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Sample records for projection tomography assessments

  1. Laser Doppler projection tomography.

    PubMed

    Zeng, Yaguang; Xiong, Ke; Lu, Xuanlong; Feng, Guanping; Han, Dingan; Wu, Jing

    2014-02-15

    We propose a laser Doppler projection tomography (LDPT) method to obtain visualization of three-dimensional (3D) flowing structures. With LDPT, the flowing signal is extracted by a modified laser Doppler method, and the 3D flowing image is reconstructed by the filtered backprojection algorithm. Phantom experiments are performed to demonstrate that LDPT is able to obtain 3D flowing structure with higher signal-to-noise ratio and spatial resolution. Our experiment results display its potentially useful application to develop 3D label-free optical angiography for the circulation system of live small animal models or microfluidic experiments.

  2. Lesion insertion in projection domain for computed tomography image quality assessment

    NASA Astrophysics Data System (ADS)

    Chen, Baiyu; Ma, Chi; Yu, Zhicong; Leng, Shuai; Yu, Lifeng; McCollough, Cynthia

    2015-03-01

    To perform task-based image quality assessment in CT, it is desirable to have a large number of realistic patient images with known diagnostic truth. One effective way to achieve this objective is to create hybrid images that combine patient images with simulated lesions. Because conventional hybrid images generated in the image-domain fails to reflect the impact of scan and reconstruction parameters on lesion appearance, this study explored a projection-domain approach. Liver lesion models were forward projected according to the geometry of a commercial CT scanner to acquire lesion projections. The lesion projections were then inserted into patient projections (decoded from commercial CT raw data with the assistance of the vendor) and reconstructed to acquire hybrid images. To validate the accuracy of the forward projection geometry, simulated images reconstructed from the forward projections of a digital ACR phantom were compared to physically acquired ACR phantom images. To validate the hybrid images, lesion models were inserted into patient images and visually assessed. Results showed that the simulated phantom images and the physically acquired phantom images had great similarity in terms of HU accuracy and high-contrast resolution. The lesions in the hybrid image had a realistic appearance and merged naturally into the liver background. In addition, the inserted lesion demonstrated reconstruction-parameter-dependent appearance. Compared to conventional image-domain approach, our method enables more realistic hybrid images for image quality assessment.

  3. Computed Tomography: Image and Dose Assessment

    NASA Astrophysics Data System (ADS)

    Valencia-Ortega, F.; Ruiz-Trejo, C.; Rodríguez-Villafuerte, M.; Buenfil, A. E.; Mora-Hernández, L. A.

    2006-09-01

    In this work an experimental evaluation of image quality and dose imparted during a computed tomography study in a Public Hospital in Mexico City is presented; The measurements required the design and construction of two phantoms at the Institute of Physics, UNAM, according to the recommendations of American Association of Physicists in Medicine (AAPM). Image assessment was performed in terms the spatial resolution and image contrast. Dose measurements were carried out using LiF: Mg,Ti (TLD-100) dosemeters and pencil-shaped ionisation chamber; The results for a computed tomography head study in single and multiple detector modes are presented.

  4. The MOZART Project - MOZAmbique Rift Tomography

    NASA Astrophysics Data System (ADS)

    Fonseca, J. F.; Chamussa, J. R.; Domingues, A.; Helffrich, G. R.; Fishwick, S.; Ferreira, A. M.; Custodio, S.; Brisbourne, A. M.; Grobbelaar, M.

    2012-12-01

    Project MOZART (MOZAmbique Rift Tomography) is an ongoing joint effort of Portuguese, Mozambican and British research groups to investigate the geological structure and current tectonic activity of the southernmost tip of the East African Rift System (EARS) through the deployment of a network of 30 broad band seismic stations in Central and Southern Mozambique. In contrast with other stretches of the EARS to the North and with the Kapvaal craton to the West and South, the lithosphere of Mozambique was not previously studied with a dense seismographic deployment on account of past political instability, and many questions remain unanswered with respect to the location and characteristics of the EARS to the south of Tanzania. In recent years, space geodesy revealed the existence of three microplates in and off Mozambique - Victoria, Rovuma, Lwandle - whose borders provide a connection of the EARS to the South West Indian Ridge as required by plate tectonics. However, the picture is still coarse concerning the location of the rift structures. The 2006 M7 Machaze earthquake in Central Mozambique highlighted the current tectonic activity of the region and added a further clue to the location of the continental rift, prompting the MOZART deployment. Besides helping unravel the current tectonics, the project is expected to shed light on the poorly known Mesoproterozoic structure described by Arthur Holmes in 1951 as the Mozambique Belt, and on the mechanisms of transition from stable craton to rifted continental crust, through the development of a tomographic model for the lithosphere. The MOZART network is distributed South of the Zambezi river at average inter-station spaces of the order of 100 km and includes four stations across the border in South Africa. Data exchange was agreed with AfricaArray. The deployment proceeded in two phases in March 2011, and November and December 2011. Decommissioning is foreseen for August 2013. We report preliminary results for this

  5. Non-uniform projection angle processing in computed tomography

    NASA Astrophysics Data System (ADS)

    Simo, Yanic; Tayag, Tristan J.

    In this paper, we present a novel approach for the collection of computed tomography data. Non-uniform increments in projection angle may be used to reduce data acquisition time with minimal reduction in the accuracy of the reconstructed profile. The key is to exploit those projection angles which correspond to regions where the object contains few high spatial frequency components. This technique is applicable to optical phase computed tomography, as well as X-ray computed tomography. We present simulation results on intraocular lenses used in cataract surgery.

  6. Quality assessment of clinical computed tomography

    NASA Astrophysics Data System (ADS)

    Berndt, Dorothea; Luckow, Marlen; Lambrecht, J. Thomas; Beckmann, Felix; Müller, Bert

    2008-08-01

    Three-dimensional images are vital for the diagnosis in dentistry and cranio-maxillofacial surgery. Artifacts caused by highly absorbing components such as metallic implants, however, limit the value of the tomograms. The dominant artifacts observed are blowout and streaks. Investigating the artifacts generated by metallic implants in a pig jaw, the data acquisition for the patients in dentistry should be optimized in a quantitative manner. A freshly explanted pig jaw including related soft-tissues served as a model system. Images were recorded varying the accelerating voltage and the beam current. The comparison with multi-slice and micro computed tomography (CT) helps to validate the approach with the dental CT system (3D-Accuitomo, Morita, Japan). The data are rigidly registered to comparatively quantify their quality. The micro CT data provide a reasonable standard for quantitative data assessment of clinical CT.

  7. An Effective CUDA Parallelization of Projection in Iterative Tomography Reconstruction.

    PubMed

    Xie, Lizhe; Hu, Yining; Yan, Bin; Wang, Lin; Yang, Benqiang; Liu, Wenyuan; Zhang, Libo; Luo, Limin; Shu, Huazhong; Chen, Yang

    2015-01-01

    Projection and back-projection are the most computationally intensive parts in Computed Tomography (CT) reconstruction, and are essential to acceleration of CT reconstruction algorithms. Compared to back-projection, parallelization efficiency in projection is highly limited by racing condition and thread unsynchronization. In this paper, a strategy of Fixed Sampling Number Projection (FSNP) is proposed to ensure the operation synchronization in the ray-driven projection with Graphical Processing Unit (GPU). Texture fetching is also used utilized to further accelerate the interpolations in both projection and back-projection. We validate the performance of this FSNP approach using both simulated and real cone-beam CT data. Experimental results show that compare to the conventional approach, the proposed FSNP method together with texture fetching is 10~16 times faster than the conventional approach based on global memory, and thus leads to more efficient iterative algorithm in CT reconstruction.

  8. An improved back projection algorithm of ultrasound tomography

    SciTech Connect

    Xiaozhen, Chen; Mingxu, Su; Xiaoshu, Cai

    2014-04-11

    Binary logic back projection algorithm is improved in this work for the development of fast ultrasound tomography system with a better effect of image reconstruction. The new algorithm is characterized by an extra logical value ‘2’ and dual-threshold processing of collected raw data. To compare with the original algorithm, a numerical simulation was conducted by the verification of COMSOL simulations formerly, and then a set of ultrasonic tomography system is established to perform the experiments of one, two and three cylindrical objects. The object images are reconstructed through the inversion of signals matrix acquired by the transducer array after a preconditioning, while the corresponding spatial imaging errors can obviously indicate that the improved back projection method can achieve modified inversion effect.

  9. [Assessing myocardial perfusion with positron emission tomography].

    PubMed

    vom Dahl, J

    2001-11-01

    Positron emission tomography (PET) of the heart has gained widespread scientific and clinical acceptance with regard to two indications: 1) The detection of perfusion abnormalities by qualitative and semiquantitative analyses of perfusion images at rest and during physical or pharmacological stress using well-validated perfusion tracers, such as N-13 ammonia, Rb-82 rubidium chloride, or O-15 labeled water. 2) Viability imaging of myocardial regions with reduced contractility by combining perfusion measurements with substrate metabolism as assessed from F-18 deoxyglucose utilization. This overview summarizes the use of PET as a perfusion imaging method. With a sensitivity > 90% in combination with high specificity, PET is today the best-validated available nuclear imaging technique for the diagnosis of coronary artery disease (CAD). The short half-life of the perfusion tracers in combination with highly sophisticated hard- and software enables rapid PET studies with high patient throughput. The high diagnostic accuracy and the methological advantages as compared to conventional scintigraphy allows one to use PET perfusion imaging to detect subtle changes in the perfusion reserve for the detection of CAD in high risk but asymptomatic patients as well as in patients with proven CAD undergoing various treatment forms such as risk factor reduction or coronary revascularization. In patients following orthotopic heart transplantation, evolving transplant vasculopathy can be detected at an early stage. Quantitative PET imaging at rest allows for detection of myocardial viability since cellular survival is based on maintenance of a minimal perfusion and structural changes correlate to the degree of perfusion reduction. Furthermore, quantitative assessment of the myocardial perfusion reserve detects the magnitude and competence of collaterals in regions with occluded epicardial collaterals and, thus, imaging of several coronary distribution territories in one noninvasive

  10. Robust registration of electron tomography projections without fiducial markers

    NASA Astrophysics Data System (ADS)

    Tran, Viet-Dung; Moreaud, Maxime; Thiébaut, Éric; Dénis, Loïc.; Becker, Jean-Marie

    2013-02-01

    A major issue in electron tomography is the misalignment of the projections contributing to the reconstruction. The current alignment techniques currently use fiducial markers such as gold particles. When the use of markers is not possible, the accurate alignment of the projections is a challenge. We describe a new method for the alignment of transmission electron microscopy (TEM) images series without the need of fiducial markers. The proposed approach is composed of two steps. The first step consists of an initial alignment process, which relies on the minimization of a cost function based on robust statistics measuring the similarity of a projection to its previous projections in the series. It reduces strong shifts resulting from the acquisition between successive projections. The second step aligns the projections finely. The issue is formalized as an inverse problem. The pre­ registered projections are used to initialize an iterative alignment-refinement process which alternates between (i) volume reconstructions and (ii) registrations of measured projections onto simulated projections computed from the volume reconstructed in (i). The accuracy of our method is very satisfying; we illustrate it on simulated data and real projections of different zeolite supports catalyst.

  11. Applicability, usability, and limitations of murine embryonic imaging with optical coherence tomography and optical projection tomography

    PubMed Central

    Singh, Manmohan; Raghunathan, Raksha; Piazza, Victor; Davis-Loiacono, Anjul M.; Cable, Alex; Vedakkan, Tegy J.; Janecek, Trevor; Frazier, Michael V.; Nair, Achuth; Wu, Chen; Larina, Irina V.; Dickinson, Mary E.; Larin, Kirill V.

    2016-01-01

    We present an analysis of imaging murine embryos at various embryonic developmental stages (embryonic day 9.5, 11.5, and 13.5) by optical coherence tomography (OCT) and optical projection tomography (OPT). We demonstrate that while OCT was capable of rapid high-resolution live 3D imaging, its limited penetration depth prevented visualization of deeper structures, particularly in later stage embryos. In contrast, OPT was able to image the whole embryos, but could not be used in vivo because the embryos must be fixed and cleared. Moreover, the fixation process significantly altered the embryo morphology, which was quantified by the volume of the eye-globes before and after fixation. All of these factors should be weighed when determining which imaging modality one should use to achieve particular goals of a study. PMID:27375945

  12. Applicability, usability, and limitations of murine embryonic imaging with optical coherence tomography and optical projection tomography.

    PubMed

    Singh, Manmohan; Raghunathan, Raksha; Piazza, Victor; Davis-Loiacono, Anjul M; Cable, Alex; Vedakkan, Tegy J; Janecek, Trevor; Frazier, Michael V; Nair, Achuth; Wu, Chen; Larina, Irina V; Dickinson, Mary E; Larin, Kirill V

    2016-06-01

    We present an analysis of imaging murine embryos at various embryonic developmental stages (embryonic day 9.5, 11.5, and 13.5) by optical coherence tomography (OCT) and optical projection tomography (OPT). We demonstrate that while OCT was capable of rapid high-resolution live 3D imaging, its limited penetration depth prevented visualization of deeper structures, particularly in later stage embryos. In contrast, OPT was able to image the whole embryos, but could not be used in vivo because the embryos must be fixed and cleared. Moreover, the fixation process significantly altered the embryo morphology, which was quantified by the volume of the eye-globes before and after fixation. All of these factors should be weighed when determining which imaging modality one should use to achieve particular goals of a study.

  13. Fast Optical Transillumination Tomography with Large-Size Projection Acquisition

    PubMed Central

    Huang, Hsuan-Ming; Xia, Jinjun; Haidekker, Mark A.

    2008-01-01

    Techniques such as optical coherence tomography and diffuse optical tomography have been shown to effectively image highly scattering samples such as tissue. An additional modality has received much less attention: Optical transillumination tomography (OT), a modality that promises very high acquisition speed for volumetric scans. With the motivation to image tissue-engineered blood vessels for possible biomechanical testing, we have developed a fast OT device using a collimated, non-coherent beam with a large diameter together with a large-size CMOS camera that has the ability to acquire 3D projections in a single revolution of the sample. In addition, we used accelerated iterative reconstruction techniques to improve image reconstruction speed, while at the same time obtaining better image quality than through filtered back projection. The device was tested using ink-filled PTFE tubes to determine geometric reconstruction accuracy and recovery of absorbance. Even in the presence of minor refractive index mismatch, the weighted error of the measured radius was less than 5% in all cases, and a high linear correlation of ink absorbance determined with a photospectrometer of R 2 =0.99 was found, although the OT device systematically underestimated absorbance. Reconstruction time was improved from several hours (standard arithmetic reconstruction) to 90 seconds per slice with our optimized algorithm. Composed of only a light source, two spatial filters, a sample bath, and a CMOS camera, this device was extremely simple and cost-efficient to build. PMID:18704687

  14. Perforated Appendicitis: Assessment With Multidetector Computed Tomography.

    PubMed

    Iacobellis, Francesca; Iadevito, Isabella; Romano, Federica; Altiero, Michele; Bhattacharjee, Bikram; Scaglione, Mariano

    2016-02-01

    Appendicitis is one of the most common abdominal surgical emergencies. In some cases, the correct diagnosis may be challenging, owing to different conditions that can mimic this pathology. In this context, abdominal computed tomography (CT) is the imaging modality of choice, leading to an accurate diagnosis and to a reduction in unnecessary laparotomies. The diagnosis of perforated appendix is crucial, but the detection of the perforation signs by CT may not be so simple in the early process. The aim of this article is to review the multiple detector CT signs of perforated appendicitis.

  15. High dynamic range optical projection tomography (HDR-OPT).

    PubMed

    Fei, Peng; Yu, Zhilong; Wang, Xu; Lu, Peter J; Fu, Yusi; He, Zi; Xiong, Jingwei; Huang, Yanyi

    2012-04-01

    Traditional optical projection tomography (OPT) acquires a single image at each rotation angle, thereby suffering from limitations in CCD dynamic range; this conventional usage cannot resolve features in samples with highly heterogeneous absorption, such as in small animals with organs of varying size. We present a novel technique, applying multiple-exposure high dynamic range (HDR) imaging to OPT, and demonstrate its ability to resolve fine details in zebrafish embryos, without complicated chemical clearing. We implement the tomographic reconstruction algorithm on the GPU, yielding a performance increase of two orders of magnitude. These features give our method potential application in high-throughput, high-resolution in vivo 3D imaging.

  16. Assessment of asthmatic inflammation using hybrid fluorescence molecular tomography-x-ray computed tomography

    NASA Astrophysics Data System (ADS)

    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.

  17. Superresolved tomography by convex projections and detector motion.

    PubMed

    Wernick, M N; Chen, C T

    1992-09-01

    If the spatial resolution of an image-acquisition system is limited by the size of its component detector elements, then scanning may be required for the signal to be fully sampled. In such cases interpolation methods are normally applied to reproduce a uniformly sampled signal from the set of observations. Alternatively, however, this step can be treated as a restoration problem, in which case the extra measurements made accessible by detector motion may contain sufficient information to superresolve the signal, i.e., to recover information beyond the limit normally associated with finite detector size. We describe the application of this concept to the problem of constructing the projection matrix from a set of noise-corrupted tomographic measurements made by a moving detector array. In particular we focus on the case encountered in many tomographic applications in which the spatial response functions are approximately stationary with object depth. The method of projections onto convex sets is used in conjunction with an underrelaxation scheme to recover the projection matrix, from which the image is reconstructed by the standard filtered backprojection algorithm. Simulation results demonstrate that this approach applied to data acquired by a wobbling positron emission tomography system can substantially enhance the quality of the reconstructed image, even in the presence of high levels of quantum noise. The projection-matrix recovery step can be performed in a matter of seconds; thus the benefits of signal recovery are gained without a significant sacrifice in computation time.

  18. Local regularization of tilt projections reduces artifacts in electron tomography.

    PubMed

    Maiorca, Mauro; Millet, Coralie; Hanssen, Eric; Abbey, Brian; Kazmierczak, Edmund; Tilley, Leann

    2014-04-01

    Electron tomography produces very high resolution 3D image volumes useful for investigating the structure and function of cellular components. Unfortunately, unavoidable discontinuities and physical constraints in the acquisition geometry lead to a range of artifacts that can affect the reconstructed image. In particular, highly electron dense regions, such as gold nanoparticles, can hide proximal biological structures and degrade the overall quality of the reconstructed tomograms. In this work we introduce a pre-reconstruction non-conservative non-linear isotropic diffusion (NID) filter that automatically identifies and reduces local irregularities in the tilt projections. We illustrate the improvement in quality obtained using this approach for reconstructed tomograms generated from samples of malaria parasite-infected red blood cells. A quantitative and qualitative evaluation for our approach on both simulated and real data is provided.

  19. Assessing carotid atherosclerosis by fiber-optic multispectral photoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Hui, Jie; Li, Rui; Wang, Pu; Phillips, Evan; Bruning, Rebecca; Liao, Chien-Sheng; Sturek, Michael; Goergen, Craig J.; Cheng, Ji-Xin

    2015-03-01

    Atherosclerotic plaque at the carotid bifurcation is the underlying cause of the majority of ischemic strokes. Noninvasive imaging and quantification of the compositional changes preceding gross anatomic changes within the arterial wall is essential for diagnosis of disease. Current imaging modalities such as duplex ultrasound, computed tomography, positron emission tomography are limited by the lack of compositional contrast and the detection of flow-limiting lesions. Although high-resolution magnetic resonance imaging has been developed to characterize atherosclerotic plaque composition, its accessibility for wide clinical use is limited. Here, we demonstrate a fiber-based multispectral photoacoustic tomography system for excitation of lipids and external acoustic detection of the generated ultrasound. Using sequential ultrasound imaging of ex vivo preparations we achieved ~2 cm imaging depth and chemical selectivity for assessment of human arterial plaques. A multivariate curve resolution alternating least squares analysis method was applied to resolve the major chemical components, including intravascular lipid, intramuscular fat, and blood. These results show the promise of detecting carotid plaque in vivo through esophageal fiber-optic excitation of lipids and external acoustic detection of the generated ultrasound. This imaging system has great potential for serving as a point-ofcare device for early diagnosis of carotid artery disease in the clinic.

  20. Positron Emission Tomography for the Assessment of Myocardial Viability

    PubMed Central

    2010-01-01

    Executive Summary In July 2009, the Medical Advisory Secretariat (MAS) began work on Non-Invasive Cardiac Imaging Technologies for the Assessment of Myocardial Viability, an evidence-based review of the literature surrounding different cardiac imaging modalities to ensure that appropriate technologies are accessed by patients undergoing viability assessment. This project came about when the Health Services Branch at the Ministry of Health and Long-Term Care asked MAS to provide an evidentiary platform on effectiveness and cost-effectiveness of non-invasive cardiac imaging modalities. After an initial review of the strategy and consultation with experts, MAS identified five key non-invasive cardiac imaging technologies that can be used for the assessment of myocardial viability: positron emission tomography, cardiac magnetic resonance imaging, dobutamine echocardiography, and dobutamine echocardiography with contrast, and single photon emission computed tomography. A 2005 review conducted by MAS determined that positron emission tomography was more sensitivity than dobutamine echocardiography and single photon emission tomography and dominated the other imaging modalities from a cost-effective standpoint. However, there was inadequate evidence to compare positron emission tomography and cardiac magnetic resonance imaging. Thus, this report focuses on this comparison only. For both technologies, an economic analysis was also completed. The Non-Invasive Cardiac Imaging Technologies for the Assessment of Myocardial Viability is made up of the following reports, which can be publicly accessed at the MAS website at: www.health.gov.on.ca/mas or at www.health.gov.on.ca/english/providers/program/mas/mas_about.html Positron Emission Tomography for the Assessment of Myocardial Viability: An Evidence-Based Analysis Magnetic Resonance Imaging for the Assessment of Myocardial Viability: An Evidence-Based Analysis Objective The objective of this analysis is to assess the

  1. Optical Coherence Tomography to Assess Neurodegeneration in Multiple Sclerosis.

    PubMed

    Petzold, Axel

    2016-01-01

    Retinal spectral domain optical coherence tomography (OCT) has emerged as a clinical and research tool in multiple sclerosis (MS) and optic neuritis (ON). This chapter summarizes a short OCT protocol as included in international consensus guidelines. The protocol was written for hands-on style such that both clinicians and OCT technicians can make use of it. The protocol is suitable for imaging of the optic nerve head and macular regions as a baseline for follow-up investigations, individual layer segmentation, and diagnostic assessment.

  2. Can Dental Cone Beam Computed Tomography Assess Bone Mineral Density?

    PubMed Central

    2014-01-01

    Mineral density distribution of bone tissue is altered by active bone modeling and remodeling due to bone complications including bone disease and implantation surgery. Clinical cone beam computed tomography (CBCT) has been examined whether it can assess oral bone mineral density (BMD) in patient. It has been indicated that CBCT has disadvantages of higher noise and lower contrast than conventional medical computed tomography (CT) systems. On the other hand, it has advantages of a relatively lower cost and radiation dose but higher spatial resolution. However, the reliability of CBCT based mineral density measurement has not yet been fully validated. Thus, the objectives of this review are to discuss 1) why assessment of BMD distribution is important and 2) whether the clinical CBCT can be used as a potential tool to measure the BMD. Brief descriptions of image artefacts associated with assessment of gray value, which has been used to account for mineral density, in CBCT images are provided. Techniques to correct local and conversion errors in obtaining the gray values in CBCT images are also introduced. This review can be used as a quick reference for users who may encounter these errors during analysis of CBCT images. PMID:25006568

  3. Positron Emission Tomography for the Assessment of Myocardial Viability

    PubMed Central

    2005-01-01

    Executive Summary Objective The objective was to update the 2001 systematic review conducted by the Institute For Clinical Evaluative Sciences (ICES) on the use of positron emission tomography (PET) in assessing myocardial viability. The update consisted of a review and analysis of the research evidence published since the 2001 ICES review to determine the effectiveness and cost-effectiveness of PET in detecting left ventricular (LV) viability and predicting patient outcomes after revascularization in comparison with other noninvasive techniques. Background Left Ventricular Viability Heart failure is a complex syndrome that impairs the contractile ability of the heart to maintain adequate blood circulation, resulting in poor functional capacity and increased risk of morbidity and mortality. It is the leading cause of hospitalization in elderly Canadians. In more than two-thirds of cases, heart failure is secondary to coronary heart disease. It has been shown that dysfunctional myocardium resulting from coronary heart disease (CAD) may recover contractile function (i.e. considered viable). Dysfunctional but viable myocardium may have been stunned by a brief episode of ischemia, followed by restoration of perfusion, and may regain function spontaneously. It is believed that repetitive stunning results in hibernating myocardium that will only regain contractile function upon revascularization. For people with CAD and severe LV dysfunction (left ventricular ejection fraction [LVEF] <35%) refractory to medical therapy, coronary artery bypass and heart transplantation are the only treatment options. The opportunity for a heart transplant is limited by scarcityof donor hearts. Coronary artery bypass in these patients is associated with high perioperative complications; however, there is evidence that revascularization in the presence of dysfunctional but viable myocardium is associated with survival benefits and lower rates of cardiac events. The assessment of left

  4. Pulmonary malignant melanoma with distant metastasis assessed by positron emission tomography-computed tomography.

    PubMed

    Kim, So Ri; Yoon, Ha-Yong; Jin, Gong Yong; Choe, Yeong Hun; Park, Seung Yong; Lee, Yong Chul

    2016-07-01

    Melanoma is a cutaneous malignant neoplasm of melanocytes. Primary malignant melanoma (MM) of the lung is very rare. Although previous reports have described the radiologic features of pulmonary MM, its rarity means that many factors are unknown. Thus, radiologic diagnosis is very difficult. Furthermore, there is little information regarding diagnostic application and/or the usefulness of [(18)F]-fluorine-2-fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography (FDG-PET-CT) for primary pulmonary MM. A 69-year-old patient with a productive cough lasting three weeks was admitted to our hospital. Chest CT showed a large single mass with a multi-lobulated margin and homogeneous enhancement in the right upper lobe, which was subsequently diagnosed as a primary pulmonary MM with multiple metastases. On PET-CT images, the pulmonary mass and multiple bone lesions showed very increased uptakes of FDG. Considering that pulmonary metastasis from a mucocutaneous melanoma is the main differential diagnosis of primary pulmonary MM, systemic assessment of the whole body is more important than for other types of lung malignancies. This report introduces PET-CT as a useful diagnostic modality for pulmonary MM, especially in cases of distant multiple metastases. PMID:27385996

  5. Free-space fluorescence molecular tomography utilizing 360° geometry projections

    NASA Astrophysics Data System (ADS)

    Deliolanis, Nikolaos; Lasser, Tobias; Hyde, Damon; Soubret, Antoine; Ripoll, Jorge; Ntziachristos, Vasilis

    2007-02-01

    Fluorescence tomography of diffuse media can yield optimal three-dimensional imaging when multiple projections over 360° geometries are captured, compared with limited projection angle systems such as implementations in the slab geometry. We demonstrate how it is possible to perform noncontact, 360° projection fluorescence tomography of mice using CCD-camera-based detection in free space, i.e., in the absence of matching fluids. This approach achieves high spatial sampling of photons propagating through tissue and yields a superior information content data set compared with fiber-based 360° implementations. Reconstruction feasibility using 36 projections in 10° steps is demonstrated in mice.

  6. Assessment of liver ablation using cone beam computed tomography

    PubMed Central

    Abdel-Rehim, Mohamed; Ronot, Maxime; Sibert, Annie; Vilgrain, Valérie

    2015-01-01

    AIM: To investigate the feasibility and accuracy of cone beam computed tomography (CBCT) in assessing the ablation zone after liver tumor ablation. METHODS: Twenty-three patients (17 men and 6 women, range: 45-85 years old, mean age 65 years) with malignant liver tumors underwent ultrasound-guided percutaneous tumor ablation [radiofrequency (n = 14), microwave (n = 9)] followed by intravenous contrast-enhanced CBCT. Baseline multidetector computed tomography (MDCT) and peri-procedural CBCT images were compared. CBCT image quality was assessed as poor, good, or excellent. Image fusion was performed to assess tumor coverage, and quality of fusion was rated as bad, good, or excellent. Ablation zone volumes on peri-procedural CBCT and post-procedural MDCT were compared using the non-parametric paired Wilcoxon t-test. RESULTS: Rate of primary ablation effectiveness was 100%. There were no complications related to ablation. Local tumor recurrence and new liver tumors were found 3 mo after initial treatment in one patient (4%). The ablation zone was identified in 21/23 (91.3%) patients on CBCT. The fusion of baseline MDCT and peri-procedural CBCT images was feasible in all patients and showed satisfactory tumor coverage (at least 5-mm margin). CBCT image quality was poor, good, and excellent in 2 (9%), 8 (35%), and 13 (56%), patients respectively. Registration quality between peri-procedural CBCT and post-procedural MDCT images was good to excellent in 17/23 (74%) patients. The median ablation volume on peri-procedural CBCT and post-procedural MDCT was 30 cm3 (range: 4-95 cm3) and 30 cm3 (range: 4-124 cm3), respectively (P-value > 0.2). There was a good correlation (r = 0.79) between the volumes of the two techniques. CONCLUSION: Contrast-enhanced CBCT after tumor ablation of the liver allows early assessment of the ablation zone. PMID:25593467

  7. WESTERN AIRBORNE CONTAMINANTS ASSESSMENT PROJECT RESEARCH PLAN

    EPA Science Inventory

    The goal of the Western Airborne Contaminants Assessment Project (WACAP) is to assess the deposition of airborne contaminants in Western National Parks, providing regional and local information on exposure, accumulation, impacts, and probable sources. This project is being desig...

  8. Quantitative Assessment of Radionuclide Uptake and Positron Emission Tomography-computed Tomography Image Contrast

    PubMed Central

    Francis, Hasford; Amuasi, John Humphrey; Kwame, Kyere Augustine; Vangu, Mboyo Di Tamba

    2016-01-01

    Radionuclide uptake and contrast for positron emission tomography-computed tomography (PET-CT) images have been assessed in this study using NEMA image quality phantom filled with background activity concentration of 5.3 kBq/mL fluorodeoxyglucose (F-18 FDG). Spheres in the phantom were filled in turns with water to mimic cold lesions and FDG of higher activity concentrations to mimic tumor sites. Transaxial image slices were acquired on the PET-CT system and used for the evaluation of mean standard uptake value (SUVmean) and contrasts for varying sphere sizes at different activity concentrations of 10.6 kBq/mL, 21.2 kBq/mL, and 42.4 kBq/mL. For spheres of same sizes, SUVmean increased with increase in activity concentration. SUVmean was increased by 80.6%, 83.5%, 63.2%, 87.4%, and 63.2% when activity concentrations of spheres with a diameter of 1.3 cm, 1.7 cm, 2.2 cm, 2.8 cm, and 3.7 cm, respectively, were increased from 10.6 kBq/mL to 42.4 kBq/mL. Average percentage contrast between cold spheres (cold lesions) and background activity concentration was estimated to be 89.96% for the spheres. Average contrast for the spheres containing 10.6 kBq/mL, 21.2 kBq/mL, and 42.4 kBq/mL were found to be 110.92%, 134.48%, and 150.52%, respectively. The average background contrast variability was estimated to be 2.97% at 95% confidence interval (P < 0.05). PMID:27650938

  9. Quantitative Assessment of Radionuclide Uptake and Positron Emission Tomography-computed Tomography Image Contrast

    PubMed Central

    Francis, Hasford; Amuasi, John Humphrey; Kwame, Kyere Augustine; Vangu, Mboyo Di Tamba

    2016-01-01

    Radionuclide uptake and contrast for positron emission tomography-computed tomography (PET-CT) images have been assessed in this study using NEMA image quality phantom filled with background activity concentration of 5.3 kBq/mL fluorodeoxyglucose (F-18 FDG). Spheres in the phantom were filled in turns with water to mimic cold lesions and FDG of higher activity concentrations to mimic tumor sites. Transaxial image slices were acquired on the PET-CT system and used for the evaluation of mean standard uptake value (SUVmean) and contrasts for varying sphere sizes at different activity concentrations of 10.6 kBq/mL, 21.2 kBq/mL, and 42.4 kBq/mL. For spheres of same sizes, SUVmean increased with increase in activity concentration. SUVmean was increased by 80.6%, 83.5%, 63.2%, 87.4%, and 63.2% when activity concentrations of spheres with a diameter of 1.3 cm, 1.7 cm, 2.2 cm, 2.8 cm, and 3.7 cm, respectively, were increased from 10.6 kBq/mL to 42.4 kBq/mL. Average percentage contrast between cold spheres (cold lesions) and background activity concentration was estimated to be 89.96% for the spheres. Average contrast for the spheres containing 10.6 kBq/mL, 21.2 kBq/mL, and 42.4 kBq/mL were found to be 110.92%, 134.48%, and 150.52%, respectively. The average background contrast variability was estimated to be 2.97% at 95% confidence interval (P < 0.05).

  10. Quantitative Assessment of Radionuclide Uptake and Positron Emission Tomography-computed Tomography Image Contrast.

    PubMed

    Francis, Hasford; Amuasi, John Humphrey; Kwame, Kyere Augustine; Vangu, Mboyo Di Tamba

    2016-09-01

    Radionuclide uptake and contrast for positron emission tomography-computed tomography (PET-CT) images have been assessed in this study using NEMA image quality phantom filled with background activity concentration of 5.3 kBq/mL fluorodeoxyglucose (F-18 FDG). Spheres in the phantom were filled in turns with water to mimic cold lesions and FDG of higher activity concentrations to mimic tumor sites. Transaxial image slices were acquired on the PET-CT system and used for the evaluation of mean standard uptake value (SUVmean) and contrasts for varying sphere sizes at different activity concentrations of 10.6 kBq/mL, 21.2 kBq/mL, and 42.4 kBq/mL. For spheres of same sizes, SUVmean increased with increase in activity concentration. SUVmean was increased by 80.6%, 83.5%, 63.2%, 87.4%, and 63.2% when activity concentrations of spheres with a diameter of 1.3 cm, 1.7 cm, 2.2 cm, 2.8 cm, and 3.7 cm, respectively, were increased from 10.6 kBq/mL to 42.4 kBq/mL. Average percentage contrast between cold spheres (cold lesions) and background activity concentration was estimated to be 89.96% for the spheres. Average contrast for the spheres containing 10.6 kBq/mL, 21.2 kBq/mL, and 42.4 kBq/mL were found to be 110.92%, 134.48%, and 150.52%, respectively. The average background contrast variability was estimated to be 2.97% at 95% confidence interval (P < 0.05). PMID:27650938

  11. Toward Microendoscopic Electrical Impedance Tomography for Intraoperative Surgical Margin Assessment

    PubMed Central

    Halter, Ryan J.; Kim, Young-Joong

    2015-01-01

    No clinical protocols are routinely used to intraoperatively assess surgical margin status during prostate surgery. Instead, margins are evaluated through pathological assessment of the prostate following radical prostatectomy, when it is too late to provide additional surgical intervention. An intraoperative device potentially capable of assessing surgical margin status based on the electrical property contrast between benign and malignant prostate tissue has been developed. Specifically, a microendoscopic electrical impedance tomography (EIT) probe has been constructed to sense and image, at near millimeter resolution, the conductivity contrast within heterogeneous biological tissues with the goal of providing surgeons with real-time assessment of margin pathologies. This device consists of a ring of eight 0.6-mm diameter electrodes embedded in a 5-mm diameter probe tip to enable access through a 12-mm laparoscopic port. Experiments were performed to evaluate the volume of tissue sensed by the probe. The probe was also tested with inclusions in gelatin, as well as on a sample of porcine tissue with clearly defined regions of adipose and muscle. The probe's area of sensitivity consists of a circular area of 9.1 mm2 and the maximum depth of sensitivity is approximately 1.5 mm. The probe is able to distinguish between high contrast muscle and adipose tissue on a sub-mm scale (~500 μm). These preliminary results suggest that EIT is possible in a probe designed to fit within a 12-mm laparoscopic access port. PMID:24951675

  12. Clinical significance of computed tomography assessment for third molar surgery.

    PubMed

    Nakamori, Kenji; Tomihara, Kei; Noguchi, Makoto

    2014-07-28

    Surgical extraction of the third molar is the most commonly performed surgical procedure in the clinical practice of oral surgery. Third molar surgery is warranted when there is inadequate space for eruption, malpositioning, or risk for cyst or odontogenic tumor formation. Preoperative assessment should include a detailed morphologic analysis of the third molar and its relationship to adjacent structures and surrounding tissues. Due to developments in medical engineering technology, computed tomography (CT) now plays a critical role in providing the clear images required for adequate assessment prior to third molar surgery. Removal of the maxillary third molar is associated with a risk for maxillary sinus perforation, whereas removal of the mandibular third molar can put patients at risk for a neurosensory deficit from damage to the lingual nerve or inferior alveolar nerve. Multiple factors, including demographic, anatomic, and treatment-related factors, influence the incidence of nerve injury during or following removal of the third molar. CT assessment of the third molar prior to surgery can identify some of these risk factors, such as the absence of cortication between the mandibular third molar and the inferior alveolar canal, prior to surgery to reduce the risk for nerve damage. This topic highlight presents an overview of the clinical significance of CT assessment in third molar surgery. PMID:25071882

  13. Clinical significance of computed tomography assessment for third molar surgery

    PubMed Central

    Nakamori, Kenji; Tomihara, Kei; Noguchi, Makoto

    2014-01-01

    Surgical extraction of the third molar is the most commonly performed surgical procedure in the clinical practice of oral surgery. Third molar surgery is warranted when there is inadequate space for eruption, malpositioning, or risk for cyst or odontogenic tumor formation. Preoperative assessment should include a detailed morphologic analysis of the third molar and its relationship to adjacent structures and surrounding tissues. Due to developments in medical engineering technology, computed tomography (CT) now plays a critical role in providing the clear images required for adequate assessment prior to third molar surgery. Removal of the maxillary third molar is associated with a risk for maxillary sinus perforation, whereas removal of the mandibular third molar can put patients at risk for a neurosensory deficit from damage to the lingual nerve or inferior alveolar nerve. Multiple factors, including demographic, anatomic, and treatment-related factors, influence the incidence of nerve injury during or following removal of the third molar. CT assessment of the third molar prior to surgery can identify some of these risk factors, such as the absence of cortication between the mandibular third molar and the inferior alveolar canal, prior to surgery to reduce the risk for nerve damage. This topic highlight presents an overview of the clinical significance of CT assessment in third molar surgery. PMID:25071882

  14. Radial differential interior tomography and its image reconstruction with differentiated backprojection and projection onto convex sets

    SciTech Connect

    Tang, Shaojie; Tang, Xiangyang

    2013-09-15

    Purpose: Interior tomography has been recognized as one of the most effective approaches in computed tomography (CT) to reduce radiation dose rendered to patients. In this work, the authors propose and evaluate an imaging method of radial differential interior tomography.Methods: In interior tomography, an x-ray beam is collimated to only irradiate the region of interest (ROI) with suspected lesions while the surrounding area/volume of normal tissues/organs is spared. In the proposed imaging method of radial differential interior tomography, the outcome is a ROI image that has gone through a radial differential filtering. The image reconstruction algorithm for the radial differential interior tomography is kept in the fashion of differentiated backprojection and projection onto convex sets, but the required a priori knowledge in a small round area becomes zero and may be more readily available in practice.Results: Using the projection data simulated by computer and acquired by CT scanner, the authors evaluate and verify the performance of the proposed radial differential interior tomography method and its associated image reconstruction algorithm. The preliminary results show that the proposed imaging method can generate an image that is the radial differentiation of a conventional tomographic image and is robust over noise that inevitably exist in practice.Conclusions: It is believed that the proposed imaging method may find its utility in advanced clinical applications wherein a ROI-based image processing and analysis is required for lesion visualization, characterization, and diagnosis.

  15. In-vivo imaging of murine tumors using complete-angle projection fluorescence molecular tomography

    NASA Astrophysics Data System (ADS)

    Deliolanis, Nikolaos C.; Dunham, Joshua; Wurdinger, Thomas; Figueiredo, Jose-Luiz; Bakhos, Tannous; Ntziachristos, Vasilis

    2009-05-01

    We interrogate the ability of free-space fluorescence tomography to image small animals in vivo using charge-coupled device (CCD) camera measurements over 360-deg noncontact projections. We demonstrate the performance of normalized dual-wavelength measurements that are essential for in-vivo use, as they account for the heterogeneous distribution of photons in tissue. In-vivo imaging is then showcased on mouse lung and brain tumors cross-validated by x-ray microcomputed tomography and histology.

  16. Quantitative Computed Tomography and Image Analysis for Advanced Muscle Assessment

    PubMed Central

    Edmunds, Kyle Joseph; Gíslason, Magnus K.; Arnadottir, Iris D.; Marcante, Andrea; Piccione, Francesco; Gargiulo, Paolo

    2016-01-01

    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. PMID:27478562

  17. Assessment of metabolic bone diseases by quantitative computed tomography

    NASA Technical Reports Server (NTRS)

    Richardson, M. L.; Genant, H. K.; Cann, C. E.; Ettinger, B.; Gordan, G. S.; Kolb, F. O.; Reiser, U. J.

    1985-01-01

    Advances in the radiologic sciences have permitted the development of numerous noninvasive techniques for measuring the mineral content of bone, with varying degrees of precision, accuracy, and sensitivity. The techniques of standard radiography, radiogrammetry, photodensitometry, Compton scattering, neutron activation analysis, single and dual photon absorptiometry, and quantitative computed tomography (QCT) are described and reviewed in depth. Results from previous cross-sectional and longitudinal QCT investigations are given. They then describe a current investigation in which they studied 269 subjects, including 173 normal women, 34 patients with hyperparathyroidism, 24 patients with steroid-induced osteoporosis, and 38 men with idiopathic osteoporosis. Spinal quantitative computed tomography, radiogrammetry, and single photon absorptiometry were performed, and a spinal fracture index was calculated on all patients. The authors found a disproportionate loss of spinal trabecular mineral compared to appendicular mineral in the men with idiopathic osteoporosis and the patients with steroid-induced osteoporosis. They observed roughly equivalent mineral loss in both the appendicular and axial regions in the hyperparathyroid patients. The appendicular cortical measurements correlated moderately well with each other but less well with spinal trabecular QCT. The spinal fracture index correlated well with QCT and less well with the appendicular measurements. Knowledge of appendicular cortical mineral status is important in its own right but is not a valid predictor of axial trabecular mineral status, which may be disproportionately decreased in certain diseases. Quantitative CT provides a reliable means of assessing the latter region of the skeleton, correlates well with the spinal fracture index (a semiquantitative measurement of end-organ failure), and offers the clinician a sensitive means of following the effects of therapy.

  18. Role of Optical Coherence Tomography in Assessing Anterior Chamber Angles

    PubMed Central

    Kochupurakal, Reema Thomas; Jha, Kirti Nath; Rajalakshmi, A.R.; Nagarajan, Swathi; Ezhumalai, G.

    2016-01-01

    Introduction Gonioscopy is the gold standard in assessing anterior chamber angles. However, interobserver variations are common and there is a need for reliable objective method of assessment. Aim To compare the anterior chamber angle by gonioscopy and Spectral Domain Optical Coherence Tomography (SD-OCT) in individuals with shallow anterior chamber. Materials and Methods This comparative observational study was conducted in a rural tertiary multi-speciality teaching hospital. A total of 101 eyes of 54 patients with shallow anterior chamber on slit lamp evaluation were included. Anterior chamber angle was graded by gonioscopy using the shaffer grading system. Angles were also assessed by SD-OCT with Trabecular Iris Angle (TIA) and Angle Opening Distance (AOD). Chi-square test, sensitivity, specificity, positive and negative predictive value to find correlation between OCT parameters and gonioscopy grading. Results Females represented 72.7%. The mean age was 53.93 ±8.24 years and mean anterior chamber depth was 2.47 ± 0.152 mm. Shaffer grade ≤ 2 were identified in 95(94%) superior, 42(41.5%) inferior, 65(64.3%) nasal and 57(56.4%) temporal quadrants. Cut-off values of TIA ≤ 22° and AOD ≤ 290 μm were taken as narrow angles on SD-OCT. TIA of ≤ 22° were found in 88(92.6%) nasal and 87(87%) temporal angles. AOD of ≤ 290 μm was found in 73(76.8%) nasal and 83(83%) temporal quadrants. Sensitivity in detecting narrow angles was 90.7% and 82.2% for TIA and AOD, while specificity was 11.7% and 23.4%, respectively. Conclusion Individuals were found to have narrow angles more with SD-OCT. Sensitivity was high and specificity was low in detecting narrow angles compared to gonioscopy, making it an unreliable tool for screening. PMID:27190851

  19. Assessment of the Circle of Willis with Cranial Tomography Angiography

    PubMed Central

    Karatas, Ayse; Coban, Gokmen; Cinar, Celal; Oran, Ismail; Uz, Aysun

    2015-01-01

    Background The circle of Willis is a major collateral pathway important in ischemic conditions. The aim of our study was to assess the structural characteristics of the circle of Willis within the Turkish adult population, along with variations and arteries involved in the measurement of diameters and lengths on cranial computed tomography angiography (CTA). Material/Methods One hundred adult patients who underwent CTA images were evaluated retrospectively. Results Results of the study revealed 82% adult, 17% fetal, and 1% transitional configurations. A complete polygonal structure was observed in 28% of cases. Variations of the circle of Willis were more common in the posterior portion. Hypoplasia was found to be the most common variation and was observed as a maximum in the posterior communicating artery (AComP). Conclusions The patency and size of arteries in the circle of Willis are important in occlusive cerebrovascular diseases and cerebrovascular surgery. Although CTA is an easily accessible non-invasive clinical method for demonstrating the vascular structure, CTA should be evaluated taking into account image resolution quality and difficulties in the identification of small vessels. PMID:26343887

  20. Donor disc attachment assessment with intraoperative spectral optical coherence tomography during descemet stripping automated endothelial keratoplasty

    PubMed Central

    Wylegala, Edward; Nowinska, Anna K; Wroblewska-Czajka, Ewa; Janiszewska, Dominika

    2013-01-01

    Optical coherence tomography has already been proven to be useful for pre- and post-surgical anterior eye segment assessment, especially in lamellar keratoplasty procedures. There is no evidence for intraoperative usefulness of optical coherence tomography (OCT). We present a case report of the intraoperative donor disc attachment assessment with spectral-domain optical coherence tomography in case of Descemet stripping automated endothelial keratoplasty (DSAEK) surgery combined with corneal incisions. The effectiveness of the performed corneal stab incisions was visualized directly by OCT scan analysis. OCT assisted DSAEK allows the assessment of the accuracy of the Descemet stripping and donor disc attachment. PMID:24104711

  1. Cyst-based measurements for assessing lymphangioleiomyomatosis in computed tomography

    SciTech Connect

    Lo, P. Brown, M. S.; Kim, H.; Kim, H.; Goldin, J. G.; Argula, R.; Strange, C.

    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. Positron emission tomography for the assessment of myocardial viability

    SciTech Connect

    Schelbert, H.R. )

    1991-09-01

    The detection of viable myocardium or ischemically injured myocardium with a reversible impairment of contractile function remains clinically important but challenging. Detection of reversible dysfunction and distinction from irreversible tissue injury by positron emission tomography is based on identification of preserved or even enhanced glucose metabolism with F-18 2-fluoro 2-deoxyglucose. Regional patterns of myocardial glucose utilization and blood flow, defined as perfusion-metabolism mismatches or matches, on positron emission tomography in patients with chronic or even acute ischemic heart disease are highly accurate in predicting the functional outcome after interventional revascularization. Compared with thallium-201 redistribution scintigraphy, positron emission tomography appears to be diagnostically more accurate, especially in patients with severely impaired left ventricular function. While larger clinical trials are needed for further confirmation, positron emission tomography has already proved clinically useful for stratifying patients with poor left ventricular function to the most appropriate therapeutic approach.

  3. Progress of projection computed tomography by upgrading of the beamline 37XU of SPring-8

    NASA Astrophysics Data System (ADS)

    Terada, Yasuko; Suzuki, Yoshio; Uesugi, Kentaro; Miura, Keiko

    2016-01-01

    Beamline 37XU at SPring-8 has been upgraded for nano-focusing applications. The length of the beamline has been extended to 80 m. By utilizing this length, the beamline has advantages for experiments such as X-ray focusing, X-ray microscopic imaging and X-ray computed tomography. Projection computed tomography measurements were carried out at experimental hutch 3 located 80 m from the light source. CT images of a microcapsule have been successfully obtained with a wide X-ray energy range.

  4. Environmental assessment: The Eden project

    NASA Astrophysics Data System (ADS)

    Roza, Christodoulaki

    Non domestic buildings account for about one-sixth of the U.K.'s entire C02 emissions and one-third of the building related ones 2 . Their proportion of energy consumption, particularly electricity, has also been growing 2 . New buildings are not necessarily better, with energy use often proving to be much higher than their designers anticipated 2 . Annual C02 emissions of two- and sometimes three- times design expectations are far from unusual, leaving a massive credibility gap 2 . These and other global environmental and human health related concerns have motivated an increasing number of designers, developers and building users to pursue more environmentally sustainable designs and construction strategies 5 . However, these buildings can be difficult to evaluate, since they are large in scale, complex in materials and function and temporally dynamic due to limited service life of building components and changing user requirements 5 . All of these factors make environmental assessment of the buildings challenging. Previous Post Occupancy Review of Buildings and their Engineering (PROBE) building investigations have uncovered serious shortcomings in facilities management, or at least mismatches between a building's management needs and the ability of the occupiers to provide the right level of management 1 . Consequently, large differences between energy performance expectations and outcomes can occur virtually unnoticed, while designers continue to repeat flawed descriptions 2 . This investigation attempts to evaluate the building's operation and to help achieving demonstrable improvements in terms of energy efficiency and occupant satisfaction. The scope of this study is to evaluate the actual environmental performance of a building notable for its advanced design. The Education Resource Centre at the Eden Project was selected to compare design expectations with post occupancy performance. This report contains a small-scale survey of user satisfaction with the

  5. Three-dimensional angular domain optical projection tomography

    NASA Astrophysics Data System (ADS)

    Ng, Eldon; Vasefi, Fartash; Roumeliotis, Michael; Kaminska, Bozena; Carson, Jeffrey J. L.

    2011-03-01

    Angular Domain Imaging (ADI) has been previously demonstrated to generate projection images of attenuating targets embedded within a turbid medium. The imaging system employs a silicon micro-tunnel array positioned between the sample and the detection system to reject scattered photons that have deviated from the initial propagation direction and to select for ballistic and quasi-ballistic photons that have retained their forward trajectory. Two dimensional tomographic images can be reconstructed from ADI projections collected at a multitude of angles. The objective of this work was to extend the system to three dimensions by collecting several tomographic images and stacking the reconstructed slices to generate a three dimensional volume representative of the imaging target. A diode laser (808nm, CW) with a beam expander was used to illuminate the sample cuvette. An Angular Filter Array (AFA) of 80 μm × 80 μm square-shaped tunnels 2 cm in length was used to select for image forming quasi-ballistic photons. Images were detected with a linear CCD. Our approach was to use a SCARA robot to rotate and translate the sample to collect sufficient projections to reconstruct a three dimensional volume. A custom designed 3D target consisting of 4 truncated cones was imaged and reconstructed with filtered backprojection and iterative methods. A 0.5 mm graphite rod was used to collect the forward model, while a truncated pseudoinverse was used to approximate the backward model for the iterative algorithm.

  6. Environmental Assessment Lakeview Geothermal Project

    SciTech Connect

    Treis, Tania

    2012-04-30

    The Town of Lakeview is proposing to construct and operate a geothermal direct use district heating system in Lakeview, Oregon. The proposed project would be in Lake County, Oregon, within the Lakeview Known Geothermal Resources Area (KGRA). The proposed project includes the following elements: Drilling, testing, and completion of a new production well and geothermal water injection well; construction and operation of a geothermal production fluid pipeline from the well pad to various Town buildings (i.e., local schools, hospital, and Lake County Industrial Park) and back to a geothermal water injection well. This EA describes the proposed project, the alternatives considered, and presents the environmental analysis pursuant to the National Environmental Policy Act. The project would not result in adverse effects to the environment with the implementation of environmental protection measures.

  7. Algorithms for image reconstruction from projections in optical tomography

    NASA Astrophysics Data System (ADS)

    Zhu, Lin-Sheng; Huang, Su-Yi

    1993-09-01

    It is well known that the determination ofthe temperature field by holographic interferometry is a successful method in the measurement of thermophysics. In this paper some practical algorithms for image reconstruction from projections are presented to produce the temperature field. The algorithms developed consists in that the Radon transform integral equation is directly solved by grid method and that the Radon inversion formula is numerically evaluated by twodimensional Fourier transform technique. Some examples are given to verify the validity of the above methods in practice.

  8. Optical coherence tomography: a new method to assess aneurysm healing

    PubMed Central

    Thorell, William E.; Chow, Michael M.; Prayson, Richard A.; Shure, Mark A.; Jeon, Sung W.; Huang, David; Zeynalov, Emil; Woo, Henry H.; Rasmussen, Peter A.; Rollins, Andrew M.; Masaryk, Thomas J.

    2007-01-01

    Object Aneurysmal subarachnoid hemorrhage affects approximately 10/100,000 people per year. Endovascular coil embolization is used increasingly to treat cerebral aneurysms and its safety and durability is rapidly developing. The long-term durability of coil embolization of cerebral aneurysms remains in question; patients treated using this modality require multiple follow-up angiography studies and occasional repeated treatments. Methods Optical coherence tomography (OCT) is an emerging imaging modality that uses backscattered light to produce high-resolution tomography of optically accessible biological tissues such as the eye, luminal surface of blood vessels, and gastrointestinal tract. Vascular OCT probes in the form of imaging microwires are presently available—although not Food and Drug Administration–approved—and may be adapted for use in the cerebral circulation. In this study the authors describe the initial use of OCT to make visible the neck of aneurysms created in a canine model and treated with coil embolization. Optical coherence tomography images demonstrate changes that correlate with the histological findings of healing at the aneurysm neck and thus may be capable of demonstrating human cerebral aneurysm healing. Conclusions Optical coherence tomography may obviate the need for subsequent follow-up angiography studies as well as aid in the understanding of endovascular tissue healing. Data in this study demonstrate that further investigation of in vivo imaging with such probes is warranted. PMID:15739565

  9. Time-Gated Optical Projection Tomography Allows Visualization of Adult Zebrafish Internal Structures

    PubMed Central

    Foglia, Efrem Alessandro; Pistocchi, Anna; D'Andrea, Cosimo; Valentini, Gianluca; Cubeddu, Rinaldo; De Silvestri, Sandro; Cerullo, Giulio; Cotelli, Franco

    2012-01-01

    Optical imaging through biological samples is compromised by tissue scattering and currently various approaches aim to overcome this limitation. In this paper we demonstrate that an all optical technique, based on non-linear upconversion of infrared ultrashort laser pulses and on multiple view acquisition, allows the reduction of scattering effects in tomographic imaging. This technique, namely Time-Gated Optical Projection Tomography (TGOPT), is used to reconstruct three dimensionally the internal structure of adult zebrafish without staining or clearing agents. This method extends the use of Optical Projection Tomography to optically diffusive samples yielding reconstructions with reduced artifacts, increased contrast and improved resolution with respect to those obtained with non-gated techniques. The paper shows that TGOPT is particularly suited for imaging the skeletal system and nervous structures of adult zebrafish. PMID:23185643

  10. Ares Project Technology Assessment: Approach and Tools

    NASA Technical Reports Server (NTRS)

    Hueter, Uwe; Tyson, Richard

    2010-01-01

    Technology assessments provide a status of the development maturity of specific technologies. Along with benefit analysis, the risks the project assumes can be quantified. Normally due to budget constraints, the competing technologies are prioritized and decisions are made which ones to fund. A detailed technology development plan is produced for the selected technologies to provide a roadmap to reach the desired maturity by the project s critical design review. Technology assessments can be conducted for both technology only tasks or for product development programs. This paper is primarily biased toward the product development programs. The paper discusses the Ares Project s approach to technology assessment. System benefit analysis, risk assessment, technology prioritization, and technology readiness assessment are addressed. A description of the technology readiness level tool being used is provided.

  11. The convergence of block cyclic projection with underrelaxation parameters for compressed sensing based tomography.

    PubMed

    Arroyo, Fangjun; Arroyo, Edward; Li, Xiezhang; Zhu, Jiehua

    2014-01-01

    The block cyclic projection method in the compressed sensing framework (BCPCS) was introduced for image reconstruction in computed tomography and its convergence had been proven in the case of unity relaxation (λ=1). In this paper, we prove its convergence with underrelaxation parameters λ∈(0,1). As a result, the convergence of compressed sensing based block component averaging algorithm (BCAVCS) and block diagonally-relaxed orthogonal projection algorithm (BDROPCS) with underrelaxation parameters under a certain condition are derived. Experiments are given to illustrate the convergence behavior of these algorithms with selected parameters. PMID:24699347

  12. Mexico Wind Resource Assessment Project

    SciTech Connect

    Schwartz, M.N.; Elliott, D.L.

    1995-05-01

    A preliminary wind energy resource assessment of Mexico that produced wind resource maps for both utility-scale and rural applications was undertaken as part of the Mexico-U.S. Renewable Energy Cooperation Program. This activity has provided valuable information needed to facilitate the commercialization of small wind turbines and windfarms in Mexico and to lay the groundwork for subsequent wind resource activities. A surface meteorological data set of hourly data in digital form was utilized to prepare a more detailed and accurate wind resource assessment of Mexico than otherwise would have been possible. Software was developed to perform the first ever detailed analysis of the wind characteristics data for over 150 stations in Mexico. The hourly data set was augmented with information from weather balloons (upper-air data), ship wind data from coastal areas, and summarized wind data from sources in Mexico. The various data were carefully evaluated for their usefulness in preparing the wind resource assessment. The preliminary assessment has identified many areas of good-to-excellent wind resource potential and shows that the wind resource in Mexico is considerably greater than shown in previous surveys.

  13. Use of frozen-hydrated axonemes to assess imaging parameters and resolution limits in cryoelectron tomography.

    PubMed

    McEwen, Bruce F; Marko, Michael; Hsieh, Chyong-Ere; Mannella, Carmen

    2002-01-01

    Using a 400-kV cryoelectron microscope, we have obtained tomographic reconstructions of frozen-hydrated sea urchin axonemes with 8-10-nm resolution, as assessed by detection of characteristic components including doublet microtubules, radial spokes, central sheath projections, and outer dynein arms. We did not detect the inner dynein arms or the microtubule lattice. The 1/(8 nm) and 1/(16 nm) layer lines are consistently present in power spectra of both projection images and tomographic reconstructions. Strength and detection of the layer lines are dependent upon total electron dose and defocus. Both layer lines are surprisingly resistant to electron doses of up to 11000 electrons/nm(2). We present a summary of resolution considerations in cryoelectron tomography and conclude that the fundamental limitation is the total electron dose required for statistical significance. The electron dose can be fractionated among the numerous angular views in a tomographic data set, but there is an unavoidable fourth-power dependence of total dose on target resolution. Since higher-resolution features are more beam-sensitive, this dose requirement places an ultimate limit on the resolution of individual tomographic reconstructions. Instrumental and computational strategies to circumvent this limitation are discussed.

  14. River Protection Project information systems assessment

    SciTech Connect

    JOHNSON, A.L.

    1999-07-28

    The Information Systems Assessment Report documents the results from assessing the Project Hanford Management Contract (PHMC) Hanford Data Integrator 2000 (HANDI 2000) system, Business Management System (BMS) and Work Management System phases (WMS), with respect to the System Engineering Capability Assessment Model (CAM). The assessment was performed in accordance with the expectations stated in the fiscal year (FY) 1999 Performance Agreement 7.1.1, item (2) which reads, ''Provide an assessment report on the selected Integrated Information System by July 31, 1999.'' This report assesses the BMS and WMS as implemented and planned for the River Protection Project (RPP). The systems implementation is being performed under the PHMC HANDI 2000 information system project. The project began in FY 1998 with the BMS, proceeded in FY 1999 with the Master Equipment List portion of the WMS, and will continue the WMS implementation as funding provides. This report constitutes an interim quality assessment providing information necessary for planning RPP's information systems activities. To avoid confusion, HANDI 2000 will be used when referring to the entire system, encompassing both the BMS and WMS. A graphical depiction of the system is shown in Figure 2-1 of this report.

  15. Development of Ultrasound Tomography for Breast Imaging: Technical Assessment

    SciTech Connect

    Duric, N; Littrup, P; Babkin, A; Chambers, D; Azevedo, S; Arkady, K; Pevzner, R; Tokarev, M; Holsapple, E

    2004-09-30

    Ultrasound imaging is widely used in medicine because of its benign characteristics and real-time capabilities. Physics theory suggests that the application of tomographic techniques may allow ultrasound imaging to reach its full potential as a diagnostic tool allowing it to compete with other tomographic modalities such as X-ray CT and MRI. This paper describes the construction and use of a prototype tomographic scanner and reports on the feasibility of implementing tomographic theory in practice and the potential of US tomography in diagnostic imaging. Data were collected with the prototype by scanning two types of phantoms and a cadaveric breast. A specialized suite of algorithms was developed and utilized to construct images of reflectivity and sound speed from the phantom data. The basic results can be summarized as follows: (1) A fast, clinically relevant US tomography scanner can be built using existing technology. (2) The spatial resolution, deduced from images of reflectivity, is 0.4 mm. The demonstrated 10 cm depth-of-field is superior to that of conventional ultrasound and the image contrast is improved through the reduction of speckle noise and overall lowering of the noise floor. (3) Images of acoustic properties such as sound speed suggest that it is possible to measure variations in the sound speed of 5 m/s. An apparent correlation with X-ray attenuation suggests that the sound speed can be used to discriminate between various types of soft tissue. (4) Ultrasound tomography has the potential to improve diagnostic imaging in relation to breast cancer detection.

  16. Assessment of Coronary Plaque Vulnerability with Optical Coherence Tomography

    PubMed Central

    Uemura, Shiro; Soeda, Tsunenari; Sugawara, Yu; Ueda, Tomoya; Watanabe, Makoto; Saito, Yoshihiko

    2014-01-01

    Several catheter-based imaging modalities have been developed over the past 2 decades for visualizing the morphological features of coronary atherosclerotic plaques that are susceptible to future development of serious cardiovascular events. Optical coherence tomography (OCT) is a new high-resolution intracoronary imaging modality based on near-infrared interferometry, and it has been shown to be able to identify various components of atheromatous plaques. In this review, we examine the histopathology of vulnerable plaques as a target for imaging technology, and discuss the evidence of OCT in identifying vulnerable atherosclerotic lesions in patients with coronary artery disease. PMID:27122761

  17. Assessment of cardiac function: magnetic resonance and computed tomography.

    PubMed

    Greenberg, S B

    2000-10-01

    A complete cardiac study requires both anatomic and physiologic evaluation. Cardiac function can be evaluated noninvasively by magnetic resonance imaging (MRI)or ultrafast computed tomography (CT). MRI allows for evaluation of cardiac function by cine gradient echo imaging of the ventricles and flow analysis across cardiac valves and the great vessels. Cine gradient echo imaging is useful for evaluation of cardiac wall motion, ventricular volumes and ventricular mass. Flow analysis allows for measurement of velocity and flow during the cardiac cycle that reflects cardiac function. Ultrafast CT allows for measurement of cardiac indices similar to that provided by gradient echo imaging of the ventricles.

  18. Assessment of natural enamel lesions with optical coherence tomography in comparison with microfocus x-ray computed tomography.

    PubMed

    Espigares, Jorge; Sadr, Alireza; Hamba, Hidenori; Shimada, Yasushi; Otsuki, Masayuki; Tagami, Junji; Sumi, Yasunori

    2015-01-01

    A technology to characterize early enamel lesions is needed in dentistry. Optical coherence tomography (OCT) is a noninvasive method that provides high-resolution cross-sectional images. The aim of this study is to compare OCT with microfocus x-ray computed tomography ([Formula: see text]) for assessment of natural enamel lesions in vitro. Ten human teeth with visible white spot-like changes on the enamel smooth surface and no cavitation (ICDAS code 2) were subjected to imaging by μCT (SMX-100CT, Shimadzu) and 1300-nm swept-source OCT (Dental SS-OCT, Panasonic Health Care). In [Formula: see text], the lesions appeared as radiolucent dark areas, while in SS-OCT, they appeared as areas of increased signal intensity beneath the surface. An SS-OCT attenuation coefficient based on Beer-Lambert law could discriminate lesions from sound enamel. Lesion depth ranged from 175 to [Formula: see text] in SS-OCT. A correlation between [Formula: see text] and SS-OCT was found regarding lesion depth ([Formula: see text], [Formula: see text]) and also surface layer thickness ([Formula: see text], [Formula: see text]). The images obtained clinically in real time using the dental SS-OCT system are suitable for the assessment of natural subsurface lesions and their surface layer, providing comparable images to a laboratory high-resolution [Formula: see text] without the use of x-ray. PMID:26158079

  19. Assessment of natural enamel lesions with optical coherence tomography in comparison with microfocus x-ray computed tomography

    PubMed Central

    Espigares, Jorge; Sadr, Alireza; Hamba, Hidenori; Shimada, Yasushi; Otsuki, Masayuki; Tagami, Junji; Sumi, Yasunori

    2015-01-01

    Abstract. A technology to characterize early enamel lesions is needed in dentistry. Optical coherence tomography (OCT) is a noninvasive method that provides high-resolution cross-sectional images. The aim of this study is to compare OCT with microfocus x-ray computed tomography (μCT) for assessment of natural enamel lesions in vitro. Ten human teeth with visible white spot-like changes on the enamel smooth surface and no cavitation (ICDAS code 2) were subjected to imaging by μCT (SMX-100CT, Shimadzu) and 1300-nm swept-source OCT (Dental SS-OCT, Panasonic Health Care). In μCT, the lesions appeared as radiolucent dark areas, while in SS-OCT, they appeared as areas of increased signal intensity beneath the surface. An SS-OCT attenuation coefficient based on Beer–Lambert law could discriminate lesions from sound enamel. Lesion depth ranged from 175 to 606  μm in SS-OCT. A correlation between μCT and SS-OCT was found regarding lesion depth (R=0.81, p<0.001) and also surface layer thickness (R=0.76, p<0.005). The images obtained clinically in real time using the dental SS-OCT system are suitable for the assessment of natural subsurface lesions and their surface layer, providing comparable images to a laboratory high-resolution μCT without the use of x-ray. PMID:26158079

  20. Project Assessment Skills Web Application

    NASA Technical Reports Server (NTRS)

    Goff, Samuel J.

    2013-01-01

    The purpose of this project is to utilize Ruby on Rails to create a web application that will replace a spreadsheet keeping track of training courses and tasks. The goal is to create a fast and easy to use web application that will allow users to track progress on training courses. This application will allow users to update and keep track of all of the training required of them. The training courses will be organized by group and by user, making readability easier. This will also allow group leads and administrators to get a sense of how everyone is progressing in training. Currently, updating and finding information from this spreadsheet is a long and tedious task. By upgrading to a web application, finding and updating information will be easier than ever as well as adding new training courses and tasks. Accessing this data will be much easier in that users just have to go to a website and log in with NDC credentials rather than request the relevant spreadsheet from the holder. In addition to Ruby on Rails, I will be using JavaScript, CSS, and jQuery to help add functionality and ease of use to my web application. This web application will include a number of features that will help update and track progress on training. For example, one feature will be to track progress of a whole group of users to be able to see how the group as a whole is progressing. Another feature will be to assign tasks to either a user or a group of users. All of these together will create a user friendly and functional web application.

  1. Acute Perforated Diverticulitis: Assessment With Multidetector Computed Tomography.

    PubMed

    Sessa, Barbara; Galluzzo, Michele; Ianniello, Stefania; Pinto, Antonio; Trinci, Margherita; Miele, Vittorio

    2016-02-01

    Colonic diverticulitis is a common condition in the western population. Complicated diverticulitis is defined as the presence of extraluminal air or abscess, peritonitis, colon occlusion, or fistulas. Multidetector row computed tomography (MDCT) is the modality of choice for the diagnosis and the staging of diverticulitis and its complications, which enables performing an accurate differential diagnosis and addressing the patients to a correct management. MDCT is accurate in diagnosing the site of perforation in approximately 85% of cases, by the detection of direct signs (focal bowel wall discontinuity, extraluminal gas, and extraluminal enteric contrast) and indirect signs, which are represented by segmental bowel wall thickening, abnormal bowel wall enhancement, perivisceral fat stranding of fluid, and abscess. MDCT is accurate in the differentiation from complicated colon diverticulitis and colon cancer, often with a similar imaging. The computed tomography-guided classification is recommended to discriminate patients with mild diverticulitis, generally treated with antibiotics, from those with severe diverticulitis with a large abscess, which may be drained with a percutaneous approach.

  2. Assessment of metabolic bone diseases by quantitative computed tomography

    SciTech Connect

    Richardson, M.L.; Genant, H.K.; Cann, C.E.; Ettinger, B.; Gordan, G.S.; Kolb, F.O.; Reiser, U.J.

    1985-05-01

    Advances in the radiologic sciences have permitted the development of numerous noninvasive techniques for measuring the mineral content of bone, with varying degrees of precision, accuracy, and sensitivity. The techniques of standard radiography, radiogrammetry, photodensitometry, Compton scattering, neutron activation analysis, single and dual photon absorptiometry, and quantitative computed tomography (QCT) are described and reviewed in depth. Results from previous cross-sectional and longitudinal QCT investigations are given. They then describe a current investigation in which they studied 269 subjects, including 173 normal women, 34 patients with hyperparathyroidism, 24 patients with steroid- induced osteoporosis, and 38 men with idiopathic osteoporosis. Spinal quantitative computed tomography, radiogrammetry, and single photon absorptiometry were performed, and a spinal fracture index was calculated on all patients. The authors found a disproportionate loss of spinal trabecular mineral compared to appendicular mineral in the men with idiopathic osteoporosis and the patients with steroid-induced osteoporosis. They observed roughly equivalent mineral loss in both the appendicular and axial regions in the hyperparathyroid patients. The appendicular cortical measurements correlated moderately well with each other but less well with spinal trabecular QCT. The spinal fracture index correlated well with QCT and less well with the appendicular measurements.

  3. Mesoscopic in vivo 3-D tracking of sparse cell populations using angular multiplexed optical projection tomography

    PubMed Central

    Chen, Lingling; Alexandrov, Yuriy; Kumar, Sunil; Andrews, Natalie; Dallman, Margaret J.; French, Paul M. W.; McGinty, James

    2015-01-01

    We describe an angular multiplexed imaging technique for 3-D in vivo cell tracking of sparse cell distributions and optical projection tomography (OPT) with superior time-lapse resolution and a significantly reduced light dose compared to volumetric time-lapse techniques. We demonstrate that using dual axis OPT, where two images are acquired simultaneously at different projection angles, can enable localization and tracking of features in 3-D with a time resolution equal to the camera frame rate. This is achieved with a 200x reduction in light dose compared to an equivalent volumetric time-lapse single camera OPT acquisition with 200 projection angles. We demonstrate the application of this technique to mapping the 3-D neutrophil migration pattern observed over ~25.5 minutes in a live 2 day post-fertilisation transgenic LysC:GFP zebrafish embryo following a tail wound. PMID:25909009

  4. Research of inverse synthetic aperture imaging lidar based on filtered back-projection tomography technique

    NASA Astrophysics Data System (ADS)

    Liu, Zhi-chao; Yang, Jin-hua

    2014-07-01

    In order to obtain clear two-dimensional image under the conditions without using heterodyne interferometry by inverse synthetic aperture lidar(ISAL), designed imaging algorithms based on filtered back projection tomography technique, and the target "A" was reconstructed with simulation algorithm by the system in the turntable model. Analyzed the working process of ISAL, and the function of the reconstructed image was given. Detail analysis of the physical meaning of the various parameters in the process of echo data, and its parameters affect the reconstructed image. The image in test area was reconstructed by the one-dimensional distance information with filtered back projection tomography technique. When the measured target rotated, the sum of the echo light intensity at the same distance was constituted by the different position of the measured target. When the total amount collected is large enough, multiple equations can be solved change. Filtered back-projection image of the ideal image is obtained through MATLAB simulation, and analyzed that the angle intervals affected the reconstruction of image. The ratio of the intensity of echo light and loss light affected the reconstruction of image was analyzed. Simulation results show that, when the sampling angle is smaller, the resolution of the reconstructed image of measured target is higher. And the ratio of the intensity of echo light and loss light is greater, the resolution of the reconstructed image of measured target is higher. In conclusion after some data processing, the reconstructed image basically meets be effective identification requirements.

