitative Comparison of Commercial and Non-Commercial Metal Artifact Reduction Techniques in Computed Tomography

    NARCIS (Netherlands)

    Wagenaar, Dirk; van der Graaf, Emiel R.; van der Schaaf, Arjen; Greuter, Marcel J. W.

    2015-01-01

    Objectives Typical streak artifacts known as metal artifacts occur in the presence of strongly attenuating materials in computed tomography (CT). Recently, vendors have started offering metal artifact reduction (MAR) techniques. In addition, a MAR technique called the metal deletion technique (MDT)

  3. Quantitative Functional Imaging Using Dynamic Positron Computed Tomography and Rapid Parameter Estimation Techniques

    Science.gov (United States)

    Koeppe, Robert Allen

    Positron computed tomography (PCT) is a diagnostic imaging technique that provides both three dimensional imaging capability and quantitative measurements of local tissue radioactivity concentrations in vivo. This allows the development of non-invasive methods that employ the principles of tracer kinetics for determining physiological properties such as mass specific blood flow, tissue pH, and rates of substrate transport or utilization. A physiologically based, two-compartment tracer kinetic model was derived to mathematically describe the exchange of a radioindicator between blood and tissue. The model was adapted for use with dynamic sequences of data acquired with a positron tomograph. Rapid estimation techniques were implemented to produce functional images of the model parameters by analyzing each individual pixel sequence of the image data. A detailed analysis of the performance characteristics of three different parameter estimation schemes was performed. The analysis included examination of errors caused by statistical uncertainties in the measured data, errors in the timing of the data, and errors caused by violation of various assumptions of the tracer kinetic model. Two specific radioindicators were investigated. ('18)F -fluoromethane, an inert freely diffusible gas, was used for local quantitative determinations of both cerebral blood flow and tissue:blood partition coefficient. A method was developed that did not require direct sampling of arterial blood for the absolute scaling of flow values. The arterial input concentration time course was obtained by assuming that the alveolar or end-tidal expired breath radioactivity concentration is proportional to the arterial blood concentration. The scale of the input function was obtained from a series of venous blood concentration measurements. The method of absolute scaling using venous samples was validated in four studies, performed on normal volunteers, in which directly measured arterial concentrations

  4. Multi-institutional Quantitative Evaluation and Clinical Validation of Smart Probabilistic Image Contouring Engine (SPICE) Autosegmentation of Target Structures and Normal Tissues on Computer Tomography Images in the Head and Neck, Thorax, Liver, and Male Pelvis Areas

    DEFF Research Database (Denmark)

    Zhu, Mingyao; Bzdusek, Karl; Brink, Carsten

    2013-01-01

    Clinical validation and quantitative evaluation of computed tomography (CT) image autosegmentation using Smart Probabilistic Image Contouring Engine (SPICE).......Clinical validation and quantitative evaluation of computed tomography (CT) image autosegmentation using Smart Probabilistic Image Contouring Engine (SPICE)....

  5. [High resolution peripheral quantitative computed tomography for the assessment of morphological and mechanical bone parameters].

    Science.gov (United States)

    Fuller, Henrique; Fuller, Ricardo; Pereira, Rosa Maria R

    2015-01-01

    High resolution peripheral quantitative computed tomography (HR-pQCT) is a new technology commercially available for less than 10 years that allows performing in vivo assessment of bone parameters. HR-pQCT assesses the trabecular thickness, trabecular separation, trabecular number and connectivity density and, in addition, cortical bone density and thickness and total bone volume and density in high-definition mode, which additionally allows obtaining digital constructs of bone microarchitecture. The application of mathematics to captured data, a method called finite element analysis (FEA), allows the estimation of the physical properties of the tissue, simulating supported loads in a non-invasive way. Thus, HR-pQCT simultaneously acquires data previously provided separately by dual energy x-ray absorptiometry (DXA), magnetic resonance imaging and histomorphometry, aggregating biomechanical estimates previously only possible in extracted tissues. This method has a satisfactory reproducibility, with coefficients of variation rarely exceeding 3%. Regarding accuracy, the method shows a fair to good agreement (r(2) = 0.37-0.97). The main clinical application of this method is in the quantification and monitoring of metabolic bone disorders, more fully evaluating bone strength and fracture risk. In rheumatoid arthritis patients, this allows gauging the number and size of erosions and cysts, in addition to joint space. In osteoarthritis, it is possible to characterize the bone marrow edema-like areas that show a correlation with cartilage breakdown. Given its high cost, HR-pQCT is still a research tool, but the high resolution and efficiency of this method reveal advantages over the methods currently used for bone assessment, with a potential to become an important tool in clinical practice. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

  6. High Resolution Peripheral Quantitative Computed Tomography for Assessment of Bone Quality

    Science.gov (United States)

    Kazakia, Galateia

    2014-03-01

    The study of bone quality is motivated by the high morbidity, mortality, and societal cost of skeletal fractures. Over 10 million people are diagnosed with osteoporosis in the US alone, suffering 1.5 million osteoporotic fractures and costing the health care system over 17 billion annually. Accurate assessment of fracture risk is necessary to ensure that pharmacological and other interventions are appropriately administered. Currently, areal bone mineral density (aBMD) based on 2D dual-energy X-ray absorptiometry (DXA) is used to determine osteoporotic status and predict fracture risk. Though aBMD is a significant predictor of fracture risk, it does not completely explain bone strength or fracture incidence. The major limitation of aBMD is the lack of 3D information, which is necessary to distinguish between cortical and trabecular bone and to quantify bone geometry and microarchitecture. High resolution peripheral quantitative computed tomography (HR-pQCT) enables in vivo assessment of volumetric BMD within specific bone compartments as well as quantification of geometric and microarchitectural measures of bone quality. HR-pQCT studies have documented that trabecular bone microstructure alterations are associated with fracture risk independent of aBMD.... Cortical bone microstructure - specifically porosity - is a major determinant of strength, stiffness, and fracture toughness of cortical tissue and may further explain the aBMD-independent effect of age on bone fragility and fracture risk. The application of finite element analysis (FEA) to HR-pQCT data permits estimation of patient-specific bone strength, shown to be associated with fracture incidence independent of aBMD. This talk will describe the HR-pQCT scanner, established metrics of bone quality derived from HR-pQCT data, and novel analyses of bone quality currently in development. Cross-sectional and longitudinal HR-pQCT studies investigating the impact of aging, disease, injury, gender, race, and

  7. Assessment of Regional Bone Density in Fractured Vertebrae Using Quantitative Computed Tomography

    Science.gov (United States)

    Soliman, Hany A.G.; Mac-Thiong, Jean-Marc; Levasseur, Annie; Parent, Stefan

    2017-01-01

    Study Design Cohort study. Purpose The aim of this study is to propose and evaluate a new technique to assess bone mineral density of fractured vertebrae using quantitative computed tomography (QCT). Overview of Literature There is no available technique to estimate bone mineral density (BMD) at the fractured vertebra because of the alterations in bony structures at the fracture site. Methods Forty patients with isolated fracture from T10 to L2 were analyzed from the vertebrae above and below the fracture level. Apparent density (AD) was measured based on the relationship between QCT images attenuation coefficients and the density of calibration objects. AD of 8 independent regions of interest (ROI) within the vertebral body and 2 ROI within the pedicles of vertebrae above and below the fractured vertebra were measured. At the level of the fractured vertebra, AD was measured at the pedicles, which are typically intact. AD of the fractured vertebral body was linearly interpolated, based on the assumption that AD at the fractured vertebra is equivalent to the average AD measured in vertebrae adjacent to the fracture. Estimated and measured AD of the pedicles at the fractured level were compared to verify our assumption of linear interpolation from adjacent vertebrae. Results The difference between the measured and the interpolated density of the pedicles at the fractured vertebra was 0.006 and 0.003 g/cm3 for right and left pedicle respectively. The highest mean AD located at the pedicles and the lowest mean AD was found at the anterior ROI of the vertebral body. Significant negative correlation exist between age and AD of ROI in the vertebral body. Conclusions This study suggests that the proposed technique is adequate to estimate the AD of a fractured vertebra from the density of adjacent vertebrae. PMID:28243370

  8. Quantitative assessment of the superior sagittal sinus on unenhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Fanous, Randy, E-mail: randy.fanous@gmail.co [University of Toronto, Department of Medical Imaging (Canada); Leung, Andrew; Karlik, Stephen [University of Western Ontario, Department of Diagnostic Radiology and Nuclear Medicine (Canada)

    2010-09-15

    Purpose: To determine the relationship between hemoglobin levels and attenuation measurements of the superior sagittal sinus (SSS) on unenhanced computed tomography (UECT). Secondly, to determine if SSS attenuation values are normally distributed such that measurements below and above certain thresholds are suggestive of pathology, such as anemia or acute venous thrombosis respectively. Methods: Institutional review board approval was obtained for retrospective review of adult patients having both an UECT head examination and a complete blood count within 24 h of the scan. A cohort of 151 consecutive patients formed the study sample (76 males and 75 females, 17-91 years of age with a mean of 61). The dorsal aspect of the SSS was divided into upper, middle and lower segments. Using freehand and circle region of interest (ROI) techniques, a total of six attenuation measurements were obtained from each patient. Next, statistical analyses were preformed to assess the correlation between Hgb levels and attenuation values, and distribution curves were plotted to assess the normal range of SSS attenuation measurements. Results: There is a moderate, yet statistically significant (p < 0.001), correlation between Hgb levels and attenuation values in upper, middle and lower segments of the SSS (r = 0.487, 0.497 and 0.533 respectively). Based on the calculated mean, median and mode, the attenuation values are normally distributed. When using the freehand ROI technique, the mean value is 50 Hounsfield Units (HU) with a standard deviation (SD) of 7.5. Attenuation values less than 2 SDs (35 HU) are highly suggestive of anemia (specificity and PPV = 100%). Conclusion: There is a moderate, yet statistically significant, correlation between Hgb levels and attenuation of the SSS on UECT. Furthermore, attenuation measurements of the SSS are normally distributed with a mean of 50 HU and a SD of 7.5. Therefore, quantitative assessment of the SSS may prove useful in the clinical practice

  9. Geometric properties of distal radius and pathogenesis of Colles fracture: a peripheral quantitative computed tomography study.

    Science.gov (United States)

    Nielsen, S P; Xie, X; Bärenholdt, O

    2001-01-01

    It is well known among clinicians that Colles fracture patients may have normal projected axial bone mineral density and that bone mass is not synonymous with bone strength. The aim of this work was to investigate whether cross-sectional properties of the distal radius in female patients with recent Colles fracture differ from those of a younger group of normal women without fracture. It was hypothesized that patients with Colles fracture had petite distal radii and that cortical thinning and reduced cortical and trabecular volumetric density are dominant features of this fracture type. We used a multilayer high-precision peripheral quantitative computed tomography (pQCT) device with a long-term precision error of 0.1% for a dedicated phantom during the measurement period (152 d). Clinical measurements were made at an ultradistal site rich in trabecular bone and a less ultradistal site rich in cortical bone. The results show that the following pQCT variables were significantly reduced in the nonfractured radius of the Colles fracture cases: mean ultradistal trabecular volumetric density, mean ultradistal and distal cortical volumetric density, mean ultradistal and distal cortical thickness (p differences). The outer cortical diameter, cross-sectional bone area, and cortical bending moment of inertia were not statistically different in the two groups. Thus, it would appear that Colles fracture cases did not have petite distal radii. The results suggest that the deforming force of Colles fracture has a transaxial direction (fall on outstretched arm), resulting in a crush fracture, and that it is not a bending force. We suggest that Colles fracture occurs as a result of the combined effect of a fall on the out-stretched arm, low trabecular and cortical volumetric bone density, and reduced cortical thickness.

  10. Automated simulation of areal bone mineral density assessment in the distal radius from high-resolution peripheral quantitative computed tomography

    OpenAIRE

    Burghardt, A. J.; Kazakia, G. J.; Link, T.M.; Majumdar, S

    2009-01-01

    Summary An automated image processing method is presented for simulating areal bone mineral density measures using high-resolution peripheral quantitative computed tomography (HR-pQCT) in the ultra-distal radius. The accuracy of the method is validated against clinical dual X-ray absorptiometry (DXA). This technique represents a useful reference to gauge the utility of novel 3D quantification methods applied to HR-pQCT in multi-center clinical studies and potentially negates the need for sepa...

  11. The effects of iterative reconstruction and kernel selection on quantitative computed tomography measures of lung density.

    Science.gov (United States)

    Rodriguez, Alfonso; Ranallo, Frank N; Judy, Philip F; Fain, Sean B

    2017-06-01

    To determine the effects of iterative reconstruction (IR) and high-frequency kernels on quantitative computed tomography (qCT) density measures at reduced X-ray dose. The COPDGene 2 Phantom (CTP 698, The Phantom Laboratory, Salem, NY) with four embedded lung mimicking foam densities (12lb, 20lb, and 4lb), as well as water, air, and acrylic reference inserts, was imaged using a GE 64 slice CT750 HD scanner in helical mode with four current-time products ranging from 12 to 100 mAs. The raw acquired data were reconstructed using standard (STD - low frequency) and Bone (high frequency) kernels with filtered back projection (FBP), 100% ASiR, and Veo reconstruction algorithms. The reference density inserts were manually segmented using Slicer3D (www.slicer.org), and the mean, standard deviation, and histograms of the segmented regions were generated using Fiji (http://fiji.sc/Fiji) for each reconstruction. Measurements of threshold values placed on the cumulative frequency distribution of voxels determined by these measured histograms at 5%, PD5phant , and 15%, PD15phant , (analogous to the relative area below -950 HU (RA-950) and percent density 15 (PD15) in human lung emphysema quantification, respectively), were also performed. The use of high-resolution kernels in conjunction with ASiR and Veo did not significantly affect the mean Hounsfield units (HU) of each of the density standards (density regions. The density histogram became more sharply peaked, and standard deviation was reduced for IR, directly effecting density thresholds, PD5phant and PD15phant, placed on the cumulative frequency distribution of each region in the phantom, which serve as analogs to RA-950 and PD15 typically used in lung density quantitation. The combination of high-frequency kernels (Bone) with ASiR mitigates this effect and preserves density measures derived from the image histogram. Moreover, previous studies have shown improved accuracy of qCT airway measures of wall thickness (WT) and

  12. Quantitative material analysis by dual-energy computed tomography for industrial NDT applications

    Science.gov (United States)

    Nachtrab, F.; Weis, S.; Keßling, P.; Sukowski, F.; Haßler, U.; Fuchs, T.; Uhlmann, N.; Hanke, R.

    2011-05-01

    Dual-energy computed tomography (DECT) is an established method in the field of medical CT to obtain quantitative information on a material of interest instead of mean attenuation coefficients only. In the field of industrial X-ray imaging dual-energy techniques have been used to solve special problems on a case-by-case basis rather than as a standard tool. Our goal is to develop an easy-to-use dual-energy solution that can be handled by the average industrial operator without the need for a specialist. We are aiming at providing dual-energy CT as a measurement tool for those cases where qualitative images are not enough and one needs additional quantitative information (e.g. mass density ρ and atomic number Z) about the sample at hand. Our solution is based on an algorithm proposed by Heismann et al. (2003) [1] for application in medical CT . As input data this algorithm needs two CT data sets, one with low (LE) and one with high effective energy (HE). A first order linearization is applied to the raw data, and two volumes are reconstructed thereafter. The dual-energy analysis is done voxel by voxel, using a pre-calculated function F(Z) that implies the parameters of the low and high energy measurement (such as tube voltage, filtration and detector sensitivity). As a result, two volume data sets are obtained, one providing information about the mass density ρ in each voxel, the other providing the effective atomic number Z of the material therein. One main difference between medical and industrial CT is that the range of materials that can be contained in a sample is much wider and can cover the whole range of elements, from hydrogen to uranium. Heismann's algorithm is limited to the range of elements Z=1-30, because for Z>30 the function F(Z) as given by Heismann is not a bijective function anymore. While this still seems very suitable for medical application, it is not enough to cover the complete range of industrial applications. We therefore investigated the

  13. Differentiating malignant from benign gastric mucosal lesions with quantitative analysis in dual energy spectral computed tomography

    Science.gov (United States)

    Meng, Xiaoyan; Ni, Cheng; Shen, Yaqi; Hu, Xuemei; Chen, Xiao; Li, Zhen; Hu, Daoyu

    2017-01-01

    Abstract To investigate the value of quantitative analysis in dual energy spectral computed tomography (DESCT) for differentiating malignant gastric mucosal lesions from benign gastric mucosal lesions (including gastric inflammation [GI] and normal gastric mucosa [NGM]). This study was approved by the ethics committee, and all patients provided written informed consent. A total of 161 consecutive patients (63 with gastric cancer [GC], 48 with GI, and 50 with NGM) who underwent dual-phase contrast enhanced DESCT scans in the arterial phase (AP) and portal venous phase (PVP) were included in this study. Iodine concentration (IC) in lesions was derived from the iodine-based material-decomposition images and normalized to that in the aorta to obtain normalized IC (nIC). The ratios of IC and nIC between the AP and PVP were calculated. Diagnostic confidence for GC and GI was evaluated with reviewing the features including gastric wall thickness, focal, and eccentric on the conventional polychromatic images. All statistical analyses were performed by using statistical software SPSS 17.0 (SPSS, Chicago, IL). IC and nIC in GC differed significantly from those in GI and NGM, except for nICAP in comparing GC with GI. Mean nIC values of GC (0.18 ± 0.06 in AP and 0.62 ± 0.16 in PVP) were significantly higher than that of NGM (0.12 ± 0.03 in AP and 0.37 ± 0.08 in PVP) (all P nIC and IC in PVP had high sensitivities of 88.89% and 90.48%, respectively, in differentiating GC from NGM, while the sensitivities were 71.43% and 88.89% during AP. Ratios IC and nIC ratios did not provide adequate diagnostic accuracy with their area under curves less than 0.65. With the conventional features, the diagnostic accuracies for GC and GI were 75.0% and 98.0%, respectively. Quantitative analysis of DESCT imaging parameters for gastric mucosa, such as nIC and IC, is useful for differentiating malignant from benign gastric mucosal lesions. PMID:28079827

  14. Emission Computed Tomography: A New Technique for the Quantitative Physiologic Study of Brain and Heart in Vivo

    Science.gov (United States)

    Phelps, M. E.; Hoffman, E. J.; Huang, S. C.; Schelbert, H. R.; Kuhl, D. E.

    1978-01-01

    Emission computed tomography can provide a quantitative in vivo measurement of regional tissue radionuclide tracer concentrations. This facility when combined with physiologic models and radioactively labeled physiologic tracers that behave in a predictable manner allow measurement of a wide variety of physiologic variables. This integrated technique has been referred to as Physiologic Tomography (PT). PT requires labeled compounds which trace physiologic processes in a known and predictable manner, and physiologic models which are appropriately formulated and validated to derive physiologic variables from ECT data. In order to effectively achieve this goal, PT requires an ECT system that is capable of performing truly quantitative or analytical measurements of tissue tracer concentrations and which has been well characterized in terms of spatial resolution, sensitivity and signal to noise ratios in the tomographic image. This paper illustrates the capabilities of emission computed tomography and provides examples of physiologic tomography for the regional measurement of cerebral and myocardial metabolic rate for glucose, regional measurement of cerebral blood volume, gated cardiac blood pools and capillary perfusion in brain and heart. Studies on patients with stroke and myocardial ischemia are also presented.

  15. Quantitative assessment of scatter correction techniques incorporated in next generation dual-source computed tomography

    Science.gov (United States)

    Mobberley, Sean David

    Accurate, cross-scanner assessment of in-vivo air density used to quantitatively assess amount and distribution of emphysema in COPD subjects has remained elusive. Hounsfield units (HU) within tracheal air can be considerably more positive than -1000 HU. With the advent of new dual-source scanners which employ dedicated scatter correction techniques, it is of interest to evaluate how the quantitative measures of lung density compare between dual-source and single-source scan modes. This study has sought to characterize in-vivo and phantom-based air metrics using dual-energy computed tomography technology where the nature of the technology has required adjustments to scatter correction. Anesthetized ovine (N=6), swine (N=13: more human-like rib cage shape), lung phantom and a thoracic phantom were studied using a dual-source MDCT scanner (Siemens Definition Flash. Multiple dual-source dual-energy (DSDE) and single-source (SS) scans taken at different energy levels and scan settings were acquired for direct quantitative comparison. Density histograms were evaluated for the lung, tracheal, water and blood segments. Image data were obtained at 80, 100, 120, and 140 kVp in the SS mode (B35f kernel) and at 80, 100, 140, and 140-Sn (tin filtered) kVp in the DSDE mode (B35f and D30f kernels), in addition to variations in dose, rotation time, and pitch. To minimize the effect of cross-scatter, the phantom scans in the DSDE mode was obtained by reducing the tube current of one of the tubes to its minimum (near zero) value. When using image data obtained in the DSDE mode, the median HU values in the tracheal regions of all animals and the phantom were consistently closer to -1000 HU regardless of reconstruction kernel (chapters 3 and 4). Similarly, HU values of water and blood were consistently closer to their nominal values of 0 HU and 55 HU respectively. When using image data obtained in the SS mode the air CT numbers demonstrated a consistent positive shift of up to 35 HU

  16. Comparative evaluation of modified canal staining and clearing technique, cone-beam computed tomography, peripheral quantitative computed tomography, spiral computed tomography, and plain and contrast medium-enhanced digital radiography in studying root canal morphology.

    Science.gov (United States)

    Neelakantan, Prasanna; Subbarao, Chandana; Subbarao, Chandragiri V

    2010-09-01

    This study investigated the accuracy of cone-beam computed tomography (CBCT), peripheral quantitative computed tomography (pQCT), spiral computed tomography (SCT), plain (plain digi), and contrast medium-enhanced digital radiographs (contrast digi) in studying root canal morphology. The root canal anatomy was analyzed in 95 teeth using CBCT, pQCT, SCT, plain digi, and contrast digi. After flushing out the radiopaque dye, access cavities were sealed, and the teeth were subject to the modified canal staining and clearing technique. The number of root canals (Vertucci classification and Gulabivala's additional classes) was calculated by three calibrated endodontists and two maxillofacial radiologists. Erroneous or unsuccessful identifications of root canals were statistically analyzed by one-way analysis of variance (p = 0.05). The modified canal staining and clearing technique identified an average of 1.8 root canals per mandibular central incisor, 2.3 per maxillary first premolar, 3.9 per maxillary first molar, 3.8 per maxillary and mandibular second molar, and 4.3 per mandibular first molar. CBCT and pQCT were erroneous in 0.29% and 2.05% cases, whereas SCT, contrast digi, and plain digi were unsuccessful in 15.58%, 14.7%, and 23.8%, respectively. There was a significant difference between all the methods (p 0.05). CBCT and pQCT were as accurate as the modified canal staining and tooth clearing technique in identifying root canal systems. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. Quantitative material decomposition using spectral computed tomography with an energy-resolved photon-counting detector.

    Science.gov (United States)

    Lee, Seungwan; Choi, Yu-Na; Kim, Hee-Joung

    2014-09-21

    Dual-energy computed tomography (CT) techniques have been used to decompose materials and characterize tissues according to their physical and chemical compositions. However, these techniques are hampered by the limitations of conventional x-ray detectors operated in charge integrating mode. Energy-resolved photon-counting detectors provide spectral information from polychromatic x-rays using multiple energy thresholds. These detectors allow simultaneous acquisition of data in different energy ranges without spectral overlap, resulting in more efficient material decomposition and quantification for dual-energy CT. In this study, a pre-reconstruction dual-energy CT technique based on volume conservation was proposed for three-material decomposition. The technique was combined with iterative reconstruction algorithms by using a ray-driven projector in order to improve the quality of decomposition images and reduce radiation dose. A spectral CT system equipped with a CZT-based photon-counting detector was used to implement the proposed dual-energy CT technique. We obtained dual-energy images of calibration and three-material phantoms consisting of low atomic number materials from the optimal energy bins determined by Monte Carlo simulations. The material decomposition process was accomplished by both the proposed and post-reconstruction dual-energy CT techniques. Linear regression and normalized root-mean-square error (NRMSE) analyses were performed to evaluate the quantitative accuracy of decomposition images. The calibration accuracy of the proposed dual-energy CT technique was higher than that of the post-reconstruction dual-energy CT technique, with fitted slopes of 0.97-1.01 and NRMSEs of 0.20-4.50% for all basis materials. In the three-material phantom study, the proposed dual-energy CT technique decreased the NRMSEs of measured volume fractions by factors of 0.17-0.28 compared to the post-reconstruction dual-energy CT technique. It was concluded that the

  18. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT of the sinuses is primarily used ...

  19. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... the limitations of CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, ... the body being studied. top of page How is the procedure performed? The technologist begins by positioning ...

  20. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT of the sinuses is primarily used ...

  1. Bone Structure and Estimated Bone Strength in Obese Patients Evaluated by High-Resolution Peripheral Quantitative Computed Tomography

    DEFF Research Database (Denmark)

    Andersen, Stine; Frederiksen, Katrine Diemer; Hansen, Stinus;

    2014-01-01

    Obesity is associated with high bone mineral density (BMD), but whether obesity-related higher bone mass increases bone strength and thereby protect against fractures is uncertain. We estimated effects of obesity on bone microarchitecture and estimated strength in 36 patients (12 males and 24...... females, age 25-56 years and BMI 33.2-57.6 kg/m(2)) matched with healthy controls (age 25-54 years and BMI 19.5-24.8 kg/m(2)) in regard to gender, menopausal status, age (±6 years) and height (±6 cm) using high resolution peripheral quantitative computed tomography and dual energy X-ray absorptiometry...

  2. Clinical application of skeletal scintigraphy and quantitative computed tomography (QCT) to osteoarthritis of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Muneshige (Prefectural Tajimi Hospital, Gifu (Japan))

    1989-10-01

    Skeletal scintigraphy and QCT were performed to determine changes of subchondral bone tissues in osteoarthritis of the knee and findings were compared with plain X-ray findings, knee pain and femoro-tibial angle. Results on blood pool study were especially related to pain. Results in delayed study using single photon emission computed tomography revealed hign uptake on the medial side of the femur and tibia parallel to plain X-ray and pain. The QCT value was slightly decreased as osteoarthritic changes progressed without a significant change. In addition, delayed study in cases with previous surgical intervention by high tibial osteotomy revealed a lower uptake on the medial side of the femur and tibia. When skeletal scintigraphy accurately reflects blood flow through the subchondral bone tissues and is closely related to morbidity and pain, this modality is valuable in analysis of signs and symptoms as well as postoperative outcome. (author).

  3. Quantitative analysis of the muscle atrophy in osteoarthritis of the hip by computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Tajiri, Masahiro; Hieda, Hiroshi (Kurume Univ., Fukuoka (Japan). School of Medicine)

    1984-06-01

    Twenty normal hips and 30 cases of the unilateral osteoarthritic hips were examined by computed tomography in order to measure the atrophy of the muscles around the hip. We discussed the relationship among the muscle atrophy, stages of the osteoarthritic hip, and the clinical score of the JOA's criteria. The results were as follows: 1. There is no difference between the muscle volume of both sides in normal hips. 2. Atrophy of the gluteus maximus and the gluteus medius were already observed at the preosteoarthritic stage and the gluteus minimus, the tensor fasciae latae, iliopsoas revealed atrophy at the late stage. 3. There was a negative correlation between the percentage of atrophy of the gluteus maximus and the clinical score of the JOA's criteria. 4. In cases of normal position of the greater trochanter, artophy of the gluteus medius was more distinguished in cases of abductors of grade 4 by MMT than in those of normal grade.

  4. Quantification of mitral regurgitation on cardiac computed tomography: comparison with qualitative and quantitative echocardiographic parameters.

    Science.gov (United States)

    Arnous, Samer; Killeen, Ronan P; Martos, Ramon; Quinn, Martin; McDonald, Kenneth; Dodd, Jonathan Dermot

    2011-01-01

    To assess whether cardiac computed tomographic angiography (CCTA) can quantify the severity of chronic mitral regurgitation (MR) compared to qualitative and quantitative echocardiographic parameters. Cardiac computed tomographic angiography was performed in 23 patients (mean ± SD age, 63 ± 16 years; range, 24-86 years) with MR and 20 patients without MR (controls) as determined by transthoracic echocardiography. Multiphasic reconstructions (20 data sets reconstructed at 5% increments of the electrocardiographic gated R-R interval) were used to analyze the mitral valve. Using CCTA planimetry, 2 readers measured the regurgitant mitral orifice area (CCTA ROA) during systole. A qualitative echocardiographic assessment of severity of MR was made by visual assessment of the length of the regurgitant jet. Quantitative echocardiographic measurements included the vena contracta, proximal isovelocity surface area, regurgitant volume, and estimated regurgitant orifice (ERO). Comparisons were performed using the independent t test, and correlations were assessed using the Spearman rank test. All controls and the patients with MR were correctly identified by CCTA. For patients with mild, moderate, or severe MR, mean ± SD EROs were 0.16 ± 0.03, 0.31 ± 0.08, and 0.52 ± 0.03 cm² (P qualitatively as mild, moderate, or severe, strong correlations were seen with CCTA ROA (R = 0.89; P quantitatively, the vena contracta and the ERO showed modest correlations with CCTA ROA (0.48 and 0.50; P qualitative echocardiographic parameters but only a moderate correlation with quantitative echocardiographic parameters of chronic MR. Cardiac computed tomographic angiography slightly overestimates mild MR while slightly underestimating severe MR.

  5. Quantitative analysis and prediction of regional lymph node status in rectal cancer based on computed tomography imaging

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Chunyan; Liu, Lizhi; Li, Li [Sun Yat-sen University, State Key Laboratory of Oncology in Southern China, Imaging Diagnosis and Interventional Center, Cancer Center, Guangzhou, Guangdong (China); Cai, Hongmin; Tian, Haiying [Sun Yat-Sen University, Department of Automation, School of Science Information and Technology, Guangzhou (China); Li, Liren [Sun Yat-sen University, State Key Laboratory of Oncology in Southern China, Department of Abdominal (colon and rectal) Surgery, Cancer Center, Guangzhou (China)

    2011-11-15

    To quantitatively evaluate regional lymph nodes in rectal cancer patients by using an automated, computer-aided approach, and to assess the accuracy of this approach in differentiating benign and malignant lymph nodes. Patients (228) with newly diagnosed rectal cancer, confirmed by biopsy, underwent enhanced computed tomography (CT). Patients were assigned to the benign node or malignant node group according to histopathological analysis of node samples. All CT-detected lymph nodes were segmented using the edge detection method, and seven quantitative parameters of each node were measured. To increase the prediction accuracy, a hierarchical model combining the merits of the support and relevance vector machines was proposed to achieve higher performance. Of the 220 lymph nodes evaluated, 125 were positive and 95 were negative for metastases. Fractal dimension obtained by the Minkowski box-counting approach was higher in malignant nodes than in benign nodes, and there was a significant difference in heterogeneity between metastatic and non-metastatic lymph nodes. The overall performance of the proposed model is shown to have accuracy as high as 88% using morphological characterisation of lymph nodes. Computer-aided quantitative analysis can improve the prediction of node status in rectal cancer. (orig.)

  6. Quantification of mitral regurgitation on cardiac computed tomography: comparison with qualitative and quantitative echocardiographic parameters.

    LENUS (Irish Health Repository)

    Arnous, Samer

    2012-02-01

    PURPOSE: To assess whether cardiac computed tomographic angiography (CCTA) can quantify the severity of chronic mitral regurgitation (MR) compared to qualitative and quantitative echocardiographic parameters. MATERIALS AND METHODS: Cardiac computed tomographic angiography was performed in 23 patients (mean +\\/- SD age, 63 +\\/- 16 years; range, 24-86 years) with MR and 20 patients without MR (controls) as determined by transthoracic echocardiography. Multiphasic reconstructions (20 data sets reconstructed at 5% increments of the electrocardiographic gated R-R interval) were used to analyze the mitral valve. Using CCTA planimetry, 2 readers measured the regurgitant mitral orifice area (CCTA ROA) during systole. A qualitative echocardiographic assessment of severity of MR was made by visual assessment of the length of the regurgitant jet. Quantitative echocardiographic measurements included the vena contracta, proximal isovelocity surface area, regurgitant volume, and estimated regurgitant orifice (ERO). Comparisons were performed using the independent t test, and correlations were assessed using the Spearman rank test. RESULTS: All controls and the patients with MR were correctly identified by CCTA. For patients with mild, moderate, or severe MR, mean +\\/- SD EROs were 0.16 +\\/- 0.03, 0.31 +\\/- 0.08, and 0.52 +\\/- 0.03 cm(2) (P < 0.0001) compared with mean +\\/- SD CCTA ROAs 0.09 +\\/- 0.05, 0.30 +\\/- 0.04, and 0.97 +\\/- 0.26 cm(2) (P < 0.0001), respectively. When echocardiographic measurements were graded qualitatively as mild, moderate, or severe, strong correlations were seen with CCTA ROA (R = 0.89; P < 0.001). When echocardiographic measurements were graded quantitatively, the vena contracta and the ERO showed modest correlations with CCTA ROA (0.48 and 0.50; P < 0.05 for both). Neither the proximal isovelocity surface area nor the regurgitant volume demonstrated significant correlations with CCTA ROA. CONCLUSIONS: Single-source 64-slice CCTA provides a

  7. Quantitative measurement of regional lung gas volume by synchrotron radiation computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Monfraix, Sylvie [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble (France); Bayat, Sam [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble (France); Porra, Liisa [Department of Physical Sciences, University of Helsinki, POB 64, FIN-00014 Helsinki (Finland); Berruyer, Gilles [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble (France); Nemoz, Christian [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble (France); Thomlinson, William [Canadian Light Source, 101 Perimeter Road, Saskatoon, SK S7N 0X4 (Canada); Suortti, Pekka [Department of Physical Sciences, University of Helsinki, POB 64, FIN-00014 Helsinki (Finland); Sovijaervi, Anssi R A [Department of Clinical Physiology and Nuclear Medicine, Helsinki University Central Hospital, POB 340, FIN-00029 HUS, Helsinki (Finland)

    2005-01-07

    The aim of this study was to assess the feasibility of a novel respiration-gated spiral synchrotron radiation computed tomography (SRCT) technique for direct quantification of absolute regional lung volumes, using stable xenon (Xe) gas as an inhaled indicator. Spiral SRCT with K-edge subtraction using two monochromatic x-ray beams was used to visualize and directly quantify inhaled Xe concentrations and airspace volumes in three-dimensional (3D) reconstructed lung images. Volume measurements were validated using a hollow Xe-filled phantom. Spiral images spanning 49 mm in lung height were acquired following 60 breaths of an 80% Xe-20% O{sub 2} gas mixture, in two anaesthetized and mechanically ventilated rabbits at baseline and after histamine aerosol inhalation. Volumetric images of 20 mm lung sections were obtained at functional residual capacity (FRC) and at end-inspiration. 3D images showed large patchy filling defects in peripheral airways and alveoli following histamine provocation. Local specific lung compliance was calculated based on FRC/end-inspiration images in normal lung. This study demonstrates spiral SRCT as a new technique for direct determination of regional lung volume, offering possibilities for non-invasive investigation of regional lung function and mechanics, with a uniquely high spatial resolution. An example of non-uniform volume distribution in rabbit lung following histamine inhalation is presented.

  8. Quantitative Analyses of Pediatric Cervical Spine Ossification Patterns Using Computed Tomography

    Science.gov (United States)

    Yoganandan, Narayan; Pintar, Frank A.; Lew, Sean M.; Rao, Raj D.; Rangarajan, Nagarajan

    2011-01-01

    The objective of the present study was to quantify ossification processes of the human pediatric cervical spine. Computed tomography images were obtained from a high resolution scanner according to clinical protocols. Bone window images were used to identify the presence of the primary synchondroses of the atlas, axis, and C3 vertebrae in 101 children. Principles of logistic regression were used to determine probability distributions as a function of subject age for each synchondrosis for each vertebra. The mean and 95% upper and 95% lower confidence intervals are given for each dataset delineating probability curves. Posterior ossifications preceded bilateral anterior closures of the synchondroses in all vertebrae. However, ossifications occurred at different ages. Logistic regression results for closures of different synchondrosis indicated p-values of vertebra. Fifty percent probability of three, two, and one synchondroses occurred at 2.53, 6.97, and 7.57 years of age for the atlas; 3.59, 4.74, and 5.7 years of age for the axis; and 1.28, 2.22, and 3.17 years of age for the third cervical vertebrae, respectively. Ossifications occurring at different ages indicate non-uniform maturations of bone growth/strength. They provide an anatomical rationale to reexamine dummies, scaling processes, and injury metrics for improved understanding of pediatric neck injuries PMID:22105393

  9. Quantitative wood-adhesive penetration with X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Paris, Jesse L.; Kamke, Frederick A. [Oregon State U.

    2017-03-21

    Micro X-ray computed tomography (XCT) was used to analyze the 3D adhesive penetration behavior of different wood–adhesive bondlines. Three adhesives, a phenol formaldehyde (PF), a polymeric diphenylmethane diisocyanate (pMDI), and a hybrid polyvinyl acetate (PVA), all tagged with iodine for enhanced X-ray attenuation, were used to prepare single-bondline laminates in two softwoods, Douglas-fir and loblolly pine, and one hardwood, a hybrid polar. Adhesive penetration depth was measured with two separate calculations, and results were compared with 2D fluorescent micrographs. A total of 54 XCT scans were collected, representing six replicates of each treatment type; each replicate, however, consisted of approximately 1500 individual, cross-section slices stacked along the specimen length. As these adhesives were highly modified, the presented results do not indicate typical behavior for their broader adhesive classes. Still, clear penetration differences were observed between each adhesive type, and between wood species bonded with both the PF and pMDI adhesives. Furthermore, penetration results depended on the calculation method used. Two adhesive types with noticeably different resin distributions in the cured bondline, showed relatively similar penetration depths when calculated with a traditional effective penetration equation. However, when the same data was calculated with a weighted penetration calculation, which accounts for both adhesive area and depth, the results appeared to better represent the different distributions depicted in the photomicrographs and tomograms. Additionally, individual replicate comparisons showed variation due to specimen anatomy, not easily observed or interpreted from 2D images. Finally, 3D views of segmented 3D adhesive phases offered unique, in-situ views of the cured adhesive structures. In particular, voids formed by CO2 bubbles generated during pMDI cure were clearly visible in penetrated columns of the solidified

  10. Quantitative evaluation of anatomical noise in chest digital tomosynthesis, digital radiography, and computed tomography

    Science.gov (United States)

    Lee, D.; Choi, S.; Lee, H.; Kim, D.; Choi, S.; Kim, H.-J.

    2017-04-01

    Lung cancer is currently the worldwide leading cause of death from cancer. Thus, detection of lung cancer at its early stages is critical for improving the survival rate of patients. Chest digital tomosynthesis (CDT) is a recently developed imaging modality, combining many advantages of digital radiography (DR) and computed tomography (CT). This method has the potential to be widely used in the clinical setting. In this study, we introduce a developed CDT R/F system and compare its image quality with those of DR and CT, especially with respect to anatomical noise and lung nodule conspicuity, for LUNGMAN phantoms. The developed CDT R/F system consists of a CsI scintillator flat panel detector, X-ray tube, and tomosynthesis data acquisition geometry. For CDT R/F imaging, 41 projections were acquired at different angles, over the ± 20° angular range, in a linear translation geometry. To evaluate the clinical effectiveness of the CDT R/F system, the acquired images were compared with CT (Philips brilliance CT 64, Philips healthcare, U.S.) and DR (ADR-M, LISTEM, Korea) phantom images in terms of the anatomical noise power spectrum (aNPS). DR images exhibited low conspicuity for a small-size lung nodule, while CDT R/F and CT exhibited relatively high sensitivity for all lung nodule sizes. The aNPS of the CDT R/F system was better than that of DR, by resolving anatomical overlapping problems. In conclusion, the developed CDT R/F system is likely to contribute to early diagnosis of lung cancer, while requiring a relatively low patient dose, compared with CT.

  11. Bone Health Monitoring in Astronauts: Recommended Use of Quantitative Computed Tomography [QCT] for Clinical and Operational Decisions

    Science.gov (United States)

    Sibonga, J. D.; Truskowski, P.

    2010-01-01

    This slide presentation reviews the concerns that astronauts in long duration flights might have a greater risk of bone fracture as they age than the general population. A panel of experts was convened to review the information and recommend mechanisms to monitor the health of bones in astronauts. The use of Quantitative Computed Tomography (QCT) scans for risk surveillance to detect the clinical trigger and to inform countermeasure evaluation is reviewed. An added benefit of QCT is that it facilitates an individualized estimation of bone strength by Finite Element Modeling (FEM), that can inform approaches for bone rehabilitation. The use of FEM is reviewed as a process that arrives at a composite number to estimate bone strength, because it integrates multiple factors.

  12. Ultrasonic computed tomography based on full-waveform inversion for bone quantitative imaging

    Science.gov (United States)

    Bernard, Simon; Monteiller, Vadim; Komatitsch, Dimitri; Lasaygues, Philippe

    2017-09-01

    We introduce an ultrasonic quantitative imaging method for long bones based on full-waveform inversion. The cost function is defined as the difference in the L 2-norm sense between observed data and synthetic results at a given iteration of the iterative inversion process. For simplicity, and in order to reduce the computational cost, we use a two-dimensional acoustic approximation. The inverse problem is solved iteratively based on a quasi-Newton technique called the Limited-memory Broyden-Fletcher-Goldfarb-Shanno method. We show how the technique can be made to work fine for benchmark models consisting of a single cylinder, and then five cylinders, the latter case including significant multiple diffraction effects. We then show pictures obtained for a tibia-fibula bone pair model. Convergence is fast, typically in 15 to 30 iterations in practice in each frequency band used. We discuss the so-called ‘cycle skipping’ effect that can occur in such full waveform inversion techniques and make them remain trapped in a local minimum of the cost function. We illustrate strategies that can be used in practice to avoid this. Future work should include viscoelastic materials rather than acoustic, and real data instead of synthetic data.

  13. Quantitative comparison of commercial and non-commercial metal artifact reduction techniques in computed tomography.

    Directory of Open Access Journals (Sweden)

    Dirk Wagenaar

    Full Text Available Typical streak artifacts known as metal artifacts occur in the presence of strongly attenuating materials in computed tomography (CT. Recently, vendors have started offering metal artifact reduction (MAR techniques. In addition, a MAR technique called the metal deletion technique (MDT is freely available and able to reduce metal artifacts using reconstructed images. Although a comparison of the MDT to other MAR techniques exists, a comparison of commercially available MAR techniques is lacking. The aim of this study was therefore to quantify the difference in effectiveness of the currently available MAR techniques of different scanners and the MDT technique.Three vendors were asked to use their preferential CT scanner for applying their MAR techniques. The scans were performed on a Philips Brilliance ICT 256 (S1, a GE Discovery CT 750 HD (S2 and a Siemens Somatom Definition AS Open (S3. The scans were made using an anthropomorphic head and neck phantom (Kyoto Kagaku, Japan. Three amalgam dental implants were constructed and inserted between the phantom's teeth. The average absolute error (AAE was calculated for all reconstructions in the proximity of the amalgam implants.The commercial techniques reduced the AAE by 22.0±1.6%, 16.2±2.6% and 3.3±0.7% for S1 to S3 respectively. After applying the MDT to uncorrected scans of each scanner the AAE was reduced by 26.1±2.3%, 27.9±1.0% and 28.8±0.5% respectively. The difference in efficiency between the commercial techniques and the MDT was statistically significant for S2 (p=0.004 and S3 (p<0.001, but not for S1 (p=0.63.The effectiveness of MAR differs between vendors. S1 performed slightly better than S2 and both performed better than S3. Furthermore, for our phantom and outcome measure the MDT was more effective than the commercial MAR technique on all scanners.

  14. Evaluation of dilated cardiomyopathy by /sup 201/Tl myocardial single photon emission computed tomography. Morphological and quantitative analysis

    Energy Technology Data Exchange (ETDEWEB)

    Futagami, Yasuo; Makino, Katsutoshi; Ichikawa, Takehiko

    1984-08-01

    To estimate dilated cardiomyopathy (DCM)morphologically and quantitatively, /sup 201/Tl myocardial single photon emission computed tomography (SPECT) was performed in 14 DCM and 5 normal cases. Using a rotating dual-gamma camera system, resting SPECT data were collected for 6 minutes. Quantitative analysis of clinical cases was based on phantom studies. Marked spherical left ventricular (LV) dilatation (14/14), localized-diffuse low uptake or defect (12/14), and right ventricular visualization (6/14) were characteristic features in DCM. Differentiation of DCM from ischemic heart disease by SPECT was possible through the feature indicating disproportionately large LV cavity to defect size or degree. Quantitative analysis When DCM was compared with normal control (n-5), following 3 features were impressive: DCM was significantly higher in LV myocardial /sup 201/Tl uptake ratio and LV volume than normal control; DCM was significantly lower in LV myocardial /sup 201/Tl uptake ratio of unit volume (1 ml) than normal control; DCM was significantly lower in mean myocardial count/mean lung count.ratio than normal control.

  15. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) ... are the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as a ...

  16. [Quantitative structure characteristics and fractal dimension of Chinese medicine granules measured by synchrotron radiation X-ray computed micro tomography].

    Science.gov (United States)

    Lu, Xiao-long; Zheng, Qin; Yin, Xian-zhen; Xiao, Guang-qing; Liao, Zu-hua; Yang, Ming; Zhang, Ji-wen

    2015-06-01

    The shape and structure of granules are controlled by the granulation process, which is one of the main factors to determine the nature of the solid dosage forms. In this article, three kinds of granules of a traditional Chinese medicine for improving appetite and promoting digestion, namely, Jianwei Granules, were prepared using granulation technologies as pendular granulation, high speed stirring granulation, and fluidized bed granulation and the powder properties of them were investigated. Meanwhile, synchrotron radiation X-ray computed micro tomography (SR-µCT) was applied to quantitatively determine the irregular internal structures of the granules. The three-dimensional (3D) structure models were obtained by 3D reconstruction, which were more accurately to characterize the three-dimensional structures of the particles through the quantitative data. The models were also used to quantitatively compare the structural differences of granules prepared by different granulation processes with the same formula, so as to characterize how the production process plays a role in the pharmaceutical behaviors of the granules. To focus on the irregularity of the particle structure, the box counting method was used to calculate the fractal dimensions of the granules. The results showed that the fractal dimension is more sensitive to reflect the minor differences in the structure features than the conventional parameters, and capable to specifically distinct granules in structure. It is proved that the fractal dimension could quantitatively characterize the structural information of irregular granules. It is the first time suggested by our research that the fractal dimension difference (Df,c) between two fractal dimension parameters, namely, the volume matrix fractal dimension and the surface matrix fractal dimension, is a new index to characterize granules with irregular structures and evaluate the effects of production processes on the structures of granules as a new

  17. 23.4% saline decreases brain tissue volume in severe hepatic encephalopathy as assessed by a quantitative computed tomography marker

    Science.gov (United States)

    Liotta, Eric M; Lizza, Bryan D; Romanova, Anna L; Guth, James C; Berman, Michael D; Carroll, Timothy J; Francis, Brandon; Ganger, Daniel; Ladner, Daniela P; Maas, Matthew B; Naidech, Andrew M

    2016-01-01

    Objective Cerebral edema is common in severe hepatic encephalopathy and may be life-threatening. Bolus 23.4% hypertonic saline (HTS) improves surveillance neuromonitoring scores, although its mechanism of action is not clearly established. We investigated the hypothesis that bolus HTS decreases cerebral edema in severe hepatic encephalopathy utilizing a quantitative technique to measure brain and CSF volume changes. Design Retrospective analysis of serial computed tomography (CT) scans and clinical data for a case-control series was performed. Setting Intensive care units of a tertiary care hospital. Patients Patients with severe hepatic encephalopathy treated with 23.4% HTS and control patients who did not receive 23.4% HTS. Methods We used clinically obtained CT scans to measure volumes of the ventricles, intracranial CSF, and brain using a previously validated semi-automated technique (Analyze Direct; Overland Park, KS). Volumes before and after 23.4% HTS were compared with Wilcoxon signed-rank test. Associations between total CSF volume, ventricular volume, serum sodium, and Glasgow Coma Scale Scores were assessed using Spearman correlation. Results Eleven patients with 18 administrations of 23.4% HTS met inclusion criteria. Total CSF (median 47.6 [35.1–69.4] to 61.9 [47.7–87.0] mL, pbrain tissue volume. Total CSF and ventricular volume change may be useful quantitative measures to assess cerebral edema in severe hepatic encephalopathy. PMID:26308431

  18. Parathyroidectomy improves bone geometry and microarchitecture in female patients with primary hyperparathyroidism. A 1-year prospective controlled study using high resolution peripheral quantitative computed tomography

    DEFF Research Database (Denmark)

    Hansen, Stinus; Hauge, Ellen M; Rasmussen, Lars

    2012-01-01

    controlled study, high-resolution peripheral quantitative computed tomography (HR-pQCT) was used to evaluate changes in bone geometry, volumetric BMD (vBMD), microarchitecture, and estimated strength in female patients with PHPT before and 1 year after PTX, compared to healthy controls. Twenty-seven women...

  19. Quantitative computed tomography as a test of endurance for evaluation of bony plates; Utilizacao da tomografia computadorizada quantitativa como teste de resistencia para avaliacao de placas osseas

    Energy Technology Data Exchange (ETDEWEB)

    Melo Filho, E.V.; Costa, L.A.V.S.; Oliveira, D.C. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil); Freitas, P.M.C. [Escola de Veterinaria - Universidade Federal de Minas Gerais - Belo Horizonte, MG (Brazil); Teixeira, M.W.; Costa, F.S. [Universidade Federal Rural de Pernambuco - Recife, PE (Brazil)

    2012-06-15

    Quantitative computed tomography was used to determine the radiodensity of bony plates. The CT scans provided information regarding radiodensity of bony plates and allowed to verify the uniformity of bone mineral density in their scope. The proposed methodology should be considered as another tool for determining the resistance of these biomaterials. (author)

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  1. Computed Tomography (CT) -- Head

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    Full Text Available ... limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, more ... the body being studied. top of page How is the procedure performed? The technologist begins by positioning ...

  2. Computed Tomography (CT) -- Head

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  3. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  4. Computed Tomography (CT) -- Head

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    Full Text Available ... CT scanner technique will be adjusted to their size and the area of interest to reduce the ... Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and ...

  5. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... CT scanner technique will be adjusted to their size and the area of interest to reduce the ... Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and ...

  6. Computed Tomography (CT) -- Head

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    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  7. Quantitative image analysis for the detection of motion artefacts in coronary artery computed tomography

    NARCIS (Netherlands)

    Kristanto, Wisnumurti; van Ooijen, Peter M.; Dikkers, Riksta; Greuter, Marcel J.; Zijlstra, Felix; Oudkerk, Matthijs

    2010-01-01

    Multi detector-row CT (MDCT), the current preferred method for coronary artery disease assessment, is still affected by motion artefacts. To rule out motion artefacts, qualitative image analysis is usually performed. Our study aimed to develop a quantitative image analysis for motion artefacts detec

  8. RADIATION DOSE IN PAEDIATRIC COMPUTED TOMOGRAPHY ...

    African Journals Online (AJOL)

    Computed tomography (CT) is a powerful tool for the accurate ... increasing, and estimates suggest that quantitative lifetime ... Keywords: Computed Tomography, Radiation Risk, Radiation Dose, Patient Dose ... techniques, such as MRI and ultrasound, which do not ..... in the course of management are not monitored to.

  9. Quantitative X-ray fluorescence computed tomography for low-Z samples using an iterative absorption correction algorithm

    Science.gov (United States)

    Huang, Rong; Limburg, Karin; Rohtla, Mehis

    2017-05-01

    X-ray fluorescence computed tomography is often used to measure trace element distributions within low-Z samples, using algorithms capable of X-ray absorption correction when sample self-absorption is not negligible. Its reconstruction is more complicated compared to transmission tomography, and therefore not widely used. We describe in this paper a very practical iterative method that uses widely available transmission tomography reconstruction software for fluorescence tomography. With this method, sample self-absorption can be corrected not only for the absorption within the measured layer but also for the absorption by material beyond that layer. By combining tomography with analysis for scanning X-ray fluorescence microscopy, absolute concentrations of trace elements can be obtained. By using widely shared software, we not only minimized the coding, took advantage of computing efficiency of fast Fourier transform in transmission tomography software, but also thereby accessed well-developed data processing tools coming with well-known and reliable software packages. The convergence of the iterations was also carefully studied for fluorescence of different attenuation lengths. As an example, fish eye lenses could provide valuable information about fish life-history and endured environmental conditions. Given the lens's spherical shape and sometimes the short distance from sample to detector for detecting low concentration trace elements, its tomography data are affected by absorption related to material beyond the measured layer but can be reconstructed well with our method. Fish eye lens tomography results are compared with sliced lens 2D fluorescence mapping with good agreement, and with tomography providing better spatial resolution.

  10. Quantitative and Qualitative Comparison of Single-Source Dual-Energy Computed Tomography and 120-kVp Computed Tomography for the Assessment of Pancreatic Ductal Adenocarcinoma.

    Science.gov (United States)

    Bhosale, Priya; Le, Ott; Balachandran, Aprana; Fox, Patricia; Paulson, Eric; Tamm, Eric

    2015-01-01

    The aim of this study was to compare contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) between pancreatic-phase dual-energy computed tomography (DECT) and 120-kVp CT for pancreatic ductal adenocarcinoma (PDA). Seventy-eight patients underwent multiphasic pancreatic imaging protocols for PDA (40, DECT; 38, 120-kVp CT [control]). Using pancreatic phase, CNR and SNR for PDA were obtained for DECT at monochromatic energies 50 through 80 keV, iodine material density images, and 120-kVp images. Using a 5-point scale (1, excellent; 5, markedly limited), images were qualitatively assessed by 2 radiologists in consensus for PDA detection, extension, vascular involvement, and noise. Wilcoxon signed rank and 2-sample tests were used to compare the qualitative measures, CNR and SNR, for DECT and 120-kVp images. Bonferroni correction was applied. Iodine material density image had significantly higher CNR and SNR for PDA than any monochromatic energy images (P Qualitatively, 70-keV images were rated highest in the categories of tumor extension and vascular invasion and were similar to 120-kVp images. Our results indicate that DECT improves PDA lesion conspicuity compared with routine 120-kVp CT, which may allow for better detection of PDA.

  11. Qualitative and quantitative interpretation of computed tomography of the lungs in healthy neonatal foals.

    Science.gov (United States)

    Lascola, Kara M; O'Brien, Robert T; Wilkins, Pamela A; Clark-Price, Stuart C; Hartman, Susan K; Mitchell, Mark A

    2013-09-01

    To qualitatively describe lung CT images obtained from sedated healthy equine neonates (≤ 14 days of age), use quantitative analysis of CT images to characterize attenuation and distribution of gas and tissue volumes within the lungs, and identify differences between lung characteristics of foals ≤ 7 days of age and foals > 7 days of age. 10 Standardbred foals between 2.5 and 13 days of age. Foals were sedated with butorphanol, midazolam, and propofol and positioned in sternal recumbency for thoracic CT. Image analysis software was used to exclude lung from nonlung structures. Lung attenuation was measured in Hounsfield units (HU) for analysis of whole lung and regional changes in attenuation and lung gas and tissue components. Degree of lung attenuation was classified as follows: hyperinflated or emphysema, -1,000 to -901 HU; well aerated, -900 to -501 HU; poorly aerated, -500 to -101 HU; and nonaerated, > -100 HU. Qualitative evidence of an increase in lung attenuation and patchy alveolar patterns in the ventral lung region were more pronounced in foals ≤ 7 days of age than in older foals. Quantitative analysis revealed that mean ± SD lung attenuation was greater in foals ≤ 7 days of age (-442 ± 28 HU) than in foals > 7 days of age (-521 ± 24 HU). Lung aeration and gas volumes were lower than in other regions ventrally and in the mid lung region caudal to the heart. CONCLUSIONS AND CLINICAL RELEVANCE-Identified radiographic patterns and changes in attenuation were most consistent with atelectasis and appeared more severe in foals ≤ 7 days of age than in older neonatal foals. Recognition of these changes may have implications for accurate CT interpretation in sedated neonatal foals with pulmonary disease.

  12. Assessment of Bone Mineral Density in Male Patients with Chronic Obstructive Pulmonary Disease by DXA and Quantitative Computed Tomography

    Directory of Open Access Journals (Sweden)

    George Fountoulis

    2016-01-01

    Full Text Available The purpose of this study is to identify the prevalence of osteoporosis in male patients with chronic obstructive pulmonary disease (COPD by dual-energy X-ray absorptiometry (DXA and quantitative computed tomography (QCT and to compare the diagnostic abilities of the above methods. Thirty-seven male patients with established COPD were examined with DXA and standard QCT in lumbar spine, including L1, L2, and L3 vertebrae. T-scores and bone mineral density values were calculated by DXA and QCT method, respectively. Comparative assessment of the findings was performed and statistical analysis was applied. QCT measurements found more COPD patients with impaired bone mineral density compared to DXA, namely, 13 (35.1% versus 12 (32.4% patients with osteopenia and 16 (43.2% versus 9 (16.2% patients with osteoporosis (p=0.04. More vertebrae were found with osteoporosis by QCT compared to DXA (p=0.03. The prevalence of osteoporosis among male patients with COPD is increased and DXA may underestimate this risk. QCT measurements have an improved discriminating ability to identify low BMD compared to DXA measurements because QCT is able to overcome diagnostic pitfalls including aortic calcifications and degenerative spinal osteophytes.

  13. Quantitative selenium-75-cholesterol imaging and computed tomography of the adrenal glands in Conn's syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.L. (Cape Town Univ. (South Africa). Dept. of Medicine); Smith, J.A.; Mervis, B. (Cape Town Univ. (South Africa))

    1982-10-30

    Six consecutive patients with biochemically proven primary aldosteronism (4 with unilateral aldosteronomas and 2 with bilateral hyperplasia) underwent imaging with /sup 75/Se-selenomethyl-nor-cholesterol (Scintadren; Radiochemical Centre, Amersham, UK) and computed tomography (CT) of the adrenal glands to aid in lateralizing unilateral aldosterone-producing adenomas (APA) and to differentiate APA from idiopathic adrenal hyperplasia (IAH). Scintadren quantitative imaging alone was successful in lateralizing the lesion in all 4 cases of unilateral APA; mean uptake by the affected adrenal gland was 0,47% of the administered dose as against 0,23% in the normal gland (P smaller than 0,01). The mean uptake ratio for the adenomatous as against the normal gland was 2,03 (range 1,75-2,21), which was significantly greater than the uptake ratio of 0,82 in 4 normal individuals (P smaller than 0,01). CT lateralized all the APAs. In the 2 cases of IAH, Scintadren uptake was bilaterally increased in one case in which CT was normal, whereas in the other case Scintadren uptakes were normal while CT showed two abnormal glands. The overall diagnostic yield for Scintadren was 83%; the figure for CT was also 83%. When the results of Scintadren imaging and CT are pooled, the accuracy in lateralizing APAs and differentiating APA from IAH as a cause of Conn's syndrome is 100%.

  14. Quantitative computed tomography and cranial burr holes: a model to evaluate the quality of cranial reconstruction in humans.

