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Sample records for computed tomography-based treatment

  1. Conventional four field radiotherapy versus computed tomography-based treatment planning in cancer cervix: A dosimetric study

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    Abhishek Gulia

    2013-01-01

    Full Text Available Background: With advancements in imaging, wide variations in pelvic anatomy have been observed, thus raising doubts about adequate target volume coverage by conventional external radiotherapy fields based on bony landmarks. The present study evaluates the need for integrating computed tomography (CT-based planning in the treatment of carcinoma cervix. Aims: To estimate inadequacies in target volume coverage when using conventional planning based on bony landmarks. Materials and Methods: The study consisted of 50 patients. Target volume delineation was done on planning CT scans, according to the guidelines given in literature. The volume of target receiving 95% of prescribed dose (V95 was calculated after superimposing a conventional four field box on digitally reconstructed radiograph. The geographic miss with conventional four field box technique was compared with the CT-based target volume delineation. Results: In 48 out of 50 patients, the conventional four field box failed to encompass the target volume. The areas of miss were at the superior and lateral borders of the anterior-posterior fields, and the anterior border of the lateral fields. The median V95 for conventional fields marked with bony landmarks was only 89.4% as compared to 93% for target delineation based on CT contouring. Conclusions: Our study shows inadequate target volume coverage with conventional four field box technique. We recommend routine use of CT-based planning for treatment with radiotherapy in carcinoma cervix.

  2. Is scoring system of computed tomography based metric parameters can accurately predicts shock wave lithotripsy stone-free rates and aid in the development of treatment strategies?

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    Yasser ALI Badran

    2016-01-01

    Conclusion: Stone size, stone density (HU, and SSD is simple to calculate and can be reported by radiologists to applying combined score help to augment predictive power of SWL, reduce cost, and improving of treatment strategies.

  3. Computed tomography-based subclassification of chronic obstructive pulmonary disease

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    Dirksen, Asger; Wille, Mathilde M W

    2016-01-01

    Computed tomography (CT) is an obvious modality for subclassification of COPD. Traditionally, the pulmonary involvement of chronic obstructive pulmonary disease (COPD) in smokers is understood as a combination of deleterious effects of smoking on small airways (chronic bronchitis and small airways...... observed in COPD are subtle. Furthermore, recent results indicate that emphysema may also be the essential pathophysiologic mechanism behind the airflow limitation of COPD. The definition of COPD excludes bronchiectasis as a symptomatic subtype of COPD, and CT findings in chronic bronchitis...

  4. Computed tomography-based biomarker provides unique signature for diagnosis of COPD phenotypes and disease progression.

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    Galbán, Craig J; Han, Meilan K; Boes, Jennifer L; Chughtai, Komal A; Meyer, Charles R; Johnson, Timothy D; Galbán, Stefanie; Rehemtulla, Alnawaz; Kazerooni, Ella A; Martinez, Fernando J; Ross, Brian D

    2012-11-01

    Chronic obstructive pulmonary disease (COPD) is increasingly being recognized as a highly heterogeneous disorder, composed of varying pathobiology. Accurate detection of COPD subtypes by image biomarkers is urgently needed to enable individualized treatment, thus improving patient outcome. We adapted the parametric response map (PRM), a voxel-wise image analysis technique, for assessing COPD phenotype. We analyzed whole-lung computed tomography (CT) scans acquired at inspiration and expiration of 194 individuals with COPD from the COPDGene study. PRM identified the extent of functional small airways disease (fSAD) and emphysema as well as provided CT-based evidence that supports the concept that fSAD precedes emphysema with increasing COPD severity. PRM is a versatile imaging biomarker capable of diagnosing disease extent and phenotype while providing detailed spatial information of disease distribution and location. PRM's ability to differentiate between specific COPD phenotypes will allow for more accurate diagnosis of individual patients, complementing standard clinical techniques.

  5. Small field dose delivery evaluations using cone beam optical computed tomography-based polymer gel dosimetry

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    Timothy Olding

    2011-01-01

    Full Text Available This paper explores the combination of cone beam optical computed tomography with an N-isopropylacrylamide (NIPAM-based polymer gel dosimeter for three-dimensional dose imaging of small field deliveries. Initial investigations indicate that cone beam optical imaging of polymer gels is complicated by scattered stray light perturbation. This can lead to significant dosimetry failures in comparison to dose readout by magnetic resonance imaging (MRI. For example, only 60% of the voxels from an optical CT dose readout of a 1 l dosimeter passed a two-dimensional Low′s gamma test (at a 3%, 3 mm criteria, relative to a treatment plan for a well-characterized pencil beam delivery. When the same dosimeter was probed by MRI, a 93% pass rate was observed. The optical dose measurement was improved after modifications to the dosimeter preparation, matching its performance with the imaging capabilities of the scanner. With the new dosimeter preparation, 99.7% of the optical CT voxels passed a Low′s gamma test at the 3%, 3 mm criteria and 92.7% at a 2%, 2 mm criteria. The fitted interjar dose responses of a small sample set of modified dosimeters prepared (a from the same gel batch and (b from different gel batches prepared on the same day were found to be in agreement to within 3.6% and 3.8%, respectively, over the full dose range. Without drawing any statistical conclusions, this experiment gives a preliminary indication that intrabatch or interbatch NIPAM dosimeters prepared on the same day should be suitable for dose sensitivity calibration.

  6. Computed tomography-based distribution of involved lymph nodes in patients with upper esophageal cancer.

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    Li, M; Liu, Y; Xu, L; Huang, Y; Li, W; Yu, J; Kong, L

    2015-06-01

    Delineating the nodal clinical target volume (ctvn) remains a challenging task in patients with cervical or upper thoracic esophageal carcinoma (ec). In particular, the extent of the lymph area that should be included in the irradiation field remains controversial. In the present study, the extent of the ctvn was determined based on the incidence of lymph node involvement mapped by computed tomography (ct) imaging. Our study included 468 patients who were diagnosed with cervical and upper thoracic ec and who received staging information between June 2005 and April 2011. The anatomic distribution of metastatic regional lymph nodes was mapped using ct images and grouped using the levels established by the Radiation Therapy Oncology Group. The probability of the various groups being involved was examined. If a lymph node group had a probability of 10% or more of being involved, it was considered at high risk for metastasis, and elective treatment as part of the ctvn was recommended. Lymph node involvement was mapped by ct in 256 patients (54.7%). Not all lymph node groups should be included in the ctvn. For cervical lesions, the involved lymph nodes were located mainly between the hyoid bone and the arcus aortae; the recommended ctvn should consist of the neck lymph nodes at levels iii and iv (supraclavicular group) and thoracic groups 2 and 3P. In upper thoracic ec patients, most of the involved lymph nodes were distributed between the cricoid cartilage and the subcarinal area; the ctvn should cover the supraclavicular group and thoracic nodal groups 2, 3P, 4, 5, and 7. Our ct-based study indicates a specific distribution and incidence of metastatic lymph node groups in patients with cervical and upper thoracic ec. The results suggest that regional lymph node groups should be electively included in the ctvn for precise radiation administration.

  7. Feasibility of computed tomography based thermometry during interstitial laser heating in bovine liver

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    Pandeya, G. D.; Klaessens, J. H. G. M.; Greuter, M. J. W.; Schmidt, B.; Flohr, T.; van Hillegersberg, R.; Oudkerk, M.

    2011-01-01

    To assess the feasibility of computed tomography (CT) based thermometry during interstitial laser heating in the bovine liver. Four freshly exercised cylindrical blocks of bovine tissue were heated using a continuous laser of Nd:YAG (wavelength: 1064 nm, active length: 30 mm, power: 10-30 W). All ti

  8. CdZnTe detector for computed tomography based on weighting potential

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    Lim, Hyun Jong; Park, Chan Sun; Kim, Jung Su; Kim, Jung Min; Choi, Jong Hak; Kim, Ki Hyun [Korea University, Seoul (Korea, Republic of)

    2016-03-15

    Room-temperature operating CdZnTe(CZT) material is an innovative radiation detector which could reduce the patient dose to one-tenth level of conventional CT (Computed Tomography) and mammography system. The pixel and pixel pitch in the imaging device determine the conversion efficiency of incident Xor gamma-ray and the cross-talk of signal, that is, image quality of detector system. The weighting potential is the virtual potential determined by the position and geometry of electrode. The weighting potential obtained by computer-based simulation in solving Poisson equation with proper boundaries condition. The pixel was optimized by considering the CIE (charge induced efficiency) and the signal cross-talk in CT detector system. The pixel pitch was 1-mm and the detector thickness was 2-mm in the simulation. The optimized pixel size and inter-pixel distance for maximizing the CIE and minimizing the signal cross-talk is about 750 μm and 125 μm, respectively.

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

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    Ahad Zeinali

    2007-12-01

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

  10. Cone Beam X-ray Luminescence Computed Tomography Based on Bayesian Method.

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    Zhang, Guanglei; Liu, Fei; Liu, Jie; Luo, Jianwen; Xie, Yaoqin; Bai, Jing; Xing, Lei

    2017-01-01

    X-ray luminescence computed tomography (XLCT), which aims to achieve molecular and functional imaging by X-rays, has recently been proposed as a new imaging modality. Combining the principles of X-ray excitation of luminescence-based probes and optical signal detection, XLCT naturally fuses functional and anatomical images and provides complementary information for a wide range of applications in biomedical research. In order to improve the data acquisition efficiency of previously developed narrow-beam XLCT, a cone beam XLCT (CB-XLCT) mode is adopted here to take advantage of the useful geometric features of cone beam excitation. Practically, a major hurdle in using cone beam X-ray for XLCT is that the inverse problem here is seriously ill-conditioned, hindering us to achieve good image quality. In this paper, we propose a novel Bayesian method to tackle the bottleneck in CB-XLCT reconstruction. The method utilizes a local regularization strategy based on Gaussian Markov random field to mitigate the ill-conditioness of CB-XLCT. An alternating optimization scheme is then used to automatically calculate all the unknown hyperparameters while an iterative coordinate descent algorithm is adopted to reconstruct the image with a voxel-based closed-form solution. Results of numerical simulations and mouse experiments show that the self-adaptive Bayesian method significantly improves the CB-XLCT image quality as compared with conventional methods.

  11. Chest computed tomography-based scoring of thoracic sarcoidosis: Inter-rater reliability of CT abnormalities

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    Heuvel, D.A.V. den; Es, H.W. van; Heesewijk, J.P. van; Spee, M. [St. Antonius Hospital Nieuwegein, Department of Radiology, Nieuwegein (Netherlands); Jong, P.A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Zanen, P.; Grutters, J.C. [University Medical Center Utrecht, Division Heart and Lungs, Utrecht (Netherlands); St. Antonius Hospital Nieuwegein, Center of Interstitial Lung Diseases, Department of Pulmonology, Nieuwegein (Netherlands)

    2015-09-15

    To determine inter-rater reliability of sarcoidosis-related computed tomography (CT) findings that can be used for scoring of thoracic sarcoidosis. CT images of 51 patients with sarcoidosis were scored by five chest radiologists for various abnormal CT findings (22 in total) encountered in thoracic sarcoidosis. Using intra-class correlation coefficient (ICC) analysis, inter-rater reliability was analysed and reported according to the Guidelines for Reporting Reliability and Agreement Studies (GRRAS) criteria. A pre-specified sub-analysis was performed to investigate the effect of training. Scoring was trained in a distinct set of 15 scans in which all abnormal CT findings were represented. Median age of the 51 patients (36 men, 70 %) was 43 years (range 26 - 64 years). All radiographic stages were present in this group. ICC ranged from 0.91 for honeycombing to 0.11 for nodular margin (sharp versus ill-defined). The ICC was above 0.60 in 13 of the 22 abnormal findings. Sub-analysis for the best-trained observers demonstrated an ICC improvement for all abnormal findings and values above 0.60 for 16 of the 22 abnormalities. In our cohort, reliability between raters was acceptable for 16 thoracic sarcoidosis-related abnormal CT findings. (orig.)

  12. Use of a Computed Tomography Based Approach to Validate Noninvasive Devices to Measure Rotational Knee Laxity.

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    Neumann, Simon; Maas, Stefan; Waldmann, Danièle; Ricci, Pierre-Louis; Zürbes, Arno; Arnoux, Pierre-Jean; Walter, Frédéric; Kelm, Jens

    2015-01-01

    The purpose of this study is to validate a noninvasive rotational knee laxity measuring device called "Rotameter P2" with an approach based on Computed Tomography (CT). This CT-approach using X-rays is hence invasive and can be regarded as a precise reference method that may also be applied to similar devices. An error due to imperfect femur fixation was observed but can be neglected for small torques. The most significant estimation error is due to the unavoidable soft tissues rotation and hence flexibility in the measurement chain. The error increases with the applied torque. The assessment showed that the rotational knee angle measured with the Rotameter is still overestimated because of thigh and femur displacement, soft tissues deformation, and measurement artefacts adding up to a maximum of 285% error at +15 Nm for the Internal Rotation of female volunteers. This may be questioned if such noninvasive devices for measuring the Tibia-Femoral Rotation (TFR) can help diagnosing knee pathologies and investigate ligament reconstructive surgery.

  13. Application of a computed tomography based cystic fibrosis scoring system to chest tomosynthesis

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    Söderman, Christina; Johnsson, Åse; Vikgren, Jenny; Rystedt, Hans; Ivarsson, Jonas; Rossi Norrlund, Rauni; Nyberg Andersson, Lena; Bâth, Magnus

    2013-03-01

    In the monitoring of progression of lung disease in patients with cystic fibrosis (CF), recurrent computed tomography (CT) examinations are often used. The relatively new imaging technique chest tomosynthesis (CTS) may be an interesting alternative in the follow-up of these patients due to its visualization of the chest in slices at radiation doses and costs significantly lower than is the case with CT. A first step towards introducing CTS imaging in the diagnostics of CF patients is to establish a scoring system appropriate for evaluating the severity of CF pulmonary disease based on findings in CTS images. Previously, several such CF scoring systems based on CT imaging have been published. The purpose of the present study was to develop a CF scoring system for CTS, by starting from an existing scoring system dedicated for CT images and making modifications regarded necessary to make it appropriate for use with CTS images. In order to determine any necessary changes, three thoracic radiologists independently used a scoring system dedicated for CT on both CT and CTS images from CF patients. The results of the scoring were jointly evaluated by all the observers, which lead to suggestions for changes to the scoring system. Suggested modifications include excluding the scoring of air trapping and doing the scoring of the findings in quadrants of the image instead of in each lung lobe.

  14. A New Computed Tomography-Based Radiographic Method to Detect Early Loosening of Total Wrist Implants

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    Olivecrona, H.; Noz, M.E.; Maguire, G.Q. Jr; Zeleznik, M.P.; Sollerman, C.; Olivecrona, L. [Dept. of Hand Surgery, Soedersjukhuset, Stockholm (Sweden)

    2007-11-15

    Background: Diagnosis of loosening of total wrist implants is usually late using routine radiographs. Switching modality to computed tomography (CT) should aid in early diagnosis. Purpose: To propose and evaluate the accuracy of a new CT method for assessing loosening of the carpal component in total wrist arthroplasty. Material and Methods: A protocol encompassing volume registration of paired CT scans of patients with unexplained pain in a prosthetically replaced wrist (used in clinical routine) is presented. Scans are acquired as a dynamic examination under torsional load. Using volume registration, the carpal component of the prosthesis is brought into spatial alignment. After registration, prosthetic loosening is diagnosed by a shift in position of the bones relative to the prosthesis. This study is a preclinical validation of this method using a human cadaverous arm with a cemented total wrist implant and tantalum markers. Seven CT scans of the arm were acquired. The scans were combined into 21 pairs of CT volumes. The carpal component was registered in each scan pair, and the residual mismatch of the surrounding tantalum markers and bone was analyzed both visually and numerically. Results: The detection limit for prosthetic movement was less than 1 mm. Conclusion: The results of this study demonstrate that CT volume registration holds promise to improve detection of movement of the carpal component at an earlier stage than is obtainable with plain radiography.

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

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

    2017-09-01

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

  16. Studying primate carpal kinematics in three dimensions using a computed-tomography-based markerless registration method.

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    Orr, Caley M; Leventhal, Evan L; Chivers, Spencer F; Marzke, Mary W; Wolfe, Scott W; Crisco, Joseph J

    2010-04-01

    The functional morphology of the wrist pertains to a number of important questions in primate evolutionary biology, including that of hominins. Reconstructing locomotor and manipulative capabilities of the wrist in extinct species requires a detailed understanding of wrist biomechanics in extant primates and the relationship between carpal form and function. The kinematics of carpal movement, and the role individual joints play in providing mobility and stability of the wrist, is central to such efforts. However, there have been few detailed biomechanical studies of the nonhuman primate wrist. This is largely because of the complexity of wrist morphology and the considerable technical challenges involved in tracking the movements of the many small bones that compose the carpus. The purpose of this article is to introduce and outline a method adapted from human clinical studies of three-dimensional (3D) carpal kinematics for use in a comparative context. The method employs computed tomography of primate cadaver forelimbs in increments throughout the wrist's range of motion, coupled with markerless registration of 3D polygon models based on inertial properties of each bone. The 3D kinematic principles involved in extracting motion axis parameters that describe bone movement are reviewed. In addition, a set of anatomically based coordinate systems embedded in the radius, capitate, hamate, lunate, and scaphoid is presented for the benefit of other primate functional morphologists interested in studying carpal kinematics. Finally, a brief demonstration of how the application of these methods can elucidate the mechanics of the wrist in primates illustrates the closer-packing of carpals in chimpanzees than in orangutans, which may help to stabilize the midcarpus and produce a more rigid wrist beneficial for efficient hand posturing during knuckle-walking locomotion.

  17. Combining Computed Tomography-Based Bone Density Assessment with FRAX Screening in Men with Prostate Cancer.

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    McDonald, Andrew M; Jones, Joseph A; Cardan, Rex A; Saag, Kenneth S; Mayhew, David L; Fiveash, John B

    2016-10-01

    To investigate the addition of a computed tomography (CT)-based method of osteoporosis screening to FRAX without bone mineral density (BMD) fracture risk assessment in men undergoing radiotherapy for prostate cancer, we reviewed the records of all patients with localized prostate cancer treated with external beam radiotherapy at our institution between 2001 and 2012. The 10-yr probability of hip fracture was calculated using the FRAX algorithm without BMD. The CT attenuation of the L5 trabecular bone (L5CT) was assessed by contouring the trabecular bone on a single CT slice at the level of the midvertebral body and by averaging the Hounsfield units (HU) of all included voxels. L5CT values of 105 and 130 HU were used as screening thresholds. The clinical characteristics of additional patients identified by each L5CT screening threshold value were compared to patients whose estimated 10-yr risk of hip fracture was 3% or greater by FRAX without BMD. A total of 609 patients treated between 2001 and 2012 had CT scans available for review and complete clinical information allowing for FRAX without BMD risk calculation. Seventy-four (12.2%) patients had an estimated 10-yr risk of hip fracture of 3% or greater. An additional 22 (3.6%) and 71 (11.6%) patients were identified by CT screening when thresholds L5CT = 105 HU and L5CT = 130 HU were used, respectively. Compared to the group of patients identified by FRAX without BMD, the additional patients identified by CT screening at each L5CT threshold level tended to be younger and heavier, and were more likely to be African-American or treated without androgen deprivation therapy. These results suggest that the addition of CT-based screening to FRAX without BMD risk assessment identifies additional men with different underlying clinical characteristics who may be at risk for osteoporosis and may benefit from pharmacological therapy to increase BMD and reduce fracture risk.

  18. Dynamic computed tomography based on spatio-temporal analysis in acute stroke: Preliminary study

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    Park, Ha Young; Pyeon, Do Yeong; Kim, Da Hye; Jung, Young Jin [Dongseo University, Busan (Korea, Republic of)

    2016-12-15

    Acute stroke is a one of common disease that require fast diagnosis and treatment to save patients life. however, the acute stroke may cause lifelong disability due to brain damage with no prompt surgical procedure. In order to diagnose the Stroke, brain perfusion CT examination and possible rapid implementation of 3D angiography has been widely used. However, a low-dose technique should be applied for the examination since a lot of radiation exposure to the patient may cause secondary damage for the patients. Therefore, the degradation of the measured CT images may interferes with a clinical check in that blood vessel shapes o n the CT image are significantly affected by gaussian noise. In this study, we employed the spatio-temporal technique to analyze dynamic (brain perfusion) CT data to improve an image quality for successful clinical diagnosis. As a results, proposed technique could remove gaussian noise successfully, demonstrated a possibility of new image segmentation technique for CT angiography. Qualitative evaluation was conducted by skilled radiological technologists, indicated significant quality improvement of dynamic CT images. the proposed technique will be useful tools as a clinical application for brain perfusion CT examination.

  19. Proton radiography and proton computed tomography based on time-resolved dose measurements

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    Testa, Mauro; Verburg, Joost M.; Rose, Mark; Min, Chul Hee; Tang, Shikui; Hassane Bentefour, El; Paganetti, Harald; Lu, Hsiao-Ming

    2013-11-01

    We present a proof of principle study of proton radiography and proton computed tomography (pCT) based on time-resolved dose measurements. We used a prototype, two-dimensional, diode-array detector capable of fast dose rate measurements, to acquire proton radiographic images expressed directly in water equivalent path length (WEPL). The technique is based on the time dependence of the dose distribution delivered by a proton beam traversing a range modulator wheel in passive scattering proton therapy systems. The dose rate produced in the medium by such a system is periodic and has a unique pattern in time at each point along the beam path and thus encodes the WEPL. By measuring the time dose pattern at the point of interest, the WEPL to this point can be decoded. If one measures the time-dose patterns at points on a plane behind the patient for a beam with sufficient energy to penetrate the patient, the obtained 2D distribution of the WEPL forms an image. The technique requires only a 2D dosimeter array and it uses only the clinical beam for a fraction of second with negligible dose to patient. We first evaluated the accuracy of the technique in determining the WEPL for static phantoms aiming at beam range verification of the brain fields of medulloblastoma patients. Accurate beam ranges for these fields can significantly reduce the dose to the cranial skin of the patient and thus the risk of permanent alopecia. Second, we investigated the potential features of the technique for real-time imaging of a moving phantom. Real-time tumor tracking by proton radiography could provide more accurate validations of tumor motion models due to the more sensitive dependence of proton beam on tissue density compared to x-rays. Our radiographic technique is rapid (˜100 ms) and simultaneous over the whole field, it can image mobile tumors without the problem of interplay effect inherently challenging for methods based on pencil beams. Third, we present the reconstructed p

  20. Are we ready for positron emission tomography/computed tomography-based target volume definition in lymphoma radiation therapy?

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    Yeoh, Kheng-Wei; Mikhaeel, N George

    2013-01-01

    Fluorine-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) has become indispensable for the clinical management of lymphomas. With consistent evidence that it is more accurate than anatomic imaging in the staging and response assessment of many lymphoma subtypes, its utility continues to increase. There have therefore been efforts to incorporate PET/CT data into radiation therapy decision making and in the planning process. Further, there have also been studies investigating target volume definition for radiation therapy using PET/CT data. This article will critically review the literature and ongoing studies on the above topics, examining the value and methods of adding PET/CT data to the radiation therapy treatment algorithm. We will also discuss the various challenges and the areas where more evidence is required.

  1. Clinical impact of computed tomography-based image-guided brachytherapy for cervix cancer using the tandem-ring applicator - the Addenbrooke's experience.

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    Tan, L T; Coles, C E; Hart, C; Tait, E

    2009-04-01

    We report our initial 3-year experience of chemoradiotherapy for cervical cancer with computed tomography-based image-guided high dose rate (HDR) brachytherapy using the tandem-ring applicator. Twenty-eight patients were treated between February 2005 and December 2007. All patients received initial external beam radiotherapy (EBRT) followed by HDR brachytherapy (planned dose 21 Gy to point A in three fractions over 8 days). For each insertion, a computed tomography scan was obtained with the brachytherapy applicator in situ. The cervix, uterus and organs at risk (OAR) were contoured on the computed tomography images to create an individualised dosimetry plan. The D(90) (the dose delivered to 90% of the tumour target), V(100) (the percentage of tumour target volume receiving 100% of the prescribed dose) and the minimum dose in the most exposed 2 cm(3) volume (D(2 cc)) of rectum, bladder and bowel were recorded. The equivalent dose in 2 Gy fractions delivered by EBRT and brachytherapy was calculated. The 3-year cancer-specific survival was 81%, with a pelvic control rate of 96%. In 24 patients, a D(90)>or=74 Gy (alpha/beta10) was achieved. The only patient with local recurrence had a D(90) of 63.8 Gy(alpha/beta10). The overall actuarial risk of serious late morbidity was 14%. Seventeen patients had satisfactory OAR doses using the standard loading pattern. Seven patients had modifications to reduce the risk of toxicity, whereas two had modifications to improve the tumour dose. Comparison with a previous cohort of patients treated with chemoradiotherapy and a conventionally planned low dose rate triple source brachytherapy technique showed an improvement in local pelvic control of 20% (P=0.04). The implementation of a computed tomography-based tandem-ring HDR brachytherapy technique in conjunction with individual dose adaptation has resulted in a significant improvement in local control at Addenbrooke's without increasing the risk of serious toxicity, and with little

  2. Increased incidence of adrenal gland injury in blunt abdominal trauma: a computed tomography-based study from Pakistan

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    Aziz Muhammad Usman

    2014-02-01

    Full Text Available 【Abstract】Objective: To determine the frequency of adrenal injuries in patients presenting with blunt abdominal trauma by computed tomography (CT. Methods: During a 6 month period from January 1, 2011 to June 30, 2011, 82 emergency CT examinations were performed in the setting of major abdominal trauma and retrospectively reviewed for adrenal gland injuries. Results: A total of 7 patients were identified as having adrenal gland injuries (6 males and 1 female. Two patients had isolated adrenal gland injuries. In the other 5 patients with nonisolated injuries, injuries to the liver (1 case, spleen (1 case, retroperitoneum (2 cases and mesentery (4 cases were identified. Overall 24 cases with liver injuries (29 %, 11 cases with splenic injuries (13%, 54 cases with mesenteric injuries (65%, 14 cases (17% with retroperitoneal injuries and 9 cases with renal injuries were identified. Conclusion: Adrenal gland injury is identified in 7 patients (11.7% out of a total of 82 patients who underwent CT after major abdominal trauma. Most of these cases were nonisolated injuries. Our experience indicates that adrenal injury resulting from trauma is more common than suggested by other reports. The rise in incidence of adrenal injuries could be attributed to the mode of injury.

  3. Spiral Computed Tomography Based Maxillary Sinus Imaging in Relation to Tooth Loss, Implant Placement and Potential Grafting Procedure

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    Reinhilde Jacobs

    2010-01-01

    Full Text Available Objectives: The purpose of the present study was to explore the maxillary sinus anatomy, its variations and volume in patients with a need for maxillary implant placement.Materials and Methods: Maxillary sinus data of 101 consecutive patients who underwent spiral computed tomography (CT scans for preoperative implant planning in the maxilla at the Department of Periodontology, University Hospital, Catholic University of Leuven, Leuven, Belgium were retrospectively evaluated. The alveolar bone height was measured on serial cross-sectional images between alveolar crest and sinus floor, parallel to the tooth axis. In order to describe the size of the maxillary sinus anteroposterior (AP and mediolateral (ML diameters of the sinus were measured.Results: The results indicated that the alveolar bone height was significantly higher in the premolar regions in comparison to the molar region (n = 46, P 4 mm mucosal thickening mostly at the level of the sinus floor. The present sample did not allow revealing any significant difference (P > 0.05 in maxillary sinus dimensions for partially dentate and edentulous subjects.Conclusions: Cross-sectional imaging can be used in order to obtain more accurate information on the morphology, variation, and the amount of maxillary bone adjacent to the maxillary sinus.

  4. Spiral computed tomography based maxillary sinus imaging in relation to tooth loss, implant placement and potential grafting procedure.

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    Shahbazian, Maryam; Xue, Dong; Hu, Yuqian; van Cleynenbreugel, Johan; Jacobs, Reinhilde

    2010-01-01

    The purpose of the present study was to explore the maxillary sinus anatomy, its variations and volume in patients with a need for maxillary implant placement. Maxillary sinus data of 101 consecutive patients who underwent spiral computed tomography (CT) scans for preoperative implant planning in the maxilla at the Department of Periodontology, University Hospital, Catholic University of Leuven, Leuven, Belgium were retrospectively evaluated. The alveolar bone height was measured on serial cross-sectional images between alveolar crest and sinus floor, parallel to the tooth axis. In order to describe the size of the maxillary sinus anteroposterior (AP) and mediolateral (ML) diameters of the sinus were measured. The results indicated that the alveolar bone height was significantly higher in the premolar regions in comparison to the molar region (n = 46, P maxillary sinuses were mostly located in the first premolar (49%) and second molar (84%) regions, respectively. Maxillary sinus septa were indentified in 47% of the maxillary antra. Almost 2/3 (66%) of the patients showed major (> 4 mm) mucosal thickening mostly at the level of the sinus floor. The present sample did not allow revealing any significant difference (P > 0.05) in maxillary sinus dimensions for partially dentate and edentulous subjects. Cross-sectional imaging can be used in order to obtain more accurate information on the morphology, variation, and the amount of maxillary bone adjacent to the maxillary sinus.

  5. Single-energy computed tomography-based pulmonary perfusion imaging: Proof-of-principle in a canine model.

    Science.gov (United States)

    Yamamoto, Tokihiro; Kent, Michael S; Wisner, Erik R; Johnson, Lynelle R; Stern, Joshua A; Qi, Lihong; Fujita, Yukio; Boone, John M

    2016-07-01

    Radiotherapy (RT) that selectively avoids irradiating highly functional lung regions may reduce pulmonary toxicity, which is substantial in lung cancer RT. Single-energy computed tomography (CT) pulmonary perfusion imaging has several advantages (e.g., higher resolution) over other modalities and has great potential for widespread clinical implementation, particularly in RT. The purpose of this study was to establish proof-of-principle for single-energy CT perfusion imaging. Single-energy CT perfusion imaging is based on the following: (1) acquisition of end-inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast agents, (2) deformable image registration (DIR) for spatial mapping of those two CT image data sets, and (3) subtraction of the precontrast image data set from the postcontrast image data set, yielding a map of regional Hounsfield unit (HU) enhancement, a surrogate for regional perfusion. In a protocol approved by the institutional animal care and use committee, the authors acquired CT scans in the prone position for a total of 14 anesthetized canines (seven canines with normal lungs and seven canines with diseased lungs). The elastix algorithm was used for DIR. The accuracy of DIR was evaluated based on the target registration error (TRE) of 50 anatomic pulmonary landmarks per subject for 10 randomly selected subjects as well as on singularities (i.e., regions where the displacement vector field is not bijective). Prior to perfusion computation, HUs of the precontrast end-inspiratory image were corrected for variation in the lung inflation level between the precontrast and postcontrast end-inspiratory CT scans, using a model built from two additional precontrast CT scans at end-expiration and midinspiration. The authors also assessed spatial heterogeneity and gravitationally directed gradients of regional perfusion for normal lung subjects and diseased lung subjects using a two-sample two-tailed t-test. The mean TRE

  6. Total body height estimation using sacrum height in Anatolian Caucasians: multidetector computed tomography-based virtual anthropometry

    Energy Technology Data Exchange (ETDEWEB)

    Karakas, Hakki Muammer [Inonu University Medical Faculty, Turgut Ozal Medical Center, Department of Radiology, Malatya (Turkey); Celbis, Osman [Inonu University Medical Faculty Turgut Ozal Medical Center, Department of Forensic Medicine, Malatya (Turkey); Harma, Ahmet [Inonu University Medical Faculty Turgut Ozal Medical Center, Department of Orthopaedics and Traumatology, Malatya (Turkey); Alicioglu, Banu [Trakya University Medical Faculty, Department of Radiology, Edirne (Turkey); Trakya University Health Sciences Institute, Department of Anatomy, Edirne (Turkey)

    2011-05-15

    Estimation of total body height is a major step when a subject has to be identified from his/her skeletal structures. In the presence of decomposed skeletons and missing bones, estimation is usually based on regression equation for intact long bones. If these bones are fragmented or missing, alternative structures must be used. In this study, the value of sacrum height (SH) in total body height (TBH) estimation was investigated in a contemporary population of adult Anatolian Caucasians. Sixty-six men (41.6 {+-} 14.9 years) and 43 women (41.1 {+-} 14.2 years) were scanned with 64-row multidetector computed tomography (MDCT) to obtain high-resolution anthropometric data. SH of midsagittal sections was electronically measured. The technique and methodology were validated on a standard skeletal model. Sacrum height was 111.2 {+-} 12.6 mm (77-138 mm) in men and 104.7 {+-} 8.2 (89-125 mm) in women. The difference between the two sexes regarding SH was significant (p < 0.0001). SH did not significantly correlate with age in men, whereas the correlation was significant in women (p < 0.03). The correlation between SH and the stature was significant in men (r = 0.427, p < 0.0001) and was insignificant in women. For men the regression equation was [Stature = (0.306 x SH)+137.9] (r = 0.54, SEE = 56.9, p < 0.0001). Sacrum height is not susceptible to sex, or to age in men. In the presence of incomplete male skeletons, SH helps to determine the stature. This study is also one of the initial applications of MDCT in virtual anthropometric research. (orig.)

  7. Investigation of four-dimensional computed tomography-based pulmonary ventilation imaging in patients with emphysematous lung regions.

    Science.gov (United States)

    Yamamoto, Tokihiro; Kabus, Sven; Klinder, Tobias; Lorenz, Cristian; von Berg, Jens; Blaffert, Thomas; Loo, Billy W; Keall, Paul J

    2011-04-07

    A pulmonary ventilation imaging technique based on four-dimensional (4D) computed tomography (CT) has advantages over existing techniques. However, physiologically accurate 4D-CT ventilation imaging has not been achieved in patients. The purpose of this study was to evaluate 4D-CT ventilation imaging by correlating ventilation with emphysema. Emphysematous lung regions are less ventilated and can be used as surrogates for low ventilation. We tested the hypothesis: 4D-CT ventilation in emphysematous lung regions is significantly lower than in non-emphysematous regions. Four-dimensional CT ventilation images were created for 12 patients with emphysematous lung regions as observed on CT, using a total of four combinations of two deformable image registration (DIR) algorithms: surface-based (DIR(sur)) and volumetric (DIR(vol)), and two metrics: Hounsfield unit (HU) change (V(HU)) and Jacobian determinant of deformation (V(Jac)), yielding four ventilation image sets per patient. Emphysematous lung regions were detected by density masking. We tested our hypothesis using the one-tailed t-test. Visually, different DIR algorithms and metrics yielded spatially variant 4D-CT ventilation images. The mean ventilation values in emphysematous lung regions were consistently lower than in non-emphysematous regions for all the combinations of DIR algorithms and metrics. V(HU) resulted in statistically significant differences for both DIR(sur) (0.14 ± 0.14 versus 0.29 ± 0.16, p = 0.01) and DIR(vol) (0.13 ± 0.13 versus 0.27 ± 0.15, p Jac) resulted in non-significant differences for both DIR(sur) (0.15 ± 0.07 versus 0.17 ± 0.08, p = 0.20) and DIR(vol) (0.17 ± 0.08 versus 0.19 ± 0.09, p = 0.30). This study demonstrated the strong correlation between the HU-based 4D-CT ventilation and emphysema, which indicates the potential for HU-based 4D-CT ventilation imaging to achieve high physiologic accuracy. A further study is needed to confirm these results.

  8. Healing Process of Osteonecrotic Lesions of the Femoral Head Following Transtrochanteric Rotational Osteotomy: A Computed Tomography-Based Study

    Science.gov (United States)

    Lakhotia, Devendra; Swaminathan, Siva; Oh, Jong Keon; Moon, Jun Gyu; Dwivedi, Chirayu; Hong, Suk Joo

    2017-01-01

    Background Transtrochanteric rotational osteotomy (TRO) is a controversial hip-preserving procedure with a variable success rate. The healing process of femoral head osteonecrosis after TRO has been poorly explained till now. This study aimed to evaluate the healing process of previously transposed necrotic lesion after a TRO for nontraumatic osteonecrosis of the femoral head using computed tomography (CT). Methods Among 52 patients (58 hips) who had preserved original femoral head after TRO, we retrospectively reviewed 27 patients (28 hips) who had undergone sequential CT scans and had no major complication following TRO. The average age was 34 years (range, 18 to 59 years). The mean follow-up period was 9.1 years. We evaluated the reparative process of the transposed osteonecrotic lesion with CT scans. Results Plain radiographs of the osteonecrotic lesion revealed sclerotic and lucent changes in 14 hips (50%) and normal bony architecture in the other 14 hips (50%) at the final follow-up. CT scans of the osteonecrotic lesions showed cystic changes with heterogeneous sclerosis in 13 hips (46%), normal trabecular bone with or without small cysts in 9 hips (32%), and fragmentation of the necrotic lesion in 6 hips (22%). Seventeen hips (60%) showed minimal (13 hips) to mild (4 hips) nonprogressive collapse of the transposed osteonecrotic area. The collapse of the transposed osteonecrotic area on the CT scan was significantly associated with the healing pattern (p = 0.009), as all 6 patients (6 hips) with fragmentation of the necrotic lesion had minimal (5 hips) to mild (1 hip) collapse. Furthermore, a significant association was found between the collapse of the transposed osteonecrotic area on the CT scan of 17 hips (60%) and postoperative Harris hip score (p = 0.021). We observed no differences among the healing patterns on CT scans with regard to age, gender, etiology, staging, preoperative lesion type, preoperative intact area, percentage of necrotic area

  9. Healing Process of Osteonecrotic Lesions of the Femoral Head Following Transtrochanteric Rotational Osteotomy: A Computed Tomography-Based Study.

    Science.gov (United States)

    Lakhotia, Devendra; Swaminathan, Siva; Shon, Won Yong; Oh, Jong Keon; Moon, Jun Gyu; Dwivedi, Chirayu; Hong, Suk Joo

    2017-03-01

    Transtrochanteric rotational osteotomy (TRO) is a controversial hip-preserving procedure with a variable success rate. The healing process of femoral head osteonecrosis after TRO has been poorly explained till now. This study aimed to evaluate the healing process of previously transposed necrotic lesion after a TRO for nontraumatic osteonecrosis of the femoral head using computed tomography (CT). Among 52 patients (58 hips) who had preserved original femoral head after TRO, we retrospectively reviewed 27 patients (28 hips) who had undergone sequential CT scans and had no major complication following TRO. The average age was 34 years (range, 18 to 59 years). The mean follow-up period was 9.1 years. We evaluated the reparative process of the transposed osteonecrotic lesion with CT scans. Plain radiographs of the osteonecrotic lesion revealed sclerotic and lucent changes in 14 hips (50%) and normal bony architecture in the other 14 hips (50%) at the final follow-up. CT scans of the osteonecrotic lesions showed cystic changes with heterogeneous sclerosis in 13 hips (46%), normal trabecular bone with or without small cysts in 9 hips (32%), and fragmentation of the necrotic lesion in 6 hips (22%). Seventeen hips (60%) showed minimal (13 hips) to mild (4 hips) nonprogressive collapse of the transposed osteonecrotic area. The collapse of the transposed osteonecrotic area on the CT scan was significantly associated with the healing pattern (p = 0.009), as all 6 patients (6 hips) with fragmentation of the necrotic lesion had minimal (5 hips) to mild (1 hip) collapse. Furthermore, a significant association was found between the collapse of the transposed osteonecrotic area on the CT scan of 17 hips (60%) and postoperative Harris hip score (p = 0.021). We observed no differences among the healing patterns on CT scans with regard to age, gender, etiology, staging, preoperative lesion type, preoperative intact area, percentage of necrotic area, direction of rotation and

  10. Variabilities of Magnetic Resonance Imaging-, Computed Tomography-, and Positron Emission Tomography-Computed Tomography-Based Tumor and Lymph Node Delineations for Lung Cancer Radiation Therapy Planning.

    Science.gov (United States)

    Karki, Kishor; Saraiya, Siddharth; Hugo, Geoffrey D; Mukhopadhyay, Nitai; Jan, Nuzhat; Schuster, Jessica; Schutzer, Matthew; Fahrner, Lester; Groves, Robert; Olsen, Kathryn M; Ford, John C; Weiss, Elisabeth

    2017-09-01

    To investigate interobserver delineation variability for gross tumor volumes of primary lung tumors and associated pathologic lymph nodes using magnetic resonance imaging (MRI), and to compare the results with computed tomography (CT) alone- and positron emission tomography (PET)-CT-based delineations. Seven physicians delineated the tumor volumes of 10 patients for the following scenarios: (1) CT only, (2) PET-CT fusion images registered to CT ("clinical standard"), and (3) postcontrast T1-weighted MRI registered with diffusion-weighted MRI. To compute interobserver variability, the median surface was generated from all observers' contours and used as the reference surface. A physician labeled the interface types (tumor to lung, atelectasis (collapsed lung), hilum, mediastinum, or chest wall) on the median surface. Contoured volumes and bidirectional local distances between individual observers' contours and the reference contour were analyzed. Computed tomography- and MRI-based tumor volumes normalized relative to PET-CT-based volumes were 1.62 ± 0.76 (mean ± standard deviation) and 1.38 ± 0.44, respectively. Volume differences between the imaging modalities were not significant. Between observers, the mean normalized volumes per patient averaged over all patients varied significantly by a factor of 1.6 (MRI) and 2.0 (CT and PET-CT) (P=4.10 × 10(-5) to 3.82 × 10(-9)). The tumor-atelectasis interface had a significantly higher variability than other interfaces for all modalities combined (P=.0006). The interfaces with the smallest uncertainties were tumor-lung (on CT) and tumor-mediastinum (on PET-CT and MRI). Although MRI-based contouring showed overall larger variability than PET-CT, contouring variability depended on the interface type and was not significantly different between modalities, despite the limited observer experience with MRI. Multimodality imaging and combining different imaging characteristics might be the best approach to define

  11. [Evaluation on Ability to Detect the Intracranial Hematoma with Different Density Using C-Arm Cone-beam Computed Tomography Based on Animal Model].

    Science.gov (United States)

    Zhou, Mi; Zeng, Yongming; Yu, Renqiang; Zhou, Yang; Xu, Rui; Sun, Jingkun; Gao, Zhimei

    2016-02-01

    This study aims to evaluate the ability of C-arm cone-beam CT to detect intracranial hematomas in canine models. Twenty one healthy canines were divided into seven groups and each group had three animals. Autologous blood and contrast agent (3 mL) were slowly injected into the left/right frontal lobes of each animal. Canines in the first group, the control group, were only injected with autologous blood without contrast agent. Each animal in all the 7 groups was scanned with C-arm cone-beam CT and multislice computed tomography (MSCT) after 5 minutes. The attenuation values and their standard deviations of the hematoma and uniformed brain tissues were measured to calculate the image noise, signal to noise ratio (SNR) and contrast to noise ratio (CNR). A scale with scores 1-3 was used to rate the quality of the reconstructed image of different hematoma as a subjective evaluation, and all the experimental data were processed with statistical treatment. The results revealed that when the density of hematoma was less than 65 HU, hematomata were not very clear on C-arm CT images, and when the density of hematoma was more than 65 HU, hematomata showed clearly on both C-arm CT and MSCT images and the scores of them were close. The coherence between the two physicians was very reliable. The same results were obtained with C-arm cone-beam CT and MSCT grades in measuring SD value, SNR, and CNR. The reasonable choice of density detection range of intracranial hematoma with C-arm cone-beam CT could be effectively applied to monitoring the intracranial hemorrhage during interventional diagnosis and treatment.

  12. Four-Dimensional Computed Tomography Based Respiratory-Gated Radiotherapy with Respiratory Guidance System: Analysis of Respiratory Signals and Dosimetric Comparison

    Directory of Open Access Journals (Sweden)

    Jung Ae Lee

    2014-01-01

    Full Text Available Purpose. To investigate the effectiveness of respiratory guidance system in 4-dimensional computed tomography (4DCT based respiratory-gated radiation therapy (RGRT by comparing respiratory signals and dosimetric analysis of treatment plans. Methods. The respiratory amplitude and period of the free, the audio device-guided, and the complex system-guided breathing were evaluated in eleven patients with lung or liver cancers. The dosimetric parameters were assessed by comparing free breathing CT plan and 4DCT-based 30–70% maximal intensity projection (MIP plan. Results. The use of complex system-guided breathing showed significantly less variation in respiratory amplitude and period compared to the free or audio-guided breathing regarding the root mean square errors (RMSE of full inspiration (P=0.031, full expiration (P=0.007, and period (P=0.007. The dosimetric parameters including V5 Gy, V10 Gy, V20 Gy, V30 Gy, V40 Gy, and V50 Gy of normal liver or lung in 4DCT MIP plan were superior over free breathing CT plan. Conclusions. The reproducibility and regularity of respiratory amplitude and period were significantly improved with the complex system-guided breathing compared to the free or the audio-guided breathing. In addition, the treatment plan based on the 4D CT-based MIP images acquired with the complex system guided breathing showed better normal tissue sparing than that on the free breathing CT.

  13. Prostate positioning using cone-beam computer tomography based on manual soft-tissue registration. Interobserver agreement between radiation oncologists and therapists

    Energy Technology Data Exchange (ETDEWEB)

    Jereczek-Fossa, B.A.; Pobbiati, C.; Fanti, P. [European Institute of Oncology, Department of Radiation Oncology, Milan (Italy); University of Milan, Milan (Italy); Santoro, L. [European Institute of Oncology, Department of Epidemiology and Biostatistics, Milan (Italy); Fodor, C.; Zerini, D. [European Institute of Oncology, Department of Radiation Oncology, Milan (Italy); Vigorito, S. [European Institute of Oncology, Department of Medical Physics, Milan (Italy); Baroni, G. [Politecnico di Milano, Department of Electronics Information and Bioengineering, Milan (Italy); De Cobelli, O. [European Institute of Oncology, Department of Urology, Milan (Italy); University of Milan, Milan (Italy); Orecchia, R. [European Institute of Oncology, Department of Radiation Oncology, Milan (Italy); National Center for Oncological Hadrontherapy (CNAO) Foundation, Pavia (Italy); University of Milan, Milan (Italy)

    2014-01-15

    To check the interobserver agreement between radiation oncologists and therapists (RTT) using an on- and off-line cone-beam computer tomography (CBCT) protocol for setup verification in the radiotherapy of prostate cancer. The CBCT data from six prostate cancer patients treated with hypofractionated intensity-modulated radiotherapy (IMRT) were independently reviewed off-line by four observers (one radiation oncologist, one junior and two senior RTTs) and benchmarked with on-line CBCT positioning performed by a radiation oncologist immediately prior to treatment. CBCT positioning was based on manual soft-tissue registration. Agreement between observers was evaluated using weighted Cohen's kappa statistics. In total, 152 CBCT-based prostate positioning procedures were reviewed by each observer. The mean (± standard deviation) of the differences between off- and on-line CBCT-simCT registration translations along the three directions (antero-posterior, latero-lateral and cranio-caudal) and rotation around the antero-posterior axis were - 0.7 (3.6) mm, 1.9 (2.7) mm, 0.9 (3.6) mm and - 1.8 (5.0) degrees, respectively. Satisfactory interobserver agreement was found, being substantial (weighted kappa > 0.6) in 10 of 16 comparisons and moderate (0.41-0.60) in the remaining six comparisons. CBCT interpretation performed by RTTs is comparable to that of radiation oncologists. Our study might be helpful in the quality assurance of radiotherapy and the optimization of competencies. Further investigation should include larger sample sizes, a greater number of observers and validated methodology in order to assess interobserver variability and its impact on high-precision prostate cancer IGRT. In the future, it should enable the wider implementation of complex and evolving radiotherapy technologies. (orig.)

  14. Computed tomography-based morphometric analysis of cervical pedicles in Indian population: A pilot study to assess feasibility of transpedicular screw fixation

    Directory of Open Access Journals (Sweden)

    A R Patwardhan

    2012-01-01

    Full Text Available Background: Cervical transpedicular screw fixation is safe and is probably going to be the gold standard for cervical spine fixation. However, cervical transpedicular screw use in the Asian population can be limited as the transverse diameter in this group of patients may not be adequate to accommodate the 3.5-mm pedicular screw thus injuring the vital structures located in the close proximity of the pedicles. Thus lateral mass fixation remains the mainstay of treatment. The present study evaluated the transverse cervical pedicle diameter of C2-C7 vertebrae in a pilot study in 27 Indian subjects using computed tomography (CT imaging and evaluated the feasibility of transpedicular screw fixation in them. Aims: To evaluate the feasibility of transpedicular screw fixation in the Indian population. Settings and Design: The cervical pedicle diameter size differs between the Asian and non-Asian population. The authors studied the transverse pedicle diameter of the C2-C7 of the cervical spine in the Indian population using CT measurements. This cross-sectional study was carried out at a tertiary care centre for a period of four months from October 2010 to December 2010. Material and Methods: Measurements of cervical pedicles in the subjects were performed on the CT workstation from the CT images taken at 2.5-mm interval. The transverse pedicle diameter was defined as the outermost diameter of the pedicle, taken perpendicular to the axis of the pedicle at the narrowest point and measured in millimeters±0.1 mm. Statistical Analysis: Descriptive statistics was used to represent percentage of transverse diameter of cervical pedicles less than 5 mm in male and female subjects at C2-C7 levels. Since there is no previous study done in India, we initiated the study with sample size of 27 as a pilot study. The statistical analysis was performed using SPSS software. Results: The mean transverse diameters of the cervical pedicles of C2, C3, C4, C5, C6 and C7 in

  15. Thermal-stress analysis of ceramic laminate veneer restorations with different incisal preparations using micro-computed tomography-based 3D finite element models.

    Science.gov (United States)

    Celebi, Alper Tunga; Icer, Esra; Eren, Meltem Mert; Baykasoglu, Cengiz; Mugan, Ata; Yildiz, Esra

    2017-11-01

    Main objective of this study is to investigate the thermal behavior of ceramic laminate veneer restorations of the maxillary central incisor with different incisal preparations such as butt joint and palatinal chamfer using finite element method. In addition, it is also aimed to understand the effect of different thermal loads which simulates hot and cold liquid imbibing in the mouth. Three-dimensional solid models of the sound tooth and prepared veneer restorations were obtained using micro-computed tomography images. Each ceramic veneer restoration was made up of ceramic, luting resin cement and adhesive layer which were generated based on the scanned images using computer-aided design software. Our solid model also included the remaining dental tissues such as periodontal ligament and surrounding cortical and spongy bones. Time-dependent linear thermal analyses were carried out to compare temperature changes and stress distributions of the sound and restored tooth models. The liquid is firstly in contact with the crown area where the maximum stresses were obtained. For the restorations, stresses on palatinal surfaces were found larger than buccal surfaces. Through interior tissues, the effect of thermal load diminished and smaller stress distributions were obtained near pulp and root-dentin regions. We found that the palatinal chamfer restoration presents comparatively larger stresses than the butt joint preparation. In addition, cold thermal loading showed larger temperature changes and stress distributions than those of hot thermal loading independent from the restoration technique. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. The Plastered Skulls from the Pre-Pottery Neolithic B Site of Yiftahel (Israel) – A Computed Tomography-Based Analysis

    Science.gov (United States)

    Slon, Viviane; Sarig, Rachel; Hershkovitz, Israel; Khalaily, Hamoudi; Milevski, Ianir

    2014-01-01

    Three plastered skulls, dating to the Pre-Pottery Neolithic B, were found at the site of Yiftahel, in the Lower Galilee (Israel). The skulls underwent refitting and restoration processes, details of which are described herein. All three belong to adults, of which two appear to be males and one appears to be a female. Virtual cross-sections were studied and a density analysis of the plaster was performed using computed tomography scans. These were utilized to yield information regarding the modeling process. Similarities and differences between the Yiftahel and other plastered skulls from the Levant are examined. The possible role of skull plastering within a society undergoing a shift from a hunting-gathering way of life to a food producing strategy is discussed. PMID:24586625

  17. A computer tomography-based spatial normalization for the analysis of [{sup 18}F]fluorodeoxyglucose position emission tomography of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Hanna; Choi, Jae Yong; Ryu, Young Hoon; Lyoo, Chul Hyoung [Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Jin Su [Molecular Imaging Research Center, Korea Institute Radiological and Medical Science, Seoul(Korea, Republic of)

    2014-12-15

    We developed a new computed tomography (CT)-based spatial normalization method and CT template to demonstrate its usefulness in spatial normalization of positron emission tomography (PET) images with [{sup 18}F] fluorodeoxyglucose (FDG) PET studies in healthy controls. Seventy healthy controls underwent brain CT scan (120 KeV, 180 mAs, and 3 mm of thickness) and [{sup 18}F] FDG PET scans using a PET/CT scanner. T1-weighted magnetic resonance (MR) images were acquired for all subjects. By averaging skull-stripped and spatially-normalized MR and CT images, we created skull-stripped MR and CT templates for spatial normalization. The skull-stripped MR and CT images were spatially normalized to each structural template. PET images were spatially normalized by applying spatial transformation parameters to normalize skull-stripped MR and CT images. A conventional perfusion PET template was used for PET-based spatial normalization. Regional standardized uptake values (SUV) measured by overlaying the template volume of interest (VOI) were compared to those measured with FreeSurfer-generated VOI (FSVOI). All three spatial normalization methods underestimated regional SUV values by 0.3-20% compared to those measured with FSVOI. The CT-based method showed slightly greater underestimation bias. Regional SUV values derived from all three spatial normalization methods were correlated significantly (p < 0.0001) with those measured with FSVOI. CT-based spatial normalization may be an alternative method for structure-based spatial normalization of [18F] FDG PET when MR imaging is unavailable. Therefore, it is useful for PET/CT studies with various radiotracers whose uptake is expected to be limited to specific brain regions or highly variable within study population.

  18. Computed tomography-based prediction of the straight antegrade humeral nail's entry point and exposure of "critical types": truth or fiction?

    Science.gov (United States)

    Euler, Simon A; Hengg, Clemens; Boos, Matthias; Dornan, Grant J; Turnbull, Travis Lee; Wambacher, Markus; Kralinger, Franz S; Millett, Peter J; Petri, Maximilian

    2017-05-01

    Straight antegrade intramedullary nailing of proximal humerus fractures has shown promising clinical results. However, up to 36% of all humeri seem to be "critical types" in terms of the potential violation of the supraspinatus (SSP) tendon footprint by the nail's insertion zone. The aims of this study were to evaluate if a computed tomography (CT) scan could reliably predict the nail's entry point on the humeral head and if it would be possible to preoperatively estimate the individual risk of iatrogenic violation of the SSP tendon footprint by evaluating the uninjured contralateral humerus. Twenty matched pairs of human cadaveric shoulders underwent CT scans, and the entry point for an antegrade nail as well as measurements regarding critical distances between the entry point and the rotator cuff were determined. Next, gross anatomic measurements of the same data were performed and compared. Furthermore, specimens were reviewed for critical types. Overall, 42.5% of all specimens were found to be critical types. The CT measurements exhibited excellent intra-rater and inter-rater reliability (intraclass correlation coefficients >0.90). Similarly, excellent agreement between the CT scan and gross anatomic measurements in contralateral shoulders (intraclass correlation coefficients >0.88) was found. Assessing the uninjured contralateral side, CT can reliably predict the entry point in antegrade humeral nailing and preoperatively identify critical types of humeral heads at risk of iatrogenic implantation damage to the SSP tendon footprint. This study may help surgeons in the decision-making processon which surgical technique should be used without putting the patient at risk for iatrogenic, implant-related damage to the rotator cuff. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  19. Are pedicle screw perforation rates influenced by distance from the reference frame in multilevel registration using a computed tomography-based navigation system in the setting of scoliosis?