  5. Optical coherence tomography for vulnerability assessment of sandstone.

    PubMed

    Bemand, Elizabeth; Liang, Haida

    2013-05-10

    Sandstone is an important cultural heritage material, in both architectural and natural settings, such as neolithic rock art panels. The majority of deterioration effects in porous materials such as sandstone are influenced by the presence and movement of water through the material. The presence of water within the porous network of a material results in changes in the optical coherence tomography signal intensity that can be used to monitor the wetting front of water penetration of dry porous materials at various depths. The technique is able to detect wetting front velocities from 1 cm s(-1) to 10(-6) cm s(-1), covering the full range of hydraulic conductivities likely to occur in natural sandstones from pervious to impervious.

  6. Remote focal scanning optical projection tomography with an electrically tunable lens

    PubMed Central

    Chen, Lingling; Kumar, Sunil; Kelly, Douglas; Andrews, Natalie; Dallman, Margaret J.; French, Paul M. W.; McGinty, James

    2014-01-01

    We describe a remote focal scanning technique for optical projection tomography (OPT) implemented with an electrically tunable lens (ETL) that removes the need to scan the specimen or objective lens. Using a 4× objective lens the average spatial resolution is improved by ∼46% and the light collection efficiency by a factor of ∼6.76, thereby enabling increased acquisition speed and reduced light dose. This convenient implementation is particularly appropriate for lower magnifications and larger sample diameters where axial objective scanning would encounter problems with speed and stability. PMID:25360356

  7. A Pluralistic View of Early Assessment: The Project Spectrum Approach.

    ERIC Educational Resources Information Center

    Wexler-Sherman, Carey; And Others

    1988-01-01

    Project Spectrum is a pilot project to fuse assessment and the curriculum of preschool and daycare programs. The article reviews standard assessment methods, describes alternative notions of intelligence, and examines the implementation of Project Spectrum in detail. (JL)

  8. Project Assessment Framework through Design (PAFTD) - A Project Assessment Framework in Support of Strategic Decision Making

    NASA Technical Reports Server (NTRS)

    Depenbrock, Brett T.; Balint, Tibor S.; Sheehy, Jeffrey A.

    2014-01-01

    Research and development organizations that push the innovation edge of technology frequently encounter challenges when attempting to identify an investment strategy and to accurately forecast the cost and schedule performance of selected projects. Fast moving and complex environments require managers to quickly analyze and diagnose the value of returns on investment versus allocated resources. Our Project Assessment Framework through Design (PAFTD) tool facilitates decision making for NASA senior leadership to enable more strategic and consistent technology development investment analysis, beginning at implementation and continuing through the project life cycle. The framework takes an integrated approach by leveraging design principles of useability, feasibility, and viability and aligns them with methods employed by NASA's Independent Program Assessment Office for project performance assessment. The need exists to periodically revisit the justification and prioritization of technology development investments as changes occur over project life cycles. The framework informs management rapidly and comprehensively about diagnosed internal and external root causes of project performance.

  9. Project Approval, Environmental Assessment and Public Participation.

    ERIC Educational Resources Information Center

    Elder, P. S.

    1982-01-01

    Presents a case study of a heavy oil project proposed by Esso Resources Canada Limited at Cold Lake, Alberta, Canada. Focuses on the approval process, environmental and social impact assessments, and public participation. Evaluates the case and makes recommendations concerning the approval process. (DC)

  10. Needs Assessment Project: Factor Analytic Studies.

    ERIC Educational Resources Information Center

    Shively, Joe E.; Holcomb, Zelda J.

    Data collected by the Appalachia Educational Laboratory (AEL) in its 1980 Needs Assessment Project was reduced to eight marker variables for use in subsequent individual state factor analyses. These variables concern (1) high need family situations; (2) effective career education/guidance; (3) increased school capacity for working with families;…

  11. Unilateral primary adrenal natural killer/T-cell lymphoma: Role of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography for staging and interim response assessment

    PubMed Central

    Kabnurkar, Rasika; Agrawal, Archi; Epari, Sridhar; Purandare, Nilendu; Shah, Sneha; Rangarajan, Venkatesh

    2016-01-01

    Primary adrenal lymphoma (PAL) is a rare malignancy often involving bilateral adrenal glands. Diffuse large B-cell is the most common histological type. Unilateral presentation and T-cell/natural killer (T/NK) cell histological type is rarer. We report fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography scan findings in a case of unilateral T/NK cell PAL performed for staging and interim treatment response assessment. PMID:26917897

  12. Ultrasound attenuation computed tomography assessment of PAGAT gel dose

    NASA Astrophysics Data System (ADS)

    Khoei, S.; Trapp, J. V.; Langton, C. M.

    2014-08-01

    Ultrasound has been previously investigated as an alternative readout method for irradiated polymer gel dosimeters, with authors reporting varying dose responses. We extend previous work utilizing a new computed tomography ultrasound scanner comprising of two identical 5 MHz, 128-element linear-array ultrasound transducers, co-axially aligned and submerged in water as a coupling agent, with rotational of the gel dosimeter between the transducers facilitated by a robotic arm. We have investigated the dose-dependence of both ultrasound bulk attenuation and broadband ultrasound attenuation (BUA) for the PAGAT gel dosimeter. The ultrasound bulk attenuation dose sensitivity was found to be 1.46  ±  0.04 dB m -1 Gy -1, being in agreement with previously published results for PAG and MAGIC gels. BUA was also found to be dose dependent and was measured to be 0.024  ±  0.003 dB MHz -1 Gy -1 the advantage of BUA being its insensitivity to frequency-independent attenuation mechanisms including reflection and refraction, thereby minimizing image reconstruction artefacts.

  13. A projection-based approach to diffraction tomography on curved boundaries

    NASA Astrophysics Data System (ADS)

    Clement, Gregory T.

    2014-12-01

    An approach to diffraction tomography is investigated for two-dimensional image reconstruction of objects surrounded by an arbitrarily-shaped curve of sources and receivers. Based on the integral theorem of Helmholtz and Kirchhoff, the approach relies upon a valid choice of the Green’s functions for selected conditions along the (possibly-irregular) boundary. This allows field projections from the receivers to an arbitrary external location. When performed over all source locations, it will be shown that the field caused by a hypothetical source at this external location is also known along the boundary. This field can then be projected to new external points that may serve as a virtual receiver. Under such a reformation, data may be put in a form suitable for image construction by synthetic aperture methods. Foundations of the approach are shown, followed by a mapping technique optimized for the approach. Examples formed from synthetic data are provided.

  14. Digital Radiography and Computed Tomography Project -- Fully Integrated Linear Detector ArrayStatus Report

    SciTech Connect

    Tim Roney; Robert Seifert; Bob Pink; Mike Smith

    2011-09-01

    The field-portable Digital Radiography and Computed Tomography (DRCT) x-ray inspection systems developed for the Project Manager for NonStockpile Chemical Materiel (PMNSCM) over the past 13 years have used linear diode detector arrays from two manufacturers; Thomson and Thales. These two manufacturers no longer produce this type of detector. In the interest of insuring the long term viability of the portable DRCT single munitions inspection systems and to improve the imaging capabilities, this project has been investigating improved, commercially available detectors. During FY-10, detectors were evaluated and one in particular, manufactured by Detection Technologies (DT), Inc, was acquired for possible integration into the DRCT systems. The remainder of this report describes the work performed in FY-11 to complete evaluations and fully integrate the detector onto a representative DRCT platform.

  15. Two-Dimensional Tomography from Noisy Projections Taken at Unknown Random Directions*

    PubMed Central

    Singer, A.; Wu, H.-T.

    2013-01-01

    Computerized tomography is a standard method for obtaining internal structure of objects from their projection images. While CT reconstruction requires the knowledge of the imaging directions, there are some situations in which the imaging directions are unknown, for example, when imaging a moving object. It is therefore desirable to design a reconstruction method from projection images taken at unknown directions. Another difficulty arises from the fact that the projections are often contaminated by noise, practically limiting all current methods, including the recently proposed diffusion map approach. In this paper, we introduce two denoising steps that allow reconstructions at much lower signal-to-noise ratios (SNRs) when combined with the diffusion map framework. In the first denoising step we use principal component analysis (PCA) together with classical Wiener filtering to derive an asymptotically optimal linear filter. In the second step, we denoise the graph of similarities between the filtered projections using a network analysis measure such as the Jaccard index. Using this combination of PCA, Wiener filtering, graph denoising, and diffusion maps, we are able to reconstruct the two-dimensional (2-D) Shepp–Logan phantom from simulative noisy projections at SNRs well below their currently reported threshold values. We also report the results of a numerical experiment corresponding to an abdominal CT. Although the focus of this paper is the 2-D CT reconstruction problem, we believe that the combination of PCA, Wiener filtering, graph denoising, and diffusion maps is potentially useful in other signal processing and image analysis applications. PMID:24563691

  16. Reverse projection retrieval in edge illumination x-ray phase contrast computed tomography

    NASA Astrophysics Data System (ADS)

    Hagen, Charlotte K.; Endrizzi, Marco; Diemoz, Paul C.; Olivo, Alessandro

    2016-06-01

    Edge illumination (EI) x-ray phase contrast computed tomography (CT) can provide three-dimensional distributions of the real and imaginary parts of the complex refractive index (n=1-δ +\\text{i}β ) of the sample. Phase retrieval, i.e. the separation of attenuation and refraction data from projections that contain a combination of both, is a key step in the image reconstruction process. In EI-based x-ray phase contrast CT, this is conventionally performed on the basis of two projections acquired in opposite illumination configurations (i.e. with different positions of the pre-sample mask) at each CT angle. Displacing the pre-sample mask at each projection makes the scan susceptible to motor-induced misalignment and prevents a continuous sample rotation. We present an alternative method for the retrieval of attenuation and refraction data that does not require repositioning the pre-sample mask. The method is based on the reverse projection relation published by Zhu et al (2010 Proc. Natl Acad. Sci. USA 107 13576–81) for grating interferometry-based x-ray phase contrast CT. We use this relation to derive a simplified acquisition strategy that allows acquiring data with a continuous sample rotation, which can reduce scan time when combined with a fast read-out detector. Besides discussing the theory and the necessary alignment of the experimental setup, we present tomograms obtained with reverse projection retrieval and demonstrate their agreement with those obtained with the conventional EI retrieval.

  17. Reverse projection retrieval in edge illumination x-ray phase contrast computed tomography

    NASA Astrophysics Data System (ADS)

    Hagen, Charlotte K.; Endrizzi, Marco; Diemoz, Paul C.; Olivo, Alessandro

    2016-06-01

    Edge illumination (EI) x-ray phase contrast computed tomography (CT) can provide three-dimensional distributions of the real and imaginary parts of the complex refractive index (n=1-δ +\\text{i}β ) of the sample. Phase retrieval, i.e. the separation of attenuation and refraction data from projections that contain a combination of both, is a key step in the image reconstruction process. In EI-based x-ray phase contrast CT, this is conventionally performed on the basis of two projections acquired in opposite illumination configurations (i.e. with different positions of the pre-sample mask) at each CT angle. Displacing the pre-sample mask at each projection makes the scan susceptible to motor-induced misalignment and prevents a continuous sample rotation. We present an alternative method for the retrieval of attenuation and refraction data that does not require repositioning the pre-sample mask. The method is based on the reverse projection relation published by Zhu et al (2010 Proc. Natl Acad. Sci. USA 107 13576-81) for grating interferometry-based x-ray phase contrast CT. We use this relation to derive a simplified acquisition strategy that allows acquiring data with a continuous sample rotation, which can reduce scan time when combined with a fast read-out detector. Besides discussing the theory and the necessary alignment of the experimental setup, we present tomograms obtained with reverse projection retrieval and demonstrate their agreement with those obtained with the conventional EI retrieval.

  18. Facility Interface Capability Assessment (FICA) project report

    SciTech Connect

    Pope, R.B.; MacDonald, R.R.; Viebrock, J.M.; Mote, N.

    1995-09-01

    The US Department of Energy`s (DOE) Office of Civilian Radioactive Waste Management (OCRWM) is responsible for developing the Civilian Radioactive Waste Management System (CRWMS) to accept spent nuclear fuel from commercial facilities. The objective of the Facility Interface Capability Assessment (FICA) project was to assess the capability of each commercial spent nuclear fuel (SNF) storage facility, at which SNF is stored, to handle various SNF shipping casks. The purpose of this report is to present and analyze the results of the facility assessments completed within the FICA project. During Phase 1, the data items required to complete the facility assessments were identified and the database for the project was created. During Phase 2, visits were made to 122 facilities on 76 sites to collect data and information, the database was updated, and assessments of the cask-handling capabilities at each facility were performed. Each assessment of cask-handling capability contains three parts: the current capability of the facility (planning base); the potential enhanced capability if revisions were made to the facility licensing and/or administrative controls; and the potential enhanced capability if limited physical modifications were made to the facility. The main conclusion derived from the planning base assessments is that the current facility capabilities will not allow handling of any of the FICA Casks at 49 of the 122 facilities evaluated. However, consideration of potential revisions and/or modifications showed that all but one of the 49 facilities could be adapted to handle at least one of the FICA Casks. For this to be possible, facility licensing, administrative controls, and/or physical aspects of the facility would need to be modified.

  19. Assessment of transcutaneous vaccine delivery by optical coherence tomography Assessment of transcutaneous vaccine delivery by OCT

    NASA Astrophysics Data System (ADS)

    Kamali, T.; Doronin, A.; Rattanapak, T.; Hook, S.; Meglinski, I.

    2012-08-01

    Immunization is one of the most efficient and cost-effective means for the prevention of diseases. The latest trend for inducing protective immunity is topical application of vaccines to intact skin rather than invasive administration via injection. Apart from being a non-invasive route of drug delivery, skin itself also offers advantages through the presence of cells of the immune system in both the dermis and epidermis. However, vaccine penetration through the outermost layers of skin is limited by the barrier provided by the Stratum corneum. In the current study utilizing conventional Optical Coherence Tomography (OCT) we investigate the transcutaneous delivery of a nano- particulate peptide vaccine into mouse skin in vivo. We demonstrate that a front of molecular diffusion within the skin can be clearly observed by using cross-correlations of successive 2D OCT images. Thus, OCT provides a unique tool for quantitative assessment of dynamics of diffusion of drugs, target compounds, analytes, cosmetics and various chemical agents in biological tissues in vivo.

  20. Accelerated Optical Projection Tomography Applied to In Vivo Imaging of Zebrafish

    PubMed Central

    Correia, Teresa; Yin, Jun; Ramel, Marie-Christine; Andrews, Natalie; Katan, Matilda; Bugeon, Laurence; Dallman, Margaret J.; McGinty, James; Frankel, Paul; French, Paul M. W.; Arridge, Simon

    2015-01-01

    Optical projection tomography (OPT) provides a non-invasive 3-D imaging modality that can be applied to longitudinal studies of live disease models, including in zebrafish. Current limitations include the requirement of a minimum number of angular projections for reconstruction of reasonable OPT images using filtered back projection (FBP), which is typically several hundred, leading to acquisition times of several minutes. It is highly desirable to decrease the number of required angular projections to decrease both the total acquisition time and the light dose to the sample. This is particularly important to enable longitudinal studies, which involve measurements of the same fish at different time points. In this work, we demonstrate that the use of an iterative algorithm to reconstruct sparsely sampled OPT data sets can provide useful 3-D images with 50 or fewer projections, thereby significantly decreasing the minimum acquisition time and light dose while maintaining image quality. A transgenic zebrafish embryo with fluorescent labelling of the vasculature was imaged to acquire densely sampled (800 projections) and under-sampled data sets of transmitted and fluorescence projection images. The under-sampled OPT data sets were reconstructed using an iterative total variation-based image reconstruction algorithm and compared against FBP reconstructions of the densely sampled data sets. To illustrate the potential for quantitative analysis following rapid OPT data acquisition, a Hessian-based method was applied to automatically segment the reconstructed images to select the vasculature network. Results showed that 3-D images of the zebrafish embryo and its vasculature of sufficient visual quality for quantitative analysis can be reconstructed using the iterative algorithm from only 32 projections—achieving up to 28 times improvement in imaging speed and leading to total acquisition times of a few seconds. PMID:26308086

  1. A field assessment of the value of steady shape hydraulic tomography for characterization of aquifer heterogeneities

    USGS Publications Warehouse

    Bohling, G.C.; Butler, J.J.; Zhan, X.; Knoll, M.D.

    2007-01-01

    Hydraulic tomography is a promising approach for obtaining information on variations in hydraulic conductivity on the scale of relevance for contaminant transport investigations. This approach involves performing a series of pumping tests in a format similar to tomography. We present a field-scale assessment of hydraulic tomography in a porous aquifer, with an emphasis on the steady shape analysis methodology. The hydraulic conductivity (K) estimates from steady shape and transient analyses of the tomographic data compare well with those from a tracer test and direct-push permeameter tests, providing a field validation of the method. Zonations based on equal-thickness layers and cross-hole radar surveys are used to regularize the inverse problem. The results indicate that the radar surveys provide some useful information regarding the geometry of the K field. The steady shape analysis provides results similar to the transient analysis at a fraction of the computational burden. This study clearly demonstrates the advantages of hydraulic tomography over conventional pumping tests, which provide only large-scale averages, and small-scale hydraulic tests (e.g., slug tests), which cannot assess strata connectivity and may fail to sample the most important pathways or barriers to flow. Copyright 2007 by the American Geophysical Union.

  2. Confined Zone Dispersion Project: A DOE assessment

    SciTech Connect

    1999-11-30

    The goal of the US Department of Energy (DOE) Clean Coal Technology (CCT) program is to furnish the energy marketplace with a number of advanced, more efficient, and environmentally responsible coal utilization technologies through demonstration projects. These projects seek to establish the commercial feasibility of the most promising advanced coal technologies that have developed beyond the proof-of-concept (POC) stage. This document serves as a DOE post-project assessment of the Confined Zone Dispersion Project in CCT Round 3. In 1990, Bechtel Corporation entered into a cooperative agreement to conduct the demonstration project. The Seward Power Station of Pennsylvania Electric Company (now GPU Genco) was the host site. DOE funded 43 percent of the total project cost of $12,173,000. The project was started in June 1990 and was scheduled to be completed in June 1993. As a result of various operating problems, the schedule was extended into 1994 without additional cost to DOE. Bechtel provided the additional financing and GPU Genco provided electricity, steam, and water to operate the unit. The independent evaluation contained herein is based primarily on information from Bechtel's final technical report (1994) as well as other references cited. Confined Zone Dispersion (CZD) is a flue gas desulfurization (FGD) process that removes sulfur dioxide (SO{sub 2}). A finely atomized slurry of reactive lime, calcium hydroxide or Ca(OH){sub 2} is injected into the flue-gas duct work, between the air preheater and the second-stage ESP. The lime reacts with the SO{sub 2}, forming dry solid reaction products. The downstream ESP captures the 2 reaction products along with the fly ash entrained in the flue gas. The CZD process was demonstrated on Unit 5, a 147-MWe utility unit with two flue gas ducts. One of the ducts was extended to provide the requisite residence time and retrofitted with the CZD lime injection equipment.

  3. Quantitative computed tomography for spinal mineral assessment: current status

    NASA Technical Reports Server (NTRS)

    Genant, H. K.; Cann, C. E.; Ettinger, B.; Gordan, G. S.; Kolb, F. O.; Reiser, U.; Arnaud, C. D.

    1985-01-01

    Quantitative CT (QCT) is an established method for the noninvasive assessment of bone mineral content in the vertebral spongiosum and other anatomic locations. The potential strengths of QCT relative to dual photon absorptiometry (DPA) are its capability for precise three-dimensional anatomic localization providing a direct density measurement and its capability for spatial separation of highly responsive cancellous bone from less responsive cortical bone. The extraction of this quantitative information from the CT image, however, requires sophisticated calibration and positioning techniques and careful technical monitoring.

  4. The potential optical coherence tomography in tooth bleaching quantitative assessment

    NASA Astrophysics Data System (ADS)

    Ni, Y. R.; Guo, Z. Y.; Shu, S. Y.; Zeng, C. C.; Zhong, H. Q.; Chen, B. L.; Liu, Z. M.; Bao, Y.

    2011-12-01

    In this paper, we report the outcomes from a pilot study on using OCT functional imaging method to evaluate and quantify color alteration in the human teeth in vitro. The image formations of the dental tissues without and with treatment 35% hydrogen peroxide were obtained by an OCT system at a 1310 nm central wavelength. One parameter for the quantification of optical properties from OCT measurements is introduced in our study: attenuate coefficient (μ). And the attenuate coefficient have significant decrease ( p < 0.001) in dentine as well as a significant increase ( p < 0.001) in enamel was observed during tooth bleaching process. From the experimental results, it is found that attenuate coefficient could be useful to assess color alteration of the human tooth samples. OCT has a potential to become an effective tool for the assessment tooth bleaching. And our experiment offer a now method to evaluate color change in visible region by quantitative analysis of the infrared region information from OCT.

  5. Maximum-Intensity-Projection Imaging for Dynamic Analysis of Mental Sweating by Optical Coherence Tomography

    NASA Astrophysics Data System (ADS)

    Saigusa, Hiroyuki; Ueda, Yoshihiro; Yamada, Akihiro; Ohmi, Masato; Ohnishi, Makoto; Kuwabara, Mitsuo; Haruna, Masamitsu

    2008-09-01

    Optical coherence tomography (OCT) shows great potential for microscopic observation of human sweating dynamics. It should be a key technology in the development of new techniques for the study of dynamic physiology. In this study, the dynamic motion of eccrin sweat glands is visualized by three-dimensional (3-D) OCT imaging, and a novel 3-D image construction method, using maximum intensity projection (MIP) of B-mode OCT images, is proposed for in vivo dynamic analysis of mental sweating on human fingertips. Time-sequential MIP-OCT images with a frame spacing of 1.4 s provide quantitative analysis of the sweating dynamics, which in turn leads to the evaluation of the activity of the sympathetic nerve. Dynamic changes in the microstructure of eccrin sweat glands can be clearly observed in the 3-D images constructed by volume rendering.

  6. Agreement of angle closure assessments between gonioscopy, anterior segment optical coherence tomography and spectral domain optical coherence tomography

    PubMed Central

    Tay, Elton Lik Tong; Yong, Vernon Khet Yau; Lim, Boon Ang; Sia, Stelson; Wong, Elizabeth Poh Ying; Yip, Leonard Wei Leon

    2015-01-01

    AIM To determine angle closure agreements between gonioscopy and anterior segment optical coherence tomography (AS-OCT), as well as gonioscopy and spectral domain OCT (SD-OCT). A secondary objective was to quantify inter-observer agreements of AS-OCT and SD-OCT assessments. METHODS Seventeen consecutive subjects (33 eyes) were recruited from the study hospital's Glaucoma clinic. Gonioscopy was performed by a glaucomatologist masked to OCT results. OCT images were read independently by 2 other glaucomatologists masked to gonioscopy findings as well as each other's analyses of OCT images. RESULTS Totally 84.8% and 45.5% of scleral spurs were visualized in AS-OCT and SD-OCT images respectively (P<0.01). The agreement for angle closure between AS-OCT and gonioscopy was fair at k=0.31 (95% confidence interval, CI: 0.03-0.59) and k=0.35 (95% CI: 0.07-0.63) for reader 1 and 2 respectively. The agreement for angle closure between SD-OCT and gonioscopy was fair at k=0.21 (95% CI: 0.07-0.49) and slight at k=0.17 (95% CI: 0.08-0.42) for reader 1 and 2 respectively. The inter-reader agreement for angle closure in AS-OCT images was moderate at 0.51 (95% CI: 0.13-0.88). The inter-reader agreement for angle closure in SD-OCT images was slight at 0.18 (95% CI: 0.08-0.45). CONCLUSION Significant proportion of scleral spurs were not visualised with SD-OCT imaging resulting in weaker inter-reader agreements. Identifying other angle landmarks in SD-OCT images will allow more consistent angle closure assessments. Gonioscopy and OCT imaging do not always agree in angle closure assessments but have their own advantages, and should be used together and not exclusively. PMID:25938053

  7. Fan-beam reconstruction in computer tomography from full and partial projection data

    SciTech Connect

    Peng, H.

    1988-01-01

    The problems of image reconstruction in this thesis appear in medical tomography, nondestructive testing, astrophysics, electromicroscopy and other fields. The problem is to image the internal structure of the object of interest from the shadows (raysums) at different angles. Fan-beam reconstruction is required when the probing source is a point source. Fan-beam geometry also has the advantage of fast scanning in computer tomography. The conventional reconstruction algorithm (Filter/Convolution Back projection) requires O(N{sup 3}) computations to reconstruct a 2-D image. Investigated are an alternative way to do fan-beam reconstruction which uses O(N{sup 2}log N) computations through the use of the direct Fourier reconstruction method. Partial-data image reconstruction occurs when the collection of full data is impossible due to an internal opacity, an exterior obstruction, imaging a time varying event, or reducing the dosage or scanning time. Other prior knowledge is incorporated of the image function to compensate for the effect of missing data. The explicit minimum distance solution is derived for the incomplete data problem in a one step implementation of the iterative algebraic reconstruction technique (ART). This solution is a projector and can be used with projector of other prior knowledge constraint sets in the framework of the method of Projection Onto Convex Sets (POCS). The POCS algorithm solution has all the known properties of the object and is consistent with all the data. We also formulate a new set which utilizes prior information based on the similarity of the unknown object to some known reference. The full algorithm for partial-data reconstruction using POCS is implemented. Simulations demonstrate the efficacy of the method. The shape of an opacity from the raysum data is directly estimated and used with a performance analysis in terms of system parameter.

  8. Metal artifact reduction in cone beam computed tomography using forward projected reconstruction information.

    PubMed

    Meilinger, Manuel; Schmidgunst, Christian; Schütz, Oliver; Lang, Elmar W

    2011-09-01

    In this work we present a new method to reduce artifacts, produced by high-density objects, especially metal implants, in X-ray cone beam computed tomography (CBCT). These artifacts influence clinical diagnostics and treatments using CT data, if metal objects are located in the field of view (FOV). Our novel method reduces metal artifacts by virtually replacing the metal objects with tissue objects of the same shape. First, the considered objects must be segmented in the original 2D projection data as well as in a reconstructed 3D volume. The attenuation coefficients of the segmented voxels are replaced with adequate attenuation coefficients of tissue (or water), then the required parts of the volume are projected onto the segmented 2D pixels, to replace the original information. This corrected 2D data can then be reconstructed with reduced artifacts, i. e. all metal objects virtually vanished. After the reconstruction, the segmented 3D metal objects were re-inserted into the corrected 3D volume. Our method was developed for mobile C-arm CBCTs; as it is necessary that they are of low weight, the C-arm results in unpredictable distortion. This misalignment between the original 2D data and the forward projection of the reconstructed 3D volume must be adjusted before the correction of the segmented 2D pixels. We applied this technique to clinical data and will now present the results.

  9. Feature-space assessment of electrical impedance tomography coregistered with computed tomography in detecting multiple contrast targets

    SciTech Connect

    Krishnan, Kalpagam; Liu, Jeff; Kohli, Kirpal

    2014-06-15

    Purpose: Fusion of electrical impedance tomography (EIT) with computed tomography (CT) can be useful as a clinical tool for providing additional physiological information about tissues, but requires suitable fusion algorithms and validation procedures. This work explores the feasibility of fusing EIT and CT images using an algorithm for coregistration. The imaging performance is validated through feature space assessment on phantom contrast targets. Methods: EIT data were acquired by scanning a phantom using a circuit, configured for injecting current through 16 electrodes, placed around the phantom. A conductivity image of the phantom was obtained from the data using electrical impedance and diffuse optical tomography reconstruction software (EIDORS). A CT image of the phantom was also acquired. The EIT and CT images were fused using a region of interest (ROI) coregistration fusion algorithm. Phantom imaging experiments were carried out on objects of different contrasts, sizes, and positions. The conductive medium of the phantoms was made of a tissue-mimicking bolus material that is routinely used in clinical radiation therapy settings. To validate the imaging performance in detecting different contrasts, the ROI of the phantom was filled with distilled water and normal saline. Spatially separated cylindrical objects of different sizes were used for validating the imaging performance in multiple target detection. Analyses of the CT, EIT and the EIT/CT phantom images were carried out based on the variations of contrast, correlation, energy, and homogeneity, using a gray level co-occurrence matrix (GLCM). A reference image of the phantom was simulated using EIDORS, and the performances of the CT and EIT imaging systems were evaluated and compared against the performance of the EIT/CT system using various feature metrics, detectability, and structural similarity index measures. Results: In detecting distilled and normal saline water in bolus medium, EIT as a stand

  10. Assessment of cardiac single-photon emission computed tomography performance using a scanning linear observer

    SciTech Connect

    Lee, Chih-Jie; Kupinski, Matthew A.; Volokh, Lana

    2013-01-15

    Purpose: Single-photon emission computed tomography (SPECT) is widely used to detect myocardial ischemia and myocardial infarction. It is important to assess and compare different SPECT system designs in order to achieve the highest detectability of cardiac defects. Methods: Whitaker et al.'s study ['Estimating random signal parameters from noisy images with nuisance parameters: linear and scanning-linear methods,' Opt. Express 16(11), 8150-8173 (2008)] on the scanning linear observer (SLO) shows that the SLO can be used to estimate the location and size of signals. One major advantage of the SLO is that it can be used with projection data rather than with reconstruction data. Thus, this observer model assesses the overall hardware performance independent of any reconstruction algorithm. In addition, the computation time of image quality studies is significantly reduced. In this study, three systems based on the design of the GE cadmium zinc telluride-based dedicated cardiac SPECT camera Discovery 530c were assessed. This design, which is officially named the Alcyone Technology: Discovery NM 530c, was commercialized in August, 2009. The three systems, GE27, GE19, and GE13, contain 27, 19, and 13 detectors, respectively. Clinically, a human heart can be virtually segmented into three coronary artery territories: the left-anterior descending artery, left-circumflex artery, and right coronary artery. One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can accurately predict in which territory the defect exists [http://www.asnc.org/media/PDFs/PPReporting081511.pdf, Guideline from American Society of Nuclear Cardiology]. A good estimation of the extent of the defect from the projection images is also very helpful for determining the seriousness of the myocardial ischemia. In this study, both the location and extent of defects were estimated by the SLO, and the system performance was assessed by localization

  11. Signal enhancement in optical projection tomography via virtual high dynamic range imaging of single exposure

    NASA Astrophysics Data System (ADS)

    Yang, Yujie; Dong, Di; Shi, Liangliang; Wang, Jun; Yang, Xin; Tian, Jie

    2015-03-01

    Optical projection tomography (OPT) is a mesoscopic scale optical imaging technique for specimens between 1mm and 10mm. OPT has been proven to be immensely useful in a wide variety of biological applications, such as developmental biology and pathology, but its shortcomings in imaging specimens containing widely differing contrast elements are obvious. The longer exposure for high intensity tissues may lead to over saturation of other areas, whereas a relatively short exposure may cause similarity with surrounding background. In this paper, we propose an approach to make a trade-off between capturing weak signals and revealing more details for OPT imaging. This approach consists of three steps. Firstly, the specimens are merely scanned in 360 degrees above a normal exposure but non-overexposure to acquire the projection data. This reduces the photo bleaching and pre-registration computation compared with multiple different exposures in conventional high dynamic range (HDR) imaging method. Secondly, three virtual channels are produced for each projection image based on the histogram distribution to simulate the low, normal and high exposure images used in the traditional HDR technology in photography. Finally, each virtual channel is normalized to the full gray scale range and three channels are recombined into one image using weighting coefficients optimized by a standard eigen-decomposition method. After applying our approach on the projection data, filtered back projection (FBP) algorithm is carried out for 3-dimentional reconstruction. The neonatal wild-type mouse paw has been scanned to verify this approach. Results demonstrated the effectiveness of the proposed approach.

  12. Ecological Compliance Assessment Project: 1994 Summary report

    SciTech Connect

    Brandt, C.A.

    1994-11-01

    The Ecological Compliance Assessment Project (ECAP) began full operation on March 1, 1994. The project is designed around a baseline environmental data concept that includes intensive biological field surveys of key areas of the Hanford Site where the majority of Site activities occur. These surveys are conducted at biologically appropriate times of year to ensure that the data gathered are current and accurate. The data are entered into the ECAP database, which serves as a reference for the evaluation of review requests coming in to the project. This methodology provided the basis for over 90 percent of the review requests received. Field surveys conducted under ECAP are performed to document occurrence information for species of concern and to obtain habitat descriptions. There are over 200 species of concern on the Hanford Site, including plants, birds, mammals, reptiles, amphibians, fish, and invertebrates. In addition, Washington State has designated mature sagebrush-steppe habitat as a Priority Habitat meriting special protective measures. Of the projects reviewed, 17 resulted or will result in impacts to species or habitats of concern on the Hanford Site. The greatest impact has been on big sagebrush habitat. Most of the impact has been or will be within the 600 Area of the Site.

  13. Klickitat Cogeneration Project : Final Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration; Klickitat Energy Partners

    1994-09-01

    To meet BPA`s contractual obligation to supply electrical power to its customers, BPA proposes to acquire power generated by Klickitat Cogeneration Project. BPA has prepared an environmental assessment evaluating the proposed project. Based on the EA analysis, BPA`s proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 for the following reasons: (1)it will not have a significant impact land use, upland vegetation, wetlands, water quality, geology, soils, public health and safety, visual quality, historical and cultural resources, recreation and socioeconomics, and (2) impacts to fisheries, wildlife resources, air quality, and noise will be temporary, minor, or sufficiently offset by mitigation. Therefore, the preparation of an environmental impact statement is not required and BPA is issuing this FONSI (Finding of No Significant Impact).

  14. Session: Pre-development project risk assessment

    SciTech Connect

    Curry, Richard; Linehan, Andy

    2004-09-01

    This second session at the Wind Energy and Birds/Bats workshop consisted of two presentations followed by a discussion/question and answer period. The focus of the presentations was on the practices and methodologies used in the wind energy industry for assessing risk to birds and bats at candidate project sites. Presenters offered examples of pre-development siting evaluation requirements set by certain states. Presentation one was titled ''Practices and Methodologies and Initial Screening Tools'' by Richard Curry of Curry and Kerlinger, LLC. Presentation two was titled ''State of the Industry in the Pacific Northwest'' by Andy Linehan, CH2MHILL.

  15. IV&V Project Assessment Process Validation

    NASA Technical Reports Server (NTRS)

    Driskell, Stephen

    2012-01-01

    The Space Launch System (SLS) will launch NASA's Multi-Purpose Crew Vehicle (MPCV). This launch vehicle will provide American launch capability for human exploration and travelling beyond Earth orbit. SLS is designed to be flexible for crew or cargo missions. The first test flight is scheduled for December 2017. The SLS SRR/SDR provided insight into the project development life cycle. NASA IV&V ran the standard Risk Based Assessment and Portfolio Based Risk Assessment to identify analysis tasking for the SLS program. This presentation examines the SLS System Requirements Review/System Definition Review (SRR/SDR), IV&V findings for IV&V process validation correlation to/from the selected IV&V tasking and capabilities. It also provides a reusable IEEE 1012 scorecard for programmatic completeness across the software development life cycle.

  16. Automated Quantification of Nonperfusion in Three Retinal Plexuses Using Projection-Resolved Optical Coherence Tomography Angiography in Diabetic Retinopathy

    PubMed Central

    Zhang, Miao; Hwang, Thomas S.; Dongye, Changlei; Wilson, David J.; Huang, David; Jia, Yali

    2016-01-01

    Purpose The purpose of this study was to evaluate an automated algorithm for detecting avascular area (AA) in optical coherence tomography angiograms (OCTAs) separated into three individual plexuses using a projection-resolved technique. Methods A 3 × 3 mm macular OCTA was obtained in 13 healthy and 13 mild nonproliferative diabetic retinopathy (NPDR) participants. A projection-resolved algorithm segmented OCTA into three vascular plexuses: superficial, intermediate, and deep. An automated algorithm detected AA in each of the three plexuses that were segmented and in the combined inner-retinal angiograms. We assessed the diagnostic accuracy of extrafoveal and total AA using segmented and combined angiograms, the agreement between automated and manual detection of AA, and the within-visit repeatability. Results The sum of extrafoveal AA from the segmented angiograms was larger in the NPDR group by 0.17 mm2 (P < 0.001) and detected NPDR with 94.6% sensitivity (area under the receiver operating characteristic curve [AROC] = 0.99). In the combined inner-retinal angiograms, the extrafoveal AA was larger in the NPDR group by 0.01 mm2 (P = 0.168) and detected NPDR with 26.9% sensitivity (AROC = 0.62). The total AA, inclusive of the foveal avascular zone, in the segmented and combined angiograms, detected NPDR with 23.1% and 7.7% sensitivity, respectively. The agreement between the manual and automated detection of AA had a Jaccard index of >0.8. The pooled SDs of AA were small compared with the difference in mean for control and NPDR groups. Conclusions An algorithm to detect AA in OCTA separated into three individual plexuses using a projection-resolved algorithm accurately distinguishes mild NPDR from control eyes. Automatically detected AA agrees with manual delineation and is highly repeatable. PMID:27699408

  17. Assessment of CO{sub 2} projections

    SciTech Connect

    Enting, I.G.; Wigley, T.M.L.; Heimann, M.

    1994-07-01

    Various projections of the relation between future CO{sub 2} concentrations and future emissions were undertaken as part of the scientific assessment for Working Group 1 of the Intergovernmental Panel on Climate Change. There were three type of calculation: (1) forward projections, calculating the atmospheric CO{sub 2} concentrations resulting from specified emission scenarios, (2) inverse calculations determining the emission rates that would be required to achieve stabilization of CO{sub 2} concentrations via specified pathways and (3) impulse response function calculations required for determining Global Warming Potentials. The use of a standardized set of conditions allows an intercomparison of models. The ocean models used in the calculations presented here span a range of forms from response function descriptions to general circulation models. The general issue for all levels of modelling is whether the model parameters can reasonably be regarded as being the same in the future as at present. Sensitivity studies explore other aspects of the uncertainties of such projections. This report documents the specifications, the models that were used and the results that were obtained. Some preliminary interpretations of the results are included.

  18. Phase-retrieved optical projection tomography for 3D imaging through scattering layers

    NASA Astrophysics Data System (ADS)

    Ancora, Daniele; Di Battista, Diego; Giasafaki, Georgia; Psycharakis, Stylianos; Liapis, Evangelos; Zacharopoulos, Athanasios; Zacharakis, Giannis

    2016-03-01

    Recently great progress has been made in biological and biomedical imaging by combining non-invasive optical methods, novel adaptive light manipulation and computational techniques for intensity-based phase recovery and three dimensional image reconstruction. In particular and in relation to the work presented here, Optical Projection Tomography (OPT) is a well-established technique for imaging mostly transparent absorbing biological models such as C. Elegans and Danio Rerio. On the contrary, scattering layers like the cocoon surrounding the Drosophila during the pupae stage constitutes a challenge for three dimensional imaging through such a complex structure. However, recent studies enabled image reconstruction through scattering curtains up to few transport mean free paths via phase retrieval iterative algorithms allowing to uncover objects hidden behind complex layers. By combining these two techniques we explore the possibility to perform a three dimensional image reconstruction of fluorescent objects embedded between scattering layers without compromising its structural integrity. Dynamical cross correlation registration was implemented for the registration process due to translational and flipping ambiguity of the phase retrieval problem, in order to provide the correct aligned set of data to perform the back-projection reconstruction. We have thus managed to reconstruct a hidden complex object between static scattering curtains and compared with the effective reconstruction to fully understand the process before the in-vivo biological implementation.

  19. Reconstruction of fluorescence molecular tomography via a nonmonotone spectral projected gradient pursuit method

    NASA Astrophysics Data System (ADS)

    Ye, Jinzuo; Du, Yang; An, Yu; Chi, Chongwei; Tian, Jie

    2014-12-01

    Fluorescence molecular tomography (FMT) is a promising imaging technique in preclinical research, enabling three-dimensional location of the specific tumor position for small animal imaging. However, FMT presents a challenging inverse problem that is quite ill-posed and ill-conditioned. Thus, the reconstruction of FMT faces various challenges in its robustness and efficiency. We present an FMT reconstruction method based on nonmonotone spectral projected gradient pursuit (NSPGP) with l1-norm optimization. At each iteration, a spectral gradient-projection method approximately minimizes a least-squares problem with an explicit one-norm constraint. A nonmonotone line search strategy is utilized to get the appropriate updating direction, which guarantees global convergence. Additionally, the Barzilai-Borwein step length is applied to build the optimal step length, further improving the convergence speed of the proposed method. Several numerical simulation studies, including multisource cases as well as comparative analyses, have been performed to evaluate the performance of the proposed method. The results indicate that the proposed NSPGP method is able to ensure the accuracy, robustness, and efficiency of FMT reconstruction. Furthermore, an in vivo experiment based on a heterogeneous mouse model was conducted, and the results demonstrated that the proposed method held the potential for practical applications of FMT.

  20. Image reconstruction based on L1 regularization and projection methods for electrical impedance tomography.

    PubMed

    Wang, Qi; Wang, Huaxiang; Zhang, Ronghua; Wang, Jinhai; Zheng, Yu; Cui, Ziqiang; Yang, Chengyi

    2012-10-01

    Electrical impedance tomography (EIT) is a technique for reconstructing the conductivity distribution by injecting currents at the boundary of a subject and measuring the resulting changes in voltage. Image reconstruction in EIT is a nonlinear and ill-posed inverse problem. The Tikhonov method with L(2) regularization is always used to solve the EIT problem. However, the L(2) method always smoothes the sharp changes or discontinue areas of the reconstruction. Image reconstruction using the L(1) regularization allows addressing this difficulty. In this paper, a sum of absolute values is substituted for the sum of squares used in the L(2) regularization to form the L(1) regularization, the solution is obtained by the barrier method. However, the L(1) method often involves repeatedly solving large-dimensional matrix equations, which are computationally expensive. In this paper, the projection method is combined with the L(1) regularization method to reduce the computational cost. The L(1) problem is mainly solved in the coarse subspace. This paper also discusses the strategies of choosing parameters. Both simulation and experimental results of the L(1) regularization method were compared with the L(2) regularization method, indicating that the L(1) regularization method can improve the quality of image reconstruction and tolerate a relatively high level of noise in the measured voltages. Furthermore, the projected L(1) method can also effectively reduce the computational time without affecting the quality of reconstructed images.

  1. Multi-projection bioluminescence tomography guided system for small animal radiation research platform (SARRP)

    NASA Astrophysics Data System (ADS)

    Zhang, Bin; Iordachita, Iulian; Wong, John W.; Wang, Ken Kang-Hsin

    2016-03-01

    Cone beam computed tomography (CBCT) is limited in guiding irradiation for soft tissue targets. As a complementary imaging modality, bioluminescence tomography (BLT) provides strong soft tissue contrast. We developed a dual-use BLT system which consists of an optical assembly, a mobile cart and an independent mouse bed. The system is motorized which can easily dock onto an independent mouse bed operating as a standalone system for longitudinal bioluminescence imaging (BLI)/BLT studies and also dock onto the SARRP for on-line radiation guidance. Our initial tests for the system demonstrate that (i) the imaging depth is 28 mm, (ii) the optical background is sufficiently low and uniform, (iii) the non-uniform response of the optical imaging can be corrected by the flat field correction, and (iv) the imaging acquisition speed was improved by an average of 3.7 times faster than our previous systems. We also presented a geometry calibration procedure to map the planar BLIs acquired at multi-projections onto the surface of the CBCT image. The CBCT is required to generate the mesh for BLT reconstruction and used for treatment planning and radiation delivery. Feasibility study of the geometry calibration was performed on a manual-docking prototype. The mean and maximum mapping accuracy is 0.3 and 0.6 mm. The performance of the proposed motorized dual-use system is expected to be superior to that of the manual-docking prototype because of the mechanism stability. We anticipate the dual-use system as a highly efficient and cost-effective platform to facilitate optical imaging for preclinical radiation research.

  2. In vivo bioluminescence tomography based on multi-view projection and 3D surface reconstruction

    NASA Astrophysics Data System (ADS)

    Zhang, Shuang; Wang, Kun; Leng, Chengcai; Deng, Kexin; Hu, Yifang; Tian, Jie

    2015-03-01

    Bioluminescence tomography (BLT) is a powerful optical molecular imaging modality, which enables non-invasive realtime in vivo imaging as well as 3D quantitative analysis in preclinical studies. In order to solve the inverse problem and reconstruct inner light sources accurately, the prior structural information is commonly necessary and obtained from computed tomography or magnetic resonance imaging. This strategy requires expensive hybrid imaging system, complicated operation protocol and possible involvement of ionizing radiation. The overall robustness highly depends on the fusion accuracy between the optical and structural information. In this study we present a pure optical bioluminescence tomographic system (POBTS) and a novel BLT method based on multi-view projection acquisition and 3D surface reconstruction. The POBTS acquired a sparse set of white light surface images and bioluminescent images of a mouse. Then the white light images were applied to an approximate surface model to generate a high quality textured 3D surface reconstruction of the mouse. After that we integrated multi-view luminescent images based on the previous reconstruction, and applied an algorithm to calibrate and quantify the surface luminescent flux in 3D.Finally, the internal bioluminescence source reconstruction was achieved with this prior information. A BALB/C mouse with breast tumor of 4T1-fLuc cells mouse model were used to evaluate the performance of the new system and technique. Compared with the conventional hybrid optical-CT approach using the same inverse reconstruction method, the reconstruction accuracy of this technique was improved. The distance error between the actual and reconstructed internal source was decreased by 0.184 mm.

  3. Ionospheric Asymmetry Evaluation using Tomography to Assess the Effectiveness of Radio Occultation Data Inversion

    NASA Astrophysics Data System (ADS)

    Shaikh, M. M.; Notarpietro, R.; Yin, P.; Nava, B.

    2013-12-01

    The Multi-Instrument Data Analysis System (MIDAS) algorithm is based on the oceanographic imaging techniques first applied to do the imaging of 2D slices of the ionosphere. The first version of MIDAS (version 1.0) was able to deal with any line-integral data such as GPS-ground or GPS-LEO differential-phase data or inverted ionograms. The current version extends tomography into four dimensional (lat, long, height and time) spatial-temporal mapping that combines all observations simultaneously in a single inversion with the minimum of a priori assumptions about the form of the ionospheric electron-concentration distribution. This work is an attempt to investigate the Radio Occultation (RO) data assimilation into MIDAS by assessing the ionospheric asymmetry and its impact on RO data inversion, when the Onion-peeling algorithm is used. Ionospheric RO data from COSMIC mission, specifically data collected during 24 September 2011 storm over mid-latitudes, has been used for the data assimilation. Using output electron density data from Midas (with/without RO assimilation) and ideal RO geometries, we tried to assess ionospheric asymmetry. It has been observed that the level of asymmetry was significantly increased when the storm was active. This was due to the increased ionization, which in turn produced large gradients along occulted ray path in the ionosphere. The presence of larger gradients was better observed when Midas was used with RO assimilated data. A very good correlation has been found between the evaluated asymmetry and errors related to the inversion products, when the inversion is performed considering standard techniques based on the assumption of spherical symmetry of the ionosphere. Errors are evaluated considering the peak electron density (NmF2) estimate and the Vertical TEC (VTEC) evaluation. This work highlights the importance of having a tool which should be able to state the effectiveness of Radio Occultation data inversion considering standard

  4. Assessment of sub-milli-sievert abdominal computed tomography with iterative reconstruction techniques of different vendors

    PubMed Central

    Padole, Atul; Sainani, Nisha; Lira, Diego; Khawaja, Ranish Deedar Ali; Pourjabbar, Sarvenaz; Lo Gullo, Roberto; Otrakji, Alexi; Kalra, Mannudeep K

    2016-01-01

    AIM: To assess diagnostic image quality of reduced dose (RD) abdominal computed tomography (CT) with 9 iterative reconstruction techniques (IRTs) from 4 different vendors to the standard of care (SD) CT. METHODS: In an Institutional Review Board approved study, 66 patients (mean age 60 ± 13 years, 44 men, and 22 women) undergoing routine abdomen CT on multi-detector CT (MDCT) scanners from vendors A, B, and C (≥ 64 row CT scanners) (22 patients each) gave written informed consent for acquisition of an additional RD CT series. Sinogram data of RD CT was reconstructed with two vendor-specific and a vendor-neutral IRTs (A-1, A-2, A-3; B-1, B-2, B-3; and C-1, C-2, C-3) and SD CT series with filtered back projection. Subjective image evaluation was performed by two radiologists for each SD and RD CT series blinded and independently. All RD CT series (198) were assessed first followed by SD CT series (66). Objective image noise was measured for SD and RD CT series. Data were analyzed by Wilcoxon signed rank, kappa, and analysis of variance tests. RESULTS: There were 13/50, 18/57 and 9/40 missed lesions (size 2-7 mm) on RD CT for vendor A, B, and C, respectively. Missed lesions includes liver cysts, kidney cysts and stone, gall stone, fatty liver, and pancreatitis. There were also 5, 4, and 4 pseudo lesions (size 2-3 mm) on RD CT for vendor A, B, and C, respectively. Lesions conspicuity was sufficient for clinical diagnostic performance for 6/24 (RD-A-1), 10/24 (RD-A-2), and 7/24 (RD-A-3) lesions for vendor A; 5/26 (RD-B-1), 6/26 (RD-B-2), and 7/26 (RD-B-3) lesions for vendor B; and 4/20 (RD-C-1) 6/20 (RD-C-2), and 10/20 (RD-C-3) lesions for vendor C (P = 0.9). Mean objective image noise in liver was significantly lower for RD A-1 compared to both RD A-2 and RD A-3 images (P < 0.001). Similarly, mean objective image noise lower for RD B-2 (compared to RD B-1, RD B-3) and RD C-3 (compared to RD C-1 and C-2) (P = 0.016). CONCLUSION: Regardless of IRTs and MDCT vendors

  5. Noninvasive assessment of the developing Xenopus cardiovascular system using optical coherence tomography

    PubMed Central

    Boppart, Stephen A.; Tearney, Gary J.; Bouma, Brett E.; Southern, James F.; Brezinski, Mark E.; Fujimoto, James G.

    1997-01-01

    Studies investigating normal and abnormal cardiac development are frequently limited by an inability to assess cardiovascular function within the intact organism. In this work, optical coherence tomography (OCT), a new method of micron-scale, noninvasive imaging based on the measurement of backscattered infrared light, was introduced for the high resolution assessment of structure and function in the developing Xenopus laevis cardiovascular system. Microstructural details, such as ventricular size and wall positions, were delineated with OCT at 16-μm resolution and correlated with histology. Three-dimensional representation of the cardiovascular system also was achieved by repeated cross-sectional imaging at intervals of 25 μm. In addition to structural information, OCT provides high speed in vivo axial ranging and imaging, allowing quantitative dynamic activity, such as ventricular ejection fraction, to be assessed. The sensitivity of OCT for dynamic assessment was demonstrated with an inotropic agent that altered cardiac function and dimensions. Optical coherence tomography is an attractive new technology for assessing cardiovascular development because of its high resolution, its ability to image through nontransparent structures, and its inexpensive portable design. In vivo and in vitro imaging are performed at a resolution approaching that of histopathology without the need for animal killing. PMID:9113976

  6. Regional Assessment of Supplementation Project. Status report

    SciTech Connect

    Not Available

    1991-10-01

    The Fish and Wildlife Program of the Northwest Power Planning Council (NPPC) prescribes several approaches to achieve its goal of doubling the salmon and steelhead runs of the Columbia River. Among those approaches are habitat restoration, improvements in adult and juvenile passage at dams and artificial propagation. Supplementation will be a major part of the new hatchery programs. The purpose of the Regional Assessment of Supplementation Project (RASP) is to provide an overview of ongoing and planned supplementation activities, to construct a conceptual framework and model for evaluating the potential benefits and risks of supplementation and to develop a plan for better regional coordination of research and monitoring and evaluation of supplementation. RASP has completed its first year of work. Progress toward meeting the first year`s objectives and recommendations for future tasks are contained in this report.

  7. Regional Assessment of Supplementation Project : Status Report.

    SciTech Connect

    Unknown author

    1991-10-01

    The Fish and Wildlife Program of the Northwest Power Planning Council (NPPC) prescribes several approaches to achieve its goal of doubling the salmon and steelhead runs of the Columbia River. Among those approaches are habitat restoration, improvements in adult and juvenile passage at dams and artificial propagation. Supplementation will be a major part of the new hatchery programs. The purpose of the Regional Assessment of Supplementation Project (RASP) is to provide an overview of ongoing and planned supplementation activities, to construct a conceptual framework and model for evaluating the potential benefits and risks of supplementation and to develop a plan for better regional coordination of research and monitoring and evaluation of supplementation. RASP has completed its first year of work. Progress toward meeting the first year's objectives and recommendations for future tasks are contained in this report.

  8. Final rapid reactivation project environmental assessment

    SciTech Connect

    1999-02-10

    The US Department of Energy (DOE) has prepared an environmental assessment (EA) for the Rapid Reactivation Project at Sandia National Laboratories, New Mexico. The EA analyzes the potential effects of a proposal to increase production of neutron generators from the current capability of 600 units per year up to 2,000 units per year. The project would use existing buildings and infrastructure to the maximum extent possible to meet the additional production needs. The increased production levels would necessitate modifications and additions involving a total area of approximately 26,290 gross square feet at Sandia National Laboratories, New Mexico, Technical Area 1. Additional production equipment would be procured and installed. The no-action alternative would be to continue production activities at the current capability of 600 units per year. The EA analyzes effects on health, safety, and air quality, resulting from construction and operation and associated cumulative effects. A detailed description of the proposed action and its environmental consequences is presented in the EA.

  9. Flicker stimulated retinal perfusion changes assessed with high-speed Doppler tomography

    NASA Astrophysics Data System (ADS)

    Schmoll, Tilman; Singh, Amardeep S. G.; Frily, Karine; Blatter, Cedric; Villiger, Martin; Pache, Christoph; Lasser, Theo; Leitgeb, R. A.

    2010-02-01

    We developed a high speed Doppler tomography system together with flow extraction algorithms that provide a flexible tool to assess retinal perfusion. The aim of the present study is to stimulate perfusion by flickering with light of adjustable color and to measure changes depending on light frequency and flicker location. We observed relative changes in arterial flow velocity during flicker stimulation up to 50%. We found in arteries close to the optic nerve head the highest flicker response at a frequency of 8Hz. We believe that a multimodal functional imaging concept is of high value for an accurate and early diagnosis and understanding of retinal pathologies and pathogenesis.

  10. Computed tomography-based finite element analysis to assess fracture risk and osteoporosis treatment

    PubMed Central

    Imai, Kazuhiro

    2015-01-01

    Finite element analysis (FEA) is a computer technique of structural stress analysis and developed in engineering mechanics. FEA has developed to investigate structural behavior of human bones over the past 40 years. When the faster computers have acquired, better FEA, using 3-dimensional computed tomography (CT) has been developed. This CT-based finite element analysis (CT/FEA) has provided clinicians with useful data. In this review, the mechanism of CT/FEA, validation studies of CT/FEA to evaluate accuracy and reliability in human bones, and clinical application studies to assess fracture risk and effects of osteoporosis medication are overviewed. PMID:26309819

  11. Computed tomography evaluation of the adrenal gland in the preoperative assessment of bronchogenic carcinoma

    SciTech Connect

    Sandler, M.A.; Pearlberg, J.L.; Madrazo, B.L.; Gitschlag, K.F.; Gross, S.C.

    1982-12-01

    One hundred ten patients with proved bronchogenic carcinoma who were undergoing computed tomography (CT) of the thorax also underwent CT of the adrenals to determine the value of routine preoperative assessement of this gland. Sixteen adrenal masses were found in 11 patients. In five patients the adrenals were the only site of metastasis. CT of the adrenals should be performed routinely when the thorax is examined pre-operatively in patients with non-oat-cell bronchogenic carcinoma to improve patient selection for thoractomy.

  12. [Capabilities of Multidetector Computed Tomography in Assessment of Atherosclerosis of Coronary Arteries].

    PubMed

    Barysheva, N A; Merkulova, I N; Sharia, M A; Veselova, T N

    2015-01-01

    The prevalence of ischemic heart disease (IHD) as well as high mortality from its exacerbations led to an active search and study of diagnostic methods to predict the possible development of acute coronary events. At the moment, it is proved that the morphological properties of atherosclerotic plaque largely determine the course of IHD. Contemporary multidetector computed tomography (MDCT) is the only non-invasive method which allows to study the state of coronary arteries. In this review we have analyzed capabilities of MDCT in assessing the severity of stenosis and calcification in the coronary arteries, as well as the structure of atherosclerotic plaques, including signs of "instability".

  13. [Capabilities of Multidetector Computed Tomography in Assessment of Atherosclerosis of Coronary Arteries].

    PubMed

    Barysheva, N A; Merkulova, I N; Sharia, M A; Veselova, T N

    2015-01-01

    The prevalence of ischemic heart disease (IHD) as well as high mortality from its exacerbations led to an active search and study of diagnostic methods to predict the possible development of acute coronary events. At the moment, it is proved that the morphological properties of atherosclerotic plaque largely determine the course of IHD. Contemporary multidetector computed tomography (MDCT) is the only non-invasive method which allows to study the state of coronary arteries. In this review we have analyzed capabilities of MDCT in assessing the severity of stenosis and calcification in the coronary arteries, as well as the structure of atherosclerotic plaques, including signs of "instability". PMID:26502511

  14. In vivo assessment of human burn scars through automated quantification of vascularity using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Liew, Yih Miin; McLaughlin, Robert A.; Gong, Peijun; Wood, Fiona M.; Sampson, David D.

    2013-06-01

    In scars arising from burns, objective assessment of vascularity is important in the early identification of pathological scarring, and in the assessment of progression and treatment response. We demonstrate the first clinical assessment and automated quantification of vascularity in cutaneous burn scars of human patients in vivo that uses optical coherence tomography (OCT). Scar microvasculature was delineated in three-dimensional OCT images using speckle decorrelation. The diameter and area density of blood vessels were automatically quantified. A substantial increase was observed in the measured density of vasculature in hypertrophic scar tissues (38%) when compared against normal, unscarred skin (22%). A proliferation of larger vessels (diameter≥100 μm) was revealed in hypertrophic scarring, which was absent from normal scars and normal skin over the investigated physical depth range of 600 μm. This study establishes the feasibility of this methodology as a means of clinical monitoring of scar progression.

  15. An assessment of computerized tomography parameters in spinal bone mineralization determination

    SciTech Connect

    Davis, J.S.

    1988-01-01

    This research investigates the effects of changes in clinical parameters on measured bone density values using Quantitative Computed Tomography (QCT). These parameters include changes in patient size, geometry, internal anatomic conditions such as aortic calcifications and bowel gas, gantry slice position and angulation, spin-water bolus air gap distance, and field uniformity effects. It also assesses the reproducibility of the QCT technique on the G.E. 9800 CT scanner as well as the dose to radiosensitive tissues. The CIRS torso phantom was used in each of three size configurations to assess size effects. Mean bone mineral density (BMD) did not significantly vary with phantom size. Variations in patient cross-sectional geometry at constant volume were assessed using a custom manufactured body phantom.

  16. Comparison of different numerical treatments for x-ray phase tomography of soft tissue from differential phase projections

    NASA Astrophysics Data System (ADS)

    Pelliccia, Daniele; Vaz, Raquel; Svalbe, Imants; Morgan, Kaye S.; Marathe, Shashidhara; Xiao, Xianghui; Assoufid, Lahsen; Anderson, Rebecca A.; Topczewski, Jacek; Bryson-Richardson, Robert J.

    2015-04-01

    X-ray imaging of soft tissue is made difficult by their low absorbance. The use of x-ray phase imaging and tomography can significantly enhance the detection of these tissues and several approaches have been proposed to this end. Methods such as analyzer-based imaging or grating interferometry produce differential phase projections that can be used to reconstruct the 3D distribution of the sample refractive index. We report on the quantitative comparison of three different methods to obtain x-ray phase tomography with filtered back-projection from differential phase projections in the presence of noise. The three procedures represent different numerical approaches to solve the same mathematical problem, namely phase retrieval and filtered back-projection. It is found that obtaining individual phase projections and subsequently applying a conventional filtered back-projection algorithm produces the best results for noisy experimental data, when compared with other procedures based on the Hilbert transform. The algorithms are tested on simulated phantom data with added noise and the predictions are confirmed by experimental data acquired using a grating interferometer. The experiment is performed on unstained adult zebrafish, an important model organism for biomedical studies. The method optimization described here allows resolution of weak soft tissue features, such as muscle fibers.

  17. Swept source optical coherence tomography for quantitative and qualitative assessment of dental composite restorations

    NASA Astrophysics Data System (ADS)

    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.

  18. Kalispell Maintenance Headquarters Project : Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration.

    1991-01-01

    The facilities needed to maintain and repair Bonneville Power Administration (BPA's) electrical equipment in northwest Montana are currently in two locations: A maintenance headquarters at the Kalispell Substation, and a temporary leased facility south of Kalispell. The present situation is not efficient. There is not enough space to accommodate the equipment needed at each site, and coordination and communication between the two sites is difficult. Also, two sites means duplication of equipment and facilities. BPA needs a single, centralized facility that would efficiently accommodate all the area's maintenance activities and equipment. BPA proposes to build a maintenance headquarters facility consisting of 2 to 4 single-story buildings totaling about 35,000 square feet (office spaces and workshop areas); an open-ended vehicle storage building (carport style); a fenced-in storage year; a storage building for flammables, herbicides, and hazardous wastes; and a parking lot. The facility would require developing about 6 to 10 acres of land. Two sites are being considered for the proposed project (see the attached map for locations). This report is the environmental assessment of the two options.

  19. Quantitative assessment of the retinal microvasculature using optical coherence tomography angiography

    NASA Astrophysics Data System (ADS)

    Chu, Zhongdi; Lin, Jason; Gao, Chen; Xin, Chen; Zhang, Qinqin; Chen, Chieh-Li; Roisman, Luis; Gregori, Giovanni; Rosenfeld, Philip J.; Wang, Ruikang K.

    2016-06-01

    Optical coherence tomography angiography (OCTA) is clinically useful for the qualitative assessment of the macular microvasculature. However, there is a need for comprehensive quantitative tools to help objectively analyze the OCT angiograms. Few studies have reported the use of a single quantitative index to describe vessel density in OCT angiograms. In this study, we introduce a five-index quantitative analysis of OCT angiograms in an attempt to detect and assess vascular abnormalities from multiple perspectives. The indices include vessel area density, vessel skeleton density, vessel diameter index, vessel perimeter index, and vessel complexity index. We show the usefulness of the proposed indices with five illustrative cases. Repeatability is tested on both a healthy case and a stable diseased case, giving interclass coefficients smaller than 0.031. The results demonstrate that our proposed quantitative analysis may be useful as a complement to conventional OCTA for the diagnosis of disease and monitoring of treatment.

  20. Assessing the Relationship between Ethical Project Management and Information Technology Project Success

    ERIC Educational Resources Information Center

    Howell, Byron Winter

    2010-01-01

    The purpose of this quantitative study was to assess the relationship between ethical project management and information technology (IT) project success. The success of IT projects is important for organizational success, but the rate of IT projects is historically low, costing billions of dollars annually. Using four key ethical variables…

  1. Design and implementation of a custom built optical projection tomography system.

    PubMed

    Wong, Michael D; Dazai, Jun; Walls, Johnathon R; Gale, Nicholas W; Henkelman, R Mark

    2013-01-01

    Optical projection tomography (OPT) is an imaging modality that has, in the last decade, answered numerous biological questions owing to its ability to view gene expression in 3 dimensions (3D) at high resolution for samples up to several cm(3). This has increased demand for a cabinet OPT system, especially for mouse embryo phenotyping, for which OPT was primarily designed for. The Medical Research Council (MRC) Technology group (UK) released a commercial OPT system, constructed by Skyscan, called the Bioptonics OPT 3001 scanner that was installed in a limited number of locations. The Bioptonics system has been discontinued and currently there is no commercial OPT system available. Therefore, a few research institutions have built their own OPT system, choosing parts and a design specific to their biological applications. Some of these custom built OPT systems are preferred over the commercial Bioptonics system, as they provide improved performance based on stable translation and rotation stages and up to date CCD cameras coupled with objective lenses of high numerical aperture, increasing the resolution of the images. Here, we present a detailed description of a custom built OPT system that is robust and easy to build and install. Included is a hardware parts list, instructions for assembly, a description of the acquisition software and a free download site, and methods for calibration. The described OPT system can acquire a full 3D data set in 10 minutes at 6.7 micron isotropic resolution. The presented guide will hopefully increase adoption of OPT throughout the research community, for the OPT system described can be implemented by personnel with minimal expertise in optics or engineering who have access to a machine shop.

  2. Multi-scale volumetric cell and tissue imaging based on optical projection tomography (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Ban, Sungbea; Cho, Nam Hyun; Ryu, Yongjae; Jung, Sunwoo; Vavilin, Andrey; Min, Eunjung; Jung, Woonggyu

    2016-04-01

    Optical projection tomography is a new optical imaging method for visualizing small biological specimens in three dimension. The most important advantage of OPT is to fill the gap between MRI and confocal microscope for the specimen having the range of 1-10 mm. Thus, it has been mainly used for whole-mount small animals and developmental study since this imaging modality was developed. The ability of OPT delivering anatomical and functional information of relatively large tissue in 3D has made it a promising platform in biomedical research. Recently, the potential of OPT spans its coverage to cellular scale. Even though there are increasing demand to obtain better understanding of cellular dynamics, only few studies to visualize cellular structure, shape, size and functional morphology over tissue has been investigated in existing OPT system due to its limited field of view. In this study, we develop a novel optical imaging system for 3D cellular imaging with OPT integrated with dynamic focusing technique. Our tomographic setup has great potential to be used for identifying cell characteristic in tissue because it can provide selective contrast on dynamic focal plane allowing for fluorescence as well as absorption. While the dominant contrast of optical imaging technique is to use the fluorescence for detecting certain target only, the newly developed OPT system will offer considerable advantages over currently available method when imaging cellar molecular dynamics by permitting contrast variation. By achieving multi-contrast, it is expected for this new imaging system to play an important role in delivering better cytological information to pathologist.

  3. Design and implementation of a custom built optical projection tomography system.

    PubMed

    Wong, Michael D; Dazai, Jun; Walls, Johnathon R; Gale, Nicholas W; Henkelman, R Mark

    2013-01-01

    Optical projection tomography (OPT) is an imaging modality that has, in the last decade, answered numerous biological questions owing to its ability to view gene expression in 3 dimensions (3D) at high resolution for samples up to several cm(3). This has increased demand for a cabinet OPT system, especially for mouse embryo phenotyping, for which OPT was primarily designed for. The Medical Research Council (MRC) Technology group (UK) released a commercial OPT system, constructed by Skyscan, called the Bioptonics OPT 3001 scanner that was installed in a limited number of locations. The Bioptonics system has been discontinued and currently there is no commercial OPT system available. Therefore, a few research institutions have built their own OPT system, choosing parts and a design specific to their biological applications. Some of these custom built OPT systems are preferred over the commercial Bioptonics system, as they provide improved performance based on stable translation and rotation stages and up to date CCD cameras coupled with objective lenses of high numerical aperture, increasing the resolution of the images. Here, we present a detailed description of a custom built OPT system that is robust and easy to build and install. Included is a hardware parts list, instructions for assembly, a description of the acquisition software and a free download site, and methods for calibration. The described OPT system can acquire a full 3D data set in 10 minutes at 6.7 micron isotropic resolution. The presented guide will hopefully increase adoption of OPT throughout the research community, for the OPT system described can be implemented by personnel with minimal expertise in optics or engineering who have access to a machine shop. PMID:24023880

  4. Automated patient setup and gating using cone beam computed tomography projections

    NASA Astrophysics Data System (ADS)

    Wan, Hanlin; Bertholet, Jenny; Ge, Jiajia; Poulsen, Per; Parikh, Parag

    2016-03-01

    In radiation therapy, fiducial markers are often implanted near tumors and used for patient positioning and respiratory gating purposes. These markers are then used to manually align the patients by matching the markers in the cone beam computed tomography (CBCT) reconstruction to those in the planning CT. This step is time-intensive and user-dependent, and often results in a suboptimal patient setup. We propose a fully automated, robust method based on dynamic programming (DP) for segmenting radiopaque fiducial markers in CBCT projection images, which are then used to automatically optimize the treatment couch position and/or gating window bounds. The mean of the absolute 2D segmentation error of our DP algorithm is 1.3+/- 1.0 mm for 87 markers on 39 patients. Intrafraction images were acquired every 3 s during treatment at two different institutions. For gated patients from Institution A (8 patients, 40 fractions), the DP algorithm increased the delivery accuracy (96+/- 6% versus 91+/- 11% , p  <  0.01) compared to the manual setup using kV fluoroscopy. For non-gated patients from Institution B (6 patients, 16 fractions), the DP algorithm performed similarly (1.5+/- 0.8 mm versus 1.6+/- 0.9 mm, p  =  0.48) compared to the manual setup matching the fiducial markers in the CBCT to the mean position. Our proposed automated patient setup algorithm only takes 1-2 s to run, requires no user intervention, and performs as well as or better than the current clinical setup.

  5. Assessment and Improvement of Related Services (AIRS) Project. Final Report.

    ERIC Educational Resources Information Center

    McClelland, Robert A.; Hirata, Glenn T.

    The document presents the final report of the Assessment and Improvement of Related Services (AIRS) Project, an effort to assess the impact and effectiveness of special education related services in Hawaii. Each of the four project objectives focused on accomplishment of one of the evaluation types specified in the Context-Input-Process-Product…

  6. Multiple Intelligences: Curriculum and Assessment Project. Final Report

    ERIC Educational Resources Information Center

    Hyland, Aine, Ed.

    2011-01-01

    The "Multiple Intelligences, Curriculum and Assessment Project" at University College Cork was a collaborative project carried out between 1995 and 1999. The key research question focused on whether Howard Gardner's theory of Multiple Intelligences could be applied to, and enhance, aspects of curriculum and assessment at primary and second level…

  7. Investigation of noise properties in grating-based x-ray phase tomography with reverse projection method

    NASA Astrophysics Data System (ADS)

    Bao, Yuan; Wang, Yan; Gao, Kun; Wang, Zhi-Li; Zhu, Pei-Ping; Wu, Zi-Yu

    2015-10-01

    The relationship between noise variance and spatial resolution in grating-based x-ray phase computed tomography (PCT) imaging is investigated with reverse projection extraction method, and the noise variances of the reconstructed absorption coefficient and refractive index decrement are compared. For the differential phase contrast method, the noise variance in the differential projection images follows the same inverse-square law with spatial resolution as in conventional absorption-based x-ray imaging projections. However, both theoretical analysis and simulations demonstrate that in PCT the noise variance of the reconstructed refractive index decrement scales with spatial resolution follows an inverse linear relationship at fixed slice thickness, while the noise variance of the reconstructed absorption coefficient conforms with the inverse cubic law. The results indicate that, for the same noise variance level, PCT imaging may enable higher spatial resolution than conventional absorption computed tomography (ACT), while ACT benefits more from degraded spatial resolution. This could be a useful guidance in imaging the inner structure of the sample in higher spatial resolution. Project supported by the National Basic Research Program of China (Grant No. 2012CB825800), the Science Fund for Creative Research Groups, the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant Nos. KJCX2-YW-N42 and Y4545320Y2), the National Natural Science Foundation of China (Grant Nos. 11475170, 11205157, 11305173, 11205189, 11375225, 11321503, 11179004, and U1332109).