    Science.gov (United States)

    Worm, Paulo Valdeci; Ferreira, Nelson Pires; Ferreira, Marcelo Paglioli; Kraemer, Jorge Luiz; Lenhardt, Rene; Alves, Ronnie Peterson Marcondes; Wunderlich, Ricardo Castilho; Collares, Marcus Vinicius Martins

    2012-05-01

    Current methods to evaluate the biologic development of bone grafts in human beings do not quantify results accurately. Cranial burr holes are standardized critical bone defects, and the differences between bone powder and bone grafts have been determined in numerous experimental studies. This study evaluated quantitative computed tomography (QCT) as a method to objectively measure cranial bone density after cranial reconstruction with autografts. In each of 8 patients, 2 of 4 surgical burr holes were reconstructed with autogenous wet bone powder collected during skull trephination, and the other 2 holes, with a circular cortical bone fragment removed from the inner table of the cranial bone flap. After 12 months, the reconstructed areas and a sample of normal bone were studied using three-dimensional QCT; bone density was measured in Hounsfield units (HU). Mean (SD) bone density was 1535.89 (141) HU for normal bone (P < 0.0001), 964 (176) HU for bone fragments, and 453 (241) HU for bone powder (P < 0.001). As expected, the density of the bone fragment graft was consistently greater than that of bone powder. Results confirm the accuracy and reproducibility of QCT, already demonstrated for bone in other locations, and suggest that it is an adequate tool to evaluate cranial reconstructions. The combination of QCT and cranial burr holes is an excellent model to accurately measure the quality of new bone in cranial reconstructions and also seems to be an appropriate choice of experimental model to clinically test any cranial bone or bone substitute reconstruction.

  15. Quantitative computed tomography (QCT) as a radiology reporting tool by using optical character recognition (OCR) and macro program.

    Science.gov (United States)

    Lee, Young Han; Song, Ho-Taek; Suh, Jin-Suck

    2012-12-01

    The objectives are (1) to introduce a new concept of making a quantitative computed tomography (QCT) reporting system by using optical character recognition (OCR) and macro program and (2) to illustrate the practical usages of the QCT reporting system in radiology reading environment. This reporting system was created as a development tool by using an open-source OCR software and an open-source macro program. The main module was designed for OCR to report QCT images in radiology reading process. The principal processes are as follows: (1) to save a QCT report as a graphic file, (2) to recognize the characters from an image as a text, (3) to extract the T scores from the text, (4) to perform error correction, (5) to reformat the values into QCT radiology reporting template, and (6) to paste the reports into the electronic medical record (EMR) or picture archiving and communicating system (PACS). The accuracy test of OCR was performed on randomly selected QCTs. QCT as a radiology reporting tool successfully acted as OCR of QCT. The diagnosis of normal, osteopenia, or osteoporosis is also determined. Error correction of OCR is done with AutoHotkey-coded module. The results of T scores of femoral neck and lumbar vertebrae had an accuracy of 100 and 95.4 %, respectively. A convenient QCT reporting system could be established by utilizing open-source OCR software and open-source macro program. This method can be easily adapted for other QCT applications and PACS/EMR.

  16. Age estimation during the blow fly intra-puparial period: a qualitative and quantitative approach using micro-computed tomography.

    Science.gov (United States)

    Martín-Vega, Daniel; Simonsen, Thomas J; Wicklein, Martina; Hall, Martin J R

    2017-05-04

    Minimum post-mortem interval (minPMI) estimates often rely on the use of developmental data from blow flies (Diptera: Calliphoridae), which are generally the first colonisers of cadavers and, therefore, exemplar forensic indicators. Developmental data of the intra-puparial period are of particular importance, as it can account for more than half of the developmental duration of the blow fly life cycle. During this period, the insect undergoes metamorphosis inside the opaque, barrel-shaped puparium, formed by the hardening and darkening of the third instar larval cuticle, which shows virtually no external changes until adult emergence. Regrettably, estimates based on the intra-puparial period are severely limited due to the lack of reliable, non-destructive ageing methods and are frequently based solely on qualitative developmental markers. In this study, we use non-destructive micro-computed tomography (micro-CT) for (i) performing qualitative and quantitative analyses of the morphological changes taking place during the intra-puparial period of two forensically relevant blow fly species, Calliphora vicina and Lucilia sericata, and (ii) developing a novel and reliable method for estimating insect age in forensic practice. We show that micro-CT provides age-diagnostic qualitative characters for most 10% time intervals of the total intra-puparial period, which can be used over a range of temperatures and with a resolution comparable to more invasive and time-consuming traditional imaging techniques. Moreover, micro-CT can be used to yield a quantitative measure of the development of selected organ systems to be used in combination with qualitative markers. Our results confirm micro-CT as an emerging, powerful tool in medico-legal investigations.

  17. Quantitative strain analysis in analogue modelling experiments: insights from X-ray computed tomography and tomographic image correlation

    Science.gov (United States)

    Adam, J.; Klinkmueller, M.; Schreurs, G.; Wieneke, B.

    2009-04-01

    The combination of scaled analogue modelling experiments, advanced research in analogue material mechanics (Lohrmann et al. 2003, Panien et al. 2006), X-ray computed tomography and new high-resolution deformation monitoring techniques (2D/3D Digital Image Correlation) is a new powerful tool not only to examine the evolution and interaction of faulting in analogue models, but also to evaluate relevant controlling factors such as mechanics, sedimentation, erosion and climate. This is of particular interest for applied problems in the energy sector (e.g., structurally complex reservoirs, LG & CO2 underground storage) because the results are essential for geological and seismic interpretation as well as for more realistically constrained fault/fracture simulations and reservoir characterisation. X-ray computed tomography (CT) analysis has been successfully applied to analogue models since the late 1980s. This technique permits visualisation of the interior of an analogue model without destroying it. Technological improvements have resulted in more powerful X-ray CT scanners that allow periodic acquisition of volumetric data sets thus making it possible to follow the 3-D evolution of the model structures with time (e.g. Schreurs et al., 2002, 2003). Optical strain monitoring (Digital Image Correlation, DIC) in analogue experiments (Adam et al., 2005) represents an important advance in quantitative physical modelling and in helping to understand non-linear rock deformation processes. Optical non-intrusive 2D/3D strain and surface flow analysis by DIC is a new methodology in physical modelling that enables the complete quantification of localised and distributed model deformation. The increase in spatial/temporal strain data resolution of several orders of magnitude makes physical modelling - used for decades to visualize the kinematic processes of geological deformation processes - a unique research tool to determine what fundamental physical processes control tectonic

  18. Prediction of Human Vertebral Compressive Strength Using Quantitative Computed Tomography Based Nonlinear Finite Element Method

    Directory of Open Access Journals (Sweden)

    Ahad Zeinali

    2007-12-01

    Full Text Available Introduction: Because of the importance of vertebral compressive fracture (VCF role in increasing the patients’ death rate and reducing their quality of life, many studies have been conducted for a noninvasive prediction of vertebral compressive strength based on bone mineral density (BMD determination and recently finite element analysis. In this study, QCT-voxel based nonlinear finite element method is used for predicting vertebral compressive strength. Material and Methods: Four thoracolumbar vertebrae were excised from 3 cadavers with an average age of 42 years. They were then put in a water phantom and were scanned using the QCT. Using a computer program prepared in MATLAB, detailed voxel based geometry and mechanical characteristics of the vertebra were extracted from the CT images. The three dimensional finite element models of the samples were created using ANSYS computer program. The compressive strength of each vertebra body was calculated based on a linearly elastic-linearly plastic model and large deformation analysis in ANSYS and was compared to the value measured experimentally for that sample. Results: Based on the obtained results the QCT-voxel based nonlinear finite element method (FEM can predict vertebral compressive strength more effectively and accurately than the common QCT-voxel based linear FEM. The difference between the predicted strength values using this method and the measured ones was less than 1 kN for all the samples. Discussion and Conclusion: It seems that the QCT-voxel based nonlinear FEM used in this study can predict more effectively and accurately the vertebral strengths based on every vertebrae specification by considering their detailed geometric and densitometric characteristics.

  19. Osteochondritis dissecans of the capitellum: lesion size and pattern analysis using quantitative 3-dimensional computed tomography and mapping technique.

    Science.gov (United States)

    Bexkens, Rens; Oosterhoff, Jacobien H; Tsai, Tsung-Yuan; Doornberg, Job N; van den Bekerom, Michel P J; Eygendaal, Denise; Oh, Luke S

    2017-09-01

    The goals of this study were to evaluate the reliability of a quantitative 3-dimensional computed tomography (Q3DCT) technique for measurement of the capitellar osteochondritis dissecans (OCD) surface area, to analyze OCD distribution using a mapping technique, and to investigate associations between Q3DCT lesion quantification and demographic characteristics and/or clinical examination findings. We identified patients with capitellar OCD who presented to our orthopedic sports medicine practice between January 2001 and January 2016 and who had undergone a preoperative computed tomography scan (slice thickness ≤1.25 mm). A total of 17 patients with a median age of 15 years (range, 12-23 years) were included in this study. Three-dimensional polygon models were reconstructed after osseous structures were marked in 3 planes. Surface areas of the OCD lesion as well as the capitellum were measured. Observer agreement was assessed with the intraclass correlation coefficient (ICC). Heat maps were created to visualize OCD distribution. Measurements of the OCD surface area showed almost perfect intraobserver agreement (ICC, 0.99; confidence interval [CI], 0.98-0.99) and interobserver agreement (ICC, 0.93; CI, 0.86-0.97). Measurements of the capitellar surface area also showed almost perfect intraobserver agreement (ICC, 0.97;CI, 0.91-0.99) and interobserver agreement (ICC, 0.86; CI, 0.46-0.96). The median OCD surface area was 101 mm(2) (range, 49-217 mm(2)). On the basis of OCD heat mapping, the posterolateral zone of the capitellum was most frequently affected. OCDs in which the lateral wall was involved were associated with larger lesion size (P = .041), longer duration of symptoms (P = .030), and worse elbow extension (P = .013). The ability to quantify the capitellar OCD surface area and lesion location in a reliable manner using Q3DCT and a mapping technique should be considered when detailed knowledge of lesion size and location is desired

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Computed Tomography ( ... stroke and brain tumors. It also helps your doctor to evaluate your face, sinuses, and skull or ...

  1. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Computed Tomography ( ... the best imaging modality for sinusitis. Tell your doctor if there’s a possibility you are pregnant and ...

  2. Population=stratified analysis of bone mineral density distribution in cervical and lumbar vertebrae of chinese from quantitative computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yong; Cheng, Xiaoguang; Cai, Wei; Wang, Ling; Duanmu, Yangyang; Zhang, Chen Xin [Dept. of Radiology, The Fourth Clinical Medical College of Peking University, Beijing Jishuitan Hospital, Beijing (China); Zhou, Zhuang [Dept. of Orthopedic Oncology, The Third Hospital of Hebei Medical University, Shijiazhuang (China); Wu, Cheng' ai; Zhao, Danhui; Wang, Chao [Beijing Institute of Traumatology and Orthopedics, Beijing (China); Tian, Wei [Dept. of Spine Surgery, The Fourth Clinical Medical College of Peking University, Beijing Jishuitan Hospital, Beijing (China)

    2016-09-15

    To investigate the bone mineral density (BMD) of cervical vertebrae in a population-stratified manner and correlate with that of the lumbar vertebrae. Five hundred and ninety-eight healthy volunteers (254 males, 344 females), ranging from 20 to 64 years of age, were recruited for volumetric BMD (vBMD) measurements by quantitative computed tomography. Basic information (age, height, weight, waistline, and hipline), and vBMD of the cervical and lumbar vertebrae (C2–7 and L2–4) were recorded. Comparisons among sex, age groups and different levels of vertebrae were analyzed using analysis of variance. Linear regression was performed for relevance of different vertebral levels. The vBMD of cervical and lumbar vertebrae was higher in females than males in each age group. The vBMD of the cervical and lumbar vertebrae in males and the vBMD of lumbar vertebrae in females decreased with aging. In each age group, the vBMD of the cervical vertebrae was higher than that of the lumbar vertebrae with gradual decreases from C2 to C7 except for C3; moreover, the vBMD of C6 and C7 was significantly different from that of C2–5. Correlations of vBMD among different cervical vertebrae (females: r = 0.62–0.94; males: r = 0.63–0.94) and lumbar vertebrae (males: r = 0.93–0.98; females: r = 0.82–0.97) were statistically significant at each age group. The present study provided normative data of cervical vertebrae in an age- and sex-stratified manner. Sex differences in vBMD prominently vary with age, which can be helpful to design a more comprehensive pre-operative surgical plan.

  3. Population-Stratified Analysis of Bone Mineral Density Distribution in Cervical and Lumbar Vertebrae of Chinese from Quantitative Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yong [Department of Radiology, The Fourth Clinical Medical College of Peking University, Beijing Jishuitan Hospital, Beijing 100035 (China); Zhou, Zhuang [Department of Orthopedic Oncology, The Third Hospital of Hebei Medical University, Shijiazhuang 050051 (China); Wu, Cheng' ai; Zhao, Danhui; Wang, Chao [Beijing Institute of Traumatology and Orthopedics, Beijing 100035 (China); Cheng, Xiaoguang; Cai, Wei; Wang, Ling; Duanmu, Yangyang; Zhang, Chenxin [Department of Radiology, The Fourth Clinical Medical College of Peking University, Beijing Jishuitan Hospital, Beijing 100035 (China); Tian, Wei [Department of Spine Surgery, The Fourth Clinical Medical College of Peking University, Beijing Jishuitan Hospital, Beijing 100035 (China)

    2016-11-01

    To investigate the bone mineral density (BMD) of cervical vertebrae in a population-stratified manner and correlate with that of the lumbar vertebrae. Five hundred and ninety-eight healthy volunteers (254 males, 344 females), ranging from 20 to 64 years of age, were recruited for volumetric BMD (vBMD) measurements by quantitative computed tomography. Basic information (age, height, weight, waistline, and hipline), and vBMD of the cervical and lumbar vertebrae (C2–7 and L2–4) were recorded. Comparisons among sex, age groups and different levels of vertebrae were analyzed using analysis of variance. Linear regression was performed for relevance of different vertebral levels. The vBMD of cervical and lumbar vertebrae was higher in females than males in each age group. The vBMD of the cervical and lumbar vertebrae in males and the vBMD of lumbar vertebrae in females decreased with aging. In each age group, the vBMD of the cervical vertebrae was higher than that of the lumbar vertebrae with gradual decreases from C2 to C7 except for C3; moreover, the vBMD of C6 and C7 was significantly different from that of C2–5. Correlations of vBMD among different cervical vertebrae (females: r = 0.62–0.94; males: r = 0.63–0.94) and lumbar vertebrae (males: r = 0.93–0.98; females: r = 0.82–0.97) were statistically significant at each age group. The present study provided normative data of cervical vertebrae in an age- and sex-stratified manner. Sex differences in vBMD prominently vary with age, which can be helpful to design a more comprehensive pre-operative surgical plan.

  4. A Quantitative Volumetric Micro-Computed Tomography Method to Analyze Lung Tumors in Genetically Engineered Mouse Models

    Directory of Open Access Journals (Sweden)

    Brian B. Haines

    2009-01-01

    Full Text Available Two genetically engineered, conditional mouse models of lung tumor formation, K-rasLSL-G12D and K-rasLSL-G12D/p53LSL-R270H, are commonly used to model human lung cancer. Developed by Tyler Jacks and colleagues, these models have been invaluable to study in vivo lung cancer initiation and progression in a genetically and physiologically relevant context. However, heterogeneity, multiplicity and complexity of tumor formation in these models make it challenging to monitor tumor growth in vivo and have limited the application of these models in oncology drug discovery. Here, we describe a novel analytical method to quantitatively measure total lung tumor burden in live animals using micro-computed tomography imaging. Applying this methodology, we studied the kinetics of tumor development and response to targeted therapy in vivo in K-ras and K-ras/p53 mice. Consistent with previous reports, lung tumors in both models developed in a time- and dose (Cre recombinase-dependent manner. Furthermore, the compound K-rasLSL-G12D/p53LSL-R270H mice developed tumors faster and more robustly than mice harboring a single K-rasLSL-G12D oncogene, as expected. Erlotinib, a small molecule inhibitor of the epidermal growth factor receptor, significantly inhibited tumor growth in K-rasLSL-G12D/p53LSL-R270H mice. These results demonstrate that this novel imaging technique can be used to monitor both tumor progression and response to treatment and therefore supports a broader application of these genetically engineered mouse models in oncology drug discovery and development.

  5. Fusion of morphological data obtained by coronary computed tomography angiography with quantitative echocardiographic data on regional myocardial function.

    Science.gov (United States)

    Lipiec, Piotr; Wejner-Mik, Paulina; Wdowiak-Okrojek, Katarzyna; Szymczyk, Ewa; Skurski, Adam; Napieralski, Andrzej; Kamiński, Marek; Szymczyk, Konrad; Kasprzak, Jarosław D

    2016-01-01

    Three-dimensional (3D) fusion of morphological data obtained by coronary computed tomography angiography (CCTA) with functional data from resting and stress echocardiography could potentially provide additional information compared to examination results analyzed separately and increase the diagnostic and prognostic value of non-invasive imaging in patients with suspected coronary artery disease (CAD). Using vendor-independent software developed in our institution, we aimed to assess the feasibility and reproducibility of 3D fusion of morphological CCTA data with echocardiographic data regarding regional myocardial function. Thirty patients with suspected CAD underwent CCTA and resting transthoracic echocardiography. From CCTA we obtained 3D reconstructions of coronary arteries and left ventricle (LV). Offline speckle-tracking analysis of the echocardiographic images provided parametric maps depicting myocardial longitudinal strain in 17 segments of the LV. Using our software, 3 independent investigators fused echocardiographic maps with CCTA reconstruc-tions in all patients. Based on the obtained fused models, each segment of the LV was assigned to one of the major coronary artery branches. Mean time necessary for data fusion was 65 ± 7 s. Complete agreement between independent investigators in assignment of LV segments to coronary branches was obtained in 94% of the segments. The average coefficient of agreement (kappa) between the investigators was 0.950 and the intra-class correlation coefficient was 0.9329 (95% CI 0.9227-0.9420). Three-dimensional fusion of morphological CCTA data with quantitative echocardiographic data on regional myocardial function is feasible and allows highly repro-ducible assignment of myocardial segments to coronary artery branches.

  6. Definition for Rheumatoid Arthritis Erosions Imaged with High Resolution Peripheral Quantitative Computed Tomography and Interreader Reliability for Detection and Measurement.

    Science.gov (United States)

    Barnabe, Cheryl; Toepfer, Dominique; Marotte, Hubert; Hauge, Ellen-Margrethe; Scharmga, Andrea; Kocijan, Roland; Kraus, Sebastian; Boutroy, Stephanie; Schett, Georg; Keller, Kresten Krarup; de Jong, Joost; Stok, Kathryn S; Finzel, Stephanie

    2016-10-01

    High-resolution peripheral quantitative computed tomography (HR-pQCT) sensitively detects erosions in rheumatoid arthritis (RA); however, nonpathological cortical bone disruptions are potentially misclassified as erosive. Our objectives were to set and test a definition for pathologic cortical bone disruptions in RA and to standardize reference landmarks for measuring erosion size. HR-pQCT images of metacarpophalangeal joints of RA and control subjects were used in an iterative process to achieve consensus on the definition and reference landmarks. Independent readers (n = 11) applied the definition to score 58 joints and measure pathologic erosions in 2 perpendicular multiplanar reformations for their maximum width and depth. Interreader reliability for erosion detection and variability in measurements between readers [root mean square coefficient of variation (RMSCV), intraclass correlation (ICC)] were calculated. Pathologic erosions were defined as cortical breaks extending over a minimum of 2 consecutive slices in perpendicular planes, with underlying trabecular bone loss and a nonlinear shape. Interreader agreement for classifying pathologic erosions was 90.2%, whereas variability for width and depth erosion assessment was observed (RMSCV perpendicular width 12.3%, axial width 20.6%, perpendicular depth 24.0%, axial depth 22.2%; ICC perpendicular width 0.206, axial width 0.665, axial depth 0.871, perpendicular depth 0.783). Mean erosion width was 1.84 mm (range 0.16-8.90) and mean depth was 1.86 mm (range 0.30-8.00). We propose a new definition for erosions visualized with HR-pQCT imaging. Interreader reliability for erosion detection is good, but further refinement of selection of landmarks for erosion size measurement, or automated volumetric methods, will be pursued.

  7. Bilateral Asymmetry of Radius and Tibia Bone Macroarchitecture and Microarchitecture: A High-Resolution Peripheral Quantitative Computed Tomography Study.

    Science.gov (United States)

    Hildebrandt, Erin M; Manske, Sarah L; Hanley, David A; Boyd, Steven K

    2016-01-01

    Studies assessing bone health often select the dominant or nondominant limb to scan, but not both, for efficiency reasons. New scanning technology allows 3-dimensional (3D) visualization of the microarchitecture in bone, but it is not well understood whether there are differences between the dominant and nondominant limbs. Using 3D high-resolution peripheral quantitative computed tomography (HR-pQCT), the aim of this study is to investigate the effect of limb dominance on bone macroarchitecture and microarchitecture. Healthy male and female participants (N=100; 59 female, 41 male), mean age 30.7±12.1 years, were scanned at both radii and tibiae using HR-pQCT. Hand and foot dominance were determined by the participant's self-report. Most participants were right hand dominant (94.0%) and right foot dominant (91.0%). In the pooled cohort, the dominant radius had significantly greater cortical area (2.11%; p=0.002) and failure load (3.00%; p=0.001). At the tibia, the dominant foot had significantly lower bone mineral density (-0.77%; p=0.042), cortical area (-1.05%; p=0.031), and thickness (-1.51%; p=0.017). For females, there were no differences at the radius, but at the tibia, the dominant side had greater cross-sectional area (1.03%; p=0.044). Our data suggest that dominance has a small yet significant effect on macroarchitecture at both the ultradistal radius and tibia but not microarchitecture. This work emphasizes that it is important to be consistent in the selection of either dominant or nondominant limbs for HR-pQCT cohort studies; however, in the case where the opposite limb needs to be scanned, there would be small differences in macroarchitecture and no significant differences in microarchitecture anticipated.

  8. Beneficial effect of coronary artery bypass grafting as assessed by quantitative gated single-photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hida, Satoshi; Chikamori, Taishiro; Hirayama, Tetsuzo; Usui, Yasuhiro; Yanagisawa, Hidefumi; Morishima, Takayuki; Ishimaru, Shin; Yamashina, Akira [Tokyo Medical Coll. (Japan)

    2003-06-01

    The development of quantitative gated single-photon emission computed tomography (SPECT) has enabled the assessment of left ventricular perfusion, function and wall thickness in a single examination. Accordingly, the present study used gated SPECT to assess the benefit of coronary artery bypass grafting (CABG) in patients with coronary artery disease; 47 of those patients were evaluated before and 5 months after CABG. As a result of coronary revascularization, a significant improvement was observed in global ejection fraction (50{+-}12{yields}53{+-}11%; p<0.05). In 107 revascularized territories, the average regional reversible defect score (0.8{+-}0.5{yields}0.2{+-}0.3; p<0.0001), average regional perfusion score at rest (0.6{+-}0.6{yields}0.3{+-}0.4; p<0.0001), average regional wall motion score (0.9{+-}0.7{yields}0.7{+-}0.5; p<0.05), and end-diastolic wall thickness (8.1{+-}1.3{yields}8.6{+-}1.5 mm; p<0.0005) all improved significantly. Even in 34 non-revascularized territories, the average regional reversible defect score (0.5{+-}0.7{yields}0.2{+-}0.5; p<0.03), average regional wall motion score (0.8{+-}1.1{yields}0.5{+-}1.0; p<0.03) and end-diastolic wall thickness (8.0{+-}1.4{yields}9.1{+-}2.0 mm; p<0.03) all improved significantly. These results indicate that improvement in myocardial ischemia, hibernation and left ventricular function with CABG can be assessed in detail with gated SPECT. (author)

  9. Correlation analysis of cortical geometry of tibia and humerus of white leghorns using clinical quantitative computed tomography and microcomputed tomography scans1.

    Science.gov (United States)

    Regmi, P; Cox, A G; Robison, C I; Karcher, D M

    2017-03-24

    Peripheral quantitative computed tomography (QCT) has been used in poultry bone research in recent years to analyze cortical and cross-sectional geometry. For QCT to be used as a standard research tool for analysis of bones of laying hens (cortical thickness correlate the cortical parameters measured using clinical CT scans with the measurements from micro-CT, the current gold standard. A total of 15 tibiae and 14 humeri of Lohmann White hens was scanned using clinical CT and micro-CT. Reconstruction of the scans generated images with final voxel resolution of 195 μm for clinical CT scans and 46 μm for micro-CT scans. Cortical and total area were measured using MIMICS® software at proximal, middle, and distal locations of 20 mm sections of humerus diaphysis and 30 mm sections of tibia diaphysis. The total area for proximal and middle locations as well as proximal cortical area measurements for humeri produced strong correlation coefficients (R ≥ 0.70). Moderate strength correlation coefficients (R = 0.40 to 0.60) in humeri were seen in middle and distal cortical areas. Distal total area in humeri displayed a weak correlation coefficient (R ≤ 0.3; P = 0.25). Overall, tibiae demonstrated a weaker correlation. Proximal and middle cortical areas indicated moderate correlation coefficients (R = 0.40 to 0.60), while proximal and middle total areas accompanied by distal cortical and total area displayed weak correlation coefficients (R ≤ 0.3). Only the middle cortical area measurement for tibiae was significant (P = 0.03). These results indicate stronger correlation for humeri measurements among the scans than tibia. Overall, cross-sectional area measurements were only low to moderately correlated between clinical and micro-CT scans. © 2017 Poultry Science Association Inc.

  10. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is ... a CT scan. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  11. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... for a recovery period and will be given instructions on any limitations in activity for the day. ... Images related to Children's (Pediatric) CT (Computed Tomography) Videos related to Children's (Pediatric) CT (Computed Tomography) Sponsored ...

  12. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses special x-ray equipment ... period of time. Modern CT scanners are so fast that they can scan through large sections of ...

  13. Children's (Pediatric) CT (Computed Tomography)

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is ... a CT scan. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  14. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Us News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography ( ... more commonly known as a CT or CAT scan, is a diagnostic medical test that, like traditional ...

  15. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses special x-ray equipment ... period of time. Modern CT scanners are so fast that they can scan through large sections of ...

  16. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless ... table. Other imaging methods such as ultrasound or magnetic resonance (MR) imaging can provide pictures of certain areas ...

  17. Proton computed tomography

    Science.gov (United States)

    Bucciantonio, Martina; Sauli, Fabio

    2015-05-01

    Proton computed tomography (pCT) is a diagnostic method capable of in situ imaging the three-dimensional density distribution in a patient before irradiation with charged particle beams. Proposed long time ago, this technology has been developed by several groups, and may become an essential tool for advanced quality assessment in hadrontherapy. We describe the basic principles of the method, its performance and limitations as well as provide a summary of experimental systems and of results achieved.

  18. Effect of Spinal Degenerative Changes on Volumetric Bone Mineral Density of the Central Skeleton as Measured by Quantitative Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Guglielmi, G. [Hospital ' Casa Sollievo della Sofferenza' , San Giovanni Rotondo (Italy). Dept. of Radiology; Floriani, I.; Torri, V.; Li, J.; Kuijk, C. van; Genant, H.K.; Lang, T.F. [Scientific Inst. ' Mario Negri' , Milan (Italy). Biometry and Data Management Unit

    2005-05-01

    Purpose: To evaluate the impact of degenerative changes due to osteoarthritis (OA) at the spine on volumetric bone mineral density (BMD) as measured by volumetric quantitative computed tomography (vQCT). Material and Methods: Eighty-four elderly women (mean age 73 {+-}6 years), comprising 33 with vertebral fractures assessed by radiographs and 51 without vertebral fractures, were studied. Trabecular, cortical, and integral BMD were examined at the spine and hip using a helical CT scanner and were compared to dual X-ray absorptiometry (DXA) measurements at the same sites. OA changes visible on the radiographs were categorized into two grades according to severity. Differences in BMD measures obtained in the two groups of patients defined by OA grade using the described radiologic methods were compared using analysis of variance. Standardized difference (effect sizes) was also compared between radiologic methods. Results: Spinal trabecular BMD did not differ significantly between OA grade 0 and OA grade. Spinal cortical and integral BMD measures showed statistically significant differences, as did the lumbar spine DXA BMD measurement (13%, P{approx_equal}0.02). The QCT measurements at the hip were also higher in OA subjects. Femoral trabecular BMD was 3-15% higher in OA grade subjects than in OA grade 0 subjects. The cortical BMD measures in the CT{sub T}OT{sub F}EM and CT{sub T}ROCH ROI's were also higher in the OA subjects. The integral QCT BMD measures in the hip showed difference between grades OA and 0. The DXA measurements in the neck and trochanter ROI's showed smaller differences (9 and 1%, respectively). There were no statistically significant differences in bone size. Conclusion: There is no evidence supporting that trabecular BMD measurements by QCT are influenced by OA. Instead, degenerative changes have an effect on both cortical and integral QCT, and on DXA at the lumbar spine and the hip. For subjects with established OA, assessment of BMD by

  19. Computer processing of tomography data

    OpenAIRE

    Konečný, Jan

    2011-01-01

    Computer processing of tomography data Tomographs are one of the most important diagnostic devices, which are used in every hospital nowadays; they have already been so for a considerable period of time. The different types of tomographs and the processing of tomographic data and imaging of these data are the subject of this thesis. I have described the four most common types of tomography: X-ray Computed Tomography, Magnetic Resonance Imaging, Positron Emission Tomography and Single Photon E...

  20. Multiplanner spine computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H. K.; Jeon, H. J.; Hong, K. C.; Chung, K. B.; Suh, W. H. [Korea University College of Medicine, Seoul (Korea, Republic of)

    1983-06-15

    The computed tomography is useful in evaluation of bony structures and adjacent soft tissues of the spine. Recently, the multiplanar spine CT scan is highly superior than usual axial scan, because of easily demonstrable longitudinal dimension, level of spine and spinal canal. We evaluated 62 cases of spine CT, whom complains of spinal symptoms, from July, 1982 to January, 1983. The results were as follows: 1. The sex distribution of cases were 45 male and 17 female, ages were from 15 years to 76 years, and sites were 15 cervical spine, 7 thoracic spine, 42 lumbar spine and 21 sacral spine. 2. Sixty two cases of the CT diagnosis were reviewed and shows 19 cases of herniated intervertebral disc, 7 cases of spine fracture, 5 cases of degenerative disease, 4 cases of metastatic cancer, 2 cases of posterior longitudinal ligament ossification, 1 case of cord injury and 24 cases of normal. 3. The CT findings of herniated intervertebral disc were protruding disc, obliteration of anterior epidural fat, with or without indentation of dural sac and calcification within posterior disc margin. In cases of trauma, the multiplanar spine CT scan detects more specific extension of the fracture sites, and it is able to demonstrate relationship between fracture fragment and spinal cord, therefore operability can be decided. In case of posterior longitudinal ligament ossification, it is easy to demonstrate linear high density along posterior margin of vertebral bodies on sagittal reconstruction scan. 4. The computed tomography is diagnostic in detection of spinal disease. However, multiplanar spine CT is more diagnostic than axial computed tomography such as detecting the longitudinal dimension and demonstration of spinal canal.

  1. Abdominal perfusion computed tomography.

    Science.gov (United States)

    Ogul, Hayri; Bayraktutan, Ummugulsum; Kizrak, Yesim; Pirimoglu, Berhan; Yuceler, Zeynep; Sagsoz, M Erdem; Yilmaz, Omer; Aydinli, Bulent; Ozturk, Gurkan; Kantarci, Mecit

    2013-02-01

    The purpose of this article is to provide an up to date review on the spectrum of applications of perfusion computed tomography (CT) in the abdomen. New imaging techniques have been developed with the objective of obtaining a structural and functional analysis of different organs. Recently, perfusion CT has aroused the interest of many researchers who are studying the applicability of imaging modalities in the evaluation of abdominal organs and diseases. Per-fusion CT enables fast, non-invasive imaging of the tumor vascular physiology. Moreover, it can act as an in vivo biomarker of tumor-related angiogenesis.

  2. Chest computed tomography

    DEFF Research Database (Denmark)

    Loeve, Martine; Krestin, Gabriel P.; Rosenfeld, Margaret

    2013-01-01

    Clinical trials for the treatment of cystic fibrosis (CF) lung disease are important to test and optimize new therapeutic interventions. To evaluate the effect of these interventions, sensitive and accurate outcome measures are needed. The most commonly used endpoints are spirometric variables...... are not suitable to study CF lung disease in young children. Chest computed tomography (CT) holds great promise for use as a sensitive surrogate endpoint in CF. A large body of evidence has been produced to validate the use of chest CT as primary endpoint to study CF lung disease. However, before chest CT can...

  3. Stored Luminescence Computed Tomography

    CERN Document Server

    Cong, Wenxiang; Wang, Ge

    2013-01-01

    The phosphor nanoparticles made of doped semiconductors, pre-excited by well-collimated X-ray radiation, were recently reported for their light emission upon NIR light stimulation. The characteristics of X-ray energy storage and NIR stimulated emission is highly desirable to design targeting probes and improve molecular and cellular imaging. Here we propose stored luminescence computed tomography (SLCT), perform realistic numerical simulation, and demonstrate a much-improved spatial resolution in a preclinical research context. The future opportunities are also discussed along this direction.

  4. The effect of in situ/in vitro three-dimensional quantitative computed tomography image voxel size on the finite element model of human vertebral cancellous bone.

    Science.gov (United States)

    Lu, Yongtao; Engelke, Klaus; Glueer, Claus-C; Morlock, Michael M; Huber, Gerd

    2014-11-01

    Quantitative computed tomography-based finite element modeling technique is a promising clinical tool for the prediction of bone strength. However, quantitative computed tomography-based finite element models were created from image datasets with different image voxel sizes. The aim of this study was to investigate whether there is an influence of image voxel size on the finite element models. In all 12 thoracolumbar vertebrae were scanned prior to autopsy (in situ) using two different quantitative computed tomography scan protocols, which resulted in image datasets with two different voxel sizes (0.29 × 0.29 × 1.3 mm(3) vs 0.18 × 0.18 × 0.6 mm(3)). Eight of them were scanned after autopsy (in vitro) and the datasets were reconstructed with two voxel sizes (0.32 × 0.32 × 0.6 mm(3) vs. 0.18 × 0.18 × 0.3 mm(3)). Finite element models with cuboid volume of interest extracted from the vertebral cancellous part were created and inhomogeneous bilinear bone properties were defined. Axial compression was simulated. No effect of voxel size was detected on the apparent bone mineral density for both the in situ and in vitro cases. However, the apparent modulus and yield strength showed significant differences in the two voxel size group pairs (in situ and in vitro). In conclusion, the image voxel size may have to be considered when the finite element voxel modeling technique is used in clinical applications.

  5. A model for quantitative correction of coronary calcium scores on multidetector, dual source, and electron beam computed tomography for influences of linear motion, calcification density, and temporal resolution : A cardiac phantom study

    NARCIS (Netherlands)

    Greuter, M. J. W.; Groen, J. M.; Nicolai, L. J.; Dijkstra, H.; Oudkerk, M.

    2009-01-01

    Purpose: The objective of this study is to quantify the influence of linear motion, calcification density, and temporal resolution on coronary calcium determination using multidetector computed tomography (MDCT), dual source CT (DSCT), and electron beam tomography (EBT) and to find a quantitative me

  6. Effects of particle size, slice thickness, and reconstruction algorithm on coronary calcium quantitation using ultrafast computed tomography

    Science.gov (United States)

    Tang, Weiyi; Detrano, Robert; Kang, Xingping; Garner, D.; Nickerson, Sharon; Desimone, P.; Mahaisavariya, Paiboon; Brundage, B.

    1994-05-01

    The recent emphasis on early diagnosis of coronary artery disease has stimulated research for a reliable and non-invasive screening method. Radiographically detectable coronary calcium has been shown to predict both pathologic and angiographic findings. Ultrafast computed tomography (UFCT), in quantifying coronary calcium, may become an accurate non-invasive method to evaluate the severity of coronary disease. The currently applied index of UFCT coronary calcium amount is the coronary calcium score of Agatston et al. This score has not been thoroughly evaluated as to its accuracy and dependence on scanning parameters. A potential drawback of the score is its dependence on predetermined CT number thresholds. In this investigation we used a chest phantom to determine the effects of particle size, slice thickness, and reconstruction algorithm on the coronary calcium score, and on the calcium mass estimated with a new method which is not dependent on thresholds.

  7. Quantitative computed tomography analysis of the airways in patients with cystic fibrosis using automated software: correlation with spirometry in the evaluation of severity*

    Science.gov (United States)

    Santos, Marcel Koenigkam; Cruvinel, Danilo Lemos; de Menezes, Marcelo Bezerra; Teixeira, Sara Reis; Vianna, Elcio de Oliveira; Elias Júnior, Jorge; Martinez, José Antonio Baddini

    2016-01-01

    Objective To perform a quantitative analysis of the airways using automated software, in computed tomography images of patients with cystic fibrosis, correlating the results with spirometric findings. Materials and Methods Thirty-four patients with cystic fibrosis were studied-20 males and 14 females; mean age 18 ± 9 years-divided into two groups according to the spirometry findings: group I (n = 21), without severe airflow obstruction (forced expiratory volume in first second [FEV1] > 50% predicted), and group II (n = 13), with severe obstruction (FEV1 ≤ 50% predicted). The following tracheobronchial tree parameters were obtained automatically: bronchial diameter, area, thickness, and wall attenuation. Results On average, 52 bronchi per patient were studied. The number of bronchi analyzed was higher in group II. The correlation with spirometry findings, especially between the relative wall thickness of third to eighth bronchial generation and predicted FEV1, was better in group I. Conclusion Quantitative analysis of the airways by computed tomography can be useful for assessing disease severity in cystic fibrosis patients. In patients with severe airflow obstruction, the number of bronchi studied by the method is higher, indicating more bronchiectasis. In patients without severe obstruction, the relative bronchial wall thickness showed a good correlation with the predicted FEV1. PMID:28100929

  8. Quantitative computed tomography analysis of the airways in patients with cystic fibrosis using automated software: correlation with spirometry in the evaluation of severity

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Marcel Koenigkam; Cruvinel, Danilo Lemos; Menezes, Marcelo Bezerra de; Teixeira, Sara Reis; Vianna, Elcio de Oliveira; Elias Junior, Jorge; Martinez, Jose Antonio Baddini, E-mail: marcelk46@yahoo.com.br [Universidade de Sao Paulo (HC/FMRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina

    2016-11-15

    Objective: To perform a quantitative analysis of the airways using automated software, in computed tomography images of patients with cystic fibrosis, correlating the results with spirometric findings. Materials and methods: Thirty-four patients with cystic fibrosis were studied-20 males and 14 females; mean age 18 ± 9 years - divided into two groups according to the spirometry findings: group I (n = 21), without severe airflow obstruction (forced expiratory volume in first second [FEV1] > 50% predicted), and group II (n = 13), with severe obstruction (FEV1 ≤ 50% predicted). The following tracheobronchial tree parameters were obtained automatically: bronchial diameter, area, thickness, and wall attenuation. Results: On average, 52 bronchi per patient were studied. The number of bronchi analyzed was higher in group II. The correlation with spirometry findings, especially between the relative wall thickness of third to eighth bronchial generation and predicted FEV1, was better in group I. Conclusion: Quantitative analysis of the airways by computed tomography can be useful for assessing disease severity in cystic fibrosis patients. In patients with severe airflow obstruction, the number of bronchi studied by the method is higher, indicating more bronchiectasis. In patients without severe obstruction, the relative bronchial wall thickness showed a good correlation with the predicted FEV1. (author)

  9. Quantitative coronary plaque analysis predicts high-risk plaque morphology on coronary computed tomography angiography: results from the ROMICAT II trial.

    Science.gov (United States)

    Liu, Ting; Maurovich-Horvat, Pál; Mayrhofer, Thomas; Puchner, Stefan B; Lu, Michael T; Ghemigian, Khristine; Kitslaar, Pieter H; Broersen, Alexander; Pursnani, Amit; Hoffmann, Udo; Ferencik, Maros

    2017-08-12

    Semi-automated software can provide quantitative assessment of atherosclerotic plaques on coronary CT angiography (CTA). The relationship between established qualitative high-risk plaque features and quantitative plaque measurements has not been studied. We analyzed the association between quantitative plaque measurements and qualitative high-risk plaque features on coronary CTA. We included 260 patients with plaque who underwent coronary CTA in the Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT) II trial. Quantitative plaque assessment and qualitative plaque characterization were performed on a per coronary segment basis. Quantitative coronary plaque measurements included plaque volume, plaque burden, remodeling index, and diameter stenosis. In qualitative analysis, high-risk plaque was present if positive remodeling, low CT attenuation plaque, napkin-ring sign or spotty calcium were detected. Univariable and multivariable logistic regression analyses were performed to assess the association between quantitative and qualitative high-risk plaque assessment. Among 888 segments with coronary plaque, high-risk plaque was present in 391 (44.0%) segments by qualitative analysis. In quantitative analysis, segments with high-risk plaque had higher total plaque volume, low CT attenuation plaque volume, plaque burden and remodeling index. Quantitatively assessed low CT attenuation plaque volume (odds ratio 1.12 per 1 mm(3), 95% CI 1.04-1.21), positive remodeling (odds ratio 1.25 per 0.1, 95% CI 1.10-1.41) and plaque burden (odds ratio 1.53 per 0.1, 95% CI 1.08-2.16) were associated with high-risk plaque. Quantitative coronary plaque characteristics (low CT attenuation plaque volume, positive remodeling and plaque burden) measured by semi-automated software correlated with qualitative assessment of high-risk plaque features.

  10. Metrizamide computed tomography in syringomyelia

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, T.; Tamakawa, Y.; Arii, H. (Akita Univ. (Japan). Faculty of Medicine); Takahashi, M.; Hirota, K.

    1981-11-01

    Serial computed tomography of the cervical cord was performed following metrizamide myelography in five cases of clinically suspected syringomyelia. The syrinx filled with refluxed metrizamide was demonstrated in all of the cases. The reflux of metrizamide into the syrinx was most marked several hours following intrathecal injection of metrizamide. Computed tomography combined with metrizamide myelography is essential in the diagnosis of communicating syringomyelia.

  11. Quantitative computed tomography of pulmonary emphysema and ventricular function in chronic obstructive pulmonary disease patients with pulmonary hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yu San; Jaw, Fu Shan [Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei (China); Chen, Jo Yu; Tai, Mei Hwa [Dept. of Medical Imaging, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei (China); Hsu, Hsao Hsun [Dept. of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei (China)

    2014-12-15

    This study strived to evaluate the relationship between degree of pulmonary emphysema and cardiac ventricular function in chronic obstructive pulmonary disease (COPD) patients with pulmonary hypertension (PH) using electrocardiographic-gated multidetector computed tomography (CT). Lung transplantation candidates with the diagnosis of COPD and PH were chosen for the study population, and a total of 15 patients were included. The extent of emphysema is defined as the percentage of voxels below -910 Hounsfield units in the lung windows in whole lung CT without intravenous contrast. Heart function parameters were measured by electrocardiographic-gated CT angiography. Linear regression analysis was conducted to examine the associations between percent emphysema and heart function indicators. Significant correlations were found between percent emphysema and right ventricular (RV) measurements, including RV end-diastolic volume (R2 = 0.340, p = 0.023), RV stroke volume (R2 = 0.406, p = 0.011), and RV cardiac output (R2 = 0.382, p = 0.014); the correlations between percent emphysema and left ventricular function indicators were not observed. The study revealed that percent emphysema is correlated with RV dysfunction among COPD patients with PH. Based on our findings, percent emphysema can be considered for use as an indicator to predict the severity of right ventricular dysfunction among COPD patients.

  12. SedCT: MATLAB™ tools for standardized and quantitative processing of sediment core computed tomography (CT) data collected using a medical CT scanner

    Science.gov (United States)

    Reilly, B. T.; Stoner, J. S.; Wiest, J.

    2017-08-01

    Computed tomography (CT) of sediment cores allows for high-resolution images, three-dimensional volumes, and down core profiles. These quantitative data are generated through the attenuation of X-rays, which are sensitive to sediment density and atomic number, and are stored in pixels as relative gray scale values or Hounsfield units (HU). We present a suite of MATLAB™ tools specifically designed for routine sediment core analysis as a means to standardize and better quantify the products of CT data collected on medical CT scanners. SedCT uses a graphical interface to process Digital Imaging and Communications in Medicine (DICOM) files, stitch overlapping scanned intervals, and create down core HU profiles in a manner robust to normal coring imperfections. Utilizing a random sampling technique, SedCT reduces data size and allows for quick processing on typical laptop computers. SedCTimage uses a graphical interface to create quality tiff files of CT slices that are scaled to a user-defined HU range, preserving the quantitative nature of CT images and easily allowing for comparison between sediment cores with different HU means and variance. These tools are presented along with examples from lacustrine and marine sediment cores to highlight the robustness and quantitative nature of this method.

  13. Quantitative Assessment of Optical Coherence Tomography Imaging Performance with Phantom-Based Test Methods And Computational Modeling

    Science.gov (United States)

    Agrawal, Anant

    Optical coherence tomography (OCT) is a powerful medical imaging modality that uniquely produces high-resolution cross-sectional images of tissue using low energy light. Its clinical applications and technological capabilities have grown substantially since its invention about twenty years ago, but efforts have been limited to develop tools to assess performance of OCT devices with respect to the quality and content of acquired images. Such tools are important to ensure information derived from OCT signals and images is accurate and consistent, in order to support further technology development, promote standardization, and benefit public health. The research in this dissertation investigates new physical and computational models which can provide unique insights into specific performance characteristics of OCT devices. Physical models, known as phantoms, are fabricated and evaluated in the interest of establishing standardized test methods to measure several important quantities relevant to image quality. (1) Spatial resolution is measured with a nanoparticle-embedded phantom and model eye which together yield the point spread function under conditions where OCT is commonly used. (2) A multi-layered phantom is constructed to measure the contrast transfer function along the axis of light propagation, relevant for cross-sectional imaging capabilities. (3) Existing and new methods to determine device sensitivity are examined and compared, to better understand the detection limits of OCT. A novel computational model based on the finite-difference time-domain (FDTD) method, which simulates the physics of light behavior at the sub-microscopic level within complex, heterogeneous media, is developed to probe device and tissue characteristics influencing the information content of an OCT image. This model is first tested in simple geometric configurations to understand its accuracy and limitations, then a highly realistic representation of a biological cell, the retinal

  14. Comparison of panoramic radiography and cone-beam computed tomography for qualitative and quantitative measurements regarding localization of permanent impacted maxillary canines

    Directory of Open Access Journals (Sweden)

    Çiğdem Sarıkır

    2017-01-01

    Full Text Available Objective: The purpose of this retrospective study was to compare the correlation between digital panoramic radiography (DPR and cone-beam computed tomography (CBCT evaluations for localization of impacted permanent maxillary canines (IPMCs and for other qualitative and quantitative parameters. Materials and Method: DPR and CBCT images of 60 patients (17 men and 43 women were examined independently by two observers. Correlations between DPR and CBCT images were evaluated regarding qualitative (bucco-palatal positioning of IPMCs, morphology and presence of root resorption of adjacent permanent lateral incisors, and contact relationship between IPMCs and adjacent permanent lateral incisors and quantitative (angle measurements variables. All evaluations were repeated 1 month later by each observer. Chi-square and t-tests were used for statistical analysis. Kappa statistics were used to assess intra- and interobserver agreement (Cohen’s κ. Results: No correlation was observed for determination of bucco-palatal positioning of IPMCs between DPR and CBCT images (p>0.05. Correlations were observed for other qualitative variables (p<0.05. Differences between DPR and CBCT images were seen for all examined quantitative variables (p<0.01. Intra- and interobserver agreements were substantial to almost-perfect. Conclusion: No significant correlation was found between DPR and CBCT images for determination of bucco-palatal positioning of IPMCs. All quantitative measurements performed on DPR and CBCT images significantly differed from each other.

  15. Quantitative evaluation of maxillary interradicular bone with cone-beam computed tomography for bicortical placement of orthodontic mini-implants.

    Science.gov (United States)

    Yang, Lei; Li, Feifei; Cao, Meng; Chen, Hong; Wang, Xi; Chen, Xuepeng; Yang, Le; Gao, Weiran; Petrone, Joseph F; Ding, Yin

    2015-06-01

    The purpose of this study was to propose a protocol for safe bicortical placement of mini-implants by measuring the interradicular spaces of the maxillary teeth and the bone quality. Cone-beam computed tomography data were obtained from 50 adults. Three-dimensional reconstructions and measurements were made with SimplantPro software (Materialise, Leuven, Belgium). For each interradicular site, the bone thicknesses and interradicular distances at the planes 1.5, 3, 6, and 9 mm above the cementoenamel junction were measured. Standard bone units were defined to evaluate the influences of bone density and the different placement patterns on the stability of the mini-implants. The safe interradicular sites in the maxilla for bicortical placement of 1.5-mm-diameter mini-implants were in all planes between the first and second premolars, and between the second premolar and the first molar. The safe palatal sites were between the first and second molars, and the safe labial sites of the 9-mm plane were between the central incisors, and between the lateral incisor and the canine. The safe buccal sites of the 6- and 9-mm planes were between the first and second molars, and the safe buccal sites of the 3-, 6-, and 9-mm planes were between the canine and the first premolar. Most bone thicknesses were from 8 to 12 mm. The optimal placement angle between the second premolar and the first molar was 58°. Bicortical placement could have more standard bone units than unicortical placement in the maxilla. Bicortical placement would be more stable in the maxilla. For the site between the molars, special care should be taken at a plane higher than 6 mm to prevent maxillary sinus penetration. The most favorable interradicular area in the maxilla was between the second premolar and the first molar. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  16. Dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and micro-computed tomography techniques are discordant for bone density and geometry measurements in the guinea pig.

    Science.gov (United States)

    Mak, Ivy L; DeGuire, Jason R; Lavery, Paula; Agellon, Sherry; Weiler, Hope A

    2016-05-01

    This study aims to examine agreement among bone mineral content (BMC) and density (BMD) estimates obtained using dual-energy X-ray absorptiometry (DXA), peripheral quantitative computed tomography (pQCT), and micro-computed tomography (μCT) against high-resolution μCT and bone ash of the guinea pig femur. Middle-aged (n = 40, 86 weeks) male guinea pigs underwent in vivo followed by ex vivo DXA (Hologic QDR 4500A) scanning for intact and excised femur BMC and areal density. To assess bone architecture and strength, excised femurs were scanned on pQCT (Stratec XCT 2000L) as well as on two μCT scanners (LaTheta LCT-200; Skyscan 1174), followed by three-point bending test. Reproducibility was determined using triplicate scans; and agreement assessed using Bland-Altman plots with reference methods being high-resolution μCT (Skyscan) for BMD and bone ashing for BMC. All techniques showed satisfactory ex vivo precision (CV 0.05-4.3 %). However, bias compared to the reference method was highest (207.5 %) in trabecular bone volume fraction (BV/TV) measured by LaTheta, and unacceptable in most total femur and cortical bone measurements. Volumetric BMD (vBMD) and BV/TV derived by LaTheta and pQCT at the distal metaphysis were biased from the Skyscan by an average of 49.3 and 207.5 %, respectively. Variability of vBMD, BV/TV and cross-sectional area at the diaphysis ranged from -5.5 to 30.8 %. LaTheta best quantified total femur BMC with an upper bias of 3.3 %. The observed differences among imaging techniques can be attributable to inherent dissimilarity in construction design, calibration, segmentation and scanning resolution used. These bone imaging tools are precise but are not comparable, at least when assessing guinea pig bones.

  17. Phantom study to evaluate quantitative changes in myocardial radioisotope concentration for single photon emission computed tomography; Comparison between Tl-201 and Tc-99m

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Takashi; Kitabata, Yoshiki; Tanaka, Takeshi; Hasegawa, Mitsuo; Kato, Kazuzo (Cardiovascular Inst., Tokyo (Japan)); Okabe, Akifumi

    1990-01-01

    Quantitative changes in Tl-201 and Tc-99m in myocardial single photon emission computed tomography (SPECT) were evaluated using phantom studies. The absorption rate of gamma ray by the tissues surrounding the myocardium was less for Tc-99m (maximum, 61.2%) than Tl-201 (maximum, 70.8%). In studies on quantification of defects with various concentrations of the radioisotopes, Tc-99m was found superior to Tl-201. In comparing a focal defect in the anterior wall near the surface of the thorax (Defect A) with that in the posterior wall deep in the thorax (Defect B), Defect A had a better quantification than Defect B. Absorber, scattering, and background, however, precluded quantification, especially in Defect B. Although scatter subtraction may in part improve quantification, quantification seemed to be dependent on algorithm in image reconstruction, as well as spatial resolution of the equipment. (N.K.).

  18. Sex- and Age-Related Differences in Bone Microarchitecture in Men Relative to Women Assessed by High-Resolution Peripheral Quantitative Computed Tomography

    Directory of Open Access Journals (Sweden)

    Shreyasee Amin

    2012-01-01

    Full Text Available The trabecular and cortical compartments of bone each contributes to bone strength. Until recently, assessment of trabecular and cortical microstructure has required a bone biopsy. Now, trabecular and cortical microstructure of peripheral bone sites can be determined noninvasively using high-resolution peripheral quantitative computed tomography (HR-pQCT. Studies that have used HR-pQCT to evaluate cohorts of both men and women have provided novel insights into the changes in bone microarchitecture that occur with age between the sexes, which may help to explain the lower fracture incidence in older men relative to women. This review will highlight observations from these studies on both the sex- and age-related differences in trabecular and cortical microstructure that may underlie the differences in bone strength, and thereby fracture risk, between men and women.

  19. Effect of Polyester and Plaster of Paris Casts on Determination of Volumetric Bone Mineral Density Assessed by Peripheral Quantitative Computed Tomography (pQCT).

    Science.gov (United States)

    Bullen, Michael; Blanchard, Romane; Rodda, Christine; Pivonka, Peter

    2016-11-01

    Peripheral quantitative computed tomography (pQCT) is a non-invasive, low-radiation tool for measuring volumetric bone mineral density. It has potential for use in fracture healing applications; however, the unknown attenuation effects of cast material on peripheral quantitative computed tomography have contributed to its limited use in this area. The effect of two common cast materials, polyester and Plaster of Paris was investigated by performing both in vitro and in vivo studies. The in vitro study tested the effect of increasing layers of cast material on bone density measurements performed on a hydroxyapatite phantom. Cast thickness was directly associated with a reduction in bone mineral density, with twelve layers of polyester and Plaster of Paris resulting in a 0.55 and 2.21 % decrease in bone density measurements. Precision error in situ with polyester cast material was 0.71 %, and 2.31 % with Plaster of Paris cast material. The in vivo study comprised a prospective trial with 28 healthy adult participants to evaluate the effect of the two cast materials. Trabecular bone mineral density was increased by 0.5 % in the presence of a polyester cast and decreased by 4.22 % in the presence of a Plaster of Paris cast. Cortical bone mineral density was decreased by 3.46 and 5.54 % for polyester and Plaster of Paris, respectively. This study quantified the effects of orthopaedic casts on pQCT-derived bone parameters. The results suggest applicability of commonly utilised cast materials in combination with pQCT to assess fracture healing.

  20. Use of Relative vs Fixed Offset Distance to Define Region of Interest at the Distal Radius and Tibia in High-Resolution Peripheral Quantitative Computed Tomography.

    Science.gov (United States)

    Shanbhogue, Vikram V; Hansen, Stinus; Halekoh, Ulrich; Brixen, Kim

    2015-01-01

    Although the region of interest in high-resolution peripheral quantitative computed tomography, defined based on the manufacturer's protocol for in vivo scanning, provides consistency and is practically convenient, it does not take into account possible variation in morphology in the regions adjacent to the measurement site. This study aimed at compare the morphologic variation in measurements using the standard fixed offset distance to define the distal starting slice against those obtained by using a relative measurement position scaled to the individual bone length at the distal radius and tibia in normal healthy adult subjects. A total of 40 healthy adult subjects (median height, 175.3 cm; range: 150.0-196.0 cm) were included in the study. High-resolution peripheral quantitative computed tomography at the distal radius and tibia was performed in all subjects, the region of interest defined by, first, the standard measurement protocol, where the most distal CT slice was 9.5 mm and 22.5 mm from the end plate of the radius and tibia, respectively, and second, the relative measurement method, where the most distal CT slice was at 4% and 7% of the radial and tibial lengths, respectively. Volumetric densities and microarchitectural parameters were compared between the 2 methods. Measurements of the total and cortical volumetric density and cortical thickness at the radius and tibia and cortical porosity, trabecular volumetric density, and trabecular number at the tibia were significantly different between the 2 methods (all p radius (up to 34%) and the tibia (up to 36%). A lack of consideration to height (and in turn the bone lengths) in the standard patient protocol could lead to the introduction of systematic errors in radial and tibial measurements. Although this may not be of particular significance in longitudinal studies in the same individual, it potentially assumes critical importance in cross-sectional studies.

  1. [Computed tomography of the heart

    DEFF Research Database (Denmark)

    Kristensen, T.S.; Kofoed, K.F.; der, Recke P. von;

    2009-01-01

    Noninvasive evaluation of the coronary arteries by multi-detector row computed tomography is a promising new alternative to conventional invasive coronary angiography. This article describes the technical background, methods, limitations and clinical applications and reviews current literature...

  2. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... What are the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as ... the body being studied. top of page How is the procedure performed? The technologist begins by positioning ...

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  4. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like ... contrast materials and a metallic taste in your mouth that lasts for at most a minute or ...

  6. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like ... contrast materials and a metallic taste in your mouth that lasts for at most a minute or ...

  7. Computed tomography of the prostate.

    Science.gov (United States)

    Van Engelshoven, J M; Kreel, L

    1979-02-01

    The conventional anatomy of the prostate is reviewed and the computed tomography (CT) anatomy described and illustrated. The results of 55 "normal" cases were analyzed for size and relationship to the symphysis pubis, retropubic space, and bladder, as shown on CT sections correlating the features with age and possible urinary symptoms. Attention is also drawn to the differences between phleboliths and prostatic calcification. Computed tomography is an effective method of demonstrating the prostate and surrounding structures and of assessing prostatic enlargement.

  8. Quantitative assessment of scattering contributions in high energy cone-beam computed tomography; Quantitative Untersuchung der Streubeitraege in Hochenergie-Roentgencomputertomografie

    Energy Technology Data Exchange (ETDEWEB)

    Stritt, Carina; Schuetz, Philipp; Plamondon, Mathieu; Hofmann, Juergen; Sennhauser, Urs [Empa, Duebendorf (Switzerland). Reliability Science and Technology Laboratory; Flisch, Alexander [Empa, Duebendorf (Switzerland). Reliability Science and Technology Laboratory; Empa, Duebendorf (Switzerland). Center for X-Ray Analytics

    2016-02-01

    X-ray computed tomography (CT) is an established method in the fields of failure analysis and quality control. The energy of the X-ray beam determines the penetration length of the radiation and hereby limits the size and the density of the object that is investigated. For the case of large, dense and heavy objects, X-ray energies exceeding one mega electronvolt (MeV) are needed to achieve measureable transmission values. An important factor for the quality of X-ray CT is the contribution of scattered radiation in the radiographies. X-ray photons can be scattered from the object as well as the instrumentation and the environment which leads to a distorted transmission image. Besides scattered radiation, the physical effect of pair production has to be taken into account for radiation in the range of MeV. This work investigates the impact of each of the scattering processes on the radiography. Detailed Monte Carlo simulations help to distinguish the physical interactions as well as scattered radiation from system components. In contrast to previous studies, not only a set of simple geometric objects made of different materials is examined, but also models of the components of a CT scanner are used to estimate the contribution of scattering of various system components.