    Science.gov (United States)

    Uehara, Masashi; Takahashi, Jun; Ikegami, Shota; Kuraishi, Shugo; Shimizu, Masayuki; Futatsugi, Toshimasa; Oba, Hiroki; Kato, Hiroyuki

    2017-04-01

    Pedicle screw fixation is commonly employed for the surgical correction of scoliosis but carries a risk of serious neurovascular or visceral structure events during screw insertion. To avoid these complications, we have been using a computed tomography (CT)-based navigation system during pedicle screw placement. As this could also prolong operation time, multilevel registration for pedicle screw insertion for posterior scoliosis surgery was developed to register three consecutive vertebrae in a single time with CT-based navigation. The reference frame was set either at the caudal end of three consecutive vertebrae or at one or two vertebrae inferior to the most caudal registered vertebra, and then pedicle screws were inserted into the three consecutive registered vertebrae and into the one or two adjacent vertebrae. This study investigated the perforation rates of vertebrae at zero, one, two, three, or four or more levels above or below the vertebra at which the reference frame was set. This is a retrospective, single-center, single-surgeon study. One hundred sixty-one scoliosis patients who had undergone pedicle screw fixation were reviewed. Screw perforation rates were evaluated by postoperative CT. We evaluated 161 scoliosis patients (34 boys and 127 girls; mean±standard deviation age: 14.6±2.8 years) who underwent pedicle screw fixation guided by a CT-based navigation system between March 2006 and December 2015. A total of 2,203 pedicle screws were inserted into T2-L5 using multilevel registration with CT-based navigation. The overall perforation rates for Grade 1, 2, or 3, Grade 2 or 3 (major perforations), and Grade 3 perforations (violations) were as follows: vertebrae at which the reference frame was set: 15.9%, 6.1%, and 2.5%; one vertebra above or below the reference frame vertebra: 16.5%, 4.0%, and 1.2%; two vertebrae above or below the reference frame vertebra: 20.7%, 8.7%, and 2.3%; three vertebrae above or below the reference frame vertebra: 23

  20. Computational treatment of metalloproteins.

    Science.gov (United States)

    Nechay, Michael R; Valdez, Crystal E; Alexandrova, Anastassia N

    2015-05-14

    Metalloproteins present a considerable challenge for modeling, especially when the starting point is far from thermodynamic equilibrium. Examples include formidable problems such as metalloprotein folding and structure prediction upon metal addition, removal, or even just replacement; metalloenzyme design, where stabilization of a transition state of the catalyzed reaction in the specific binding pocket around the metal needs to be achieved; docking to metal-containing sites and design of metalloenzyme inhibitors. Even more conservative computations, such as elucidations of the mechanisms and energetics of the reaction catalyzed by natural metalloenzymes, are often nontrivial. The reason is the vast span of time and length scales over which these proteins operate, and thus the resultant difficulties in estimating their energies and free energies. It is required to perform extensive sampling, properly treat the electronic structure of the bound metal or metals, and seamlessly merge the required techniques to assess energies and entropies, or their changes, for the entire system. Additionally, the machinery needs to be computationally affordable. Although a great advancement has been made over the years, including some of the seminal works resulting in the 2013 Nobel Prize in chemistry, many aforementioned exciting applications remain far from reach. We review the methodology on the forefront of the field, including several promising methods developed in our lab that bring us closer to the desired modern goals. We further highlight their performance by a few examples of applications.

  1. Computers in the treatment of chronic aphasia.

    Science.gov (United States)

    Katz, Richard C

    2010-02-01

    Computers and related technology can increase the amount of treatment received by adults with chronic aphasia. Computers used in treatment, however, are only valuable to the patient if the intervention is efficacious. Real and potential applications of computer technology are discussed in the context of three roles of computerized aphasia treatment for adults with chronic aphasia. Pertinent studies regarding Phases 1 and 2 are briefly described. The only Phase 3 study of efficacy of computerized aphasia treatment is more fully described and its implications discussed.

  2. Four-dimensional computed tomography based assessment and analysis of lung tumor motion during free-breathing respiration%基于四维CT影像肺内肿瘤运动度的测量与分析

    Institute of Scientific and Technical Information of China (English)

    王彦; 包勇; 张黎; 樊卫; 邓小武; 陈明

    2010-01-01

    目的 以四维CT(4DCT)影像量化肺内肿瘤因呼吸导致的运动,分析其影响因素,寻找运动度大的肿瘤特征.方法 在平静呼吸状态下接受4DCT扫描的肺内肿瘤患者43例,肺内可测量病灶44个.由同一位医生在4DCT各时相数据集卜勾画肿瘤GTV,分别测量GTV中心点在上下、左右、前后三维方向上的运动幅度.对与运动度可能相关的临床变量和解剖学因素进行统计学分析.以任意方向运动幅度>5 mm作为分界点,分析此类肿瘤特征.结果 肺内肿瘤运动度与T分期、GTV体积、肺内所处上下位置、与固定组织(如胸壁、纵隔、脊柱)粘连程度相关.10例患者肺内肿瘤的运动幅度>5 mm,均位于胸腔下部及后部,上下方向运动度最大,最大值为14.4 mm.95%肺内肿瘤的运动幅度在上下方向<11.8 mm,前后方向<4.6 mm,左右方向<2.7 mm.结论 呼吸导致的肺内肿瘤运动度受肿瘤位置、体积、T分期及粘连程度等因素影响.下叶肺内孤立肿瘤的运动度最大,主要发生在上下方向,上叶后段肿瘤的运动度次之.%Objective To quantify the amplitudes of lung tumor motion during free-breathing using four dimensional computed tomography (4DCT), and seek the characteristics of tumors with large motion. Methods Respiratory-induced tumor motion was analyzed for 44 tumors from 43 patients. All patients un-derwent 4DCT during free-breathing before treatment. Gross tumor volumes (GTV) on ten respiratory phases were contoured by the same doctor. The eentroids of GTVs were autoplaeed with treatment software (ADAC Pinnacle 7.4f), then the amplitudes of tumor motion were assessed. The various clinical and anatomic fac-tors associated with GTV motion were analyzed. The characteristics of tumors with motion greater than 5 mm in any direction were explored. Results The tumor motion was found to be associated with T stage, GTV size, the superior-inferior (SI) tumor location in the lung, and the attachment

  3. A high-resolution computed tomography-based scoring system to differentiate the most infectious active pulmonary tuberculosis from community-acquired pneumonia in elderly and non-elderly patients

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Jun-Jun [Ditmanson Medical Foundation Chia-Yi Christian Hospital, Section of Thoracic Imaging, Department of Chest Medicine and Family Medicine, Chiayi City (China); Chia Nan University of Pharmacy and Science, Tainan (China); Meiho University, Pingtung (China); Pingtung Christian Hospital, Pingtung (China); Chen, Solomon Chih-Cheng; Chen, Cheng-Ren [Ditmanson Medical Foundation Chia-Yi Christian Hospital, Department of Medical Research, Chiayi City (China); Yeh, Ting-Chun; Lin, Hsin-Kai; Hong, Jia-Bin; Wu, Bing-Tsang [Ditmanson Medical Foundation Chia-Yi Christian Hospital, Department of Family Medicine, Chiayi City (China); Wu, Ming-Ting [Department of Radiology, Kaohsiung Veterans General Hospital, Section of Thoracic and Circulation Imaging, Kaohsiung (China); School of Medicine, National Yang Ming University, Faculty of Medicine, Taipei (China)

    2014-10-15

    The objective of this study was to use high-resolution computed tomography (HRCT) imaging to predict the presence of smear-positive active pulmonary tuberculosis (PTB) in elderly (at least 65 years of age) and non-elderly patients (18-65 years of age). Patients with active pulmonary infections seen from November 2010 through December 2011 received HRCT chest imaging, sputum smears for acid-fast bacilli and sputum cultures for Mycobacterium tuberculosis. Smear-positive PTB was defined as at least one positive sputum smear and a positive culture for M. tuberculosis. Multivariate logistic regression analyses were performed to determine the HRCT predictors of smear-positive active PTB, and a prediction score was developed on the basis of receiver operating characteristic curve analysis. Of 1,255 patients included, 139 were diagnosed with smear-positive active PTB. According to ROC curve analysis, the sensitivity, specificity, positive predictive value, negative predictive value, false positive rates and false negative rates were 98.6 %, 95.8 %, 78.5 %, 99.8 %, 4.2 % and 1.4 %, respectively, for diagnosing smear-positive active PTB in elderly patients, and 100.0 %, 96.9 %, 76.5 %, 100.0 %, 3.1 % and 0.0 %, respectively, for non-elderly patients. HRCT can assist in the early diagnosis of the most infectious active PTB, thereby preventing transmission and minimizing unnecessary immediate respiratory isolation. (orig.)

  4. Computed tomography-based anatomic assessment overestimates local tumor recurrence in patients with mass-like consolidation after stereotactic body radiotherapy for early-stage non-small cell lung cancer.

    Science.gov (United States)

    Dunlap, Neal E; Yang, Wensha; McIntosh, Alyson; Sheng, Ke; Benedict, Stanley H; Read, Paul W; Larner, James M

    2012-12-01

    To investigate pulmonary radiologic changes after lung stereotactic body radiotherapy (SBRT), to distinguish between mass-like fibrosis and tumor recurrence. Eighty consecutive patients treated with 3- to 5-fraction SBRT for early-stage peripheral non-small cell lung cancer with a minimum follow-up of 12 months were reviewed. The mean biologic equivalent dose received was 150 Gy (range, 78-180 Gy). Patients were followed with serial CT imaging every 3 months. The CT appearance of consolidation was defined as diffuse or mass-like. Progressive disease on CT was defined according to Response Evaluation Criteria in Solid Tumors 1.1. Positron emission tomography (PET) CT was used as an adjunct test. Tumor recurrence was defined as a standardized uptake value equal to or greater than the pretreatment value. Biopsy was used to further assess consolidation in select patients. Median follow-up was 24 months (range, 12.0-36.0 months). Abnormal mass-like consolidation was identified in 44 patients (55%), whereas diffuse consolidation was identified in 12 patients (15%), at a median time from end of treatment of 10.3 months and 11.5 months, respectively. Tumor recurrence was found in 35 of 44 patients with mass-like consolidation using CT alone. Combined with PET, 10 of the 44 patients had tumor recurrence. Tumor size (hazard ratio 1.12, P=.05) and time to consolidation (hazard ratio 0.622, P=.03) were predictors for tumor recurrence. Three consecutive increases in volume and increasing volume at 12 months after treatment in mass-like consolidation were highly specific for tumor recurrence (100% and 80%, respectively). Patients with diffuse consolidation were more likely to develop grade ≥ 2 pneumonitis (odds ratio 26.5, P=.02) than those with mass-like consolidation (odds ratio 0.42, P=.07). Incorporating the kinetics of mass-like consolidation and PET to the current criteria for evaluating posttreatment response will increase the likelihood of correctly identifying

  5. Computed Tomography-Based Anatomic Assessment Overestimates Local Tumor Recurrence in Patients With Mass-like Consolidation After Stereotactic Body Radiotherapy for Early-Stage Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dunlap, Neal E. [Department of Radiation Oncology, University of Louisville, Louisville, KY (United States); Yang Wensha [Department of Radiation Oncology, Cedars Sinai Medical Center, Los Angeles, CA (United States); McIntosh, Alyson [Department of Radiation Oncology, John and Dorothy Morgan Cancer Center, Lehigh Valley Hospital, Allentown, PA (United States); Sheng, Ke [Department of Radiation Oncology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA (United States); Benedict, Stanley H.; Read, Paul W. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Larner, James M., E-mail: jml2p@virginia.edu [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)

    2012-12-01

    Purpose: To investigate pulmonary radiologic changes after lung stereotactic body radiotherapy (SBRT), to distinguish between mass-like fibrosis and tumor recurrence. Methods and Materials: Eighty consecutive patients treated with 3- to 5-fraction SBRT for early-stage peripheral non-small cell lung cancer with a minimum follow-up of 12 months were reviewed. The mean biologic equivalent dose received was 150 Gy (range, 78-180 Gy). Patients were followed with serial CT imaging every 3 months. The CT appearance of consolidation was defined as diffuse or mass-like. Progressive disease on CT was defined according to Response Evaluation Criteria in Solid Tumors 1.1. Positron emission tomography (PET) CT was used as an adjunct test. Tumor recurrence was defined as a standardized uptake value equal to or greater than the pretreatment value. Biopsy was used to further assess consolidation in select patients. Results: Median follow-up was 24 months (range, 12.0-36.0 months). Abnormal mass-like consolidation was identified in 44 patients (55%), whereas diffuse consolidation was identified in 12 patients (15%), at a median time from end of treatment of 10.3 months and 11.5 months, respectively. Tumor recurrence was found in 35 of 44 patients with mass-like consolidation using CT alone. Combined with PET, 10 of the 44 patients had tumor recurrence. Tumor size (hazard ratio 1.12, P=.05) and time to consolidation (hazard ratio 0.622, P=.03) were predictors for tumor recurrence. Three consecutive increases in volume and increasing volume at 12 months after treatment in mass-like consolidation were highly specific for tumor recurrence (100% and 80%, respectively). Patients with diffuse consolidation were more likely to develop grade {>=}2 pneumonitis (odds ratio 26.5, P=.02) than those with mass-like consolidation (odds ratio 0.42, P=.07). Conclusion: Incorporating the kinetics of mass-like consolidation and PET to the current criteria for evaluating posttreatment response will

  6. Comparison of Positron Emission Tomography Quantification Using Magnetic Resonance- and Computed Tomography-Based Attenuation Correction in Physiological Tissues and Lesions: A Whole-Body Positron Emission Tomography/Magnetic Resonance Study in 66 Patients.

    Science.gov (United States)

    Seith, Ferdinand; Gatidis, Sergios; Schmidt, Holger; Bezrukov, Ilja; la Fougère, Christian; Nikolaou, Konstantin; Pfannenberg, Christina; Schwenzer, Nina

    2016-01-01

    Attenuation correction (AC) in fully integrated positron emission tomography (PET)/magnetic resonance (MR) systems plays a key role for the quantification of tracer uptake. The aim of this prospective study was to assess the accuracy of standardized uptake value (SUV) quantification using MR-based AC in direct comparison with computed tomography (CT)-based AC of the same PET data set on a large patient population. Sixty-six patients (22 female; mean [SD], 61 [11] years) were examined by means of combined PET/CT and PET/MR (11C-choline, 18F-FDG, or 68Ga-DOTATATE) subsequently. Positron emission tomography images from PET/MR examinations were corrected with MR-derived AC based on tissue segmentation (PET(MR)). The same PET data were corrected using CT-based attenuation maps (μ-maps) derived from PET/CT after nonrigid registration of the CT to the MR-based μ-map (PET(MRCT)). Positron emission tomography SUVs were quantified placing regions of interest or volumes of interest in 6 different body regions as well as PET-avid lesions, respectively. The relative differences of quantitative PET values when using MR-based AC versus CT-based AC were varying depending on the organs and body regions assessed. In detail, the mean (SD) relative differences of PET SUVs were as follows: -7.8% (11.5%), blood pool; -3.6% (5.8%), spleen; -4.4% (5.6%)/-4.1% (6.2%), liver; -0.6% (5.0%), muscle; -1.3% (6.3%), fat; -40.0% (18.7%), bone; 1.6% (4.4%), liver lesions; -6.2% (6.8%), bone lesions; and -1.9% (6.2%), soft tissue lesions. In 10 liver lesions, distinct overestimations greater than 5% were found (up to 10%). In addition, overestimations were found in 2 bone lesions and 1 soft tissue lesion adjacent to the lung (up to 28.0%). Results obtained using different PET tracers show that MR-based AC is accurate in most tissue types, with SUV deviations generally of less than 10%. In bone, however, underestimations can be pronounced, potentially leading to inaccurate SUV quantifications. In

  7. The Relationships between Metabolic Disorders (Hypertension, Dyslipidemia, and Impaired Glucose Tolerance and Computed Tomography-Based Indices of Hepatic Steatosis or Visceral Fat Accumulation in Middle-Aged Japanese Men.

    Directory of Open Access Journals (Sweden)

    Kazutoshi Fujibayashi

    Full Text Available Most studies on the relationships between metabolic disorders (hypertension, dyslipidemia, and impaired glucose tolerance and hepatic steatosis (HS or visceral fat accumulation (VFA have been cross-sectional, and thus, these relationships remain unclear. We conducted a retrospective cohort study to clarify the relationships between components of metabolic disorders and HS/VFA.The participants were 615 middle-aged men who were free from serious liver disorders, diabetes, and HS/VFA and underwent multiple general health check-ups at our institution between 2009 and 2013. The data from the initial and final check-ups were used. HS and VFA were assessed by computed tomography. HS was defined as a liver to spleen attenuation ratio of ≤1.0. VFA was defined as a visceral fat cross-sectional area of ≥100 cm2 at the level of the navel. Metabolic disorders were defined using Japan's metabolic syndrome diagnostic criteria. The participants were divided into four groups based on the presence (+ or absence (- of HS/VFA. The onset rates of each metabolic disorder were compared among the four groups.Among the participants, 521, 55, 24, and 15 were classified as HS(-/VFA(-, HS(-/VFA(+, HS(+/VFA(-, and HS(+/VFA(+, respectively, at the end of the study. Impaired glucose tolerance was more common among the participants that exhibited HS or VFA (p = 0.05. On the other hand, dyslipidemia was more common among the participants that displayed VFA (p = 0.01.It is likely that VFA is associated with impaired glucose tolerance and dyslipidemia, while HS might be associated with impaired glucose tolerance. Unfortunately, our study failed to detect associations between HS/VFA and metabolic disorders due to the low number of subjects that exhibited fat accumulation. Although our observational study had major limitations, we consider that it obtained some interesting results. HS and VFA might affect different metabolic disorders. Further large-scale longitudinal studies

  8. Comparison of the clinical accuracy of cervical (C2-C7) pedicle screw insertion assisted by fluoroscopy, computed tomography-based navigation, and intraoperative three-dimensional C-arm navigation

    Institute of Scientific and Technical Information of China (English)

    LIU Ya-jun; TIAN Wei; LIU Bo; LI Qin; HU Lin; LI Zhi-yu; YUAN Qiang; L(U) Yan-wei; SUN Yu-zhen

    2010-01-01

    Background The complicated anatomy of the cervical spine and the variation among pedicles reduces the accuracy and increases the risk of neurovascular complications associated with screw implantation in this region. In this study, we compared the accuracy of cervical (C2-C7) pedicle screw fixation assisted by X-ray fluoroscopy, computed tomography (CT)-based navigation, or intraoperative three-dimensional (3D) C-arm navigation.Methods This prospective cohort study was performed in 82 consecutive patients who underwent cervical pedicle screw fixation. The accuracy of screw insertion was assessed by postoperative CT scan with 3D reconstruction. The accuracy of screw insertion was assessed as: excellent (screw completely within pedicle); acceptable (≤ 1 mm screw outside pedicle cortex); poor (>1 mm screw outside pedicle cortex).Results A total of 145 screws were inserted in 24 patients who underwent C-arm fluoroscopy. Of these, 96 screws (66.2%) were excellent, 37 (25.5%) were acceptable, and 12 (8.3%) were poor. One hundred and fifty-nine screws were inserted in 29 patients in the CT-based navigation group. Among these, 141 (88.7%) were excellent, 14 (8.8%) were acceptable, and 4 (2.5%) were poor. A total of 140 screws were inserted in 29 patients in the intraoperative 3D C-arm navigation group, of which 127 (90.7%) were excellent, and 13 (9.3%) were acceptable. No severe or permanent neurovascular complications associated with screw insertion were observed in any patient.Conclusione CT-based and intraoperative 3D C-arm navigation were similarly accurate, and were both significantly more accurate than C-arm fluoroscopy for guiding cervical pedicle screw fixation. They were able to accurately guide the angle and depth of screw placement using visual 3D images. These two techniques are therefore preferable for high-risk cervical pedicle screw fixation. The ease and convenience of intraoperative 3D C-arm navigation suggests that it may replace virtual

  9. Computer-Assisted Exposure Treatment for Flight Phobia

    Science.gov (United States)

    Tortella-Feliu, Miguel; Bornas, Xavier; Llabres, Jordi

    2008-01-01

    This review introduces the state of the art in computer-assisted treatment for behavioural disorders. The core of the paper is devoted to describe one of these interventions providing computer-assisted exposure for flight phobia treatment, the Computer-Assisted Fear of Flying Treatment (CAFFT). The rationale, contents and structure of the CAFFT…

  10. Three-dimensional treatment planning of orthognathic surgery in the era of virtual imaging.

    NARCIS (Netherlands)

    Swennen, G.R.; Mollemans, W.; Schutyser, F.A.C.

    2009-01-01

    PURPOSE: The aim of this report was to present an integrated 3-dimensional (3D) virtual approach toward cone-beam computed tomography-based treatment planning of orthognathic surgery in the clinical routine. MATERIALS AND METHODS: We have described the different stages of the workflow process for ro

  11. Mathematical Model of ComputerHeat Treatment and Its Simulation

    Institute of Scientific and Technical Information of China (English)

    PanJiansheng; ZhangWeimin; TianDong; GuJianfeng; HuMingjuan

    2004-01-01

    Computer simulation on heat treatment is the foundation of intelligent heat treatment. The simulations of temperature field,phase transformation, stress/strain complicate quenching operation were realized by using the model of three dimensional non-linear finite element method and the treatment methods of abruptly changing interface conditions. The simulation results basically fit those measured in experiments. The intelligent sealed multipurpose furnace production line has been developed based on the combination of computer simulation on gaseous carburizing and computer control technology. More than 3000 batches of workpieces have been processed on this production line, and all are up to standard. The application of computer simulation technology can significantly improve the loading ability and reliability of nitriding and carburizing workpieces, reduce heat treatment distortion, and shorten carburizing duration. It is recommended that the reliable product design without redundancy should be performed with the combination of the CAD of mechanical products, the CAE of materials selection and heat treatment, and the dynamic evaluation technology of product reliability.

  12. 3D Computer aided treatment planning in endodontics.

    Science.gov (United States)

    van der Meer, Wicher J; Vissink, Arjan; Ng, Yuan Ling; Gulabivala, Kishor

    2016-02-01

    Obliteration of the root canal system due to accelerated dentinogenesis and dystrophic calcification can challenge the achievement of root canal treatment goals. This paper describes the application of 3D digital mapping technology for predictable navigation of obliterated canal systems during root canal treatment to avoid iatrogenic damage of the root. Digital endodontic treatment planning for anterior teeth with severely obliterated root canal systems was accomplished with the aid of computer software, based on cone beam computer tomography (CBCT) scans and intra-oral scans of the dentition. On the basis of these scans, endodontic guides were created for the planned treatment through digital designing and rapid prototyping fabrication. The custom-made guides allowed for an uncomplicated and predictable canal location and management. The method of digital designing and rapid prototyping of endodontic guides allows for reliable and predictable location of root canals of teeth with calcifically metamorphosed root canal systems. The endodontic directional guide facilitates difficult endodontic treatments at little additional cost. Copyright © 2016. Published by Elsevier Ltd.

  13. COMPARATIVE STUDY OF TERTIARY WASTEWATER TREATMENT BY COMPUTER SIMULATION

    Directory of Open Access Journals (Sweden)

    Stefania Iordache

    2010-01-01

    Full Text Available The aim of this work is to asses conditions for implementation of a Biological Nutrient Removal (BNR process in theWastewater Treatment Plant (WWTP of Moreni city (Romania. In order to meet the more increased environmentalregulations, the wastewater treatment plant that was studied, must update the actual treatment process and have tomodernize it. A comparative study was undertaken of the quality of effluents that could be obtained by implementationof biological nutrient removal process like A2/O (Anaerobic/Anoxic/Oxic and VIP (Virginia Plant Initiative aswastewater tertiary treatments. In order to asses the efficiency of the proposed treatment schemata based on the datamonitored at the studied WWTP, it were realized computer models of biological nutrient removal configurations basedon A2/O and VIP process. Computer simulation was realized using a well-known simulator, BioWin by EnviroSimAssociates Ltd. The simulation process allowed to obtain some data that can be used in design of a tertiary treatmentstage at Moreni WWTP, in order to increase the efficiency in operation.

  14. Alternative treatment technology information center computer database system

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, D. [Environmental Protection Agency, Edison, NJ (United States)

    1995-10-01

    The Alternative Treatment Technology Information Center (ATTIC) computer database system was developed pursuant to the 1986 Superfund law amendments. It provides up-to-date information on innovative treatment technologies to clean up hazardous waste sites. ATTIC v2.0 provides access to several independent databases as well as a mechanism for retrieving full-text documents of key literature. It can be accessed with a personal computer and modem 24 hours a day, and there are no user fees. ATTIC provides {open_quotes}one-stop shopping{close_quotes} for information on alternative treatment options by accessing several databases: (1) treatment technology database; this contains abstracts from the literature on all types of treatment technologies, including biological, chemical, physical, and thermal methods. The best literature as viewed by experts is highlighted. (2) treatability study database; this provides performance information on technologies to remove contaminants from wastewaters and soils. It is derived from treatability studies. This database is available through ATTIC or separately as a disk that can be mailed to you. (3) underground storage tank database; this presents information on underground storage tank corrective actions, surface spills, emergency response, and remedial actions. (4) oil/chemical spill database; this provides abstracts on treatment and disposal of spilled oil and chemicals. In addition to these separate databases, ATTIC allows immediate access to other disk-based systems such as the Vendor Information System for Innovative Treatment Technologies (VISITT) and the Bioremediation in the Field Search System (BFSS). The user may download these programs to their own PC via a high-speed modem. Also via modem, users are able to download entire documents through the ATTIC system. Currently, about fifty publications are available, including Superfund Innovative Technology Evaluation (SITE) program documents.

  15. Scattered Neutron Tomography Based on A Neutron Transport Inverse Problem

    Energy Technology Data Exchange (ETDEWEB)

    William Charlton

    2007-07-01

    Neutron radiography and computed tomography are commonly used techniques to non-destructively examine materials. Tomography refers to the cross-sectional imaging of an object from either transmission or reflection data collected by illuminating the object from many different directions.

  16. Diffuse optical tomography based on time-resolved compressive sensing

    Science.gov (United States)

    Farina, A.; Betcke, M.; Di Sieno, L.; Bassi, A.; Ducros, N.; Pifferi, A.; Valentini, G.; Arridge, S.; D'Andrea, C.

    2017-02-01

    Diffuse Optical Tomography (DOT) can be described as a highly multidimensional problem generating a huge data set with long acquisition/computational times. Biological tissue behaves as a low pass filter in the spatial frequency domain, hence compressive sensing approaches, based on both patterned illumination and detection, are useful to reduce the data set while preserving the information content. In this work, a multiple-view time-domain compressed sensing DOT system is presented and experimentally validated on non-planar tissue-mimicking phantoms containing absorbing inclusions.

  17. Orthodontics: computer-aided diagnosis and treatment planning

    Science.gov (United States)

    Yi, Yaxing; Li, Zhongke; Wei, Suyuan; Deng, Fanglin; Yao, Sen

    2000-10-01

    The purpose of this article is to introduce the outline of our newly developed computer-aided 3D dental cast analyzing system with laser scanning, and its preliminary clinical applications. The system is composed of a scanning device and a personal computer as a scanning controller and post processor. The scanning device is composed of a laser beam emitter, two sets of linear CCD cameras and a table which is rotatable by two-degree-of-freedom. The rotating is controlled precisely by a personal computer. The dental cast is projected and scanned with a laser beam. Triangulation is applied to determine the location of each point. Generation of 3D graphics of the dental cast takes approximately 40 minutes. About 170,000 sets of X,Y,Z coordinates are store for one dental cast. Besides the conventional linear and angular measurements of the dental cast, we are also able to demonstrate the size of the top surface area of each molar. The advantage of this system is that it facilitates the otherwise complicated and time- consuming mock surgery necessary for treatment planning in orthognathic surgery.

  18. Computer-aided simulation of the heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Arola, R.; Martikainen, H.; Virta, J. [Technical Research Centre of Finland, Espoo (Finland). Metallurgy Lab.

    1993-12-31

    Computer-aided simulation of the heat treatment of components and charges is examined. Existing programs for the simulation of heat treatment are reviewed. Test simulations including calculation of temperature, phase composition and stresses and strains during heating and cooling are performed with selected programs. The results of the simulations are compared with the results of heat treating experiments. Heat transfer during heating-up varies considerably between different treatments, components of the charge and surfaces of the component. Therefore, heat transfer data defined on the basis of the measurements has to be used in exact simulation instead of literature data. According to the simulation results non-uniform temperature distribution, plastic straining and residual stresses after heating can be formed in an AISI 316 bar heated up at the edge of a charge in a pit furnace. Permanent bending of these bars as a result of heating is not observed. In the oil quenching of a 42CrMo4 cylinder, where martensite and bainite are formed in austenite decomposition, the simulation results (especially amounts of phases and residual stresses) are crucially dependent on the TTT-diagram describing the kinetics of the phase transformations. Several TTT-diagrams for the steel grade are found, leading to different simulation results

  19. Guided Wave Tomography Based on Full-Waveform Inversion.

    Science.gov (United States)

    Rao, Jing; Ratassepp, Madis; Fan, Zheng

    2016-02-29

    In this paper, a guided wave tomography method based on Full Waveform Inversion (FWI) is developed for accurate and high resolu- tion reconstruction of the remaining wall thickness in isotropic plates. The forward model is computed in the frequency domain by solving a full-wave equation in a two-dimensional acoustic model, accounting for higher order eects such as diractions and multiple scattering. Both numerical simulations and experiments were carried out to obtain the signals of a dispersive guided mode propagating through defects. The inversion was based on local optimization of a waveform mist func- tion between modeled and measured data, and was applied iteratively to discrete frequency components from low to high frequencies. The resulting wave velocity maps were then converted to thickness maps by the dispersion characteristics of selected guided modes. The results suggest that the FWI method is capable to reconstruct the thickness map of a irregularly shaped defect accurately on a 10 mm thick plate with the thickness error within 0.5 mm.

  20. Computational neuroscience approach to biomarkers and treatments for mental disorders.

    Science.gov (United States)

    Yahata, Noriaki; Kasai, Kiyoto; Kawato, Mitsuo

    2017-04-01

    Psychiatry research has long experienced a stagnation stemming from a lack of understanding of the neurobiological underpinnings of phenomenologically defined mental disorders. Recently, the application of computational neuroscience to psychiatry research has shown great promise in establishing a link between phenomenological and pathophysiological aspects of mental disorders, thereby recasting current nosology in more biologically meaningful dimensions. In this review, we highlight recent investigations into computational neuroscience that have undertaken either theory- or data-driven approaches to quantitatively delineate the mechanisms of mental disorders. The theory-driven approach, including reinforcement learning models, plays an integrative role in this process by enabling correspondence between behavior and disorder-specific alterations at multiple levels of brain organization, ranging from molecules to cells to circuits. Previous studies have explicated a plethora of defining symptoms of mental disorders, including anhedonia, inattention, and poor executive function. The data-driven approach, on the other hand, is an emerging field in computational neuroscience seeking to identify disorder-specific features among high-dimensional big data. Remarkably, various machine-learning techniques have been applied to neuroimaging data, and the extracted disorder-specific features have been used for automatic case-control classification. For many disorders, the reported accuracies have reached 90% or more. However, we note that rigorous tests on independent cohorts are critically required to translate this research into clinical applications. Finally, we discuss the utility of the disorder-specific features found by the data-driven approach to psychiatric therapies, including neurofeedback. Such developments will allow simultaneous diagnosis and treatment of mental disorders using neuroimaging, thereby establishing 'theranostics' for the first time in clinical

  1. Development of computer algorithms for radiation treatment planning.

    Science.gov (United States)

    Cunningham, J R

    1989-06-01

    As a result of an analysis of data relating tissue response to radiation absorbed dose the ICRU has recommended a target for accuracy of +/- 5 for dose delivery in radiation therapy. This is a difficult overall objective to achieve because of the many steps that make up a course of radiotherapy. The calculation of absorbed dose is only one of the steps and so to achieve an overall accuracy of better than +/- 5% the accuracy in dose calculation must be better yet. The physics behind the problem is sufficiently complicated so that no exact method of calculation has been found and consequently approximate solutions must be used. The development of computer algorithms for this task involves the search for better and better approximate solutions. To achieve the desired target of accuracy a fairly sophisticated calculation procedure must be used. Only when this is done can we hope to further improve our knowledge of the way in which tissues respond to radiation treatments.

  2. Analysis of sagittal anatomic structure of upper airway in patients with ankylosing spondylitis: computed tomography-based three-dimensional reconstruction%强直性脊柱炎患者上气道矢状位解剖结构分析:CT三维重建法

    Institute of Scientific and Technical Information of China (English)

    王幸双; 汪小海; 李文媛; 佟琪; 朱斌

    2013-01-01

    Objective To investigate the characteristics of sagittal anatomic structure of the upper airway in patients with ankylosing spondylitis using three-dimensional reconstruction based on computed tomography (CT).Methods Thirty-one male patients with ankylosing spondylitis,aged 20-60 yr (AS group),and 41 common patients (male) without difficult airways,aged 20-60 yr (control group),who underwent spiral CT scan of the head and neck using Helical CT from January 2007 to February 2011 in our hospital,were enrolled in the study.Reconstructed images of the upper airway were obtained using AW4.4 workstation and six distances (D1-D6) and four angles (α-δ) were recorded and analyzed:(1)D1,the arc distance between the upper central incisor and root of epiglottis; D2,the distance between the upper central incisor and root of epiglottis; D3 and D4,the lengths of maxilla and mandible ; D5,the distance between the root of epiglottis and midpoint of glottis; D6,the distance between the end of mandible and midpoint of glottis; (2) angle α,the angle of line D2 and D5; angle β,the angle of line D2 and the lower edge of the upper central incisor to the midpoint of glottis; angle γ,the angle of line D4 and D6; angle δ,the angle of the point of the lower edge of the upper central incisor to the trailing edge of the hard palate and then to the root of epiglottis.Results Compared with control group,no significant change was found in D1,D2,D3,D4 and D5 (P > 0.05),and D6,angle α and angle δ were significantly increased,whereas angle β and angle γ were decreased in AS group (P < 0.05).Conclusion The anatomic structure of the upper airway has the characteristics of specific changes and a laryngoscope blade with a large degree of curvature may be helpful for successful tracheal intubation in patients with ankylosing spondylitis.%目的 采用CT三维重建技术探讨强直性脊柱炎患者上气道解剖结构的特点.方法 选择2007年1月至2011年2月在本院行头颈部

  3. Principle of diffraction enhanced imaging(DEI) and computed tomography based on DEI method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In the first part of this article a more general DEI equation was derived using simple concepts. Not only does the new DEI equation explain all the problems that can be done by the DEI equation proposed by Chapman, but also explains the problem that can not be explained with the old DEI equation, such as the noise background caused by the small angle scattering reflected by the analyzer. In the second part, a DEI-PI-CT formula has been proposed and the contour contrast caused by the extinction of refraction beam has been qualitatively explained, and then based on the work of Ando's group two formulae of refraction CT with DEI method has been proposed. Combining one refraction CT formula proposed by Dilmanian with the two refraction CT formulae proposed by us, the whole framework of CT algorithm can be made to reconstruct three components of the gradient of refractive index.

  4. Virtual Reality versus Computer-Aided Exposure Treatments for Fear of Flying

    Science.gov (United States)

    Tortella-Feliu, Miquel; Botella, Cristina; Llabres, Jordi; Breton-Lopez, Juana Maria; del Amo, Antonio Riera; Banos, Rosa M.; Gelabert, Joan M.

    2011-01-01

    Evidence is growing that two modalities of computer-based exposure therapies--virtual reality and computer-aided psychotherapy--are effective in treating anxiety disorders, including fear of flying. However, they have not yet been directly compared. The aim of this study was to analyze the efficacy of three computer-based exposure treatments for…

  5. Virtual Reality versus Computer-Aided Exposure Treatments for Fear of Flying

    Science.gov (United States)

    Tortella-Feliu, Miquel; Botella, Cristina; Llabres, Jordi; Breton-Lopez, Juana Maria; del Amo, Antonio Riera; Banos, Rosa M.; Gelabert, Joan M.

    2011-01-01

    Evidence is growing that two modalities of computer-based exposure therapies--virtual reality and computer-aided psychotherapy--are effective in treating anxiety disorders, including fear of flying. However, they have not yet been directly compared. The aim of this study was to analyze the efficacy of three computer-based exposure treatments for…

  6. Refractive index tomography based on optical coherence tomography and tomographic reconstruction algorithm

    Science.gov (United States)

    Kitazawa, Takahiro; Nomura, Takanori

    2017-09-01

    Refractive index (RI) tomography based on not quantitative phase imaging (QPI) but optical coherence tomography (OCT) is proposed. In conventional RI tomography, the phase unwrapping process deteriorates measurement accuracy owing to the unwrapping error. To eliminate the unwrapping process, the introduction of OCT is proposed, because OCT directly provides optical thickness. The proposed method can improve measurement accuracy owing to the removal of the phase unwrapping error. The feasibility of the method is confirmed by numerical simulations and optical experiments. These results show that the proposed method can reduce measurement errors even when an object shows phase changes much larger than a wavelength.

  7. Review: the physiological and computational approaches for atherosclerosis treatment.

    Science.gov (United States)

    Wang, Wuchen; Lee, Yugyung; Lee, Chi H

    2013-09-01

    The cardiovascular disease has long been an issue that causes severe loss in population, especially those conditions associated with arterial malfunction, being attributable to atherosclerosis and subsequent thrombotic formation. This article reviews the physiological mechanisms that underline the transition from plaque formation in atherosclerotic process to platelet aggregation and eventually thrombosis. The physiological and computational approaches, such as percutaneous coronary intervention and stent design modeling, to detect, evaluate and mitigate this malicious progression were also discussed.

  8. Pathological fracture prediction in patients with metastatic lesions can be improved with quantitative computed tomography based computer models.

    NARCIS (Netherlands)

    Tanck, E.J.M.; Aken, J.B. van; Linden, Y.M. van der; Schreuder, H.W.B.; Binkowski, M.; Huizenga, H.; Verdonschot, N.J.J.

    2009-01-01

    PURPOSE: In clinical practice, there is an urgent need to improve the prediction of fracture risk for cancer patients with bone metastases. The methods that are currently used to estimate fracture risk are dissatisfying, hence affecting the quality of life of patients with a limited life expectancy.

  9. Pathological fracture prediction in patients with metastatic lesions can be improved with quantitative computed tomography based computer models

    NARCIS (Netherlands)

    Tanck, Esther; Aken, van Jantien B.; Linden, van der Yvette M.; Schreuder, H.W. Bart; Binkowski, Marcin; Huizenga, Henk; Verdonschot, Nico

    2009-01-01

    Purpose: In clinical practice, there is an urgent need to improve the prediction of fracture risk for cancer patients with bone metastases. The methods that are currently used to estimate fracture risk are dissatisfying, hence affecting the quality of life of patients with a limited life expectancy.

  10. Quality of data computational models and telemedicine treatment effects

    NARCIS (Netherlands)

    Larburu, Nekane; Bults, Richard G.A.; Widya, Ing; Hermens, Hermie J.

    2014-01-01

    Clinical decision-support functions of telemedicine systems use patient's monitored clinical data to support treatment of outpatients. However, the quality of monitored clinical data may vary due to performance variations of technological resources inside a deployed telemedicine system. This paper d

  11. 3D Computer aided treatment planning in endodontics

    NARCIS (Netherlands)

    van der Meer, Wicher J.; Vissink, Arjan; Ng, Yuan Ling; Gulabivala, Kishor

    Objectives: Obliteration of the root canal system due to accelerated dentinogenesis and dystrophic calcification can challenge the achievement of root canal treatment goals. This paper describes the application of 3D digital mapping technology for predictable navigation of obliterated canal systems

  12. Coronary revascularization treatment based on dual-source computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Dikkers, R.; Willems, T.P.; Jonge, G.J. de; Zaag-Loonen, H.J. van der; Ooijen, P.M.A. van; Oudkerk, M. [University of Groningen, Department of Radiology, Groningen (Netherlands); University Medical Center, Groningen (Netherlands); Piers, L.H.; Tio, R.A.; Zijlstra, F. [University of Groningen, Department of Cardiology, Groningen (Netherlands); University Medical Center, Groningen (Netherlands)

    2008-09-15

    Therapy advice based on dual-source computed tomography (DSCT) in comparison with coronary angiography (CAG) was investigated and the results evaluated after 1-year follow-up. Thirty-three consecutive patients (mean age 61.9 years) underwent DSCT and CAG and were evaluated independently. In an expert reading (the ''gold standard''), CAG and DSCT examinations were evaluated simultaneously by an experienced radiologist and cardiologist. Based on the presence of significant stenosis and current guidelines, therapy advice was given by all readers blinded from the results of other readings and clinical information. Patients were treated based on a multidisciplinary team evaluation including all clinical information. In comparison with the gold standard, CAG had a higher specificity (91%) and positive predictive value (PPV) (95%) compared with DSCT (82% and 91%, respectively). DSCT had a higher sensitivity (96%) and negative predictive value (NPV) (89%) compared with CAG (91% and 83%, respectively). The DSCT-based therapy advice did not lead to any patient being denied the revascularization they needed according to the multidisciplinary team evaluation. During follow-up, two patients needed additional revascularization. The high NPV for DSCT for revascularization assessment indicates that DSCT could be safely used to select patients benefiting from medical therapy only. (orig.)

  13. Computational modeling and real-time control of patient-specific laser treatment of cancer.

    Science.gov (United States)

    Fuentes, D; Oden, J T; Diller, K R; Hazle, J D; Elliott, A; Shetty, A; Stafford, R J

    2009-04-01

    An adaptive feedback control system is presented which employs a computational model of bioheat transfer in living tissue to guide, in real-time, laser treatments of prostate cancer monitored by magnetic resonance thermal imaging. The system is built on what can be referred to as cyberinfrastructure-a complex structure of high-speed network, large-scale parallel computing devices, laser optics, imaging, visualizations, inverse-analysis algorithms, mesh generation, and control systems that guide laser therapy to optimally control the ablation of cancerous tissue. The computational system has been successfully tested on in vivo, canine prostate. Over the course of an 18 min laser-induced thermal therapy performed at M.D. Anderson Cancer Center (MDACC) in Houston, Texas, the computational models were calibrated to intra-operative real-time thermal imaging treatment data and the calibrated models controlled the bioheat transfer to within 5 degrees C of the predetermined treatment plan. The computational arena is in Austin, Texas and managed at the Institute for Computational Engineering and Sciences (ICES). The system is designed to control the bioheat transfer remotely while simultaneously providing real-time remote visualization of the on-going treatment. Post-operative histology of the canine prostate reveal that the damage region was within the targeted 1.2 cm diameter treatment objective.

  14. Computer-Based Script Training for Aphasia: Emerging Themes from Post-Treatment Interviews

    Science.gov (United States)

    Cherney, Leora R.; Halper, Anita S.; Kaye, Rosalind C.

    2011-01-01

    This study presents results of post-treatment interviews following computer-based script training for persons with chronic aphasia. Each of the 23 participants received 9 weeks of AphasiaScripts training. Post-treatment interviews were conducted with the person with aphasia and/or a significant other person. The 23 interviews yielded 584 coded…

  15. Pregnancy and the Acceptability of Computer-Based Versus Traditional Mental Health Treatments.

    Science.gov (United States)

    Hantsoo, Liisa; Podcasy, Jessica; Sammel, Mary; Epperson, Cynthia Neill; Kim, Deborah R

    2017-04-20

    Recent recommendations urge increased depression screening in pregnant and postpartum women, potentially increasing demand for treatment. Computer-based psychotherapy treatments may address some of perinatal women's unique mental health treatment needs and barriers. We conducted a quantitative survey of pregnant women (≥12 weeks of gestation) on preferences regarding computer-based therapies compared with traditional therapies (psychotherapy and medication). Nonpregnant women and men served as comparison groups. Participants were provided descriptions of three computer-based therapies: video telehealth therapy (VTT), computer-assisted therapy (CAT), and self-guided online therapy (SGO). Participants were asked to select all options that they would consider for treatment as well as first choice preference. The Patient Health Questionnaire-9 (PHQ-9) assessed current depressive symptomatology, and the Mini International Neuropsychiatric Interview (MINI) assessed psychiatric history. Participants included pregnant females (n = 111), nonpregnant females (n = 147), and males (n = 54). Among pregnant women, 77.5% (n = 86) indicated that they would consider some form of computer-based therapy for mental health treatment during pregnancy; VTT was the most commonly considered, followed by CAT and SGO. When asked to select their preferred intervention, traditional talk therapy was the first choice among all three groups, controlling for treatment history and PHQ-9 score. About one-third of pregnant women chose some form of computer-based therapy as their top choice. While computer-based therapies were acceptable to most pregnant women in this sample, traditional talk therapy was the preferred option. Future research should consider how to tailor computer-based therapies to the unique needs of perinatal women.

  16. Constructing evidence-based treatment strategies using methods from computer science.

    Science.gov (United States)

    Pineau, Joelle; Bellemare, Marc G; Rush, A John; Ghizaru, Adrian; Murphy, Susan A

    2007-05-01

    This paper details a new methodology, instance-based reinforcement learning, for constructing adaptive treatment strategies from randomized trials. Adaptive treatment strategies are operationalized clinical guidelines which recommend the next best treatment for an individual based on his/her personal characteristics and response to earlier treatments. The instance-based reinforcement learning methodology comes from the computer science literature, where it was developed to optimize sequences of actions in an evolving, time varying system. When applied in the context of treatment design, this method provides the means to evaluate both the therapeutic and diagnostic effects of treatments in constructing an adaptive treatment strategy. The methodology is illustrated with data from the STAR*D trial, a multi-step randomized study of treatment alternatives for individuals with treatment-resistant major depressive disorder.

  17. A Computer Simulation of Progesterone and Cox2 Inhibitor Treatment for Preterm Labor

    OpenAIRE

    Ozlem Equils; Priya Nambiar; Hobel, Calvin J.; Roger Smith; Simmons, Charles F.; Shireen Vali

    2010-01-01

    BACKGROUND: Sufficient information from in vitro and in vivo studies has become available to permit computer modeling of the processes that occur in the myometrium during labor. This development allows the in silico investigation of pathological mechanisms and the trialing of potential treatments. METHODS/RESULTS: Based on the human literature, we developed a computer model of the immune-endocrine environment of the myometrial cell. The interactions between molecules are represented by differ...

  18. Computer vision syndrome: a review of ocular causes and potential treatments.

    Science.gov (United States)

    Rosenfield, Mark

    2011-09-01

    Computer vision syndrome (CVS) is the combination of eye and vision problems associated with the use of computers. In modern western society the use of computers for both vocational and avocational activities is almost universal. However, CVS may have a significant impact not only on visual comfort but also occupational productivity since between 64% and 90% of computer users experience visual symptoms which may include eyestrain, headaches, ocular discomfort, dry eye, diplopia and blurred vision either at near or when looking into the distance after prolonged computer use. This paper reviews the principal ocular causes for this condition, namely oculomotor anomalies and dry eye. Accommodation and vergence responses to electronic screens appear to be similar to those found when viewing printed materials, whereas the prevalence of dry eye symptoms is greater during computer operation. The latter is probably due to a decrease in blink rate and blink amplitude, as well as increased corneal exposure resulting from the monitor frequently being positioned in primary gaze. However, the efficacy of proposed treatments to reduce symptoms of CVS is unproven. A better understanding of the physiology underlying CVS is critical to allow more accurate diagnosis and treatment. This will enable practitioners to optimize visual comfort and efficiency during computer operation.

  19. Experiments of Tomography-Based SAR Techniques with P-Band Polarimetric Data

    Science.gov (United States)

    Lombardini, F.; Pardini, M.

    2009-04-01

    New opportunities are arising in the synthetic aperture radar (SAR) observation of forest scenarios, especially with decimetric and metric radio wavelengths, which possess the capability of penetrating into volumes. Given its capabilities in the three-dimensional imaging of the scattering properties of the observed scene, SAR Tomography (Tomo-SAR) constitutes a good candidate for the analysis of the vertical structure of the forest. In this work, the results are presented of the application of tomography-based SAR techniques to P-band airborne data over a boreal forest from the ESA BioSAR-1 project. Results of an adaptive tomographic analysis are presented, also with a low resolution dataset, which emulates a satellite acquisition. In order to mitigate the geometric perspective effects due to the poor range resolution, the principle is introduced of the application of a common band pre-filtering to tomography. Then, a coherent layer canceller is derived to possibly apply interferometric techniques conceived for single layer scenarios to two layer scenarios. Finally, a stabilized adaptive polarimetric Tomo-SAR (PolTomo-SAR) method is proposed for estimating the 3D polarimetric scattering mechanism of the scene with low distorsions.

  20. Computational Intelligence Techniques for Control and Optimization of Wastewater Treatment Plants

    OpenAIRE

    2016-01-01

    The development of novel, practice-oriented and reliable instrumentation and control strategies for wastewater treatment plants in order to improve energy efficiency, while guaranteeing process stability and maintenance of high cleaning capacity, has become a priority for WWTP operators due to increasing treatment costs. To achieve these ambitious and even contradictory objectives, this thesis investigates a combination of online measurement systems, computational intelligence and...

  1. NO-FEAR Airlines: A Computer-aided Self-help Treatment for Flying Phobia.

    Science.gov (United States)

    Quero, Soledad; Campos, Daniel; Riera Del Amo, Antonio; Bretón-López, Juana; Tortella-Feliu, Miquel; Baños, Rosa Ma; Botella, Cristina

    2015-01-01

    In vivo exposure is the treatment of choice for specific phobias. However, this treatment is linked to a number of limitations in its implementation. Therefore, it is important to develop strategies for improving treatment adherence, acceptance, and dissemination of evidence-based treatments. Information and Communication Technologies, specifically, computerized programs boast advantages in treating flying phobia. NO-FEAR Airlines is a Computer-aided Self-help Treatment for this problem, which can be self-applied via Internet. NO-FEAR Airlines treatment protocol comprises three therapeutic components: psychoeducation, exposure and overlearning. Exposure is carried out through 6 scenarios that are composed by images and real sounds related to a flight in process. The aim of the present work is to describe NO-FEAR Airlines program.

  2. The outcome of root-canal treatments assessed by cone-beam computed tomography

    NARCIS (Netherlands)

    Liang, Y.H.

    2013-01-01

    In this thesis, in-vivo and ex-vivo methods were utilized to assess the outcome of root canal treatments determined by cone-beam computed tomography (CBCT) and the reliability of the CBCT-findings. CBCT provided useful and reliable information leading to a better understanding of the outcome and fac

  3. Computer Simulation of an Anesthesia Service at a U.S. Army Medical Treatment Facility

    Science.gov (United States)

    1999-08-01

    Anesthesia Simulation Study 1 Running head : ANESTHESIA SIMULATION Computer Simulation of an Anesthesia Service at a U.S. Army Medical Treatment...bettering marketing efforts). There are several articles that address staffing from the perspective of what type of provider is the most cost

  4. SU-E-T-222: Computational Optimization of Monte Carlo Simulation On 4D Treatment Planning Using the Cloud Computing Technology

    Energy Technology Data Exchange (ETDEWEB)

    Chow, J [Princess Margaret Cancer Center, Toronto, ON (Canada)

    2015-06-15

    Purpose: This study evaluated the efficiency of 4D lung radiation treatment planning using Monte Carlo simulation on the cloud. The EGSnrc Monte Carlo code was used in dose calculation on the 4D-CT image set. Methods: 4D lung radiation treatment plan was created by the DOSCTP linked to the cloud, based on the Amazon elastic compute cloud platform. Dose calculation was carried out by Monte Carlo simulation on the 4D-CT image set on the cloud, and results were sent to the FFD4D image deformation program for dose reconstruction. The dependence of computing time for treatment plan on the number of compute node was optimized with variations of the number of CT image set in the breathing cycle and dose reconstruction time of the FFD4D. Results: It is found that the dependence of computing time on the number of compute node was affected by the diminishing return of the number of node used in Monte Carlo simulation. Moreover, the performance of the 4D treatment planning could be optimized by using smaller than 10 compute nodes on the cloud. The effects of the number of image set and dose reconstruction time on the dependence of computing time on the number of node were not significant, as more than 15 compute nodes were used in Monte Carlo simulations. Conclusion: The issue of long computing time in 4D treatment plan, requiring Monte Carlo dose calculations in all CT image sets in the breathing cycle, can be solved using the cloud computing technology. It is concluded that the optimized number of compute node selected in simulation should be between 5 and 15, as the dependence of computing time on the number of node is significant.

  5. Mechanical and dosimetric quality control for computer controlled radiotherapy treatment equipment.

    Science.gov (United States)

    Thompson, A V; Lam, K L; Balter, J M; McShan, D L; Martel, M K; Weaver, T A; Fraass, B A; Ten Haken, R K

    1995-05-01

    Modern computer controlled radiotherapy treatment equipment offers the possibility of delivering complex, multiple field treatments with minimal operator intervention, thus making multiple field conformal therapy practical. Conventional quality control programs are inadequate for this new technology, so new quality control procedures are needed. A reasonably fast, sensitive, and complete daily quality control program has been developed in our clinic that includes nearly automated mechanical as well as dosimetric tests. Automated delivery of these quality control fields is performed by the control system of the MM50 racetrack microtron, directed by the CCRS sequence processor [D. L. McShan and B. A. Fraass, Proceedings of the XIth International Conference on the use of computers in Radiation Therapy, 20-24 March 1994, Manchester, U.K. (North Western Medical Physics Department, Manchester, U.K., 1994), pp. 210-211], which controls the treatment process. The mechanical tests involve multiple irradiations of a single film to check the accuracy and reproducibility of the computer controlled setup of gantry and collimator angles, table orientation, collimator jaws, and multileaf collimator shape. The dosimetric tests, which involve multiple irradiations of an array of ionization chambers in a commercial dose detector (Keithly model 90100 Tracker System) rigidly attached to the head of the treatment gantry, check the output and symmetry of the treatment unit as a function of gantry and collimator angle and other parameters. For each of the dosimetric tests, readings from the five ionization chambers are automatically read out, stored, and analyzed by the computer, along with the geometric parameters of the treatment unit for that beam.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Computational fluid dynamics evaluation of flow reversal treatment of giant basilar tip aneurysm.

    Science.gov (United States)

    Alnæs, Martin Sandve; Mardal, Kent-Andre; Bakke, Søren; Sorteberg, Angelika

    2015-10-01

    Therapeutic parent artery flow reversal is a treatment option for giant, partially thrombosed basilar tip aneurysms. The effectiveness of this treatment has been variable and not yet studied by applying computational fluid dynamics. Computed tomography images and blood flow velocities acquired with transcranial Doppler ultrasonography were obtained prior to and after bilateral endovascular vertebral artery occlusion for a giant basilar tip aneurysm. Patient-specific geometries and velocity waveforms were used in computational fluid dynamics simulations in order to determine the velocity and wall shear stress changes induced by treatment. Therapeutic parent artery flow reversal lead to a dramatic increase in aneurysm inflow and wall shear stress (30 to 170 Pa) resulting in an increase in intra-aneurysmal circulation. The enlargement of the circulated area within the aneurysm led to a re-normalization of the wall shear stress and the aneurysm remained stable for more than 8 years thereafter. Therapeutic parent artery flow reversal can lead to unintended, potentially harmful changes in aneurysm inflow which can be quantified and possibly predicted by applying computational fluid dynamics.

  7. COMPUTING

    CERN Multimedia

    M. Kasemann

    Overview In autumn the main focus was to process and handle CRAFT data and to perform the Summer08 MC production. The operational aspects were well covered by regular Computing Shifts, experts on duty and Computing Run Coordination. At the Computing Resource Board (CRB) in October a model to account for service work at Tier 2s was approved. The computing resources for 2009 were reviewed for presentation at the C-RRB. The quarterly resource monitoring is continuing. Facilities/Infrastructure operations Operations during CRAFT data taking ran fine. This proved to be a very valuable experience for T0 workflows and operations. The transfers of custodial data to most T1s went smoothly. A first round of reprocessing started at the Tier-1 centers end of November; it will take about two weeks. The Computing Shifts procedure was tested full scale during this period and proved to be very efficient: 30 Computing Shifts Persons (CSP) and 10 Computing Resources Coordinators (CRC). The shift program for the shut down w...

  8. COMPUTING

    CERN Multimedia

    M. Kasemann

    Overview During the past three months activities were focused on data operations, testing and re-enforcing shift and operational procedures for data production and transfer, MC production and on user support. Planning of the computing resources in view of the new LHC calendar in ongoing. Two new task forces were created for supporting the integration work: Site Commissioning, which develops tools helping distributed sites to monitor job and data workflows, and Analysis Support, collecting the user experience and feedback during analysis activities and developing tools to increase efficiency. The development plan for DMWM for 2009/2011 was developed at the beginning of the year, based on the requirements from the Physics, Computing and Offline groups (see Offline section). The Computing management meeting at FermiLab on February 19th and 20th was an excellent opportunity discussing the impact and for addressing issues and solutions to the main challenges facing CMS computing. The lack of manpower is particul...