  8. Portfolio Assessment of an Undergraduate Group Project

    ERIC Educational Resources Information Center

    Kuisma, Raija

    2007-01-01

    Students in the Physiotherapy Programme carried out a group project in their final year of studies. The objectives of the project were that the students learn and appreciate the process and activities involved in research, acquire deeper understanding of a topic in their professional interest, learn to work as a team, manage their own time,…

  9. Assessment of the Projects with Industry Program.

    ERIC Educational Resources Information Center

    Reisner, Elizabeth R.; And Others

    A study evaluated the Projects With Industry (PWI) program. (Authorized in 1968 to provide funding opportunities to organizations for the purpose of assisting severely disabled persons in obtaining competitive employment, the PWI program has provided support to projects that involve private sector representatives in the design of placement,…

  10. TH-E-17A-05: Optimizing Four Dimensional Cone Beam Computed Tomography Projection Allocation to Respiratory Bins

    SciTech Connect

    OBrien, R; Shieh, C; Kipritidis, J; Keall, P

    2014-06-15

    Purpose: Four dimensional cone beam computed tomography (4DCBCT) is an emerging image guidance strategy but it can suffer from poor image quality. To avoid repeating scans it is beneficial to make the best use of the imaging data obtained. For conventional 4DCBCT the location and size of respiratory bins is fixed and projections are allocated to the respiratory bin within which it falls. Strictly adhering to this rule is unnecessary and can compromise image quality. In this study we optimize the size and location of respiratory bins and allow projections to be sourced from adjacent phases of the respiratory cycle. Methods: A mathematical optimization framework using mixed integer quadratic programming has been developed that determines when to source projections from adjacent respiratory bins and optimizes the size and location of the bins. The method, which we will call projection sharing, runs in under 2 seconds of CPU time. Five 4DCBCT datasets of stage III-IV lung cancer patients were used to test the algorithm. The standard deviation of the angular separation between projections (SD-A) and the standard deviation in the volume of the reconstructed fiducial gold coil (SD-V) were used as proxies to measure streaking artefacts and motion blur respectively. Results: The SD-A using displacement binning and projection sharing was 30%–50% smaller than conventional phase based binning and 59%–76% smaller than conventional displacement binning indicating more uniformly spaced projections and fewer streaking artefacts. The SD-V was 20–90% smaller when using projection sharing than using conventional phase based binning suggesting more uniform marker segmentation and less motion blur. Conclusion: Image quality was visibly and significantly improved with projection sharing. Projection sharing does not require any modifications to existing hardware and offers a more robust replacement to phase based binning, or, an option if phase based reconstruction is not of a

  11. Optical coherence tomography for assessment of microbicide safety in a small animal model

    PubMed Central

    Bell, Brent A.; Vincent, Kathleen L.; Bourne, Nigel; Vargas, Gracie

    2013-01-01

    Abstract. Sensitive imaging techniques for small animals are needed to assess drug toxicity in preclinical studies. Optical coherence tomography (OCT) provides a noninvasive tool for high-resolution, depth-resolved visualization of drug-induced changes in tissue morphology. In a mouse model, we utilize OCT to assess vaginal tissue integrity following the application of topical microbicides (drugs used to prevent infection). Mice are challenged with herpes simplex virus-2 (HSV-2) to determine the correlation of tissue damage as quantified by OCT to increased susceptibility. The microbicide benzalkonium chloride (BZK) (0.02, 0.2, or 2%) or phosphate buffered saline control is administered intravaginally. In vivo OCT imaging and collection of tissue samples are performed after treatment. A quantitative OCT scoring system is applied to assess epithelial damage, and the results are compared with those of histology. A separate group of mice are treated similarly then challenged with HSV-2. Epithelial morphology quantified noninvasively by OCT and histology are dose-dependent (p<0.0001). The OCT scoring system detected a significant increase in epithelial damage with increasing BZK concentration (p<0.0001). These results paralleled an increase in HSV-2 susceptibility (p<0.005). OCT can be used as a noninvasive tool to assess topical drug toxicity in a small animal model with potential to predict increased susceptibility to vaginal infection. PMID:23588808

  12. Optical coherence tomography for assessment of microbicide safety in a small animal model

    NASA Astrophysics Data System (ADS)

    Bell, Brent A.; Vincent, Kathleen L.; Bourne, Nigel; Vargas, Gracie; Motamedi, Massoud

    2013-04-01

    Sensitive imaging techniques for small animals are needed to assess drug toxicity in preclinical studies. Optical coherence tomography (OCT) provides a noninvasive tool for high-resolution, depth-resolved visualization of drug-induced changes in tissue morphology. In a mouse model, we utilize OCT to assess vaginal tissue integrity following the application of topical microbicides (drugs used to prevent infection). Mice are challenged with herpes simplex virus-2 (HSV-2) to determine the correlation of tissue damage as quantified by OCT to increased susceptibility. The microbicide benzalkonium chloride (BZK) (0.02, 0.2, or 2%) or phosphate buffered saline control is administered intravaginally. In vivo OCT imaging and collection of tissue samples are performed after treatment. A quantitative OCT scoring system is applied to assess epithelial damage, and the results are compared with those of histology. A separate group of mice are treated similarly then challenged with HSV-2. Epithelial morphology quantified noninvasively by OCT and histology are dose-dependent (p<0.0001). The OCT scoring system detected a significant increase in epithelial damage with increasing BZK concentration (p<0.0001). These results paralleled an increase in HSV-2 susceptibility (p<0.005). OCT can be used as a noninvasive tool to assess topical drug toxicity in a small animal model with potential to predict increased susceptibility to vaginal infection.

  13. Transmission and fluorescence angular domain optical projection tomography of turbid media.

    PubMed

    Vasefi, Fartash; Ng, Eldon; Kaminska, Bozena; Chapman, Glenn H; Jordan, Kevin; Carson, Jeffery J L

    2009-11-20

    When imaging through turbid media, objects are often blurred by scattered light. An optical collimator (i.e., an angular filter array) improves images by accepting only photons propagating within a narrow solid angle about the direction of the incident light. These photons are expected to participate in a limited number of small-angle scattering events, maintaining their original propagation direction and, finally, contributing to the development of a faithful image of an object within a turbid medium. The collimation method, also referred to as angular domain imaging (ADI), applies to a see-through configuration where the incident collimated light beam can be aligned with the collimator in a transillumination mode of operation. In this paper, we present angular domain optical projection tomography (ADOPT), a method that can extract depth information of optical contrast in turbid media with high longitudinal resolution based on ADI technology. The resolution of the ADI system has been tested over various depths in a 5 cm optical cuvette using a resolution target suspended in a homogeneous turbid medium. The ADOPT system reconstructed images from a series of angular domain projections collected at angular intervals. The system was used to measure the attenuation of an absorbing target in transmission mode (t-ADOPT) and to measure the light emitting from a fluorescent target (f-ADOPT). Tissue-mimicking phantoms were used to validate the performance of the method. In the t-ADOPT configuration, a background scattered light estimation and subtraction methodology was introduced to improve the imaging contrast. A target consisting of two graphite rods (0.9 mm diameter) was suspended in the cuvette by a rotation stage. An Indocyanine Green-filled glass rod was used as an imaging target in the f-ADOPT arrangement. The target was placed in a manner such that the line of laser light was perpendicular to the longitudinal axis of the rods. Several projections were collected at

  14. Evaluation of dental enamel caries assessment using Quantitative Light Induced Fluorescence and Optical Coherence Tomography.

    PubMed

    Maia, Ana Marly Araújo; de Freitas, Anderson Zanardi; de L Campello, Sergio; Gomes, Anderson Stevens Leônidas; Karlsson, Lena

    2016-06-01

    An in vitro study of morphological alterations between sound dental structure and artificially induced white spot lesions in human teeth, was performed through the loss of fluorescence by Quantitative Light-Induced Fluorescence (QLF) and the alterations of the light attenuation coefficient by Optical Coherence Tomography (OCT). To analyze the OCT images using a commercially available system, a special algorithm was applied, whereas the QLF images were analyzed using the software available in the commercial system employed. When analyzing the sound region against white spot lesions region by QLF, a reduction in the fluorescence intensity was observed, whilst an increase of light attenuation by the OCT system occurred. Comparison of the percentage of alteration between optical properties of sound and artificial enamel caries regions showed that OCT processed images through the attenuation of light enhanced the tooth optical alterations more than fluorescence detected by QLF System. QLF versus OCT imaging of enamel caries: a photonics assessment.

  15. Electron beam computed tomography for assessment of patients presenting to the emergency department with chest pain.

    PubMed

    McCord, James; Amsterdam, Ezra A

    2004-12-01

    Electron beam computed tomography (EBCT) is a unique, noninvasive radiologic method capable of high-resolution imaging that is being increasingly used for evaluation of the cardiovascular system. Among its multiple applications, coronary artery calcium (CAC) imaging has attracted considerable attention because of the potential of this technique for early detection of coronary artery disease (CAD), the leading cause of mortality in our society. Although measurement of CAC has been primarily performed in the outpatient setting in both symptomatic and asymptomatic subjects, several studies have assessed the utility of the method to identify CAD in patients presenting to the emergency department with chest pain suggestive of myocardial ischemia but without objective evidence of the latter. This group comprises a majority of those presenting to the emergency department with chest pain, and their safe, accurate and cost-effective evaluation has been a continuing challenge. PMID:18340176

  16. Experimental assessment of bone mineral density using quantitative computed tomography in holstein dairy cows

    PubMed Central

    MAETANI, Ayami; ITOH, Megumi; NISHIHARA, Kahori; AOKI, Takahiro; OHTANI, Masayuki; SHIBANO, Kenichi; KAYANO, Mitsunori; YAMADA, Kazutaka

    2016-01-01

    The aim of this study was to assess the measurement of bone mineral density (BMD) by quantitative computed tomography (QCT), comparing the relationships of BMD between QCT and dual-energy X-ray absorptiometry (DXA) and between QCT and radiographic absorptiometry (RA) in the metacarpal bone of Holstein dairy cows (n=27). A significant positive correlation was found between QCT and DXA measurements (r=0.70, P<0.01), and a significant correlation was found between QCT and RA measurements (r=0.50, P<0.01). We conclude that QCT provides quantitative evaluation of BMD in dairy cows, because BMD measured by QCT showed positive correlations with BMD measured by the two conventional methods: DXA and RA. PMID:27075115

  17. Assessing the Accuracy of Cone-Beam Computerized Tomography in Measuring Thinning Oral and Buccal Bone.

    PubMed

    Raskó, Zoltán; Nagy, Lili; Radnai, Márta; Piffkó, József; Baráth, Zoltán

    2016-06-01

    The aim of this study was to assess the accuracy and reliability of cone-beam computerized tomography (CBCT) in measuring thinning bone surrounding dental implants. Three implants were inserted into the mandible of a domestic pig at 6 different bone thicknesses on the vestibular and the lingual sides, and measurements were recorded using CBCT. The results were obtained, analyzed, and compared with areas without implants. Our results indicated that the bone thickness and the neighboring implants decreased the accuracy and reliability of CBCT for measuring bone volume around dental implants. We concluded that CBCT slightly undermeasured the bone thickness around the implant, both buccally and orally, compared with the same thickness without the implant. These results support that using the i-CAT NG with a 0.2 voxel size is not accurate for either qualitative or quantitative bone evaluations, especially when the bone is thinner than 0.72 mm in the horizontal dimension.

  18. Environmental Assessment : Happy Valley [Substation Project].

    SciTech Connect

    United States. Bonneville Power Administration.

    1982-05-01

    The proposed Happy Valley project consists of construction of a new BPA customer service 69-kV substation south of Sequim in Clallam County, Washington. A tie line, to be constructed by the customer as part of this project, will link the new BPA facility to the existing customer's transmission system in the area. This project responds to rapid load growth in the Olympic Peninsula, and will strengthen the existing BPA system and interconnected utility systems. It will reduce transmission losses presently incurred, especially on the BPA system supplying power to the Olympic Peninsula. This report describes the potential environmental impact of the proposed actions. 2 figs., 1 tab.

  19. Measurement of changes in blood oxygenation using Multispectral Optoacoustic Tomography (MSOT) allows assessment of tumor development

    NASA Astrophysics Data System (ADS)

    Tomaszewski, Michal R.; Quiros-Gonzalez, Isabel; Joseph, James; Bohndiek, Sarah E.

    2016-03-01

    The ability to evaluate tumor oxygenation in the clinic could indicate prognosis and enable treatment monitoring, since oxygen deficient cancer cells are more resistant to chemotherapy and radiotherapy. MultiSpectral Optoacoustic Tomography (MSOT) is a hybrid technique combining the high contrast of optical imaging with the spatial resolution and penetration depth similar to ultrasound. We aim to demonstrate that MSOT can be used to monitor the development of tumor vasculature. To establish the relationship between MSOT derived imaging biomarkers and biological changes during tumor development, we performed MSOT on nude mice (n=10) bearing subcutaneous xenograft U87 glioblastoma tumors using a small animal optoacoustic tomography system. The mice were maintained under inhalation anesthesia during imaging and respired oxygen content was modified between 21% and 100%. The measurements from early (week 4) and late (week 7) stages of tumor development were compared. To further explore the functionality of the blood vessels, we examined the evolution of changes in the abundance of oxy- and deoxyhemoglobin in the tumors in response to a gas challenge. We found that the kinetics of the change in oxygen saturation (SO2) were significantly different between small tumors and the healthy blood vessels in nearby normal tissue (p=0.0054). Furthermore, we showed that there was a significant difference in the kinetics of the gas challenge between small and large tumors (p=0.0015). We also found that the tumor SO2 was significantly correlated (p=0.0057) with the tumor necrotic fraction as assessed by H&E staining in histology. In the future, this approach may be of use in the clinic as a method for tumor staging and assessment of treatment response.

  20. Solar Resource and Meteorological Assessment Project (SOLRMAP)

    SciTech Connect

    Wilcox, S.

    2008-10-29

    The purpose of this collaborative project between NREL and industry is: (1) provide high quality solar measurements in support of deploying Concentrating Solar Thermal projects; and (2) provide NREL with research-quality data sets for refining solar models and developing solar forecasting capabilities. The benefits of this project are: (1) lends NREL credibility to data sets used for economic analyses and commercial justification; (2) helps minimize costly mistakes in estimating capacity and economic return on investment; (3) helps maximize the development of projects for which adequate solar resources exist; (4) provides data to NREL for research to improve/validate models and explore RA innovations; and (5) helps maintain collaborative channels between NREL and industry.

  1. Assessing Projection Bias in Consumers' Food Preferences.

    PubMed

    de-Magistris, Tiziana; Gracia, Azucena

    2016-01-01

    The aim of this study is to test whether projection bias exists in consumers' purchasing decisions for food products. To achieve our aim, we used a non-hypothetical experiment (i.e., experimental auction), where hungry and non-hungry participants were incentivized to reveal their willingness to pay (WTP). The results confirm the existence of projection bias when consumers made their decisions on food products. In particular, projection bias existed because currently hungry participants were willing to pay a higher price premium for cheeses than satiated ones, both in hungry and satiated future states. Moreover, participants overvalued the food product more when they were delivered in the future hungry condition than in the satiated one. Our study provides clear, quantitative and meaningful evidence of projection bias because our findings are based on economic valuation of food preferences. Indeed, the strength of this study is that findings are expressed in terms of willingness to pay which is an interpretable amount of money.

  2. Technology Assessment Requirements for Programs and Projects

    NASA Technical Reports Server (NTRS)

    Bilbro, James W.

    2006-01-01

    Program/project uncertainty can most simply be defined as the unpredictability of its outcome. As might be expected, the degree of uncertainty depends substantially on program/project type. For hi-tech programs/projects, uncertainty all too frequently translates into schedule slips, cost overruns and occasionally even to cancellations or failures - consummations root cause of such events is often attributed to inadequate definition of requirements. If such were indeed the root cause, then correcting the situation would simply be a matter of requiring better requirements definition, but since history seems frequently to repeat itself, this must not be the case - at least not in total. There are in fact many contributors to schedule slips, cost overruns, project cancellations and failures, among them lack of adequate requirements definition. The case can be made, however, that many of these contributors are related to the degree of uncertainty at the outset of the project. And further, that a dominant factor in the degree of uncertainty is the maturity of the technology required to bring the project to fruition. This presentation discusses the concept of relating degrees of uncertainty to Technology Readiness Levels (TRL) and their associated Advancement Degree of Difficulty (AD2) levels. It also briefly describes a quantifiable process to establish the appropriate TRL for a given technology and quantifies through the AD2 what is required to move it from its current TRL to the desired TRL in order to reduce risk and maximize likelihood of successfully infusing the technology.

  3. Spiral and Project-Based Learning with Peer Assessment in a Computer Science Project Management Course

    ERIC Educational Resources Information Center

    Jaime, Arturo; Blanco, José Miguel; Domínguez, César; Sánchez, Ana; Heras, Jónathan; Usandizaga, Imanol

    2016-01-01

    Different learning methods such as project-based learning, spiral learning and peer assessment have been implemented in science disciplines with different outcomes. This paper presents a proposal for a project management course in the context of a computer science degree. Our proposal combines three well-known methods: project-based learning,…

  4. Rapid maxillary expansion effects: An alternative assessment method by means of cone-beam tomography

    PubMed Central

    Melgaço, Camilo Aquino; Columbano, José; Jurach, Estela Maris; Nojima, Matilde da Cunha Gonçalves; Sant'Anna, Eduardo Franzotti; Nojima, Lincoln Issamu

    2014-01-01

    INTRODUCTION: This study aims to develop a method to assess the changes in palatal and lingual cross-sectional areas in patients submitted to rapid maxillary expansion (RME). METHODS: The sample comprised 31 Class I malocclusion individuals submitted to RME and divided into two groups treated with Haas (17 patients) and Hyrax (14 patients) expanders. Cone-beam computed tomography scans were acquired at T0 (before expansion ) and T1 (six months after screw stabilization). Maxillary and mandibular cross-sectional areas were assessed at first permanent molars and first premolars regions and compared at T0 and T1. Mandibular occlusal area was also analyzed. RESULTS: Maxillary cross-sectional areas increased in 56.18 mm2 and 44.32 mm2 for the posterior and anterior regions. These values were smaller for the mandible, representing augmentation of 40.32 mm2 and 39.91 mm2 for posterior and anterior sections. No differences were found when comparing both expanders. Mandibular occlusal area increased 43.99mm2 and mandibular incisors proclined. Increments of 1.74 mm and 1.7 mm occurred in mandibular intermolar and interpremolar distances. These same distances presented increments of 5.5 mm and 5.57 mm for the maxillary arch. CONCLUSION: Occlusal and cross-sectional areas increased significantly after RME. The method described seems to be reliable and precise to assess intraoral area changes. PMID:25715721

  5. To assess vascular calcification in the patients of hypoparathyroidism using multidetector computed tomography scan

    PubMed Central

    Agarwal, Pooja; Prakash, Mahesh; Singhal, Manphool; Bhadada, Sanjay Kumar; Gupta, Yashdeep; Khandelwal, Niranjan

    2015-01-01

    Background: Our pilot data showed an increased intima media thickness in the patients with sporadic idiopathic hypoparathyroidism (SIH). Alteration in homeostasis of calcium, phosphate, and parathyroid hormone (PTH) may predispose to increase the risk of cardiovascular morbidity and mortality. The data on objective assessment of this increased risk is however lacking. Objective: To assess the effect of altered calcium, phosphate, and PTH homeostasis in the patients with SIH on coronary calcium score (a marker of increase vascular risk) by multidetector computed tomography scan (MDCT). Methods: In this case-control study, we measured coronary CT calcium score in 30 patients of SIH and compared with 40 age and sex matched healthy subjects. Correlation of coronary calcium score with biochemical parameters was evaluated. Results: Three of the 30 cases (10%) with SIH were found to have coronary artery calcification (CAC) of varying degree, whereas none of the control showed CAC (P = 0.07). The patients with CAC had significantly lower serum calcium levels (albumin corrected), as compared to the patients without CAC. Inverse correlation of CAC was found with serum calcium levels. No correlation was found with other biochemical parameters. Conclusion: The vascular risk is increased in the patients with SIH as assessed by coronary calcium score measured by MDCT. Low serum calcium levels might be a predisposing factor for this increased risk. PMID:26693429

  6. Is computed tomography volumetric assessment of the liver reliable in patients with cirrhosis?

    PubMed Central

    Goumard, Claire; Perdigao, Fabiano; Cazejust, Julien; Zalinski, Stéphane; Soubrane, Olivier; Scatton, Olivier

    2014-01-01

    Objectives: The estimation of liver volume (LV) has been widely studied in normal liver, the density of which is considered to be equivalent to 1 kg/l. In cirrhosis, volumetric evaluation and its correlation to liver mass remain unclear. The aim of this study was to evaluate the accuracy of computed tomography (CT) scanning to assess LV in patients with cirrhosis. Methods: Liver volume was evaluated by CT (CTLV) and correlated to the explanted liver weight (LW) in 49 patients. Liver density (LD) and its association with clinical features were analysed. Commonly used formulae for estimating LV were also evaluated. The real density of cirrhotic liver was prospectively measured in explant specimens. Results: Wide variations between CTLV (in ml) and LW (in g) were found (range: 3–748). Cirrhotic livers in patients with hepatitis B virus infection presented significantly increased LD (P = 0.001) with lower CTLV (P = 0.005). Liver volume as measured by CT was also decreased in patients with Model for End-stage Liver Disease scores of >15 (P = 0.023). Formulae estimating LV correlated poorly with CTLV and LW. The density of cirrhotic liver measured prospectively in 15 patients was 1.1 kg/l. Conclusions: In cirrhotic liver, LV assessed by CT did not correspond to real LW. Liver density changed according to the aetiology and severity of liver disease. Commonly used formulae did not accurately assess LV. PMID:23679861

  7. Rhodopsin molecular contrast imaging by optical coherence tomography for functional assessment of photoreceptors (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Nafra, Zahra; Liu, Tan; Jiao, Shuliang

    2016-03-01

    Rhodopsin, the light-sensing molecule in the outer segments of rod photoreceptors, is responsible for converting light into neuronal signals in a process known as phototransduction. Rhodopsin is thus a functional biomarker for rod photoreceptors. We developed a novel technology based on visible-light optical coherence tomography (VIS-OCT) for in vivo molecular imaging of rhodopsin. The depth resolution of OCT allows the visualization of the location where the change of optical absorption occurs and provides a potentially accurate assessment of rhodopsin content by segmentation of the image at the location. A broadband supercontinuum laser, whose filtered output was centered at 520 nm, was used as the illuminating light source. To test the capabilities of the system on rhodopsin mapping we imaged the retina of albino rats. The rats were dark adapted before imaging. An integrated near infrared OCT was used to guide the alignment in dark. VIS-OCT three-dimensional images were then acquired under dark- and light- adapted states sequentially. Rhodopsin distribution was calculated from the differential image. The rhodopsin distributions can be displayed in both en face view and depth-resolved cross-sectional image. Rhodopsin OCT can be used to quantitatively image rhodopsin distribution and thus assess the distribution of functional rod photoreceptors in the retina. Rhodopsin OCT can bring significant impact into ophthalmic clinics by providing a tool for the diagnosis and severity assessment of a variety of retinal conditions.

  8. Trauma management incorporating focused assessment with computed tomography in trauma (FACTT) - potential effect on survival

    PubMed Central

    2010-01-01

    Background Immediate recognition of life-threatening conditions and injuries is the key to trauma management. To date, the impact of focused assessment with computed tomography in trauma (FACTT) has not been formally assessed. We aimed to find out whether the concept of using FACTT during primary trauma survey has a negative or positive effect on survival. Methods In a retrospective, multicentre study, we compared our time management and probability of survival (Ps) in major trauma patients who received FACTT during trauma resuscitation with the trauma registry of the German Trauma Society (DGU). FACTT is defined as whole-body computed tomography (WBCT) during primary trauma survey. We determined the probability of survival according to the Trauma and Injury Severity Score (TRISS), the Revised Injury Severity Classification score (RISC) and the standardized mortality ratio (SMR). Results We analysed 4.817 patients from the DGU database from 2002 until 2004, 160 (3.3%) were from our trauma centre at the Ludwig-Maximilians-University (LMU) and 4.657 (96.7%) from the DGU group. 73.2% were male with a mean age of 42.5 years, a mean ISS of 29.8. 96.2% had suffered from blunt trauma. Time from admission to FAST (focused assessment with sonography for trauma)(4.3 vs. 8.7 min), chest x-ray (8.1 vs. 16.0 min) and whole-body CT (20.7 vs. 36.6 min) was shorter at the LMU compared to the other trauma centres (p < 0.001). SMR calculated by TRISS was 0.74 (CI95% 0.40-1.08) for the LMU (p = 0.24) and 0.92 (CI95% 0.84-1.01) for the DGU group (p = 0.10). RISC methodology revealed a SMR of 0.69 (95%CI 0.47-0.92) for the LMU (p = 0.043) and 1.00 (95%CI 0.94-1.06) for the DGU group (p = 0.88). Conclusion Trauma management incorporating FACTT enhances a rapid response to life-threatening problems and enables a comprehensive assessment of the severity of each relevant injury. Due to its speed and accuracy, FACTT during primary trauma survey supports rapid decision-making and may

  9. Involving Assessment Buddies in the Assessment of Design Project Work

    ERIC Educational Resources Information Center

    Osmond, Jane; Clough, Brian

    2012-01-01

    This paper discusses the impact of a specially developed assessment and feedback system implemented within a second year industrial design module at Coventry University, UK. The "Assessment Buddy" system was developed in response to the need for a successful assessment and feedback method that could cope with the complexities of a creative…

  10. Images of gravitational and magnetic phenomena derived from two-dimensional back-projection Doppler tomography of interacting binary stars

    SciTech Connect

    Richards, Mercedes T.; Cocking, Alexander S.; Fisher, John G.; Conover, Marshall J. E-mail: asc5097@psu.edu

    2014-11-10

    We have used two-dimensional back-projection Doppler tomography as a tool to examine the influence of gravitational and magnetic phenomena in interacting binaries that undergo mass transfer from a magnetically active star onto a non-magnetic main-sequence star. This multitiered study of over 1300 time-resolved spectra of 13 Algol binaries involved calculations of the predicted dynamical behavior of the gravitational flow and the dynamics at the impact site, analysis of the velocity images constructed from tomography, and the influence on the tomograms of orbital inclination, systemic velocity, orbital coverage, and shadowing. The Hα tomograms revealed eight sources: chromospheric emission, a gas stream along the gravitational trajectory, a star-stream impact region, a bulge of absorption or emission around the mass-gaining star, a Keplerian accretion disk, an absorption zone associated with hotter gas, a disk-stream impact region, and a hot spot where the stream strikes the edge of a disk. We described several methods used to extract the physical properties of the emission sources directly from the velocity images, including S-wave analysis, the creation of simulated velocity tomograms from hydrodynamic simulations, and the use of synthetic spectra with tomography to sequentially extract the separate sources of emission from the velocity image. In summary, the tomography images have revealed results that cannot be explained solely by gravitational effects: chromospheric emission moving with the mass-losing star, a gas stream deflected from the gravitational trajectory, and alternating behavior between stream state and disk state. Our results demonstrate that magnetic effects cannot be ignored in these interacting binaries.

  11. The Assessment of Performance in Science Project.

    ERIC Educational Resources Information Center

    Driver, Rosalind; Worsley, Christopher

    1979-01-01

    Described are national methods of assessing and monitoring the achievement in science of students of 11, 13, and 16 years old in England and Wales. The tasks of the Assessment of Performance Unit (APU), a unit within the Department of Education and Science, are also described. (HM)

  12. Using the CAS Standards in Assessment Projects

    ERIC Educational Resources Information Center

    Dean, Laura A.

    2013-01-01

    This chapter provides an overview of the use of professional standards of practice in assessment and of the Council for the Advancement of Standards in Higher Education (CAS). It outlines a model for conducting program self-studies and discusses the importance of implementing change based on assessment results.

  13. Spiral and Project-Based Learning with Peer Assessment in a Computer Science Project Management Course

    NASA Astrophysics Data System (ADS)

    Jaime, Arturo; Blanco, José Miguel; Domínguez, César; Sánchez, Ana; Heras, Jónathan; Usandizaga, Imanol

    2016-06-01

    Different learning methods such as project-based learning, spiral learning and peer assessment have been implemented in science disciplines with different outcomes. This paper presents a proposal for a project management course in the context of a computer science degree. Our proposal combines three well-known methods: project-based learning, spiral learning and peer assessment. Namely, the course is articulated during a semester through the structured (progressive and incremental) development of a sequence of four projects, whose duration, scope and difficulty of management increase as the student gains theoretical and instrumental knowledge related to planning, monitoring and controlling projects. Moreover, the proposal is complemented using peer assessment. The proposal has already been implemented and validated for the last 3 years in two different universities. In the first year, project-based learning and spiral learning methods were combined. Such a combination was also employed in the other 2 years; but additionally, students had the opportunity to assess projects developed by university partners and by students of the other university. A total of 154 students have participated in the study. We obtain a gain in the quality of the subsequently projects derived from the spiral project-based learning. Moreover, this gain is significantly bigger when peer assessment is introduced. In addition, high-performance students take advantage of peer assessment from the first moment, whereas the improvement in poor-performance students is delayed.

  14. Preliminary assessment of potential CDM early start projects in Brazil

    SciTech Connect

    Meyers, S.; Sathaye, J.; Lehman, B.; Schumacher, K.; van Vliet, O.; Moreira, J.R.

    2000-11-01

    The Brazil/US Aspen Global Forum on Climate Change Policies and Programs has facilitated a dialogue between key Brazil and US public and private sector leaders on the subject of the Clean Development Mechanism (CDM). With support from the US government, a cooperative effort between Lawrence Berkeley National Laboratory and the University of Sao Paulo conducted an assessment of a number of projects put forth by Brazilian sponsors. Initially, we gathered information and conducted a screening assessment for ten projects in the energy sector and six projects in the forestry sector. Some of the projects appeared to offer greater potential to be attractive for CDM, or had better information available. We then conducted a more detailed assessment of 12 of these projects, and two other projects that were submitted after the initial screening. An important goal was to assess the potential impact of Certified Emission Reductions (CERs) on the financial performance of projects. With the exception of the two forestry-based fuel displacement projects, the impact of CERs on the internal rate of return (IRR) is fairly small. This is true for both the projects that displace grid electricity and those that displace local (diesel-based) electricity production. The relative effect of CERs is greater for projects whose IRR without CERs is low. CERs have a substantial effect on the IRR of the two short-rotation forestry energy substitution projects. One reason is that the biofuel displaces coke and oil, both of which are carbon-intensive. Another factor is that the product of these projects (charcoal and woodfuel, respectively) is relatively low value, so the revenue from carbon credits has a strong relative impact. CERs also have a substantial effect on the NPV of the carbon sequestration projects. Financial and other barriers pose a challenge for implementation of most of the projects. In most cases, the sponsor lacks sufficient capital, and loans are available only at high interest

  15. Novel Assessment of Renal Motion in Children as Measured via Four-Dimensional Computed Tomography

    SciTech Connect

    Pai Panandiker, Atmaram S.; Sharma, Shelly; Naik, Mihir H.; Wu, Shengjie; Hua, Chiaho; Beltran, Chris; Krasin, Matthew J.; Merchant, Thomas E.

    2012-04-01

    Objectives: Abdominal intensity-modulated radiation therapy and proton therapy require quantification of target and organ motion to optimize localization and treatment. Although addressed in adults, there is no available literature on this issue in pediatric patients. We assessed physiologic renal motion in pediatric patients. Methods and Materials: Twenty free-breathing pediatric patients at a median age of 8 years (range, 2-18 years) with intra-abdominal tumors underwent computed tomography simulation and four-dimensional computed tomography acquisition (slice thickness, 3 mm). Kidneys and diaphragms were contoured during eight phases of respiration to estimate center-of-mass motion. We quantified center of kidney mass mobility vectors in three dimensions: anteroposterior (AP), mediolateral (ML), and superoinferior (SI). Results: Kidney motion decreases linearly with decreasing age and height. The 95% confidence interval for the averaged minima and maxima of renal motion in children younger than 9 years was 5-9 mm in the ML direction, 4-11 mm in the AP direction, and 12-25 mm in the SI dimension for both kidneys. In children older than 9 years, the same confidence interval reveals a widening range of motion that was 5-16 mm in the ML direction, 6-17 mm in the AP direction, and 21-52 mm in the SI direction. Although not statistically significant, renal motion correlated with diaphragm motion in older patients. The correlation between diaphragm motion and body mass index was borderline (r = 0.52, p = 0.0816) in younger patients. Conclusions: Renal motion is age and height dependent. Measuring diaphragmatic motion alone does not reliably quantify pediatric renal motion. Renal motion in young children ranges from 5 to 25 mm in orientation-specific directions. The vectors of motion range from 5 to 52 mm in older children. These preliminary data represent novel analyses of pediatric intra-abdominal organ motion.

  16. Regional myocardial metabolism in patients with acute myocardial infarction assessed by positron emission tomography

    SciTech Connect

    Schwaiger, M.; Brunken, R.; Grover-McKay, M.; Krivokapich, J.; Child, J.; Tillisch, J.H.; Phelps, M.E.; Schelbert, H.R.

    1986-10-01

    Positron emission tomography has been shown to distinguish between reversible and irreversible ischemic tissue injury. Using this technique, 13 patients with acute myocardial infarction were studied within 72 hours of onset of symptoms to evaluate regional blood flow and glucose metabolism with nitrogen (N)-13 ammonia and fluorine (F)-18 deoxyglucose, respectively. Serial noninvasive assessment of wall motion was performed to determine the prognostic value of metabolic indexes for functional tissue recovery. Segmental blood flow and glucose utilization were evaluated using a circumferential profile technique and compared with previously established semiquantitative criteria. Relative N-13 ammonia uptake was depressed in 32 left ventricular segments. Sixteen segments demonstrated a concordant decrease in flow and glucose metabolism. Regional function did not change over time in these segments. In contrast, 16 other segments with reduced blood flow revealed maintained F-18 deoxyglucose uptake consistent with remaining viable tissue. The average wall motion score improved significantly in these segments (p less than 0.01), yet the degree of recovery varied considerably among patients. Coronary anatomy was defined in 9 of 13 patients: patent infarct vessels supplied 8 of 10 segments with F-18 deoxyglucose uptake, while 10 of 13 segments in the territory of an occluded vessel showed concordant decreases in flow and metabolism (p less than 0.01). Thus, positron emission tomography reveals a high incidence of residual tissue viability in ventricular segments with reduced flow and impaired function during the subacute phase of myocardial infarction. Absence of residual tissue metabolism is associated with irreversible injury, while preservation of metabolic activity identifies segments with a variable outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Neutron Tomography Using Mobile Neutron Generators for Assessment of Void Distributions in Thermal Hydraulic Test Loops

    NASA Astrophysics Data System (ADS)

    Andersson, P.; Bjelkenstedt, T.; Sundén, E. Andersson; Sjöstrand, H.; Jacobsson-Svärd, S.

    Detailed knowledge of the lateral distribution of steam (void) and water in a nuclear fuel assembly is of great value for nuclear reactor operators and fuel manufacturers, with consequences for both reactor safety and economy of operation. Therefore, nuclear relevant two-phase flows are being studied at dedicated thermal-hydraulic test loop, using two-phase flow systems ranging from simplified geometries such as heated circular pipes to full scale mock-ups of nuclear fuel assemblies. Neutron tomography (NT) has been suggested for assessment of the lateral distribution of steam and water in such test loops, motivated by a good ability of neutrons to penetrate the metallic structures of metal pipes and nuclear fuel rod mock-ups, as compared to e.g. conventional X-rays, while the liquid water simultaneously gives comparatively good contrast. However, these stationary test loops require the measurement setup to be mobile, which is often not the case for NT setups. Here, it is acknowledged that fast neutrons of 14 MeV from mobile neutron generators constitute a viable option for a mobile NT system. We present details of the development of neutron tomography for this purpose at the division of Applied Nuclear Physics at Uppsala University. Our concept contains a portable neutron generator, exploiting the fusion reaction of deuterium and tritium, and a detector with plastic scintillator elements designed to achieveadequate spatial and energy resolution, all mounted in a light-weight frame without collimators or bulky moderation to allow for a mobile instrument that can be moved about the stationary thermal hydraulic test sections. The detector system stores event-to-event pulse-height information to allow for discrimination based on the energy deposition in the scintillator elements.

  18. Changes in root canal geometry after preparation assessed by high-resolution computed tomography.

    PubMed

    Peters, O A; Laib, A; Göhring, T N; Barbakow, F

    2001-01-01

    Root canal morphology changes during canal preparation, and these changes may vary depending on the technique used. Such changes have been studied in vitro by measuring cross-sections of canals before and after preparation. This current study used nondestructive high-resolution scanning tomography to assess changes in the canals' paths after preparation. A microcomputed tomography scanner (cubic resolution 34 microm) was used to analyze 18 canals in 6 extracted maxillary molars. Canals were scanned before and after preparation using either K-Files, Lightspeed, or ProFile .04 rotary instruments. A special mounting device enabled precise repositioning and scanning of the specimens after preparation. Differences in surface area (deltaA in mm2) and volume (deltaV in mm3) of each canal before and after preparation were calculated using custom-made software. deltaV ranged from 0.64 to 2.86, with a mean of 1.61 +/- 0.7, whereas deltaA varied from 0.72 to 9.66, with a mean of 4.16 +/- 2.63. Mean deltaV and deltaA for the K-File, ProFile, and Lightspeed groups were 1.28 +/- 0.57 and 2.58 +/- 1.83; 1.79 +/- 0.66 and 4.86 +/- 2.53; and 1.81 +/- 0.57 and 5.31 +/- 2.98, respectively. Canal anatomy and the effects of preparation were further analyzed using the Structure Model Index and the Transportation of Centers of Mass. Under the conditions of this study variations in canal geometry before preparation had more influence on the changes during preparation than the techniques themselves. Consequently studies comparing the effects of root canal instruments on canal anatomy should also consider details of the preoperative canal geometry. PMID:11487156

  19. Positron emission tomography (PET) for assessing aerosol deposition of orally inhaled drug products.

    PubMed

    Dolovich, Myrna B; Bailey, Dale L

    2012-12-01

    The topical distribution of inhaled therapies in the lung can be viewed using radionuclides and imaging. Positron emission tomography (PET) is a three-dimensional functional imaging technique providing quantitatively accurate localization of the quantity and distribution of an inhaled or injected PET radiotracer in the lung. A series of transaxial slices through the lungs are obtained, comparable to an X-ray computed tomography (CT) scan. Subsequent reformatting allows coronal and sagittal images of the distribution of radioactivity to be viewed. This article describes procedures for administering [(18)F]-fluorodeoxyglucose aerosol to human subjects for the purpose of determining dose and distribution following inhalation from an aerosol drug delivery device (ADDD). The advantages of using direct-labeled PET drugs in the ADDD are discussed with reference to the literature. The methods for designing the inhalation system, determining proper radiation shielding, calibration, and validation of administered radioactivity, scanner setup, and data handling procedures are described. Obtaining an X-ray CT or radionuclide transmission scan to provide accurate geometry of the lung and also correct for tissue attenuation of the PET radiotracer is discussed. Protocols for producing accurate images, including factors that need to be incorporated into the data calibration, are described, as well as a proposed standard method for partitioning the lung into regions of interest. Alternate methods are described for more detailed assessments. Radiation dosimetry/risk calculations for the procedures are appended, as well as a sample data collection form and spreadsheet for calculations. This article should provide guidance for those interested in using PET to determine quantity and distribution of inhaled therapeutics. PMID:23215847

  20. Assessing Projection Bias in Consumers’ Food Preferences

    PubMed Central

    de-Magistris, Tiziana; Gracia, Azucena

    2016-01-01

    The aim of this study is to test whether projection bias exists in consumers’ purchasing decisions for food products. To achieve our aim, we used a non-hypothetical experiment (i.e., experimental auction), where hungry and non-hungry participants were incentivized to reveal their willingness to pay (WTP). The results confirm the existence of projection bias when consumers made their decisions on food products. In particular, projection bias existed because currently hungry participants were willing to pay a higher price premium for cheeses than satiated ones, both in hungry and satiated future states. Moreover, participants overvalued the food product more when they were delivered in the future hungry condition than in the satiated one. Our study provides clear, quantitative and meaningful evidence of projection bias because our findings are based on economic valuation of food preferences. Indeed, the strength of this study is that findings are expressed in terms of willingness to pay which is an interpretable amount of money. PMID:26828930

  1. Absorption Reconstruction Improves Biodistribution Assessment of Fluorescent Nanoprobes Using Hybrid Fluorescence-mediated Tomography

    PubMed Central

    Gremse, Felix; Theek, Benjamin; Kunjachan, Sijumon; Lederle, Wiltrud; Pardo, Alessa; Barth, Stefan; Lammers, Twan; Naumann, Uwe; Kiessling, Fabian

    2014-01-01

    Aim: Fluorescence-mediated tomography (FMT) holds potential for accelerating diagnostic and theranostic drug development. However, for proper quantitative fluorescence reconstruction, knowledge on optical scattering and absorption, which are highly heterogeneous in different (mouse) tissues, is required. We here describe methods to assess these parameters using co-registered micro Computed Tomography (µCT) data and nonlinear whole-animal absorption reconstruction, and evaluate their importance for assessment of the biodistribution and target site accumulation of fluorophore-labeled drug delivery systems. Methods: Besides phantoms with varying degrees of absorption, mice bearing A431 tumors were imaged 15 min and 48 h after i.v. injection of a fluorophore-labeled polymeric drug carrier (pHPMA-Dy750) using µCT-FMT. The outer shape of mice and a scattering map were derived using automated segmentation of the µCT data. Furthermore, a 3D absorption map was reconstructed from the trans-illumination data. We determined the absorption of five interactively segmented regions (heart, liver, kidney, muscle, tumor). Since blood is the main near-infrared absorber in vivo, the absorption was also estimated from the relative blood volume (rBV), determined by contrast-enhanced µCT. We compared the reconstructed absorption with the rBV-based values and analyzed the effect of using the absorption map on the fluorescence reconstruction. Results: Phantom experiments demonstrated that absorption reconstruction is possible and necessary for quantitative fluorescence reconstruction. In vivo, the reconstructed absorption showed high values in strongly blood-perfused organs such as the heart, liver and kidney. The absorption values correlated strongly with the rBV-based absorption values, confirming the accuracy of the absorption reconstruction. Usage of homogenous absorption instead of the reconstructed absorption map resulted in reduced values in the heart, liver and kidney, by

  2. Computed tomography of the brain, chest, and abdomen in the preoperative assessment of non-small cell lung cancer.

    PubMed Central

    Grant, D; Edwards, D; Goldstraw, P

    1988-01-01

    The benefit to be gained from carrying out computed tomography of brain and abdomen in addition to the chest has been evaluated retrospectively in 114 consecutive patients with non-small cell lung cancer who, on the basis of history, clinical examination, chest radiography, and bronchoscopy had been considered potentially operable. Computed tomography of the chest showed potentially inoperable tumour in 37 patients, of whom 25 had tumour confined to the chest. Three patients were shown to have malignant disease within the mediastinum and abdomen; five within the mediastinum and brain; and four within the mediastinum, abdomen, and brain. Computed tomography of the abdomen disclosed deposits in nine patients, but in only two were the abnormalities restricted to the abdomen. Computed tomography of the brain showed metastases in 10 patients, of whom only one had metastatic disease confined to the brain. Thus three patients had isolated deposits in the abdomen and brain. In 12 patients the identification of metastases in the abdomen and brain removed the need for mediastinoscopy. Preoperative computed tomography of the abdomen and brain detected occult metastases in 15 patients (13%) in this study. In three patients the extrathoracic abnormality proved the only contraindication to surgery, but in the other 12 it provided valuable corroborative evidence of incurability and facilitated the assessment of the mediastinal abnormality. PMID:2851880

  3. Assessment of murine bone ultrastructure using synchrotron light: towards nano-computed tomography

    NASA Astrophysics Data System (ADS)

    Schneider, Philipp; Voide, Romain; Stauber, Martin; Stampanoni, Marco; Donahue, Leah Rae; Wyss, Peter; Sennhauser, Urs; Müller, Ralph

    2006-08-01

    To describe the different aspects of bone quality, we follow a hierarchical approach and assess bone tissue properties in different regimes of spatial resolution, beginning at the organ level and going down to cellular dimensions. For these purposes we developed different synchrotron radiation (SR) based computed-tomography (CT) methods to assess murine bone ultrastructure. In a first step, a tubular system and the osteocyte lacunar system within murine cortical bone have been established as novel ultrastructural quantitative traits. Results in two mouse strains showed that morphometry of these quantitative traits was dependent on strain and partially on gender, and that their scaling behavior with bone size was fundamentally different. In a second step, we explored bone competence on an ultrastructural level and related our findings to the two ultrastructural quantitative traits introduced before. We showed that SR CT imaging is a powerful tool to investigate the initiation and propagation of microcracks, which may alter bone quality and may lead to increased fracture risk by means of microdamage accumulation. In summary, investigation of ultrastructural bone tissue properties will eventually lead to a better understanding of bone quality and its relative contribution to bone competence.

  4. Comparison between multislice and cone-beam computerized tomography in the volumetric assessment of cleft palate.

    PubMed

    Albuquerque, Marco Antonio; Gaia, Bruno Felipe; Cavalcanti, Marcelo Gusmão Paraíso

    2011-08-01

    The aim of this study was to determine the applicability of multislice and cone-beam computerized tomography (CT) in the assessment of bone defects in patients with oral clefts. Bone defects were produced in 9 dry skulls to mimic oral clefts. All defects were modeled with wax. The skulls were submitted to multislice and cone-beam CT. Subsequently, physical measurements were obtained by the Archimedes principle of water displacement of wax models. The results demonstrated that multislice and cone-beam CT showed a high efficiency rate and were considered to be effective for volumetric assessment of bone defects. It was also observed that both CT modalities showed excellent results with high reliability in the study of the volume of bone defects, with no difference in performance between them. The clinical applicability of our research has shown these CT modalities to be immediate and direct, and they is important for the diagnosis and therapeutic process of patients with oral cleft. PMID:21664153

  5. Hardware Implementation of Multiple Fan Beam Projection Technique in Optical Fibre Process Tomography

    PubMed Central

    Rahim, Ruzairi Abdul; Fazalul Rahiman, Mohd Hafiz; Leong, Lai Chen; Chan, Kok San; Pang, Jon Fea

    2008-01-01

    The main objective of this project is to implement the multiple fan beam projection technique using optical fibre sensors with the aim to achieve a high data acquisition rate. Multiple fan beam projection technique here is defined as allowing more than one emitter to transmit light at the same time using the switch-mode fan beam method. For the thirty-two pairs of sensors used, the 2-projection technique and 4-projection technique are being investigated. Sixteen sets of projections will complete one frame of light emission for the 2-projection technique while eight sets of projection will complete one frame of light emission for the 4-projection technique. In order to facilitate data acquisition process, PIC microcontroller and the sample and hold circuit are being used. This paper summarizes the hardware configuration and design for this project.

  6. Assessment of coronary plaque collagen with polarization sensitive optical coherence tomography (PS-OCT)

    NASA Astrophysics Data System (ADS)

    Giattina, Susanne D.; Courtney, Brian K.; Herz, Paul R.; Harman, Michelle; Shortkroff, Sonya; Stamper, Debra L.; Liu, Bin; Fujimoto, James G.; Brezinski, Mark E.

    2006-02-01

    Current evidence indicates that most plaques classified as vulnerable or ruptured plaques do not lead to unstable angina or myocardial infarction. Improved methods are needed to risk stratify plaques to identify those which lead to most acute coronary syndromes. Collagen depletion in the intima overlying lipid collections appears to be a critical component of unstable plaques. In this study, we use polarization sensitive optical coherence tomography (PS-OCT) for the assessment of coronary plaque collagen. Collagen is birefringent, meaning that different polarization states travel through it at different velocities. Changes in PS-OCT images are a measure of tissue birefringence. Twenty-two coronary artery segments were imaged with PS-OCT and analyzed by picrosirius staining (a measure of collagen intensity and fiber size) and trichrome blue. The regression plot between PS-OCT changes and measured collagen yielded a correlation coefficient value of 0.475 (p<0.002). Good correlation was noted between two blinded investigators both with respect to PS-OCT measurements as well as luminosity as assessed by picrosirius. The predictive value of a PS-OCT measurement of negligible birefringence (less than 33% change) for minimal collagen was 93% while the predictive value of high birefringence (greater than 66% change) for high collagen concentrations was 89%. The effect of fiber type (chemical composition) was minimal relative to the effect due to fiber concentration. The capability of PS-OCT to assess plaque collagen content, in addition to its ability to generate high resolution structural assessments, make it a potentially powerful technology for identifying high risk plaques.

  7. High-definition optical coherence tomography intrinsic skin ageing assessment in women: a pilot study.

    PubMed

    Boone, M A L M; Suppa, M; Marneffe, A; Miyamoto, M; Jemec, G B E; Del Marmol, V

    2015-10-01

    Several non-invasive two-dimensional techniques with different lateral resolution and measurable depth range have proved to be useful in assessing and quantifying morphological changes in skin ageing. Among these, only in vivo microscopy techniques permit histometric measurements in vivo. Qualitative and quantitative assessment of chronological (intrinsic) age-related (IAR) morphological changes of epidermis, dermo-epidermal junction (DEJ), papillary dermis (PD), papillary-reticular dermis junction and reticular dermis (RD) have been performed by high-definition optical coherence tomography in real time 3-D. HD-OCT images were taken at the internal site of the right upper arm. Qualitative HD-OCT IAR descriptors were reported at skin surface, at epidermal layer, DEJ, PD and upper RD. Quantitative evaluation of age-related compaction and backscattered intensity or brightness of different skin layers was performed by using the plugin plot z-axis profile of ImageJ(®) software permitting intensity assessment of HD-OCT (DICOM) images (3-D images). Analysis was in blind from all clinical information. Sixty, fair-skinned (Fitzpatrick types I-III) healthy females were analysed retrospectively in this study. The subjects belonged to three age groups: twenty in group I aged 20-39, twenty in group II aged 40-59 and twenty in group III aged 60-79. Only intrinsic ageing in women has been studied. Significant age-related qualitative and quantitative differences could be noticed. IAR changes in dermal matrix fibers morphology/organisation and in microvasculature were observed. The brightness and compaction of the different skin layers increased significantly with intrinsic skin ageing. The depth of visibility of fibers in RD increased significantly in the older age group. In conclusion, HD-OCT allows 3-D in vivo and real time qualitative and quantitative assessment of chronological (intrinsic) age-related morphological skin changes at high resolution from skin surface to a depth

  8. Project 6: Cumulative Risk Assessment (CRA) Methods and Applications

    EPA Science Inventory

    Project 6: CRA Methods and Applications addresses the need to move beyond traditional risk assessment practices by developing CRA methods to integrate and evaluate impacts of chemical and nonchemical stressors on the environment and human health. Project 6 has three specific obje...

  9. Undergraduate Lab Project in Personality Assessment: Measurement of Anal Character.

    ERIC Educational Resources Information Center

    Davidson, William B.

    1987-01-01

    This article describes a project which required students to write assessment items for a personality inventory. The 104 items generated were administered to 126 subjects. Results showed the items were reasonably reliable and valid. The pedagogical value of the project is discussed. (Author/JDH)

  10. The ECLSS Advanced Automation Project Evolution and Technology Assessment

    NASA Technical Reports Server (NTRS)

    Dewberry, Brandon S.; Carnes, James R.; Lukefahr, Brenda D.; Rogers, John S.; Rochowiak, Daniel M.; Mckee, James W.; Benson, Brian L.

    1990-01-01

    Viewgraphs on Environmental Control and Life Support System (ECLSS) advanced automation project evolution and technology assessment are presented. Topics covered include: the ECLSS advanced automation project; automatic fault diagnosis of ECLSS subsystems descriptions; in-line, real-time chemical and microbial fluid analysis; and object-oriented, distributed chemical and microbial modeling of regenerative environmental control systems description.

  11. Antelope-Fossil Rebuild Project : Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration.

    1992-04-01

    The Columbia Power Cooperative Association (CPCA), Monument, Oregon, proposes to upgrade a 69-kV transmission line in Wasco and Wheeler Counties, Oregon, between the Antelope Substation and the Bonneville Power Administration's (BPA) Fossil Substation. The project involves rebuilding and reconductoring 23.2 miles of transmission line, including modifying it for future use at 115 kV. Related project activities will include setting new wood pole structures, removing and disposing of old structures, conductors, and insulators, and stringing new conductor, all within the existing right-of-way. No new access roads will be required. A Borrower's Environmental Report was prepared for the 1992--1993 Work Plan for Columbia Power Cooperative Association in March 1991. This report investigated cultural resources, threatened or endangered species, wetlands, and floodplains, and other environmental issues, and included correspondence with appropriate Federal, state, and local agencies. The report was submitted to the Rural Electrification Administration for their use in preparing their environmental documentation for the project.

  12. Antelope-Fossil Rebuild Project : Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration.

    1992-04-01

    The Columbia Power Cooperative Association (CPCA), Monument, Oregon, proposes to upgrade a 69-kV transmission line in Wasco and Wheeler Counties, Oregon, between the Antelope Substation and the Bonneville Power Administration`s (BPA) Fossil Substation. The project involves rebuilding and reconductoring 23.2 miles of transmission line, including modifying it for future use at 115 kV. Related project activities will include setting new wood pole structures, removing and disposing of old structures, conductors, and insulators, and stringing new conductor, all within the existing right-of-way. No new access roads will be required. A Borrower`s Environmental Report was prepared for the 1992--1993 Work Plan for Columbia Power Cooperative Association in March 1991. This report investigated cultural resources, threatened or endangered species, wetlands, and floodplains, and other environmental issues, and included correspondence with appropriate Federal, state, and local agencies. The report was submitted to the Rural Electrification Administration for their use in preparing their environmental documentation for the project.

  13. On the computational implementation of forward and back-projection operations for cone-beam computed tomography.

    PubMed

    Karimi, Davood; Ward, Rabab

    2016-08-01

    Forward- and back-projection operations are the main computational burden in iterative image reconstruction in computed tomography. In addition, their implementation has to be accurate to ensure stable convergence to a high-quality image. This paper reviews and compares some of the variations in the implementation of these operations in cone-beam computed tomography. We compare four algorithms for computing the system matrix, including a distance-driven algorithm, an algorithm based on cubic basis functions, another based on spherically symmetric basis functions, and a voxel-driven algorithm. The focus of our study is on understanding how the choice of the implementation of the system matrix will influence the performance of iterative image reconstruction algorithms, including such factors as the noise strength and spatial resolution in the reconstructed image. Our experiments with simulated and real cone-beam data reveal the significance of the speed-accuracy trade-off in the implementation of the system matrix. Our results suggest that fast convergence of iterative image reconstruction methods requires accurate implementation of forward- and back-projection operations, involving a direct estimation of the convolution of the footprint of the voxel basis function with the surface of the detectors. The required accuracy decreases by increasing the resolution of the projection measurements beyond the resolution of the reconstructed image. Moreover, reconstruction of low-contrast objects needs more accurate implementation of these operations. Our results also show that, compared with regularized reconstruction methods, the behavior of iterative reconstruction algorithms that do not use a proper regularization is influenced more significantly by the implementation of the forward- and back-projection operations.

  14. Assessing the horizontal refraction of ocean acoustic tomography signals using high-resolution ocean state estimates.

    PubMed

    Dushaw, Brian D

    2014-07-01

    The analysis of signals for acoustic tomography sent between a source and a receiver most often uses the unrefracted geodesic path, an approximation that is justified from theoretical considerations, relying on estimates of horizontal gradients of sound speed, or on simple theoretical models. To quantify the effects of horizontal refraction caused by a realistic ocean environment, horizontal refractions of long-range signals were computed using global ocean state estimates for 2004 from the Estimating the Circulation and Climate of the Ocean (ECCO2) project. Basin-scale paths in the eastern North Pacific Ocean and regional-scale paths in the Philippine Sea were used as examples. At O(5 Mm) basin scales, refracted geodesic and geodesic paths differed by only about 5 km. Gyre-scale features had the greatest refractive influence, but the precise refractive effects depended on the path geometry with respect to oceanographic features. Refraction decreased travel times by 5-10 ms and changed azimuthal angles by about 0.2°. At O(500 km) regional scales, paths deviated from the geodesic by only 250 m, and travel times deviated by less than 0.5 ms. Such effects are of little consequence in the analysis of tomographic data. Refraction details depend only slightly on mode number and frequency. PMID:24993200

  15. Micro-computed tomography assessment of fracture healing: relationships among callus structure, composition, and mechanical function.

    PubMed

    Morgan, Elise F; Mason, Zachary D; Chien, Karen B; Pfeiffer, Anthony J; Barnes, George L; Einhorn, Thomas A; Gerstenfeld, Louis C

    2009-02-01

    Non-invasive characterization of fracture callus structure and composition may facilitate development of surrogate measures of the regain of mechanical function. As such, quantitative computed tomography- (CT-) based analyses of fracture calluses could enable more reliable clinical assessments of bone healing. Although previous studies have used CT to quantify and predict fracture healing, it is unclear which of the many CT-derived metrics of callus structure and composition are the most predictive of callus mechanical properties. The goal of this study was to identify the changes in fracture callus structure and composition that occur over time and that are most closely related to the regain of mechanical function. Micro-computed tomography (microCT) imaging and torsion testing were performed on murine fracture calluses (n=188) at multiple post-fracture timepoints and under different experimental conditions that alter fracture healing. Total callus volume (TV), mineralized callus volume (BV), callus mineralized volume fraction (BV/TV), bone mineral content (BMC), tissue mineral density (TMD), standard deviation of mineral density (sigma(TMD)), effective polar moment of inertia (J(eff)), torsional strength, and torsional rigidity were quantified. Multivariate statistical analyses, including multivariate analysis of variance, principal components analysis, and stepwise regression were used to identify differences in callus structure and composition among experimental groups and to determine which of the microCT outcome measures were the strongest predictors of mechanical properties. Although calluses varied greatly in the absolute and relative amounts of mineralized tissue (BV, BMC, and BV/TV), differences among timepoints were most strongly associated with changes in tissue mineral density. Torsional strength and rigidity were dependent on mineral density as well as the amount of mineralized tissue: TMD, BV, and sigma(TMD) explained 62% of the variation in

  16. Needs Assessment Project: FY83 Reverification Study.

    ERIC Educational Resources Information Center

    Shively, Joe E.

    As part of a continuing assessment of educational needs in a seven-state region, researchers conducted a reverification study to check the validity of educational needs first identified in fiscal year (FY) 1980. The seven states are Alabama, Kentucky, Ohio, Pennsylvania, Tennessee, Virginia, and West Virginia. The original FY80 Needs Assessment…

  17. Needs Assessment Project: FY 82 Verification Study.

    ERIC Educational Resources Information Center

    Shively, Joe E.; O'Donnell, Phyllis

    As part of a continuing assessment of educational needs in a seven-state region, researchers conducted a verification study to check the validity of educational needs first identified in fiscal year (FY) 1980. The seven states comprise Alabama, Kentucky, Ohio, Pennsylvania, Tennessee, Virginia, and West Virginia. This report describes assessment…

  18. The West Virginia Health Education Assessment Project

    ERIC Educational Resources Information Center

    Tompkins, Nancy O'Hara; Kamal, Khalid M.; Chapman, Don

    2005-01-01

    Well-designed school health education should provide students with the knowledge and skills to prevent the health risk behaviors most responsible for the major causes of morbidity and mortality. This paper reports the methodology and findings of a West Virginia statewide health education assessment initiative and describes how the findings are…

  19. Perioperative Computed Tomography Assessments of the Pancreas Predict Nonalcoholic Fatty Liver Disease After Pancreaticoduodenectomy.

    PubMed

    Ohgi, Katsuhisa; Okamura, Yukiyasu; Yamamoto, Yusuke; Ashida, Ryo; Ito, Takaaki; Sugiura, Teiichi; Aramaki, Takeshi; Uesaka, Katsuhiko

    2016-02-01

    Nonalcoholic fatty liver disease (NAFLD) after pancreaticoduodenectomy (PD) has become a clinically important issue. Although pancreatic exocrine insufficiency has been reported to be a main cause of NAFLD after PD, a clinically practical examination to assess the pancreatic exocrine function has not been established. The aim of this study was to evaluate risk factors for NAFLD after PD with a focus on perioperative computed tomography (CT) assessments of the pancreas.A retrospective review of 245 patients followed for more than 6 months after PD was conducted. We evaluated several pancreatic CT parameters, including the pancreatic parenchymal thickness, pancreatic duct-to-parenchymal ratio, pancreatic attenuation, and remnant pancreatic volume (RPV) on pre- and/or postoperative CT around 6 months after surgery. The variables, including the pancreatic CT parameters, were compared between the groups with and without NAFLD after PD.The incidence of NAFLD after PD was 19.2%. A multivariate analysis identified 5 independent risk factors for NAFLD after PD: a female gender (odds ratio [OR] 5.66, P < 0.001), RPV < 12 mL (OR 4.73, P = 0.001), preoperative pancreatic attenuation of <30 Hounsfield units (OR 4.50, P = 0.002), dissection of the right-sided nerve plexus around the superior mesenteric artery (OR 3.02, P = 0.017) and a preoperative serum carbohydrate antigen 19-9 level of ≥70 U/mL (OR 2.58, P = 0.029).Our results showed that 2 pancreatic CT parameters, the degree of preoperative pancreatic attenuation and RPV, significantly influence the development of NAFLD after PD. Perioperative CT assessments of the pancreas may be helpful for predicting NAFLD after PD.

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

    PubMed

    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.

  1. Perioperative Computed Tomography Assessments of the Pancreas Predict Nonalcoholic Fatty Liver Disease After Pancreaticoduodenectomy

    PubMed Central

    Ohgi, Katsuhisa; Okamura, Yukiyasu; Yamamoto, Yusuke; Ashida, Ryo; Ito, Takaaki; Sugiura, Teiichi; Aramaki, Takeshi; Uesaka, Katsuhiko

    2016-01-01

    Abstract Nonalcoholic fatty liver disease (NAFLD) after pancreaticoduodenectomy (PD) has become a clinically important issue. Although pancreatic exocrine insufficiency has been reported to be a main cause of NAFLD after PD, a clinically practical examination to assess the pancreatic exocrine function has not been established. The aim of this study was to evaluate risk factors for NAFLD after PD with a focus on perioperative computed tomography (CT) assessments of the pancreas. A retrospective review of 245 patients followed for more than 6 months after PD was conducted. We evaluated several pancreatic CT parameters, including the pancreatic parenchymal thickness, pancreatic duct-to-parenchymal ratio, pancreatic attenuation, and remnant pancreatic volume (RPV) on pre- and/or postoperative CT around 6 months after surgery. The variables, including the pancreatic CT parameters, were compared between the groups with and without NAFLD after PD. The incidence of NAFLD after PD was 19.2%. A multivariate analysis identified 5 independent risk factors for NAFLD after PD: a female gender (odds ratio [OR] 5.66, P < 0.001), RPV < 12 mL (OR 4.73, P = 0.001), preoperative pancreatic attenuation of <30 Hounsfield units (OR 4.50, P = 0.002), dissection of the right-sided nerve plexus around the superior mesenteric artery (OR 3.02, P = 0.017) and a preoperative serum carbohydrate antigen 19–9 level of ≥70 U/mL (OR 2.58, P = 0.029). Our results showed that 2 pancreatic CT parameters, the degree of preoperative pancreatic attenuation and RPV, significantly influence the development of NAFLD after PD. Perioperative CT assessments of the pancreas may be helpful for predicting NAFLD after PD. PMID:26871772

  2. Assessment of patient selection criteria for quantitative imaging with respiratory-gated positron emission tomography.

    PubMed

    Bowen, Stephen R; Pierce, Larry A; Alessio, Adam M; Liu, Chi; Wollenweber, Scott D; Stearns, Charles W; Kinahan, Paul E

    2014-07-01

    The objective of this investigation was to propose techniques for determining which patients are likely to benefit from quantitative respiratory-gated imaging by correlating respiratory patterns to changes in positron emission tomography (PET) metrics. Twenty-six lung and liver cancer patients underwent PET/computed tomography exams with recorded chest/abdominal displacements. Static and adaptive amplitude-gated [[Formula: see text

  3. Assessing Fieldwork Risk for Undergraduate Projects. Directions: JGHE Study Guide.

    ERIC Educational Resources Information Center

    Higgitt, David; Bullard, Jo

    1999-01-01

    Discusses the five steps involved in conducting risk assessment for fieldwork using two examples of typical student projects: (1) identity the hazards; (2) identify who might be harmed; (3) evaluate the risks; (4) record the findings; and (5) review the assessment periodically. Addresses expeditions and work overseas. (CMK)

  4. Final Report of the Vocational Assessment Project, 1979-80.

    ERIC Educational Resources Information Center

    Rutgers, The State Univ., New Brunswick, NJ. School of Medicine.

    To improve vocational rehabilitation programs for schizophrenic persons, a project sought to design an effective assessment strategy. Inactive records of schizophrenic clients at New Jersey sheltered workshops were examined to determine validity and reliability of assessment instruments being used. General Aptitude Test Battery (GATB) profiles of…

  5. Assessment of Inquiry Skills in the SAILS Project

    ERIC Educational Resources Information Center

    Harrison, Chris

    2014-01-01

    Inquiry provides both the impetus and experience that helps students acquire problem solving and lifelong learning skills. Teachers on the Strategies for Assessment of Inquiry Learning in Science Project (SAILS) strengthened their inquiry pedagogy, through focusing on seeking assessment evidence for formative action. This paper reports on both the…

  6. Balancing Formative and Summative Science Assessment Practices: Year One of the GenScope Assessment Project.

    ERIC Educational Resources Information Center

    Hickey, Daniel T.; Kruger, Ann Cale; Fredrick, Laura D.; Schafer, Nancy Jo; Kindfield, Ann C. H.

    This paper describes the GenScope Assessment Project, a project that is exploring ways of using multimedia computers to teach complex science content, refining sociocultural views of assessment and motivation, and considering different ways of reconciling the differences between these newer views and prior behavioral and cognitive views. The…

  7. Assessing image quality and dose reduction of a new x-ray computed tomography iterative reconstruction algorithm using model observers

    SciTech Connect

    Tseng, Hsin-Wu Kupinski, Matthew A.; Fan, Jiahua; Sainath, Paavana; Hsieh, Jiang

    2014-07-15

    Purpose: A number of different techniques have been developed to reduce radiation dose in x-ray computed tomography (CT) imaging. In this paper, the authors will compare task-based measures of image quality of CT images reconstructed by two algorithms: conventional filtered back projection (FBP), and a new iterative reconstruction algorithm (IR). Methods: To assess image quality, the authors used the performance of a channelized Hotelling observer acting on reconstructed image slices. The selected channels are dense difference Gaussian channels (DDOG).A body phantom and a head phantom were imaged 50 times at different dose levels to obtain the data needed to assess image quality. The phantoms consisted of uniform backgrounds with low contrast signals embedded at various locations. The tasks the observer model performed included (1) detection of a signal of known location and shape, and (2) detection and localization of a signal of known shape. The employed DDOG channels are based on the response of the human visual system. Performance was assessed using the areas under ROC curves and areas under localization ROC curves. Results: For signal known exactly (SKE) and location unknown/signal shape known tasks with circular signals of different sizes and contrasts, the authors’ task-based measures showed that a FBP equivalent image quality can be achieved at lower dose levels using the IR algorithm. For the SKE case, the range of dose reduction is 50%–67% (head phantom) and 68%–82% (body phantom). For the study of location unknown/signal shape known, the dose reduction range can be reached at 67%–75% for head phantom and 67%–77% for body phantom case. These results suggest that the IR images at lower dose settings can reach the same image quality when compared to full dose conventional FBP images. Conclusions: The work presented provides an objective way to quantitatively assess the image quality of a newly introduced CT IR algorithm. The performance of the

  8. Fundamental Fluidization Research Project. Environmental Assessment

    SciTech Connect

    Not Available

    1994-01-01

    Morgantown Energy Technology Center proposes to conduct fundamental research on fluidization technology by designing, constructing, and operating a 2-foot diameter, 50-foot high, pressurized fluidized-bed unit. The anticipated result of the proposed project would be a better, understanding of fluidization phenomena under pressurized and high velocity conditions. This improved understanding would, provide a sound basis for design and scale-up of pressurized circulating fluidized-bed combustion (PCFBC) processes for fossil energy applications. Based on the analysis in the EA, DOE has determined that the proposed action is not a major, Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement is not required and the Department is issuing this FONSI.

  9. Nondestructive Assessment of Early Tooth Demineralization Using Cross-Polarization Optical Coherence Tomography.

    PubMed

    Kang, Hobin; Jiao, Jian J; Lee, Chulsung; Le, Michael H; Darling, Cynthia L; Fried, Daniel

    2010-07-01

    New methods are needed for the nondestructive measurement of tooth demineralization and remineralization to monitor the progression of incipient caries lesions (tooth decay) for effective nonsurgical intervention and to evaluate the performance of anticaries treatments such as chemical treatments or laser irradiation. Studies have shown that optical coherence tomography (OCT) has great potential to fulfill this role since it can be used to measure the depth and severity of early lesions with an axial resolution exceeding 10 µm, it is easy to apply in vivo and it can be used to image the convoluted topography of tooth occlusal surfaces. In this paper, a review of the use of polarization-sensitive-OCT for the measurement of tooth demineralization is provided along with some recent results regarding improved methods for the detection of caries lesions in the earliest stages of development. Automated methods of analysis were used to measure the depth and severity of demineralized bovine enamel produced using simulated caries models that emulate demineralization in the mouth. Significant differences in the depth and integrated reflectivity from the lesions were detected after only a few hours of demineralization. These results demonstrate that cross-polarization-OCT is ideally suited for the nondestructive assessment of early demineralization.

  10. Nondestructive Assessment of Early Tooth Demineralization Using Cross-Polarization Optical Coherence Tomography

    PubMed Central

    Kang, Hobin; Jiao, Jian J.; Lee, Chulsung; Le, Michael H.; Darling, Cynthia L.; Fried, Daniel

    2011-01-01

    New methods are needed for the nondestructive measurement of tooth demineralization and remineralization to monitor the progression of incipient caries lesions (tooth decay) for effective nonsurgical intervention and to evaluate the performance of anticaries treatments such as chemical treatments or laser irradiation. Studies have shown that optical coherence tomography (OCT) has great potential to fulfill this role since it can be used to measure the depth and severity of early lesions with an axial resolution exceeding 10 µm, it is easy to apply in vivo and it can be used to image the convoluted topography of tooth occlusal surfaces. In this paper, a review of the use of polarization-sensitive-OCT for the measurement of tooth demineralization is provided along with some recent results regarding improved methods for the detection of caries lesions in the earliest stages of development. Automated methods of analysis were used to measure the depth and severity of demineralized bovine enamel produced using simulated caries models that emulate demineralization in the mouth. Significant differences in the depth and integrated reflectivity from the lesions were detected after only a few hours of demineralization. These results demonstrate that cross-polarization-OCT is ideally suited for the nondestructive assessment of early demineralization. PMID:21660217

  11. Assessing vertebral fracture risk on volumetric quantitative computed tomography by geometric characterization of trabecular bone structure

    NASA Astrophysics Data System (ADS)

    Checefsky, Walter A.; Abidin, Anas Z.; Nagarajan, Mahesh B.; Bauer, Jan S.; Baum, Thomas; Wismüller, Axel

    2016-03-01

    The current clinical standard for measuring Bone Mineral Density (BMD) is dual X-ray absorptiometry, however more recently BMD derived from volumetric quantitative computed tomography has been shown to demonstrate a high association with spinal fracture susceptibility. In this study, we propose a method of fracture risk assessment using structural properties of trabecular bone in spinal vertebrae. Experimental data was acquired via axial multi-detector CT (MDCT) from 12 spinal vertebrae specimens using a whole-body 256-row CT scanner with a dedicated calibration phantom. Common image processing methods were used to annotate the trabecular compartment in the vertebral slices creating a circular region of interest (ROI) that excluded cortical bone for each slice. The pixels inside the ROI were converted to values indicative of BMD. High dimensional geometrical features were derived using the scaling index method (SIM) at different radii and scaling factors (SF). The mean BMD values within the ROI were then extracted and used in conjunction with a support vector machine to predict the failure load of the specimens. Prediction performance was measured using the root-mean-square error (RMSE) metric and determined that SIM combined with mean BMD features (RMSE = 0.82 +/- 0.37) outperformed MDCT-measured mean BMD (RMSE = 1.11 +/- 0.33) (p < 10-4). These results demonstrate that biomechanical strength prediction in vertebrae can be significantly improved through the use of SIM-derived texture features from trabecular bone.