  9. Effects of calibration methods on quantitative material decomposition in photon-counting spectral computed tomography using a maximum a posteriori estimator.

    Science.gov (United States)

    Curtis, Tyler E; Roeder, Ryan K

    2017-07-06

    Advances in photon-counting detectors have enabled quantitative material decomposition using multi-energy or spectral computed tomography (CT). Supervised methods for material decomposition utilize an estimated attenuation for each material of interest at each photon energy level, which must be calibrated based upon calculated or measured values for known compositions. Measurements using a calibration phantom can advantageously account for system-specific noise, but the effect of calibration methods on the material basis matrix and subsequent quantitative material decomposition has not been experimentally investigated. Therefore, the objective of this study was to investigate the influence of the range and number of contrast agent concentrations within a modular calibration phantom on the accuracy of quantitative material decomposition in the image domain. Gadolinium was chosen as a model contrast agent in imaging phantoms, which also contained bone tissue and water as negative controls. The maximum gadolinium concentration (30, 60, and 90 mM) and total number of concentrations (2, 4, and 7) were independently varied to systematically investigate effects of the material basis matrix and scaling factor calibration on the quantitative (root mean squared error, RMSE) and spatial (sensitivity and specificity) accuracy of material decomposition. Images of calibration and sample phantoms were acquired using a commercially available photon-counting spectral micro-CT system with five energy bins selected to normalize photon counts and leverage the contrast agent k-edge. Material decomposition of gadolinium, calcium, and water was performed for each calibration method using a maximum a posteriori estimator. Both the quantitative and spatial accuracy of material decomposition were most improved by using an increased maximum gadolinium concentration (range) in the basis matrix calibration; the effects of using a greater number of concentrations were relatively small in

  10. A synchrotron-based local computed tomography combined with data-constrained modelling approach for quantitative analysis of anthracite coal microstructure.

    Science.gov (United States)

    Chen, Wen Hao; Yang, Sam Y S; Xiao, Ti Qiao; Mayo, Sherry C; Wang, Yu Dan; Wang, Hai Peng

    2014-05-01

    Quantifying three-dimensional spatial distributions of pores and material compositions in samples is a key materials characterization challenge, particularly in samples where compositions are distributed across a range of length scales, and where such compositions have similar X-ray absorption properties, such as in coal. Consequently, obtaining detailed information within sub-regions of a multi-length-scale sample by conventional approaches may not provide the resolution and level of detail one might desire. Herein, an approach for quantitative high-definition determination of material compositions from X-ray local computed tomography combined with a data-constrained modelling method is proposed. The approach is capable of dramatically improving the spatial resolution and enabling finer details within a region of interest of a sample larger than the field of view to be revealed than by using conventional techniques. A coal sample containing distributions of porosity and several mineral compositions is employed to demonstrate the approach. The optimal experimental parameters are pre-analyzed. The quantitative results demonstrated that the approach can reveal significantly finer details of compositional distributions in the sample region of interest. The elevated spatial resolution is crucial for coal-bed methane reservoir evaluation and understanding the transformation of the minerals during coal processing. The method is generic and can be applied for three-dimensional compositional characterization of other materials.

  11. Multi-institutional Quantitative Evaluation and Clinical Validation of Smart Probabilistic Image Contouring Engine (SPICE) Autosegmentation of Target Structures and Normal Tissues on Computer Tomography Images in the Head and Neck, Thorax, Liver, and Male Pelvis Areas

    NARCIS (Netherlands)

    Zhu, Mingyao; Bzdusek, Karl; Brink, Carsten; Eriksen, Jesper Grau; Hansen, Olfred; Jensen, Helle Anita; Gay, Hiram A.; Thorstad, Wade; Widder, Joachim; Brouwer, Charlotte L.; Steenbakkers, Roel J. H. M.; Vanhauten, Hubertus A. M.; Cao, Jeffrey Q.; McBrayne, Gail; Patel, Salil H.; Cannon, Donald M.; Hardcastle, Nicholas; Tome, Wolfgang A.; Guckenberg, Matthias; Parikh, Parag J.

    2013-01-01

    Purpose: Clinical validation and quantitative evaluation of computed tomography (CT) image autosegmentation using Smart Probabilistic Image Contouring Engine (SPICE). Methods and Materials: CT images of 125 treated patients (32 head and neck [HN], 40 thorax, 23 liver, and 30 prostate) in 7 independe

  12. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  13. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  14. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  15. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  16. Cone beam computed tomography for diagnosis of bisphosphonate-related osteonecrosis of the jaw: evaluation of quantitative and qualitative image parameters

    Energy Technology Data Exchange (ETDEWEB)

    Guggenberger, Roman; Koral, Emrah; Andreisek, Gustav [University Hospital Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); Zemann, Wolfgang; Jacobsen, Christine; Metzler, Philipp [University Hospital Zurich, Department of Cranio-Maxillofacial and Oral Surgery, Zurich (Switzerland)

    2014-12-15

    To assess the diagnostic performance of quantitative and qualitative image parameters in cone-beam computed tomography (CBCT) for diagnosis of bisphosphonate-related osteonecrosis of the jaw (BRONJ). A BRONJ (22 patients, mean age 70.0 years) group was age and gender matched to a healthy control group (22 patients, mean age 68.0 years). On CBCT images two independent readers performed quantitative bone density value (BDV) measurements with region and volume-of-interest (ROI and VOI) based approaches and qualitative scoring of BRONJ-associated necrosis, sclerosis and periosteal thickening (1 = not present to 5 = definitely present). Intraoperative and clinical findings served as standard of reference. Interreader agreements and diagnostic performance were assessed by intraclass correlation coefficients (ICC), kappa-statistics and receiver-operating characteristic (ROC) analysis. Twenty-three regions in 22 patients were affected by BRONJ. ICC values for mean BDV VOI and mean BDV ROI were 0.864 and 0.968, respectively (p < 0.001). The area under the curve (AUC) for mean BDV VOI and mean BDV ROI was 0.58/0.83 with a sensitivity of 57/83 % and specificity of 61/77 % for diagnosis of BRONJ, respectively. Kappa values for presence of necrosis, sclerosis and periosteal thickening were 0.575, 0.617 and 0.885, respectively. AUC values for qualitative parameters ranged between 0.90-0.96 with sensitivity of 96 % and specificities between 79-96 % at respective cutoff scores. BRONJ can be effectively diagnosed with CBCT. Qualitative image parameters yield a higher diagnostic performance than quantitative parameters, and ROI-based attenuation measurements were more accurate than VOI-based measurements. (orig.)

  17. Computer-aided diagnosis in phase contrast imaging X-ray computed tomography for quantitative characterization of ex vivo human patellar cartilage.

    Science.gov (United States)

    Nagarajan, Mahesh B; Coan, Paola; Huber, Markus B; Diemoz, Paul C; Glaser, Christian; Wismuller, Axel

    2013-10-01

    Visualization of ex vivo human patellar cartilage matrix through the phase contrast imaging X-ray computed tomography (PCI-CT) has been previously demonstrated. Such studies revealed osteoarthritis-induced changes to chondrocyte organization in the radial zone. This study investigates the application of texture analysis to characterizing such chondrocyte patterns in the presence and absence of osteoarthritic damage. Texture features derived from Minkowski functionals (MF) and gray-level co-occurrence matrices (GLCM) were extracted from 842 regions of interest (ROI) annotated on PCI-CT images of ex vivo human patellar cartilage specimens. These texture features were subsequently used in a machine learning task with support vector regression to classify ROIs as healthy or osteoarthritic; classification performance was evaluated using the area under the receiver operating characteristic curve (AUC). The best classification performance was observed with the MF features perimeter (AUC: 0.94 ±0.08 ) and "Euler characteristic" (AUC: 0.94 ±0.07 ), and GLCM-derived feature "Correlation" (AUC: 0.93 ±0.07). These results suggest that such texture features can provide a detailed characterization of the chondrocyte organization in the cartilage matrix, enabling classification of cartilage as healthy or osteoarthritic with high accuracy.

  18. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  19. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  20. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ...

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ...

  2. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of ... Society of Urogenital Radiology note that the available data suggest that it is safe to continue breastfeeding ...

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of ... Society of Urogenital Radiology note that the available data suggest that it is safe to continue breastfeeding ...

  4. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... images can be viewed on a computer monitor, printed on film or transferred to a CD or ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ...

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... images can be viewed on a computer monitor, printed on film or transferred to a CD or ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ...

  6. Computed tomography:the details.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2007-07-01

    Computed Tomography (CT) is a well established technique, particularly in medical imaging, but also applied in Synthetic Aperture Radar (SAR) imaging. Basic CT imaging via back-projection is treated in many texts, but often with insufficient detail to appreciate subtleties such as the role of non-uniform sampling densities. Herein are given some details often neglected in many texts.

  7. Quantitative assessment of the latarjet procedure for large glenoid defects by computed tomography: a coracoid graft can sufficiently restore the glenoid arc.

    Science.gov (United States)

    Moon, Seong Cheol; Cho, Nam Su; Rhee, Yong Girl

    2015-05-01

    Coracoid transfer to a large glenoid defect is considered an excellent method to restore the surface area of the anteroinferior glenoid. However, there is little quantitative evidence supporting whether a coracoid graft can sufficiently restore the glenoid arc. To assess whether the Latarjet procedure can sufficiently restore the surface area of the glenoid. Case series; Level of evidence, 4. A total of 44 patients who underwent a Latarjet operation for a large glenoid defect between February 2009 and July 2011 were enrolled in this study. Three-dimensional computed tomography was used to calculate the surface areas of the preoperative glenoid defect size and the reconstructed glenoid. Preoperative and postoperative clinical results also were assessed. At the last follow-up, the mean visual analog scale score for instability during motion improved significantly from 5.1 points (range, 3-10 points) preoperatively to 1.3 points (range, 0-4 points) (PLatarjet procedure, the mean surface area of the reconstructed glenoid was 706±32 mm2 (range, 639-749 mm2). Finally, postoperative glenoid defect size was 5±11 mm2 (range, 3-28 mm2; 1.5%±2% of the intact glenoid surface). The Latarjet procedure can provide satisfactory outcomes, including a low recurrence rate and reliable functional recovery. Defects at the anteroinferior glenoid were restored to nearly normal after coracoid transfer by use of the Latarjet procedure, which is an anatomically matched reconstruction. © 2015 The Author(s).

  8. Quantitative assessment of selective in-plane shielding of tissues in computed tomography through evaluation of absorbed dose and image quality

    Energy Technology Data Exchange (ETDEWEB)

    Geleijns, J.; Veldkamp, W.J.H. [Leiden University Medical Center, Radiology Department, ZA Leiden (Netherlands); Salvado Artells, M.; Lopez Tortosa, M. [Universitat Rovira i Virgili, Facultat de Medicina i Ciencies de la Salut, Departament de Ciencies Mediques Basiques, Reus, Tarragona (Spain); Calzado Cantera, A. [Universidad Complutense de Madrid, Departamento de Radiologia, Madrid (Spain)

    2006-10-15

    This study aimed at assessment of efficacy of selective in-plane shielding in adults by quantitative evaluation of the achieved dose reduction and image quality. Commercially available accessories for in-plane shielding of the eye lens, thyroid and breast, and an anthropomorphic phantom were used for the evaluation of absorbed dose and image quality. Organ dose and total energy imparted were assessed by means of a Monte Carlo technique taking into account tube voltage, tube current, and scanner type. Image quality was quantified as noise in soft tissue. Application of the lens shield reduced dose to the lens by 27% and to the brain by 1%. The thyroid shield reduced thyroid dose by 26%; the breast shield reduced dose to the breasts by 30% and to the lungs by 15%. Total energy imparted (unshielded/shielded) was 88/86 mJ for computed tomography (CT) brain, 64/60 mJ for CT cervical spine, and 289/260 mJ for CT chest scanning. An increase in image noise could be observed in the ranges were bismuth shielding was applied. The observed reduction of organ dose and total energy imparted could be achieved more efficiently by a reduction of tube current. The application of in-plane selective shielding is therefore discouraged. (orig.)

  9. Correlation of X-ray computed tomography with quantitative nuclear magnetic resonance methods for pre-clinical measurement of adipose and lean tissues in living mice.

    Science.gov (United States)

    Metzinger, Matthew N; Miramontes, Bernadette; Zhou, Peng; Liu, Yueying; Chapman, Sarah; Sun, Lucy; Sasser, Todd A; Duffield, Giles E; Stack, M Sharon; Leevy, W Matthew

    2014-10-08

    Numerous obesity studies have coupled murine models with non-invasive methods to quantify body composition in longitudinal experiments, including X-ray computed tomography (CT) or quantitative nuclear magnetic resonance (QMR). Both microCT and QMR have been separately validated with invasive techniques of adipose tissue quantification, like post-mortem fat extraction and measurement. Here we report a head-to-head study of both protocols using oil phantoms and mouse populations to determine the parameters that best align CT data with that from QMR. First, an in vitro analysis of oil/water mixtures was used to calibrate and assess the overall accuracy of microCT vs. QMR data. Next, experiments were conducted with two cohorts of living mice (either homogenous or heterogeneous by sex, age and genetic backgrounds) to assess the microCT imaging technique for adipose tissue segmentation and quantification relative to QMR. Adipose mass values were obtained from microCT data with three different resolutions, after which the data were analyzed with different filter and segmentation settings. Strong linearity was noted between the adipose mass values obtained with microCT and QMR, with optimal parameters and scan conditions reported herein. Lean tissue (muscle, internal organs) was also segmented and quantified using the microCT method relative to the analogous QMR values. Overall, the rigorous calibration and validation of the microCT method for murine body composition, relative to QMR, ensures its validity for segmentation, quantification and visualization of both adipose and lean tissues.

  10. Peripheral quantitative computed tomography (pQCT) for the assessment of bone strength in most of bone affecting conditions in developmental age: a review.

    Science.gov (United States)

    Stagi, Stefano; Cavalli, Loredana; Cavalli, Tiziana; de Martino, Maurizio; Brandi, Maria Luisa

    2016-09-26

    Peripheral quantitative computed tomography provides an automatical scan analysis of trabecular and cortical bone compartments, calculating not only their bone mineral density (BMD), but also bone geometrical parameters, such as marrow and cortical Cross-Sectional Area (CSA), Cortical Thickness (CoTh), both periosteal and endosteal circumference, as well as biomechanical parameters like Cross-Sectional Moment of Inertia (CSMI), a measure of bending, polar moment of inertia, indicating bone strength in torsion, and Strength Strain Index (SSI). Also CSA of muscle and fat can be extracted. Muscles, which are thought to stimulate bones to adapt their geometry and mineral content, are determinant to preserve or increase bone strength; thus, pQCT provides an evaluation of the functional 'muscle-bone unit', defined as BMC/muscle CSA ratio. This functional approach to bone densitometry can establish if bone strength is normally adapted to the muscle force, and if muscle force is adequate for body size, providing more detailed insights to targeted strategies for the prevention and treatment of bone fragility. The present paper offers an extensive review of technical features of pQCT and its possible clinical application in the diagnostic of bone status as well as in the monitoring of the skeleton's health follow-up.

  11. Non-invasive Assessment of Lower Limb Geometry and Strength Using Hip Structural Analysis and Peripheral Quantitative Computed Tomography: A Population-Based Comparison.

    Science.gov (United States)

    Litwic, A E; Clynes, M; Denison, H J; Jameson, K A; Edwards, M H; Sayer, A A; Taylor, P; Cooper, C; Dennison, E M

    2016-02-01

    Hip fracture is the most significant complication of osteoporosis in terms of mortality, long-term disability and decreased quality of life. In the recent years, different techniques have been developed to assess lower limb strength and ultimately fracture risk. Here we examine relationships between two measures of lower limb bone geometry and strength; proximal femoral geometry and tibial peripheral quantitative computed tomography. We studied a sample of 431 women and 488 men aged in the range 59-71 years. The hip structural analysis (HSA) programme was employed to measure the structural geometry of the left hip for each DXA scan obtained using a Hologic QDR 4500 instrument while pQCT measurements of the tibia were obtained using a Stratec 2000 instrument in the same population. We observed strong sex differences in proximal femoral geometry at the narrow neck, intertrochanteric and femoral shaft regions. There were significant (p strength (strength strain index) with each corresponding HSA variable (all p lower limb bone strength: HSA and pQCT. Validation in prospective cohorts to study associations of each with incident fracture is now indicated.

  12. Viewing Welds By Computer Tomography

    Science.gov (United States)

    Pascua, Antonio G.; Roy, Jagatjit

    1990-01-01

    Computer tomography system used to inspect welds for root penetration. Source illuminates rotating welded part with fan-shaped beam of x rays or gamma rays. Detectors in circular array on opposite side of part intercept beam and convert it into electrical signals. Computer processes signals into image of cross section of weld. Image displayed on video monitor. System offers only nondestructive way to check penetration from outside when inner surfaces inaccessible.

  13. Exploring the utility of high resolution "nano-" computed tomography imaging to place quantitative constraints on shell biometric changes in marine pteropods in response to ocean acidification

    Science.gov (United States)

    Eagle, R.; Howes, E.; Lischka, S.; Rudolph, R.; Büdenbender, J.; Bijma, J.; Gattuso, J. P.; Riebesell, U.

    2014-12-01

    Understanding and quantifying the response of marine organisms to present and future ocean acidification remains a major challenge encompassing observations on single species in culture and scaling up to the ecosystem and global scale. Understanding calcification changes in culture experiments designed to simulate present and future ocean conditions under potential CO2 emissions scenarios, and especially detecting the likely more subtle changes that may occur prior to the onset of more extreme ocean acidification, depends on the tools available. Here we explore the utility of high-resolution computed tomography (nano-CT) to provide quantitative biometric data on field collected and cultured marine pteropods, using the General Electric Company Phoenix Nanotom S Instrument. The technique is capable of quantitating the whole shell of the organism, allowing shell dimensions to be determined as well as parameters such as average shell thickness, the variation in thickness across the whole shell and in localized areas, total shell volume and surface area and when combined with weight measurements shell density can be calculated. The potential power of the technique is the ability to derive these parameters even on very small organisms less than 1 millimeter in size. Tuning the X-ray strength of the instrument allows organic material to be excluded from the analysis. Through replicate analysis of standards, we assess the reproducibility of data, and by comparison with dimension measurements derived from light microscopy we assess the accuracy of dimension determinations. We present results from historical and modern pteropod populations from the Mediterranean and cultured polar pteropods, resolving statistically significant differences in shell biometrics in both cases that may represent responses to ocean acidification.

  14. Computed Tomography of the Human Pineal Gland for Study of the Sleep-Wake Rhythm: Reproducibility of a Semi-Quantitative Approach

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, S.A.; Platzek, I.; Kunz, D.; Mahlberg, R.; Wolf, K.J.; Heidenreich, J.O. [Charite - Universitaetsmedizin Berlin, Campus Benjamin Franklin, Berlin (Germany). Dept. of Radiology and Nuclear Medicine

    2006-10-15

    Purpose: To propose a semi-quantitative computed tomography (CT) protocol for determining uncalcified pineal tissue (UCPT), and to evaluate its reproducibility in modification of studies showing that the degree of calcification is a potential marker of deficient melatonin production and may prove an instability marker of circadian rhythm. Material and Methods: Twenty-two pineal gland autopsy specimens were scanned in a skull phantom with different slice thickness twice and the uncalcified tissue visually assessed using a four-point scale. The maximum gland density was measured and its inverse graded on a non-linear four-point scale. The sum of both scores was multiplied by the gland volume to yield the UCPT. The within-subject variance of UCPT was determined and compared between scans of different slice thickness. Results: The UCPT of the first measurement, in arbitrary units, was 39{+-}52.5 for 1 mm slice thickness, 44{+-}51.1 for 2 mm, 45{+-}34.8 for 4 mm, and 84{+-}58.0 for 8 mm. Significant differences of within-subject variance of UCPT were found between 1 and 4 mm, 1 and 8 mm, and 2 and 8 mm slice thicknesses ( P <0.05). Conclusion: A superior reproducibility of the semi-quantitative CT determination of UCPT was found using 1 and 2 mm slice thicknesses. These data support the use of thin slices of 1 and 2 mm. The benefit in reproducibility from thin slices has to be carefully weighted against their considerably higher radiation exposure.

  15. Validation of quantitative computed tomography-derived areal bone mineral density with dual energy X-ray absorptiometry in an elderly Chinese population

    Institute of Scientific and Technical Information of China (English)

    Cheng Xiaoguang; Wang Ling; Wang Qianqian; Ma Yimin; Su Yongbin; Li Kai

    2014-01-01

    Background The performance of computed tomography X-ray absorptiometry (CTXA) against the dual energy X-ray absorptiometry (DXA) as standard has not been studied in Chinese population.The aim of this study was to evaluate the precision of this measurement and validate the value of quantitative computed tomography (QCT) by comparing CTXA results with DXA results in an elderly Chinese population.Methods One hundred and three females of 46 to 76 years old and 49 males of 52 to 76 years old were recruited from the Prospective Urban Rural Epidemiology study.All subjects underwent hip scans by both QCT and DXA on the same day.For precision determination,30 subjects had duplicate DXA hip scans.The hip QCT data of a subset of 27 subjects were separately analyzed by two observers and reanalyzed by one observer at a different time.The inter-and intra-observer variations of CTXA measurement were assessed,and the difference and correlation between CTXA and DXA results were analyzed.Results The inter-and intra-observer variations of CTXA were 0.070 and 0.024 g/cm2 in the femoral neck (FN),and 0.030 and 0.012 g/cm2 in the total hip (TH),which were comparable to the DXA inter-scan variations (0.013 g/cm2 for FN and 0.014 g/cm2 for TH).The results of CTXA bone mineral density (BMD) were highly correlated with those of DXA (R2 =0.810 for FN and R2=0.878 for TH).The BMD values of CTXA in FN and TH were lower than those of DXA by 21.0% and 17.8% (P<0.05),respectively.However,after appropriate transformation,the difference was eliminated and a comparable T score could be obtained.Conclusions CTXA shows good agreement with DXA for the measurement of BMD in the proximal femur,which makes QCT suitable for the quantification of bone mineral content in the hip and helpful for the diagnosis of osteoporosis.

  16. Cranial computed tomography in pediatrics

    Energy Technology Data Exchange (ETDEWEB)

    Boltshauser, E. (Zuerich Univ. (Switzerland). Kinderklinik)

    1984-01-01

    This paper deals mainly with methodical aspects (such as sedation, intravenous and intrathecal application of contrast media) and with common difficulties in interpretation of computed tomography images. The indications for cranial CT are discussed in respect to probable therapeutic consequences and expected diagnostic yield. In the view of the author CT is, as a rule, not required in assessing chronic headache, generalised epileptic convulsions, non-specific mental retardation and cerebral palsy.

  17. Distal radius plate of CFR-PEEK has minimal effect compared to titanium plates on bone parameters in high-resolution peripheral quantitative computed tomography: a pilot study.

    Science.gov (United States)

    de Jong, Joost J A; Lataster, Arno; van Rietbergen, Bert; Arts, Jacobus J; Geusens, Piet P; van den Bergh, Joop P W; Willems, Paul C

    2017-02-27

    Carbon-fiber-reinforced poly-ether-ether-ketone (CFR-PEEK) has superior radiolucency compared to other orthopedic implant materials, e.g. titanium or stainless steel, thus allowing metal-artifact-free postoperative monitoring by computed tomography (CT). Recently, high-resolution peripheral quantitative CT (HRpQCT) proved to be a promising technique to monitor the recovery of volumetric bone mineral density (vBMD), micro-architecture and biomechanical parameters in stable conservatively treated distal radius fractures. When using HRpQCT to monitor unstable distal radius fractures that require volar distal radius plating for fixation, radiolucent CFR-PEEK plates may be a better alternative to currently used titanium plates to allow for reliable assessment. In this pilot study, we assessed the effect of a volar distal radius plate made from CFR-PEEK on bone parameters obtained from HRpQCT in comparison to two titanium plates. Plates were instrumented in separate cadaveric human fore-arms (n = 3). After instrumentation and after removal of the plates duplicate HRpQCT scans were made of the region covered by the plate. HRpQCT images were visually checked for artifacts. vBMD, micro-architectural and biomechanical parameters were calculated, and compared between the uninstrumented and instrumented radii. No visible image artifacts were observed in the CFR-PEEK plate instrumented radius, and errors in bone parameters ranged from -3.2 to 2.6%. In the radii instrumented with the titanium plates, severe image artifacts were observed and errors in bone parameters ranged between -30.2 and 67.0%. We recommend using CFR-PEEK plates in longitudinal in vivo studies that monitor the healing process of unstable distal radius fractures treated operatively by plating or bone graft ingrowth.

  18. Bone strength measured by peripheral quantitative computed tomography and the risk of nonvertebral fractures: the osteoporotic fractures in men (MrOS) study.

    Science.gov (United States)

    Sheu, Yahtyng; Zmuda, Joseph M; Boudreau, Robert M; Petit, Moira A; Ensrud, Kristine E; Bauer, Douglas C; Gordon, Christopher L; Orwoll, Eric S; Cauley, Jane A

    2011-01-01

    Many fractures occur in individuals without osteoporosis defined by areal bone mineral density (aBMD). Inclusion of other aspects of skeletal strength may be useful in identifying at-risk subjects. We used surrogate measures of bone strength at the radius and tibia measured by peripheral quantitative computed tomography (pQCT) to evaluate their relationships with nonvertebral fracture risk. Femoral neck (FN) aBMD, measured by dual-energy X-ray absorptiometry (DXA), also was included. The study population consisted of 1143 white men aged 69+ years with pQCT measures at the radius and tibia from the Minneapolis and Pittsburgh centers of the Osteoporotic Fractures in Men (MrOS) study. Principal-components analysis and Cox proportional-hazards modeling were used to identify 21 of 58 pQCT variables with a major contribution to nonvertebral incident fractures. After a mean 2.9 years of follow-up, 39 fractures occurred. Men without incident fractures had significantly greater bone mineral content, cross-sectional area, and indices of bone strength than those with fractures by pQCT. Every SD decrease in the 18 of 21 pQCT parameters was significantly associated with increased fracture risk (hazard ration ranged from 1.4 to 2.2) independent of age, study site, body mass index (BMI), and FN aBMD. Using area under the receiver operation characteristics curve (AUC), the combination of FN aBMD and three radius strength parameters individually increased fracture prediction over FN aBMD alone (AUC increased from 0.73 to 0.80). Peripheral bone strength measures are associated with fracture risk and may improve our ability to identify older men at high risk of fracture.

  19. Correlation of X-Ray Computed Tomography with Quantitative Nuclear Magnetic Resonance Methods for Pre-Clinical Measurement of Adipose and Lean Tissues in Living Mice

    Directory of Open Access Journals (Sweden)

    Matthew N. Metzinger

    2014-10-01

    Full Text Available Numerous obesity studies have coupled murine models with non-invasive methods to quantify body composition in longitudinal experiments, including X-ray computed tomography (CT or quantitative nuclear magnetic resonance (QMR. Both microCT and QMR have been separately validated with invasive techniques of adipose tissue quantification, like post-mortem fat extraction and measurement. Here we report a head-to-head study of both protocols using oil phantoms and mouse populations to determine the parameters that best align CT data with that from QMR. First, an in vitro analysis of oil/water mixtures was used to calibrate and assess the overall accuracy of microCT vs. QMR data. Next, experiments were conducted with two cohorts of living mice (either homogenous or heterogeneous by sex, age and genetic backgrounds to assess the microCT imaging technique for adipose tissue segmentation and quantification relative to QMR. Adipose mass values were obtained from microCT data with three different resolutions, after which the data were analyzed with different filter and segmentation settings. Strong linearity was noted between the adipose mass values obtained with microCT and QMR, with optimal parameters and scan conditions reported herein. Lean tissue (muscle, internal organs was also segmented and quantified using the microCT method relative to the analogous QMR values. Overall, the rigorous calibration and validation of the microCT method for murine body composition, relative to QMR, ensures its validity for segmentation, quantification and visualization of both adipose and lean tissues.

  20. A customized protocol to assess bone quality in the metacarpal head, metacarpal shaft and distal radius: a high resolution peripheral quantitative computed tomography precision study.

    Science.gov (United States)

    Feehan, Lynne; Buie, Helen; Li, Linda; McKay, Heather

    2013-12-24

    High Resolution-Peripheral Quantitative Computed Tomography (HR-pQCT) is an emerging technology for evaluation of bone quality in Rheumatoid Arthritis (RA). However, there are limitations with standard HR-pQCT imaging protocols for examination of regions of bone commonly affected in RA. We developed a customized protocol for evaluation of volumetric bone mineral density (vBMD) and microstructure at the metacarpal head (MH), metacarpal shaft (MS) and ultra-ultra-distal (UUD) radius; three sites commonly affected in RA. The purpose was to evaluate short-term measurement precision for bone density and microstructure at these sites. 12 non-RA participants, individuals likely to have no pre-existing bone damage, consented to participate [8 females, aged 23 to 71 y [median (IQR): 44 (28) y]. The custom protocol includes more comfortable/stable positioning and adapted cortical segmentation and direct transformation analysis methods. Dominant arm MH, MS and UUD radius scans were completed on day one; repeated twice (with repositioning) three to seven days later. Short-term precision for repeated measures was explored using intraclass correlational coefficient (ICC), mean coefficient of variation (CV%), root mean square coefficient of variation (RMSCV%) and least significant change (LSC%95). Bone density and microstructure precision was excellent: ICCs varied from 0.88 (MH2 trabecular number) to .99 (MS3 polar moment of inertia); CV% varied from 3 on 5 point scale. In our facility, this custom protocol extends the potential for in vivo HR-pQCT imaging to assess, with high precision, regional differences in bone quality at three sites commonly affected in RA. Our methods are easy to adopt and we recommend other users of HR-pQCT consider this protocol for further evaluations of its precision and feasibility in their imaging facilities.

  1. Cluster analysis of bone microarchitecture from high resolution peripheral quantitative computed tomography demonstrates two separate phenotypes associated with high fracture risk in men and women.

    Science.gov (United States)

    Edwards, M H; Robinson, D E; Ward, K A; Javaid, M K; Walker-Bone, K; Cooper, C; Dennison, E M

    2016-07-01

    Osteoporosis is a major healthcare problem which is conventionally assessed by dual energy X-ray absorptiometry (DXA). New technologies such as high resolution peripheral quantitative computed tomography (HRpQCT) also predict fracture risk. HRpQCT measures a number of bone characteristics that may inform specific patterns of bone deficits. We used cluster analysis to define different bone phenotypes and their relationships to fracture prevalence and areal bone mineral density (BMD). 177 men and 159 women, in whom fracture history was determined by self-report and vertebral fracture assessment, underwent HRpQCT of the distal radius and femoral neck DXA. Five clusters were derived with two clusters associated with elevated fracture risk. "Cluster 1" contained 26 women (50.0% fractured) and 30 men (50.0% fractured) with a lower mean cortical thickness and cortical volumetric BMD, and in men only, a mean total and trabecular area more than the sex-specific cohort mean. "Cluster 2" contained 20 women (50.0% fractured) and 14 men (35.7% fractured) with a lower mean trabecular density and trabecular number than the sex-specific cohort mean. Logistic regression showed fracture rates in these clusters to be significantly higher than the lowest fracture risk cluster [5] (pcluster 5 in women in cluster 1 and 2 (pcluster 2 (pclusters in both men and women which may differ in etiology and response to treatment. As cluster 1 in men does not have low areal BMD, these men may not be identified as high risk by conventional DXA alone. Copyright © 2016. Published by Elsevier Inc.

  2. Distribution of bone density and cortical thickness in the proximal femur and their association with hip fracture in postmenopausal women: a quantitative computed tomography study.

    Science.gov (United States)

    Yang, L; Udall, W J M; McCloskey, E V; Eastell, R

    2014-01-01

    The quantitative computed tomography (QCT) scans in an individually matched case-control study of women with hip fracture were analysed. There were widespread deficits in the femoral volumetric bone mineral density (vBMD) and cortical thickness of cases, and cortical vBMD and thickness discriminated hip fracture independently of BMD by dual-energy X-ray absorptiometry (DXA). Acknowledging the limitations of QCT associated with partial volume effects, we used QCT in an individually matched case-control study of women with hip fracture to better understand its structural basis. Fifty postmenopausal women (55-89 years) who had sustained hip fractures due to low-energy trauma underwent QCT scans of the contralateral hip within 3 months of the fracture. For each case, postmenopausal women, matched by age (±5 years), weight (±5 kg) and height (±5 cm), were recruited as controls. We quantified cortical, trabecular and integral vBMD and apparent cortical thickness (AppCtTh) in four quadrants of cross-sections along the length of the femoral head (FH), femoral neck (FN), intertrochanter and trochanter and examined their association with hip fracture. Women with hip or intracapsular (IC) fracture had significantly (p hip and IC fractures independent of hip areal BMD (aBMD). The combination of AppCtTh and trabecular or integral vBMD discriminated hip fracture, whereas the combination of FH and FN AppCtTh discriminated IC fracture significantly (p hip aBMD. Deficits in vBMD and AppCtTh in cases were widespread in the proximal femur, and cortical vBMD and AppCtTh discriminated hip fracture independently of aBMD by DXA.

  3. Cortical and trabecular bone at the radius and tibia in male and female adolescents with Down syndrome: a peripheral quantitative computed tomography (pQCT) study.

    Science.gov (United States)

    González-Agüero, A; Vicente-Rodríguez, G; Gómez-Cabello, A; Casajús, J A

    2013-03-01

    We aimed to describe the structure and strength of the tibia and radius of adolescents with Down syndrome. We observed that despite higher levels of volumetric bone mineral density in determined skeletal sites, they are at higher risk of developing osteoporotic fractures in the future due to their lower bone strength indexes. The aims of the study were to describe the cortical and trabecular volumetric bone mineral density (vBMD), bone mineral content (BMC), area, and bone strength in adolescents with Down syndrome (DS) and to compare them with adolescents without disabilities. Thirty adolescents (11 girls) with DS and 28 without disabilities (10 girls) participated in the study. Peripheral quantitative computed tomography measurements were taken at proximal and distal sites of the tibia and radius. Values of total, trabecular, and cortical BMC; vBMD; and area were obtained of each scan. Cortical thickness and endosteal and periosteal circumferences were also measured, and different bone strength indexes were calculated. Student's t tests were applied between groups. The DS group showed greater vBMD at distal radius, BMC at proximal radius, and total and cortical vBMD at proximal tibia. The non-DS group showed higher total and trabecular area at the distal radius and total, cortical, and trabecular BMC and area at distal tibia. Higher values of periosteal and endosteal circumference and bone strength were also found in non-DS group. From these results, it can be believed that even with higher vBMD in determined skeletal sites, adolescents with DS are at higher risk of suffering bone fractures due to an increased fragility by lower resistance to load bending or torsion.

  4. 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.).

  5. Measuring Marrow Density and Area Using Peripheral Quantitative Computed Tomography at the Tibia: Precision in Young and Older Adults and Individuals With Spinal Cord Injury.

    Science.gov (United States)

    Gibbs, Jenna C; Brown, Zachary M; Wong, Andy K O; Craven, B Catharine; Adachi, Jonathan D; Giangregorio, Lora M

    2017-03-27

    The objective of this study was to compare the test-retest precision error for peripheral quantitative computed tomography (pQCT)-derived marrow density and marrow area segmentation at the tibia using 3 software packages. A secondary analysis of pQCT data in young adults (n = 18, mean ± standard deviation 25.4 ± 3.2 yr), older adults (n = 47, 71.8 ± 8.2 yr), and individuals with spinal cord injury (C1-T12 American Spinal Injury Association Impairment Scale, classes A-C; n = 19, 43.5 ± 8.6 yr) was conducted. Repeat scans of the tibial shaft (66%) were performed using pQCT (Stratec XCT2000). Test-retest precision errors (root mean square standard deviation and root mean square coefficient of variation [RMSCV%]) for marrow density (mg/cm(3)) and marrow area (mm(2)) were reported for the watershed-guided manual segmentation method (SliceOmatic version 4.3 [Sliceo-WS]) and the 2 threshold-based edge detection methods (Stratec version 6.0 [Stratec-TB] and BoneJ version 1.3.14 [BoneJ-TB]). Bland-Altman plots and 95% limits of agreement were computed to evaluate test-retest discrepancies within and between methods of analysis and subgroups. RMSCV% for marrow density segmentation was >5% for all methods across subgroups (Stratec-TB: 12.2%-28.5%, BoneJ-TB: 14.5%-25.2%, and Sliceo-WS: 10.9%-23.0%). RMSCV% for marrow area segmentation was within 5% for all methods across subgroups (Stratec-TB: 1.9%-4.4%, BoneJ-TB: 2.6%-5.1%, and Sliceo-WS: 2.4%-4.5%), except using BoneJ-TB in older adults. Intermethod discrepancies in marrow density appeared to be present across the range of marrow density values and did not differ by subgroup. Intermethod discrepancies varied to a greater extent for marrow area and were found to be more frequently at mid- to higher-range values for those with spinal cord injury. Precision error for pQCT-derived marrow density segmentation exceeded 5% for all methods of analysis across a range of bone mineral densities and

  6. Sparse Image Reconstruction in Computed Tomography

    DEFF Research Database (Denmark)

    Jørgensen, Jakob Sauer

    In recent years, increased focus on the potentially harmful effects of x-ray computed tomography (CT) scans, such as radiation-induced cancer, has motivated research on new low-dose imaging techniques. Sparse image reconstruction methods, as studied for instance in the field of compressed sensing...... and limitations of sparse reconstruction methods in CT, in particular in a quantitative sense. For example, relations between image properties such as contrast, structure and sparsity, tolerable noise levels, suficient sampling levels, the choice of sparse reconstruction formulation and the achievable image...

  7. Industrial applications of computed tomography

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Carmignato, S.; Kruth, J. -P.

    2014-01-01

    The number of industrial applications of Computed Tomography(CT) is large and rapidly increasing. After a brief market overview, the paper gives a survey of state of the art and upcoming CT technologies, covering types of CT systems, scanning capabilities, and technological advances. The paper...... contains a survey of application examples from the manufacturing industry as well as from other industries, e.g., electrical and electronic devices, inhomogeneous materials, and from the food industry. Challenges as well as major national and international coordinated activities in the field of industrial...

  8. Computed Tomography in Forensic Medicine

    DEFF Research Database (Denmark)

    Leth, Peter Mygind

    2015-01-01

    Modern diagnostic imagining techniques are gaining popularity in forensic medicine. Denmark has been involved in the development of this use of imaging techniques from the beginning. The Institute of Forensic Medicine at the University of Southern Denmark acquired a helical computed tomography (CT...... AND METHODS: This thesis investigated 900 forensic cases that were CT-scanned and autopsied at the Institute of Forensic Medicine, University of Southern Denmark, from 2006-2011. The scanner was a Siemens Somatom Spirit dual-slice CT-scanner with a Siemens Syngo MultiModality workstation. Contrast enhancement...

  9. Future of cardiac computed tomography

    Institute of Scientific and Technical Information of China (English)

    Carlo N De Cecco; U Joseph Schoepf

    2015-01-01

    Coronary computed tomography angiography(CCTA)has become an integral tool in the noninvasive diagnostic workup of patients with suspected coronary artery disease in both elective and emergency settings. Today, it represents a mature technique providing accurate, non-invasive morphological assessment of the coronary arteries and atherosclerotic plaque burden. Iterative reconstruction algorithms, low kV imaging, and single-heart beat acquisitions hold promise to further reduce dose requirements and improve the safety and robustness of the technique in several circumstances including imaging of heavily calcified vessels, patients with morbid obesity or irregular heart rates, and assessment in the emergency setting. However, it has become clear over recent years that cardiac radiologists need to take further steps towards the development and integration of functional imaging with morphological CCTA assessment to truly provide a comprehensive evaluation of the heart. Computed tomography myocardial perfusion imaging, including both dynamic and static dual-energy approaches, has demonstrated the ability to directly assess and quantify myocardial ischemia with simultaneous CCTA acquisition with a reasonable contrast medium volume and radiation dose delivered to the patient. In order to promote CCTA in the clinical and research environments, radiologists should prepare to embrace the change from morphological to functional imaging, furnishing all the necessary resources and information to referring clinicians.

  10. Adaptive Computed Tomography Imaging Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The present proposal describes the development of an adaptive Computed Tomography Imaging Spectrometer (CTIS), or "Snapshot" spectrometer which can "instantaneously"...

  11. Cerebral computed tomography angiography using a low tube voltage (80 kVp) and a moderate concentration of iodine contrast material: a quantitative and qualitative comparison with conventional computed tomography angiography.

    Science.gov (United States)

    Cho, Eun-Suk; Chung, Tae-Sub; Oh, Dae Kun; Choi, Hyun Seok; Suh, Sang Hyun; Lee, Hyeon-Kyeong; Lee, Kyung Hee

    2012-02-01

    To investigate the feasibility of an 80-kVp protocol using a moderate concentration contrast material (MC-CM) for cerebral computed tomography angiography by comparison with a conventional 120-kVp protocol using a high concentration contrast material (HC-CM). Attenuation values and signal-to-noise ratios (SNRs) were determined in a head phantom for 2 tube voltages (80 and 120 kVp) and 2 different iodine concentration contrast materials (HC-CM and MC-CM). Among 90 consecutive patients, 45 patients were scanned with 120 kVp and 150 mAs(eff) after administration of 70 mL of HC-CM (370 mg iodine [mgI]/mL), whereas the other 45 patients were scanned with 80 kVp and 370 mAs(eff) after administration of 70 mL of MC-CM (300 mgI/mL). The Hounsfield units (HU) of the internal carotid artery T junction, SNR, contrast-to-noise ratio (CNR), subjective degree of arterial enhancement, image noise, sharpness of the cerebral arterial boundary, and overall diagnostic image quality were compared between the 2 groups. The mean attenuation of the internal carotid artery T junction, SNR, and CNR was significantly higher in the 80 kVp with MC-CM group (379.2, 33.7, and 31.1 HU, respectively) than in the 120 kVp with HC-CM group (282.2, 31.1, and 27.2 HU, respectively). The 80-kVp protocol resulted in significantly higher score in arterial enhancement, sharpness of the cerebral arteries, and overall diagnostic image quality. The effective dose of 80 kVp (0.7 mSv) was 22.2% lower than that of 120 kVp (0.9 mSv). The use of 80 kVp with MC-CM improved arterial enhancement, SNR, and CNR and provided superior quality images using a smaller amount of iodine and a lower radiation dose than the conventional protocol of 120 kVp with HC-CM.

  12. Computed tomography of the gallbladder.

    Science.gov (United States)

    Havrilla, T R; Reich, N E; Haaga, J R; Seidelmann, F E; Cooperman, A M; Alfidi, R J

    1978-06-01

    Computed tomography (CT) was used to study 79 patients with suspected gallbladder disease. First and second generation scanners were used to determine the efficacy of CT in detecting cholecystitis or cholelithiasis. Manifestations of gallbladder disease such as hydrops, opaque and nonopaque gallstones, chronic cholecystitis with thickened inflammatory walls, and secondary liver abscesses can be easily detected. It is a useful technique for individuals in whom the gallbladder has failed to opacity on oral cholecystography. The scanning method is described, and estimates of reliability are given including its accuracy, limitations, and place in the management of gallbladder disease, especially cholelithiasis. When conventional radiographic examinations or ultrasound fail to give definitive diagnostic information, CT can be a useful alternative with an overall diagnostic accuracy greater than 80%.

  13. [Computer tomography of sports injuries].

    Science.gov (United States)

    Reiser, M; Rupp, N

    1984-01-01

    Computed tomography (CT) provides axial slices plane and shows excellent details of bones and different soft tissues, favoring its use in traumatic lesions caused by sporting activities. Complex anatomical structures such as the shoulder, the vertebral column, the pelvis, the knee, the tarsal and carpal bones are often better recognized in detail than by conventional radiography. Fracture lines, localization of bone fragments and involvement of soft tissues are clearly demonstrated. Luxations and bone changes leading to luxations can be shown. CT arthrography provides for the first time a direct visualization of joint cartilage and of cruciate ligaments in the knee joint, so traumatic lesions such as chondropathia patellae or rupture of the cruciate ligaments are shown with a high degree of reliability.

  14. Computed tomography in sport injuries

    Energy Technology Data Exchange (ETDEWEB)

    Reiser, M.; Rupp, N.

    1984-01-01

    Computed tomography (CT) provides axial slices plane and shows excellent details of bones and different soft tissues, favoring its use in traumatic lesions caused by sporting activities. Complex anatomical structures such as the shoulder, the vertebral column, the pelvis, the knee, the tarsal and carpal bones are often better recognized in detail than by conventional radiography. Fracture lines, localization of bone fragments and involvement of soft tissues are clearly demonstrated. Luxations and bone changes leading to luxations can be shown. CT arthrography provides for the first time a direct visualization of joint cartilage and of cruciate ligaments in the knee joint, so traumatic lesions such as chondropathia patellae or rupture of the cruciate ligaments are shown with a high degree of reliability.

  15. Computed tomography of cryogenic cells

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Gerd; Anderson, E.; Vogt, S.; Knochel, C.; Weiss, D.; LeGros, M.; Larabell, C.

    2001-08-30

    Due to the short wavelengths of X-rays and low numerical aperture of the Fresnel zone plates used as X-ray objectives, the depth of field is several microns. Within the focal depth, imaging a thick specimen is to a good approximation equivalent to projecting the specimen absorption. Therefore, computed tomography based on a tilt series of X-ray microscopic images can be used to reconstruct the local linear absorption coefficient and image the three-dimensional specimen structure. To preserve the structural integrity of biological objects during image acquisition, microscopy is performed at cryogenic temperatures. Tomography based on X-ray microscopic images was applied to study the distribution of male specific lethal 1 (MSL-1), a nuclear protein involved in dosage compensation in Drosophila melanogaster, which ensures that males with single X chromosome have the same amount of most X-linked gene products as females with two X chromosomes. Tomographic reconstructions of X-ray microscopic images were used to compute the local three-dimensional linear absorption coefficient revealing the arrangement of internal structures of Drosophila melanogaster cells. Combined with labelling techniques, nanotomography is a new technique to study the 3D distribution of selected proteins inside whole cells. We want to improve this technique with respect to resolution and specimen preparation. The resolution in the reconstruction can be significantly improved by reducing the angular step size to collect more viewing angles, which requires an automated data acquisition. In addition, fast-freezing with liquid ethane instead of cryogenic He gas will be applied to improve the vitrification of the hydrated samples. We also plan to apply cryo X-ray nanotomography in order to study different types of cells and their nuclear protein distributions.

  16. Cardiac Computed Tomography (Multidetector CT, or MDCT)

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Cardiac Computed Tomography (Multidetector CT, or MDCT) Updated:Sep 19, ... The ECG is also needed to help the computer that is connected to the CT scanner create ...

  17. [Computed tomography and cranial paleoanthropology].

    Science.gov (United States)

    Cabanis, Emmanuel Alain; Badawi-Fayad, Jackie; Iba-Zizen, Marie-Thérèse; Istoc, Adrian; de Lumley, Henry; de Lumley, Marie-Antoinette; Coppens, Yves

    2007-06-01

    Since its invention in 1972, computed tomography (C.T.) has significantly evolved. With the advent of multi-slice detectors (500 times more sensitive than conventional radiography) and high-powered computer programs, medical applications have also improved. CT is now contributing to paleoanthropological research. Its non-destructive nature is the biggest advantage for studying fossil skulls. The second advantage is the possibility of image analysis, storage, and transmission. Potential disadvantages include the possible loss of files and the need to keep up with rapid technological advances. Our experience since the late 1970s, and a recent PhD thesis, led us to describe routine applications of this method. The main contributions of CT to cranial paleoanthropology are five-fold: --Numerical anatomy with rapid acquisition and high spatial resolution (helicoidal and multidetector CT) offering digital storage and stereolithography (3D printing). --Numerical biometry (2D and 3D) can be used to create "normograms" such as the 3D craniofacial reference model used in maxillofacial surgery. --Numerical analysis offers thorough characterization of the specimen and its state of conservation and/or restoration. --From "surrealism" to virtual imaging, anatomical structures can be reconstructed, providing access to hidden or dangerous zones. --The time dimension (4D imaging) confers movement and the possibility for endoscopic simulation and internal navigation (see Iconography). New technical developments will focus on data processing and networking. It remains our duty to deal respectfully with human fossils.

  18. Perfusion computed tomography to assist decision making for stroke thrombolysis

    Science.gov (United States)

    Levi, Christopher; Krishnamurthy, Venkatesh; McElduff, Patrick; Miteff, Ferdi; Spratt, Neil J.; Bateman, Grant; Donnan, Geoffrey; Davis, Stephen; Parsons, Mark

    2015-01-01

    The use of perfusion imaging to guide selection of patients for stroke thrombolysis remains controversial because of lack of supportive phase three clinical trial evidence. We aimed to measure the outcomes for patients treated with intravenous recombinant tissue plasminogen activator (rtPA) at a comprehensive stroke care facility where perfusion computed tomography was routinely used for thrombolysis eligibility decision assistance. Our overall hypothesis was that patients with ‘target’ mismatch on perfusion computed tomography would have improved outcomes with rtPA. This was a prospective cohort study of consecutive ischaemic stroke patients who fulfilled standard clinical/non-contrast computed tomography eligibility criteria for treatment with intravenous rtPA, but for whom perfusion computed tomography was used to guide the final treatment decision. The ‘real-time’ perfusion computed tomography assessments were qualitative; a large perfusion computed tomography ischaemic core, or lack of significant perfusion lesion-core mismatch were considered relative exclusion criteria for thrombolysis. Specific volumetric perfusion computed tomography criteria were not used for the treatment decision. The primary analysis compared 3-month modified Rankin Scale in treated versus untreated patients after ‘off-line’ (post-treatment) quantitative volumetric perfusion computed tomography eligibility assessment based on presence or absence of ‘target’ perfusion lesion-core mismatch (mismatch ratio >1.8 and volume >15 ml, core perfusion computed tomography-selected rtPA-treated patients to an Australian historical cohort of non-contrast computed tomography-selected rtPA-treated patients. Of 635 patients with acute ischaemic stroke eligible for rtPA by standard criteria, thrombolysis was given to 366 patients, with 269 excluded based on visual real-time perfusion computed tomography assessment. After off-line quantitative perfusion computed tomography classification

  19. High-resolution peripheral quantitative computed tomography (HR-pQCT) can assess microstructural and biomechanical properties of both human distal radius and tibia: Ex vivo computational and experimental validations.

    Science.gov (United States)

    Zhou, Bin; Wang, Ji; Yu, Y Eric; Zhang, Zhendong; Nawathe, Shashank; Nishiyama, Kyle K; Rosete, Fernando Rey; Keaveny, Tony M; Shane, Elizabeth; Guo, X Edward

    2016-05-01

    High-resolution peripheral quantitative computed tomography (HR-pQCT) provides in vivo three-dimensional (3D) imaging at the distal radius and tibia and has been increasingly used to characterize cortical and trabecular bone morphology in clinical studies. In this study, we comprehensively examined the accuracy of HR-pQCT and HR-pQCT based micro finite element (μFE) analysis predicted bone elastic stiffness and strength through comparisons with gold-standard micro computed tomography (μCT) based morphological/μFE measures and direct mechanical testing results. Twenty-six sets of human cadaveric distal radius and tibia segments were imaged by HR-pQCT and μCT. Microstructural analyses were performed for the registered HR-pQCT and μCT images. Bone stiffness and yield strength were determined by both HR-pQCT and μCT based linear and nonlinear μFE predictions and mechanical testing. Our results suggested that strong and significant correlations existed between the HR-pQCT standard, model-independent and corresponding μCT measurements. HR-pQCT based nonlinear μFE overestimated stiffness and yield strength while the linear μFE underestimated yield strength, but both were strongly correlated with those predicted by μCT μFE and measured by mechanical testing at both radius and tibia (R(2)>0.9). The microstructural differences between HR-pQCT and μCT were also examined by the Bland-Altman plots. Our results showed HR-pQCT morphological measurements of BV/TV(d), Tb.Th, and Tb.Sp, can be adjusted by correction values to approach true values measured by gold-standard μCT. In addition, we observed moderate correlations of HR-pQCT biomechanical and microstructural parameters between the distal radius and tibia. We concluded that morphological and mechanical properties of human radius and tibia bone can be assessed by HR-pQCT based measures.

  20. Operator radiation exposure in cone-beam computed tomography guidance

    NARCIS (Netherlands)

    Braak, S.J.; Strijen Van, M. J L; Meijer, E.; Heesewijk Van, J. P M; Mali, W. P T M

    2016-01-01

    Objectives: Quantitative analysis of operator dose in cone-beam computed tomography guidance (CBCT-guidance) and the effect of protective shielding. Methods: Using a Rando phantom, a model was set-up to measure radiation dose for the operator hand, thyroid and gonad region. The effect of sterile rad

  1. X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kalender, Willi A [Institute of Medical Physics, University Erlangen-Nuernberg, Henkestr. 91, D-91052 Erlangen (Germany)

    2006-07-07

    X-ray computed tomography (CT), introduced into clinical practice in 1972, was the first of the modern slice-imaging modalities. To reconstruct images mathematically from measured data and to display and to archive them in digital form was a novelty then and is commonplace today. CT has shown a steady upward trend with respect to technology, performance and clinical use independent of predictions and expert assessments which forecast in the 1980s that it would be completely replaced by magnetic resonance imaging. CT not only survived but exhibited a true renaissance due to the introduction of spiral scanning which meant the transition from slice-by-slice imaging to true volume imaging. Complemented by the introduction of array detector technology in the 1990s, CT today allows imaging of whole organs or the whole body in 5 to 20 s with sub-millimetre isotropic resolution. This review of CT will proceed in chronological order focussing on technology, image quality and clinical applications. In its final part it will also briefly allude to novel uses of CT such as dual-source CT, C-arm flat-panel-detector CT and micro-CT. At present CT possibly exhibits a higher innovation rate than ever before. In consequence the topical and most recent developments will receive the greatest attention. (review)

  2. Computed tomography of arachnoid cyst

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Min Gi; Bae, Weon Tae; Kim, Jae Kyu; Park, Jin Gyoon; Kang, Heoung Keun; Chung, Hyun De [College of Medicine, Chonnam National University, Kwangju (Korea, Republic of)

    1988-02-15

    The preoperative diagnosis of intracranial arachnoid cysts has been simplified, and made more rapid and accurate with computed tomography (CT). Using CT cisternography, detailed anatomic and physiologic information of arachnoid cysts could be obtained. CT features of pathologically proven 21 arachnoid cysts that were examined at Chonnam National University Hospital from June 1983 to May 1987 were analyzed. The results were as follows: 1.Prevalent age group was the 1st decade (8 cases) and male to female ratio was 17:4. 2.Clinical features were related to the location of arachnoid cyst, common symptoms were headache (53.3%), convulsion, mental change and walking disturbance. 3.Location of the arachnoid cyst were in supratentorial region (15 cases) most in middle cranial fossa (12 cases), and infratentorial region (6 cases), common at the retrocerebellar cisternal space (3 cases). 4.Shapes of arachnoid cyst were biconvex with straight inner margin (8 cases), spherical (7 cases), simple biconvex (3 cases) and others (3 cases). 5.Size of the arachnoid cyst, in the greatest dimension, was ranged from 2cm to 9cm and commonly distributed between 3cm to 5cm (14 cases). 6.Of all 14 cases, who did CT cisternography using metrizamide (11 cases) and iopamidol (3 cases), 2 cases had communication with the subarachnoid space.

  3. A Freeware Path to Neutron Computed Tomography

    Science.gov (United States)

    Schillinger, Burkhard; Craft, Aaron E.

    Neutron computed tomography has become a routine method at many neutron sources due to the availability of digital detection systems, powerful computers and advanced software. The commercial packages Octopus by Inside Matters and VGStudio by Volume Graphics have been established as a quasi-standard for high-end computed tomography. However, these packages require a stiff investment and are available to the users only on-site at the imaging facility to do their data processing. There is a demand from users to have image processing software at home to do further data processing; in addition, neutron computed tomography is now being introduced even at smaller and older reactors. Operators need to show a first working tomography setup before they can obtain a budget to build an advanced tomography system. Several packages are available on the web for free; however, these have been developed for X-rays or synchrotron radiation and are not immediately useable for neutron computed tomography. Three reconstruction packages and three 3D-viewers have been identified and used even for Gigabyte datasets. This paper is not a scientific publication in the classic sense, but is intended as a review to provide searchable help to make the described packages usable for the tomography community. It presents the necessary additional preprocessing in ImageJ, some workarounds for bugs in the software, and undocumented or badly documented parameters that need to be adapted for neutron computed tomography. The result is a slightly complicated, but surprisingly high-quality path to neutron computed tomography images in 3D, but not a replacement for the even more powerful commercial software mentioned above.

  4. Orbital computed tomography for exophthalmos

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ok Keun; Lee, Hyun; Sol, Chang Hyo; Kim, Byung Soo [College of Medicine, Pusan National University, Busan (Korea, Republic of)

    1987-06-15

    Since exophthalmos is caused by any decrease in the size of bony orbit or occurrence of mass within the rigid orbit, the accurate diagnosis of its causes are essential in determining the therapeutic aims. Exophthalmos is one of the important signs being the indication for orbital computed tomography along with periorbital swelling, visual loss, orbital trauma and diplopia. CT as the diagnostic tool for the cause of exophthalmos not only displays a superb role with uncomparable quality in comparison to any conventional diagnostic methods but also has a decisive role in determining the therapeutic aims and the appropriate operative method when the operation is indicated. The orbital CT was performed from May in 1983 to May in 1985 whose with chief complaints were exophthalmos and 23 cases were confirmed by operation, biopsy, clinical progression or other diagnostic procedures. Here was report thoroughly analyzed 23 cases. The results were as follows : 1. The etiologic disease of exophthalmos were 6 cases of pseudotumor, 4 cases of thyroid ophthalmopathy, 4 cases of maxill ary sinus and nasal cavity Ca., 3 cases of mucocele and 1 case of alveolar soft part sarcoma, osteoma, dermoid cyst, pleomorphic adenoma, meningioma, and C.C.F. each. 2. The origin of the etiologic diseases of exophthalmos were 13 cases of primary within bony orbit and 10 cases of secondary from adjacent structure. 3. The site of lesions were 11 cases of intraconal and extraconal, 10 cases of extraconal, and 2 cases of intraconal origin. 4. The degree of exophthalmos in CT scan was in proportion to the volume of the mass except in the case of thyroid ophthalmopathy. The upper limit of normal range by CT scan using regression line equation was 16.2 mm in approximation. 5. CT was a very useful diagnostic tool in the accurate assessment of the kinds of lesion, its location, and its relationship to adjacent structures in the diagnosis of etiologic diseases of exophthalmos.

  5. Iterative Reconstruction for Cardiopulmonary Computed Tomography

    NARCIS (Netherlands)

    Willemink, M.J.

    2015-01-01

    Introduction The number of computed tomography (CT) examinations has increased rapidly since CT became commercially available. This resulted in growing concerns regarding the risk of malignancies induced by application of medical ionizing radiation. Therefore, radiation dose reduction strategies ar

  6. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like ... materials and a metallic taste in his/her mouth that lasts for a few minutes. Occasionally, a ...