  9. COMPUTING

    CERN Multimedia

    I. Fisk

    2011-01-01

    Introduction CMS distributed computing system performed well during the 2011 start-up. The events in 2011 have more pile-up and are more complex than last year; this results in longer reconstruction times and harder events to simulate. Significant increases in computing capacity were delivered in April for all computing tiers, and the utilisation and load is close to the planning predictions. All computing centre tiers performed their expected functionalities. Heavy-Ion Programme The CMS Heavy-Ion Programme had a very strong showing at the Quark Matter conference. A large number of analyses were shown. The dedicated heavy-ion reconstruction facility at the Vanderbilt Tier-2 is still involved in some commissioning activities, but is available for processing and analysis. Facilities and Infrastructure Operations Facility and Infrastructure operations have been active with operations and several important deployment tasks. Facilities participated in the testing and deployment of WMAgent and WorkQueue+Request...

  10. COMPUTING

    CERN Multimedia

    P. McBride

    The Computing Project is preparing for a busy year where the primary emphasis of the project moves towards steady operations. Following the very successful completion of Computing Software and Analysis challenge, CSA06, last fall, we have reorganized and established four groups in computing area: Commissioning, User Support, Facility/Infrastructure Operations and Data Operations. These groups work closely together with groups from the Offline Project in planning for data processing and operations. Monte Carlo production has continued since CSA06, with about 30M events produced each month to be used for HLT studies and physics validation. Monte Carlo production will continue throughout the year in the preparation of large samples for physics and detector studies ramping to 50 M events/month for CSA07. Commissioning of the full CMS computing system is a major goal for 2007. Site monitoring is an important commissioning component and work is ongoing to devise CMS specific tests to be included in Service Availa...

  11. QA issues for computer-controlled treatment delivery: this is not your old R/V system any more!

    Science.gov (United States)

    Fraass, Benedick A

    2008-01-01

    State-of-the-art radiotherapy treatment delivery has changed dramatically during the past decade, moving from manual individual field setup and treatment to automated computer-controlled delivery of complex treatments, including intensity-modulated radiotherapy and other similarly complex delivery strategies. However, the quality assurance methods typically used to ensure treatment is performed precisely and correctly have not evolved in a similarly dramatic way. This paper reviews the old manual treatment process and use of record-and-verify systems, and describes differences with modern computer-controlled treatment delivery. The process and technology used for computer-controlled treatment delivery are analyzed in terms of potential (and actual) problems, as well as relevant published guidance on quality assurance. The potential for improved quality assurance for computer-controlled delivery is discussed.

  12. Three-dimensional computed tomography image based endovascular treatment for hepatic vein.

    Science.gov (United States)

    Ninomiya, Mizuki; Ikeda, Tetsuo; Shirabe, Ken; Kayashima, Hiroto; Harimoto, Norifumi; Iguchi, Tomohiro; Sugimachi, Keishi; Yamashita, Yo-Ichi; Ikegami, Toru; Saeki, Hiroshi; Oki, Eiji; Uchiyama, Hideaki; Yoshizumi, Tomoharu; Soejima, Yuji; Kawanaka, Hirofumi; Morita, Masaru; Maehara, Yoshihiko

    2013-11-01

    Along with the expansion of living donor liver transplantation, whereby hepatic venous anastomosis is mandatory, the frequency of hepatic venous stenosis that need interventional treatment is increasing. Due to its anatomical features, there are several pitfalls in the process of endovascular intervention for hepatic vein. Insufficient information of and around the hepatic vein may lead to miss-diagnosis of target lesion. Simulation by using three-dimensional computed tomography images was useful in planning the direction of X-ray projection and, as a consequence, contributed to safe endovascular treatment for hepatic venous stenosis.

  13. A computer-based anaglyphic system for the treatment of amblyopia

    Directory of Open Access Journals (Sweden)

    Rastegarpour A

    2011-09-01

    Full Text Available Ali Rastegarpour Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Purpose: Virtual reality (VR-based treatment has been introduced as a potential option for amblyopia management, presumably without involving the problems of occlusion and penalization, including variable and unsatisfactory outcomes, long duration of treatment, poor compliance, psychological impact, and complications. However, VR-based treatment is costly and not accessible for most children. This paper introduces a method that encompasses the advantages of VR-based treatment at a lower cost. Methods: The presented system consists of a pair of glasses with two color filters and software for use on a personal computer. The software is designed such that some active graphic components can only be seen by the amblyopic eye and are filtered out for the other eye. Some components would be seen by both to encourage fusion. The result is that the patient must use both eyes, and specifically the amblyopic eye, to play the games. Results: A prototype of the system, the ABG InSight, was found capable of successfully filtering out elements of a certain color and therefore, could prove to be a viable alternative to VR-based treatment for amblyopia. Conclusion: The anaglyphic system maintains most of the advantages of VR-based systems, but is less costly and highly accessible. It fulfills the means that VR-based systems are designed to achieve, and warrants further investigation. Keywords: amblyopia, computer-based, open source, virtual reality, color filters, 3-D

  14. G-computation of average treatment effects on the treated and the untreated

    Directory of Open Access Journals (Sweden)

    Aolin Wang

    2017-01-01

    Full Text Available Abstract Background Average treatment effects on the treated (ATT and the untreated (ATU are useful when there is interest in: the evaluation of the effects of treatments or interventions on those who received them, the presence of treatment heterogeneity, or the projection of potential outcomes in a target (sub- population. In this paper we illustrate the steps for estimating ATT and ATU using g-computation implemented via Monte Carlo simulation. Methods To obtain marginal effect estimates for ATT and ATU we used a three-step approach: fitting a model for the outcome, generating potential outcome variables for ATT and ATU separately, and regressing each potential outcome variable on treatment intervention. Results The estimates for ATT, ATU and average treatment effect (ATE were of similar magnitude, with ATE being in between ATT and ATU as expected. In our illustrative example, the effect (risk difference [RD] of a higher education on angina among the participants who indeed have at least a high school education (ATT was −0.019 (95% CI: −0.040, −0.007 and that among those who have less than a high school education in India (ATU was −0.012 (95% CI: −0.036, 0.010. Conclusions The g-computation algorithm is a powerful way of estimating standardized estimates like the ATT and ATU. Its use should be encouraged in modern epidemiologic teaching and practice.

  15. A computational tool integrating host immunity with antibiotic dynamics to study tuberculosis treatment.

    Science.gov (United States)

    Pienaar, Elsje; Cilfone, Nicholas A; Lin, Philana Ling; Dartois, Véronique; Mattila, Joshua T; Butler, J Russell; Flynn, JoAnne L; Kirschner, Denise E; Linderman, Jennifer J

    2015-02-21

    While active tuberculosis (TB) is a treatable disease, many complex factors prevent its global elimination. Part of the difficulty in developing optimal therapies is the large design space of antibiotic doses, regimens and combinations. Computational models that capture the spatial and temporal dynamics of antibiotics at the site of infection can aid in reducing the design space of costly and time-consuming animal pre-clinical and human clinical trials. The site of infection in TB is the granuloma, a collection of immune cells and bacteria that form in the lung, and new data suggest that penetration of drugs throughout granulomas is problematic. Here we integrate our computational model of granuloma formation and function with models for plasma pharmacokinetics, lung tissue pharmacokinetics and pharmacodynamics for two first line anti-TB antibiotics. The integrated model is calibrated to animal data. We make four predictions. First, antibiotics are frequently below effective concentrations inside granulomas, leading to bacterial growth between doses and contributing to the long treatment periods required for TB. Second, antibiotic concentration gradients form within granulomas, with lower concentrations toward their centers. Third, during antibiotic treatment, bacterial subpopulations are similar for INH and RIF treatment: mostly intracellular with extracellular bacteria located in areas non-permissive for replication (hypoxic areas), presenting a slowly increasing target population over time. Finally, we find that on an individual granuloma basis, pre-treatment infection severity (including bacterial burden, host cell activation and host cell death) is predictive of treatment outcome.

  16. Computer aided diagnosis and treatment planning for developmental dysplasia of the hip

    Science.gov (United States)

    Li, Bin; Lu, Hongbing; Cai, Wenli; Li, Xiang; Meng, Jie; Liang, Zhengrong

    2005-04-01

    The developmental dysplasia of the hip (DDH) is a congenital malformation affecting the proximal femurs and acetabulum that are subluxatable, dislocatable, and dislocated. Early diagnosis and treatment is important because failure to diagnose and improper treatment can result in significant morbidity. In this paper, we designed and implemented a computer aided system for the diagnosis and treatment planning of this disease. With the design, the patient received CT (computed tomography) or MRI (magnetic resonance imaging) scan first. A mixture-based PV partial-volume algorithm was applied to perform bone segmentation on CT image, followed by three-dimensional (3D) reconstruction and display of the segmented image, demonstrating the special relationship between the acetabulum and femurs for visual judgment. Several standard procedures, such as Salter procedure, Pemberton procedure and Femoral Shortening osteotomy, were simulated on the screen to rehearse a virtual treatment plan. Quantitative measurement of Acetabular Index (AI) and Femoral Neck Anteversion (FNA) were performed on the 3D image for evaluation of DDH and treatment plans. PC graphics-card GPU architecture was exploited to accelerate the 3D rendering and geometric manipulation. The prototype system was implemented on PC/Windows environment and is currently under clinical trial on patient datasets.

  17. COMPUTING

    CERN Multimedia

    I. Fisk

    2013-01-01

    Computing activity had ramped down after the completion of the reprocessing of the 2012 data and parked data, but is increasing with new simulation samples for analysis and upgrade studies. Much of the Computing effort is currently involved in activities to improve the computing system in preparation for 2015. Operations Office Since the beginning of 2013, the Computing Operations team successfully re-processed the 2012 data in record time, not only by using opportunistic resources like the San Diego Supercomputer Center which was accessible, to re-process the primary datasets HTMHT and MultiJet in Run2012D much earlier than planned. The Heavy-Ion data-taking period was successfully concluded in February collecting almost 500 T. Figure 3: Number of events per month (data) In LS1, our emphasis is to increase efficiency and flexibility of the infrastructure and operation. Computing Operations is working on separating disk and tape at the Tier-1 sites and the full implementation of the xrootd federation ...

  18. SU-C-206-03: Metal Artifact Reduction in X-Ray Computed Tomography Based On Local Anatomical Similarity

    Energy Technology Data Exchange (ETDEWEB)

    Dong, X; Yang, X; Rosenfield, J; Elder, E; Dhabaan, A [Emory University, Winship Cancer Institute, Atlanta, GA (United States)

    2016-06-15

    Purpose: Metal implants such as orthopedic hardware and dental fillings cause severe bright and dark streaking in reconstructed CT images. These artifacts decrease image contrast and degrade HU accuracy, leading to inaccuracies in target delineation and dose calculation. Additionally, such artifacts negatively impact patient set-up in image guided radiation therapy (IGRT). In this work, we propose a novel method for metal artifact reduction which utilizes the anatomical similarity between neighboring CT slices. Methods: Neighboring CT slices show similar anatomy. Based on this anatomical similarity, the proposed method replaces corrupted CT pixels with pixels from adjacent, artifact-free slices. A gamma map, which is the weighted summation of relative HU error and distance error, is calculated for each pixel in the artifact-corrupted CT image. The minimum value in each pixel’s gamma map is used to identify a pixel from the adjacent CT slice to replace the corresponding artifact-corrupted pixel. This replacement only occurs if the minimum value in a particular pixel’s gamma map is larger than a threshold. The proposed method was evaluated with clinical images. Results: Highly attenuating dental fillings and hip implants cause severe streaking artifacts on CT images. The proposed method eliminates the dark and bright streaking and improves the implant delineation and visibility. In particular, the image non-uniformity in the central region of interest was reduced from 1.88 and 1.01 to 0.28 and 0.35, respectively. Further, the mean CT HU error was reduced from 328 HU and 460 HU to 60 HU and 36 HU, respectively. Conclusions: The proposed metal artifact reduction method replaces corrupted image pixels with pixels from neighboring slices that are free of metal artifacts. This method proved capable of suppressing streaking artifacts, improving HU accuracy and image detectability.

  19. A virtual sinogram method to reduce dental metallic implant artefacts in computed tomography-based attenuation correction for PET

    NARCIS (Netherlands)

    Abdoli, Mehrsima; Ay, Mohammad Reza; Ahmadian, Alireza; Zaidi, Habib

    2010-01-01

    Objective Attenuation correction of PET data requires accurate determination of the attenuation map (mu map), which represents the spatial distribution of linear attenuation coefficients of different tissues at 511 keV. The presence of high-density metallic dental filling material in head and neck X

  20. Phantom-less bone mineral density (BMD) measurement using dual energy computed tomography-based 3-material decomposition

    Science.gov (United States)

    Hofmann, Philipp; Sedlmair, Martin; Krauss, Bernhard; Wichmann, Julian L.; Bauer, Ralf W.; Flohr, Thomas G.; Mahnken, Andreas H.

    2016-03-01

    Osteoporosis is a degenerative bone disease usually diagnosed at the manifestation of fragility fractures, which severely endanger the health of especially the elderly. To ensure timely therapeutic countermeasures, noninvasive and widely applicable diagnostic methods are required. Currently the primary quantifiable indicator for bone stability, bone mineral density (BMD), is obtained either by DEXA (Dual-energy X-ray absorptiometry) or qCT (quantitative CT). Both have respective advantages and disadvantages, with DEXA being considered as gold standard. For timely diagnosis of osteoporosis, another CT-based method is presented. A Dual Energy CT reconstruction workflow is being developed to evaluate BMD by evaluating lumbar spine (L1-L4) DE-CT images. The workflow is ROI-based and automated for practical use. A dual energy 3-material decomposition algorithm is used to differentiate bone from soft tissue and fat attenuation. The algorithm uses material attenuation coefficients on different beam energy levels. The bone fraction of the three different tissues is used to calculate the amount of hydroxylapatite in the trabecular bone of the corpus vertebrae inside a predefined ROI. Calibrations have been performed to obtain volumetric bone mineral density (vBMD) without having to add a calibration phantom or to use special scan protocols or hardware. Accuracy and precision are dependent on image noise and comparable to qCT images. Clinical indications are in accordance with the DEXA gold standard. The decomposition-based workflow shows bone degradation effects normally not visible on standard CT images which would induce errors in normal qCT results.

  1. Computer

    CERN Document Server

    Atkinson, Paul

    2011-01-01

    The pixelated rectangle we spend most of our day staring at in silence is not the television as many long feared, but the computer-the ubiquitous portal of work and personal lives. At this point, the computer is almost so common we don't notice it in our view. It's difficult to envision that not that long ago it was a gigantic, room-sized structure only to be accessed by a few inspiring as much awe and respect as fear and mystery. Now that the machine has decreased in size and increased in popular use, the computer has become a prosaic appliance, little-more noted than a toaster. These dramati

  2. COMPUTING

    CERN Multimedia

    I. Fisk

    2010-01-01

    Introduction It has been a very active quarter in Computing with interesting progress in all areas. The activity level at the computing facilities, driven by both organised processing from data operations and user analysis, has been steadily increasing. The large-scale production of simulated events that has been progressing throughout the fall is wrapping-up and reprocessing with pile-up will continue. A large reprocessing of all the proton-proton data has just been released and another will follow shortly. The number of analysis jobs by users each day, that was already hitting the computing model expectations at the time of ICHEP, is now 33% higher. We are expecting a busy holiday break to ensure samples are ready in time for the winter conferences. Heavy Ion An activity that is still in progress is computing for the heavy-ion program. The heavy-ion events are collected without zero suppression, so the event size is much large at roughly 11 MB per event of RAW. The central collisions are more complex and...

  3. COMPUTING

    CERN Multimedia

    M. Kasemann P. McBride Edited by M-C. Sawley with contributions from: P. Kreuzer D. Bonacorsi S. Belforte F. Wuerthwein L. Bauerdick K. Lassila-Perini M-C. Sawley

    Introduction More than seventy CMS collaborators attended the Computing and Offline Workshop in San Diego, California, April 20-24th to discuss the state of readiness of software and computing for collisions. Focus and priority were given to preparations for data taking and providing room for ample dialog between groups involved in Commissioning, Data Operations, Analysis and MC Production. Throughout the workshop, aspects of software, operating procedures and issues addressing all parts of the computing model were discussed. Plans for the CMS participation in STEP’09, the combined scale testing for all four experiments due in June 2009, were refined. The article in CMS Times by Frank Wuerthwein gave a good recap of the highly collaborative atmosphere of the workshop. Many thanks to UCSD and to the organizers for taking care of this workshop, which resulted in a long list of action items and was definitely a success. A considerable amount of effort and care is invested in the estimate of the comput...

  4. Computed tomography for the diagnosis and treatment monitoring of bacterial pneumonia in Indian pythons (Python molurus).

    Science.gov (United States)

    Pees, M; Kiefer, I; Oechtering, G; Krautwald-Junghanns, M-E

    2008-08-02

    Eight Indian pythons (Python molurus) with clinical and microbiological evidence of pneumonia were examined by computed tomography (ct) before and after treatment. The results were assessed subjectively and measurements were taken following a standard protocol. Changes in the lung tissue of all the pythons were diagnosed, and the extent of the disease could be assessed. ct examinations after treatment showed an improvement in the six pythons whose clinical condition had improved, but in the other two pythons they demonstrated the severity of the disease. The subjective assessments were superior to the evaluation of measurements of attenuation in regions of interest. However, the average and the maximum attenuation provided additional information on the extent of the disease. Except for one python with only mild clinical signs, the attenuation after successful treatment was still higher than in healthy pythons.

  5. Go-Smart: Web-based Computational Modeling of Minimally Invasive Cancer Treatments

    CERN Document Server

    Weir, Phil; Ellerweg, Roland; Alhonnoro, Tuomas; Pollari, Mika; Voglreiter, Philip; Mariappan, Panchatcharam; Flanagan, Ronan; Park, Chang Sub; Payne, Stephen; Staerk, Elmar; Voigt, Peter; Moche, Michael; Kolesnik, Marina

    2015-01-01

    The web-based Go-Smart environment is a scalable system that allows the prediction of minimally invasive cancer treatment. Interventional radiologists create a patient-specific 3D model by semi-automatic segmentation and registration of pre-interventional CT (Computed Tomography) and/or MRI (Magnetic Resonance Imaging) images in a 2D/3D browser environment. This model is used to compare patient-specific treatment plans and device performance via built-in simulation tools. Go-Smart includes evaluation techniques for comparing simulated treatment with real ablation lesions segmented from follow-up scans. The framework is highly extensible, allowing manufacturers and researchers to incorporate new ablation devices, mathematical models and physical parameters.

  6. 3D-CT vascular setting protocol using computer graphics for the evaluation of maxillofacial lesions

    Directory of Open Access Journals (Sweden)

    CAVALCANTI Marcelo de Gusmão Paraiso

    2001-01-01

    Full Text Available In this paper we present the aspect of a mandibular giant cell granuloma in spiral computed tomography-based three-dimensional (3D-CT reconstructed images using computer graphics, and demonstrate the importance of the vascular protocol in permitting better diagnosis, visualization and determination of the dimensions of the lesion. We analyzed 21 patients with maxillofacial lesions of neoplastic and proliferative origins. Two oral and maxillofacial radiologists analyzed the images. The usefulness of interactive 3D images reconstructed by means of computer graphics, especially using a vascular setting protocol for qualitative and quantitative analyses for the diagnosis, determination of the extent of lesions, treatment planning and follow-up, was demonstrated. The technique is an important adjunct to the evaluation of lesions in relation to axial CT slices and 3D-CT bone images.

  7. COMPUTING

    CERN Multimedia

    I. Fisk

    2010-01-01

    Introduction The first data taking period of November produced a first scientific paper, and this is a very satisfactory step for Computing. It also gave the invaluable opportunity to learn and debrief from this first, intense period, and make the necessary adaptations. The alarm procedures between different groups (DAQ, Physics, T0 processing, Alignment/calibration, T1 and T2 communications) have been reinforced. A major effort has also been invested into remodeling and optimizing operator tasks in all activities in Computing, in parallel with the recruitment of new Cat A operators. The teams are being completed and by mid year the new tasks will have been assigned. CRB (Computing Resource Board) The Board met twice since last CMS week. In December it reviewed the experience of the November data-taking period and could measure the positive improvements made for the site readiness. It also reviewed the policy under which Tier-2 are associated with Physics Groups. Such associations are decided twice per ye...

  8. COMPUTING

    CERN Multimedia

    P. McBride

    It has been a very active year for the computing project with strong contributions from members of the global community. The project has focused on site preparation and Monte Carlo production. The operations group has begun processing data from P5 as part of the global data commissioning. Improvements in transfer rates and site availability have been seen as computing sites across the globe prepare for large scale production and analysis as part of CSA07. Preparations for the upcoming Computing Software and Analysis Challenge CSA07 are progressing. Ian Fisk and Neil Geddes have been appointed as coordinators for the challenge. CSA07 will include production tests of the Tier-0 production system, reprocessing at the Tier-1 sites and Monte Carlo production at the Tier-2 sites. At the same time there will be a large analysis exercise at the Tier-2 centres. Pre-production simulation of the Monte Carlo events for the challenge is beginning. Scale tests of the Tier-0 will begin in mid-July and the challenge it...

  9. COMPUTING

    CERN Multimedia

    M. Kasemann

    Introduction During the past six months, Computing participated in the STEP09 exercise, had a major involvement in the October exercise and has been working with CMS sites on improving open issues relevant for data taking. At the same time operations for MC production, real data reconstruction and re-reconstructions and data transfers at large scales were performed. STEP09 was successfully conducted in June as a joint exercise with ATLAS and the other experiments. It gave good indication about the readiness of the WLCG infrastructure with the two major LHC experiments stressing the reading, writing and processing of physics data. The October Exercise, in contrast, was conducted as an all-CMS exercise, where Physics, Computing and Offline worked on a common plan to exercise all steps to efficiently access and analyze data. As one of the major results, the CMS Tier-2s demonstrated to be fully capable for performing data analysis. In recent weeks, efforts were devoted to CMS Computing readiness. All th...

  10. COMPUTING

    CERN Multimedia

    M. Kasemann

    CCRC’08 challenges and CSA08 During the February campaign of the Common Computing readiness challenges (CCRC’08), the CMS computing team had achieved very good results. The link between the detector site and the Tier0 was tested by gradually increasing the number of parallel transfer streams well beyond the target. Tests covered the global robustness at the Tier0, processing a massive number of very large files and with a high writing speed to tapes.  Other tests covered the links between the different Tiers of the distributed infrastructure and the pre-staging and reprocessing capacity of the Tier1’s: response time, data transfer rate and success rate for Tape to Buffer staging of files kept exclusively on Tape were measured. In all cases, coordination with the sites was efficient and no serious problem was found. These successful preparations prepared the ground for the second phase of the CCRC’08 campaign, in May. The Computing Software and Analysis challen...

  11. COMPUTING

    CERN Multimedia

    I. Fisk

    2011-01-01

    Introduction It has been a very active quarter in Computing with interesting progress in all areas. The activity level at the computing facilities, driven by both organised processing from data operations and user analysis, has been steadily increasing. The large-scale production of simulated events that has been progressing throughout the fall is wrapping-up and reprocessing with pile-up will continue. A large reprocessing of all the proton-proton data has just been released and another will follow shortly. The number of analysis jobs by users each day, that was already hitting the computing model expectations at the time of ICHEP, is now 33% higher. We are expecting a busy holiday break to ensure samples are ready in time for the winter conferences. Heavy Ion The Tier 0 infrastructure was able to repack and promptly reconstruct heavy-ion collision data. Two copies were made of the data at CERN using a large CASTOR disk pool, and the core physics sample was replicated ...

  12. COMPUTING

    CERN Multimedia

    I. Fisk

    2012-01-01

    Introduction Computing continued with a high level of activity over the winter in preparation for conferences and the start of the 2012 run. 2012 brings new challenges with a new energy, more complex events, and the need to make the best use of the available time before the Long Shutdown. We expect to be resource constrained on all tiers of the computing system in 2012 and are working to ensure the high-priority goals of CMS are not impacted. Heavy ions After a successful 2011 heavy-ion run, the programme is moving to analysis. During the run, the CAF resources were well used for prompt analysis. Since then in 2012 on average 200 job slots have been used continuously at Vanderbilt for analysis workflows. Operations Office As of 2012, the Computing Project emphasis has moved from commissioning to operation of the various systems. This is reflected in the new organisation structure where the Facilities and Data Operations tasks have been merged into a common Operations Office, which now covers everything ...

  13. COMPUTING

    CERN Multimedia

    M. Kasemann

    Introduction More than seventy CMS collaborators attended the Computing and Offline Workshop in San Diego, California, April 20-24th to discuss the state of readiness of software and computing for collisions. Focus and priority were given to preparations for data taking and providing room for ample dialog between groups involved in Commissioning, Data Operations, Analysis and MC Production. Throughout the workshop, aspects of software, operating procedures and issues addressing all parts of the computing model were discussed. Plans for the CMS participation in STEP’09, the combined scale testing for all four experiments due in June 2009, were refined. The article in CMS Times by Frank Wuerthwein gave a good recap of the highly collaborative atmosphere of the workshop. Many thanks to UCSD and to the organizers for taking care of this workshop, which resulted in a long list of action items and was definitely a success. A considerable amount of effort and care is invested in the estimate of the co...

  14. Comparative analysis of 11 different radioisotopes for palliative treatment of bone metastases by computational methods

    Energy Technology Data Exchange (ETDEWEB)

    Guerra Liberal, Francisco D. C., E-mail: meb12020@fe.up.pt, E-mail: adriana-tavares@msn.com; Tavares, Adriana Alexandre S., E-mail: meb12020@fe.up.pt, E-mail: adriana-tavares@msn.com; Tavares, João Manuel R. S., E-mail: tavares@fe.up.pt [Instituto de Engenharia Mecânica e Gestão Industrial, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, Porto 4200-465 (Portugal)

    2014-11-01

    Purpose: Throughout the years, the palliative treatment of bone metastases using bone seeking radiotracers has been part of the therapeutic resources used in oncology, but the choice of which bone seeking agent to use is not consensual across sites and limited data are available comparing the characteristics of each radioisotope. Computational simulation is a simple and practical method to study and to compare a variety of radioisotopes for different medical applications, including the palliative treatment of bone metastases. This study aims to evaluate and compare 11 different radioisotopes currently in use or under research for the palliative treatment of bone metastases using computational methods. Methods: Computational models were used to estimate the percentage of deoxyribonucleic acid (DNA) damage (fast Monte Carlo damage algorithm), the probability of correct DNA repair (Monte Carlo excision repair algorithm), and the radiation-induced cellular effects (virtual cell radiobiology algorithm) post-irradiation with selected particles emitted by phosphorus-32 ({sup 32}P), strontium-89 ({sup 89}Sr), yttrium-90 ({sup 90}Y ), tin-117 ({sup 117m}Sn), samarium-153 ({sup 153}Sm), holmium-166 ({sup 166}Ho), thulium-170 ({sup 170}Tm), lutetium-177 ({sup 177}Lu), rhenium-186 ({sup 186}Re), rhenium-188 ({sup 188}Re), and radium-223 ({sup 223}Ra). Results: {sup 223}Ra alpha particles, {sup 177}Lu beta minus particles, and {sup 170}Tm beta minus particles induced the highest cell death of all investigated particles and radioisotopes. The cell survival fraction measured post-irradiation with beta minus particles emitted by {sup 89}Sr and {sup 153}Sm, two of the most frequently used radionuclides in the palliative treatment of bone metastases in clinical routine practice, was higher than {sup 177}Lu beta minus particles and {sup 223}Ra alpha particles. Conclusions: {sup 223}Ra and {sup 177}Lu hold the highest potential for palliative treatment of bone metastases of all

  15. Application of special computer programs for diagnostics and treatment of amblyopia.

    Science.gov (United States)

    Tsitsiashvili, E

    2007-09-01

    Under amblyopia one ought to understand a variety by origin forms of reduction of vision the reason for which are functional disorders of the visual analyzer with no changes in the fundus of the eye and without any organic affections of the visual pathways and centers. At the present time, the pathophysiological mechanisms of amblyopia remain a puzzle. Diagnostics and adequate treatment of amblyopia remains so far a topical problem in clinical ophthalmology. The objective of our investigation was to estimate functional state of the visual system and efficiency of treatment of amblyopia of varying degree by means of special computer programs. Clinical researches were based on the analysis of results of 317 patients (410 eyes) with anisometropic (120 patients-120 eyes), disbinocular (127 patients-150 eyes) and refractive (70 patients-140 eyes) amblyopias of different degrees at the age from 5 to 17 with visual acuity from 0.05 up to 0.5 on the amblyopic eye, with the symptoms of functional disturbance: decrease in achromatic and color spatial contrast sensitivity in the domain of high and middle frequencies; decrease in contrast sensitivity of on-off channels of the retinal cone system; normal sensitivity to saturated colors; decrease in color sensitivity to unsaturated, red and green colors; dramatic changes in color (red and green) sensitivity in the paracentral zone (5 degrees -10 degrees ) of the retina and 20 healthy children-40 eyes. In addition to routine ophthalmologic methods we also used the special computer programs for diagnostics and adequate treatment of amblyopia: "ZEBRA"; "OFF-ON"; "eYe" ("Shooting-gallery", "Chase", "Crosses","Spiders"); "Contour"; "MEKO" ("KONSTR", "UFO", "SHOW"). Statistical analysis of results was performed with statistical method "ANOVA". Diagnostical computer methods enable quantitative estimation of the functional state of different channels of the visual system (based on the data of spatial contrast, light, color and contrast

  16. APINetworks: A general API for the treatment of complex networks in arbitrary computational environments

    Science.gov (United States)

    Niño, Alfonso; Muñoz-Caro, Camelia; Reyes, Sebastián

    2015-11-01

    The last decade witnessed a great development of the structural and dynamic study of complex systems described as a network of elements. Therefore, systems can be described as a set of, possibly, heterogeneous entities or agents (the network nodes) interacting in, possibly, different ways (defining the network edges). In this context, it is of practical interest to model and handle not only static and homogeneous networks but also dynamic, heterogeneous ones. Depending on the size and type of the problem, these networks may require different computational approaches involving sequential, parallel or distributed systems with or without the use of disk-based data structures. In this work, we develop an Application Programming Interface (APINetworks) for the modeling and treatment of general networks in arbitrary computational environments. To minimize dependency between components, we decouple the network structure from its function using different packages for grouping sets of related tasks. The structural package, the one in charge of building and handling the network structure, is the core element of the system. In this work, we focus in this API structural component. We apply an object-oriented approach that makes use of inheritance and polymorphism. In this way, we can model static and dynamic networks with heterogeneous elements in the nodes and heterogeneous interactions in the edges. In addition, this approach permits a unified treatment of different computational environments. Tests performed on a C++11 version of the structural package show that, on current standard computers, the system can handle, in main memory, directed and undirected linear networks formed by tens of millions of nodes and edges. Our results compare favorably to those of existing tools.

  17. Feasibility and effectiveness of computer-based therapy in community treatment.

    Science.gov (United States)

    Brooks, Adam C; Ryder, Deanna; Carise, Deni; Kirby, Kimberly C

    2010-10-01

    Computerized therapy approaches may expand the reach of evidence-based treatment; however, it is unclear how to integrate these therapies into community-based treatment. We conducted a two-phase pilot study to explore (a) whether clients' use of the Therapeutic Education System (TES), a Web-based community reinforcement approach (CRA) learning program, would benefit them in the absence of counselor support and (b) whether counselors and clients would use the TES in the absence of tangible research-based reinforcement. In Phase 1, clients in the TES condition (n = 14) demonstrated large improvements in knowledge, F(1, 20) = 8.90, p = .007, d = 1.05, and were significantly more likely to select CRA style coping responses, F (1, 20) = 11.95, p = .002, d = 1.16, relative to the treatment-as-usual group (n = 14). We also detected small, nonsignificant, between-group effects indicating TES decreased cocaine use during treatment. In Phase 2, counselors referred only around 10% of their caseload to the TES, and the modal number of completed modules in the absence of tangible reinforcement was three. Computer-based therapy approaches are viable in community-based treatment but must be integrated with incentive systems to ensure engagement. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  18. Computed tomographic findings and treatment of a bull with pituitary gland abscess.

    Science.gov (United States)

    Braun, Ueli; Malbon, Alexandra; Kochan, Manon; Riond, Barbara; Janett, Fredi; Iten, Cornelia; Dennler, Matthias

    2017-01-13

    In cattle, the prognosis of brain abscess is unfavourable and treatment is therefore not recommended. To the knowledge of the authors, there has been no report of successful treatment of a brain abscess in cattle.This report describes the clinical, computed tomographic and postmortem findings in a Holstein-Friesian bull with a hypophyseal abscess. The main clinical findings were generalised ataxia, ptyalism, prolapse of the tongue, dropped jaw, dysphagia, head tilt and unilateral ptosis. Cerebrospinal fluid evaluation revealed 2437 leukocytes/µl and severe pleocytosis. CT examination of the head showed a cavitary lesion consistent with an abscess in the hypophysis. Treatment consisted of gentamicin and flunixin meglumine for 3 days and amoxicillin for 40 days. The neurological signs resolved within 8 days of the start of treatment. The bull was slaughtered 11 months later because of infertility, and a postmortem examination was carried out. Histologically, a mild chronic non suppurative meningoencephalitis restricted to the ventral diencephalon was diagnosed. In addition, there was mild to moderate multifocal chronic lymphoplasmacytic hypophysitis with mild multifocal fibrosis. This case report stresses the significance of CT in confirming the clinical and laboratory diagnosis of central nervous system disorders in cattle and for localising brain lesions. Treatment of the brain abscess resulted, with respect to the central nervous disorder, in a successful outcome and was encouraging considering that most cases have an unfavourable prognosis.

  19. Cone beam computed tomography aided diagnosis and treatment of endodontic cases: Critical analysis

    Institute of Scientific and Technical Information of China (English)

    Funda Y?lmaz; K?van? Kamburoglu; Naz Yakar Yeta; Meltem Dartar ?ztan

    2016-01-01

    Although intraoral radiographs still remain the imaging method of choice for the evaluation of endodontic patients, in recent years, the utilization of cone beam computed tomography(CBCT) in endodontics showed a significant jump. This case series presentation shows the importance of CBCT aided diagnosis and treatment of complex endodontic cases such as; root resorption, missed extra canal, fusion, oblique root fracture, nondiagnosed periapical pathology and horizontal root fracture. CBCT may be a useful diagnostic method in several endodontic cases where intraoral radiography and clinical examination alone are unable to provide sufficient information.

  20. COMPUTING

    CERN Multimedia

    Matthias Kasemann

    Overview The main focus during the summer was to handle data coming from the detector and to perform Monte Carlo production. The lessons learned during the CCRC and CSA08 challenges in May were addressed by dedicated PADA campaigns lead by the Integration team. Big improvements were achieved in the stability and reliability of the CMS Tier1 and Tier2 centres by regular and systematic follow-up of faults and errors with the help of the Savannah bug tracking system. In preparation for data taking the roles of a Computing Run Coordinator and regular computing shifts monitoring the services and infrastructure as well as interfacing to the data operations tasks are being defined. The shift plan until the end of 2008 is being put together. User support worked on documentation and organized several training sessions. The ECoM task force delivered the report on “Use Cases for Start-up of pp Data-Taking” with recommendations and a set of tests to be performed for trigger rates much higher than the ...

  1. COMPUTING

    CERN Multimedia

    M. Kasemann

    Introduction A large fraction of the effort was focused during the last period into the preparation and monitoring of the February tests of Common VO Computing Readiness Challenge 08. CCRC08 is being run by the WLCG collaboration in two phases, between the centres and all experiments. The February test is dedicated to functionality tests, while the May challenge will consist of running at all centres and with full workflows. For this first period, a number of functionality checks of the computing power, data repositories and archives as well as network links are planned. This will help assess the reliability of the systems under a variety of loads, and identifying possible bottlenecks. Many tests are scheduled together with other VOs, allowing the full scale stress test. The data rates (writing, accessing and transfer¬ring) are being checked under a variety of loads and operating conditions, as well as the reliability and transfer rates of the links between Tier-0 and Tier-1s. In addition, the capa...

  2. COMPUTING

    CERN Multimedia

    P. MacBride

    The Computing Software and Analysis Challenge CSA07 has been the main focus of the Computing Project for the past few months. Activities began over the summer with the preparation of the Monte Carlo data sets for the challenge and tests of the new production system at the Tier-0 at CERN. The pre-challenge Monte Carlo production was done in several steps: physics generation, detector simulation, digitization, conversion to RAW format and the samples were run through the High Level Trigger (HLT). The data was then merged into three "Soups": Chowder (ALPGEN), Stew (Filtered Pythia) and Gumbo (Pythia). The challenge officially started when the first Chowder events were reconstructed on the Tier-0 on October 3rd. The data operations teams were very busy during the the challenge period. The MC production teams continued with signal production and processing while the Tier-0 and Tier-1 teams worked on splitting the Soups into Primary Data Sets (PDS), reconstruction and skimming. The storage sys...

  3. COMPUTING

    CERN Multimedia

    Contributions from I. Fisk

    2012-01-01

    Introduction The start of the 2012 run has been busy for Computing. We have reconstructed, archived, and served a larger sample of new data than in 2011, and we are in the process of producing an even larger new sample of simulations at 8 TeV. The running conditions and system performance are largely what was anticipated in the plan, thanks to the hard work and preparation of many people. Heavy ions Heavy Ions has been actively analysing data and preparing for conferences.  Operations Office Figure 6: Transfers from all sites in the last 90 days For ICHEP and the Upgrade efforts, we needed to produce and process record amounts of MC samples while supporting the very successful data-taking. This was a large burden, especially on the team members. Nevertheless the last three months were very successful and the total output was phenomenal, thanks to our dedicated site admins who keep the sites operational and the computing project members who spend countless hours nursing the...

  4. COMPUTING

    CERN Multimedia

    I. Fisk

    2012-01-01

      Introduction Computing activity has been running at a sustained, high rate as we collect data at high luminosity, process simulation, and begin to process the parked data. The system is functional, though a number of improvements are planned during LS1. Many of the changes will impact users, we hope only in positive ways. We are trying to improve the distributed analysis tools as well as the ability to access more data samples more transparently.  Operations Office Figure 2: Number of events per month, for 2012 Since the June CMS Week, Computing Operations teams successfully completed data re-reconstruction passes and finished the CMSSW_53X MC campaign with over three billion events available in AOD format. Recorded data was successfully processed in parallel, exceeding 1.2 billion raw physics events per month for the first time in October 2012 due to the increase in data-parking rate. In parallel, large efforts were dedicated to WMAgent development and integrati...

  5. COMPUTING

    CERN Document Server

    2010-01-01

    Introduction Just two months after the “LHC First Physics” event of 30th March, the analysis of the O(200) million 7 TeV collision events in CMS accumulated during the first 60 days is well under way. The consistency of the CMS computing model has been confirmed during these first weeks of data taking. This model is based on a hierarchy of use-cases deployed between the different tiers and, in particular, the distribution of RECO data to T1s, who then serve data on request to T2s, along a topology known as “fat tree”. Indeed, during this period this model was further extended by almost full “mesh” commissioning, meaning that RECO data were shipped to T2s whenever possible, enabling additional physics analyses compared with the “fat tree” model. Computing activities at the CMS Analysis Facility (CAF) have been marked by a good time response for a load almost evenly shared between ALCA (Alignment and Calibration tasks - highest p...

  6. COMPUTING

    CERN Multimedia

    I. Fisk

    2013-01-01

    Computing operation has been lower as the Run 1 samples are completing and smaller samples for upgrades and preparations are ramping up. Much of the computing activity is focusing on preparations for Run 2 and improvements in data access and flexibility of using resources. Operations Office Data processing was slow in the second half of 2013 with only the legacy re-reconstruction pass of 2011 data being processed at the sites.   Figure 1: MC production and processing was more in demand with a peak of over 750 Million GEN-SIM events in a single month.   Figure 2: The transfer system worked reliably and efficiently and transferred on average close to 520 TB per week with peaks at close to 1.2 PB.   Figure 3: The volume of data moved between CMS sites in the last six months   The tape utilisation was a focus for the operation teams with frequent deletion campaigns from deprecated 7 TeV MC GEN-SIM samples to INVALID datasets, which could be cleaned up...

  7. Single photon emission computed tomography (SPECT of anxiety disorders before and after treatment with citalopram

    Directory of Open Access Journals (Sweden)

    Seedat Soraya

    2004-10-01

    Full Text Available Abstract Background Several studies have now examined the effects of selective serotonin reuptake inhibitor (SSRI treatment on brain function in a variety of anxiety disorders including obsessive-compulsive disorder (OCD, posttraumatic stress disorder (PTSD, and social anxiety disorder (social phobia (SAD. Regional changes in cerebral perfusion following SSRI treatment have been shown for all three disorders. The orbitofrontal cortex (OFC (OCD, caudate (OCD, medial pre-frontal/cingulate (OCD, SAD, PTSD, temporal (OCD, SAD, PTSD and, thalamic regions (OCD, SAD are some of those implicated. Some data also suggests that higher perfusion pre-treatment in the anterior cingulate (PTSD, OFC, caudate (OCD and antero-lateral temporal region (SAD predicts subsequent treatment response. This paper further examines the notion of overlap in the neurocircuitry of treatment and indeed treatment response across anxiety disorders with SSRI treatment. Methods Single photon emission computed tomography (SPECT using Tc-99 m HMPAO to assess brain perfusion was performed on subjects with OCD, PTSD, and SAD before and after 8 weeks (SAD and 12 weeks (OCD and PTSD treatment with the SSRI citalopram. Statistical parametric mapping (SPM was used to compare scans (pre- vs post-medication, and responders vs non-responders in the combined group of subjects. Results Citalopram treatment resulted in significant deactivation (p = 0.001 for the entire group in the superior (t = 4.78 and anterior (t = 4.04 cingulate, right thalamus (t = 4.66 and left hippocampus (t = 3.96. Deactivation (p = 0.001 within the left precentral (t = 4.26, right mid-frontal (t = 4.03, right inferior frontal (t = 3.99, left prefrontal (3.81 and right precuneus (t= 3.85 was more marked in treatment responders. No pattern of baseline activation distinguished responders from non-responders to subsequent pharmacotherapy. Conclusions Although each of the anxiety disorders may be mediated by different

  8. fMRI Brain-Computer Interface: A Tool for Neuroscientific Research and Treatment

    Directory of Open Access Journals (Sweden)

    Ranganatha Sitaram

    2007-01-01

    Full Text Available Brain-computer interfaces based on functional magnetic resonance imaging (fMRI-BCI allow volitional control of anatomically specific regions of the brain. Technological advancement in higher field MRI scanners, fast data acquisition sequences, preprocessing algorithms, and robust statistical analysis are anticipated to make fMRI-BCI more widely available and applicable. This noninvasive technique could potentially complement the traditional neuroscientific experimental methods by varying the activity of the neural substrates of a region of interest as an independent variable to study its effects on behavior. If the neurobiological basis of a disorder (e.g., chronic pain, motor diseases, psychopathy, social phobia, depression is known in terms of abnormal activity in certain regions of the brain, fMRI-BCI can be targeted to modify activity in those regions with high specificity for treatment. In this paper, we review recent results of the application of fMRI-BCI to neuroscientific research and psychophysiological treatment.

  9. COMPUTING

    CERN Multimedia

    I. Fisk

    2011-01-01

    Introduction The Computing Team successfully completed the storage, initial processing, and distribution for analysis of proton-proton data in 2011. There are still a variety of activities ongoing to support winter conference activities and preparations for 2012. Heavy ions The heavy-ion run for 2011 started in early November and has already demonstrated good machine performance and success of some of the more advanced workflows planned for 2011. Data collection will continue until early December. Facilities and Infrastructure Operations Operational and deployment support for WMAgent and WorkQueue+Request Manager components, routinely used in production by Data Operations, are provided. The GlideInWMS and components installation are now deployed at CERN, which is added to the GlideInWMS factory placed in the US. There has been new operational collaboration between the CERN team and the UCSD GlideIn factory operators, covering each others time zones by monitoring/debugging pilot jobs sent from the facto...

  10. An X-Ray Tomography Based Modeling Solution For Chemical Vapor Infiltration Of Ceramic Matrix Composites

    Science.gov (United States)

    Ros, William; Vignoles, Gérard L.; Germain, Christian

    2010-05-01

    A numerical tool for the simulation of Chemical Vapor Infiltration of carbon/carbon composites is introduced. The structure of the fibrous medium can be studied by high resolution X-Ray Computed Micro Tomography. Gas transport in various regimes is simulated by a random walk technique whilst the morphological evolution of the fluid/solid interface is handled by a Marching Cube technique. The program can be used to evaluate effective diffusivity and first order reaction rate. The numerical tool is validated by comparing computed effective properties of a straight slit pore with reactive walls to their analytical expression. Simulation of CVI processing of a real complex media is then presented.

  11. Computer simulation of the off gas treatment process for the KEPCO pilot vitrification plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hey Suk; Maeng, Sung Jun; Lee, Myung Chan [Nuclear Environment Technology Institute, KEPCO, Taejon (Korea, Republic of)

    1999-07-01

    Vitrification technology for treatment of low and intermediate radioactive wastes can remarkably reduce waste volume to about one twentieth of the initial volume as they are collected and converted into a very stable form. Therefore, it can minimize environmental impact when the vitrified waste is disposed of. But an off gas treatment system is necessary to apply this technology because air pollutants and radioisotopes are generated like those of other conventional incinerators during thermal oxidation process at high temperature. KEPCO designed and installed a pilot scale vitrification plant to demonstrate the feasibility of the vitrification process and then to make a conceptual design for a commercial vitrification facility. The purpose of this study was to simulate the off gas treatment system(OGTS) in order optimize the operating conditions. Mass balance and temperature profile in the off gas treatment system were simulated for different combinations of combustible wastes by computer simulation code named OGTS code and removal efficiency of each process was also calculated with change of design parameters. The OGTS code saved efforts,time and capital because scale and configuration of the system could be easily changed. The simulation result of the pilot scale off gas process as well as pilot tests will be of great use in the future for a design of the commercial vitrification facility. (author)

  12. Treatment of bacterial brain abscess by repeated aspiration. Follow up by serial computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Masaaki; Fukushima, Takeo; Hirakawa, Katsuyuki; Kimura, Hideo; Tomonaga, Masamichi [Fukuoka Univ. (Japan). School of Medicine

    2000-02-01

    Bacterial brain abscess often requires repeated aspiration before the abscess finally resolves. However, there are no guidelines for treatment by aspiration; for example, when should the abscess be tapped again, or when can an abscess be treated by antibiotics alone without further aspiration. Eleven patients with bacterial brain abscess treated by aspiration were evaluated to establish treatment guidelines for brain abscess, in particular the abscess size on serial computed tomography (CT) after aspiration. CT was performed about 24 hours after aspiration to evaluate the size of the abscess, and almost weekly during follow up. The diameter of the brain abscess before and after the initial and last aspirations were reviewed. In eight of the 11 patients, abscesses were aspirated repeatedly: two to three times in most patients. The diameter of the abscesses was 2.5-4.5 cm (mean 3.5 cm) before the last aspiration, and 1.4-3.4 cm (mean 2.3 cm) after the last aspiration, or when continuous drainage was discontinued. Perifocal edema was moderately decreased within 3 weeks after the last aspiration by medical treatment alone, with a concomitant decrease in the volume of the abscess. There were no deaths, and most patients had a favorable outcome. These results suggest that after the diameter of the abscess becomes less than 2 to 3 cm and does not increase anymore on serial CT, medical treatment alone can be anticipated to give satisfactory results without further aspiration. (author)

  13. A computer simulation of progesterone and Cox2 inhibitor treatment for preterm labor.

    Directory of Open Access Journals (Sweden)

    Ozlem Equils

    Full Text Available BACKGROUND: Sufficient information from in vitro and in vivo studies has become available to permit computer modeling of the processes that occur in the myometrium during labor. This development allows the in silico investigation of pathological mechanisms and the trialing of potential treatments. METHODS/RESULTS: Based on the human literature, we developed a computer model of the immune-endocrine environment of the myometrial cell. The interactions between molecules are represented by differential equations. The model is designed to simulate the estrogen and progesterone receptor changes during pregnancy and particularly the changes in the progesterone receptor (PR isoforms A and B that are thought to mediate functional progesterone withdrawal in the human at labor. Parturition is represented by an increase in the PRA to PRB ratio to levels seen in women in labor. Infection is shown by inducing inflammation in the system by increasing phospho-IkB kinase concentration (IKK levels; which lead to increased NF-kappaB activation, causing an increase in the PRA/PRB ratio. We examined the effects of progesterone or cyclo-oxygenase 2 (Cox2 inhibitor treatments on the PRA/PRB ratio in silico. The model predicted that high doses of progesterone and Cox2 inhibition would be effective in preventing an NF-kappaB-induced PRA/PRB ratio increase to the levels found during labor. CONCLUSIONS: Our data illustrate the use of dynamic biological computer simulations to test the effectiveness of therapeutic interventions. This may allow the early rejection of ineffective therapies prior to expensive field trials.

  14. Cauda equina syndrome caused by epidural pneumorrhachis: treatment with percutaneous computed tomography-guided translaminar trephination.

    Science.gov (United States)

    Paik, Nam Chull; Lim, Chun Soo; Jang, Ho Suk

    2013-04-01

    A case report and review of the literature. To present a rare case, and its treatment, of cauda equina syndrome (CES) caused by epidural pneumorrhachis after repeated caudal epidural injections. Pneumorrhachis is defined as the presence of air in the epidural or subarachnoid space. Epidural pneumorrhachis is usually asymptomatic and managed conservatively, but rare cases of lumbar radiculopathy resulting from epidural air have been reported. To the best of our knowledge, there has been no previous report of CES caused by epidural air. A 63-year-old male presented with recent aggravation of a low backache, with pain radiating to both lower limbs. He also complained of newly developed numbness in the buttocks, groins, and perineum, and difficulty with urination and defecation, after repeated caudal epidural injections during a 3-week period. Computed tomography and magnetic resonance imaging revealed epidural pneumorrhachis compressing the lumbar dural sac at the L2-L3 and L3-L4 levels. The patient's symptoms persisted despite 3 days of oxygen inhalation therapy. Attempted needle aspiration of the epidural air was unsuccessful and percutaneous computed tomography-guided translaminar trephination was performed. The day after trephination, the patient's lower extremity motor strength began to improve; sphincter dysfunction began to resolve on the second day. During 8 weeks, his pain resolved and he gradually regained sensation. Two years later, the patient was free of symptoms or signs of CES. Epidural pneumorrhachis may cause dural sac compression, thus worsening a patient's previous symptoms and possibly eliciting new problems such as CES. Conservative treatment should be the first-line approach, but surgery is often necessary when the problem remains unsolved. Percutaneous computed tomography-guided translaminar trephination may be an alternative to surgical decompression of the epidural space in selected patients.

  15. COMPUTING

    CERN Multimedia

    M. Kasemann

    CMS relies on a well functioning, distributed computing infrastructure. The Site Availability Monitoring (SAM) and the Job Robot submission have been very instrumental for site commissioning in order to increase availability of more sites such that they are available to participate in CSA07 and are ready to be used for analysis. The commissioning process has been further developed, including "lessons learned" documentation via the CMS twiki. Recently the visualization, presentation and summarizing of SAM tests for sites has been redesigned, it is now developed by the central ARDA project of WLCG. Work to test the new gLite Workload Management System was performed; a 4 times increase in throughput with respect to LCG Resource Broker is observed. CMS has designed and launched a new-generation traffic load generator called "LoadTest" to commission and to keep exercised all data transfer routes in the CMS PhE-DEx topology. Since mid-February, a transfer volume of about 12 P...

  16. Motion management in positron emission tomography/computed tomography for radiation treatment planning.

    Science.gov (United States)

    Bettinardi, Valentino; Picchio, Maria; Di Muzio, Nadia; Gilardi, Maria Carla

    2012-09-01

    Hybrid positron emission tomography (PET)/computed tomography (CT) scanners combine, in a unique gantry, 2 of the most important diagnostic imaging systems, a CT and a PET tomograph, enabling anatomical (CT) and functional (PET) studies to be performed in a single study session. Furthermore, as the 2 scanners use the same spatial coordinate system, the reconstructed CT and PET images are spatially co-registered, allowing an accurate localization of the functional signal over the corresponding anatomical structure. This peculiarity of the hybrid PET/CT system results in improved tumor characterization for oncological applications, and more recently, it was found to be also useful for target volume definition (TVD) and treatment planning in radiotherapy (RT) applications. In fact, the use of combined PET/CT information has been shown to improve the RT treatment plan when compared with that obtained by a CT alone. A limiting factor to the accuracy of TVD by PET/CT is organ and tumor motion, which is mainly due to patient respiration. In fact, respiratory motion has a degrading effect on PET/CT image quality, and this is also critical for TVD, as it can lead to possible tumor missing or undertreatment. Thus, the management of respiratory motion is becoming an increasingly essential component in RT treatment planning; indeed, it has been recognized that the use of personalized motion information can improve TVD and, consequently, permit increased tumor dosage while sparing surrounding healthy tissues and organs at risk. This review describes the methods used for motion management in PET/CT for radiation treatment planning. The article covers the following: (1) problems caused by organ and lesion motion owing to respiration, and the artifacts generated on CT, PET, and PET/CT images; (2) data acquisition and processing techniques used to manage respiratory motion in PET/CT studies; and (3) the use of personalized motion information for TVD and radiation treatment planning.

  17. ASPEN computer simulations of the mixed waste treatment project baseline flowsheet

    Energy Technology Data Exchange (ETDEWEB)

    Dietsche, L.J.; Upadhye, R.S.; Camp, D.W.; Pendergrass, J.A.; Borduin, L.C.; Thompson, T.K.

    1994-07-05

    The treatment and disposal of mixed waste (i.e., waste containing both hazardous and radioactive components) is a challenging waste- management problem of particular concern to Department of Energy (DOE) sites throughout the United States. Traditional technologies used for destroying hazardous wastes must be re- evaluated for their ability to handle mixed wastes, and, in some cases, new technologies must be developed. The Mixed Waste Treatment Project (MWTP), a collaborative effort between Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory, and Pacific Northwest Laboratory (PNL), was established by the DOE`s Waste Operations Program (EM-30) to develop and analyze alternative mixed waste treatment approaches. One of the MWTP`s initiatives, and the objective of this study, was to develop flowsheets for prototype, integrated, mixed-waste treatment facilities that can serve as models for sites developing their own treatment strategies. Evaluation of these flowsheets is being facilitated through the use of computer modeling. The objectives of the flowsheet simulations are to compare process effectiveness and costs of alternative flowsheets and to determine if commercial process-simulation software could be used on the large, complex process of an integrated mixed waste processing facility. Flowsheet modeling is needed to evaluate many aspects of proposed flowsheet designs. A major advantage of modeling the complete flowsheet is the ability to define the internal recycle streams, thereby making it possible to evaluate the impact of one operation on the whole plant. Many effects that can be seen only in this way. Modeling also can be used to evaluate sensitivity and range of operating conditions, radioactive criticality, and relative costs of different flowsheet designs. Further, the modeled flowsheets must be easily modified so that one can examine how alternative technologies and varying feed streams affect the overall integrated process.

  18. Computational models as predictors of HIV treatment outcomes for the Phidisa cohort in South Africa

    Directory of Open Access Journals (Sweden)

    Andrew Revell

    2016-02-01

    Full Text Available Background: Selecting the optimal combination of HIV drugs for an individual in resourcelimited settings is challenging because of the limited availability of drugs and genotyping.Objective: The evaluation as a potential treatment support tool of computational models that predict response to therapy without a genotype, using cases from the Phidisa cohort in South Africa.Methods: Cases from Phidisa of treatment change following failure were identified that had the following data available: baseline CD4 count and viral load, details of failing and previous antiretroviral drugs, drugs in new regimen and time to follow-up. The HIV Resistance Response Database Initiative’s (RDI’s models used these data to predict the probability of a viral load < 50 copies/mL at follow-up. The models were also used to identify effective alternative combinations of three locally available drugs.Results: The models achieved accuracy (area under the receiver–operator characteristic curve of 0.72 when predicting response to therapy, which is less accurate than for an independent global test set (0.80 but at least comparable to that of genotyping with rules-based interpretation. The models were able to identify alternative locally available three-drug regimens that were predicted to be effective in 69% of all cases and 62% of those whose new treatment failed in the clinic.Conclusion: The predictive accuracy of the models for these South African patients together with the results of previous studies suggest that the RDI’s models have the potential to optimise treatment selection and reduce virological failure in different patient populations, without the use of a genotype.Keywords: HIV therapy; mathematical modelling; treatment; genotype

  19. Automation of Global Adjoint Tomography Based on ASDF and Workflow Management Tools

    Science.gov (United States)

    Lei, W.; Ruan, Y.; Bozdag, E.; Smith, J. A.; Modrak, R. T.; Krischer, L.; Chen, Y.; Lefebvre, M. P.; Tromp, J.