  12. Positron Emission Tomography to Assess the Outcome of Intraportal Islet Transplantation.

    PubMed

    Eriksson, Olof; Selvaraju, Ramkumar; Eich, Torsten; Willny, Mariam; Brismar, Torkel B; Carlbom, Lina; Ahlström, Håkan; Tufvesson, Gunnar; Lundgren, Torbjörn; Korsgren, Olle

    2016-09-01

    No imaging methodology currently exists to monitor viable islet mass after clinical intraportal islet transplantation. We investigated the potential of the endocrine positron emission tomography (PET) marker [(11)C]5-hydroxytryptophan ([(11)C]5-HTP) for this purpose. In a preclinical proof-of-concept study, the ex vivo and in vivo [(11)C]5-HTP signal was compared with the number of islets transplanted in rats. In a clinical study, human subjects with an intraportal islet graft (n = 8) underwent two [(11)C]5-HTP PET and MRI examinations 8 months apart. The tracer concentration in the liver as a whole, or in defined hotspots, was correlated to measurements of islet graft function. In rat, hepatic uptake of [(11)C]5-HTP correlated with the number of transplanted islets. In human subjects, uptake in hepatic hotspots showed a correlation with metabolic assessments of islet function. Change in hotspot standardized uptake value (SUV) predicted loss of graft function in one subject, whereas hotspot SUV was unchanged in subjects with stable graft function. The endocrine marker [(11)C]5-HTP thus shows a correlation between hepatic uptake and transplanted islet function and promise as a tool for noninvasive detection of viable islets. The evaluation procedure described can be used as a benchmark for novel agents targeting intraportally transplanted islets. PMID:27325286

  13. [Positron emission tomography (PET): a useful tool for the assessment of cardiac metabolism].

    PubMed

    Alexánderson, Erick; Gómez-Martín, Diana; Benito, Israel; Ruíz-Ramírez, Leonel; Ricalde, Alejandro; Meave, Aloha

    2004-01-01

    Under normal conditions, myocardial metabolism is based on the oxidation of fatty acids and in a lesser extent carbohydrates. Cardiac function depends upon an adequate supplement of adenosine triphosphate (ATP) by these substrates. However, the main source of energy is susceptible to change upon a various physiologic (exercise) as well as pathologic (ischemia-reperfusion) conditions. Recently, carnitine has gained attention as a modulator of fatty acids and carbohydrates metabolism by means of modifying intramitochondrial Acetyl-CoA/CoA ratio. Disturbances in fatty acids and carbohydrates metabolism in the myocardium have been associated with cardiovascular diseases (chronic ischemic disease, ventricular hypertrophy and dilated cardiomyopathy). The evaluation of cardiac metabolism attains great value regarding diagnosis, treatment and prognosis of these diseases. Currently, positron emission tomography (PET) is one of the preferred methods to evaluate cardiac energy metabolism in clinical practice. In PET images the tracers most commonly used are 11C-palmitate, 11C-acetate y 18Fluoro-2-deoxyglucose (FDG), the first two are employed to assess fatty acids oxidation and FDG is used to evaluate carbohydrates metabolism. PMID:15559875

  14. Photodynamic therapy induces epidermal thickening in hairless mice skin: an optical coherence tomography assessment

    NASA Astrophysics Data System (ADS)

    Jorge, Ana Elisa S.; Campos, Carolina P.; Freitas, Anderson Z.; Bagnato, Vanderlei S.

    2014-03-01

    Photodynamic therapy (PDT) promotes skin improvement according to many practitioners, however the immediately in vivo assessment of its response remains clinically inaccessible. As a non-invasive modality, optical coherence tomography (OCT) has been shown a feasible optical diagnostic technique that provides images in real time, avoiding tissue biopsies. For this reason, our investigation focused on evaluates the PDT effect on a rodent model by means of OCT. Therefore, a normal hairless mouse skin has undergone a single-session PDT, which was performed with topical 5- aminolevulinic acid (ALA) cream using a red (630 nm) light emitting diode (LED) which reached the light dose of 75 J/cm2. As the optical imaging tool, an OCT (930 nm) with axial resolution of 6.0 microns in air was used, generating images with contact to the mouse skin before, immediately after, 24 hours, and 2 weeks after the correspondent procedure. Our result demonstrates that, within 24 hours after ALA-PDT, the mouse skin from the PDT group has shown epidermal thickness (ET), which has substantially increased after 2 weeks from the treatment day. Moreover, the skin surface has become evener after ALA-PDT. Concluding, this investigation demonstrates that the OCT is a feasible and reliable technique that allows real-time cross-sectional imaging of skin, which can quantify an outcome and predict whether the PDT reaches its goal.

  15. The assessment of orthodontic bonding defects: optical coherence tomography followed by three-dimensional reconstruction

    NASA Astrophysics Data System (ADS)

    Rominu, R.; Sinescu, C.; Rominu, M.; Negrutiu, M.; Petrescu, E.; Pop, D.; Podoleanu, A. Gh.

    2011-10-01

    Orthodontic bonding is a simple yet important procedure that can influence the outcome of treatment in case it is performed incorrectly. An orthodontic treatment shadowed by repeated bonding failures can become unduly long and will decrease patient trust and compliance. Optical coherence tomography has been widely used in ophtalmology but is relatively new to dentistry. Using OCT one can detect aerial inclusions within the orthodontic adhesive or even identify incongruence between the bracket base and the tooth surface. The aim of our study was to identify bonding defects and reconstruct them three-dimensionally in order to be able to characterize them more accurately. We bonded 30 sound human permanent teeth with ceramic orthodontic brackets using a no-mix self-curing orthodontic adhesive. Prior to bonding all teeth were stored in tap water at 4°C and then professionally cleaned with rotary brushes and pumice. The samples were processed by the same person and the rotary brushes were changed after every fifth tooth. All interfaces were investigated by means of OCT and 4 defects were found. Subsequently, the defects were reconstructed threedimensionally using an open-source program. By identifying and reconstructing bonding defects we could assess the quality of the bonding procedure. Since bonding tends to be more accurate in vitro where the environmental conditions are close to ideal, it is probable that defects found in vivo be even greater in number, which leads to the conclusion that this type of investigation is potentially valuable.

  16. A Structural and Functional Assessment of the Lung via Multidetector-Row Computed Tomography

    PubMed Central

    Hoffman, Eric A.; Simon, Brett A.; McLennan, Geoffrey

    2006-01-01

    With advances in multidetector-row computed tomography (MDCT), it is now possible to image the lung in 10 s or less and accurately extract the lungs, lobes, and airway tree to the fifth- through seventh-generation bronchi and to regionally characterize lung density, texture, ventilation, and perfusion. These methods are now being used to phenotype the lung in health and disease and to gain insights into the etiology of pathologic processes. This article outlines the application of these methodologies with specific emphasis on chronic obstructive pulmonary disease. We demonstrate the use of our methods for assessing regional ventilation and perfusion and demonstrate early data that show, in a sheep model, a regionally intact hypoxic pulmonary vasoconstrictor (HPV) response with an apparent inhibition of HPV regionally in the presence of inflammation. We present the hypothesis that, in subjects with pulmonary emphysema, one major contributing factor leading to parenchymal destruction is the lack of a regional blunting of HPV when the regional hypoxia is related to regional inflammatory events (bronchiolitis or alveolar flooding). If maintaining adequate blood flow to inflamed lung regions is critical to the nondestructive resolution of inflammatory events, the pathologic condition whereby HPV is sustained in regions of inflammation would likely have its greatest effect in the lung apices where blood flow is already reduced in the upright body posture. PMID:16921136

  17. Automated quantitative assessment of three-dimensional bioprinted hydrogel scaffolds using optical coherence tomography

    PubMed Central

    Wang, Ling; Xu, Mingen; Zhang, LieLie; Zhou, QingQing; Luo, Li

    2016-01-01

    Reconstructing and quantitatively assessing the internal architecture of opaque three-dimensional (3D) bioprinted hydrogel scaffolds is difficult but vital to the improvement of 3D bioprinting techniques and to the fabrication of functional engineered tissues. In this study, swept-source optical coherence tomography was applied to acquire high-resolution images of hydrogel scaffolds. Novel 3D gelatin/alginate hydrogel scaffolds with six different representative architectures were fabricated using our 3D bioprinting system. Both the scaffold material networks and the interconnected flow channel networks were reconstructed through volume rendering and binarisation processing to provide a 3D volumetric view. An image analysis algorithm was developed based on the automatic selection of the spatially-isolated region-of–interest. Via this algorithm, the spatially-resolved morphological parameters including pore size, pore shape, strut size, surface area, porosity, and interconnectivity were quantified precisely. Fabrication defects and differences between the designed and as-produced scaffolds were clearly identified in both 2D and 3D; the locations and dimensions of each of the fabrication defects were also defined. It concludes that this method will be a key tool for non-destructive and quantitative characterization, design optimisation and fabrication refinement of 3D bioprinted hydrogel scaffolds. Furthermore, this method enables investigation into the quantitative relationship between scaffold structure and biological outcome. PMID:27231597

  18. Simultaneous confocal fluorescence microscopy and optical coherence tomography for drug distribution and tissue integrity assessment

    NASA Astrophysics Data System (ADS)

    Rinehart, Matthew T.; LaCroix, Jeffrey; Henderson, Marcus; Katz, David; Wax, Adam

    2011-03-01

    The effectiveness of microbicidal gels, topical products developed to prevent infection by sexually transmitted diseases including HIV/AIDS, is governed by extent of gel coverage, pharmacokinetics of active pharmaceutical ingredients (APIs), and integrity of vaginal epithelium. While biopsies provide localized information about drug delivery and tissue structure, in vivo measurements are preferable in providing objective data on API and gel coating distribution as well as tissue integrity. We are developing a system combining confocal fluorescence microscopy with optical coherence tomography (OCT) to simultaneously measure local concentrations and diffusion coefficients of APIs during transport from microbicidal gels into tissue, while assessing tissue integrity. The confocal module acquires 2-D images of fluorescent APIs multiple times per second allowing analysis of lateral diffusion kinetics. The custom Fourier domain OCT module has a maximum a-scan rate of 54 kHz and provides depth-resolved tissue integrity information coregistered with the confocal fluorescence measurements. The combined system is validated by imaging phantoms with a surrogate fluorophore. Time-resolved API concentration measured at fixed depths is analyzed for diffusion kinetics. This multimodal system will eventually be implemented in vivo for objective evaluation of microbicide product performance.

  19. Pulmonary malignant melanoma with distant metastasis assessed by positron emission tomography‐computed tomography

    PubMed Central

    Yoon, Ha‐Yong; Jin, Gong Yong; Choe, Yeong Hun; Park, Seung Yong

    2016-01-01

    Abstract Melanoma is a cutaneous malignant neoplasm of melanocytes. Primary malignant melanoma (MM) of the lung is very rare. Although previous reports have described the radiologic features of pulmonary MM, its rarity means that many factors are unknown. Thus, radiologic diagnosis is very difficult. Furthermore, there is little information regarding diagnostic application and/or the usefulness of [18F]‐fluorine‐2‐fluoro‐2‐deoxy‐D‐glucose positron emission tomography‐computed tomography (FDG‐PET‐CT) for primary pulmonary MM. A 69‐year‐old patient with a productive cough lasting three weeks was admitted to our hospital. Chest CT showed a large single mass with a multi‐lobulated margin and homogeneous enhancement in the right upper lobe, which was subsequently diagnosed as a primary pulmonary MM with multiple metastases. On PET‐CT images, the pulmonary mass and multiple bone lesions showed very increased uptakes of FDG. Considering that pulmonary metastasis from a mucocutaneous melanoma is the main differential diagnosis of primary pulmonary MM, systemic assessment of the whole body is more important than for other types of lung malignancies. This report introduces PET‐CT as a useful diagnostic modality for pulmonary MM, especially in cases of distant multiple metastases. PMID:27385996

  20. Assessment of methacholine-induced airway constriction by ultrafast high-resolution computed tomography.

    PubMed

    Amirav, I; Kramer, S S; Grunstein, M M; Hoffman, E A

    1993-11-01

    Assessment of changes in airway dimensions during bronchoconstriction is conventionally based on measurements of respiratory mechanics. We evaluated the efficacy of ultrafast high-resolution computed tomography (UHRCT) to directly determine the dynamic changes in cross-sectional area (CSA) of airways in response to methacholine (MCh). UHRCT scans were obtained at functional residual capacity before (baseline) and after intravenous bolus injections of MCh (10(-8.5)-10(-7.0) mol/kg) to seven mechanically ventilated pigs. Changes in CSA of bronchi of varying baseline size (1-10 mm diam) were determined by using a customized image processing software package (VIDA) based on a user-directed computer-adjusted edge-finding algorithm. MCh induced dose-dependent decreases in CSA, which were paralleled by increases in airway opening pressure at higher doses of MCh; at lower doses of MCh, decreases in CSA of smaller airways were detected without concomitant changes in airway opening pressure. Changes in CSA were heterogeneous and variable, especially in the smaller airway ranges. The results of the present study support the concept that UHRCT can be used in conjunction with bolus challenges to effectively determine dose-response changes in airway caliber in both large and small airways. This technique provides data that may not be reflected by conventional lung function measurements and, hence, is a useful tool to study airway reactivity.

  1. Changes in myocardial perfusion reserve after PTCA: noninvasive assessment with positron tomography.

    PubMed

    Goldstein, R A; Kirkeeide, R L; Smalling, R W; Nishikawa, A; Merhige, M E; Demer, L L; Mullani, N A; Gould, K L

    1987-08-01

    The effect of percutaneous transluminal coronary angioplasty (PTCA) on myocardial perfusion reserve has not been previously determined. Accordingly, 11 patients underwent positron imaging with [13N]ammonia or 82Rb at rest and following dipyridamole + handgrip stress before and after PTCA. The ratio of stress to rest activity (S:R) was determined for each region of interest. Relative myocardial perfusion reserve by positron tomography (RMPR) was calculated by dividing S:R of the stenotic area by a corresponding value from a normal reference area of the same patient. Automated quantitative coronary arteriography was used to objectively measure the percent diameter (%D) and the percent area narrowing (%A) of the stenoses. In nine patients with successful PTCA, %D and %A improved (68 +/- 10 to 49 +/- 15% and 92 +/- 3 to 72 +/- 5%) and RMPR increased from 0.79 +/- 0.07 to 0.96 +/- 0.05. In the two patients in whom PTCA was unsuccessful, RMPR was unchanged. Changes in RMPR correlated inversely with changes in %D (r = -0.68) and %A (r = -0.92) and directly with improved coronary flow reserve derived from all stenosis measurements (r = 0.73, p less than 0.001 for each). This study suggests that dipyridamole + handgrip stress imaging with PET can be used to assess changes in myocardial perfusion reserve before and after PTCA with the potential for determining restenosis noninvasively.

  2. Positron emission tomography to assess hypoxia and perfusion in lung cancer

    PubMed Central

    Verwer, Eline E; Boellaard, Ronald; van der Veldt, Astrid AM

    2014-01-01

    In lung cancer, tumor hypoxia is a characteristic feature, which is associated with a poor prognosis and resistance to both radiation therapy and chemotherapy. As the development of tumor hypoxia is associated with decreased perfusion, perfusion measurements provide more insight into the relation between hypoxia and perfusion in malignant tumors. Positron emission tomography (PET) is a highly sensitive nuclear imaging technique that is suited for non-invasive in vivo monitoring of dynamic processes including hypoxia and its associated parameter perfusion. The PET technique enables quantitative assessment of hypoxia and perfusion in tumors. To this end, consecutive PET scans can be performed in one scan session. Using different hypoxia tracers, PET imaging may provide insight into the prognostic significance of hypoxia and perfusion in lung cancer. In addition, PET studies may play an important role in various stages of personalized medicine, as these may help to select patients for specific treatments including radiation therapy, hypoxia modifying therapies, and antiangiogenic strategies. In addition, specific PET tracers can be applied for monitoring therapy. The present review provides an overview of the clinical applications of PET to measure hypoxia and perfusion in lung cancer. Available PET tracers and their characteristics as well as the applications of combined hypoxia and perfusion PET imaging are discussed. PMID:25493221

  3. Optical coherence tomography assessment of vessel wall degradation in thoracic aortic aneurysms

    NASA Astrophysics Data System (ADS)

    Real, Eusebio; Eguizabal, Alma; Pontón, Alejandro; Díez, Marta Calvo; Fernando Val-Bernal, José; Mayorga, Marta; Revuelta, José M.; López-Higuera, José M.; Conde, Olga M.

    2013-12-01

    Optical coherence tomography images of human thoracic aorta from aneurysms reveal elastin disorders and smooth muscle cell alterations when visualizing the media layer of the aortic wall. These disorders can be employed as indicators for wall degradation and, therefore, become a hallmark for diagnosis of risk of aneurysm under intraoperative conditions. Two approaches are followed to evaluate this risk: the analysis of the reflectivity decay along the penetration depth and the textural analysis of a two-dimensional spatial distribution of the aortic wall backscattering. Both techniques require preprocessing stages for the identification of the air-sample interface and for the segmentation of the media layer. Results show that the alterations in the media layer of the aortic wall are better highlighted when the textural approach is considered and also agree with a semiquantitative histopathological grading that assesses the degree of wall degradation. The correlation of the co-occurrence matrix attains a sensitivity of 0.906 and specificity of 0.864 when aneurysm automatic diagnosis is evaluated with a receiver operating characteristic curve.

  4. Automated Lung Segmentation and Image Quality Assessment for Clinical 3-D/4-D-Computed Tomography

    PubMed Central

    Li, Guang

    2014-01-01

    4-D-computed tomography (4DCT) provides not only a new dimension of patient-specific information for radiation therapy planning and treatment, but also a challenging scale of data volume to process and analyze. Manual analysis using existing 3-D tools is unable to keep up with vastly increased 4-D data volume, automated processing and analysis are thus needed to process 4DCT data effectively and efficiently. In this paper, we applied ideas and algorithms from image/signal processing, computer vision, and machine learning to 4DCT lung data so that lungs can be reliably segmented in a fully automated manner, lung features can be visualized and measured on the fly via user interactions, and data quality classifications can be computed in a robust manner. Comparisons of our results with an established treatment planning system and calculation by experts demonstrated negligible discrepancies (within ±2%) for volume assessment but one to two orders of magnitude performance enhancement. An empirical Fourier-analysis-based quality measure-delivered performances closely emulating human experts. Three machine learners are inspected to justify the viability of machine learning techniques used to robustly identify data quality of 4DCT images in the scalable manner. The resultant system provides a toolkit that speeds up 4-D tasks in the clinic and facilitates clinical research to improve current clinical practice. PMID:25621194

  5. Changes in myocardial perfusion reserve after PTCA: noninvasive assessment with positron tomography

    SciTech Connect

    Goldstein, R.A.; Kirkeeide, R.L.; Smalling, R.W.; Nishikawa, A.; Merhige, M.E.; Demer, L.L.; Mullani, N.A.; Gould, K.L.

    1987-08-01

    The effect of percutaneous transluminal coronary angioplasty (PTCA) on myocardial perfusion reserve has not been previously determined. Accordingly, 11 patients underwent positron imaging with (/sup 13/N)ammonia or /sup 82/Rb at rest and following dipyridamole + handgrip stress before and after PTCA. The ratio of stress to rest activity (S:R) was determined for each region of interest. Relative myocardial perfusion reserve by positron tomography (RMPR) was calculated by dividing S:R of the stenotic area by a corresponding value from a normal reference area of the same patient. Automated quantitative coronary arteriography was used to objectively measure the percent diameter (%D) and the percent area narrowing (%A) of the stenoses. In nine patients with successful PTCA, %D and %A improved (68 +/- 10 to 49 +/- 15% and 92 +/- 3 to 72 +/- 5%) and RMPR increased from 0.79 +/- 0.07 to 0.96 +/- 0.05. In the two patients in whom PTCA was unsuccessful, RMPR was unchanged. Changes in RMPR correlated inversely with changes in %D (r = -0.68) and %A (r = -0.92) and directly with improved coronary flow reserve derived from all stenosis measurements (r = 0.73, p less than 0.001 for each). This study suggests that dipyridamole + handgrip stress imaging with PET can be used to assess changes in myocardial perfusion reserve before and after PTCA with the potential for determining restenosis noninvasively.

  6. Comparison of synchrotron radiation and conventional x-ray microcomputed tomography for assessing trabecular bone microarchitecture of human femoral heads

    SciTech Connect

    Chappard, Christine; Basillais, Armelle; Benhamou, Laurent; Bonassie, Alexandra; Brunet-Imbault, Barbara; Bonnet, Nicolas; Peyrin, Francoise

    2006-09-15

    Microcomputed tomography ({mu}CT) produces three-dimensional (3D) images of trabecular bone. We compared conventional {mu}CT (C{mu}CT) with a polychromatic x-ray cone beam to synchrotron radiation (SR) {mu}CT with a monochromatic parallel beam for assessing trabecular bone microarchitecture of 14 subchondral femoral head specimens from patients with osteoarthritis (n=10) or osteoporosis (n=4). SR{mu}CT images with a voxel size of 10.13 {mu}m were reconstructed from 900 2D radiographic projections (angular step, 0.2 deg. ). C{mu}CT images with a voxel size of 10.77 {mu}m were reconstructed from 205, 413, and 825 projections obtained using angular steps of 0.9 deg., 0.45 deg., and 0.23 deg., respectively. A single threshold was used to binarize the images. We computed bone volume/tissue volume (BV/TV), bone surface/bone volume (BS/BV), trabecular number (Tb.N), trabecular thickness (Tb.Th and Tb.Th*), trabecular spacing (Tb.Sp), degree of anisotropy (DA), and Euler density. With the 0.9 deg. angular step, all C{mu}CT values were significantly different from SR{mu}CT values. With the 0.23 deg. and 0.45 deg. rotation steps, BV/TV, Tb.Th, and BS/BV by C{mu}CT differed significantly from the values by SR{mu}CT. The error due to slice matching (visual site matching {+-}10 slices) was within 1% for most parameters. Compared to SR{mu}CT, BV/TV, Tb.Sp, and Tb.Th by C{mu}CT were underestimated, whereas Tb.N and Tb.Th* were overestimated. A Bland and Altman plot showed no bias for Tb.N or DA. Bias was -0.8{+-}1.0%, +5.0{+-}1.1 {mu}m, -5.9{+-}6.3 {mu}m, and -5.7{+-}29.1 {mu}m for BV/TV, Tb.Th*, Tb.Th, and Tb.Sp, respectively, and the differences did not vary over the range of values. Although systematic differences were noted between SR{mu}CT and C{mu}CT values, correlations between the techniques were high and the differences would probably not change the discrimination between study groups. C{mu}CT provides a reliable 3D assessment of human defatted bone when working at the 0

  7. A Correlational Study Assessing the Relationships among Information Technology Project Complexity, Project Complication, and Project Success

    ERIC Educational Resources Information Center

    Williamson, David J.

    2011-01-01

    The specific problem addressed in this study was the low success rate of information technology (IT) projects in the U.S. Due to the abstract nature and inherent complexity of software development, IT projects are among the most complex projects encountered. Most existing schools of project management theory are based on the rational systems…

  8. "Triple-bottom-line" assessment of urban stormwater projects.

    PubMed

    Taylor, A C; Fletcher, T D

    2006-01-01

    New guidelines have been developed and trialled in Australia to assist urban stormwater managers to assess options for projects that aim to improve urban waterway health. These guidelines help users to examine the financial, ecological and social dimensions of projects (i.e., the so-called "triple-bottom-line"). Features of the assessment process described in the guidelines include use of multi criteria analysis, input from technical experts as well as non-technical stakeholders, and provision of three alternative levels of assessment to suit stormwater managers with differing needs and resources. This paper firstly provides a background to the new guidelines and triple-bottom-line assessment. The assessment methodology promoted in the new guidelines is then briefly summarised. This methodology is compared and contrasted with European guidelines from the "SWARD" project that have been primarily developed for assessing the relative sustainability of options involving urban water supply and sewerage assets. Finally, the paper discusses how assessment methodologies that evaluate the financial, ecological and social dimensions of projects can, under some circumstances, be used to evaluate the relative progress of options for urban water management on a journey towards the widely pursued, but vaguely defined goal of "sustainable development".

  9. Environmental projects. Volume 16: Waste minimization assessment

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Goldstone Deep Space Communications Complex (GDSCC), located in the MoJave Desert, is part of the National Aeronautics and Space Administration's (NASA's) Deep Space Network (DSN), the world's largest and most sensitive scientific telecommunications and radio navigation network. The Goldstone Complex is operated for NASA by the Jet Propulsion Laboratory. At present, activities at the GDSCC support the operation of nine parabolic dish antennas situated at five separate locations known as 'sites.' Each of the five sites at the GDSCC has one or more antennas, called 'Deep Space Stations' (DSS's). In the course of operation of these DSS's, various hazardous and non-hazardous wastes are generated. In 1992, JPL retained Kleinfelder, Inc., San Diego, California, to quantify the various streams of hazardous and non-hazardous wastes generated at the GDSCC. In June 1992, Kleinfelder, Inc., submitted a report to JPL entitled 'Waste Minimization Assessment.' This present volume is a JPL-expanded version of the Kleinfelder, Inc. report. The 'Waste Minimization Assessment' report did not find any deficiencies in the various waste-management programs now practiced at the GDSCC, and it found that these programs are being carried out in accordance with environmental rules and regulations.

  10. The NASA Space Radiobiology Risk Assessment Project

    NASA Astrophysics Data System (ADS)

    Cucinotta, Francis A.; Huff, Janice; Ponomarev, Artem; Patel, Zarana; Kim, Myung-Hee

    The current first phase (2006-2011) has the three major goals of: 1) optimizing the conventional cancer risk models currently used based on the double-detriment life-table and radiation quality functions; 2) the integration of biophysical models of acute radiation syndromes; and 3) the development of new systems radiation biology models of cancer processes. The first-phase also includes continued uncertainty assessment of space radiation environmental models and transport codes, and relative biological effectiveness factors (RBE) based on flight data and NSRL results, respectively. The second phase of the (2012-2016) will: 1) develop biophysical models of central nervous system risks (CNS); 2) achieve comphrensive systems biology models of cancer processes using data from proton and heavy ion studies performed at NSRL; and 3) begin to identify computational models of biological countermeasures. Goals for the third phase (2017-2021) include: 1) the development of a systems biology model of cancer risks for operational use at NASA; 2) development of models of degenerative risks, 2) quantitative models of counter-measure impacts on cancer risks; and 3) indiviudal based risk assessments. Finally, we will support a decision point to continue NSRL research in support of NASA's exploration goals beyond 2021, and create an archival of NSRL research results for continued analysis. Details on near term goals, plans for a WEB based data resource of NSRL results, and a space radiation Wikepedia are described.

  11. Meta-Analysis of Diagnostic Performance of Coronary Computed Tomography Angiography, Computed Tomography Perfusion, and Computed Tomography-Fractional Flow Reserve in Functional Myocardial Ischemia Assessment Versus Invasive Fractional Flow Reserve.

    PubMed

    Gonzalez, Jorge A; Lipinski, Michael J; Flors, Lucia; Shaw, Peter W; Kramer, Christopher M; Salerno, Michael

    2015-11-01

    We sought to compare the diagnostic performance of coronary computed tomography angiography (CCTA), computed tomography perfusion (CTP), and computed tomography (CT)-fractional flow reserve (FFR) for assessing the functional significance of coronary stenosis as defined by invasive FFR in patients with known or suspected coronary artery disease (CAD). CCTA has proved clinically useful for excluding obstructive CAD because of its high sensitivity and negative predictive value (NPV); however, the ability of CTA to identify functionally significant CAD has remained challenging. We searched PubMed/Medline for studies evaluating CCTA, CTP, or CT-FFR for the noninvasive detection of obstructive CAD compared with catheter-derived FFR as the reference standard. Pooled sensitivity, specificity, PPV, NPV, likelihood ratios, and odds ratio of all diagnostic tests were assessed. Eighteen studies involving a total of 1,535 patients were included. CTA demonstrated a pooled sensitivity of 0.92, specificity 0.43, PPV of 0.56, and NPV of 0.87 on a per-patient level. CT-FFR and CTP increased the specificity to 0.72 and 0.77, respectively (p = 0.004 and p = 0.0009) resulting in higher point estimates for PPV 0.70 and 0.83, respectively. There was no improvement in the sensitivity. The CTP protocol involved more radiation (3.5 mSv CCTA vs 9.6 mSv CTP) and a higher volume of iodinated contrast (145 ml). In conclusion, CTP and CT-FFR improve the specificity of CCTA for detecting functionally significant stenosis as defined by invasive FFR on a per-patient level; both techniques could advance the ability to noninvasively detect the functional significance of coronary lesions.

  12. Factors affecting computed tomography image quality for assessment of mechanical aortic valves.

    PubMed

    Suh, Young Joo; Kim, Young Jin; Hong, Yoo Jin; Lee, Hye-Jeong; Hur, Jin; Hong, Sae Rom; Im, Dong Jin; Kim, Yun Jung; Choi, Byoung Wook

    2016-06-01

    Evaluating mechanical valves with computed tomography (CT) can be problematic because artifacts from the metallic components of valves can hamper image quality. The purpose of this study was to determine factors affecting the image quality of cardiac CT to improve assessment of mechanical aortic valves. A total of 144 patients who underwent aortic valve replacement with mechanical valves (ten different types) and who underwent cardiac CT were included. Using a four-point grading system, the image quality of the CT scans was assessed for visibility of the valve leaflets and the subvalvular regions. Data regarding the type of mechanical valve, tube voltage, average heart rate (HR), and HR variability during CT scanning were compared between the non-diagnostic (overall image quality score ≤2) and diagnostic (overall image quality score >2) image quality groups. Logistic regression analyses were performed to identify predictors of non-diagnostic image quality. The percentage of valve types that incorporated a cobalt-chrome component (two types in total) and HR variability were significantly higher in the non-diagnostic image group than in the diagnostic group (P < 0.001 and P = 0.013, respectively). The average HR and tube voltage were not significantly different between the two groups (P > 0.05). Valve type was the only independent predictor of non-diagnostic quality. The CT image quality for patients with mechanical aortic valves differed significantly depending on the type of mechanical valve used and on the degree of HR variability.

  13. Quantitative assessment of the stent/scaffold strut embedment analysis by optical coherence tomography.

    PubMed

    Sotomi, Yohei; Tateishi, Hiroki; Suwannasom, Pannipa; Dijkstra, Jouke; Eggermont, Jeroen; Liu, Shengnan; Tenekecioglu, Erhan; Zheng, Yaping; Abdelghani, Mohammad; Cavalcante, Rafael; de Winter, Robbert J; Wykrzykowska, Joanna J; Onuma, Yoshinobu; Serruys, Patrick W; Kimura, Takeshi

    2016-06-01

    The degree of stent/scaffold embedment could be a surrogate parameter of the vessel wall-stent/scaffold interaction and could have biological implications in the vascular response. We have developed a new specific software for the quantitative evaluation of embedment of struts by optical coherence tomography (OCT). In the present study, we described the algorithm of the embedment analysis and its reproducibility. The degree of embedment was evaluated as the ratio of the embedded part versus the whole strut height and subdivided into quartiles. The agreement and the inter- and intra-observer reproducibility were evaluated using the kappa and the interclass correlation coefficient (ICC). A total of 4 pullbacks of OCT images in 4 randomly selected coronary lesions with 3.0 × 18 mm devices [2 lesions with Absorb BVS and 2 lesions with XIENCE (both from Abbott Vascular, Santa Clara, CA, USA)] from Absorb Japan trial were evaluated by two investigators with QCU-CMS software version 4.69 (Leiden University Medical Center, Leiden, The Netherlands). Finally, 1481 polymeric struts in 174 cross-sections and 1415 metallic struts in 161 cross-sections were analyzed. Inter- and intra-observer reproducibility of quantitative measurements of embedment ratio and categorical assessment of embedment in Absorb BVS and XIENCE had excellent agreement with ICC ranging from 0.958 to 0.999 and kappa ranging from 0.850 to 0.980. The newly developed embedment software showed excellent reproducibility. Computer-assisted embedment analysis could be a feasible tool to assess the strut penetration into the vessel wall that could be a surrogate of acute injury caused by implantation of devices. PMID:26898315

  14. Computed tomography, endoscopic, laparoscopic, and intra-operative sonography for assessing resectability of pancreatic cancer.

    PubMed

    Long, Eliza E; Van Dam, Jacques; Weinstein, Stefanie; Jeffrey, Brooke; Desser, Terry; Norton, Jeffrey A

    2005-08-01

    Pancreas cancer is the fourth leading cancer killer in adults. Cure of pancreas cancer is dependent on the complete surgical removal of localized tumor. A complete surgical resection is dependent on accurate preoperative and intra-operative imaging of tumor and its relationship to vital structures. Imaging of pancreatic tumors preoperatively and intra-operatively is achieved by pancreatic protocol computed tomography (CT), endoscopic ultrasound (EUS), laparoscopic ultrasound (LUS), and intra-operative ultrasound (IOUS). Multi-detector CT with three-dimensional (3-D) reconstruction of images is the most useful preoperative modality to assess resectability. It has a sensitivity and specificity of 90 and 99%, respectively. It is not observer dependent. The images predict operative findings. EUS and LUS have sensitivities of 77 and 78%, respectively. They both have a very high specificity. Further, EUS has the ability to biopsy tumor and obtain a definitive tissue diagnosis. IOUS is a very sensitive (93%) method to assess tumor resectability during surgery. It adds little time and no morbidity to the operation. It greatly facilitates the intra-operative decision-making. In reality, each of these methods adds some information to help in determining the extent of tumor and the surgeon's ability to remove it. We rely on pancreatic protocol CT with 3-D reconstruction and either EUS or IOUS depending on the tumor location and operability of the tumor and patient. With these modern imaging modalities, it is now possible to avoid major operations that only determine an inoperable tumor. With proper preoperative selection, surgery is able to remove tumor in the majority of patients.

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

    NASA Astrophysics Data System (ADS)

    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

  16. Assessing Regional Cerebral Blood Flow in Depression Using 320-Slice Computed Tomography

    PubMed Central

    Tang, Songlin; Liu, Xingde; O'Neil, Adrienne; Turner, Alyna; Chai, Fangxian; Chen, Fanying; Berk, Michael

    2014-01-01

    While there is evidence that the development and course of major depressive disorder (MDD) symptomatology is associated with vascular disease, and that there are changes in energy utilization in the disorder, the extent to which cerebral blood flow is changed in this condition is not clear. This study utilized a novel imaging technique previously used in coronary and stroke patients, 320-slice Computed-Tomography (CT), to assess regional cerebral blood flow (rCBF) in those with MDD and examine the pattern of regional cerebral perfusion. Thirty nine participants with depressive symptoms (Hamilton Depression Rating Scale 24 (HAMD24) score >20, and Self-Rating Depression Scale (SDS) score >53) and 41 healthy volunteers were studied. For all subjects, 3 ml of venous blood was collected to assess hematological parameters. Trancranial Doppler (TCD) ultrasound was utilized to measure parameters of cerebral artery rCBFV and analyse the Pulsatility Index (PI). 16 subjects (8 =  MDD; 8 =  healthy) also had rCBF measured in different cerebral artery regions using 320-slice CT. Differences among groups were analyzed using ANOVA and Pearson's tests were employed in our statistical analyses. Compared with the control group, whole blood viscosity (including high\\middle\\low shear rate)and hematocrit (HCT) were significantly increased in the MDD group. PI values in different cerebral artery regions and parameters of rCBFV in the cerebral arteries were decreased in depressive participants, and there was a positive relationship between rCBFV and the corresponding vascular rCBF in both gray and white matter. rCBF of the left gray matter was lower than that of the right in MDD. Major depression is characterized by a wide range of CBF impairments and prominent changes in gray matter blood flow. 320-slice CT appears to be a valid and promising tool for measuring rCBF, and could thus be employed in psychiatric settings for biomarker and treatment response purposes. PMID:25251476

  17. Importance of data quality and assessment of solution quality in local earthquake tomography: Application to the Alpine region

    NASA Astrophysics Data System (ADS)

    Husen, S.; Diehl, T.; Kissling, E.

    2009-04-01

    In arrival time tomography the minimum resolvable velocity perturbation depends on model parameterization and data quality. The quality of arrival time data is governed by picking accuracy and by consistency. While effects of the former in seismic tomography are dealt with by damping, effects of inconsistency are much more difficult to control. In this study we investigate the effect of inconsistently picked arrival time data in local earthquake tomography by comparing results from the Alpine region which were obtained using two data sets: i) a rather small data set of 13'000 arrival times that has been obtained by automated quality-weighted re-picking and ii) a rather large data set of 95'000 arrival times that has been taken from the ISC Bulletin. Three-dimensional P-wave velocity models were computed for each data set using the same model parameterization, ray tracing technique, and damping. Our results indicate that the upper crust is rather well resolved by the lower quality ISC data set due to higher data coverage compared to the smaller high-quality data set. Structures in the lower crust, however, are more clearly resolved by the smaller data set. To assess the solution quality, we ran several tests with synthetic velocity models and increasing noise level. Our results suggest that the ISC data set in principle has the potential to resolve structures with a high detail at all depth ranges but it is likely contaminated by a significant number of inconsistently picked data. Our results demonstrate that low-quality and inconsistent data can severely degrade the solution quality in seismic tomography. We further conclude that the effect of inconsistent data on the solution quality in seismic tomography can only be assessed through tests with synthetic velocity models.

  18. Incorporating the Technology Roadmap Uncertainties into the Project Risk Assessment

    SciTech Connect

    Bonnema, Bruce Edward

    2002-02-01

    This paper describes two methods, Technology Roadmapping and Project Risk Assessment, which were used to identify and manage the technical risks relating to the treatment of sodium bearing waste at the Idaho National Engineering and Environmental Laboratory. The waste treatment technology under consideration was Direct Vitrification. The primary objective of the Technology Roadmap is to identify technical data uncertainties for the technologies involved and to prioritize the testing or development studies to fill the data gaps. Similarly, project management's objective for a multi-million dollar construction project includes managing all the key risks in accordance to DOE O 413.3 - "Program and Project Management for the Acquisition of Capital Assets." In the early stages, the Project Risk Assessment is based upon a qualitative analysis for each risk's probability and consequence. In order to clearly prioritize the work to resolve the technical issues identified in the Technology Roadmap, the issues must be cross- referenced to the project's Risk Assessment. This will enable the project to get the best value for the cost to mitigate the risks.

  19. Incorporating the Technology Roadmap Uncertainties into the Project Risk Assessment

    SciTech Connect

    Bonnema, B.E.

    2002-01-16

    This paper describes two methods, Technology Roadmapping and Project Risk Assessment, which were used to identify and manage the technical risks relating to the treatment of sodium bearing waste at the Idaho National Engineering and Environmental Laboratory. The waste treatment technology under consideration was Direct Vitrification. The primary objective of the Technology Roadmap is to identify technical data uncertainties for the technologies involved and to prioritize the testing or development studies to fill the data gaps. Similarly, project management's objective for a multi-million dollar construction project includes managing all the key risks in accordance to DOE O 413.3 - ''Program and Project Management for the Acquisition of Capital Assets.'' In the early stages, the Project Risk Assessment is based upon a qualitative analysis for each risk's probability and consequence. In order to clearly prioritize the work to resolve the technical issues identified in the Technology Roadmap, the issues must be cross- referenced to the project's Risk Assessment. This will enable the project to get the best value for the cost to mitigate the risks.

  20. Optimizing 4D cone beam computed tomography acquisition by varying the gantry velocity and projection time interval.

    PubMed

    O'Brien, Ricky T; Cooper, Benjamin J; Keall, Paul J

    2013-03-21

    Four dimensional cone beam computed tomography (4DCBCT) is an emerging clinical image guidance strategy for tumour sites affected by respiratory motion. In current generation 4DCBCT techniques, both the gantry rotation speed and imaging frequency are constant and independent of the patient's breathing which can lead to projection clustering. We present a mixed integer quadratic programming (MIQP) model for respiratory motion guided-4DCBCT (RMG-4DCBCT) which regulates the gantry velocity and projection time interval, in response to the patient's respiratory signal, so that a full set of evenly spaced projections can be taken in a number of phase, or displacement, bins during the respiratory cycle. In each respiratory bin, an image can be reconstructed from the projections to give a 4D view of the patient's anatomy so that the motion of the lungs, and tumour, can be observed during the breathing cycle. A solution to the full MIQP model in a practical amount of time, 10 s, is not possible with the leading commercial MIQP solvers, so a heuristic method is presented. Using parameter settings typically used on current generation 4DCBCT systems (4 min image acquisition, 1200 projections, 10 respiratory bins) and a sinusoidal breathing trace with a 4 s period, we show that the root mean square (RMS) of the angular separation between projections with displacement binning is 2.7° using existing constant gantry speed systems and 0.6° using RMG-4DCBCT. For phase based binning the RMS is 2.7° using constant gantry speed systems and 2.5° using RMG-4DCBCT. The optimization algorithm presented is a critical step on the path to developing a system for RMG-4DCBCT.

  1. Adaptive Peircean decision aid project summary assessments.

    SciTech Connect

    Senglaub, Michael E.

    2007-01-01

    This efforts objective was to identify and hybridize a suite of technologies enabling the development of predictive decision aids for use principally in combat environments but also in any complex information terrain. The technologies required included formal concept analysis for knowledge representation and information operations, Peircean reasoning to support hypothesis generation, Mill's's canons to begin defining information operators that support the first two technologies and co-evolutionary game theory to provide the environment/domain to assess predictions from the reasoning engines. The intended application domain is the IED problem because of its inherent evolutionary nature. While a fully functioning integrated algorithm was not achieved the hybridization and demonstration of the technologies was accomplished and demonstration of utility provided for a number of ancillary queries.

  2. Assessment of the healing process in distal radius fractures by high resolution peripheral quantitative computed tomography.

    PubMed

    de Jong, Joost J A; Willems, Paul C; Arts, Jacobus J; Bours, Sandrine G P; Brink, Peter R G; van Geel, Tineke A C M; Poeze, Martijn; Geusens, Piet P; van Rietbergen, Bert; van den Bergh, Joop P W

    2014-07-01

    In clinical practice, fracture healing is evaluated by clinical judgment in combination with conventional radiography. Due to limited resolution, radiographs don't provide detailed information regarding the bone micro-architecture and bone strength. Recently, assessment of in vivo bone density, architectural and mechanical properties at the microscale became possible using high resolution peripheral quantitative computed tomography (HR-pQCT) in combination with micro finite element analysis (μFEA). So far, such techniques have been used mainly to study intact bone. The aim of this study was to explore whether these techniques can also be used to assess changes in bone density, micro-architecture and bone stiffness during fracture healing. Therefore, the fracture region in eighteen women, aged 50 years or older with a stable distal radius fracture, was scanned using HR-pQCT at 1-2 (baseline), 3-4, 6-8 and 12weeks post-fracture. At 1-2 and 12 weeks post-fracture the distal radius at the contra-lateral side was also scanned as control. Standard bone density, micro-architectural and geometric parameters were calculated and bone stiffness in compression, torsion and bending was assessed using μFEA. A linear mixed effect model with time post-fracture as fixed effect was used to detect significant (p-value ≤0.05) changes from baseline. Wrist pain and function were scored using the patient-rated wrist evaluation (PRWE) questionnaire. Correlations between the bone parameters and the PRWE score were calculated by Spearman's correlation coefficient. At the fracture site, total and trabecular bone density increased by 11% and 20%, respectively, at 6-8 weeks, whereas cortical density was decreased by 4%. Trabecular thickness increased by 23-31% at 6-8 and 12 weeks and the intertrabecular area became blurred, indicating intertrabecular bone formation. Compared to baseline, calculated bone stiffness in compression, torsion and bending was increased by 31% after 12 weeks. A

  3. Comparison of Physical Examination and Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography 4-6 Months After Radiotherapy to Assess Residual Head-and-Neck Cancer

    SciTech Connect

    Zundel, M. Tracy; Michel, Michelle A.; Schultz, Christopher J.; Maheshwari, Mohit; Wong, Stuart J.; Campbell, Bruce H.; Massey, Becky L.; Blumin, Joel; Wilson, J. Frank; Wang, Dian

    2011-12-01

    Purpose: To retrospectively compare fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and physical examination 4-6 months after radiotherapy for assessing residual head-and-neck cancer (HNC). Methods and Materials: From July 2002 through March 2006, 52 HNC patients underwent definitive radiotherapy or chemoradiotherapy. Categoric assessments of residual tumor by PET/CT and physical examination 4-6 months after therapy were correlated and compared with clinical outcomes. Pretreatment data, including tumor stage and primary site standardized uptake value, were also gathered retrospectively and correlated with clinical outcomes. Median follow-up time was 58 months. Results: Twenty-one patients had either locoregionally 'positive' (17 of 21) or 'equivocal' (4 of 21) PET/CT scans, whereas 31 patients had locoregionally negative scans. Four patients failed treatment and had biopsy-confirmed residual or recurrent local disease. All patients, including patients with locally suspicious scans or examinations who refused biopsies, were followed clinically for a minimum of 29 months after therapy, with no other cases of treatment failure detected during this time. No patient had residual nodal disease after therapy. Sensitivities of PET/CT vs. physical examination for early detection of treatment failure were 100% vs. 50%, whereas the specificities of the two modalities were 64.6% vs. 89.6%, respectively. Higher initial T stage and American Joint Commission on Cancer stage correlated with increased incidence of positive/equivocal PET/CT results and treatment failure. Maximal standardized uptake value was not predictive of any clinical outcome. Conclusions: A negative result on PET/CT obtained 4-6 months after radiotherapy is highly sensitive and correlates with successful locoregional control. Patients with negative scans may reasonably be spared invasive diagnostic procedures, such as biopsy and neck dissection, unless recurrent disease is suspected

  4. Environmental monitoring and assessment program forest health monitoring quality assurance project plan for detection monitoring project

    SciTech Connect

    Cline, S.P.; Alexander, S.A.; Barnard, J.E.

    1995-05-01

    The Quality Assurance Project Plan (QAP) is written specifically for the Detection Minitoring project of the interagency Forest Health Monitoring (FHM) program. Sections 1 through 3 briefly explain key features of the Environmental Monitoring and Assessment Program (EMAP), the FHM program, and their interrelationship, respectively. Section 4 describes the general quality assurance (QA) requirements for the FHM Detection Monitoring project. Section 5 contains the separate QAPs for each forest condition indicator: site condition and tree growth and regeneration, tree crown condition, tree damage assessment, photosynthetically active radiation (PAR), vegetation structure, ozone bioindicator plants, and lichen communities.

  5. Thallium-201 myocardial tomography with a rotating slant-hole collimator and a large number of projections

    SciTech Connect

    Dale, S.; Bone, D. )

    1990-10-01

    Tomographic imaging of the myocardium was performed using a gamma camera and a 30-degree rotating slant-hole collimator to register 64 projections from a restricted-view angle. Section images were reconstructed with a two-dimensional filtered backprojection technique. Performance in terms of resolution, effects of misalignment, and three-dimensional activity distribution was evaluated in phantom studies. In a limited clinical study, ten consecutive patients were imaged both with single-photon emission computed tomography (SPECT) and the method described. In the new method, the camera was orientated in the 30 degrees left anterior oblique position with 15 degrees cranial tilt. Due to the short distance from the myocardium to the camera, resolution within reconstructed section images was high, the noise level was comparatively low, and the mean activity level in the posterior wall was significantly higher (p less than 0.005) than in SPECT.

  6. Wabash River Coal Gasification Repowering Project: A DOE Assessment

    SciTech Connect

    National Energy Technology Laboratory

    2002-01-15

    The goal of the U.S. Department of Energy (DOE) Clean Coal Technology Program (CCT) is to furnish the energy marketplace with a number of advanced, more efficient, and environmentally responsible coal utilization technologies through demonstration projects. These projects seek to establish the commercial feasibility of the most promising advanced coal technologies that have developed beyond the proof-of-concept stage. This document serves as a DOE post-project assessment (PPA) of a project selected in CCT Round IV, the Wabash River Coal Gasification Repowering (WRCGR) Project, as described in a Report to Congress (U.S. Department of Energy 1992). Repowering consists of replacing an existing coal-fired boiler with one or more clean coal technologies to achieve significantly improved environmental performance. The desire to demonstrate utility repowering with a two-stage, pressurized, oxygen-blown, entrained-flow, integrated gasification combined-cycle (IGCC) system prompted Destec Energy, Inc., and PSI Energy, Inc., to form a joint venture and submit a proposal for this project. In July 1992, the Wabash River Coal Gasification Repowering Project Joint Venture (WRCGRPJV, the Participant) entered into a cooperative agreement with DOE to conduct this project. The project was sited at PSI Energy's Wabash River Generating Station, located in West Terre Haute, Indiana. The purpose of this CCT project was to demonstrate IGCC repowering using a Destec gasifier and to assess long-term reliability, availability, and maintainability of the system at a fully commercial scale. DOE provided 50 percent of the total project funding (for capital and operating costs during the demonstration period) of $438 million.

  7. Assessing local resources and culture before instituting quality improvement projects.

    PubMed

    Hawkins, C Matthew

    2014-12-01

    The planning phases of quality improvement projects are commonly overlooked. Disorganized planning and implementation can escalate chaos, intensify resistance to change, and increase the likelihood of failure. Two important steps in the planning phase are (1) assessing local resources available to aid in the quality improvement project and (2) evaluating the culture in which the desired change is to be implemented. Assessing local resources includes identifying and engaging key stakeholders and evaluating if appropriate expertise is available for the scope of the project. This process also involves engaging informaticists and gathering available IT tools to plan and automate (to the extent possible) the data-gathering, analysis, and feedback steps. Culture in a department is influenced by the ability and willingness to manage resistance to change, build consensus, span boundaries between stakeholders, and become a learning organization. Allotting appropriate time to perform these preparatory steps will increase the odds of successfully performing a quality improvement project and implementing change. PMID:25467724

  8. Health Impact Assessment of Urban Development Project

    PubMed Central

    Shojaei, Parisa; Karimlou, Masoud; Mohammadi, Farahnaz; Malekafzali, Hosein

    2016-01-01

    Background: Health impact assessment (HIA) has emerged to identify those activities and policies likely to have major impacts on the health of a population. Method: In this research, qualitative method was applied to identifying health determinants that urban man made lake affect on them, formatting and weighing the hierarchy of the factors, calculating AHP, and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method for decide and ranking alternatives. Results: According to the results of the study, from the structural determinants point of view, the most positive effect of man-made lake was on Recreational services by 89.5% and the most negative one was on housing. According to intermediary determinants and general average, the most positive effect of lake was on physical activity and quality of air by 88.9% and the most negative one was on noise pollution by 46.7%. Ultimately, considering the positive and negative effects of lake between constructing and not constructing the lake option, the construction option was selected. Conclusion: There is substantial potential to improve public health by bringing decision makers’ attention to the health consequences of their actions; city councilpersons, zoning commissioners, and other decision makers typically have little background in health. PMID:27157160

  9. Solar technology assessment project. Volume 6: Photovoltaic technology assessment

    NASA Astrophysics Data System (ADS)

    Backus, C. E.

    1981-04-01

    Industrial production of photovoltaic systems and volume of sales are reviewed. Low cost silicon production techniques are reviewed, including the Czochralski process, heat exchange method, edge defined film fed growth, dentritic web growth, and silicon on ceramic process. Semicrystalline silicon, amorphous silicon, and low cost poly-silicon are discussed as well as advanced materials and concentrator systems. Balance of system components beyond those needed to manufacture the solar panels are included. Nontechnical factors are assessed. The 1986 system cost goals are briefly reviewed.

  10. [Health impact assessment of building and investment projects].

    PubMed

    Thriene, B

    2003-02-01

    For regional planning and approval procedures for building projects of a certain order of magnitude and power rating according to the German Federal Act on the Prevention of Emissions with Integrated Environmental Impact Assessment (EIA), the German public health departments, acting as public authorities, increasingly perform health impact assessments (HIA). The amended Act on Environmental Impact Assessment, the Decree on industrial plants which require approval (4th Federal Decree on Emission Prevention) and the Health Service Acts of the Federal States of Germany form the legal basis for the assessment of health issues with regard to approval procedures for building and investment projects. In the framework of the "Action Programme for the Environment and Health", the present article aims at making this process binding and to ensure responsibility and general involvement of the Public Health departments in all German Federal States. Future criteria, basic principles and procedures for single-case testing as well as assessment standards should meet these requirements. The Federal Ministry for the Environment and the Federal Ministry for Health should agree on Health Impact Assessment (HIA ) as well as on the relaxant stipulations in their procedures and general administrative regulations for implementing the Environmental Impact Assessment Act (EIA). Current EIA procedures focus on urban development and road construction, industrial investment projects, intensive animal husbandry plants, waste incineration plants, and wind energy farms. This paper illustrates examples meeting with varying degrees of public acceptance. However, being involved in the regional planning procedure for the project "Extension of the federal motorway A 14 from Magdeburg to Schwerin", the Public Health Service also shares global responsibility for health and climate protection. Demands for shortest routing conflict with objectives of environmental protection which should be given long

  11. [Health impact assessment of building and investment projects].

    PubMed

    Thriene, B

    2003-02-01

    For regional planning and approval procedures for building projects of a certain order of magnitude and power rating according to the German Federal Act on the Prevention of Emissions with Integrated Environmental Impact Assessment (EIA), the German public health departments, acting as public authorities, increasingly perform health impact assessments (HIA). The amended Act on Environmental Impact Assessment, the Decree on industrial plants which require approval (4th Federal Decree on Emission Prevention) and the Health Service Acts of the Federal States of Germany form the legal basis for the assessment of health issues with regard to approval procedures for building and investment projects. In the framework of the "Action Programme for the Environment and Health", the present article aims at making this process binding and to ensure responsibility and general involvement of the Public Health departments in all German Federal States. Future criteria, basic principles and procedures for single-case testing as well as assessment standards should meet these requirements. The Federal Ministry for the Environment and the Federal Ministry for Health should agree on Health Impact Assessment (HIA ) as well as on the relaxant stipulations in their procedures and general administrative regulations for implementing the Environmental Impact Assessment Act (EIA). Current EIA procedures focus on urban development and road construction, industrial investment projects, intensive animal husbandry plants, waste incineration plants, and wind energy farms. This paper illustrates examples meeting with varying degrees of public acceptance. However, being involved in the regional planning procedure for the project "Extension of the federal motorway A 14 from Magdeburg to Schwerin", the Public Health Service also shares global responsibility for health and climate protection. Demands for shortest routing conflict with objectives of environmental protection which should be given long

  12. Hellsgate Winter Range : Wildlife Mitigation Project. Preliminary Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration.

    1995-01-01

    The Bonneville Power Administration proposes funding the Hellsgate Winter Range Wildlife Mitigation Project in cooperation with the Colville Convederated Tribes and Bureau of Indian Affairs. This Preliminary Environmental Assessment examines the potential environmental effects of acquiring and managing property for wildlife and wildlife habitat within a large project area. The Propose action is intended to meet the need for mitigation of wildlife and wild life habitat that was adversely affected by the construction of Grand Coulee and Chief Joseph Dams and their reservoirs.

  13. Project Fox: Assessing Risks Posed By Asteroids

    NASA Astrophysics Data System (ADS)

    Reinhardt, J.; Chen, X.; Liu, W.; Manchev, P.; Paté-Cornell, M.

    2013-12-01

    In order to make decisions on how to invest limited research dollars on asteroid surveillance and mitigation options, an analytic understanding of the risks posed by impacts is necessary. Qualitative and quantitative studies have been performed to assess such risks, and some reasonable point estimates have been proposed. However, since consequential asteroid impacts tend to be rare events, point estimates and expected annual death rates do not adequately convey the heavy tail of the distribution, potentially leading to misguided resource allocations. We propose and develop a framework for new risk measures, including a distribution over the number of fatalities from asteroid impacts and the probability of a globally consequential impact. We implement a simulation of asteroid impacts using probabilistic inputs for impactor characteristics, and a Poisson process for asteroid arrivals over the next 100 years. Simulation results indicate that a significant portion of the risk to humans comes from asteroids in the 300-1000 meter diameter range; this is because asteroid impacts in this range can produce global effects, and are more frequent than those from asteroids greater than 1km in diameter. The relative importance of this size regime in overall asteroid impact risk is robust in simulation results, and we find the magnitude of risks is still sensitive to factors that contribute global effects from an asteroid impact. Initial results are provided on the sensitivity of impact risks to various mitigation measures, including 'civil defense' methods. These results underscore the need for next-generation survey missions, and can help provide the basis for setting future space telescope observation requirements.

  14. Student Involvement in Assessment: A Project Designed to Assess Class Participation Fairly and Reliably

    ERIC Educational Resources Information Center

    Dancer, Diane; Kamvounias, Patty

    2005-01-01

    This article describes a project designed to ensure that class participation in a large introductory commercial law course is assessed fairly and reliably. The subjectivity often associated with this type of assessment is minimized by involving students in the specification of clear criteria and the assessment process as they were asked to assess…

  15. Micro-computed tomography assessment of the progression of fracture healing in mice.

    PubMed

    O'Neill, Kevin R; Stutz, Christopher M; Mignemi, Nicholas A; Burns, Michael C; Murry, Matthew R; Nyman, Jeffry S; Schoenecker, Jonathan G

    2012-06-01

    The mouse fracture model is ideal for research into the pathways of healing because of the availability of genetic and transgenic mice and the ability to create cell-specific genetic mutations. While biomechanical tests and histology are available to assess callus integrity and tissue differentiation, respectively, micro-computed tomography (μCT) analysis has increasingly been utilized in fracture studies because it is non-destructive and provides descriptions of the structural and compositional properties of the callus. However, the dynamic changes of μCT properties that occur during healing are not well defined. Thus, the purpose of this study was to determine which μCT properties change with the progression of fracture repair and converge to values similar to unfractured bone in the mouse femur fracture model. A unilateral femur fracture was performed in C57BL/6 mice and intramedullary fixation performed. Fractured and un-fractured contralateral specimens were harvested from groups of mice between 2 and 12 weeks post-fracture. Parameters describing callus based on μCT were obtained, including polar moment of inertia (J), bending moment of inertia (I), total volume (TV), tissue mineral density (TMD), total bone volume fraction (BV/TV), and volumetric bone mineral density (vBMD). For comparison, plain radiographs were used to measure the callus diameter (D) and area (A); and biomechanical properties were evaluated using either three-point bending or torsion. The μCT parameters J, I, TV, and TMD converged toward their respective values of the un-fractured femurs over time, although significant differences existed between the two sides at every time point evaluated (p<0.05). Radiograph measurement D changed with repair progression in similar manner to TV. In contrast, BV/TV and BMD increased and decreased over time with statistical differences between callus and un-fractured bone occurring sporadically. Similarly, none of the biomechanical properties were found

  16. Digital imaging technology assessment: Digital document storage project

    NASA Technical Reports Server (NTRS)

    1989-01-01

    An ongoing technical assessment and requirements definition project is examining the potential role of digital imaging technology at NASA's STI facility. The focus is on the basic components of imaging technology in today's marketplace as well as the components anticipated in the near future. Presented is a requirement specification for a prototype project, an initial examination of current image processing at the STI facility, and an initial summary of image processing projects at other sites. Operational imaging systems incorporate scanners, optical storage, high resolution monitors, processing nodes, magnetic storage, jukeboxes, specialized boards, optical character recognition gear, pixel addressable printers, communications, and complex software processes.

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

    NASA Astrophysics Data System (ADS)

    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 < 0.01). GLCM feature correlation also significantly outperformed MDCTmeasured mean BMD (RMSE = 1.11 ± 0.17) (p< 10-4). These results suggest that biomechanical strength prediction in spinal vertebrae can be significantly improved through characterization of trabecular bone structure with GLCM-derived texture features.

  18. Assessment of the Mandibular Incisive Canal by Panoramic Radiograph and Cone-Beam Computed Tomography

    PubMed Central

    Shimura, Elisabeth; Chilvarquer, Israel; Fenyo-Pereira, Marlene

    2014-01-01

    Objectives. The region between mental foramens is considered as a zone of choice for implants. However, complications may arise due to an extension anterior to the mental foramen that forms the mandible incisive canal [MIC]. Our goal is to evaluate identification of MIC by both panoramic radiograph [PAN] and cone-beam computed tomography [CBCT]. Methods. 150 cases with bilateral MIC were analyzed. Images of a radiolucent canal, within the trabecular bone, surrounded by a radiopaque cortical bone representing the canal walls, and extending to the anterior portion beyond the mental foramen, were considered by two independent radiologists as being images of MIC. PAN and CBCT of these cases were evaluated by 2 other radiologists at different times. Agreement between results of examination methods was assessed by the Kappa coefficient. The interexaminer and intramethod rates for detection of MIC were analyzed by the McNemar test. Gender, mandible side, examiner, and type of method were analyzed by the generalized estimating equations [GEE] model. Results. significant difference between examiners [PAN: P = 0.146; CBCT: P = 0.749] was not observed. Analysis by GEE model showed no significant difference between genders [P = 0.411] and examiners [P = 0.183]. However, significant difference was observed for identification in both mandible right side [P = 0.001], where the identification frequency was higher, and CBCT method [P < 0.001]. Conclusions. PAN was not shown to be a safe examination to identify MIC. CBCT should always be used in preoperative planning and to reduce the number of complications in implant surgeries. PMID:25332719

  19. Projection Onto Convex Sets (POCS) method for photoacoustic tomography with a non negative constraint.

    PubMed

    Salehin, S M Akramus; Huang, Shaochun; Abhayapala, Thushara D

    2013-01-01

    Photoacoustic imaging is a biomedical imaging modality capable of early cancer detection. In this paper, we proposed a novel iterative Projections Onto Convex Sets (POCS) method for improving photoacoustic reconstruction. This method aims to obtain a non negative pressure distribution satisfying the measured signals. This POCS method is performed in the Fourier Bessel space avoiding matrix inversions in the projections, speeding up projections and is capable of handling the large data sets present in photoacoustic imaging. The numerical experiments performed showed that improved reconstruction was obtained with a few iterations together with the recovery of some lost information.

  20. Assessment of the Airway Characteristics in Children with Cleft Lip and Palate using Cone Beam Computed Tomography

    PubMed Central

    Marwah, Nikhil

    2016-01-01

    ABSTRACT Objective: The aim of our study is to use cone beam computed tomography (CBCT) to assess the dimensional changes in the nasopharyngeal soft-tissue characteristics in children of Indian origin with repaired cleft lip and palate (CLP) and to compare the results with patients with ideal occlusion. Materials and methods: A sample of 20 children (10 girls, 10 boys) with repaired CLP was selected. Cone beam computed tomography scans were taken to measure the nasopharyngeal airway changes in terms of linear measurements and sagittal cross-sectional areas. Error analysis was performed to prevent systematic or random errors. Independent means t-tests and Pearson correlation analysis were used to evaluate sex differences and the correlations among the variables. Results: Nasopharyngeal soft-tissue characteristics were different in the control and the study groups. Subjects with repaired CLP had lesser lower aerial width, lower adenoidal width and lower airway width. The upper airway width was also significantly lesser. The retropalatal and the total airway area were significantly greater in the control group. Conclusion: The narrow pharyngeal airway in patients with CLP might result in functional impairment of breathing in patients. Further investigations are necessary to clarify the relationship between pharyngeal structure and airway function in patients with CLP. How to cite this article: Agarwal A, Marwah N. Assessment of the Airway Characteristics in Children with Cleft Lip and Palate using Cone Beam Computed Tomography. Int J Clin Pediatr Dent 2016;9(1):5-9. PMID:27274147

  1. The Groundwater Performance Assessment Project Quality Assurance Plan

    SciTech Connect

    Luttrell, Stuart P.

    2006-05-11

    U.S. Department of Energy (DOE) has monitored groundwater on the Hanford Site since the 1940s to help determine what chemical and radiological contaminants have made their way into the groundwater. As regulatory requirements for monitoring increased in the 1980s, there began to be some overlap between various programs. DOE established the Groundwater Performance Assessment Project (groundwater project) in 1996 to ensure protection of the public and the environment while improving the efficiency of monitoring activities. The groundwater project is designed to support all groundwater monitoring needs at the site, eliminate redundant sampling and analysis, and establish a cost-effective hierarchy for groundwater monitoring activities. This document provides the quality assurance guidelines that will be followed by the groundwater project. This QA Plan is based on the QA requirements of DOE Order 414.1C, Quality Assurance, and 10 CFR 830, Subpart A--General Provisions/Quality Assurance Requirements as delineated in Pacific Northwest National Laboratory’s Standards-Based Management System. In addition, the groundwater project is subject to the Environmental Protection Agency (EPA) Requirements for Quality Assurance Project Plans (EPA/240/B-01/003, QA/R-5). The groundwater project has determined that the Hanford Analytical Services Quality Assurance Requirements Documents (HASQARD, DOE/RL-96-68) apply to portions of this project and to the subcontractors. HASQARD requirements are discussed within applicable sections of this plan.

  2. Assessment and in vivo scoring of murine experimental autoimmune uveoretinitis using optical coherence tomography.

    PubMed

    Chu, Colin J; Herrmann, Philipp; Carvalho, Livia S; Liyanage, Sidath E; Bainbridge, James W B; Ali, Robin R; Dick, Andrew D; Luhmann, Ulrich F O

    2013-01-01

    Despite advances in clinical imaging and grading our understanding of retinal immune responses and their morphological correlates in experimental autoimmune uveoretinitis (EAU), has been hindered by the requirement for post-mortem histology. To date, monitoring changes occurring during EAU disease progression and evaluating the effect of therapeutic intervention in real time has not been possible. We wanted to establish whether optical coherence tomography (OCT) could detect intraretinal changes during inflammation and to determine its utility as a tool for accurate scoring of EAU. EAU was induced in C57BL/6J mice and animals evaluated after 15, 26, 36 and 60 days. At each time-point, contemporaneous Spectralis-OCT scanning, topical endoscopic fundal imaging (TEFI), fundus fluorescein angiography (FFA) and CD45-immunolabelled histology were performed. OCT features were further characterised on retinal flat-mounts using immunohistochemistry and 3D reconstruction. Optic disc swelling and vitreous opacities detected by OCT corresponded to CD45+ cell infiltration on histology. Vasculitis identified by FFA and OCT matched perivascular myeloid and T-cell infiltrates and could be differentiated from unaffected vessels. Evolution of these changes could be followed over time in the same eye. Retinal folds were visible and found to encapsulate mixed populations of activated myeloid cells, T-cells and microglia. Using these features, an OCT-based EAU scoring system was developed, with significant correlation to validated histological (Pearson r(2) = 0.6392, P<0.0001, n = 31 eyes) and TEFI based scoring systems (r(2) = 0.6784, P<0.0001). OCT distinguishes the fundamental features of murine EAU in vivo, permits dynamic assessment of intraretinal changes and can be used to score disease severity. As a result, it allows tissue synchronisation with subsequent cellular and functional assessment and greater efficiency of animal usage. By relating OCT signals with

  3. Rectal cancer staging: Multidetector-row computed tomography diagnostic accuracy in assessment of mesorectal fascia invasion

    PubMed Central

    Ippolito, Davide; Drago, Silvia Girolama; Franzesi, Cammillo Talei; Fior, Davide; Sironi, Sandro

    2016-01-01

    AIM: To assess the diagnostic accuracy of multidetector-row computed tomography (MDCT) as compared with conventional magnetic resonance imaging (MRI), in identifying mesorectal fascia (MRF) invasion in rectal cancer patients. METHODS: Ninety-one patients with biopsy proven rectal adenocarcinoma referred for thoracic and abdominal CT staging were enrolled in this study. The contrast-enhanced MDCT scans were performed on a 256 row scanner (ICT, Philips) with the following acquisition parameters: tube voltage 120 KV, tube current 150-300 mAs. Imaging data were reviewed as axial and as multiplanar reconstructions (MPRs) images along the rectal tumor axis. MRI study, performed on 1.5 T with dedicated phased array multicoil, included multiplanar T2 and axial T1 sequences and diffusion weighted images (DWI). Axial and MPR CT images independently were compared to MRI and MRF involvement was determined. Diagnostic accuracy of both modalities was compared and statistically analyzed. RESULTS: According to MRI, the MRF was involved in 51 patients and not involved in 40 patients. DWI allowed to recognize the tumor as a focal mass with high signal intensity on high b-value images, compared with the signal of the normal adjacent rectal wall or with the lower tissue signal intensity background. The number of patients correctly staged by the native axial CT images was 71 out of 91 (41 with involved MRF; 30 with not involved MRF), while by using the MPR 80 patients were correctly staged (45 with involved MRF; 35 with not involved MRF). Local tumor staging suggested by MDCT agreed with those of MRI, obtaining for CT axial images sensitivity and specificity of 80.4% and 75%, positive predictive value (PPV) 80.4%, negative predictive value (NPV) 75% and accuracy 78%; while performing MPR the sensitivity and specificity increased to 88% and 87.5%, PPV was 90%, NPV 85.36% and accuracy 88%. MPR images showed higher diagnostic accuracy, in terms of MRF involvement, than native axial images

  4. Label-free assay for the assessment of nonspecific binding of positron emission tomography tracer candidates.

    PubMed

    Assmus, Frauke; Seelig, Anna; Gobbi, Luca; Borroni, Edilio; Glaentzlin, Patricia; Fischer, Holger

    2015-11-15

    Positron emission tomography (PET) is a valuable non-invasive technique for the visualization of drug tissue distribution and receptor occupancy at the target site in living animals and men. Many potential PET tracers, however, fail due to an unfavorably high non-specific binding (NSB) to non-target proteins and phospholipid membranes which compromises the sensitivity of PET. Hence, there is a high demand to assess the extent of NSB as early as possible in the PET tracer development process, preferentially before ligands are radiolabeled and elaborate imaging studies are performed. The purpose of this study was to establish a novel Lipid Membrane Binding Assay (LIMBA) for assessing the tendency of potential tracers to bind non-specifically to brain tissue. The assay works with unlabeled compounds and allows the medium-throughput measurement of brain tissue/water distribution coefficients, logDbrain (pH7.4), at minimal expense of animal tissue. To validate LIMBA, logDbrain (pH7.4) values were measured and compared with NSB estimates derived from in vivo PET studies in human brain (n=10 tracers, literature data), and in vitro autoradiography studies in rat and mouse brain slices (n=30 tritiated radioligands). Good agreement between logDbrain (pH7.4) and the volume of distribution in brain of non-specifically bound tracer in PET was achieved, pertaining to compounds classified as non-substrates of P-glycoprotein (R(2)≥0.88). The ability of LIMBA for the prediction of NSB was further supported by the strong correlation between logDbrain (pH7.4) and NSB in brain autoradiography (R(2)≥0.76), whereas octanol/water distribution coefficients, logDoct (pH7.4) were less predictive. In conclusion, LIMBA provides a fast and reliable tool for identifying compounds with unfavorably high NSB in brain tissue. The data may be used in conjunction with other parameters like target affinity, density and membrane permeability for the selection of most promising compounds to be

  5. Computed Tomography and Magnetic Resonance Enterography in Crohn's Disease: Assessment of Radiologic Criteria and Endpoints for Clinical Practice and Trials.

    PubMed

    Deepak, Parakkal; Fletcher, Joel G; Fidler, Jeff L; Bruining, David H

    2016-09-01

    Early recognition of Crohn's disease with initiation of disease-modifying therapy has emerged as a prominent inflammatory bowel disease management strategy. Clinical practice and trials have often focused on patient symptoms, and more recently, serologic tests, stool inflammatory markers, and/or endoscopic inflammatory features for study entry criteria, treatment targets, disease activity monitoring, and to assess therapeutic response. Unfortunately, patient symptoms do not correlate well with biological disease activity, and endoscopy potentially misses or underestimates disease extent and severity in small bowel Crohn's disease. Computed tomography enterography and magnetic resonance enterography (MRE) are potential tools to identify and quantify transmural structural damage and disease activity in the small bowel. In this review, we discuss the role of computed tomography enterography and MRE in disease management algorithms in clinical practice. We also compare the currently developed MRE-based scoring systems, their strengths and pitfalls, as well as the role for MRE in clinical trials for Crohn's disease. PMID:27508513

  6. Rapid Response Risk Assessment in New Project Development

    NASA Technical Reports Server (NTRS)

    Graber, Robert R.