  7. Quantitative multi-slice computed tomography assessment of the mitral valvular complex for transcatheter mitral valve interventions part 1: systematic measurement methodology and inter-observer variability.

    Science.gov (United States)

    Thériault-Lauzier, Pascal; Mylotte, Darren; Dorfmeister, Magdalena; Spaziano, Marco; Andalib, Ali; Mamane, Samuel; Chetrit, Michael; Blanke, Philipp; Cecere, Renzo; Buithieu, Jean; Martucci, Giuseppe; Tchetche, Didier; Modine, Thomas; van Mieghem, Nicolas; Lange, Rüdiger; Windecker, Stephan; Bilodeau, Luc; Leipsic, Jonathon; Piazza, Nicolo

    2016-10-10

    Transcatheter mitral valve replacement (TMVR) is an emerging technology with the potential to treat patients with severe mitral regurgitation at excessive risk for surgical mitral valve surgery. Multimodality imaging of the mitral valvular complex and surrounding structures will be an important component for patient selection for TMVR. Our aim was to describe and evaluate a systematic multi-slice computed tomography (MSCT) image analysis methodology that provides measurements relevant for transcatheter mitral valve replacement. A systematic step-by-step measurement methodology is described for structures of the mitral valvular complex including: the mitral valve annulus, left ventricle, left atrium, papillary muscles and left ventricular outflow tract. To evaluate reproducibility, two observers applied this methodology to a retrospective series of 49 cardiac MSCT scans in patients with heart failure and significant mitral regurgitation. For each of 25 geometrical metrics, we evaluated inter-observer difference and intra-class correlation. The inter-observer difference was below 10% and the intra-class correlation was above 0.81 for measurements of critical importance in the sizing of TMVR devices: the mitral valve annulus diameters, area, perimeter, the inter-trigone distance, and the aorto-mitral angle. MSCT can provide measurements that are important for patient selection and sizing of TMVR devices. These measurements have excellent inter-observer reproducibility in patients with functional mitral regurgitation.

  8. Quantitative and qualitative comparison of standard-dose and low-dose pediatric head computed tomography: a retrospective study assessing the effect of adaptive statistical iterative reconstruction.

    Science.gov (United States)

    Kilic, Koray; Erbas, Gonca; Guryildirim, Melike; Konus, Oznur Leman; Arac, Mehmet; Ilgit, Erhan; Isik, Sedat

    2013-01-01

    Our aim was to assess the effect of adaptive statistical iterative reconstruction (ASIR) on pediatric head computed tomography (CT) examinations. We retrospectively reviewed 305 pediatric head CT examinations. The study population consisted of standard dose (STD, n = 152) examinations reconstructed with filtered back projection and low dose (LD, n = 153) examinations reconstructed with 30% (LD30) and 0% (LD0) ASIR. We compared groups by means of radiation dose, noise measures, and visual grading. Student t test, 1-way analysis of variance test, and Mann-Whitney U test were used for statistical analysis. The dose in the LD30 group was significantly lower (29%) than that in the STD group (P < 0.001). The noise in the white matter (P < 0.001), SNR (P < 0.001), and subjective image noise (P = 0.044) was significantly better in the STD group than those in the LD30 group. There was no significant difference between LD30 and STD groups in the sharpness (P = 0.141), diagnostic acceptability (P = 0.079), and artifacts (P = 0.750) and contrast-to-noise ratio (P = 0.718). In conclusion, we found that a blend of 30% ASIR in a 16-slice multidetector CT produces diagnostically acceptable pediatric head CT examinations with a 29% less dose.

  9. Computed tomography in abnormalities of the hip

    Energy Technology Data Exchange (ETDEWEB)

    Visser, J.D.; Jonkers, A.; Klasen, H.J. (Rijksuniversiteit Groningen (Netherlands). Academisch Ziekenhuis); Hillen, B. (Rijksuniversiteit Groningen (Netherlands). Lab. voor Anatomie en Embryologie)

    1982-06-26

    The value of computed tomography in the assessment of abnormalities of the hip is demonstrated with the aid of an anatomical preparation and in patients with, respectively, congenital dislocation of a hip, dislocation of the hip in spina bifida, an acetabular fracture and a Ewing tumour. The anteversion of the acetabulum and femur and the instability index of the hip joint can be measured by means of computed tomography.

  10. Examination of weld defects by computed tomography

    Directory of Open Access Journals (Sweden)

    M. Jovanović

    2012-04-01

    Full Text Available Defects in metal arc gas (MAG welds made in S235JR low carbon steel of 6 mm thickness were examined. A sample containing lack of fusion (LOF and pores was examined by computed tomography – CT. The computed tomography examination was performed in order to define LOF size and position as well as dimensions and distribution of accompanying pores in the weld metal.

  11. Single photon emission computed tomography/computed tomography of the skull in malignant otitis externa.

    Science.gov (United States)

    Chakraborty, Dhritiman; Bhattacharya, Anish; Kamaleshwaran, Koramadai Karuppusamy; Agrawal, Kanhaiyalal; Gupta, Ashok Kumar; Mittal, Bhagwant Rai

    2012-01-01

    Malignant otitis externa is a severe, rare infective condition of the external auditory canal and skull base. The diagnosis is generally made from a range of clinical, laboratory, and imaging findings. Technetium 99m methylene diphosphonate bone scintigraphy is known to detect osteomyelitis earlier than computed tomography. The authors present a patient with bilateral malignant otitis externa where the extent of skull base involvement was determined on 3-phase bone scintigraphy with single photon emission computed tomography/computed tomography.

  12. Quantitative computation of RHEED patterns

    Science.gov (United States)

    Lordi, Scott Andrew

    This thesis is concerned with the general problem of performing quantitative RHEED computations for both flat and rough surfaces using the multislice method. Modifications to the RHEED multislice method which make it into a practical technique for performing RHEED computations are described. Computation of convergent-beam RHEED patterns using the RHEED multislice method is demonstrated by application to the case of MgO (001). Computed patterns are compared (based on the overall pattern geometry) to energy-filtered Tanaka and convergent-beam patterns recorded in a transmission electron microscope. The validity of the RHEED multislice method for convergent-beam computations is demonstrated by the level of agreement achieved. The application of the RHEED multislice method combined with the edge patching algorithm to the computation of RHEED streaks from rough surfaces is demonstrated by applying it to the case of rough Fe (001) surfaces. The computations are done using the column approximation and by neglecting the scattering from steps parallel to the incident beam. The computations are set up using STM images of the surfaces from which the experimental RHEED patterns were recorded. The shapes of the diffuse parts of the computed and experimental streaks agree well. There is a discrepancy between experiment and theory in the magnitudes of the flat surface spot position peaks relative to the diffuse parts of the streaks. The shapes of the diffuse parts of the computed streaks are shown to be insensitive to the computational and potential parameters. The magnitudes of the flat surface spot position peaks are at least weakly dependent on the potential parameters and the long range height variations of the surface. This agreement conclusively demonstrates that the RHEED multislice method can be used to perform quantitative computations of RHEED streaks from real rough surfaces. An approximation method (the patchwork approximation) for doing RHEED computations, exact in

  13. Computed Tomography evaluation of maxillofacial injuries

    Directory of Open Access Journals (Sweden)

    V Natraj Prasad

    2017-01-01

    Full Text Available Background & Objectives: The maxillofacial region, a complex anatomical structure, can be evaluated by conventional (plain films, Tomography, Multidetector Computed Tomography, Three-Dimensional Computed Tomography, Orthopantomogram and Magnetic Resonance Imaging. The study was conducted with objective of describing various forms of maxillofacial injuries, imaging features of different types of maxillofacial fractures and the advantage of using Three- Dimensional Computed Tomography reconstructed image. Materials & Methods: A hospital based cross-sectional study was conducted among 50 patients during April 2014 to September 2016 using Toshiba Aquilion Prime 160 slice Multi Detector Computed Tomography scanner.Results: The maxillofacial fractures were significantly higher in male population (88% than female population (12 %. Road traffic accidents were the most common cause of injury others being physical assault and fall from height. It was most common in 31-40 years (26% and 21-30 (24% years age group. Maxillary sinus was the commonest fracture (36% followed by nasal bone and zygomatic bone (30%, mandible and orbital bones (28%. Soft tissue swelling was the commonest associated finding. Three dimensional images (3 D compared to the axial scans missed some fractures. However, the extension of the complex fracture lines and degree of displacement were more accurately assessed. Complex fractures found were Le fort (6% and naso-orbito-ethmoid (4% fractures.Conclusion: The proper evaluation of complex anatomy of the facial bones requires Multidetector Computed Tomography which offers excellent spatial resolution enabling multiplanar reformations and three dimensional reconstructions for enhanced diagnostic accuracy and surgical planning.

  14. Whole tumour quantitative measurement of first-pass perfusion of oesophageal squamous cell carcinoma using 64-row multidetector computed tomography: Correlation with microvessel density

    Energy Technology Data Exchange (ETDEWEB)

    Chen Tianwu, E-mail: twchenscu@yahoo.com.cn [Department of Radiology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); Sichuan Province Key Laboratory of Medical Imaging, and Department of Radiology, Affiliated Hospital of North Sichuan Medical College, 63 Wen Hua Lu, Nanchong, Sichuan 637007 (China); Yang Zhigang, E-mail: yangzg6666@yahoo.com.cn [Department of Radiology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); Wang Qiling, E-mail: xiaohongmao99@126.com [Department of Radiology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); Li Yuan, E-mail: dr.liyuan@163.com [Department of Radiology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); Qian Lingling, E-mail: moneylinglingch1999@126.com [Department of Radiology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); Chen Huijiao, E-mail: joan-ch@sohu.com [Department of Pathology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China)

    2011-08-15

    Purpose: To assess correlations between whole tumour first-pass perfusion parameters obtained with 64-row multidetector computed tomography (MDCT), and microvessel density (MVD) in oesophageal squamous cell carcinoma. Materials and Methods: Thirty-one consecutive patients with surgically confirmed oesophageal squamous cell carcinomas were enrolled into our study. All the patients underwent whole tumour first-pass perfusion scan with 64-row MDCT. Perfusion parameters, including perfusion (PF), peak enhanced density (PED), blood volume (BV), and time to peak (TTP) were measured using Philips perfusion software. Postoperative tumour specimens were assessed for MVD. Pearson correlation coefficient tests were performed to determine correlations between each perfusion parameter and MVD. Results: Mean values for PF, PED, BV and TTP of the whole tumour were 28.85 {+-} 20.29 ml/min/ml, 23.16 {+-} 8.09 HU, 12.13 {+-} 5.21 ml/100 g, and 35.05 {+-} 13.85 s, respectively. Mean MVD in whole tumour at magnification (x200) was 15.75 {+-} 4.34 microvessel/tumour sample (vessels/0.723 mm{sup 2}). PED and BV were correlated with MVD (r = 0.651 and r = 0.977, respectively, all p < 0.05). However, PF and TTP were not correlated with MVD (r = 0.070 and r = 0.100, respectively, all p > 0.05). Conclusion: The BV value of first-pass perfusion CT could reflect MVD in oesophageal squamous cell carcinoma, and can be an indicator for evaluating the tumour angiogenesis.

  15. Quantitative analysis of 3 dimensional volumetry and histogram of thyroid gland on neck computed tomography for patients with Hashimoto's thyroiditis

    Energy Technology Data Exchange (ETDEWEB)

    Nam, In Chul; Lee, Kwang Hwi; Ryu, Ji Hwa; Kim, Ok Hwa; Kim, Seung Ho; Baek, Hye Jin; Lee, Ye Daum; Kim, Tae Nyun; Kim, Mi Kyung [Haeundae Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of); Kim, Seon Jeong [Dept. of Radiology, Myongji Hospital, Seonam University College of Medicine, Goyang (Korea, Republic of); Kim, Sung Mok [Dept. of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2015-12-15

    To analyze three-dimensional (3D) volume and histogram of thyroid gland on neck computed tomography (CT) for patients with Hashimoto's thyroiditis. A total of 121 subjects who underwent neck CT between March 2013 and February 2014 were included in this study. These subjects were divided into the following two groups: 1) control group (n = 76); 2) Hashimoto's thyroiditis group (n = 45). Non-enhanced and contrast-enhanced CT images were obtained. On contrast-enhanced images, the 3D volume of thyroid gland was semi-automatically calculated. On CT histogram, attenuation number, mean, median, standard deviation (SD), and coefficient of variation (CV) of thyroid gland were calculated. These values were compared between the two groups. Total 3D volume of thyroid gland was 14.9 ± 4.8 cm{sup 3} in the control group, which was significantly (p = 0.002) lower than that (19.2 ± 8 cm{sup 3}) in the Hashimoto's thyroiditis group. On CT histogram, the mean, median, SD, and CV of thyroid gland on non-enhanced images were 95.8, 99.3, 21.7, and 0.226, respectively, in the control group and 72.2, 72.6, 19.6, and 0.28 in the Hashimoto's thyroiditis group (p < 0.05). Histogram parameters on contrast-enhanced images were not significantly (p > 0.05) different. Median at cut-off value of 83 revealed the largest Az value (Az: 0.905; 95% confidence interval: 0.837-0.951; sensitivity: 84.4%; specificity: 85.5%). The Hashimoto's thyroiditis group had larger volume but lower CT attenuation number with more prominent parenchymal heterogeneity of thyroid gland than the control group.

  16. Quantitative radiology: automated measurement of polyp volume in computed tomography colonography using Hessian matrix-based shape extraction and volume growing

    Science.gov (United States)

    Epstein, Mark L.; Obara, Piotr R.; Chen, Yisong; Liu, Junchi; Zarshenas, Amin; Makkinejad, Nazanin; Dachman, Abraham H.

    2015-01-01

    Background Current measurement of the single longest dimension of a polyp is subjective and has variations among radiologists. Our purpose was to develop a computerized measurement of polyp volume in computed tomography colonography (CTC). Methods We developed a 3D automated scheme for measuring polyp volume at CTC. Our scheme consisted of segmentation of colon wall to confine polyp segmentation to the colon wall, extraction of a highly polyp-like seed region based on the Hessian matrix, a 3D volume growing technique under the minimum surface expansion criterion for segmentation of polyps, and sub-voxel refinement and surface smoothing for obtaining a smooth polyp surface. Our database consisted of 30 polyp views (15 polyps) in CTC scans from 13 patients. Each patient was scanned in the supine and prone positions. Polyp sizes measured in optical colonoscopy (OC) ranged from 6-18 mm with a mean of 10 mm. A radiologist outlined polyps in each slice and calculated volumes by summation of volumes in each slice. The measurement study was repeated 3 times at least 1 week apart for minimizing a memory effect bias. We used the mean volume of the three studies as “gold standard”. Results Our measurement scheme yielded a mean polyp volume of 0.38 cc (range, 0.15-1.24 cc), whereas a mean “gold standard” manual volume was 0.40 cc (range, 0.15-1.08 cc). The “gold-standard” manual and computer volumetric reached excellent agreement (intra-class correlation coefficient =0.80), with no statistically significant difference [P (F≤f) =0.42]. Conclusions We developed an automated scheme for measuring polyp volume at CTC based on Hessian matrix-based shape extraction and volume growing. Polyp volumes obtained by our automated scheme agreed excellently with “gold standard” manual volumes. Our fully automated scheme can efficiently provide accurate polyp volumes for radiologists; thus, it would help radiologists improve the accuracy and efficiency of polyp volume

  17. Comparison of volumetric bone mineral density in the operated and contralateral knee after anterior cruciate ligament and reconstruction: A 1-year follow-up study using peripheral quantitative computed tomography.

    Science.gov (United States)

    Mündermann, Annegret; Payer, Nina; Felmet, Gernot; Riehle, Hartmut

    2015-12-01

    The purpose of this study was to quantify changes in volumetric bone mineral density (vBMD) in the tibial plateau of the operated and contralateral leg measured using peripheral quantitative computed tomography (pQCT) before and 3, 6, and 12 months after anterior cruciate ligament (ACL) reconstruction. The ACL was reconstructed with a hamstring tendon autograft using press-fit fixation. pQCT measurements of the proximal tibia were obtained in 61 patients after ACL reconstruction, and total, cortical, and trabecular vBMD were calculated. vBMD in the operated leg decreased from baseline to 3 months (-12% [total], -11% [cortical], and -12.6% [trabecular]; preconstruction contributed to loss in bone mineral density within the first year after surgery. The role of factors such as time of weight-bearing, joint mechanics, post-traumatic inflammatory reactions, or genetic predisposition in modulating the development of posttraumatic knee osteoarthritis after ACL injury should be further elucidated.

  18. Visualization of simulated small vessels on computed tomography using a model-based iterative reconstruction technique

    Directory of Open Access Journals (Sweden)

    Toru Higaki

    2017-08-01

    Full Text Available This article describes a quantitative evaluation of visualizing small vessels using several image reconstruction methods in computed tomography. Simulated vessels with diameters of 1–6 mm made by 3D printer was scanned using 320-row detector computed tomography (CT. Hybrid iterative reconstruction (hybrid IR and model-based iterative reconstruction (MBIR were performed for the image reconstruction.

  19. Proton computed tomography images with algebraic reconstruction

    Science.gov (United States)

    Bruzzi, M.; Civinini, C.; Scaringella, M.; Bonanno, D.; Brianzi, M.; Carpinelli, M.; Cirrone, G. A. P.; Cuttone, G.; Presti, D. Lo; Maccioni, G.; Pallotta, S.; Randazzo, N.; Romano, F.; Sipala, V.; Talamonti, C.; Vanzi, E.

    2017-02-01

    A prototype of proton Computed Tomography (pCT) system for hadron-therapy has been manufactured and tested in a 175 MeV proton beam with a non-homogeneous phantom designed to simulate high-contrast material. BI-SART reconstruction algorithms have been implemented with GPU parallelism, taking into account of most likely paths of protons in matter. Reconstructed tomography images with density resolutions r.m.s. down to 1% and spatial resolutions CT in hadron-therapy.

  20. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... a gantry, which rotates around the patient. The computer that processes the imaging information and monitor are ...

  1. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... a gantry, which rotates around the patient. The computer that processes the imaging information and monitor are ...

  2. Computed tomography versus invasive coronary angiography

    DEFF Research Database (Denmark)

    Napp, Adriane E; Haase, Robert; Laule, Michael

    2017-01-01

    OBJECTIVES: More than 3.5 million invasive coronary angiographies (ICA) are performed in Europe annually. Approximately 2 million of these invasive procedures might be reduced by noninvasive tests because no coronary intervention is performed. Computed tomography (CT) is the most accurate noninva...... angiography (ICA) is the reference standard for detection of CAD. • Noninvasive computed tomography angiography excludes CAD with high sensitivity. • CT may effectively reduce the approximately 2 million negative ICAs in Europe. • DISCHARGE addresses this hypothesis in patients with low...

  3. Quantitative analyses of maxillary sinus using computed tomography Análise quantitativa dos seios maxilares por meio da tomografia computadorizada

    Directory of Open Access Journals (Sweden)

    Andréia Perella

    2003-09-01

    Full Text Available The aim of this study was to evaluate the precision and accuracy of linear measurements of maxillary sinus made in tomographic films, by comparing with 3D reconstructed images. Linear measurements of both maxillary sinus in computed tomography CT of 17 patients, with or without lesion by two calibrated examiners independently, on two occasions, with a single manual caliper. A third examiner has done the same measurements electronically in 3D-CT reconstruction. The statistical analysis was performed using ANOVA (analyses of variance. Intra-observer percentage error was little in both cases, with and without lesion; it ranged from 1.14% to 1.82%. The inter-observer error was a little higher reaching a 2.08% value. The accuracy presented a higher value. The perceptual accuracy error was higher in samples, which had lesion compared to that which had not. CT had provided adequate precision and accuracy for maxillary sinus analyses. The precision in cases with lesion was considered inferior when compared to that without lesion, but it can't affect the method efficacy.O objetivo deste trabalho foi avaliar a precisão e acurácia de medidas lineares da região de seio maxilar realizadas em filmes tomográficos, por meio de comparação com a reconstrução da imagem em 3D. Medidas lineares de ambos os seios maxilares foram realizadas em tomografias computadorizadas (2D-TC de 17 pacientes, normais e com lesão, por dois examinadores, calibrados, separadamente, duas vezes cada um, utilizando um compasso. Um terceiro observador realizou as mesmas medidas eletronicamente na reconstrução 3D-TC. ANOVA (análise de variância foi utilizado para análise estatística. A porcentagem de erro intra-examinadores foi pequena em ambos os casos, com ou sem lesão, variando de 1,14% a 1,82%. O erro inter-examinadores foi maior alcançando o valor de 2,08% .O erro percentual de acurácia nas amostras com lesão foram maiores comparando-as às que não tinham lesão. A

  4. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... which are then displayed on a monitor. Special software can also generate three-dimensional (3-D) images ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ...

  5. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... which are then displayed on a monitor. Special software can also generate three-dimensional (3-D) images ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ...

  6. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... through the body, recording an image on photographic film or a special image recording plate . Bones appear ...

  7. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... images can be viewed on a computer monitor, printed on film or transferred to a CD or ... of the machine, the x-ray tube and electronic x-ray detectors are located opposite each other ...

  8. Paradoxical emboli: demonstration using helical computed tomography of the pulmonary artery associated with abdominal computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Delalu, P.; Ferretti, G.R.; Bricault, I.; Ayanian, D.; Coulomb, M. [Service Central de Radiologie et Imagerie Medicale, CHU Grenoble (France)

    2000-02-01

    We report the case of a 60-year-old woman with a recent history of a cerebrovascular accident. Because of clinical suspicion of pulmonary embolism and negative Doppler ultrasound findings of the lower limbs, spiral computed tomography of the pulmonary artery was performed and demonstrated pulmonary emboli. We emphasize the role of computed tomography of the abdomen, performed 3 min after the thoracic acquisition, which showed an unsuspected thrombus within the abdominal aorta and the left renal artery with infarction of the left kidney. Paradoxical embolism was highly suspected on computed tomography data and confirmed by echocardiography which demonstrated a patent foramen ovale. (orig.)

  9. Multi-institutional Quantitative Evaluation and Clinical Validation of Smart Probabilistic Image Contouring Engine (SPICE) Autosegmentation of Target Structures and Normal Tissues on Computer Tomography Images in the Head and Neck, Thorax, Liver, and Male Pelvis Areas

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Mingyao [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States); Bzdusek, Karl [Philips Healthcare, Fitchburg, Wisconsin (United States); Brink, Carsten [Institute of Clinical Research, University of Southern Denmark, Odense (Denmark); Laboratory of Radiation Physics, Odense University Hospital, Odense (Denmark); Eriksen, Jesper Grau [Department of Oncology, Odense University Hospital, Odense (Denmark); Hansen, Olfred [Institute of Clinical Research, University of Southern Denmark, Odense (Denmark); Department of Oncology, Odense University Hospital, Odense (Denmark); Jensen, Helle Anita [Department of Oncology, Odense University Hospital, Odense (Denmark); Gay, Hiram A.; Thorstad, Wade [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States); Widder, Joachim; Brouwer, Charlotte L.; Steenbakkers, Roel J.H.M.; Vanhauten, Hubertus A.M. [Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Cao, Jeffrey Q.; McBrayne, Gail [London Regional Cancer Centre, Ontario (Canada); Patel, Salil H. [Department of Radiation Oncology, Rhode Island Hospital, Providence, Rhode Island (United States); Cannon, Donald M. [Department of Human Oncology, University of Wisconsin—Madison (United States); Hardcastle, Nicholas [Department of Physical Science, Peter MacCallum Cancer Centre, Melbourne (Australia); Tomé, Wolfgang A. [Montefiore Medical Center and Institute of Onco-Physics, Albert Einstein College of Medicine, Bronx, New York (United States); Guckenberg, Matthias [University of Würzburg, Department of Radiation Oncology, Würzburg (Germany); Parikh, Parag J., E-mail: pparikh@radonc.wustl.edu [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States)

    2013-11-15

    Purpose: Clinical validation and quantitative evaluation of computed tomography (CT) image autosegmentation using Smart Probabilistic Image Contouring Engine (SPICE). Methods and Materials: CT images of 125 treated patients (32 head and neck [HN], 40 thorax, 23 liver, and 30 prostate) in 7 independent institutions were autosegmented using SPICE and computational times were recorded. The number of structures autocontoured were 25 for the HN, 7 for the thorax, 3 for the liver, and 6 for the male pelvis regions. Using the clinical contours as reference, autocontours of 22 selected structures were quantitatively evaluated using Dice Similarity Coefficient (DSC) and Mean Slice-wise Hausdorff Distance (MSHD). All 40 autocontours were evaluated by a radiation oncologist from the institution that treated the patients. Results: The mean computational times to autosegment all the structures using SPICE were 3.1 to 11.1 minutes per patient. For the HN region, the mean DSC was >0.70 for all evaluated structures, and the MSHD ranged from 3.2 to 10.0 mm. For the thorax region, the mean DSC was 0.95 for the lungs and 0.90 for the heart, and the MSHD ranged from 2.8 to 12.8 mm. For the liver region, the mean DSC was >0.92 for all structures, and the MSHD ranged from 5.2 to 15.9 mm. For the male pelvis region, the mean DSC was >0.76 for all structures, and the MSHD ranged from 4.8 to 10.5 mm. Out of the 40 autocontoured structures reviews by experts, 25 were scored useful as autocontoured or with minor edits for at least 90% of the patients and 33 were scored useful autocontoured or with minor edits for at least 80% of the patients. Conclusions: Compared with manual contouring, autosegmentation using SPICE for the HN, thorax, liver, and male pelvis regions is efficient and shows significant promise for clinical utility.

  10. Cervical diplomyelia revealed by computed tomography (CT)

    Energy Technology Data Exchange (ETDEWEB)

    Giordano, G.B.; Davidovits, P.; Cerisoli, M.; Giulioni, M.

    1982-05-01

    An unusual case of cervical diplomyelia diagnosed by Computed Tomography (CT) is reported. The usefulness of CT examination in the evaluation of spinal dysraphic defects is emphasized, though performed without CSF enhancement. Visualisation of spinal cord splitting in the absence of bony spicula allows the authors to differentiate between diplomyelia and diastematomyelia which have been often described by using both terms interchangeably.

  11. Computed tomography demonstration of cholecystogastric fistula

    Directory of Open Access Journals (Sweden)

    Chung Kuao Chou, MD, MPH

    2016-06-01

    Full Text Available Cholecystogastric fistula is a rare complication of chronic cholecystitis or long-standing cholelithiasis. It results from the gradual erosion of the approximated, chronically inflamed wall of the gall bladder and stomach with fistulous tract formation. The present case describes the direct visualization of a cholecystogastric fistula by computed tomography in a patient without prior biliary system complaints.

  12. Computed tomography in untreated congenital adrenal hyperplasia

    Energy Technology Data Exchange (ETDEWEB)

    Harinarayana, C.V.; Renu, G.; Ammini, A.C.; Khurana, M.L.; Ved, P.; Karmarkar, M.G.; Ahuja, M.M.S.; Berry, M. (AIIMS, New Delhi (India))

    1991-02-01

    Six children with untreated congenital adrenal hyperplasia (CAH) were examined by computed tomography (CT). Three cases demonstrated diffuse enlargement of both adrenal glands with preservation of normal configuration and two showed tumorous transformation in one of the enlarged glands. One had equivocal in this group (age 2 years) also showed bilateral hyperplasia. (orig.).

  13. Cone beam computed tomography in veterinary dentistry

    NARCIS (Netherlands)

    van Thielen, B.; Siguenza, F.; Hassan, B.

    2012-01-01

    The purpose of this study was to assess the feasibility of cone beam computed tomography (CBCT) in imaging dogs and cats for diagnostic dental veterinary applications. CBCT scans of heads of six dogs and two cats were made. Dental panoramic and multi-planar reformatted (MPR) para-sagittal reconstruc

  14. Cone beam computed tomography in veterinary dentistry

    NARCIS (Netherlands)

    van Thielen, B.; Siguenza, F.; Hassan, B.

    2012-01-01

    The purpose of this study was to assess the feasibility of cone beam computed tomography (CBCT) in imaging dogs and cats for diagnostic dental veterinary applications. CBCT scans of heads of six dogs and two cats were made. Dental panoramic and multi-planar reformatted (MPR) para-sagittal reconstruc

  15. Neutron computed tomography of rat lungs

    Energy Technology Data Exchange (ETDEWEB)

    Metzke, R W; Wall, W A [Institute for Computational Mechanics at Technische Universitaet Muenchen, 85747 Garching (Germany); Runck, H; Stahl, C A; Schneider, M; Guttmann, J [Department of Anesthesiology, Section for Experimental Anesthesiology, University Medical Center Freiburg, 79106 Freiburg (Germany); Schillinger, B; Calzada, E; Muehlbauer, M; Schulz, M [Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM-II) and Fakultaet fuer Physik E21 at Technische Universitaet Muenchen, 85748 Garching (Germany); Priebe, H-J, E-mail: metzke@lnm.mw.tum.d [Department of Anesthesiology, University Medical Center Freiburg, 79106 Freiburg (Germany)

    2011-01-07

    Using conventional methods, three-dimensional imaging of the lung is challenging because of the low contrast between air and tissue and the large differences in dimensions between various pulmonary structures. The small distal airway structures and the high air-to-tissue ratio of lung tissue require an imaging technique which reliably discriminates between air and water. The objective of this study was to assess whether neutron computed tomography would satisfy such a requirement. This method utilizes the unique characteristic of neutrons of directly interacting with the atomic nucleus rather than being scattered by the atomic shell. Neutron computed tomography was tested in rats and allowed differentiation of larger lung structures (e.g., lobes) and distal airways. Airways could be identified reliably down to the sixth bronchial generation, in some cases even down to the tenth generation. The lung could be stabilized for sufficiently long exposure times to achieve an image resolution of 50-60 {mu}m, which is the current physical resolution limit of the neutron computed tomography facility. Neutron computed tomography allowed excellent lung imaging without the need for additional tissue preparation or contrast media. The enhanced structural resolution obtained by applying this new research technique may improve understanding of lung physiology and respiratory therapy. (note)

  16. Parallel Computing for the Computed-Tomography Imaging Spectrometer

    Science.gov (United States)

    Lee, Seungwon

    2008-01-01

    This software computes the tomographic reconstruction of spatial-spectral data from raw detector images of the Computed-Tomography Imaging Spectrometer (CTIS), which enables transient-level, multi-spectral imaging by capturing spatial and spectral information in a single snapshot.

  17. Computed tomography of tuberculous meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Noriko; Sato, Hiromi; Kawaguchi, Tetsuro; Fujita, Katsuzo; Tanaka, Makoto (Kobe Univ. (Japan). School of Medicine)

    1982-12-01

    Recently, tuberculous meningitis has become rather rare except in areas where tuberculosis is still endemic. Six adolescents and young adults with tuberculous meningitis were evaluated by means of serial computerized tomography (CT), and the results were correlated with the findings of surgical specimens or autopsies. All cases showed meningeal irritation and fever at onset. CSF cultures revealed the presence of tuberculous bacilli. Four cases advanced rapidly to the clinical stage III and expired in a short period-between two weeks to one month from onset. On initial CT scanning, the disappearance of the basal cistern was a characteristic finding in all these cases. With the progression, an enhancement of the basal cistern on contrast injection, a localized hypodensity in adjacent parenchyma, and symmetrical ventricular dilatation appeared. Two autopsied cases showed tuberculous granulomas with purulent materials, thickened meninges, and caseous necrosis in the parenchyma around the basal cistern. The other two cases progressed rather slowly. CT findings at Stage II showed multiple enhanced spots in the basal subcortical area following contrast injection. Tuberculous granulomas were identified in these parts by means of explorative craniotomy. The authors point out the pathognomonic CT findings of tuberculous meningitis and emphasize the necessity of serial CT for the early detection and management of tuberculous meningitis.

  18. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... detectors rotate around the patient. At the same time, the examination table is moving through the scanner, so that the x-ray beam follows a spiral path. A special computer program processes this series of pictures, or slices of the body, to ...

  19. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ...

  20. Single photon emission computed tomography/computed tomography for malignant otitis externa: lesion not shown on planar image.

    Science.gov (United States)

    Chen, Yu-Hung; Hsieh, Hung-Jen

    2013-01-01

    Malignant otitis externa is a severe and rare infection of the external acoustic meatus. Triphasic bone and (67)Ga scintigraphies are used to initial detect and follow-up the response of therapy. With single photon emission computed tomography/computed tomography images, the diagnostic sensitivity is higher. We presented a case with malignant otitis externa with initial negative planar scintigraphic finding. The lesion was detected by photon emission computed tomography/computed tomography images. We concluded that the photon emission computed tomography/computed tomography should be performed routinely for patients with suspected malignant otitis externa, even without evidence of lesion on planar images.

  1. Thermoluminescent dosimetry in computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lara C, A.; Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria, Av. Legaria 694, Col. Irrigacion, 11500 Ciudad de Mexico (Mexico); Osorio V, M. [ISSSTE, Centro Medico Nacional 20 de Noviembre, Felix Cuevas 540, Col. del Valle, 03100 Ciudad de Mexico (Mexico); Hernandez O, O., E-mail: armando_lara_cam@yahoo.com.mx [Hospital General de Mexico, Dr. Balmis 148, Col. Doctores, 06726 Ciudad de Mexico (Mexico)

    2016-10-15

    In this work we studied the dosimetry performed on CT scan in two different equipment, SOMATOM and Phillips, with 16 and 64 slice respectively. We used 51 pellets of lithium fluoride doped with magnesium and titanium (LiF: Mg, Ti) also knows as TLD-100 due to its physical properties and its easy of use, in this study, first analysis a batch of 56 pellets, but only 53 pellets were optimal for this study, cesium-137 was used as source irradiation, then proceeded to calibrate the batch with X-rays source, measuring the corresponding dose in a Farmers ionization chamber, then, we obtained a calibration curve, and we used as reference to calculation of the applied dose, finally designing ergonomic mesh, were it was deposited a TLD 100, placed in a regions of interest were made to each scan type. Once characterized our material proceeded to testing in 30 patients, which were irradiated with X-ray tube, whose operation was performed at 80, 120 kV with a current of 100, 300 and 400 m A according to scanning protocol. Overall we measured dose of 5 mGy to 53 mGy, these measurements reflect significant dose to can induced cancer, due previous reports published, that doses greater than 20 mGy there is a risk of developing cancer in the long term, but in practice when it assigned a medical diagnosis, there are no dose limits due to benefits patients, however, IAEA publish recommendations that allow us to carry out optimum handling of ionizing radiation, among these is the quality control of the tomography equipment that helps greatly reduce patient dose. (Author)

  2. Computed tomography of the spine

    Energy Technology Data Exchange (ETDEWEB)

    Haughton, V.M.; Williams, A.L.

    1982-01-01

    The book describes the computed tomographic (CT) techniques for imaging the different elements comprising the spinal column and canal. The use of intravenous and intrathecal contrast enhancement and of xenon enhancement is briefly mentioned. Reconstruction techniques and special problems regarding CT of the spine are presented. CT of the spinal cord, meninges and subarachnoid space, epidural space, intervertebral discs, facet joints, and vertebrae present normal anatomy, and several common pathologic conditions. (KRM)

  3. Computed tomography in mitochondrial cytopathy

    Energy Technology Data Exchange (ETDEWEB)

    Egger, J.; Kendall, B.E.

    1981-10-01

    The clinical and computed tomographic (CT) findings in 11 proven cases of mitochondrial cytopathy (mitochondrial myopathy, Kearns Sayre syndrome, ophthalmoplegia plus) were studied. The CT changes included focal low density lesions in the basal ganglia and white matter and atrophy which could be slight or diffuse and severe. Calcification has been described in the basal ganglia, but did not occur in our series. Serial CT showed progression of the abnormalities. The differential diagnosis is discussed.

  4. Computed tomography of thymic abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Schnyder, P.; Candardjis, G.

    1987-05-01

    Computed tomographic examinations of 38 patients with surgically and histologically proven diagnosis were reviewed. Twenty subjects (52%) had an invasive thymoma and 16% an hyperplastic thymus. Myasthenia gravis was present in 6 cases (16%) of thymic abnormalities, four (10,5%) with invasive thymoma and two (5%) with thymic hyperplasia. Graves' disease was also present in one case of thymic hyperplasia. We emphasize the contribution of CT to the diagnosis and the prognosis.

  5. Cerebral candidiasis. Computed tomography appearance

    Energy Technology Data Exchange (ETDEWEB)

    Chaabane, M.; Ladeb, M.F.; Bouhaouala, M.H.; Ben Hammouda, M.; Ataalah, R.; Gannouni, A.; Krifa, H.

    1989-07-01

    A three year old child who had been suffering from oral candidiasis since the age of 1 year presented with osteitis of the clavicle, 2 cerebral frontal abscesses and an occipital abscess which extended across the calvaria and was associated with osteolysis. Histological and microbiological studies following surgery confirmed the diagnosis of candidiasis in this girl who was found to have IgA immunodefinciency. The authors report the computed tomographic appearance of the cerebral lesions and review the literature. (orig.).

  6. Trip report: Marshall Space Center computed tomography

    Science.gov (United States)

    Harbour, J. R.; Andrews, M. K.

    BIR Inc. is a small company out of the Chicago area which sells equipment for producing images by tomography. They have built a relatively large instrument, called ACTIS, for NASA at the Marshall Space Center in Huntsville, Alabama and still gave access to this instrument. BIR has a grant from the Department of Energy (DOE) to determine the utility of computed tomography (CT) for characterization of nuclear and hazardous waste within the DOE complex. As part of this effort, the potential of this technique for obtaining images of canistered waste forms has been investigated. Funding for data acquisition was provided through this grant.

  7. Quantitative computed tomography measurements to evaluate airway disease in chronic obstructive pulmonary disease: Relationship to physiological measurements, clinical index and visual assessment of airway disease.

    Science.gov (United States)

    Nambu, Atsushi; Zach, Jordan; Schroeder, Joyce; Jin, Gongyoung; Kim, Song Soo; Kim, Yu-Il; Schnell, Christina; Bowler, Russell; Lynch, David A

    2016-11-01

    To correlate currently available quantitative CT measurements for airway disease with physiological indices and the body-mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index in patients with chronic obstructive pulmonary disease (COPD). This study was approved by our institutional review board (IRB number 2778). Written informed consent was obtained from all subjects. The subjects included 188 current and former cigarette smokers from the COPDGene cohort who underwent inspiratory and expiratory CT and also had physiological measurements for the evaluation of airflow limitation, including FEF25-75%, airway resistance (Raw), and specific airway conductance (sGaw). The BODE index was used as the index of clinical symptoms. Quantitative CT measures included % low attenuation areas [% voxels≤950 Hounsfield unit (HU) on inspiratory CT, %LAA-950ins], percent gas trapping (% voxels≤-856HU on expiratory CT, %LAA -856exp), relative inspiratory to expiratory volume change of voxels with attenuation values from -856 to -950HU [Relative Volume Change (RVC)-856 to -950], expiratory to inspiratory ratio of mean lung density (E/I-ratio MLD), Pi10, and airway wall thickness (WT), luminal diameter (LD) and airway wall area percent (WA%) in the segmental, subsegmental and subsubsegmental bronchi on inspiratory CT. Correlation coefficients were calculated between the QCT measurements and physiological measurements in all subjects and in the subjects with mild emphysema (%LAA-950ins Quantitative CT measurements had significant correlations with physiological indices. Among them, E/I-ratio MLD had the strongest correlations with FEF25-75% (r=-0.648, Quantitative CT measurements of gas trapping such as E/I-ratio MLD, correlate better with physiological indices for airway disease than those of airway such as WA% or LD. In mild emphysema, however, quantitative CT measurements of airway correlate better with the physiological indices. RVC-856 to -950 is a

  8. Towards quantitative analysis of retinal features in optical coherence tomography.

    Science.gov (United States)

    Baroni, Maurizio; Fortunato, Pina; La Torre, Agostino

    2007-05-01

    The purpose of this paper was to propose a new computer method for quantitative evaluation of representative features of the retina using optical coherence tomography (OCT). A multi-step approach was devised and positively tested for segmentation of the three main retinal layers: the vitreo-retinal interface and the inner and outer retina. Following a preprocessing step, three regions of interest were delimited. Significant peaks corresponding to high and low intensity strips were located along the OCT A-scan lines and accurate boundaries between different layers were obtained by maximizing an edge likelihood function. For a quantitative description, thickness measurement, densitometry, texture and curvature analyses were performed. As a first application, the effect of intravitreal injection of triamcinolone acetonide (IVTA) for the treatment of vitreo-retinal interface syndrome was evaluated. Almost all the parameters, measured on a set of 16 pathologic OCT images, were statistically different before and after IVTA injection (pvitreo-retinal interface and in the inner retinal layers. Texture parameters in the inner and outer retinal layers significantly correlated with the visual acuity restoration. According to these findings an IVTA injection might be considered a possible alternative to surgery for selected patients. In conclusion, the proposed approach appeared to be a promising tool for the investigation of tissue changes produced by pathology and/or therapy.

  9. Introducing Seismic Tomography with Computational Modeling

    Science.gov (United States)

    Neves, R.; Neves, M. L.; Teodoro, V.

    2011-12-01

    Learning seismic tomography principles and techniques involves advanced physical and computational knowledge. In depth learning of such computational skills is a difficult cognitive process that requires a strong background in physics, mathematics and computer programming. The corresponding learning environments and pedagogic methodologies should then involve sets of computational modelling activities with computer software systems which allow students the possibility to improve their mathematical or programming knowledge and simultaneously focus on the learning of seismic wave propagation and inverse theory. To reduce the level of cognitive opacity associated with mathematical or programming knowledge, several computer modelling systems have already been developed (Neves & Teodoro, 2010). Among such systems, Modellus is particularly well suited to achieve this goal because it is a domain general environment for explorative and expressive modelling with the following main advantages: 1) an easy and intuitive creation of mathematical models using just standard mathematical notation; 2) the simultaneous exploration of images, tables, graphs and object animations; 3) the attribution of mathematical properties expressed in the models to animated objects; and finally 4) the computation and display of mathematical quantities obtained from the analysis of images and graphs. Here we describe virtual simulations and educational exercises which enable students an easy grasp of the fundamental of seismic tomography. The simulations make the lecture more interactive and allow students the possibility to overcome their lack of advanced mathematical or programming knowledge and focus on the learning of seismological concepts and processes taking advantage of basic scientific computation methods and tools.

  10. Relationships between diffusing capacity for carbon monoxide (D{sub L}CO), and quantitative computed tomography measurements and visual assessment for chronic obstructive pulmonary disease

    Energy Technology Data Exchange (ETDEWEB)

    Nambu, Atsushi, E-mail: nambu-a@gray.plala.or.jp [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206 (United States); Department of Radiology, Teikyo University Mizonokuchi Hospital (Japan); Zach, Jordan, E-mail: ZachJ@NJHealth.org [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206 (United States); Schroeder, Joyce, E-mail: Joyce.schroeder@stanfordalumni.org [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206 (United States); Jin, Gong Yong, E-mail: gyjin@chonbuk.ac.kr [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206 (United States); Department of Radiology, Chonbuk National University Hospital (Korea, Republic of); Kim, Song Soo, E-mail: haneul88@hanmail.net [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206 (United States); Department of Radiology, Chungnam National Hospital, Chungnam National University School of Medicine (Korea, Republic of); Kim, Yu-IL, E-mail: kyionly@chonnam.ac.kr [Department of Medicine, National Jewish Health, Denver, CO (United States); Department of Internal Medicine, Chonnam National University Hospital, Gwangju (Korea, Republic of); Schnell, Christina, E-mail: SchnellC@NJHealth.org [Department of Medicine, National Jewish Health, Denver, CO (United States); Bowler, Russell, E-mail: BowlerR@NJHealth.org [Division of Pulmonary Medicine, Department of Medicine, National Jewish Health (United States); Lynch, David A., E-mail: LynchD@NJHealth.org [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206 (United States)

    2015-05-15

    Highlights: • Quantitative CT measurements significantly correlated with D{sub L}CO/V{sub A}. • 15{sup th} percentile HU had the strongest correlation with D{sub L}CO/V{sub A}. • Visual scoring of emphysema had independent significant correlations with D{sub L}CO/V{sub A}. - Abstract: Purpose: To evaluate the relationships between D{sub L}CO, and Quantitative CT (QCT) measurements and visual assessment of pulmonary emphysema and to test the relative roles of visual and quantitative assessment of emphysema. Materials and methods: The subjects included 199 current and former cigarette smokers from the COPDGene cohort who underwent inspiratory and expiratory CT and also had diffusing capacity for carbon monoxide corrected for alveolar volume (D{sub L}CO/V{sub A}). Quantitative CT measurements included % low attenuation areas (%LAA−950ins = voxels ≤−950 Hounsfield unit (HU), % LAA{sub −910ins}, and % LAA{sub −856ins}), mean CT attenuation and 15th percentile HU value on inspiratory CT, and %LAA{sub −856exp} (voxels ≤−856 HU on expiratory CT). The extent of emphysema was visually assessed using a 5-point grading system. Univariate and multiple variable linear regression analyses were employed to evaluate the correlations between D{sub L}CO/V{sub A} and QCT parameters and visual extent of emphysema. Results: The D{sub L}CO/V{sub A} correlated most strongly with 15th percentile HU (R{sup 2} = 0.440, p < 0.001) closely followed by % LAA{sub −950ins} (R{sup 2} = 0.417, p < 0.001) and visual extent of emphysema (R{sup 2} = 0.411, p < 0.001). Multiple variable analysis showed that visual extent of emphysema and 15th percentile HU were independent significant predictors of D{sub L}CO/V{sub A} at an R{sup 2} of 0.599. Conclusions: 15th percentile HU seems the best parameter to represent the respiratory condition of COPD. Visual and Quantitative CT assessment of emphysema provide complementary information to QCT analysis.

  11. Computed tomography of bones and joints.

    Science.gov (United States)

    Bruna, J; Sehr, A

    1989-01-01

    The monograph sums up the problem of CT diagnosis of bones and joints making use of predominantly the authors' own experience based on CT tests of more than 45,000 patients examined at the Department of Radiology, Charles University Medical Faculty of Hygiene teaching hospital in Prague in the years 1980-1988. Specific scans of the skeleton were made in 4,500 patients, mostly for suspicion or closer assessment of neoplasms (43.5%), the radicular lumbosacral syndrome (34.5%), and injuries (12%). The opening chapters sum up basic facts about the principle of computed tomography, the apparatus in use, the evaluation of CT images, CT radiation doses, and the patients' preparation for CT scanning. The use of contrast media is discussed with regard to the possible hazards involved and to the need to hear allergological opinion first. For spinal canal visualization non-ionogenic contrast media are used exclusively. The management of side reactions to contrast medium application is also reviewed. Indications for bone and joint computed tomography now comprise a whole series of traumatological, orthopaedic, oncological, rheumatological, neurological and rehabilitation conditions, each of which is discussed in detail in a separate chapter. CT anatomical studies offer the advantage of being applicable even in patients examined for other than bone or articular diseases. The option of simultaneous soft tissue assessment represents another advantage. The authors describe different anatomical structures in terms of CT images, some of them complete with dimensional and density values. The chapter on anomalies and developmental variants stresses the relevance of computed tomography for precise characteristics of clefts of the spinal column and facial bones and for the diagnosis of anomalies and dysplasias of the spinal column and the chest. A rare case of cephalothoracopagus is demonstrated. As for traumatology, computed tomography is found useful in diagnosing fractures of the

  12. [Qualitative and quantitative diagnostic performance of 320-slice computed tomography for detecting coronary artery disease with respect to atherosclerotic plaque characteristics].

    Science.gov (United States)

    Li, Suhua; Liu, Jinlai; Peng, Long; Dong, Ruimin; Wu, Huilan; Wang, Chenlin; Ni, Qiongqiong; Luo, Yanting; Zhu, Jieming; Chen, Lin

    2014-10-28

    To investigate qualitatively and quantitatively the diagnostic performance of 320-slice CT for detection of coronary artery disease with respect to different atherosclerotic plaque characteristics. A retrospective search was performed for inpatients underwent both coronary CT and further coronary angiography (CAG) from December 1, 2008 to December 31, 2012. The diagnostic performance of 320-slice CTA for detecting significant stenosis ( ≥ 50% diameter) with respect to atherosclerotic plaque characteristics were analyzed by calculating sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, kappa index (κ), and area under the receiver operating characteristic curve (AUC). Chi-square test was used to evaluate whether there were significant differences of the true-case frequency (true positive + true negative) and false-case frequency (false positive + false negative) among groups. Bland-Altman analysis was used to determine limits of agreement between CTA and CAG. A total of 454 patients and 6 779 segments were analyzed. Diagnostic accuracy was higher in non-calcified segments; whereas they decreased in the presence of both mild-moderately and heavily calcified plaques. Excellent agreement (κ = 0.810) between CT and CAG was observed for non-calcified segments, while good agreement was observed for both mild-moderately (κ = 0.701) and heavily calcified segments (κ = 0.750). Both mild-moderate (P = 0.000) and heavy (P = 0.000) calcification decreased the true-case frequency and increased the false-case frequency when compared to non-calcification. There were no significant underestimation or overestimation for non-calcified (P = 0.087) and mild-moderately calcified (P = 0.704) segments, while there was significant overestimation for heavily calcified segments (P = 0.001). Great qualitative and quantitative diagnostic performances of 320-slice CT were observed in non-calcified coronary segments. However, qualitative

  13. Quantitative single photon emission computed thallium-201 tomography for detection and localization of coronary artery disease: Optimization and prospective validation of a new technique

    Energy Technology Data Exchange (ETDEWEB)

    Maddahi, J.; Van Train, K.; Prigent, F.; Garcia, E.V.; Friedman, J.; Ostrzega, E.; Berman, D. (Cedars-Sinai Medical Center, Los Angeles, CA (USA))

    1989-12-01

    One hundred eight-three men underwent stress-redistribution thallium-201 myocardial perfusion tomography. After evaluation of various preprocessing filters in a phantom study, the Butterworth filter with a frequency cutoff of 0.2 cycles/pixel, order 5 (which provided optimal filter power) was used in the back projection algorithm of the patient studies. All short-axis and apical portions of vertical long-axis images were quantified by dividing each myocardial slice into 60 equal sectors and displaying the maximal count per sector as a linear profile. In a pilot group consisting of 20 normal men (less than 5% likelihood of coronary artery disease) and 25 men with coronary artery disease (greater than or equal to 50% coronary stenosis by angiography), profiles representing the lowest observed value below the mean normal profiles provided the best threshold for defining normal limits. Abnormal portions of the patient profiles were plotted on a two-dimensional polar map. The polar map was divided into 102 sectors, and sectors with a probability of greater than or equal to 80% for disease of each one of the three major coronary arteries were clustered to represent specific coronary artery territories. Receiver operating characteristic curve analysis for defect size showed that the optimal threshold for defining a definite perfusion defect was 12% for the left anterior descending and left circumflex and 8% for the right coronary artery territories. These criteria were prospectively applied to an additional 92 patients with angiographic coronary artery disease, 18 patients with normal coronary arteriograms and 28 patients with less than 5% likelihood of coronary disease. Sensitivity, specificity and normalcy rate for overall detection of coronary disease were 96%, 56% and 86%, respectively.

  14. Evaluation of the Possibility of Applying Spatial 3D Imaging Using X-Ray Computed Tomography Reconstruction Methods for Quantitative Analysis of Multiphase Materials / Rentgenowska Analiza Ilościowa Materiałów Wielofazowych Z Wykorzystaniem Przestrzennego Obrazowania (3D Przy Użyciu Metod Rekonstrukcji Tomografii Komputerowej

    Directory of Open Access Journals (Sweden)

    Matysik P.

    2015-12-01

    Full Text Available In this paper the possibility of using X-ray computed tomography (CT in quantitative metallographic studies of homogeneous and composite materials is presented. Samples of spheroidal cast iron, Fe-Ti powder mixture compact and epoxy composite reinforced with glass fibers, were subjected to comparative structural tests. Volume fractions of each of the phase structure components were determined by conventional methods with the use of a scanning electron microscopy (SEM and X-ray diffraction (XRD quantitative analysis methods. These results were compared with those obtained by the method of spatial analysis of the reconstructed CT image. Based on the comparative analysis, taking into account the selectivity of data verification methods and the accuracy of the obtained results, the authors conclude that the method of computed tomography is suitable for quantitative analysis of several types of structural materials.

  15. The Western Denmark Cardiac Computed Tomography Registry

    DEFF Research Database (Denmark)

    Nielsen, Lene Hüche; Nørgaard, Bjarne Linde; Tilsted, Hans Henrik;

    2015-01-01

    -CCTR, showed that coronary CT angiographies accounted for only 23% of all nonregistered cardiac CTs, indicating >90% completeness of coronary CT angiographies in the WDHR-CCTR. The completeness of individual variables varied substantially (range: 0%-100%), but was >85% for more than 70% of all variables. Using......BACKGROUND: As a subregistry to the Western Denmark Heart Registry (WDHR), the Western Denmark Cardiac Computed Tomography Registry (WDHR-CCTR) is a clinical database established in 2008 to monitor and improve the quality of cardiac computed tomography (CT) in Western Denmark. OBJECTIVE: We...... expected numbers; and 4) positive predictive values as well as negative predictive values of 19 main patient and procedure variables. RESULTS: By December 31, 2012, almost 22,000 cardiac CTs with up to 40 variables for each procedure have been registered. Of these, 87% were coronary CT angiography...

  16. [Pneumothorax revealed by postoperative computed tomography].

    Science.gov (United States)

    Ikeda, Shizuka; Katori, Kiyoshi; Fujimoto, Minoru; Nitahara, Keiichi; Higa, Kazuo

    2005-11-01

    We report a case of pneumothorax revealed by postoperative computed tomography. A 39-year-old obese woman (height 153 cm, weight 70 kg) with fractures of the radius, ulna, clavicle, and femur in a traffic accident, was scheduled for osteosynthesis. Anesthesia was induced with thiopental and maintained with 50% nitrous oxide in oxygen and sevoflurane. The Spo2 decreased from 99% to 94% during the surgery. Bilateral chest sounds were symmetrical. The Spo2 increased to 100% after discontinuation of nitrous oxide. Pneumothorax was not evident on a postoperative chest X-ray, but computed tomography of the chest demonstrated right-sided pneumothorax. An ECG electrode had overlapped the fractured rib on the preoperative chest X-ray.

  17. Cone beam computed tomography in endodontic

    Energy Technology Data Exchange (ETDEWEB)

    Durack, Conor; Patel, Shanon, E-mail: conordurack1@hotmail.com [Unit of Endodontology, Department of Conservative Dentistry, King' s College London, London (United Kingdom)

    2012-07-01

    Cone beam computed tomography (CBCT) is a contemporary, radiological imaging system designed specifically for use on the maxillofacial skeleton. The system overcomes many of the limitations of conventional radiography by producing undistorted, three-dimensional images of the area under examination. These properties make this form of imaging particularly suitable for use in endodontic. The clinician can obtain an enhanced appreciation of the anatomy being assessed, leading to an improvement in the detection of endodontic disease and resulting in more effective treatment planning. In addition, CBCT operates with a significantly lower effective radiation dose when compared with conventional computed tomography (CT). The purpose of this paper is to review the current literature relating to the limitations and potential applications of CBCT in endodontic practice. (author)

  18. Contrast-induced nephropathy after computed tomography

    Directory of Open Access Journals (Sweden)

    Luciano da Silva Selistre

    2015-03-01

    Full Text Available Introduction: Contrast induced nephropathy is the third most prevalent preventable cause of acute kidney injury in hospitalized patients. It defined as an absolute increase in serum creatinine ≥ 0.5 mg/dL and relative ≥ 25% increase. Objective: We studied the risk factors to intravenous injection contrast nephropathy after computed tomography. Methods: We studied 400 patients prospectively. Results: The incidence of contrast induced nephropathy, with an absolute or a relative increase were 4.0% and 13.9%, respectively. Diabetes and cardiac failure were independent risk factors for CIN a relative increase de serum creatinine (O.R.: 3.5 [95% CI: 1.92-6.36], p < 0.01, 2.61 [95% CI: 1.14-6.03%], p < 0.05, respectively. Conclusions: We showed association between uses of intravenous injection contrast after computed tomography with acute injury renal, notably with diabetes and heart failure.

  19. Cone beam computed tomography in endodontics.

    Science.gov (United States)

    Durack, Conor; Patel, Shanon

    2012-01-01

    Cone beam computed tomography (CBCT) is a contemporary, radiological imaging system designed specifically for use on the maxillo-facial skeleton. The system overcomes many of the limitations of conventional radiography by producing undistorted, three-dimensional images of the area under examination. These properties make this form of imaging particularly suitable for use in endodontics. The clinician can obtain an enhanced appreciation of the anatomy being assessed, leading to an improvement in the detection of endodontic disease and resulting in more effective treatment planning. In addition, CBCT operates with a significantly lower effective radiation dose when compared with conventional computed tomography (CT). The purpose of this paper is to review the current literature relating to the limitations and potential applications of CBCT in endodontic practice.

  20. Myocardial blood flow quantification for evaluation of coronary artery disease by positron emission tomography, cardiac magnetic resonance imaging, and computed tomography.

    Science.gov (United States)

    Waller, Alfonso H; Blankstein, Ron; Kwong, Raymond Y; Di Carli, Marcelo F

    2014-05-01

    The noninvasive detection of the presence and functional significance of coronary artery stenosis is important in the diagnosis, risk assessment, and management of patients with known or suspected coronary artery disease. Quantitative assessment of myocardial perfusion can provide an objective and reproducible estimate of myocardial ischemia and risk prediction. Positron emission tomography, cardiac magnetic resonance, and cardiac computed tomography perfusion are modalities capable of measuring myocardial blood flow and coronary flow reserve. In this review, we will discuss the technical aspects of quantitative myocardial perfusion imaging with positron emission tomography, cardiac magnetic resonance imaging, and computed tomography, and its emerging clinical applications.

  1. Computed tomography of ancient Egyptian mummies.

    Science.gov (United States)

    Harwood-Nash, D C

    1979-12-01

    This first report of the application of computed tomography (CT) to the study of ancient mummies, the desiccated brain of a boy and the body of a young woman within her cartonnage, shows that CT is uniquely suitable for the study of such antiquities, a study that does not necessitate destruction of the mummy or its cartonnage. Exquisite images result that are of great paleoanatomical, paleopathological, and archeological significance.

  2. Computed tomography and obstructive biliary disease.

    Science.gov (United States)

    Havrilla, T R; Haaga, J R; Alfidi, R J; Reich, N E

    1977-05-01

    Forty-four patients with confirmed biliary diseases were studied to determine the value of computed tomography (CT) in the diagnosis of biliary pathology. The results indicate that CT is useful and highly accurate in differentiating between obstructive (surgical) and nonobstructive (medical) disease entities. Of the cases with proved obstruction, 88% were correctly identified. All of the nonobstructive cases had positive CT correlation. In addition, the underlying cause of the occlusion was determined in the majority of cases.

  3. Cone Beam Computed Tomography - Know its Secrets

    OpenAIRE

    Kumar, Mohan; Shanavas, Muhammad; Sidappa, Ashwin; Kiran, Madhu

    2015-01-01

    Cone-beam computed tomography (CBCT) is an advanced imaging modality that has high clinical applications in the field of dentistry. CBCT proved to be a successful investigative modality that has been used for dental and maxillofacial imaging. Radiation exposure dose from CBCT is 10 times less than from conventional CT scans during maxillofacial exposure. Furthermore, CBCT is highly accurate and can provide a three-dimensional volumetric data in axial, sagittal and coronal planes. This article...