    2016-12-01

    Global adjoint tomography is computationally expensive, requiring thousands of wavefield simulations and massive data processing. Though a collaboration with the Oak Ridge National Laboratory computing group and an allocation on the `Titan' GPU-accelerated supercomputer, we have begun to assimilate waveform data from more than 4,000 earthquakes, from 1995 to 2015, in our inversions. However, since conventional file formats and signal processing tools were not designed for parallel processing of massive data volumes, use of such tools in high-resolution global inversions leads to major bottlenecks. To overcome such problems and allow for continued scientific progress, we designed the Adaptive Seismic Data Format (ASDF) and developed a set of processing tools based on ASDF, covering from signal processing (pytomo3d), time window selection (pyflex) to adjoint source (pyadjoint). These new tools greatly enhance the reproducibility and accountability of our research while taking full advantage of parallel computing, showing superior scaling on modern computational platforms. The entire inversion workflow, intrinsically complex and sensitive to human errors, is carefully handled and automated by modern workflow management tools, preventing data contamination and saving a huge amount of time. Our starting model GLAD-M15 (Bozdag et al., 2016), an elastic model with transversely isotropic upper mantle, is based on 253 earthquakes and 15 nonlinear conjugate gradient iterations. We have now completed source inversions for more than 1,000 earthquakes and have started structural inversions using a quasi-Newton optimization algorithm. We will discuss the challenges of large-scale workflows on HPC systems, the solutions offered by our new adjoint tomography tools, and the initial tomographic results obtained using the new expanded dataset.

  20. 2D Magnetic resonance electrical property tomography based on B1(-) field mapping.

    Science.gov (United States)

    Yuqing Wan; Negishi, Michiro; Constable, R Todd

    2014-01-01

    Magnetic Resonance Electrical Property Tomography (MREPT) is a method to visualize electrical conductivity and permittivity distributions in the object. Traditional MREPT relies on either the radio frequency (RF) transmit field (B(+)1) mapping, or using a transmit/receive RF coil, to compute tissue's electrical conductivity and permittivity. This paper introduces an alternative approach based on the reconstructed receive field (B(-)1) By solving a system of homogeneous equations consisting of the signal ratios from multi-channel receive coils, the receive field distribution with both magnitude and phase can be computed. Similar to (B(+)1) based MREPT method, the conductivity and permittivity in the imaging object can be calculated from the (B(-)1) field. We demonstrated the feasibility to image electrical property contrasts through computer simulated studies and phantom experiments. Although this study focuses on the 2D reconstruction, the presented method can be extended to full 3D. This method can be applied to regular MR imaging collected with multi-channel receive coils, and therefore, tissue anomaly based on electrical properties can potentially be revealed with a higher imaging quality, providing useful information for clinical diagnosis.

  1. Cone beam computed tomography guided treatment delivery and planning verification for magnetic resonance imaging only radiotherapy of the brain

    DEFF Research Database (Denmark)

    Edmund, Jens M.; Andreasen, Daniel; Mahmood, Faisal;

    2015-01-01

    Background. Radiotherapy based on MRI only (MRI-only RT) shows a promising potential for the brain. Much research focuses on creating a pseudo computed tomography (pCT) from MRI for treatment planning while little attention is often paid to the treatment delivery. Here, we investigate if cone beam...

  2. Outcome of root canal treatment in dogs determined by periapical radiography and cone-beam computed tomography scans

    NARCIS (Netherlands)

    de Paula-Silva, F.W.G.; Hassan, B.; da Silva, L.A.B.; Leonardo, M.R.; Wu, M.K.

    2009-01-01

    The purpose of this study was to compare the favorable outcome of root canal treatment determined by periapical radiographs (PRs) and cone beam computed tomography (CBCT) scans. Ninety-six roots of dogs' teeth were used to form four groups (n= 24). In group 1, root canal treatments were performed in

  3. Radiation treatment planning for bladder cancer: a comparison of cystogram localisation with computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Rothwell, R.I.; Ash, D.V.; Jones, W.G. (Cookridge Hospital, Leeds (UK))

    1983-01-01

    A comparison has been made between the target volumes of radical radiotherapy treatment plans produced with the aid of marker cystograms, and target volumes derived from computed tomography (CT) scans in 60 patients with bladder cancer. This has demonstrated inadequacies of the cystograms due to the inability to delineate extravesical spread of tumour and, as many patients with bladder cancer had a significant residual urine, emptying the bladder by catheterisation may have given a false impression of the shape and size of the target volume. Analysis of the results showed that cystographic localisation resulted in serious underdosage of the tumour in 18% of patients and failure to include all the bladder in 37%. Conventionally produced target volumes showed potentially significant discrepancies in 85% of patients when compared with target volumes delineated by CT.

  4. Eddy Current Tomography Based on a Finite Difference Forward Model with Additive Regularization

    Science.gov (United States)

    Trillon, A.; Girard, A.; Idier, J.; Goussard, Y.; Sirois, F.; Dubost, S.; Paul, N.

    2010-02-01

    Eddy current tomography is a nondestructive evaluation technique used for characterization of metal components. It is an inverse problem acknowledged as difficult to solve since it is both ill-posed and nonlinear. Our goal is to derive an inversion technique with improved tradeoff between quality of the results, computational requirements and ease of implementation. This is achieved by fully accounting for the nonlinear nature of the forward problem by means of a system of bilinear equations obtained through a finite difference modeling of the problem. The bilinear character of equations with respect to the electric field and the relative conductivity is taken advantage of through a simple contrast source inversion-like scheme. The ill-posedness is dealt with through the addition of regularization terms to the criterion, the form of which is determined according to computational constraints and the piecewise constant nature of the medium. Therefore an edge-preserving functional is selected. The performance of the resulting method is illustrated using 2D synthetic data examples.

  5. Mixed Total Variation and L1 Regularization Method for Optical Tomography Based on Radiative Transfer Equation

    Directory of Open Access Journals (Sweden)

    Jinping Tang

    2017-01-01

    Full Text Available Optical tomography is an emerging and important molecular imaging modality. The aim of optical tomography is to reconstruct optical properties of human tissues. In this paper, we focus on reconstructing the absorption coefficient based on the radiative transfer equation (RTE. It is an ill-posed parameter identification problem. Regularization methods have been broadly applied to reconstruct the optical coefficients, such as the total variation (TV regularization and the L1 regularization. In order to better reconstruct the piecewise constant and sparse coefficient distributions, TV and L1 norms are combined as the regularization. The forward problem is discretized with the discontinuous Galerkin method on the spatial space and the finite element method on the angular space. The minimization problem is solved by a Jacobian-based Levenberg-Marquardt type method which is equipped with a split Bregman algorithms for the L1 regularization. We use the adjoint method to compute the Jacobian matrix which dramatically improves the computation efficiency. By comparing with the other imaging reconstruction methods based on TV and L1 regularizations, the simulation results show the validity and efficiency of the proposed method.

  6. Image reconstruction of fluorescent molecular tomography based on the tree structured Schur complement decomposition

    Directory of Open Access Journals (Sweden)

    Wang Jiajun

    2010-05-01

    Full Text Available Abstract Background The inverse problem of fluorescent molecular tomography (FMT often involves complex large-scale matrix operations, which may lead to unacceptable computational errors and complexity. In this research, a tree structured Schur complement decomposition strategy is proposed to accelerate the reconstruction process and reduce the computational complexity. Additionally, an adaptive regularization scheme is developed to improve the ill-posedness of the inverse problem. Methods The global system is decomposed level by level with the Schur complement system along two paths in the tree structure. The resultant subsystems are solved in combination with the biconjugate gradient method. The mesh for the inverse problem is generated incorporating the prior information. During the reconstruction, the regularization parameters are adaptive not only to the spatial variations but also to the variations of the objective function to tackle the ill-posed nature of the inverse problem. Results Simulation results demonstrate that the strategy of the tree structured Schur complement decomposition obviously outperforms the previous methods, such as the conventional Conjugate-Gradient (CG and the Schur CG methods, in both reconstruction accuracy and speed. As compared with the Tikhonov regularization method, the adaptive regularization scheme can significantly improve ill-posedness of the inverse problem. Conclusions The methods proposed in this paper can significantly improve the reconstructed image quality of FMT and accelerate the reconstruction process.

  7. Assess and improve the sustainability of water treatment facility using Computational Fluid Dynamics

    Science.gov (United States)

    Zhang, Jie; Tejada-Martinez, Andres; Lei, Hongxia; Zhang, Qiong

    2016-11-01

    Fluids problems in water treatment industry are often simplified or omitted since the focus is usually on chemical process only. However hydraulics also plays an important role in determining effluent water quality. Recent studies have demonstrated that computational fluid dynamics (CFD) has the ability to simulate the physical and chemical processes in reactive flows in water treatment facilities, such as in chlorine and ozone disinfection tanks. This study presents the results from CFD simulations of reactive flow in an existing full-scale ozone disinfection tank and in potential designs. Through analysis of the simulation results, we found that baffling factor and CT10 are not optimal indicators of disinfection performance. We also found that the relationship between effluent CT (the product of disinfectant concentration and contact time) obtained from CT transport simulation and baffling factor depends on the location of ozone release. In addition, we analyzed the environmental and economic impacts of ozone disinfection tank designs and developed a composite indicator to quantify the sustainability of ozone disinfection tank in technological, environmental and economic dimensions.

  8. [Testing a computer-assisted bending machine for manufacturing orthodontic treatment elements].

    Science.gov (United States)

    Verma, D; Bourauel, C; May, O; Jäger, A

    2000-10-01

    The use of suitable orthodontic devices producing desired defined force systems is of importance for successful orthodontic treatment. Bending loops can be difficult and time-consuming. Computerised fabrication would enable very precise reproduction of individual loops. A bending machine has now been developed within the framework of a computer-assisted treatment concept. In this study, a prototype machine was used to fabricate U-, T- and delta loops made of stainless steel, cobalt chromium and titanium molybdenum wire. The various geometric parameters of each loop were measured to determine how precisely they had been produced. Furthermore, the force system of each loop were experimentally investigated during simulated activation in an orthodontic measurement and simulation system. The results indicate that the geometric parameters had an average error of 2.8 degrees for angles and 0.9 mm for lengths. Owing to the fabrication errors, loops of the same type produced different force systems. Overall, the new bending machine can fabricate different types of loop, but the requirements of very precise fabrication are currently not met. This fact, together with further limitations in terms of configuration, means that the machine cannot be used routinely at present. However, the machine can nevertheless be considered a good basis for further development.

  9. Optical coherence tomography based microangiography: A tool good for dermatology applications (Conference Presentation)

    Science.gov (United States)

    Wang, Ruikang K.; Baran, Utku; Choi, Woo J.

    2016-02-01

    Optical coherence tomography (OCT) based microangiography (OMAG) is a new imaging technique enabling the visualization of blood flow within microcirculatory tissue beds in vivo with high resolution. In this talk, the concept and advantages of OMAG will be discussed and its potential clinical applications in the dermatology will be shown, demonstrating its usefulness in the clinical monitoring and therapeutic treatment of various skin pathologies, e.g. acne, port wine stain and wound healing.

  10. Sound field of thermoacoustic tomography based on a modified finite-difference time-domain method

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chi; WANG Yuanyuan

    2009-01-01

    A modified finite-difference time-domain (FDTD) method is proposed for the sound field simulation of the thermoacoustic tomography (TAT) in the acoustic speed inhomogeneous medium. First, the basic equations of the TAT are discretized to difference ones by the FDTD. Then the electromagnetic pulse, the excitation source of the TAT, is modified twice to eliminate the error introduced by high frequency electromagnetic waves. Computer simulations are carried out to validate this method. It is shown that the FDTD method has a better accuracy than the commonly used time-of-flight (TOF) method in the TAT with the inhomogeneous acoustic speed. The error of the FDTD is ten times smaller than that of the TOF in the simulation for the acoustic speed difference larger than 50%. So this FDTD method is an efficient one for the sound field simulation of the TAT and can provide the theoretical basis for the study of reconstruction algorithms of the TAT in the acoustic heterogeneous medium.

  11. Beam hardening correction for interior tomography based on exponential formed model and radon inversion transform

    Science.gov (United States)

    Chen, Siyu; Zhang, Hanming; Li, Lei; Xi, Xiaoqi; Han, Yu; Yan, Bin

    2016-10-01

    X-ray computed tomography (CT) has been extensively applied in industrial non-destructive testing (NDT). However, in practical applications, the X-ray beam polychromaticity often results in beam hardening problems for image reconstruction. The beam hardening artifacts, which manifested as cupping, streaks and flares, not only debase the image quality, but also disturb the subsequent analyses. Unfortunately, conventional CT scanning requires that the scanned object is completely covered by the field of view (FOV), the state-of-art beam hardening correction methods only consider the ideal scanning configuration, and often suffer problems for interior tomography due to the projection truncation. Aiming at this problem, this paper proposed a beam hardening correction method based on radon inversion transform for interior tomography. Experimental results show that, compared to the conventional correction algorithms, the proposed approach has achieved excellent performance in both beam hardening artifacts reduction and truncation artifacts suppression. Therefore, the presented method has vitally theoretic and practicable meaning in artifacts correction of industrial CT.

  12. Transducer combination for high-quality ultrasound tomography based on speed of sound imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Hun; Park, Kwan Kyu [Dept. of Mechanical Engineering, Hanyang University, Seoul (Korea, Republic of)

    2016-02-15

    The type of ultrasound transducer used influences the quality of a reconstructed ultrasound image. This study analyzed the effect of transducer type on ultrasound computed tomography (UCT) image quality. The UCT was modeled in an ultrasound simulator by using a 5 cm anatomy model and a ring-shape 5 MHz 128 transducer array, which considered attenuation, refraction, and reflection. Speed-of-sound images were reconstructed by the Radon transform as the UCT image modality. Acoustic impedance images were also reconstructed by the delayand-sum (DAS) method, which considered the speed of sound information. To determine the optimal combination of transducers in observation, point-source, flat, and focused transducers were tested in combination as trasmitters and receivers; UCT images were constructed from each combination. The combination of point-source/flat transducer as transmitting and receiving devices presented the best reconstructed image quality. In UCT implementation, the combination of a flat transducer for transmitting and a point transducer for receiving permitted acceptable image quality.

  13. Locating Impedance Change in Electrical Impedance Tomography Based on Multilevel BP Neural Network

    Institute of Scientific and Technical Information of China (English)

    彭源; 莫玉龙

    2003-01-01

    Electrical impedance tomography (EIT) is a new computer tomography technology, which reconstructs an impedance (resistivity, conductivity) distribution, or change of impedance, by making voltage and current measurements on the object's periphery.Image reconstruction in EIT is an ill-posed, non-linear inverse problem. A method for finding the place of impedance change in EIT is proposed in this paper, in which a multilevel BP neural network (MBPNN) is used to express the non-linear relation between theimpedance change inside the object and the voltage change measured on the surface of the object. Thus, the location of the impedance change can be decided by the measured voltage variation on the surface. The impedance change is then reconstructed using a linear approximate method. MBPNN can decide the impedance change location exactly without long training time. It alleviates some noise effects and can be expanded, ensuring high precision and space resolution of the reconstructed image that are not possible by using the back projection method.

  14. Effect of anticoagulant treatment in deep vein thrombosis: A patient-specific computational fluid dynamics study.

    Science.gov (United States)

    Fortuny, Gerard; Herrero, Joan; Puigjaner, Dolors; Olivé, Carme; Marimon, Francesc; Garcia-Bennett, Josep; Rodríguez, Daniel

    2015-07-16

    A methodology that might help physicians to establish a diagnostic and treatment tailored for each specific patient with a pathological thrombus is presented. A realistic model for the geometry of a popliteal vein with a thrombus just above the knee was reconstructed from in vivo computed tomography images acquired from one specific patient and then it was used to perform computational fluid dynamics (CFD) simulations. The wall shear stress (WSS) response to the administration of anticoagulant drugs and the influence of viscosity on the shape of the velocity distribution were investigated. Both a Newtonian and a non-Newtonian viscosity model were implemented for different blood flow rates in the range 3-7 cm(3)/s. The effect of anticoagulants on the blood was simulated by setting three different levels of viscosity in the Newtonian model (μ/μ∞=0.60, 0.80 and 1 with μ∞=3.45×10(-3) Pas). A reduction of μ by a given amount always led to a more modest reduction, typically by a factor of two, of the resulting WSS levels. Moreover, for a given flow rate the calculation with the non-Newtonian viscosity model yielded WSS levels between 20% and 40% larger than those obtained in the corresponding Newtonian fluid simulation. It was also found that blood moves slowly in the region between the thrombus and the vein wall, a fact that will favor the growth of the thrombotic mass. Both the mean WSS levels and the degree of sluggishness of the blood flow can be described by functions of the Reynolds number.

  15. Positron emission tomography/computed tomography and biomarkers for early treatment response evaluation in metastatic colon cancer

    DEFF Research Database (Denmark)

    Engelmann, Bodil E.; Loft, Annika; Kjær, Andreas;

    2014-01-01

    BACKGROUND: Treatment options for metastatic colon cancer (mCC) are widening. We prospectively evaluated serial 2-deoxy-2-[18F]fluoro-d-glucose positron-emission tomography/computed tomography (PET/CT) and measurements of tissue inhibitor of metalloproteinases-1 (TIMP-1), carcinoembryonic antigen...... evaluated by PET/CT before treatment, after one and four treatment series. Morphological and metabolic response was independently assessed according to Response Evaluation Criteria in Solid Tumors and European Organization for Research and Treatment of Cancer PET criteria. Plasma TIMP-1, plasma u...

  16. Accuracy of treatment planning based on stereolithography in computer assisted surgery.

    Science.gov (United States)

    Schicho, Kurt; Figl, Michael; Seemann, Rudolf; Ewers, Rolf; Lambrecht, J Thomas; Wagner, Arne; Watzinger, Franz; Baumann, Arnulf; Kainberger, Franz; Fruehwald, Julia; Klug, Clemens

    2006-09-01

    Three-dimensional stereolithographic models (SL models), made of solid acrylic resin derived from computed-tomography (CT) data, are an established tool for preoperative treatment planning in numerous fields of medicine. An innovative approach, combining stereolithography with computer-assisted point-to-point navigation, can support the precise surgical realization of a plan that has been defined on an SL model preoperatively. The essential prerequisites for the application of such an approach are: (1) The accuracy of the SL models (including accuracy of the CT scan and correspondence of the model with the patient's anatomy) and (2) the registration method used for the transfer of the plan from the SL model to the patient (i.e., whether the applied registration markers can be added to the SL model corresponding to the markers at the patient with an accuracy that keeps the "cumulative error" at the end of the chain of errors, in the order of the accuracy of contemporary navigation systems). In this study, we focus on these two topics: By applying image-matching techniques, we fuse the original CT data of the patient with the corresponding CT data of the scanned SL model, and measure the deviations of defined parameter (e.g., distances between anatomical points). To evaluate the registration method used for the planning transfer, we apply a point-merge algorithm, using four marker points that should be located at exactly corresponding positions at the patient and at connective bars that are added to the surface of the SL model. Again, deviations at defined anatomical structures are measured and analyzed statistically. Our results prove sufficient correspondence of the two data sets and accuracy of the registration method for routine clinical application. The evaluation of the SL model accuracy revealed an arithmetic mean of the relative deviations from 0.8% to 5.4%, with an overall mean deviation of 2.2%. Mean deviations of the investigated anatomical structures

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

    Science.gov (United States)

    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.

  18. Computed tomography imaging parameters for inhomogeneity correction in radiation treatment planning

    Directory of Open Access Journals (Sweden)

    Indra J Das

    2016-01-01

    Full Text Available Modern treatment planning systems provide accurate dosimetry in heterogeneous media (such as a patient' body with the help of tissue characterization based on computed tomography (CT number. However, CT number depends on the type of scanner, tube voltage, field of view (FOV, reconstruction algorithm including artifact reduction and processing filters. The impact of these parameters on CT to electron density (ED conversion had been subject of investigation for treatment planning in various clinical situations. This is usually performed with a tissue characterization phantom with various density plugs acquired with different tube voltages (kilovoltage peak, FOV reconstruction and different scanners to generate CT number to ED tables. This article provides an overview of inhomogeneity correction in the context of CT scanning and a new evaluation tool, difference volume dose-volume histogram (DVH, dV-DVH. It has been concluded that scanner and CT parameters are important for tissue characterizations, but changes in ED are minimal and only pronounced for higher density materials. For lungs, changes in CT number are minimal among scanners and CT parameters. Dosimetric differences for lung and prostate cases are usually insignificant (<2% in three-dimensional conformal radiation therapy and < 5% for intensity-modulated radiation therapy (IMRT with CT parameters. It could be concluded that CT number variability is dependent on acquisition parameters, but its dosimetric impact is pronounced only in high-density media and possibly in IMRT. In view of such small dosimetric changes in low-density medium, the acquisition of additional CT data for financially difficult clinics and countries may not be warranted.

  19. Comprehensive vascular imaging using optical coherence tomography-based angiography and photoacoustic tomography

    Science.gov (United States)

    Zabihian, Behrooz; Chen, Zhe; Rank, Elisabet; Sinz, Christoph; Bonesi, Marco; Sattmann, Harald; Ensher, Jason; Minneman, Michael P.; Hoover, Erich; Weingast, Jessika; Ginner, Laurin; Leitgeb, Rainer; Kittler, Harald; Zhang, Edward; Beard, Paul; Drexler, Wolfgang; Liu, Mengyang

    2016-09-01

    Studies have proven the relationship between cutaneous vasculature abnormalities and dermatological disorders, but to image vasculature noninvasively in vivo, advanced optical imaging techniques are required. In this study, we imaged a palm of a healthy volunteer and three subjects with cutaneous abnormalities with photoacoustic tomography (PAT) and optical coherence tomography with angiography extension (OCTA). Capillaries in the papillary dermis that are too small to be discerned with PAT are visualized with OCTA. From our results, we speculate that the PA signal from the palm is mostly from hemoglobin in capillaries rather than melanin, knowing that melanin concentration in volar skin is significantly smaller than that in other areas of the skin. We present for the first time OCTA images of capillaries along with the PAT images of the deeper vessels, demonstrating the complementary effective imaging depth range and the visualization capabilities of PAT and OCTA for imaging human skin in vivo. The proposed imaging system in this study could significantly improve treatment monitoring of dermatological diseases associated with cutaneous vasculature abnormalities.

  20. Use of Positron Emission Tomography/Computed Tomography in Radiation Treatment Planning for Lung Cancer

    Directory of Open Access Journals (Sweden)

    Kezban Berberoğlu

    2016-06-01

    Full Text Available Radiotherapy (RT plays an important role in the treatment of lung cancer. Accurate diagnosis and staging are crucial in the delivery of RT with curative intent. Target miss can be prevented by accurate determination of tumor contours during RT planning. Currently, tumor contours are determined manually by computed tomography (CT during RT planning. This method leads to differences in delineation of tumor volume between users. Given the change in RT tools and methods due to rapidly developing technology, it is now more significant to accurately delineate the tumor tissue. F18 fluorodeoxyglucose positron emission tomography/CT (F18 FDG PET/CT has been established as an accurate method in correctly staging and detecting tumor dissemination in lung cancer. Since it provides both anatomic and biologic information, F18 FDG PET decreases interuser variability in tumor delineation. For instance, tumor volumes may be decreased as atelectasis and malignant tissue can be more accurately differentiated, as well as better evaluation of benign and malignant lymph nodes given the difference in FDG uptake. Using F18 FDG PET/CT, the radiation dose can be escalated without serious adverse effects in lung cancer. In this study, we evaluated the contribution of F18 FDG PET/CT for RT planning in lung cancer.

  1. Computer Aided Image Enhancement Of Tongue For Diagnosis In Ayurvedic Medical Treatment

    Directory of Open Access Journals (Sweden)

    Dhanalakshmi MIRYALA

    2014-03-01

    Full Text Available Ayurveda is one of the traditional medical systems practiced in India and south Asian countries from ancient times. Tongue diagnosis is one of the important areas in physical diagnosis of treatment of health disorders in Ayurveda. The diagnosis is usually carried out by the medical practitioner with visually understanding the tongue, but the process of understanding the tongue image is not an easy task to carry out. The difficulty arises because of the irregular shape of the tongue, overlapping of colors, effect of outside light, dominance of saliva on cracks and buds etc. In this paper, we propose an application of computer aided digital image enhancement methods for processing the tongue image to highlight the true color and white coating, cracks, pimples/buds etc., so that the practitioner can get more valuable information compared to direct visual examination of the tongue. The method mainly consists of two techniques; first, color image filtering and enhancement for identifying the true nature of colors on different parts of the tongue and to bring out white coating; second, contrast enhancement and image sharpening in grey scale for highlighting the shape, cracks, buds and pimples. The aim of our method is to help in reducing the complexity in tongue image understanding for the practitioner. The data of the experimental results reveal that our method produces significant useful result for the tongue diagnosis

  2. THREE-DIMENSIONAL COMPUTED TOMOGRAPHY-GUIDED RADIOFREQUENCY TRIGEMINAL RHIZOTOMY FOR TREATMENT OF IDIOPATHIC TRIGEMINAL NEURALGIA

    Institute of Scientific and Technical Information of China (English)

    Meng Liu; Cheng-yuan Wu; Yu-guang Liu; Hong-wei Wang; Fan-gang Meng

    2005-01-01

    Objective To evaluate the effectiveness of three-dimensional computed tomography (3D-CT) guided radiofrequency trige minal rhizotomy (RF-TR) in treatment of idiopathic trigeminal neuralgia (ITN). Methods From 1999 to 2001, 18 patients with ITN were treated with percutaneous controlled RF-TR. Intraoperative 3D-CT scanning was performed to guide the trajectory of the puncture. After correction of the needle tip according to the CT scans and stimulation effects, 2 to 5 lesions were made for a duration of 60-90 seconds at a temperature of 60℃ to 75℃ depend ing on the pain distribution and the age of patient. Results The needles located in foramen ovale. Pain alleviated immediately with no serious complication in all patients. The patients were followed up for an average of 31.5 months (range 24-41 months). Acute pain relief was experienced by 17 patients after the procedure, reaching an initial success rate of 94.4%. Early (< 6 months) pain recurrence was observed in 2 patients (11.1%), whereas late (> 6 months) recurrence was reported in 3 patients (16.7%). Thirteen patients had complete pain control, with no need for medication thereafter. Five cases experienced partial pain relief, but required medication at a lower dose than in the preoperative period. Conclusion 3D-CT foramen ovale locations can raise the successful rate of puncture, enhance the safety, and reduce the incidence rate of complication.

  3. Comparison of the pain levels of computer-controlled and conventional anesthesia techniques in prosthodontic treatment

    Directory of Open Access Journals (Sweden)

    Murat Yenisey

    2009-10-01

    Full Text Available OBJECTIVE: The objective of this study was to compare the pain levels on opposite sides of the maxilla at needle insertion during delivery of local anesthetic solution and tooth preparation for both conventional and anterior middle superior alveolar (AMSA technique with the Wand computer-controlled local anesthesia application. MATERIAL AND METHODS: Pain scores of 16 patients were evaluated with a 5-point verbal rating scale (VRS and data were analyzed nonparametrically. Pain differences at needle insertion, during delivery of local anesthetic, and at tooth preparation, for conventional versus the Wand technique, were analyzed using the Mann-Whitney U test (p=0.01. RESULTS: The Wand technique had a lower pain level compared to conventional injection for needle insertion (p0.05. CONCLUSIONS: The AMSA technique using the Wand is recommended for prosthodontic treatment because it reduces pain during needle insertion and during delivery of local anaesthetic. However, these two techniques have the same pain levels for tooth preparation.

  4. Influence of statin treatment on coronary atherosclerosis visualised using multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Hans [Charite, Medical School, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Department of Radiology, Berlin (Germany); Klinikum Brandenburg, Department of Cardiology, Angiology, and Pulmonology, Brandenburg an der Havel (Germany); Frieler, Katja [Charite, Medical School, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Department of Medical Statistics, Berlin (Germany); Potsdam Institut fuer Klimaforschung, Potsdam (Germany); Schlattmann, Peter [Charite, Medical School, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Department of Medical Statistics, Berlin (Germany); Hamm, Bernd [Charite, Medical School, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Department of Radiology, Berlin (Germany); Dewey, Marc [Charite, Medical School, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Department of Radiology, Berlin (Germany); Charite - Universitaetsmedizin Berlin, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Department of Radiology (Germany)

    2010-12-15

    Coronary angiography using multidetector computed tomography (MDCT) allows non-invasive assessment of non-calcified, calcified and mixed plaques. Progression of coronary plaques may be influenced by statins. Sixty-three consecutive patients underwent MDCT as a follow-up to their original CT angiography in a retrospective longitudinal study. MDCT was performed by using a voxel size of 0.5 x 0.35 x 0.35 mm{sup 3} at two time points 25 {+-} 3 months apart. Non-calcified, calcified and mixed coronary plaque components were analysed by using volumetric measurement. The influence of statin, low-density lipoprotein (LDL) and risk factors was assessed by using a linear random intercept model for plaque growth. The volumes of non-calcified, calcified and mixed coronary plaques significantly (P < 0.001) increased from baseline (medians/interquartile ranges = 21/15-39, 7/3-20 and 36/16-69 mm{sup 3}) to follow-up (29/17-44, 13/6-29 and 41/20-75 mm{sup 3}). Statins significantly slowed the growth of non-calcified plaques (statin coefficient {beta} = -0.0036, P = 0.01) but did not significantly affect the growth rate of mixed or calcified plaques. The effect of statin treatment on non-calcified plaques remained significant after adjusting for LDL levels and cardiac risk factors. Quantification using MDCT shows that progression of non-calcified coronary plaques may be slowed by statins. (orig.)

  5. Correlation of uptake patterns on single-photon emission computed tomography/computed tomography (SPECT/CT)and treatment response in patients with knee pain

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Geon; Hwang, Kyung Hoon; Lee, Hae Jin; Kim, Seog Gyun; Lee, Beom Koo [Gachon University Gil Hospital, Incheon (Korea, Republic of)

    2016-06-15

    To determine whether treatment response in patients with knee pain could be predicted using uptake patterns on single-photon emission computed tomography/computed tomography (SPECT/CT) images. Ninety-five patients with knee pain who had undergone SPECT/CT were included in this retrospective study. Subjects were divided into three groups: increased focal uptake (FTU), increased irregular tracer uptake (ITU), and no tracer uptake (NTU). A numeric rating scale (NRS-11) assessed pain intensity. We analyzed the association between uptake patterns and treatment response using Pearson's chi-square test and Fisher's exact test. Uptake was quantified from SPECT/CT with region of interest (ROI) counting, and an intraclass correlation coefficient (ICC) calculated agreement. We used Student' t-test to calculate statistically significant differences of counts between groups and the Pearson correlation to measure the relationship between counts and initial NRS-1k1. Multivariate logistic regression analysis determined which variables were significantly associated with uptake. The FTU group included 32 patients; ITU, 39; and NTU, 24. With conservative management, 64 % of patients with increased tracer uptake (TU, both focal and irregular) and 36 % with NTU showed positive response. Conservative treatment response of FTU was better than NTU, but did not differ from that of ITU. Conservative treatment response of TU was significantly different from that of NTU (OR 3.1; p 0.036). Moderate positive correlation was observed between ITU and initial NRS-11. Age and initial NRS-11 significantly predicted uptake. Patients with uptake in their knee(s) on SPECT/CT showed positive treatment response under conservative treatment.

  6. Measurement of diabetic wounds with optical coherence tomography-based air-jet indentation system and a material testing system.

    Science.gov (United States)

    Choi, M-C; Cheung, K-K; Ng, G Y-F; Zheng, Y-P; Cheing, G L-Y

    2015-11-01

    Material testing system is a conventional but destructive method for measuring the biomechanical properties of wound tissues in basic research. The recently developed optical coherence tomography-based air-jet indentation system is a non-destructive method for measuring these properties of soft tissues in a non-contact manner. The aim of the study was to examine the correlation between the biomechanical properties of wound tissues measured by the two systems. Young male Sprague-Dawley rats with streptozotocin-induced diabetic were wounded by a 6 mm biopsy punch on their hind limbs. The biomechanical properties of wound tissues were assessed with the two systems on post-wounding days 3, 7, 10, 14, and 21. Wound sections were stained with picro-sirius red for analysis on the collagen fibres. Data obtained on the different days were charted to obtain the change in biomechanical properties across the time points, and then pooled to examine the correlation between measurements made by the two devices. Qualitative analysis to determine any correlation between indentation stiffness measured by the air-jet indentation system and the orientation of collagen fibres. The indentation stiffness is significantly negatively correlated to the maximum load, maximum tensile stress, and Young's modulus by the material testing system (all pbased air-jet indentation system to evaluate the biomechanical properties of wounds in a non-contact manner. It is a potential clinical device to examine the biomechanical properties of chronic wounds in vivo in a repeatable manner.

  7. Treatment of congenital radial head dislocation with a computer-assisted hexapod external fixator: A case report

    Directory of Open Access Journals (Sweden)

    Özgür Karakoyun

    2015-09-01

    Full Text Available Congenital dislocation of the radial head (CDRH, a congenital anomaly of the elbow, can cause symptoms such as joint stiffness, snapping, locking, or pain, however the diagnosis is sometimes made incidentally from x-rays. The treatment goal is to ameliorate the symptoms and obtain a joint with a full range of motion. This paper presents a case of unilateral CDRH that was asymptomatic until adolescence, when locking and snapping developed. Several treatment options are described in the literature. Although the conventional and computer-assisted external fixator systems are used in several clinical pictures such as extremity deformities, joint contractures and fixation of acute fractures etc a computer-assisted external fixator system has not been used for CDRH. We successfully performed ulnar dorsal translation and a lengthening osteotomy with a computer-assisted external fixator to reduce the radial head indirectly and had satisfactory functional and clinical results. J Clin Exp Invest 2015; 6 (3: 301-305

  8. New Computational Framework for the Treatment of Joint Constraints and Connectivity Conditions in Finite Element/Multibody System Algorithms

    Science.gov (United States)

    2014-03-21

    NEW COMPUTATIONAL FRAMEWORK FOR THE TREATMENT OF JOINT CONSTRAINTS AND CONNECTIVITY CONDITIONS IN FINITE ELEMENT/MULTIBODY SYSTEM ALGORITMS Ahmed... ALGORITMS 5a. CONTRACT NUMBER W56hzv-13-c-0032 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Ahmed Shabana; Paramsothy Jayakumar; Michael

  9. A Computer-Aided Analysis Method of SPECT Brain Images for Quantitative Treatment Monitoring: Performance Evaluations and Clinical Applications

    Science.gov (United States)

    Wei, Wentao; Huang, Qiu; Wan, Jieqing; Huang, Gang

    2017-01-01

    The objective and quantitative analysis of longitudinal single photon emission computed tomography (SPECT) images are significant for the treatment monitoring of brain disorders. Therefore, a computer aided analysis (CAA) method is introduced to extract a change-rate map (CRM) as a parametric image for quantifying the changes of regional cerebral blood flow (rCBF) in longitudinal SPECT brain images. The performances of the CAA-CRM approach in treatment monitoring are evaluated by the computer simulations and clinical applications. The results of computer simulations show that the derived CRMs have high similarities with their ground truths when the lesion size is larger than system spatial resolution and the change rate is higher than 20%. In clinical applications, the CAA-CRM approach is used to assess the treatment of 50 patients with brain ischemia. The results demonstrate that CAA-CRM approach has a 93.4% accuracy of recovered region's localization. Moreover, the quantitative indexes of recovered regions derived from CRM are all significantly different among the groups and highly correlated with the experienced clinical diagnosis. In conclusion, the proposed CAA-CRM approach provides a convenient solution to generate a parametric image and derive the quantitative indexes from the longitudinal SPECT brain images for treatment monitoring. PMID:28251150

  10. Toward a web-based real-time radiation treatment planning system in a cloud computing environment

    Science.gov (United States)

    Hum Na, Yong; Suh, Tae-Suk; Kapp, Daniel S.; Xing, Lei

    2013-09-01

    To exploit the potential dosimetric advantages of intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT), an in-depth approach is required to provide efficient computing methods. This needs to incorporate clinically related organ specific constraints, Monte Carlo (MC) dose calculations, and large-scale plan optimization. This paper describes our first steps toward a web-based real-time radiation treatment planning system in a cloud computing environment (CCE). The Amazon Elastic Compute Cloud (EC2) with a master node (named m2.xlarge containing 17.1 GB of memory, two virtual cores with 3.25 EC2 Compute Units each, 420 GB of instance storage, 64-bit platform) is used as the backbone of cloud computing for dose calculation and plan optimization. The master node is able to scale the workers on an ‘on-demand’ basis. MC dose calculation is employed to generate accurate beamlet dose kernels by parallel tasks. The intensity modulation optimization uses total-variation regularization (TVR) and generates piecewise constant fluence maps for each initial beam direction in a distributed manner over the CCE. The optimized fluence maps are segmented into deliverable apertures. The shape of each aperture is iteratively rectified to be a sequence of arcs using the manufacture’s constraints. The output plan file from the EC2 is sent to the simple storage service. Three de-identified clinical cancer treatment plans have been studied for evaluating the performance of the new planning platform with 6 MV flattening filter free beams (40 × 40 cm2) from the Varian TrueBeamTM STx linear accelerator. A CCE leads to speed-ups of up to 14-fold for both dose kernel calculations and plan optimizations in the head and neck, lung, and prostate cancer cases considered in this study. The proposed system relies on a CCE that is able to provide an infrastructure for parallel and distributed computing. The resultant plans from the cloud computing are identical

  11. Toward a web-based real-time radiation treatment planning system in a cloud computing environment.

    Science.gov (United States)

    Na, Yong Hum; Suh, Tae-Suk; Kapp, Daniel S; Xing, Lei

    2013-09-21

    To exploit the potential dosimetric advantages of intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT), an in-depth approach is required to provide efficient computing methods. This needs to incorporate clinically related organ specific constraints, Monte Carlo (MC) dose calculations, and large-scale plan optimization. This paper describes our first steps toward a web-based real-time radiation treatment planning system in a cloud computing environment (CCE). The Amazon Elastic Compute Cloud (EC2) with a master node (named m2.xlarge containing 17.1 GB of memory, two virtual cores with 3.25 EC2 Compute Units each, 420 GB of instance storage, 64-bit platform) is used as the backbone of cloud computing for dose calculation and plan optimization. The master node is able to scale the workers on an 'on-demand' basis. MC dose calculation is employed to generate accurate beamlet dose kernels by parallel tasks. The intensity modulation optimization uses total-variation regularization (TVR) and generates piecewise constant fluence maps for each initial beam direction in a distributed manner over the CCE. The optimized fluence maps are segmented into deliverable apertures. The shape of each aperture is iteratively rectified to be a sequence of arcs using the manufacture's constraints. The output plan file from the EC2 is sent to the simple storage service. Three de-identified clinical cancer treatment plans have been studied for evaluating the performance of the new planning platform with 6 MV flattening filter free beams (40 × 40 cm(2)) from the Varian TrueBeam(TM) STx linear accelerator. A CCE leads to speed-ups of up to 14-fold for both dose kernel calculations and plan optimizations in the head and neck, lung, and prostate cancer cases considered in this study. The proposed system relies on a CCE that is able to provide an infrastructure for parallel and distributed computing. The resultant plans from the cloud computing are

  12. Evaluation of safe surgical treatment of peritonsillar abscess using computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Kasumi; Aramaki, Hajime; Arai, Yasuko; Uchimura, Kanako; Okabe, Kunihiko; Nishida, Motoko; Yoda, Keiko [Tokyo Women' s Medical Coll. (Japan). Daini Hospital

    2002-03-01

    With the development of new antimicrobial agents, the incidence of peritonsillar abscess (PTA) is on the decline. PTA is still often encountered in general practice, however, where it requires immediate diagnosis and treatment. Because the internal carotid artery runs medially to the medial parapharyngeal space, damage to nearby vascular or other structures is a surgical risk of PTA. We used contrast computed tomography (CT) from PTA patients to investigate the anatomical relationship between the abscess and parapharyngeal space, and to determine safe surgical sites. We observed 31 patients with PTA, 19 men and 12 women, between February 1997 and April 1999, all examined by contrast CT and undergoing drainage or incision. The average age was 30.7 years (range: 12-54 years). The abscess was on the right side in 20 cases and on the left side in 11. We determined the sites of the abscess and carotid artery, internal jugular vein, and surrounding soft tissue density area including nerves in the parapharyngeal space based on the angle and distance from recognizable anatomical structures in CT scans. The anterior margin of the parapharyngeal space was 29{+-}5 mm posterior from the upper posterior alveolar margin. The medial margin of that space was at 15{+-}2 deg laterally from the midline of the incisors, and 24{+-}4 mm laterally from the midline sagittal plane. The internal carotid artery was located medially to the parapharyngeal space, running on the sagittal plane containing the upper posterior alveolar margin. The distance from the anterior margin of the parapharyngeal space to the posterior wall of the PTA was 9{+-}4 mm, and the distance to the anterior wall of the abscess (including the pharyngeal mucosa) was 31{+-}5 cm. The relationship between the upper posterior alveolar margin and midline sagittal plane was useful for determining the site of the parapharyngeal space. Because the internal carotid artery is located on the same sagittal plane as the upper

  13. Effect of Nasal Obstruction on Continuous Positive Airway Pressure Treatment: Computational Fluid Dynamics Analyses.

    Directory of Open Access Journals (Sweden)

    Tadashi Wakayama

    Full Text Available Nasal obstruction is a common problem in continuous positive airway pressure (CPAP therapy for obstructive sleep apnea and limits treatment compliance. The purpose of this study is to model the effects of nasal obstruction on airflow parameters under CPAP using computational fluid dynamics (CFD, and to clarify quantitatively the relation between airflow velocity and pressure loss coefficient in subjects with and without nasal obstruction.We conducted an observational cross-sectional study of 16 Japanese adult subjects, of whom 9 had nasal obstruction and 7 did not (control group. Three-dimensional reconstructed models of the nasal cavity and nasopharynx with a CPAP mask fitted to the nostrils were created from each subject's CT scans. The digital models were meshed with tetrahedral cells and stereolithography formats were created. CPAP airflow simulations were conducted using CFD software. Airflow streamlines and velocity contours in the nasal cavities and nasopharynx were compared between groups. Simulation models were confirmed to agree with actual measurements of nasal flow rate and with pressure and flow rate in the CPAP machine.Under 10 cmH2O CPAP, average maximum airflow velocity during inspiration was 17.6 ± 5.6 m/s in the nasal obstruction group but only 11.8 ± 1.4 m/s in the control group. The average pressure drop in the nasopharynx relative to inlet static pressure was 2.44 ± 1.41 cmH2O in the nasal obstruction group but only 1.17 ± 0.29 cmH2O in the control group. The nasal obstruction and control groups were clearly separated by a velocity threshold of 13.5 m/s, and pressure loss coefficient threshold of approximately 10.0. In contrast, there was no significant difference in expiratory pressure in the nasopharynx between the groups.This is the first CFD analysis of the effect of nasal obstruction on CPAP treatment. A strong correlation between the inspiratory pressure loss coefficient and maximum airflow velocity was found.

  14. A computational hypothesis for allostasis: delineation of substance dependence, conventional therapies, and alternative treatments

    Directory of Open Access Journals (Sweden)

    Yariv Z. Levy

    2013-12-01

    Full Text Available The allostatic theory of drug abuse describes the brain's reward system alterations as substance misuse progresses. Neural adaptations arising from the reward system itself and from the antireward system provide the subject with functional stability, while affecting the person's mood. We propose a computational hypothesis describing how a virtual subject's drug consumption, cognitive substrate, and mood interface with reward and antireward systems. Reward system adaptations are assumed interrelated with the ongoing neural activity defining behavior towards drug intake, including activity in the nucleus accumbens, ventral tegmental area, and prefrontal cortex (PFC. Antireward system adaptations are assumed to mutually connect with higher-order cognitive processes occurring within PFC, orbitofrontal cortex, and anterior cingulate cortex. The subject's mood estimation is a provisional function of reward components.The presented knowledge repository model incorporates pharmacokinetic, pharmacodynamic, neuropsychological, cognitive, and behavioral components. Patterns of tobacco smoking exemplify the framework's predictive properties: escalation of cigarette consumption, conventional treatments similar to nicotine patches, and alternative medical practices comparable to meditation. The primary outcomes include an estimate of the virtual subject's mood and the daily account of drug intakes. The main limitation of this study resides in the 21 time-dependent processes which partially describe the complex phenomena of drug addiction and involve a large number of parameters which may underconstrain the framework.Our model predicts that reward system adaptations account for mood stabilization, whereas antireward system adaptations delineate mood improvement and reduction in drug consumption. This investigation provides formal arguments encouraging current rehabilitation therapies to include meditation-like practices along with pharmaceutical drugs and

  15. Comparison of Snellen and Early Treatment Diabetic Retinopathy Study charts using a computer simulation.

    Science.gov (United States)

    Shamir, Reuben R; Friedman, Yael; Joskowicz, Leo; Mimouni, Michael; Blumenthal, Eytan Z

    2016-01-01

    To compare accuracy, reproducibility and test duration for the Snellen and the Early Treatment Diabetic Retinopathy Study (ETDRS) charts, two main tools used to measure visual acuity (VA). A computer simulation was programmed to run multiple virtual patients, each with a unique set of assigned parameters, including VA, false-positive and false-negative error values. For each virtual patient, assigned VA was randomly chosen along a continuous scale spanning the range between 1.0 to 0.0 logMAR units (equivalent to 20/200 to 20/20). Each of 30 000 virtual patients were run ten times on each of the two VA charts. Average test duration (expressed as the total number of characters presented during the test ±SD) was 12.6±11.1 and 31.2±14.7 characters, for the Snellen and ETDRS, respectively. Accuracy, defined as the absolute difference (± SD) between the assigned VA and the measured VA, expressed in logMAR units, was superior in the ETDRS charts: 0.12±0.14 and 0.08±0.08, for the Snellen and ETDRS charts, respectively. Reproducibility, expressed as test-retest variability, was superior in the ETDRS charts: 0.23±0.17 and 0.11±0.09 logMAR units, for the Snellen and ETDRS charts, respectively. A comparison of true (assigned) VA to measured VA, demonstrated, on average, better accuracy and reproducibility of the ETDRS chart, but at the penalty of significantly longer test duration. These differences were most pronounced in the low VA range. The reproducibility using a simulation approach is in line with reproducibility values found in several clinical studies.

  16. Comparison of Snellen and Early Treatment Diabetic Retinopathy Study charts using a computer simulation

    Directory of Open Access Journals (Sweden)

    Reuben R. Shamir

    2016-01-01

    Full Text Available AIM: To compare accuracy, reproducibility and test duration for the Snellen and the Early Treatment Diabetic Retinopathy Study (ETDRS charts, two main tools used to measure visual acuity (VA. METHODS: A computer simulation was programmed to run multiple virtual patients, each with a unique set of assigned parameters, including VA, false-positive and false-negative error values. For each virtual patient, assigned VA was randomly chosen along a continuous scale spanning the range between 1.0 to 0.0 logMAR units (equivalent to 20/200 to 20/20. Each of 30 000 virtual patients were run ten times on each of the two VA charts. RESULTS: Average test duration (expressed as the total number of characters presented during the test ±SD was 12.6±11.1 and 31.2±14.7 characters, for the Snellen and ETDRS, respectively. Accuracy, defined as the absolute difference (± SD between the assigned VA and the measured VA, expressed in logMAR units, was superior in the ETDRS charts: 0.12±0.14 and 0.08±0.08, for the Snellen and ETDRS charts, respectively. Reproducibility, expressed as test-retest variability, was superior in the ETDRS charts: 0.23±0.17 and 0.11±0.09 logMAR units, for the Snellen and ETDRS charts, respectively. CONCLUSION: A comparison of true (assigned VA to measured VA, demonstrated, on average, better accuracy and reproducibility of the ETDRS chart, but at the penalty of significantly longer test duration. These differences were most pronounced in the low VA range. The reproducibility using a simulation approach is in line with reproducibility values found in several clinical studies.

  17. X-ray computed tomography in the post treatment evaluation of carcinoma of the cervix

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Hiroshi

    1988-12-01

    The diagnostic value of X-ray computed tomography scan for early detection of recurrence and/or metastasis were analyzed as an index of a sensitivity, a specificity, a positive predictive value, a negative predictive value and an accuracy among one hundred and thirty-one patients with carcinoma of the cervix as part of post-treatment evaluation during a period from 1980 to 1987. The diagnostic points of CT scan was the following criteria which including (1) parametrial involvement, (2) enlargement of uterine cervix, (3) invasion to vaginal wall, (4) bladder and/or rectal invasion, (5) pyometra, (6) enlargement of pelvic and/or paraaortic lymph nodes, (7) laterality of pelvic muscle, (8) intrapelvic abnormal shadow or ascites retension, (9) hydronephrosis, and (10) distant metastasis. (1) Among the patients treated with surgery, accuracy of each diagnostic point for early detection of recurrence was as follows: (8) 73%, (6) 60%, (9) 47%, (10) 47%, (3) 40%, (1) 33%, (4) 27%, (7) 27%, respectively. (2) Among the patients reated with radiotherapy, accuracy of each diagnostic point for early detection of recurrence was as follws: (1) 65%, (8) 64%, (5) 63%, (4) 61%, (10) 58%, (6) 55%, (9) 53%, (2) 42%, (3) 41%, (7) 41%, respectively. (3) Among the patients treated with surgery and radiotherapy, accuracy of each diagnostic point for early detection of recurrence was as follows: (8) 76%, (10) 76%, (9) 57%, (6) 52%, (1) 48%, (4) 43%, (7) 33%, (3) 19%, respectively. In conclusion, CT findings such as paraaortic lymphadenopathy and invasion to vaginal wall including distant metastasis were most important for early detection of recurrence during the follow-up study.

  18. Using of computer simulation in surgical treatment of patients with fractures of proximal femur

    Directory of Open Access Journals (Sweden)

    I.A. Norkin

    2010-06-01

    Full Text Available In this article questions of femur computer models base making for future it using in free patients medicine are discussed. Last allows possibility for educate doctors using computer models, increase their professional level and makes complications decrease. Comparing of fixation properties of DHS and PFN-A was performed

  19. SU-E-T-628: A Cloud Computing Based Multi-Objective Optimization Method for Inverse Treatment Planning.

    Science.gov (United States)

    Na, Y; Suh, T; Xing, L

    2012-06-01

    Multi-objective (MO) plan optimization entails generation of an enormous number of IMRT or VMAT plans constituting the Pareto surface, which presents a computationally challenging task. The purpose of this work is to overcome the hurdle by developing an efficient MO method using emerging cloud computing platform. As a backbone of cloud computing for optimizing inverse treatment planning, Amazon Elastic Compute Cloud with a master node (17.1 GB memory, 2 virtual cores, 420 GB instance storage, 64-bit platform) is used. The master node is able to scale seamlessly a number of working group instances, called workers, based on the user-defined setting account for MO functions in clinical setting. Each worker solved the objective function with an efficient sparse decomposition method. The workers are automatically terminated if there are finished tasks. The optimized plans are archived to the master node to generate the Pareto solution set. Three clinical cases have been planned using the developed MO IMRT and VMAT planning tools to demonstrate the advantages of the proposed method. The target dose coverage and critical structure sparing of plans are comparable obtained using the cloud computing platform are identical to that obtained using desktop PC (Intel Xeon® CPU 2.33GHz, 8GB memory). It is found that the MO planning speeds up the processing of obtaining the Pareto set substantially for both types of plans. The speedup scales approximately linearly with the number of nodes used for computing. With the use of N nodes, the computational time is reduced by the fitting model, 0.2+2.3/N, with r̂2>0.99, on average of the cases making real-time MO planning possible. A cloud computing infrastructure is developed for MO optimization. The algorithm substantially improves the speed of inverse plan optimization. The platform is valuable for both MO planning and future off- or on-line adaptive re-planning. © 2012 American Association of Physicists in Medicine.

  20. Routine Bone Marrow Biopsy Has Little or No Therapeutic Consequence for Positron Emission Tomography/Computed Tomography-Staged Treatment-Naive Patients With Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    El-Galaly, Tarec Christoffer; d´Amore, Francesco; Juul Mylam, Karen

    2012-01-01

    Routine Bone Marrow Biopsy Has Little or No Therapeutic Consequence for Positron Emission Tomography/Computed Tomography-Staged Treatment-Naive Patients With Hodgkin Lymphoma......Routine Bone Marrow Biopsy Has Little or No Therapeutic Consequence for Positron Emission Tomography/Computed Tomography-Staged Treatment-Naive Patients With Hodgkin Lymphoma...

  1. A 3D computer-aided design system applied to diagnosis and treatment planning in orthodontics and orthognathic surgery.

    Science.gov (United States)

    Motohashi, N; Kuroda, T

    1999-06-01

    The purpose of this article is to describe a newly developed 3D computer-aided design (CAD) system for the diagnostic set-up of casts in orthodontic diagnosis and treatment planning, and its preliminary clinical applications. The system comprises a measuring unit which obtains 3D information from the dental model using laser scanning, and a personal computer to generate the 3D graphics. When measuring the 3D shape of the model, to minimize blind sectors, the model is scanned from two different directions with the slit-ray laser beam by rotating the mounting angle of the model on the measuring device. For computed simulation of tooth movement, the representative planes, defined by the anatomical reference points, are formed for each individual tooth and are arranged along a guideline descriptive of the individual arch form. Subsequently, the 3D shape is imparted to each of the teeth arranged on the representative plane to form an arrangement of the 3D profile. When necessary, orthognathic surgery can be simulated by moving the mandibular dental arch three-dimensionally to establish the optimum occlusal relationship. Compared with hand-made set-up models, the computed diagnostic cast has advantages such as high-speed processing and quantitative evaluation on the amount of 3D movement of the individual tooth relative to the craniofacial plane. Trial clinical applications demonstrated that the use of this system facilitated the otherwise complicated and time-consuming mock surgery for treatment planning in orthognathic surgery.

  2. Effects of a computer feedback treatment and behavioral support protocol on drop out from a newly initiated exercise program.

    Science.gov (United States)

    Annesi, James J

    2007-08-01

    Drop out from newly initiated exercise regimens is problematic. Three treatments intended to support new exercise programs (standard exercise counseling, computer feedback, and behavioral support) were tested to estimate their association with drop out over the initial 3 and 6 mo. Data from a total of 1,336 adults (44% men; M(age) = 41.9 yrs., SD = 9.8) initiating exercise programs at 18 community exercise facilities (six in each of the three treatment groups) were aggregated by facility on a measure of drop out and were then contrasted both within and between groups. After a mixed model repeated-measures analysis of variance was significant overall, planned contrasts were conducted using the Tukey-Kramer test. Significantly less drop out was found at Month 3 for both the computer support (27%) and behavioral support (17%) groups, when contrasted with the standard exercise counseling group (38%). Behavioral support had significantly less drop out than computer feedback at Month 3. The behavioral support group showed significantly less drop out at Month 6 (33%) when contrasted with both the standard exercise counseling (58%) and computer feedback (52%) groups, which did not significantly differ from one another. Limitations and the need to evaluate and extend research on interventions for reducing drop out from exercise programs were discussed.

  3. Application of a Computer-Assisted Navigation System (CANS) in the Delayed Treatment of Zygomatic Fractures: A Randomized Controlled Trial.