    2010-01-01

    A capability for rapidly performing quantitative risk assessments has been developed by JSC Safety and Mission Assurance for use on project design trade studies early in the project life cycle, i.e., concept development through preliminary design phases. A risk assessment tool set has been developed consisting of interactive and integrated software modules that allow a user/project designer to assess the impact of alternative design or programmatic options on the probability of mission success or other risk metrics. The risk and design trade space includes interactive options for selecting parameters and/or metrics for numerous design characteristics including component reliability characteristics, functional redundancy levels, item or system technology readiness levels, and mission event characteristics. This capability is intended for use on any project or system development with a defined mission, and an example project will used for demonstration and descriptive purposes, e.g., landing a robot on the moon. The effects of various alternative design considerations and their impact of these decisions on mission success (or failure) can be measured in real time on a personal computer. This capability provides a high degree of efficiency for quickly providing information in NASA s evolving risk-based decision environment

  7. Integrated economic and climate projections for impact assessment

    EPA Science Inventory

    We designed scenarios for impact assessment that explicitly address policy choices and uncertainty in climate response. Economic projections and the resulting greenhouse gas emissions for the “no climate policy” scenario and two stabilization scenarios: at 4.5 W/m2 and 3.7 W/m2 b...

  8. Transmission tomography under Poisson noise using the Anscombe transformation and Wiener filtering of the projections

    NASA Astrophysics Data System (ADS)

    Mascarenhas, Nelson D. A.; Santos, Cid A. N.; Cruvinel, Paulo E.

    1999-03-01

    A minitomograph scanner for soil science was developed by the National Center for Research and Development of Agricultural Instrumentation (EMBRAPA/CNPDIA). The purpose of this paper is twofold. First, a statistical characterization of the noise affecting the projection measurements of this scanner is presented. Second, having determined the Poisson nature of this noise, a new method of filtering the projection data prior to the reconstruction is proposed. It is based on transforming the Poisson noise into Gaussian additive noise, filtering the projections in blocks through the Wiener filter and performing the inverse tranformation. Results with real data indicate that this method gives superior results, as compared to conventional backprojection with the ramp filter, by taking into consideration both resolution and noise, through a mean square error criterion.

  9. Environmental Restoration Disposal Facility (Project W-296) Safety Assessment

    SciTech Connect

    Armstrong, D.L.

    1994-08-01

    This Safety Assessment is based on information derived from the Conceptual Design Report for the Environmental Restoration Disposal Facility (DOE/RL 1994) and ancillary documentation developed during the conceptual design phase of Project W-296. The Safety Assessment has been prepared to support the Solid Waste Burial Ground Interim Safety Basis document. The purpose of the Safety Assessment is to provide an evaluation of the design to determine if the process, as proposed, will comply with US Department of Energy (DOE) Limits for radioactive and hazardous material exposures and be acceptable from an overall health and safety standpoint. The evaluation considered affects on the worker, onsite personnel, the public, and the environment.

  10. Environmental assessment, expanded Ponnequin wind energy project, Weld County, Colorado

    SciTech Connect

    1999-02-01

    The US Department of Energy (DOE) has considered a proposal from the State of Colorado, Office of Energy Conservation (OEC), for funding construction of the Expanded Ponnequin Wind Project in Weld County, Colorado. OEC plans to enter into a contracting arrangement with Public Service Company of Colorado (PSCo) for the completion of these activities. PSCo, along with its subcontractors and business partners, are jointly developing the Expanded Ponnequin Wind Project. The purpose of this Final Environmental Assessment (EA) is to provide DOE and the public with information on potential environmental impacts associated with the Expanded Ponnequin Wind Energy Project. This EA, and public comments received on it, were used in DOE`s deliberations on whether to release funding for the expanded project under the Commercialization Ventures Program.

  11. Malingering dissociative identity disorder: objective and projective assessment.

    PubMed

    Labott, Susan M; Wallach, Heather R

    2002-04-01

    Verification of dissociative identity disorder presents challenges given the complex nature of the illness. This study addressed the concern that this disorder can be successfully malingered on objective and projective psychological tests. 50 undergraduate women were assigned to a Malingering or a Control condition, then completed the Rorschach Inkblot Test and the Dissociative Experiences Scale II. The Malingering group were asked to simulate dissociative identity disorder; controls received instructions to answer all materials honestly. Analysis indicated that malingerers were significantly more likely to endorse dissociative experiences on the Dissociative Experiences Scale II in the range common to patients with diagnosed dissociative identity disorder. However, on the Rorschach there were no significant differences between the two groups. Results suggest that the assessment of dissociative identity disorder requires a multifaceted approach with both objective and projective assessment tools. Research is needed to assess these issues in clinical populations.

  12. Wabash River Coal Gasification Repowering Project: A DOE Assessment

    SciTech Connect

    National Energy Technology Laboratory

    2002-01-15

    The goal of the U.S. Department of Energy (DOE) Clean Coal Technology Program (CCT) is to furnish the energy marketplace with a number of advanced, more efficient, and environmentally responsible coal utilization technologies through demonstration projects. These projects seek to establish the commercial feasibility of the most promising advanced coal technologies that have developed beyond the proof-of-concept stage. This document serves as a DOE post-project assessment (PPA) of a project selected in CCT Round IV, the Wabash River Coal Gasification Repowering (WRCGR) Project, as described in a Report to Congress (U.S. Department of Energy 1992). Repowering consists of replacing an existing coal-fired boiler with one or more clean coal technologies to achieve significantly improved environmental performance. The desire to demonstrate utility repowering with a two-stage, pressurized, oxygen-blown, entrained-flow, integrated gasification combined-cycle (IGCC) system prompted Destec Energy, Inc., and PSI Energy, Inc., to form a joint venture and submit a proposal for this project. In July 1992, the Wabash River Coal Gasification Repowering Project Joint Venture (WRCGRPJV, the Participant) entered into a cooperative agreement with DOE to conduct this project. The project was sited at PSI Energy's Wabash River Generating Station, located in West Terre Haute, Indiana. The purpose of this CCT project was to demonstrate IGCC repowering using a Destec gasifier and to assess long-term reliability, availability, and maintainability of the system at a fully commercial scale. DOE provided 50 percent of the total project funding (for capital and operating costs during the demonstration period) of $438 million. Construction for the demonstration project was started in July 1993. Pre-operational tests were initiated in August 1995, and construction was completed in November 1995. Commercial operation began in November 1995, and the demonstration period was completed in December

  13. Quantification for complex assessment: uncertainty estimation in final year project thesis assessment

    NASA Astrophysics Data System (ADS)

    Kim, Ho Sung

    2013-12-01

    A quantitative method for estimating an expected uncertainty (reliability and validity) in assessment results arising from the relativity between four variables, viz examiner's expertise, examinee's expertise achieved, assessment task difficulty and examinee's performance, was developed for the complex assessment applicable to final year project thesis assessment including peer assessment. A guide map can be generated by the method for finding expected uncertainties prior to the assessment implementation with a given set of variables. It employs a scale for visualisation of expertise levels, derivation of which is based on quantified clarities of mental images for levels of the examiner's expertise and the examinee's expertise achieved. To identify the relevant expertise areas that depend on the complexity in assessment format, a graphical continuum model was developed. The continuum model consists of assessment task, assessment standards and criterion for the transition towards the complex assessment owing to the relativity between implicitness and explicitness and is capable of identifying areas of expertise required for scale development.

  14. Contrast and resolution analysis of angular domain imaging for iterative optical projection tomography reconstruction

    NASA Astrophysics Data System (ADS)

    Ng, Eldon; Vasefi, Fartash; Kaminska, Bozena; Chapman, Glenn H.; Carson, Jeffrey J. L.

    2010-02-01

    Angular domain imaging (ADI) generates a projection image of an attenuating target within a turbid medium by employing a silicon micro-tunnel array to reject photons that have deviated from the initial propagation direction. In this imaging method, image contrast and resolution are position dependent. The objective of this work was to first characterize the contrast and resolution of the ADI system at a multitude of locations within the imaging plane. The second objective was to compare the reconstructions of different targets using filtered back projection and iterative reconstruction algorithms. The ADI system consisted of a diode laser laser (808nm, CW, ThorLabs) with a beam expander for illumination of the sample cuvette. At the opposite side of the cuvette, an Angular Filter Array (AFA) of 80 μm x 80 μm square-shaped tunnels 1 cm in length was used to reject the transmitted scattered light. Image-forming light exiting the AFA was detected by a linear CCD (16-bit, Mightex). Our approach was to translate two point attenuators (0.5 mm graphite rod, 0.368 mm drill bit) submerged in a 0.6% IntralipidTM dilution using a SCARA robot (Epson E2S351S) to cover a 37x37 and 45x45 matrix of grid points in the imaging plane within the 1 cm path length sample cuvette. At each grid point, a one-dimensional point-spread distribution was collected and system contrast and resolution were measured. Then, the robot was used to rotate the target to collect projection images at several projection angles of various objects, and reconstructed with a filtered back projection and an iterative reconstruction algorithm.

  15. Impact of Age on Stent Strut Coverage and Neointimal Remodeling as Assessed by Optical Coherence Tomography

    PubMed Central

    Han, Zhigang; Feng, Linxing; Du, Hongwei; Sun, Zhao; Hu, Sining; Dai, Jiannan; Sun, Meng; Xing, Lei; Hou, Jingbo; Zhang, Shaosong; Yu, Bo

    2015-01-01

    Abstract While older age associates with adverse percutaneous coronary intervention (PCI) outcomes, detailed information relating age to stent strut coverage and neointimal characteristics is lacking. One hundred nineteen patients with 123 sirolimus-eluting stents (SESs) were divided into 3 groups: group A (≤55 years), group B (56–65 years), and group C (>65 years). At 6 and 12 months of follow-up, optical coherence tomography was performed to assess strut coverage and neointimal remodeling. At 6 months, the proportion of uncovered struts increased with age: 6.1% in group A versus 7.3% in group B versus 11.7% in group C (P < 0.001) while the proportion of embedded struts decreased: 72.1% versus 57.0% vs. 55.0%, respectively (P < 0.001). Mean neointimal thicknesses were 90 μm versus 60 μm versus 60 μm, respectively (P < 0.001), and neointimal areas were 0.82 mm2 versus 0.52 mm2 versus 0.57 mm2 (P < 0.001). At 12 months, the proportion of uncovered struts increased with age (3.9% vs. 3.3% vs. 4.9 %; P < 0.001), while mean neointimal thicknesses were 100 versus 70 versus 80 μm (P < 0.001) and neointimal areas were 0.87 versus 0.60 versus 0.67 mm2 (P < 0.001). Patients ≤55 years receiving SES showed highest strut coverage and neointimal repair rate compared with the other 2 groups. A “catch-up phenomenon” appeared to occur in the oldest patients, as in the first 6 months the neointima showed lowest endothelial cell coverage and lowest neointimal proliferation rate, whereas from 6 to 12 months, the highest neointimal proliferation rate was seen in the oldest patients. PMID:26683940

  16. Assessment of mandibular posterior regional landmarks using cone-beam computed tomography in dental implant surgery.

    PubMed

    de Souza, Lílian Azevedo; Souza Picorelli Assis, Neuza Maria; Ribeiro, Rosangela Almeida; Pires Carvalho, Antônio Carlos; Devito, Karina Lopes

    2016-05-01

    The aim of this study has been to evaluate and correlate the anatomical features of the posterior mandibular region (submandibular fossa depth, bone height and thickness, and mandibular canal corticalization) to improve accident prevention and allow safe planning in implantology. Four parasagittal sections of cone-beam computed tomography (CBCT) from 100 patients were bilaterally analyzed. Linear measurements of the submandibular fossa depth, bone height and thickness were performed. The submandibular fossa was also classified into non-influential undercuts and influential undercuts for implant placement. Mandibular canal corticalization was also evaluated and classified according to the visualization. Data on patient age and gender were also collected. Forty-one scans (41%) were from male patients, and 59 (59%) were from female patients. Patient age ranged between 18 and 84 years, with an average age of 51.37 years. The submandibular fossa depth and implant bone thickness had a significant effect on the variability of the sample (46.1% and 22.3%, respectively). The submandibular fossa depth was quite variable, and the highest values were observed in the posterior regions. In 18.27% of the cases, the presence of the fossa directly influenced implant placement, considering a bone height of 10mm (standard implant). A significant correlation was observed between fossa depth and bone thickness. Thus, greater attention should be paid to thick ridges; although thick ridges are favorable, they may be associated with deeper submandibular fossae. The mandibular canal was the most influential anatomical structure in the premolar region due to the reduced bone height in this region and the greater difficulty in viewing the canal, and the submandibular fossa was the most influential structure in the molar region due to lower bone height leading up to the fossa and the greater fossa depth in this region. Therefore, CBCT is an important tool for assessing the mandibular region

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

    NASA Astrophysics Data System (ADS)

    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

  18. Comparison of cone-beam computed tomography cephalometric measurements using a midsagittal projection and conventional two-dimensional cephalometric measurements

    PubMed Central

    Jung, Pil-Kyo; Lee, Gung-Chol

    2015-01-01

    Objective This study investigated whether it is possible to use a two-dimensional (2D) standard in three-dimensional (3D) analysis, by comparing the angles and lengths measured from a midsagittal projection in 3D cone-beam computed tomography (CBCT) with those measured by 2D lateral cephalometric radiography (LCR). Methods Fifty patients who underwent both LCR and CBCT were selected as subjects. CBCT was reoriented in 3 different methods and the measuring-points were projected onto the midsagittal plane. Twelve angle values and 8 length values were measured on both LCR and CBCT and compared. Results Repeated measures analysis of the variance revealed statistically significant differences in 7 angular and 5 linear measurements among LCR and 3 types of CBCT (p < 0.05). Of these 12 measurements, multiple comparisons showed that 6 measurements (ANB, AB to FH, IMPA, FMA, Co-Gn, Go-Me) were not significantly different in pairwise comparisons. LCR was significantly different from 3 types of CBCT in 3 angular (SN to FH, interincisal angle, FMIA) and 2 linear (S-Go, Co-ANS) measurements. The CBCT method was similar for all measurements, except for 1 linear measurement, i.e., S-N. However, the disparity between the mean values for all parameters was within the range of clinical measurement error. Conclusions 3D-CBCT analysis, using midsagittal projection, is a useful method in which the 2D-LCR normative values can be used. Although the measurements changed with reorientation, these changes were not clinically significant. PMID:26629474

  19. Electrical impedance tomography for assessing ventilation/perfusion mismatch for pulmonary embolism detection without interruptions in respiration.

    PubMed

    Nguyen, Doan Trang; Thiagalingam, Aravinda; Bhaskaran, Abhishek; Barry, Michael A; Pouliopoulos, Jim; Jin, Craig; McEwan, Alistair L

    2014-01-01

    Recent studies have shown high correlation between pulmonary perfusion mapping with impedance contrast enhanced Electrical Impedance Tomography (EIT) and standard perfusion imaging methods such as Computed Tomography (CT) and Single Photon Emission Computerized Tomography (SPECT). EIT has many advantages over standard imaging methods as it is highly portable and non-invasive. Contrast enhanced EIT uses hypertonic saline bolus instead of nephrotoxic contrast medium that are utilized by CT and nuclear Ventilation/Perfusion (V/Q) scans. However, current implementation of contrast enhanced EIT requires induction of an apnea period for perfusion measurement, rendering it disadvantageous compared with current gold standard imaging modalities. In the present paper, we propose the use of a wavelet denoising algorithm to separate perfusion signal from ventilation signal such that no interruption in patient's ventilation would be required. Furthermore, right lung to left lung perfusion ratio and ventilation ratio are proposed to assess the mismatch between ventilation and perfusion for detection of Pulmonary Embolism (PE). The proposed methodology was validated on an ovine model (n=3, 83.7±7.7 kg) with artificially induced PE in the right lung. The results showed a difference in right lung to left lung perfusion ratio between baseline and diseased states in all cases with all paired t-tests between baseline and PE yielding p <; 0.01, while the right lung to left lung ventilation ratio remained unchanged in two out of three experiments. Statistics were pooled from multiple repetitions of measurements per experiment.

  20. Attention Performance in Autism and Regional Brain Metabolic Rate Assessed by Positron Emission Tomography. Brief Report.

    ERIC Educational Resources Information Center

    Buchsbaum, M. S.; And Others

    1992-01-01

    This evaluation of seven high functioning adults with autism utilized positron emission tomography on a visual vigilance task. Although the subjects, as a group, did as well as normal controls on the task, there was a lack of normal hemispheric asymmetry in glucose metabolic rate. A heterogeneous etiology for autism is suggested to explain…

  1. Coronary Computed Tomography Angiography in the Assessment of Acute Chest Pain in the Emergency Room

    PubMed Central

    dos Prazeres, Carlos Eduardo Elias; Cury, Roberto Caldeira; Carneiro, Adriano Camargo de Castro; Rochitte, Carlos Eduardo

    2013-01-01

    The coronary computed tomography angiography has recently emerged as an accurate diagnostic tool in the evaluation of coronary artery disease, providing diagnostic and prognostic data that correlate directly with the data provided by invasive coronary angiography. The association of recent technological developments has allowed improved temporal resolution and better spatial coverage of the cardiac volume with significant reduction in radiation dose, and with the crucial need for more effective protocols of risk stratification of patients with chest pain in the emergency room, recent evaluation of the computed tomography coronary angiography has been performed in the setting of acute chest pain, as about two thirds of invasive coronary angiographies show no significantly obstructive coronary artery disease. In daily practice, without the use of more efficient technologies, such as coronary angiography by computed tomography, safe and efficient stratification of patients with acute chest pain remains a challenge to the medical team in the emergency room. Recently, several studies, including three randomized trials, showed favorable results with the use of this technology in the emergency department for patients with low to intermediate likelihood of coronary artery disease. In this review, we show data resulting from coronary angiography by computed tomography in risk stratification of patients with chest pain in the emergency room, its diagnostic value, prognosis and cost-effectiveness and a critical analysis of recently published multicenter studies. PMID:24145392

  2. Guidance on internal dose assessments from monitoring data (project IDEAS).

    PubMed

    Doerfel, H; Andrasi, A; Bailey, M; Berkovski, V; Castellani, C M; Hurtgen, C; Jourdain, J R; LeGuen, B

    2003-01-01

    Several international inter-comparison exercises on intake and internal dose assessments from monitoring data led to the conclusion that the results calculated by different participants varied significantly, mainly due to the broad variety of methods and assumptions applied in the assessment procedure. Based on these experiences, the need of harmonisation of the procedures has been formulated as an EU research project under the 5th Framework Programme, with the aim of developing general guidelines for standardising assessments of intakes and internal doses. In the IDEAS project, eight institutions from seven European countries are participating, also using inputs from internal dosimetry professionals from across Europe to ensure broad consensus in the outcome of the project. To ensure that the guidelines are applicable to a wide range of practical situations, the first step will be to compile a database on well documented cases of internal contamination. In parallel, an improved version of existing software will be developed and distributed to the partners for further use. Many cases from the database will be evaluated independently by more partners using the same software and the results will be discussed and the draft guidelines prepared. The guidelines will then be revised and refined on the basis of the experiences and discussions of two workshops, and an intercomparison exercise organised in the frame of the project which will be open to all internal dosimetry professionals.

  3. Environmental Assessment Expanded Ponnequin Wind Energy Project Weld County, Colorado

    SciTech Connect

    N /A

    1999-03-02

    The U.S.Department of Energy (DOE) has considered a proposal from the State of Colorado, Office of Energy Conservation (OEC), for funding construction of the Expanded Ponnequin Wind Project in Weld County, Colorado. OEC plans to enter into a contracting arrangement with Public Service Company of Colorado (PSCO) for the completion of these activities. PSCo, along with its subcontractors and business partners, are jointly developing the Expanded Ponnequin Wind Project. DOE completed an environmental assessment of the original proposed project in August 1997. Since then, the geographic scope and the design of the project changed, necessitating additional review of the project under the National Environmental Policy Act. The project now calls for the possible construction of up to 48 wind turbines on State and private lands. PSCo and its partners have initiated construction of the project on private land in Weld County, Colorado. A substation, access road and some wind turbines have been installed. However, to date, DOE has not provided any funding for these activities. DOE, through its Commercialization Ventures Program, has solicited applications for financial assistance from state energy offices, in a teaming arrangement with private-sector organizations, for projects that will accelerate the commercialization of emerging renewable energy technologies. The Commercialization Ventures Program was established by the Renewable Energy and Energy Efficiency Technology Competitiveness Act of 1989 (P.L. 101-218) as amended by the Energy Policy Act of 1992 (P.L. 102-486). The Program seeks to assist entry into the marketplace of newly emerging renewable energy technologies, or of innovative applications of existing technologies. In short, an emerging renewable energy technology is one which has already proven viable but which has had little or no operational experience. The Program is managed by the Department of Energy, Office of Energy Efficiency and Renewable Energy. The

  4. A Conceptual Framework for Post-Project Assessment Applied to the Provo River Restoration Project, Utah

    NASA Astrophysics Data System (ADS)

    Goetz, R. R.; Schmidt, J. C.; Erwin, S.; Gooseff, M. N.

    2007-12-01

    Comprehensive assessment of stream restoration projects necessitates evaluation of: 1) the actual pre-project condition in relation to the public perception of impairment, 2) the project concept, goals, and objectives, 3) the project design, 4) the project as actually built, and 5) the project performance. We applied this framework in assessing the recently completed Provo River Restoration Project (PRRP). Begun in 1999 and completed in 2007, the PRRP's budget was 10 million for construction of approximately 16 km of channel and adjacent floodplain wetlands. We analyzed project planning documents, design documents, and made field measurements of the Provo River channel before and after channel re-alignment. Although the impaired, pre-project channel was never explicitly measured by restoration designers, our measurements demonstrate that the bed material organization and floodplain inundation frequency was perturbed from those attributes typical of channels in similar physiographic settings. Project designers did not develop quantitative project goals, and there were no metrics by which performance success was to be measured. Design documents demonstrate that the realigned channel has the potential to re-establish channel and floodplain connection. Surprisingly, there were significant differences between design and as-built channel geometry. These discrepancies have the potential to adversely impact project performance in re-establishing the ecosystem benefits provided by a naturalized channel/floodplain connection. However, field construction of a channel whose capacity is larger than designed has been compensated by a hydrologic regime whose common floods have been larger than anticipated. In addition, the original channel design did not explicitly consider sediment supply, which has the potential to rearrange reconstructed channel elements in the downstream part of the project. Collectively, this analysis demonstrates the degree of uncertainty and ambiguity

  5. Dose Assessment in Computed Tomography Examination and Establishment of Local Diagnostic Reference Levels in Mazandaran, Iran

    PubMed Central

    Janbabanezhad Toori, A.; Shabestani-Monfared, A.; Deevband, M.R.; Abdi, R.; Nabahati, M.

    2015-01-01

    Background Medical X-rays are the largest man-made source of public exposure to ionizing radiation. While the benefits of Computed Tomography (CT) are well known in accurate diagnosis, those benefits are not risk-free. CT is a device with higher patient dose in comparison with other conventional radiation procedures. Objective This study is aimed at evaluating radiation dose to patients from Computed Tomography (CT) examination in Mazandaran hospitals and defining diagnostic reference level (DRL). Methods Patient-related data on CT protocol for four common CT examinations including brain, sinus, chest and abdomen & pelvic were collected. In each center, Computed Tomography Dose Index (CTDI) measurements were performed using pencil ionization chamber and CT dosimetry phantom according to AAPM report No. 96 for those techniques. Then, Weighted Computed Tomography Dose Index (CTDIW), Volume Computed Tomography Dose Index (CTDI vol) and Dose Length Product (DLP) were calculated. Results The CTDIw for brain, sinus, chest and abdomen & pelvic ranged (15.6-73), (3.8-25. 8), (4.5-16.3) and (7-16.3), respectively. Values of DLP had a range of (197.4-981), (41.8-184), (131-342.3) and (283.6-486) for brain, sinus, chest and abdomen & pelvic, respectively. The 3rd quartile of CTDIW, derived from dose distribution for each examination is the proposed quantity for DRL. The DRLs of brain, sinus, chest and abdomen & pelvic are measured 59.5, 17, 7.8 and 11 mGy, respectively. Conclusion Results of this study demonstrated large scales of dose for the same examination among different centers. For all examinations, our values were lower than international reference doses. PMID:26688796

  6. Mod-2 wind turbine project assessment and cluster test plans

    NASA Technical Reports Server (NTRS)

    Gordon, L. H.

    1982-01-01

    An assessment of the Mod-2 Wind Turbine project is presented based on initial goals and present results. Specifically, the Mod-2 background, project flow, and a chronology of events/results leading to Mod-2 acceptance is presented. After checkout/acceptance of the three operating turbines, NASA/LeRC will continue management of a two year test program performed at the DOE Goodnoe Hills test site. This test program is expected to yield data necessary for the continued development and optimization of wind energy systems. These test activities, the implementation of, and the results to date are also presented.

  7. Impact of the agricultural research service watershed assessment studies on the conservation effects assessment project cropland national assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    USDA initiated the Conservation Effects Assessment Project (CEAP) in 2002 to analyze societal and environmental benefits gained from the increased conservation program funding provided in the 2002 Farm Bill. The Natural Resources Conservation Service (NRCS), Agricultural Research Service (ARS), and...

  8. Assessment of wear and periacetabular osteolysis using dual energy computed tomography on a pig cadaver to identify the lowest acceptable radiation dose

    PubMed Central

    Skorpil, M.; Nowik, P.; Olivecrona, H.; Crafoord, J.; Weidenhielm, L.; Persson, A.

    2016-01-01

    Objectives Computed tomography (CT) plays an important role in evaluating wear and periacetabular osteolysis (PAO) in total hip replacements. One concern with CT is the high radiation exposure since standard pelvic CT provides approximately 3.5 millisieverts (mSv) of radiation exposure, whereas a planar radiographic examination with three projections totals approximately 0.5 mSv. The objective of this study was to evaluate the lowest acceptable radiation dose for dual-energy CT (DECT) images when measuring wear and periacetabular osteolysis in uncemented metal components. Materials and Methods A porcine pelvis with bilateral uncemented hip prostheses and with known linear wear and acetabular bone defects was examined in a third-generation multidetector DECT scanner. The examinations were performed with four different radiation levels both with and without iterative reconstruction techniques. From the high and low peak kilo voltage acquisitions, polychrmoatic images were created together with virtual monochromatic images of energies 100 kiloelectron volts (keV) and 150 keV. Results We could assess wear and PAO while substantially lowering the effective radiation dose to 0.7 mSv for a total pelvic view with an accuracy of around 0.5 mm for linear wear and 2 mm to 3 mm for PAO. Conclusion CT for detection of prosthetic wear and PAO could be used with clinically acceptable accuracy at a radiation exposure level equal to plain radiographic exposures. Cite this article: B. Sandgren, M. Skorpil, P. Nowik, H. Olivecrona, J. Crafoord, L. Weidenhielm, A. Persson. Assessment of wear and periacetabular osteolysis using dual energy computed tomography on a pig cadaver to identify the lowest acceptable radiation dose. Bone Joint Res 2016;5:307–313. DOI: 10.1302/2046-3758.57.2000566. PMID:27445358

  9. Assessment of strain and strain rate in embryonic chick heart in vivo using tissue Doppler optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Li, Peng; Liu, Aiping; Shi, Liang; Yin, Xin; Rugonyi, Sandra; Wang, Ruikang K.

    2011-11-01

    We present a method to assess the in vivo radial strain and strain rate of the myocardial wall, which is of great importance to understand the biomechanics of cardiac development, using tissue Doppler optical coherence tomography (tissue-DOCT). Combining the structure and velocity information acquired from tissue-DOCT, the velocity distribution in the myocardial wall is plotted, from which the radial strain and strain rate are evaluated. The results demonstrate that tissue-DOCT can be used as a useful tool to describe tissue deformation, especially, the biomechanical characteristics of the embryonic heart.

  10. An uncertainty assessment of discharge projections for eight Swiss catchments

    NASA Astrophysics Data System (ADS)

    Addor, Nans; Rössler, Ole; Köplin, Nina; Bernhard, Luzi; Bosshard, Thomas; Weingartner, Rolf; Seibert, Jan

    2013-04-01

    Projections of discharge under future climate are impaired by uncertainties arising from different sources: the emission scenarios, the climate models, the post-processing of the climate projections, the hydrological models structure and parameterisation. In this project we investigated the contribution of each of these sources to the final simulation uncertainty for discharge using analyses of variance (ANOVA) in eight catchments representative of the typical Swiss discharge regimes. The catchments are distributed among the Jura, the Swiss Plateau and the Alps, and are known to react differently to climate change. We used climate projections of the CH2011 dataset obtained from the Center for Climate Systems Modeling (C2SM). This dataset consists of two types of projections, both based on the climate model runs of the ENSEMBLES project: one relies on the delta change technique applied to 10 runs and the other is based on a Bayesian multi-model approach combining 20 runs until 2050, and then 14 runs until 2099. In addition to the climate projections for emission scenario A1B chosen for the ENSEMBLES project, the CH2011 team generated simulations for the scenarios A2 and RCP3PD using pattern scaling. This enabled us to address the influence of the uncertainty in green house gases emissions on discharge projections. We ran hydrological simulations using three conceptual models: HBV, PREVAH and WaSiM. HBV and PREVAH rely on a similar reservoir structure, while WaSiM uses the process-oriented Richards-equation approach. PREVAH and WaSiM use a higher level of spatial discretization than the lumped HBV model. The use of the three different models allowed evaluation of the sensitivity of discharge projections to the hydrological model complexity and structure. Simulations were run for the periods 2020-2049, 2045-2074 and 2070-2099 to assess the variation of the different sources of uncertainty over time. The pattern scaling enabled the assessment of uncertainty arising

  11. Imaging of skin birefringence for human scar assessment using polarization-sensitive optical coherence tomography aided by vascular masking.

    PubMed

    Gong, Peijun; Chin, Lixin; Es'haghian, Shaghayegh; Liew, Yih Miin; Wood, Fiona M; Sampson, David D; McLaughlin, Robert A

    2014-12-01

    We demonstrate the in vivo assessment of human scars by parametric imaging of birefringence using polarization-sensitive optical coherence tomography (PS-OCT). Such in vivo assessment is subject to artifacts in the detected birefringence caused by scattering from blood vessels. To reduce these artifacts, we preprocessed the PS-OCT data using a vascular masking technique. The birefringence of the remaining tissue regions was then automatically quantified. Results from the scars and contralateral or adjacent normal skin of 13 patients show a correspondence of birefringence with scar type: the ratio of birefringence of hypertrophic scars to corresponding normal skin is 2.2 ± 0.2 (mean ± standard deviation ), while the ratio of birefringence of normotrophic scars to normal skin is 1.1 ± 0.4 . This method represents a new clinically applicable means for objective, quantitative human scar assessment. PMID:25539060

  12. Prognostic Significance of Tumor Response as Assessed by Sequential {sup 18}F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography During Concurrent Chemoradiation Therapy for Cervical Cancer

    SciTech Connect

    Oh, Dongryul; Lee, Jeong Eun; Huh, Seung Jae; Park, Won; Nam, Heerim; Choi, Joon Young; Kim, Byung-Tae

    2013-11-01

    Purpose: To investigate the prognostic role of metabolic response by the use of serial sets of positron emission tomography/computed tomography (PET/CT) in patients with cervical cancer who were treated with concurrent chemoradiation therapy (CCRT). Methods and Materials: A total of 60 patients who were treated with CCRT between February 2009 and December 2010 were analyzed. Three sequential PET/CT images were acquired for each patient: pre-CCRT, during-CCRT at 4 weeks of CCRT, and 1 month post-CCRT PET/CT. Metabolic responses were assessed qualitatively. The percentage changes in the maximum values of standardized uptake value (ΔSUV{sub max}%) from the PET/CT images acquired pre-CCRT and during-CCRT were calculated. Receiver operating characteristic (ROC) curve analysis was performed to evaluate whether ΔSUV{sub max}% could predict complete response (CR) on the post-CCRT PET/CT and to identify the best cutoff value. Prognostic factors of progression-free survival (PFS) were analyzed. Results: During-CCRT PET/CT showed that 8 patients (13%) had CR, and the other 52 patients (87%) had partial response (PR). On the post-CCRT PET/CT, 43 patients (73%) had CR, 12 patients (20%) had PR, and 4 patients (7%) had progressive disease. The average SUV{sub max} in primary tumors was 16.3 (range, 6.4-53.0) on the pre-CCRT PET/CT images and 5.3 (range, 0-19.4) on the during-CCRT PET/CT images. According to ROC curve analysis, ΔSUV{sub max}% could predict CR response on post-CCRT PET/CT (P<.001, cutoff value of 59.7%). In all patients, the PFS rate was 71.9% at 2 years. Multivariate analysis showed that ΔSUV{sub max}% ≥60% (P=.045) and CR response on the post-CCRT PET/CT (P=.012) were statistically significant predictors of PFS. Conclusion: Metabolic responses on the during-CCRT images at 4 weeks of treatment and 1-month post-CCRT PET/CT images may predict treatment outcomes in patients with cervical cancer. ΔSUV{sub max}% ≥60% at 4 weeks of CCRT may predict CR response

  13. Maximum intensity projection imaging for dynamic analysis of mental sweating by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Saigusa, Hiroyuki; Ueda, Yoshihiro; Ohmi, Masato; Ohnishi, Makoto; Kuwabara, Mitsuo; Haruna, Masamitsu

    2009-02-01

    A novel 3-D image construction method with maximum intensity projection (MIP) of B-mode OCT images is proposed for in vivo dynamic analysis of mental sweating on human fingertips. Time-sequential MIP-OCT images with the frame spacing as short as 1.4 sec provide us quantitative analysis of the sweating dynamics to evaluate of activity of sympathetic nerve. Dynamic changes in the microstructure of eccrin sweat glands can be clearly observed in the 3-D images constructed by volume rendering.

  14. Parallel optics technology assessment for the versatile link project

    SciTech Connect

    Chramowicz, J.; Kwan, S.; Rivera, R.; Prosser, A.; /Fermilab

    2011-01-01

    This poster describes the assessment of commercially available and prototype parallel optics modules for possible use as back end components for the Versatile Link common project. The assessment covers SNAP12 transmitter and receiver modules as well as optical engine technologies in dense packaging options. Tests were performed using vendor evaluation boards (SNAP12) as well as custom evaluation boards (optical engines). The measurements obtained were used to compare the performance of these components with single channel SFP+ components operating at a transmission wavelength of 850 nm over multimode fibers.

  15. Stability in computed optical interferometric tomography (Part II): in vivo stability assessment

    PubMed Central

    Shemonski, Nathan D.; Ahmad, Adeel; Adie, Steven G.; Liu, Yuan-Zhi; South, Fredrick A.; Carney, P. Scott; Boppart, Stephen A.

    2014-01-01

    Stability is of utmost importance to a wide range of phase-sensitive processing techniques. In Doppler optical coherence tomography and optical coherence elastography, in addition to defocus and aberration correction techniques such as interferometric synthetic aperture microscopy and computational/digital adaptive optics, a precise understanding of the system and sample stability helps to guide the system design and choice of imaging parameters. This article focuses on methods to accurately and quantitatively measure the stability of an imaging configuration in vivo. These methods are capable of partially decoupling axial from transverse motion and are compared against the stability requirements for computed optical interferometric tomography laid out in the first part of this article. PMID:25321016

  16. Super-resolution reconstruction for 4D computed tomography of the lung via the projections onto convex sets approach

    SciTech Connect

    Zhang, Yu E-mail: qianjinfeng08@gmail.com; Wu, Xiuxiu; Yang, Wei; Feng, Qianjin E-mail: qianjinfeng08@gmail.com; Chen, Wufan

    2014-11-01

    Purpose: The use of 4D computed tomography (4D-CT) of the lung is important in lung cancer radiotherapy for tumor localization and treatment planning. Sometimes, dense sampling is not acquired along the superior–inferior direction. This disadvantage results in an interslice thickness that is much greater than in-plane voxel resolutions. Isotropic resolution is necessary for multiplanar display, but the commonly used interpolation operation blurs images. This paper presents a super-resolution (SR) reconstruction method to enhance 4D-CT resolution. Methods: The authors assume that the low-resolution images of different phases at the same position can be regarded as input “frames” to reconstruct high-resolution images. The SR technique is used to recover high-resolution images. Specifically, the Demons deformable registration algorithm is used to estimate the motion field between different “frames.” Then, the projection onto convex sets approach is implemented to reconstruct high-resolution lung images. Results: The performance of the SR algorithm is evaluated using both simulated and real datasets. Their method can generate clearer lung images and enhance image structure compared with cubic spline interpolation and back projection (BP) method. Quantitative analysis shows that the proposed algorithm decreases the root mean square error by 40.8% relative to cubic spline interpolation and 10.2% versus BP. Conclusions: A new algorithm has been developed to improve the resolution of 4D-CT. The algorithm outperforms the cubic spline interpolation and BP approaches by producing images with markedly improved structural clarity and greatly reduced artifacts.

  17. Environmental Management Assessment of the Fernald Environmental Management Project (FEMP)

    SciTech Connect

    Not Available

    1993-04-01

    This report documents the results of the Environmental Management Assessment performed at the Fernald Environmental Management Project (FEMP) in Fernald, Ohio. During this assessment, the activities conducted by the assessment team included review of internal documents and reports from previous audits and assessments; interviews with US Department of Energy (DOE) and FEMP contractor personnel; and inspection and observation of selected facilities and operations. The onsite portion of the assessment was conducted from March 15 through April 1, 1993, by DOE`s Office of Environmental Audit (EH-24) located within the Office of the Assistant Secretary for Environment, Safety, and Health (EH-1). EH-24 carries out independent assessments of DOE facilities and activities as part of the EH-1 Environment, Safety, and Health (ES&H) Oversight Audit Program. The EH-24 program is designed to evaluate the status of DOE facilities and activities with respect to compliance with Federal, state, and local environmental laws and regulations; compliance with DOE Orders, Guidance and Directives; conformance with accepted industry practices and standards of performance; and the status and adequacy of management systems developed to address environmental requirements. The Environmental Management Assessment of FEMP focused on the adequacy of environmental management systems. Further, in response to requests by the Office of Environmental Restoration and Waste Management (EM) and Fernald Field Office (FN), Quality Assurance and Environmental Radiation activities at FEMP were evaluated from a programmatic standpoint. The results of the evaluation of these areas are contained in the Environmental Protection Programs section in this report.

  18. Environmentally Conscious Manufacturing Project: ECM assessment guidance manual

    SciTech Connect

    Not Available

    1994-11-01

    The purpose of this document is to provide a summary of the basic tools that will be used in conducting assessments under the Environmentally Conscious Manufacturing (ECM) Project assessment program. ECM can cover a wide range of issues including: finding safer alternatives to toxic materials; changing processes to become more efficient; environmental costs and regulatory compliance; waste reduction; energy conservation; product packaging; and product reuse/recycling. The assessments performed as part of this program will try to identify opportunities to implement technologies/actions that will promote the types of results listed above. The general methodology, or sequence of events, that will be used in conducting assessments is as follows: 1. Form an Assessment Team; 2. Map Process by flow diagrams and materials accounting; 3. Identify opportunities for ECM by activity based accounting and pareto analysis; 4. Identify and evaluate ECM/pollution prevention alternatives; 5. Implement alternatives; 6. Monitor progress. All of the assessment steps listed above are addressed in this document except forming the assessment team. The tools discussed in this document are well known, widely used process analysis or quality improvement tools which have been adapted for use in evaluating opportunities for ECM/Pollution prevention.

  19. Integrative neural networks models for stream assessment in restoration projects

    NASA Astrophysics Data System (ADS)

    Gazendam, Ed; Gharabaghi, Bahram; Ackerman, Josef D.; Whiteley, Hugh

    2016-05-01

    Stream-habitat assessment for evaluation of restoration projects requires the examination of many parameters, both watershed-scale and reach-scale, to incorporate the complex non-linear effects of geomorphic, riparian, watershed and hydrologic factors on aquatic ecosystems. Rapid geomorphic assessment tools used by many jurisdictions to assess natural channel design projects seldom include watershed-level parameters, which have been shown to have a significant effect on benthic habitat in stream systems. In this study, Artificial Neural Network (ANN) models were developed to integrate complex non-linear relationships between the aquatic ecosystem health indices and key watershed-scale and reach-scale parameters. Physical stream parameters, based on QHEI parameters, and watershed characteristics data were collected at 112 sites on 62 stream systems located in Southern Ontario. Benthic data were collected separately and benthic invertebrate summary indices, specifically Hilsenhoff's Biotic Index (HBI) and Richness, were determined. The ANN models were trained on the randomly selected 3/4 of the dataset of 112 streams in Ontario, Canada and validated on the remaining 1/4. The R2 values for the developed ANN model predictions were 0.86 for HBI and 0.92 for Richness. Sensitivity analysis of the trained ANN models revealed that Richness was directly proportional to Erosion and Riparian Width and inversely proportional to Floodplain Quality and Substrate parameters. HBI was directly proportional to Velocity Types and Erosion and inversely proportional to Substrate, % Treed and 1:2 Year Flood Flow parameters. The ANN models can be useful tools for watershed managers in stream assessment and restoration projects by allowing consideration of watershed properties in the stream assessment.

  20. Social cost impact assessment of pipeline infrastructure projects

    SciTech Connect

    Matthews, John C.; Allouche, Erez N.; Sterling, Raymond L.

    2015-01-15

    A key advantage of trenchless construction methods compared with traditional open-cut methods is their ability to install or rehabilitate underground utility systems with limited disruption to the surrounding built and natural environments. The equivalent monetary values of these disruptions are commonly called social costs. Social costs are often ignored by engineers or project managers during project planning and design phases, partially because they cannot be calculated using standard estimating methods. In recent years some approaches for estimating social costs were presented. Nevertheless, the cost data needed for validation of these estimating methods is lacking. Development of such social cost databases can be accomplished by compiling relevant information reported in various case histories. This paper identifies eight most important social cost categories, presents mathematical methods for calculating them, and summarizes the social cost impacts for two pipeline construction projects. The case histories are analyzed in order to identify trends for the various social cost categories. The effectiveness of the methods used to estimate these values is also discussed. These findings are valuable for pipeline infrastructure engineers making renewal technology selection decisions by providing a more accurate process for the assessment of social costs and impacts. - Highlights: • Identified the eight most important social cost factors for pipeline construction • Presented mathematical methods for calculating those social cost factors • Summarized social cost impacts for two pipeline construction projects • Analyzed those projects to identify trends for the social cost factors.

  1. Prostate cancer nodal oligometastasis accurately assessed using prostate-specific membrane antigen positron emission tomography-computed tomography and confirmed histologically following robotic-assisted lymph node dissection

    PubMed Central

    O’Kane, Dermot B.; Lawrentschuk, Nathan; Bolton, Damien M.

    2016-01-01

    We herein present a case of a 76-year-old gentleman, where prostate-specific membrane antigen positron emission tomography-computed tomography (PSMA PET-CT) was used to accurately detect prostate cancer (PCa), pelvic lymph node (LN) metastasis in the setting of biochemical recurrence following definitive treatment for PCa. The positive PSMA PET-CT result was confirmed with histological examination of the involved pelvic LNs following pelvic LN dissection. PMID:27141207

  2. Dual seven pinhole tomography

    SciTech Connect

    Bizais, Y.; Zubal, I.G.; Rowe, R.W.; Bennett, G.W.; Brill, A.B.

    1982-01-01

    Emission tomography using two orthogonal sets of projections through seven pinhole collimators is considered. This paper describes the acquisition system, the reconstruction algorithm, presents results obtained in phantom studies, and discusses the advantages and disadvantages of this method over conventional Seven Pinhole Tomography.

  3. Two-step iterative reconstruction of region-of-interest with truncated projection in computed tomography

    NASA Astrophysics Data System (ADS)

    Yamakawa, Keisuke; Kojima, Shinichi

    2014-03-01

    Iteratively reconstructing data only inside the region of interest (ROI) is widely used to acquire CT images in less computation time while maintaining high spatial resolution. A method that subtracts projected data outside the ROI from full-coverage measured data has been proposed. A serious problem with this method is that the accuracy of the measured data confined inside the ROI decreases according to the truncation error outside the ROI. We propose a two-step iterative method that reconstructs image inside the full-coverage in addition to a conventional iterative method inside the ROI to reduce the truncation error inside full-coverage images. Statistical information (e.g., quantum-noise distributions) acquired by detected X-ray photons is generally used in iterative methods as a photon weight to efficiently reduce image noise. Our proposed method applies one of two kinds of weights (photon or constant weights) chosen adaptively by taking into consideration the influence of truncation error. The effectiveness of the proposed method compared with that of the conventional method was evaluated in terms of simulated CT values by using elliptical phantoms and an abdomen phantom. The standard deviation of error and the average absolute error of the proposed method on the profile curve were respectively reduced from 3.4 to 0.4 [HU] and from 2.8 to 0.8 [HU] compared with that of the conventional method. As a result, applying a suitable weight on the basis of a target object made it possible to effectively reduce the errors in CT images.

  4. Comprehensive assessment of projected changes in water availability and aridity

    NASA Astrophysics Data System (ADS)

    Greve, Peter; Seneviratne, Sonia I.

    2015-04-01

    Substantial changes in the hydrological cycle are projected for the 21st century, with potential major impacts, particularly at regional scale. However, the projections are subject to major uncertainties and the metrics generally used to assess such changes do not fully account for the hydroclimatological characteristics of the land surface. In this context, the 'dry gets drier, wet gets wetter' paradigm is often used as a simplifying summary. However, recent studies have challenged the validity of the paradigm both for observations (Greve et al., 2014) and projections (Roderick et al., 2014), especially casting doubt on applying the widely used P-E (precipitation - evapotranspiration) metric over global land surfaces. Here we show in a comprehensive assessment that projected changes in mean annual P-E are generally not significant in most land areas, with the exception of the northern high latitudes where significant changes towards wetter conditions are found. We further show that the combination of decreasing P and increasing atmospheric demand (potential evapotranspiration, Ep) leads to a significant increase in aridity in many subtropical and neighbouring regions, thus confirming the paradigm for some dry regions, but invalidating it for the relative large fraction of the affected area which is currently in a humid or transitional climate regime. Combining both metrics (P-E and P-E_p) we conclude that the 'dry gets drier, wet gets wetter' paradigm is generally not confirmed for projected changes in most land areas (despite notable exceptions in the high latitudes and subtropics), because of a lack of robustness of the projected changes in some regions (tropics) and because humid to transitional regions are shifting to drier conditions, i.e. not following the paradigm. References Greve, P., Orlowsky, B., Mueller, B., Sheffield, J., Reichstein, M., & Seneviratne, S. I. Global assessment of trends in wetting and drying over land. Nature Geosci. 7, 716-721 (2014

  5. Dynamic diffuse optical tomography for assessing changes of breast tumors during neoadjuvant chemotherapy

    NASA Astrophysics Data System (ADS)

    Gunther, Jacqueline E.; Lim, Emerson; Kim, Hyun Keol; Brown, Mindy; Refice, Susan; Kalinsky, Kevin; Hershman, Dawn; Hielscher, Andreas H.

    2015-03-01

    We have developed a dynamic diffuse optical tomography imaging system that is capable of 3D imaging of both breasts simultaneously. In an ongoing study subjects receiving neoadjuvant chemotherapy are imaged at 6 time points throughout their 5-month treatment. At each time point the subjects preform a breath hold to observe the hemodynamic effects in the breasts. For each session the percent change of various hemodynamic parameters during the breath hold is determined. Preliminary results from show statistically significant differences in washout rates and deoxyhemoglobin changes at the 2-week imaging point between subjects that respond and do not respond to treatment.

  6. 2-D Fused Image Reconstruction approach for Microwave Tomography: a theoretical assessment using FDTD Model.

    PubMed

    Bindu, G; Semenov, S

    2013-01-01

    This paper describes an efficient two-dimensional fused image reconstruction approach for Microwave Tomography (MWT). Finite Difference Time Domain (FDTD) models were created for a viable MWT experimental system having the transceivers modelled using thin wire approximation with resistive voltage sources. Born Iterative and Distorted Born Iterative methods have been employed for image reconstruction with the extremity imaging being done using a differential imaging technique. The forward solver in the imaging algorithm employs the FDTD method of solving the time domain Maxwell's equations with the regularisation parameter computed using a stochastic approach. The algorithm is tested with 10% noise inclusion and successful image reconstruction has been shown implying its robustness.

  7. Assessment of Smolt Condition for Travel Time Analysis Project, 1987-1997 Project Review.

    SciTech Connect

    Schrock, Robin M.; Hans, Karen M.; Beeman, John W.

    1997-12-01

    The assessment of Smolt Condition for Travel Time Analysis Project (Bonneville Power Administration Project 87-401) monitored attributes of salmonid smolt physiology in the Columbia and Snake River basins from 1987 to 1997, under the Northwest Power Planning Council Fish and Wildlife Program, in cooperation with the Smolt Monitoring Program of the Fish Passage Center. The primary goal of the project was to investigate the physiological development of juvenile salmonids related to migration rates. The assumption was made that the level of smolt development, interacting with environmental factos such as flow, would be reflected in travel times. The Fish Passage Center applied the physiological measurements of smolt condition to Water Budget management, to regulate flows so as to decrease travel time and increase survival.

  8. 78 FR 43183 - Notice of Availability for Sharpe Permit Relinquishment Project Environmental Assessment Finding...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-19

    ... of the Secretary Notice of Availability for Sharpe Permit Relinquishment Project Environmental... Availability (NOA) for Sharpe Permit Relinquishment Project Environmental Assessment (EA) Finding of No... satisfy the project's purpose and need; however, the alternative was included in the...

  9. Hellsgate Winter Range : Wildlife Mitigation Project. Final Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration.

    1995-03-01

    Bonneville Power Administration (BPA) proposes to fund the Hellsgate Winter Range Wildlife Mitigation Project (Project) in a cooperative effort with the Colville Confederated Tribes and the Bureau of Indian Affairs (BIA). The proposed action would allow the sponsors to secure property and conduct wildlife management activities within the boundaries of the Colville Indian Reservation. This Final Environmental Assessment (EA) examines the potential environmental effects of acquiring and managing property for wildlife and wildlife habitat within a large project area. This area consists of several separated land parcels, of which 2,000 hectares (4,943 acres) have been purchased by BPA and an additional 4,640 hectares (11,466 acres) have been identified by the Colville Confederated Tribes for inclusion in the Project. Four proposed activities (habitat protection, habitat enhancement, operation and maintenance, and monitoring and evaluation) are analyzed. The proposed action is intended to meet the need for mitigation of wildlife and wildlife habitat that was adversely affected by the construction of Grand Coulee and Chief Joseph Dams and their reservoirs.

  10. 78 FR 25258 - Notice of Availability (NOA) for Sharpe Permit Relinquishment Project Environmental Assessment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-30

    ... of the Secretary Notice of Availability (NOA) for Sharpe Permit Relinquishment Project Environmental... Relinquishment Project Environmental Assessment. SUMMARY: The Defense Logistics Agency (DLA) announces the availability of an environmental assessment (EA) for the potential environmental impacts associated with...

  11. Wildlife Habitat Impact Assessment, Chief Joseph Dam Project, Washington : Project Report 1992.

    SciTech Connect

    Kuehn, Douglas; Berger, Matthew

    1992-01-01

    Under the Pacific Northwest Electric Power Planning and Conservation Act of 1980, and the subsequent Northwest Power Planning Council`s Columbia River Basin Fish and Wildlife Program, a wildlife habitat impact assessment and identification of mitigation objectives have been developed for the US Army Corps of Engineer`s Chief Joseph Dam Project in north-central Washington. This study will form the basis for future mitigation planning and implementation.

  12. Assessing human rights impacts in corporate development projects

    SciTech Connect

    Salcito, Kendyl; Utzinger, Jürg; Weiss, Mitchell G.; Münch, Anna K.; Singer, Burton H.; Krieger, Gary R.; Wielga, Mark

    2013-09-15

    Human rights impact assessment (HRIA) is a process for systematically identifying, predicting and responding to the potential impact on human rights of a business operation, capital project, government policy or trade agreement. Traditionally, it has been conducted as a desktop exercise to predict the effects of trade agreements and government policies on individuals and communities. In line with a growing call for multinational corporations to ensure they do not violate human rights in their activities, HRIA is increasingly incorporated into the standard suite of corporate development project impact assessments. In this context, the policy world's non-structured, desk-based approaches to HRIA are insufficient. Although a number of corporations have commissioned and conducted HRIA, no broadly accepted and validated assessment tool is currently available. The lack of standardisation has complicated efforts to evaluate the effectiveness of HRIA as a risk mitigation tool, and has caused confusion in the corporate world regarding company duties. Hence, clarification is needed. The objectives of this paper are (i) to describe an HRIA methodology, (ii) to provide a rationale for its components and design, and (iii) to illustrate implementation of HRIA using the methodology in two selected corporate development projects—a uranium mine in Malawi and a tree farm in Tanzania. We found that as a prognostic tool, HRIA could examine potential positive and negative human rights impacts and provide effective recommendations for mitigation. However, longer-term monitoring revealed that recommendations were unevenly implemented, dependent on market conditions and personnel movements. This instability in the approach to human rights suggests a need for on-going monitoring and surveillance. -- Highlights: • We developed a novel methodology for corporate human rights impact assessment. • We piloted the methodology on two corporate projects—a mine and a plantation. • Human

  13. Project W-151 Tank 101-AZ Waste Retrieval System Year 2000 Compliance Assessment Project Plan

    SciTech Connect

    BUSSELL, J.H.

    1999-08-02

    This assessment describes the potential Year 2000 (Y2K) problems and describes the methods for achieving Y2K compliance for Project W-151, Tank 101-AZ Waste Retrieval System. The purpose of this assessment is to give an overview of the project. This document will not be updated and any dates contained in this document are estimates and may change. Two mixer pumps and instrumentation have been or are planned to be installed in waste tank 101-AZ to demonstrate solids mobilization. The information and experience gained during this process test will provide data for comparison with sludge mobilization prediction models and provide indication of the effects of mixer pump operation on an Aging Waste Facility tank. A limited description of system dates, functions, interfaces, potential Y2K problems, and date resolutions is presented. The project is presently on hold, and definitive design and procurement have been completed. This assessment will describe the methods, protocols, and practices to ensure that equipment and systems do not have Y2K problems.

  14. [Dosage values for characterization of patient exposure in computerized tomography and their significance for risk assessment].

    PubMed

    Hidajat, N; Schröder, R J; Wolf, M; Vogl, T; Felix, R

    1997-06-01

    In order to evaluate patients' exposure to radiation in computed tomography, dose quantities such as the computed tomography dose index (CTDI), multiple scan average dose (MSAD) and dose free in air on the axis of rotation are used. The CTDI and the MSAD, derivable from the CTDI, are a good measure for the absorbed doses in the examined volume, but they do not take the biological sensitivity of the organs into account and do not describe the radiogenic risk that is actually relevant for patients and doctors. The dose on the axis of rotation is not an accurate measure of the effective dose and the radiogenic risk. The declaration of a limit for the dose on the axis of rotation should take the different regions into account, in order to guarantee acceptable image quality on one hand and to avoid an unnecessarily high risk on the other side. As physical dose quantities, the CTDI, MSAD and dose on the axis of rotation are useful to characterize and differentiate between programs and systems concerning radiation exposure.

  15. Catecholamine stimulation, substrate competition, and myocardial glucose uptake in conscious dogs assessed with positron emission tomography.

    PubMed

    Merhige, M E; Ekas, R; Mossberg, K; Taegtmeyer, H; Gould, K L

    1987-11-01

    Uptake of radiolabelled deoxyglucose out of proportion to reduced coronary flow demonstrated by positron emission tomography has been used to identify reversibly ischemic, viable myocardium. For this concept to be applied reliably in the clinical setting, factors that may depress glucose availability independent of tissue viability, such as adrenergic stimulation and substrate competition, must be examined. Accordingly, we studied the effect of catecholamine stimulation by dopamine on myocardial glucose uptake in vivo using chronically instrumented, intact dogs and positron emission tomography. We measured myocardial activity of [2-18F]-2-deoxyglucose (FDG) and 82Rb in glucose-loaded animals randomly studied during dopamine infusion, during insulin infusion, and then during their combined infusion. Myocardial FDG uptake was significantly decreased when animals were treated with dopamine, compared with treatment in the same animals with insulin. When insulin was added to the dopamine infusion, myocardial FDG uptake was restored. In contrast, myocardial activity of 82Rb, which is taken up in proportion to coronary flow, was similar under all three experimental conditions. Plasma glucose, free fatty acid, and lactate concentrations were determined before and during each infusion. The depression of myocardial FDG activity seen during dopamine infusion and its reversal with addition of insulin can be explained on the basis of effects of these hormones on substrate availability and competition.

  16. Idaho National Engineering Laboratory Sewer System Upgrade Project. Environmental Assessment

    SciTech Connect

    Not Available

    1994-04-01

    The Department of Energy (DOE) has prepared an environmental assessment for a proposed Sewer System Upgrade Project at the Idaho National Engineering Laboratory (INEL) near Idaho Falls, Idaho. The proposed action would include activities conducted at the Central Facilities Area, Test Reactor Area, and the Containment Test Facility at the Test Area North at INEL. The proposed action would consist of replacing or remodeling the existing sewage treatment plants at the Central Facilities Area, Test Reactor Area, and Containment Test Facility. Also, a new sewage testing laboratory would be constructed at the Central Facilities Area. Finally, the proposed action would include replacing, repairing, and/or adding sewer lines in areas where needed.

  17. Poster — Thur Eve — 01: The effect of the number of projections on MTF and CNR in Compton scatter tomography

    SciTech Connect

    Chighvinadze, T; Pistorius, S

    2014-08-15

    Purpose: To investigate the dependence of the reconstructed image quality on the number of projections in multi-projection Compton scatter tomography (MPCST). The conventional relationship between the projection number used for reconstruction and reconstructed image quality pertained to CT does not necessarily apply to MPCST, which can produce images from a single projection if the detectors have sufficiently high energy and spatial resolution. Methods: The electron density image was obtained using filtered-backprojection of the scatter signal over circular arcs formed using Compton equation. The behavior of the reconstructed image quality as a function of the projection number was evaluated through analytical simulations and characterized by CNR and MTF. Results: The increase of the projection number improves the contrast with this dependence being a function of fluence. The number of projections required to approach the asymptotic maximum contrast decreases as the fluence increases. Increasing projection number increases the CNR but not spatial resolution. Conclusions: For MPCST using a 500eV energy resolution and a 2×2mm{sup 2} size detector, an adequate image quality can be obtained with a small number of projections provided the incident fluence is high enough. This is conceptually different from conventional CT where a minimum number of projections is required to obtain an adequate image quality. While increasing projection number, even for the lowest dose value, the CNR increases even though the number of photons per projection decreases. The spatial resolution of the image is improved by increasing the sampling within a projection rather than by increasing the number of projections.

  18. The meaning of interior tomography.

    PubMed

    Wang, Ge; Yu, Hengyong

    2013-08-21

    The classic imaging geometry for computed tomography is for the collection of un-truncated projections and the reconstruction of a global image, with the Fourier transform as the theoretical foundation that is intrinsically non-local. Recently, interior tomography research has led to theoretically exact relationships between localities in the projection and image spaces and practically promising reconstruction algorithms. Initially, interior tomography was developed for x-ray computed tomography. Then, it was elevated to have the status of a general imaging principle. Finally, a novel framework known as 'omni-tomography' is being developed for a grand fusion of multiple imaging modalities, allowing tomographic synchrony of diversified features.

  19. Tiering strategic environmental assessment and project environmental impact assessment in highway planning in Sao Paulo, Brazil

    SciTech Connect

    Sanchez, Luis E. Silva-Sanchez, Solange S.

    2008-10-15

    Constructing highways in dense urban areas is always a challenge. In Sao Paulo Metropolitan Region, heavy truck traffic contributes to clog streets and expressways alike. As part of the traffic neither originates nor head to the region, a peripheral highway has been proposed to reduce traffic problems. This project, called Rodoanel, is an expressway approximately 175 km long. The fact that the projected south and north sections would cross catchments that supply most of the metropolis water demand was strongly disputed and made the environmental permitting process particularly difficult. The agency in charge commissioned a strategic environmental assessment (SEA) of a revamped project, and called it the Rodoanel Programme. However, the SEA report failed to satisfactorily take account of significant strategic issues. Among these, the highway potential effect of inducing urban sprawl over water protection zones is the most critical issue, as it emerged later as a hurdle to project licensing. Conclusion is that, particularly where no agreed-upon framework for SEA exists, when vertical tiering with downstream project EIA is sought, then a careful scoping of strategic issues is more than necessary. If an agreement on 'what is strategic' is not reached and not recognized by influential stakeholders, then the unsettled conflicts will be transferred to project EIA. In such a context, SEA will have added another loop to the usually long road to project approval.

  20. Open Ocean Assessments for Management in the GEF Transboundary Waters Assessment Project (TWAP)

    NASA Astrophysics Data System (ADS)

    Fischer, A. S.; Alverson, K. D.

    2010-12-01

    A methodology for a thematic and scientifically-credible assessment of Open Ocean waters as a part of the Global Environment Facility (GEF) Transboundary Waters Assessment Project (TWAP) has been developed in the last 18 months by the Intergovernmental Oceanographic Commission of UNESCO, and is presented for feedback and comment. While developed to help the GEF International Waters focal area target investment to manage looming environmental threats in interlinked freshwater and marine systems (a very focused decision support system), the assessment methodology could contribute to other assessment and management efforts in the UN system and elsewhere. Building on a conceptual framework that describes the relationships between human systems and open ocean natural systems, and on mapping of the human impact on the marine environment, the assessment will evaluate and make projections on a thematic basis, identifying key metrics, indices, and indicators. These themes will include the threats on key ecosystem services of climate change through sea level rise, changed stratification, warming, and ocean acidification; vulnerabilities of ecosystems, habitats, and living marine resources; the impact and sustainability of fisheries; and pollution. Global-level governance arrangements will also be evaluated, with an eye to identifying scope for improved global-level management. The assessment will build on sustained ocean observing systems, model projections, and an assessment of scientific literature, as well as tools for combining knowledge to support identification of priority concerns and in developing scenarios for management. It will include an assessment of key research and observing needs as one way to deal with the scientific uncertainty inherent in such an exercise, and to better link policy and science agendas.

  1. Functional imaging and assessment of the glucose diffusion rate in epithelial tissues in optical coherence tomography

    SciTech Connect

    Larin, K V; Tuchin, V V

    2008-06-30

    Functional imaging, monitoring and quantitative description of glucose diffusion in epithelial and underlying stromal tissues in vivo and controlling of the optical properties of tissues are extremely important for many biomedical applications including the development of noninvasive or minimally invasive glucose sensors as well as for therapy and diagnostics of various diseases, such as cancer, diabetic retinopathy, and glaucoma. Recent progress in the development of a noninvasive molecular diffusion biosensor based on optical coherence tomography (OCT) is described. The diffusion of glucose was studied in several epithelial tissues both in vitro and in vivo. Because OCT provides depth-resolved imaging of tissues with high in-depth resolution, the glucose diffusion is described not only as a function of time but also as a function of depth. (special issue devoted to application of laser technologies in biophotonics and biomedical studies)

  2. Functional imaging and assessment of the glucose diffusion rate in epithelial tissues in optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Larin, K. V.; Tuchin, V. V.

    2008-06-01

    Functional imaging, monitoring and quantitative description of glucose diffusion in epithelial and underlying stromal tissues in vivo and controlling of the optical properties of tissues are extremely important for many biomedical applications including the development of noninvasive or minimally invasive glucose sensors as well as for therapy and diagnostics of various diseases, such as cancer, diabetic retinopathy, and glaucoma. Recent progress in the development of a noninvasive molecular diffusion biosensor based on optical coherence tomography (OCT) is described. The diffusion of glucose was studied in several epithelial tissues both in vitro and in vivo. Because OCT provides depth-resolved imaging of tissues with high in-depth resolution, the glucose diffusion is described not only as a function of time but also as a function of depth.

  3. Regional cerebral glucose metabolic rate in human sleep assessed by positron emission tomography

    SciTech Connect

    Buchsbaum, M.S.; Wu, J.; Hazlett, E.; Sicotte, N.; Bunney, W.E. Jr. ); Gillin, J.C. )

    1989-01-01

    The cerebral metabolic rate of glucose was measured during nighttime sleep in 36 normal volunteers using positron emission tomography and fluorine-18-labeled 2-deoxyglucose (FDG). In comparison to waking controls, subjects given FDG during non-rapid eye movement (NREM) sleep showed about a 23% reduction in metabolic rate across the entire brain. This decrease was greater for the frontal than temporal or occipital lobes, and greater for basal ganglia and thalamus than cortex. Subjects in rapid eye movement (REM) sleep tended to have higher cortical metabolic rates than walking subjects. The cingulate gyrus was the only cortical structure to show a significant increase in glucose metabolic rate in REM sleep in comparison to waking. The basal ganglia were relatively more active on the right in REM sleep and symmetrical in NREM sleep.

  4. Assessment of errors in static electrical impedance tomography with adjacent and trigonometric current patterns.

    PubMed

    Kolehmainen, V; Vauhkonen, M; Karjalainen, P A; Kaipio, J P

    1997-11-01

    In electrical impedance tomography (EIT), difference imaging is often preferred over static imaging. This is because of the many unknowns in the forward modelling which make it difficult to obtain reliable absolute resistivity estimates. However, static imaging and absolute resistivity values are needed in some potential applications of EIT. In this paper we demonstrate by simulation the effects of different error components that are included in the reconstruction of static EIT images. All simulations are carried out in two dimensions with the so-called complete electrode model. Errors that are considered are the modelling error in the boundary shape of an object, errors in the electrode sizes and localizations and errors in the contact impedances under the electrodes. Results using both adjacent and trigonometric current patterns are given.

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

    PubMed

    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.

  6. Functional Optical Coherence Tomography Enables In Vivo Physiological Assessment of Retinal Rod and Cone Photoreceptors

    NASA Astrophysics Data System (ADS)

    Zhang, Qiuxiang; Lu, Rongwen; Wang, Benquan; Messinger, Jeffrey D.; Curcio, Christine A.; Yao, Xincheng

    2015-04-01

    Transient intrinsic optical signal (IOS) changes have been observed in retinal photoreceptors, suggesting a unique biomarker for eye disease detection. However, clinical deployment of IOS imaging is challenging due to unclear IOS sources and limited signal-to-noise ratios (SNRs). Here, by developing high spatiotemporal resolution optical coherence tomography (OCT) and applying an adaptive algorithm for IOS processing, we were able to record robust IOSs from single-pass measurements. Transient IOSs, which might reflect an early stage of light phototransduction, are consistently observed in the photoreceptor outer segment almost immediately (<4 ms) after retinal stimulation. Comparative studies of dark- and light-adapted retinas have demonstrated the feasibility of functional OCT mapping of rod and cone photoreceptors, promising a new method for early disease detection and improved treatment of diseases such as age-related macular degeneration (AMD) and other eye diseases that can cause photoreceptor damage.

  7. Assessing the benefits and harms of low-dose computed tomography screening for lung cancer

    PubMed Central

    Pinsky, Paul F

    2015-01-01

    Summary The concept of using low-dose computed tomography (LDCT) for lung cancer screening goes back almost 25 years. In 2011, the National Lung Screening Trial (NLST) reported that LDCT screening significantly reduced mortality from lung cancer in a high risk population. This article evaluates the benefits and harms of LDCT screening, based largely on evidence from randomized trials. Harms include false-positive screens and resultant diagnostic procedures, overdiagnosed cancers, and radiation exposure. Benefits can be expressed as the number needed to be screened to prevent one lung cancer death or as estimated overall reductions in lung cancer mortality assuming LDCT population screening as recommended by guidelines. Indirect metrics of benefit, such as lung cancer survival and stage distribution, as well as measures of harms, will be important to monitor in the future as LDCT screening disseminates in the population. PMID:26617677

  8. Application of optical coherence tomography for assessment of transcutaneous vaccine delivery

    NASA Astrophysics Data System (ADS)

    Kamali, T.; Rattanapak, T.; Hook, S.; Meglinski, I.

    2012-03-01

    Immunization is one of the most efficient and cost-effective means for the prevention of diseases, but most vaccines have to be administered invasively. A novel strategy of inducing an immune response is topical application of vaccines to intact skin. Apart from being a non-invasive route of drug delivery, skin delivery also offers an advantageous mode of immunization due to the ability of skin immune cells to present antigens to the immune system. Topical vaccine penetration through the outermost layers of skin is based on the percutaneous diffusion of lipid-based nano-particles. In the current study we investigate the applicability of Optical Coherence Tomography for monitoring transcutaneous delivery of a peptide vaccine into the skin in vivo.

  9. Application of optical coherence tomography for assessment of transcutaneous vaccine delivery

    NASA Astrophysics Data System (ADS)

    Kamali, T.; Rattanapak, T.; Hook, S.; Meglinski, I.

    2011-10-01

    Immunization is one of the most efficient and cost-effective means for the prevention of diseases, but most vaccines have to be administered invasively. A novel strategy of inducing an immune response is topical application of vaccines to intact skin. Apart from being a non-invasive route of drug delivery, skin delivery also offers an advantageous mode of immunization due to the ability of skin immune cells to present antigens to the immune system. Topical vaccine penetration through the outermost layers of skin is based on the percutaneous diffusion of lipid-based nano-particles. In the current study we investigate the applicability of Optical Coherence Tomography for monitoring transcutaneous delivery of a peptide vaccine into the skin in vivo.

  10. Intraoperative Optical Coherence Tomography Imaging and Assessment of the Macula During Cataract Surgery: A Novel Technique.

    PubMed

    Tripathy, Koushik; Chawla, Rohan; Kumawat, Babulal; Sharma, Yog Raj

    2016-09-01

    The authors describe a technique to qualitatively analyze the posterior segment during cataract surgery using intraoperative optical coherence tomography (iOCT). Macular iOCT can be done before and after intraocular lens implantation after the media is rendered clear following phacoemulsification. A handheld irrigating planoconcave contact lens is placed over the cornea with the operating microscope in retroillumination mode. After focusing the microscope and upon getting a clear view of the posterior segment, iOCT is switched on, centered at the macula, and focused. This technique enables the surgeon to intraoperatively analyze and document the macular morphology and vitreoretinal interface. Potential uses of this technique include intraoperative decision-making regarding concurrent use of anti-vascular endothelial growth factor agents or steroids in cases with dense cataracts where preoperative OCT is difficult. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:846-847.]. PMID:27631481

  11. Greater left cerebral hemispheric metabolism in bulimia assessed by positron emission tomography

    SciTech Connect

    Wu, J.C.; Hagman, J.; Buchsbaum, M.S.; Blinder, B.; Derrfler, M.; Tai, W.Y.; Hazlett, E.; Sicotte, N. )

    1990-03-01

    Eight women with bulimia and eight age- and sex-matched normal control subjects were studied with positron emission tomography using (18F)-fluorodeoxyglucose (FDG) as a tracer of brain metabolic rate. Subjects performed a visual vigilance task during FDG uptake. In control subjects, the metabolic rate was higher in the right hemisphere than in the left, but patients with bulimia did not have this normal asymmetry. Lower metabolic rates in the basal ganglia, found in studies of depressed subjects, and higher rates in the basal ganglia, reported in a study of anorexia nervosa, were not found. This is consistent with the suggestion that bulimia is a diagnostic grouping distinct from these disorders.