  4. Computed Tomography of Transverse Phase Space

    Energy Technology Data Exchange (ETDEWEB)

    Watts, A. [Fermilab; Johnstone, C. [Fermilab; Johnstone, J. [Fermilab

    2016-09-19

    Two computed tomography techniques are explored to reconstruct beam transverse phase space using both simulated beam and multi-wire profile data in the Fermilab Muon Test Area ("MTA") beamline. Both Filtered Back-Projection ("FBP") and Simultaneous Algebraic Reconstruction Technique ("SART") algorithms [2] are considered and compared. Errors and artifacts are compared as a function of each algorithm’s free parameters, and it is shown through simulation and MTA beamline profiles that SART is advantageous for reconstructions with limited profile data.

  5. Cone beam computed tomography use in orthodontics.

    Science.gov (United States)

    Nervina, J M

    2012-03-01

    Cone beam computed tomography (CBCT) is widely used by orthodontists to obtain three-dimensional (3-D) images of their patients. This is of value as malocclusion results from discrepancies in three planes of space. This review tracks the use of CBCT in orthodontics, from its validation as an accurate and reliable tool, to its use in diagnosing and treatment planning, and in assessing treatment outcomes in orthodontics.

  6. Encapsulating peritonitis: computed tomography and surgical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kadow, Juliana Santos; Fingerhut, Carla Jeronimo Peres; Fernandes, Vinicius de Barros; Coradazzi, Klaus Rizk Stuhr; Silva, Lucas Marciel Soares; Penachim, Thiago Jose, E-mail: vinicius.barros.fernandes@gmail.com [Pontificia Universidade Catolica de Campinas (PUC-Campinas), Campinas, SP (Brazil). Hospital e Maternidade Celso Pierro

    2014-07-15

    Sclerosing encapsulating peritonitis is a rare and frequently severe entity characterized by total or partial involvement of small bowel loops by a membrane of fibrous tissue. The disease presents with nonspecific clinical features of intestinal obstruction, requiring precise imaging diagnosis to guide the treatment. The present report emphasizes the importance of computed tomography in the diagnosis of this condition and its confirmation by surgical correlation. (author)

  7. Computed tomography of human joints and radioactive waste drums

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, E; Bernardi, R; Hollerbach, K; Logan, C; Martz, H; Roberson, G P

    1999-06-01

    X- and gamma-ray imaging techniques in nondestructive evaluation (NDE) and assay (NDA) have been increasing use in an array of industrial, environmental, military, and medical applications. Much of this growth in recent years is attributed to the rapid development of computed tomography (CT) and the use of NDE throughout the life-cycle of a product. Two diverse examples of CT are discussed. (1) The computational approach to normal joint kinematics and prosthetic joint analysis offers an opportunity to evaluate and improve prosthetic human joint replacements before they are manufactured or surgically implanted. Computed tomography data from scanned joints are segmented, resulting in the identification of bone and other tissues of interest, with emphasis on the articular surfaces. (2) They are developing NDE and NDE techniques to analyze closed waste drums accurately and quantitatively. Active and passive computed tomography (A and PCT) is a comprehensive and accurate gamma-ray NDA method that can identify all detectable radioisotopes present in a container and measure their radioactivity.

  8. Correlation of structural abnormalities of the wrist and metacarpophalangeal joints evaluated by high-resolution peripheral quantitative computed tomography, 3 Tesla magnetic resonance imaging and conventional radiographs in rheumatoid arthritis.

    Science.gov (United States)

    Lee, Chan Hee; Srikhum, Waraporn; Burghardt, Andrew J; Virayavanich, Warapat; Imboden, John B; Link, Thomas M; Li, Xiaojuan

    2015-07-01

    In rheumatoid arthritis (RA) hands, we applied high-resolution peripheral quantitative computed tomography (HR-pQCT) and 3 Tesla (3 T) magnetic resonance imaging (MRI), which are new methods for erosion detection and bone marrow edema (BME) quantification. We compared the erosion measurements between these techniques with conventional radiographs (CR) in order to examine their significance for evaluating structural abnormalities. In 16 RA patients, HR-pQCT of metacarpophalangeal and wrist joints, 3 T MRI of wrist joints, as well as CR in both hands and feet were performed. Ten patients had 1-year follow-up CR. CRs were graded according to the modified Sharp score (MSS). Bone erosions were evaluated in HR-pQCT and MRI. BME pattern was quantified from MRI for volume, signal change and total burden. The erosion detection sensitivity of MRI was 85.7% and CR was 60.9% when HR-pQCT was considered as a reference method. The smallest dimensions of erosion detected by HR-pQCT, MRI and CR were 0.09, 0.14 and 0.66 cm, respectively. Baseline total MSS was correlated with HR-pQCT erosion measures, MRI erosion measures and MRI BME volume (P < 0.05). The mean difference between baseline and 1-year follow-up MSS (delta MSS) was 1.2. A trend was observed toward a correlation between delta MSS and MRI BME volume and burden. This study demonstrates that HR-pQCT detects more and smaller bone erosions compared to MRI and CR. In addition, 3 T MRI can provide quantitative measurement of BME. Combination of HR-pQCT and MRI modalities may provide powerful tools to evaluate joint inflammation and bone damage in RA. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  9. Impaired exercise-related myocardial uptake of technetium-99m-tetrofosmin in relation to coronary narrowing and diabetic state: assessment with quantitative single photon emission computed tomography.

    Science.gov (United States)

    Sasao, H; Nakata, T; Tsuchihashi, K; Wakabayashi, T; Nakaihara, N; Doi, A; Hashimoto, A; Kobayashi, H; Shimamoto, K

    2001-01-01

    Despite the diagnostic efficacy of stress myocardial perfusion imaging, the correlation between the actual perfusion tracer activity and diseased state of a coronary artery has not been studied in detail. We estimated exercise-related perfusion augmentation in relation to disease states of a coronary artery in diabetic and non-diabetic patients by a newly developed quantitative technetium (Tc)-99m-tetrofosmin myocardial imaging technique. Tc-99m-tetrofosmin tomographic imaging with an exercise-rest protocol was performed in 26 stable coronary patients and in 8 age-matched controls. Percent increase (%IR) in myocardial count during symptom-limited submaximal exercise-stress was calculated in 16 non-infarcted polar map segments and in each coronary territory by a subtraction technique with corrections for physical decay and injected tracer doses, and the results were compared with those of angiographically quantified coronary diameter stenosis (%DS). Percent IR and peak heart rate during exercise showed a positive linear correlation both in coronary territories with significant stenosis (%DS > or = 75%) and in control or nonstenotic (%DS more was identified by a %IR cutoff value of 40% with 77% sensitivity, 70% specificity, and an accuracy of 72%. In coronary territories with a %DS of less than 75%, %IR in diabetic patients was significantly lower (46+/-15%) than that in nondiabetic patients (61+/-25%). Thus, blunted exercise-related augmentation of myocardial uptake of Tc-99m-tetrofosmin correlates with the severity of coronary narrowing and diabetic state.

  10. Therapy response evaluation with positron emission tomography-computed tomography.

    Science.gov (United States)

    Segall, George M

    2010-12-01

    Positron emission tomography-computed tomography with F-18-fluorodeoxyglucose is widely used for evaluation of therapy response in patients with solid tumors but has not been as readily adopted in clinical trials because of the variability of acquisition and processing protocols and the absence of universal response criteria. Criteria proposed for clinical trials are difficult to apply in clinical practice, and gestalt impression is probably accurate in individual patients, especially with respect to the presence of progressive disease and complete response. Semiquantitative methods of determining tissue glucose metabolism, such as standard uptake value, can be a useful descriptor for levels of tissue glucose metabolism and changes in response to therapy if technical quality control measures are carefully maintained. The terms partial response, complete response, and progressive disease are best used in clinical trials in which the terms have specific meanings and precise definitions. In clinical practice, it may be better to use descriptive terminology agreed upon by imaging physicians and clinicians in their own practice.

  11. Quantitative contrast-enhanced optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Winetraub, Yonatan; SoRelle, Elliott D. [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Biophysics Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Liba, Orly [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Electrical Engineering, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Zerda, Adam de la [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Biophysics Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Electrical Engineering, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States)

    2016-01-11

    We have developed a model to accurately quantify the signals produced by exogenous scattering agents used for contrast-enhanced Optical Coherence Tomography (OCT). This model predicts distinct concentration-dependent signal trends that arise from the underlying physics of OCT detection. Accordingly, we show that real scattering particles can be described as simplified ideal scatterers with modified scattering intensity and concentration. The relation between OCT signal and particle concentration is approximately linear at concentrations lower than 0.8 particle per imaging voxel. However, at higher concentrations, interference effects cause signal to increase with a square root dependence on the number of particles within a voxel. Finally, high particle concentrations cause enough light attenuation to saturate the detected signal. Predictions were validated by comparison with measured OCT signals from gold nanorods (GNRs) prepared in water at concentrations ranging over five orders of magnitude (50 fM to 5 nM). In addition, we validated that our model accurately predicts the signal responses of GNRs in highly heterogeneous scattering environments including whole blood and living animals. By enabling particle quantification, this work provides a valuable tool for current and future contrast-enhanced in vivo OCT studies. More generally, the model described herein may inform the interpretation of detected signals in modalities that rely on coherence-based detection or are susceptible to interference effects.

  12. Dynamic contrast enhanced magnetic resonance perfusion imaging in high-risk smokers and smoking-related COPD: correlations with pulmonary function tests and quantitative computed tomography.

    Science.gov (United States)

    Xia, Yi; Guan, Yu; Fan, Li; Liu, Shi-Yuan; Yu, Hong; Zhao, Li-Ming; Li, Bing

    2014-09-01

    The study aimed to prospectively evaluate correlations between dynamic contrast-enhanced (DCE) MR perfusion imaging, pulmonary function tests (PFT) and volume quantitative CT in smokers with or without chronic obstructive pulmonary disease (COPD) and to determine the value of DCE-MR perfusion imaging and CT volumetric imaging on the assessment of smokers. According to the ATS/ERS guidelines, 51 male smokers were categorized into five groups: At risk for COPD (n = 8), mild COPD (n = 9), moderate COPD (n = 12), severe COPD (n = 10), and very severe COPD (n = 12). Maximum slope of increase (MSI), positive enhancement integral (PEI), etc. were obtained from MR perfusion data. The signal intensity ratio (RSI) of the PDs and normal lung was calculated (RSI = SIPD/SInormal). Total lung volume (TLV), total emphysema volume (TEV) and emphysema index (EI) were obtained from volumetric CT data. For "at risk for COPD," the positive rate of PDs on MR perfusion images was higher than that of abnormal changes on non-enhanced CT images (p < 0.05). Moderate-to-strong positive correlations were found between all the PFT parameters and SIPD, or RSI (r range 0.445∼0.683, p ≤ 0.001). TEV and EI were negatively correlated better with FEV1/FVC than other PFT parameters (r range -0.48 --0.63, p < 0.001). There were significant differences in RSI and SIPD between "at risk for COPD" and "very severe COPD," and between "mild COPD" and "very severe COPD". Thus, MR perfusion imaging may be a good approach to identify early evidence of COPD and may have potential to assist in classification of COPD.

  13. Computed tomography to quantify tooth abrasion

    Science.gov (United States)

    Kofmehl, Lukas; Schulz, Georg; Deyhle, Hans; Filippi, Andreas; Hotz, Gerhard; Berndt-Dagassan, Dorothea; Kramis, Simon; Beckmann, Felix; Müller, Bert

    2010-09-01

    Cone-beam computed tomography, also termed digital volume tomography, has become a standard technique in dentistry, allowing for fast 3D jaw imaging including denture at moderate spatial resolution. More detailed X-ray images of restricted volumes for post-mortem studies in dental anthropology are obtained by means of micro computed tomography. The present study evaluates the impact of the pipe smoking wear on teeth morphology comparing the abraded tooth with its contra-lateral counterpart. A set of 60 teeth, loose or anchored in the jaw, from 12 dentitions have been analyzed. After the two contra-lateral teeth were scanned, one dataset has been mirrored before the two datasets were registered using affine and rigid registration algorithms. Rigid registration provides three translational and three rotational parameters to maximize the overlap of two rigid bodies. For the affine registration, three scaling factors are incorporated. Within the present investigation, affine and rigid registrations yield comparable values. The restriction to the six parameters of the rigid registration is not a limitation. The differences in size and shape between the tooth and its contra-lateral counterpart generally exhibit only a few percent in the non-abraded volume, validating that the contralateral tooth is a reasonable approximation to quantify, for example, the volume loss as the result of long-term clay pipe smoking. Therefore, this approach allows quantifying the impact of the pipe abrasion on the internal tooth morphology including root canal, dentin, and enamel volumes.

  14. Improving Bone-Health Monitoring in Astronauts: Recommended Use of Quantitative Computed Tomography [QCT] for Clinical and Operational Decisions by NASA

    Science.gov (United States)

    Sibonga, J. D.; Truszkowski, P.

    2010-01-01

    DXA measurement of areal bone mineral density [aBMD,g/cm2] is required by NASA for assessing skeletal integrity in astronauts. Due to the abundance of population-based data that correlate hip and spine BMDs to fragility fractures, BMD is widely applied as a predictor of fractures in the general aging population. In contrast, QCT is primarily a research technology that measures three-dimensional , volumetric BMD (vBMD,mg/cm3) of bone and is therefore capable of differentiating between cortical and trabecular components. Additionally, when combined with Finite Element Modeling [FEM], a computational tool, QCT data can be used to estimate the whole bone strength of the hip [FE strength] for a specific load vector. A recent report demonstrated that aBMD failed to correlate with incurred changes in FE strength (for fall and stance loading) by astronauts over typical 180-day ISS (International Space Station) missions. While there are no current guidelines for using QCT data in clinical practice, QCT increases the understanding of how bone structure and mineral content are affected by spaceflight and recovery on Earth. In order to understand/promote/consider the use of QCT, NASA convened a panel of clinicians specializing in osteoporosis. After reviewing the available, albeit limited, medical and research information from long-duration astronauts (e.g., data from DXA, QCT, FEM, biochemistry analyses, medical records and in-flight exercise performance) the panelists were charged with recommending how current and future research data and analyses could inform clinical and operational decisions. The Panel recommended that clinical bone tests on astronauts should include QCT (hip and lumbar spine) for occupational risk surveillance and for the estimation of whole hip bone strength as derived by FEM. FE strength will provide an improved index that NASA could use to select astronauts of optimal bone health for extended duration missions, for repeat missions or for specific

  15. The APOSTEL recommendations for reporting quantitative optical coherence tomography studies

    DEFF Research Database (Denmark)

    Cruz-Herranz, Andrés; Balk, Lisanne J; Oberwahrenbrock, Timm

    2016-01-01

    OBJECTIVE: To develop consensus recommendations for reporting of quantitative optical coherence tomography (OCT) study results. METHODS: A panel of experienced OCT researchers (including 11 neurologists, 2 ophthalmologists, and 2 neuroscientists) discussed requirements for performing and reporting...... quantitative analyses of retinal morphology and developed a list of initial recommendations based on experience and previous studies. The list of recommendations was subsequently revised during several meetings of the coordinating group. RESULTS: We provide a 9-point checklist encompassing aspects deemed...... relevant when reporting quantitative OCT studies. The areas covered are study protocol, acquisition device, acquisition settings, scanning protocol, funduscopic imaging, postacquisition data selection, postacquisition data analysis, recommended nomenclature, and statistical analysis. CONCLUSIONS...

  16. Quantitative analysis of the image quality in megavoltage cone-beam computed tomography%兆伏级锥形束CT影像质量定量分析

    Institute of Scientific and Technical Information of China (English)

    胡伟刚; 章真; 常熙; 朱骥; 徐志勇; 唐劲天; 蒋国梁

    2009-01-01

    目的 定量分析不同成像条件下兆伏级锥形束CT(MVCBCT)的影像质量,为临床应用提供参考.方法 采用西门子ONCOR直线加速器上的MVCBCT设备,在不同的成像条件下扫描影像质昔模体.通过分析影像均匀性、噪声、空间分辨率、对比度分辨率及成像剂量来评估其影像质量,并与常规大孔径CT影像进行定量比较.结果 MVCBCT影像噪声随加速器出束跳数(MU)增加而减少.均匀性指数与成像MU数及重建矩阵无线件关系.空间分辨率上采用256×256重建矩阵除5MU条件下为0.25 lp/mm,其他皆为0.4 lp/mm.随MU数增加对比度分辨率增加.成像剂量上头颈患者接受最大剂量为1.2 cGy/MU,中心位置剂量为0.8~0.9 cGy/MU,腹部最大和中心处分别为1.3cGy/MU和0.7 cGy/MU.结论 MVCBCT的噪声、均匀性、空间分辨率及对比度分辨率都差于常规扇形束CT.通过选择恰当成像参数和重建参数,可在患者接受尽量低成像剂量的同时获得足够分辨率来分辨骨组织、空腔及部分软组织用于影像引导放疗.%Objective To quantitatively analyze the image quality of megavoltage cone-beam CT (MVCBCT) under different scanning conditions to provide reference in clinical applications. Methods Si-emens ONCOR linear accelerator with MVCBCT was used to scan the phantom under different conditions. The image quality was evaluated in terms of image noise, uniformity, spatial resolution, contrast resolution, the number of Monitor Units(MUs) used in imaging,and the size of the reconstruction matrix. The comparison of the image quality between MVCBCT and conventional simulator CT was also analyzed. Results The image noise was decreased with the increase of the number of MUs. The uniformity index showed that the system u-niformity was weakly dependent on MU numbers or the size of the reconstruction matrix. Except for the ima-ges with 5 MUs,all other images had the spatial resolution of 0.4 lp/mm with a

  17. Positron Computed Tomography: Current State, Clinical Results and Future Trends

    Science.gov (United States)

    Schelbert, H. R.; Phelps, M. E.; Kuhl, D. E.

    1980-09-01

    An overview is presented of positron computed tomography: its advantages over single photon emission tomography, its use in metabolic studies of the heart and chemical investigation of the brain, and future trends. (ACR)

  18. Quantitative nanoscale analysis in 3D using electron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kuebel, Christian [Karlsruhe Institute of Technology, INT, 76344 Eggenstein-Leopoldshafen (Germany)

    2011-07-01

    State-of-the-art electron tomography has been established as a powerful tool to image complex structures with nanometer resolution in 3D. Especially STEM tomography is used extensively in materials science in such diverse areas as catalysis, semiconductor materials, and polymer composites mainly providing qualitative information on morphology, shape and distribution of materials. However, for an increasing number of studies quantitative information, e.g. surface area, fractal dimensions, particle distribution or porosity are needed. A quantitative analysis is typically performed after segmenting the tomographic data, which is one of the main sources of error for the quantification. In addition to noise, systematic errors due to the missing wedge and due to artifacts from the reconstruction algorithm itself are responsible for these segmentation errors and improved algorithms are needed. This presentation will provide an overview of the possibilities and limitations of quantitative nanoscale analysis by electron tomography. Using catalysts and nano composites as applications examples, intensities and intensity variations observed for the 3D volume reconstructed by WBP and SIRT will be quantitatively compared to alternative reconstruction algorithms; implications for quantification of electron (or X-ray) tomographic data will be discussed and illustrated for quantification of particle size distributions, particle correlations, surface area, and fractal dimensions in 3D.

  19. Computed tomography appearances of sclerosing encapsulating peritonitis

    Energy Technology Data Exchange (ETDEWEB)

    George, C. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom)]. E-mail: cheriangeorge@hotmail.com; Al-Zwae, K. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom); Nair, S. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom); Cast, J.E.I. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom)

    2007-08-15

    Sclerosing encapsulating peritonitis (SEP) is a serious complication of peritoneal dialysis (PD) characterized by thickened peritoneal membranes, which lead to decreased ultra-filtration and intestinal obstruction. Its early clinical features are nonspecific, and it is often diagnosed late following laparotomy and peritoneal biopsy, when the patient develops small bowel obstruction, which can be a life-threatening complication. However, this is changing with increasing awareness of computed tomography (CT) findings in SEP. CT can yield an early, non-invasive diagnosis that may improve patient outcome. We present a review of the CT appearances of SEP.

  20. Computed tomography in neuronal ceroid lipofuscinosis

    Energy Technology Data Exchange (ETDEWEB)

    Valavanis, A.; Schubiger, O.; Hayek, J.; Friede, R.L

    1981-01-01

    The computed tomography (CT) findings in a verified case of neuronal ceroid lipofuscinosis (NCL) are presented. CT revealed diffuse and severe cerebral atrophy, reflected by generalized subarachnoid space enlargement and symmetric ventricular dilatation. There was no evidence of abnormalities of the white matter. The CT features in our case of NCL correspond perfectly with the neuropathologic changes of the disease mentioned in the literature. Furthermore, CT is of considerable help in differentiating between those inherited metabolic brain diseases characterized primarily by white matter involvement and those presenting predominantly with changes of grey matter.

  1. Comparison on Computed Tomography using industrial items

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo

    2014-01-01

    In a comparison involving 27 laboratories from 8 countries, measurements on two common industrial items, a polymer part and a metal part, were carried out using X-ray Computed Tomography. All items were measured using coordinate measuring machines before and after circulation, with reference...... measurement uncertainties in the range 1.5–5.5 μm, showing a good stability over the 6 months of the circulation. The comparison has shown that CT measurements on the industrial parts used lie in the range 6–53 μm, with maximum values up to 158 μm....

  2. Tomography and spectroscopy as quantum computations

    CERN Document Server

    Miquel, C; Saraceno, M; Knill, E H; Laflamme, R; Negrevergne, C; Miquel, Cesar; Paz, Juan Pablo; Saraceno, Marcos; Knill, Emmanuel; Laflamme, Raymond; Negrevergne, Camille

    2001-01-01

    Determining the state of a system and measuring properties of its evolution are two of the most important tasks a physicist faces. For the first purpose one can use tomography, a method that after subjecting the system to a number of experiments determines all independent elements of the density matrix. For the second task, one can resort to spectroscopy, a set of techniques used to determine the spectrum of eigenvalues of the evolution operator. In this letter, we show that tomography and spectroscopy can be naturally interpreted as dual forms of quantum computation. We show how to adapt the simplest case of the well-known phase estimation quantum algorithm to perform both tasks, giving it a natural interpretation as a simulated scattering experiment. We show how this algorithm can be used to implement an interesting form of tomography by performing a direct measurement of the Wigner function of a quantum system. We present results of such measurements performed on a system of three qubits using liquid state...

  3. Assessment of bone microarchitecture in chronic kidney disease: a comparison of 2D bone texture analysis and high-resolution peripheral quantitative computed tomography at the radius and tibia.

    Science.gov (United States)

    Bacchetta, Justine; Boutroy, Stéphanie; Vilayphiou, Nicolas; Fouque-Aubert, Anne; Delmas, Pierre D; Lespessailles, Eric; Fouque, Denis; Chapurlat, Roland

    2010-11-01

    Bone microarchitecture can be studied noninvasively using high-resolution peripheral quantitative computed tomography (HR-pQCT). However, this technique is not widely available, so more simple techniques may be useful. BMA is a new 2D high-resolution digital X-ray device, allowing for bone texture analysis with a fractal parameter (H(mean)). The aims of this study were (1) to evaluate the reproducibility of BMA at two novel sites (radius and tibia) in addition to the conventional site (calcaneus), (2) to compare the results obtained with BMA at all of those sites, and (3) to study the relationship between H(mean) and trabecular microarchitecture measured with an in vivo 3D device (HR-pQCT) at the distal tibia and radius. BMA measurements were performed at three sites (calcaneus, distal tibia, and radius) in 14 healthy volunteers to measure the short-term reproducibility and in a group of 77 patients with chronic kidney disease to compare BMA results to HR-pQCT results. The coefficient of variation of H(mean) was 1.2, 2.1, and 4.7% at the calcaneus, radius, and tibia, respectively. We found significant associations between trabecular volumetric bone mineral density and microarchitectural variables measured by HR-pQCT and H(mean) at the three sites (e.g., Pearson correlation between radial trabecular number and radial H(mean) r = 0.472, P technique with few technical constraints. Thus, it may represent an interesting tool for evaluating bone structure, in association with biological parameters and DXA.

  4. Quantitative photoacoustic tomography using forward and adjoint Monte Carlo models of radiance

    CERN Document Server

    Hochuli, Roman; Arridge, Simon; Cox, Ben

    2016-01-01

    Forward and adjoint Monte Carlo (MC) models of radiance are proposed for use in model-based quantitative photoacoustic tomography. A 2D radiance MC model using a harmonic angular basis is introduced and validated against analytic solutions for the radiance in heterogeneous media. A gradient-based optimisation scheme is then used to recover 2D absorption and scattering coefficients distributions from simulated photoacoustic measurements. It is shown that the functional gradients, which are a challenge to compute efficiently using MC models, can be calculated directly from the coefficients of the harmonic angular basis used in the forward and adjoint models. This work establishes a framework for transport-based quantitative photoacoustic tomography that can fully exploit emerging highly parallel computing architectures.

  5. Stability for Quantitative Photoacoustic Tomography with well chosen illuminations

    OpenAIRE

    Alessandrini, Giovanni; Di Cristo, Michele; Francini, Elisa; Vessella, Sergio

    2015-01-01

    We treat the stability issue for the three dimensional inverse imaging modality called Quantitative Photoacoustic Tomography. We provide universal choices of the illuminations which enable to recover, in a H\\"older stable fashion, the diffusion and absorption coefficients from the interior pressure data. With such choices of illuminations we do not need the nondegeneracy conditions commonly used in previous studies, which are difficult to be verified a-priori.

  6. COMPUTED TOMOGRAPHY OF TOOTH RESORPTION IN CATS.

    Science.gov (United States)

    Lang, Linda G; Wilkinson, Thomas E; White, Tammy L; Farnsworth, Raelynn K; Potter, Kathleen A

    2016-09-01

    Tooth resorption is the most common dental disease in cats and can be a source of oral pain. The current clinical gold standard for diagnosis includes a combination of oral exam and dental radiography, however early lesions are not always detected. Computed tomography (CT) of the skull, including the dental arches, is a commonly performed diagnostic procedure, however the appearance of tooth resorption on CT and the diagnostic ability of CT to detect tooth resorption have not been evaluated. The purpose of this prospective, descriptive, diagnostic accuracy study was to characterize the CT appearance of tooth resorption in a sample of affected cats and to evaluate the sensitivity and specificity of CT for tooth resorption compared to the clinical gold standard of oral exam and intraoral dental radiography. Twenty-eight cat cadaver specimens were recruited for inclusion. Each specimen was evaluated using oral exam, intraoral dental radiography, and computed tomography (four different slice thicknesses). Each tooth was evaluated for the presence or absence of tooth resorption. Teeth with lesions and a subset of normal teeth were evaluated with histopathology. On CT, tooth resorption appeared as irregularly marginated hypoattenuating defects in the mineral attenuating tooth components, most commonly involving the root or cementoenamel junction. Sensitivity for CT detection of tooth resorption was fair to poor (42.2-57.7%) and specificity was good to excellent (92.8-96.3%). Findings from this study indicated that CT has high specificity but low sensitivity for detection of tooth resorption in cats.

  7. Computed tomography in pelvic and acetabular fractures

    Energy Technology Data Exchange (ETDEWEB)

    Born, H.; Schmidt, C.

    1988-06-01

    In a retrospective study we analyzed the results of 127 patients, who were examined not only by means of conventional radiography but also by means of computed tomography after a trauma of the pelvic. Our investigations were based upon such patients, to whom a definite diagnostic procedure of plain radiography had been performed. Therefore all polytraumatized patients were inapplicable. They were only examined by computed tomography because of other more important accompanying injuries of other body regions. We compared the results of 127 patients with pelvic trauma. The results of the CT were in accordance with the results of the plain radiography for 103 patients. The results of the CT concerning the availability and the localization of the fractures were basically coincident with the plain radiography for 22 patients, but the CT showed a higher degree of trauma and additional intraarticular fragments. Two isolated lesions of the sacroiliac joint could not be recognized by both methods. They could only be diagnosed by bone scintigraphy on the third day after trauma.

  8. Computer Architecture A Quantitative Approach

    CERN Document Server

    Hennessy, John L

    2011-01-01

    The computing world today is in the middle of a revolution: mobile clients and cloud computing have emerged as the dominant paradigms driving programming and hardware innovation today. The Fifth Edition of Computer Architecture focuses on this dramatic shift, exploring the ways in which software and technology in the cloud are accessed by cell phones, tablets, laptops, and other mobile computing devices. Each chapter includes two real-world examples, one mobile and one datacenter, to illustrate this revolutionary change.Updated to cover the mobile computing revolutionEmphasizes the two most im

  9. SADMFR guidelines for the use of cone-beam computed tomography/ Digital Volume Tomography

    OpenAIRE

    Dula, Karl; Bornstein, Michael M.; Buser, Daniel; Dagassan-Berndt, Dorothea; Ettlin, Dominik A; Filippi, Andreas; Gabioud, François; Katsaros, Christos; Krastl, Gabriel; Lambrecht, J. Thomas; Lauber, Roland; Luebbers, Heinz-Theo; Pazera, Pawel; Türp, Jens C.

    2014-01-01

    Cone-Beam Computed Tomography (CBCT) has been introduced in 1998. This radiological imaging procedure has been provided for dentistry and is comparable to computed tomography (CT) in medicine. It is expected that CBCT will have the same success in dental diagnostic imaging as computed tomography had in medicine. Just as CT is responsible for a significant rise in radiation dose to the population from medical X-ray diagnostics, CBCT studies will be accompanied by a significant increase of the ...

  10. Enhancement of photoacoustic tomography in the tissue with speed-of-sound variance using ultrasound computed tomography

    Institute of Scientific and Technical Information of China (English)

    程任翔; 陶超; 刘晓峻

    2015-01-01

    The speed-of-sound variance will decrease the imaging quality of photoacoustic tomography in acoustically inhomo-geneous tissue. In this study, ultrasound computed tomography is combined with photoacoustic tomography to enhance the photoacoustic tomography in this situation. The speed-of-sound information is recovered by ultrasound computed to-mography. Then, an improved delay-and-sum method is used to reconstruct the image from the photoacoustic signals. The simulation results validate that the proposed method can obtain a better photoacoustic tomography than the conventional method when the speed-of-sound variance is increased. In addition, the influences of the speed-of-sound variance and the fan-angle on the image quality are quantitatively explored to optimize the image scheme. The proposed method has a good performance even when the speed-of-sound variance reaches 14.2%. Furthermore, an optimized fan angle is revealed, which can keep the good image quality with a low cost of hardware. This study has a potential value in extending the biomedical application of photoacoustic tomography.

  11. Computed Tomography Technology: Development and Applications for Defence

    Science.gov (United States)

    Baheti, G. L.; Saxena, Nisheet; Tripathi, D. K.; Songara, K. C.; Meghwal, L. R.; Meena, V. L.

    2008-09-01

    Computed Tomography(CT) has revolutionized the field of Non-Destructive Testing and Evaluation (NDT&E). Tomography for industrial applications warrants design and development of customized solutions catering to specific visualization requirements. Present paper highlights Tomography Technology Solutions implemented at Defence Laboratory, Jodhpur (DLJ). Details on the technological developments carried out and their utilization for various Defence applications has been covered.

  12. Use of high-resolution computed tomography and positron emission tomography/computed tomography in the management of stage IA adenocarcinoma.

    Science.gov (United States)

    Miyata, Yoshihiro; Tsutani, Yasuhiro; Okada, Morihito

    2012-01-01

    Preoperative determination of malignant behavior is critical in choosing suitable therapeutic strategies such as sublobar resection for patients with small lung cancers. The aim of present review was to evaluate high-resolution computed tomography and fluorodeoxyglucose-positron emission tomography/computed tomography as tools for management of clinical stage IA adenocarcinoma.

  13. Development of a Computed Tomography Simulator: SimCT, Application to Health Monitoring and Remaining Life Assessment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this activity is to develop a quantitative NDE simulation tool for computed tomography suitable for desktop work using realistic geometry...

  14. Spatiotemporal computed tomography of dynamic processes

    Science.gov (United States)

    Kaestner, Anders; Münch, Beat; Trtik, Pavel; Butler, Les

    2011-12-01

    Modern computed tomography (CT) equipment allowing fast 3-D imaging also makes it possible to monitor dynamic processes by 4-D imaging. Because the acquisition time of various 3-D-CT systems is still in the range of at least milliseconds or even hours, depending on the detector system and the source, the balance of the desired temporal and spatial resolution must be adjusted. Furthermore, motion artifacts will occur, especially at high spatial resolution and longer measuring times. We propose two approaches based on nonsequential projection angle sequences allowing a convenient postacquisition balance of temporal and spatial resolution. Both strategies are compatible with existing instruments, needing only a simple reprograming of the angle list used for projection acquisition and care with the projection order list. Both approaches will reduce the impact of artifacts due to motion. The strategies are applied and validated with cold neutron imaging of water desorption from originally saturated particles during natural air-drying experiments and with x-ray tomography of a polymer blend heated during imaging.

  15. Imaging of Cardiac Valves by Computed Tomography

    Directory of Open Access Journals (Sweden)

    Gudrun Feuchtner

    2013-01-01

    Full Text Available This paper describes “how to” examine cardiac valves with computed tomography, the normal, diseased valves, and prosthetic valves. A review of current scientific literature is provided. Firstly, technical basics, “how to” perform and optimize a multislice CT scan and “how to” interpret valves on CT images are outlined. Then, diagnostic imaging of the entire spectrum of specific valvular disease by CT, including prosthetic heart valves, is highlighted. The last part gives a guide “how to” use CT for planning of transcatheter aortic valve implantation (TAVI, an emerging effective treatment option for patients with severe aortic stenosis. A special focus is placed on clinical applications of cardiac CT in the context of valvular disease.

  16. Advanced proton imaging in computed tomography

    CERN Document Server

    Mattiazzo, S; Giubilato, P; Pantano, D; Pozzobon, N; Snoeys, W; Wyss, J

    2015-01-01

    In recent years the use of hadrons for cancer radiation treatment has grown in importance, and many facilities are currently operational or under construction worldwide. To fully exploit the therapeutic advantages offered by hadron therapy, precise body imaging for accurate beam delivery is decisive. Proton computed tomography (pCT) scanners, currently in their R&D phase, provide the ultimate 3D imaging for hadrons treatment guidance. A key component of a pCT scanner is the detector used to track the protons, which has great impact on the scanner performances and ultimately limits its maximum speed. In this article, a novel proton-tracking detector was presented that would have higher scanning speed, better spatial resolution and lower material budget with respect to present state-of-the-art detectors, leading to enhanced performances. This advancement in performances is achieved by employing the very latest development in monolithic active pixel detectors (to build high granularity, low material budget, ...

  17. Analysis of airways in computed tomography

    DEFF Research Database (Denmark)

    Petersen, Jens

    Chronic Obstructive Pulmonary Disease (COPD) is major cause of death and disability world-wide. It affects lung function through destruction of lung tissue known as emphysema and inflammation of airways, leading to thickened airway walls and narrowed airway lumen. Computed Tomography (CT) imaging...... have become the standard with which to assess emphysema extent but airway abnormalities have so far been more challenging to quantify. Automated methods for analysis are indispensable as the visible airway tree in a CT scan can include several hundreds of individual branches. However, automation...... of scan on airway dimensions in subjects with and without COPD. The results show measured airway dimensions to be affected by differences in the level of inspiration and this dependency is again influenced by COPD. Inspiration level should therefore be accounted for when measuring airways, and airway...

  18. Findings of computed tomography in intracranial tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Jo, H. G.; Bae, K. S.; Lee, H. K.; Kwon, K. H.; Kim, K. J. [Soonchunhyang University College of Medicine, Seoul (Korea, Republic of)

    1983-12-15

    In intracranial tuberculosis, the Computed Tomography (CT) is a new radiological technique which is helpful in diagnosis and determining the location, extents of the lesion. It can also make it possible to assess the presence and degree of the complications and to evaluate the effectiveness of treatment. 25 cases of clinically proven intracranial tuberculosis were studied by CT, in Soonchunhyang hospital from Jun. 1980 to Jun. 1983. The result were as follows; 1. 4 cases were normal in CT finding, despite of the clinically proven tuberculous meningitis. 2. Total or partial obliteration of cisterns were observed in 13 cases. 3. Intense abnormal contrast enhancement of the cisterns were observed in 8 cases. 4. 19 cases show moderate to marked ventricular dilatation. 5. 2 cases of cerebral infarction were observed. 6. One case of tuberculoma was observed.

  19. Computed Tomography in the Modern Slaughterhouse

    DEFF Research Database (Denmark)

    Mosbech, Thomas Hammershaimb

    of technology. Recently, the use of X-ray computed tomography (CT) coupled with methods from image analysis has been introduced as a powerful means to optimise production, by providing detailed information on the raw materials. This thesis covers two aspects of the application of CT in the modern abattoir...... concerns measurements of each single carcass, to improve the raw material utilisation by individually adapted processing. Measurements performed online in the abattoir demand fast, robust and cost-effective imaging. We propose a tomographic reconstruction algorithm, enabling a substantial reduction...... of the subject-specific X-ray data needed to produce high quality images for accurate measurements. This is very beneficial for the abattoirs, as a reduction in acquired data translates directly into higher speed and a lower cost. The thesis demonstrates the great potential of CT as a technology for improving...

  20. Computed Tomography (CT) Perfusion in Abdominal Cancer

    DEFF Research Database (Denmark)

    Hansen, Martin Lundsgaard; Norling, Rikke; Lauridsen, Carsten

    2013-01-01

    Computed Tomography (CT) Perfusion is an evolving method to visualize perfusion in organs and tissue. With the introduction of multidetector CT scanners, it is now possible to cover up to 16 cm in one rotation, and thereby making it possible to scan entire organs such as the liver with a fixed...... table position. Advances in reconstruction algorithms make it possible to reduce the radiation dose for each examination to acceptable levels. Regarding abdominal imaging, CT perfusion is still considered a research tool, but several studies have proven it as a reliable non-invasive technique...... for assessment of vascularity. CT perfusion has also been used for tumor characterization, staging of disease, response evaluation of newer drugs targeted towards angiogenesis and as a method for early detection of recurrence after radiation and embolization. There are several software solutions available...

  1. Computed tomography in metastatic renal cell carcinoma.

    Science.gov (United States)

    Griffin, Nyree; Grant, Lee Alexander; Bharwani, Nishat; Sohaib, S Aslam

    2009-08-01

    Recent developments in chemotherapy have resulted in several new drug treatments for metastatic renal cell carcinoma (RCC). These therapies have shown improved progression-free survival and are applicable to many more patients than the conventional cytokine-based treatments for metastatic RCC. Consequently imaging is playing a greater part in the management of such patients. Computed tomography (CT) remains the primary imaging modality with other imaging modalities playing a supplementary role. CT is used in the diagnosis and staging of metastatic RCC. It is used in the follow-up of patients after nephrectomy, in assessing the extent of metastatic disease, and in evaluating response to treatment. This review looks at the role of CT in patients with metastatic RCC and describes the appearances of metastatic RCC before and following systemic therapy.

  2. Computed tomography of the abnormal thymus

    Energy Technology Data Exchange (ETDEWEB)

    Baron, R.L.; Lee, J.K.T.; Sagel, S.S.; Levitt, R.G.

    1982-01-01

    Computed tomography (CT) should be the imaging method of choice following plain chest radiographs when a suspected thymic abnormality requires further evaluation. Based upon a six-year experience, including the evaluation of 25 patients with thymic pathology, CT was found useful in suggesting or excluding a diagnosis of thymoma and in distinguishing thymic hyperplasis from thymoma in patients with myasthenia gravis. The thickness of the thymic lobes determined by CT was found to be a more accurate indicator of infiltrative disease (thymic hyperplasia and lymphoma) than the width. CT was helpful in differentiating benign thymic cysts from solid tumors, and in defining the extent of a thymic neoplasms. On occasion, CT may suggest the specific histologic nature of a thymic lesion.

  3. Reconstructing cetacean brain evolution using computed tomography.

    Science.gov (United States)

    Marino, Lori; Uhen, Mark D; Pyenson, Nicholas D; Frohlich, Bruno

    2003-05-01

    Until recently, there have been relatively few studies of brain mass and morphology in fossil cetaceans (dolphins, whales, and porpoises) because of difficulty accessing the matrix that fills the endocranial cavity of fossil cetacean skulls. As a result, our knowledge about cetacean brain evolution has been quite limited. By applying the noninvasive technique of computed tomography (CT) to visualize, measure, and reconstruct the endocranial morphology of fossil cetacean skulls, we can gain vastly more information at an unprecedented rate about cetacean brain evolution. Here, we discuss our method and demonstrate it with several examples from our fossil cetacean database. This approach will provide new insights into the little-known evolutionary history of cetacean brain evolution.

  4. Computed tomography findings of malignant pleural mesothelioma

    Energy Technology Data Exchange (ETDEWEB)

    Shiota, Yutaro; Sato, Toshio; Yamaguchi, Kazuo; Ono, Tetsuya; Kaji, Masaro; Niiya, Harutaka (Kure Kyosai Hospital, Hiroshima (Japan))

    1994-04-01

    Computed tomography (CT) findings were assessed in 7 patients with malignant mesothelioma. CT findings were also reviewed in 9 patients with lung cancer and pleuritis carcinomatosa and in 11 patients with tuberculous pleuritis. Five patients with malignant mesothelioma underwent CT scans twice, on admission and from 1 to 7 months after admission. Tuberculous pleuritis could be distinguished from pleuritis carcinomatosa and malignant mesothelioma by the presence or absence of pleural nodularity and chest wall invasion. Although it was difficult to identify specific CT features clearly distinguishing malignant mesothelioma from pleuritis carcinomatosa, characteristic findings of malignant mesothelioma appeared to include the rapid development and progression of pleural rind and a tendency to spread directly into the chest wall. We divided the pleural into the four regions; upper anterior, upper posterior, lower anterior and lower posterior regions. Pleural changes were more frequently seen in the lower pleural regions than in the upper pleural regions in malignant mesothelioma. (author).

  5. Ultra-high resolution computed tomography imaging

    Energy Technology Data Exchange (ETDEWEB)

    Paulus, Michael J. (Knoxville, TN); Sari-Sarraf, Hamed (Knoxville, TN); Tobin, Jr., Kenneth William (Harriman, TN); Gleason, Shaun S. (Knoxville, TN); Thomas, Jr., Clarence E. (Knoxville, TN)

    2002-01-01

    A method for ultra-high resolution computed tomography imaging, comprising the steps of: focusing a high energy particle beam, for example x-rays or gamma-rays, onto a target object; acquiring a 2-dimensional projection data set representative of the target object; generating a corrected projection data set by applying a deconvolution algorithm, having an experimentally determined a transfer function, to the 2-dimensional data set; storing the corrected projection data set; incrementally rotating the target object through an angle of approximately 180.degree., and after each the incremental rotation, repeating the radiating, acquiring, generating and storing steps; and, after the rotating step, applying a cone-beam algorithm, for example a modified tomographic reconstruction algorithm, to the corrected projection data sets to generate a 3-dimensional image. The size of the spot focus of the beam is reduced to not greater than approximately 1 micron, and even to not greater than approximately 0.5 microns.

  6. Inter laboratory comparison on Industrial Computed Tomography

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo

    An interlaboratory comparison on industrial X-ray Computed Tomography (CT) was organized by the Centre for Geometrical Metrology (CGM), Department of Mechanical Engineering, Technical University of Denmark (DTU) and carried out within the project “Centre for Industrial Application of CT scanning...... - CIA-CT”. In the comparison, 27 laboratories from 8 countries were involved, and CT scanned two items selected among common industrial parts: a polymer part and a metal part. Altogether, 27 sets of items were circulated in parallel to the participants. Different measurands are considered, encompassing...... influence from the surrounding wall thickness on the measurement of roundness was documented for the metal item. The comparison shows that CT scanning on small industrial parts, generally speaking, is connected with uncertainties in the range 8-53 μm, as compared to an uncertainty range of 1.5-5.5 μm using...

  7. Evaluation of high-resolution peripheral quantitative computed tomography, finite element analysis and biomechanical testing in a pre-clinical model of osteoporosis: a study with odanacatib treatment in the ovariectomized adult rhesus monkey.

    Science.gov (United States)

    Jayakar, Richa Y; Cabal, Antonio; Szumiloski, John; Sardesai, Swanand; Phillips, Eual A; Laib, Andres; Scott, Boyd B; Pickarski, Maureen; Duong, Le T; Winkelmann, Christopher T; McCracken, Paul J; Hargreaves, Richard; Hangartner, Thomas N; Williams, Donald S

    2012-06-01

    This study aimed to validate finite element analysis (FEA) estimation of strength, identify high-resolution peripheral quantitative computed tomography (HR-pQCT) measures correlating with strength, and evaluate the precision of HR-pQCT measurements to longitudinally monitor effects of osteoporosis treatment in ovariectomized (OVX) non-human primates (NHPs). HR-pQCT images were acquired in three groups of NHPs: Intact (n=10), OVX-odanacatib treated (OVX-ODN 30 mg/kg, n=10) and OVX-vehicle treated (OVX-Veh, n=10) at the ultradistal (UD) and distal 1/3 radii and tibia at 12, 16 and 20 months. FEA estimates of bone strength using the Pistoia criterion were validated by ex-vivo mechanical compression (r(2)=0.95) of the UD radius. Single linear regressions of FEA-determined ultimate stress showed high correlation with HR-pQCT derived parameters: integral vBMD (r(2)=0.86), bone volume fraction (r(2)=0.84) and cortical thickness (r(2)=0.79). Precision of HR-pQCT measurements, obtained from an excised radius and tibia, showed low variation (CV=0.005%-5.6%) and helped identify possible sources of error. Comparison of OVX-Veh and Intact groups showed decreases in bone parameters demonstrating trends consistent with bone loss. Comparison of OVX-ODN and OVX-Veh groups showed a treatment effect with increases in bone parameters: integral vBMD (477±27 vs. 364±22 mgHA/cm(3)) and cortical thickness (Ct.Th) (0.90±0.07 vs. 0.64±0.04 mm) at the UD radius, Ct.Th (2.15±0.28 vs. 1.56±0.08 mm) at the distal 1/3 radius. Axial compression peak stress calculated and obtained experimentally showed the OVX-ODN group was 33% stronger than the OVX-Veh group. We conclude that HR-pQCT and FEA serve as robust techniques to longitudinally monitor bone parameters and strength in NHP's.

  8. Exercise-induced bone gain is due to enlargement in bone size without a change in volumetric bone density: a peripheral quantitative computed tomography study of the upper arms of male tennis players.

    Science.gov (United States)

    Haapasalo, H; Kontulainen, S; Sievänen, H; Kannus, P; Järvinen, M; Vuori, I

    2000-09-01

    Bilateral bone characteristics of the humerus (proximal, shaft, and distal sites) and radius (shaft and distal sites) in 12 former Finnish national-level male tennis players (mean age 30 years) and their 12 age-, height-, and weight-matched controls were measured with peripheral quantitative computed tomography (pQCT). The pQCT variables analyzed were bone mineral content (BMC), total cross-sectional area of bone (Tot.Ar), cross-sectional area of the marrow cavity (M.Cav.Ar), cortical bone (Co.Ar) and trabecular bone (Tr.Ar), volumetric density of cortical (Co.Dn) and trabecular (Tr. Dn) bone, cortical wall thickness (Co.Wi.Th), bone strength index (BSI), and principal moments of inertia (I(min) and I(max)). In the players, significant side-to-side differences, in favor of the dominant (playing) arm, were found in BMC (ranging 14%-27%), Tot.Ar (16%-21%), Co.Ar (12%-32%), BSI (23%-37%), I(min) (33%-61%), and I(max) (27%-67%) at all measured bone sites, and in Co.Wi.Th. (5%-25%) at the humeral and radial shafts, and distal humerus. The side-to-side M.Cav.Ar difference was significant at the proximal humerus (19%) and radial shaft (29%). Concerning the players' Co.Dn and Tr.Dn, the only significant side-to-side difference was found in the Co.Dn of the distal humerus, with the playing arm showing a slightly smaller Co.Dn than the nonplaying arm (-2%). In controls, significant dominant-to-nondominant side differences were also found, but with the majority of the differences being rather small, and significantly lower than those of the players. In conclusion, despite the large side-to-side differences in BMC, the volumetric bone density (Co.Dn, Tr.Dn) was almost identical in the dominant and nondominant arms of the players and controls. Thus, the players' high playing-arm BMC was due to increases in the Tot.Ar, M.Cav.Ar, Co.Ar, and CW.Th. In other words, the playing arm's extra bone mineral, and thus increased bone strength, was mainly due to increased bone size and not

  9. Intravenous coronary angiography using electron beam computed tomography

    NARCIS (Netherlands)

    Rensing, B J; Bongaerts, A H; van Geuns, R J; van Ooijen, P M; Oudkerk, M; de Feyter, P J

    1999-01-01

    Intravenous coronary angiography with electron beam computed tomography (EBCT) allows for the noninvasive visualisation of coronary arteries. With dedicated computer hardware and software, three-dimensional renderings of the coronary arteries, veins, and other cardiac structures can be constructed f

  10. Quantitative damage imaging using Lamb wave diffraction tomography

    Science.gov (United States)

    Zhang, Hai-Yan; Ruan, Min; Zhu, Wen-Fa; Chai, Xiao-Dong

    2016-12-01

    In this paper, we investigate the diffraction tomography for quantitative imaging damages of partly through-thickness holes with various shapes in isotropic plates by using converted and non-converted scattered Lamb waves generated numerically. Finite element simulations are carried out to provide the scattered wave data. The validity of the finite element model is confirmed by the comparison of scattering directivity pattern (SDP) of circle blind hole damage between the finite element simulations and the analytical results. The imaging method is based on a theoretical relation between the one-dimensional (1D) Fourier transform of the scattered projection and two-dimensional (2D) spatial Fourier transform of the scattering object. A quantitative image of the damage is obtained by carrying out the 2D inverse Fourier transform of the scattering object. The proposed approach employs a circle transducer network containing forward and backward projections, which lead to so-called transmission mode (TMDT) and reflection mode diffraction tomography (RMDT), respectively. The reconstructed results of the two projections for a non-converted S0 scattered mode are investigated to illuminate the influence of the scattering field data. The results show that Lamb wave diffraction tomography using the combination of TMDT and RMDT improves the imaging effect compared with by using only the TMDT or RMDT. The scattered data of the converted A0 mode are also used to assess the performance of the diffraction tomography method. It is found that the circle and elliptical shaped damages can still be reasonably identified from the reconstructed images while the reconstructed results of other complex shaped damages like crisscross rectangles and racecourse are relatively poor. Project supported by the National Natural Science Foundation of China (Grant Nos. 11474195, 11274226, 11674214, and 51478258).

  11. Cone beam computed tomography in Endodontics - a review

    NARCIS (Netherlands)

    Patel, S.; Durack, C.; Abella, F.; Shemesh, H.; Roig, M.; Lemberg, K.

    2015-01-01

    Cone beam computed tomography (CBCT) produces undistorted three-dimensional information of the maxillofacial skeleton, including the teeth and their surrounding tissues with a lower effective radiation dose than computed tomography. The aim of this paper is to: (i) review the current literature on

  12. Computed tomography and magnetic resonance findings in lipoid pneumonia.

    OpenAIRE

    Bréchot, J M; Buy, J.N.; Laaban, J P; Rochemaure, J

    1991-01-01

    A case of exogenous lipoid pneumonia was documented by computed tomography and magnetic resonance imaging. Although strongly suggesting the presence of fat on T1 weighted images, magnetic resonance does not produce images specific for this condition. Computed tomography is the best imaging modality for its diagnosis.

  13. Computed tomography in traumatic defects of the diaphragm.

    Science.gov (United States)

    Demos, T C; Solomon, C; Posniak, H V; Flisak, M J

    1989-03-01

    Two patients with traumatic diaphragmatic defects visible on computed tomography are presented. The diagnosis was delayed for several years in both patients. The diagnosis of these acquired diaphragmatic defects is often difficult. Computed tomography can lead to earlier diagnosis by demonstrating the defect in some patients when radiographic studies are not diagnostic.

  14. Diagnosis of lumbar disc hernia with computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizumi, Atsuro; Ohira, Nobuhiro; Ojima, Tadashi; Oshida, Midori; Horaguchi, Mitsuru (Tohoku Rosai Hospital, Sendai (Japan))

    1982-07-01

    Results of computed tomography performed on patients with clinically diagnosed hernia were compared with those of myelography and operative findings. This comparative study suggested that computed tomography is quite different from other methods and very useful in diagnosis of hernia. Some cases of hernia were shown, and the characteristics of CT were reviewed.

  15. Cone beam computed tomography in Endodontics - a review

    NARCIS (Netherlands)

    Patel, S.; Durack, C.; Abella, F.; Shemesh, H.; Roig, M.; Lemberg, K.

    2015-01-01

    Cone beam computed tomography (CBCT) produces undistorted three-dimensional information of the maxillofacial skeleton, including the teeth and their surrounding tissues with a lower effective radiation dose than computed tomography. The aim of this paper is to: (i) review the current literature on t

  16. X-Ray Computed Tomography for Advanced Materials and Processes.

    Science.gov (United States)

    1992-06-30

    percent. In this example, we have assumed $I M, $5(X)K and $200K CT systems operating at 10 percent of the capital investment per year for maintenance...Computed Tomo &:aphy of Composites," WRDC-TR-90-4014, July 1990. 5. P. Burstein and R. H. Bossi, "A Guide to Computed Tomography System Specifications," WRDC...Lannutti, "Applications of High- Resolution Computed Tomography," Proceedings of the 1991 Industrial Computed Tomography II Topical Conference, May 20-24

  17. Non-diffusing photochromic gel for optical computed tomography phantoms

    Science.gov (United States)

    Jordan, K.

    2013-06-01

    This study examines photochromic response in radiation sensitive hydrogels. Genipin, crosslinked, gelatin gel can support high resolution images because the chromophores do not diffuse. A low power, 633 nm He-Ne laser was used to write lines into the gels by a photobleaching reaction. Optical cone-beam computed tomography (CBCT) scans mapped the high resolution images in 3D with 0.25 mm voxel resolution. A straight line was written into a deformed gel and then readout in its relaxed, initial shape. The curved, photo-bleached line demonstrated deformable 3D dosimetry is possible with this system to the balloon edge. High resolution, photochromic images provide key information for characterizing optical CT scanners and 3D dosimeters. Many, ionizing radiation, dosimeter materials demonstrate either a photochromic or photothermal response, allowing this approach to be widely used in quantitative 3D scanning.

  18. Glasses for 3D ultrasound computer tomography: phase compensation

    Science.gov (United States)

    Zapf, M.; Hopp, T.; Ruiter, N. V.

    2016-03-01

    Ultrasound Computer Tomography (USCT), developed at KIT, is a promising new imaging system for breast cancer diagnosis, and was successfully tested in a pilot study. The 3D USCT II prototype consists of several hundreds of ultrasound (US) transducers on a semi-ellipsoidal aperture. Spherical waves are sequentially emitted by individual transducers and received in parallel by many transducers. Reflectivity volumes are reconstructed by synthetic aperture focusing (SAFT). However, straight forward SAFT imaging leads to blurred images due to system imperfections. We present an extension of a previously proposed approach to enhance the images. This approach includes additional a priori information and system characteristics. Now spatial phase compensation was included. The approach was evaluated with a simulation and clinical data sets. An increase in the image quality was observed and quantitatively measured by SNR and other metrics.

  19. Quantitative photoacoustic tomography using illuminations from a single direction.

    Science.gov (United States)

    Pulkkinen, Aki; Cox, Ben T; Arridge, Simon R; Kaipio, Jari P; Tarvainen, Tanja

    2015-03-01

    Quantitative photoacoustic tomography is an emerging imaging technique aimed at estimating optical parameters inside tissues from photoacoustic images, which are formed by combining optical information and ultrasonic propagation. This optical parameter estimation problem is ill-posed and needs to be approached within the framework of inverse problems. It has been shown that, in general, estimating the spatial distribution of more than one optical parameter is a nonunique problem unless more than one illumination pattern is used. Generally, this is overcome by illuminating the target from various directions. However, in some cases, for example when thick samples are investigated, illuminating the target from different directions may not be possible. In this work, the use of spatially modulated illumination patterns at one side of the target is investigated with simulations. The results show that the spatially modulated illumination patterns from a single direction could be used to provide multiple illuminations for quantitative photoacoustic tomography. Furthermore, the results show that the approach can be used to distinguish absorption and scattering inclusions located near the surface of the target. However, when compared to a full multidirection illumination setup, the approach cannot be used to image as deep inside tissues.

  20. Using x-ray computed tomography in hydrology: Systems, resolutions, and limitations

    DEFF Research Database (Denmark)

    Wildenschild, Dorthe; Hopmans, J.W.; Vaz, C.M.P.;

    2002-01-01

    A combination of advances in experimental techniques and mathematical analysis has made it possible to characterize phase distribution and pore geometry in porous media using non-destructive X-ray computed tomography (CT). We present qualitative and quantitative CT results for partially saturated...

  1. Micro computed tomography for vascular exploration

    Directory of Open Access Journals (Sweden)

    Zhuang Zhen W

    2010-03-01

    Full Text Available Abstract Vascular exploration of small animals requires imaging hardware with a very high spatial resolution, capable of differentiating large as well as small vessels, in both in vivo and ex vivo studies. Micro Computed Tomography (micro-CT has emerged in recent years as the preferred modality for this purpose, providing high resolution 3D volumetric data suitable for analysis, quantification, validation, and visualization of results. The usefulness of micro-CT, however, can be adversely affected by a range of factors including physical animal preparation, numerical quantification, visualization of results, and quantification software with limited possibilities. Exacerbating these inherent difficulties is the lack of a unified standard for micro-CT imaging. Most micro-CT today is aimed at particular applications and the software tools needed for quantification, developed mainly by imaging hardware manufacturers, lack the level of detail needed to address more specific aims. This review highlights the capabilities of micro-CT for vascular exploration, describes the current state of imaging protocols, and offers guidelines and suggestions aimed at making micro-CT more accurate, replicable, and robust.

  2. Radiation doses from computed tomography in Australia

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, J.E.M.; Tingey, D.R.C

    1997-11-01

    Recent surveys in various countries have shown that computed tomography (CT) is a significant and growing contributor to the radiation dose from diagnostic radiology. Australia, with 332 CT scanners (18 per million people), is well endowed with CT equipment compared to European countries (6 to 13 per million people). Only Japan, with 8500 units (78 per million people), has a significantly higher proportion of CT scanners. In view of this, a survey of CT facilities, frequency of examinations, techniques and patient doses has been performed in Australia. It is estimated that there are 1 million CT examinations in Australia each year, resulting in a collective effective dose of 7000 Sv and a per caput dose of 0.39 mSv. This per caput dose is much larger than found in earlier studies in the UK and New Zealand but is less than 0.48 mSv in Japan. Using the ICRP risk factors, radiation doses from CT could be inducing about 280 fatal cancers per year in Australia. CT is therefore a significant, if not the major, single contributor to radiation doses and possible risk from diagnostic radiology. (authors) 28 refs., 11 tabs., 10 figs.