    Science.gov (United States)

    Gong, Xi; He, Yang; An, Jingang; Yang, Yao; Huang, Xiuling; Liu, Meng; Zhao, Yangyang; Zhang, Yi

    2017-07-01

    The delayed treatment of zygomatic complex (ZMC) fracture presents a difficult challenge to surgeons. The aim of this study was to compare the treatment effects of delayed surgery of ZMC fractures with and without a computer-assisted navigation system (CANS). In this observer-blinded single-site randomized clinical trial, patients with unilateral ZMC fracture were included and randomized 1:1 to delayed treatment with or without CANS. The primary outcome measurement was the absolute bilateral differences of the ZMC eminence and width based on computed tomographic (CT) measurements 48 to 72 hours after surgery. One hundred three patients with unilateral ZMC fracture without immediate treatment were enrolled, and 78 were randomized to each group. Postoperative CT measurements showed that the bilateral difference in ZMC eminence was significantly less for the navigation group than for the control group (1.24 vs 2.22 mm; P control group (P = .001). Photogrammetry showed that the average difference between the postoperative CT data and the preoperative design was smaller in the navigation group (1.30 vs 2.40 mm; P = .012). Use of CANS improved ZMC symmetry in patients with unilateral ZMC fracture who had delayed treatment by allowing for more accurate implementation of the preoperative plan. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  4. Computer-Aided Treatment Design of a Distal Upper Extremity Soft Tissue Tumor with Electron Beam Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chun; Crawford, Susan; Mundt, A.J.; Vijayakumar, S.

    2015-01-15

    We present here a novel approach for the planning and treatment of a distal upper extremity soft tissue tumor. Utilizing computed tomography (CT) based electron dose calculations, a customized compensating wax bolus was designed in order to deliver sufficient dose coverage to the tumor volume while sparing the draining lymphatics of the patient’s hand and digits. A clinical case is presented as well as the design and construction of the compensator. Outcome and clinical implications are discussed.

  5. Real-time computer treatment of THz passive device images with the high image quality

    Science.gov (United States)

    Trofimov, Vyacheslav A.; Trofimov, Vladislav V.

    2012-06-01

    We demonstrate real-time computer code improving significantly the quality of images captured by the passive THz imaging system. The code is not only designed for a THz passive device: it can be applied to any kind of such devices and active THz imaging systems as well. We applied our code for computer processing of images captured by four passive THz imaging devices manufactured by different companies. It should be stressed that computer processing of images produced by different companies requires using the different spatial filters usually. The performance of current version of the computer code is greater than one image per second for a THz image having more than 5000 pixels and 24 bit number representation. Processing of THz single image produces about 20 images simultaneously corresponding to various spatial filters. The computer code allows increasing the number of pixels for processed images without noticeable reduction of image quality. The performance of the computer code can be increased many times using parallel algorithms for processing the image. We develop original spatial filters which allow one to see objects with sizes less than 2 cm. The imagery is produced by passive THz imaging devices which captured the images of objects hidden under opaque clothes. For images with high noise we develop an approach which results in suppression of the noise after using the computer processing and we obtain the good quality image. With the aim of illustrating the efficiency of the developed approach we demonstrate the detection of the liquid explosive, ordinary explosive, knife, pistol, metal plate, CD, ceramics, chocolate and other objects hidden under opaque clothes. The results demonstrate the high efficiency of our approach for the detection of hidden objects and they are a very promising solution for the security problem.

  6. Discrepant imaging findings of portal vein thrombosis with dynamic computed tomography and computed tomography during arterial portography in hepatocellular carcinoma: possible cause leading to inappropriate treatment selection.

    Science.gov (United States)

    Toyoda, Hidenori; Kumada, Takashi; Tada, Toshifumi; Mizuno, Kazuyuki; Kobayashi, Natsuko; Inukai, Yosuke; Takeda, Akira; Sone, Yasuhiro

    2017-04-01

    We encountered a patient with hepatocellular carcinoma who had discrepant imaging findings on portal vein thrombosis with portal phase dynamic computed tomography (CT) and CT during arterial portography (CTAP). CTAP, via the superior mesenteric artery and via the splenic artery, both showed a portal perfusion defect in the right hepatic lobe, indicating portal vein thrombosis in the main trunk of the right portal vein. Portal phase dynamic CT clearly depicted portal perfusion of the same hepatic area. Transarterial chemoembolization was successfully performed, but it was associated with severe liver injury. Clinicians should be cautious about this possible discrepancy based on imaging technique. The inaccurate evaluation of portal vein thrombosis may result in inappropriate treatment selection, which can worsen patient prognosis.

  7. Assessment of the nature of residual masses at end of treatment in lymphoma patients using volume perfusion computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Syha, R.; Gruenwald, L.; Spira, D.; Ketelsen, D.; Claussen, C.D.; Horger, M. [Eberhard Karls University, Department of Diagnostic Radiology, Tuebingen (Germany); Horger, T. [Technische Universitaet Muenchen, M2 - Lehrstuhl fuer Numerische, Garching (Germany); Vogel, W. [Eberhard Karls University, Department of Medical Oncology and Haematology, Tuebingen (Germany)

    2014-03-15

    To determine the diagnostic benefit of volume perfusion computed tomography (VPCT) at end of treatment for response assessment in lymphoma patients. Seventy-five patients with different lymphoma subtypes were included: 50/75 patients had residual masses at end of treatment, 26/50 patients underwent VPCT at baseline and at end of treatment, and 24/50 patients only had end-of-treatment VPCTs. We evaluated the size of the main lymphoma mass, its blood flow (BF), blood volume (BV) and k-trans, calculated ratios (baseline and end of treatment) as well as sensitivity/specificity/negative (NPV)/positive predictive values (PPV). For VPCT at end of treatment, a cutoff threshold between responders and non-responders was calculated. For patients undergoing VPCT at baseline and end of treatment, reduction in size, BF, BV and k-trans was significant (P < 0.001). Identification of non-response was reached at: <53 % reduction in size (sensitivity/specificity/accuracy/PPV/NPV of 88.89 %/62.5 %/80.77 %/84.21 %/71.43 %), <15 % reduction of BF (sensitivity/specificity/accuracy/PPV/NPV of 100 %/37.5 %/80.77 %/0.26 %/100 %), or <45 % reduction of k-trans (sensitivity/specificity/accuracy/PPV/NPV of 88.89 %/75 %/84.62 %/88.89 %/75 %). In the subgroup undergoing VPCT at end of treatment, BF >18.51 ml/100 ml indicated non-responsiveness (sensitivity 92.86 %, specificity 72.73 %, accuracy 84 %, PPV 81.25 %, NPV 88.89 %). VPCT seems adequate for assessment of lymphoma response at end of treatment. The degree of residual lymphoma perfusion at end of treatment helps to identify patients likely to remain in remission 1 year after completion of therapy. (orig.)

  8. Optimization of beam angles for intensity modulated radiation therapy treatment planning using genetic algorithm on a distributed computing platform.

    Science.gov (United States)

    Nazareth, Daryl P; Brunner, Stephen; Jones, Matthew D; Malhotra, Harish K; Bakhtiari, Mohammad

    2009-07-01

    Planning intensity modulated radiation therapy (IMRT) treatment involves selection of several angle parameters as well as specification of structures and constraints employed in the optimization process. Including these parameters in the combinatorial search space vastly increases the computational burden, and therefore the parameter selection is normally performed manually by a clinician, based on clinical experience. We have investigated the use of a genetic algorithm (GA) and distributed-computing platform to optimize the gantry angle parameters and provide insight into additional structures, which may be necessary, in the dose optimization process to produce optimal IMRT treatment plans. For an IMRT prostate patient, we produced the first generation of 40 samples, each of five gantry angles, by selecting from a uniform random distribution, subject to certain adjacency and opposition constraints. Dose optimization was performed by distributing the 40-plan workload over several machines running a commercial treatment planning system. A score was assigned to each resulting plan, based on how well it satisfied clinically-relevant constraints. The second generation of 40 samples was produced by combining the highest-scoring samples using techniques of crossover and mutation. The process was repeated until the sixth generation, and the results compared with a clinical (equally-spaced) gantry angle configuration. In the sixth generation, 34 of the 40 GA samples achieved better scores than the clinical plan, with the best plan showing an improvement of 84%. Moreover, the resulting configuration of beam angles tended to cluster toward the patient's sides, indicating where the inclusion of additional structures in the dose optimization process may avoid dose hot spots. Additional parameter selection in IMRT leads to a large-scale computational problem. We have demonstrated that the GA combined with a distributed-computing platform can be applied to optimize gantry angle

  9. Computational dosimetry of a simulated combined standard X-Rays and BNCT treatment

    Energy Technology Data Exchange (ETDEWEB)

    Casal, M.R., E-mail: mcasal@cnea.gov.ar [Instituto de Oncologia ' Angel H. Roffo' , Universidad de Buenos Aires, Av. San Martin 5481, Bs.As. (Argentina)] [Comision Nacional de Energia Atomica, Av. General Paz 1499, San Martin, Buenos Aires (Argentina); Herrera, M.S., E-mail: mariettaherrera@gmail.com [Comision Nacional de Energia Atomica, Av. General Paz 1499, San Martin, Buenos Aires (Argentina)] [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) Av. Rivadavia 191, Buenos Aires (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad de General San Martin, 25 de Mayo and M. de Irigoyen, San Martin (Argentina); Gonzalez, S.J., E-mail: srgonzal@cnea.gov.ar [Comision Nacional de Energia Atomica, Av. General Paz 1499, San Martin, Buenos Aires (Argentina)] [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) Av. Rivadavia 191, Buenos Aires (Argentina)

    2011-12-15

    There has been increasing interest in combining Boron Neutron Capture Therapy (BNCT) with standard radiotherapy, either concomitantly or as a BNCT treatment of a recurrent tumor that was previously irradiated with a medical electron linear accelerator (LINAC). In this work we report the simulated dosimetry of treatments combining X-rays and BNCT

  10. COMPUTER-BASED ANALYSIS OF THERMAL TREATMENT PARAMETERS APPLICABLE TO MINERAL WOOL PRODUCTS

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2013-01-01

    Full Text Available Properties of mineral wool products are, to a significant extent, pre-set by conditions of their thermal treatment. The findings of analytical and experimental researches into patterns of thermal treatment of mineral wool carpets have been converted into dominant factors of influence used to compile a network of factor-to-factor dependencies and resulting characteristics. Dependencies derived in pursuance of the aforementioned pattern serve as the basis for the algorithm of software programmes integrated into a single software facility. The software facility is designated for the analysis of the value of hydraulic resistance of a mineral wool carpet exposed to thermal treatment using the method of heat carrier blowing through the mineral wool carpet layer spread over the punched surface of the transporter. The software facility may be used to identify the minimal length of the thermal treatment chamber and the thermal treatment exposure time.

  11. Evaluation of preoperative computed tomography angiography in association with conventional angiography versus computed tomography angiography only, in the endovascular treatment of aortic diseases

    Energy Technology Data Exchange (ETDEWEB)

    Metzger, Patrick Bastos; Novero, Eduardo Rafael; Rossi, Fabio Henrique; Moreira, Samuel Martins; Linhares, Frederico Augusto; Almeida, Bruno Lorencao de; Barbato, Heraldo Antonio; Izukawa, Nilo Mitsuru; Kambara, Antonio Massamitsu, E-mail: patrickvascular@gmail.com [Instituto Dante Pazzanese de Cardiologia, Sao Paulo, SP (Brazil)

    2013-09-15

    Objective: to evaluate the association of conventional angiography (AG) with computed tomography angiography (CTA) as compared with CTA only, preoperatively, in the treatment of aortic diseases. Materials and methods: retrospective study involving patients submitted to endovascular treatment of aortic diseases, in the period from January 2009 to July 2010, with use of preoperative CTA + conventional AG or CTA only. The patients were divided into two groups, namely: G1 - thoracic aortic diseases; and G2 - abdominal aortic diseases. G1 was subdivided into 1A (preoperative AG + CTA) and 1B (preoperative CTA). G2 was subdivided into 2C (CTA + AG) and 2D (CTA only). Results: the authors evaluated 156 patients. In subgroups 1A and 1B, the rate of technical success was, respectively, 100% and 94.7% (p = 1.0); and the rate of therapeutic success was, respectively, 81% and 58% (p = 0.13). A higher number of complications were observed in subgroup 1B (p = 0.057). The accuracy in the calculation of the prosthesis was higher in subgroup 1A (p = 0.065). In their turn, the rate of technical success in subgroups 2C and 2D was, respectively, 92.3% and 98.6% (p = 0.17). The rate of therapeutic success was 73% and 98.6% (p = 0.79). Conclusion: preoperative conventional AG should be reserved for cases where CTA cannot provide all the information in the planning of a therapeutic intervention. (author)

  12. Evaluation of Cone Beam Computed Tomography in Diagnosis and Treatment Plan of Impacted Maxillary Canines Evaluation of Cone Beam Computed Tomography in Diagnosis and Treatment Plan of Impacted Maxillary Canines

    Directory of Open Access Journals (Sweden)

    Seyed Hossein Hoseini Zarch

    2013-06-01

    Full Text Available Introduction: Maxillary canines have important roles in facial appearance, development of arch, and functional occlusion. Radiographs are important in evaluating the location and nature of these anomalies. The purpose of this study was to evaluate two types of 2D and 3D imaging technique in diagnosis and treatment of maxillary impacted canines. Methods: Thirty eight patients (50 impacted canines were enrolled. An oral radiologist assessed all of patients’ panoramic radiographs and then cone beam computed tomography (CBCT to determine the presence of adjacent teeth root resorption, root dilacerations before dental extraction, dental rotation, and buccolingual localization ofimpacted canine crown and root contact with sinus and nasal cavity.Then using the patient’s radiographs the treatment plan of each impacted canine was determined by an orthodontist. Results: Differences between panoramic radiography and CBCT in diagnosis of root resorption and dental rotation were significant. There was an agreement between panoramic radiographs and CBCT in localization of impacted teeth crown. Only the treatment plans of 20% of impacted canines were different between panoramic radiographs and CBCT and treatment plan of 80% of impacted teeth was similar. Conclusion: These results showed that 2D and 3D images of impacted maxillary canines can produce different diagnoses and treatment plans.  

  13. Development of a computed tomographic scanner for radiation therapy treatment planning.

    Science.gov (United States)

    Smith, V; Parker, D L; Stanley, J H; Phillips, T L; Boyd, D P; Kan, P T

    1980-08-01

    The authors describe a low-cost CT scanner integrated with a radiotherapy simulator and designed for treatment planning. The standard rotational gantry and x-ray tube of the simulator are used with a multiwire xenon lonization chamber and simple current-proportional readout system to measure patient attenuation, avoiding problems associated with diagnostic CT scanners in treatment planning. Although design constraints limit performance, software compensation techniques have reduced artifacts and given satisfactory images.

  14. Comparison of five segmentation tools for 18F-fluoro-deoxy-glucose-positron emission tomography-based target volume definition in head and neck cancer.

    NARCIS (Netherlands)

    Schinagl, D.A.X.; Vogel, W.V.; Hoffmann, A.L.; Dalen, J.A. van; Oyen, W.J.G.; Kaanders, J.H.A.M.

    2007-01-01

    PURPOSE: Target-volume delineation for radiation treatment to the head and neck area traditionally is based on physical examination, computed tomography (CT), and magnetic resonance imaging. Additional molecular imaging with (18)F-fluoro-deoxy-glucose (FDG)-positron emission tomography (PET) may imp

  15. Computed tomography-guided bupivacaine and corticosteroid injection for the treatment of symptomatic calcification in the great toe tendon

    Directory of Open Access Journals (Sweden)

    Karatoprak O

    2014-04-01

    Full Text Available Omer Karatoprak,1 Sinan Karaca,2 Mehmet Nuri Erdem,3 Ozgur Karaman,2 Azmi Hamzaoglu41Department of Orthopedic Surgery, Kadikoy Florence Nightingale Hospital, Istanbul, Turkey; 2Department of Orthopedic Surgery, Fatih Sultan Mehmet Training and Research Hospital Atasehir, Istanbul, Turkey; 3Department of Orthopedics and Traumatology, Kolan International Hospital Sisli, Istanbul, Turkey; 4Department of Orthopedic Surgery, Istanbul Florence Nightingale Hospital, Istanbul TurkeyBackground: Calcification in the great toe tendon is a rare disorder that is characterized by the deposition of calcium on degenerative collagen fibrils.Case presentations: In this report, we present two cases of calcific tendonitis: one in the adductor hallucis and the other in the flexor hallucis longus tendon. We preferred computed tomography-guided steroid injection in our cases because of pain unresponsive to conservative treatment. Patients were free of symptoms at the follow-up visit, 4 weeks after injection.Conclusion: Calcification of the hallux tendons is a rare disorder. Treatment of tendonitis consists of nonsteroidal anti-inflammatory drugs. Local anesthetic and steroid injection may be considered in cases unresponsive to conservative treatment. Because of the anatomic location of tendons, injection could be difficult. Computed tomography guidance may improve the success rate of injections.Keywords: bupivacaine, calcification, great toe tendons, corticosteroid injection

  16. Impact of computer-based treatment planning software on clinical judgment of dental students for planning prosthodontic rehabilitation

    Directory of Open Access Journals (Sweden)

    Deshpande S

    2014-08-01

    Full Text Available Saee Deshpande, Jayashree Chahande Department of Prosthodontics, Vidya Shikshan Prasarak Mandal's (VPSM Dental College and Research Centre, Nagpur, Maharashtra, India Purpose: Successful prosthodontic rehabilitation involves making many interrelated clinical decisions which have an impact on each other. Self-directed computer-based training has been shown to be a very useful tool to develop synthetic and analytical problem-solving skills among students. Thus, a computer-based case study and treatment planning (CSTP software program was developed which would allow students to work through the process of comprehensive, multidisciplinary treatment planning for patients in a structured and logical manner. The present study was aimed at assessing the effect of this CSTP software on the clinical judgment of dental students while planning prosthodontic rehabilitation and to assess the students' perceptions about using the program for its intended use. Methods: A CSTP software program was developed and validated. The impact of this program on the clinical decision making skills of dental graduates was evaluated by real life patient encounters, using a modified and validated mini-CEX. Students' perceptions about the program were obtained by a pre-validated feedback questionnaire. Results: The faculty assessment scores of clinical judgment improved significantly after the use of this program. The majority of students felt it was an informative, useful, and innovative way of learning and they strongly felt that they had learnt the logical progression of planning, the insight into decision making, and the need for flexibility in treatment planning after using this program. Conclusion: CSTP software was well received by the students. There was significant improvement in students' clinical judgment after using this program. It should thus be envisaged fundamentally as an adjunct to conventional teaching techniques to improve students' decision making skills

  17. Application of positron emission tomography/computed tomography in radiation treatment planning for head and neck cancers

    Institute of Scientific and Technical Information of China (English)

    Musaddiq; J; Awan; Farzan; Siddiqui; David; Schwartz; Jiankui; Yuan; Mitchell; Machtay; Min; Yao

    2015-01-01

    18-fluorodeoxygluocose positron emission tomography/computed tomography(18FDG-PET/CT) provides significant information in multiple settings in the management of head and neck cancers(HNC). This article seeks to define the additional benefit of PET/CT as related to radiation treatment planning for squamous cell carcinomas(SCCs) of the head and neck through a review of relevant literature. By helping further define both primary and nodal volumes, radiation treatment planning can be improved using PET/CT. Special attention is paid to the independent benefit of PET/CT in targeting mucosal primaries as well as in detecting nodal metastases. The utility of PET/CT is also explored for treatment planning in the setting of SCC of unknown primary as PET/CT may help define a mucosal target volume by guiding biopsies for examination under anesthesia thus changing the treatment paradigm and limiting the extent of therapy. Implications of the use of PET/CT for proper target delineation in patients with artifact from dental procedures are discussed and the impact of dental artifact on CT-based PET attenuation correction is assessed. Finally, comment is made upon the role of PET/CT in the high-risk post-operative setting, particularly in the context of radiation dose escalation. Real case examples are used in these settings to elucidate the practical benefits of PET/CT as related to radiation treatment planning in HNCs.

  18. Comparison of Cone-Beam Computed Tomography and Periapical Radiography in Predicting Treatment Decision for Periapical Lesions: A Clinical Study

    Directory of Open Access Journals (Sweden)

    Ashok Balasundaram

    2012-01-01

    Full Text Available Objectives. To compare the ability of endodontists to determine the size of apical pathological lesions and select the most appropriate choice of treatment based on lesions’ projected image characteristics using 2 D and 3 D images. Study Design. Twenty-four subjects were selected. Radiographic examination of symptomatic study teeth with an intraoral periapical radiograph revealed periapical lesions equal to or greater than 3 mm in the greatest diameter. Cone-beam Computed tomography (CBCT images were made of the involved teeth after the intraoral periapical radiograph confirmed the size of lesion to be equal to greater than 3 mm. Six observers (endodontists viewed both the periapical and CBCT images. Upon viewing each of the images from the two imaging modalities, observers (1 measured lesion size and (2 made decisions on treatment based on each radiograph. Chi-square test was used to look for differences in the choice of treatment among observers. Results. No significant difference was noted in the treatment plan selected by observers using the two modalities (χ2(3=.036, P>0.05. Conclusion. Lesion size and choice of treatment of periapical lesions based on CBCT radiographs do not change significantly from those made on the basis of 2 D radiographs.

  19. Novel diode-based laser system for combined transcutaneous monitoring and computer-controlled intermittent treatment of jaundiced neonates

    Science.gov (United States)

    Hamza, Mostafa; El-Ahl, Mohammad H. S.; Hamza, Ahmad M.

    2001-06-01

    The high efficacy of laser phototherapy combined with transcutaneous monitoring of serum bilirubin provides optimum safety for jaundiced infants from the risk of bilirubin encephalopathy. In this paper the authors introduce the design and operating principles of a new laser system that can provide simultaneous monitoring and treatment of several jaundiced babies at one time. The new system incorporates diode-based laser sources oscillating at selected wavelengths to achieve both transcutaneous differential absorption measurements of bilirubin concentration in addition to the computer controlled intermittent laser therapy through a network of optical fibers. The detailed description and operating characteristics of this system are presented.

  20. Treatment of early and late reflections in a hybrid computer model for room acoustics

    DEFF Research Database (Denmark)

    Naylor, Graham

    1992-01-01

    The ODEON computer model for acoustics in large rooms is intended for use both in design (by predicting room acoustical indices quickly and easily) and in research (by forming the basis of an auralization system and allowing study of various room acoustical phenomena). These conflicting demands...... preclude the use of both ``pure'' image source and ``pure'' particle tracing methods. A hybrid model has been developed, in which rays discover potential image sources up to a specified order. Thereafter, the same ray tracing process is used in a different way to rapidly generate a dense reverberant decay...

  1. Value of Computed Tomographic Perfusion-Based Patient Selection for Intra-Arterial Acute Ischemic Stroke Treatment.

    Science.gov (United States)

    Borst, Jordi; Berkhemer, Olvert A; Roos, Yvo B W E M; van Bavel, Ed; van Zwam, Wim H; van Oostenbrugge, Robert J; van Walderveen, Marianne A A; Lingsma, Hester F; van der Lugt, Aad; Dippel, Diederik W J; Yoo, Albert J; Marquering, Henk A; Majoie, Charles B L M

    2015-12-01

    The utility of computed tomographic perfusion (CTP)-based patient selection for intra-arterial treatment of acute ischemic stroke has not been proven in randomized trials and requires further study in a cohort that was not selected based on CTP. Our objective was to study the relationship between CTP-derived parameters and outcome and treatment effect in patients with acute ischemic stroke because of a proximal intracranial arterial occlusion. We included 175 patients who underwent CTP in the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in The Netherlands (MR CLEAN). Association of CTP-derived parameters (ischemic-core volume, penumbra volume, and percentage ischemic core) with outcome was estimated with multivariable ordinal logistic regression as an adjusted odds ratio for a shift in the direction of a better outcome on the modified Rankin Scale. Interaction between CTP-derived parameters and treatment effect was determined using multivariable ordinal logistic regression. Interaction with treatment effect was also tested for mismatch (core 1.2; penumbra core >10 mL). The adjusted odds ratio for improved functional outcome for ischemic core, percentage ischemic core, and penumbra were 0.79 per 10 mL (95% confidence interval: 0.71-0.89; P<0.001), 0.82 per 10% (95% confidence interval: 0.66-0.90; P=0.002), and 0.97 per 10 mL (96% confidence interval: 0.92-1.01; P=0.15), respectively. No significant interaction between any of the CTP-derived parameters and treatment effect was observed. We observed no significant interaction between mismatch and treatment effect. CTP seems useful for predicting functional outcome, but cannot reliably identify patients who will not benefit from intra-arterial therapy. © 2015 American Heart Association, Inc.

  2. Differential Effectiveness of Three Color Treatments in Learning Geometric Concepts via Computer-Guided Teaching.

    Science.gov (United States)

    Hativa, Nira; Teper, Avigdor

    1988-01-01

    Discussion of the use of color in microcomputer-based educational software focuses on a study of Israeli ninth graders that examined the differential effects of three color treatments on the learning of geometric concepts by students with differential aptitudes. Hypotheses tested are described and results are analyzed. (28 references) (Author/LRW)

  3. Computer-aided Framework for Synthesis, Design and Retrofit of Wastewater Treatment Plants

    DEFF Research Database (Denmark)

    Bozkurt, Hande

    plant (WWTP) design is a formidable challenge. One of the key steps involved is the process synthesis - defined as the selection of treatment processes as a combination of unit operations and processes to create the process flow diagram.As a consequence of the emerging technological developments...

  4. Positron Emission Tomography/Computed Tomography in the Staging and Treatment of Anal Cancer

    DEFF Research Database (Denmark)

    Sveistrup, Joen; Loft, Annika; Berthelsen, Anne Kiil

    2012-01-01

    PURPOSE: This study was intended to determine the role of PET/CT in the staging of anal cancer as a supplement to three-dimensional transanal ultrasound (TAUS) and inguinal ultrasound (US). The impact of the PET/CT on the initial stage and treatment plan proposed by TAUS/US was assessed. METHODS ...

  5. Realistic virtual intracranial stenting and computational fluid dynamics for treatment analysis.

    Science.gov (United States)

    Janiga, Gábor; Rössl, Christian; Skalej, Martin; Thévenin, Dominique

    2013-01-01

    In order to support the decisions of medical experts and to develop better stent designs, the availability of a simulation tool for virtual stenting would be extremely useful. An innovative virtual stenting technique is described in this work, which is directly applicable for complex patient-specific geometries. A basilar tip aneurysm provided for the Virtual Intracranial Stenting Challenge 2010 is considered to demonstrate the advantages of this approach. A free-form deformation is introduced for a wall-tight stent deployment. Numerical flow simulations on sufficiently fine computational meshes are performed for different configurations in order to characterize the inflow rate into the aneurysm and the corresponding residence time in the aneurysm sac. A Neuroform and a SILK stent have been deployed at various locations and the computed residence times have been evaluated and compared, demonstrating the advantage associated with a lower stent porosity. It has been found that the SILK stent leads to a large increase in the residence time and to a significant reduction in the maximum wall shear stress in the aneurysm sac. This is only observed when placing the stent in the appropriate position, showing that virtual stenting might be employed for operation support.

  6. COMPUTED TOMOGRAPHIC CHARACTERISTICS OF THE THYROID GLANDS IN EIGHT HYPERTHYROID CATS PRE- AND POSTMETHIMAZOLE TREATMENT COMPARED WITH SEVEN EUTHYROID CATS.

    Science.gov (United States)

    Bush, Jennifer L; Nemanic, Sarah; Gordon, Jana; Bobe, Gerd

    2017-03-01

    Hyperthyroidism is the most common feline endocrinopathy; thyroid computed tomography (CT) may improve disease detection and methimazole dose selection. Objectives of this experimental pre-post with historical case-control study were to perform thyroid CT imaging in awake or mildly sedated hyperthyroid cats, compare thyroid gland CT appearance in euthyroid and hyperthyroid cats pre- and postmethimazole treatment, and determine whether thyroid size or attenuation correlate with methimazole dose needed for euthyroidism. Premethimazole treatment, eight hyperthyroid cats received CT scans from the head to heart, which were compared to CT of seven euthyroid cats. Total thyroxine levels were monitored every 3-4 weeks. Postmethimazole CT was performed 30 days after achieving euthyroid status. Computed tomography parameters recorded included thyroid length, width, height, attenuation, and heterogeneity. Median time between CT was 70 days (53-213 days). Mild sedation was needed in five hyperthyroid cats premethimazole, and none postmethimazole. Thyroid volume was significantly larger in hyperthyroid cats compared to euthyroid cats (785.0 mm(3) vs. 154.9 mm(3) ; P = 0.002) and remained unchanged by methimazole treatment (-4.5 mm3; P = 0.50). Thyroid attenuation and heterogeneity decreased with methimazole treatment (96.1 HU vs. 85.9 HU; P = 0.02. 12.4 HU vs. 8.1 HU; P = 0.009). Methimazole dose ranged from 2.5 to 10 mg daily with a positive correlation between pretreatment thyroid gland volume and dose needed to achieve euthyroidism (P = 0.03). Euthyroid and hyperthyroid cats are easily imaged awake or mildly sedated with CT. Methimazole in hyperthyroid cats significantly lowers thyroid attenuation and heterogeneity, but not size. © 2016 American College of Veterinary Radiology.

  7. Evaluating the effectiveness of treatment of corneal ulcers via computer-based automatic image analysis

    Science.gov (United States)

    Otoum, Nesreen A.; Edirisinghe, Eran A.; Dua, Harminder; Faraj, Lana

    2012-06-01

    Corneal Ulcers are a common eye disease that requires prompt treatment. Recently a number of treatment approaches have been introduced that have been proven to be very effective. Unfortunately, the monitoring process of the treatment procedure remains manual and hence time consuming and prone to human errors. In this research we propose an automatic image analysis based approach to measure the size of an ulcer and its subsequent further investigation to determine the effectiveness of any treatment process followed. In Ophthalmology an ulcer area is detected for further inspection via luminous excitation of a dye. Usually in the imaging systems utilised for this purpose (i.e. a slit lamp with an appropriate dye) the ulcer area is excited to be luminous green in colour as compared to rest of the cornea which appears blue/brown. In the proposed approach we analyse the image in the HVS colour space. Initially a pre-processing stage that carries out a local histogram equalisation is used to bring back detail in any over or under exposed areas. Secondly we deal with the removal of potential reflections from the affected areas by making use of image registration of two candidate corneal images based on the detected corneal areas. Thirdly the exact corneal boundary is detected by initially registering an ellipse to the candidate corneal boundary detected via edge detection and subsequently allowing the user to modify the boundary to overlap with the boundary of the ulcer being observed. Although this step makes the approach semi automatic, it removes the impact of breakages of the corneal boundary due to occlusion, noise, image quality degradations. The ratio between the ulcer area confined within the corneal area to the corneal area is used as a measure of comparison. We demonstrate the use of the proposed tool in the analysis of the effectiveness of a treatment procedure adopted for corneal ulcers in patients by comparing the variation of corneal size over time.

  8. Oral omega-3 fatty acids treatment in computer vision syndrome related dry eye.

    Science.gov (United States)

    Bhargava, Rahul; Kumar, Prachi; Phogat, Hemant; Kaur, Avinash; Kumar, Manjushri

    2015-06-01

    To assess the efficacy of dietary consumption of omega-3 fatty acids (O3FAs) on dry eye symptoms, Schirmer test, tear film break up time (TBUT) and conjunctival impression cytology (CIC) in patients with computer vision syndrome. Interventional, randomized, double blind, multi-centric study. Four hundred and seventy eight symptomatic patients using computers for more than 3h per day for minimum 1 year were randomized into two groups: 220 patients received two capsules of omega-3 fatty acids each containing 180mg eicosapentaenoic acid (EPA) and 120mg docosahexaenoic acid (DHA) daily (O3FA group) and 236 patients received two capsules of a placebo containing olive oil daily for 3 months (placebo group). The primary outcome measure was improvement in dry eye symptoms and secondary outcome measures were improvement in Nelson grade and an increase in Schirmer and TBUT scores at 3 months. In the placebo group, before dietary intervention, the mean symptom score, Schirmer, TBUT and CIC scores were 7.5±2, 19.9±4.7mm, 11.5±2s and 1±0.9 respectively, and 3 months later were 6.8±2.2, 20.5±4.7mm, 12±2.2s and 0.9±0.9 respectively. In the O3FA group, these values were 8.0±2.6, 20.1±4.2mm, 11.7±1.6s and 1.2±0.8 before dietary intervention and 3.9±2.2, 21.4±4mm, 15±1.7s, 0.5±0.6 after 3 months of intervention, respectively. This study demonstrates the beneficial effect of orally administered O3FAs in alleviating dry eye symptoms, decreasing tear evaporation rate and improving Nelson grade in patients suffering from computer vision syndrome related dry eye. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  9. Accurate treatments of electrostatics for computer simulations of biological systems: A brief survey of developments and existing problems

    Science.gov (United States)

    Yi, Sha-Sha; Pan, Cong; Hu, Zhong-Han

    2015-12-01

    Modern computer simulations of biological systems often involve an explicit treatment of the complex interactions among a large number of molecules. While it is straightforward to compute the short-ranged Van der Waals interaction in classical molecular dynamics simulations, it has been a long-lasting issue to develop accurate methods for the longranged Coulomb interaction. In this short review, we discuss three types of methodologies for the accurate treatment of electrostatics in simulations of explicit molecules: truncation-type methods, Ewald-type methods, and mean-field-type methods. Throughout the discussion, we brief the formulations and developments of these methods, emphasize the intrinsic connections among the three types of methods, and focus on the existing problems which are often associated with the boundary conditions of electrostatics. This brief survey is summarized with a short perspective on future trends along the method developments and applications in the field of biological simulations. Project supported by the National Natural Science Foundation of China (Grant Nos. 91127015 and 21522304) and the Open Project from the State Key Laboratory of Theoretical Physics, and the Innovation Project from the State Key Laboratory of Supramolecular Structure and Materials.

  10. Computational approaches for understanding the diagnosis and treatment of Parkinson's disease.

    Science.gov (United States)

    Smith, Stephen L; Lones, Michael A; Bedder, Matthew; Alty, Jane E; Cosgrove, Jeremy; Maguire, Richard J; Pownall, Mary Elizabeth; Ivanoiu, Diana; Lyle, Camille; Cording, Amy; Elliott, Christopher J H

    2015-12-01

    This study describes how the application of evolutionary algorithms (EAs) can be used to study motor function in humans with Parkinson's disease (PD) and in animal models of PD. Human data is obtained using commercially available sensors via a range of non-invasive procedures that follow conventional clinical practice. EAs can then be used to classify human data for a range of uses, including diagnosis and disease monitoring. New results are presented that demonstrate how EAs can also be used to classify fruit flies with and without genetic mutations that cause Parkinson's by using measurements of the proboscis extension reflex. The case is made for a computational approach that can be applied across human and animal studies of PD and lays the way for evaluation of existing and new drug therapies in a truly objective way.

  11. Computational Modeling of a Mechanized Benchtop Apparatus for Leading-Edge Slat Noise Treatment Device Prototypes

    Science.gov (United States)

    Turner, Travis L.; Moore, James B.; Long, David L.

    2017-01-01

    Airframe noise is a growing concern in the vicinity of airports because of population growth and gains in engine noise reduction that have rendered the airframe an equal contributor during the approach and landing phases of flight for many transport aircraft. The leading-edge-slat device of a typical high-lift system for transport aircraft is a prominent source of airframe noise. Two technologies have significant potential for slat noise reduction; the slat-cove filler (SCF) and the slat-gap filler (SGF). Previous work was done on a 2D section of a transport-aircraft wing to demonstrate the implementation feasibility of these concepts. Benchtop hardware was developed in that work for qualitative parametric study. The benchtop models were mechanized for quantitative measurements of performance. Computational models of the mechanized benchtop apparatus for the SCF were developed and the performance of the system for five different SCF assemblies is demonstrated.

  12. Diagnosis and Treatment of a Type III Dens Invagination Using Cone-Beam Computed Tomography

    Science.gov (United States)

    Bahmani, Mohsen; Adl, Alireza; Javanmardi, Samane; Naghizadeh, Sina

    2016-01-01

    A 20-year-old man presented with the history of pain and swelling in the anterior maxillary segment. The periapical radiography was indicative of a dental anomaly in right maxillary lateral incisor. Due to the insufficient information from conventional radiography, cone-beam computed tomography (CBCT) was ordered. CBCT showed apical root resorption, large apical lucency and two separate canals with distinct apical foramen (Oehlers type III dens invagination). The CBCT image was used as a guide for dentine removal with an ultrasonic tip. Conventional root canal therapy was done using lateral compaction technique. One-and two-year follow-up radiographies revealed periapical repair and absence of symptoms. PMID:27790268

  13. Computational particle-haemodynamics analysis of liver radioembolization pretreatment as an actual treatment surrogate.

    Science.gov (United States)

    Aramburu, Jorge; Antón, Raúl; Rivas, Alejandro; Ramos, Juan Carlos; Sangro, Bruno; Bilbao, José Ignacio

    2017-02-01

    Liver radioembolization (RE) is a treatment option for patients with unresectable and chemorefractory primary and metastatic liver tumours. RE consists of intra-arterially administering via catheter radioactive microspheres that locally attack the tumours, sparing healthy tissue. Prior to RE, the standard practice is to conduct a treatment-mimicking pretreatment assessment via the infusion of (99m) Tc-labelled macroaggregated albumin microparticles. The usefulness of this pretreatment has been debated in the literature, and thus, the aim of the present study is to shed light on this issue by numerically simulating the liver RE pretreatment and actual treatment particle-haemodynamics in a patient-specific hepatic artery under two different literature-based cancer scenarios and two different placements of a realistic end-hole microcatheter in the proper hepatic artery. The parameters that are analysed are the following: microagent quantity and size (accounting for RE pretreatment and treatment), catheter-tip position (near the proper hepatic artery bifurcation and away from it), and cancer burden (10% and 30% liver involvement). The conclusion that can be reached from the simulations is that when it comes to mimicking RE in terms of delivering particles to tumour-bearing segments, the catheter-tip position is much more important (because of the importance of local haemodynamic pattern alteration) than the infused microagents (i.e. quantity and size). Cancer burden is another important feature because the increase in blood flow rate to tumour-bearing segments increases the power to drag particles. These numerical simulation-based conclusions are in agreement with clinically observed events reported in the literature. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Acoustic Emission tomography based on simultaneous algebraic reconstruction technique to visualize the damage source location in Q235B steel plate

    Science.gov (United States)

    Jiang, Yu; Xu, Feiyun; Xu, Bingsheng

    2015-12-01

    Acoustic Emission (AE) tomography based on Simultaneous Algebraic Reconstruction Technique (SART), which combines the traditional location algorithm with the SART algorithm by using AE events as its signal sources, is a new visualization method for inspecting and locating the internal damages in the structure. In this paper, the proposed method is applied to examine and visualize two man-made damage source locations in the Q235B steel plate to validate its effectiveness. Firstly, the Q235B steel plate with two holes specimen is fabricated and the pencil lead break (PLB) signal is taken as the exciting source for AE tomography.Secondly, A 6-step description of the SART algorithm is provided and the three dimensional(3D)image contained the damage source locations is visualized by using the proposed algorithm in terms of a locally varying wave velocity distribution. It is shown that the AE tomography based on SART has great potential in the application of structure damage detection. Finally, to further improve the quality of 3D imaging, the Median Filter and the Adaptive Median Filter are used to reduce the noises resulting from AE tomography. The experiment results indicate that Median Filter is the optimal method to remove Salt & Pepper noises.

  15. Computer Enabled Neuroplasticity Treatment: A Clinical Trial of a Novel Design for Neurofeedback Therapy in Adult ADHD

    Science.gov (United States)

    Cowley, Benjamin; Holmström, Édua; Juurmaa, Kristiina; Kovarskis, Levas; Krause, Christina M.

    2016-01-01

    .O.V.A. Comprehensive analysis will be reported elsewhere. Trial Registration: “Computer Enabled Neuroplasticity Treatment (CENT),” ISRCTN13915109. PMID:27242472

  16. Artificial intelligence in medicine and cardiac imaging: harnessing big data and advanced computing to provide personalized medical diagnosis and treatment.

    Science.gov (United States)

    Dilsizian, Steven E; Siegel, Eliot L

    2014-01-01

    Although advances in information technology in the past decade have come in quantum leaps in nearly every aspect of our lives, they seem to be coming at a slower pace in the field of medicine. However, the implementation of electronic health records (EHR) in hospitals is increasing rapidly, accelerated by the meaningful use initiatives associated with the Center for Medicare & Medicaid Services EHR Incentive Programs. The transition to electronic medical records and availability of patient data has been associated with increases in the volume and complexity of patient information, as well as an increase in medical alerts, with resulting "alert fatigue" and increased expectations for rapid and accurate diagnosis and treatment. Unfortunately, these increased demands on health care providers create greater risk for diagnostic and therapeutic errors. In the near future, artificial intelligence (AI)/machine learning will likely assist physicians with differential diagnosis of disease, treatment options suggestions, and recommendations, and, in the case of medical imaging, with cues in image interpretation. Mining and advanced analysis of "big data" in health care provide the potential not only to perform "in silico" research but also to provide "real time" diagnostic and (potentially) therapeutic recommendations based on empirical data. "On demand" access to high-performance computing and large health care databases will support and sustain our ability to achieve personalized medicine. The IBM Jeopardy! Challenge, which pitted the best all-time human players against the Watson computer, captured the imagination of millions of people across the world and demonstrated the potential to apply AI approaches to a wide variety of subject matter, including medicine. The combination of AI, big data, and massively parallel computing offers the potential to create a revolutionary way of practicing evidence-based, personalized medicine.

  17. Long-term evaluation of apical root resorption after orthodontic treatment using periapical radiography and cone beam computed tomography

    Directory of Open Access Journals (Sweden)

    Jairo Curado de Freitas

    2013-08-01

    Full Text Available OBJECTIVE: To evaluate the frequency of Apical Root Resorption (ARR after orthodontic treatment at 52-288 months using periapical radiography (PR and cone beam computed tomography (CBCT. METHODS: Radiographic images obtained from 58 patients, before (T1 and after orthodontic treatment (T2, and following 52-288 months of treatment were analyzed by three members of the Brazilian Board of Orthodontics. Apical structures were evaluated by PR images (T2 and T3, using Levander and Malmgren scores. The presence of ARR on CBCT images were detected only at T3. The Kolmogorov-Smirnov test was used for statistical analyses, and the level of significance was set at 5%. Kappa statistics determined interobserver agreement. RESULTS: The more frequent ARR were with scores 1 in T2 (51.6% and T3 (53.1%, when evaluated by PR (p > 0.05. When compared the frequencies of ARR in T3 among PR and CBCT images, the differences were significant for maxillary and mandibular pre-molar groups, and for mandibular molar group (p > 0.05. The teeth with highest frequency of ARR presence using CBCT images were maxillary lateral incisors (94.5% and mandibular central incisors (87.7%, while the premolars showed the lowest frequency. The CBCT images showed that the teeth involved in orthodontic treatment with extraction present higher ARR frequency (p < 0.05. CONCLUSION: PR showed more frequency of ARR in posterior teeth groups when compared with CBCT images. ARR did not change in long-term post treatment.

  18. Feasibility of differential quantification of 3D temporomandibular kinematics during various oral activities using a cone-beam computed tomography-based 3D fluoroscopic method

    Directory of Open Access Journals (Sweden)

    Chien-Chih Chen

    2013-06-01

    Conclusion: A new CBCT-based 3D fluoroscopic method was proposed and shown to be capable of quantitatively differentiating TMJ movement patterns among complicated functional activities. It also enabled a complete description of the rigid-body mandibular motion and descriptions of as many reference points as needed for future clinical applications. It will be helpful for dental practice and for a better understanding of the functions of the TMJ.

  19. Diagnosis of drowning using post-mortem computed tomography based on the volume and density of fluid accumulation in the maxillary and sphenoid sinuses

    Energy Technology Data Exchange (ETDEWEB)

    Kawasumi, Yusuke, E-mail: ssu@rad.med.tohoku.ac.jp [Tohoku University Graduate School of Medicine, Department of Clinical Imaging, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575 (Japan); Kawabata, Tomoyoshi; Sugai, Yusuke [Tohoku University Graduate School of Medicine, Department of Clinical Imaging, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575 (Japan); Usui, Akihito, E-mail: t7402r0506@med.tohoku.ac.jp [Tohoku University Graduate School of Medicine, Department of Diagnostic Image Analysis, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575 (Japan); Hosokai, Yoshiyuki, E-mail: hosokai@med.tohoku.ac.jp [Tohoku University Graduate School of Medicine, Department of Diagnostic Image Analysis, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575 (Japan); Sato, Miho, E-mail: meifan58@m.tains.tohoku.ac.jp [Tohoku University Graduate School of Medicine, Department of Clinical Imaging, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575 (Japan); Saito, Haruo, E-mail: hsaito@med.tohoku.ac.jp [Tohoku University Graduate School of Medicine, Department of Diagnostic Image Analysis, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575 (Japan); Ishibashi, Tadashi, E-mail: tisibasi@med.tohoku.ac.jp [Tohoku University Graduate School of Medicine, Department of Clinical Imaging, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575 (Japan); Hayashizaki, Yoshie, E-mail: yoshie@forensic.med.tohoku.ac.jp [Tohoku University Graduate School of Medicine, Department of Forensic Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575 (Japan); Funayama, Masato, E-mail: funayama@forensic.med.tohoku.ac.jp [Tohoku University Graduate School of Medicine, Department of Forensic Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575 (Japan)

    2013-10-01

    Recent studies have reported that drowning victims frequently have fluid accumulation in the paranasal sinuses, most notably the maxillary and sphenoid sinuses. However, in our previous study, many non-drowning victims also had fluid accumulation in the sinuses. Therefore, we evaluated the qualitative difference in fluid accumulation between drowning and non-drowning cases in the present study. Thirty-eight drowning and 73 non-drowning cases were investigated retrospectively. The fluid volume and density of each case were calculated using a DICOM workstation. The drowning cases were compared with the non-drowning cases using the Mann–Whitney U-test because the data showed non-normal distribution. The median fluid volume was 1.82 (range 0.02–11.7) ml in the drowning cases and 0.49 (0.03–8.7) ml in the non-drowning cases, and the median fluid density was 22 (−14 to 66) and 39 (−65 to 77) HU, respectively. Both volume and density differed significantly between the drowning and non-drowning cases (p = 0.001, p = 0.0007). Regarding cut-off levels in the ROC analysis, the points on the ROC curve closest (0, 1) were 1.03 ml (sensitivity 68%, specificity 68%, PPV 53%, NPV 81%) and 27.5 HU (61%, 70%, 51%, 77%). The Youden indices were 1.03 ml and 37.8 HU (84%, 51%, 47%, 86%). When the cut-off level was set at 1.03 ml and 27.5 HU, the sensitivity was 42%, specificity 45%, PPV 29% and NPV 60%. When the cut-off level was set at 1.03 ml and 37.8 HU, sensitivity was 58%, specificity 32%, PPV 31% and NPV 59%.

  20. Optimal C-arm angulation during transcatheter aortic valve replacement: Accuracy of a rotational C-arm computed tomography based three dimensional heart model.

    Science.gov (United States)

    Veulemans, Verena; Mollus, Sabine; Saalbach, Axel; Pietsch, Max; Hellhammer, Katharina; Zeus, Tobias; Westenfeld, Ralf; Weese, Jürgen; Kelm, Malte; Balzer, Jan

    2016-10-26

    To investigate the accuracy of a rotational C-arm CT-based 3D heart model to predict an optimal C-arm configuration during transcatheter aortic valve replacement (TAVR). Rotational C-arm CT (RCT) under rapid ventricular pacing was performed in 57 consecutive patients with severe aortic stenosis as part of the pre-procedural cardiac catheterization. With prototype software each RCT data set was segmented using a 3D heart model. From that the line of perpendicularity curve was obtained that generates a perpendicular view of the aortic annulus according to the right-cusp rule. To evaluate the accuracy of a model-based overlay we compared model- and expert-derived aortic root diameters. For all 57 patients in the RCT cohort diameter measurements were obtained from two independent operators and were compared to the model-based measurements. The inter-observer variability was measured to be in the range of 0°-12.96° of angular C-arm displacement for two independent operators. The model-to-operator agreement was 0°-13.82°. The model-based and expert measurements of aortic root diameters evaluated at the aortic annulus (r = 0.79, P r = 0.93, P r = 0.92, P < 0.01) correlated on a high level and the Bland-Altman analysis showed good agreement. The interobserver measurements did not show a significant bias. Automatic segmentation of the aortic root using an anatomical model can accurately predict an optimal C-arm configuration, potentially simplifying current clinical workflows before and during TAVR.

  1. TU-CD-BRA-08: Single-Energy Computed Tomography-Based Pulmonary Perfusion Imaging: Proof-Of-Principle in a Canine Model

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, T; Boone, J [University of California Davis School of Medicine, Sacramento, CA (United States); Kent, M; Wisner, E [University of California Davis School of Veterinary Medicine, Davis, CA (United States); Fujita, Y [Tokai University, Isehara (Japan)

    2015-06-15

    Purpose: Pulmonary perfusion imaging has provided significant insights into pulmonary diseases, and can be useful in radiotherapy. The purpose of this study was to prospectively establish proof-of-principle in a canine model for single-energy CT-based perfusion imaging, which has the potential for widespread clinical implementation. Methods: Single-energy CT perfusion imaging is based on: (1) acquisition of inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast medium, (2) deformable image registration (DIR) of the two CT image data sets, and (3) subtraction of the pre-contrast image from post-contrast image, yielding a map of Hounsfield unit (HU) enhancement. These subtraction image data sets hypothetically represent perfused blood volume, a surrogate for perfusion. In an IACUC-approved clinical trial, we acquired pre- and post-contrast CT scans in the prone posture for six anesthetized, mechanically-ventilated dogs. The elastix algorithm was used for DIR. The registration accuracy was quantified using the target registration errors (TREs) for 50 pulmonary landmarks in each dog. The gradient of HU enhancement between gravity-dependent (ventral) and non-dependent (dorsal) regions was evaluated to quantify the known effect of gravity, i.e., greater perfusion in ventral regions. Results: The lung volume difference between the two scans was 4.3±3.5% on average (range 0.3%–10.1%). DIR demonstrated an average TRE of 0.7±1.0 mm. HU enhancement in lung parenchyma was 34±10 HU on average and varied considerably between individual dogs, indicating the need for improvement of the contrast injection protocol. HU enhancement in ventral (gravity-dependent) regions was found to be greater than in dorsal regions. A population average ventral-to-dorsal gradient of HU enhancement was strong (R{sup 2}=0.94) and statistically significant (p<0.01). Conclusion: This canine study demonstrated relatively accurate DIR and a strong ventral-to-dorsal gradient of HU enhancement, providing proof-of-principle for single-energy CT pulmonary perfusion imaging. This ongoing study will enroll more dogs and investigate the physiological significance. This study was supported by a Philips Healthcare/Radiological Society of North America (RSNA) Research Seed Grant (RSD1458)

  2. Positron Emission Tomography/Computed Tomography in the Staging and Treatment of Anal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Sveistrup, Joen, E-mail: joensveistrup@hotmail.com [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark); Loft, Annika [PET and Cyclotron Unit, Department of Clinical Physiology and Nuclear Medicine, Centre of Diagnostic Investigations, Rigshospitalet, Copenhagen (Denmark); Berthelsen, Anne Kiil [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark); PET and Cyclotron Unit, Department of Clinical Physiology and Nuclear Medicine, Centre of Diagnostic Investigations, Rigshospitalet, Copenhagen (Denmark); Henriksen, Birthe Merete; Nielsen, Michael Bachmann [Department of Radiology, Section of Ultrasound X4123, Rigshospitalet, Copenhagen (Denmark); Engelholm, Svend Aage [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark)

    2012-05-01

    Purpose: This study was intended to determine the role of PET/CT in the staging of anal cancer as a supplement to three-dimensional transanal ultrasound (TAUS) and inguinal ultrasound (US). The impact of the PET/CT on the initial stage and treatment plan proposed by TAUS/US was assessed. Methods and Materials: Ninety-five (95) patients referred to our clinic between July 1, 2005, and December 31, 2009, were retrospectively reviewed. All patients had biopsy-proven primary squamous cell cancer of the anal canal. There were 65 females (68%) and 30 males (32%), and the median age was 58 years (range, 35-88 years). Six (6%) of the patients were HIV positive. All patients were staged with TAUS/US and PET/CT. Results: Twenty-eight (28) patients were diagnosed with suspicious perirectal node metastases. TAUS visualized 24 of these, whereas PET/CT detected 15. Suspicious inguinal nodes were visualized on either US or PET/CT in 41 patients. Seventeen (17) of these had confirmed malignant disease on biopsy, and 15 had confirmed benign disease. All 17 patients (100%) with malignant inguinal nodes were diagnosed by PET/CT, whereas US identified 16 (94%). Ten patients were diagnosed with suspicious inguinal nodes on PET/CT that had not been seen on US. One of these was malignant, three were benign, and six were not biopsied. PET/CT diagnosed eight metastatic sites, whereas TAUS/US diagnosed three. PET/CT discovered three of the five synchronous cancers seen in this study. PET/CT upstaged the disease in 14% of the cases and changed the treatment plan proposed by TAUS/US in 17%. Conclusion: PET/CT has great potential influence on the staging and treatment of anal cancer. TAUS is important in the staging of the primary tumor and N1-stage, whereas PET/CT seems necessary for the N2/3-stage, the M-stage and synchronous cancers.

  3. The Developments and Application of Computer Simulation in Heat Treatment Process Based on Metallo-Thermo-Mechanical Theory

    Institute of Scientific and Technical Information of China (English)

    Dong-Ying Ju

    2000-01-01

    The aim of this paper is to introduce the application and future of computer simulation in heat treatment process, as an important method in manufacturing of material. Here, developments of the finite element based on a code "HEARTS will are presented by using some experiments to be applied simulation of general quenching, quenching-tempering and quenching with carbonization or induction. The code "HEARTS" for 3-D simulation of heat treatment process based on a metallo-thermo-mechanical theory is presented. Coupled equations of heat conduction, inelastic stresses and kinetics of phase transformations are derived as well as the diffusion equation during carbonization, followed by finite element formulation. The program is available for 2-D and 3-D simulation of various heat treatment processes, such as quenching,tempering and so on. The system is used in the CAE environment of some pre-and post-processors over "Ⅰ-DEAS ", "PATRAN" or "FEMAP". Some examples of simulated results of carbonized quenching processes for cylindrical rod, ring and gear wheel are also presented.

  4. Thin-section computed tomography findings before and after azithromycin treatment of neutrophilic reversible lung allograft dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Jong, Pim A. de [Department of Radiology, Katholieke Universiteit Leuven, Leuven (Belgium); Lung Transplantation Unit, Katholieke Universiteit Leuven, Leuven (Belgium); University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Vos, Robin; Verleden, Geert M.; Vanaudenaerde, Bart M. [Lung Transplantation Unit, Katholieke Universiteit Leuven, Leuven (Belgium); Verschakelen, Johny A. [Department of Radiology, Katholieke Universiteit Leuven, Leuven (Belgium)

    2011-12-15

    Recently a novel subgroup of bronchiolitis obliterans syndrome (BOS) has been described in patients after lung transplantation with high neutrophil counts in broncho-alveolar lavage and recovery of lung functional decline with azithromycin treatment. We aimed to describe the thin-section computed tomography (CT) findings of these neutrophilic reversible allograft dysfunction (NRAD) patients before and after azithromycin. A cohort of 100 lung transplant recipients with BOS were treated with azithromycin and underwent lung function testing, broncho-alveolar lavage and CT before azithromycin treatment and during follow-up. The 200 CT data sets were scored for bronchial dilatation, mucus plugging, centrilobular abnormalities, airway wall thickening, consolidation, ground glass and end-expiratory air trapping. NRAD was characterized by more centrilobular abnormalities on CT (p = 0.03 for prevalence and p = 0.06 for severity) compared to non-responders. At follow-up NRAD patients showed improvement in all CT abnormalities including air trapping, but the degree of improvement in all CT abnormalities was significantly different between responders and non-responders (who showed progression of bronchus dilatation, consolidation and air trapping). Within BOS patients those with NRAD differ from azithromycin non-responders by more centrilobular abnormalities on CT before azithromycin and improvement in bronchus dilatation, consolidation and air trapping during treatment. (orig.)