  12. Interfractional Variations in Patient Setup and Anatomic Change Assessed by Daily Computed Tomography

    SciTech Connect

    Li, X. Allen . E-mail: ali@radonc.mcw.edu; Qi, X. Sharon; Pitterle, Marissa; Kalakota, Kapila; Mueller, Kevin; Erickson, Beth A.; Wang Dian; Schultz, Christopher J.; Firat, Selim Y.; Wilson, J. Frank

    2007-06-01

    Purpose: To analyze the interfractional variations in patient setup and anatomic changes at seven anatomic sites observed in image-guided radiotherapy. Methods and Materials: A total of 152 patients treated at seven anatomic sites using a Hi-Art helical tomotherapy system were analyzed. Daily tomotherapy megavoltage computed tomography images acquired before each treatment were fused to the planning kilovoltage computed tomography images to determine the daily setup errors and organ motions and deformations. The setup errors were corrected before treatment and were used, along with the organ motions, to determine the clinical target volume/planning target volume margins. The organ motions and deformations for 3 representative patient cases (pancreas, uterus, and soft-tissue sarcoma) and for 14 kidneys of 7 patients are presented. Results: Interfractional setup errors in the skull, brain, and head and neck are significantly smaller than those in the chest, abdomen, pelvis, and extremities. These site-specific relationships are statistically significant. The margins required to account for these setup errors range from 3 to 8 mm for the seven sites. The margin to account for both setup errors and organ motions for kidney is 16 mm. Substantial interfractional anatomic changes were observed. For example, the pancreas moved up to {+-}20 mm and volumes of the uterus and sarcoma varied {<=}30% and 100%, respectively. Conclusion: The interfractional variations in patient setup and in shapes, sizes, and positions of both targets and normal structures are site specific and may be used to determine the site-specific margins. The data presented in this work dealing with seven anatomic sites may be useful in developing adaptive radiotherapy.

  13. MicroCT and optical coherence tomography imagistic assessment of the dental roots adhesive

    NASA Astrophysics Data System (ADS)

    Sinescu, Cosmin; Negrutiu, Meda Lavinia; Nica, Luminita; Manescu, Adrian; Duma, Virgil-Florin; Podoleanu, Adrian G.

    2015-03-01

    Several obturation methods are available today to study the 3D filling of the root canal. There are also several methods capable to evaluate the ability to seal apically the root canals. However, the common methods of investigation are invasive; they also lead to the destruction of the samples. If the sectioning differs slightly from the desired area, the investigation is non-conclusive regarding the micro-leakages. Also, although the use of Cone-Beam Micro Computer Tomography (CBCT) appears to be most promising for endodontic purposes, its effective radiation doses are higher than with conventional intra-oral and panoramic imaging. In contrast, enface (ef) Optical Coherence Tomography (OCT) proves to be efficient for the investigation of material defects of dental restorations, dental materials, and micro-leakage at the interfaces, where the penetration depth depends on the material. Therefore, ef OCT has been proposed in our studies as a potential tool for in vivo endodontic imaging. Twenty five recently extracted human maxillary molars were selected for the study for caries or periodontal reasons. The pulp chambers were completely opened, the dental pulp was removed, and the root canals were shaped. Silver nanoparticles were used in half of the samples in order to increase the scattering of the adhesive material in comparison with the dental roots walls. The sample teeth were then probed using Time Domain (TD) OCT working at 1300 nm. A synchrotron radiation X-Ray microCT experiment was also performed. The imagistic results pointed out the efficiency of the silver nanoparticle layer used in order to increase the scattering of the root canal adhesive scattering for the OCT non-invasive investigation. MicroCT allowed for obtaining qualitative data related to the depth penetration of the root canal adhesive into the dentin walls.

  14. Blue Creek Winter Range : Wildlife Mitigation Project : Final Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration; United States. Bureau of Indian Affairs; Spokane Tribe of the Spokane Reservation, Washington

    1994-11-01

    Bonneville Power Administration (BPA) proposes to fund that portion of the Washington Wildlife Agreement pertaining to the Blue Creek Winter Range Wildlife Mitigation Project (Project) in a cooperative effort with the Spokane Tribe, Upper Columbia United Tribes, and the Bureau of Indian Affairs (BIA). If fully implemented, the proposed action would allow the sponsors to protect and enhance 2,631 habitat units of big game winter range and riparian shrub habitat on 2,185 hectares (5,400 acres) of Spokane Tribal trust lands, and to conduct long term wildlife management activities within the Spokane Indian Reservation project area. This Final Environmental Assessment (EA) examines the potential environmental effects of securing land and conducting wildlife habitat enhancement and long term management activities within the boundaries of the Spokane Indian Reservation. Four proposed activities (habitat protection, habitat enhancement, operation and maintenance, and monitoring and evaluation) are analyzed. The proposed action is intended to meet the need for mitigation of wildlife and wildlife habitat adversely affected by the construction of Grand Coulee Dam and its reservoir.

  15. Willow Creek Wildlife Mitigation Project. Final Environmental Assessment.

    SciTech Connect

    1995-04-01

    Today`s notice announces BPA`s proposal to fund land acquisition or acquisition of a conservation easement and a wildlife management plan to protect and enhance wildlife habitat at the Willow Creek Natural Area in Eugene, Oregon. This action would provide partial mitigation for wildlife and wildlife habitat lost by the development of Federal hydroelectric projects in the Willamette River Basin. The project is consistent with BPA`s obligations under provisions of the Pacific Northwest Electric Power Planning and Conservation Act of 1980 as outlined by the Northwest Power Planning Council`s 1994 Columbia River Basin Fish and Wildlife Program. BPA has prepared an environmental assessment (DOE/EA-1023) evaluating the proposed project. Based on the analysis in the EA, BPA has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an environmental impact statement (EIS) is not required and BPA is issuing this FONSI.

  16. Assessing ex vivo dental biofilms and in vivo composite restorations using cross-polarization optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Jones, R.; Aparicio, C.; Chityala, R.; Chen, R.; Fok, A.; Rudney, J.

    2012-01-01

    A cross-polarization 1310-nm optical coherence tomography system (CP-OCT), using a beam splitter based design, was used to assess ex vivo growth of complex multi-species dental biofilms. These biofilm microcosms were derived from plaque samples along the interface of composite or amalgam restoration in children with a history of early childhood caries. This paper presents a method of measuring the mean biofilm height of mature biofilms using CP-OCT. For our in vivo application, the novel swept source based CP-OCT intraoral probe (Santec Co. Komaki, Japan) dimensions and system image acquisition speed (20 image frames/second) allowed imaging pediatric subjects as young as 4 years old. The subsurface enamel under the interface of composite resin restorations of pediatric subjects were imaged using CP-OCT. Cavitated secondary caries is clearly evident from sound resin composite restorations.

  17. Toward noninvasive assessment of flap viability with time-resolved diffuse optical tomography: a preclinical test on rats.

    PubMed

    Di Sieno, Laura; Bettega, Georges; Berger, Michel; Hamou, Cynthia; Aribert, Marion; Mora, Alberto Dalla; Puszka, Agathe; Grateau, Henri; Contini, Davide; Hervé, Lionel; Coll, Jean-Luc; Dinten, Jean-Marc; Pifferi, Antonio; Planat-Chrétien, Anne

    2016-02-01

    The noninvasive assessment of flap viability in autologous reconstruction surgery is still an unmet clinical need. To cope with this problem, we developed a proof-of-principle fully automatized setup for fast time-gated diffuse optical tomography exploiting Mellin-Laplace transform to obtain three-dimensional tomographic reconstructions of oxy- and deoxy-hemoglobin concentrations. We applied this method to perform preclinical tests on rats inducing total venous occlusion in the cutaneous abdominal flaps. Notwithstanding the use of just four source-detector couples, we could detect a spatially localized increase of deoxyhemoglobin following the occlusion (up to 550 μM in 54 min). Such capability to image spatio-temporal evolution of blood perfusion is a key issue for the noninvasive monitoring of flap viability.

  18. Quantitative assessment of rat corneal thickness and morphology during stem cell therapy by high-speed optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Lal, Cerine; McGrath, James; Subhash, Hrebesh; Rani, Sweta; Ritter, Thomas; Leahy, Martin

    2016-03-01

    Optical Coherence Tomography (OCT) is a non-invasive 3 dimensional optical imaging modality that enables high resolution cross sectional imaging in biological tissues and materials. Its high axial and lateral resolution combined with high sensitivity, imaging depth and wide field of view makes it suitable for wide variety of high resolution medical imaging applications at clinically relevant speed. With the advent of swept source lasers, the imaging speed of OCT has increased considerably in recent years. OCT has been used in ophthalmology to study dynamic changes occurring in the cornea and iris, thereby providing physiological and pathological changes that occur within the anterior segment structures such as in glaucoma, during refractive surgery, lamellar keratoplasty and corneal diseases. In this study, we assess the changes in corneal thickness in the anterior segment of the eye during wound healing process in a rat corneal burn model following stem cell therapy using high speed swept source OCT.

  19. Toward noninvasive assessment of flap viability with time-resolved diffuse optical tomography: a preclinical test on rats

    NASA Astrophysics Data System (ADS)

    Di Sieno, Laura; Bettega, Georges; Berger, Michel; Hamou, Cynthia; Aribert, Marion; Mora, Alberto Dalla; Puszka, Agathe; Grateau, Henri; Contini, Davide; Hervé, Lionel; Coll, Jean-Luc; Dinten, Jean-Marc; Pifferi, Antonio; Planat-Chrétien, Anne

    2016-02-01

    The noninvasive assessment of flap viability in autologous reconstruction surgery is still an unmet clinical need. To cope with this problem, we developed a proof-of-principle fully automatized setup for fast time-gated diffuse optical tomography exploiting Mellin-Laplace transform to obtain three-dimensional tomographic reconstructions of oxy- and deoxy-hemoglobin concentrations. We applied this method to perform preclinical tests on rats inducing total venous occlusion in the cutaneous abdominal flaps. Notwithstanding the use of just four source-detector couples, we could detect a spatially localized increase of deoxyhemoglobin following the occlusion (up to 550 μM in 54 min). Such capability to image spatio-temporal evolution of blood perfusion is a key issue for the noninvasive monitoring of flap viability.

  20. Geohazard assessment lifecycle for a natural gas pipeline project

    NASA Astrophysics Data System (ADS)

    Lekkakis, D.; Boone, M. D.; Strassburger, E.; Li, Z.; Duffy, W. P.

    2015-09-01

    the assessment, further exploration was proposed. In cases where rerouting was constrained, mitigation via structural measures was proposed. This paper further discusses the cost, schedule and resource challenges of planning and executing such a large-scale geotechnical investigation, the interfaces between the various disciplines involved during the assessment, the innovative tools employed for the field mapping, the classifications developed for mapping landslides, karst geology, and trench excavatability, determining liquefaction stretches and the process for the site localization of the Above Ground Installations (AGI). It finally discusses the objectives of the FEED study in terms of providing a route, a ± 20% project cost estimate and a schedule, and the additional engineering work foreseen to take place in the detailed engineering phase of the project.

  1. The ENCOAL Mild Coal Gasification Project, A DOE Assessment

    SciTech Connect

    National Energy Technology Laboratory

    2002-03-15

    This report is a post-project assessment of the ENCOAL{reg_sign} Mild Coal Gasification Project, which was selected under Round III of the U.S. Department of Energy (DOE) Clean Coal Technology (CCT) Demonstration Program. The CCT Demonstration Program is a government and industry cofunded technology development effort to demonstrate a new generation of innovative coal utilization processes in a series of commercial-scale facilities. The ENCOAL{reg_sign} Corporation, a wholly-owned subsidiary of Bluegrass Coal Development Company (formerly SMC Mining Company), which is a subsidiary of Ziegler Coal Holding Company, submitted an application to the DOE in August 1989, soliciting joint funding of the project in the third round of the CCT Program. The project was selected by DOE in December 1989, and the Cooperative Agreement (CA) was approved in September 1990. Construction, commissioning, and start-up of the ENCOAL{reg_sign} mild coal gasification facility was completed in June 1992. In October 1994, ENCOAL{reg_sign} was granted a two-year extension of the CA with the DOE, that carried through to September 17, 1996. ENCOAL{reg_sign} was then granted a six-month, no-cost extension through March 17, 1997. Overall, DOE provided 50 percent of the total project cost of $90,664,000. ENCOAL{reg_sign} operated the 1,000-ton-per-day mild gasification demonstration plant at Triton Coal Company's Buckskin Mine near Gillette, Wyoming, for over four years. The process, using Liquids From Coal (LFC{trademark}) technology originally developed by SMC Mining Company and SGI International, utilizes low-sulfur Powder River Basin (PRB) coal to produce two new fuels, Process-Derived Fuel (PDF{trademark}) and Coal-Derived Liquids (CDL{trademark}). The products, as alternative fuel sources, are capable of significantly lowering current sulfur emissions at industrial and utility boiler sites throughout the nation thus reducing pollutants causing acid rain. In support of this overall objective

  2. Ultrasound Volume Projection Imaging for Assessment of Scoliosis.

    PubMed

    Cheung, Chung-Wai James; Zhou, Guang-Quan; Law, Siu-Yin; Mak, Tak-Man; Lai, Ka-Lee; Zheng, Yong-Ping

    2015-08-01

    The standing radiograph is used as a gold standard to diagnose spinal deformity including scoliosis, a medical condition defined as lateral spine curvature > 10°. However, the health concern of X-ray and large inter-observer variation of measurements on X-ray images have significantly restricted its application, particularly for scoliosis screening and close follow-up for adolescent patients. In this study, a radiation-free freehand 3-D ultrasound system was developed for scoliosis assessment using a volume projection imaging method. Based on the obtained coronal view images, two measurement methods were proposed using transverse process and spinous profile as landmarks, respectively. As a reliability study, 36 subjects (age: 30.1 ±14.5; male: 12; female: 24) with different degrees of scoliosis were scanned using the system to test the inter- and intra-observer repeatability. The intra- and inter-observer tests indicated that the new assessment methods were repeatable, with ICC larger than 0.92. Small intra- and inter-observer variations of measuring spine curvature were observed for the two measurement methods (intra-: 1.4 ±1.0° and 1.4 ±1.1°; inter-: 2.2 ±1.6° and 2.5 ±1.6°). The results also showed that the spinal curvature obtained by the new method had good linear correlations with X-ray Cobb's method (R2 = 0.8, p < 0.001, 29 subjects). These results suggested that the ultrasound volume projection imaging method can be a promising approach for the assessment of scoliosis, and further research should be followed up to demonstrate its potential clinical applications for mass screening and curve progression and treatment outcome monitoring of scoliosis patients.

  3. Background and Reflections on the Life Cycle Assessment Harmonization Project

    SciTech Connect

    Heath, G. A.; Mann, M. K.

    2012-04-01

    Despite the ever-growing body of life cycle assessment (LCA) literature on electricity generation technologies, inconsistent methods and assumptions hamper comparison across studies and pooling of published results. Synthesis of the body of previous research is necessary to generate robust results to assess and compare environmental performance of different energy technologies for the benefit of policy makers, managers, investors, and citizens. With funding from the U.S. Department of Energy, the National Renewable Energy Laboratory initiated the LCA Harmonization Project in an effort to rigorously leverage the numerous individual studies to develop collective insights. The goals of this project were to: (1) understand the range of published results of LCAs of electricity generation technologies, (2) reduce the variability in published results that stem from inconsistent methods and assumptions, and (3) clarify the central tendency of published estimates to make the collective results of LCAs available to decision makers in the near term. The LCA Harmonization Project's initial focus was evaluating life cycle greenhouse gas (GHG) emissions from electricity generation technologies. Six articles from this first phase of the project are presented in a special supplemental issue of the Journal of Industrial Ecology on Meta-Analysis of LCA: coal (Whitaker et al. 2012), concentrating solar power (Burkhardt et al. 2012), crystalline silicon photovoltaics (PVs) (Hsu et al. 2012), thin-film PVs (Kim et al. 2012), nuclear (Warner and Heath 2012), and wind (Dolan and Heath 2012). Harmonization is a meta-analytical approach that addresses inconsistency in methods and assumptions of previously published life cycle impact estimates. It has been applied in a rigorous manner to estimates of life cycle GHG emissions from many categories of electricity generation technologies in articles that appear in this special supplemental supplemental issue, reducing the variability and

  4. Life Cycle Assessment of Biochar - EuroChar Project

    NASA Astrophysics Data System (ADS)

    Rack, M.; Woods, J.

    2012-04-01

    One of the most significant challenges faced by modern-day society is that of global warming. An exclusive focus on reducing the greenhouse gas (GHG) emissions will not suffice and therefore technologies capable of removing CO2 directly from the atmosphere at low or minimal cost are gaining increased attention. The production and use of biochar is an example of such an emerging mitigation strategy. However, as with any novel product, process and technology it is vital to conduct an assessment of the entire life cycle in order to determine the environmental impacts of the new concept in addition to analysing the other sustainability criteria. Life Cycle Assessment (LCA), standardized by ISO (2006a), is an example of a tool used to calculate the environmental impacts of a product or process. Imperial College London will follow the guidelines and recommendations of the ISO 14040 series (ISO 2002, ISO 2006a-b) and the International Life Cycle Data System (ILCD) Handbook (EC JRC IES, 2010a-e), and will use the SimaPro software to conduct a LCA of the biochar supply chains for the EuroChar project. EuroChar ('biochar for Carbon sequestration and large-scale removal of GHG from the atmosphere') is a project funded by the European Commission under its Seventh Framework Programme (FP7). EuroChar aims to investigate and reduce uncertainties around the impacts of, and opportunities for, biochar and, in particular, explore a possible introduction into modern agricultural systems in Europe, thereby moving closer to the determination of the true potential of biochar. EuroChar will use various feedstocks, ranging from wheat straw to olive residues and poplar, as feedstocks for biochar production and will focus on two conversion technologies, Hydrothermal Carbonization (HTC) and Thermochemical Carbonization (TC), followed by the application of the biochar in crop-growth field trials in England, France and Italy. In April 2012, the EuroChar project will be at its halfway mark and

  5. Three-dimensional localization of impacted canines and root resorption assessment using cone beam computed tomography.

    PubMed

    Almuhtaseb, Eyad; Mao, Jing; Mahony, Derek; Bader, Rawan; Zhang, Zhi-xing

    2014-06-01

    The purpose of this study was to develop a new way to localize the impacted canines from three dimensions and to investigate the root resorption of the adjacent teeth by using cone beam computed tomography (CBCT). Forty-six patients undergoing orthodontic treatments and having impacted canines in Tongji Hospital were examined. The images of CBCT scans were obtained from KaVo 3D exam vision. Angular and linear measurements of the cusp tip and root apex according to the three planes (mid-sagittal, occlusal and frontal) have been taken using the cephalometric tool of the InVivo Dental Anatomage Version 5.1.10. The measurements of the angular and linear coordinates of the maxillary and mandibular canines were obtained. Using this technique the operators could envision the location of the impacted canine according to the three clinical planes. Adjacent teeth root resorption of 28.26 % was in the upper lateral incisors while 17.39% in upper central incisors, but no lower root resorption was found in our samples. Accurate and reliable localization of the impacted canines could be obtained from the novel analysis system, which offers a better surgical and orthodontic treatment for the patients with impacted canines.

  6. Assessment of cervical demineralization induced by Streptococcus mutans using swept-source optical coherence tomography.

    PubMed

    Tezuka, Hiroki; Shimada, Yasushi; Matin, Khairul; Ikeda, Masaomi; Sadr, Alireza; Sumi, Yasunori; Tagami, Junji

    2016-01-01

    Exposed root surfaces due to gingival recession are subject to biofilm stagnation that can result in caries formation. Cervical enamel and dentin demineralization induced by a cariogenic biofilm was evaluated using swept-source optical coherence tomography (SS-OCT). The cementoenamel junction (CEJ) sections of extracted human teeth were subjected to demineralization for 1, 2, or 3 weeks. A suspension of Streptococcus mutans was applied to form a cariogenic biofilm using an oral biofilm reactor. After incubation, demineralization was observed by SS-OCT. For the analysis of SS-OCT signal, the value of the area under the curve (AUC) of the signal profile was measured. Statistical analyses were performed with 95% level of confidence. Cervical demineralization was displayed as a bright zone in SS-OCT. The demineralization depth of dentin was significantly deeper than that of enamel ([Formula: see text]). Enamel near the CEJ demonstrated a significant increase of AUC over the other enamel region after the demineralization. The gaps along the dentinoenamel junction were additionally observed in SS-OCT. SS-OCT was capable of monitoring the cervical demineralization induced by a cariogenic biofilm and is considered to be a promising modality for the diagnosis of cervical demineralization. PMID:27014718

  7. Assessment of nasal septum after Le Fort I osteotomy with computer tomography.

    PubMed

    Moroi, Akinori; Yoshizawa, Kunio; Tsutsui, Takamitsu; Saida, Yuriko; Hotta, Asami; Fukaya, Kenichi; Hiraide, Ryota; Takayama, Akihiro; Tunoda, Tatsuya; Saito, Yuuki; Ueki, Koichiro

    2016-09-01

    The purpose of this study was to evaluate the effects of Le Fort I osteotomy on nasal septum deviation and differences in left and right airway sizes, and to determine whether the nasal septum was affected by differences in the direction of movement. Forty patients underwent conventional Le Fort I osteotomy, and computed tomography (CT) was performed preoperatively, and 1 week and 1 year postoperatively. The nasal septum angle and airway area were measured at the anterior, middle, and posterior positions on the CT images Patients were divided into 2 groups depending on each difference in movement (impaction ≥5 mm or other; anterior movement or other; and impaction asymmetry or other). There were no significant differences in the nasal septum angle and the airway of all patients. Among the patient groups, there were no significant differences in the nasal septum angle and airway. We concluded that conventional LI osteotomy did not influence the nasal septum deviation or the left and right airway asymmetry. Differences in the method of moving the maxilla have not been shown to affect changes in the nasal septum.

  8. Assessing potato tuber diel growth by means of X-ray computed tomography.

    PubMed

    Pérez-Torres, Eduardo; Kirchgessner, Norbert; Pfeifer, Johannes; Walter, Achim

    2015-11-01

    The formation and development of belowground organs is difficult to study. X-ray computed tomography (CT) provides the possibility to analyse and interpret subtle volumetric changes of belowground organs such as tubers, storage roots and nodules. Here, we report on the establishment of a method based on a voxel dimension of 240 μm and precision (standard deviation) of 30 μL that allows interpreting growth differences among potato tubers happening within 3 h. Plants were not stressed by the application of X-ray radiation, which was shown both by morphological comparison with control plants and by analysis of lipid peroxidation as a measure of oxidative stress. Diel (24 h) tuber growth fluctuations of three potato genotypes were monitored in soil-filled pots of 10 L. In contrast to the results from previous reports, most tubers grew at similar rates during day and night. Tuber growth was not related to the developmental stage of plants and tubers. Pronounced differences were observed between average growth rates in different tubers within a plant. These results are discussed in the context of restrictions of past methods to study tuber growth and in the context of their potential for the characterization of the formation and development of other belowground plant organs.

  9. Assessment of knowledge and awareness among radiology personnel regarding current computed tomography technology and radiation dose

    NASA Astrophysics Data System (ADS)

    Karim, M. K. A.; Hashim, S.; Bradley, D. A.; Bahruddin, N. A.; Ang, W. C.; Salehhon, N.

    2016-03-01

    In this paper, we evaluate the level of knowledge and awareness among 120 radiology personnel working in 7 public hospitals in Johor, Malaysia, concerning Computed Tomography (CT) technology and radiation doses based on a set of questionnaires. Subjects were divided into two groups (Medical profession (Med, n=32) and Allied health profession (AH, n=88). The questionnaires are addressed: (1) demographic data (2) relative radiation dose and (3) knowledge of current CT technology. One-third of respondents from both groups were able to estimate relative radiation dose for routine CT examinations. 68% of the allied health profession personnel knew of the Malaysia regulations entitled ‘Basic Safety Standard (BSS) 2010’, although notably 80% of them had previously attended a radiation protection course. No significant difference (p < 0.05) in mean scores of CT technology knowledge detected between the two groups, with the medical professions producing a mean score of (26.7 ± 2.7) and the allied health professions a mean score of (25.2 ± 4.3). This study points to considerable variation among the respondents concerning their understanding of knowledge and awareness of risks of radiation and CT optimization techniques.

  10. Assessment of Localized Deformations in Sand Using X-Ray Computed Tomography

    NASA Technical Reports Server (NTRS)

    Alshibli, Khalid A; Sture, Stein; Costes, Nicholas C.; Frank, Mellisa L.; Lankton, Mark R.; Batiste, Susan N.; Swanson, Roy A.

    1999-01-01

    The internal fabric and localized deformation patterns of triaxial sand specimens were investigated using Computed Tomography (CT). Three displacement-controlled, conventional, drained axisymmetric (triaxial) experiments were conducted on dry Ottawa sand specimens at very low effective confining stresses (0.05, 0.52, and 1.30 kPa) in a microgravity environment aboard the Space Shuttle during the NASA STS-79 mission. CT scanning was p'erformed on these flight specimens, as well as on an uncompressed specimen and a specimen tested in a terrestrial laboratory at 1.30 kPa effective confining stress. CT demonstrated high accuracy in detecting specimen inhomogeneity and localization patterns. Formation of deformation patterns is dependent on the effective confining stress and gravity. Multiple symmetrical radial shear bands were observed in the specimens tested in a microgravity environment. In the axial direction, two major conical surfaces were developed. Nonsymmetrical spatial deformation was observed in the 1-G specimen. Analysis tools were developed to quantify the spatial density change. Void ratio variation within and outside the shear bands was calculated and discussed.

  11. Noninvasive Assessment of Early Dental Lesion Using a Dual-Contrast Photoacoustic Tomography

    NASA Astrophysics Data System (ADS)

    Cheng, Renxiang; Shao, Jiaojiao; Gao, Xiaoxiang; Tao, Chao; Ge, Jiuyu; Liu, Xiaojun

    2016-02-01

    Dental hard tissue lesions, including caries, cracked-tooth, etc., are the most prevalent diseases of people worldwide. Dental lesions and correlative diseases greatly decrease the life quality of patients throughout their lifetime. It is still hard to noninvasively detect these dental lesions in their early stages. Photoacoustic imaging is an emerging hybrid technology combining the high spatial resolution of ultrasound in deep tissue with the rich optical contrasts. In this study, a dual-contrast photoacoustic tomography is applied to detect the early dental lesions. One contrast, named B-mode, is related to the optical absorption. It is good at providing the sharp image about the morphological and macro-structural features of the teeth. Another contrast, named S-mode, is associated with the micro-structural and mechanical properties of the hard tissue. It is sensitive to the change of tissue properties induced by the early dental lesions. Experiments show that the comprehensive analysis of dual-contrast information can provide reliable information of the early dental lesions. Moreover, the imaging parameter of S-mode is device-independent and it could measure tissue properties quantitatively. We expect that the proposed scheme could be beneficial for improving safety, accuracy and sensitivity of the clinical diagnosis of the dental lesion.

  12. Optical Coherence Tomography Assessment Before and After Vitamin Supplementation in a Patient With Vitamin A Deficiency

    PubMed Central

    Saenz-de-Viteri, Manuel; Sádaba, Luis M.

    2016-01-01

    Abstract Vitamin A is an essential fat-soluble vitamin important for the function of various body systems. In the eye, vitamin A is essential for the synthesis of visual pigments in photoreceptors. Vitamin A deficiency is a rare condition in the developed countries and might follow bariatric or intestinal bypass surgery. We present the case of a 67-year-old male that complained of visual loss and nyctalopia. Patient had bariatric surgery 15 years before for weight loss. Low serum levels of vitamin A confirmed the diagnosis and patient started vitamin A supplementation. Visual fields, macular thickness, and ganglion cell layer thickness were recorded and monitored 1 month, 6 months, and 1 year after the beginning of therapy. Visual fields were significantly altered and central macular thickness and ganglion cell layer thickness were reduced, but the first 2 showed a significant recovery with vitamin supplementation therapy. By the 1st month of treatment patient referred a complete remission of visual symptoms. Further, we observed hyperreflective material accumulating beneath a partially disrupted ellipsoid band in the high definition optical coherence tomography that also improved progressively with vitamin repletion. Newer and more sophisticated imaging systems have increased our knowledge of the mechanisms responsible for retinal diseases. To our knowledge, this is the first description of the effect of vitamin A deficiency and vitamin supplementation on macular thickness. This case also highlights the importance of considering bariatric bypass surgery as a cause of vitamin A deficiency in developed countries. PMID:26871796

  13. Quantitative assessment of cervical vertebral maturation using cone beam computed tomography in Korean girls.

    PubMed

    Byun, Bo-Ram; Kim, Yong-Il; Yamaguchi, Tetsutaro; Maki, Koutaro; Son, Woo-Sung

    2015-01-01

    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 R (2) 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.

  14. Intracochlear assessment of electrode position after cochlear implant surgery by means of multislice computer tomography.

    PubMed

    van Wermeskerken, Gijs K A; Prokop, Mathias; van Olphen, Adriaan F; Albers, Frans W J

    2007-12-01

    The development of electrode arrays, the past years, has focused on modiolus-hugging cochlear implant electrodes. Besides, atraumatic implantation of electrodes is of importance for the use in hearing preservation, in cases of combined electric and acoustic stimulation. Intracochlear positioning of the individual electrodes by means of multislice computer tomography (CT) has not yet been shown. In this study we formulated and tested a CT imaging protocol for postoperative scanning of the temporal bone in cochlear implant subjects. Both a fresh human temporal bone and a fresh human cadaver head were implanted with a cochlear implant. Multislice CT was performed for adequate depiction of the cochlear implant. All scans were analyzed on a viewing workstation. After mid-modiolar reconstruction we were able to identify the intracochlear electrode position relative to the scala tympani and scala vestibuli. This was possible in both the implanted isolated temporal bone and the fresh human cadaver head. The feasibility of imaging the electrode position of the cochlear implant within the intracochlear spaces is shown with multislice CT. An imaging protocol is suggested. PMID:17632730

  15. Assessment of Cancer-Associated Biomarkers by Positron Emission Tomography: Advances and Challenges

    PubMed Central

    Collier, T. Lee; Lecomte, Roger; McCarthy, Timothy J.; Meikle, Steve; Ruth, Thomas J.; Scopinaro, Francesco; Signore, Alberto; Van Brocklin, Henry; Van de Wiele, Christophe; Waterhouse, Rikki N.

    2002-01-01

    Positron emission tomography (PET) provides a powerful means to non-invasively image and quantify protein expression and biochemical changes in living subjects at nano- and picomolar levels. As the field of molecular imaging develops, and as advances in the biochemistry, pharmacology, therapeutics, and molecular biology of disease are made, there is a corresponding increase in the number of clinically relevant, novel disease-associated biomarkers that are brought to the attention of those developing imaging probes for PET. In addition, due to the high specificity of the PET radiotracers being developed, there is a demand for PET cameras with higher sensitivity and resolution. This manuscript reviews advances over the past five years in clinical and pre-clinical PET instrumentation and in new PET probes and imaging methods associated with the latest trends in the molecular imaging of cancer. Included in the PET tracer review is a description of new radioligands for steroid receptors, growth factor receptors, receptor tyrosine kinases, sigma receptors, tumor-associated enzymes, gene reporter probes, markers for tumor hypoxia and metabolism, and sites associated with angiogenesis and cellular proliferation. The use of PET imaging in drug development, including the monitoring of cancer chemotherapy, also is discussed. PMID:14646039

  16. Noninvasive Assessment of Early Dental Lesion Using a Dual-Contrast Photoacoustic Tomography

    PubMed Central

    Cheng, Renxiang; Shao, Jiaojiao; Gao, Xiaoxiang; Tao, Chao; Ge, Jiuyu; Liu, Xiaojun

    2016-01-01

    Dental hard tissue lesions, including caries, cracked-tooth, etc., are the most prevalent diseases of people worldwide. Dental lesions and correlative diseases greatly decrease the life quality of patients throughout their lifetime. It is still hard to noninvasively detect these dental lesions in their early stages. Photoacoustic imaging is an emerging hybrid technology combining the high spatial resolution of ultrasound in deep tissue with the rich optical contrasts. In this study, a dual-contrast photoacoustic tomography is applied to detect the early dental lesions. One contrast, named B-mode, is related to the optical absorption. It is good at providing the sharp image about the morphological and macro-structural features of the teeth. Another contrast, named S-mode, is associated with the micro-structural and mechanical properties of the hard tissue. It is sensitive to the change of tissue properties induced by the early dental lesions. Experiments show that the comprehensive analysis of dual-contrast information can provide reliable information of the early dental lesions. Moreover, the imaging parameter of S-mode is device-independent and it could measure tissue properties quantitatively. We expect that the proposed scheme could be beneficial for improving safety, accuracy and sensitivity of the clinical diagnosis of the dental lesion. PMID:26902394

  17. Assessment of dental caries with optical coherence tomography: effect of ambient factors

    NASA Astrophysics Data System (ADS)

    Amaechi, Bennett T.; Podoleanu, Adrian Gh.; Higham, Susan M.; Jackson, David A.

    2002-06-01

    Optical Coherence Tomography (OCT) has been used to produce longitudinal images of dental tissues. We investigated the influence on OCT system, of factors that could limit detection and quantitative monitoring of incipient caries. The effect of such factors as saliva, dental plaque, lesion staining, ambient lighting, and Dacron gauze (used to encourage plaque growth in in situ caries studies) on OCT imaging and analysis were determined during demineralization to produce early caries. The system can collect A-scans, B- scans (longitudinal images) and C-scans (en-face images). Caries lesions were shown as volumes of reduced reflectivity. A-scan, which showed the levels of reflectivity versus the depth of penetration into the tooth tissue, was used for the quantitative analysis of the reflectivity loss. The reflectivity of the tooth tissue decreased with demineralization. The percentage change in reflectivity of the tissue was quantified as a measure of the change in mineral status of the tissue following demineralization. Neither the presence of saliva, plaque, Dacron gauze, plaque/Dacron gauze, nor lesion staining nor the level of ambient lighting significantly affected OCT detection and analysis of an incipient caries.

  18. Assessment of Cardiovascular Disease Using Permeability Rates: Quantification by Optical Coherence Tomography

    NASA Astrophysics Data System (ADS)

    Ghosn, Mohamad G.; Mashiatulla, Maleeha; Morrisett, Joel D.; Larin, Kirill V.

    In order to prevent major damage to the cardiovascular system, it is of vital importance to monitor molecular changes in vascular tissues. Symptoms of cardiovascular diseases frequently do not manifest themselves until it is too late for effective treatment; therefore, methodologies that facilitate early detection are crucial. Atherosclerosis is a major underlying cause of many cardiovascular diseases; thus, elucidating the mechanisms of atherosclerosis is essential for shedding light on the initiation and progression of atherosclerotic lesions. Atherosclerosis includes an inflammatory process in arterial tissue that involves subintimal accumulation of lipoproteins particles, mainly low-density lipoprotein and lipoprotein[a]. Measurement of the permeation rates of these particles should extend our understanding of this disease and lead to methods for early disease detection. Over the past decade, optical coherence tomography (OCT) has become widely used in research and, more recently, has been used as a high-resolution imaging technique, capable of quantifying molecular permeability in biological tissues. OCT enables highly sensitive and accurate measurement of permeability rates of molecules and particles in vascular tissue. This sensitivity is due to high in-depth and transverse resolution along with a high dynamic range. In this chapter, we discuss the permeation of molecules and particles through human and animal vascular tissue.

  19. Polarization-sensitive optical coherence tomography for the nondestructive assessment of the remineralization of dentin

    NASA Astrophysics Data System (ADS)

    Manesh, Saman K.; Darling, Cynthia L.; Fried, Daniel

    2009-07-01

    Previous studies have demonstrated that polarization-sensitive optical coherence tomography (PS-OCT) can be used to image caries lesions in dentin, measure nondestructively the severity of dentin demineralization, and determine the efficacy of intervention with anticaries agents including fluoride and lasers. The objective of this study is to determine if PS-OCT can be used to nondestructively measure a reduction in the reflectivity of dentin lesions after exposure to a remineralization solution. Although studies have shown the ability of PS-OCT to image the remineralization of lesions in enamel, none have included dentin. PS-OCT images of dentin surfaces are acquired after exposure to an artificial demineralizing solution for six days and a remineralizing solution for 20 days. The integrated reflectivity, depth of demineralization, and thickness of the layer of remineralization are calculated for each of the two treatment groups on each sample. Polarized light microscopy and microradiography are used to measure lesion severity on histological thin sections for comparison. PS-OCT successfully measured the formation of a layer of increased mineral content near the lesion surface. Polorized light microscopy (PLM) and transverse microradiography (TMR) corroborated those results. PS-OCT can be used for the nondestructive measurement of the remineralization of dentin.

  20. Assessing tumor hypoxia by positron emission tomography with Cu-ATSM.

    PubMed

    Holland, J P; Lewis, J S; Dehdashti, F

    2009-04-01

    For the last several decades, hypoxia has been recognized to be one of the key factors in tumor aggression and an important impediment to local and distant control of malignant tumors. In addition, hypoxia is a major cause of failure of both radiation therapy and chemotherapy. It has been shown that hypoxia is an independent negative prognostic factor for patient outcome in various solid tumors. Clinical studies using polarographic oxygen electrodes, as a tool for measuring hypoxia, were the first to demonstrate the presence of hypoxia in human tumors and its association with poor prognosis. However, this method is invasive and has technical limitations that prevent its routine clinical use. Over the years, imaging as a noninvasive method has attracted a lot of attention and several radiotracers have been developed for noninvasive evaluation of hypoxia. One of the most promising radiotracers is the copper(II) complex of diacetyl-2,3-bis(N(4)-methyl-3-thiosemicarbazonato) ligand (Cu-ATSM) for imaging with positron emission tomography. In this review, the preclinical evaluation of Cu-ATSM as well as its clinical value in several solid tumors will be discussed.

  1. Assessment of contamination by intensive cattle activity through electrical resistivity tomography

    NASA Astrophysics Data System (ADS)

    Sainato, Claudia M.; Losinno, Beatriz N.; Malleville, Horacio J.

    2012-01-01

    The intensive animal production is considered highly risky for groundwater and soil because of high mobility of some contaminants from animal wastes. The aim of this work was to obtain an electrical conductivity image of unsaturated and saturated zones at a feedlot (cattle feeding field) at the surroundings of Buenos Aires city (Argentina) in order to detect the most critical sectors of the field, with regard to contamination by animal wastes. Dipole-dipole electrical soundings (electrical resistivity tomography) were performed at the corral zone and the surroundings. 2D and 3D models of conductivity were obtained. Even if there is a calcareous plate below some parts of the corrals and soil compaction is high, vertical infiltration or subsurface runoff may have occurred since these sites, with high animal charge, show soil conductivities higher than the surroundings. The models showed higher conductivities of saturated zone increasing in the direction of groundwater flow. These results were taken into account for further designs of soil and groundwater sampling. Groundwater conductivity was three times greater downgradient from the corrals with high concentrations of nitrates and phosphorous. A zone of high conductivity was found below a small channel of effluents from the corrals.

  2. Assessing potato tuber diel growth by means of X-ray computed tomography.

    PubMed

    Pérez-Torres, Eduardo; Kirchgessner, Norbert; Pfeifer, Johannes; Walter, Achim

    2015-11-01

    The formation and development of belowground organs is difficult to study. X-ray computed tomography (CT) provides the possibility to analyse and interpret subtle volumetric changes of belowground organs such as tubers, storage roots and nodules. Here, we report on the establishment of a method based on a voxel dimension of 240 μm and precision (standard deviation) of 30 μL that allows interpreting growth differences among potato tubers happening within 3 h. Plants were not stressed by the application of X-ray radiation, which was shown both by morphological comparison with control plants and by analysis of lipid peroxidation as a measure of oxidative stress. Diel (24 h) tuber growth fluctuations of three potato genotypes were monitored in soil-filled pots of 10 L. In contrast to the results from previous reports, most tubers grew at similar rates during day and night. Tuber growth was not related to the developmental stage of plants and tubers. Pronounced differences were observed between average growth rates in different tubers within a plant. These results are discussed in the context of restrictions of past methods to study tuber growth and in the context of their potential for the characterization of the formation and development of other belowground plant organs. PMID:25850677

  3. The role of computed tomography in assessment of tumoral pathology of the adrenal glands.

    PubMed

    Eghrari, M; McLoughlin, M J; Rosen, I E; St Louis, E L; Wilson, S R; Yeung, H P

    1980-02-01

    The findings at computed tomography (CT) of the adrenal glands in 58 patients are presented. Most patients (50) were referred for suspected adrenal dysfunction. In three, adrenal masses were suspected from other radiological studies. Three patients had palpable abdominal masses, and incidental adrenal metastases were found in two. Pathological findings included pheochromocytomas (nine patients), adrenocortical adenomas (six), adrenocortical carcinomas (three), metastases (two), and one example each of myelolipoma, hemorrhagic renal cyst, and probable granuloma. Of 24 adrenal masses, 23 were clearly apparent in the scans and one was suspected. The smallest tumor diagnosed was 0.5 cm in diameter. There was on false positive diagnosis of a small tumor and no known false negatives. Because of their consistent location and unusual shape and because they are usually surrounded by retroperitoneal fat, the adrenal glands are ideal organs for study by CT, a highly accurate method for detecting and excluding mass lesions that may render arteriography and venography unnecessary. Surgery was performed in five patients with tumors following localization by CT only. Limitations and potential diagnostic pitfalls in interpretation are discussed.

  4. Present and future utility of computed tomography scanning in the assessment and management of COPD.

    PubMed

    Ostridge, Kristoffer; Wilkinson, Tom M A

    2016-07-01

    Computed tomography (CT) is the modality of choice for imaging the thorax and lung structure. In chronic obstructive pulmonary disease (COPD), it used to recognise the key morphological features of emphysema, bronchial wall thickening and gas trapping. Despite this, its place in the investigation and management of COPD is yet to be determined, and it is not routinely recommended. However, lung CT already has important clinical applications where it can be used to diagnose concomitant pathology and determine which patients with severe emphysema are appropriate for lung volume reduction procedures. Furthermore, novel quantitative analysis techniques permit objective measurements of pulmonary and extrapulmonary manifestations of the disease. These techniques can give important insights into COPD, and help explore the heterogeneity and underlying mechanisms of the condition. In time, it is hoped that these techniques can be used in clinical trials to help develop disease-specific therapy and, ultimately, as a clinical tool in identifying patients who would benefit most from new and existing treatments. This review discusses the current clinical applications for CT imaging in COPD and quantification techniques, and its potential future role in stratifying disease for optimal outcome. PMID:27230448

  5. Computed Tomography Perfusion Assessment of Radiation Therapy Effects on Spinal Cord Hemodynamics

    SciTech Connect

    Spampinato, Maria Vittoria; Bisdas, Sotirios; Sharma, Anand K.; McDonald, Daniel; Strojan, Primoz; Rumboldt, Zoran

    2010-07-01

    Purpose: We used computed tomography (CT) perfusion to evaluate the acute and late effect of radiation therapy (RT) on spinal cord (SC) hemodynamics in patients without symptoms of myelopathy. We hypothesized that SC perfusion could be acutely altered during RT. Methods and Materials: We analyzed neck CT perfusion studies of 36 head-and-neck cancer patients (N1), 16 of whom had previously undergone RT. In a separate group of 6 patients (N2), CT perfusion studies were obtained before RT, after 40 Gy, and after treatment completion. Results: In the N1 group, SC blood flow (BF), blood volume (BV), mean transit time (MTT), and capillary permeability (CP) maps were not significantly different between RT-treated and RT-naive patients. In the N2 group, BF and CP were significantly increased during treatment compared with the baseline and post-RT studies. Conclusions: Radiation therapy of the head and neck may cause transient perturbations of SC perfusion that seem to reverse after treatment. There are no definite chronic effects of RT on SC perfusion observeable at the typical doses administered during treatment of head and neck malignancies.

  6. Glucose utilization in a patient with hepatoma and hypoglycemia. Assessment by a positron emission tomography.

    PubMed Central

    Eastman, R C; Carson, R E; Orloff, D G; Cochran, C S; Perdue, J F; Rechler, M M; Lanau, F; Roberts, C T; Shapiro, J; Roth, J

    1992-01-01

    Tumor glucose use in patients with non-islet-cell tumors has been difficult to measure, particularly in hepatoma, because of hepatic involvement by neoplasm. We studied a patient with nonhepatic recurrence of hepatoma after successful liver transplantation. Tumor tissue contained messenger RNA for insulin-like growth factor-II (IGF-II), and circulating high molecular weight components and E-peptide of IGF-II were increased. Glucose use measured by isotope dilution with [3-3H]glucose was 7.94 mg/kg fat-free mass per min, and splanchnic glucose production was 0.93 mg/kg fat-free mass per min. Glucose uptake and glucose model parameters were independently measured in tissues by positron emission tomography with 18F-fluoro-2-deoxy-D-glucose. Glucose uptake by heart muscle, liver, skeletal muscle, and neoplasm accounted for 0.8, 14, 44, and 15% of total glucose use, respectively. Model parameters in liver and neoplasm were not significantly different, and glucose transport and phosphorylation were twofold and fourfold greater than in muscle. This suggests that circulating IGF-II-like proteins are partial insulin agonists, and that hypoglycemia in hepatoma with IGF-II production is predominantly due to glucose uptake by skeletal muscle and suppression of glucose production. PMID:1318326

  7. Clinical cross-polarization optical coherence tomography assessment of subsurface enamel below dental resin composite restorations.

    PubMed

    Lenton, Patricia; Rudney, Joel; Fok, Alex; Jones, Robert S

    2014-04-01

    A newly designed intraoral swept source cross-polarization optical coherence tomography (CP-OCT) imaging system was used to examine the integrity of the subsurface enamel below resin composite restorations placed in primary teeth. CP-OCT analysis was performed using images obtained from resin composite restoration in 62 ([Formula: see text]) pediatric subjects. Clinical examination was performed by a single examiner prior to CP-OCT imaging and analysis. CP-OCT images are presented using a unique combined intensity image, where a false color scale is overlaid on the grayscale intensity image. There was a clear difference in the distribution of the mean-backscattered intensity (mR) between restorations recently placed and those possessing frank cavitation (Student's t-test, [Formula: see text]). For mR above 15.49 dB, the sensitivity was 80% and specificity 86%. The Youden index J was 0.8 above 12.3 dB where sensitivity was 100% and specificity was 80%. CP-OCT imaging may be used to confirm the subsurface marginal integrity below resin composite restorations but with careful consideration of limitations of the imaging modality. CP-OCT imaging may be a useful adjunct to clinical visual investigation to confirm that a composite margin has a sound and well-adapted interface.

  8. Assess the flood resilience tools integration in the landuse projects

    NASA Astrophysics Data System (ADS)

    Moulin, E.; Deroubaix, J.-F.

    2012-04-01

    Despite a severe regulation concerning the building in flooding areas, 80% of these areas are already built in the Greater Paris (Paris, Val-de-Marne, Hauts-de-Seine and Seine-Saint-Denis). The land use in flooding area is presented as one of the main solutions to solve the ongoing real estate pressure. For instance some of the industrial wastelands located along the river are currently in redevelopment and residential buildings are planned. So the landuse in the flooding areas is currently a key issue in the development of the Greater Paris area. To deal with floods there are some resilience tools, whether structural (such as perimeter barriers or building aperture barriers, etc) or non structural (such as warning systems, etc.). The technical solutions are available and most of the time efficient1. Still, we notice that these tools are not much implemented. The people; stakeholders and inhabitants, literally seems to be not interested. This papers focus on the integration of resilience tools in urban projects. Indeed one of the blockages in the implementation of an efficient flood risk prevention policy is the lack of concern of the landuse stakeholders and the inhabitants for the risk2. We conducted an important number of interviews with stakeholders involved in various urban projects and we assess, in this communication, to what extent the improvement of the resilience to floods is considered as a main issue in the execution of an urban project? How this concern is maintained or could be maintained throughout the project. Is there a dilution of this concern? In order to develop this topic we rely on a case study. The "Ardoines" is a project aiming at redeveloping an industrial site (South-East Paris), into a project including residential and office buildings and other amenities. In order to elaborate the master plan, the urban planning authority brought together some flood risk experts. According to the comments of the experts, the architect in charge of the

  9. Automated registration of optical coherence tomography and dermoscopy in the assessment of sub-clinical spread in basal cell carcinoma

    PubMed Central

    Penney, G. P.; Richardson, T. J.; Guyot, A.; Choi, M. J.; Sheth, N.; Craythorne, E.; Robson, A.; Mallipeddi, R.

    2014-01-01

    Optical coherence tomography (OCT) has been shown to be of clinical value in imaging basal cell carcinoma (BCC). A novel dual OCT-video imaging system, providing automated registration of OCT and dermoscopy, has been developed to assess the potential of OCT in measuring the degree of sub-clinical spread of BCC. Seventeen patients selected for Mohs micrographic surgery (MMS) for BCC were recruited to the study. The extent of BCC infiltration beyond a segment of the clinically assessed pre-surgical border was evaluated using OCT. Sufficiently accurate (<0.5 mm) registration of OCT and dermoscopy images was achieved in 9 patients. The location of the OCT-assessed BCC border was also compared with that of the final surgical defect. Infiltration of BCC across the clinical border ranged from 0 mm to >2.5 mm. In addition, the OCT border lay between 0.5 mm and 2.0 mm inside the final MMS defect in those cases where this could be assessed. In one case, where the final MMS defect was over 17 mm from the clinical border, OCT showed >2.5 mm infiltration across the clinical border at the FOV limit. These results provide evidence that OCT allows more accurate assessment of sub-clinical spread of BCC than clinical observation alone. Such a capability may have clinical value in reducing the number of surgical stages in MMS for BCC. There may also be a role for OCT in aiding the selection of patients most suitable for MMS. PMID:24784842

  10. Assessment of a novel neutron tomography instrument and other nondestructive technologies for the characterization of degradation in honeycomb composites

    NASA Astrophysics Data System (ADS)

    Hungler, P. C.

    The feasibility of developing a nondestructive evaluation technique (NDE) or combination of techniques capable of characterizing degradation in honeycomb composites was investigated. To enable the determination of the exact location of water ingress inside a honeycomb composite structure, a novel neutron tomography instrument (NTI) was designed and developed at RMC. The system represents the only NTI available in Canada and allows a range of objects to be investigated including honeycomb coupons and complete CF 188 rudders. In order to produce 3D volumetric reconstructions of sufficient quality to assess the location of water, the system was optimized in terms of optics, spatial resolution and signal-to-noise ratio (SNR). An imaging test object was designed to enable the quantitative measurement of the spatial resolution in 2D images and 3D reconstructions, filling a gap in the current neutron imaging standards. Several noise reduction filters were applied to 2D and 3D images produced by the NTI, which improved the spatial resolution and SNR. Appropriate coupons that were purposely degraded to represent honeycomb composites subjected to water ingress were designed, constructed and tested. To produce coupons with different degrees of degradation in the skin to core bond, varying numbers of freeze-thaw cycles were used. Destructive flat-wise tension tests were then performed to evaluate the coupons and the results showed a strong first-order linear decay relationship between the number of freeze-thaw cycles and the filet bond strength. The method developed to reliably degrade the filet bond, provides a more appropriate degradation mechanism compared to other available methods for producing degraded coupons. The degraded coupons were subsequently inspected using several adapted NDE techniques: neutron tomography, infrared thermography, through-transmission ultrasonics and acoustic bond testing. Neutron tomography was capable of detailing the exact location of water in

  11. Assessing soil and groundwater contamination in a metropolitan redevelopment project.

    PubMed

    Yun, Junki; Lee, Ju Young; Khim, Jeehyeong; Ji, Won Hyun

    2013-08-01

    The purpose of this study was to assess contaminated soil and groundwater for the urban redevelopment of a rapid transit railway and a new mega-shopping area. Contaminated soil and groundwater may interfere with the progress of this project, and residents and shoppers may be exposed to human health risks. The study area has been remediated after application of first remediation technologies. Of the entire area, several sites were still contaminated by waste materials and petroleum. For zinc (Zn) contamination, high Zn concentrations were detected because waste materials were disposed in the entire area. For petroleum contamination, high total petroleum hydrocarbon (TPH) and hydrocarbon degrading microbe concentrations were observed at the depth of 7 m because the underground petroleum storage tank had previously been located at this site. Correlation results suggest that TPH (soil) concentration is still related with TPH (groundwater) concentration. The relationship is taken into account in the Spearman coefficient (α). PMID:23307052

  12. Advanced Seismic Probabilistic Risk Assessment Demonstration Project Plan

    SciTech Connect

    Justin Coleman

    2014-09-01

    Idaho National Laboratories (INL) has an ongoing research and development (R&D) project to remove excess conservatism from seismic probabilistic risk assessments (SPRA) calculations. These risk calculations should focus on providing best estimate results, and associated insights, for evaluation and decision-making. This report presents a plan for improving our current traditional SPRA process using a seismic event recorded at a nuclear power plant site, with known outcomes, to improve the decision making process. SPRAs are intended to provide best estimates of the various combinations of structural and equipment failures that can lead to a seismic induced core damage event. However, in general this approach has been conservative, and potentially masks other important events (for instance, it was not the seismic motions that caused the Fukushima core melt events, but the tsunami ingress into the facility).

  13. Assessing soil and groundwater contamination in a metropolitan redevelopment project.

    PubMed

    Yun, Junki; Lee, Ju Young; Khim, Jeehyeong; Ji, Won Hyun

    2013-08-01

    The purpose of this study was to assess contaminated soil and groundwater for the urban redevelopment of a rapid transit railway and a new mega-shopping area. Contaminated soil and groundwater may interfere with the progress of this project, and residents and shoppers may be exposed to human health risks. The study area has been remediated after application of first remediation technologies. Of the entire area, several sites were still contaminated by waste materials and petroleum. For zinc (Zn) contamination, high Zn concentrations were detected because waste materials were disposed in the entire area. For petroleum contamination, high total petroleum hydrocarbon (TPH) and hydrocarbon degrading microbe concentrations were observed at the depth of 7 m because the underground petroleum storage tank had previously been located at this site. Correlation results suggest that TPH (soil) concentration is still related with TPH (groundwater) concentration. The relationship is taken into account in the Spearman coefficient (α).

  14. Mathematical modeling of positron emission tomography (PET) data to assess radiofluoride transport in living plants following petiolar administration

    DOE PAGES

    Converse, Alexander K.; Ahlers, Elizabeth O.; Bryan, Tom W.; Hetue, Jackson D.; Lake, Katherine A.; Ellison, Paul A.; Engle, Jonathan W.; Barnhart, Todd E.; Nickles, Robert J.; Williams, Paul H.; et al

    2015-03-15

    Background: Ion transport is a fundamental physiological process that can be studied non-invasively in living plants with radiotracer imaging methods. Fluoride is a known phytotoxic pollutant and understanding its transport in plants after leaf absorption is of interest to those in agricultural areas near industrial sources of airborne fluoride. Here we report the novel use of a commercial, high-resolution, animal positron emission tomography (PET) scanner to trace a bolus of [¹⁸F]fluoride administered via bisected petioles of Brassica oleracea, an established model species, to simulate whole plant uptake of atmospheric fluoride. This methodology allows for the first time mathematical compartmental modelingmore » of fluoride transport in the living plant. Radiotracer kinetics in the stem were described with a single-parameter free- and trapped-compartment model and mean arrival times at different stem positions were calculated from the free-compartment time-activity curves. Results: After initiation of administration at the bisected leaf stalk, [¹⁸F] radioactivity climbed for approximately 10 minutes followed by rapid washout from the stem and equilibration within leaves. Kinetic modeling of transport in the stem yielded a trapping rate of 1.5 +/- 0.3%/min (mean +/- s.d., n = 3), velocity of 2.2 +/- 1.1 cm/min, and trapping fraction of 0.8 +/- 0.5%/cm. Conclusion: Quantitative assessment of physiologically meaningful transport parameters of fluoride in living plants is possible using standard positron emission tomography in combination with petiolar radiotracer administration. Movement of free fluoride was observed to be consistent with bulk flow in xylem, namely a rapid and linear change in position with respect to time. Trapping, likely in the apoplast, was observed. Future applications of the methods described here include studies of transport of other ions and molecules of interest in plant physiology.« less

  15. Mathematical modeling of positron emission tomography (PET) data to assess radiofluoride transport in living plants following petiolar administration

    SciTech Connect

    Converse, Alexander K.; Ahlers, Elizabeth O.; Bryan, Tom W.; Hetue, Jackson D.; Lake, Katherine A.; Ellison, Paul A.; Engle, Jonathan W.; Barnhart, Todd E.; Nickles, Robert J.; Williams, Paul H.; DeJesus, Onofre T.

    2015-03-15

    Background: Ion transport is a fundamental physiological process that can be studied non-invasively in living plants with radiotracer imaging methods. Fluoride is a known phytotoxic pollutant and understanding its transport in plants after leaf absorption is of interest to those in agricultural areas near industrial sources of airborne fluoride. Here we report the novel use of a commercial, high-resolution, animal positron emission tomography (PET) scanner to trace a bolus of [¹⁸F]fluoride administered via bisected petioles of Brassica oleracea, an established model species, to simulate whole plant uptake of atmospheric fluoride. This methodology allows for the first time mathematical compartmental modeling of fluoride transport in the living plant. Radiotracer kinetics in the stem were described with a single-parameter free- and trapped-compartment model and mean arrival times at different stem positions were calculated from the free-compartment time-activity curves. Results: After initiation of administration at the bisected leaf stalk, [¹⁸F] radioactivity climbed for approximately 10 minutes followed by rapid washout from the stem and equilibration within leaves. Kinetic modeling of transport in the stem yielded a trapping rate of 1.5 +/- 0.3%/min (mean +/- s.d., n = 3), velocity of 2.2 +/- 1.1 cm/min, and trapping fraction of 0.8 +/- 0.5%/cm. Conclusion: Quantitative assessment of physiologically meaningful transport parameters of fluoride in living plants is possible using standard positron emission tomography in combination with petiolar radiotracer administration. Movement of free fluoride was observed to be consistent with bulk flow in xylem, namely a rapid and linear change in position with respect to time. Trapping, likely in the apoplast, was observed. Future applications of the methods described here include studies of transport of other ions and molecules of interest in plant physiology.

  16. Global assessment of nitrogen fertilizer: the SCOPE/IGBP nitrogen fertilizer rapid assessment project.

    PubMed

    Mosier, Arvin R; Syers, J Keith; Freney, John R

    2005-12-01

    Nitrogen (N) availability is a key role in food and fiber production. Providing plant-available N through synthetic fertilizer in the 20th and early 21st century has been a major contributor to the increased production required to feed and clothe the growing human population. To continue to meet the global demands and to minimize environmental problems, significant improvements are needed in the efficiency with which fertilizer N is utilized within production systems. There are still major uncertainties regarding the fate of fertilizer N added to agricultural soils and the potential for reducing losses to the environment. Enhancing the technical and economic efficiency of fertilizer N is seen to promote a favorable situation for both agricultural production and the environment, and this has provided much of the impetus for a new N fertilizer project. To address this important issue, a rapid assessment project on N fertilizer (NFRAP) was conducted by SCOPE (the Scientific Committee on Problems of the Environment) during late 2003 and early 2004. This was the first formal project of the International Nitrogen Initiative (INI). As part of this assessment, a successful international workshop was held in Kampala, Uganda on 12 -16 January, 2004. This workshop brought together scientists from around the world to assess the fate of synthetic fertilizer N in the context of overall N inputs to agricultural systems, with a view to enhancing the efficiency of N use and reducing negative impacts on the environment. Regionalization of the assessment highlighted the problems of too little N for crop production to meet the nutrient requirements of sub-Saharan Africa and the oversupply of N in the major rice-growing areas of China. The results of the assessment are presented in a book (SCOPE 65) which is now available to provide a basis for further discussions on N fertilizer.

  17. 75 FR 10500 - Environmental Assessment Prepared for Proposed Cape Wind Energy Project in Nantucket Sound, MA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-08

    ... Minerals Management Service Environmental Assessment Prepared for Proposed Cape Wind Energy Project in... review and comment of an EA and Draft FONNSI prepared by MMS for the Cape Wind Energy Project proposed... Environmental Impact Statement (FEIS) for the Cape Wind Energy Project. The FEIS assessed the...

  18. 78 FR 15355 - Proposed Information Collection; Comment Request; Pilot Project Assessing Economic Benefits of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-11

    ...-213), NOAA's Marine Debris Division (MDD) is conducting a pilot project designed to assess the economic benefits to beach visitors of marine debris removal. The project will use a revealed preference... Project Assessing Economic Benefits of Marine Debris Removal AGENCY: National Oceanic and...

  19. 75 FR 23798 - Environmental Assessment Prepared for Proposed Cape Wind Energy Project in Nantucket Sound...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-04

    ... Minerals Management Service Environmental Assessment Prepared for Proposed Cape Wind Energy Project in...), announces the availability of an EA and FONNSI for the Cape Wind Energy Project proposed for Nantucket Sound... Impact Statement (FEIS) for the Cape Wind Energy Project. The FEIS assessed the physical, biological,...

  20. Detection of coronary calcifications from computed tomography scans for automated risk assessment of coronary artery disease

    SciTech Connect

    Isgum, Ivana; Rutten, Annemarieke; Prokop, Mathias; Ginneken, Bram van

    2007-04-15

    A fully automated method for coronary calcification detection from non-contrast-enhanced, ECG-gated multi-slice computed tomography (CT) data is presented. Candidates for coronary calcifications are extracted by thresholding and component labeling. These candidates include coronary calcifications, calcifications in the aorta and in the heart, and other high-density structures such as noise and bone. A dedicated set of 64 features is calculated for each candidate object. They characterize the object's spatial position relative to the heart and the aorta, for which an automatic segmentation scheme was developed, its size and shape, and its appearance, which is described by a set of approximated Gaussian derivatives for which an efficient computational scheme is presented. Three classification strategies were designed. The first one tested direct classification without feature selection. The second approach also utilized direct classification, but with feature selection. Finally, the third scheme employed two-stage classification. In a computationally inexpensive first stage, the most easily recognizable false positives were discarded. The second stage discriminated between more difficult to separate coronary calcium and other candidates. Performance of linear, quadratic, nearest neighbor, and support vector machine classifiers was compared. The method was tested on 76 scans containing 275 calcifications in the coronary arteries and 335 calcifications in the heart and aorta. The best performance was obtained employing a two-stage classification system with a k-nearest neighbor (k-NN) classifier and a feature selection scheme. The method detected 73.8% of coronary calcifications at the expense of on average 0.1 false positives per scan. A calcium score was computed for each scan and subjects were assigned one of four risk categories based on this score. The method assigned the correct risk category to 93.4% of all scans.

  1. Long-term macrobioerosion in the Mediterranean Sea assessed by micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Färber, Claudia; Titschack, Jürgen; Schönberg, Christine Hanna Lydia; Ehrig, Karsten; Boos, Karin; Baum, Daniel; Illerhaus, Bernhard; Asgaard, Ulla; Granville Bromley, Richard; Freiwald, André; Wisshak, Max

    2016-06-01

    Biological erosion is a key process for the recycling of carbonate and the formation of calcareous sediments in the oceans. Experimental studies showed that bioerosion is subject to distinct temporal variability, but previous long-term studies were restricted to tropical waters. Here, we present results from a 14-year bioerosion experiment that was carried out along the rocky limestone coast of the island of Rhodes, Greece, in the Eastern Mediterranean Sea, in order to monitor the pace at which bioerosion affects carbonate substrate and the sequence of colonisation by bioeroding organisms. Internal macrobioerosion was visualised and quantified by micro-computed tomography and computer-algorithm-based segmentation procedures. Analysis of internal macrobioerosion traces revealed a dominance of bioeroding sponges producing eight types of characteristic Entobia cavity networks, which were matched to five different clionaid sponges by spicule identification in extracted tissue. The morphology of the entobians strongly varied depending on the species of the producing sponge, its ontogenetic stage, available space, and competition by other bioeroders. An early community developed during the first 5 years of exposure with initially very low macrobioerosion rates and was followed by an intermediate stage when sponges formed large and more diverse entobians and bioerosion rates increased. After 14 years, 30 % of the block volumes were occupied by boring sponges, yielding maximum bioerosion rates of 900 g m-2 yr-1. A high spatial variability in macrobioerosion prohibited clear conclusions about the onset of macrobioerosion equilibrium conditions. This highlights the necessity of even longer experimental exposures and higher replication at various factor levels in order to better understand and quantify temporal patterns of macrobioerosion in marine carbonate environments.

  2. Assessment of the Anterior Loop of the Mental Nerve Using Cone Beam Computerized Tomography Scan.

    PubMed

    Lu, Chun-I; Won, John; Al-Ardah, Aladdin; Santana, Ruben; Rice, Dwight; Lozada, Jaime

    2015-12-01

    The purpose of this study is to use cone-beam computerized tomography (CBCT) scans with oblique-transverse reconstruction modality to measure and compare the anterior loop length (AnLL) of the mental nerve between gender and age groups and to compare the difference between the right and left sides. Sixty-one female and 61 male CBCT scans were randomly selected for each age group: 21-40, 41-60, and 61-80 years. Both right- and left-side AnLLs were measured in each subject using i-CATVision software to measure AnLLs on the oblique transverse plane using multiplanar reconstruction. The anterior loop was identified in 85.2% of cases, with the mean AnLL of the 366 subjects (732 hemimandibles) being 1.46 ± 1.25 mm with no statistically significant difference between right and left sides or between different gender groups. However, the mean AnLL in the 21-40 year group (1.89 ± 1.35 mm) was larger than the AnLL in the 41-60 year group (1.35 ± 1.19 mm) and the 61-80 year group (1.13 ± 1.08 mm). In conclusion, when placing implants in close proximity to mental foramina, caution is recommended to avoid injury to the inferior alveolar nerve. No fixed distance anteriorly from the mental foramen should be considered safe. Using CBCT scans with the oblique-transverse method to accurately identify and measure the AnLL is of utmost importance in avoiding and protecting its integrity. PMID:24552176

  3. Anthropometric Assessment of Neck Adipose Tissue and Airway Volume Using Multidetector Computed Tomography

    PubMed Central

    Maresky, Hillel S.; Sharfman, Zachary; Ziv-Baran, Tomer; Gomori, J.M.; Copel, Laurian; Tal, Sigal

    2015-01-01

    Abstract Neck adiposity tissue volume (NATV) accumulation is an indicator for metabolic syndrome and cardiovascular disease (CVD). Neck circumference is a poor measure of NATV, and a quantifier for this entity has not yet been established. To evaluate volumetric quantification by multidetector computed tomography (MDCT) as a reproducible anthropometric tool to measure NATV and airway volume (AWV). A total of 519 patients, including a subset of 70 random patients who underwent head and neck CT scanning in our hospital within 1 year (2013), were studied. Included patients were all those undergoing nonenhanced CT (NECT) or CT angiography (CTA). Neck cross-sectional areas (NCSA) were measured at 2 separate levels of the neck, and 3D postprocessing tissue reconstruction was performed, and NATV and AWVs were quantified volumetrically for all patients within the year. The average NCSA at the level of the soft palate and thyroid cartilage was 22,579 and 14,500 mm2, respectively. NATV when compared to the upper and lower levels of NCSA showed correlations of 0.64 and 0.79, respectively (P < 0.001). Interobserver analysis showed mean deviations of 0.46% and 0.32% for NATV and AWV, respectively. A strong correlation between NATV and body mass index (BMI) was found (r = 0.658, P < 0.001), and the top quartile of NATV:AWV patients (out of 519 patients) displayed a statistically significant mortality rate during 670 days of follow-up (d = 7.5%, P = 0.032). After adjustment for age and gender, the association between NATV:AWV and mortality was close to significant (P = 0.072). Volumetric quantification of NATV and AWV is a reproducible and prognostic anthropometric tool, as a high NATV:AWV demonstrated a significant risk factor for mortality; future research may further advance our understanding of this phenomenon. PMID:26559286

  4. Least-squares dual characterization for ROI assessment in emission tomography

    NASA Astrophysics Data System (ADS)

    Ben Bouallègue, F.; Crouzet, J. F.; Dubois, A.; Buvat, I.; Mariano-Goulart, D.

    2013-06-01

    Our aim is to describe an original method for estimating the statistical properties of regions of interest (ROIs) in emission tomography. Drawn upon the works of Louis on the approximate inverse, we propose a dual formulation of the ROI estimation problem to derive the ROI activity and variance directly from the measured data without any image reconstruction. The method requires the definition of an ROI characteristic function that can be extracted from a co-registered morphological image. This characteristic function can be smoothed to optimize the resolution-variance tradeoff. An iterative procedure is detailed for the solution of the dual problem in the least-squares sense (least-squares dual (LSD) characterization), and a linear extrapolation scheme is described to compensate for sampling partial volume effect and reduce the estimation bias (LSD-ex). LSD and LSD-ex are compared with classical ROI estimation using pixel summation after image reconstruction and with Huesman's method. For this comparison, we used Monte Carlo simulations (GATE simulation tool) of 2D PET data of a Hoffman brain phantom containing three small uniform high-contrast ROIs and a large non-uniform low-contrast ROI. Our results show that the performances of LSD characterization are at least as good as those of the classical methods in terms of root mean square (RMS) error. For the three small tumor regions, LSD-ex allows a reduction in the estimation bias by up to 14%, resulting in a reduction in the RMS error of up to 8.5%, compared with the optimal classical estimation. For the large non-specific region, LSD using appropriate smoothing could intuitively and efficiently handle the resolution-variance tradeoff.

  5. The effect of respiratory motion variability and tumor size on the accuracy of average intensity projection from four-dimensional computed tomography: an investigation based on dynamic MRI.

    PubMed

    Cai, Jing; Read, Paul W; Sheng, Ke

    2008-11-01

    Composite images such as average intensity projection (AIP) and maximum intensity projection (MIP) derived from four-dimensional computed tomography (4D-CT) images are commonly used in radiation therapy for treating lung and abdominal tumors. It has been reported that the quality of 4D-CT images is influenced by the patient respiratory variability, which can be assessed by the standard deviation of the peak and valley of the respiratory trajectory. Subsequently, the resultant MIP underestimates the actual tumor motion extent. As a more general application, AIP comprises not only the tumor motion extent but also the probability that the tumor is present. AIP generated from 4D-CT can also be affected by the respiratory variability. To quantitate the accuracy of AIP and develop clinically relevant parameters for determining suitability of the 4D-CT study for AIP-based treatment planning, real time sagittal dynamic magnetic resonance imaging (dMRI) was used as the basis for generating simulated 4D-CT. Five-minute MRI scans were performed on seven healthy volunteers and eight lung tumor patients. In addition, images of circular phantoms with diameter 1, 3, or 5 cm were generated by software to simulate lung tumors. Motion patterns determined by dMRI images were reproduced by the software generated phantoms. Resorted dMRI using a 4D-CT acquisition method (RedCAM) based on phantom or patient images was reconstructed by simulating the imaging rebinning processes. AIP images and the corresponding color intensity projection (CIP) images were reconstructed from RedCAM and the full set of dMRI for comparison. AIP similarity indicated by the Dice index between RedCAM and dMRI was calculated and correlated with respiratory variability (v) and tumor size (s). The similarity of percentile intrafractional motion target area (IMTA), defined by the area that the tumor presented for a given percentage of time, and MIP-to-percentile IMTA similarity as a function of percentile were also

  6. Comparative assessments of the effects of alcohol exposure on fetal brain development using optical coherence tomography and ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Sudheendran, Narendran; Bake, Shameena; Miranda, Rajesh C.; Larin, Kirill V.

    2013-02-01

    The developing fetal brain is vulnerable to a variety of environmental agents including maternal ethanol consumption. Preclinical studies on the development and amelioration of fetal teratology would be significantly facilitated by the application of high resolution imaging technologies like optical coherence tomography (OCT) and high-frequency ultrasound (US). This study investigates the ability of these imaging technologies to measure the effects of maternal ethanol exposure on brain development, ex vivo, in fetal mice. Pregnant mice at gestational day 12.5 were administered ethanol (3 g/Kg b.wt.) or water by intragastric gavage, twice daily for three consecutive days. On gestational day 14.5, fetuses were collected and imaged. Three-dimensional images of the mice fetus brains were obtained by OCT and high-resolution US, and the volumes of the left and right ventricles of the brain were measured. Ethanol-exposed fetuses exhibited a statistically significant, 2-fold increase in average left and right ventricular volumes compared with the ventricular volume of control fetuses, with OCT-derived measures of 0.38 and 0.18 mm3, respectively, whereas the boundaries of the fetal mouse lateral ventricles were not clearly definable with US imaging. Our results indicate that OCT is a useful technology for assessing ventriculomegaly accompanying alcohol-induced developmental delay. This study clearly demonstrated advantages of using OCT for quantitative assessment of embryonic development compared with US imaging.

  7. Comparative assessments of the effects of alcohol exposure on fetal brain development using optical coherence tomography and ultrasound imaging.