  3. Dedicated breast computed tomography: Basic aspects

    Energy Technology Data Exchange (ETDEWEB)

    Sarno, Antonio; Mettivier, Giovanni, E-mail: mettivier@na.infn.it; Russo, Paolo [Dipartimento di Fisica, Università di Napoli Federico II, Via Cintia, Napoli I-80126, Italy and INFN Sezione di Napoli, Napoli I-80126 (Italy)

    2015-06-15

    X-ray mammography of the compressed breast is well recognized as the “gold standard” for early detection of breast cancer, but its performance is not ideal. One limitation of screening mammography is tissue superposition, particularly for dense breasts. Since 2001, several research groups in the USA and in the European Union have developed computed tomography (CT) systems with digital detector technology dedicated to x-ray imaging of the uncompressed breast (breast CT or BCT) for breast cancer screening and diagnosis. This CT technology—tracing back to initial studies in the 1970s—allows some of the limitations of mammography to be overcome, keeping the levels of radiation dose to the radiosensitive breast glandular tissue similar to that of two-view mammography for the same breast size and composition. This paper presents an evaluation of the research efforts carried out in the invention, development, and improvement of BCT with dedicated scanners with state-of-the-art technology, including initial steps toward commercialization, after more than a decade of R and D in the laboratory and/or in the clinic. The intended focus here is on the technological/engineering aspects of BCT and on outlining advantages and limitations as reported in the related literature. Prospects for future research in this field are discussed.

  4. Computed tomography characterisation of additive manufacturing materials.

    Science.gov (United States)

    Bibb, Richard; Thompson, Darren; Winder, John

    2011-06-01

    Additive manufacturing, covering processes frequently referred to as rapid prototyping and rapid manufacturing, provides new opportunities in the manufacture of highly complex and custom-fitting medical devices and products. Whilst many medical applications of AM have been explored and physical properties of the resulting parts have been studied, the characterisation of AM materials in computed tomography has not been explored. The aim of this study was to determine the CT number of commonly used AM materials. There are many potential applications of the information resulting from this study in the design and manufacture of wearable medical devices, implants, prostheses and medical imaging test phantoms. A selection of 19 AM material samples were CT scanned and the resultant images analysed to ascertain the materials' CT number and appearance in the images. It was found that some AM materials have CT numbers very similar to human tissues, FDM, SLA and SLS produce samples that appear uniform on CT images and that 3D printed materials show a variation in internal structure.

  5. Portable Digital Radiography and Computed Tomography Manual

    Energy Technology Data Exchange (ETDEWEB)

    2007-11-01

    This user manual describes the function and use of the portable digital radiography and computed tomography (DRCT) scanner. The manual gives a general overview of x-ray imaging systems along with a description of the DRCT system. An inventory of the all the system components, organized by shipping container, is also included. In addition, detailed, step-by-step procedures are provided for all of the exercises necessary for a novice user to successfully collect digital radiographs and tomographic images of an object, including instructions on system assembly and detector calibration and system alignment. There is also a short section covering the limited system care and maintenance needs. Descriptions of the included software packages, the DRCT Digital Imager used for system operation, and the DRCT Image Processing Interface used for image viewing and tomographic data reconstruction are given in the appendixes. The appendixes also include a cheat sheet for more experienced users, a listing of known system problems and how to mitigate them, and an inventory check-off sheet suitable for copying and including with the machine for shipment purposes.

  6. Computed Tomography Following Body Stuffing Heroin

    Directory of Open Access Journals (Sweden)

    Sean P. Nordt

    2015-12-01

    Full Text Available A 37-year-old male presented to the emergency department (ED in police custody for “medical clearance” before being taken to jail. The patient was approached by police officers for suspicion of selling illicit drugs. When approached by police he ran away and was witnessed to swallow several small plastic baggies suspected to contain heroin. He was apprehended and brought to the ED. On arrival, he was asymptomatic with a blood pressure 144/83mmHg, heart rate 67bpm, respiratory rate of 19bpm, oxygen saturation of 99% on room air and afebrile. A Glasgow coma score was 15 and he was alert and oriented to person, place and time. Patient had a negative review of systems. On physical examination pupils were 4mm and reactive to light, lungs clear to auscultation and had normal respiratory rate with normal cardiovascular exam. Abdomen was soft, non-tender and non-distended with present bowel sounds. The patient admitted to ingesting approximately 20 packets of heroin to avoid being charged with possession. The patient declined activated charcoal and whole bowel irrigation (WBI with polyethylene glycol-electrolyte solution (PEG-ELS. The patient declined a urine toxicology immunoassay screen. A computed tomography (CT of his abdomen with contrast was obtained and read as normal except for a cluster of foreign bodies within the distal stomach likely contained within a plastic bag.

  7. Virtual computed tomography cystoscopy in bladder pathologies

    Directory of Open Access Journals (Sweden)

    Halil Arslan

    2006-04-01

    Full Text Available OBJECTIVE: Assessed the usefulness of virtual cystoscopy performed with multidetector computed tomography (CT in patients with different urinary bladder pathologies compared to the conventional cystoscopy. MATERIALS AND METHODS: Eighteen patients with different bladder pathologies, which consisted of 11 tumors, 3 diverticula, 2 trabecular changes and 2 stones, were assessed with conventional cystoscopy and virtual CT cystoscopy. The results of virtual CT cystoscopy were compared with the findings of conventional cystoscopy. We determined the detection rate and positive predictive value of CT imaging based virtual cystoscopy in the diagnosis of urinary bladder lesions. RESULTS: CT scanning was well tolerated by all patients, and no complications occurred. Images in 16 (88% of the 18 virtual cystoscopic examinations were either of excellent or good quality. All tumors except one, 2 trabecular changes and 2 stones were characterized with similar findings in the both of methods. The masses ranged from 0.4 to 7.0 cm in diameter. While conventional cystoscopy could not evaluate interior part of the diverticulum, virtual CT cystoscopy could demonstrate clearly within it. There were no false-positive findings in our series. CONCLUSION: Virtual CT cystoscopy is a promising technique to be used in the detection of bladder lesions. It should be considered especially at the evaluation of bladder diverticula. In the future, it may be possible or even advantageous to incorporate into the imaging algorithm for evaluation of bladder lesion.

  8. Virtual computed tomography cystoscopy in bladder pathologies

    Energy Technology Data Exchange (ETDEWEB)

    Arslan, Halil; Ceylan, Kadir; Harman, Mustafa; Yilmaz, Yuksel; Temizoz, Osman; Can, Saban [Yuzuncu Yil University School of Medicine, Van (Turkey). Dept. of Radiology and Urology]. E-mail: drhalilarslan@hotmail.com

    2006-03-15

    Objective: assessed the usefulness of virtual cystoscopy performed with multidetector computed tomography (CT) in patients with different urinary bladder pathologies compared to the conventional cystoscopy.Materials and methods: eighteen patients with different bladder pathologies, which consisted of 11 tumors, 3 diverticula, 2 trabecular changes and 2 stones, were assessed with conventional cystoscopy and virtual CT cystoscopy. The results of virtual CT cystoscopy were compared with the findings of conventional cystoscopy. We determined the detection rate and positive predictive value of CT imaging based virtual cystoscopy in the diagnosis of urinary bladder lesions. Results: CT scanning was well tolerated by all patients, and no complications occurred. Images in 16 (88%) of the 18 virtual cystoscopic examinations were either of excellent or good quality. All tumors except one, 2 trabecular changes and 2 stones were characterized with similar findings in the both of methods. The masses ranged from 0.4 to 7.0 cm in diameter. While conventional cystoscopy could not evaluate interior part of the diverticulum, virtual CT cystoscopy could demonstrate clearly within it. There were no false-positive findings in our series. Conclusion: virtual CT cystoscopy is a promising technique to be used in the detection of bladder lesions. It should be considered especially at the evaluation of bladder diverticula. In the future, it may be possible or even advantageous to incorporate into the imaging algorithm for evaluation of bladder lesion. (author)

  9. Application of computed tomography to spinal disorders

    Energy Technology Data Exchange (ETDEWEB)

    Sha, N.; Kurihara, A.; Kataoka, O. (Kobe Univ. (Japan). School of Medicine)

    1980-08-01

    The axial tomographic examination of the spine and its soft tissues is now readily available for orthopaedic surgery. If the appropriate conditions are maintained, computed tomography (CT) can provide useful information concerning the diagnosis and the treatment of spinal diseases. There are, however, some pitfalls in interpreting CT scans: 1) the existence of the lesion may be masked, and 2) its extent and configuration may be over- or under-evaluated depending on such technical factors as the slicing level, the slicing angle, the window width, and the window level. Experimental studies were carried out on a plaster of Paris model of the spine and a cadaver spine to determine the appropriate technical factors by which the CT (EMI whole body CT scanner 5005) can be applied accurately to a diseased spine. The factors obtained were then applied in examining ninety-nine patients with various spinal disorders. Window levels ranging between 100 and 150 were found to be most appropriate. The slicing angle should be 90/sup 0/, or perpendicular to the long axis of the object under study. However, deviations of +10 or -10 degrees are acceptable. The CT view of the spine may be divided into two patterns at the cervical and thoracic levels and into three patterns at the lumbar level. In addition, the usefulness and the diagnostic value of CT for various spinal problems are discussed based on our clinical material.

  10. Computed tomography in acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Loevblad, Karl-Olof [HUG-Geneva University Hospital, Geneva University Medical School, Department of Neuroradiology, Department of Imaging and Medical Informatics, Geneva (Switzerland); Baird, Alison E. [SUNY Downstate Medical Center, Cerebrovascular Disease and Stroke, 450 Clarkson Avenue, Box 1213, Brooklyn, NY (United States)

    2010-03-15

    Stroke remains the third most important cause of mortality in industrialized countries; this has prompted research for improvements in both diagnostic and therapeutic strategies for patients with signs of acute cerebral ischemia. Over the last decade, there has been a parallel in progress in techniques in both diagnostic and therapeutic options. While previously only used for excluding hemorrhage, imaging now has the possibility to detect ischemia, vascular occlusion, as well as detect tissue at risk in one setting. It should also allow to monitor treatment and predict/exclude therapeutic complications. Parallel to advances in magnetic resonance imaging of stroke, computed tomography has improved immensely over the last decade due to the development of CT scanners that are faster and that allow to acquire studies such as CT perfusion or CT angiography in a reliable way. CT can detect many signs that might help us detect impending signs of massive infarction, but we still lack the experience to use these alone to prevent a patient from benefitting from possible therapy. (orig.)

  11. Application of computed tomography in paleoanthropological research

    Institute of Scientific and Technical Information of China (English)

    Xiujie Wu; Lynne A.Schepartz

    2009-01-01

    Hominin fossils are the most important materials for exploring questions about human origins and evolution. Because human fossils are very rare, it is impossible to use highly destructive techniques in order to study their morphology. Traditional analyses can only rely on the information gained from the study of the external morphology of specimens, and these approaches limited the study of human evolution. The application of computed tomography (CT) has facilitated major developments in paleoanthropology. To date, few studies on Chinese hominin fossils have used CT scanning methodology, but this is rapidly changing. In order to better understand the appli-cation of CT methodology in paleoanthropology, we review the applications of CT scanning on hominin fossils throughout the world.Studies examined include virtual fossil reconstruction, the use of endocasts to elucidate brain morphology, biomechanical analyses of bone distribution, imaging of mummies and research on early human health, and skeletal and dental microanatomical research.2009 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.

  12. Computed tomography of the orbital lesions

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seong Eon; Suh, Soo Jhi; Kim, Ho Kyun; Kim, Soon Yong [Kyung Hee University School of Medicine, Seoul (Korea, Republic of)

    1980-06-15

    The use of computed tomography in investigation of orbital lesions was of value for the localization of the lesions as well as making the specific diagnosis. We advocated the combined use of transverse axial section and contrast enhancement in CT as a routine procedure often including coronal section in the diagnosis of orbital lesions because of its usefulness and more precise three dimensional imaging. The authors examined 68 patients with various ophthalmic problems by EMI-CT scanner 5005 from October 1977 to November 1979. Fifty one orbital lesions out of 68 CT scans were analyzed by CT, angiography and operative findings and results were as follows; 1. Among 43 males and 25 females, their age range was from 4 months to 66 years with the most frequent age group of first decade (17 cases; 25%) 2. The distribution of the lesions was mucocele, pseudotumor, optic nerve atrophy, metastasis, lacrimal gland tumor, persistent hypertrophic primary vitreous, granulosa cell myoblastoma, hemangioma in order with 13 malignancies (25%). 3. It was difficult to differentiate pathological diagnosis of the lesions, but the character of the lesions was determined by its characteristic location, and its relationship to eyeball, optic nerve, extraocular muscles and bony orbit. 4. It was thought that more accurate diagnosis of orbital lesions could be made by development of CT scanner having fine matrix, short time exposure and thin slice in the future.

  13. Portable Digital Radiography and Computed Tomography Manual

    Energy Technology Data Exchange (ETDEWEB)

    2007-11-01

    This user manual describes the function and use of the portable digital radiography and computed tomography (DRCT) scanner. The manual gives a general overview of x-ray imaging systems along with a description of the DRCT system. An inventory of the all the system components, organized by shipping container, is also included. In addition, detailed, step-by-step procedures are provided for all of the exercises necessary for a novice user to successfully collect digital radiographs and tomographic images of an object, including instructions on system assembly and detector calibration and system alignment. There is also a short section covering the limited system care and maintenance needs. Descriptions of the included software packages, the DRCT Digital Imager used for system operation, and the DRCT Image Processing Interface used for image viewing and tomographic data reconstruction are given in the appendixes. The appendixes also include a cheat sheet for more experienced users, a listing of known system problems and how to mitigate them, and an inventory check-off sheet suitable for copying and including with the machine for shipment purposes.

  14. Gradient computation for VTI acoustic wavefield tomography

    KAUST Repository

    Li, Vladimir

    2016-09-06

    Wavefield tomography can handle complex subsurface geology better than ray-based techniques and, ultimately, provide a higher resolution. Here, we implement forward and adjoint wavefield extrapolation for VTI (transversely isotropic with a vertical symmetry axis) media using a pseudospectral operator that employes a separable approximation of the P-wave dispersion relation. This operator is employed to derive the gradients of the differential semblance optimization (DSO) and modified stack-power objective functions. We also obtain the gradient expressions for the data-domain objective function, which can incorporate borehole information necessary for stable VTI velocity analysis. These gradients are compared to the ones obtained with a space-time finite-difference (FD) scheme for a system of coupled wave equations. Whereas the kernels computed with the two wave-equation operators are similar, the pseudospectral method is not hampered by the imprint of the shear-wave artifact. Numerical examples also show that the modified stack-power objective function produces cleaner gradients than the more conventional DSO operator.

  15. Perfusion computed tomography in renal cell carcinoma

    Institute of Scientific and Technical Information of China (English)

    Chandan; J; Das; Usha; Thingujam; Ananya; Panda; Sanjay; Sharma; Arun; Kumar; Gupta

    2015-01-01

    Various imaging modalities are available for the diagnosis, staging and response evaluation of patients with renal cell carcinoma(RCC). While contrast enhanced computed tomography(CT) is used as the standard of imaging for size, morphological evaluation and response assessment in RCC, a new functional imaging technique like perfusion CT(p CT), goes down to the molecular level and provides new perspectives in imaging of RCC. p CT depicts regional tumor perfusion and vascular permeability which are indirect parameters of tumor angiogenesis and thereby provides vital information regarding tumor microenvironment. Also response evaluation using p CT may predate the size criteria used in Response Evaluation Criteria in Solid Tumors, as changes in the perfusion occurs earlier following tissue kinase inhibitors before any actual change in size. This may potentially help in predicting prognosis, better selection of therapy and more accurate and better response evaluation in patients with RCC. This article describes the techniques and role of p CT in staging and response assessment in patients with RCCs.

  16. REVIEW: X-ray computed tomography

    Science.gov (United States)

    Kalender, Willi A.

    2006-07-01

    X-ray computed tomography (CT), introduced into clinical practice in 1972, was the first of the modern slice-imaging modalities. To reconstruct images mathematically from measured data and to display and to archive them in digital form was a novelty then and is commonplace today. CT has shown a steady upward trend with respect to technology, performance and clinical use independent of predictions and expert assessments which forecast in the 1980s that it would be completely replaced by magnetic resonance imaging. CT not only survived but exhibited a true renaissance due to the introduction of spiral scanning which meant the transition from slice-by-slice imaging to true volume imaging. Complemented by the introduction of array detector technology in the 1990s, CT today allows imaging of whole organs or the whole body in 5 to 20 s with sub-millimetre isotropic resolution. This review of CT will proceed in chronological order focussing on technology, image quality and clinical applications. In its final part it will also briefly allude to novel uses of CT such as dual-source CT, C-arm flat-panel-detector CT and micro-CT. At present CT possibly exhibits a higher innovation rate than ever before. In consequence the topical and most recent developments will receive the greatest attention.

  17. Computer tomography-aided ventriculography and cisternography

    Energy Technology Data Exchange (ETDEWEB)

    Cernoch, Z.; Sercl, M.; Heger, L.; Parizek, J. (Karlova Univ., Hradec Kralove (Czechoslovakia). Lekarska Fakulta)

    1983-01-28

    Computer tomography was used in 42 patients for the exploration of ventricular and subarachnoidal spaces following intraventricular, lumbar or suboccipital injections of 3 to 5 ml Amipaque using the kind of manoeuvre to permit optimum filling of the region concerned. This type of CT ventriculo- or cisternography is a significant supplement to plain CT examination particularly because it supplies data on the causes of CSF passage blocks. Thus, in two female patients it proved possible to localize cysts in the 3rd ventricle, the density of which was no different from that of CSF. As regards benign stenoses of the aqueduct, it is likely to yield less information than conventional specific ventriculography. On the other hand, the technique gives perfect visualization of all possible communications between pathological intracranial cavities and the ventricular system. CT cisternography proved useful for the identification of small-size isodense growths in the region of the sella turcica, and brought convincing evidence of the causes of profuse liquorrhea by demonstrating the presence of nasal meningocele. It was also found helpful in the analysis of the craniocervical region, otherwise difficult to survey.

  18. Intraperitoneal tuberculous abscess: computed tomography features

    Institute of Scientific and Technical Information of China (English)

    Peng; Dong; Jing-Jing; Chen; Xi-Zhen; Wang; Ya-Qin; Wang

    2015-01-01

    AIM: To evaluate the computed tomography(CT) features of intraperitoneal tuberculous abscess(IPTA). METHODS: Eight patients with IPTA confirmed by pathology were analyzed retrospectively. The clinical symptoms, medical images, and surgical findings were evaluated. Involvement of the intestine, peritoneum, viscera, and lymph nodes was also assessed. RESULTS: All 8 patients had a history of abdominal discomfort for 1 to 6 mo. Physical examination revealed a palpable abdominal mass in 6 patients. Three patients had no evidence of pulmonary tuberculosis(TB). All IPTAs(11 abscesses) were seen as a multiseptated, peripherally enhanced, hypodense mass with enlarged, rim-enhanced lymph nodes. The largest abscess diameter ranged from 4.5 cm to 12.2 cm. CT showed 2 types of IPTA: Lymph node fusion and encapsulation. Of the 8 patients, one had liver tuberculosis and one had splenic and ovarian tuberculosis. Two cases showed involvement of the terminal ileum and ileocecal junction. Ascites were found in 4 cases. Three patients had peritonitis and mesenteritis. Three patients showed involvement of the omentum. Three patients had histological evidence of caseating granuloma, and 5 had histological evidence of acid-fast bacilli. CONCLUSION: CT is crucial in the detection and characterization of IPTA. Certain CT findings are necessary for correct diagnosis.

  19. A Detector for Proton Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Blazey, G.; et al.

    2013-12-06

    Radiation therapy is a widely recognized treatment for cancer. Energetic protons have distinct features that set them apart from photons and make them desirable for cancer therapy as well as medical imaging. The clinical interest in heavy ion therapy is due to the fact that ions deposit almost all of their energy in a sharp peak – the Bragg peak- at the very end of their path. Proton beams can be used to precisely localize a tumor and deliver an exact dose to the tumor with small doses to the surrounding tissue. Proton computed tomography (pCT) provides direct information on the location on the target tumor, and avoids position uncertainty caused by treatment planning based on imaging with X-ray CT. The pCT project goal is to measure and reconstruct the proton relative stopping power distribution directly in situ. To ensure the full advantage of cancer treatment with 200 MeV proton beams, pCT must be realized.

  20. Acute Calculous Cholecystitis Missed on Computed Tomography and Ultrasound but Diagnosed with Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

    Directory of Open Access Journals (Sweden)

    Carina Mari Aparici

    2016-01-01

    Full Text Available We present a case of a 69-year-old patient who underwent ascending aortic aneurysm repair with aortic valve replacement. On postsurgical day 12, he developed leukocytosis and low-grade fevers. The chest computed tomography (CT showed a periaortic hematoma which represents a postsurgical change from aortic aneurysm repair, and a small pericardial effusion. The abdominal ultrasound showed cholelithiasis without any sign of cholecystitis. Finally, a fluorodeoxyglucose (FDG-positron emission tomography (PET/CT examination was ordered to find the cause of fever of unknown origin, and it showed increased FDG uptake in the gallbladder wall, with no uptake in the lumen. FDG-PET/CT can diagnose acute cholecystitis in patients with nonspecific clinical symptoms and laboratory results.

  1. Diffuse abnormalities of the trachea: computed tomography findings

    Energy Technology Data Exchange (ETDEWEB)

    Marchiori, Edson [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Radiologia]. E-mail: edmarchiori@gmail.com; Pozes, Aline Serfaty [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia; Souza Junior, Arthur Soares [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Escola de Medicina. Dept. de Radiologia; Escuissato, Dante Luiz [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Radiologia; Irion, Klaus Loureiro [The Cardiothoracic Centre NHS Trust, Liverpool (United Kingdom); Araujo Neto, Cesar de [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Dept. de Radiologia; Barillo, Jorge Luiz; Zanetti, Glaucia [Faculdade de Medicina de Petropolis (FMP), RJ (Brazil). Dept. de Cirurgia Clinica; Souza, Carolina Althoff [University of Ottawa, Ottawa, ON (Canada)

    2008-01-15

    The aim of this pictorial essay was to present the main computed tomography findings seen in diffuse diseases of the trachea. The diseases studied included amyloidosis, tracheobronchopathia osteochondroplastica, tracheobronchomegaly, laryngotracheobronchial papillomatosis, lymphoma, neurofibromatosis, relapsing polychondritis, Wegener's granulomatosis, tuberculosis, paracoccidioidomycosis, and tracheobronchomalacia. The most common computed tomography finding was thickening of the walls of the trachea, with or without nodules, parietal calcifications, or involvement of the posterior wall. Although computed tomography allows the detection and characterization of diseases of the central airways, and the correlation with clinical data reduces the diagnostic possibilities, bronchoscopy with biopsy remains the most useful procedure for the diagnosis of diffuse lesions of the trachea. (author)

  2. Abdominal alterations in disseminated paracoccidioidomycosis: computed tomography findings*

    Science.gov (United States)

    Vermelho, Marli Batista Fernandes; Correia, Ademir Silva; Michailowsky, Tânia Cibele de Almeida; Suzart, Elizete Kazumi Kuniyoshi; Ibanês, Aline Santos; Almeida, Lanamar Aparecida; Khoury, Zarifa; Barba, Mário Flores

    2015-01-01

    Objective To evaluate the incidence and spectrum of abdominal computed tomography imaging findings in patients with paracoccidioidomycosis. Materials and Methods Retrospective analysis of abdominal computed tomography images of 26 patients with disseminated paracoccidioidomycosis. Results Abnormal abdominal tomographic findings were observed in 18 patients (69.2%), while no significant finding was observed in the other 8 (30.8%) patients. Conclusion Computed tomography has demonstrated to play a relevant role in the screening and detection of abdominal abnormalities in patients with disseminated paracoccidioidomycosis. PMID:25987748

  3. Abdominal alterations in disseminated paracoccidioidomycosis: computed tomography findings

    Energy Technology Data Exchange (ETDEWEB)

    Vermelho, Marli Batista Fernandes; Correia, Ademir Silva; Michailowsky, Tania Cibele de Almeida; Suzart, Elizete Kazumi Kuniyoshi; Ibanes, Aline Santos; Almeida, Lanamar Aparecida; Khoury, Zarifa; Barba, Mario Flores, E-mail: marlivermelho@globo.com [Instituto de Infectologia Emilio Ribas (IIER), Sao Paulo, SP (Brazil)

    2015-03-15

    Objective: to evaluate the incidence and spectrum of abdominal computed tomography imaging findings in patients with paracoccidioidomycosis. Materials and methods: retrospective analysis of abdominal computed tomography images of 26 patients with disseminated paracoccidioidomycosis. Results: abnormal abdominal tomographic findings were observed in 18 patients (69.2%), while no significant finding was observed in the other 8 (30.8%) patients. Conclusion: computed tomography has demonstrated to play a relevant role in the screening and detection of abdominal abnormalities in patients with disseminated paracoccidioidomycosis. (author)

  4. Quantifying the debonding of inclusions through tomography and computational homology.

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei-Yang; Johnson, George C. (University of California, Berkeley, Berkeley, CA); Mota, Alejandro; Foulk, James W., III; Jin, Huiqing

    2010-09-01

    This report describes a Laboratory Directed Research and Development (LDRD) project to use of synchrotron-radiation computed tomography (SRCT) data to determine the conditions and mechanisms that lead to void nucleation in rolled alloys. The Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory (LBNL) has provided SRCT data of a few specimens of 7075-T7351 aluminum plate (widely used for aerospace applications) stretched to failure, loaded in directions perpendicular and parallel to the rolling direction. The resolution of SRCT data is 900nm, which allows elucidation of the mechanisms governing void growth and coalescence. This resolution is not fine enough, however, for nucleation. We propose the use statistics and image processing techniques to obtain sub-resolution scale information from these data, and thus determine where in the specimen and when during the loading program nucleation occurs and the mechanisms that lead to it. Quantitative analysis of the tomography data, however, leads to the conclusion that the reconstruction process compromises the information obtained from the scans. Alternate, more powerful reconstruction algorithms are needed to address this problem, but those fall beyond the scope of this project.

  5. Calcium score of small coronary calcifications on multidetector computed tomography

    DEFF Research Database (Denmark)

    Groen, J M; Kofoed, K F; Zacho, M;

    2013-01-01

    Multi detector computed tomography (MDCT) underestimates the coronary calcium score as compared to electron beam tomography (EBT). Therefore clinical risk stratification based on MDCT calcium scoring may be inaccurate. The aim of this study was to assess the feasibility of a new phantom which ena...

  6. Positron emission tomography-computed tomography has a clinical impact for patients with cervical cancer

    DEFF Research Database (Denmark)

    Sandvik, Rikke Mulvad; Jensen, Pernille Tine; Hendel, Helle W

    2011-01-01

    Many studies have found that positron emission tomography-computed tomography (PET-CT) has a high sensitivity and specificity in the identification of metastasis in cervical cancer. Herlev Hospital, Denmark, has been performing PET-CTs in stage I-IV cervical cancer since 1 May 2006. The present...

  7. Assessment of coronary artery bypass graft patency by multidetector computed tomography and electron-beam tomography

    NARCIS (Netherlands)

    Piers, LH; Dorgelo, J; Tio, RA; Jessurun, GAJ; Oudkerk, M; Zijlstra, F

    2005-01-01

    This case report describes the use of retrospectively ECG-gated 16-slice multidetector computed tomography (MDCT) and electron-beam tomography (EBT) for assessing bypass graft patency in two patients with recurrent angina after coronary artery bypass graft surgery. The results of each tomographic mo

  8. Positron emission tomography-computed tomography has a clinical impact for patients with cervical cancer

    DEFF Research Database (Denmark)

    Sandvik, Rikke Mulvad; Jensen, Pernille Tine; Hendel, Helle W

    2011-01-01

    Many studies have found that positron emission tomography-computed tomography (PET-CT) has a high sensitivity and specificity in the identification of metastasis in cervical cancer. Herlev Hospital, Denmark, has been performing PET-CTs in stage I-IV cervical cancer since 1 May 2006. The present...

  9. Positron emission tomography/computed tomography for optimized colon cancer staging and follow up

    DEFF Research Database (Denmark)

    Engelmann, Bodil Elisabeth; Loft, Annika; Kjær, Andreas;

    2014-01-01

    OBJECTIVES: Optimal management of colon cancer (CC) requires detailed assessment of extent of disease. This study prospectively investigates the diagnostic accuracy of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (PET/CT) for staging and detection of recurrence...

  10. Bayesian parameter estimation in spectral quantitative photoacoustic tomography

    Science.gov (United States)

    Pulkkinen, Aki; Cox, Ben T.; Arridge, Simon R.; Kaipio, Jari P.; Tarvainen, Tanja

    2016-03-01

    Photoacoustic tomography (PAT) is an imaging technique combining strong contrast of optical imaging to high spatial resolution of ultrasound imaging. These strengths are achieved via photoacoustic effect, where a spatial absorption of light pulse is converted into a measurable propagating ultrasound wave. The method is seen as a potential tool for small animal imaging, pre-clinical investigations, study of blood vessels and vasculature, as well as for cancer imaging. The goal in PAT is to form an image of the absorbed optical energy density field via acoustic inverse problem approaches from the measured ultrasound data. Quantitative PAT (QPAT) proceeds from these images and forms quantitative estimates of the optical properties of the target. This optical inverse problem of QPAT is illposed. To alleviate the issue, spectral QPAT (SQPAT) utilizes PAT data formed at multiple optical wavelengths simultaneously with optical parameter models of tissue to form quantitative estimates of the parameters of interest. In this work, the inverse problem of SQPAT is investigated. Light propagation is modelled using the diffusion equation. Optical absorption is described with chromophore concentration weighted sum of known chromophore absorption spectra. Scattering is described by Mie scattering theory with an exponential power law. In the inverse problem, the spatially varying unknown parameters of interest are the chromophore concentrations, the Mie scattering parameters (power law factor and the exponent), and Gruneisen parameter. The inverse problem is approached with a Bayesian method. It is numerically demonstrated, that estimation of all parameters of interest is possible with the approach.

  11. The Use of GPUs for Solving the Computed Tomography Problem

    Directory of Open Access Journals (Sweden)

    A.E. Kovtanyuk

    2014-07-01

    Full Text Available Computed tomography (CT is a widespread method used to study the internal structure of objects. The method has applications in medicine, industry and other fields of human activity. In particular, Electronic Imaging, as a species CT, can be used to restore the structure of nanosized objects. Accurate and rapid results are in high demand in modern science. However, there are computational limitations that bound the possible usefulness of CT. On the other hand, the introduction of high-performance calculations using Graphics Processing Units (GPUs provides improving quality and performance of computed tomography investigations. Moreover, parallel computing with GPUs gives significantly higher computation speeds when compared with (Central Processing Units CPUs, because of architectural advantages of the former. In this paper a computed tomography method of recovering the image using parallel computations powered by NVIDIA CUDA technology is considered. The implementation of this approach significantly reduces the required time for solving the CT problem.

  12. Single-photon emission computed tomography/computed tomography in brain tumors.

    Science.gov (United States)

    Schillaci, Orazio; Filippi, Luca; Manni, Carlo; Santoni, Riccardo

    2007-01-01

    Anatomic imaging procedures (computed tomography [CT] and magnetic resonance imaging [MRI]) have become essential tools for brain tumor assessment. Functional images (positron emission tomography [PET] and single-photon emission computed tomography [SPECT]) can provide additional information useful during the diagnostic workup to determine the degree of malignancy and as a substitute or guide for biopsy. After surgery and/or radiotherapy, nuclear medicine examinations are essential to assess persistence of tumor, to differentiate recurrence from radiation necrosis and gliosis, and to monitor the disease. The combination of functional images with anatomic ones is of the utmost importance for a full evaluation of these patients, which can be obtained by means of imaging fusion. Despite the fast-growing diffusion of PET, in most cases of brain tumors, SPECT studies are adequate and provide results that parallel those obtained with PET. The main limitation of SPECT imaging with brain tumor-seeking radiopharmaceuticals is the lack of precise anatomic details; this drawback is overcome by the fusion with morphological studies that provide an anatomic map to scintigraphic data. In the past, software-based fusion of independently performed SPECT and CT or MRI demonstrated usefulness for brain tumor assessment, but this process is often time consuming and not practical for everyday nuclear medicine studies. The recent development of dual-modality integrated imaging systems, which allow the acquisition of SPECT and CT images in the same scanning session, and their co-registration by means of the hardware, has facilitated this process. In SPECT studies of brain tumors with various radiopharmaceuticals, fused images are helpful in providing the precise localization of neoplastic lesions, and in excluding the disease in sites of physiologic tracer uptake. This information is useful for optimizing diagnosis, therapy monitoring, and radiotherapy treatment planning, with a

  13. Computed tomography (CT) and diastematomyelia's diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Santos, M.B. dos; Luca, V. de; Ferreira, M.A.S. (Rio de Janeiro Univ. (Brazil). Faculdade de Medicina); Barros, A.P. de (Rio de Janeiro Univ. (Brazil). Hospital Universitario)

    After a case of diastematomyelia observed at the University Hospital (Federal University of Rio de Janeiro, Brazil) a review is done of the pertaining literature, and the contribution of the computed tomography for the diagnosis of this disease is emphasized.

  14. Time Domain Terahertz Axial Computed Tomography Non Destructive Evaluation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to demonstrate key elements of feasibility for a high speed automated time domain terahertz computed axial tomography (TD-THz CT) non destructive...

  15. Time Domain Terahertz Axial Computed Tomography Non Destructive Evaluation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this Phase 2 project, we propose to develop, construct, and deliver to NASA a computed axial tomography time-domain terahertz (CT TD-THz) non destructive...

  16. Computed tomography and childhood seizure disorder in Ibadan ...

    African Journals Online (AJOL)

    Computed tomography and childhood seizure disorder in Ibadan. ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING ... the subjects who had cranial scans done in five years were children with seizures disorders.

  17. Computer-aided classification of lung nodules on computed tomography images via deep learning technique.

    Science.gov (United States)

    Hua, Kai-Lung; Hsu, Che-Hao; Hidayati, Shintami Chusnul; Cheng, Wen-Huang; Chen, Yu-Jen

    2015-01-01

    Lung cancer has a poor prognosis when not diagnosed early and unresectable lesions are present. The management of small lung nodules noted on computed tomography scan is controversial due to uncertain tumor characteristics. A conventional computer-aided diagnosis (CAD) scheme requires several image processing and pattern recognition steps to accomplish a quantitative tumor differentiation result. In such an ad hoc image analysis pipeline, every step depends heavily on the performance of the previous step. Accordingly, tuning of classification performance in a conventional CAD scheme is very complicated and arduous. Deep learning techniques, on the other hand, have the intrinsic advantage of an automatic exploitation feature and tuning of performance in a seamless fashion. In this study, we attempted to simplify the image analysis pipeline of conventional CAD with deep learning techniques. Specifically, we introduced models of a deep belief network and a convolutional neural network in the context of nodule classification in computed tomography images. Two baseline methods with feature computing steps were implemented for comparison. The experimental results suggest that deep learning methods could achieve better discriminative results and hold promise in the CAD application domain.

  18. Nonlinear quantitative photoacoustic tomography with two-photon absorption

    CERN Document Server

    Ren, Kui

    2016-01-01

    Two-photon photoacoustic tomography (TP-PAT) is a non-invasive optical molecular imaging modality that aims at inferring two-photon absorption property of heterogeneous media from photoacoustic measurements. In this work, we analyze an inverse problem in quantitative TP-PAT where we intend to reconstruct optical coefficients in a semilinear elliptic PDE, the mathematical model for the propagation of near infra-red photons in tissue-like optical media with two-photon absorption, from the internal absorbed energy data. We derive uniqueness and stability results on the reconstructions of single and multiple optical coefficients, and present some numerical reconstruction results based on synthetic data to complement the theoretical analysis.

  19. Optimisation of post mortem cardiac computed tomography compared to optical coherence tomography and histopathology - Technical note

    DEFF Research Database (Denmark)

    Precht, Helle; Leth, Peter Mygind; Thygesen, Jesper

    2014-01-01

    Introduction: Coronary atherosclerosis is a leading cause of mortality. New technological developments in computed tomography (CT), including dual energy, iterative reconstructions and high definition scanning, could significantly improve the non-invasive identification of atherosclerosis plaques...

  20. Central benzodiazepine receptor imaging and quantitation with single photon emission computerised tomography

    DEFF Research Database (Denmark)

    Okocha, C I; Kapczinski, F; Lassen, N

    1995-01-01

    This review discusses the current use of single photon emission computerised tomography (SPECT) for central benzodiazepine receptor imaging and quantitation. The general principles underlying SPECT imaging and receptor quantitation methods such as the kinetic, pseudo-equilibrium and steady...

  1. Cone beam computed tomography in Endodontics - a review.

    Science.gov (United States)

    Patel, S; Durack, C; Abella, F; Shemesh, H; Roig, M; Lemberg, K

    2015-01-01

    Cone beam computed tomography (CBCT) produces undistorted three-dimensional information of the maxillofacial skeleton, including the teeth and their surrounding tissues with a lower effective radiation dose than computed tomography. The aim of this paper is to: (i) review the current literature on the applications and limitations of CBCT; (ii) make recommendations for the use of CBCT in Endodontics; (iii) highlight areas of further research of CBCT in Endodontics. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  2. A Clinical Evaluation of Cone Beam Computed Tomography

    Science.gov (United States)

    2013-07-31

    multidetector computed tomography and cone beam computed tomography in the assessment of dental implant site dimensions. Dentomaxillofac Radiol 2011;40:67-75...submitted to the Faculty of the Endodontics Graduate Program Naval Postgraduate Dental School Uniformed Services University of the Health Sciences...in partial fulfillment of the requirements of the degree of Master of Science in Oral Biology June 2013 Naval Postgraduate Dental

  3. Computed tomography of the mediastinum in myasthenia gravis

    Energy Technology Data Exchange (ETDEWEB)

    Guertler, K.F.; Janzen, R.W.C.; Hagemann, J.; Otto, H.F.

    1982-01-01

    Computed tomography of the mediastinum was performed in 45 patients with myasthenia gravis. Surgery was carried out in fourteen. Amongst these, there were four thymomas, one thymolipoma, eight thymic hyperplasias and one normal thymus gland. A further patient, who did not have surgery, probably also had a thymic tumour. The normal thymus and thymic hyperplasia cannot be distinguished on computed tomography. Differentiation of small thymomas from normal thymus is not always possible. Invasion by thymomas can only be appreciated with large tumours.

  4. Comparison between conventional tomography and computer tomography in diseases of the sacroiliac joints. Vergleich von konventioneller Tomographie und Computertomographie bei Erkrankungen der Sakroiliakalgelenke

    Energy Technology Data Exchange (ETDEWEB)

    Moritz, J.D.; Ganter, H.; Winter, C. (Bundeswehrkrankenhaus, Giessen (Germany, F.R.). Roentgenabteilung Evangelisches Krankenhaus, Giessen (Germany, F.R.). Roentgenabteilung)

    1990-10-01

    16 patients with diseases of the sacroiliac joints were examined both with computer tomography and with conventional tomography. Both techniques were characterized by a high sensitivity. Computer tomography was superior in exactly delineating the extent of the pathologic changes. In conventional tomography the joint surface was more blurred, erosions were larger, and signs of ankylosis were more expanded, so that the joints seemed to be more altered in 8 cases than demonstrated by computer tomography. Very accurate changes like subchondral cysts were recognized only in the computer tomograms. In all cases in which anteroposterior radiographs revealed no clear result, the authors recommend to additionally employ computer tomography. (orig.).

  5. A quantitative comparison of gross tumor volumes delineated on [18F]-FDG-PET/CT scan and contrast-enhanced computed tomography scan in locally advanced head and neck carcinoma treated with Intensity Modulated Radiotherapy

    Directory of Open Access Journals (Sweden)

    Nagarjuna Burela

    2017-05-01

    Full Text Available Accurate tumor diagnosis is important in highly conformal techniques such as Intensity Modulated Radiotherapy (IMRT, which aims for high therapeutic ratio. We compared Gross Tumor Volume (GTV (primary and nodal delineated on 18F-fluorodeoxyglucose positron emission tomography ([18F]-FDG-PET scan to those delineated on contrast-enhanced computed tomography (CECT scan and its impact on staging treated by IMRT. A total of 30 consecutive patients with locally advanced squamous cell carcinoma of head and neck were included in this study. FDG-PET and CECT scans were performed with dedicated positron emission tomography–computed tomography (PET/CT scanner in a single session as part of radiotherapy treatment planning for IMRT. After treatment with concurrent chemoradiotherapy, all patients were followed for one year. Three out of 30 patients were excluded from the final analysis, as there was complete remission in PET/CT after neoadjuvant chemotherapy. For remaining 27 cases, the primary sites were 17 oropharynx, 2 hypopharynx, 7 larynx and 1 unknown primary with secondary neck node. PET–CT resulted in changes of CT-based staging in 25% patients (up-staged in 3 and down-staged in 4. GTV delineated on PET vs CT scan was GTV-PET (primary of 20.15 cm3 vs GTV-CT (primary of 18.75 cm3, p = 0.803; and GTV-PET (nodes of 28.45 cm3 vs GTV-CT (nodes of 21.56 cm3, p = 0.589. The mismatch between two target volumes was statistically insignificant (p = 0.635 for GTV primary, p = 0.187 for nodes. The mean GTV-PET outside CT for primary was 5.83 cm3, and for node was 8.47 cm3. Median follow-up was 12 months. One-year loco-regional control was 92%. The target delineation of GTV can be improved with functional imaging [18F]-FDG-PET/CT.

  6. Multiscale and multimodality computed tomography for cortical bone analysis

    Science.gov (United States)

    Ostertag, A.; Peyrin, F.; Gouttenoire, P. J.; Laredo, J. D.; DeVernejoul, M. C.; Cohen Solal, M.; Chappard, C.

    2016-12-01

    In clinical studies, high resolution peripheral quantitative computed tomography (HR-pQCT) is used to separately evaluate cortical bone and trabecular bone with an isotropic voxel of 82 µm3, and typical cortical parameters are cortical density (D.comp), thickness (Ct.Th), and porosity (Ct.Po). In vitro, micro-computed tomography (micro-CT) is used to explore the internal cortical bone micro-structure with isotropic voxels and high resolution synchrotron radiation (SR); micro-CT is considered the ‘gold standard’. In 16 tibias and 8 femurs, HR-pQCT measurements were compared to conventional micro-CT measurements. To test modality effects, conventional micro-CT measurements were compared to SR micro-CT measurements at 7.5 µm3 SR micro-CT measurements were also tested at different voxel sizes for the femurs, specifically, 7.5 µm3 versus 2.8 µm3. D.comp (r  =  -0.88, p  images provided consistent results compared to those obtained using conventional micro-CT at the distal tibia. D.comp was highly correlated to Po.V/TV because it considers both the micro-porosity (Haversian systems) and macro-porosity (resorption lacunae) of cortical bone. The complexity of canal organization, (including shape, connectivity, and surface) are not fully considered in conventional micro-CT in relation to beam hardening and cone beam reconstruction artifacts. With the exception of Po.V/TV measurements, morphological and topological measurements depend on the characteristics of the x-ray beam, and to a lesser extent, on image resolution.

  7. Computed tomography of the orbital tumors

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jai Korl; Lee, Hwang Bok; Kang, Eun Young; Seol, Hae Young; Suh, Won Hyuck [College of Medicine, Korea University, Seoul (Korea, Republic of); Ahn, Byeong Yeob [Han Mi Hospital, Seoul (Korea, Republic of)

    1987-04-15

    The development of computed tomography (CT) provided a noninvasive safe technique for imaging the orbit in any plane exquisitely demonstrating its normal anatomy as well as its pathologic process. The orbit is an ideal structure to be examined by CT because of large difference of absorption values between the intraorbital fat, muscle, optic nerve and vessels. In this study, the authors reviewed CT findings of 66 pathologically proven orbital tumors and tumorous conditions among the total of 98 cases who had taken orbital CT scan because if exophthalmos, ocular pain, diplopia and other ophthalmologic symptoms suggesting orbital masses during the period of 3 years. For the analysis of characteristic CT findings of the orbital lesions, all lesions are divided into 4 groups according to the site of origin, i.e., tumors arising in the eyeball (group 1); from intraconal space (group 2); from extraconal space (group 3); and from extraorbital regions (group 4). The results are as follows; 1.Extra tumor detection and localization was possible in 63 cases. Thus the detection rate was 95% with CT scan. 2.Among 36 males and 30 females, their age ranged from 10 months to 72 years. 3.Intraocular tumors (group 1) were 10 cases. Retinoblastoma occurred wholly in the young children under 5 years and combined with calcification in 57%. Choroidal melanoma occurred wholly in adults. 4.Intraconal tumors (group 2) were 9 cases. Vascular tumors (7 cases) were the most frequent and well enhancing mass. 5.The tumors arising in the extraconal region (group 3) were pseudotumor (12 cases), lymphoma (3 cases), dermoid cyst (4 cases), metastasis (2 cases), adenoid cystic carcinoma (1 case) and teratoma (1 case). A case of lymphoma demonstrating retrobulbar ill defined mass with scleral l thickening could not be differentiated from the pseudotumor which showing similar finding. 6.The lesions arising from extraorbital region (group 4) were PNS cancer (9 cases), mucocele (3 cases), lid cancer (4

  8. Incidence of blunt craniocervical artery injuries: use of whole-body computed tomography trauma imaging with adapted computed tomography angiography.

    Science.gov (United States)

    Fleck, Steffen K; Langner, Soenke; Baldauf, Joerg; Kirsch, Michael; Kohlmann, Thomas; Schroeder, Henry W S

    2011-09-01

    The incidence of traumatic craniocervical artery dissection varies in published trauma series. To determine the frequency of traumatic craniocervical artery injury in polytrauma patients by using standardized whole-body trauma computed tomography with adapted computed tomography angiography of the craniocervical vessels. A total of 718 consecutive patients requiring whole-body trauma computed tomography (16-row multislice) because of the mechanism of their injury patterns and an Injury Severity Scale score greater than 16 were analyzed prospectively. After a cranial scan, computed tomography angiography of the craniocervical vessels with 40 mL of iodinated contrast agent was performed using bolus tracking. The overall incidence of blunt carotid and vertebral injuries (BCVIs) in the screened population was 1.7%. BCVIs were observed in 27.3% of patients with detected isolated cervical spine injuries and in 3.9% of patients with isolated cranial fractures with or without intracranial hemorrhage, whereas 5.3% of patients with combined cervical and cranial lesions were associated with BCVIs. In addition, 0.4% of BCVIs occurred in patients without evidence of head or neck trauma. Whole-body trauma computed tomography with an adapted scanning protocol for the craniocervical vessels is a fast, safe, and feasible method for detecting vascular injuries. It allows prompt further treatment if necessary. Computed tomography angiography could be a part of a broad screening protocol for craniocervical vessels in documented injuries of the head and neck and in trauma mechanisms influencing the craniocervical region as well.

  9. Dynamic 3D computed tomography scanner for vascular imaging

    Science.gov (United States)

    Lee, Mark K.; Holdsworth, David W.; Fenster, Aaron

    2000-04-01

    A 3D dynamic computed-tomography (CT) scanner was developed for imaging objects undergoing periodic motion. The scanner system has high spatial and sufficient temporal resolution to produce quantitative tomographic/volume images of objects such as excised arterial samples perfused under physiological pressure conditions and enables the measurements of the local dynamic elastic modulus (Edyn) of the arteries in the axial and longitudinal directions. The system was comprised of a high resolution modified x-ray image intensifier (XRII) based computed tomographic system and a computer-controlled cardiac flow simulator. A standard NTSC CCD camera with a macro lens was coupled to the electro-optically zoomed XRII to acquire dynamic volumetric images. Through prospective cardiac gating and computer synchronized control, a time-resolved sequence of 20 mm thick high resolution volume images of porcine aortic specimens during one simulated cardiac cycle were obtained. Performance evaluation of the scanners illustrated that tomographic images can be obtained with resolution as high as 3.2 mm-1 with only a 9% decrease in the resolution for objects moving at velocities of 1 cm/s in 2D mode and static spatial resolution of 3.55 mm-1 with only a 14% decrease in the resolution in 3D mode for objects moving at a velocity of 10 cm/s. Application of the system for imaging of intact excised arterial specimens under simulated physiological flow/pressure conditions enabled measurements of the Edyn of the arteries with a precision of +/- kPa for the 3D scanner. Evaluation of the Edyn in the axial and longitudinal direction produced values of 428 +/- 35 kPa and 728 +/- 71 kPa, demonstrating the isotropic and homogeneous viscoelastic nature of the vascular specimens. These values obtained from the Dynamic CT systems were not statistically different (p less than 0.05) from the values obtained by standard uniaxial tensile testing and volumetric measurements.

  10. Foveola pharyngea - demonstration in conventional tomography and computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Fiegler, W.; Stolle, E.

    1980-08-01

    The foveola pharyngea is a cavity on the underside of the clivus, located before the tuberculum pharyngeum and, as a larger pit it was detectable in approx. 1% overall in approx. 4% of the personally examined X-rays (11/284) and computed tomograms (6/154) of the skull base. The canalis basilaris medianus inferior and canalis basilaris medianus bifurcatus almost always empties into one of the three forms of the foveola pharyngea (foveola pharyngea infundibuliformis posterior). The differential diagnosis to canalis basilaris medianus, canalis craniopharyngeus, sutura sphenooccipitalis and bone destruction is discussed.

  11. Development of a proton Computed Tomography Detector System

    CERN Document Server

    Naimuddin, Md; Blazey, G; Boi, S; Dyshkant, A; Erdelyi, B; Hedin, D; Johnson, E; Krider, J; Rukalin, V; Uzunyan, S A; Zutshi, V; Fordt, R; Sellberg, G; Rauch, J E; Roman, M; Rubinov, P; Wilson, P

    2015-01-01

    Computer tomography is one of the most promising new methods to image abnormal tissues inside the human body. Tomography is also used to position the patient accurately before radiation therapy. Hadron therapy for treating cancer has become one of the most advantageous and safe options. In order to fully utilize the advantages of hadron therapy, there is a necessity of performing radiography with hadrons as well. In this paper we present the development of a proton computed tomography system. Our second-generation proton tomography system consists of two upstream and two downstream trackers made up of fibers as active material and a range detector consisting of plastic scintillators. We present details of the detector system, readout electronics, and data acquisition system as well as the commissioning of the entire system. We also present preliminary results from the test beam of the range detector.

  12. Development of a proton Computed Tomography Detector System

    Energy Technology Data Exchange (ETDEWEB)

    Naimuddin, Md. [Delhi U.; Coutrakon, G. [Northern Illinois U.; Blazey, G. [Northern Illinois U.; Boi, S. [Northern Illinois U.; Dyshkant, A. [Northern Illinois U.; Erdelyi, B. [Northern Illinois U.; Hedin, D. [Northern Illinois U.; Johnson, E. [Northern Illinois U.; Krider, J. [Northern Illinois U.; Rukalin, V. [Northern Illinois U.; Uzunyan, S. A. [Northern Illinois U.; Zutshi, V. [Northern Illinois U.; Fordt, R. [Fermilab; Sellberg, G. [Fermilab; Rauch, J. E. [Fermilab; Roman, M. [Fermilab; Rubinov, P. [Fermilab; Wilson, P. [Fermilab

    2016-02-04

    Computer tomography is one of the most promising new methods to image abnormal tissues inside the human body. Tomography is also used to position the patient accurately before radiation therapy. Hadron therapy for treating cancer has become one of the most advantegeous and safe options. In order to fully utilize the advantages of hadron therapy, there is a necessity of performing radiography with hadrons as well. In this paper we present the development of a proton computed tomography system. Our second-generation proton tomography system consists of two upstream and two downstream trackers made up of fibers as active material and a range detector consisting of plastic scintillators. We present details of the detector system, readout electronics, and data acquisition system as well as the commissioning of the entire system. We also present preliminary results from the test beam of the range detector.

  13. Development of a proton Computed Tomography detector system

    Science.gov (United States)

    Naimuddin, Md.; Coutrakon, G.; Blazey, G.; Boi, S.; Dyshkant, A.; Erdelyi, B.; Hedin, D.; Johnson, E.; Krider, J.; Rukalin, V.; Uzunyan, S. A.; Zutshi, V.; Fordt, R.; Sellberg, G.; Rauch, J. E.; Roman, M.; Rubinov, P.; Wilson, P.

    2016-02-01

    Computer tomography is one of the most promising new methods to image abnormal tissues inside the human body. Tomography is also used to position the patient accurately before radiation therapy. Hadron therapy for treating cancer has become one of the most advantegeous and safe options. In order to fully utilize the advantages of hadron therapy, there is a necessity of performing radiography with hadrons as well. In this paper we present the development of a proton computed tomography system. Our second-generation proton tomography system consists of two upstream and two downstream trackers made up of fibers as active material and a range detector consisting of plastic scintillators. We present details of the detector system, readout electronics, and data acquisition system as well as the commissioning of the entire system. We also present preliminary results from the test beam of the range detector.

  14. Evaluating iterative reconstruction performance in computed tomography.

    Science.gov (United States)

    Chen, Baiyu; Ramirez Giraldo, Juan Carlos; Solomon, Justin; Samei, Ehsan

    2014-12-01

    Iterative reconstruction (IR) offers notable advantages in computed tomography (CT). However, its performance characterization is complicated by its potentially nonlinear behavior, impacting performance in terms of specific tasks. This study aimed to evaluate the performance of IR with both task-specific and task-generic strategies. The performance of IR in CT was mathematically assessed with an observer model that predicted the detection accuracy in terms of the detectability index (d'). d' was calculated based on the properties of the image noise and resolution, the observer, and the detection task. The characterizations of image noise and resolution were extended to accommodate the nonlinearity of IR. A library of tasks was mathematically modeled at a range of sizes (radius 1-4 mm), contrast levels (10-100 HU), and edge profiles (sharp and soft). Unique d' values were calculated for each task with respect to five radiation exposure levels (volume CT dose index, CTDIvol: 3.4-64.8 mGy) and four reconstruction algorithms (filtered backprojection reconstruction, FBP; iterative reconstruction in imaging space, IRIS; and sinogram affirmed iterative reconstruction with strengths of 3 and 5, SAFIRE3 and SAFIRE5; all provided by Siemens Healthcare, Forchheim, Germany). The d' values were translated into the areas under the receiver operating characteristic curve (AUC) to represent human observer performance. For each task and reconstruction algorithm, a threshold dose was derived as the minimum dose required to achieve a threshold AUC of 0.9. A task-specific dose reduction potential of IR was calculated as the difference between the threshold doses for IR and FBP. A task-generic comparison was further made between IR and FBP in terms of the percent of all tasks yielding an AUC higher than the threshold. IR required less dose than FBP to achieve the threshold AUC. In general, SAFIRE5 showed the most significant dose reduction potentials (11-54 mGy, 77%-84%), followed by

  15. Lens dosimetry during examination of the sella turcica: comparison between conventional tomography and computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Louis, O.; Bette, L.; Noseda, A.

    1986-01-01

    Lens irradiation measurements were performed with thermo-luminescent lithium fluoride dosimeters during tomographic examinations of the sella turcica, simulated on a phantom head. Lens dosimetry during linear or hypocycloidal conventional tomography was compared with that during computed tomography (CT). Results showed that CT involved much lower radiation exposure to the lens than did conventional tomography and that the major part of the irradiation delivered by CT was related to axial scanning. Therefore, the major finding was that lens irradiation during CT of the sella can be kept at a particularly low level (< 1 m Gy/8 sections) when only coronal scanning is performed.

  16. Acute mediastinitis: multidetector computed tomography findings following cardiac surgery

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, Clarissa Aguiar de [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina. Instituto do Coracao (InCor)]. E-mail: clarissaaguiarm@yahoo.com.br; Baena, Marcos Eduardo da Silva [Instituto do Coracao (InCor), Sao Paulo, SP (Brazil). Unit of Ultrasonography; Uezumi, Kiyomi Kato [Instituto do Coracao (InCor), Sao Paulo, SP (Brazil). Unit of Computed Tomography; Castro, Claudio Campi de [Instituto do Coracao (InCor), Sao Paulo, SP (Brazil). Unit of Magnetic Resonance Imaging; Lucarelli, Claudio Luiz [Instituto do Coracao (InCor), Sao Paulo, SP (Brazil). Center of Diagnosis; Cerri, Giovanni Guido [Universidade de Sao Paulo (USP), SP (Brazil). School of Medicine. Dept. of Radiology

    2008-07-15

    Postoperative mediastinitis is defined as an infection of the organs and tissues in the mediastinal space, with an incidence ranging between 0.4% and 5% of cases. This disease severity varies from infection of superficial tissues in the chest wall to fulminant mediastinitis with sternal involvement. Diagnostic criterion for postoperative detection of acute mediastinitis at computed tomography is the presence of fluid collections and gas in the mediastinal space, which might or might not be associated with peristernal abnormalities such as edema of soft tissues, separation of sternal segments with marginal bone resorption, sclerosis and osteomyelitis. Other associated findings include lymphadenomegaly, pulmonary consolidation and pleural/ pericardial effusion. Some of these findings, such as mediastinal gas and small fluid collections can be typically found in the absence of infection, early in the period following thoracic surgery where the effectiveness of computed tomography is limited. After approximately two weeks, computed tomography achieves almost 100% sensitivity and specificity. Patients with clinical suspicion of mediastinitis should be submitted to computed tomography for investigating the presence of fluid collections to identify the extent and nature of the disease. Multidetector computed tomography allows 3D images reconstruction, contributing particularly to the evaluation of the sternum. (author)

  17. Positron emission tomography-computed tomography has a clinical impact for patients with cervical cancer

    DEFF Research Database (Denmark)

    Sandvik, Rikke Mulvad; Jensen, Pernille Tine; Hendel, Helle Westergren;

    2011-01-01

    Many studies have found that positron emission tomography-computed tomography (PET-CT) has a high sensitivity and specificity in the identification of metastasis in cervical cancer. Herlev Hospital, Denmark, has been performing PET-CTs in stage I-IV cervical cancer since 1 May 2006. The present...... study investigates the positive (PPV) and negative predictive value (NPV) of PET-CT in stage I disease and the clinical impact of the scan results in all disease stages....

  18. Pigmented villonodular synovitis mimics metastases on fluorine 18 fluorodeoxyglucose position emission tomography-computed tomography.

    Science.gov (United States)

    Elumogo, Comfort O; Kochenderfer, James N; Civelek, A Cahid; Bluemke, David A

    2016-04-01

    Pigmented villonodular synovitis (PVNS) is a benign joint disease best characterized on magnetic resonance imaging (MRI). The role of fluorine 18 fluorodeoxyglucose ((18)F-FDG) position emission tomography-computed tomography (PET-CT) in the diagnosis or characterization remains unclear. PVNS displays as a focal FDG avid lesion, which can masquerade as a metastatic lesion, on PET-CET. We present a case of PVNS found on surveillance imaging of a lymphoma patient.

  19. Optimisation of post mortem cardiac computed tomography compared to optical coherence tomography and histopathology - Technical note

    DEFF Research Database (Denmark)

    Precht, Helle; Leth, Peter Mygind; Thygesen, Jesper

    2014-01-01

    Introduction: Coronary atherosclerosis is a leading cause of mortality. New technological developments in computed tomography (CT), including dual energy, iterative reconstructions and high definition scanning, could significantly improve the non-invasive identification of atherosclerosis plaques....... Here, a new method for optimising cardiac coronary CT with optical coherence tomography (OCT) and histopathology is presented. Materials and methods: Twenty human hearts obtained from autopsies were used. A contrast agent that solidifies after cooling was injected into the coronary arteries. CT...