  5. A computational implementation and comparison of several intensity modulated proton therapy treatment planning algorithms.

    Science.gov (United States)

    Li, Haisen S; Romeijn, H Edwin; Fox, Christopher; Palta, Jatinder R; Dempsey, James F

    2008-03-01

    The authors present a comparative study of intensity modulated proton therapy (IMPT) treatment planning employing algorithms of three-dimensional (3D) modulation, and 2.5-dimensional (2.5D) modulation, and intensity modulated distal edge tracking (DET) [A. Lomax, Phys. Med. Biol. 44, 185-205 (1999)] applied to the treatment of head-and-neck cancer radiotherapy. These three approaches were also compared with 6 MV photon intensity modulated radiation therapy (IMRT). All algorithms were implemented in the University of Florida Optimized Radiation Therapy system using a finite sized pencil beam dose model and a convex fluence map optimization model. The 3D IMPT and the DET algorithms showed considerable advantages over the photon IMRT in terms of dose conformity and sparing of organs at risk when the beam number was not constrained. The 2.5D algorithm did not show an advantage over the photon IMRT except in the dose reduction to the distant healthy tissues, which is inherent in proton beam delivery. The influences of proton beam number and pencil beam size on the IMPT plan quality were also studied. Out of 24 cases studied, three cases could be adequately planned with one beam and 12 cases could be adequately planned with two beams, but the dose uniformity was often marginally acceptable. Adding one or two more beams in each case dramatically improved the dose uniformity. The finite pencil beam size had more influence on the plan quality of the 2.5D and DET algorithms than that of the 3D IMPT. To obtain a satisfactory plan quality, a 0.5 cm pencil beam size was required for the 3D IMPT and a 0.3 cm size was required for the 2.5D and the DET algorithms. Delivery of the IMPT plans produced in this study would require a proton beam spot scanning technique that has yet to be developed clinically.

  6. Computed tomography characterization of neuroendocrine tumors of the thymus can aid identification and treatment

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hui; Wang, De-ling; Liu, Xue-wen; Geng, Zhi-jun; Xie, Chuan-miao [State Key Lab. of Oncology in Southern China, Guangzhou (China); Medical Imaging and Minimally Invasive Interventional Center, Cancer Center, Sun Yat-sen Univ., Guangzhou (China)], e-mail: xchuanm@sysucc.org.cn

    2013-03-15

    Background: Neuroendocrine tumors of the thymus are extremely rare anterior mediastinal tumors. The few studies reporting these tumors have focused on the clinical manifestations and do not provide a summary of characteristic computed tomography (CT) findings. Purpose: To investigate the CT appearances of neuroendocrine tumors of the thymus in order to improve the diagnostic and resection efficacy. Material and Methods: Nine cases of pathologically identified thymic neuroendocrine tumors were retrospectively analyzed by CT. All the patients underwent non-enhanced and contrast-enhanced CT. Multiple CT features were examined, including tumor location, shape, margins, CT attenuation, involvement of surrounding structures, and distant metastasis. Results: A total of nine masses were examined in this study. The maximum tumor diameter ranged from 5 to 14 cm (average, 9 cm). The shapes of six masses were lobulated and three were rounded or oval and the margins of seven masses were unclear while two masses were sharp. All the masses showed hypo density or isodensity compared to muscles in the anterior thoracic wall on non-enhanced CT images. Two masses showed homogeneous attenuation by non-enhanced CT imaging and moderate homogeneous enhancement after contrast administration, while seven masses showed heterogeneous attenuation with patchy low-attenuation foci and showed moderate to strong heterogeneous enhancement. Involvement of adjacent structures was observed in six cases. Five cases were observed to have lymph node metastases and four cases had distant metastases. Conclusion: Neuroendocrine tumors of the thymus are rare tumors of the anterior mediastinum with a number of distinct CT characteristics. Most importantly, the density of the tumors was heterogeneous with necrosis or cystic degeneration and moderately or strongly enhancement after bolus injection of contrast medium, which may allow for more efficient tumor identification. Thus, CT can improve of the diagnosis

  7. Endodontic Treatment of a Maxillary First Molar with Seven Root Canals Confirmed with Cone Beam Computer Tomography – Case Report

    Science.gov (United States)

    2014-01-01

    The most common configuration of the maxillary first molar is the presence of three roots and four root canals, although the presence of several other configurations have already been reported. The objective of this work is to present a rare anatomic configuration with seven root canals diagnosed during an endodontic therapy. Endodontic treatment was performed using a dental operating microscope. Exploring the grooves surrounding the main canals with ultrasonic troughing was able expose unexpected root canals. Instrumentation with files of smaller sizes and tapers was performed to prevent root physical weakness. The anatomic configuration was confirmed with a Cone Beam Computer Tomography image analysis which was able to clearly show the presence of seven root canals. An electronic database search was conducted to identify all the published similar cases and the best techniques to approach them are discussed. PMID:25121069

  8. The effect of influent temperature variations in a sedimentation tank for potable water treatment--a computational fluid dynamics study.

    Science.gov (United States)

    Goula, Athanasia M; Kostoglou, Margaritis; Karapantsios, Thodoris D; Zouboulis, Anastasios I

    2008-07-01

    A computational fluid dynamics (CFD) model is used to assess the effect of influent temperature variation on solids settling in a sedimentation tank for potable water treatment. The model is based on the CFD code Fluent and exploits several specific aspects of the potable water application to derive a computational tool much more efficient than the corresponding tools employed to simulate primary and secondary wastewater settling tanks. The linearity of the particle conservation equations allows separate calculations for each particle size class, leading to the uncoupling of the CFD problem from a particular inlet particle size distribution. The usually unknown and difficult to be measured particle density is determined by matching the theoretical to the easily measured experimental total settling efficiency. The present model is adjusted against data from a real sedimentation tank and then it is used to assess the significance of influent temperature variation. It is found that a temperature difference of only 1 degrees C between influent and tank content is enough to induce a density current. When the influent temperature rises, the tank exhibits a rising buoyant plume that changes the direction of the main circular current. This process keeps the particles in suspension and leads to a higher effluent suspended solids concentration, thus, worse settling. As the warmer water keeps coming in, the temperature differential decreases, the current starts going back to its original position, and, thus, the suspended solids concentration decreases.

  9. Treatment planning for brachytherapy: an integer programming model, two computational approaches and experiments with permanent prostate implant planning.

    Science.gov (United States)

    Lee, E K; Gallagher, R J; Silvern, D; Wuu, C S; Zaider, M

    1999-01-01

    An integer linear programming model is proposed as a framework for optimizing seed placement and dose distribution in brachytherapy treatment planning. The basic model involves using 0/1 indicator variables to describe the placement or non-placement of seeds in a prespecified three-dimensional grid of potential locations. The dose delivered to each point in a discretized representation of the diseased organ and neighbouring healthy tissue can then be modelled as a linear combination of the indicator variables. A system of linear constraints is imposed to attempt to keep the dose level at each point to within specified target bounds. Since it is physically impossible to satisfy all constraints simultaneously, each constraint uses a variable to either record when the target dose level is achieved, or to record the deviation from the desired level. These additional variables are embedded into an objective function to be optimized. Variations on this model are discussed and two computational approaches--a branch-and-bound algorithm and a genetic algorithm--for finding 'optimal' seed placements are described. Results of computational experiments on a collection of prostate cancer cases are reported. The results indicate that both optimization algorithms are capable of producing good solutions within 5 to 15 min, and that small variations in model parameters can have a measurable effect on the dose distribution of the resulting plans.

  10. Application of an EPID for fast daily dosimetric quality control of a fully computer-controlled treatment unit

    Energy Technology Data Exchange (ETDEWEB)

    Dirkx, M.L.P.; Kroonwijk, M.; De Boer, J.C.J.; Heijmen, B.J.M. [Nederlands Kanker Inst. `Antoni van Leeuwenhoekhuis`, Amsterdam (Netherlands)

    1995-12-01

    The MM50 Racetrack Microtron, suited for sophisticated three-dimensional computer-controlled conformal radiotherapy techniques, is a complex treatment unit in various respects. Therefore, for a number of gantry angles, daily quality control of the absolute output and the profiles of the scanned photon beams in mandatory. A fast method for these daily checks, based on dosimetric measurements with the Philips SRI-100 Electronic Portal Imaging Device, has been developed and tested. Open beams are checked for four different gantry angles; for gantry angle 0, a wedged field is checked as well. The fields are set up one after another under full computer control. Performing and analyzing the measurements takes about ten minutes. The applied EPID has favourable characteristics for dosimetric quality control measurements: absolute measurements reproduce within 0.5% (1 SD) and the reproducibility of a relative (2-D) fluence profile is 0.2% (1 SD). The day-to-day sensitivity stability over a period of a month is 0.6% (1 SD). EPID-signals are within 0.2% linear with the applied dose. The 2-D fluence profile of the 25 MV photon beam of the MM50 is very stable in time: during a period of one year, a maximum fluctuation of 2.6% was observed. Once, a deviation in the cGy/MU-value of 6% was detected. Only because of the performed morning quality control checks with the EPID, erroneous dose delivery to patients could be avoided; there is no interlock in the MM50-system that would have prevented patient treatment. Based on our experiences and on clinical requirements regarding the acceptability of deviations of beam characteristics, a protocol has been developed including action levels for additional investigations. Studies on the application of the SRI-100 for in vivo dosimetry on the MM50 have been started.

  11. Successful orthograde treatment of dens invaginatus Type 3 with a main C-shaped canal based on cone-beam computed tomography evaluation

    Science.gov (United States)

    Solomonov, Michael; Itzhak, Joe Ben; Levin, Avi; Katzenell, Vered; Shemesh, Avi

    2016-01-01

    Dens invaginatus is a rare anatomic variation that is found primarily in maxillary lateral incisors. The management of dens invaginatus is challenging for clinicians; diagnosing the type of malformation, choosing the most appropriate treatment, and carrying out treatment are complicated by the intricate root system of these teeth. The following case report describes the diagnosis and treatment planning of dens invaginatus Type 3 after cone-beam computed tomography evaluation. PMID:27994325

  12. Computer-based psychological treatment for comorbid depression and problematic alcohol and/or cannabis use: a randomized controlled trial of clinical efficacy.

    Science.gov (United States)

    Kay-Lambkin, Frances J; Baker, Amanda L; Lewin, Terry J; Carr, Vaughan J

    2009-03-01

    To evaluate computer- versus therapist-delivered psychological treatment for people with comorbid depression and alcohol/cannabis use problems. Randomized controlled trial. Community-based participants in the Hunter Region of New South Wales, Australia. Ninety-seven people with comorbid major depression and alcohol/cannabis misuse. All participants received a brief intervention (BI) for depressive symptoms and substance misuse, followed by random assignment to: no further treatment (BI alone); or nine sessions of motivational interviewing and cognitive behaviour therapy (intensive MI/CBT). Participants allocated to the intensive MI/CBT condition were selected at random to receive their treatment 'live' (i.e. delivered by a psychologist) or via a computer-based program (with brief weekly input from a psychologist). Depression, alcohol/cannabis use and hazardous substance use index scores measured at baseline, and 3, 6 and 12 months post-baseline assessment. (i) Depression responded better to intensive MI/CBT compared to BI alone, with 'live' treatment demonstrating a strong short-term beneficial effect which was matched by computer-based treatment at 12-month follow-up; (ii) problematic alcohol use responded well to BI alone and even better to the intensive MI/CBT intervention; (iii) intensive MI/CBT was significantly better than BI alone in reducing cannabis use and hazardous substance use, with computer-based therapy showing the largest treatment effect. Computer-based treatment, targeting both depression and substance use simultaneously, results in at least equivalent 12-month outcomes relative to a 'live' intervention. For clinicians treating people with comorbid depression and alcohol problems, BIs addressing both issues appear to be an appropriate and efficacious treatment option. Primary care of those with comorbid depression and cannabis use problems could involve computer-based integrated interventions for depression and cannabis use, with brief regular

  13. Positioning of Tacrolimus for the Treatment of Diabetic Nephropathy Based on Computational Network Analysis

    Science.gov (United States)

    Heinzel, Andreas; Sunzenauer, Judith; Oberbauer, Rainer

    2017-01-01

    Objective To evaluate tacrolimus as therapeutic option for diabetic nephropathy (DN) based on molecular profile and network-based molecular model comparisons. Materials and Methods We generated molecular models representing pathophysiological mechanisms of DN and tacrolimus mechanism of action (MoA) based on literature derived data and transcriptomics datasets. Shared enriched molecular pathways were identified based on both model datasets. A newly generated transcriptomics dataset studying the effect of tacrolimus on mesangial cells in vitro was added to identify mechanisms in DN pathophysiology. We searched for features in interference between the DN molecular model and the tacrolimus MoA molecular model already holding annotation evidence as diagnostic or prognostic biomarker in the context of DN. Results Thirty nine molecular features were shared between the DN molecular model, holding 252 molecular features and the tacrolimus MoA molecular model, holding 209 molecular features, with six additional molecular features affected by tacrolimus in mesangial cells. Significantly affected molecular pathways by both molecular model sets included cytokine-cytokine receptor interactions, adherens junctions, TGF-beta signaling, MAPK signaling, and calcium signaling. Molecular features involved in inflammation and immune response contributing to DN progression were significantly downregulated by tacrolimus (e.g. the tumor necrosis factor alpha (TNF), interleukin 4, or interleukin 10). On the other hand, pro-fibrotic stimuli being detrimental to renal function were induced by tacrolimus like the transforming growth factor beta 1 (TGFB1), endothelin 1 (EDN1), or type IV collagen alpha 1 (COL4A1). Conclusion Patients with DN and elevated TNF levels might benefit from tacrolimus treatment regarding maintaining GFR and reducing inflammation. TGFB1 and EDN1 are proposed as monitoring markers to assess degree of renal damage. Next to this stratification approach, the use of drug

  14. Computer-aided patch planning for treatment of complex coarctation of the aorta

    Science.gov (United States)

    Rietdorf, Urte; Riesenkampff, Eugénie; Kuehne, Titus; Huebler, Michael; Meinzer, Hans-Peter; Wolf, Ivo

    2009-02-01

    Between five and eight percent of all children born with congenitally malformed hearts suffer from coarctations of the aorta. Some severe coarctations can only be treated by surgical repair. Untreated, this defect can cause serious damage to organ development or even lead to death. Patch repair requires open surgery. It can affect patients of any age: newborns with severe coarctation and/or hypoplastic aortic arch as well as older patients with late diagnosis of coarctation of the aorta. Another patient group are patients of varying age with re-coarctation of the aorta or hypoplastic aortic arch after surgical and/or interventional repair. If anatomy is complex and interventional treatment by catheterization, balloon angioplasty or stent placement is not possible, surgery is indicated. The choice of type of surgery depends not only on the given anatomy but also on the experience the surgical team has with each method. One surgical approach is patch repair. A patch of a suitable shape and size is sewed into the aorta to expand the aortic lumen at the site of coarctation. At present, the shape and size of the patch are estimated intra-operatively by the surgeon. We have developed a software application that allows planning of the patch pre-operatively on the basis of magnetic resonance angiographic data. The application determines the diameter of the coarctation and/or hypoplastic segment and constructs a patch proposal by calculating the difference to the normal vessel diameter pre-operatively. Evaluation of MR angiographic datasets from 12 test patients with different kinds of aortic arch stenosis shows a divergence of only (1.5+/-1.2) mm in coarctation diameters between manual segmentations and our approach, with comparable time expenditure. Following this proposal the patch can be prepared and adapted to the patient's anatomy pre-operatively. Ideally, this leads to shorter operation times and a better long-term outcome with a reduced rate of residual stenosis and

  15. Computer algorithms and applications used to assist the evaluation and treatment of adolescent idiopathic scoliosis: a review of published articles 2000-2009.

    Science.gov (United States)

    Phan, Philippe; Mezghani, Neila; Aubin, Carl-Éric; de Guise, Jacques A; Labelle, Hubert

    2011-07-01

    Adolescent idiopathic scoliosis (AIS) is a complex spinal deformity whose assessment and treatment present many challenges. Computer applications have been developed to assist clinicians. A literature review on computer applications used in AIS evaluation and treatment has been undertaken. The algorithms used, their accuracy and clinical usability were analyzed. Computer applications have been used to create new classifications for AIS based on 2D and 3D features, assess scoliosis severity or risk of progression and assist bracing and surgical treatment. It was found that classification accuracy could be improved using computer algorithms that AIS patient follow-up and screening could be done using surface topography thereby limiting radiation and that bracing and surgical treatment could be optimized using simulations. Yet few computer applications are routinely used in clinics. With the development of 3D imaging and databases, huge amounts of clinical and geometrical data need to be taken into consideration when researching and managing AIS. Computer applications based on advanced algorithms will be able to handle tasks that could otherwise not be done which can possibly improve AIS patients' management. Clinically oriented applications and evidence that they can improve current care will be required for their integration in the clinical setting.

  16. Computer Enabled Neuroplasticity Treatment: a Clinical Trial of a Novel Design for Neurofeedback Therapy in Adult ADHD

    Directory of Open Access Journals (Sweden)

    Benjamin eCowley

    2016-05-01

    analysis will be reported elsewhere.Trial RegistrationComputer Enabled Neuroplasticity Treatment (CENT, ISRCTN13915109.Partly funded by Finnish science agency TEKES, project #440078.

  17. SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY-BASED MICROSTRUCTURAL ANALYSIS OF RETINAL ARCHITECTURE POST INTERNAL LIMITING MEMBRANE PEELING FOR SURGERY OF IDIOPATHIC MACULAR HOLE REPAIR.

    Science.gov (United States)

    Modi, Aditya; Giridhar, Anantharaman; Gopalakrishnan, Mahesh

    2017-02-01

    Spectral domain optical coherence tomography-based analysis of retinal architecture after internal limiting membrane peeling for macular hole surgery. Prospective, interventional study. Fifty eyes underwent the surgical procedure with minimum internal limiting membrane peel of 3 mm diameter. Automatic segmentation software was used to assess individual layers preoperatively and postoperatively, 1.5 millimeters medial and lateral to fovea at 3 months postoperative visit. Main outcome measures were final central macular thickness and variation in individual retinal layer thickness. Mean central macular thickness postoperatively was 201 microns. Retinal thickening was observed, 1.5 mm medial to fovea (P Internal limiting membrane peel is associated with significant alteration in inner retinal architecture, especially in ganglion cell layer, which can adversely influence functional outcome of the surgery and makes it imperative to avoid peeling internal limiting membrane over a larger surface area.

  18. A Computationally-Efficient Kinetic Approach for Gas/Particle Mass Transfer Treatments: Development, Testing, and 3-D Application

    Science.gov (United States)

    Hu, X.; Zhang, Y.

    2007-05-01

    The Weather Research and Forecast/Chemistry Model (WRF/Chem) that simulates chemistry simultaneously with meteorology has recently been developed for real-time forecasting by the U.S. National Center for Atmospheric Research (NCAR) and National Oceanic & Atmospheric Administration (NOAA). As one of the six air quality models, WRF/Chem with a modal aerosol module has been applied for ozone and PM2.5 ensemble forecasts over eastern North America as part of the 2004 New England Air Quality Study (NEAQS) program (NEAQS-2004). Significant differences exist in the partitioning of volatile species (e.g., ammonium and nitrate) simulated by the six models. Model biases are partially attributed to the equilibrium assumption used in the gas/particles mass transfer approach in some models. Development of a more accurate, yet computationally- efficient gas/particle mass transfer approach for three-dimensional (3-D) applications, in particular, real-time forecasting, is therefore warranted. Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (MADRID) has been implemented into WRF/Chem (referred to as WRF/Chem-MADRID). WRF/Chem-MADRID offers three gas/particle partitioning treatments: equilibrium, kinetic, and hybrid approaches. The equilibrium approach is computationally-efficient and commonly used in 3-D air quality models but less accurate under certain conditions (e.g., in the presence of coarse, reactive particles such as PM containing sea-salts in the coastal areas). The kinetic approach is accurate but computationally-expensive, limiting its 3-D applications. The hybrid approach attempts to provide a compromise between merits and drawbacks of the two approaches by treating fine PM (typically MADRID has recently been developed for 3-D applications based on an Analytical Predictor of Condensation (referred to as kinetic/APC). In this study, WRF/Chem-MADRID with the kinetic/APC approach will be further evaluated along with the equilibrium and hybrid approaches

  19. Flat-detector computed tomography evaluation in an experimental animal aneurysm model after endovascular treatment: A pilot study

    Science.gov (United States)

    Gölitz, Philipp; Adamek, Edyta; Royalty, Kevin; Doerfler, Arnd; Struffert, Tobias

    2015-01-01

    We compared flat-detector computed tomography angiography (FD-CTA) to multislice computed tomography (MS-CTA) and digital subtracted angiography (DSA) for the visualization of experimental aneurysms treated with stents, coils or a combination of both. In 20 rabbits, aneurysms were created using the rabbit elastase aneurysm model. Seven aneurysms were treated with coils, seven with coils and stents, and six with self-expandable stents alone. Imaging was performed by DSA, MS-CTA and FD-CTA immediately after treatment. Multiplanar reconstruction (MPR) was performed and two experienced reviewers compared aneurysm/coil package size, aneurysm occlusion, stent diameters and artifacts for each modality. In aneurysms treated with stents alone, the visualization of the aneurysms was identical in all three imaging modalities. Residual aneurysm perfusion was present in two cases and visible in DSA and FD-CTA but not in MS-CTA. The diameter of coil-packages was overestimated in MS-CT by 56% and only by 16% in FD-CTA compared to DSA (p < 0.05). The diameter of stents was identical for DSA and FD-CTA and was significantly overestimated in MS-CTA (p < 0.05). Beam/metal hardening artifacts impaired image quality more severely in MS-CTA compared to FD-CTA. MS-CTA is impaired by blooming and beam/metal hardening artifacts in the visualization of implanted devices. There was no significant difference between measurements made with noninvasive FD-CTA compared to gold standard of DSA after stenting and after coiling/stent-assisted coiling of aneurysms. FD-CTA may be considered as a non-invasive alternative to the gold standard 2D DSA in selected patients that require follow up imaging after stenting. PMID:26111985

  20. Positron Emission Tomography Based Elucidation of the Enhanced Permeability and Retention Effect in Dogs with Cancer Using Copper-64 Liposomes

    DEFF Research Database (Denmark)

    Hansen, Anders Elias; Petersen, Anncatrine Luisa; Henriksen, Jonas Rosager

    2015-01-01

    Since the first report of the enhanced permeability and retention (EPR) effect, the research in nanocarrier based antitumor drugs has been intense. The field has been devoted to treatment of cancer by exploiting EPR-based accumulation of nanocarriers in solid tumors, which for many years was cons......Since the first report of the enhanced permeability and retention (EPR) effect, the research in nanocarrier based antitumor drugs has been intense. The field has been devoted to treatment of cancer by exploiting EPR-based accumulation of nanocarriers in solid tumors, which for many years......-effect in large animals and humans with spontaneously developed cancer. In the present paper, we describe a novel loading method of copper-64 into PEGylated liposomes and use these liposomes to evaluate the EPR-effect in 11 canine cancer patients with spontaneous solid tumors by PET/CT imaging. We thereby provide...

  1. Computer design, synthesis, and bioactivity analyses of drugs like fingolimod used in the treatment of multiple sclerosis.

    Science.gov (United States)

    Turgut, Gurbet Çelik; Doyduk, Doğukan; Yıldırır, Yılmaz; Yavuz, Serkan; Akdemir, Atilla; Dişli, Ali; Şen, Alaattin

    2017-01-15

    Multiple sclerosis (MS) is a very common disease of vital importance. In the MS treatment, some drugs such as fingolimod which help to protect nerves from damage are used. The main goal of the drug therapy in MS is to take control of the inflammation which leads to the destruction of myelin and axons in nerve cell and thus prevent and stop the progression of the disease. Fingolimod (FTY720) is an orally active immunomodulatory drug that has been used for the treatment of relapsing-remitting multiple sclerosis. It is a sphingosine-1-phosphate receptor modulator which prevents lymphocytes from contributing to an autoimmune reaction by inhibiting egress of lymphocytes them from lymph nodes. In this study, we have computer designed, synthesized and characterized two novel derivatives of FTY720, F1-12h and F2-9, and have determined their underlying mechanism of their beneficial effect in SH-SY5Y, SK-N-SH, and U-118 MG cell lines. For this purpose, we first determined the regulation of the cAMP response element (CRE) activity and cAMP concentration by F1-12h and F2-9 together with FTY720 using pGL4.29 luciferase reporter assay and cAMP immunoassay, respectively. Then, we have determined their effect on MS- and GPCR-related gene expression profiles using custom arrays along with FTY720 treatment at non-toxic doses (EC10). It was found that both derivatives significantly activate CRE and increase cAMP concentration in all three cell lines, indicating that they activate cAMP pathway through cell surface receptors as FTY720 does. Furthermore, F1-12h and F2-9 modulate the expression of the pathway related genes that are important in inflammatory signaling, cAMP signaling pathway, cell migration as well as diverse receptor and transcription factors. Expression of the genes involved in myelination was also increased by the treatment with F1-12h and F2-9. In summary, our data demonstrate that the two novel FTY720 derivatives act as anti-inflammatory ultimately by influencing the

  2. Successful treatment of a free-moving abdominal mass with radiation therapy guided by cone-beam computed tomography: a case report

    Directory of Open Access Journals (Sweden)

    Shihadeh Ferial

    2010-10-01

    Full Text Available Abstract Introduction Because tumors in the abdomen can change position, targeting these tumors for radiation therapy should be done with caution; use of daily image-guided radiation therapy is advised. Case presentation We report the case of a 72-year-old Caucasian man with recurrent mantle cell lymphoma who was referred for palliative radiation therapy for an abdominopelvic tumor. Computed tomography was used to generate images for radiation treatment planning. Comparison of those planning images with a positron emission tomography/computed tomography scan ordered during the planning period revealed that the tumor had moved from one side of the abdomen to the other during the three-day interval between scans. To account for this unusual tumor movement, we obtained a second set of planning computed tomography scans and used a Varian cone-beam computed tomography scanner with on-board imaging capability to target the tumor before each daily treatment session, leading to successful treatment and complete resolution of the mass. Conclusion Abdominal masses associated with the mesentery should be considered highly mobile; thus, radiation therapy for such masses should be used with the utmost caution. Modern radiation therapy techniques offer the ability to verify the tumor location in real time and shift the treatment ports accordingly over the course of treatment.

  3. Prediction of lung density changes after radiotherapy by cone beam computed tomography response markers and pre-treatment factors for non-small cell lung cancer patients

    DEFF Research Database (Denmark)

    Bernchou, Uffe; Hansen, Olfred; Schytte, Tine;

    2015-01-01

    BACKGROUND AND PURPOSE: This study investigates the ability of pre-treatment factors and response markers extracted from standard cone-beam computed tomography (CBCT) images to predict the lung density changes induced by radiotherapy for non-small cell lung cancer (NSCLC) patients. METHODS...... AND MATERIALS: Density changes in follow-up computed tomography scans were evaluated for 135 NSCLC patients treated with radiotherapy. Early response markers were obtained by analysing changes in lung density in CBCT images acquired during the treatment course. The ability of pre-treatment factors and CBCT...... markers to predict lung density changes induced by radiotherapy was investigated. RESULTS: Age and CBCT markers extracted at 10th, 20th, and 30th treatment fraction significantly predicted lung density changes in a multivariable analysis, and a set of response models based on these parameters were...

  4. Preserving plantar flexion strength after surgical treatment for contracture of the triceps surae: a computer simulation study.

    Science.gov (United States)

    Delp, S L; Statler, K; Carroll, N C

    1995-01-01

    Contractures of the triceps surae commonly are treated by surgical lengthening of the gastrocnemius aponeurosis or the Achilles tendon. Although these procedures generally relieve contractures, patients sometimes are left with dramatically decreased plantar flexion strength (i.e., decreased capacity to generate plantar flexion moment). The purpose of this study was to examine the trade-off between restoring range of motion and maintaining plantar flexion strength after surgical treatment for contracture of the triceps surae. A computer model representing the normal moment-generating characteristics of the triceps surae was altered to represent two conditions: isolated contracture of the gastrocnemius and contracture of both the gastrocnemius and the soleus. The effects of lengthening the gastrocnemius aponeurosis and the Achilles tendon were simulated for each condition. The simulations showed that nearly normal moment-generating characteristics could be restored when isolated gastrocnemius contracture was treated with lengthening of the gastrocnemius aponeurosis. However, when isolated gastrocnemius contracture was treated with lengthening of the Achilles tendon, the moment-generating capacity of the plantar flexors decreased greatly. This suggests that lengthening of the Achilles tendon should be avoided in persons with isolated gastrocnemius contracture. Our simulations also suggest that neither lengthening of the gastrocnemius aponeurosis nor lengthening of the Achilles tendon by itself is an effective treatment for combined contracture of the gastrocnemius and soleus. Lengthening the gastrocnemius aponeurosis did not decrease the excessive passive moment developed by the contracted soleus. Lengthening the Achilles tendon restored the normal passive range of motion but substantially decreased the active force-generating capacity of the muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Brain-computer interface game applications for combined neurofeedback and biofeedback treatment for children on the autism spectrum

    Directory of Open Access Journals (Sweden)

    Elisabeth V C Friedrich

    2014-07-01

    Full Text Available Individuals with Autism Spectrum Disorder (ASD show deficits in social and communicative skills, including imitation, empathy, and shared attention, as well as restricted interests and repetitive patterns of behaviors. Evidence for and against the idea that dysfunctions in the mirror neuron system are involved in imitation and could be one underlying cause for ASD is discussed in this review. Neurofeedback interventions have reduced symptoms in children with ASD by self-regulation of brain rhythms. However, cortical deficiencies are not the only cause of these symptoms. Peripheral physiological activity, such as the heart rate, is closely linked to neurophysiological signals and associated with social engagement. Therefore, a combined approach targeting the interplay between brain, body and behavior could be more effective. Brain-computer interface applications for combined neurofeedback and biofeedback treatment for children with ASD are currently nonexistent. To facilitate their use, we have designed an innovative game that includes social interactions and provides neural- and body-based feedback that corresponds directly to the underlying significance of the trained signals as well as to the behavior that is reinforced.

  6. Regenerative Endodontic Treatment of an Infected Immature Dens Invaginatus with the Aid of Cone-Beam Computed Tomography

    Science.gov (United States)

    Kaya-Büyükbayram, Işıl; Özalp, Şerife; Aydemir, Seda

    2014-01-01

    Dens invaginatus is a developmental anomaly that results in an enamel-lined cavity intruding into the crown or root before the mineralization phase. This report presents regenerative endodontic treatment of a necrotic immature tooth with Oehler's type III dens invaginatus of a nine-year-old female patient. A diagnosis of dens invaginatus (Oehler's type III) and a large periapical lesion was established with the aid of cone-beam computed tomography (CBCT). In the presented case contrary to the classic revascularization protocol, mechanical instrumentation was performed which apparently did not interfere with the regeneration process. After mechanical instrumentation of the invaginated canal by manual K-files, the invaginated canal space was disinfected by triple antibiotic paste followed by blood clot induction from the periapical tissues and the placement of mineral trioxide aggregate. At one-year follow-up, the tooth remained clinically asymptomatic. Radiographic examination revealed complete healing of the periapical lesion. At the 20-month follow-up, the radiographic examination also showed that the open apex was closed and the walls of the root canal were thickened. PMID:25530890

  7. Regenerative Endodontic Treatment of an Infected Immature Dens Invaginatus with the Aid of Cone-Beam Computed Tomography

    Directory of Open Access Journals (Sweden)

    Işıl Kaya-Büyükbayram

    2014-01-01

    Full Text Available Dens invaginatus is a developmental anomaly that results in an enamel-lined cavity intruding into the crown or root before the mineralization phase. This report presents regenerative endodontic treatment of a necrotic immature tooth with Oehler’s type III dens invaginatus of a nine-year-old female patient. A diagnosis of dens invaginatus (Oehler’s type III and a large periapical lesion was established with the aid of cone-beam computed tomography (CBCT. In the presented case contrary to the classic revascularization protocol, mechanical instrumentation was performed which apparently did not interfere with the regeneration process. After mechanical instrumentation of the invaginated canal by manual K-files, the invaginated canal space was disinfected by triple antibiotic paste followed by blood clot induction from the periapical tissues and the placement of mineral trioxide aggregate. At one-year follow-up, the tooth remained clinically asymptomatic. Radiographic examination revealed complete healing of the periapical lesion. At the 20-month follow-up, the radiographic examination also showed that the open apex was closed and the walls of the root canal were thickened.

  8. CARL: a LabVIEW 3 computer program for conducting exposure therapy for the treatment of dental injection fear.

    Science.gov (United States)

    Coldwell, S E; Getz, T; Milgrom, P; Prall, C W; Spadafora, A; Ramsay, D S

    1998-04-01

    This paper describes CARL (Computer Assisted Relaxation Learning), a computerized, exposure-based therapy program for the treatment of dental injection fear. The CARL program operates primarily in two different modes; in vitro, which presents a video-taped exposure hierarchy, and in vivo, which presents scripts for a dentist or hygienist to use while working with a subject. Two additional modes are used to train subjects to use the program and to administer behavioral assessment tests. The program contains five different modules, which function to register a subject, train subjects to use physical and cognitive relaxation techniques, deliver an exposure hierarchy, question subjects about the helpfulness of each of the therapy components, and test for memory effects of anxiolytic medication. Nine subjects have completed the CARL therapy program and 1-yr follow-up as participants in a placebo-controlled clinical trial examining the effects of alprazolam on exposure therapy for dental injection phobia. All nine subjects were able to receive two dental injections, and all reduced their general fear of dental injections. Initial results therefore indicate that the CARL program successfully reduces dental injection fear.

  9. Interface and permittivity simultaneous reconstruction in electrical capacitance tomography based on boundary and finite-elements coupling method.

    Science.gov (United States)

    Ren, Shangjie; Dong, Feng

    2016-06-28

    Electrical capacitance tomography (ECT) is a non-destructive detection technique for imaging the permittivity distributions inside an observed domain from the capacitances measurements on its boundary. Owing to its advantages of non-contact, non-radiation, high speed and low cost, ECT is promising in the measurements of many industrial or biological processes. However, in the practical industrial or biological systems, a deposit is normally seen in the inner wall of its pipe or vessel. As the actual region of interest (ROI) of ECT is surrounded by the deposit layer, the capacitance measurements become weakly sensitive to the permittivity perturbation occurring at the ROI. When there is a major permittivity difference between the deposit and the ROI, this kind of shielding effect is significant, and the permittivity reconstruction becomes challenging. To deal with the issue, an interface and permittivity simultaneous reconstruction approach is proposed. Both the permittivity at the ROI and the geometry of the deposit layer are recovered using the block coordinate descent method. The boundary and finite-elements coupling method is employed to improve the computational efficiency. The performance of the proposed method is evaluated with the simulation tests. This article is part of the themed issue 'Supersensing through industrial process tomography'.

  10. Positron Emission Tomography Based Elucidation of the Enhanced Permeability and Retention Effect in Dogs with Cancer Using Copper-64 Liposomes

    DEFF Research Database (Denmark)

    Hansen, Anders Elias; Petersen, Anncatrine Luisa; Henriksen, Jonas Rosager;

    2015-01-01

    -effect in large animals and humans with spontaneously developed cancer. In the present paper, we describe a novel loading method of copper-64 into PEGylated liposomes and use these liposomes to evaluate the EPR-effect in 11 canine cancer patients with spontaneous solid tumors by PET/CT imaging. We thereby provide......Since the first report of the enhanced permeability and retention (EPR) effect, the research in nanocarrier based antitumor drugs has been intense. The field has been devoted to treatment of cancer by exploiting EPR-based accumulation of nanocarriers in solid tumors, which for many years...... included carcinomas displayed high uptake levels of liposomes, whereas one of four sarcomas displayed signs of liposome retention. We conclude that nanocarrier-radiotracers could be important in identifying cancer patients that will benefit from nanocarrier-based therapeutics in clinical practice....

  11. The use of technological support in communication disorders : how development of computer-based tools can refine the treatment of motor speech disorders.

    NARCIS (Netherlands)

    Umanski, Daniil

    2012-01-01

    The goal of this project is to investigate new possibilities of employing interactive technologies in the delivery of treatment for patients with Motor Speech Disorders (MSD). Specifically, the project explores how computer-based tools can refine current methodologies, when considering the three

  12. The use of technological support in communication disorders : how development of computer-based tools can refine the treatment of motor speech disorders.

    NARCIS (Netherlands)

    Umanski, Daniil

    2012-01-01

    The goal of this project is to investigate new possibilities of employing interactive technologies in the delivery of treatment for patients with Motor Speech Disorders (MSD). Specifically, the project explores how computer-based tools can refine current methodologies, when considering the three mai

  13. Unified treatment of microscopic boundary conditions and efficient algorithms for estimating tangent operators of the homogenized behavior in the computational homogenization method

    Science.gov (United States)

    Nguyen, Van-Dung; Wu, Ling; Noels, Ludovic

    2017-03-01

    This work provides a unified treatment of arbitrary kinds of microscopic boundary conditions usually considered in the multi-scale computational homogenization method for nonlinear multi-physics problems. An efficient procedure is developed to enforce the multi-point linear constraints arising from the microscopic boundary condition either by the direct constraint elimination or by the Lagrange multiplier elimination methods. The macroscopic tangent operators are computed in an efficient way from a multiple right hand sides linear system whose left hand side matrix is the stiffness matrix of the microscopic linearized system at the converged solution. The number of vectors at the right hand side is equal to the number of the macroscopic kinematic variables used to formulate the microscopic boundary condition. As the resolution of the microscopic linearized system often follows a direct factorization procedure, the computation of the macroscopic tangent operators is then performed using this factorized matrix at a reduced computational time.

  14. Mars surface-based factory: Computer control of a water treatment system to support a space colony on Mars

    Science.gov (United States)

    Brice, R.; Mosley, J.; Willis, D.; Coleman, K.; Martin, C.; Shelby, L.; Kelley, U.; Renfro, E.; Griffith, G.; Warsame, A.

    1989-01-01

    In a continued effort to design a surface-based factory on Mars for the production of oxygen and water, the Design Group at Prairie View A&M University made a preliminary study of the surface and atmospheric composition on Mars and determined the mass densities of the various gases in the martian atmosphere. Based on the initial studies, the design group determined oxygen and water to be the two products that could be produced economically under the martian conditions. Studies were also made on present production techniques to obtain water and oxygen. Analyses were made to evaluate the current methods of production that were adaptable to the martian conditions. The detailed report was contained in an Interim Report submitted to NASA/USRA in Aug. of 1986. Even though the initial effort was the production of oxygen and water, we found it necessary to produce some diluted gases that can be mixed with oxygen to constitute 'breathable' air. In Phase 2--Task 1A, the Prairie View A&M University team completed the conceptual design of a breathable-air manufacturing system, a means of drilling for underground water, and storage of water for future use. The design objective of the team for the 1987-1988 academic year was the conceptual design of an integrated system for the supply of quality water for biological consumption, farming, and residential and industrial use. The design has also been completed. Phase 2--Task 1C is the present task for the Prairie View Design Team. This is a continuation of the previous task, and the continuation of this effort is the investigation into the extraction of water from beneath the surface and an alternative method of extraction from ice formations on the surface of Mars if accessible. In addition to investigation of water extraction, a system for computer control of extraction and treatment was developed with emphasis on fully automated control with robotic repair and maintenance. It is expected that oxygen- and water-producing plants

  15. Mars surface-based factory: Computer control of a water treatment system to support a space colony on Mars

    Science.gov (United States)

    Brice, R.; Mosley, J.; Willis, D.; Coleman, K.; Martin, C.; Shelby, L.; Kelley, U.; Renfro, E.; Griffith, G.; Warsame, A.

    1989-01-01

    In a continued effort to design a surface-based factory on Mars for the production of oxygen and water, the Design Group at Prairie View A&M University made a preliminary study of the surface and atmospheric composition on Mars and determined the mass densities of the various gases in the martian atmosphere. Based on the initial studies, the design group determined oxygen and water to be the two products that could be produced economically under the martian conditions. Studies were also made on present production techniques to obtain water and oxygen. Analyses were made to evaluate the current methods of production that were adaptable to the martian conditions. The detailed report was contained in an Interim Report submitted to NASA/USRA in Aug. of 1986. Even though the initial effort was the production of oxygen and water, we found it necessary to produce some diluted gases that can be mixed with oxygen to constitute 'breathable' air. In Phase 2--Task 1A, the Prairie View A&M University team completed the conceptual design of a breathable-air manufacturing system, a means of drilling for underground water, and storage of water for future use. The design objective of the team for the 1987-1988 academic year was the conceptual design of an integrated system for the supply of quality water for biological consumption, farming, and residential and industrial use. The design has also been completed. Phase 2--Task 1C is the present task for the Prairie View Design Team. This is a continuation of the previous task, and the continuation of this effort is the investigation into the extraction of water from beneath the surface and an alternative method of extraction from ice formations on the surface of Mars if accessible. In addition to investigation of water extraction, a system for computer control of extraction and treatment was developed with emphasis on fully automated control with robotic repair and maintenance. It is expected that oxygen- and water-producing plants

  16. Positron Emission Tomography Based Elucidation of the Enhanced Permeability and Retention Effect in Dogs with Cancer Using Copper-64 Liposomes.

    Science.gov (United States)

    Hansen, Anders E; Petersen, Anncatrine L; Henriksen, Jonas R; Boerresen, Betina; Rasmussen, Palle; Elema, Dennis R; af Rosenschöld, Per Munck; Kristensen, Annemarie T; Kjær, Andreas; Andresen, Thomas L

    2015-07-28

    Since the first report of the enhanced permeability and retention (EPR) effect, the research in nanocarrier based antitumor drugs has been intense. The field has been devoted to treatment of cancer by exploiting EPR-based accumulation of nanocarriers in solid tumors, which for many years was considered to be a ubiquitous phenomenon. However, the understanding of differences in the EPR-effect between tumor types, heterogeneities within each patient group, and dependency on tumor development stage in humans is sparse. It is therefore important to enhance our understanding of the EPR-effect in large animals and humans with spontaneously developed cancer. In the present paper, we describe a novel loading method of copper-64 into PEGylated liposomes and use these liposomes to evaluate the EPR-effect in 11 canine cancer patients with spontaneous solid tumors by PET/CT imaging. We thereby provide the first high-resolution analysis of EPR-based tumor accumulation in large animals. We find that the EPR-effect is strong in some tumor types but cannot be considered a general feature of solid malignant tumors since we observed a high degree of accumulation heterogeneity between tumors. Six of seven included carcinomas displayed high uptake levels of liposomes, whereas one of four sarcomas displayed signs of liposome retention. We conclude that nanocarrier-radiotracers could be important in identifying cancer patients that will benefit from nanocarrier-based therapeutics in clinical practice.

  17. A web-based remote radiation treatment planning system using the remote desktop function of a computer operating system: a preliminary report.

    Science.gov (United States)

    Suzuki, Keishiro; Hirasawa, Yukinori; Yaegashi, Yuji; Miyamoto, Hideki; Shirato, Hiroki

    2009-01-01

    We developed a web-based, remote radiation treatment planning system which allowed staff at an affiliated hospital to obtain support from a fully staffed central institution. Network security was based on a firewall and a virtual private network (VPN). Client computers were installed at a cancer centre, at a university hospital and at a staff home. We remotely operated the treatment planning computer using the Remote Desktop function built in to the Windows operating system. Except for the initial setup of the VPN router, no special knowledge was needed to operate the remote radiation treatment planning system. There was a time lag that seemed to depend on the volume of data traffic on the Internet, but it did not affect smooth operation. The initial cost and running cost of the system were reasonable.

  18. Effects of a manualized short-term treatment of internet and computer game addiction (STICA: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Jäger Susanne

    2012-04-01

    Full Text Available Abstract Background In the last few years, excessive internet use and computer gaming have increased dramatically. Salience, mood modification, tolerance, withdrawal symptoms, conflict, and relapse have been defined as diagnostic criteria for internet addiction (IA and computer addiction (CA in the scientific community. Despite a growing number of individuals seeking help, there are no specific treatments of established efficacy. Methods/design This clinical trial aims to determine the effect of the disorder-specific manualized short-term treatment of IA/CA (STICA. The cognitive behavioural treatment combines individual and group interventions with a total duration of 4 months. Patients will be randomly assigned to STICA treatment or to a wait list control group. Reliable and valid measures of IA/CA and co-morbid mental symptoms (for example social anxiety, depression will be assessed prior to the beginning, in the middle, at the end, and 6 months after completion of treatment. Discussion A treatment of IA/CA will establish efficacy and is desperately needed. As this is the first trial to determine efficacy of a disorder specific treatment, a wait list control group will be implemented. Pros and cons of the design were discussed. Trial Registration ClinicalTrials (NCT01434589

  19. Effective anti-thrombotic therapy without stenting: intravascular optical coherence tomography-based management in plaque erosion (the EROSION study).

    Science.gov (United States)

    Jia, Haibo; Dai, Jiannan; Hou, Jingbo; Xing, Lei; Ma, Lijia; Liu, Huimin; Xu, Maoen; Yao, Yuan; Hu, Sining; Yamamoto, Erika; Lee, Hang; Zhang, Shaosong; Yu, Bo; Jang, Ik-Kyung

    2017-03-14

    Plaque erosion, compared with plaque rupture, has distinctly different underlying pathology and therefore may merit tailored therapy. In this study, we aimed to assess whether patients with acute coronary syndrome (ACS) caused by plaque erosion might be stabilized by anti-thrombotic therapy without stent implantation. This was a single-centre, uncontrolled, prospective, proof-of concept study. Patients with ACS including ST-segment elevation myocardial infarction were prospectively enrolled. If needed, aspiration thrombectomy was performed. Patients diagnosed with plaque erosion by optical coherence tomography (OCT) and residual diameter stenosis 50% reduction of thrombus volume at 1 month compared with baseline. The secondary endpoint was a composite of cardiac death, recurrent ischaemia requiring revascularization, stroke, and major bleeding. Among 405 ACS patients with analysable OCT images, plaque erosion was identified in 103 (25.4%) patients. Sixty patients enrolled and 55 patients completed the 1-month follow-up. Forty-seven patients (47/60, 78.3%; 95% confidence interval: 65.8-87.9%) met the primary endpoint, and 22 patients had no visible thrombus at 1 month. Thrombus volume decreased from 3.7 (1.3, 10.9) mm3 to 0.2 (0.0, 2.0) mm3. Minimal flow area increased from 1.7 (1.4, 2.4) mm2 to 2.1 (1.5, 3.8) mm2. One patient died of gastrointestinal bleeding, and another patient required repeat percutaneous coronary intervention. The rest of the patients remained asymptomatic. For patients with ACS caused by plaque erosion, conservative treatment with anti-thrombotic therapy without stenting may be an option.

  20. Pretreatment Staging Positron Emission Tomography/Computed Tomography in Patients With Inflammatory Breast Cancer Influences Radiation Treatment Field Designs

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Gary V. [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Niikura, Naoki [Department of Breast and Endocrine Surgery, Tokai University School of Medicine, Kanagawa (Japan); Yang Wei [Department of Diagnostic Radiology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rohren, Eric [Department of Nuclear Medicine, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Valero, Vicente [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Woodward, Wendy A. [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Alvarez, Ricardo H. [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Lucci, Anthony [Department of Surgical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Ueno, Naoto T. [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Buchholz, Thomas A., E-mail: tbuchhol@mdanderson.org [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2012-08-01

    Purpose: Positron emission tomography/computed tomography (PET/CT) is increasingly being utilized for staging of inflammatory breast cancer (IBC). The purpose of this study was to define how pretreatment PET/CT studies affected postmastectomy radiation treatment (PMRT) planning decisions for IBC. Methods and Materials: We performed a retrospective analysis of 62 patients diagnosed with IBC between 2004 and 2009, who were treated with PMRT in our institution and who had a staging PET/CT within 3 months of diagnosis. Patients received a baseline physical examination, staging mammography, ultrasonographic examination of breast and draining lymphatics, and chest radiography; most patients also had a bone scan (55 patients), liver imaging (52 patients), breast MRI (46 patients), and chest CT (25 patients). We compared how PET/CT findings affected PMRT, assuming that standard PMRT would target the chest wall, level III axilla, supraclavicular fossa, and internal mammary chain (IMC). Any modification of target volumes, field borders, or dose prescriptions was considered a change. Results: PET/CT detected new areas of disease in 27 of the 62 patients (44%). The areas of additional disease included the breast (1 patient), ipsilateral axilla (1 patient), ipsilateral supraclavicular (4 patients), ipsilateral infraclavicular (1 patient), ipsilateral IMC (5 patients), ipsilateral subpectoral (3 patients), mediastinal (8 patients), other distant/contralateral lymph nodes (15 patients), or bone (6 patients). One patient was found to have a non-breast second primary tumor. The findings of the PET/CT led to changes in PMRT in 11 of 62 patients (17.7%). These changes included additional fields in 5 patients, adjustment of fields in 2 patients, and higher doses to the supraclavicular fossa (2 patients) and IMC (5 patients). Conclusions: For patients with newly diagnosed IBC, pretreatment PET/CT provides important information concerning involvement of locoregional lymph nodes

  1. The initial feasibility of a computer-based motivational intervention for adherence for youth newly recommended to start antiretroviral treatment.

    Science.gov (United States)

    Outlaw, Angulique Y; Naar-King, Sylvie; Tanney, Mary; Belzer, Marvin E; Aagenes, Anna; Parsons, Jeffrey T; Merlo, Lisa J

    2014-01-01

    Young people represent the largest number of new HIV infections, thus youth living with HIV (YLH) are likely to be the largest group to initiate antiretroviral treatment (ART). Adherence patterns for behaviorally infected YLH are not adequate to effectively manage the disease; therefore, novel interventions are needed to improve medication adherence. The purpose of the current study, which will precede a randomized controlled trial, was to assess the initial feasibility of an individually tailored computer-based two-session interactive motivational interviewing (MI) intervention for YLH newly recommended to start ART. Intervention development occurred in collaboration with three youth advisory groups. Ten youth (ages 18-24) were recruited to participate in this study. Participants completed the intervention online. Intervention components focused on medication adherence (rating perceived importance and confidence, and goal setting). Retention was 100% for both intervention sessions. All participants (n=10) felt medication adherence was important, but 80% felt confident they could manage their adherence to HIV medications. Ninety percent of participants set the goal of taking their HIV medications exactly as prescribed and reported success achieving this goal at follow-up. Additionally, participants were satisfied with the quality of the sessions and the amount of assistance they received for managing their adherence to HIV medications (90% participants for Session 1; 89% for Session 2). Per exit interview responses, participants felt that the intervention made them think more about their health and was a motivator for them to take better care of their health. In conclusion, the intervention was feasible for YLH enrolled in the study.

  2. Pattern of Retained Contrast on Immediate Postprocedure Computed tomography (CT) After Particle Embolization of Liver Tumors Predicts Subsequent Treatment Response

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xiaodong, E-mail: wangxde@gmail.com; Erinjeri, Joseph P., E-mail: erinjerj@mskcc.org [Memorial Sloan-Kettering Cancer Center, Interventional Radiology Service, Department of Radiology (United States); Jia Xiaoyu, E-mail: jiax@mskcc.org; Gonen, Mithat, E-mail: gonenm@mskcc.org [Memorial Sloan-Kettering Cancer Center, Department of Epidemiology and Biostatistics (United States); Brown, Karen T., E-mail: brown6@mskcc.org; Sofocleous, Constantinos T., E-mail: sofoclec@mskcc.org; Getrajdman, George I., E-mail: getrajdg@mskcc.org; Brody, Lynn A., E-mail: brodyl@mskcc.org; Thornton, Raymond H., E-mail: throntor@mskcc.org; Maybody, Majid, E-mail: maybodym@mskcc.org; Covey, Ann M., E-mail: covey@mskcc.org; Siegelbaum, Robert H., E-mail: siegelbr@mskcc.org; Alago, William, E-mail: alagow@mskcc.org; Solomon, Stephen B., E-mail: solomons@mskcc.org [Memorial Sloan-Kettering Cancer Center, Interventional Radiology Service, Department of Radiology (United States)

    2013-08-01

    PurposeTo determine if the pattern of retained contrast on immediate postprocedure computed tomography (CT) after particle embolization of hepatic tumors predicts modified Response Evaluation Criteria in Solid Tumors (mRECIST) response.Materials and MethodsThis study was approved by the Institutional Review Board with a waiver of authorization. One hundred four liver tumors were embolized with spherical embolic agents (Embospheres, Bead Block, LC Bead) and polyvinyl alcohol. Noncontrast CT was performed immediately after embolization to assess contrast retention in the targeted tumors, and treatment response was assessed by mRECIST criteria on follow-up CT (average time 9.0 {+-} 7.7 weeks after embolization). Tumor contrast retention (TCR) was determined based on change in Hounsfield units (HUs) of the index tumors between the preprocedure and immediate postprocedure scans; vascular contrast retention (VCR) was rated; and defects in contrast retention (DCR) were also documented. The morphology of residual enhancing tumor on follow-up CT was described as partial, circumferential, or total. Association between TCR variables and tumor response were assessed using multivariate logistic regression.ResultsOf 104 hepatic tumors, 51 (49 %) tumors had complete response (CR) by mRECIST criteria; 23 (22.1 %) had partial response (PR); 21 (20.2 %) had stable disease (SD); and 9 (8.7 %) had progressive disease (PD). By multivariate analysis, TCR, VCR, and tumor size are independent predictors of CR (p = 0.02, 0.05, and 0.005 respectively). In 75 tumors, DCR was found to be an independent predictor of failure to achieve complete response (p < 0.0001) by imaging criteria.ConclusionTCR, VCR, and DCR on immediate posttreatment CT are independent predictors of CR by mRECIST criteria.

  3. Determination of Internal Target Volume for Radiation Treatment Planning of Esophageal Cancer by Using 4-Dimensional Computed Tomography (4DCT)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaojian [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Lu, Haijun [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Radiation Oncology Center, Affiliated Hospital of Medical College, Qingdao University, Qingdao (China); Tai, An; Johnstone, Candice; Gore, Elizabeth [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Li, X. Allen, E-mail: ali@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States)

    2014-09-01

    Purpose: To determine an efficient strategy for the generation of the internal target volume (ITV) for radiation treatment planning for esophageal cancer using 4-dimensional computed tomography (4DCT). Methods and Materials: 4DCT sets acquired for 20 patients with esophageal carcinoma were analyzed. Each of the 4DCT sets was binned into 10 respiratory phases. For each patient, the gross tumor volume (GTV) was delineated on the 4DCT set at each phase. Various strategies to derive ITV were explored, including the volume from the maximum intensity projection (MIP; ITV{sub M}IP), unions of the GTVs from selected multiple phases ITV2 (0% and 50% phases), ITV3 (ITV2 plus 80%), and ITV4 (ITV3 plus 60%), as well as the volumes expanded from ITV2 and ITV3 with a uniform margin. These ITVs were compared to ITV10 (the union of the GTVs for all 10 phases) and the differences were measured with the overlap ratio (OR) and relative volume ratio (RVR) relative to ITV10 (ITVx/ITV10). Results: For all patients studied, the average GTV from a single phase was 84.9% of ITV10. The average ORs were 91.2%, 91.3%, 94.5%, and 96.4% for ITV{sub M}IP, ITV2, ITV3, and ITV4, respectively. Low ORs were associated with irregular breathing patterns. ITV3s plus 1 mm uniform margins (ITV3+1) led to an average OR of 98.1% and an average RVR of 106.4%. Conclusions: The ITV generated directly from MIP underestimates the range of the respiration motion for esophageal cancer. The ITV generated from 3 phases (ITV3) may be used for regular breathers, whereas the ITV generated from 4 phases (ITV4) or ITV3 plus a 1-mm uniform margin may be applied for irregular breathers.