    PubMed

    Sudheendran, Narendran; Bake, Shameena; Miranda, Rajesh C; Larin, Kirill V

    2013-02-01

    The developing fetal brain is vulnerable to a variety of environmental agents including maternal ethanol consumption. Preclinical studies on the development and amelioration of fetal teratology would be significantly facilitated by the application of high resolution imaging technologies like optical coherence tomography (OCT) and high-frequency ultrasound (US). This study investigates the ability of these imaging technologies to measure the effects of maternal ethanol exposure on brain development, ex vivo, in fetal mice. Pregnant mice at gestational day 12.5 were administered ethanol (3 g/Kg b.wt.) or water by intragastric gavage, twice daily for three consecutive days. On gestational day 14.5, fetuses were collected and imaged. Three-dimensional images of the mice fetus brains were obtained by OCT and high-resolution US, and the volumes of the left and right ventricles of the brain were measured. Ethanol-exposed fetuses exhibited a statistically significant, 2-fold increase in average left and right ventricular volumes compared with the ventricular volume of control fetuses, with OCT-derived measures of 0.38 and 0.18 mm3, respectively, whereas the boundaries of the fetal mouse lateral ventricles were not clearly definable with US imaging. Our results indicate that OCT is a useful technology for assessing ventriculomegaly accompanying alcohol-induced developmental delay. This study clearly demonstrated advantages of using OCT for quantitative assessment of embryonic development compared with US imaging.

  8. In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

    PubMed Central

    van Deel, Elza; Ridwan, Yanto; van Vliet, J. Nicole; Belenkov, Sasha; Essers, Jeroen

    2016-01-01

    The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most importantly, with the development of a novel preclinical iodinated contrast agent called eXIA160, functional and metabolic assessment of the heart became possible. However, prior to the advent of commercial MicroCT scanners equipped with X-ray flat-panel detector technology and easy-to-use cardio-respiratory gating, preclinical studies of cardiovascular disease (CVD) in small animals required a MicroCT technologist with advanced skills, and thus were impractical for widespread implementation. The goal of this work is to provide a practical guide to the use of the high-speed Quantum FX MicroCT system for comprehensive determination of myocardial global and regional function along with assessment of myocardial perfusion, metabolism and viability in healthy mice and in a cardiac ischemia mouse model induced by permanent occlusion of the left anterior descending coronary artery (LAD). PMID:26967592

  9. In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography.

    PubMed

    van Deel, Elza; Ridwan, Yanto; van Vliet, J Nicole; Belenkov, Sasha; Essers, Jeroen

    2016-01-01

    The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most importantly, with the development of a novel preclinical iodinated contrast agent called eXIA160, functional and metabolic assessment of the heart became possible. However, prior to the advent of commercial MicroCT scanners equipped with X-ray flat-panel detector technology and easy-to-use cardio-respiratory gating, preclinical studies of cardiovascular disease (CVD) in small animals required a MicroCT technologist with advanced skills, and thus were impractical for widespread implementation. The goal of this work is to provide a practical guide to the use of the high-speed Quantum FX MicroCT system for comprehensive determination of myocardial global and regional function along with assessment of myocardial perfusion, metabolism and viability in healthy mice and in a cardiac ischemia mouse model induced by permanent occlusion of the left anterior descending coronary artery (LAD). PMID:26967592

  10. Environmental assessment: Kotzebue Wind Installation Project, Kotzebue, Alaska

    SciTech Connect

    1998-05-01

    The DOE is proposing to provide financial assistance to the Kotzebue Electric Association to expand its existing wind installation near Kotzebue, Alaska. Like many rural Alaska towns, Kotzebue uses diesel-powered generators to produce its electricity, the high cost of which is currently subsidized by the Alaska State government. In an effort to provide a cost effective and clean source of electricity, reduce dependence on diesel fuel, and reduce air pollutants, the DOE is proposing to fund an experimental wind installation to test commercially available wind turbines under Arctic conditions. The results would provide valuable information to other Alaska communities experiencing similar dependence on diesel-powered generators. The environmental assessment for the proposed wind installation assessed impacts to biological resources, land use, electromagnetic interference, coastal zone, air quality, cultural resources, and noise. It was determined that the project does not constitute a major Federal action significantly affecting the quality of the human environment. Therefore, the preparation of an environmental impact statement is not required, and DOE has issued a Finding of No Significant Impact.

  11. NREL Solar Radiation Resource Assessment Project: Status and outlook

    SciTech Connect

    Renne, D.; Riordan, C.; Maxwell, E.; Stoffel, T.; Marion, B.; Rymes, M.; Wilcox, S.; Myers, D.

    1992-05-01

    This report summarizes the activities and accomplishments of NREL's Solar Radiation Resource Assessment Project during fiscal year 1991. Currently, the primary focus of the SRRAP is to produce a 1961--1990 National Solar Radiation Data Base, providing hourly values of global horizontal, diffuse, and direct normal solar radiation at approximately 250 sites around the United States. Because these solar radiation quantities have been measured intermittently at only about 50 of these sites, models were developed and applied to the majority of the stations to provide estimates of these parameters. Although approximately 93% of the data base consists of modeled data this represents a significant improvement over the SOLMET/ERSATZ 1952--1975 data base. The magnitude and importance of this activity are such that the majority of SRRAP human and financial in many other activities, which are reported here. These include the continued maintenance of a solar radiation monitoring network in the southeast United States at six Historically Black Colleges and Universities (HBCU's), the transfer of solar radiation resource assessment technology through a variety of activities, participation in international programs, and the maintenance and operation of NREL's Solar Radiation Research Laboratory. 17 refs.

  12. The SKI repository performance assessment project Site-94

    SciTech Connect

    Andersson, J.; Dverstorp, B.; Sjoeblom, R.; Wingefors, S.

    1995-12-01

    SITE-94 is a research project conducted as a performance assessment of a hypothetical repository for spent nuclear fuel, but with real pre-excavation data from a real site. The geosphere, the engineered barriers and the processes for radionuclide release and transport comprise an integrated interdependent system, which is described by an influence diagram (PID) that reflects how different Features, Events or Processes (FEPs) inside the system interact. Site evaluation is used to determine information of transport paths in the geosphere and to deliver information on geosphere interaction with the engineered barriers. A three-dimensional geological structure model of the site as well as alternative conceptual models consistent with the existing hydrological field data, have been analyzed. Groundwater chemistry is evaluated and a model, fairly consistent with the flow model, for the origin of the different waters has been developed. The geological structure model is also used for analyzing the mechanical stability of the site. Several phenomena of relevance for copper corrosion in a repository environment have been investigated. For Reference Case conditions and regardless of flow variability, output is dominated by I-129, which, for a single canister, may give rise to drinking water well doses in the order of 10{sup -6}Sv/yr. Finally, it appears that the procedures involved in the development of influence diagrams may be a promising tool for quality assurance of performance assessments.

  13. Noninvasive assessment of macrovesicular liver steatosis in cadaveric donors based on computed tomography liver-to-spleen attenuation ratio.

    PubMed

    Rogier, Julien; Roullet, Stéphanie; Cornélis, François; Biais, Matthieu; Quinart, Alice; Revel, Philippe; Bioulac-Sage, Paulette; Le Bail, Brigitte

    2015-05-01

    Fatty liver disease, including liver steatosis, is a major health problem worldwide. In liver transplantation, macrovesicular steatosis in donor livers is a major cause of graft failure and remains difficult to assess. On one hand, several imaging modalities can be used for the assessment of liver fat, but liver biopsy, which is still considered the gold standard, may be difficult to perform in this context. On the other hand, computed tomography (CT) is commonly used by teams managing cadaveric donors to assess donors and to minimize the risk of complications in recipients. The purpose of our study was to validate the use of CT as a semiquantitative method for assessing macrovesicular steatosis in cadaveric donors with liver biopsy as a reference standard. A total of 109 consecutive cadaveric donors were included between October 2009 and May 2011. Brain death was diagnosed according to French legislation. Liver biopsy and then CT were performed on the same day to determine the degree of macrovesicular steatosis. All liver biopsies and CT scans were analyzed in a double-blinded fashion by a senior pathologist and a senior radiologist, respectively. For CT, we used the liver-to-spleen (L/S) attenuation ratio, which is a validated method for determining 30% or greater steatosis in living liver donors. Fourteen of 109 biopsies exhibited macrovesicular steatosis > 30% upon histologic analysis. A receiver operating characteristic curve was generated for the L/S ratio to identify its ability to predict significant steatosis, which was defined as >30%. A cutoff value of 0.9 for the CT L/S ratio provided a sensitivity of 79% and a specificity of 97% to detect significant steatosis. PMID:25761371

  14. Multidetector computed tomography angiography for assessment of in-stent restenosis: meta-analysis of diagnostic performance

    PubMed Central

    Vanhoenacker, Piet K; Decramer, Isabel; Bladt, Olivier; Sarno, Giovanna; Van Hul, Erik; Wijns, William; Dwamena, Ben A

    2008-01-01

    Background Multi-detector computed tomography angiography (MDCTA)of the coronary arteries after stenting has been evaluated in multiple studies. The purpose of this study was to perform a structured review and meta-analysis of the diagnostic performance of MDCTA for the detection of in-stent restenosis in the coronary arteries. Methods A Pubmed and manual search of the literature on in-stent restenosis (ISR) detected on MDCTA compared with conventional coronary angiography (CA) was performed. Bivariate summary receiver operating curve (SROC) analysis, with calculation of summary estimates was done on a stent and patient basis. In addition, the influence of study characteristics on diagnostic performance and number of non-assessable segments (NAP) was investigated with logistic meta-regression. Results Fourteen studies were included. On a stent basis, Pooled sensitivity and specificity were 0.82(0.72–0.89) and 0.91 (0.83–0.96). Pooled negative likelihood ratio and positive likelihood ratio were 0.20 (0.13–0.32) and 9.34 (4.68–18.62) respectively. The exclusion of non-assessable stents and the strut thickness of the stents had an influence on the diagnostic performance. The proportion of non-assessable stents was influenced by the number of detectors, stent diameter, strut thickness and the use of an edge-enhancing kernel. Conclusion The sensitivity of MDTCA for the detection of in-stent stenosis is insufficient to use this test to select patients for further invasive testing as with this strategy around 20% of the patients with in-stent stenosis would be missed. Further improvement of scanner technology is needed before it can be recommended as a triage instrument in practice. In addition, the number of non-assessable stents is also high. PMID:18671850

  15. Noninvasive assessment of macrovesicular liver steatosis in cadaveric donors based on computed tomography liver-to-spleen attenuation ratio.

    PubMed

    Rogier, Julien; Roullet, Stéphanie; Cornélis, François; Biais, Matthieu; Quinart, Alice; Revel, Philippe; Bioulac-Sage, Paulette; Le Bail, Brigitte

    2015-05-01

    Fatty liver disease, including liver steatosis, is a major health problem worldwide. In liver transplantation, macrovesicular steatosis in donor livers is a major cause of graft failure and remains difficult to assess. On one hand, several imaging modalities can be used for the assessment of liver fat, but liver biopsy, which is still considered the gold standard, may be difficult to perform in this context. On the other hand, computed tomography (CT) is commonly used by teams managing cadaveric donors to assess donors and to minimize the risk of complications in recipients. The purpose of our study was to validate the use of CT as a semiquantitative method for assessing macrovesicular steatosis in cadaveric donors with liver biopsy as a reference standard. A total of 109 consecutive cadaveric donors were included between October 2009 and May 2011. Brain death was diagnosed according to French legislation. Liver biopsy and then CT were performed on the same day to determine the degree of macrovesicular steatosis. All liver biopsies and CT scans were analyzed in a double-blinded fashion by a senior pathologist and a senior radiologist, respectively. For CT, we used the liver-to-spleen (L/S) attenuation ratio, which is a validated method for determining 30% or greater steatosis in living liver donors. Fourteen of 109 biopsies exhibited macrovesicular steatosis > 30% upon histologic analysis. A receiver operating characteristic curve was generated for the L/S ratio to identify its ability to predict significant steatosis, which was defined as >30%. A cutoff value of 0.9 for the CT L/S ratio provided a sensitivity of 79% and a specificity of 97% to detect significant steatosis.

  16. Assessment of atherosclerotic plaque collagen content and architecture using polarization-sensitive optical coherence tomography (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Doradla, Pallavi; Villiger, Martin; Tshikudi, Diane M.; Bouma, Brett E.; Nadkarni, Seemantini K.

    2016-02-01

    Acute myocardial infarction, caused by the rupture of vulnerable coronary plaques, is the leading cause of death worldwide. Collagen is the primary extracellular matrix macromolecule that imparts the mechanical stability to a plaque and its reduction causes plaque instability. Intracoronary polarization sensitive optical coherence tomography (PS-OCT) measures the polarization states of the backscattered light from the tissue to evaluate plaque birefringence, a material property that is elevated in proteins such as collagen with an ordered structure. Here we investigate the dependence of the PS-OCT parameters on the quantity of the plaque collagen and fiber architecture. In this study, coronary arterial segments from human cadaveric hearts were evaluated with intracoronary PS-OCT and compared with Histopathological assessment of collagen content and architecture from picrosirius-red (PSR) stained sections. PSR sections were visualized with circularly-polarized light microscopy to quantify collagen birefringence, and the additional assessment of color hue indicated fibril thickness. Due to the ordered architecture of thick collagen fibers, a positive correlation between PS-OCT retardation and quantity of thick collagen fibers (r=0.54, p=0.04), and similarly with the total collagen content (r=0.51, p=0.03) was observed. In contrast, there was no perceivable relationship between PS-OCT retardation and the presence of thin collagen fibers (r=0.08, p=0.07), suggesting that thin and disorganized collagen fiber architecture did not significantly contribute to the PS-OCT retardation. Further analysis will be performed to assess the relationship between PS-OCT retardation and collagen architecture based on immunohistochemical analysis of collagen type. These results suggest that intracoronary PS-OCT may open the opportunity to assess collagen architecture in addition total collagen content, potentially enabling an improved understanding of coronary plaque rupture.

  17. The Luneburg Sustainable University Project in International Comparison: An Assessment against North American Peers

    ERIC Educational Resources Information Center

    Beringer, Almut

    2007-01-01

    Purpose: To assess the Luneburg Sustainable University Project (the Project) in a non-European international context; to relate the project scholarly approach to selected scholarly and practice-oriented North American sustainability in higher education (SHE) methods; to analyze project innovations against North American initiatives.…

  18. Environmental assessment of USAID housing projects in the Russian Federation

    SciTech Connect

    Loran, B.; Miller, C.

    1995-12-01

    Parsons was selected by the United States Agency for International Development (USAID) as the general contractor for construction management for the construction of 2,500 housing units within the Russian Federation. These housing units, to be occupied by Russian officers returning from the Baltic States, are under construction on 15 sites, selected from an initial list of 200, based on habitability, capability of successful final construction. Cost meeting USAID guidelines, and impacts on the environment. USAID fulfilled NEPA requirements by preparing, with assistance of Parsons Engineering Science, a Programmatic Environmental Assessment and 15 site specific Environmental Assessments for the project. The sites were scattered over the entire Russian Federation west of the Ural Mountains. The site offerors completed an environmental checklist covering a broad range of possible impacts. Significant environmental issues and concerns were further identified during scoping meetings held at the site locations. The most important issues discussed were: soil contamination; gaseous, liquid, and solid pollutants to which the site may be exposed; incompatible adjacent land uses; ready access to utilities and social services; and socioeconomic situation favorable to resettlement of Russian military officers. No major environmental issues or concerns were identified for the 15 selected sites. Certificates indicating the absence of chemical and radiological surface and subsurface contamination at the proposed sites were provided by the local environmental officers. Polynuclear aromatic hydrocarbons were found present at one of the sites considered in a preliminary selection, and later rejected due to the failure of contractual negotiations. The environmental assessments included mitigation and monitoring measures for construction and operation (occupancy) impacts.

  19. Environmental Assessment: geothermal direct heat project, Marlin, Texas

    SciTech Connect

    Not Available

    1980-08-01

    The Federal action addressed by this Environmental Assessment (EA) is joint funding the retrofitting of a heating and hot water system in a hospital at Marlin, Texas, with a geothermal preheat system. The project will be located within the existing hospital boiler room. One supply well was drilled in an existing adjacent parking lot. It was necessary to drill the well prior to completion of this environmental assessment in order to confirm the reservoir and to obtain fluids for analysis in order to assess the environmental effects of fluid disposal. Fluid from operation will be disposed of by discharging it directly into existing street drains, which will carry the fluid to Park Lake and eventually the Brazos River. Fluid disposal activities are regulated by the Texas Railroad Commission. The local geology is determined by past displacements in the East Texas Basin. Boundaries are marked by the Balcones and the Mexia-Talco fault systems. All important water-bearing formations are in the cretaceous sedimentary rocks and are slightly to highly saline. Geothermal fluids are produced from the Trinity Group; they range from approximately 3600 to 4000 ppM TDS. Temperatures are expected to be above 64/sup 0/C (147/sup 0/F). Surface water flows southeastward as a part of the Brazos River Basin. The nearest perennial stream is the Brazos River 5.6 km (3.5 miles) away, to which surface fluids will eventually discharge. Environmental impacts of construction were small because of the existing structures and paved areas. Construction run-off and geothermal flow-test fluid passed through a small pond in the city park, lowering its water quality, at least temporarily. Construction noise was not out of character with existing noises around the hospital.

  20. California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project--shallow aquifer assessment

    USGS Publications Warehouse

    ,

    2013-01-01

    The California State Water Resources Control Board’s (SWRCB) GAMA Program is a comprehensive assessment of statewide groundwater quality in California. From 2004 to 2012, the GAMA Program’s Priority Basin Project focused on assessing groundwater resources used for public drinking-water supplies. More than 2,000 public-supply wells were sampled by U.S. Geological Survey (USGS) for this effort. Starting in 2012, the GAMA Priority Basin Project began an assessment of water resources in shallow aquifers in California. These shallow aquifers provide water for domestic and small community-supply wells, which are often drilled to shallower depths in the groundwater system than public-supply wells. Shallow aquifers are of interest because shallow groundwater may respond more quickly and be more susceptible to contamination from human activities at the land surface, than the deeper aquifers. The SWRCB’s GAMA Program was developed in response to the Groundwater Quality Monitoring Act of 2001 (Water Code sections 10780-10782.3): a public mandate to assess and monitor the quality of groundwater resources used for drinking-water supplies, and to increase the availability of information about groundwater quality to the public. The U.S. Geological Survey is the technical lead of the Priority Basin Project. Stewardship of California’s groundwater resources is a responsibility shared between well owners, communities, and the State. Participants and collaborators in the GAMA Program include Regional Water Quality Control Boards, Department of Water Resources, Department of Public Health, local and regional groundwater management entities, county and local water agencies, community groups, and private citizens. Well-owner participation in the GAMA Program is entirely voluntary.

  1. Optical Coherence Tomography for Quantitative Assessment of Microstructural and Microvascular Alterations in Late Oral Radiation Toxicity

    NASA Astrophysics Data System (ADS)

    Davoudi, Bahar

    More than half of head-and-neck cancer patients undergo radiotherapy at some point during their treatment. Even though the use of conformed therapeutic beams has increased radiation dose localization to the tumor, resulting in more normal tissue sparing, still, in many head-and-neck cancer patients, the healthy tissue of the oral cavity still receives a sizeable amount of radiation. This causes acute and / or late complications in these patients. The latter occur as late as several months or even years after the completion of treatment and are typically associated with severe symptoms. Currently, the clinical method for diagnosing these complications is visual examination of the oral tissue surface. However, it has been well established that such complications originate in subsurface oral tissue layers including its microvasculature. Therefore, to better understand the mechanism of these complications and to be able to diagnose them earlier, there exists a need for subsurface monitoring of the irradiated oral tissue. Histology has been used as such a tool for research purposes; however, its use in clinical diagnosis is limited due to its invasive and hazardous nature. Therefore, in this thesis, I propose to use optical coherence tomography (OCT) as a subsurface, micron-scale resolution optical imaging tool that can provide images of oral tissue subsurface layers down to a depth of 1-2 mm (structural OCT), as well as images demonstrating vessel morphology (speckle variance OCT) and blood flow information (Doppler OCT). This thesis explains the development of an OCT setup and an oral probe to acquire images in-vivo. Moreover, it introduces a software-based quantification platform for extracting specific biologically-meaningful metrics from the structural and vascular OCT images. It then describes the application of the developed imaging and quantification platform in a feasibility clinical study that was performed on 15 late oral radiation toxicity patients and 5 age

  2. How to scientifically assess a restoration project: a case study

    NASA Astrophysics Data System (ADS)

    Alvarez de Buergo, M.; Fort, R.; Freire, D. M.; Lopez-Arce, P.; Vazquez-Calvo, C.

    2012-04-01

    Commonly, it is said that there is lack of communication among scientists, conservators, restorers, project managers and architects. But sometimes this communication flows, and we can find enormous benefits from and for all the participating agents. This is the case we present in this work, in which technical agents in charge of the restoration of a building, asked for some scientific advice to perform the restoration of a heritage building. The results were successful and fantastic for both of them, in terms of one part asking for consultation and the other answering to the demands and resolving real problems. This is the case of a marvellous Renaissance building (Medinaceli Dukes palace, 15th-16th centuries) in the central area of Spain (Cogolludo, Guadalajara). Focused on the restoration project, we were asked for consultancy on how to solve matters like the assessment of the already fixed in project cleaning method for the stone façades, the efficacy and durability methods for some conservation products to be applied, the presence or not of a patina on the stone; the viability of using some restoration mortars, and the origin of some efflorescences that came out just after placed in the building a restoration rendering mortar. Responses to these matters were answered by performing tests both in the lab and on site in the building. The efficiency and effects on stone of the blasting cleaning method was assessed by first analysing the nature and thickness of the surface deposits to be removed (SEM-EDS analyses); secondly, roughness and colour measurements were performed, and thirdly, SEM-EDS analyses were carried out again to determine whether the cleaning method was able to remove part of the surface deposits, completely, or even part of the stone substrate. Some conservation products were tested on stone specimens, both their efficacy and their durability, concluding that it was better not to apply any of them. A patina was found on the stone façade under SEM

  3. Thoracic target volume delineation using various maximum-intensity projection computed tomography image sets for radiotherapy treatment planning

    SciTech Connect

    Zamora, David A.; Riegel, Adam C.; Sun Xiaojun; Balter, Peter; Starkschall, George; Mawlawi, Osama; Pan Tinsu

    2010-11-15

    Purpose: Four-dimensional computed tomography (4D-CT) is commonly used to account for respiratory motion of target volumes in radiotherapy to the thorax. From the 4D-CT acquisition, a maximum-intensity projection (MIP) image set can be created and used to help define the tumor motion envelope or the internal gross tumor volume (iGTV). The purpose of this study was to quantify the differences in automatically contoured target volumes for usage in the delivery of stereotactic body radiation therapy using MIP data sets generated from one of the four methods: (1) 4D-CT phase-binned (PB) based on retrospective phase calculations, (2) 4D-CT phase-corrected phase-binned (PC-PB) based on motion extrema, (3) 4D-CT amplitude-binned (AB), and (4) cine CT built from all available images. Methods: MIP image data sets using each of the four methods were generated for a cohort of 28 patients who had prior thoracic 4D-CT scans that exhibited lung tumor motion of at least 1 cm. Each MIP image set was automatically contoured on commercial radiation treatment planning system. Margins were added to the iGTV to observe differences in the final simulated planning target volumes (PTVs). Results: For all patients, the iGTV measured on the MIP generated from the entire cine CT data set (iGTV{sub cine}) was the largest. Expressed as a percentage of iGTV{sub cine}, 4D-CT iGTV (all sorting methods) ranged from 83.8% to 99.1%, representing differences in the absolute volume ranging from 0.02 to 4.20 cm{sup 3}; the largest average and range of 4D-CT iGTV measurements was from the PC-PB data set. Expressed as a percentage of PTV{sub cine} (expansions applied to iGTV{sub cine}), the 4D-CT PTV ranged from 87.6% to 99.6%, representing differences in the absolute volume ranging from 0.08 to 7.42 cm{sup 3}. Regions of the measured respiratory waveform corresponding to a rapid change of phase or amplitude showed an increased susceptibility to the selection of identical images for adjacent bins

  4. Assessment of coronary bypass graft patency by first-line multi-detector computed tomography.

    PubMed

    Pesenti-Rossi, D; Baron, N; Georges, J-L; Augusto, S; Gibault-Genty, G; Livarek, B

    2014-11-01

    The purpose of the study was to assess whether a strategy based on a MDCT performed routinely before CA can reduce the radiation dose during the CA, without increased global exposure in patients who need imaging of CABG. A total of 147 consecutive patients were included. The radiation dose during CA (KAP 12.1 vs 22.0 Gy/cm(2), P<.01) and the volume of iodinated contrast (155 vs 200 mL, P<.02) were reduced when preceded by a MDCT. Patients' cumulative exposures were not different in the 2 strategies (5.0 vs 5.1 mSv, P=.76). MDCT performed in first line is a valuable strategy for the assessment of CABG. PMID:25258019

  5. Convergence and stability assessment of Newton-Kantorovich reconstruction algorithms for microwave tomography.

    PubMed

    Joachimowicz, N; Mallorqui, J J; Bolomey, J C; Broquetas, A

    1998-08-01

    For newly developed iterative Newton-Kantorovitch reconstruction techniques, the quality of the final image depends on both experimental and model noise. Experimental noise is inherent to any experimental acquisition scheme, while model noise refers to the accuracy of the numerical model, used in the reconstruction process, to reproduce the experimental setup. This paper provides a systematic assessment of the major sources of experimental and model noise on the quality of the final image. This assessment is conducted from experimental data obtained with a microwave circular scanner operating at 2.33 GHz. Targets to be imaged include realistic biological structures, such as a human forearm, as well as calibrated samples for the sake of accuracy evaluation. The results provide a quantitative estimation of the effect of experimental factors, such as temperature of the immersion medium, frequency, signal-to-noise ratio, and various numerical parameters. PMID:9845312

  6. Tumor Delineation Based on Time-Activity Curve Differences Assessed With Dynamic Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Rectal Cancer Patients

    SciTech Connect

    Janssen, Marco Aerts, Hugo; Ollers, Michel C.; Bosmans, Geert; Lee, John A.; Buijsen, Jeroen; Ruysscher, Dirk de; Lambin, Philippe; Lammering, Guido; Dekker, Andre L.A.J.

    2009-02-01

    Purpose: To develop an unsupervised tumor delineation method based on time-activity curve (TAC) shape differences between tumor tissue and healthy tissue and to compare the resulting contour with the two tumor contouring methods mostly used nowadays. Methods and Materials: Dynamic positron emission tomography-computed tomography (PET-CT) acquisition was performed for 60 min starting directly after fluorodeoxyglucose (FDG) injection. After acquisition and reconstruction, the data were filtered to attenuate noise. Correction for tissue motion during acquisition was applied. For tumor delineation, the TAC slope values were k-means clustered into two clusters. The resulting tumor contour (Contour I) was compared with a contour manually drawn by the radiation oncologist (Contour II) and a contour generated using a threshold of the maximum standardized uptake value (SUV; Contour III). Results: The tumor volumes of Contours II and III were significantly larger than the tumor volumes of Contour I, with both Contours II and III containing many voxels showing flat TACs at low activities. However, in some cases, Contour II did not cover all voxels showing upward TACs. Conclusion: Both automated SUV contouring and manual tumor delineation possibly incorrectly assign healthy tissue, showing flat TACs, as being malignant. On the other hand, in some cases the manually drawn tumor contours do not cover all voxels showing steep upward TACs, suspected to be malignant. Further research should be conducted to validate the possible superiority of tumor delineation based on dynamic PET analysis.

  7. Documentation assessment, Project C-018H, 200-E area effluent treatment facility

    SciTech Connect

    Peres, M.W.; Connor, M.D.; Mertelendy, J.I.

    1994-12-21

    Project C-018H is one of the fourteen subprojects to the Hanford Environmental Compliance (HEC) Project. Project C-018H provides treatment and disposal for the 242-A Evaporator and PUREX plant process condensate waste streams. This project used the Integrated Management Team (IMT) approach proposed by RL. The IMT approach included all affected organizations on the project team to coordinate and execute all required project tasks, while striving to integrate and satisfy all technical, operational, functional, and organizational objectives. The HEC Projects were initiated in 1989. Project C-018H began in early 1990, with completion of construction currently targeted for mid-1995. This assessment was performed to evaluate the effectiveness of the management control on design documents and quality assurance records developed and submitted for processing, use, and retention for the Project. The assessment focused primarily on the overall adequacy and quality of the design documentation currently being submitted to the project document control function.

  8. nGASP - the nematode genome annotation assessment project

    SciTech Connect

    Coghlan, A; Fiedler, T J; McKay, S J; Flicek, P; Harris, T W; Blasiar, D; Allen, J; Stein, L D

    2008-12-19

    While the C. elegans genome is extensively annotated, relatively little information is available for other Caenorhabditis species. The nematode genome annotation assessment project (nGASP) was launched to objectively assess the accuracy of protein-coding gene prediction software in C. elegans, and to apply this knowledge to the annotation of the genomes of four additional Caenorhabditis species and other nematodes. Seventeen groups worldwide participated in nGASP, and submitted 47 prediction sets for 10 Mb of the C. elegans genome. Predictions were compared to reference gene sets consisting of confirmed or manually curated gene models from WormBase. The most accurate gene-finders were 'combiner' algorithms, which made use of transcript- and protein-alignments and multi-genome alignments, as well as gene predictions from other gene-finders. Gene-finders that used alignments of ESTs, mRNAs and proteins came in second place. There was a tie for third place between gene-finders that used multi-genome alignments and ab initio gene-finders. The median gene level sensitivity of combiners was 78% and their specificity was 42%, which is nearly the same accuracy as reported for combiners in the human genome. C. elegans genes with exons of unusual hexamer content, as well as those with many exons, short exons, long introns, a weak translation start signal, weak splice sites, or poorly conserved orthologs were the most challenging for gene-finders. While the C. elegans genome is extensively annotated, relatively little information is available for other Caenorhabditis species. The nematode genome annotation assessment project (nGASP) was launched to objectively assess the accuracy of protein-coding gene prediction software in C. elegans, and to apply this knowledge to the annotation of the genomes of four additional Caenorhabditis species and other nematodes. Seventeen groups worldwide participated in nGASP, and submitted 47 prediction sets for 10 Mb of the C. elegans genome

  9. Overview of the Texas Source Water Assessment Project

    USGS Publications Warehouse

    Ulery, Randy L.

    2000-01-01

    The 1996 Amendments to the Safe Drinking Water Act require, for the first time, that each state prepare a source water assessment for all PWS. Previously, Federal regulations focused on sampling and enforcement with emphasis on the quality of delivered water. These Amendments emphasize the importance of protecting the source water. States are required to determine the drinking-water source, the origin of contaminants monitored or the potential contaminants to be monitored, and the intrinsic susceptibility of the source water. Under the amendments to the Act, States must create SWAP Programs. The programs must include an individual source water assessment for each public water system regulated by the State. These assessments will determine whether an individual drinking water source is susceptible to contamination. During 1997?99, TNRCC and USGS staff met as subject-matter working groups to develop an approach to conducting Source Water Susceptibility Assessments (SWSA) and a draft workplan. The draft workplan was then presented to and reviewed by various stakeholder and technical advisory groups. Comments and suggestions from these groups were considered, and a final workplan was produced and presented to the EPA. After EPA approval, work formally began on the Texas SWAP Project. The project has an expected completion date of September 2002. At that time, initial SWSA of all Texas public water supplies should be complete. Ground-water supplies can be considered susceptible if a possible source of contamination (PSOC) exists in the contributing area for the public-supply well field or spring, the contaminant travel time to the well field or spring is short, and the soil zone, vadose zone, and aquifer-matrix materials are unlikely to adequately attenuate the contaminants associated with the PSOC. In addition, particular types of land use/cover within the contributing area may cause the supply to be deemed more susceptible to contamination. Finally, detection of

  10. Subjective assessment of right ventricle enlargement from computed tomography pulmonary angiography images.

    PubMed

    Kumamaru, Kanako K; Hunsaker, Andetta R; Bedayat, Arash; Soga, Shigeyoshi; Signorelli, Jason; Adams, Kimberly; Wake, Nicole; Lu, Michael T; Rybicki, Frank J

    2012-04-01

    To retrospectively evaluate prognostic accuracy of subjective assessment of right ventricle (RV) enlargement on CT pulmonary angiography (CTPA) images in comparison with objective measures of RV enlargement in patients with acute pulmonary embolism (PE). For 200 consecutive patients with acute PE, two readers blinded to patient outcomes subjectively determined whether the maximum RV diameter was greater than that of the left ventricle (LV) using axial CTPA images. For the objective measurements, RV/LV diameter ratios were calculated using axial images and 4-chamber reformatted images. For all assessments, sensitivities and specificities for predicting PE-related death within 30-days and a composite outcome including PE-related death or the need for intensive therapies were compared. The agreement between two readers was 91.5% (kappa = 0.83) and all other assessments had pair-wise agreement over 75% (kappa = 0.53-0.72). There was no significant difference in sensitivity between the subjective and objective methods for predicting both outcomes. The specificity for subjective RV enlargement (55.4-67.7%) was significantly higher than objective measures (45.8-53.1%), except for the 4-chamber views where, for one reader, the specificity of the subjective evaluation was higher but did not reach statistical significance. Complex measurements of RV/LV diameter ratios may not be needed to maximize the prognostic value from CTPA. The radiologist who interprets the CTPA images should report RV enlargement when the RV diameter subjectively appears larger than the LV.

  11. Volumetric Imaging by Megavoltage Computed Tomography for Assessment of Internal Organ Motion During Radiotherapy for Cervical Cancer

    SciTech Connect

    Collen, Christine; Engels, Benedikt; Duchateau, Michael; Tournel, Koen; De Ridder, Mark; Bral, Samuel; Verellen, Dirk; Storme, Guy

    2010-08-01

    Purpose: To assess the internal organ motion of the cervix and uterus by megavoltage computed tomography (MVCT) during intensity-modulated radiotherapy (IMRT). Methods and Materials: Ten patients with Stage IIB-IVA cervical cancer underwent daily MVCT imaging. Internal organ motion was evaluated on 150 pretreatment MVCT images by measuring shifts in their boundaries between the MVCT and kilovoltage (kV) planning CT scan in the anterior, posterior, left and right lateral, and superior and inferior direction. Additional intrafractional patient movement was evaluated on 50 posttreatment MVCT images. Results: Measured cervical motion (mean {+-} SD) was 0.4 {+-} 10.1 mm in the anterior, -3.0 {+-} 6.9 mm in the posterior direction, -3.5 {+-} 4.9 mm in the left and 0.2 {+-} 4.5 mm in the right lateral direction, 2.2 {+-} 8.0 mm in the superior and 0.5 {+-} 5.0 mm in the inferior direction. Compared to the cervix, larger uterine motion was observed. Patient movement during treatment was limited to 1.1 {+-} 1.3 mm, -0.3 {+-} 1.6 mm, and 0.2 {+-} 2.3 mm in anteroposterior, laterolateral and superoinferior direction respectively. Conclusions: MVCT imaging can be used to study patient setup accuracy and cervical and uterine motion during IMRT. This data may be used to refine treatment margins.

  12. Pulsed Photonuclear Assessment (PPA) Technique: CY-05 Project Summary Report

    SciTech Connect

    J.L. Jones; B.D. Bennett; K.J. Haskell; J.T. Johnson; D.R. Norman; J.W. Sterbentz; R.W. Watson; S.M. Watson; W.Y. Yoon; J.M. Zabriskie; C.E. Moss; K.L. Folkman; C.C. O'Neil; A.W. Hunt; R.J. Spaulding

    2005-12-01

    Idaho National Laboratory, along with Idaho State University’s Idaho Accelerator Center and Los Alamos National Laboratory, is developing an electron accelerator-based, photonuclear inspection technology, called the Pulsed Photonuclear Assessment (PPA) system, for the detection of nuclear material concealed within air-, rail-, and, primarily, maritime-cargo transportation containers. This report summarizes the advances and progress of the system’s development in 2005. The contents of this report include an overview of the prototype inspection system, selected Receiver-Operator-Characteristic curves for system detection performance characterization, a description of the approach used to integrate the three major detection components of the PPA inspection system, highlights of the gray-scale density mapping technique being used for significant shield material detection, and higher electron beam energy detection results to support an evaluation for an optimal interrogating beam energy. This project is supported by the Department of Homeland Security Office of Research and Development and, more recently, the Domestic Nuclear Detection Office.

  13. Environmental Assessment -- Test Area North pool stabilization project update

    SciTech Connect

    1997-08-01

    The purpose of this Environmental Assessment (EA) is to update the ``Test Area North Pool Stabilization Project`` EA (DOE/EA-1050) and finding of no significant impact (FONSI) issued May 6, 1996. This update analyzes the environmental and health impacts of a drying process for the Three Mile Island (TMI) nuclear reactor core debris canisters now stored underwater in a facility on the Idaho National Engineering and Environmental Laboratory (INEEL). A drying process was analyzed in the predecision versions of the EA released in 1995 but that particular process was determined to be ineffective and dropped from the EA/FONSI issued May 6, 1996. A new drying process was subsequently developed and is analyzed in Section 2.1.2 of this document. As did the 1996 EA, this update analyzes the environmental and health impacts of removing various radioactive materials from underwater storage, dewatering these materials, constructing a new interim dry storage facility, and transporting and placing the materials into the new facility. Also, as did the 1996 EA, this EA analyzes the removal, treatment and disposal of water from the pool, and placement of the facility into a safe, standby condition. The entire action would take place within the boundaries of the INEEL. The materials are currently stored underwater in the Test Area North (TAN) building 607 pool, the new interim dry storage facility would be constructed at the Idaho Chemical Processing Plant (ICPP) which is about 25 miles south of TAN.

  14. Draft environmental assessment -- Test Area North pool stabilization project update

    SciTech Connect

    1997-06-01

    The purpose of this Environmental Assessment (EA) is to update the ``Test Area North Pool Stabilization Project`` EA (DOE/EA-1050) and finding of no significant impact (FONSI) issued May 6, 1996. This update analyzes the environmental and health impacts of a drying process for the Three Mile Island (TMI) nuclear reactor core debris canisters now stored underwater in a facility on the Idaho National Engineering and Environmental Laboratory (INEEL). A drying process was analyzed in the predecision versions of the EA released in 1995 but that particular process was determined to be ineffective and dropped form the Ea/FONSI issued May 6, 1996. The origin and nature of the TMI core debris and the proposed drying process are described and analyzed in detail in this EA. As did the 1996 EA, this update analyzes the environmental and health impacts of removing various radioactive materials from underwater storage, dewatering these materials, constructing a new interim dry storage facility, and transporting and placing the materials into the new facility. Also, as did the 1996 EA, this EA analyzes the removal, treatment and disposal of water from the pool, and placement of the facility into a safe, standby condition. The entire action would take place within the boundaries of the INEEL. The materials are currently stored underwater in the Test Area North (TAN) building 607 pool, the new interim dry storage facility would be constructed at the Idaho Chemical Processing Plant (ICPP) which is about 25 miles south of TAN.

  15. Human Variome Project Quality Assessment Criteria for Variation Databases.

    PubMed

    Vihinen, Mauno; Hancock, John M; Maglott, Donna R; Landrum, Melissa J; Schaafsma, Gerard C P; Taschner, Peter

    2016-06-01

    Numerous databases containing information about DNA, RNA, and protein variations are available. Gene-specific variant databases (locus-specific variation databases, LSDBs) are typically curated and maintained for single genes or groups of genes for a certain disease(s). These databases are widely considered as the most reliable information source for a particular gene/protein/disease, but it should also be made clear they may have widely varying contents, infrastructure, and quality. Quality is very important to evaluate because these databases may affect health decision-making, research, and clinical practice. The Human Variome Project (HVP) established a Working Group for Variant Database Quality Assessment. The basic principle was to develop a simple system that nevertheless provides a good overview of the quality of a database. The HVP quality evaluation criteria that resulted are divided into four main components: data quality, technical quality, accessibility, and timeliness. This report elaborates on the developed quality criteria and how implementation of the quality scheme can be achieved. Examples are provided for the current status of the quality items in two different databases, BTKbase, an LSDB, and ClinVar, a central archive of submissions about variants and their clinical significance.

  16. Assessing corporate project impacts in changeable contexts: A human rights perspective

    SciTech Connect

    Salcito, Kendyl; Singer, Burton H.; Krieger, Gary R.; Weiss, Mitchell G.; Wielga, Mark; Utzinger, Jürg

    2014-07-01

    Project-level impact assessment was originally conceived as a snapshot taken in advance of project implementation, contrasting current conditions with a likely future scenario involving a variety of predicted impacts. Current best practice guidance has encouraged a shift towards longitudinal assessments from the pre-project stage through the implementation and operating phases. Experience and study show, however, that assessment of infrastructure-intensive projects rarely endures past the project's construction phase. Negative consequences for environmental, social and health outcomes have been documented. Such consequences clarify the pressing need for longitudinal assessment in each of these domains, with human rights impact assessment (HRIA) as an umbrella over, and critical augmentation of, environmental, social and health assessments. Project impacts on human rights are more closely linked to political, economic and other factors beyond immediate effects of a company's policy and action throughout the project lifecycle. Delineating these processes requires an adequate framework, with strategies for collecting longitudinal data, protocols that provide core information for impact assessment and guidance for adaptive mitigation strategies as project-related effects change over time. This article presents general principles for the design and implementation of sustained, longitudinal HRIA, based on experience assessing and responding to human rights impact in a uranium mining project in Malawi. The case study demonstrates the value of longitudinal assessment both for limiting corporate risk and improving human welfare. - Graphical abstract: Assessing changes in human rights condition as affected by both project and context, over time. - Highlights: • Corporate capital projects affect human rights in myriad ways. • Ongoing, longitudinal impact assessment techniques are needed. • We present an approach for conducting longitudinal human rights impact assessment

  17. The Challenge of Assessing Project-Based Learning

    ERIC Educational Resources Information Center

    Boss, Suzie

    2012-01-01

    For their ambitious project, called America at War, high school juniors at Da Vinci Charter Academy in the Davis (California) Joint Unified School District didn't just study history. They became historians. Their project offers compelling evidence of what students can accomplish through project-based learning (PBL), an instructional approach that…

  18. Comparison of different computed tomography post-processing modalities in assessment of various middle ear disorders.

    PubMed

    Mehanna, Ahmed Mohamed; Baki, Fatthi Abdel; Eid, Mohamed; Negm, Magdy

    2015-06-01

    Several anatomic structures of the middle ear are not optimally depicted in the standard axial and coronal planes. Several 2D and 3D image-processing modalities are currently available for CT examinations in clinical radiology departments. Till now 3D reconstructions of the temporal bone have not been widely used yet, and attracted only academic interest. The aim of this study was to compare axial (source images), 2D and 3DCT post-processing modalities, and to evaluate the value of 3D reconstructed images/virtual endoscopy (VE) in assessment of various middle ear disorders for identification of the best modality/view for assessment of a particular middle ear structure or pathology. 40 patients with various middle ear disorders, planned for surgical intervention were included in prospective study. Multi-slice CT was performed for all patients. Scans were acquired in the axial plane. The axial source datasets were utilized for generation of 2D reformations and 3D reconstructed images. All studied images were divided into three categories: axial (source images), 2D reformations (MPR and sliding-thin-slab MIP) and 3D reconstruction (virtual endoscopy). The visibility of middle ear structures and pathologies with each modality were scored qualitatively using three-point scoring system in reference to operative findings. Stapes superstructure and footplate, incudostapedial joint, oval and round windows, tympanic segment of the facial nerve and tegmen were not optimally depicted in the axial plane. Sinus tympani and facial recess were best visualized with axial images or VE. 3D reconstruction/VE allowed good visualization of all parts of ossicular chain except stapes superstructure. Regarding pathologic changes, 2D reformations and 3D reconstructed images allowed better visualization of erosion of ossicles and tegmen. 3D reconstruction/VE did not allow detection of foci of otospongiosis. 2D reformations can be considered the mainstay in assessment of most middle ear

  19. Magnetic resonance imaging and computed tomography in emergency assessment of patients with suspected acute stroke: a prospective comparison

    PubMed Central

    Chalela, Julio A; Kidwell, Chelsea S; Nentwich, Lauren M; Luby, Marie; Butman, John A; Demchuk, Andrew M; Hill, Michael D; Patronas, Nicholas; Latour, Lawrence; Warach, Steven

    2007-01-01

    Summary Background Although the use of magnetic resonance imaging (MRI) for the diagnosis of acute stroke is increasing, this method has not proved more effective than computed tomography (CT) in the emergency setting. We aimed to prospectively compare CT and MRI for emergency diagnosis of acute stroke. Methods We did a single-centre, prospective, blind comparison of non-contrast CT and MRI (with diffusion-weighted and susceptibility weighted images) in a consecutive series of patients referred for emergency assessment of suspected acute stroke. Scans were independently interpreted by four experts, who were unaware of clinical information, MRI-CT pairings, and follow-up imaging. Results 356 patients, 217 of whom had a final clinical diagnosis of acute stroke, were assessed. MRI detected acute stroke (ischaemic or haemorrhagic), acute ischaemic stroke, and chronic haemorrhage more frequently than did CT (p<0.0001, for all comparisons). MRI was similar to CT for the detection of acute intracranial haemorrhage. MRI detected acute ischaemic stroke in 164 of 356 patients (46%; 95% CI 41-51%), compared with CT in 35 of 356 patients (10%; 7-14%). In the subset of patients scanned within 3 h of symptom onset, MRI detected acute ischaemic stroke in 41 of 90 patients (46%; 35-56%); CT in 6 of 90 (7%; 3-14%). Relative to the final clinical diagnosis, MRI had a sensitivity of 83% (181 of 217; 78-88%) and CT of 26% (56 of 217; 20-32%) for the diagnosis of any acute stroke. Interpretation MRI is better than CT for detection of acute ischaemia, and can detect acute and chronic haemorrhage; therefore it should be the preferred test for accurate diagnosis of patients with suspected acute stroke. Because our patient sample encompassed the range of disease that is likely to be encountered in emergency cases of suspected stroke, our results are directly applicable to clinical practice. PMID:17258669

  20. Transmural myocardial perfusion gradients in relation to coronary artery stenoses severity assessed by cardiac multidetector computed tomography.

    PubMed

    Linde, Jesper James; Kühl, Jørgen Tobias; Hove, Jens Dahlgaard; Sørgaard, Mathias; Kelbæk, Henning; Nielsen, Walter Bjørn; Kofoed, Klaus Fuglsang

    2015-01-01

    To assess the relationship between epicardial coronary artery stenosis severity and the corresponding regional transmural perfusion at rest and during adenosine stress, using multidetector computed tomography (MDCT). We evaluated the relationship between the severity of coronary artery diameter stenosis assessed by MDCT angiography and semi-quantitative myocardial MDCT perfusion in 200 symptomatic patients. The perfusion index (PI = mean myocardial attenuation density/mean left ventricular lumen attenuation density) at rest and during adenosine stress, the myocardial perfusion reserve (MPR = stress - PI/rest - PI), and the transmural perfusion ratio (TPR = subendocardium/subepicardium) were calculated. A coronary artery stenosis ≥50 % was present in 49 patients (25 %). Rest-PI and rest-TPR values were similar in patients with and without a coronary artery stenosis ≥50 %, whereas stress-PI, stress-TPR and MPR were significantly reduced in patients with a stenosis ≥50 % (p < 0.001, p < 0.0001 and p = 0.02, respectively). Subendocardial PI was significantly higher than subepicardial PI at rest and during stress for patients without a significant stenosis, whereas this difference was blurred during stress in patients with ≥50 % stenosis. In a broad spectrum of stenosis severity groups, TPR at rest remained unchanged until the group of patients with total occlusions, whereas TPR during stress decreased progressively when a threshold of 50 % was superseded. In this study we establish the relationship between semi-quantitative perfusion measurements by MDCT and severity of coronary artery stenoses and find the transmural myocardial perfusion ratio to be a potential strong functional index of the hemodynamic significance of coronary artery atherosclerotic lesions.

  1. The nigrostriatal dopaminergic system assessed in vivo by positron emission tomography in healthy volunteer subjects and patients with Parkinson's disease

    SciTech Connect

    Leenders, K.L.; Salmon, E.P.; Tyrrell, P.; Perani, D.; Brooks, D.J.; Sager, H.; Jones, T.; Marsden, C.D.; Frackowiak, R.S. )

    1990-12-01

    A group of healthy control subjects and patients with Parkinson's disease were investigated using positron emission tomography and two tracers as indicators of different specific properties of the presynaptic dopaminergic system in caudate nucleus and putamen. The first tracer, 6-L-(18F)-fluorodopa, was used as an analog of levodopa to assess its regional brain uptake, conversion into, and retention as dopamine and further metabolites. The second tracer, (11C)-nomifensine was employed as an indicator of striatal monaminergic reuptake sites that are principally dopaminergic. We have used this tracer to assess dopaminergic nerve terminal density. In patients with Parkinson's disease, striatal uptake of both tracers was decreased, putamen being significantly more affected than caudate. Side-to-side differences of uptake in putamen, but not caudate, correlated with corresponding left-right differences of scored clinical motor performance. Both 6-L(18F)-fluorodopa and (11C)-nomifensine tracer uptake in putamen was decreased on average to 40% of normal values, suggesting that a substantial part of the cellular elements of the dopaminergic nigrostriatal system is still intact in living parkinsonian patients. This is in contrast to the generally extreme depletion of endogenous dopamine in the putamen of patients found at postmortem. Our results lend support to the search for drug treatments that protect against further nigrostriatal cell loss and that could be exhibited as soon as the disease manifests clinically. If successful, a sufficient striatal nerve terminal pool would remain so that the effectiveness of levodopa as a dopamine repletor could persist.

  2. Assessment of glucose metabolism from the projections using the wavelet technique in small animal pet imaging.

    PubMed

    Arhjoul, Lahcen; Bentourkia, M'hamed

    2007-04-01

    The dynamic positron emission tomography (PET) images are usually modeled to extract the physiological parameters. However, to avoid reconstruction of the dynamic sequence of images with subjective data filtering, it is advantageous to apply the kinetic modeling in the projection space and to reconstruct single parametric image slices. Using the advantage of the wavelets to compress the data and to filter the noise in the sinogram, we applied the graphical analysis method (Patlak) to generate a single parametric sinogram (WAV-SINO) from PET data acquired in seven normal rats measured with fluorodeoxyglucose (FDG) in the heart. The same data set was analysed with the graphical method in the spatial domain from the sinograms (USUAL-SINO), and also from images reconstructed with non-filtered backprojection (USUAL-nFBP) and filtered backprojection (USUAL-FBP). The myocardial metabolic rates for glucose (MMRG) obtained with USUAL-nFBP, USUAL-FBP, USUAL-SINO and WAV-SINO were found to be, respectively, 7.54, 6.75, 6.52 and 6.98micromol/100g/min. While the variance with respect to USUAL-FBP was about 142% for USUAL-nFBP, 99.6% for USUAL-SINO and 101.9% for WAV-SINO, the spatial resolution as assessed from the profiles through the myocardial walls of the reconstructed images was 112% for USUAL-FBP and 105% for WAV-SINO relative to the high resolution USUAL-nFBP. The WAV-SINO parametric images showed slightly better visual quality than those obtained from the spatial domain. Finally, the wavelet filtering technique allowed to reduce the computing time, the storage space and particularly the variance in the MMRG parametric images while preserving the spatial resolution.

  3. Comparative effects of hydrofluoroalkane and chlorofluorocarbon beclomethasone dipropionate inhalation on small airways: assessment with functional helical thin-section computed tomography.

    PubMed

    Goldin, J G; Tashkin, D P; Kleerup, E C; Greaser, L E; Haywood, U M; Sayre, J W; Simmons, M D; Suttorp, M; Colice, G L; Vanden Burgt, J A; Aberle, D R

    1999-12-01

    A double-blind, randomized, parallel-group pilot study compared the relative efficacy of hydrofluoroalkane-134a beclomethasone dipropionate (HFA-BDP [QVAR]; mass median aerodynamic diameter, 0. 8-1.2 m) versus cholorofluorocarbon-11/12 BDP (CFC-BDP [Beclovent]; mass median aerodynamic diameter, 3.5-4.0 m) in 31 steroid naive patients with mild to moderate asthma (PC(20,) 4 mg/mL). Functional high-resolution computed tomography was used to assess the relative efficacy of HFA-BDP and CFC-BDP on regional air trapping, as an indirect measure of small airways function and on regional hyperreactivity. Pretreatment functional computed tomography was performed at residual volume before and after methacholine challenge. After 4 weeks of treatment, functional imaging was repeated before and after the same concentration of methacholine that was administered before the treatment (n = 19 patients). Quantitative assessment of changes in distribution of lung attenuation was performed. After 4 weeks of treatment, the HFA-BDP group showed significantly more improvement in air trapping overall (a shift in the lung attenuation curve at residual volume toward more attenuation) on the posttreatment computed tomography scan (P <.05; Fisher's Exact Test). After an equal constrictor stimulus (methacholine concentration), subjects treated with HFA-BDP (n = 10 patients) showed less increase in air trapping overall than subjects treated with CFC-BDP (n = 9 patients) on the posttreatment scans compared with the pretreatment scans (P <.001; Fisher's Exact Test). No significant difference was demonstrated between the 2 treatment groups with respect to improvement in symptoms, spirometry, or methacholine responsiveness assessed by FEV(1), except for a greater reduction in breathlessness in the HFA-BDP group (P <.05). We conclude that HFA-BDP may have greater efficacy in the peripheral airways and that this effect is better assessed with functional imaging computed tomography techniques than with

  4. [Comparative assessment of MR-semiotics of acutest intracerebral hematomas in low- and extra high-field frequency magnetic resonance tomography].

    PubMed

    Skvortsova, V I; Burenchev, D V; Tvorogova, T V; Guseva, O I; Prokhorov, A V; Smirnov, A M; Kupriianov, D A; Pirogov, Iu A

    2009-01-01

    An objective of the study was to compare sensitivity of low- and extra high-field frequency magnetic resonance (MR) tomography of acutest intracerebral hematomas (ICH) and to assess differences between symptoms in obtained images. A study was conducted using experimental ICH in rats (n=6). Hematomas were formed by two injections of autologic blood into the brain. MR-devices "Bio Spec 70/30" with magnetic field strength of 7 T and "Ellipse-150" with magnetic field strength of 0,15 T were used in the study. MR-tomography was carried out 3-5 h after the injections. Both MR-devices revealed the presence of pathological lesion in all animals. Extra highfield frequency MR-tomography showed the specific signs of ICH caused by the paramagnetic effect of deoxyhemoglobin in T2 and T2*-weighted images (WI) and low frequency MR-tomography - in T2*-WI only. The comparable sensitivity of low- and extra high-field frequency MR-devices in acutest ICH was established.

  5. Environmental assessment -- Proposed neutrino beams at the Main Injector project

    SciTech Connect

    1997-12-01

    The US Department of Energy (DOE) proposes to build a beamline on the Fermi National Accelerator Laboratory (Fermilab) site to accommodate an experimental research program in neutrino physics. The proposed action, called Neutrino Beams at the Main Injector (NuMI), is to design, construct, operate and decommission a facility for producing and studying a high flux beam of neutrinos in the energy range of 1 to 40 GeV (1 GeV is one billion or 10{sup 9} electron volts). The proposed facility would initially be dedicated to two experiments, COSMOS (Cosmologically Significant Mass Oscillations) and MINOS (Main Injector Neutrino Oscillation Search). The neutrino beam would pass underground from Fermilab to northern Minnesota. A tunnel would not be built in this intervening region because the neutrinos easily pass through the earth, not interacting, similar to the way that light passes through a pane of glass. The beam is pointed towards the MINOS detector in the Soudan Underground Laboratory in Minnesota. Thus, the proposed project also includes construction, operation and decommissioning of the facility located in the Soudan Underground Laboratory in Minnesota that houses this MINOS detector. This environmental assessment (EA) has been prepared by the US Department of Energy (DOE) in accordance with the DOE`s National Environmental Policy Act (NEPA) Implementing Procedures (10 CFR 1021). This EA documents DOE`s evaluation of potential environmental impacts associated with the proposed construction and operation of NuMI at Fermilab and its far detector facility located in the Soudan Underground Laboratory in Minnesota. Any future use of the facilities on the Fermilab site would require the administrative approval of the Director of Fermilab and would undergo a separate NEPA review. Fermilab is a Federal high-energy physics research laboratory in Batavia, Illinois operated on behalf of the DOE by Universities Research Association, Inc.

  6. Micro-computed tomography (CT) based assessment of dental regenerative therapy in the canine mandible model

    NASA Astrophysics Data System (ADS)

    Khobragade, P.; Jain, A.; Setlur Nagesh, S. V.; Andreana, S.; Dziak, R.; Sunkara, S. K.; Sunkara, S.; Bednarek, D. R.; Rudin, S.; Ionita, C. N.

    2015-03-01

    High-resolution 3D bone-tissue structure measurements may provide information critical to the understanding of the bone regeneration processes and to the bone strength assessment. Tissue engineering studies rely on such nondestructive measurements to monitor bone graft regeneration area. In this study, we measured bone yield, fractal dimension and trabecular thickness through micro-CT slices for different grafts and controls. Eight canines underwent surgery to remove a bone volume (defect) in the canine's jaw at a total of 44 different locations. We kept 11 defects empty for control and filled the remaining ones with three regenerative materials; NanoGen (NG), a FDA-approved material (n=11), a novel NanoCalcium Sulfate (NCS) material (n=11) and NCS alginate (NCS+alg) material (n=11). After a minimum of four and eight weeks, the canines were sacrificed and the jaw samples were extracted. We used a custombuilt micro-CT system to acquire the data volume and developed software to measure the bone yield, fractal dimension and trabecular thickness. The software used a segmentation algorithm based on histograms derived from volumes of interest indicated by the operator. Using bone yield and fractal dimension as indices we are able to differentiate between the control and regenerative material (p<0.005). Regenerative material NCS showed an average 63.15% bone yield improvement over the control sample, NCS+alg showed 55.55% and NanoGen showed 37.5%. The bone regeneration process and quality of bone were dependent upon the position of defect and time period of healing. This study presents one of the first quantitative comparisons using non-destructive Micro-CT analysis for bone regenerative material in a large animal with a critical defect model. Our results indicate that Micro-CT measurement could be used to monitor invivo bone regeneration studies for greater regenerative process understanding.

  7. 76 FR 64991 - Environmental Assessment for the I-395 Air Rights Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-19

    ... Federal Highway Administration Environmental Assessment for the I-395 Air Rights Project AGENCY: Federal... Department of Transportation are announcing the availability for public review of the Environmental Assessment (EA) prepared for the I-395 Air Rights Projects in conjunction with the District Department...

  8. 75 FR 7029 - Notice of Availability of the Final Environmental Assessment for Solar Roof Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-16

    ... Geological Survey Notice of Availability of the Final Environmental Assessment for Solar Roof Project AGENCY..., the US Geological Survey (USGS) has prepared a Final Environmental Assessment for the Solar Roof... for the Solar Roof Project should immediately contact the USGS S.O. Conte Anadromous Fish...

  9. Lessons Learned from Net Zero Energy Assessments and Renewable Energy Projects at Military Installations

    SciTech Connect

    Callahan, M.; Anderson, K.; Booth, S.; Katz, J.; Tetreault, T.

    2011-09-01

    Report highlights the increase in resources, project speed, and scale that is required to achieve the U.S. Department of Defense (DoD) energy efficiency and renewable energy goals and summarizes the net zero energy installation assessment (NZEI) process and the lessons learned from NZEI assessments and large-scale renewable energy projects implementations at DoD installations.

  10. A Case Study of Teacher Learning in an Assessment for Learning Project in Hong Kong

    ERIC Educational Resources Information Center

    Tang, Sylvia Yee Fan; Leung, Pamela Pui Wan; Chow, Alice Wai Kwan; Wong, Ping Man

    2010-01-01

    Changes in assessment practices in the direction of assessment for learning (AfL) can be a powerful force to enhance student learning. This article presents a case study of teacher learning in an AfL project in Hong Kong. In the Project, AfL strategies were adopted in Chinese Language and English Language classrooms at the junior secondary level.…

  11. Centralisation of Assessment: Meeting the Challenges of Multi-Year Team Projects in Information Systems Education

    ERIC Educational Resources Information Center

    Cooper, Grahame; Heinze, Aleksej

    2007-01-01

    This paper focuses on the difficulties of assessing multi-year team projects, in which a team of students drawn from all three years of a full-time degree course works on a problem with and for a real-life organization. Although potential solutions to the problem of assessing team projects may be context-dependent, we believe that discussing these…

  12. Project ADAPT: A Program to Assess Depression and Provide Proactive Treatment in Rural Areas

    ERIC Educational Resources Information Center

    Luptak, Marilyn; Kaas, Merrie J.; Artz, Margaret; McCarthy, Teresa

    2008-01-01

    Purpose: We describe and evaluate a project designed to pilot test an evidence-based clinical intervention for assessing and treating depression in older adults in rural primary care clinics. Project ADAPT--Assuring Depression Assessment and Proactive Treatment--utilized existing primary care resources to overcome barriers to sustainability…

  13. Electron tomography of cells.

    PubMed

    Gan, Lu; Jensen, Grant J

    2012-02-01

    The electron microscope has contributed deep insights into biological structure since its invention nearly 80 years ago. Advances in instrumentation and methodology in recent decades have now enabled electron tomography to become the highest resolution three-dimensional (3D) imaging technique available for unique objects such as cells. Cells can be imaged either plastic-embedded or frozen-hydrated. Then the series of projection images are aligned and back-projected to generate a 3D reconstruction or 'tomogram'. Here, we review how electron tomography has begun to reveal the molecular organization of cells and how the existing and upcoming technologies promise even greater insights into structural cell biology. PMID:22082691

  14. Augusta Newsprint: Paper Mill Pursues Five Projects Following Plant-Wide Energy Efficiency Assessment

    SciTech Connect

    Not Available

    2003-07-01

    Augusta Newsprint undertook a plant-wide energy efficiency assessment of its Augusta, Georgia, plant in 2001. The assessment helped the company decide to implement five energy efficiency projects. Four of the five projects will save the company 11,000 MWh of electrical energy (about$369,000) each year. The remaining project will produce more than$300,000 annually, from sale of the byproduct turpentine. The largest annual savings,$881,000, will come from eliminating Kraft pulp by using better process control. All of the projects could be applied to other paper mills and most of the projects could be applied in other industries.

  15. Iterative performance assessments as a regulatory tool for evaluating repository safety: How experiences from SKI Project-90 were used in formulating the new performance assessment project SITE-94

    SciTech Connect

    Andersson, J.

    1993-12-31

    The Swedish Nuclear Power Inspectorate, SKI, regulatory research program has to prepare for the process of licensing a repository for spent nuclear fuel, by building up the necessary knowledge and review capacity. SKIs main strategy for meeting this demand is to develop an independent performance assessment capability. SKIs first own performance assessment project, Project-90, was completed in 1991 and is now followed by a new project, SITE-94. SITE-94 is based on conclusions reached within Project-90. An independent review of Project-90, carried out by a NEA team of experts, has also contributed to the formation of the project. Another important reason for the project is that the implementing organization in Sweden, SKB, has proposed to submit an application to start detailed investigation of a repository candidate site around 1997. SITE-94 is a performance assessment of a hypothetical repository at a real site. The main objective of the project is to determine how site specific data should be assimilated into the performance assessment process, and to evaluate how uncertainties inherent in site characterization will influence performance assessment results. This will be addressed by exploring multiple interpretations, conceptual models, and parameters consistent with the site data. The site evaluation will strive for consistency between geological, hydrological, rock mechanical, and geochemical descriptions. Other important elements of SITE-94 are the development of a practical and defensible methodology for defining, constructing and analyzing scenarios, the development of approaches for treatment of uncertainties, evaluation of canister integrity, and the development and application of an appropriate quality assurance plan for performance assessments.

  16. Conflicting or complementary role of computed tomography (CT) and positron emission tomography (PET)/CT in the assessment of thymic cancer and thymoma: our experience and literature review

    PubMed Central

    Scagliori, Elena; Evangelista, Laura; Panunzio, Annalori; Calabrese, Fiorella; Nannini, Nazarena; Polverosi, Roberta; Pomerri, Fabio

    2015-01-01

    Background To evaluate the role of computed tomography (CT) and positron emission tomography (PET)/CT in patients with thymic cancer and thymoma at initial staging. Methods We retrospectively reviewed CT and PET/CT scans of 26 patients with a thymic cancer (n = 9) or thymoma (n = 17). Chest CT findings documented were qualitative and quantitative. Both qualitative and semiquantitative data were recovered by PET/CT. The comparisons among histological entities, outcome, and qualitative data from CT and PET/CT were made by non-parametric analysis. Results PET/CT resulted positive in 15/17 patients with thymoma. CT was available in 5/9 (56%) patients with thymic cancer and in 3/17 with thymoma. All quantitative CT parameters were significantly higher in patients with thymic cancer than thymoma (maximum axial diameter: 45 vs. 20 mm, maximum longitudinal diameter: 69 vs. 21 mm and volume: 77.91 vs. 4.52 mL; all P < 0.05). Conversely, only metabolic tumor volume (MTV) and total lesion glycolysis were significantly different in patients with thymic cancer than thymoma (126.53 vs. 6.03 cm3 and 246.05 vs. 20.32, respectively; both P < 0.05). After a median follow-up time of 17.45 months, four recurrences of disease occurred: three in patients with thymic cancer and one with a type B2 thymoma. CT volume in patients with recurrent disease was 102.19 mL versus a median value of 62.5 mL in six disease-free patients. MTV was higher in the recurrent than disease-free patient subset (143.3 vs. 81.13 cm3), although not statistically significant (P = 0.075). Conclusion Our preliminary results demonstrated that both morphological and metabolic volume could be useful from a diagnostic and prognostic point of view in thymic cancer and thymoma patients. A large multi-center clinical trial experience for confirming the findings of this study seems mandatory. PMID:26273398

  17. Preclinical assessment of carboplatin treatment efficacy in lung cancer by 18F-ICMT-11-positron emission tomography.

    PubMed

    Witney, Timothy H; Fortt, R; Fortt, Robin R; Aboagye, Eric O

    2014-01-01

    Tumour response to therapy is assessed primarily in the clinic by monitoring reductions in tumour size. However, this approach lacks sensitivity since in many cases several weeks may elapse before there is evidence of tumour shrinkage. There is therefore a need to develop non-invasive imaging techniques for monitoring tumour treatment response in the clinic. Here, we assessed the pre-clinical utility of (18)F-ICMT-11 positron emission tomography--a method for detecting caspase 3/7 activation--in non-small cell lung cancer (NSCLC). (18)F-ICMT-11 uptake was compared to molecular biochemical measures of cell death in PC9 and A549 NSCLC cells following treatment with carboplatin in vitro and in vivo. Carboplatin-induced apoptosis in the ERCC1 low/mutant EGFR PC9 cells was characterised by time and dose-related increased caspase-3/7 activation, poly-ADP-ribose polymerase cleavage and Annexin V staining. 18F-ICMT-11 uptake was consequently increased up to 14-fold at 200 µM carboplatin compared to vehicle treated cells (P<0.01). In contrast, necrosis was the predominant death mechanism in ERCC1 high/wt EGFR A549 cells and no change in (18)F-ICMT-11 uptake was detected. In vivo, histological analysis of PC9 tumour xenografts indicated high pre-therapy necrosis. A 4.6-fold increase in cleaved caspase-3/7 was measured in non-necrotic regions of PC9 tumours at 48 h post carboplatin therapy. Average PET-derived tumour (18)F-ICMT-11 uptake was insensitive to changes in apoptosis in the presence of substantial pre-existing necrosis. PET-based voxel intensity sorting however, identified intra-tumoural regions of high (18)F-ICMT-11 uptake, enabling accurate assessment of apoptosis and therefore therapy response. In A549 tumours that lacked high pre-therapy necrosis, carboplatin induced growth inhibition that was only minimally associated with apoptosis and thus not detectable by (18)F-ICMT-11 PET.

  18. A Bayesian approach to assess the importance of crustal corrections in global anisotropic surface wave tomography

    NASA Astrophysics Data System (ADS)

    Xing, Z.; Beghein, C.

    2015-12-01

    Several recent studies have demonstrated the importance of crustal corrections when inverting surface wave data to model lateral variations in mantle radial anisotropy. It has also been shown that the choice of the prior crustal model to correct the data can strongly influence the anisotropy model and potentially lead to different geodynamic interpretations. In comparing tomographic models of radial anisotropy obtained from different crustal corrections, these studies did not, however, determine quantitative model uncertainties. Nevertheless, mantle models resulting from different prior crustal corrections are statistically different only if the posterior model errors stemming from the non-uniqueness of the inverse problem are smaller than the effect of the crustal correction itself. Here, we applied a model space search approach to global fundamental and higher mode Rayleigh and Love wave phase velocity maps to determine reliable, quantitative model uncertainties on seismic velocities and radial anisotropy. The technique employed enabled us to describe the model space with a posterior probability density function, and therefore to test whether models obtained from different crustal corrections are statistically different. We thus assessed the significance of the choice of the crustal model by comparing the posterior model errors to the differences in mantle structure resulting from different crustal corrections. We tested prior crustal models CRUST2.0, CRUST1.0 and 3SMAC. Our study shows that the use of prior crustal corrections from different crustal models yields significant discrepancies in mantle velocities around 50 km depth and in radial anisotropy down to 100 km. The impact of the crustal correction on radial anisotropy can extend down to 250 km in some locations. We found that choosing 3SMAC instead of the other crustal models has a stronger influence on the mantle model, but that CRUST1.0 and CRUST2.0 yield statistically identical anisotropy models at all

  19. Milliken Clean Coal Demonstration Project: A DOE Assessment

    SciTech Connect

    National Energy Technology Laboratory

    2001-08-15

    The goal of the U.S. Department of Energy's (DOE) Clean Coal Technology (CCT) program is to furnish the energy marketplace with a number of advanced, more efficient, and environmentally responsible coal-utilization technologies through demonstration projects. These projects seek to establish the commercial feasibility of the most promising advanced coal technologies that have developed beyond the proof-of-concept stage.

  20. Programming and Training Booklet 4: How To Assess a Project.

    ERIC Educational Resources Information Center

    Peace Corps, Washington, DC. Information Collection and Exchange Div.

    This booklet is one of five in the Peace Corps (PC) Programming and Training Guidelines collection that provides agency-wide programming and training guidance for PC staff and project partners. It shows how to design and implement a monitoring and evaluation (M&E) plan for PC projects. Chapter 1 provides an overview of M&E, including what they are…

  1. Document Selection and Relevance Assessments during a Research Project.

    ERIC Educational Resources Information Center

    White, Marilyn Domas; Wang, Peiling

    User's information needs and the tasks they face change over the stages of a research project. In previous research by Peiling Wang, a cognitive model of users' document selection behavior for their research projects was developed. This study looks at the general applicability of Wang's model to subsequent decision-making about items selected…

  2. Evolving Project E-Scape for National Assessment

    ERIC Educational Resources Information Center

    Kimbell, Richard

    2012-01-01

    In the opening paper in this Special Edition I outlined the major issues that led to the establishment of "project e-scape". The project was intended to develop systems and approaches that enabled learners to build real-time web-based portfolios of their performance (initially) in design & technology and additionally to build systems and…

  3. Lower Columbia River Terminal Fisheries Research Project : Final Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration.

    1995-04-01

    This notice announces BPA`S`s decision to fund the Oregon Department of Fish and Wildlife (ODFW), the Washington Department of Fish and Wildlife (WDFW), and the Clatsop Economic Development Committee for the Lower Columbia River Terminal Fisheries Research Project (Project). The Project will continue the testing of various species/stocks, rearing regimes, and harvest options for terminal fisheries, as a means to increase lower river sport and commercial harvest of hatchery fish, while providing both greater protection of weaker wild stocks and increasing the return of upriver salmon runs to potential Zone 6 Treaty fisheries. The Project involves relocating hatchery smolts to new, additional pen locations in three bays/sloughs in the lower Columbia River along both the Oregon and Washington sides. The sites are Blind Slough and Tongue Point in Clatsop County, Oregon, and Grays Bay/Deep River, Wahkiakum County, Washington. The smolts will be acclimated for various lengths of time in the net pens and released from these sites. The Project will expand upon an existing terminal fisheries project in Youngs Bay, Oregon. The Project may be expanded to other sites in the future, depending on the results of this initial expansion. BPA`S has determined the project is not a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an environmental impact statement is not required, and BPA`S is issuing this FONSI.