  20. Multifocal sparganosis mimicking lymphoma involvement: Multimodal imaging findings of ultrasonography, CT, MRI, and position emission tomography-computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Heo, So Young; Park, Ji Yeon; Park, Noh Hyuck; Park, Chan Sub; Kim, Tae Jung [Myongji Hospital, Seonam University College of Medicine, Goyang (Korea, Republic of); Yi, Seong Yoon [Dev. of Hematology-Omcology, Dept. of Internal Medicine, Inje University Ilsan Paik Hospital, Goyang (Korea, Republic of); Jun, Hyun Jung [Dev. of Hematology-Omcology, Dept. of Internal Medicine, Seoul Medical Center, Seoul (Korea, Republic of)

    2016-01-15

    Sparganosis is a rare parasitic disease caused by the migrating plerocercoid larva of Spirometra species tapeworms. The most frequent clinical manifestation is a subcutaneous nodule resembling a neoplasm. In this study, we presented multimodal findings of ultrasonography, computed tomography, magnetic resonance imaging, positron emission tomography-computed tomography and follow-up imagings on multifocal sparganosis, mimicking lymphoma involvement in a patient with lymphoma.

  1. Quantitative characterization of developing collagen gels using optical coherence tomography

    Science.gov (United States)

    Levitz, David; Hinds, Monica T.; Choudhury, Niloy; Tran, Noi T.; Hanson, Stephen R.; Jacques, Steven L.

    2010-03-01

    Nondestructive optical imaging methods such as optical coherence tomography (OCT) have been proposed for characterizing engineered tissues such as collagen gels. In our study, OCT was used to image collagen gels with different seeding densities of smooth muscle cells (SMCs), including acellular gels, over a five-day period during which the gels contracted and became turbid with increased optical scattering. The gels were characterized quantitatively by their optical properties, specified by analysis of OCT data using a theoretical model. At 6 h, seeded cell density and scattering coefficient (μs) were correlated, with μs equal to 10.8 cm-1/(106 cells/mL). Seeded cell density and the scattering anisotropy (g) were uncorrelated. Over five days, the reflectivity in SMC gels gradually doubled with little change in optical attenuation, which indicated a decrease in g that increased backscatter, but only a small drop in μs. At five days, a subpopulation of sites on the gel showed substantially higher reflectivity (approximately a tenfold increase from the first 24 h). In summary, the increased turbidity of SMC gels that develops over time is due to a change in the structure of collagen, which affects g, and not simply due to a change in number density of collagen fibers due to contraction.

  2. Concluding Report: Quantitative Tomography Simulations and Reconstruction Algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Aufderheide, M B; Martz, H E; Slone, D M; Jackson, J A; Schach von Wittenau, A E; Goodman, D M; Logan, C M; Hall, J M

    2002-02-01

    In this report we describe the original goals and final achievements of this Laboratory Directed Research and Development project. The Quantitative was Tomography Simulations and Reconstruction Algorithms project (99-ERD-015) funded as a multi-directorate, three-year effort to advance the state of the art in radiographic simulation and tomographic reconstruction by improving simulation and including this simulation in the tomographic reconstruction process. Goals were to improve the accuracy of radiographic simulation, and to couple advanced radiographic simulation tools with a robust, many-variable optimization algorithm. In this project, we were able to demonstrate accuracy in X-Ray simulation at the 2% level, which is an improvement of roughly a factor of 5 in accuracy, and we have successfully coupled our simulation tools with the CCG (Constrained Conjugate Gradient) optimization algorithm, allowing reconstructions that include spectral effects and blurring in the reconstructions. Another result of the project was the assembly of a low-scatter X-Ray imaging facility for use in nondestructive evaluation applications. We conclude with a discussion of future work.

  3. Computer-aided classification of lung nodules on computed tomography images via deep learning technique

    Directory of Open Access Journals (Sweden)

    Hua KL

    2015-08-01

    Full Text Available Kai-Lung Hua,1 Che-Hao Hsu,1 Shintami Chusnul Hidayati,1 Wen-Huang Cheng,2 Yu-Jen Chen3 1Department of Computer Science and Information Engineering, National Taiwan University of Science and Technology, 2Research Center for Information Technology Innovation, Academia Sinica, 3Department of Radiation Oncology, MacKay Memorial Hospital, Taipei, Taiwan Abstract: Lung cancer has a poor prognosis when not diagnosed early and unresectable lesions are present. The management of small lung nodules noted on computed tomography scan is controversial due to uncertain tumor characteristics. A conventional computer-aided diagnosis (CAD scheme requires several image processing and pattern recognition steps to accomplish a quantitative tumor differentiation result. In such an ad hoc image analysis pipeline, every step depends heavily on the performance of the previous step. Accordingly, tuning of classification performance in a conventional CAD scheme is very complicated and arduous. Deep learning techniques, on the other hand, have the intrinsic advantage of an automatic exploitation feature and tuning of performance in a seamless fashion. In this study, we attempted to simplify the image analysis pipeline of conventional CAD with deep learning techniques. Specifically, we introduced models of a deep belief network and a convolutional neural network in the context of nodule classification in computed tomography images. Two baseline methods with feature computing steps were implemented for comparison. The experimental results suggest that deep learning methods could achieve better discriminative results and hold promise in the CAD application domain. Keywords: nodule classification, deep learning, deep belief network, convolutional neural network

  4. Shielding Calculations for Positron Emission Tomography - Computed Tomography Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Baasandorj, Khashbayar [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Yang, Jeongseon [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-10-15

    Integrated PET-CT has been shown to be more accurate for lesion localization and characterization than PET or CT alone, and the results obtained from PET and CT separately and interpreted side by side or following software based fusion of the PET and CT datasets. At the same time, PET-CT scans can result in high patient and staff doses; therefore, careful site planning and shielding of this imaging modality have become challenging issues in the field. In Mongolia, the introduction of PET-CT facilities is currently being considered in many hospitals. Thus, additional regulatory legislation for nuclear and radiation applications is necessary, for example, in regulating licensee processes and ensuring radiation safety during the operations. This paper aims to determine appropriate PET-CT shielding designs using numerical formulas and computer code. Since presently there are no PET-CT facilities in Mongolia, contact was made with radiological staff at the Nuclear Medicine Center of the National Cancer Center of Mongolia (NCCM) to get information about facilities where the introduction of PET-CT is being considered. Well-designed facilities do not require additional shielding, which should help cut down overall costs related to PET-CT installation. According to the results of this study, building barrier thicknesses of the NCCM building is not sufficient to keep radiation dose within the limits.

  5. Evaluation of myocardial ischemia by multiple detector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Fabio Vieira, E-mail: rccury@me.com [Hospital do Coracao (HCor), Sao Paulo, SP (Brazil); Cury, Roberto Caldeira [Hospital Samaritano, Sao Paulo, SP (Brazil)

    2015-01-15

    For years, cardiovascular diseases have been the leading cause of death worldwide, bringing on important social and economic consequences. Given this scenario, the search for a method capable of diagnosing coronary artery diseases in an early and accurate way is increasingly higher. The coronary computed tomography angiogram is already widely established for the stratification of coronary artery diseases, and, more recently, the computed tomography myocardial perfusion imaging has been providing relevant information by correlating ischemia and the coronary anatomy. The objective of this review is to describe the evaluation of myocardial ischemia by multiple detector computed tomography. This study will resort to controlled clinical trials that show the possibility of a single method to identify the atherosclerotic load, presence of coronary artery luminal narrowing and possible myocardial ischemia, by means of a fast, practical and reliable method validated by a multicenter study. (author)

  6. Utility of the computed tomography indices on cone beam computed tomography images in the diagnosis of osteoporosis in women

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Kwang Joon; Kim, Kyung A [School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of)

    2011-09-15

    This study evaluated the potential use of the computed tomography indices (CTI) on cone beam CT (CBCT) images for an assessment of the bone mineral density (BMD) in postmenopausal osteoporotic women. Twenty-one postmenopausal osteoporotic women and 21 postmenopausal healthy women were enrolled as the subjects. The BMD of the lumbar vertebrae and femur were calculated by dual energy X-ray absorptiometry (DXA) using a DXA scanner. The CBCT images were obtained from the unilateral mental foramen region using a PSR-9000N Dental CT system. The axial, sagittal, and coronal images were reconstructed from the block images using OnDemend3D. The new term 'CTI' on CBCT images was proposed. The relationship between the CT measurements and BMDs were assessed and the intra-observer agreement was determined. There were significant differences between the normal and osteoporotic groups in the computed tomography mandibular index superior (CTI(S)), computed tomography mandibular index inferior (CTI(I)), and computed tomography cortical index (CTCI). On the other hand, there was no difference between the groups in the computed tomography mental index (CTMI: inferior cortical width). CTI(S), CTI(I), and CTCI on the CBCT images can be used to assess the osteoporotic women.

  7. Molecular imaging with dynamic contrast-enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Miles, K.A., E-mail: k.a.miles@bsms.ac.u [Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton (United Kingdom)

    2010-07-15

    Dynamic contrast-enhanced computed tomography (DCE-CT) is a quantitative technique that employs rapid sequences of CT images after bolus administration of intravenous contrast material to measure a range of physiological processes related to the microvasculature of tissues. By combining knowledge of the molecular processes underlying changes in vascular physiology with an understanding of the relationship between vascular physiology and CT contrast enhancement, DCE-CT can be redefined as a molecular imaging technique. Some DCE-CT derived parameters reflect tissue hypoxia and can, therefore, provide information about the cellular microenvironment. DCE-CT can also depict physiological processes, such as vasodilatation, that represent the physiological consequences of molecular responses to tissue hypoxia. To date the main applications have been in stroke and oncology. Unlike some other molecular imaging approaches, DCE-CT benefits from wide availability and ease of application along with the use of contrast materials and software packages that have achieved full regulatory approval. Hence, DCE-CT represents a molecular imaging technique that is applicable in clinical practice today.

  8. Perfusion computed tomography evaluation of angiogenesis in liver cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Han Feng [Xuanwu Hospital, Capital Medical University, Department of Clinical Pain, Beijing (China); Hospital of North Sichuan Medical College, Department of Radiology, Nanchong City, Sichuan Province (China); Du, Yong; Xu, Xiao Xue; Li, Yang [Hospital of North Sichuan Medical College, Department of Radiology, Nanchong City, Sichuan Province (China); Ni, Jia Xiang [Xuanwu Hospital, Capital Medical University, Department of Clinical Pain, Beijing (China); Zhou, Xiang Ping [West China Hospital, Sichuan University, Department of Radiology, Chengdu City, Sichuan Province (China); Li, Jin Dong [Hospital of North Sichuan Medical College, Department of General Surgery, Nanchong City, Sichuan Province (China); Zhang, Qing [Hospital of North Sichuan Medical College, Department of Ultrasound, Nanchong City, Sichuan Province (China)

    2010-06-15

    To investigate the value of computed tomography (CT) perfusion imaging for assessment of angiogenesis in liver cancer. Twenty-one patients with histologically proven liver cancer underwent CT perfusion examination. We compared the following perfusion parameters in the tumour area versus the non-tumour area: total blood flow (TBF), hepatic arterial perfusion (HAP), hepatic portal perfusion (HPP) and hepatic arterial perfusion index (HAPI). Slices of postoperative specimen were stained with haematoxylin-eosin and anti-CD34 immunohistochemistry. The slices were evaluated with emphasis on the CD34-positive neovasculature in the tumour parenchyma. Tumour microvascular density (MVD) was calculated according to the Weidner method. Pearson correlation was used to detect correlations between tumour MVD and tumour perfusion parameters. TBF and HPP in the tumour area were lower than in the non-tumour area (P < 0.05). HAP and HAPI in the tumour area were higher than those of the non-tumour area (P < 0.05). TBF and HAP in the tumour area correlated with MVD in the tumour (P < 0.05), with correlation coefficients of 0.849 and 0.829, respectively. CT perfusion imaging can quantitatively assess the blood supply and its distribution in liver cancer. TBF or HAP may be a useful parameter in assessing angiogenesis of liver cancer. (orig.)

  9. Direct reconstruction of enhanced signal in computed tomography perfusion

    Science.gov (United States)

    Li, Bin; Lyu, Qingwen; Ma, Jianhua; Wang, Jing

    2016-04-01

    High imaging dose has been a concern in computed tomography perfusion (CTP) as repeated scans are performed at the same location of a patient. On the other hand, signal changes only occur at limited regions in CT acquired at different time points. In this work, we propose a new reconstruction strategy by effectively utilizing the initial phase high-quality CT to reconstruct the later phase CT acquired with a low-dose protocol. In the proposed strategy, initial high-quality CT is considered as a base image and enhanced signal (ES) is reconstructed directly by minimizing the penalized weighted least-square (PWLS) criterion. The proposed PWLS-ES strategy converts the conventional CT reconstruction into a sparse signal reconstruction problem. Digital and anthropomorphic phantom studies were performed to evaluate the performance of the proposed PWLS-ES strategy. Both phantom studies show that the proposed PWLS-ES method outperforms the standard iterative CT reconstruction algorithm based on the same PWLS criterion according to various quantitative metrics including root mean squared error (RMSE) and the universal quality index (UQI).

  10. Noninvasive coronary artery angiography using electron beam computed tomography

    Science.gov (United States)

    Rumberger, John A.; Rensing, Benno J.; Reed, Judd E.; Ritman, Erik L.; Sheedy, Patrick F., II

    1996-04-01

    Electron beam computed tomography (EBCT), also known as ultrafast-CT or cine-CT, uses a unique scanning architecture which allows for multiple high spatial resolution electrocardiographic triggered images of the beating heart. A recent study has demonstrated the feasibility of qualitative comparisons between EBCT derived 3D coronary angiograms and invasive angiography. Stenoses of the proximal portions of the left anterior descending and right coronary arteries were readily identified, but description of atherosclerotic narrowing in the left circumflex artery (and distal epicardial disease) was not possible with any degree of confidence. Although these preliminary studies support the notion that this approach has potential, the images overall were suboptimal for clinical application as an adjunct to invasive angiography. Furthermore, these studies did not examine different methods of EBCT scan acquisition, tomographic slice thicknesses, extent of scan overlap, or other segmentation, thresholding, and interpolation algorithms. Our laboratory has initiated investigation of these aspects and limitations of EBCT coronary angiography. Specific areas of research include defining effects of cardiac orientation; defining the effects of tomographic slice thickness and intensity (gradient) versus positional (shaped based) interpolation; and defining applicability of imaging each of the major epicardial coronary arteries for quantitative definition of vessel size, cross-sectional area, taper, and discrete vessel narrowing.

  11. Computed tomography of sellar and parasellar lesions

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, Mitsunori; Aoki, Hideo (Yamaguchi Univ., Ube (Japan). School of Medicine)

    1982-06-01

    Neuroradiological modalities, particularly CT, for sellar and parasellar lesions were reviewed. Although accurate preoperative diagnosis is sometimes difficult, CT diagnosed 83% as far as pituitary adenoma, craniopharyngioma and meningioma were concerned and demonstrated abnormal findings in 95% of parasellar tumors. At the authors' department, CT visualized abnormalities in all cases, with the exception of suprasellar arachnoid cyst, but a histological diagnosis was possible only in 84%. Since lesions including tumors cannot be completely denied even if CT shows normal images, findings by modalities such as plain craniography, cerebral tomography, cerebral angiography and cisternography should be judged comprehensively.

  12. Characterization of a lead breast shielding for dose reduction in computed tomography*

    OpenAIRE

    Correia,Paula Duarte; Granzotti, Cristiano Roberto Fabri; Santos, Yago da Silva; Brochi,Marco Aurelio Corte; Azevedo-Marques,Paulo Mazzoncini de

    2014-01-01

    Objective Several studies have been published regarding the use of bismuth shielding to protect the breast in computed tomography (CT) scans and, up to the writing of this article, only one publication about barium shielding was found. The present study was aimed at characterizing, for the first time, a lead breast shielding. Materials and Methods The percentage dose reduction and the influence of the shielding on quantitative imaging parameters were evaluated. Dose measurements were made on ...

  13. Anaesthesia for magnetic resonance imaging/computed tomography.

    Science.gov (United States)

    Funk, W; Taeger, K

    2000-08-01

    The need for general anaesthesia for magnetic resonance imaging/computed tomography investigations can be reduced by the implementation of structured sedation programmes supervised by anaesthetists. Despite its side-effects, chloral hydrate is still the drug most widely used. Rectal thiopental or intravenous propofol are suggested anaesthetic agents for pre-school children and uncooperative or claustrophobic individuals. Spiral computed tomography scans and ultrafast magnetic resonance imaging shorten immobilization times further. However, functional magnetic resonance imaging and intervention techniques in neuroradiology depend on a motionless patient. A useful strategy for testing anaesthesia equipment has been outlined.

  14. Computed tomography and magnetic resonance imaging of the pericardium.

    Science.gov (United States)

    Olson, M C; Posniak, H V; McDonald, V; Wisniewski, R; Moncada, R

    1989-07-01

    Computed tomography is an established modality for the evaluation of the pericardium. It is used to evaluate complicated pericardial effusions, pericardial thickening, calcific pericarditis, pericardial cysts, postoperative changes and primary and metastatic neoplasms of the pericardium. Magnetic resonance imaging is being used with increasing frequency in the evaluation of pericardial disease. It offers advantages over computed tomography, including a potential for tissue characterization, absence of ionizing radiation or need for intravenous contrast medium, and the ability to scan in any plane. Disadvantages include greater cost, longer examination times and the inability to identify calcification positively.

  15. Investigation of a near-infrared-ray computed tomography scanner

    Science.gov (United States)

    Sato, Eiichi; Oda, Yasuyuki; Satoi, Yuichi; Yamaguchi, Satoshi; Ishii, Tomotaka; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Watanabe, Manabu; Kusachi, Shinya

    2016-10-01

    In the near-infrared-ray computed tomography (NIR-CT) scanner, NIR rays are produced from a light-emitting diode (LED) and detected using an NIR phototransistor (PT). The wavelengths of the LED peak intensity and the PT high sensitivity in the data table are both 940 nm. The photocurrents flowing through the PTR are converted into voltages using an emitter-follower circuit, and the output voltages are sent to a personal computer through an analog-digital converter. The NIR projection curves for tomography are obtained by repeated linear scans and rotations of the object, and the scanning is conducted in both directions of its movement.

  16. Direct sagital computed tomography of the temporomandibular joint

    Energy Technology Data Exchange (ETDEWEB)

    Manzione, J.V. (Harvard Medical School, Boston, MA); Seltzer, S.E.; Katzberg, R.W.; Hammerschlag, S.B.; Chiango, B.F.

    1983-01-01

    Temporomandibular joint dysfunction is a common clinical problem that has been reported to affect 4%-28% of adults. Temporomandibular joint arthrography has shown that many of these patients have intraarticular abnormalities involving the meniscus. A noninvasive test that could demonstrate the meniscus as well as bony abnormalities of the joint would be an important advance. In an attempt to develop such a noninvasive test, we have performed direct sagittal computed tomography (CT) on cadaver temporomandibular joints and have correlated the images with anatomic sections. We are currently applying this technique clinically and report one representative example in which direct sagittal computed tomography of the temporomandibular joint accurately demonstrated an anteriorly displaced meniscus.

  17. High-resolution peripheral quantitative computed tomography and finite element analysis of bone strength at the distal radius in ovariectomized adult rhesus monkey demonstrate efficacy of odanacatib and differentiation from alendronate.

    Science.gov (United States)

    Cabal, Antonio; Jayakar, Richa Y; Sardesai, Swanand; Phillips, Eual A; Szumiloski, John; Posavec, Diane J; Mathers, Parker D; Savitz, Alan T; Scott, Boyd B; Winkelmann, Christopher T; Motzel, Sherri; Cook, Lynn; Hargreaves, Richard; Evelhoch, Jeffrey L; Dardzinski, Bernard J; Hangartner, Thomas N; McCracken, Paul J; Duong, Le T; Williams, Donald S

    2013-10-01

    Translational evaluation of disease progression and treatment response is critical to the development of therapies for osteoporosis. In this study, longitudinal in-vivo monitoring of odanacatib (ODN) treatment efficacy was compared to alendronate (ALN) in ovariectomized (OVX) non-human primates (NHPs) using high-resolution peripheral computed tomography (HR-pQCT). Treatment effects were evaluated using several determinants of bone strength, density and quality, including volumetric bone mineral density (vBMD), three-dimensional structure, finite element analysis (FEA) estimated peak force and biomechanical properties at the ultradistal (UD) radius at baseline, 3, 6, 9, 12, and 18 months of dosing in three treatment groups: vehicle (VEH), low ODN (2 mg/kg/day, L-ODN), and ALN (30 μg/kg/week). Biomechanical axial compression tests were performed at the end of the study. Bone strength estimates using FEA were validated by ex-vivo mechanical compression testing experiments. After 18months of dosing, L-ODN demonstrated significant increases from baseline in integral vBMD (13.5%), cortical thickness (24.4%), total bone volume fraction BV/TV (13.5%), FEA-estimated peak force (26.6%) and peak stress (17.1%), respectively. Increases from baseline for L-ODN at 18 months were significantly higher than that for ALN in DXA-based aBMD (7.6%), cortical thickness (22.9%), integral vBMD (12.2%), total BV/TV (10.1%), FEA peak force (17.7%) and FEA peak stress (11.5%), respectively. These results demonstrate a superior efficacy of ODN treatment compared to ALN at the UD radii in ovariectomized NHPs.

  18. Endocrine radionuclide scintigraphy with fusion single photon emission computed tomography/computed tomography

    Institute of Scientific and Technical Information of China (English)

    Ka-Kit Wong; Arpit Gandhi; Benjamin L Viglianti; Lorraine M Fig; Domenico Rubello; Milton D Gross

    2016-01-01

    AIM: To review the benefits of single photon emission computed tomography(SPECT)/computed tomography(CT) hybrid imaging for diagnosis of various endocrine disorders.METHODS: We performed MEDLINE and Pub Med searches using the terms: "SPECT/CT"; "functional anatomic mapping"; "transmission emission tomography"; "parathyroid adenoma"; "thyroid cancer"; "neuroendocrine tumor"; "adrenal"; "pheochromocytoma"; "paraganglioma"; in order to identify relevant articles published in English during the years 2003 to 2015. Reference lists from the articles were reviewed to identify additional pertinent articles. Retrieved manuscripts(case reports, reviews, meta-analyses and abstracts) concerning the application of SPECT/CT to endocrine imaging were analyzed to provide a descriptive synthesis of the utility of this technology.RESULTS: The emergence of hybrid SPECT/CT camera technology now allows simultaneous acquisition of combined multi-modality imaging, with seamless fusion of three-dimensional volume datasets. The usefulness of combining functional information to depict the biodistribution of radiotracers that map cellular processes of the endocrine system and tumors of endocrine origin, with anatomy derived from CT, has improved the diagnostic capability of scintigraphy for a range of disorders of endocrine gland function. The literature describes benefits of SPECT/CT for 99mTc-sestamibi parathyroid scintigraphy and 99mTc-pertechnetate thyroid scintigraphy, 123I- or 131I-radioiodine for staging of differentiated thyroid carcinoma, 111In- and 99mTclabeled somatostatin receptor analogues for detection of neuroendocrine tumors, 131I-norcholesterol(NP-59) scans for assessment of adrenal cortical hyperfunction, and 123I- or 131I-metaiodobenzylguanidine imaging for evaluation of pheochromocytoma and paraganglioma.CONCLUSION: SPECT/CT exploits the synergism between the functional information from radiopharmaceutical imaging and anatomy from CT, translating to

  19. Industrial Computed Tomography using Proximal Algorithm

    KAUST Repository

    Zang, Guangming

    2016-04-14

    In this thesis, we present ProxiSART, a flexible proximal framework for robust 3D cone beam tomographic reconstruction based on the Simultaneous Algebraic Reconstruction Technique (SART). We derive the proximal operator for the SART algorithm and use it for minimizing the data term in a proximal algorithm. We show the flexibility of the framework by plugging in different powerful regularizers, and show its robustness in achieving better reconstruction results in the presence of noise and using fewer projections. We compare our framework to state-of-the-art methods and existing popular software tomography reconstruction packages, on both synthetic and real datasets, and show superior reconstruction quality, especially from noisy data and a small number of projections.

  20. Objective breast tissue image classification using Quantitative Transmission ultrasound tomography

    Science.gov (United States)

    Malik, Bilal; Klock, John; Wiskin, James; Lenox, Mark

    2016-12-01

    Quantitative Transmission Ultrasound (QT) is a powerful and emerging imaging paradigm which has the potential to perform true three-dimensional image reconstruction of biological tissue. Breast imaging is an important application of QT and allows non-invasive, non-ionizing imaging of whole breasts in vivo. Here, we report the first demonstration of breast tissue image classification in QT imaging. We systematically assess the ability of the QT images’ features to differentiate between normal breast tissue types. The three QT features were used in Support Vector Machines (SVM) classifiers, and classification of breast tissue as either skin, fat, glands, ducts or connective tissue was demonstrated with an overall accuracy of greater than 90%. Finally, the classifier was validated on whole breast image volumes to provide a color-coded breast tissue volume. This study serves as a first step towards a computer-aided detection/diagnosis platform for QT.

  1. Cyst-based measurements for assessing lymphangioleiomyomatosis in computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lo, P., E-mail: pechinlo@mednet.edu.ucla; Brown, M. S.; Kim, H.; Kim, H.; Goldin, J. G. [Center for Computer Vision and Imaging Biomarkers, Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California 90024 (United States); Argula, R.; Strange, C. [Division of Pulmonary and Critical Care Medicine, Medical University of South Carolina, Charleston, South Carolina 29425 (United States)

    2015-05-15

    Purpose: To investigate the efficacy of a new family of measurements made on individual pulmonary cysts extracted from computed tomography (CT) for assessing the severity of lymphangioleiomyomatosis (LAM). Methods: CT images were analyzed using thresholding to identify a cystic region of interest from chest CT of LAM patients. Individual cysts were then extracted from the cystic region by the watershed algorithm, which separates individual cysts based on subtle edges within the cystic regions. A family of measurements were then computed, which quantify the amount, distribution, and boundary appearance of the cysts. Sequential floating feature selection was used to select a small subset of features for quantification of the severity of LAM. Adjusted R{sup 2} from multiple linear regression and R{sup 2} from linear regression against measurements from spirometry were used to compare the performance of our proposed measurements with currently used density based CT measurements in the literature, namely, the relative area measure and the D measure. Results: Volumetric CT data, performed at total lung capacity and residual volume, from a total of 49 subjects enrolled in the MILES trial were used in our study. Our proposed measures had adjusted R{sup 2} ranging from 0.42 to 0.59 when regressing against the spirometry measures, with p < 0.05. For previously used density based CT measurements in the literature, the best R{sup 2} was 0.46 (for only one instance), with the majority being lower than 0.3 or p > 0.05. Conclusions: The proposed family of CT-based cyst measurements have better correlation with spirometric measures than previously used density based CT measurements. They show potential as a sensitive tool for quantitatively assessing the severity of LAM.

  2. Computed tomography angiography and perfusion to assess coronary artery stenosis causing perfusion defects by single photon emission computed tomography

    DEFF Research Database (Denmark)

    Rochitte, Carlos E; George, Richard T; Chen, Marcus Y

    2014-01-01

    AIMS: To evaluate the diagnostic power of integrating the results of computed tomography angiography (CTA) and CT myocardial perfusion (CTP) to identify coronary artery disease (CAD) defined as a flow limiting coronary artery stenosis causing a perfusion defect by single photon emission computed...... tomography (SPECT). METHODS AND RESULTS: We conducted a multicentre study to evaluate the accuracy of integrated CTA-CTP for the identification of patients with flow-limiting CAD defined by ≥50% stenosis by invasive coronary angiography (ICA) with a corresponding perfusion deficit on stress single photon...

  3. Diagnostic Performance of Coronary Computed Tomography Angiography and Myocardial Perfusion Imaging in Kidney Transplantation Candidates

    DEFF Research Database (Denmark)

    Winther, Simon; Svensson, My; Jørgensen, Hanne Mari Skou;

    2014-01-01

    Objectives To compare the diagnostic accuracy of coronary artery calcium score (CACS), coronary computed tomography angiography (CCTA), single-photon emission computed tomography (SPECT), and a combination of these in the diagnosis of obstructive coronary artery disease (CAD) in patients with chr......Objectives To compare the diagnostic accuracy of coronary artery calcium score (CACS), coronary computed tomography angiography (CCTA), single-photon emission computed tomography (SPECT), and a combination of these in the diagnosis of obstructive coronary artery disease (CAD) in patients...... stress tests, while the diagnostic performance of CCTA remains unknown. Methods We prospectively studied 138 patients referred for pre-transplant cardiac evaluation (mean age 54 [22-72] years, 68% males, 43% treated with dialysis). All patients underwent CACS, CCTA, SPECT, and invasive coronary...... angiography. The results of the noninvasive tests were merged into integrated Hybrid (CACS/SPECT) and Hybrid (CCTA/SPECT). Results The overall prevalence of obstructive CAD (≥50% reduction in luminal diameter) according to quantitative invasive coronary angiography was 22%. Two-thirds of the patients...

  4. 3D artefact for concurrent scale calibration in Computed Tomography

    DEFF Research Database (Denmark)

    Stolfi, Alessandro; De Chiffre, Leonardo

    2016-01-01

    A novel artefact for calibration of the scale in 3D X-ray Computed Tomography (CT) is presented. The artefact comprises a carbon fibre tubular structure on which a number of reference ruby spheres are glued. The artefact is positioned and scanned together with the workpiece inside the CT scanner ...

  5. Computer tomography in Caisson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, F.; Csobaly, S.

    1981-07-01

    Computer tomography was performed on 20 patients with the early stages of Caisson osteoarthropathy, as well as in other patients with chronic bone infarcts. From their results the authors have formed the opinion that CT is valuable, not only in the diagnosis of early cases, but that it can provide significant information concerning the osteopathy and bone infarcts.

  6. A Clinical Evaluation Of Cone Beam Computed Tomography

    Science.gov (United States)

    2016-06-01

    subject number. The principal investigator collated all data collection sheets and organized them into a spreadsheet for final analysis. Data...available cone-beam computed tomography machine . Am J 01ihod Dentofacial Orthop 2008; 134:573-82. 7. Moshfeghi M, Tavakoli MA, Hosseini ET, et al

  7. Geometrical metrology on silicone rubber by computed tomography

    DEFF Research Database (Denmark)

    Müller, Pavel; Pacurar, Ramona Alexandra; De Chiffre, Leonardo

    2011-01-01

    Computed tomography (CT) represents a suitable measuring technique for investigation of deformable materials, since no forces are developed on the part during scanning. As for any other measuring instruments, the traceability of the CT scanners needs to be assured. An investigation on geometrical...

  8. Traceability investigation in Computed Tomography using industry-inspired workpieces

    DEFF Research Database (Denmark)

    Kraemer, Alexandra; Stolfi, Alessandro; Schneider, Timm

    2017-01-01

    This paper concerns an investigation of the accuracy of Computed Tomography (CT) measurements using four industry-inspired workpieces. A total of 16 measurands were selected and calibrated using CMMs. CT measurements on industry-inspired workpieces were carried out using two CTs having different...

  9. Tracheo-oesophageal fistula diagnosed with multidetector computed tomography.

    LENUS (Irish Health Repository)

    Hodnett, Pa

    2009-04-01

    This case highlights important issues in investigation of patients with suspected tracheo-oesophageal fistula including the value of multidetector computed tomography, the importance of thorough imaging evaluation when high clinical suspicion of tracheo-oesophageal fistula exists and the value of close interaction between radiologists and intensive care physicians in the investigation of these patients.

  10. Computed Tomography Features of Spontaneously Perforated Pyometra: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Chan, K.S.; Tan, C.K.; Mak, C.W.; Chia, C.C.; Kuo, C.Y.; Yu, W.L. [Chi-Mei Medical Center, Tainan, Taiwan (China). Depts. of Intensive Care Medicine, Radiology, Obstetrics and Gynecology, and Surgery

    2006-03-15

    Spontaneous perforation of pyometra is an extremely rare emergent gynecologic disease. We report a 73-year-old woman with a spontaneously perforated pyometra presenting with acute abdomen in the emergency department. A dedicated computed tomography examination of the abdominal and pelvic regions revealed the diagnosis. The patient recovered well after surgical intervention and antibiotic treatment.

  11. Fractional flow reserve derived from coronary computed tomography angiography

    DEFF Research Database (Denmark)

    Eftekhari, Ashkan; Min, James; Achenbach, Stephan

    2016-01-01

    AIMS: Fractional flow reserve (FFR) derived from coronary computed tomography (FFRCT) has high diagnostic performance in stable coronary artery disease (CAD). The diagnostic performance of FFRCT in patients with hypertension (HTN) and diabetes (DM), who are at risk of microvascular impairment, is...

  12. Computed tomography of the human developing anterior skull base

    NARCIS (Netherlands)

    J. van Loosen (J.); A.I.J. Klooswijk (A. I J); D. van Velzen (D.); C.D.A. Verwoerd (Carel)

    1990-01-01

    markdownabstractAbstract The ossification of the anterior skull base, especially the lamina cribrosa, has been studied by computed tomography and histopathology. Sixteen human fetuses, (referred to our laboratory for pathological examination after spontaneous abortion between 18 and 32 weeks of ge

  13. COMPUTED TOMOGRAPHY IN HYDATID CYST OF THE ORBIT

    Directory of Open Access Journals (Sweden)

    K. Abbassioun

    1982-07-01

    Full Text Available Two cases of hydatid cysts of the orbit causing unilateral exophthalmos are reported. Diagnosis were suspected by means of computed tomography (CT and confirmed at Operation. CT changes are described and its value in diagnosis of this lesion particularly in the endemic areas is stressed.

  14. Use of Computed Tomography Scans for Cochlear Implants

    OpenAIRE

    Whiting, Bruce R.; Holden, Timothy A.; Brunsden, Barry S.; Finley, Charles C.; Skinner, Margaret W.

    2007-01-01

    While 3-dimensional (3D) imaging by computed tomography has long been desirable for research and treatment of cochlear-implant patients, technical challenges have limited its wide application. Recent developments in scanner hardware and image processing techniques now allow image quality improvements that make clinical applications feasible. Validation experiments were performed to characterize a new methodology and its imaging performance.

  15. Computed tomography diagnosis of partial anomalous pulmonary venous drainage.

    Science.gov (United States)

    Posniak, H V; Dudiak, C M; Olson, M C

    1993-01-01

    A case of the rarely occurring partial anomalous pulmonary venous drainage of the right upper lobe into the azygos arch is presented. Computed tomography (CT) clearly demonstrated the abnormal vessel coursing through the right upper lobe and draining into the azygos arch.

  16. Coronary computed tomography - present status and future directions

    NARCIS (Netherlands)

    Apfaltrer, P.; Schoepf, U. J.; Vliegenthart, R.; Rowe, G. W.; Spears, J. R.; Fink, C.; Nance, J. W.

    2011-01-01

    The use of coronary computed tomography angiography (cCTA) is growing rapidly, in large part because of fast-paced technical innovations that have increased diagnostic accuracy while providing new opportunities for radiation dose reduction. cCTA using recent generation CT scanners has been repeatedl

  17. Coronary artery fly-through using electron beam computed tomography

    NARCIS (Netherlands)

    van Ooijen, P M; Oudkerk, M; van Geuns, R J; Rensing, B J; de Feyter, P J

    2000-01-01

    BACKGROUND: Virtual reality techniques have recently been introduced into clinical medicine. This study examines the possibility of coronary artery fly-through using a dataset obtained by noninvasive coronary angiography with contrast-enhanced electron-beam computed tomography. METHODS AND RESULTS:

  18. Cost-effectiveness of PET and PET/Computed Tomography

    DEFF Research Database (Denmark)

    Gerke, Oke; Hermansson, Ronnie; Hess, Søren

    2015-01-01

    measure by means of incremental cost-effectiveness ratios when considering the replacement of the standard regimen by a new diagnostic procedure. This article discusses economic assessments of PET and PET/computed tomography reported until mid-July 2014. Forty-seven studies on cancer and noncancer...

  19. Tolerance Verification of an Industrial Assembly using Computed Tomography

    DEFF Research Database (Denmark)

    Stolfi, Alessandro; De Chiffre, Leonardo; Regi, Francesco

    2016-01-01

    This paper reports on results of tolerance verification of a multi-material assembly by using Computed Tomography (CT). The workpiece comprises three parts which are made out of different materials. Five different measurands were inspected. The calculation of measurement uncertainties was attempt...

  20. Position emission tomography with or without computed tomography in the primary staging of Hodgkin's lymphoma

    DEFF Research Database (Denmark)

    Hutchings, Martin; Jakobsen, Annika Loft; Hansen, Mads;

    2006-01-01

    In order to receive the most appropriate therapy, patients with Hodgkin's lymphoma (HL) must be accurately stratified into different prognostic staging groups. Computed tomography (CT) plays a pivotal role in the conventional staging. The aim of the present study was to investigate the value...

  1. Quantitation of regional cerebral blood flow by single photon emission computed tomography of CBF-tracer combined with whole-brain CBF; A comparison between [sup 123]I-IMP and [sup 99m]Tc-HMPAO in healthy volunteers

    Energy Technology Data Exchange (ETDEWEB)

    Isaka, Yoshinari; Imaizumi, Masatoshi; Ashida, Keiichi; Ohe, Yosuke; Okamoto, Masaya; Abe, Tohru; Tanaka, Seiji (Osaka National Hospital (Japan))

    1994-05-01

    A simple, noninvasive method of measuring cerebral blood flow (CBF) that uses single-photon emission computed tomography (SPECT) of CBF-tracer and whole brain CBF obtained by xenon-133 ([sup 133]Xe) clearance technique was developed. In nine healthy volunteers, SPECT data were normalized to the count density of [sup 123]I-IMP or [sup 99m]Tc-HMPAO uptake in the whole-brain, and then converted to the absolute units of CBF by multiplying average [sup 133]Xe-CBF in the whole brain. The CBF values measured by [sup 99m]Tc-HMPA CBF-SPECT was significantly lower in the high flow regions of cortical gray matter (bilateral frontal lobe; p<0.05 and right occipital lobe; p<0.05), and was significantly higher in the bilateral white matter (p<0.05 or 0.01) and the cerebellum (p<0.005) compared with the flow values measured by [sup 123]I-IMP CBF-SPECT. Whereas, the IMP-CBF values were significantly lower in the bilateral striatum (p<0.02 or 0.05) compared with the HMPAO-CBF values. Good correlations were found between IMP-CBF and the HMPAO-CBF values in the cortical gray matter (r[sub s]=0.761; p<0.001, n=108), the white matter (r[sub s]=0.739; p<0.001, n=18) and the cerebellum (r[sub s]=0.731; p<0.001, n=18). In the striatum (r[sub s]=0.58; p<0.05, n=18) and the thalamus (r[sub s]=0.628; p<0.05, n=18), the correlations between IMP-CBF and HMPAO-CBF values were inferior to those of the other three regions. The results indicated that the contrast between high and low CBF regions in the HMPAO CBF-SPECT was significantly less than that in the IMP CBF-SPECT. However, this assumption is not applicable in all of the cerebral regions. (author).

  2. Global seismic tomography and modern parallel computers

    Directory of Open Access Journals (Sweden)

    A. Piersanti

    2006-06-01

    Full Text Available A fast technological progress is providing seismic tomographers with computers of rapidly increasing speed and RAM, that are not always properly taken advantage of. Large computers with both shared-memory and distributedmemory architectures have made it possible to approach the tomographic inverse problem more accurately. For example, resolution can be quantified from the resolution matrix rather than checkerboard tests; the covariance matrix can be calculated to evaluate the propagation of errors from data to model parameters; the L-curve method can be applied to determine a range of acceptable regularization schemes. We show how these exercises can be implemented efficiently on different hardware architectures.

  3. Inter laboratory comparison on Industrial Computed Tomography

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo; Larsen, Erik

    The ‘CIA-CT comparison - Inter laboratory comparison on industrial Computed Tomography” is organized by DTU Department of Mechanical Engineering within the Danish project “Centre for Industrial Application of CT scanning - CIA-CT”. The project is co-financed by the Danish Ministry of Science, Tec...

  4. Comparison of Computed Tomography Scout Based Reference Point Localization to Conventional Film and Axial Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Lan; Templeton, Alistair; Turian, Julius; Kirk, Michael; Zusag, Thomas; Chu, James C.H., E-mail: jchu@rush.edu

    2011-01-01

    Identification of source positions after implantation is an important step in brachytherapy planning. Reconstruction is traditionally performed from films taken by conventional simulators, but these are gradually being replaced in the clinic by computed tomography (CT) simulators. The present study explored the use of a scout image-based reconstruction algorithm that replaces the use of traditional film, while exhibiting low sensitivity to metal-induced artifacts that can appear in 3D CT methods. In addition, the accuracy of an in-house graphical software implementation of scout-based reconstruction was compared with seed location reconstructions for 2 phantoms by conventional simulator and CT measurements. One phantom was constructed using a planar fixed grid of 1.5-mm diameter ball bearings (BBs) with 40-mm spacing. The second was a Fletcher-Suit applicator embedded in Styrofoam (Dow Chemical Co., Midland, MI) with one 3.2-mm-diameter BB inserted into each of 6 surrounding holes. Conventional simulator, kilovoltage CT (kVCT), megavoltage CT, and scout-based methods were evaluated by their ability to calculate the distance between seeds (40 mm for the fixed grid, 30-120 mm in Fletcher-Suit). All methods were able to reconstruct the fixed grid distances with an average deviation of <1%. The worst single deviations (approximately 6%) were exhibited in the 2 volumetric CT methods. In the Fletcher-Suit phantom, the intermodality agreement was within approximately 3%, with the conventional sim measuring marginally larger distances, with kVCT the smallest. All of the established reconstruction methods exhibited similar abilities to detect the distances between BBs. The 3D CT-based methods, with lower axial resolution, showed more variation, particularly with the smaller BBs. With a software implementation, scout-based reconstruction is an appealing approach because it simplifies data acquisition over film-based reconstruction without requiring any specialized equipment

  5. High-performance computing and networking as tools for accurate emission computed tomography reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Passeri, A. [Dipartimento di Fisiopatologia Clinica - Sezione di Medicina Nucleare, Universita` di Firenze (Italy); Formiconi, A.R. [Dipartimento di Fisiopatologia Clinica - Sezione di Medicina Nucleare, Universita` di Firenze (Italy); De Cristofaro, M.T.E.R. [Dipartimento di Fisiopatologia Clinica - Sezione di Medicina Nucleare, Universita` di Firenze (Italy); Pupi, A. [Dipartimento di Fisiopatologia Clinica - Sezione di Medicina Nucleare, Universita` di Firenze (Italy); Meldolesi, U. [Dipartimento di Fisiopatologia Clinica - Sezione di Medicina Nucleare, Universita` di Firenze (Italy)

    1997-04-01

    It is well known that the quantitative potential of emission computed tomography (ECT) relies on the ability to compensate for resolution, attenuation and scatter effects. Reconstruction algorithms which are able to take these effects into account are highly demanding in terms of computing resources. The reported work aimed to investigate the use of a parallel high-performance computing platform for ECT reconstruction taking into account an accurate model of the acquisition of single-photon emission tomographic (SPET) data. An iterative algorithm with an accurate model of the variable system response was ported on the MIMD (Multiple Instruction Multiple Data) parallel architecture of a 64-node Cray T3D massively parallel computer. The system was organized to make it easily accessible even from low-cost PC-based workstations through standard TCP/IP networking. A complete brain study of 30 (64 x 64) slices could be reconstructed from a set of 90 (64 x 64) projections with ten iterations of the conjugate gradients algorithm in 9 s, corresponding to an actual speed-up factor of 135. This work demonstrated the possibility of exploiting remote high-performance computing and networking resources from hospital sites by means of low-cost workstations using standard communication protocols without particular problems for routine use. The achievable speed-up factors allow the assessment of the clinical benefit of advanced reconstruction techniques which require a heavy computational burden for the compensation effects such as variable spatial resolution, scatter and attenuation. The possibility of using the same software on the same hardware platform with data acquired in different laboratories with various kinds of SPET instrumentation is appealing for software quality control and for the evaluation of the clinical impact of the reconstruction methods. (orig.). With 4 figs., 1 tab.

  6. Cranial computed tomography in psychiatry. Kraniale Computertomographie in der Psychiatrie

    Energy Technology Data Exchange (ETDEWEB)

    Falkai, P. (Rheinische Landes- und Hochschulklinik Duesseldorf, Psychiatrische Klinik der Heinrich-Heine-Universitaet (Germany)); Bogerts, B. (Rheinische Landes- und Hochschulklinik Duesseldorf, Psychiatrische Klinik der Heinrich-Heine-Universitaet (Germany))

    1993-08-13

    Computed tomography has gained importance as a diagnostic tool in psychiatry to exclude structural brain pathology, but has passed on its role in research to magnetic resonance tomography. It helps to distinguish between senile dementia of Alzheimer type and multi-infarct dementia. The enlargement of the ventricular system and cortical sulci is well established in schizophrenic and affective psychosis. Some alcohol addicts show a considerable degree of cerebral atrophy, only exceeded by demented patients, but this condition is potentially reversible. To screen psychiatric patients by CT is recommendable, as 2-10% of hospitalized psychiatric patients have structural brain disease. (orig.)

  7. Assessment of asthmatic inflammation using hybrid fluorescence molecular tomography-x-ray computed tomography

    Science.gov (United States)

    Ma, Xiaopeng; Prakash, Jaya; Ruscitti, Francesca; Glasl, Sarah; Stellari, Fabio Franco; Villetti, Gino; Ntziachristos, Vasilis

    2016-01-01

    Nuclear imaging plays a critical role in asthma research but is limited in its readings of biology due to the short-lived signals of radio-isotopes. We employed hybrid fluorescence molecular tomography (FMT) and x-ray computed tomography (XCT) for the assessment of asthmatic inflammation based on resolving cathepsin activity and matrix metalloproteinase activity in dust mite, ragweed, and Aspergillus species-challenged mice. The reconstructed multimodal fluorescence distribution showed good correspondence with ex vivo cryosection images and histological images, confirming FMT-XCT as an interesting alternative for asthma research.

  8. HAADF-STEM atom counting in atom probe tomography specimens: Towards quantitative correlative microscopy.

    Science.gov (United States)

    Lefebvre, W; Hernandez-Maldonado, D; Moyon, F; Cuvilly, F; Vaudolon, C; Shinde, D; Vurpillot, F

    2015-12-01

    The geometry of atom probe tomography tips strongly differs from standard scanning transmission electron microscopy foils. Whereas the later are rather flat and thin (atom probe tomography specimens. Based on simulations (electron probe propagation and image simulations), the possibility to apply quantitative high angle annular dark field scanning transmission electron microscopy to of atom probe tomography specimens has been tested. The influence of electron probe convergence and the benefice of deconvolution of electron probe point spread function electron have been established. Atom counting in atom probe tomography specimens is for the first time reported in this present work. It is demonstrated that, based on single projections of high angle annular dark field imaging, significant quantitative information can be used as additional input for refining the data obtained by correlative analysis of the specimen in APT, therefore opening new perspectives in the field of atomic scale tomography.

  9. X-ray computed tomography of PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Pfrang, Andreas; Veyret, Damien; Tsotridis, Georgios [Commission of the European Communities, Petten (Netherlands). Joint Reseach Centre, Inst. for Energy; Janssen, Gaby [Energy Research Centre of the Netherlands ECN, Petten (Netherlands). Dept. of Hydrogen and Clean Fossil Fuels

    2010-07-01

    Proton exchange membrane (PEM) fuel cells were investigated by 3D x-ray computed tomography at a voxel size of 0.7 {mu}m. It is shown that this lab-based technique is not only suitable for the investigation of gas diffusion layers (GDL) as well as the investigation of membrane electrode assemblies (MEA), but also allows the calculation of macroscopic physical properties. The resolution of computed tomography is clearly sufficient to image the carbon fiber structure of gas diffusion layers in the as received GDLs as well as GDLs integrated into membrane electrode assemblies. It is also possible to visualize the catalyst layer within the MEA, which allows the investigation of layer thickness and structural defects on a larger scale than with conventional techniques. The macroscopic effective thermal conductivities of the gas diffusion layers were computed based on the 3D GDL structure reconstructed from tomography data to produce more reliable input data for fuel cell modeling. The computation was carried out by solving the energy equation considering a pure thermal conduction problem. The computations show - in agreement with the expectation and experimental data - that the through-plane thermal conductivities are lower than the in-plane thermal conductivities. (orig.)

  10. Ptychographic X-ray computed tomography of extended colloidal networks in food emulsions

    DEFF Research Database (Denmark)

    Schou Nielsen, Mikkel; Bøgelund Munk, Merete; Diaz, Ana

    2016-01-01

    of suitable non-destructive 3D imaging techniques with submicron resolution. We present results of quantitative ptychographic X-ray computed tomography applied to a palm kernel oil based oil-in-water emulsion. The measurements were carried out at ambient pressure and temperature. The 3D structure...... of the extended colloidal network of fat globules was obtained with a resolution of around 300 nm. Through image analysis of the network structure, the fat globule size distribution was computed and compared to previous findings. In further support, the reconstructed electron density values were within 4...

  11. Dictionary-based image denoising for dual energy computed tomography

    Science.gov (United States)

    Mechlem, Korbinian; Allner, Sebastian; Mei, Kai; Pfeiffer, Franz; Noël, Peter B.

    2016-03-01

    Compared to conventional computed tomography (CT), dual energy CT allows for improved material decomposition by conducting measurements at two distinct energy spectra. Since radiation exposure is a major concern in clinical CT, there is a need for tools to reduce the noise level in images while preserving diagnostic information. One way to achieve this goal is the application of image-based denoising algorithms after an analytical reconstruction has been performed. We have developed a modified dictionary denoising algorithm for dual energy CT aimed at exploiting the high spatial correlation between between images obtained from different energy spectra. Both the low-and high energy image are partitioned into small patches which are subsequently normalized. Combined patches with improved signal-to-noise ratio are formed by a weighted addition of corresponding normalized patches from both images. Assuming that corresponding low-and high energy image patches are related by a linear transformation, the signal in both patches is added coherently while noise is neglected. Conventional dictionary denoising is then performed on the combined patches. Compared to conventional dictionary denoising and bilateral filtering, our algorithm achieved superior performance in terms of qualitative and quantitative image quality measures. We demonstrate, in simulation studies, that this approach can produce 2d-histograms of the high- and low-energy reconstruction which are characterized by significantly improved material features and separation. Moreover, in comparison to other approaches that attempt denoising without simultaneously using both energy signals, superior similarity to the ground truth can be found with our proposed algorithm.

  12. Under-reporting of osteoporotic vertebral fractures on computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Alexandra L. [Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester (United Kingdom)], E-mail: alexandra.firth@virgin.net; Al-Busaidi, Aisha [Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester (United Kingdom)], E-mail: albusaidi@doctors.org.uk; Sparrow, Patrick J. [Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester (United Kingdom)], E-mail: patsparrow@doctors.org.uk; Adams, Judith E. [Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester (United Kingdom); Department of Clinical Radiology, Imaging Science and Biomedical Engineering, Stopford Building, , University of Manchester, Oxford Road, Manchester M13 9PT (United Kingdom)], E-mail: judith.adams@manchester.ac.uk; Whitehouse, Richard W. [Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester (United Kingdom)], E-mail: Richard.Whitehouse@cmmc.nhs.uk

    2009-01-15

    Purpose: Osteoporotic vertebral fractures are frequently asymptomatic. They are often not diagnosed clinically or radiologically. Despite this, prevalent osteoporotic vertebral fractures predict future osteoporotic fractures and are associated with increased mortality and morbidity. Appropriate management of osteoporosis can reduce future fracture risk. Fractures on lateral chest radiographs taken for other conditions are frequently overlooked by radiologists. Our aim was to assess the value of computed tomography (CT) in the diagnosis of vertebral fracture and identify the frequency with which significant fractures are missed. Materials and methods: The thoracic CT scans of 100 consecutive male and 100 consecutive female patients over 55 years were reviewed. CT images were acquired on General Electric Lightspeed multi-detector (MD) CT scanners (16 or 32 row) using 1.25 mm slice thickness. Midline sagittal images were reconstructed from the 3D volume images. The presence of moderate (25-40% height loss) or severe (>40% height loss) vertebral fractures between T1 and L1 was determined using an established semi-quantitative method and confirmed by morphological measurement. Results were compared with the formal CT report. Results: Scans of 192 patients were analysed (95 female; 97 male); mean age 70.1 years. Thirty-eight (19.8%) patients had one or more moderate to severe vertebral fractures. Only 5 (13%) were correctly reported as having osteoporotic fractures in the official report. The sensitivity of axial CT images to vertebral fracture was 0.35. Conclusion: Incidental osteoporotic vertebral fractures are under-reported on CT. The sensitivity of axial images in detecting these fractures is poor. Sagittal reformations are strongly recommended to improve the detection rate.

  13. Coordinate Metrology by Traceable Computed Tomography

    DEFF Research Database (Denmark)

    Müller, Pavel

    metrology and coordinate metrology and is currently becoming more and more important measuring technique for dimensional measurements. This is mainly due to the fact that with CT, a complete three-dimensional model of the scanned part is in a relatively short time visualized using a computer...... is an important factor for decision making about manufactured parts. However, due to many influences in CT, estimation of the uncertainty is a challenge, also because standardized procedures and guidelines are not available yet. In this thesis, several methods for uncertainty estimation were applied in connection...

  14. Comparison of radiation absorbed dose in target organs in maxillofacial imaging with panoramic, conventional linear tomography, cone beam computed tomography and computed tomography

    Directory of Open Access Journals (Sweden)

    Panjnoush M.

    2009-12-01

    Full Text Available "nBackground and Aim: The objective of this study was to measure and compare the tissue absorbed dose in thyroid gland, salivary glands, eye and skin in maxillofacial imaging with panoramic, conventional linear tomography, cone beam computed tomography (CBCT and computed tomography (CT."nMaterials and Methods: Thermoluminescent dosimeters (TLD were implanted in 14 sites of RANDO phantom to measure average tissue absorbed dose in thyroid gland, parotid glands, submandibular glands, sublingual gland, lenses and buccal skin. The Promax (PLANMECA, Helsinki, Finland unit was selected for Panoramic, conventional linear tomography and cone beam computed tomography examinations and spiral Hispeed/Fxi (General Electric,USA was selected for CT examination. The average tissue absorbed doses were used for the calculation of the equivalent and effective doses in each organ."nResults: The average absorbed dose for Panoramic ranged from 0.038 mGY (Buccal skin to 0.308 mGY (submandibular gland, linear tomography ranged from 0.048 mGY (Lens to 0.510 mGY (submandibular gland,CBCT ranged from 0.322 mGY (thyroid glad to 1.144 mGY (Parotid gland and in CT ranged from 2.495 mGY (sublingual gland to 3.424 mGY (submandibular gland. Total effective dose in CBCT is 5 times greater than Panoramic and 4 times greater than linear tomography, and in CT, 30 and 22 times greater than Panoramic and linear tomography, respectively. Total effective dose in CT is 6 times greater than CBCT."nConclusion: For obtaining 3-dimensional (3D information in maxillofacial region, CBCT delivers the lower dose than CT, and should be preferred over a medical CT imaging. Furthermore, during maxillofacial imaging, salivary glands receive the highest dose of radiation.

  15. Compositional volumetry of non-calcified coronary plaques by multislice computed tomography: An ex vivo feasibility study

    NARCIS (Netherlands)

    N. Bruining (Nico); J.R.T.C. Roelandt (Jos); S. Verheye (Stefan); M.W. Knaapen (Michiel); Y. Onuma (Yoshinobu); E.S. Regar (Eveline); F. Cademartiri (Filippo); S. de Winter (Sebastiaan); G.J.J. van Langenhove (Glenn); P.W.J.C. Serruys (Patrick); R. Hamers (Ronald); P.J. de Feyter (Pim)

    2009-01-01

    textabstractAims: Non-invasive quantitative compositional analysis of coronary plaque would be a major advantage to study coronary artery disease. This study explores the application to use the Hounsfield units (HU) distribution of coronary plaques imaged by multislice computed tomography-coronary

  16. Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block

    Directory of Open Access Journals (Sweden)

    Estêvan Vieira Cabeda

    2015-01-01

    Full Text Available AbstractBackground:Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB.Objective:To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA (stenosis ≥ 70% as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA and compare the results with those of single photon emission computed tomography (SPECT myocardial perfusion scintigraphy.Methods:Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution’s ethics committee.Results:The patients’ mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001. The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001. In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001.Conclusion:The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB.

  17. Computed tomography of the acetabular fractures

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Ho Young; Suh, Jin Suck; Park, Chang Yun; Lee, Kil Woo [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1986-04-15

    In a retrospective study of 21 patients, in whom the acetabular fractures were suspected on initial radiographs, we compared and analysed the computed tomographic findings and plain radiographic findings. The results were as follow: 1. In patients with multiple trauma, no further change in position was required during CT examinations. 2. CT showed intraarticular loose bodies, which were invisible on plain radiographs. 3. CT was useful in detecting the fractures of acetabular rims, medial wall of acetabulum, and femoral head. 4. CT permitted better evaluation of shape, extent, and degree of separation of fracture fragments. 5. CT was helpful in detecting the associated fractures and soft tissue injuries. 6. CT also demonstrated the adequacy of reduction, the position of metallic fixation devices, and the presence or absence of remaining intraarticular osseous fragments after surgery.

  18. Micro-Computed Tomography and Finite Element Method Study of Open-Cell Porous Materials

    Directory of Open Access Journals (Sweden)

    Wejrzanowski Tomasz

    2015-01-01

    Full Text Available In the present paper the characterization of structure and properties of open-cell porous materials by high-resolution x-ray micro-computed tomography (μCT and finite element method (FEM is addressed. The unique properties of open porosity foams make them interesting in a range of applications in science and engineering such as energy absorbers, lightweight construction materials or heat insulators. Consequently, a detailed knowledge of structure as well as mechanical properties (i.e. Young’s Modulus, Poisson’s Ratio of such foams is essential. The resulting pixel size of the μCT was 40 μm, which enabled satisfactory visualization of the complex foam structure and quantitative characterization. Foam morphology was studied on post-processed computed tomography images, while mechanical properties were analyzed with use of the finite element method on numerical model obtained from μCT results.

  19. Cone-Beam Computed Tomography contrast validation of an artificial periodontal phantom for use in endodontics.

    Science.gov (United States)

    Michetti, Jerome; Basarab, Adrian; Tran, Michel; Diemer, Franck; Kouame, Denis

    2015-01-01

    Validation of image processing techniques such as endodontic segmentations in cone-beam computed tomography (CBCT) is a challenging issue because of the lack of ground truth in in vivo experiments. The purpose of our study was to design an artificial surrounding tissues phantom able to provide CBCT image quality of real extracted teeth, similar to in vivo conditions. Note that these extracted teeth could be previously scanned using micro computed tomography (μCT) to access true quantitative measurements of the root canal anatomy. Different design settings are assessed in our study by comparison to in vivo images, in terms of the contrast-to-noise ratio (CNR) obtained between different anatomical structures. Concerning the root canal and the dentine, the best design setup allowed our phantom to provide a CNR difference of only 3% compared to clinical cases.