  4. Extracting a high-quality data space for stereo-tomography based on a 3D structure tensor algorithm and kinematic de-migration

    Science.gov (United States)

    Xiong, Kai; Yang, Kai; Wang, Yu-Xiang

    2017-08-01

    To extract a high-quality data space (the so-called kinematic invariants) is a key factor to a successful implementation of stereo-tomography. The structure tensor algorithm demonstrated itself a robust tool to pick the kinematic invariants for stereo-tomography. However, if there are lots of diffractions and other noises in the data, it could be risky to extract the data space from the data domain. Meanwhile, for any reflector, we try to pick all the relevant primary reflections as much as possible within a wide offset range. To achieve this, in this paper, we design a scheme to extract a high-quality data space for stereo-tomography based on 3D structure tensor and kinematic de-migration. Firstly, we apply an automatic, dense volumetric picking for residual move-out (RMO) and the structural dip in the depth-migrated domain with an advanced 3D structure tensor algorithm. Then, a set of key horizons are picked manually in a few selected depth-migrated common offset gathers. Finally, all the picked horizons are extrapolated along the offset axis based on the RMO information picked in advance. Thus, the initial high-density points picked in the depth-migrated volume are greatly refined. After this processing, a final and refined data space for stereo-tomography is extracted through a kinematic de-migration. We demonstrate the correctness and the robustness of the presented scheme with synthetic and real data examples.

  5. Study protocol: a randomized controlled trial of a computer-based depression and substance abuse intervention for people attending residential substance abuse treatment

    Directory of Open Access Journals (Sweden)

    Kelly Peter J

    2012-02-01

    Full Text Available Abstract Background A large proportion of people attending residential alcohol and other substance abuse treatment have a co-occurring mental illness. Empirical evidence suggests that it is important to treat both the substance abuse problem and co-occurring mental illness concurrently and in an integrated fashion. However, the majority of residential alcohol and other substance abuse services do not address mental illness in a systematic way. It is likely that computer delivered interventions could improve the ability of substance abuse services to address co-occurring mental illness. This protocol describes a study in which we will assess the effectiveness of adding a computer delivered depression and substance abuse intervention for people who are attending residential alcohol and other substance abuse treatment. Methods/Design Participants will be recruited from residential rehabilitation programs operated by the Australian Salvation Army. All participants who satisfy the diagnostic criteria for an alcohol or other substance dependence disorder will be asked to participate in the study. After completion of a baseline assessment, participants will be randomly assigned to either a computer delivered substance abuse and depression intervention (treatment condition or to a computer-delivered typing tutorial (active control condition. All participants will continue to complete The Salvation Army residential program, a predominantly 12-step based treatment facility. Randomisation will be stratified by gender (Male, Female, length of time the participant has been in the program at the commencement of the study (4 weeks or less, 4 weeks or more, and use of anti-depressant medication (currently prescribed medication, not prescribed medication. Participants in both conditions will complete computer sessions twice per week, over a five-week period. Research staff blind to treatment allocation will complete the assessments at baseline, and then 3, 6, 9

  6. Transoesophageal ultrasound and computer tomographic assessment of the equine cricoarytenoid dorsalis muscle: Relationship between muscle geometry and exercising laryngeal function.

    Science.gov (United States)

    Kenny, M; Cercone, M; Rawlinson, J J; Ducharme, N G; Bookbinder, L; Thompson, M; Cheetham, J

    2017-05-01

    Early detection of recurrent laryngeal neuropathy (RLN) is of considerable interest to the equine industry. To describe two imaging modalities, transoesophageal ultrasound (TEU) and computed tomography (CT) with multiplanar reconstruction to assess laryngeal muscle geometry, and determine the relationship between cricoarytenoid dorsalis (CAD) geometry and function. Two-phase study evaluating CAD geometry in experimental horses and horses with naturally occurring RLN. Equine CAD muscle volume was determined from CT scan sets using volumetric reconstruction with LiveWire. The midbody and caudal dorsal-ventral thickness of the CAD muscle was determined using a TEU in the same horses; and in horses with a range of severity of RLN (n = 112). Transoesophageal ultrasound was able to readily image the CAD muscles and lower left:right CAD thickness ratios were observed with increasing disease severity. Computed tomography based muscle volume correlated very closely with ex vivo muscle volume (R(2) = 0.77). Computed tomography reconstruction can accurately determine intrinsic laryngeal muscle geometry. A relationship between TEU measurements of CAD geometry and laryngeal function was established. These imaging techniques could be used to track the response of the CAD muscle to restorative surgical treatments such as nerve muscle pedicle graft, nerve anastomosis and functional electrical stimulation. © 2016 EVJ Ltd.

  7. Computed tomography of cryogenic cells

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-08-30

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

  8. Impact of computer-based treatment planning software on clinical judgment of dental students for planning prosthodontic rehabilitation

    OpenAIRE

    Deshpande S; Chahande J

    2014-01-01

    Saee Deshpande, Jayashree Chahande Department of Prosthodontics, Vidya Shikshan Prasarak Mandal's (VPSM) Dental College and Research Centre, Nagpur, Maharashtra, India Purpose: Successful prosthodontic rehabilitation involves making many interrelated clinical decisions which have an impact on each other. Self-directed computer-based training has been shown to be a very useful tool to develop synthetic and analytical problem-solving skills among students. Thus, a computer-based case s...

  9. Surgical orthodontic treatment for a patient with advanced periodontal disease: evaluation with electromyography and 3-dimensional cone-beam computed tomography.

    Science.gov (United States)

    Nakajima, Kan; Yamaguchi, Tetsutaro; Maki, Koutaro

    2009-09-01

    We report here the case of a woman with Class III malocclusion and advanced periodontal disease who was treated with surgical orthodontic correction. Functional recovery after orthodontic treatment is often monitored by serial electromyography of the masticatory muscles, whereas 3-dimensional cone-beam computed tomography can provide detailed structural information about, for example, periodontal bone defects. However, it is unclear whether the information obtained via these methods is sufficient to determine the treatment goal. It might be useful to address this issue for patients with advanced periodontal disease because of much variability between patients in the determination of treatment goals. We used detailed information obtained by 3-dimensional cone-beam computed tomography to identify periodontal bone defects and set appropriate treatment goals for inclination of the incisors and mandibular surgery. Results for this patient included stable occlusion and improved facial esthetics. This case report illustrates the benefits of establishing treatment goals acceptable to the patient, based on precise 3-dimensional assessment of dentoalveolar bone, and by using masticatory muscle activity to monitor the stability of occlusion.

  10. Treatment

    National Research Council Canada - National Science Library

    Safaa M. Raghab; Ahmed M. Abd El Meguid; Hala A. Hegazi

    2013-01-01

    .... This paper presents the results of the analyses of leachate treatment from the solid waste landfill located in Borg El Arab landfill in Alexandria using an aerobic treatment process which was applied...

  11. The AUSGeoid98 geoid model of Australia: data treatment, computations and comparisons with GPS-levelling data

    DEFF Research Database (Denmark)

    Featherstone, W.E.; Kirby, J.F.; Kearsley, A.H.W.

    2001-01-01

    The AUSGeoid98 gravimetric geoid model of Australia has been computed using data from the EGM96 global geopotential model, the 1996 release of the Australian gravity database, a nationwide digital elevation model, and satellite altimeter-derived marine gravity anomalies. The geoid heights...... are on a 2 by 2 arcminute grid with respect to the GRS80 ellipsoid, and residual geoid heights were computed using the I-D fast Fourier transform technique. This has been adapted to include a deterministically modified kernel over a spherical cap of limited spatial extent in the generalised Stokes scheme...

  12. Renal and perirenal abscess: the role of ultrasound and computed tomography in its diagnosis, localization and treatment

    Energy Technology Data Exchange (ETDEWEB)

    Det, R.J. van (Municipal Hospital Leyenburg, The Hague (Netherlands). Dept. of Surgery); Helsdingen, P.J.R.O. van (Municipal Hospital Leyenburg, The Hague (Netherlands). Dept. of Urology); Mallens, W.M.C. (Municipal Hospital Leyenburg, The Hague (Netherlands). Dept. of Radiology)

    1984-10-01

    Perirenal abscesses are difficult to diagnose by clinical examination and traditional radiographic techniques. Four cases are reported in which ultrasound and computed tomography were very helpful in this respect. The role in the diagnosis and management of such abscesses with these two new technics of renal and perirenal imaging is discussed.

  13. Clot resolution after 3 weeks of anticoagulant treatment of pulmonary embolism: Comparison of computed tomography and perfusion scintigraphy

    NARCIS (Netherlands)

    Van Es, J.; Douma, Renee; Kamphuisen, P.W.; Gerdes, V.E.A.; Verhamme, P.; Wells, P.S.; Bounameaux, H.; Lensing, A.W.A.; Büller, H.R.

    2013-01-01

    Introduction: Little is known about the natural history of clot resolution in the initial weeks of anticoagulant therapy in patients with acute pulmonary embolism (PE). Aim: To assess clot resolution of acute PE with either computed tomography pulmonary angiography (CT-scan) or perfusion

  14. Computational identification of potential multitarget treatments for ameliorating the adverse effects of amyloid-beta on synaptic plasticity

    Directory of Open Access Journals (Sweden)

    Thomas J. Anastasio

    2014-05-01

    Full Text Available The leading hypothesis on Alzheimer Disease (AD is that it is caused by buildup of the peptide amyloid-beta (Abeta, which initially causes dysregulation of synaptic plasticity and eventually causes destruction of synapses and neurons. Pharmacological efforts to limit Abeta buildup have proven ineffective, and this raises the twin challenges of understanding the adverse effects of Abeta on synapses and of suggesting pharmacological means to prevent it. The purpose of this paper is to initiate a computational approach to understanding the dysregulation by Abeta of synaptic plasticity and to offer suggestions whereby combinations of various chemical compounds could be arrayed against it. This data-driven approach confronts the complexity of synaptic plasticity by representing findings from the literature in a course-grained manner, and focuses on understanding the aggregate behavior of many molecular interactions. The same set of interactions is modeled by two different computer programs, each written using a different programming modality: one imperative, the other declarative. Both programs compute the same results over an extensive test battery, providing an essential crosscheck. Then the imperative program is used for the computationally intensive purpose of determining the effects on the model of every combination of ten different compounds, while the declarative program is used to analyze model behavior using temporal logic. Together these two model implementations offer new insights into the mechanisms by which Abeta dysregulates synaptic plasticity and suggest many drug combinations that potentially may reduce or prevent it.

  15. Clot resolution after 3 weeks of anticoagulant treatment for pulmonary embolism : comparison of computed tomography and perfusion scintigraphy

    NARCIS (Netherlands)

    van Es, J.; Douma, R. A.; Kamphuisen, P. W.; Gerdes, V. E. A.; Verhamme, P.; Wells, P. S.; Bounameaux, H.; Lensing, A. W. A.; Bueller, H. R.

    2013-01-01

    Introduction Little is known about the natural history of clot resolution in the initial weeks of anticoagulant therapy in patients with acute pulmonary embolism (PE). Clot resolution of acute PE was assessed with either computed tomography pulmonary angiography scan (CT-scan) or perfusion scintigra

  16. Virtual reality exposure treatment of agoraphobia: a comparison of computer automatic virtual environment and head-mounted display

    NARCIS (Netherlands)

    Meyerbröker, K.; Morina, N.; Kerkhof, G.; Emmelkamp, P.M.G.; Wiederhold, B.K.; Bouchard, S.; Riva, G.

    2011-01-01

    In this study the effects of virtual reality exposure therapy (VRET) were investigated in patients with panic disorder and agoraphobia. The level of presence in VRET was compared between using either a head-mounted display (HMD) or a computer automatic virtual environment (CAVE). Results indicate

  17. Endodontic treatment of a maxillary lateral incisor with a perforating internal resorption by using cone beam computed tomography as a diagnostic aid: a case report.

    Science.gov (United States)

    Takita, Toshiya; Tsurumachi, Tamotsu; Ogiso, Bunnai

    2011-10-01

    This case report presents the endodontic treatment of a maxillary right lateral incisor with a perforating internal resorption in a 50-year-old woman. Radiographically, internal resorption appears as a fairly uniform, radiolucent enlargement of the pulp canal and distortion of the original root canal outline. The use of cone beam computed tomography can help the clinician in making a confirmatory diagnosis and determining the treatment plan before undertaking the actual treatment. After cleaning the root canal space and the resorptive defect by mechanic instrumentation, irrigation, and interim calcium hydroxide dressing, the apical third canal was filled with a gutta-percha point by lateral condensation. The resorptive defect was filled with mineral trioxide aggregate. Follow-up radiographs at 3 years showed adequate repair of the resorption, and the tooth remained asymptomatic.

  18. Methods and computer executable instructions for rapidly calculating simulated particle transport through geometrically modeled treatment volumes having uniform volume elements for use in radiotherapy

    Science.gov (United States)

    Frandsen, Michael W.; Wessol, Daniel E.; Wheeler, Floyd J.

    2001-01-16

    Methods and computer executable instructions are disclosed for ultimately developing a dosimetry plan for a treatment volume targeted for irradiation during cancer therapy. The dosimetry plan is available in "real-time" which especially enhances clinical use for in vivo applications. The real-time is achieved because of the novel geometric model constructed for the planned treatment volume which, in turn, allows for rapid calculations to be performed for simulated movements of particles along particle tracks there through. The particles are exemplary representations of neutrons emanating from a neutron source during BNCT. In a preferred embodiment, a medical image having a plurality of pixels of information representative of a treatment volume is obtained. The pixels are: (i) converted into a plurality of substantially uniform volume elements having substantially the same shape and volume of the pixels; and (ii) arranged into a geometric model of the treatment volume. An anatomical material associated with each uniform volume element is defined and stored. Thereafter, a movement of a particle along a particle track is defined through the geometric model along a primary direction of movement that begins in a starting element of the uniform volume elements and traverses to a next element of the uniform volume elements. The particle movement along the particle track is effectuated in integer based increments along the primary direction of movement until a position of intersection occurs that represents a condition where the anatomical material of the next element is substantially different from the anatomical material of the starting element. This position of intersection is then useful for indicating whether a neutron has been captured, scattered or exited from the geometric model. From this intersection, a distribution of radiation doses can be computed for use in the cancer therapy. The foregoing represents an advance in computational times by multiple factors of

  19. Computational Streetscapes

    Directory of Open Access Journals (Sweden)

    Paul M. Torrens

    2016-09-01

    Full Text Available Streetscapes have presented a long-standing interest in many fields. Recently, there has been a resurgence of attention on streetscape issues, catalyzed in large part by computing. Because of computing, there is more understanding, vistas, data, and analysis of and on streetscape phenomena than ever before. This diversity of lenses trained on streetscapes permits us to address long-standing questions, such as how people use information while mobile, how interactions with people and things occur on streets, how we might safeguard crowds, how we can design services to assist pedestrians, and how we could better support special populations as they traverse cities. Amid each of these avenues of inquiry, computing is facilitating new ways of posing these questions, particularly by expanding the scope of what-if exploration that is possible. With assistance from computing, consideration of streetscapes now reaches across scales, from the neurological interactions that form among place cells in the brain up to informatics that afford real-time views of activity over whole urban spaces. For some streetscape phenomena, computing allows us to build realistic but synthetic facsimiles in computation, which can function as artificial laboratories for testing ideas. In this paper, I review the domain science for studying streetscapes from vantages in physics, urban studies, animation and the visual arts, psychology, biology, and behavioral geography. I also review the computational developments shaping streetscape science, with particular emphasis on modeling and simulation as informed by data acquisition and generation, data models, path-planning heuristics, artificial intelligence for navigation and way-finding, timing, synthetic vision, steering routines, kinematics, and geometrical treatment of collision detection and avoidance. I also discuss the implications that the advances in computing streetscapes might have on emerging developments in cyber

  20. [Endodontics in motion: new concepts, materials and techniques 2. The use of cone-beam computed tomography in endodontic diagnosis and treatment planning].

    Science.gov (United States)

    Özok, A R; Metska, M E

    2015-09-01

    Systems for cone-beam computed tomography make a high-quality 3D reconstruction of dentomaxillofacial structures possible, without exposing the patient to excessive doses of radiation. Due to its 3D nature cone-beam computed tomography is superior to conventional dental radiographic imaging methods for many aspects of endodontic diagnosis and treatment planning. There are multiple indications for the use of cone-beam computed tomography scans in endodontics, including detection of periapical lesions or root fractures and the exploration of the root canal anatomy and its deviations. Depending on conditions, a judicious decision will always have to be made with regard to the radiographic technique to be applied. Primary in that respect must be the means by which the most accurate diagnostic image can be achieved with the lowest possible dose of radiation. Making a cone-beam computed tomography scan is justified only when the required diagnostic information cannot be achieved adequately using lower dose conventional dental radiographic imaging techniques.

  1. Multidetector computed tomography-guided treatment strategy in patients with non-ST elevation acute coronary syndromes: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Dorgelo, J.; Willems, T.P.; Ooijen, P.M.A. van; Oudkerk, M. [University Hospital Groningen, Department of Radiology, Groningen (Netherlands); Geluk, C.A.; Zijlstra, F. [University Hospital Groningen, Department of Cardiology, Groningen (Netherlands)

    2005-04-01

    Patients with non-ST elevation acute coronary syndrome (ACS) and evidence of myocardial ischaemia are scheduled for coronary angiography (CAG). In most patients CAG remains a single diagnostic procedure only. A prospective study was performed to evaluate whether 16-slice multidetector CT (MDCT) could predict treatment of the patients and to determine how many CAGs could have been prevented by MDCT scanning prior to CAG. Twenty-two patients with ACS were scanned prior to CAG. Based on MDCT data, a fictive treatment was proposed and compared to CAG-based treatment. Excellent accuracy was observed to detect significant stenoses using MDCT (sensitivity 94%, specificity 96%). In 45%, no PCI was performed during CAG, because of the absence of significant coronary artery disease (27%) or severe coronary artery disease, demanding CABG (18%). MDCT predicted correct treatment in 86%. By using MDCT data, 32% of the CAGs could have been prevented. (orig.)

  2. Usefulness of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in dermatofibrosarcoma protuberans on treatment with imatinib

    Science.gov (United States)

    Kashyap, Raghava; Muddu, Vamshi Krishna; Anantamakula, Sameera; Sri, Satya

    2016-01-01

    Dermatofibrosarcoma protuberans (DFSP) is a rare locally aggressive tumor with distant metastases being unusual. We present a case of metastatic DFSP treated with imatinib showing complete metabolic response to treatment. PMID:27385888

  3. Impacted lower third molar fused with a supernumerary tooth--diagnosis and treatment planning using cone-beam computed tomography.

    Science.gov (United States)

    Ferreira-Junior, Osny; de Avila, Luciana Dorigatti; Sampieri, Marcelo Bonifácio da Silva; Dias-Ribeiro, Eduardo; Chen, Wei-liang; Fan, Song

    2009-12-01

    This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radiography was complemented by the Donovan's radiographic technique; but because of the proximity of the dental element to the mandibular ramus, it was not possible to have a final fusion diagnosis. Hence, the Cone-Beam Computed Tomography-which provides precise three-dimensional information-was used to determinate the fusion diagnosis and also to help in the surgical planning. In this case report we observed that the periapical, occlusal and panoramic were not able to show details which could only be examined through the cone-beam computed tomography.

  4. Accuracy of Cone Beam Computed Tomography in Diagnosis and Treatment Planning of Periodontal Bone Defects: A Case Report

    OpenAIRE

    Songa, Vajra Madhuri; Jampani, Narendra Dev; Babu, Venkateshwara; Buggapati, Lahari; Mittapally, Sowjanya

    2014-01-01

    Diagnosis of periodontitis depend mostly on traditional two-dimensional (2-D) radiographic assessment. Regardless of efforts in improving reliability, present methods of detecting bone level changes over time or determining three-dimensional (3-D) architecture of osseous defects are lacking. To improve the diagnostic potential, an imaging modality which would give an undistorted 3-D vision of a tooth and surrounding structures is imperative. Cone beam computed tomography (CBCT) generates 3D v...

  5. Current opinion on computer-aided surgical navigation and robotics: role in the treatment of sports-related injuries.

    Science.gov (United States)

    Musahl, Volker; Plakseychuk, Anton; Fu, Freddie H

    2002-01-01

    Computer-assisted surgery (CAS) may allow surgeons to be more precise and minimally invasive, in addition to being an excellent research tool. Medical imaging, such as magnetic resonance and computed tomography is not only an important diagnostic tool, but also a necessary planning tool. In orthopaedic sports medicine, precision is needed when placing tunnels for soft tissue fixation of replacement grafts. Two types of CAS systems -- passive and active -- have been developed. Passive systems, or surgical navigation systems, provide the surgeon with additional information prior to and during the surgical procedure (in real time). Active systems have the ability of performing certain surgical steps autonomously. Both active and passive CAS systems are currently a subject of basic science and clinical investigations and will be discussed and commented on in this article. In summary, passive navigation systems can provide additional information to the surgeon and can therefore lead to more precise tunnel placement. Active robotic technology seems to be accurate and feasible with promising initial results from Europe. However, active and passive CAS can only be as precise as the surgeon who plans the procedure. Therefore, future studies have to focus on integrating, arthroscopy, 3-D image-enhanced computer navigation, and virtual kinematics, as well as to increase precision in surgical techniques.

  6. Use of computational fluid dynamics to estimate hemodynamic effects of respiration on hypoplastic left heart syndrome surgery: total cavopulmonary connection treatments.

    Science.gov (United States)

    Liu, Jinlong; Qian, Yi; Sun, Qi; Liu, Jinfen; Umezu, Mitsuo

    2013-01-01

    Total cavopulmonary connection (TCPC), a typical kind of Fontan procedure, is commonly used in the treatment of a functional single ventricle. The palliative cardiothoracic procedure is performed by connecting the superior vena cava and the inferior vena cava to the pulmonary arteries. Due to the difficulty of direct study in vivo, in this paper, computational fluid dynamics (CFD) was introduced to estimate the outcomes of patient-specific TCPC configuration. We mainly focused on the influence of blood pulsation and respiration. Fast Fourier transforms method was employed to separate the measured flow conditions into the rate of breath and heart beat. Blood flow performance around the TCPC connection was investigated by analyzing the results of time-varying energy losses, blood flow distribution rate, local pressure, and wall shear stress distributions. It was found that the value of energy loss including the influence of respiration was 1.5 times higher than the value of energy loss disregarding respiratory influences. The results indicated that the hemodynamic outcomes of TCPC treatment are obviously influenced by respiration. The influence of respiration plays an important role in estimating the results of TCPC treatment and thus should be included as one of the important conditions of computational haemodynamic analysis.

  7. Understanding molecular mechanisms of traditional Chinese medicine for the treatment of influenza viruses infection by computational approaches.

    Science.gov (United States)

    Gu, Shuo; Yin, Ning; Pei, Jianfeng; Lai, Luhua

    2013-11-01

    The battle against influenza is an enduring one. For hundreds of years, people have fought such small viruses with practices such as traditional Chinese medicine (TCM), however only recently has it been possible to use cutting-edge technology to investigate their mechanisms. Here, we re-created this ancient Chinese knowledge to explore the chemistry of herbs and elucidate their mechanism of action using molecular computational methods. Our results show that TCM compounds can inhibit influenza viral proteins in a multi-target/multi-component manner, revealing the versatility of TCM for treating different influenza virus subtypes, including the recently emerged H7N9.

  8. Computational oncology.

    Science.gov (United States)

    Lefor, Alan T

    2011-08-01

    Oncology research has traditionally been conducted using techniques from the biological sciences. The new field of computational oncology has forged a new relationship between the physical sciences and oncology to further advance research. By applying physics and mathematics to oncologic problems, new insights will emerge into the pathogenesis and treatment of malignancies. One major area of investigation in computational oncology centers around the acquisition and analysis of data, using improved computing hardware and software. Large databases of cellular pathways are being analyzed to understand the interrelationship among complex biological processes. Computer-aided detection is being applied to the analysis of routine imaging data including mammography and chest imaging to improve the accuracy and detection rate for population screening. The second major area of investigation uses computers to construct sophisticated mathematical models of individual cancer cells as well as larger systems using partial differential equations. These models are further refined with clinically available information to more accurately reflect living systems. One of the major obstacles in the partnership between physical scientists and the oncology community is communications. Standard ways to convey information must be developed. Future progress in computational oncology will depend on close collaboration between clinicians and investigators to further the understanding of cancer using these new approaches.

  9. Endovascular treatment of thoracic aortic diseases: Follow-up and complications with multi-detector computed tomography angiography

    Energy Technology Data Exchange (ETDEWEB)

    Iezzi, Roberto [Department of Radiology, University ' G. D' Annunzio' , Chieti (Italy)], E-mail: r.iezzi@rad.unich.it; Cotroneo, Antonio Raffaele; Marano, Riccardo; Filippone, Antonella; Storto, Maria Luigia [Department of Radiology, University ' G. D' Annunzio' , Chieti (Italy)

    2008-03-15

    Endovascular procedures with placement of stent-graft has become an accepted alternative to traditional open surgery for treatment of descending thoracic aortic aneurysms, ulcers, post-traumatic rupture, or complications of type-B dissection, due to significant reduction in perioperative mortality, rate of complications and length of hospitalization. Moreover, increasing operator experience and continuous advances in stent-graft technology are making treatment of a wider range of cases possible with redefinition of guidelines for endovascular stent-graft. The feasibility of endovascular stent-graft is mainly dependent on anatomic factors which represent the important predictors of the success of this procedure as well as on strictly follow-up in order to obtain early detection and treatment of eventual complications. Multi-detector CT-angiography is a fast, safe, and minimally invasive imaging technique that represents the standard of reference in the follow-up of patients who have undergone endovascular stent-graft, as it is effective and specific in the detection of procedure-correlated complications. The purpose of this article is to give a brief review of those techniques most commonly used for endovascular treatment of thoracic aortic diseases together with a more detailed description of post-procedural complications and their appearance on multi-detector CT-angiography.

  10. Development and validation of a computational model of the knee joint for the evaluation of surgical treatments for osteoarthritis

    Science.gov (United States)

    Mootanah, R.; Imhauser, C.W.; Reisse, F.; Carpanen, D.; Walker, R.W.; Koff, M.F.; Lenhoff, M.W.; Rozbruch, S.R.; Fragomen, A.T.; Dewan, Z.; Kirane, Y.M.; Cheah, Pamela A.; Dowell, J.K.; Hillstrom, H.J.

    2014-01-01

    A three-dimensional (3D) knee joint computational model was developed and validated to predict knee joint contact forces and pressures for different degrees of malalignment. A 3D computational knee model was created from high-resolution radiological images to emulate passive sagittal rotation (full-extension to 65°-flexion) and weight acceptance. A cadaveric knee mounted on a six-degree-of-freedom robot was subjected to matching boundary and loading conditions. A ligament-tuning process minimised kinematic differences between the robotically loaded cadaver specimen and the finite element (FE) model. The model was validated by measured intra-articular force and pressure measurements. Percent full scale error between EE-predicted and in vitro-measured values in the medial and lateral compartments were 6.67% and 5.94%, respectively, for normalised peak pressure values, and 7.56% and 4.48%, respectively, for normalised force values. The knee model can accurately predict normalised intra-articular pressure and forces for different loading conditions and could be further developed for subject-specific surgical planning. PMID:24786914

  11. Physical and numerical sources of computational inefficiency in integration of chemical kinetic rate equations: Etiology, treatment and prognosis

    Science.gov (United States)

    Pratt, D. T.; Radhakrishnan, K.

    1986-01-01

    The design of a very fast, automatic black-box code for homogeneous, gas-phase chemical kinetics problems requires an understanding of the physical and numerical sources of computational inefficiency. Some major sources reviewed in this report are stiffness of the governing ordinary differential equations (ODE's) and its detection, choice of appropriate method (i.e., integration algorithm plus step-size control strategy), nonphysical initial conditions, and too frequent evaluation of thermochemical and kinetic properties. Specific techniques are recommended (and some advised against) for improving or overcoming the identified problem areas. It is argued that, because reactive species increase exponentially with time during induction, and all species exhibit asymptotic, exponential decay with time during equilibration, exponential-fitted integration algorithms are inherently more accurate for kinetics modeling than classical, polynomial-interpolant methods for the same computational work. But current codes using the exponential-fitted method lack the sophisticated stepsize-control logic of existing black-box ODE solver codes, such as EPISODE and LSODE. The ultimate chemical kinetics code does not exist yet, but the general characteristics of such a code are becoming apparent.

  12. Computer modelling integrated with micro-CT and material testing provides additional insight to evaluate bone treatments: Application to a beta-glycan derived whey protein mice model.

    Science.gov (United States)

    Sreenivasan, D; Tu, P T; Dickinson, M; Watson, M; Blais, A; Das, R; Cornish, J; Fernandez, J

    2016-01-01

    The primary aim of this study was to evaluate the influence of a whey protein diet on computationally predicted mechanical strength of murine bones in both trabecular and cortical regions of the femur. There was no significant influence on mechanical strength in cortical bone observed with increasing whey protein treatment, consistent with cortical tissue mineral density (TMD) and bone volume changes observed. Trabecular bone showed a significant decline in strength with increasing whey protein treatment when nanoindentation derived Young׳s moduli were used in the model. When microindentation, micro-CT phantom density or normalised Young׳s moduli were included in the model a non-significant decline in strength was exhibited. These results for trabecular bone were consistent with both trabecular bone mineral density (BMD) and micro-CT indices obtained independently. The secondary aim of this study was to characterise the influence of different sources of Young׳s moduli on computational prediction. This study aimed to quantify the predicted mechanical strength in 3D from these sources and evaluate if trends and conclusions remained consistent. For cortical bone, predicted mechanical strength behaviour was consistent across all sources of Young׳s moduli. There was no difference in treatment trend observed when Young׳s moduli were normalised. In contrast, trabecular strength due to whey protein treatment significantly reduced when material properties from nanoindentation were introduced. Other material property sources were not significant but emphasised the strength trend over normalised material properties. This shows strength at the trabecular level was attributed to both changes in bone architecture and material properties.

  13. The Tarsoft software: A computer program to learn the elemental theory for the urban wastewater treatment; Tarsoft: programa de ordenador para el aprendizaje de la teoria basica sobre la depuracion de las aguas residuales urbanas

    Energy Technology Data Exchange (ETDEWEB)

    Parra Narvaez, R.; Baldasano Recio, J.M. [Universitat Politecnica de Catalunya. Barcelona (Spain)

    1998-12-31

    It` ve been developed a first version of the computer program Tarsoft, with the objective to be a Informatic contribution for the education and training of the knowledge about the urban wastewater treatment. This article describe in general form, the main characteristic of this computer program, the minimal hardware and software requirements, the theoretical topics than it include, the presentation form of the variety alfanumerical and graphical interactive information and design modules of the different treatment process. (Author) 20 refs.

  14. The Correlation Between Pre-treatment Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Parameters and Clinical Prognostic Factors in Pediatric Hodgkin Lymphoma

    Science.gov (United States)

    Tatcı, Ebru; Uslu Biner, İnci; Emir, Suna; Tanyıldız, Hikmet Gülşah; Özmen, Özlem; Alagöz, Engin; Gökçek, Atila; Şahin, Gürses

    2017-01-01

    Objective: To compare standardized uptake values (SUV) derived from pre-treatment 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging and clinical prognostic factors in pediatric patients with Hodgkin lymphoma (HL). Methods: Pre-treatment FDG PET/CT findings of 28 children with HL were evaluated in this retrospective study. Metabolic tumor volume (MTV), SUVmax normalized by weight (SUVweight), lean body mass (SUVlbm), body surface area (SUVbsa) and plasma glucose levels of tumors (SUVglucose) were calculated using pre-treatment FDG PET/CT scan images. These metabolic parameters were correlated with clinical factors [age, sex, number of lymph node groups, presence of splenic involvement, bulky mediastinal disease, Ann Arbor stage, serum white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), serum albumin and hemoglobin levels]. Results: SUVbsa, SUVlbm, SUVweight, SUVglucose and MTV were higher in patients with stage III-IV disease, bulky tumor and ≥3 lymph node groups (p0.05). SUVbsa and SUVlbm were higher in patients with anemia (p0.05). Conclusion: Metabolic parameters derived from pre-treatment FDG PET/CT may have an important role in predicting high-risk disease in patients with HL. Also, SUVbsa and SUVlbm may be better markers than SUVweight in the quantitative evaluation of FDG PET/CT scans in pediatric patients. PMID:28291005

  15. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography evaluation of subcutaneous panniculitis-like T cell lymphoma and treatment response

    Science.gov (United States)

    Gorodetskiy, Vadim R; Mukhortova, Olga V; Aslanidis, Irakli P; Klapper, Wolfram; Probatova, Natalya A

    2016-01-01

    Subcutaneous panniculitis-like T cell lymphoma (SPTCL) is a very rare variant of non-Hodgkin’s lymphoma. Currently, there is no standard imaging method for staging of SPTCL nor for assessment of treatment response. Here, we describe our use of fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for staging and monitoring of treatment response in 3 cases of SPTCL. Primary staging by PET/CT showed that all 3 patients had multiple foci in the subcutaneous fat tissue, with SUVmax from 10.5 to 14.6. Involvement of intra-abdominal fat with high SUVmax was identified in 2 of the patients. Use of the triple drug regimen of gemcitabine, cisplatin and methylprednisolone (commonly known as “GEM-P”) as first-line therapy or second-line therapy facilitated complete metabolic response for all 3 cases. FDG PET/CT provides valuable information for staging and monitoring of treatment response and can reveal occult involvement of the intra-abdominal visceral fat. High FDG uptake on pre-treatment PET can identify patients with aggressive disease and help in selection of first-line therapy. PMID:27672640

  16. Predicting treatment failure, death and drug resistance using a computed risk score among newly diagnosed TB patients in Tamaulipas, Mexico.

    Science.gov (United States)

    Abdelbary, B E; Garcia-Viveros, M; Ramirez-Oropesa, H; Rahbar, M H; Restrepo, B I

    2017-09-14

    The purpose of this study was to develop a method for identifying newly diagnosed tuberculosis (TB) patients at risk for TB adverse events in Tamaulipas, Mexico. Surveillance data between 2006 and 2013 (8431 subjects) was used to develop risk scores based on predictive modelling. The final models revealed that TB patients failing their treatment regimen were more likely to have at most a primary school education, multi-drug resistance (MDR)-TB, and few to moderate bacilli on acid-fast bacilli smear. TB patients who died were more likely to be older males with MDR-TB, HIV, malnutrition, and reporting excessive alcohol use. Modified risk scores were developed with strong predictability for treatment failure and death (c-statistic 0·65 and 0·70, respectively), and moderate predictability for drug resistance (c-statistic 0·57). Among TB patients with diabetes, risk scores showed moderate predictability for death (c-statistic 0·68). Our findings suggest that in the clinical setting, the use of our risk scores for TB treatment failure or death will help identify these individuals for tailored management to prevent these adverse events. In contrast, the available variables in the TB surveillance dataset are not robust predictors of drug resistance, indicating the need for prompt testing at time of diagnosis.

  17. Predicting effects of blood flow rate and size of vessels in a vasculature on hyperthermia treatments using computer simulation

    Directory of Open Access Journals (Sweden)

    Shih Tzu-Ching

    2010-03-01

    Full Text Available Abstract Background Pennes Bio Heat Transfer Equation (PBHTE has been widely used to approximate the overall temperature distribution in tissue using a perfusion parameter term in the equation during hyperthermia treatment. In the similar modeling, effective thermal conductivity (Keff model uses thermal conductivity as a parameter to predict temperatures. However the equations do not describe the thermal contribution of blood vessels. A countercurrent vascular network model which represents a more fundamental approach to modeling temperatures in tissue than do the generally used approximate equations such as the Pennes BHTE or effective thermal conductivity equations was presented in 1996. This type of model is capable of calculating the blood temperature in vessels and describing a vasculature in the tissue regions. Methods In this paper, a countercurrent blood vessel network (CBVN model for calculating tissue temperatures has been developed for studying hyperthermia cancer treatment. We use a systematic approach to reveal the impact of a vasculature of blood vessels against a single vessel which most studies have presented. A vasculature illustrates branching vessels at the periphery of the tumor volume. The general trends present in this vascular model are similar to those shown for physiological systems in Green and Whitmore. The 3-D temperature distributions are obtained by solving the conduction equation in the tissue and the convective energy equation with specified Nusselt number in the vessels. Results This paper investigates effects of size of blood vessels in the CBVN model on total absorbed power in the treated region and blood flow rates (or perfusion rate in the CBVN on temperature distributions during hyperthermia cancer treatment. Also, the same optimized power distribution during hyperthermia treatment is used to illustrate the differences between PBHTE and CBVN models. Keff (effective thermal conductivity model delivers the

  18. The Study of Factors Influencing on Orthodontic Treatment Difficulty of Impacted Maxillary Canine with Cone Beam Computed Tomography

    Directory of Open Access Journals (Sweden)

    A.F. Miresmaeili

    2012-10-01

    Full Text Available Introduction & Objective: Maxillary canines are esthetically and functionally important, but patients with impacted maxillary canines are perceived to be more difficult and time-consuming to treat than the average orthodontic patient. The aim of this study was to define orthodontic Treatment Difficulty Index (TDI of impacted maxillary canine with CBCT according to experts' opinions.Materials & Methods: In this cross sectional study, nine variables in CBCT of thirty six consecutive patients with 50 impacted maxillary canines were measured using Dolphin 3D. The related 3D and 2D pictures and the measured data were uploaded on a website. Ten orthodontists were asked to judge the difficulty of bringing the impacted canine to occlusal plane from 1 to 10 (1 = easy, 10 = extremely difficult.Then, they were also asked to evaluate the effect of each variable on treatment from 1 to 5 (1= very low, 5= very high. Random effect linear regression was used in exploration stage and then simple linear regression was used for the application of the model.Results: The patients mean age was 19.08 ± 5.8 years. Mean clinical experience of examiners was 22.7 ±12.02 years. Three variables were deleted at exploration stage and two other in model application stage. Vertical distance to the occlusal plane (P=0.000, overlap in frontal view (P=0.000, angulations of the canine to the occlusal plan (P=0.029, dilacerations (P=0.000, and rotation (P=0.029 had a significant relationship with TDI.Conclusion: Treatment difficulty of impacted maxillary canines could be predicted quantitatively by measuring variables in CBCT.(Sci J Hamadan Univ Med Sci 2012;19(3:30-35

  19. CLINICAL VALUE OF MULTISLICE SPIRAL X-RAY COMPUTED TOMOGRAPHY WHEN PLANNING THE TREATMENT OF PATIENTS WITH LARYNGEAL CANCER

    Directory of Open Access Journals (Sweden)

    L. G. Kozhanov

    2012-01-01

    Full Text Available Cancers remain a priority for modern society. According to the WHO estimates, global cancer morbidity  and mortality rates will triple in the period 1999 to 2030: from 10 to 30 million new cases and from 6 to 17 million deaths recorded every year, which will exceed deaths from cardiovascular diseases and injuries. The efficiency of treatment in cancer patients and their prediction are determined by timely disease diagnosis, tumor extent estimation, and adequate therapeutic measures. So search for ways to cardinally improve the early recognition of cancer is one of the major tasks in the study of the problems of cancer patients, those with throat cancer in particular.

  20. Advantages of cone beam computed tomography (CBCT in the orthodontic treatment planning of cleidocranial dysplasia patients: a case report

    Directory of Open Access Journals (Sweden)

    Zotti Francesca

    2011-02-01

    Full Text Available Abstract Our aim was to discuss, by presenting a case, the possibilities connected to the use of a CBCT exam in the dental evaluation of patients with Cleidocranial Dysplasia (CCD, an autosomal dominant skeletal dysplasia with delayed exfoliation of deciduous and eruption of permanent teeth and multiple supernumeraries, often impacted. We think that CBCT in this patient was adequate to accurately evaluate impacted teeth position and anatomy, resulting thus useful both in the diagnostic process and in the treatment planning, with an important reduction in the radiation dose absorbed by the patient.

  1. User's manual of a supporting system for treatment planning in boron neutron capture therapy. JAERI computational dosimetry system

    CERN Document Server

    Kumada, H

    2002-01-01

    A boron neutron capture therapy (BNCT) with epithermal neutron beam is expected to treat effectively for malignant tumor that is located deeply in the brain. It is indispensable to estimate preliminarily the irradiation dose in the brain of a patient in order to perform the epithermal neutron beam BNCT. Thus, the JAERI Computational Dosimetry System (JCDS), which can calculate the dose distributions in the brain, has been developed. JCDS is a software that creates a 3-dimensional head model of a patient by using CT and MRI images and that generates a input data file automatically for calculation neutron flux and gamma-ray dose distribution in the brain by the Monte Carlo code: MCNP, and that displays the dose distribution on the head model for dosimetry by using the MCNP calculation results. JCDS has any advantages as follows; By treating CT data and MRI data which are medical images, a detail three-dimensional model of patient's head is able to be made easily. The three-dimensional head image is editable to ...

  2. To test or to treat? An analysis of influenza testing and antiviral treatment strategies using economic computer modeling.

    Directory of Open Access Journals (Sweden)

    Bruce Y Lee

    Full Text Available BACKGROUND: Due to the unpredictable burden of pandemic influenza, the best strategy to manage testing, such as rapid or polymerase chain reaction (PCR, and antiviral medications for patients who present with influenza-like illness (ILI is unknown. METHODOLOGY/PRINCIPAL FINDINGS: We developed a set of computer simulation models to evaluate the potential economic value of seven strategies under seasonal and pandemic influenza conditions: (1 using clinical judgment alone to guide antiviral use, (2 using PCR to determine whether to initiate antivirals, (3 using a rapid (point-of-care test to determine antiviral use, (4 using a combination of a point-of-care test and clinical judgment, (5 using clinical judgment and confirming the diagnosis with PCR testing, (6 treating all with antivirals, and (7 not treating anyone with antivirals. For healthy younger adults ( or = 65 years old, in both seasonal and pandemic influenza scenarios, employing PCR was the most cost-effective option, with the closest competitor being clinical judgment (when judgment accuracy > or = 50%. Point-of-care testing plus clinical judgment was cost-effective with higher probabilities of influenza. Treating all symptomatic ILI patients with antivirals was cost-effective only in older adults. CONCLUSIONS/SIGNIFICANCE: Our study delineated the conditions under which different testing and antiviral strategies may be cost-effective, showing the importance of accuracy, as seen with PCR or highly sensitive clinical judgment.

  3. Presentation of the PyDEF post-treatment Python software to compute publishable charts for defect energy formation

    Science.gov (United States)

    Péan, Emmanuel; Vidal, Julien; Jobic, Stéphane; Latouche, Camille

    2017-03-01

    In this paper we present a new software, Python for Defect Energy Formation (PyDEF), especially dedicated to the calculation of defect formation energy including its various corrections as developed by the theoretical community through the years. This program offers an intuitive graphical user interface which allows one to easily compute the corrected formation energy of any defect using theoretical calculation results. PyDEF is particularly suited for semiconductor materials as it includes finite size error corrections due to spurious intercell interactions as it is able to plot the formation energy of the different charge states and to determine the more stable ones as a function of the Fermi energy. Moreover PyDEF is able to plot Density Of States (DOS) with various parameters such as the projection on atoms or atomic species allowing a more comprehensive representation of defect-related electronic states. This software is developed in such a way that even non specialist or coder can use it and easily and quickly obtain reliable results.

  4. An examination of errors in computed water-leaving radiances due to a simplified treatment of water Raman scattering effects

    Science.gov (United States)

    Bismarck, Jonas von; Fischer, Jürgen

    2013-05-01

    Studies in the past have shown that solar shortwave radiation that has been Raman scattered in the ocean, and therefore undergone a wavelength shift, can contribute significantly to the signals observed by remote sensing satellites. While radiative transfer models that qualitatively approximate the effect of water Raman scattering on the water leaving irradiance have been available for a while, we have developed a new version of the radiative transfer code MOMO, which enables the accurate and fully angle resolved inclusion of inelastic scattering sources, and therefore allows detailed quantitative analyses of the effect on the light field in the ocean-atmosphere system. This article focuses on a study performed with this new model on the impact of azimuthally averaging the Raman scattering phase function, which is done in some RT models and significantly decreases computation time, on the water-leaving radiance. At the request of the authors and Proceedings Editors the above article has been updated to include a number of post-publication amendments. Changes made to the previously published article are detailed in the pages attached to the end of the updated article PDF file. The updated article was re-published on 15 August 2013.

  5. Evaluation of stability after pre-orthodontic orthognathic surgery using cone-beam computed tomography: A comparison with conventional treatment

    Science.gov (United States)

    Ann, Hye-Rim; Jung, Young-Soo; Lee, Kee-Joon

    2016-01-01

    Objective The aim of this study was to evaluate the skeletal and dental changes after intraoral vertical ramus osteotomy (IVRO) with and without presurgical orthodontics by using cone-beam computed tomography (CBCT). Methods This retrospective cohort study included 24 patients (mean age, 22.1 years) with skeletal Class III malocclusion who underwent bimaxillary surgery with IVRO. The patients were divided into the preorthodontic orthognathic surgery (POGS) group (n = 12) and conventional surgery (CS) group (n = 12). CBCT images acquired preoperatively, 1 month after surgery, and 1 year after surgery were analyzed to compare the intergroup differences in postoperative three-dimensional movements of the maxillary and mandibular landmarks and the changes in lateral cephalometric variables. Results Baseline demographics (sex and age) were similar between the two groups (6 men and 6 women in each group). During the postsurgical period, the POGS group showed more significant upward movement of the mandible (p < 0.05) than did the CS group. Neither group showed significant transverse movement of any of the skeletal landmarks. Moreover, none of the dental and skeletal variables showed significant intergroup differences 1 year after surgery. Conclusions Compared with CS, POGS with IVRO resulted in significantly different postsurgical skeletal movement in the mandible. Although both groups showed similar skeletal and dental outcomes at 1 year after surgery, upward movement of the mandible during the postsurgical period should be considered to ensure a more reliable outcome after POGS. PMID:27668193

  6. Evidence for excited-state intramolecular proton transfer in 4-chlorosalicylic acid from combined experimental and computational studies: Quantum chemical treatment of the intramolecular hydrogen bonding interaction

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Bijan Kumar [Department of Chemistry, University of Calcutta, 92 Acharya Prafulla Chandra Road, Calcutta 700009 (India); Guchhait, Nikhil, E-mail: nikhil.guchhait@rediffmail.com [Department of Chemistry, University of Calcutta, 92 Acharya Prafulla Chandra Road, Calcutta 700009 (India)

    2012-07-25

    Highlights: Black-Right-Pointing-Pointer Experimental and computational studies on the photophysics of 4-chlorosalicylic acid. Black-Right-Pointing-Pointer Spectroscopically established ESIPT reaction substantiated by theoretical calculation. Black-Right-Pointing-Pointer Quantum chemical treatment of IMHB unveils strength, nature and directional nature. Black-Right-Pointing-Pointer Superiority of quantum chemical treatment of H-bond over geometric criteria. Black-Right-Pointing-Pointer Role of H-bond as a modulator of aromaticity. -- Abstract: The photophysical study of a pharmaceutically important chlorine substituted derivative of salicylic acid viz., 4-chlorosalicylic acid (4ClSA) has been carried out by steady-state absorption, emission and time-resolved emission spectroscopy. A large Stokes shifted emission band with negligible solvent polarity dependence marks the spectroscopic signature of excited-state intramolecular proton transfer (ESIPT) reaction in 4ClSA. Theoretical calculation by ab initio and Density Functional Theory methods yields results consistent with experimental findings. Theoretical potential energy surfaces predict the occurrence of proton transfer in S{sub 1}-state. Geometrical and energetic criteria, Atoms-In-Molecule topological parameters, Natural Bond Orbital population analysis have been exploited to evaluate the intramolecular hydrogen bond (IMHB) interaction and to explore its directional nature. The inter-correlation between aromaticity and resonance assisted H-bond is also discussed in this context. Our results unveil that the quantum chemical treatment is a more accurate tool to assess hydrogen bonding interaction in comparison to geometrical criteria.

  7. Cone Beam Computed Tomography Evaluation of the Diagnosis, Treatment Planning, and Long-Term Followup of Large Periapical Lesions Treated by Endodontic Surgery: Two Case Reports

    Directory of Open Access Journals (Sweden)

    Vijay Shekhar

    2013-01-01

    Full Text Available The aim of this case report is to present two cases where cone beam computed tomography (CBCT was used for the diagnosis, treatment planning, and followup of large periapical lesions in relation to maxillary anterior teeth treated by endodontic surgery. Periapical disease may be detected sooner using CBCT, and their true size, extent, nature, and position can be assessed. It allows clinician to select the most relevant views of the area of interest resulting in improved detection of periapical lesions. CBCT scan may provide a better, more accurate, and faster method to differentially diagnose a solid (granuloma from a fluid-filled lesion or cavity (cyst. In the present case report, endodontic treatment was performed for both the cases followed by endodontic surgery. Biopsy was done to establish the confirmatory histopathological diagnosis of the periapical lesions. Long-term assessment of the periapical healing following surgery was done in all the three dimensions using CBCT and was found to be more accurate than IOPA radiography. It was concluded that CBCT was a useful modality in making the diagnosis and treatment plan and assessing the outcome of endodontic surgery for large periapical lesions.

  8. Cone beam computed tomography evaluation of the diagnosis, treatment planning, and long-term followup of large periapical lesions treated by endodontic surgery: two case reports.

    Science.gov (United States)

    Shekhar, Vijay; Shashikala, K

    2013-01-01

    The aim of this case report is to present two cases where cone beam computed tomography (CBCT) was used for the diagnosis, treatment planning, and followup of large periapical lesions in relation to maxillary anterior teeth treated by endodontic surgery. Periapical disease may be detected sooner using CBCT, and their true size, extent, nature, and position can be assessed. It allows clinician to select the most relevant views of the area of interest resulting in improved detection of periapical lesions. CBCT scan may provide a better, more accurate, and faster method to differentially diagnose a solid (granuloma) from a fluid-filled lesion or cavity (cyst). In the present case report, endodontic treatment was performed for both the cases followed by endodontic surgery. Biopsy was done to establish the confirmatory histopathological diagnosis of the periapical lesions. Long-term assessment of the periapical healing following surgery was done in all the three dimensions using CBCT and was found to be more accurate than IOPA radiography. It was concluded that CBCT was a useful modality in making the diagnosis and treatment plan and assessing the outcome of endodontic surgery for large periapical lesions.

  9. Fluorodeoxyglucose-positron emission tomography/computed tomography in the staging and evaluation of treatment response in a patient with Castleman's disease: a case report

    Directory of Open Access Journals (Sweden)

    Pelosi Ettore

    2008-04-01

    Full Text Available Abstract Introduction Castleman's disease is a rare lymphatic polyclonal disorder that is characterised by unicentric or multicentric lymph node hyperplasia and non-specific symptoms and signs including fever, asthenia, weight loss, enlarged liver and abnormally high blood levels of antibodies. Case presentation We present the case of a 74-year-old man with Castleman's disease. The disease was detected with a contrast-enhanced computed tomography (CT scan and a fluorodeoxyglucose (FDG-positron emission tomography (PET/CT study; diagnosis was made with histopathology. After treatment with surgical excision followed by chemotherapy, the disease response was evaluated using both diagnostic techniques. However, only the PET study was able to identify the spread of the disease to the abdominal lymph nodes, which were both enlarged and normal size, and, after treatment, to evaluate the disease response. Conclusion Based on the results of previous case reports and on those of the present study, it seems that Castleman's disease has a high glucose metabolic activity. Therefore, the use of PET can be considered appropriate in order to stage or restage the disease and to evaluate the response of the disease to treatment.

  10. Exploring the efficacy of endoscopic ventriculostomy for hydrocephalus treatment via a multicompartmental poroelastic model of CSF transport: a computational perspective.

    Directory of Open Access Journals (Sweden)

    John C Vardakis

    Full Text Available This study proposes the implementation of a Multiple-Network Poroelastic Theory (MPET model coupled with finite-volume computational fluid dynamics for the purpose of studying, in detail, the effects of obstructing CSF transport within an anatomically accurate cerebral environment. The MPET representation allows the investigation of fluid transport between CSF, brain parenchyma and cerebral blood, in an integral and comprehensive manner. A key novelty in the model is the amalgamation of anatomically accurate choroid plexuses with their feeding arteries and a simple relationship relaxing the constraint of a unique permeability for the CSF compartment. This was done in order to account for the Aquaporin-4-mediated swelling characteristics. The aim of this varying permeability compartment was to bring to light a feedback mechanism that could counteract the effects of ventricular dilation and subsequent elevations of CSF pressure through the efflux of excess CSF into the blood system. This model is used to demonstrate the impact of aqueductal stenosis and fourth ventricle outlet obstruction (FVOO. The implications of treating such a clinical condition with the aid of endoscopic third (ETV and endoscopic fourth (EFV ventriculostomy are considered. We observed peak CSF velocities in the aqueduct of the order of 15.6 cm/s in the healthy case, 45.4 cm/s and 72.8 cm/s for the mild and severe cases respectively. The application of ETV reduced the aqueductal velocity to levels around 16-17 cm/s. Ventricular displacement, CSF pressure, wall shear stress (WSS and pressure difference between lateral and fourth ventricles (ΔP increased with applied stenosis, and subsequently dropped to nominal levels with the application of ETV. The greatest reversal of the effects of atresia come by opting for ETV rather than the more complicated procedure of EFV.

  11. Computer-assisted virtual treatment planning combined with flapless surgery and immediate loading in the rehabilitation of partial edentulies.

    Science.gov (United States)

    DE Vico, G; Spinelli, D; Bonino, M; Schiavetti, R; Pozzi, A; Ottria, L

    2012-01-01

    It has been suggested that for success with immediate loaded dental implants it is necessary that, prior to their placement, bone quality and quantity as well as the biomechanical environment in which the implants are to function be evaluated.However, conventional techniques currently used for immediate implant placement lack sufficient precision and are usually accomplished by opening flap procedures. Nowadays computer-guided flapless surgery for implant placement using stereolithographic templates is gaining popularity among clinicians and patients. The advantages of this surgical protocol are its minimally invasive nature, accuracy of implant placement, predictability, less post-surgical disconfort and reduced time required for definitive rehabilitation. The introduction of digital planning programs has made it possible to place dental implants in preplanned positions and being immediately functionally loaded by using prefabricated prostheses. The surgical guide is used, infact, to develop a master model and fabricate the provisional bridge that will be secured to the implants immediately after their placement using the guided surgery template. In this way patients are able to achieve, in the same day of the surgery, a comfortable fixed rehabilitation needing only minor occlusal adjustments. Job S. et al during the three-month period, have demonstrated that the average reduction of crestal bone height around the implants placed with flapless surgery (0.06 mm) is not statistically significant, while the average reduction of crestal bone height around the implants placed using flap surgery (0.4 mm) is statistically significant, concluding that the use of stereolithographic appliances in accordance with flapless surgery makes immediate placement of the implants more predictable. However, the documentation of this technique in partial rehabilitations is limited. PURPOSE of this paper is to report the benefit of sophisticated pre-operative diagnostic implant planning

  12. Scintimammography and single-photon emission computed tomography for postoperative image guidance for radiation treatment planning in breast cancer patients.

    Science.gov (United States)

    Piperkova, E; Chavdarova, L; Garanina, Z; Gocheva, L; Parvanova, V; Tzonevska, A; Dimitrova, M

    2011-01-01

    To evaluate post-surgical tumor-metabolic regions outside of the computed tomography (CT)-defined volume for radiation therapy (RT) planning using functional imaging of scintimammography (SMG) ± single photon emission computerized tomography (SPECT) in breast cancer (BC) patients. 62 operated high-risk BC females, mean age 50.45 years, underwent SMG±SPECT before RT planning. Twenty-one and twelve patients with stage I and IIa respectively had lumpectomy (LT) with axillary lymph node dissection (ALND), and modified radical mastectomy (Patay) + ALND was realized in 29 stage IIb-III patients. All SMG images, positive for viable tumor tissue (VTT) or metastatically involved lymph nodes (LNs) were verified cytologically/ histologically. Three early planar and delayed images were acquired after i.v. administration of 550-740 MBq 99mTc- MIBI or 99mTc-TF. Uptake values (UV) > 1.65 revealed VTT. Data in 49 (79%) of 62 patients were characterized as true-negative (TN; UVVTT in scars, 1 newly defined BC in the contralateral breast and 18 regional LN metastases (6 axillary, 6 parasternal, 1 sub- and 5 supraclavicular). All 22 TP VTT lesions were imaged by scintigraphy using different tumor-seeking radiopharmaceuticals: 99mTc-MIBI - 17 (77%) and 99mTc- TF - 5 (23%) of the TP lesions. One false-positive (FP) (inflammation: UV>1.65) and one false-negative (FN) (UVVTT, LN metastases or altered biological activity in the scars after BC surgery and could modify the irradiated volume, optimizing the therapeutic effect and minimizing RT side effects.