  4. Assessment of Project-Based Learning in a MECHATRONICS Context

    ERIC Educational Resources Information Center

    Doppelt, Yaron

    2005-01-01

    Project-based learning (PBL) that has authenticity in the pupils' world enables the teaching of science and technology to pupils from a variety of backgrounds. PBL has the potential to enable pupils to research, plan, design, and reflect on the creation of technological projects (Doppelt, 2000). Engineering education, which is common in Israel,…

  5. Assessment of linear measurements of bone for implant sites in the presence of metallic artefacts using cone beam computed tomography and multislice computed tomography.

    PubMed

    Cremonini, C C; Dumas, M; Pannuti, C M; Neto, J B C; Cavalcanti, M G P; Lima, L A

    2011-08-01

    The objective was to evaluate the influence of dental metallic artefacts on implant sites using multislice and cone-beam computed tomography techniques. Ten dried human mandibles were scanned twice by each technique, with and without dental metallic artefacts. Metallic restorations were placed at the top of the alveolar ridge adjacent to the mental foramen region for the second scanning. Linear measurements (thickness and height) for each cross-section were performed by a single examiner using computer software. All mandibles were analysed at both the right and the left mental foramen regions. For the multislice technique, dental metallic artefact produced an increase of 5% in bone thickness and a reduction of 6% in bone height; no significant differences (p>0.05) were detected when comparing measurements performed with and without metallic artefacts. With respect to the cone-beam technique, dental metallic artefact produced an increase of 6% in bone thickness and a reduction of 0.68% in bone height. No significant differences (p>0.05) were observed when comparing measurements performed with and without metallic artefacts. The presence of dental metallic artefacts did not alter the linear measurements obtained with both techniques, although its presence made the location of the alveolar bone crest more difficult.

  6. Assessment of freeware programs for the reconstruction of tomography datasets obtained with a monochromatic synchrotron-based X-ray source.

    PubMed

    Wolkowski, Bailey; Snead, Elisabeth; Wesolowski, Michal; Singh, Jaswant; Pettitt, Murray; Chibbar, Rajni; Melli, Seyedali; Montgomery, James

    2015-07-01

    Synchrotron-based in-line phase-contrast computed tomography (PC-CT) allows soft tissue to be imaged with sub-gross resolution and has potential to be used as a diagnostic tool. The reconstruction and processing of in-line PC-CT datasets is a computationally demanding task; thus, an efficient and user-friendly software program is desirable. Four freeware programs (NRecon, PITRE, H-PITRE and Athabasca Recon) were compared for the availability of features such as dark- and flat-field calibration, beam power normalization, ring artifact removal, and alignment tools for optimizing image quality. An in-line PC-CT projection dataset (3751 projections, 180° rotation, 10.13 mm × 0.54 mm) was collected from a formalin-fixed canine prostate at the Biomedical Imaging and Therapy Bending Magnet (BMIT-BM) beamline of the Canadian Light Source. This dataset was processed with each of the four software programs and usability of the program was evaluated. Efficiency was assessed by how each program maximized computer processing power during computation. Athabasca Recon had the least-efficient memory usage, least user-friendly interface, and lacked a ring artifact removal feature. NRecon, PITRE and H-PITRE produced similar quality images, but the Athabasca Recon reconstruction suffered from the lack of a native ring remover algorithm. The 64-bit version of NRecon uses GPU (graphics processor unit) memory for accelerated processing and is user-friendly, but does not provide necessary parameters for in-line PC-CT data, such as dark-field and flat-field correction and beam power normalization. PITRE has many helpful features and tools, but lacks a comprehensive user manual and help section. H-PITRE is a condensed version of PITRE and maximizes computer memory for efficiency. To conclude, NRecon has fewer imaging processing tools than PITRE and H-PITRE, but is ideal for less experienced users due to a simple user interface. Based on the quality of reconstructed images, efficient

  7. Assessment of freeware programs for the reconstruction of tomography datasets obtained with a monochromatic synchrotron-based X-ray source.

    PubMed

    Wolkowski, Bailey; Snead, Elisabeth; Wesolowski, Michal; Singh, Jaswant; Pettitt, Murray; Chibbar, Rajni; Melli, Seyedali; Montgomery, James

    2015-07-01

    Synchrotron-based in-line phase-contrast computed tomography (PC-CT) allows soft tissue to be imaged with sub-gross resolution and has potential to be used as a diagnostic tool. The reconstruction and processing of in-line PC-CT datasets is a computationally demanding task; thus, an efficient and user-friendly software program is desirable. Four freeware programs (NRecon, PITRE, H-PITRE and Athabasca Recon) were compared for the availability of features such as dark- and flat-field calibration, beam power normalization, ring artifact removal, and alignment tools for optimizing image quality. An in-line PC-CT projection dataset (3751 projections, 180° rotation, 10.13 mm × 0.54 mm) was collected from a formalin-fixed canine prostate at the Biomedical Imaging and Therapy Bending Magnet (BMIT-BM) beamline of the Canadian Light Source. This dataset was processed with each of the four software programs and usability of the program was evaluated. Efficiency was assessed by how each program maximized computer processing power during computation. Athabasca Recon had the least-efficient memory usage, least user-friendly interface, and lacked a ring artifact removal feature. NRecon, PITRE and H-PITRE produced similar quality images, but the Athabasca Recon reconstruction suffered from the lack of a native ring remover algorithm. The 64-bit version of NRecon uses GPU (graphics processor unit) memory for accelerated processing and is user-friendly, but does not provide necessary parameters for in-line PC-CT data, such as dark-field and flat-field correction and beam power normalization. PITRE has many helpful features and tools, but lacks a comprehensive user manual and help section. H-PITRE is a condensed version of PITRE and maximizes computer memory for efficiency. To conclude, NRecon has fewer imaging processing tools than PITRE and H-PITRE, but is ideal for less experienced users due to a simple user interface. Based on the quality of reconstructed images, efficient

  8. Nondestructive assessment of dentin demineralization using polarization sensitive optical coherence tomography after exposure to fluoride and laser irradiation

    PubMed Central

    Manesh, Saman K.; Darling, Cynthia L.; Fried, Daniel

    2009-01-01

    Previous studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to image natural and artificial caries in dentin. The purpose of this study was to measure non-destructively the severity of artificial caries lesions in dentin and determine the efficacy of intervention with anti-caries agents including fluoride and lasers. Although several studies have assessed the utility of PS-OCT to image caries lesions in enamel and to quantify the lesion severity, only a few studies have focused on lesions in dentin. In this study images of artificial dentin lesions on extracted human teeth were acquired with PS-OCT. Before exposure to an artificial demineralizing solution, three incisions were made on the sample surfaces using either Er:YAG, Nd:YAG (λ=355-nm), or TEA CO2 lasers and selected areas were treated with topical fluoride to create six unique treatment areas for each of the three laser conditions investigated. The integrated reflectivity and depth of demineralization were calculated for each of the six areas on each sample using the PS-OCT images. Polarized light microscopy (PLM) and transverse microradiography (TMR) were used to measure lesion severity on histological thin sections for comparison. PS-OCT successfully measured the inhibition of demineralization by topical fluoride. Laser irradiation was not particularly effective in increasing or decreasing the rate of dentin demineralization. PLM and TMR corroborated those results. This study demonstrates that PS-OCT can be used to measure demineralization on dentin surfaces and determine the degree of inhibition of demineralization by anti-caries agents. PMID:19283826

  9. Comparison of frequency domain optical coherence tomography and quantitative coronary angiography for the assessment of coronary lesions

    NASA Astrophysics Data System (ADS)

    Zafar, Haroon; Sharif, Faisal; Leahy, Martin J.

    2014-03-01

    Quantitative coronary angiography (QCA) has been used as a standard technique for the evaluation of coronary artery disease for many years. Intracoronary optical coherence tomography (OCT) offers higher resolution, faster image acquisition speeds and greater sensitivity than the intravascular ultrasound (IVUS). Recently developed frequency domain OCT (FD-OCT) systems overcome many technical limitations of conventional time domain OCT systems (TDOCT). The main objective of this study was to compare the FD-OCT and QCA measurements for the assessment of coronary lesions. A total of 21 stenoses in 18 patients were analysed using QCA and FD-OCT. The average minimum lumen diameter (MLD) and percent lumen area stenosis (%AS) by QCA were 1.52+/-0.44 mm and 68+/-9% respectively. The average MLD and %AS by FD-OCT were 1.32+/-0.38 mm and 63+/-14% respectively. There was a moderate but significant correlation between QCA and FD-OCT measured MLD (r = 0.5, p < 0.01) and %AS (r = 0.56, p < 0.01). Bland-Altman analysis showed that the mean differences between the QCA and FD-OCT measurements were 0.18+/-0.81 (limits of agreement: -0.63 to 0.99) for MLD and 4.4+/-22.8 (limits of agreement: -18.4 to 27.2) for %AS. The root mean square error (RMSE) between the QCA and FD-OCT measured MLD and %AS was +/-0.44 mm and +/-12.1% respectively.

  10. Computed Tomography and Optical Imaging of Osteogenesis-angiogenesis Coupling to Assess Integration of Cranial Bone Autografts and Allografts.

    PubMed

    Cohn Yakubovich, Doron; Tawackoli, Wafa; Sheyn, Dmitriy; Kallai, Ilan; Da, Xiaoyu; Pelled, Gadi; Gazit, Dan; Gazit, Zulma

    2015-01-01

    A major parameter determining the success of a bone-grafting procedure is vascularization of the area surrounding the graft. We hypothesized that implantation of a bone autograft would induce greater bone regeneration by abundant blood vessel formation. To investigate the effect of the graft on neovascularization at the defect site, we developed a micro-computed tomography (µCT) approach to characterize newly forming blood vessels, which involves systemic perfusion of the animal with a polymerizing contrast agent. This method enables detailed vascular analysis of an organ in its entirety. Additionally, blood perfusion was assessed using fluorescence imaging (FLI) of a blood-borne fluorescent agent. Bone formation was quantified by FLI using a hydroxyapatite-targeted probe and µCT analysis. Stem cell recruitment was monitored by bioluminescence imaging (BLI) of transgenic mice that express luciferase under the control of the osteocalcin promoter. Here we describe and demonstrate preparation of the allograft, calvarial defect surgery, µCT scanning protocols for the neovascularization study and bone formation analysis (including the in vivo perfusion of contrast agent), and the protocol for data analysis. The 3D high-resolution analysis of vasculature demonstrated significantly greater angiogenesis in animals with implanted autografts, especially with respect to arteriole formation. Accordingly, blood perfusion was significantly higher in the autograft group by the 7(th) day after surgery. We observed superior bone mineralization and measured greater bone formation in animals that received autografts. Autograft implantation induced resident stem cell recruitment to the graft-host bone suture, where the cells differentiated into bone-forming cells between the 7(th) and 10(th) postoperative day. This finding means that enhanced bone formation may be attributed to the augmented vascular feeding that characterizes autograft implantation. The methods depicted may serve

  11. Cone Beam Computed Tomography Assessment of the Maxillary Incisive Canal and Foramen: Considerations of Anatomical Variations When Placing Immediate Implants

    PubMed Central

    Al-Amery, Samah M.; Nambiar, Phrabhakaran; Jamaludin, Marhazlinda; John, Jacob; Ngeow, Wei Cheong

    2015-01-01

    Introduction The maxillary incisive canal connects the roof of the oral cavity with the floor of nasal cavity and has the incisive and nasal foramina respectively at its two opposite ends. Its close proximity with the anterior incisors affects one’s ability to place immediate implants in ideal position. Objective To avoid causing complication, variations in their dimensions were studied. Material and Methods Images of ninety Mongoloids patients examined with i-CAT Cone Beam Computed Tomography were included. The sizes of the nasopalatine foramen, the incisive canal and foramen, and anterior maxillary bone thickness were measured. The direction and course of the canals were assessed. Results The mean labiopalatal and mesiodistal measurements of the incisive foramen were 2.80mm and 3.49 mm respectively, while the labiopalatal width of the nasal foramen was 6.06mm. The incisive canal was 16.33mm long and 3.85 mm wide. The anterior maxillary bone has an average thickness of 7.63 mm. The dimensions of the incisive foramen and incisive canal, and anterior maxillary bone thickness demonstrated gender differences with males showing greater values. The anterior maxillary bone thickness was affected by age but this difference was not observed in canal dimensions. The majority of subjects have a funnel shape-like incisive canal with the broader opening located at its superior. They seem to have a longer slanted-curve canal with one channel at its middle portion and a narrower incisive foramen opening than those reported elsewhere. Conclusions This study found that gender is an important factor that affected the characteristics of the IC and the amount of bone anterior to it. Male generally had bigger IC and thicker anterior bone. In addition, the anterior maxillary bone thickness was affected by aging, where it becomes thinner with increased age even though the subjects were fully dentate. PMID:25679505

  12. Qualitative and Quantitative Assessment of Adenosine Triphosphate Stress Whole-Heart Dynamic Myocardial Perfusion Imaging Using 256-Slice Computed Tomography

    PubMed Central

    Kurata, Akira; Kawaguchi, Naoto; Kido, Teruhito; Inoue, Katsuji; Suzuki, Jun; Ogimoto, Akiyoshi; Funada, Jun-ichi; Higaki, Jitsuo; Miyagawa, Masao; Vembar, Mani; Mochizuki, Teruhito

    2013-01-01

    Background The aim of this study was to investigate the correlation of the qualitative transmural extent of hypoperfusion areas (HPA) using stress dynamic whole-heart computed tomography perfusion (CTP) imaging by 256-slice CT with CTP-derived myocardial blood flow (MBF) for the estimation of the severity of coronary artery stenosis. Methods and Results Eleven patients underwent adenosine triphosphate (0.16 mg/kg/min, 5 min) stress dynamic CTP by 256-slice CT (coverage: 8 cm, 0.27 s/rotation), and 9 of the 11 patients underwent coronary angiography (CAG). Stress dynamic CTP (whole–heart datasets over 30 consecutive heart beats in systole without spatial and temporal gaps) was acquired with prospective ECG gating (effective radiation dose: 10.4 mSv). The extent of HPAs was visually graded using a 3-point score (normal, subendocardial, transmural). MBF (ml/100g/min) was measured by deconvolution. Differences in MBF (mean ± standard error) according to HPA and CAG results were evaluated. In 27 regions (3 major coronary territories in 9 patients), 11 coronary stenoses (> 50% reduction in diameter) were observed. In 353 myocardial segments, HPA was significantly related to MBF (P < 0.05; normal 295 ± 94; subendocardial 186 ± 67; and transmural 80 ± 53). Coronary territory analysis revealed a significant relationship between coronary stenosis severity and MBF (P < 0.05; non-significant stenosis [< 50%], 284 ± 97; moderate stenosis [50–70%], 184 ± 74; and severe stenosis [> 70%], 119 ± 69). Conclusion The qualitative transmural extent of HPA using stress whole-heart dynamic CTP imaging by 256-slice CT exhibits a good correlation with quantitative CTP-derived MBF and may aid in assessing the hemodynamic significance of coronary artery disease. PMID:24376774

  13. Assessment of Anterior Segment Measurements with Swept Source Optical Coherence Tomography before and after Ab Interno Trabeculotomy (Trabectome) Surgery

    PubMed Central

    Huang, Ping

    2016-01-01

    Purpose. To compare the changes of anterior segment parameters, assessed by swept source anterior segment optical coherence tomography (AS-OCT) after combined Trabectome-cataract surgery and Trabectome-only surgery in open angle glaucoma patients. Methods. Thirty-eight eyes of 24 patients with open angle glaucoma were scanned with swept source AS-OCT before and 4 weeks after combined Trabectome-cataract or Trabectome-only surgery. Intraocular pressure, number of medications, and AS-OCT parameters, such as angle opening distance at 500 and 750 μm from the scleral spur (AOD500 and AOD750), trabecular-iris space area at 500 and 750 mm2 (TISA500, TISA750), angle recess area at 500 and 750 mm2 (ARA500, ARA750), trabecular iris angle (TIA), anterior chamber depth (ACD), anterior chamber width (ACW), and anterior chamber volume (ACV), were obtained before the surgery. These parameters were compared to evaluate whether the outcome of the surgery differed among the patients after the surgery. The width of the trabecular cleft was also measured for both groups. Results. The reduction of IOP and number of medications was found to be statistically significant in both groups (p < 0.001). ACD, ACV, and angle parameters such as AOD 500/750, TISA 500/750, ARA 500/750, and TIA500 showed significantly greater changes from the preoperative values to postoperative 1st month values in combined Trabectome-cataract surgery group (p < 0.05), whereas Trabectome-only group did not show statistically significant difference (p > 0.05). There was no statistically significant difference between two groups for the width of the trabecular cleft (p = 0.7). Conclusion. Anterior chamber angle parameters measured with swept source AS-OCT may be useful for evaluating glaucoma patients before and after Trabectome surgery with or without cataract surgery. PMID:27795855

  14. A review of NASA-sponsored technology assessment projects

    NASA Technical Reports Server (NTRS)

    Mascy, A. C.; Alexander, A. D., III; Wood, R. D.

    1978-01-01

    Recent technology assessment studies sponsored by NASA are reviewed, and a summary of the technical results as well as a critique of the methodologies are presented. The reviews include Assessment of Lighter-Than-Air Technology, Technology Assessment of Portable Energy RDT&P, Technology Assessment of Future Intercity Passenger Transportation Systems, and Technology Assessment of Space Disposal of Radioactive Nuclear Waste. The use of workshops has been introduced as a unique element of some of these assessments. Also included in this report is a brief synopsis of a method of quantifying opinions obtained through such group interactions. Representative of the current technology assessments, these studies cover a broad range of socio-political factors and issues in greater depth than previously considered in NASA sponsored studies. In addition to the lessons learned through the conduct of these studies, a few suggestions for improving the effectiveness of future technology assessments are provided.

  15. Three-dimensional resistivity tomography in extreme coastal terrain amidst dense cultural signals: application to cliff stability assessment at the historic D-Day site

    NASA Astrophysics Data System (ADS)

    Udphuay, Suwimon; Günther, Thomas; Everett, Mark E.; Warden, Robert R.; Briaud, Jean-Louis

    2011-04-01

    Pointe du Hoc overlooking the English Channel in Normandy, France was host to one of the most important military engagements of World War II but is vulnerable to cliff collapses that threaten important German fortifications including the forward observation post (OP) and Rudder's command post. The objective of this study is to apply advanced 3-D resistivity tomography towards a detailed site stability assessment with special attention to the two at-risk buildings. 3-D resistivity tomography data sets at Pointe du Hoc in the presence of extreme topography and dense cultural clutter have been successfully acquired, inverted and interpreted. A cliff stability hazard assessment scheme has been designed in which regions of high resistivity are interpreted as zones of open, dry fractures with a moderate mass movement potential. Regions of low resistivity are zones of wet, clay-filled fractures with a high mass movement potential. The OP tomography results indicate that the highest mass movement hazard appears to be associated with the marine caverns at the base of the cliff that are positioned at the point of strongest wave attack. These caverns likely occupy the future site of development of a sea arch that will threaten the OP building. The mass movement potential at the Rudder's command post area is low to moderate. The greatest risk there is associated with soil wedge failures at the top of the cliffs.

  16. South Carolina Higher Education Assessment (SCHEA) Project. Final Report.

    ERIC Educational Resources Information Center

    Johnson, Reid

    A consortium of South Carolina colleges and universities developed assessment programs which would fully satisfy state and accreditation assessment mandates and increase program quality and institutional effectiveness. A South Carolina Higher Education Assessment Network was established with a Coordinating Center at Winthrop College to provide…

  17. Current Knowledge and Projection on Assessing the Effectiveness of Training.

    ERIC Educational Resources Information Center

    Orlansky, Jesse

    This discussion of methods used to assess the effectiveness of training for U.S. Army personnel identifies various types of training, describes methods currently used, and suggests ways of improving the assessment process. The methodology and results of assessments of effectiveness, including the costs associated with the level of performance, are…

  18. An Investigation of Rater Cognition in the Assessment of Projects

    ERIC Educational Resources Information Center

    Crisp, Victoria

    2012-01-01

    In the United Kingdom, the majority of national assessments involve human raters. The processes by which raters determine the scores to award are central to the assessment process and affect the extent to which valid inferences can be made from assessment outcomes. Thus, understanding rater cognition has become a growing area of research in the…

  19. Needs Assessment Model: East Stroudsburg. Project NAMES Workbook. Second Edition.

    ERIC Educational Resources Information Center

    Rookey, T. Jerome

    Intended as a simple, economical method of needs assessment, this model presents four primary tasks: goal definition, program assessment, needs identification, and decision-making. Each step is explained in detail and sample instruments, preplans, goals, and questionnaire items are given. The needs assessment concept is defined as a blending of…

  20. WE-G-BRF-05: Feasibility of Markerless Motion Tracking Using Dual Energy Cone Beam Computed Tomography (DE-CBCT) Projections

    SciTech Connect

    Panfil, J; Patel, R; Surucu, M; Roeske, J

    2014-06-15

    Purpose: To compare markerless template-based tracking of lung tumors using dual energy (DE) cone-beam computed tomography (CBCT) projections versus single energy (SE) CBCT projections. Methods: A RANDO chest phantom with a simulated tumor in the upper right lung was used to investigate the effectiveness of tumor tracking using DE and SE CBCT projections. Planar kV projections from CBCT acquisitions were captured at 60 kVp (4 mAs) and 120 kVp (1 mAs) using the Varian TrueBeam and non-commercial iTools Capture software. Projections were taken at approximately every 0.53° while the gantry rotated. Due to limitations of the phantom, angles for which the shoulders blocked the tumor were excluded from tracking analysis. DE images were constructed using a weighted logarithmic subtraction that removed bony anatomy while preserving soft tissue structures. The tumors were tracked separately on DE and SE (120 kVp) images using a template-based tracking algorithm. The tracking results were compared to ground truth coordinates designated by a physician. Matches with a distance of greater than 3 mm from ground truth were designated as failing to track. Results: 363 frames were analyzed. The algorithm successfully tracked the tumor on 89.8% (326/363) of DE frames compared to 54.3% (197/363) of SE frames (p<0.0001). Average distance between tracking and ground truth coordinates was 1.27 +/− 0.67 mm for DE versus 1.83+/−0.74 mm for SE (p<0.0001). Conclusion: This study demonstrates the effectiveness of markerless template-based tracking using DE CBCT. DE imaging resulted in better detectability with more accurate localization on average versus SE. Supported by a grant from Varian Medical Systems.

  1. Personalized Assessment of kV Cone Beam Computed Tomography Doses in Image-guided Radiotherapy of Pediatric Cancer Patients

    SciTech Connect

    Zhang Yibao; Yan Yulong; Nath, Ravinder; Bao Shanglian; Deng Jun

    2012-08-01

    Purpose: To develop a quantitative method for the estimation of kV cone beam computed tomography (kVCBCT) doses in pediatric patients undergoing image-guided radiotherapy. Methods and Materials: Forty-two children were retrospectively analyzed in subgroups of different scanned regions: one group in the head-and-neck and the other group in the pelvis. Critical structures in planning CT images were delineated on an Eclipse treatment planning system before being converted into CT phantoms for Monte Carlo simulations. A benchmarked EGS4 Monte Carlo code was used to calculate three-dimensional dose distributions of kVCBCT scans with full-fan high-quality head or half-fan pelvis protocols predefined by the manufacturer. Based on planning CT images and structures exported in DICOM RT format, occipital-frontal circumferences (OFC) were calculated for head-and-neck patients using DICOMan software. Similarly, hip circumferences (HIP) were acquired for the pelvic group. Correlations between mean organ doses and age, weight, OFC, and HIP values were analyzed with SigmaPlot software suite, where regression performances were analyzed with relative dose differences (RDD) and coefficients of determination (R{sup 2}). Results: kVCBCT-contributed mean doses to all critical structures decreased monotonically with studied parameters, with a steeper decrease in the pelvis than in the head. Empirical functions have been developed for a dose estimation of the major organs at risk in the head and pelvis, respectively. If evaluated with physical parameters other than age, a mean RDD of up to 7.9% was observed for all the structures in our population of 42 patients. Conclusions: kVCBCT doses are highly correlated with patient size. According to this study, weight can be used as a primary index for dose assessment in both head and pelvis scans, while OFC and HIP may serve as secondary indices for dose estimation in corresponding regions. With the proposed empirical functions, it is possible

  2. Assessment of local hydraulic properties from electrical resistivity tomography monitoring of a three-dimensional synthetic tracer test experiment

    NASA Astrophysics Data System (ADS)

    Camporese, M.; Cassiani, G.; Deiana, R.; Salandin, P.

    2011-12-01

    In recent years geophysical methods have become increasingly popular for hydrological applications. Time-lapse electrical resistivity tomography (ERT) represents a potentially powerful tool for subsurface solute transport characterization since a full picture of the spatiotemporal evolution of the process can be obtained. However, the quantitative interpretation of tracer tests is difficult because of the uncertainty related to the geoelectrical inversion, the constitutive models linking geophysical and hydrological quantities, and the a priori unknown heterogeneous properties of natural formations. Here an approach based on the Lagrangian formulation of transport and the ensemble Kalman filter (EnKF) data assimilation technique is applied to assess the spatial distribution of hydraulic conductivity K by incorporating time-lapse cross-hole ERT data. Electrical data consist of three-dimensional cross-hole ERT images generated for a synthetic tracer test in a heterogeneous aquifer. Under the assumption that the solute spreads as a passive tracer, for high Peclet numbers the spatial moments of the evolving plume are dominated by the spatial distribution of the hydraulic conductivity. The assimilation of the electrical conductivity 4D images allows updating of the hydrological state as well as the spatial distribution of K. Thus, delineation of the tracer plume and estimation of the local aquifer heterogeneity can be achieved at the same time by means of this interpretation of time-lapse electrical images from tracer tests. We assess the impact on the performance of the hydrological inversion of (i) the uncertainty inherently affecting ERT inversions in terms of tracer concentration and (ii) the choice of the prior statistics of K. Our findings show that realistic ERT images can be integrated into a hydrological model even within an uncoupled inverse modeling framework. The reconstruction of the hydraulic conductivity spatial distribution is satisfactory in the portion

  3. Short Mountain Landfill Gas Recovery Project : Stage 1 Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration.

    1992-05-01

    The Bonneville Power Administration (BPA), a Federal power marketing agency, has statutory responsibilities to supply electrical power to its utility, industrial, and other customers in the Pacific Northwest. BPA`s latest load/resource balance forecast, projects the capability of existing resources to satisfy projected Federal system loads. The forecast indicates a potential resource deficit. The underlying need for action is to satisfy BPA customers` demand for electrical power.

  4. An Economic Evaluation Framework for Assessing Renewable Energy Projects

    SciTech Connect

    Omitaomu, Olufemi A; Badiru, Adedeji B

    2012-01-01

    It is becoming increasingly imperative to integrate renewable energy, such as solar and wind, into electricity generation due to increased regulations on air and water pollution and a sociopolitical desire to develop more clean energy sources. This increased spotlight on renewable energy requires evaluating competing projects using either conventional economic analysis techniques or other economics-based models and approaches in order to select a subset of the projects to be funded. Even then, there are reasons to suspect that techniques applied to renewable energy projects may result in decisions that will reject viable projects due to the use of a limited number of quantifiable and tangible attributes about the projects. This paper presents a framework for economic evaluation of renewable energy projects. The framework is based on a systems approach in which the processes within the entire network of the system, from generation to consumption, are accounted for. Furthermore, the framework uses the concept of fuzzy system to calculate the value of information under conditions of uncertainty.

  5. Project RAILS: Lessons Learned about Rubric Assessment of Information Literacy Skills

    ERIC Educational Resources Information Center

    Belanger, Jackie; Zou, Ning; Mills, Jenny Rushing; Holmes, Claire; Oakleaf, Megan

    2015-01-01

    Rubric assessment of information literacy is an important tool for librarians seeking to show evidence of student learning. The authors, who collaborated on the Rubric Assessment of Informational Literacy Skills (RAILS) research project, draw from their shared experience to present practical recommendations for implementing rubric assessment in a…

  6. The Effect of Peer Assessment on Project Performance of Students at Different Learning Levels

    ERIC Educational Resources Information Center

    Li, Lan; Gao, Fei

    2016-01-01

    Peer assessment has been increasingly integrated in educational settings as a strategy to foster student learning. Yet little has been studied about how students at different learning levels may benefit from peer assessment. This study examined how peer-assessment and students' learning levels influenced students' project performance using a…

  7. Accuracy Assessment of Three-dimensional Surface Reconstructions of In vivo Teeth from Cone-beam Computed Tomography

    PubMed Central

    Sang, Yan-Hui; Hu, Hong-Cheng; Lu, Song-He; Wu, Yu-Wei; Li, Wei-Ran; Tang, Zhi-Hui

    2016-01-01

    Background: The accuracy of three-dimensional (3D) reconstructions from cone-beam computed tomography (CBCT) has been particularly important in dentistry, which will affect the effectiveness of diagnosis, treatment plan, and outcome in clinical practice. The aims of this study were to assess the linear, volumetric, and geometric accuracy of 3D reconstructions from CBCT and to investigate the influence of voxel size and CBCT system on the reconstructions results. Methods: Fifty teeth from 18 orthodontic patients were assigned to three groups as NewTom VG 0.15 mm group (NewTom VG; voxel size: 0.15 mm; n = 17), NewTom VG 0.30 mm group (NewTom VG; voxel size: 0.30 mm; n = 16), and VATECH DCTPRO 0.30 mm group (VATECH DCTPRO; voxel size: 0.30 mm; n = 17). The 3D reconstruction models of the teeth were segmented from CBCT data manually using Mimics 18.0 (Materialise Dental, Leuven, Belgium), and the extracted teeth were scanned by 3Shape optical scanner (3Shape A/S, Denmark). Linear and volumetric deviations were separately assessed by comparing the length and volume of the 3D reconstruction model with physical measurement by paired t-test. Geometric deviations were assessed by the root mean square value of the imposed 3D reconstruction and optical models by one-sample t-test. To assess the influence of voxel size and CBCT system on 3D reconstruction, analysis of variance (ANOVA) was used (α = 0.05). Results: The linear, volumetric, and geometric deviations were −0.03 ± 0.48 mm, −5.4 ± 2.8%, and 0.117 ± 0.018 mm for NewTom VG 0.15 mm group; −0.45 ± 0.42 mm, −4.5 ± 3.4%, and 0.116 ± 0.014 mm for NewTom VG 0.30 mm group; and −0.93 ± 0.40 mm, −4.8 ± 5.1%, and 0.194 ± 0.117 mm for VATECH DCTPRO 0.30 mm group, respectively. There were statistically significant differences between groups in terms of linear measurement (P < 0.001), but no significant difference in terms of volumetric measurement (P = 0.774). No statistically significant difference were

  8. Computed Tomography

    NASA Astrophysics Data System (ADS)

    Castellano, Isabel; Geleijns, Jacob

    After its clinical introduction in 1973, computed tomography developed from an x-ray modality for axial imaging in neuroradiology into a versatile three dimensional imaging modality for a wide range of applications in for example oncology, vascular radiology, cardiology, traumatology and even in interventional radiology. Computed tomography is applied for diagnosis, follow-up studies and screening of healthy subpopulations with specific risk factors. This chapter provides a general introduction in computed tomography, covering a short history of computed tomography, technology, image quality, dosimetry, room shielding, quality control and quality criteria.

  9. NRC assessment of the Department of Energy annealing demonstration project

    SciTech Connect

    Jackson, D.A.; Malik, S.N.

    1997-02-01

    Thermal annealing is the only known method for mitigating the effects of neutron irradiation embrittlement in reactor pressure vessel (RPV) steels. In May 1996, the US Department of Energy (DOE) in conjunction with the American Society of Mechanical Engineers, Westinghouse, Cooperheat, Electric Power Research Institute (with participating utilities), Westinghouse Owner`s Group, Consumers Power, Electricite` de France, Duquesne Light and the Central Research Institute of the Electric Power Industry (Japan) sponsored an annealing demonstration project (ADP) at Marble Hill. The Marble Hill Plant, located in Madison, Indiana, is a Westinghouse 4 loop design. The plant was nearly 70% completed when the project was canceled. Hence, the RPV was never irradiated. The paper will present highlights from the NRCs independent evaluation of the Marble Hill Annealing Demonstration Project.

  10. Post-project geomorphic assessment of a large process-based river restoration project

    USGS Publications Warehouse

    Erwin, Susannah O.; Schmidt, John C.; Allred, Tyler M.

    2016-01-01

    This study describes channel changes following completion of the Provo River Restoration Project (PRRP), the largest stream restoration project in Utah and one of the largest projects in the United States in which a gravel-bed river was fully reconstructed. We summarize project objectives and the design process, and we analyze monitoring data collected during the first 7 years after project completion. Post-project channel adjustment during the study period included two phases: (i) an initial phase of rapid, but small-scale, adjustment during the first years after stream flow was introduced to the newly constructed channel and (ii) a subsequent period of more gradual topographic adjustment and channel migration. Analysis of aerial imagery and ground-survey data demonstrate that the channel has been more dynamic in the downstream 4 km where a local source contributes a significant annual supply of bed material. Here, the channel migrates and exhibits channel adjustments that are more consistent with project objectives. The upstream 12 km of the PRRP are sediment starved, the channel has been laterally stable, and this condition may not be consistent with large-scale project objectives.

  11. Post-project geomorphic assessment of a large process-based river restoration project

    NASA Astrophysics Data System (ADS)

    Erwin, Susannah O.; Schmidt, John C.; Allred, Tyler M.

    2016-10-01

    This study describes channel changes following completion of the Provo River Restoration Project (PRRP), the largest stream restoration project in Utah and one of the largest projects in the United States in which a gravel-bed river was fully reconstructed. We summarize project objectives and the design process, and we analyze monitoring data collected during the first 7 years after project completion. Post-project channel adjustment during the study period included two phases: (i) an initial phase of rapid, but small-scale, adjustment during the first years after stream flow was introduced to the newly constructed channel and (ii) a subsequent period of more gradual topographic adjustment and channel migration. Analysis of aerial imagery and ground-survey data demonstrate that the channel has been more dynamic in the downstream 4 km where a local source contributes a significant annual supply of bed material. Here, the channel migrates and exhibits channel adjustments that are more consistent with project objectives. The upstream 12 km of the PRRP are sediment starved, the channel has been laterally stable, and this condition may not be consistent with large-scale project objectives.

  12. Performance Evaluation and Opportunity Assessment for St. Bernard Project

    SciTech Connect

    Dickson, Bruce

    2011-06-01

    This report describes efforts by IBACOS, a Building America research team, in the St. Bernard Project, a nonprofit, community-based organization whose mission is to assist Hurricane Katrina survivors to return to their homes in the New Orleans area. The report focuses on energy modeling results of two plans that the St. Bernard Project put forth as 'typical' building types and on quality issues that were observed during the field walk and best practice recommendations that could improve the energy efficiency and durability of the renovated homes.

  13. Performance Evaluation and Opportunity Assessment for St. Bernard Project

    SciTech Connect

    Dickson, B.

    2011-06-01

    This report describes efforts by IBACOS, a Department of Energy Building America research team, in the St. Bernard Project, a nonprofit, community-based organization whose mission is to assist Hurricane Katrina survivors return to their homes in the New Orleans area. The report focuses on energy modeling results of two plans that the St. Bernard Project put forth as 'typical' building types and on quality issues that were observed during the field walk and Best Practice recommendations that could improve the energy efficiency and durability of the renovated homes.

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

    NASA Astrophysics Data System (ADS)

    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

  15. Bone-composition imaging using coherent-scatter computed tomography: Assessing bone health beyond bone mineral density

    SciTech Connect

    Batchelar, Deidre L.; Davidson, Melanie T.M.; Dabrowski, Waldemar; Cunningham, Ian A.

    2006-04-15

    Quantitative analysis of bone composition is necessary for the accurate diagnosis and monitoring of metabolic bone diseases. Accurate assessment of the bone mineralization state is the first requirement for a comprehensive analysis. In diagnostic imaging, x-ray coherent scatter depends upon the molecular structure of tissues. Coherent-scatter computed tomography (CSCT) exploits this feature to identify tissue types in composite biological specimens. We have used CSCT to map the distributions of tissues relevant to bone disease (fat, soft tissue, collagen, and mineral) within bone-tissue phantoms and an excised cadaveric bone sample. Using a purpose-built scanner, we have measured hydroxyapatite (bone mineral) concentrations based on coherent-scatter patterns from a series of samples with varying hydroxyapatite content. The measured scatter intensity is proportional to mineral density in true g/cm{sup 3}. Repeated measurements of the hydroxyapatite concentration in each sample were within, at most, 2% of each other, revealing an excellent precision in determining hydroxyapatite concentration. All measurements were also found to be accurate to within 3% of the known values. Phantoms simulating normal, over-, and under-mineralized bone were created by mixing known masses of pure collagen and hydroxyapatite. An analysis of the composite scatter patterns gave the density of each material. For each composite, the densities were within 2% of the known values. Collagen and hydroxyapatite concentrations were also examined in a bone-mimicking phantom, incorporating other bone constituents (fat, soft tissue). Tomographic maps of the coherent-scatter properties of each specimen were reconstructed, from which material-specific images were generated. Each tissue was clearly distinguished and the collagen-mineral ratio determined from this phantom was also within 2% of the known value. Existing bone analysis techniques cannot determine the collagen-mineral ratio in intact

  16. Assessment of Retinal and Choroidal Measurements in Chinese School-Age Children with Cirrus-HD Optical Coherence Tomography

    PubMed Central

    Li, Tao; Zhou, Xiaodong; Wang, Zhi; Zhu, Jie; Shen, Wenli; Jiang, Bo

    2016-01-01

    Purpose To evaluate retinal thickness (RT), retinal volume (RV) and choroidal thickness (ChT) in Chinese children using Cirrus-HD optical coherence tomography (OCT), and assess their associations with spherical equivalent (SE), age and gender. Methods This was a prospective study that recruited 193 healthy Chinese children (193 eyes) with no ophthalmic disease history between December 2012 and December 2013. RT and RV were acquired using OCT. Subfoveal ChT (SFCT) and ChT1-mm and 2-mm temporal, nasal, superior and inferior to the fovea were measured manually. Results RT in the inner temporal and nasal regionsdiffered significantly between refraction groups (both P<0.05). Significant differences were also found inSFCT andChT 1- and 2-mm inferior to the fovea (all P<0.05). RT differed significantly between males and females in the outer superior region in the emmetropia group (P<0.05). ChT differed significantly between males and females 2-mm temporal to the fovea in the emmetropia group (P<0.05), and 1-mm temporal to the fovea in the mild myopia group (P<0.05). SE correlated positively with RT in the inner temporal (r = 0.230),nasal (r = 0.252) and inferior (r = 0.149) regions (all P<0.05). Age correlated positively with foveolar (r = 0.169), total macular (r = 0.202), inner temporal (r = 0.237), inner nasal (r = 0.248), inner superior (r = 0.378) and inner inferior (r = 0.345) region thicknesses, and with RV (r = 0.207)(all P<0.05). SE correlated positively with SFCT (r = 0.195), and with ChT1-mm temporal (r = 0.167), 1- and 2-mm nasal (r = 0.144 and r = 0.162), 2-mm superior (r = 0.175), and 1- and 2-mm inferior (r = 0.207 and r = 0.238) to the fovea (all P<0.05). Age had no significant association with ChT. Conclusions SE, age and gender did not influence macular RT and ChT in most regions, and correlations of RT with age and ChT with SE were weak. PMID:27391015

  17. Computer-aided assessment of head computed tomography (CT) studies in patients with suspected traumatic brain injury.

    PubMed

    Yuh, Esther L; Gean, Alisa D; Manley, Geoffrey T; Callen, Andrew L; Wintermark, Max

    2008-10-01

    In this study, we sought to determine the accuracy of a computer algorithm that automatically assesses head computed tomography (CT) studies in patients with suspected traumatic brain injury (TBI) for features of intracranial hemorrhage and mass effect, employing a neuroradiologist's interpretation as the gold standard. To this end, we designed a suite of computer algorithms that evaluates in a fully automated fashion the presence of intracranial blood and/or mass effect based on the following CT findings: (1) presence or absence of a subdural or epidural hematoma, (2) presence or absence of subarachnoid hemorrhage, (3) presence or absence of an intraparenchymal hematoma, (4) presence or absence of clinically significant midline shift (>or=5 mm), and (5) normal, partly effaced, or completely effaced basal cisterns. The algorithm displays abnormal findings as color overlays on the original head CT images, and calculates the volume of each type of blood collection, the midline shift, and the volume of the basal cisterns, based on the above-described features. Thresholds and parameters yielding optimal accuracy of the computer algorithm were determined using a development sample of 33 selected, nonconsecutive patients. The software was then applied to a validation sample of 250 consecutive patients evaluated for suspicion of acute TBI at our institution in 2006-2007. Software detection of the presence of at least one noncontrast CT (NCT) feature of acute TBI demonstrated high sensitivity of 98% and high negative predictive value (NPV) of 99%. There was actually only one false negative case, where a very subtle subdural hematoma, extending exclusively along the falx, was diagnosed by the neuroradiologist, while the case was considered as normal by the computer algorithm. The software was excellent at detecting the presence of mass effect and intracranial hemorrhage, but showed some disagreements with the neuroradiologist in quantifying the degree of mass effect and

  18. Development and Assessment of Service Learning Projects in General Biology

    ERIC Educational Resources Information Center

    Felzien, Lisa; Salem, Laura

    2008-01-01

    Service learning involves providing service to the community while requiring students to meet learning goals in a specific course. A service learning project was implemented in a general biology course at Rockhurst University to involve students in promoting scientific education in conjunction with community partner educators. Students were…

  19. The Application of Games Theory to Group Project Assessment.

    ERIC Educational Resources Information Center

    Pitt, M. J.

    2000-01-01

    Application of game theory to small-group project evaluation in higher education instruction finds that the best strategy for students wishing high grades may not be a strategy that promotes teamwork and cooperation. Suggests that putting students into groups may randomly disadvantage some students relative to others, producing serious unfairness…

  20. An Assessment of the Immigrant Resources Project Preschools.

    ERIC Educational Resources Information Center

    Fraser, Susan; Coulthard, Eleanor

    The effectiveness of the "Immigrant Resource Project" preschool program is evaluated. The preschools meet for two hours twice a week while the childrens' parents are in English as second language classes. Pupils range in age from 2 to 6 years and are drawn from a wide variety of immigrant backgrounds. The objectives are to teach English and foster…

  1. Performance assessment of the PNM Prosperity electricity storage project :

    SciTech Connect

    Roberson, Dakota; Ellison, James F.; Bhatnagar, Dhruv; Schoenwald, David A.

    2014-05-01

    The purpose of this study is to characterize the technical performance of the PNM Prosperity electricity storage project, and to identify lessons learned that can be used to improve similar projects in the future. The PNM Prosperity electricity storage project consists of a 500 kW/350 kWh advanced lead-acid battery with integrated supercapacitor (for energy smoothing) and a 250 kW/1 MWh advanced lead-acid battery (for energy shifting), and is co-located with a 500 kW solar photovoltaic (PV) resource. The project received American Reinvestment and Recovery Act (ARRA) funding. The smoothing system is e ective in smoothing intermittent PV output. The shifting system exhibits good round-trip efficiencies, though the AC-to-AC annual average efficiency is lower than one might hope. Given the current utilization of the smoothing system, there is an opportunity to incorporate additional control algorithms in order to increase the value of the energy storage system.

  2. Alternative Assessment: A Monthly Portfolio Project Improves Student Performance.

    ERIC Educational Resources Information Center

    Valdez, Penelope S.

    2001-01-01

    Describes the use of monthly portfolio projects to track student progress and improve science performance in a 7th grade life science course. Students explain concepts they have learned, produce products to present what they have learned, and use the concepts to critique magazine articles, advertisements, or news stories. Provides an evaluation…

  3. Multimedia Projects in Education: Designing, Producing, and Assessing. Second Edition.

    ERIC Educational Resources Information Center

    Ivers, Karen S.; Barron, Ann E.

    This handbook provides educators with strategies and ideas for incorporating multimedia projects into the curriculum for grades 4-12. With a focus on student learning, the authors show how to plan and implement multimedia activities and engage students in expressing themselves through a variety of media. Using the DDD-E model (Decide, Design,…

  4. Multimedia Projects in Education: Designing, Producing, and Assessing, Third Edition

    ERIC Educational Resources Information Center

    Ivers, Karen S.; Barron, Ann E.

    2005-01-01

    Building on the materials in the two previous successful editions, this book features approximately 40% all new material and updates the previous information. The authors use the DDD-E model (Decide, Design, Develop--Evaluate) to show how to select and plan multimedia projects, use presentation and development tools, manage graphics, audio, and…

  5. Sequential Assessment of Engineering Design Projects at University Level

    ERIC Educational Resources Information Center

    Oehlers, Deric John

    2006-01-01

    Seven years of industrial experience followed by 30 years of academic research and teaching in structural engineering have led the author to believe that the prime objective of a university design course is not the design project itself but to train students to solve problems, as this will last them throughout their careers. It is shown how design…

  6. Assessment of Communication Competencies in Engineering Design Projects.

    ERIC Educational Resources Information Center

    Brinkman, Gert W.; van der Geest, Thea M.

    2003-01-01

    Notes that reforms in engineering education have caused a shift from the traditional stand-alone courses in technical communication for engineering students towards communication training integrated in courses and design projects that allows students to develop four levels of competence. Describes three formats for integrated communication…

  7. Report of the Project on Contracting, Review, and Assessment Procedures.

    ERIC Educational Resources Information Center

    Vermont Community Colleges, Montpelier.

    The broad purpose of this project was to examine all aspects of the Community College of Vermont (CCV) review and contracting process and to recommend changes to the CCV Review Board and Decision Team for implementation. Examination focused on the present program, the contract format, Local Review Committee procedures, the counseling process, and…

  8. Project Prevocational: Prevocational Curriculum and Prevocational Assessment Battery.

    ERIC Educational Resources Information Center

    Burell, Lewis P.; Talarico, Robert L.

    Two products are presented from Project PREVOCATIONAL, designed to focus on entry-level skills and performance levels in 30 vocational education programs for mildly and moderately mentally retarded students. The curriculum is based on a philosophy of exploration, practice and attainment and focuses on short term instructional objectives for 31…

  9. Data-Based Performance Assessments for the DOE Hydropower Advancement Project

    SciTech Connect

    March, Patrick; Wolff, Dr. Paul; Smith, Brennan T; Zhang, Qin Fen; Dham, Rajesh

    2012-01-01

    The U. S. Department of Energy s Hydropower Advancement Project (HAP) was initiated to characterize and trend hydropower asset conditions across the U.S.A. s existing hydropower fleet and to identify and evaluate the upgrading opportunities. Although HAP includes both detailed performance assessments and condition assessments of existing hydropower plants, this paper focuses on the performance assessments. Plant performance assessments provide a set of statistics and indices that characterize the historical extent to which each plant has converted the potential energy at a site into electrical energy for the power system. The performance metrics enable benchmarking and trending of performance across many projects in a variety contexts (e.g., river systems, power systems, and water availability). During FY2011 and FY2012, assessments will be performed on ten plants, with an additional fifty plants scheduled for FY2013. This paper focuses on the performance assessments completed to date, details the performance assessment process, and describes results from the performance assessments.

  10. An assessment of adherence to basic ecological principles by payments for ecosystem service projects.

    PubMed

    Prager, C M; Varga, A; Olmsted, P; Ingram, J C; Cattau, M; Freund, C; Wynn-Grant, R; Naeem, S

    2016-08-01

    Programs and projects employing payments for ecosystem service (PES) interventions achieve their objectives by linking buyers and sellers of ecosystem services. Although PES projects are popular conservation and development interventions, little is known about their adherence to basic ecological principles. We conducted a quantitative assessment of the degree to which a global set of PES projects adhered to four ecological principles that are basic scientific considerations for any project focused on ecosystem management: collection of baseline data, identification of threats to an ecosystem service, monitoring, and attention to ecosystem dynamics or the formation of an adaptive management plan. We evaluated 118 PES projects in three markets-biodiversity, carbon, and water-compiled using websites of major conservation organizations; ecology, economic, and climate-change databases; and three scholarly databases (ISI Web of Knowledge, Web of Science, and Google Scholar). To assess adherence to ecological principles, we constructed two scientific indices (one additive [ASI] and one multiplicative [MSI]) based on our four ecological criteria and analyzed index scores by relevant project characteristics (e.g., sector, buyer, seller). Carbon-sector projects had higher ASI values (P < 0.05) than water-sector projects and marginally higher ASI scores (P < 0.1) than biodiversity-sector projects, demonstrating their greater adherence to ecological principles. Projects financed by public-private partnerships had significantly higher ASI values than projects financed by governments (P < 0.05) and marginally higher ASI values than those funded by private entities (P < 0.1). We did not detect differences in adherence to ecological principles based on the inclusion of cobenefits, the spatial extent of a project, or the size of a project's budget. These findings suggest, at this critical phase in the rapid growth of PES projects, that fundamental ecological principles should be

  11. An assessment of adherence to basic ecological principles by payments for ecosystem service projects.

    PubMed

    Prager, C M; Varga, A; Olmsted, P; Ingram, J C; Cattau, M; Freund, C; Wynn-Grant, R; Naeem, S

    2016-08-01

    Programs and projects employing payments for ecosystem service (PES) interventions achieve their objectives by linking buyers and sellers of ecosystem services. Although PES projects are popular conservation and development interventions, little is known about their adherence to basic ecological principles. We conducted a quantitative assessment of the degree to which a global set of PES projects adhered to four ecological principles that are basic scientific considerations for any project focused on ecosystem management: collection of baseline data, identification of threats to an ecosystem service, monitoring, and attention to ecosystem dynamics or the formation of an adaptive management plan. We evaluated 118 PES projects in three markets-biodiversity, carbon, and water-compiled using websites of major conservation organizations; ecology, economic, and climate-change databases; and three scholarly databases (ISI Web of Knowledge, Web of Science, and Google Scholar). To assess adherence to ecological principles, we constructed two scientific indices (one additive [ASI] and one multiplicative [MSI]) based on our four ecological criteria and analyzed index scores by relevant project characteristics (e.g., sector, buyer, seller). Carbon-sector projects had higher ASI values (P < 0.05) than water-sector projects and marginally higher ASI scores (P < 0.1) than biodiversity-sector projects, demonstrating their greater adherence to ecological principles. Projects financed by public-private partnerships had significantly higher ASI values than projects financed by governments (P < 0.05) and marginally higher ASI values than those funded by private entities (P < 0.1). We did not detect differences in adherence to ecological principles based on the inclusion of cobenefits, the spatial extent of a project, or the size of a project's budget. These findings suggest, at this critical phase in the rapid growth of PES projects, that fundamental ecological principles should be

  12. UMTRA project disposal cell cover biointrusion sensitivity assessment, Revision 1

    SciTech Connect

    1995-10-01

    This study provides an analysis of potential changes that may take place in a Uranium Mill Tailings Remedial Action (UMTRA) Project disposal cell cover system as a result of plant biointrusion. Potential changes are evaluated by performing a sensitivity analysis of the relative impact of root penetrations on radon flux out of the cell cover and/or water infiltration into the cell cover. Data used in this analysis consist of existing information on vegetation growth on selected cell cover systems and information available from published studies and/or other available project research. Consistent with the scope of this paper, no new site-specific data were collected from UMTRA Project sites. Further, this paper does not focus on the issue of plant transport of radon gas or other contaminants out of the disposal cell cover though it is acknowledged that such transport has the potential to be a significant pathway for contaminants to reach the environment during portions of the design life of a disposal cell where plant growth occurs. Rather, this study was performed to evaluate the effects of physical penetration and soil drying caused by plant roots that have and are expected to continue to grow in UMTRA Project disposal cell covers. An understanding of the biological and related physical processes that take place within the cover systems of the UMTRA Project disposal cells helps the U.S. Department of Energy (DOE) determine if the presence of a plant community on these cells is detrimental, beneficial, or of mixed value in terms of the cover system`s designed function. Results of this investigation provide information relevant to the formulation of a vegetation control policy.

  13. The Maricopa Integrated Risk Assessment Project: A New Way of Looking at Risk

    ERIC Educational Resources Information Center

    Unks, Ruth A.; Thor, Linda

    2008-01-01

    This article reviews the Maricopa Integrated Risk Assessment (MIRA) project and discusses its challenges and successes. Strategies and resources are offered for assisting community college administrators, faculty, and staff to successfully implement enterprise risk management at their institutions.

  14. Summary results of an assessment of research projects in the Solar Federal Wind Energy Research Program

    NASA Astrophysics Data System (ADS)

    1992-12-01

    The Office of Program Analysis (OPA) undertook an assessment of 26 research projects (listed in Appendix A) sponsored by the Solar Thermal Electric Program. This report summarizes the results of that review.

  15. Social impact evaluation: Some implications of the specific decisional context approach for Anticipatory Project Assessment (ARA)

    NASA Technical Reports Server (NTRS)

    Mayo, L. H.

    1975-01-01

    An anticipatory project assessment is discussed which is characterized as the capacity to perform, and the disposition to take into account in relevant decisional areas, the following operations: identification of the significant effects which will result from the introduction of a specified project configuration into alternative projected future social environments during the planning, implementation, and operational states; evaluation of such effects in terms of social impacts on affected participants and social value-institutional processes in accord with specified concepts of social justice.

  16. Implementation and Outcomes of Online Self and Peer Assessment on Group Based Honours Research Projects

    ERIC Educational Resources Information Center

    Wu, Chengqing; Chanda, Emmanuel; Willison, John

    2014-01-01

    Honours research projects in the School of Civil, Environmental and Mining Engineering at the University of Adelaide are run with small groups of students working with an academic supervisor in a chosen area for one year. The research project is mainly self-directed study, which makes it very difficult to fairly assess the contribution of…

  17. Using Projects Scoring Rubrics to Assess Student Learning in an Information Systems Program

    ERIC Educational Resources Information Center

    Petkov, Doncho; Petkova, Olga; D'Onofrio, Marianne; Jarmoszko, A. T.

    2008-01-01

    This paper is about using projects for assessment of student learning in different courses of an Information Systems (IS) program. An overview of the role of educational projects in student learning is presented. The various aspects of defining standardized rubrics across an IS program are discussed. A methodology for the use of such rubrics in…

  18. Understanding Project-Based Learning in Second Life with a Pedagogy, Training, and Assessment Trio

    ERIC Educational Resources Information Center

    Jarmon, Leslie; Traphagan, Tomoko; Mayrath, Michael

    2008-01-01

    This paper presents an empirical study of how Second Life (SL) was utilized for a highly successful project-based graduate interdisciplinary communication course. Researchers found that an integrated threefold approach emphasizing project-based pedagogy, technical training and support, and assessment/research was effective in cultivating and…

  19. Qualitative assessment of agritourism safety guidelines: a demonstration project.

    PubMed

    Tutor-Marcom, Robin; Greer, Annette; Clay, Maria; Ellis, Tammy; Thompson, Tami; Adam-Samura, Esther Seisay

    2013-01-01

    In 2007, the National Children's Center for Rural and Agricultural Health and Safety (NCCRAHS) published Agritourism Health and Safety Guidelines for Children to provide helpful recommendations for protecting the health and safety of children visiting agritourism farms. Supplement A: Policies and Procedures Guide and Supplement B: Worksite Guide were subsequently published in 2009 and provided agritourism farms with checklists to use in reviewing, planning, and implementing their own health and safety practices. In order to better understand what would be required of a farm wishing to implement the guidelines using Supplements A and B, the North Carolina Agromedicine Institute conducted a single-family farm demonstration project with support from the NCCRAHS. The aims of the project were to (1) determine child health and safety risks associated with an existing agritourism farm; (2) determine the cost of making improvements necessary to reduce risks; and (3) use project findings to motivate other agritourism farms, Cooperative Extension agents, and agritourism insurers to adopt or recommend Agritourism Health and Safety Guidelines for Children for their own farms or farms with which they work. At the conclusion of the study, the target farm was in compliance with an average of 86.9% of items in Supplements A and B. Furthermore, 89% of individuals self-identifying as farmers or farm workers and 100% of Cooperative Extension agents and agritourism insurers attending an end-of-project workshop indicated their intent to adopt or recommend Agritourism Health and Safety Guidelines for Children for their own farms or farms with which they work. PMID:23540301

  20. The Project MACULA Retinal Pigment Epithelium Grading System for Histology and Optical Coherence Tomography in Age-Related Macular Degeneration

    PubMed Central

    Zanzottera, Emma C.; Messinger, Jeffrey D.; Ach, Thomas; Smith, R. Theodore; Freund, K. Bailey; Curcio, Christine A.

    2015-01-01

    Purpose. To seek pathways of retinal pigment epithelium (RPE) fate in age-related macular degeneration via a morphology grading system; provide nomenclature, visualization targets, and metrics for clinical imaging and model systems. Methods. Donor eyes with geographic atrophy (GA) or choroidal neovascularization (CNV) and one GA eye with previous clinical spectral-domain optical coherence tomography (SDOCT) imaging were processed for histology, photodocumented, and annotated at predefined locations. Retinal pigment epithelial cells contained spindle-shaped melanosomes, apposed a basal lamina or basal laminar deposit (BLamD), and exhibited recognizable morphologies. Thicknesses and unbiased estimates of frequencies were obtained. Results. In 13 GA eyes (449 locations), ‘Shedding,’ ‘Sloughed,’ and ‘Dissociated’ morphologies were abundant; 22.2% of atrophic locations had ‘Dissociated’ RPE. In 39 CNV eyes (1363 locations), 37.3% of locations with fibrovascular/fibrocellular scar had ‘Entombed’ RPE; ‘Sloughed,’ ‘Dissociated,’ and ‘Bilaminar’ morphologies were abundant. Of abnormal RPE, CNV and GA both had ∼35% ‘Sloughed’/‘Intraretinal,’ with more Intraretinal in CNV (9.5% vs. 1.8%). ‘Shedding’ cells associated with granule aggregations in BLamD. The RPE layer did not thin, and BLamD remained thick, with progression. Granule-containing material consistent with three morphologies correlated to SDOCT hyperreflective foci in the previously examined GA patient. Conclusions. Retinal pigment epithelium morphology indicates multiple pathways in GA and CNV. Atrophic/scarred areas have numerous cells capable of transcribing genes and generating imaging signals. Shed granule aggregates, possibly apoptotic, are visible in SDOCT, as are ‘Dissociated’ and ‘Sloughed’ cells. The significance of RPE phenotypes is addressable in longitudinal, high-resolution imaging in clinic populations. Data can motivate future molecular phenotyping

  1. A quality improvement project for reducing cardiac computed tomography radiation dose in a community-based, multihospital setting.

    PubMed

    Winchester, David E; Chauffe, Ryan J; Liu, Tong; Badiye, Amit; Patel, Mrugesh; Bello, David

    2013-06-01

    Radiation associated with computed tomography coronary angiography (CTCA) is a persistent concern. Strategies for reducing radiation exposure have been described, primarily in academic settings. We developed a standard protocol for CTCA acquisition focused on radiation reduction strategies in a community-based, multihospital setting and hypothesized that the protocol would be effective at reducing radiation in this setting. The protocol included the use of body mass index based tube voltage adjustment and routine use of prospective electrocardiographic gating with either dose modulation or step-and-shoot acquisition. Data on radiation exposure were collected retrospectively and compared by nonparametric testing. Some hospitals failed to routinely record radiation exposure data; only 2 facilities had data available from both before and after the intervention for direct comparison. Data were acquired from 124 subjects, 41 from the standard of care group and 83 scanned under the new protocol. In hospital A, radiation was significantly reduced by 61% from 20.5 ± 4.6 millisieverts (mSv) to 7.9 ± 4.8 mSv (P < 0.001). Within the new protocol group for hospital A, radiation was lower with step-and-shoot (4.0 ± 1.5 mSv) as compared to dose modulation (10.2 ± 4.2 mSv, P < 0.001). In hospital B, which already employed step-and-shoot acquisition, radiation dose was reduced 16% from 9.3 ± 3.0 mSv to 7.9 ± 2.2 mSv (P < 0.017) by applying body mass index-based tube voltage adjustment alone. In conclusion, a minimal investment in institutional resources can result in a reduction in radiation exposure from CTCA, even in a community-based, multihospital setting. Some facilities do not routinely record radiation exposure data. PMID:23680808

  2. Intelligent Vehicle Charging Benefits Assessment Using EV Project Data

    SciTech Connect

    Letendre, Steven; Gowri, Krishnan; Kintner-Meyer, Michael CW; Pratt, Richard M.

    2013-12-01

    PEVs can represent a significant power resource for the grid. An IVCI with bi-direction V2G capabilities would allow PEVs to provide grid support services and thus generate a source of revenue for PEV owners. The fleet of EV Project vehicles represents a power resource between 30 MW and 90 MW, depending on the power rating of the grid connection (5-15 kW). Aggregation of vehicle capacity would allow PEVs to participate in wholesale reserve capacity markets. One of the key insights from EV Project data is the fact that vehicles are connected to an EVSE much longer than is necessary to deliver a full charge. During these hours when the vehicles are not charging, they can be participating in wholesale power markets providing the high-value services of regulation and spinning reserves. The annual gross revenue potential for providing these services using the fleet of EV Project vehicles is several hundred thousands of dollars to several million dollars annually depending on the power rating of the grid interface, the number of hours providing grid services, and the market being served. On a per vehicle basis, providing grid services can generate several thousands of dollars over the life of the vehicle.

  3. Accelerator Production of Tritium project process waste assessment

    SciTech Connect

    Carson, S.D.; Peterson, P.K.

    1995-09-01

    DOE has made a commitment to compliance with all applicable environmental regulatory requirements. In this respect, it is important to consider and design all tritium supply alternatives so that they can comply with these requirements. The management of waste is an integral part of this activity and it is therefore necessary to estimate the quantities and specific wastes that will be generated by all tritium supply alternatives. A thorough assessment of waste streams includes waste characterization, quantification, and the identification of treatment and disposal options. The waste assessment for APT has been covered in two reports. The first report was a process waste assessment (PWA) that identified and quantified waste streams associated with both target designs and fulfilled the requirements of APT Work Breakdown Structure (WBS) Item 5.5.2.1. This second report is an expanded version of the first that includes all of the data of the first report, plus an assessment of treatment and disposal options for each waste stream identified in the initial report. The latter information was initially planned to be issued as a separate Waste Treatment and Disposal Options Assessment Report (WBS Item 5.5.2.2).

  4. Indications for digital volume tomography in orthodontics.

    PubMed

    Müssig, Eva; Wörtche, René; Lux, Christopher J

    2005-05-01

    Disturbances in tooth eruption and tooth impactions make great demands on radiographic diagnostics. There is often need for radiographic images in various projections to assess the exact position of unerupted and impacted teeth. Digital volume tomography (DVT) is a method for localizing hard tissue structures such as bone and teeth on various planes. Moreover, it makes a three-dimensional image of the teeth, jaws and the viscerocranium possible. From an orthodontic point of view, digital volume tomography is indicated to detect impacted and ectopic teeth and to demonstrate the amount of bone available for orthodontic tooth movement. In patients with cleft lip and palate, DVT can be used to visualize the size of the alveolar cleft and to evaluate the position and development of multiple teeth, as these patients often suffer from disturbances in tooth eruption. PMID:15959637

  5. Financial Information Project: Assessing the Financial Interests of College Students

    ERIC Educational Resources Information Center

    Masuo, Diane M.; Kutara, Pamela; Wall, Ronald; Cheang, Michael

    2007-01-01

    College graduates are entering the world of work with record levels of school-related debt despite being generally unprepared to face the financial challenges of life after college. Findings from a needs assessment survey of financial topics of interest to college students and staff/faculty and preferences for how the information should be…

  6. Project Ethnography: An Anthropological Approach To Assessing Digital Library Services.

    ERIC Educational Resources Information Center

    Seadle, Michael

    2000-01-01

    Suggests that in digital library services assessment, anthropology can provide the initial understanding, the intellectual basis, on which informed choices about sample population, survey design, or focus group selection can reasonably be made. Analyzes the National Gallery of the Spoken Word (NGSW). Includes brief descriptions of nine NGSW…

  7. Principles of Assessment for Project and Research Based Learning

    ERIC Educational Resources Information Center

    Hunaiti, Ziad; Grimaldi, Silvia; Goven, Dharmendra; Mootanah, Rajshree; Martin, Louise

    2010-01-01

    Purpose: The purpose of this paper is to provide assessment guidelines which help to implement research-based education in science and technology areas, which would benefit from the quality of this type of education within this subject area. Design/methodology/approach: This paper is a reflection on, and analysis of, different aspects of…

  8. The Findings of an Assessment Audit: An NTFS Project Report

    ERIC Educational Resources Information Center

    Hughes, Ian

    2006-01-01

    An Assessment Audit is described consisting of 47 questions, each being scored 0 to 4, by the module team depending on the extent to which the audit point was satisfied. Scores of 2 or less indicated unsatisfactory provision. Audits were carried out on 14 bioscience- or medicine-based modules in 13 universities. There was great variability between…

  9. Assessing Learning from a Student Community Engagement Project

    ERIC Educational Resources Information Center

    Jung, Jessica

    2011-01-01

    Purpose: The purpose of this paper is to chart developments in a community engagement scheme run by two Universities in the North East, offering students academic credit in return for work within the local community. The particular focus is on how learning has been assessed from this work experience, within the requirements of higher education…

  10. Health impact assessment of industrial development projects: a spatio-temporal visualization.

    PubMed

    Winkler, Mirko S; Krieger, Gary R; Divall, Mark J; Singer, Burton H; Utzinger, Jürg

    2012-05-01

    Development and implementation of large-scale industrial projects in complex eco-epidemiological settings typically require combined environmental, social and health impact assessments. We present a generic, spatio-temporal health impact assessment (HIA) visualization, which can be readily adapted to specific projects and key stakeholders, including poorly literate communities that might be affected by consequences of a project. We illustrate how the occurrence of a variety of complex events can be utilized for stakeholder communication, awareness creation, interactive learning as well as formulating HIA research and implementation questions. Methodological features are highlighted in the context of an iron ore development in a rural part of Africa.

  11. 4D Electron Tomography

    NASA Astrophysics Data System (ADS)

    Kwon, Oh-Hoon; Zewail, Ahmed H.

    2010-06-01

    Electron tomography provides three-dimensional (3D) imaging of noncrystalline and crystalline equilibrium structures, as well as elemental volume composition, of materials and biological specimens, including those of viruses and cells. We report the development of 4D electron tomography by integrating the fourth dimension (time resolution) with the 3D spatial resolution obtained from a complete tilt series of 2D projections of an object. The different time frames of tomograms constitute a movie of the object in motion, thus enabling studies of nonequilibrium structures and transient processes. The method was demonstrated using carbon nanotubes of a bracelet-like ring structure for which 4D tomograms display different modes of motion, such as breathing and wiggling, with resonance frequencies up to 30 megahertz. Applications can now make use of the full space-time range with the nanometer-femtosecond resolution of ultrafast electron tomography.

  12. Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography

    PubMed Central

    Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

    2015-01-01

    Background Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Material/Methods Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. Results ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Conclusions Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal. PMID:26092929

  13. Wildlife Impact Assessment Palisades Project, Idaho, Final Report.

    SciTech Connect

    Sather-Blair, Signe

    1985-02-01

    The Habitat Evaluation Procedures were used to evaluate pre- and post-construction habitat conditions of the US Bureau of Reclamation's Palisades Project in eastern Idaho. Eight evaluation species were selected with losses expressed in the number of Habitat Units (HU's). One HU is equivalent to one acre of prime habitat. The evaluation estimated that a loss of 2454 HU's of mule deer habitat, 2276 HU's of mink habitat, 2622 HU's of mallard habitat, 805 HU's of Canada goose habitat, 2331 HU's of ruffed grouse habitat, 5941 and 18,565 HU's for breeding and wintering bald eagles, and 1336 and 704 HU's for forested and scrub-shrub wetland nongame species occurred as a result of the project. The study area currently has 29 active osprey nests located around the reservoir and the mudflats probably provide more feeding habitat for migratory shore birds and waterfowl than was previously available along the river. A comparison of flow conditions on the South Fork of the Snake River below the dam between pre- and post-construction periods also could not substantiate claims that water releases from the dam were causing more Canada goose nest losses than flow in the river prior to construction. 41 refs., 16 figs., 9 tabs.

  14. Mid-Columbia Coho Salmon Reintroduction Feasibility Project : Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration; Washington Department of Fish and Wildlife; Confederated Tribes and Bands of the Yakama Nation

    1999-01-01

    Before the Bonneville Power Administration (BPA) decides whether to fund a program to reintroduce coho salmon to mid-Columbia River basin tributaries, research is needed to determine the ecological risks and biological feasibility of such an effort. Since the early 1900s, the native stock of coho has been decimated in the tributaries of the middle reach of the Columbia River. The four Columbia River Treaty Tribes identified coho reintroduction in the mid-Columbia as a priority in the Tribal Restoration Plan. It is a comprehensive plan put forward by the Tribes to restore the Columbia River fisheries. In 1996, the Northwest Power Planning Council (NPPC) recommended the tribal mid-Columbia reintroduction project for funding by BPA. It was identified as one of fifteen high-priority supplementation projects for the Columbia River basin, and was incorporated into the NPPC`s Fish and Wildlife Program. The release of coho from lower Columbia hatcheries into mid-Columbia tributaries is also recognized in the Columbia River Fish Management Plan.

  15. 75 FR 44805 - Central Utah Project Completion Act; Notice of Availability, Draft Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-29

    ... Central Utah Project Completion Act; Notice of Availability, Draft Environmental Assessment (Draft EA); Realignment of a Portion of the Utah Lake Drainage Basin Water Delivery System AGENCY: Office of the Assistant Secretary--Water and Science, Interior ACTION: Notice of Availability, Draft Environmental Assessment...

  16. The ILSI-HESI Project on Animal Alternative Needs in Environmental Risk Assessment

    EPA Science Inventory

    The ILSI Health and Environmental Sciences Institute (HESI) established a project in 2009 on Animal Alternatives in Environmental Risk Assessment (AA-ERA) following a successful two-year emerging issues assessment of the topic. The early stages of this work included the execution...

  17. 43 CFR 413.4 - Assessment of other project act lands and rights of way.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Assessment of other project act lands and rights of way. 413.4 Section 413.4 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR ASSESSMENT BY IRRIGATION DISTRICTS OF LANDS OWNED BY THE UNITED...

  18. Peer Assessment in Group Projects Accounting for Assessor Reliability by an Iterative Method

    ERIC Educational Resources Information Center

    Ko, Sung-Seok

    2014-01-01

    This study proposes an advanced method to factor in the contributions of individual group members engaged in an integrated group project using peer assessment procedures. Conway et al. proposed the Individual Weight Factor (IWF) method for peer assessment which has been extensively developed over the years. However, most methods associated with…

  19. Assessing the Status of Women Students and Employees in Vocational Education in California. Project PASSEVE.

    ERIC Educational Resources Information Center

    Graesser, Cheryl C.; Rose, Clare

    The Project to Assess the Status of Women Students and Employees in Vocational Education assessed number and distribution of women students and employees in vocational programs, their perceptions of equal access, and extent of efforts to address sex equity. Its main activity was a survey of 3,609 vocational students, 455 faculty, 126 counselors,…

  20. Constructivism and the projective assessment of meaning in Rorschach administration.

    PubMed

    Raskin, J D

    2001-08-01

    Constructivist perspectives on the Rorschach are outlined. I discuss ways in which constructivism complements and adds to existing Rorschach methodologies. It is suggested hat the constructivist emphasis on personally and socially constructed meanings is very consistent with many of the ways the Rorschach has been used and resonates with recent emphases on the Rorschach as a representational task. Furthermore, constructivist perspectives on Rorschach also provide an opportunity to supplement Exner's (1993, 1995) efforts to standardize and norm the Rorschach in a way that maintains the instrument's historic and admirable attention to relational elements of assessment and psychotherapy. I present a variety of meaning-based techniques for conducting Rorschach assessment, incorporating both the constructivist and social constructionist perspective.