  20. Comparison of computed tomography scout based reference point localization to conventional film and axial computed tomography.

    Science.gov (United States)

    Jiang, Lan; Templeton, Alistair; Turian, Julius; Kirk, Michael; Zusag, Thomas; Chu, James C H

    2011-01-01

    Identification of source positions after implantation is an important step in brachytherapy planning. Reconstruction is traditionally performed from films taken by conventional simulators, but these are gradually being replaced in the clinic by computed tomography (CT) simulators. The present study explored the use of a scout image-based reconstruction algorithm that replaces the use of traditional film, while exhibiting low sensitivity to metal-induced artifacts that can appear in 3D CT methods. In addition, the accuracy of an in-house graphical software implementation of scout-based reconstruction was compared with seed location reconstructions for 2 phantoms by conventional simulator and CT measurements. One phantom was constructed using a planar fixed grid of 1.5-mm diameter ball bearings (BBs) with 40-mm spacing. The second was a Fletcher-Suit applicator embedded in Styrofoam (Dow Chemical Co., Midland, MI) with one 3.2-mm-diameter BB inserted into each of 6 surrounding holes. Conventional simulator, kilovoltage CT (kVCT), megavoltage CT, and scout-based methods were evaluated by their ability to calculate the distance between seeds (40 mm for the fixed grid, 30-120 mm in Fletcher-Suit). All methods were able to reconstruct the fixed grid distances with an average deviation of <1%. The worst single deviations (approximately 6%) were exhibited in the 2 volumetric CT methods. In the Fletcher-Suit phantom, the intermodality agreement was within approximately 3%, with the conventional sim measuring marginally larger distances, with kVCT the smallest. All of the established reconstruction methods exhibited similar abilities to detect the distances between BBs. The 3D CT-based methods, with lower axial resolution, showed more variation, particularly with the smaller BBs. With a software implementation, scout-based reconstruction is an appealing approach because it simplifies data acquisition over film-based reconstruction without requiring any specialized equipment

  1. Swept source optical coherence tomography for quantitative and qualitative assessment of dental composite restorations

    Science.gov (United States)

    Sadr, Alireza; Shimada, Yasushi; Mayoral, Juan Ricardo; Hariri, Ilnaz; Bakhsh, Turki A.; Sumi, Yasunori; Tagami, Junji

    2011-03-01

    The aim of this work was to explore the utility of swept-source optical coherence tomography (SS-OCT) for quantitative evaluation of dental composite restorations. The system (Santec, Japan) with a center wavelength of around 1300 nm and axial resolution of 12 μm was used to record data during and after placement of light-cured composites. The Fresnel phenomenon at the interfacial defects resulted in brighter areas indicating gaps as small as a few micrometers. The gap extension at the interface was quantified and compared to the observation by confocal laser scanning microscope after trimming the specimen to the same cross-section. Also, video imaging of the composite during polymerization could provide information about real-time kinetics of contraction stress and resulting gaps, distinguishing them from those gaps resulting from poor adaptation of composite to the cavity prior to polymerization. Some samples were also subjected to a high resolution microfocus X-ray computed tomography (μCT) assessment; it was found that differentiation of smaller gaps from the radiolucent bonding layer was difficult with 3D μCT. Finally, a clinical imaging example using a newly developed dental SS-OCT system with an intra-oral scanning probe (Panasonic Healthcare, Japan) is presented. SS-OCT is a unique tool for clinical assessment and laboratory research on resin-based dental restorations. Supported by GCOE at TMDU and NCGG.

  2. Initial water quantification results using neutron computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.K. [Department of Mechanical and Nuclear Engineering, Pennsylvania State University (United States)], E-mail: axh174@psu.edu; Shi, L.; Brenizer, J.S.; Mench, M.M. [Department of Mechanical and Nuclear Engineering, Pennsylvania State University (United States)

    2009-06-21

    Neutron computed tomography is an important imaging tool in the field of non-destructive testing and in fundamental research for many engineering applications. Contrary to X-rays, neutrons can be attenuated by some light materials, such as hydrogen, but can penetrate many heavy materials. Thus, neutron computed tomography is useful in obtaining important three-dimensional information about a sample's interior structure and material properties that other traditional methods cannot provide. The neutron computed tomography system at Pennsylvania State University's Radiation Science and Engineering Center is being utilized to develop a water quantification technique for investigation of water distribution in fuel cells under normal conditions. A hollow aluminum cylinder test sample filled with a known volume of water was constructed for purposes of testing the quantification technique. Transmission images of the test sample at different angles were easily acquired through the synthesis of a dedicated image acquisition computer driving a rotary table controller and an in-house developed synchronization software package. After data acquisition, Octopus (version 8.2) and VGStudio Max (version 1.2) were used to perform cross-sectional and three-dimensional reconstructions of the sample, respectively. The initial reconstructions and water quantification results are presented.

  3. Brain computed tomography of the hypertensive patients

    Energy Technology Data Exchange (ETDEWEB)

    Bae, W. K.; Park, C. K.; Cho, O. K.; Hahm, C. K. [College of Medicine, Hanyang University, Seoul (Korea, Republic of)

    1980-12-15

    Now a day, hypertension is more increasing in frequency and ranked the top of the causes of death in Korea and other nations. Most of cerebrovascular accidents in hypertensive patients are composed of vascular occlusive changes and hemorrhages. In cerebral angiogram, we can only detect occlusion of large artery and large mass effect from hematoma or cerebral infarction without identification of its entity. The computed tomogram, however, is the best way for evaluation of cerebrovascular diseases including detection of nature, location, amount, and associated changes. This study includes evaluation of computed tomograms of 106 patients with hypertension during the period of 17 months from Feb. 1979 to June 1980 in the department of radiology, college of Medicine, Hanyang University. The results were as follows. 1. Age distribution of the total 106 patients was broad ranging from 25 years to 76 years. 67.9% of patients were over the age of 50. The male and female sex ratio was 3:2. 2. 28 out of 106 patients were normal and 78 patients revealed abnormal on C. T. findings; those were intracranial hemorrhage (35 patients), cerebral infarction (32 patients) and brain atrophy (11 patients). 3. All of the intracranial hemorrhage except one were intracerebral hemorrhage; those were located in the cerebral hemisphere (19 patients), basal ganglia (15 patients) and brain stem (1 patient). The except one case of intracranial hemorrhage was subdural hematoma. 7 patients of intraventricular hemorrhage and 1 patient of subarachnoid hemorrhage were combined with intracerebral hemorrhage. 2/3 of patients who had hemorrhage in cerebral hemisphere revealed lesions in the parietal and temporal lobes. 4. In cases of cerebral infarction, the cerebral hemisphere was most common site of lesion (20 cases), and the next was basal ganglia (11 cases). Most of the infarcts in cerebral hemisphere were located in the parietal and temporal lobes. The left basal ganglia was more commonly involved

  4. Prospectively electrocardiogram-triggered high-pitch spiral acquisition coronary computed tomography angiography for assessment of biodegradable vascular scaffold expansion: Comparison with optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    D’Alfonso, Maria Grazia [Interventional Cardiology Unit University Of Florence, Heart and Vessels department, AOU Careggi, Florence (Italy); Mattesini, Alessio, E-mail: amattesini@gmail.com [Interventional Cardiology Unit University Of Florence, Heart and Vessels department, AOU Careggi, Florence (Italy); Meucci, Francesco [Interventional Cardiology Unit University Of Florence, Heart and Vessels department, AOU Careggi, Florence (Italy); Acquafresca, Manlio [Radiology Unit 4, Radiology Department, AOU Careggi, Florence (Italy); Gensini, Gian Franco; Valente, Serafina [Interventional Cardiology Unit University Of Florence, Heart and Vessels department, AOU Careggi, Florence (Italy)

    2014-11-15

    BVS polymeric struts are transparent to the light so that the vessel wall contour can be easily visualized using optical coherence tomography (OCT). Therefore OCT represents a unique tool for both the evaluation of the resorption process and for the assessment of acute BVS mechanical failure. Similarly, the metal-free struts allow unrestricted coronary computed tomography angiography (CCTA), thus this non invasive method might become the gold standard for a non invasive assessment of BVS. In this case we show the ability of CCTA, performed with a low X-Ray dose, to provide a good evaluation of scaffold expansion. The quantitative measurements were in agreement with those obtained with OCT.

  5. Computed Tomography of the Normal Bovine Tarsus.

    Science.gov (United States)

    Hagag, U; Tawfiek, M; Brehm, W; Gerlach, K

    2016-12-01

    The objective of this study was to provide a detailed multiplanar computed tomographic (CT) anatomic reference for the bovine tarsus. The tarsal regions from twelve healthy adult cow cadavers were scanned in both soft and bone windows via a 16-slice multidetector CT scanner. Tarsi were frozen at -20(o) C and sectioned to 10-mm-thick slices in transverse, dorsal and sagittal planes respecting the imaging protocol. The frozen sections were cleaned and then photographed. Anatomic structures were identified, labelled and compared with the corresponding CT images. The sagittal plane was indispensable for evaluation of bone contours, the dorsal plane was valuable in examination of the collateral ligaments, and both were beneficial for assessment of the tarsal joint articulations. CT images allowed excellent delineation between the cortex and medulla of bones, and the trabecular structure was clearly depicted. The tarsal soft tissues showed variable shades of grey, and the synovial fluid was the lowest attenuated structure. This study provided full assessment of the clinically relevant anatomic structures of the bovine tarsal joint. This technique may be of value when results from other diagnostic imaging techniques are indecisive. Images presented in this study should serve as a basic CT reference and assist in the interpretation of various bovine tarsal pathology. © 2016 Blackwell Verlag GmbH.

  6. Role of computed tomography in pancreatic trauma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun Hee; Kim, Ki Whang; Lee, Jong Tae; Oh, Sei Jung [College of Medicine, Yonsei University, Seoul (Korea, Republic of)

    1991-03-15

    At Yonsei University Hospital from January 1984 to August 1990, computed tomographic (CT) scans of 13 patients with surgically proven pancreatic injuries after blunt abdominal trauma, including 6 pancreatic lacerations or contusions, 6 pancreatic fractures, and one post-traumatic pseudocyst, were retrospectively reviewed to determine the role and accuracy of the CT in evaluating pancreatic injury. CT can document gross pancreatic injury by showing focal or diffuse enlargement (1), area of diminished attenuation (3), separation (5), focal hematoma (2), and peripancreatic change, including peripancreatic hematoma (2), fluid collection (11), perirenal fascial thickening (10), omental and mesenteric change (5), and bowel change (2). CT correctly diagnosed pancreatic fracture in 5 cases, post-raumatic pseudocyst in 1 case, and pancreatic laceration in 3 cases in 9 of these patients. There were 4 false negative diagnoses, including 3 pancreatic lacerations and 1 pancreatic fracture. A CT is of pancreatic trauma could be difficult to diagnosis in patients who are scanned within 24 hrs after an injury or to distinguish a motion or streak artifact caused by a nasogastric tube or air-oral contrast fluid level in the stomach.

  7. Use of cone beam computed tomography in identifying postmenopausal women with osteoporosis.

    Science.gov (United States)

    Brasileiro, C B; Chalub, L L F H; Abreu, M H N G; Barreiros, I D; Amaral, T M P; Kakehasi, A M; Mesquita, R A

    2017-12-01

    The aim of this study is to correlate radiometric indices from cone beam computed tomography (CBCT) images and bone mineral density (BMD) in postmenopausal women. Quantitative CBCT indices can be used to screen for women with low BMD. Osteoporosis is a disease characterized by the deterioration of bone tissue and the consequent decrease in BMD and increase in bone fragility. Several studies have been performed to assess radiometric indices in panoramic images as low-BMD predictors. The aim of this study is to correlate radiometric indices from CBCT images and BMD in postmenopausal women. Sixty postmenopausal women with indications for dental implants and CBCT evaluation were selected. Dual-energy X-ray absorptiometry (DXA) was performed, and the patients were divided into normal, osteopenia, and osteoporosis groups, according to the World Health Organization (WHO) criteria. Cross-sectional images were used to evaluate the computed tomography mandibular index (CTMI), the computed tomography index (inferior) (CTI (I)) and computed tomography index (superior) (CTI (S)). Student's t test was used to compare the differences between the indices of the groups' intraclass correlation coefficient (ICC). Statistical analysis showed a high degree of interobserver and intraobserver agreement for all measurements (ICC > 0.80). The mean values of CTMI, CTI (S), and CTI (I) were lower in the osteoporosis group than in osteopenia and normal patients (p < 0.05). In comparing normal patients and women with osteopenia, there was no statistically significant difference in the mean value of CTI (I) (p = 0.075). Quantitative CBCT indices may help dentists to screen for women with low spinal and femoral bone mineral density so that they can refer postmenopausal women for bone densitometry.

  8. Monochromatic computed tomography with a compact laser-driven X-ray source.

    Science.gov (United States)

    Achterhold, K; Bech, M; Schleede, S; Potdevin, G; Ruth, R; Loewen, R; Pfeiffer, F

    2013-01-01

    A laser-driven electron-storage ring can produce nearly monochromatic, tunable X-rays in the keV energy regime by inverse Compton scattering. The small footprint, relative low cost and excellent beam quality provide the prospect for valuable preclinical use in radiography and tomography. The monochromaticity of the beam prevents beam hardening effects that are a serious problem in quantitative determination of absorption coefficients. These values are important e.g. for osteoporosis risk assessment. Here, we report quantitative computed tomography (CT) measurements using a laser-driven compact electron-storage ring X-ray source. The experimental results obtained for quantitative CT measurements on mass absorption coefficients in a phantom sample are compared to results from a rotating anode X-ray tube generator at various peak voltages. The findings confirm that a laser-driven electron-storage ring X-ray source can indeed yield much higher CT image quality, particularly if quantitative aspects of computed tomographic imaging are considered.

  9. Quantitative imaging of magnetic nanoparticles by magneto-relaxometric tomography for biomedical applications; Quantitative Bildgebung magnetischer Nanopartikel mittels magnetrelaxometrischer Tomographie fuer biomedizinische Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Liebl, Maik

    2016-11-18

    Current biomedical research focuses on the development of novel biomedical applications based on magnetic nanoparticles (MNPs), e.g. for local cancer treatment. These therapy approaches employ MNPs as remotely controlled drug carriers or local heat generators. Since location and quantity of MNPs determine drug enrichment and heat production, quantitative knowledge of the MNP distribution inside a body is essential for the development and success of these therapies. Magnetorelaxometry (MRX) is capable to provide such quantitative information based on the specific response of the MNPs after switching-off an applied magnetic field. Applying a uniform (homogeneous) magnetic field to a MNP distribution and measuring the MNP response by multiple sensors at different locations allows for spatially resolved MNP quantification. However, to reconstruct the MNP distribution from this spatially resolved MRX data, an ill posed inverse problem has to be solved. So far, the solution of this problem was stabilized incorporating a-priori knowledge in the forward model, e.g. by setting priors on the vertical position of the distribution using a 2D reconstruction grid or setting priors on the number and geometry of the MNP sources inside the body. MRX tomography represents a novel approach for quantitative 3D imaging of MNPs, where the inverse solution is stabilized by a series of MRX measurements. In MRX tomography, only parts of the MNP distribution are sequentially magnetized by the use of inhomogeneous magnetic fields. Each magnetizing is followed by detection of the response of the corresponding part of the distribution by multiple sensors. The 3D reconstruction of the MNP distribution is then accomplished by a common evaluation of the distinct MRX measurement series. In this thesis the first experimental setup for MRX tomography was developed for quantitative 3D imaging of biomedical MNP distributions. It is based on a multi-channel magnetizing unit which has been engineered to

  10. High Resolution Muon Computed Tomography at Neutrino Beam Facilities

    CERN Document Server

    Suerfu, Burkhant

    2015-01-01

    X-ray computed tomography (CT) has an indispensable role in constructing 3D images of objects made from light materials. However, limited by absorption coefficients, X-rays cannot deeply penetrate materials such as copper and lead. Here we show via simulation that muon beams can provide high resolution tomographic images of dense objects and of structures within the interior of dense objects. The effects of resolution broadening from multiple scattering diminish with increasing muon momentum. As the momentum of the muon increases, the contrast of the image goes down and therefore requires higher resolution in the muon spectrometer to resolve the image. The variance of the measured muon momentum reaches a minimum and then increases with increasing muon momentum. The impact of the increase in variance is to require a higher integrated muon flux to reduce fluctuations. The flux requirements and level of contrast needed for high resolution muon computed tomography are well matched to the muons produced in the pio...

  11. Didactics and training in cardiovascular computed tomography angiography.

    Science.gov (United States)

    Bhojraj, Sanjay D; Al-Mallah, Mouaz H

    2009-01-01

    As the role of cardiovascular computed tomography angiography (CCTA) is further expanded through research, the use of this technology will expand as a result of demand both from medical professionals and the public. To ensure a standardized quality of interpretation of these scans in the face of an increased demand for physicians qualified to interpret these studies, the Society of Cardiovascular Computed Tomography, along with several other professional societies, has proposed a didactic curriculum for the study of CCTA. This review highlights the currently proposed didactic curriculum for the study of CCTA, examines current trends in training for both medical trainees and physicians in practice, and proposes future directions for the study of CCTA.

  12. Project of evaluation of doses in computed tomography in Poland

    Energy Technology Data Exchange (ETDEWEB)

    Slusarczyk-Kacprzyk, W.; Skrzynski, W.; Bulski, W. [Centre of Oncology, Medical Physics Dept., Warsaw (Poland)

    2006-07-01

    Project of evaluation of doses in computed tomography in Poland bases on the organization solutions implemented and evaluated at one of Polish oncological centres. In this study we analyzed doses for a group of 484 patients who underwent an examination with a G.E. HiSpeed CT scanner at the Centre of Oncology in Warsaw. Patient doses (weighted computed tomography dose index, C.T.D.I.w. and dose length product, D.L.P.) have been compared against reference values published by the Polish Ministry of Health. We found that typical patient doses do not exceed reference values. As reference dose levels are defined only for a standard-size patients, sometimes they may be exceeded for a properly done examination. Polish reference dose levels are not based on up-to-date data and should be revised. (authors)

  13. Mandibular condyle position in cone beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Hyoung Joo; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan [Kyung Hee Univ. School of Dentistry, Seoul (Korea, Republic of)

    2006-06-15

    To evaluate position of the mandibular condyle within articular fossa in an asymptomatic population radiographically by a cone beam computed tomography. Cone beam computed tomography of 60 temporomandibular joints was performed on 15 males and 15 females with no history of any temporomandibular disorders, or any other orthodontic or photoconductors treatments. Position of mandibular condyle within articular fossa at centric occlusion was evaluated. A statistical evaluation was done using a SPSS. In the sagittal views, mandibular condyle within articular fossa was laterally located at central section. Mandibular condyles in the right and left sides were showed asymmetric positional relationship at medial, central, and lateral sections. Mandibular condyle within articular fossa in an asymptomatic population was observed non-concentric position in the sagittal and coronal views.

  14. Common findings and pseudolesions at computed tomography colonography: pictorial essay

    OpenAIRE

    Augusto Castelli von Atzingen; Dario Ariel Tiferes; Carlos Alberto Matsumoto; Thiago Franchi Nunes; Marcos Vinicius Alvim Soares Maia; Giuseppe D'Ippolito

    2012-01-01

    Computed tomography colonography is a minimally invasive method for screening for polyps and colorectal cancer, with extremely unusual complications, increasingly used in the clinical practice. In the last decade, developments in bowel preparation, imaging, and in the training of investigators have determined a significant increase in the method sensitivity. Images interpretation is accomplished through a combined analysis of two-dimensional source images and several types of three-dimensiona...

  15. Moulding process characterization of paper bottles using computed tomography

    DEFF Research Database (Denmark)

    Saxena, Prateek; Bissacco, Giuliano

    2016-01-01

    The paper presents an approach of evaluating the moulding process for production of paper bottlesusing Computed Tomography (CT). Moulded Pulp Products (MPP) are made of a formed, dewateredand dried mixture of pulp fibers and water. Modern industrial pulp moulding is datedback to the year 1903 when...... a patent for MPP production was acquired by Martin L. Keyes1. Withan increasing demand for environmental friendly products, researchers are now focusing on investigatingadvance manufacturing process for production of MPP2....

  16. Computed tomography-based subclassification of chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Dirksen, Asger; Wille, Mathilde M W

    2016-01-01

    Computed tomography (CT) is an obvious modality for subclassification of COPD. Traditionally, the pulmonary involvement of chronic obstructive pulmonary disease (COPD) in smokers is understood as a combination of deleterious effects of smoking on small airways (chronic bronchitis and small airways...... observed in COPD are subtle. Furthermore, recent results indicate that emphysema may also be the essential pathophysiologic mechanism behind the airflow limitation of COPD. The definition of COPD excludes bronchiectasis as a symptomatic subtype of COPD, and CT findings in chronic bronchitis...

  17. Computed tomography changes following cryotherapy for hepatic cancer

    Energy Technology Data Exchange (ETDEWEB)

    King, J.; Morris, D. L. [University of NSW, Sydney (Australia). Department of Surgery; Glenn, D. [St George Hospital, Kogarah, Sydney (Australia). Department of Radiology

    1997-05-01

    Encouraging survival and tumour marker results have been described in patients where the focally destructive technique, hepatic cryotherapy, is used to treat primary and secondary hepatic malignancy. Radiology allows assessment of the cryotherapy procedure and follow-up treatment. This paper aims to review and describe the appearance of hepatic cryotherapy by computed tomography which allows assessment of the adequacy of surgical technique and offers the ability to identify recurrences that may be suitable for further treatment. 11 refs., 1 tab., 9 figs.

  18. Predicting Neck Abscess with Contrast-Enhanced Computed Tomography

    OpenAIRE

    2014-01-01

    Neck abscesses are difficult to diagnose and treat. Currently, contrast-enhanced computed tomography (CECT) is the imaging modality of choice. The study aims to determine the predictive value of CECT findings in diagnosing neck abscess, causes of neck abscess and the most common neck space involved in the local population. 84 consecutive patients clinically suspected to have neck abscess who underwent CECT and surgical confirmation of pus were included. Demographic and clinical data were reco...

  19. Use of Cone Beam Computed Tomography in Endodontics

    Science.gov (United States)

    Scarfe, William C.; Levin, Martin D.; Gane, David; Farman, Allan G.

    2009-01-01

    Cone Beam Computed Tomography (CBCT) is a diagnostic imaging modality that provides high-quality, accurate three-dimensional (3D) representations of the osseous elements of the maxillofacial skeleton. CBCT systems are available that provide small field of view images at low dose with sufficient spatial resolution for applications in endodontic diagnosis, treatment guidance, and posttreatment evaluation. This article provides a literature review and pictorial demonstration of CBCT as an imaging adjunct for endodontics. PMID:20379362

  20. The role of computed tomography in modern paediatric uroradiology

    Energy Technology Data Exchange (ETDEWEB)

    Maudgil, D.D.; McHugh, K. E-mail: kmchugh@gosh.nhs.uk

    2002-08-01

    Computed tomography (CT) has developed a well-recognised role within paediatric uroradiology, especially in imaging of trauma, malignancy (in particular Wilms' tumour), atypical infection, and congenital urogenital abnormalities. CT can also be used for problem solving in nephrolithiasis and renal transplant assessment. These applications are illustrated and discussed, with an emphasis on particular information that can be gained from the CT study.

  1. Contraindications to lumbar puncture as defined by computed cranial tomography.

    OpenAIRE

    Gower, D. J.; Baker, A. L.; Bell, W O; Ball, M R

    1987-01-01

    Papilloedema is not always an adequate predictor of potential complications from lumbar puncture, and many clinicians are using computed tomography (CT) before lumbar puncture in an effort to identify more accurately the "at risk" patient. This paper identifies the following anatomical criteria defined by CT scanning that correlate with unequal pressures between intracranial compartments and predispose a patient to herniation following decompression of the spinal compartment: lateral shift of...

  2. Computed tomography angiography in the investigation of carotid stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, A.J.P.; Mendelow, A.D.; Birchall, D

    2001-07-01

    The assessment of carotid atherosclerotic disease is an essential pre-requisite for determining a patients suitability for carotid endarterectomy to prevent ischaemic stroke. Catheter angiography is regarded as the most accurate investigative tool for this purpose. However, with its finite morbidity and invasiveness, there is an increasing reliance upon non-invasive methods to accurately assess carotid disease. We present a review of the technique and applications of computed tomography angiography. Goddard, A.J. P.et al. (2001)

  3. Ureterolithiasis: classical and atypical findings on unenhanced helical computed tomography.

    Science.gov (United States)

    Vaswani, Kuldeep K; El-Dieb, Adam; Vitellas, Kenneth M; Bennett, William F; Bova, James G

    2002-03-01

    Evaluation of patients with acute flank pain using helical computed tomography (CT) is a well-accepted, rapid, and safe procedure in the emergency setting. Various primary and secondary signs are described in the literature for evaluation of these patients. Our purpose is to demonstrate both the classical findings associated with ureteral calculi on unenhanced helical CT and atypical findings and potential pitfalls. We also provide readers with a systematic approach to interpreting unenhanced helical CT scans performed for acute flank pain.

  4. Use of Cone Beam Computed Tomography in Endodontics

    OpenAIRE

    Scarfe, William C.; Martin D. Levin; David Gane; Farman, Allan G.

    2009-01-01

    Cone Beam Computed Tomography (CBCT) is a diagnostic imaging modality that provides high-quality, accurate three-dimensional (3D) representations of the osseous elements of the maxillofacial skeleton. CBCT systems are available that provide small field of view images at low dose with sufficient spatial resolution for applications in endodontic diagnosis, treatment guidance, and posttreatment evaluation. This article provides a literature review and pictorial demonstration of CBCT as an imagin...

  5. Hypoplasia of the parotid gland: computed tomography sialography diagnosis.

    Science.gov (United States)

    Sun, Lisha; Sun, Zhipeng; Ma, Xuchen

    2013-10-01

    We report two unusual cases of non-syndromic hypoplasia of the parotid gland. The hypoplastic parotid gland mimicked a preauricular parotid tumor in one case and presented as an incidental image finding in the other case. Absence of the deep lobe and isthmus of the parotid parenchyma could be determined on axial computed tomography (CT) by revealing fat tissue composition of the parotid space. The underdeveloped superficial lobe of the gland was observed on three-dimensional CT sialography.

  6. Computed tomography of common congenital lesions of the temporal bone

    Energy Technology Data Exchange (ETDEWEB)

    Yuen, H.Y. E-mail: drhyyuen@doctors.org.uk; Ahuja, A.T.; Wong, K.T.; Yue, V.; Hasselt, A.C. van

    2003-09-01

    This pictorial review describes the application of high-resolution computed tomography to the investigation and pre-operative work-up of the common lesions of congenital hearing loss, including congenital aural dysplasia, various congenital ossicular anomalies, inner ear dysmorphology, large vestibular aqueduct syndrome, and congenital absence of cochlear nerve and labyrinthitis ossificans from previous infection. The aim is to help radiologists to provide a more accurate diagnosis of underlying aetiology and assist in surgical planning.

  7. Computed tomography of partial unilateral agenesis of the pectoralis muscles.

    Science.gov (United States)

    Demos, T C; Johnson, C; Love, L; Posniak, H

    1985-01-01

    The most common congenitally absent muscles are the pectoralis major and minor. Absence is usually incomplete. This anomaly is often one component of a syndrome associated with other hand (Poland syndrome) and thoracic anomalies. Computed tomography can identify partial absence of the pectoralis muscle and exactly define the altered anatomy. A patient with myasthenia gravis and isolated partial agenesis of the pectoralis muscle is presented.

  8. Analysis of Multilayered Printed Circuit Boards using Computed Tomography

    Science.gov (United States)

    2014-05-01

    resistors harder to identify as Carbon is lower in the periodic table than Aluminium Oxide . Sample 2: Colour Bar Appendix D.2...Aluminium Al2O3 Aluminium Oxide BGA Ball Grid Array Coronal XZ Plane COTS Commercial Off The Shelf C Carbon CT Computed Tomography DC Direct Current...encapsulated in steel housing. Red Circle: Thin film resistors harder to identify as Carbon is lower in the periodic table than Aluminium Oxide . Sample 2

  9. Soil Macropore Structure Characterized by X-Ray Computed Tomography

    Institute of Scientific and Technical Information of China (English)

    FENG Jie; ZHANG Jia-Bao; ZHU An-Ning; BI Jing-Wei

    2003-01-01

    Undisturbed soil core with many macropores and disturbed soil core with only one macropore (diameter is 10 mm) were probed by x-ray computed tomography (CT). The size, number, shape and continuity of macropores in the transverse and vertical sections of soil were characterized using CT scanning images. The probability densities of macropores in the transverse section of soil core exhibited a logarithmic Γ distribution.Results indicated that CT scanning was a promising nondestructive method for characterizing macropores in soils.

  10. Role of computed tomography in the study of vascular pathology

    Energy Technology Data Exchange (ETDEWEB)

    Procacci, C.; Bicego, E.; Bergamo, I.A. and others

    1988-01-01

    The most important indications to the use of computed tomography (CT) in the study of vascular pathology are considered. They may be divided as follows: 1) demonstration of vascular involvement by thoraco-abdominal neoplasms; 2) differential diagnosis between primary vascular and extra-vascular pathology; 3) assessment of primary arterial pathology. For each group, those pathologies are considered, for which CT plays a fundamental role.

  11. Computed tomography of the pathological temporal bone. Malformations. Otospongiosis

    Energy Technology Data Exchange (ETDEWEB)

    Azais, O.; Drouineau, J.; Vandermarcq, P.; Barret, D.; Gasquet, C.

    1988-01-01

    The authors evaluate the value of computed tomography in the investigation of malformations and otospongiosis of the ear. Although the CT scan appears to be essential in the preoperative of malformations of the ear, especially as otological examination frequently contributes little to the evaluation of the middle ear, otospongiosis seems to be a less formal indication, except in the predominantly cochlear forms of the disease.

  12. Computed tomography in patients with Ehlers-Danlos syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Hagino, Hiroshi; Sugitani, Akitoshi; Eda, Isematsu; Takashima, Sachio; Takeshita, Kenzo

    1985-09-01

    Three patients with Ehlers-Danlos syndrome were reported. Unusual findings on computed tomography were seen in two of the three patients. One case showed peculiar and marked dilatation of the 4th ventricle, supracerebellar cistern and lateral ventricle. The other case presented disproportionate enlargement of the anterior horn of the lateral ventricle. These CT findings in the two patients suggest that developmental abnormalities may constitute a structural defect.

  13. Dosimetry in abdominal imaging by 6-slice computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Sonia Isabel [Hospital de Faro, EPE (Portugal); Abrantes, Antonio Fernando; Ribeiro, Luis Pedro; Almeida, Rui Pedro Pereira [University of Algarve (Portugal). School of Health. Dept. of Radiology

    2012-11-15

    Objective: To determine the effective dose in abdominal computed tomography imaging and to study the influence of patients' characteristics on the received dose. Materials and Methods: Dose values measurements were performed with an ionization chamber on phantoms to check the agreement between dose values and those presented by the computed tomography apparatus, besides their compliance with the recommended reference dose levels. Later, values of dose received by physically able patients submitted to abdominal computed tomography (n = 100) were measured and correlated with their anthropometric characteristics. Finally, the dose to organs was simulated with the Monte Carlo method using the CT-Expo V 1.5 software, and the effect of automatic exposure control on such examinations. Results: The main characteristics directly influencing the dose include the patients' body mass, abdominal perimeter and body mass index, whose correlation is linear and positive. Conclusion: The radiation dose received from abdominal CT scans depends on some patient's characteristics, and it is important to adjust the acquisition parameters to their dimensions (author)

  14. Multidetector computed tomography in the preoperative staging of gastric adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Ricardo Hoelz de Oliveira; Penachim, Thiago Jose; Martins, Daniel Lahan; Andreollo, Nelson Adami; Caserta, Nelson Marcio Gomes, E-mail: rhobarros@hotmail.com [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil)

    2015-03-15

    Objective: To evaluate the role of multidetector computed tomography in the preoperative investigation of tumor invasion depth and lymph node and metastatic involvement according to the TNM classification, in patients with gastric adenocarcinoma. Materials and Methods: Fifty-four patients with biopsy-confirmed gastric cancer underwent preoperative staging with 64-channel multidetector computed tomography. Two independent radiologists analyzed the images and classified the findings. Sensitivity, specificity, accuracy and overall accuracy were calculated for each observer. The interobserver agreement was also evaluated. Results: The accuracy in the classification of categories T ranged from 74% to 96% for observer 1 and from 80% to 92% for observer 2. The overall accuracy was 70% for both observers. The weighted kappa index was 0.75, consistent with a significant interobserver agreement. The accuracy in the classification of lymph node involvement (category N) ranged from 55% to 79% for observer 1 and from 73% to 82% for observer 2. The evaluation of metastatic involvement showed an overall accuracy of 89.6% for both observers. Conclusion: 64-channel multidetector computed tomography demonstrated clinically relevant accuracy in the preoperative staging of gastric adenocarcinoma as regards invasion depth (T category) and metastatic involvement (M category). (author)

  15. Helical computed tomography in the assessment of abdominal aortic pathology

    Energy Technology Data Exchange (ETDEWEB)

    Vicaretti, M.; Young, N.; Jenkins, J.; Fletcher, J. [Westmead Hospital, Westmead, NSW (Australia)

    1997-05-01

    A pilot study was undertaken to evaluate the role of helical computed tomography in the assessment of abdominal aortic pathology. A total of 17 patients underwent intra-arterial digital subtraction angiography (IADSA) and helical computed tomography, with eight patients undergoing subsequent operative intervention. A comparison of radiological findings between IADSA and helical computed tomography (CT) was made and, where applicable, a comparison was made with operative findings. Pathology included abdominal aortic aneurysm (AAA) (n=12), thoraco abdominal aneurysm (n=2) and dissection (n=1), graft distension following AAA repair (n=1) and plaque haemorrhage in the distal aorta following percutaneous transluminal angioplasty (PTA) of the iliac artery (n=1). Planned operative management as based on pre-operative helical CT imaging findings, in particular with reference to the type of graft used (straight or bifurcated) was not changed at operation. Our findings on helical CT in regards to AAA, thoraco-abdominal aneurysm and dissection correlated well with angiography and surgery findings. (authors). 26 refs., 2 tabs., 5 figs.

  16. Efficacy of multislice computed tomography for gastroenteric and hepatic surgeries

    Institute of Scientific and Technical Information of China (English)

    Hiroshi Ohtani; Mitsuo Tsubakimoto; Hidemi Kawajiri; Yuichi Arimoto; Koichi Ohno; Yasuhisa Fujimoto; Hiroko Oba; Kenji Adachi; Masaya Hirano; Shoichi Terakawa

    2005-01-01

    AIM: To determine the efficacy of multislice CT for gastroenteric and hepatic surgery.METHODS: Dual-phase helical computed tomography was performed in 50 of 51 patients who underwent gastroenteric and hepatic surgeries. Twenty-eight, eighteen and four patients suffering from colorectal cancer, gastric cancer,and liver cancer respectively underwent colorectal surgery (laparoscopic surgery: 6 cases), gastrectomy, and hepatectomy. Three-dimensional computed tomography imaging of the inferior mesenteric artery, celiac artery and hepatic artery was performed. And in the follow-up examination of postoperative patients, multiplanar reconstruction image was made in case of need.RESULTS: Scans in 50 patients were technically satisfactory and included in the analysis. Depiction of major visceral arteries, which were important for surgery and other treatments, could be done in all patients.Preoperative visualization of the left colic artery and sigmoidal arteries, the celiac artery and its branches, and hepatic artery was very useful to lymph node dissection,the planning of a reservoir and hepatectomy. And multiplanar reconstruction image was helpful to diagnosis for the postoperative follow-up of patients.CONCLUSION: Three-dimensional volume rendering or multiplanar reconstruction imaging performed by multislice computed tomography was very useful for gastroenteric and hepatic surgeries.

  17. Anatomical structure of lingual foramen in cone beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ki, Min Woo; Hwang, Eui Hwan; Lee, Sang Rae [Kyunghee University College of Medicine, Seoul (Korea, Republic of)

    2004-07-15

    To evaluate whether cone beam computed tomography can depict the distribution, position, frequency, relative vertical dimension, and the diameter of the lingual foramen and direction of lingual bone canal. Cone beam computed tomography of mandible was performed on 25 males and 25 females with no history of any orthodontic treatments or any other dental surgeries. A statistical comparison was done on the mean values of males and females. In the location and distribution of lingual foramina, median lingual foramen was found in all subjects and lateral lingual foramen in 58%. In the lateral lingual foramen, bilateral type was found in 28% and unilateral type in 30%. In the number of lingual foramina, median lingual foramen had two foramina and lateral lingual foramen had one foramen, mostly. In the relative mean vertical dimension of lingual foramina, median lingual foramen was 0.03 {+-} 0.08, and both lateral lingual foramina was 0.20 {+-} 0.04. The mean diameter of lingual foramina, median lingual foramen was 0.9 mm {+-} 0.28, right lateral lingual foramen was 0.92 mm {+-} 0.23, and left lateral lingual foramen was 0.88 mm {+-} 0.27. The most frequent direction of the lingual bone canals, median lingual bone canal proceeded in anteroinferior direction and lateral lingual bone canal in anterosuperolateral direction. Cone beam computed tomography can be helpful for surgery and implantation on the mandibular area. Radiologist should be aware of this anatomical feature and its possible implications.

  18. SADMFR guidelines for the use of Cone-Beam Computed Tomography/ Digital Volume Tomography.

    Science.gov (United States)

    Dula, Karl; Bornstein, Michael M; Buser, Daniel; Dagassan-Berndt, Dorothea; Ettlin, Dominik A; Filippi, Andreas; Gabioud, François; Katsaros, Christos; Krastl, Gabriel; Lambrecht, J Thomas; Lauber, Roland; Luebbers, Heinz-Theo; Pazera, Pawel; Türp, Jens C

    2014-01-01

    Cone-Beam Computed Tomography (CBCT) has been introduced in 1998. This radiological imaging procedure has been provided for dentistry and is comparable to computed tomography (CT) in medicine. It is expected that CBCT will have the same success in dental diagnostic imaging as computed tomography had in medicine. Just as CT is responsible for a significant rise in radiation dose to the population from medical X-ray diagnostics, CBCT studies will be accompanied by a significant increase of the dose to our patients by dentistry. Because of the growing concern for an uncritical and consequently rapidly increasing use of CBCT the Swiss Society of Dentomaxillofacial Radiology convened a first consensus conference in 2011 to formulate indications for CBCT, which can be used as guidelines. In this meeting, oral and maxillofacial surgery, orthodontics and temporomandibular joint disorders and diseases were treated and the most important and most experienced users of DVT in these areas were asked to participate. In general, a highly restrictive use of CBCT is required. Justifying main criterion for CBCT application is that additional, therapy-relevant information is expected that should lead to a significant benefit in patient care. All users of CBCT should have completed a structured, high-level training, just like that offered by the Swiss Society of Dentomaxillofacial Radiology.

  19. Clinical utility of dental cone-beam computed tomography: current perspectives

    Directory of Open Access Journals (Sweden)

    Jaju PP

    2014-04-01

    Full Text Available Prashant P Jaju,1 Sushma P Jaju21Oral Medicine and Radiology, 2Conservative Dentistry and Endodontics, Rishiraj College of Dental Sciences and Research Center, Bhopal, IndiaAbstract: Panoramic radiography and computed tomography were the pillars of maxillofacial diagnosis. With the advent of cone-beam computed tomography, dental practice has seen a paradigm shift. This review article highlights the potential applications of cone-beam computed tomography in the fields of dental implantology and forensic dentistry, and its limitations in maxillofacial diagnosis.Keywords: dental implants, cone-beam computed tomography, panoramic radiography, computed tomography

  20. Computed Tomography and Computed Radiography of late Bronze Age Cremation Urns from Denmark

    DEFF Research Database (Denmark)

    Harvig, Lise Lock; Lynnerup, Niels; Amsgaard Ebsen, Jannie

    2012-01-01

    To improve methods used to study prehistoric cremation rituals, cremation urns from the Danish late Bronze Age were examined using Computed Tomography and Computed Radiography (Digital X-ray). During microexcavation, the digital images were used as registration tool. Our results suggest...

  1. Multi-scale analysis of lung computed tomography images

    CERN Document Server

    Gori, I; Fantacci, M E; Preite Martinez, A; Retico, A; De Mitri, I; Donadio, S; Fulcheri, C

    2007-01-01

    A computer-aided detection (CAD) system for the identification of lung internal nodules in low-dose multi-detector helical Computed Tomography (CT) images was developed in the framework of the MAGIC-5 project. The three modules of our lung CAD system, a segmentation algorithm for lung internal region identification, a multi-scale dot-enhancement filter for nodule candidate selection and a multi-scale neural technique for false positive finding reduction, are described. The results obtained on a dataset of low-dose and thin-slice CT scans are shown in terms of free response receiver operating characteristic (FROC) curves and discussed.

  2. [Role of cone-beam computed tomography in diagnostic otorhinolaryngological imaging].

    Science.gov (United States)

    Perényi, Ádám; Bella, Zsolt; Baráth, Zoltán; Magyar, Péter; Nagy, Katalin; Rovó, László

    2016-01-10

    Accurate diagnosis and preoperative planning in modern otorhinolaryngology is strongly supported by imaging with enhanced visualization. Computed tomography is often used to examine structures within bone frameworks. Given the hazards of ionizing radiation, repetitive imaging studies exponentially increase the risk of damages to radiosensitive tissues. The authors compare multislice and cone-beam computed tomography and determine the role, advantages and disadvantages of cone-beam computed tomography in otorhinolaryngological imaging. They summarize the knowledge from the international literature and their individual imaging studies. They conclude that cone-beam computed tomography enables high-resolution imaging and reconstruction in any optional plane and in space with considerably lower effective radiation dose. Cone-beam computed tomography with appropriate indications proved to be an excellent diagnostic tool in otorhinolaryngological imaging. It makes an alternative to multislice computed tomography and it is an effective tool in perioperative and postoperative follow-up, especially in those cases which necessitate repetitive imaging with computed tomography.

  3. [Analysis of single-photon emission computed tomography in patients with hypertensive encephalopathy complicated with previous hypertensive crisis].

    Science.gov (United States)

    Kustkova, H S

    2012-01-01

    In cerebrovascular diseases pefuzionnaya single photon emission computed tomography with lipophilic amines used for the diagnosis of functional disorders of cerebral blood flow. Quantitative calculations helps clarify the nature of vascular disease and clarify the adequacy and effectiveness of the treatment. In this modern program for SPECT ensure conduct not only as to the calculation of blood flow, but also make it possible to compute also the absolute values of cerebral blood flow.

  4. [Spiral computed tomography in the diagnosis of limb osteomyelitis].

    Science.gov (United States)

    Vasil'ev, A Iu; Bulanova, T V; Onishchenko, M P

    2003-01-01

    The results of radiation studies in 121 patients of different age (4 to 75 years) examined for limb osteomyelitis are analyzed. All the patients underwent routine X-ray study and computed tomography (CT), 26 patients had X-ray fistulography; 8, linear tomography; 10, CT fistulography; 6, scintigraphy, and 15, ultrasound study. Acute hematogenous osteomyelitis (AHO), chronic hematogenous osteomyelitis (CHO), and atypical (here Garre's sclerosing osteomyelitis and Brodie's abscess) osteomyelitis were ascertained in 10.6, 26.4, and 10.1% of cases, respectively. Posttraumatic osteomyelitis was diagnosed in almost 50% of the patients. CT defined the phase of chronic limb osteomyelitis. Spiral CT has proven to be the most effective technique for diagnosing limb osteomyelitis as compared with routine X-ray study: the accuracy of X-ray study was 81.8%, its sensitivity, 84.9%, and specificity, 60.0% and those of computed tomography were 96.7, 99.1, and 80.0%, respectively.

  5. A circular aperture array for ultrasonic tomography and quantitative NDE

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, S.A.

    1998-08-01

    The main topics of this thesis are ultrasonic tomography and ultrasonic determination of elastic stiffness constants. Both issues are based on a synthetic array with transducer elements distributed uniformly along a circular aperture, i.e., a circular aperture array. The issues are treated both theoretically and experimentally by broadband pulse techniques. Ultrasonic tomography, UCT, from a circular aperture is a relatively new imaging technique in Non-destructive Evaluation (NDE) to acquire cross sectional images in bulk materials. A filtered back-projection algorithm is used to reconstruct images in four different experiments and results of attenuation, velocity and reflection tomograms in Plexiglas of AlSi-alloy cylinders are presented. Two kinds of ultrasonic tomography are introduced: bistatic and monostatic imaging. Both techniques are verified experimentally by Plexiglas cylinders. Different reconstruction artifacts are discussed and theoretical resolution constraints are discussed for various configurations of the circular aperture array. The monostatic technique is used in volumetric imaging. In the experimental verification artificial and real discontinuities in a cylindrical AlSi-alloy are compared with similar discontinuities in a Plexiglas specimen. Finally, some limitations to UCT are discussed. The circular aperture array is used to determine five independent elastic stiffness constants of a unidirectional glass/PET (Poly Ethylene Teraphtalate) laminate. Energy flux propagation and attenuation of ultrasonic waves are considered and velocity surfaces are calculated for different planes of interest. Relations between elastic stiffness constants and engineering constants (i.e., Young`s moduli, shear moduli and Poisson`s ratios) are discussed for an orthotropic composite. Six micromechanical theories are reviewed, and expressions predicting the elastic engineering constants are evaluated. The micromechanical predicted elastic stiffness constants for the

  6. Computed tomography and (18)F-fluorodeoxyglucose positron emission tomography/computed tomography findings in adrenal candidiasis and histoplasmosis: two cases.

    Science.gov (United States)

    Altinmakas, Emre; Guo, Ming; Kundu, Uma R; Habra, Mouhammed Amir; Ng, Chaan

    2015-01-01

    We report the contrast-enhanced computed tomography (CT) and (18)F-fluorodeoxyglucose positron emission tomography findings in adrenal histoplasmosis and candidiasis. Both demonstrated bilateral hypermetabolic heterogeneous adrenal masses with limited wash-out on delayed CT. Adrenal candidiasis has not been previously reported, nor have the CT wash-out findings in either infection. The adrenal imaging findings are indistinguishable from malignancy, which is more common; but in this setting, physicians should be alert to the differential diagnosis of fungal infections, since it can be equally deadly.

  7. Right parietal stroke with Gerstmann's syndrome. Appearance on computed tomography, magnetic resonance imaging, and single-photon emission computed tomography.

    Science.gov (United States)

    Moore, M R; Saver, J L; Johnson, K A; Romero, J A

    1991-04-01

    We examined a patient who exhibited Gerstmann's syndrome (left-right disorientation, finger agnosia, dyscalculia, and dysgraphia) in association with a perioperative stroke in the right parietal lobe. This is the first description of the Gerstmann tetrad occurring in the setting of discrete right hemisphere pathologic findings. A well-localized vascular lesion was demonstrated by computed tomography, magnetic resonance imaging, and single-photon emission computed tomographic studies. The patient had clinical evidence of reversed functional cerebral dominance and radiologic evidence of reversed anatomic cerebral asymmetries.

  8. The role of positron emission tomography/computed tomography in planning radiotherapy in endometrial cancer.

    Science.gov (United States)

    Simcock, Bryony; Narayan, Kailash; Drummond, Elizabeth; Bernshaw, David; Wells, Elizabeth; Hicks, Rodney J

    2015-05-01

    The optimal method of assessing disease distribution in endometrial cancer is widely debated. Knowledge of disease distribution assists in planning adjuvant radiotherapy; in this study we used positron emission tomography/computed tomography (PET/CT) to assess disease distribution before radiotherapy. Seventy-three consecutive patients referred to the Peter MacCallum Cancer Centre for adjuvant radiotherapy for endometrial cancer, with either high-risk disease after a hysterectomy or recurrent disease, had a PET/CT before treatment. The findings on PET/CT and clinical course were recorded. PET/CT found additional disease in 35% of postoperative patients, changing planned treatment in 31%. In the group with known recurrence, additional disease was found in 72%, changing management in 36%. PET/CT is a valuable tool for planning radiotherapy in endometrial cancer.

  9. Fasciola Hepatica Mimicking Malignancy on 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

    Science.gov (United States)

    Sürücü, Erdem; Demir, Yusuf; Dülger, Ahmet C.; Batur, Abdüssamed; Ölmez, Şehmus; Kitapçı, Mehmet T.

    2016-01-01

    A 48-year-old female with complaints of gastrointestinal symptoms such as abdominal pain, fatigue, vomiting, nausea, and weight loss was diagnosed with neuroendocrine tumor after removal of a 2 mm lesion from the stomach with endoscopic biopsy. Her magnetic resonance imaging that was performed due to on-going symptoms showed multiple linear hypointense lesions in the liver. Positron emission tomography/computed tomography (PET/CT) scan was performed for differential diagnosis, which showed high fluorodeoxyglucose (FDG) uptake in these lesions. Clinical and laboratory findings revealed the final diagnosis as Fasciola hepatica. The imaging features of this case is presented to aid in differentiating this infectious disease from malignancy and avoid misdiagnosis on FDG-PET/CT. PMID:27751978

  10. Reconstruction Algorithms for Positron Emission Tomography and Single Photon Emission Computed Tomography and their Numerical Implementation

    CERN Document Server

    Fokas, A S; Marinakis, V

    2004-01-01

    The modern imaging techniques of Positron Emission Tomography and of Single Photon Emission Computed Tomography are not only two of the most important tools for studying the functional characteristics of the brain, but they now also play a vital role in several areas of clinical medicine, including neurology, oncology and cardiology. The basic mathematical problems associated with these techniques are the construction of the inverse of the Radon transform and of the inverse of the so called attenuated Radon transform respectively. We first show that, by employing mathematical techniques developed in the theory of nonlinear integrable equations, it is possible to obtain analytic formulas for these two inverse transforms. We then present algorithms for the numerical implementation of these analytic formulas, based on approximating the given data in terms of cubic splines. Several numerical tests are presented which suggest that our algorithms are capable of producing accurate reconstruction for realistic phanto...

  11. Fasciola Hepatica Mimicking Malignancy on 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

    Directory of Open Access Journals (Sweden)

    Erdem Sürücü

    2016-10-01

    Full Text Available A 48-year-old female with complaints of gastrointestinal symptoms such as abdominal pain, fatigue, vomiting, nausea, and weight loss was diagnosed with neuroendocrine tumor after removal of a 2 mm lesion from the stomach with endoscopic biopsy. Her magnetic resonance imaging that was performed due to on-going symptoms showed multiple linear hypointense lesions in the liver. Positron emission tomography/computed tomography (PET/CT scan was performed for differential diagnosis, which showed high fluorodeoxyglucose (FDG uptake in these lesions. Clinical and laboratory findings revealed the final diagnosis as Fasciola hepatica. The imaging features of this case is presented to aid in differentiating this infectious disease from malignancy and avoid misdiagnosis on FDG-PET/CT.

  12. Diagnostic performance of exercise bicycle testing and single-photon emission computed tomography: Comparison with 64-slice computed tomography coronary angiography

    NARCIS (Netherlands)

    A.C. Weustink (Annick); L.A.E. Neefjes (Lisan); A. Rossi (Alexia); W.B. Meijboom (Willem Bob); K. Nieman (Koen); E. Capuano (Ermanno); H. Boersma (Eric); N.R.A. Mollet (Nico); G.P. Krestin (Gabriel); P.J. de Feyter (Pim)

    2012-01-01

    textabstractTo conduct a comparison of the diagnostic performance of exercise bicycle testing and singlephoton emission computed tomography (SPECT) with computed tomography coronary angiography (CTCA) for the detection of obstructive coronary artery disease (CAD) in patients with stable angina. 376

  13. Inside marginal adaptation of crowns by X-ray micro-computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Dos Santos, T. M.; Lima, I.; Lopes, R. T. [Nuclear Instrumentation Laboratory, Nuclear Engineering Program, Federal University of Rio de Janeiro, RJ, (Brazil); Author, S. B. Jr. [Department of Physics, Colorado State University, Ft. Collins, CO 80523, (United States)

    2015-07-01

    The objective of this work was to access dental arcade by using X-ray micro-computed tomography. For this purpose high resolution system was used and three groups were studied: Zirkonzahn CAD-CAM system, IPS e.max Press, and metal ceramic. The three systems assessed in this study showed results of marginal and discrepancy gaps clinically accepted. The great result of 2D and 3D evaluations showed that the used technique is a powerful method to investigate quantitative characteristics of dental arcade. (authors)

  14. Influence of Adaptive Statistical Iterative Reconstruction on coronary plaque analysis in coronary computed tomography angiography

    DEFF Research Database (Denmark)

    Precht, Helle; Kitslaar, Pieter H; Broersen, Alexander

    2016-01-01

    PURPOSE: The purpose of this study was to study the effect of iterative reconstruction (IR) software on quantitative plaque measurements in coronary computed tomography angiography (CCTA). METHODS: Thirty patients with a three clinical risk factors for coronary artery disease (CAD) had one CCTA...... performed. Images were reconstructed using FBP, 30% and 60% adaptive statistical IR (ASIR). Coronary plaque analysis was performed as per patient and per vessel (LM, LAD, CX and RCA) measurements. Lumen and vessel volumes and plaque burden measurements were based on automatic detected contours in each...

  15. Assessment of coronary artery disease using coronary computed tomography angiography and biochemical markers

    Institute of Scientific and Technical Information of China (English)

    Gitsios; Gitsioudis; Hugo; A; Katus; Grigorios; Korosoglou

    2014-01-01

    Chronic inflammatory mechanisms in the arterial wall lead to atherosclerosis,and include endothelial cell damage,inflammation,apoptosis,lipoprotein deposition,calcification and fibrosis.Cardiac computed tomography angiography(CCTA)has been shown to be a promising tool for non-invasive assessment of theses specific compositional and structural changes in coronary arteries.This review focuses on the technical background of CCTA-based quantitative plaque characterization.Furthermore,we discuss the available evidence for CCTA-based plaque characterization and the potential role of CCTA for risk stratification of patients with coronary artery disease.

  16. Utility of emergency cranial computed tomography in patients without trauma.

    Science.gov (United States)

    Narayanan, Vignesh; Keniston, Angela; Albert, Richard K

    2012-09-01

    The objectives of this study were to determine, in patients admitted to the hospital from the emergency department (ED) without evidence of trauma, 1) the prevalence of clinically important abnormalities on cranial computed tomography (CCT) and 2) the frequency of emergent therapeutic interventions required because of these abnormalities. The authors retrospectively reviewed the records of all patients from 2007 between the ages of 18 and 89 years who had CCT as part of their ED evaluations prior to hospitalization. Patients with any indication of trauma were excluded, as were those who had a lumbar puncture (LP). Chief complaint, results of the ED neurologic examination, tomogram findings, and whether patients had emergent interventions were recorded. Patients presenting with altered mental status (AMS) were analyzed separately. Of the 766 patients meeting inclusion criteria, 83 (11%) had focal neurologic findings, and 61 (8%) had clinically important abnormalities on computed tomography. Emergent interventions occurred in only 12 (1.6%), 11 (92%) of whom had focal neurologic findings. In the subgroup of 287 patients with AMS as their presenting problem, 14 (4.9%) had focal findings, six (2%) had clinically important abnormalities on tomography, and only two (0.7%) required emergent interventions, both of whom had focal findings. Patients presenting with AMS were less likely to have positive findings on tomography (odds ratio [OR] = 0.16, 95% confidence interval [CI] = 0.07 to 0.39). Patients presenting with motor weakness or speech abnormalities, or who were unresponsive, were more likely to have positive findings on tomography (OR = 4.7, 95% CI = 2.6 to 8.6; OR = 4.4, 95% CI = 1.5 to 2.7; and OR = 3.3, 95% CI = 1.6 to 7.1, respectively). Of patients without evidence of trauma who receive CCT in the ED, the prevalence of focal neurologic findings and clinically important abnormalities on tomography is low, the need for emergent intervention is very low, and the

  17. Routine Bone Marrow Biopsy Has Little or No Therapeutic Consequence for Positron Emission Tomography/Computed Tomography-Staged Treatment-Naive Patients With Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    El-Galaly, Tarec Christoffer; d´Amore, Francesco; Juul Mylam, Karen

    2012-01-01

    Routine Bone Marrow Biopsy Has Little or No Therapeutic Consequence for Positron Emission Tomography/Computed Tomography-Staged Treatment-Naive Patients With Hodgkin Lymphoma......Routine Bone Marrow Biopsy Has Little or No Therapeutic Consequence for Positron Emission Tomography/Computed Tomography-Staged Treatment-Naive Patients With Hodgkin Lymphoma...

  18. 4th International Conference on Quantitative Logic and Soft Computing

    CERN Document Server

    Chen, Shui-Li; Wang, San-Min; Li, Yong-Ming

    2017-01-01

    This book is the proceedings of the Fourth International Conference on Quantitative Logic and Soft Computing (QLSC2016) held 14-17, October, 2016 in Zhejiang Sci-Tech University, Hangzhou, China. It includes 61 papers, of which 5 are plenary talks( 3 abstracts and 2 full length talks). QLSC2016 was the fourth in a series of conferences on Quantitative Logic and Soft Computing. This conference was a major symposium for scientists, engineers and practitioners to present their updated results, ideas, developments and applications in all areas of quantitative logic and soft computing. The book aims to strengthen relations between industry research laboratories and universities in fields such as quantitative logic and soft computing worldwide as follows: (1) Quantitative Logic and Uncertainty Logic; (2) Automata and Quantification of Software; (3) Fuzzy Connectives and Fuzzy Reasoning; (4) Fuzzy Logical Algebras; (5) Artificial Intelligence and Soft Computing; (6) Fuzzy Sets Theory and Applications.

  19. Quantitative assessment of impedance tomography for temperature measurements in hyperthermia.

    Science.gov (United States)

    Blad, B; Persson, B; Lindström, K

    1992-01-01

    The objective of this study is a non-invasive assessment of the thermal dose in hyperthermia. Electrical impedance tomography (EIT) has previously been given a first trial as a temperature monitoring method together with microwave-induced hyperthermia treatment, but it has not been thoroughly investigated. In the present work we have examined this method in order to investigate the correlation in vitro between the true spatial temperature distribution and the corresponding measured relative resistivity changes. Different hyperthermia techniques, such as interstitial water tubings, microwave-induced, laser-induced and ferromagnetic seeds have been used. The results show that it is possible to find a correlation between the measured temperature values and the tomographically measured relative resistivity changes in tissue-equivalent phantoms. But the uncertainty of the temperature coefficients, which has been observed, shows that the method has to be improved before it can be applied to clinical in vivo applications.

  20. Quantitative Photo-acoustic Tomography with Partial Data

    CERN Document Server

    Chen, Jie

    2012-01-01

    Photo-acoustic tomography is a newly developed hybrid imaging modality that combines a high-resolution modality with a high-contrast modality. We analyze the reconstruction of diffusion and absorption parameters in an elliptic equation and improve an earlier result of Bal and Uhlmann to the partial date case. We show that the reconstruction can be uniquely determined by the knowledge of 4 internal data based on well-chosen partial boundary conditions. Stability of this reconstruction is ensured if a convexity condition is satisfied. Similar stability result is obtained without this geometric constraint if 4n well-chosen partial boundary conditions are available, where $n$ is the spatial dimension. The set of well-chosen boundary measurements is characterized by some complex geometric optics (CGO) solutions vanishing on a part of the boundary.