  13. Commissioning dose computation models for spot scanning proton beams in water for a commercially available treatment planning system

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, X. R.; Poenisch, F.; Lii, M.; Sawakuchi, G. O.; Titt, U.; Bues, M.; Song, X.; Zhang, X.; Li, Y.; Ciangaru, G.; Li, H.; Taylor, M. B.; Suzuki, K.; Mohan, R.; Gillin, M. T.; Sahoo, N. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2013-04-15

    Purpose: To present our method and experience in commissioning dose models in water for spot scanning proton therapy in a commercial treatment planning system (TPS). Methods: The input data required by the TPS included in-air transverse profiles and integral depth doses (IDDs). All input data were obtained from Monte Carlo (MC) simulations that had been validated by measurements. MC-generated IDDs were converted to units of Gy mm{sup 2}/MU using the measured IDDs at a depth of 2 cm employing the largest commercially available parallel-plate ionization chamber. The sensitive area of the chamber was insufficient to fully encompass the entire lateral dose deposited at depth by a pencil beam (spot). To correct for the detector size, correction factors as a function of proton energy were defined and determined using MC. The fluence of individual spots was initially modeled as a single Gaussian (SG) function and later as a double Gaussian (DG) function. The DG fluence model was introduced to account for the spot fluence due to contributions of large angle scattering from the devices within the scanning nozzle, especially from the spot profile monitor. To validate the DG fluence model, we compared calculations and measurements, including doses at the center of spread out Bragg peaks (SOBPs) as a function of nominal field size, range, and SOBP width, lateral dose profiles, and depth doses for different widths of SOBP. Dose models were validated extensively with patient treatment field-specific measurements. Results: We demonstrated that the DG fluence model is necessary for predicting the field size dependence of dose distributions. With this model, the calculated doses at the center of SOBPs as a function of nominal field size, range, and SOBP width, lateral dose profiles and depth doses for rectangular target volumes agreed well with respective measured values. With the DG fluence model for our scanning proton beam line, we successfully treated more than 500 patients

  14. MR-OPERA: A Multicenter/Multivendor Validation of Magnetic Resonance Imaging-Only Prostate Treatment Planning Using Synthetic Computed Tomography Images.

    Science.gov (United States)

    Persson, Emilia; Gustafsson, Christian; Nordström, Fredrik; Sohlin, Maja; Gunnlaugsson, Adalsteinn; Petruson, Karin; Rintelä, Niina; Hed, Kristoffer; Blomqvist, Lennart; Zackrisson, Björn; Nyholm, Tufve; Olsson, Lars E; Siversson, Carl; Jonsson, Joakim

    2017-06-16

    To validate the dosimetric accuracy and clinical robustness of a commercially available software for magnetic resonance (MR) to synthetic computed tomography (sCT) conversion, in an MR imaging-only workflow for 170 prostate cancer patients. The 4 participating centers had MriPlanner (Spectronic Medical), an atlas-based sCT generation software, installed as a cloud-based service. A T2-weighted MR sequence, covering the body contour, was added to the clinical protocol. The MR images were sent from the MR scanner workstation to the MriPlanner platform. The sCT was automatically returned to the treatment planning system. Four MR scanners and 2 magnetic field strengths were included in the study. For each patient, a CT-treatment plan was created and approved according to clinical practice. The sCT was rigidly registered to the CT, and the clinical treatment plan was recalculated on the sCT. The dose distributions from the CT plan and the sCT plan were compared according to a set of dose-volume histogram parameters and gamma evaluation. Treatment techniques included volumetric modulated arc therapy, intensity modulated radiation therapy, and conventional treatment using 2 treatment planning systems and different dose calculation algorithms. The overall (multicenter/multivendor) mean dose differences between sCT and CT dose distributions were below 0.3% for all evaluated organs and targets. Gamma evaluation showed a mean pass rate of 99.12% (0.63%, 1 SD) in the complete body volume and 99.97% (0.13%, 1 SD) in the planning target volume using a 2%/2-mm global gamma criteria. Results of the study show that the sCT conversion method can be used clinically, with minimal differences between sCT and CT dose distributions for target and relevant organs at risk. The small differences seen are consistent between centers, indicating that an MR imaging-only workflow using MriPlanner is robust for a variety of field strengths, vendors, and treatment techniques. Copyright © 2017 The

  15. Evaluation of Strain Distribution in Bone around Implant in Treatment Design of Overdentures Using Computer and Modeling of Finite Elements

    Directory of Open Access Journals (Sweden)

    Masoumeh Khoshhal

    2015-12-01

    Full Text Available Introduction: Introduction: Few studies have investigated the distribution of stress around implants. In this study the distribution of stress in bones around implants was investigated in five overdenture (OD treatment designs including OD-1, OD-2, OD-3, OD-4 and OD-5. Materials and methods: The Catia modeling software was used in order to simulate the tooth/implant model and bone. First, the borders of cancellous and cortical bone in each section of the CT images were attained by Photoshop software. Then, modeling softwares SolidWorks and NUMBER were applied to make the final three-dimensional model of jaw. Finally, the amount of stress on the surface of bone/implant was studied by means of stress analysis software (Ansys v11.0. Results: Protrusive movements of implants B and D in OD-1 showed the highest amount of strain, 2435 εµ. Also, high amounts of strain, 1668 and 1557 εµwere observed in OD-1 and OD-2 designs in lateral movements respectively. Conclusion: The bottom line is that no forces to the extent of destruction based on the Ferost model were found for these designs. The highest amount of strain occurred in OD-1 design, which is held in mild overload window. Moreover, the amounts of strain in the rest of designs investigated were in adaptive window.

  16. Evaluation of Strain Distribution in Bone around Implant in Treatment Design of Overdentures Using Computer and Modeling of Finite Elements

    Directory of Open Access Journals (Sweden)

    Masoumeh Khoshhal

    2016-03-01

    Full Text Available Introduction: Introduction: Few studies have investigated the distribution of stress around implants. In this study the distribution of stress in bones around implants was investigated in five overdenture (OD treatment designs including OD-1, OD-2, OD-3, OD-4 and OD-5. Materials and methods: The Catia modeling software was used in order to simulate the tooth/implant model and bone. First, the borders of cancellous and cortical bone in each section of the CT images were attained by Photoshop software. Then, modeling softwares SolidWorks and NUMBER were applied to make the final three-dimensional model of jaw. Finally, the amount of stress on the surface of bone/implant was studied by means of stress analysis software (Ansys v11.0. Results: Protrusive movements of implants B and D in OD-1 showed the highest amount of strain, 2435 εµ. Also, high amounts of strain, 1668 and 1557 εµwere observed in OD-1 and OD-2 designs in lateral movements respectively. Conclusion: The bottom line is that no forces to the extent of destruction based on the Ferost model were found for these designs. The highest amount of strain occurred in OD-1 design, which is held in mild overload window. Moreover, the amounts of strain in the rest of designs investigated were in adaptive window.

  17. As abordagens teóricas e os formalismos para o tratamento computacional do significado lexical Theoretical approaches and formalisms for the computational treatment of lexical meaning

    Directory of Open Access Journals (Sweden)

    Ariani Di Felippo

    2010-01-01

    Full Text Available No âmbito do Processamento Automático de Línguas Naturais (PLN, o desenvolvimento de recursos léxico-semânticos é premente. Ao conceber os sistemas de PLN como um exercício de "engenharia da linguagem humana", acredita-se que o desenvolvimento de tais recursos pode ser beneficiado pelos modelos de "representação do conhecimento", desenvolvidos pela Engenharia do Conhecimento. Esses modelos, em particular, fornecem simultaneamente o arcabouço teórico-metodológico e a metalinguagem formal para o tratamento computacional do significado das unidades lexicais. Neste artigo, após a apresentação da concepção linguístico-computacional de léxico, elucidam-se os principais paradigmas de representação do conhecimento, enfatizando a abordagem do significado e a metalinguagem formal vinculadas a cada um deles.The development of lexical-semantic resources for natural language processing is urgent. Conceiving the computational systems which process natural languages as an exercise of "human language engineering", the development of such resources can benefit from the "knowledge representation models" provided by Knowledge Engineering. These models provide both the theoretical-methodological premises and the formal metalanguage for the computational treatment of word meaning. In this paper, we first present the linguistic-computational conception of "lexicon". Then, we describe the main knowledge representation paradigms emphasizing the theoretical approach to word meaning and the formalism related to each of them.

  18. 锥形束CT在正畸临床中的应用%Application of cone-beam computed tomography to orthodontic diagnosis and treatment

    Institute of Scientific and Technical Information of China (English)

    刘萌萌(综述); 刘琳(审校)

    2013-01-01

    口腔影像学是口腔正畸学诊断的重要依据。锥形束CT(CBCT)的临床应用使正畸诊断从二维时代走向了三维时代。CBCT对于正畸治疗方案设计、治疗后的预测以及治疗效果的评价等具有重要的作用。%Oral imaging is an important basis for the diagnosis of orthodontics. The clinical appliancation of cone beam computed tomography(CBCT)makes orthodontic diagnosis develop from two-dimension to three-dimension age,which is very important to treatment plan,prediction and effect evaluation.

  19. A computer program for monitoring the biological treatment of waste waters (CDBAR); Programa informatico para el control de la depuracion biologica de aguas residuales (CDBAR)

    Energy Technology Data Exchange (ETDEWEB)

    Bove Porta, J.; Milan Cabre, D.

    2001-07-01

    The problems, such as bulking, foaming, etc., involved in managing a waste water treatment plant (WWTP) employing an activated sludge biological process have a biochemical origin. Correcting them requires identifying the micro-organisms responsible for the pathology in question, whether the problems are due to there being too many or too few of these organisms. It is therefore necessary to have a good microscope and staff trained in identifying such micro-organisms. Never the less, to attain speed and efficiency, it is necessary to have more means. That is why the CDBAR project was carried out. This is a simple computer application that includes numerous photographs of microscopic organisms from samples taken in Spain and Portugal. Once the anomaly has been identified, the computer application it-self includes a program of corrective actions that will allow the biological reactor, the most important part of a WWTP, to function normally. Finally, a glossary has been prepared so that the meaning of any term can be looked up quickly and easily. (Author) 16 refs.

  20. Unenhanced Cone Beam Computed Tomography and Fusion Imaging in Direct Percutaneous Sac Injection for Treatment of Type II Endoleak: Technical Note

    Energy Technology Data Exchange (ETDEWEB)

    Carrafiello, Gianpaolo, E-mail: gcarraf@gmail.com; Ierardi, Anna Maria [Insubria University, Interventional Radiology, Department of Radiology (Italy); Radaelli, Alessandro [Philips Healthcare (Netherlands); Marchi, Giuseppe De; Floridi, Chiara [Insubria University, Interventional Radiology, Department of Radiology (Italy); Piffaretti, Gabriele [University of Insubria, Vascular Surgery Department (Italy); Federico, Fontana [Insubria University, Interventional Radiology, Department of Radiology (Italy)

    2016-03-15

    AimTo evaluate safety, feasibility, technical success, and clinical success of direct percutaneous sac injection (DPSI) for the treatment of type II endoleaks (T2EL) using anatomical landmarks on cone beam computed tomography (CBCT) and fusion imaging (FI).Materials and MethodsEight patients with T2EL were treated with DPSI using CBCT as imaging guidance. Anatomical landmarks on unenhanced CBCT were used for referencing T2EL location in the first five patients, while FI between unenhanced CBCT and pre-procedural computed tomography angiography (CTA) was used in the remaining three patients. Embolization was performed with thrombin, glue, and ethylene–vinyl alcohol copolymer. Technical and clinical success, iodinated contrast utilization, procedural time, fluoroscopy time, and mean radiation dose were registered.ResultsDPSI was technically successful in all patients: the needle was correctly positioned at the first attempt in six patients, while in two of the first five patients the needle was repositioned once. Neither minor nor major complications were registered. Average procedural time was 45 min and the average administered iodinated contrast was 13 ml. Mean radiation dose of the procedure was 60.43 Gy cm{sup 2} and mean fluoroscopy time was 18 min. Clinical success was achieved in all patients (mean follow-up of 36 months): no sign of T2EL was reported in seven patients until last CT follow-up, while it persisted in one patient with stability of sac diameter.ConclusionsDPSI using unenhanced CBCT and FI is feasible and provides the interventional radiologist with an accurate and safe alternative to endovascular treatment with limited iodinated contrast utilization.

  1. Morphologic and Metabolic Comparison of Treatment Responsiveness with 18Fludeoxyglucose-Positron Emission Tomography/Computed Tomography According to Lung Cancer Type

    Directory of Open Access Journals (Sweden)

    Mehmet Fatih Börksüz

    2016-06-01

    Full Text Available Objective: The aim of the present study was to evaluate the response to treatment by histopathologic type in patients with lung cancer and under follow-up with 18F-fluoro-2deoxy-glucose-positron emission tomography/computed tomography (18F-FDG PET/CT imaging by using Response Evaluation Criteria in Solid Tumors (RECIST and European Organisation for Research and Treatment of Cancer (EORTC criteria that evaluate morphologic and metabolic parameters. Methods: On two separate (pre- and post-treatment 18F-FDG PET/CT images, the longest dimension of primary tumor as well as of secondary lesions were measured and sum of these two measurements was recorded as the total dimension in 40 patients. PET parameters such as standardized uptake value (SUVmax, metabolic volume and total lesion glycolysis (TLG were also recorded for these target lesions on two separate 18F-FDG PET/CT images. The percent (% change was calculated for all these parameters. Morphologic evaluation was based on RECIST 1.1 and the metabolic evaluation was based on EORTC. Results: When evaluated before and after treatment, in spite of the statistically significant change (p0.05. In histopathologic typing, when we compare the post-treatment phase change with the treatment responses of RECIST 1.1 and EORTC criteria; for RECIST 1.1 in squamous cell lung cancer group, progression was observed in sixteen patients (57%, stability in seven patients (25%, partial response in five patients (18%; and for EORTC progression was detected in four patients (14%, stability in thirteen patients (47%, partial response in eleven patients (39%, in 12 of these patients an increase in stage (43%, in 4 of them a decrease in stage (14%, and in 12 of them stability in stage (43% were determined. But in adenocancer patients (n=7, for RECIST 1.1, progression was determined in four patients (57%, stability in two patients (29%, partial response in one patient (14%; for EORTC, progression in one patient (14

  2. Sixteen-row multislice computed tomography in the assessment of pulmonary veins prior to ablative treatment: validation vs conventional pulmonary venography and study of reproducibility

    Energy Technology Data Exchange (ETDEWEB)

    Maksimovic, R.; Cademartiri, F.; Pattynama, P.M.T. [Erasmus Medical Center, Rotterdam (Netherlands). Dept. of Radiology; Scholten, M; Jordaens, L.J. [Erasmus Medical Center, Rotterdam (Netherlands). Dept. of Cardiology

    2004-03-01

    The aim of this study was to validate multislice computed tomography (MSCT) venography measurements of pulmonary vein (PV) diameters vs conventional pulmonary venography (CPV), and to assess the reproducibility of MSCT data. The study included 21 consecutive patients with atrial fibrillation who were planned for cryothermal ablation of PVs. One day before ablation, all patients underwent CPV and contrast-enhanced non-gated MSCT venography. The MSCT was repeated 3 months after ablation. The CPV images of the treated PVs (n=40) were analyzed and compared with the results of MSCT measurements. Reproducibility of MSCT venography-based data was assessed by interobserver (n=84 PVs) and interexamination (n=44 PVs) variability. Pre-treatment PV diameters on MSCT and CPV showed good correlation (r=0.87, p<0.01; 18.9{+-}2.3 mm, 188.5{+-}2.4 mm, respectively). Interobserver agreement and interexamination reproducibility were good (r=0.91, r=0.82, respectively, p<0.01), with narrow limits of agreement (Bland and Altman method). The MSCT venography allows accurate and reproducible assessment of PVs. It can be used both in non-invasive planning of treatment for ablative therapy and in the follow-up of patients.

  3. Sixteen multidetector row computed tomography of pulmonary veins: 3-months' follow-up after treatment of paroxysmal atrial fibrillation with cryothermal ablation

    Energy Technology Data Exchange (ETDEWEB)

    Maksimovic, Ruzica; Cademartiri, Filippo; Pattynama, Peter M.T. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Scholten, Marcoen F.; Jordaens, Luc J. [Erasmus Medical Center, Department of Cardiology, Rotterdam (Netherlands)

    2005-06-01

    The aim of the study was to assess pulmonary veins (PVs) for the presence of stenosis 3 months after cryothermal ablation (CA) with a new method of electrical isolation of PVs using contrast-enhanced 16 multidetector row computed tomography (MDCT). Twenty four patients with symptomatic atrial fibrillation underwent CA in 46 PVs. MDCT of PVs was performed before the treatment and after 3-months' follow-up. Following cryoablation, 13/24 (54%) patients showed clinical improvement and had reduced attacks of atrial fibrillation. The dimensions of the treated PVs remained unchanged: the coronal ostial diameter was 19.1{+-}2.4 preprocedural versus 18.6{+-}2.4 mm at follow-up, p>0.05; the ratio of the coronal and axial diameters at the ostium was 1.2{+-}0.2 versus 1.2{+-}0.1, p>0.05, respectively, and the coronal diameter of the proximal 10 mm was 17.1{+-}2.5 mm versus 16.5{+-}2.2 mm, p>0.05, respectively. CA is a promising technique for electrical isolation of PVs that has not been associated with stenosis at the orifice and the proximal 10 mm of the PVs after 3-months' follow-up. MDCT is a noninvasive, fast and comfortable method for assessment of PVs in a three-dimensional manner prior to ablative treatment and during the follow-up. (orig.)

  4. Cervical lymph node hyperplasia on [(18)F]-fluorodeoxyglucose positron emission tomography/computed tomography scan after treatment of children and adolescents with malignant lymphoma.

    Science.gov (United States)

    Hu, Ying-Ying; Zhang, Xu; Long, Wen; Lin, Xiao-Ping; Zhang, Ya-Rui; Li, Yuan-Hua; Xiao, Zi-Zheng; Zheng, Rong-Liang; Liang, Pei-Yan; Fan, Wei

    2015-07-01

    To define imaging manifestations and clinical prognosis of cervical lymph node hyperplasia using [(18)F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scanning after treatment of children and adolescents with malignant lymphoma. Children and adolescent patients with malignant lymphoma who had high FDG uptake in their cervical lymph nodes via PET/CT after treatment, which was not due to tumor recurrence or residue, were retrospectively analyzed. Twenty-seven patients with a median age of 12 years were included; 11 had Hodgkin's disease and 16 had non-Hodgkin's lymphoma. The time from PET/CT scan to completion of therapy was 1-36 months, 85.2% (23/27) of which took place within 12 months. Three patients had confirmed lymph node follicular hyperplasia by biopsy, while all 27 patients achieved disease-free survival during the follow-up period. The maximum standardized uptake values (SUVmax) of cervical lymph nodes were 2.2-16.2 and the maximum short axis ranged from 0.3 to 1.2 cm. Cervical lymph node hyperplasia was noted in neck levels I-V, and neck level II bilaterally had the highest incidence (100%). Bilateral cervical lymph node hyperplasia was symmetrical in terms of both the SUVmax and affected locations. Thymic hyperplasia and nasopharyngeal lymphoid hyperplasia were both observed in 24 patients (88.9%). There was no relationship in terms of the SUVmax between cervical lymph nodes and thymic tissue, cervical nodes or nasopharyngeal lymphoid tissue. Cervical lymph node hyperplasia with high FDG uptake on PET/CT scans found after treating children and adolescents with malignant lymphoma can be benign processes. Awareness of this possibility may help avoid invasive procedures and over-treatment. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. The evaluation of anti-angiogenic treatment effects for implanted rabbit VX2 breast tumors using functional multi-slice spiral computed tomography (f-MSCT)

    Energy Technology Data Exchange (ETDEWEB)

    Lei Zhen, E-mail: leizhen2004@163.com [Department of Anatomy, Chinese Medical University, No. 92, Beiermalu Road, Heping District, Shenyang, 110001 (China) and Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Ma Heji, E-mail: maheji9831@sina.com [Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Xu Na, E-mail: xuna821230@sohu.com [Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Xi Huanjiu, E-mail: xihuanjiu2004@yahoo.cn [Anthropology Institute, Liaoning Medical College, No. 40, Sanduan, Songpo Rd, Jinzhou, 121001 (China)

    2011-05-15

    Objective: Investigate the benefit of functional multi-slice spiral computed tomography (f-MSCT) perfusion imaging in the non-invasive assessment of targeted anti-angiogenesis therapy on an implanted rabbit VX2 breast tumor model. Method: 69 female pure New Zealand white rabbits were randomly assigned to one of the 4 groups and received treatment accordingly: control (saline), Endostar, neoadjuvant chemotherapy (Cyclophosphamide, Epirubicin and 5-Fluorouracil, CEF), combination therapy (Endostar and CEF). After 2 weeks of treatment, f-MSCT perfusion scannings were performed for all rabbits and information about blood flow (BF), blood volume (BV), mean transit time (MTT) and surface permeability (SP) was collected. After perfusion imaging, tumor tissues were sampled for immunohistochemistry and the Western blot test of VEGF protein expression. Results: (1) The VEGF expression level, measured by immunohistochemistry and Western blot, decreased by treatment group (control > Endostar > CEF > combination therapy). The same was true for the mean BF, BV, MTT and PS, which decreased from the control group to the combination therapy group gradually. The mean MTT level increased in reverse order from the control to the combination therapy group. The difference between any 2 groups on these measures was statistically significant (P < 0.05). (2) There was moderate positive correlation between VEGF expression and BE, BV, or PS level (P < 0.05) and a negative correlation between VEGF expression and MTT level for all 4 groups (P < 0.05). Conclusion: Therefore, f-MSCT can be used as a non-invasive approach to evaluate the effect of anti-angiogenic therapy for implanted rabbit VX2 breast tumors.

  6. Cervical lymph node hyperplasia on [{sup 18}F]-fluorodeoxyglucose positron emission tomography/computed tomography scan after treatment of children and adolescents with malignant lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Ying-Ying, E-mail: huyy@sysucc.org.cn; Zhang, Xu, E-mail: zhangxu2@sysucc.org.cn; Long, Wen, E-mail: longwen2@sysucc.org.cn; Lin, Xiao-Ping, E-mail: linxp@sysucc.org.cn; Zhang, Ya-Rui, E-mail: zhangyr@sysucc.org.cn; Li, Yuan-Hua, E-mail: liyh@sysucc.org.cn; Xiao, Zi-Zheng, E-mail: xiaozzh@sysucc.org.cn; Zheng, Rong-Liang, E-mail: zhengrl@sysucc.org.cn; Liang, Pei-Yan, E-mail: liangpy@sysucc.org.cn; Fan, Wei, E-mail: fanwei@sysucc.org.cn

    2015-07-15

    Highlights: • Cervical lymph node hyperplasia is a benign processes. • Lymph node hyperplasia found in treated children and adolescents with lymphoma. • We define imaging manifestations of cervical lymph node hyperplasia in PET/CT. • Awareness of lymph node hyperplasia avoid invasive procedures and over-treatment. - Abstract: Purpose: To define imaging manifestations and clinical prognosis of cervical lymph node hyperplasia using [{sup 18}F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scanning after treatment of children and adolescents with malignant lymphoma. Methods: Children and adolescent patients with malignant lymphoma who had high FDG uptake in their cervical lymph nodes via PET/CT after treatment, which was not due to tumor recurrence or residue, were retrospectively analyzed. Results: Twenty-seven patients with a median age of 12 years were included; 11 had Hodgkin's disease and 16 had non-Hodgkin's lymphoma. The time from PET/CT scan to completion of therapy was 1–36 months, 85.2% (23/27) of which took place within 12 months. Three patients had confirmed lymph node follicular hyperplasia by biopsy, while all 27 patients achieved disease-free survival during the follow-up period. The maximum standardized uptake values (SUV{sub max}) of cervical lymph nodes were 2.2–16.2 and the maximum short axis ranged from 0.3 to 1.2 cm. Cervical lymph node hyperplasia was noted in neck levels I–V, and neck level II bilaterally had the highest incidence (100%). Bilateral cervical lymph node hyperplasia was symmetrical in terms of both the SUV{sub max} and affected locations. Thymic hyperplasia and nasopharyngeal lymphoid hyperplasia were both observed in 24 patients (88.9%). There was no relationship in terms of the SUV{sub max} between cervical lymph nodes and thymic tissue, cervical nodes or nasopharyngeal lymphoid tissue. Conclusion: Cervical lymph node hyperplasia with high FDG uptake on PET/CT scans found

  7. SU-E-J-70: Feasibility Study of Dynamic Arc and IMRT Treatment Plans Utilizing Vero Treatment Unit and IPlan Planning Computer for SRS/FSRT Brain Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Huh, S; Lee, S; Dagan, R; Malyapa, R; Mendenhall, N; Mendenhall, W; Ho, M; Hough, D; Yam, M; Li, Z [UFPTI, Jacksonville, FL (United States)

    2014-06-01

    Purpose: To investigate the feasibility of utilizing Dynamic Arc (DA) and IMRT with 5mm MLC leaf of VERO treatment unit for SRS/FSRT brain cancer patients with non-invasive stereotactic treatments. The DA and IMRT plans using the VERO unit (BrainLab Inc, USA) are compared with cone-based planning and proton plans to evaluate their dosimetric advantages. Methods: The Vero treatment has unique features like no rotational or translational movements of the table during treatments, Dynamic Arc/IMRT, tracking of IR markers, limitation of Ring rotation. Accuracies of the image fusions using CBCT, orthogonal x-rays, and CT are evaluated less than ∼ 0.7mm with a custom-made target phantom with 18 hidden targets. 1mm margin is given to GTV to determine PTV for planning constraints considering all the uncertainties of planning computer and mechanical uncertainties of the treatment unit. Also, double-scattering proton plans with 6F to 9F beams and typical clinical parameters, multiple isocenter plans with 6 to 21 isocenters, and DA/IMRT plans are evaluated to investigate the dosimetric advantages of the DA/IMRT for complex shape of targets. Results: 3 Groups of the patients are divided: (1) Group A (complex target shape), CI's are same for IMRT, and DGI of the proton plan are better by 9.5% than that of the IMRT, (2) Group B, CI of the DA plans (1.91+/−0.4) are better than cone-based plan, while DGI of the DA plan is 4.60+/−1.1 is better than cone-based plan (5.32+/−1.4), (3) Group C (small spherical targets), CI of the DA and cone-based plans are almost the same. Conclusion: For small spherical targets, cone-based plans are superior to other 2 plans: DS proton and DA plans. For complex or irregular plans, dynamic and IMRT plans are comparable to cone-based and proton plans for complex targets.

  8. Changes in alveolar bone thickness due to retraction of anterior teeth during orthodontic treatment: A cephalometric and computed tomography comparative study

    Directory of Open Access Journals (Sweden)

    U S Nayak Krishna

    2013-01-01

    Full Text Available Objective: Evaluate the changes in alveolar bone as a result of maxillary and mandibular incisor retraction in patients with bimaxillary protrusion by means of using lateral cephalograms and computed tomography (CT scans and to investigate any occurrence of bony defects like dehiscence and fenestration. Subjects and Methods: Ten patients (age 15 ± 3 years with bimaxillary protrusion treated by extraction of four first premolars were investigated by lateral cephalograms and CT scans during pre-treatment (T1 and after 3 months of completion of incisor retraction (T2. The labial and lingual cortex of all the incisors were assessed on the CT scan with measurements taken at site adjacent to widest point of the labiolingual root in three slices separated by 3 mm at crest level (S1, mid root level (S2, and apical level (S3. Result: In the mandibular arch, after lingual movement of the incisors, the bone labial to the anterior teeth decreased in thickness at the coronal level of the left lateral and left central incisors. Left lateral incisor showed significant changes in all the three levels. In the maxilla the change in the labial bone thickness was not statistically significant. Lingual bone of all the incisors showed significant changes in S1 level and S3 levels. Few patients demonstrated bone dehiscence that was not visible macroscopically or cephalometrically. Conclusions: When incisors are retracted, the risk of adverse effect is present. This must be carefully monitored to avoid negative iatrogenic effects. This study needs follow up after 6 months or 1 year after completion of the orthodontic treatment to assess the long-term consequences.

  9. Computer modeling of the optical properties and heating of spherical gold and silica-gold nanoparticles for laser combined imaging and photothermal treatment.

    Science.gov (United States)

    Pustovalov, V; Astafyeva, L; Jean, B

    2009-06-03

    Recently, several groups of investigators (Anderson, Halas, Zharov, El-Sayed and their co-workers (Pitsillides et al 2003 Biophys. J. 84 4023-31, Zharov et al 2003 Appl. Phys. Lett. 83 4897-9, Zharov et al 2004 Proc. SPIE 5319 291-9, Loo et al 2005 Nano Lett. 5 709-11, Gobin et al 2007 Nano Lett. 7 1929-34, Fu et al 2008 Nanotechnology 19 045103, Huang et al 2006 J. Am. Chem. Soc. 128 2115-20, Jain et al 2006 J. Phys. Chem. B 110 7238-48, Jain et al 2007 Nano Today 2 18-29)) demonstrated, through pioneering results, the great potential of laser thermal therapy of cells and tissues conjugated with gold nanoparticles. It was also proposed to use combined diagnostics and therapy on the basis of nanoparticle selection for achievement of efficient contrast for laser imaging applications, as well as for photothermal therapy. However, the current understanding of the relationship between optical properties (absorption, backscattering) of nanoparticles, the efficiency of nanoparticle heating and the possibility to use them for combined imaging and therapy is limited. Here, we report the results of computer modeling of optical absorption and backscattering properties and laser heating of gold and silica-gold spherical nanoparticles for laser combined imaging and photothermal treatment of cells and tissues conjugated with nanoparticles. The efficiencies of nanoparticle heating and backscattering by nanoparticles, depending upon their radii, structure and optical properties of the metal, were investigated. This paper focuses on the analysis and determination of appropriate ranges of nanoparticle sizes for the purposes of laser combined imaging and photothermal treatment. The possibility to use spherical gold and silica-gold nanoparticles in determined ranges of radii for these purposes for laser wavelengths 532 and 800 nm is investigated.

  10. Three-dimensional noninvasive ultrasound Joule heat tomography based on the acousto-electric effect using unipolar pulses: a simulation study.

    Science.gov (United States)

    Yang, Renhuan; Li, Xu; Song, Aiguo; He, Bin; Yan, Ruqiang

    2012-11-21

    Electrical properties of biological tissues are highly sensitive to their physiological and pathological status. Thus it is of importance to image electrical properties of biological tissues. However, spatial resolution of conventional electrical impedance tomography (EIT) is generally poor. Recently, hybrid imaging modalities combining electric conductivity contrast and ultrasonic resolution based on the acousto-electric effect has attracted considerable attention. In this study, we propose a novel three-dimensional (3D) noninvasive ultrasound Joule heat tomography (UJHT) approach based on the acousto-electric effect using unipolar ultrasound pulses. As the Joule heat density distribution is highly dependent on the conductivity distribution, an accurate and high-resolution mapping of the Joule heat density distribution is expected to give important information that is closely related to the conductivity contrast. The advantages of the proposed ultrasound Joule heat tomography using unipolar pulses include its simple inverse solution, better performance than UJHT using common bipolar pulses and its independence of a priori knowledge of the conductivity distribution of the imaging object. Computer simulation results show that using the proposed method, it is feasible to perform a high spatial resolution Joule heat imaging in an inhomogeneous conductive media. Application of this technique on tumor scanning is also investigated by a series of computer simulations.

  11. Calculation of Lung Cancer Volume of Target Based on Thorax Computed Tomography Images using Active Contour Segmentation Method for Treatment Planning System

    Science.gov (United States)

    Patra Yosandha, Fiet; Adi, Kusworo; Edi Widodo, Catur

    2017-06-01

    In this research, calculation process of the lung cancer volume of target based on computed tomography (CT) thorax images was done. Volume of the target calculation was done in purpose to treatment planning system in radiotherapy. The calculation of the target volume consists of gross tumor volume (GTV), clinical target volume (CTV), planning target volume (PTV) and organs at risk (OAR). The calculation of the target volume was done by adding the target area on each slices and then multiply the result with the slice thickness. Calculations of area using of digital image processing techniques with active contour segmentation method. This segmentation for contouring to obtain the target volume. The calculation of volume produced on each of the targets is 577.2 cm3 for GTV, 769.9 cm3 for CTV, 877.8 cm3 for PTV, 618.7 cm3 for OAR 1, 1,162 cm3 for OAR 2 right, and 1,597 cm3 for OAR 2 left. These values indicate that the image processing techniques developed can be implemented to calculate the lung cancer target volume based on CT thorax images. This research expected to help doctors and medical physicists in determining and contouring the target volume quickly and precisely.

  12. Identification and Pharmacological Analysis of High Efficacy Small Molecule Inhibitors of EGF-EGFR Interactions in Clinical Treatment of Non-Small Cell Lung Carcinoma: a Computational Approach.

    Science.gov (United States)

    Gudala, Suresh; Khan, Uzma; Kanungo, Niteesh; Bandaru, Srinivas; Hussain, Tajamul; Parihar, Ms; Nayarisseri, Anuraj; Mundluru, Hema Prasad

    2015-01-01

    Inhibition of EGFR-EGF interactions forms an important therapeutic rationale in treatment of non-small cell lung carcinoma. Established inhibitors have been successful in reducing proliferative processes observed in NSCLC, however patients suffer serious side effects. Considering the narrow therapeutic window of present EGFR inhibitors, the present study centred on identifying high efficacy EGFR inhibitors through structure based virtual screening strategies. Established inhibitors - Afatinib, Dacomitinib, Erlotinib, Lapatinib, Rociletinib formed parent compounds to retrieve similar compounds by linear fingerprint based tanimoto search with a threshold of 90%. The compounds (parents and respective similars) were docked at the EGF binding cleft of EGFR. Patch dock supervised protein-protein interactions were established between EGF and ligand (query and similar) bound and free states of EGFR. Compounds ADS103317, AKOS024836912, AGN-PC-0MXVWT, GNF-Pf-3539, SCHEMBL15205939 were retrieved respectively similar to Afatinib, Dacomitinib, Erlotinib, Lapatinib, Rociletinib. Compound- AGN-PC-0MXVWT akin to Erlotinib showed highest affinity against EGFR amongst all the compounds (parent and similar) assessed in the study. Further, AGN-PC-0MXVWT brought about significant blocking of EGFR-EGF interactions in addition showed appreciable ADMET properties and pharmacophoric features. In the study, we report AGN-PC-0MXVWT to be an efficient and high efficacy inhibitor of EGFR-EGF interactions identified through computational approaches.

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

    Medline Plus

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

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

    Science.gov (United States)

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

  15. Fault tolerant computing systems

    CERN Document Server

    Randell, B

    1981-01-01

    Fault tolerance involves the provision of strategies for error detection, damage assessment, fault treatment and error recovery. A survey is given of the different sorts of strategies used in highly reliable computing systems, together with an outline of recent research on the problems of providing fault tolerance in parallel and distributed computing systems. (15 refs).

  16. Computer Engineers.

    Science.gov (United States)

    Moncarz, Roger

    2000-01-01

    Looks at computer engineers and describes their job, employment outlook, earnings, and training and qualifications. Provides a list of resources related to computer engineering careers and the computer industry. (JOW)

  17. Optical coherence tomography based microangiography for quantitative monitoring of structural and vascular changes in a rat model of acute uveitis in vivo: a preliminary study

    Science.gov (United States)

    Choi, Woo June; Pepple, Kathryn L.; Zhi, Zhongwei; Wang, Ruikang K.

    2015-01-01

    Uveitis models in rodents are important in the investigation of pathogenesis in human uveitis and the development of appropriate therapeutic strategies for treatment. Quantitative monitoring of ocular inflammation in small animal models provides an objective metric to assess uveitis progression and/or therapeutic effects. We present a new application of optical coherence tomography (OCT) and OCT-based microangiography (OMAG) to a rat model of acute anterior uveitis induced by intravitreal injection of a killed mycobacterial extract. OCT/OMAG is used to provide noninvasive three-dimensional imaging of the anterior segment of the eyes prior to injection (baseline) and two days post-injection (peak inflammation) in rats with and without steroid treatments. OCT imaging identifies characteristic structural and vascular changes in the anterior segment of the inflamed animals when compared to baseline images. Characteristics of inflammation identified include anterior chamber cells, corneal edema, pupillary membranes, and iris vasodilation. In contrast, no significant difference from the control is observed for the steroid-treated eye. These findings are compared with the histology assessment of the same eyes. In addition, quantitative measurements of central corneal thickness and iris vessel diameter are determined. This pilot study demonstrates that OCT-based microangiography promises to be a useful tool for the assessment and management of uveitis in vivo.

  18. A computer simulation of bulking at the wastewater treatment plant in Muskiz, Bizcay (Spain); Simulacion del fenomeno de bulking en la estacion depuradora de aguas residuales de Muskiz, Vizcaya

    Energy Technology Data Exchange (ETDEWEB)

    Merino Aldecoa, I.; Arevalo, L. F.; Romero, F.

    2006-07-01

    A computer simulation is used for forecasting the occurrence of bulking in the WWTP of Muskiz, including pre-treatment, a biological reactor by activated sludge and settling, through the calculation of the descriptive parameter (sludge volume index) with a regression equation obtained by statistical treatment of experimental parameters taken during 30 months and with computer programs for the calculation of the biological growth. Obtained results suggest to a get a decrease of soluble phosphates in the influent, to increase the concentration of volatile solids of the mixed liquor, to improve the efficiency in the settling, to use an inoculum of microorganisms of greater activity and the inclusion of a previous anoxic treatment. (Author)

  19. Computer Music

    Science.gov (United States)

    Cook, Perry R.

    This chapter covers algorithms, technologies, computer languages, and systems for computer music. Computer music involves the application of computers and other digital/electronic technologies to music composition, performance, theory, history, and the study of perception. The field combines digital signal processing, computational algorithms, computer languages, hardware and software systems, acoustics, psychoacoustics (low-level perception of sounds from the raw acoustic signal), and music cognition (higher-level perception of musical style, form, emotion, etc.).

  20. Individualized Nonadaptive and Online-Adaptive Intensity-Modulated Radiotherapy Treatment Strategies for Cervical Cancer Patients Based on Pretreatment Acquired Variable Bladder Filling Computed Tomography Scans

    Energy Technology Data Exchange (ETDEWEB)

    Bondar, M.L., E-mail: m.bondar@erasmusmc.nl [Department of Radiation Oncology, Erasmus-MC Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Hoogeman, M.S.; Mens, J.W.; Quint, S. [Department of Radiation Oncology, Erasmus-MC Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Ahmad, R. [Department of Radiation Oncology, Erasmus-MC Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Programme of Diagnostic Imaging and Radiotherapy, University Kebangsaan Malaysia (Malaysia); Dhawtal, G.; Heijmen, B.J. [Department of Radiation Oncology, Erasmus-MC Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

    2012-08-01

    Purpose: To design and evaluate individualized nonadaptive and online-adaptive strategies based on a pretreatment established motion model for the highly deformable target volume in cervical cancer patients. Methods and Materials: For 14 patients, nine to ten variable bladder filling computed tomography (CT) scans were acquired at pretreatment and after 40 Gy. Individualized model-based internal target volumes (mbITVs) accounting for the cervix and uterus motion due to bladder volume changes were generated by using a motion-model constructed from two pretreatment CT scans (full and empty bladder). Two individualized strategies were designed: a nonadaptive strategy, using an mbITV accounting for the full-range of bladder volume changes throughout the treatment; and an online-adaptive strategy, using mbITVs of bladder volume subranges to construct a library of plans. The latter adapts the treatment online by selecting the plan-of-the-day from the library based on the measured bladder volume. The individualized strategies were evaluated by the seven to eight CT scans not used for mbITVs construction, and compared with a population-based approach. Geometric uniform margins around planning cervix-uterus and mbITVs were determined to ensure adequate coverage. For each strategy, the percentage of the cervix-uterus, bladder, and rectum volumes inside the planning target volume (PTV), and the clinical target volume (CTV)-to-PTV volume (volume difference between PTV and CTV) were calculated. Results: The margin for the population-based approach was 38 mm and for the individualized strategies was 7 to 10 mm. Compared with the population-based approach, the individualized nonadaptive strategy decreased the CTV-to-PTV volume by 48% {+-} 6% and the percentage of bladder and rectum inside the PTV by 5% to 45% and 26% to 74% (p < 0.001), respectively. Replacing the individualized nonadaptive strategy by an online-adaptive, two-plan library further decreased the percentage of

  1. Comparative evaluation of platelet-rich fibrin versus beta-tri-calcium phosphate in the treatment of Grade II mandibular furcation defects using cone-beam computed tomography

    Science.gov (United States)

    Siddiqui, Zeba Rahman; Jhingran, Rajesh; Bains, Vivek Kumar; Srivastava, Ruchi; Madan, Rohit; Rizvi, Iram

    2016-01-01

    Objective: The objective of the study was to evaluate clinically and radiographically the efficacy of platelet-rich fibrin (PRF) versus β-tri-calcium phosphate (β-TCP) in the treatment of Grade II mandibular furcation defects. Materials and Methods: Forty-five Grade II furcation defect in mandibular molars which were assigned to open flap debridement (OFD) with PRF Group I (n = 15), to OFD with β-TCP Group II (n = 15), and to OFD alone Group III (n = 15) were analyzed for clinical parameters (probing pocket depth [PPD], vertical clinical attachment level [VCAL], horizontal clinical attachment level [HCAL], gingival recession, relative vertical height of furcation [r-VHF], and relative horizontal depth of furcation [r-HDF]) and radiographical parameters (horizontal depth of furcation [H-DOF], vertical height of furcation [V-HOF]) using cone-beam computed tomography (CBCT) at 6 months interval. Results: For clinical parameters, reduction in PPD and gain in VCAL and HCAL were higher in Group II as compared to Group I. Change in r-VHF and r-HDF was greater in Group II as compared to Group I. Mean percentage clinical vertical defect fill was higher in Group II as compared to Group I (58.52% ± 11.68% vs. 53.24% ± 13.22%, respectively). On CBCT, mean change at 6 months for all parameters showed nonsignificant difference between the two experimental groups. Mean change in V-HOF was higher in Group I as compared to Group II, but mean change in H-DOF and furcation width was more in Group II as compared to Group I. Conclusion: For both experimental and control groups, there was statistically significant improvement at 6 months follow-up from baseline values. PMID:28042265

  2. Impact of Pretreatment Combined {sup 18}F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Staging on Radiation Therapy Treatment Decisions in Locally Advanced Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Sweet Ping, E-mail: sweet.ng@petermac.org [Peter MacCallum Cancer Centre, Melbourne (Australia); David, Steven [Peter MacCallum Cancer Centre, Melbourne (Australia); Alamgeer, Muhammad; Ganju, Vinod [Monash Cancer Centre, Melbourne (Australia)

    2015-09-01

    Purpose: To assess the diagnostic performance of pretreatment {sup 18}F-fluorodeoxyglucose positron emission tomography/computed tomography ({sup 18}F-FDG PET/CT) and its impact on radiation therapy treatment decisions in patients with locally advanced breast cancer (LABC). Methods and Materials: Patients with LABC with Eastern Cooperative Oncology Group performance status <2 and no contraindication to neoadjuvant chemotherapy, surgery, and adjuvant radiation therapy were enrolled on a prospective trial. All patients had pretreatment conventional imaging (CI) performed, including bilateral breast mammography and ultrasound, bone scan, and CT chest, abdomen, and pelvis scans performed. Informed consent was obtained before enrolment. Pretreatment whole-body {sup 18}F-FDG PET/CT scans were performed on all patients, and results were compared with CI findings. Results: A total of 154 patients with LABC with no clinical or radiologic evidence of distant metastases on CI were enrolled. Median age was 49 years (range, 26-70 years). Imaging with PET/CT detected distant metastatic disease and/or locoregional disease not visualized on CI in 32 patients (20.8%). Distant metastatic disease was detected in 17 patients (11.0%): 6 had bony metastases, 5 had intrathoracic metastases (pulmonary/mediastinal), 2 had distant nodal metastases, 2 had liver metastases, 1 had pulmonary and bony metastases, and 1 had mediastinal and distant nodal metastases. Of the remaining 139 patients, nodal disease outside conventional radiation therapy fields was detected on PET/CT in 15 patients (10.8%), with involvement of ipsilateral internal mammary nodes in 13 and ipsilateral level 5 cervical nodes in 2. Conclusions: Imaging with PET/CT provides superior diagnostic and staging information in patients with LABC compared with CI, which has significant therapeutic implications with respect to radiation therapy management. Imaging with PET/CT should be considered in all patients undergoing primary

  3. Computational crystallization.

    Science.gov (United States)

    Altan, Irem; Charbonneau, Patrick; Snell, Edward H

    2016-07-15

    Crystallization is a key step in macromolecular structure determination by crystallography. While a robust theoretical treatment of the process is available, due to the complexity of the system, the experimental process is still largely one of trial and error. In this article, efforts in the field are discussed together with a theoretical underpinning using a solubility phase diagram. Prior knowledge has been used to develop tools that computationally predict the crystallization outcome and define mutational approaches that enhance the likelihood of crystallization. For the most part these tools are based on binary outcomes (crystal or no crystal), and the full information contained in an assembly of crystallization screening experiments is lost. The potential of this additional information is illustrated by examples where new biological knowledge can be obtained and where a target can be sub-categorized to predict which class of reagents provides the crystallization driving force. Computational analysis of crystallization requires complete and correctly formatted data. While massive crystallization screening efforts are under way, the data available from many of these studies are sparse. The potential for this data and the steps needed to realize this potential are discussed.

  4. Interstitial irradiation and hyperthermia for the treatment of recurrent malignant brain tumors.

    Science.gov (United States)

    Sneed, P K; Stauffer, P R; Gutin, P H; Phillips, T L; Suen, S; Weaver, K A; Lamb, S A; Ham, B; Prados, M D; Larson, D A

    1991-02-01

    Between June 1987 and June 1989, 29 recurrent malignant gliomas or recurrent solitary brain metastases in 28 patients were treated in a Phase I study of interstitial irradiation and hyperthermia. Patient age ranged from 18 to 65 years, and the Karnofsky Performance Status scores ranged from 40 to 90%. There were 13 glioblastomas, 10 anaplastic astrocytomas, 3 melanomas, and 3 adenocarcinomas. Catheters were implanted stereotactically after computed tomography-based preplanning. Hyperthermia was administered before and after brachytherapy, using one to six 2450- or 915-MHz helical coil microwave antennas and one to three multisensor fiberoptic thermometry probes. The goal was to heat as much of the tumor as possible to 42.5 degrees C for 30 minutes. Within 30 minutes after the first hyperthermia treatment, implant catheters were afterloaded with high-activity iodine-125 seeds delivering tumor doses of 32.6 to 61.0 Gy. Most patients had no sensation of heating. Complications included seizures in 5 patients, reversible neurological changes in 9 patients, a scalp burn in 1, and infections in 3. Of 28 evaluable 2-month follow-up scans, 11 showed definite improvement in the radiological appearance of the tumor, 4 were slightly improved, 7 were stable, and 6 showed tumor progression. Ten patients underwent reoperation for persistent tumor and/or necrosis. Eleven of 28 patients are alive 40 to 97 weeks after treatment. Thirteen patients died of a brain tumor, 2 died of extracranial melanoma metastases, 1 died of new brain melanoma metastases, and 1 died of a pulmonary embolus. The median survival was 55 weeks overall. Median survival has not yet been reached for the anaplastic astrocytoma subgroup. We conclude that interstitial brain hyperthermia using helical coil microwave antennas is technically feasible. The level of toxicity is acceptable, and the computed tomographic response rate is encouraging.

  5. Computer Virus

    Institute of Scientific and Technical Information of China (English)

    高振桥

    2002-01-01

    If you work with a computer,it is certain that you can not avoid dealing, with at least one computer virus.But how much do you know about it? Well,actually,a computer virus is not a biological' one as causes illnesses to people.It is a kind of computer program

  6. Grid Computing

    Indian Academy of Sciences (India)

    2016-05-01

    A computing grid interconnects resources such as high performancecomputers, scientific databases, and computercontrolledscientific instruments of cooperating organizationseach of which is autonomous. It precedes and is quitedifferent from cloud computing, which provides computingresources by vendors to customers on demand. In this article,we describe the grid computing model and enumerate themajor differences between grid and cloud computing.

  7. Analog computing

    CERN Document Server

    Ulmann, Bernd

    2013-01-01

    This book is a comprehensive introduction to analog computing. As most textbooks about this powerful computing paradigm date back to the 1960s and 1970s, it fills a void and forges a bridge from the early days of analog computing to future applications. The idea of analog computing is not new. In fact, this computing paradigm is nearly forgotten, although it offers a path to both high-speed and low-power computing, which are in even more demand now than they were back in the heyday of electronic analog computers.

  8. Computational composites

    DEFF Research Database (Denmark)

    Vallgårda, Anna K. A.; Redström, Johan

    2007-01-01

    Computational composite is introduced as a new type of composite material. Arguing that this is not just a metaphorical maneuver, we provide an analysis of computational technology as material in design, which shows how computers share important characteristics with other materials used in design...... and architecture. We argue that the notion of computational composites provides a precise understanding of the computer as material, and of how computations need to be combined with other materials to come to expression as material. Besides working as an analysis of computers from a designer’s point of view......, the notion of computational composites may also provide a link for computer science and human-computer interaction to an increasingly rapid development and use of new materials in design and architecture....

  9. Computational chemistry

    OpenAIRE

    2000-01-01

    Computational chemistry has come of age. With significant strides in computer hardware and software over the last few decades, computational chemistry has achieved full partnership with theory and experiment as a tool for understanding and predicting the behavior of a broad range of chemical, physical, and biological phenomena. The Nobel Prize award to John Pople and Walter Kohn in 1998 highlighted the importance of these advances in computational chemistry. With massively parallel computers ...

  10. High-Dose-Rate Interstitial Brachytherapy as Monotherapy for Clinically Localized Prostate Cancer: Treatment Evolution and Mature Results

    Energy Technology Data Exchange (ETDEWEB)

    Zamboglou, Nikolaos [Department of Radiation Oncology, Klinikum Offenbach, Offenbach (Germany); Tselis, Nikolaos, E-mail: ntselis@hotmail.com [Department of Radiation Oncology, Klinikum Offenbach, Offenbach (Germany); Baltas, Dimos [Department of Medical Physics and Engineering, Klinikum Offenbach, Offenbach (Germany); Buhleier, Thomas [Department of Radiation Oncology, Klinikum Offenbach, Offenbach (Germany); Martin, Thomas [Department of Radiation Oncology, Klinikum Bremen-Mitte, Bremen (Germany); Milickovic, Natasa; Papaioannou, Sokratis [Department of Medical Physics and Engineering, Klinikum Offenbach, Offenbach (Germany); Ackermann, Hanns [Institute of Biostatistics, J.W. Goethe University of Frankfurt, Frankfurt (Germany); Tunn, Ulf W. [Department of Urology, Klinikum Offenbach, Offenbach (Germany)

    2013-03-01

    Purpose: To report the clinical outcome of high-dose-rate (HDR) interstitial (IRT) brachytherapy (BRT) as sole treatment (monotherapy) for clinically localized prostate cancer. Methods and Materials: Between January 2002 and December 2009, 718 consecutive patients with clinically localized prostate cancer were treated with transrectal ultrasound (TRUS)-guided HDR monotherapy. Three treatment protocols were applied; 141 patients received 38.0 Gy using one implant in 4 fractions of 9.5 Gy with computed tomography-based treatment planning; 351 patients received 38.0 Gy in 4 fractions of 9.5 Gy, using 2 implants (2 weeks apart) and intraoperative TRUS real-time treatment planning; and 226 patients received 34.5 Gy, using 3 single-fraction implants of 11.5 Gy (3 weeks apart) and intraoperative TRUS real-time treatment planning. Biochemical failure was defined according to the Phoenix consensus, and toxicity was evaluated using Common Toxicity Criteria for Adverse Events version 3. Results: The median follow-up time was 52.8 months. The 36-, 60-, and 96-month biochemical control and metastasis-free survival rates for the entire cohort were 97%, 94%, and 90% and 99%, 98%, and 97%, respectively. Toxicity was scored per event, with 5.4% acute grade 3 genitourinary and 0.2% acute grade 3 gastrointestinal toxicity. Late grade 3 genitourinary and gastrointestinal toxicities were 3.5% and 1.6%, respectively. Two patients developed grade 4 incontinence. No other instance of grade 4 or greater acute or late toxicity was reported. Conclusion: Our results confirm IRT-HDR-BRT is safe and effective as monotherapy for clinically localized prostate cancer.

  11. 污水处理中的计算机监控及无线数据传输%Computer Monitoring Control and Wireless Data Transmission in Sewage Treatment

    Institute of Scientific and Technical Information of China (English)

    徐匆; 马东斌; 刘鹏

    2001-01-01

    On the base of analyzing computer monitoring systems of sewage treatment plant. The computer monitoring,wireless data transmission,technique principle of wireless network,interference resistance and security were analysed from theory. Part products of engineering control and products of wireless network were introduced in the paper ,and the application in the environmental sewage treatment and relevand depatrment.%在分析大型污水处理厂计算机监控系统运行的基础上,从理论上分析了计算机监控、无线数据传输、无线网络的技术原理及抗干扰性、保密性。介绍部分工控产品及无线网络产品,以及在环保水处理及相关部门中的应用。

  12. Duality Computing in Quantum Computers

    Institute of Scientific and Technical Information of China (English)

    LONG Gui-Lu; LIU Yang

    2008-01-01

    In this letter, we propose a duality computing mode, which resembles particle-wave duality property when a quantum system such as a quantum computer passes through a double-slit. In this mode, computing operations are not necessarily unitary. The duality mode provides a natural link between classical computing and quantum computing. In addition, the duality mode provides a new tool for quantum algorithm design.

  13. 电脑综合治疗仪与仙人掌外敷用于产后乳房胀痛效果观察%Effect of computer integrated therapy combined with cactus topical treatment on postpartum breast distending pain

    Institute of Scientific and Technical Information of China (English)

    秦素芳; 李春建; 潘兰

    2011-01-01

    目的 探讨妇产科电脑综合治疗仪与仙人掌外敷治疗产后乳房胀痛的临床效果.方法 选取产后乳房胀痛无其他并发症的产妇100例,观察组和对照组各50例.观察组应用电脑综合治疗仪与仙人掌外敷,对照组应用一般热敷法治疗.结果 电脑综合治疗仪与仙人掌外敷治疗产后乳房胀痛效果优于一般热敷法,差异具有统计学意义(P<0.01).结论 电脑综合治疗仪与仙人掌外敷治疗产后乳房胀痛效果理想,操作方法 简单,易于掌握且被产妇接受,提高治疗满意度,具有良好的临床应用前景.%Objective To investigate the effect of computer integrated therapy combined with cactus topical treatment on postpartum breast distending pain.Methods A total of 100 cases with postpartum breast distending pain and without other complications were randomly divided into the observation group and the control group (50 cases in each group).The observation group received the treatment of computer integrated therapy combined with cactus topical treatment,while the control group received general heat treatment.Result The effect of computer integrated therapy combined with cactus topical treatment on postpartum breast pain was significantly better than that of general heat treatment( P < 0.01 ).Conclusion The computer integrated therapy combined with cactus topical treatment can effectively reduce postpartum breast pain, which is simple and easy to master and it is accepted by patients.The treatment has good prospects in clinical application.

  14. Computed tomography in the diagnosis and preoperative planning for oral surgery of the ascending ramus of the mandible in the treatment of malocclusions. Computertomographie zur Diagnostik und praeoperativen Planung kieferchirurgischer Eingriffe am Ramus ascendens mandibulae zur Behandlung von Bissanomalien

    Energy Technology Data Exchange (ETDEWEB)

    Hoenig, J.F.; Haase, S.; Kreidler, J. (Goettingen Univ. (Germany, F.R.). Abt. Kieferchirurgie Bundeswehrkrankenhaus, Ulm (Germany, F.R.). Abt. Mund-, Kiefer- und Gesichtschirurgie)

    1990-01-01

    With the aid of special computed tomography software, such as for density and distance measurements, it is now possible to employ purpose-oriented methods of examination with unrestricted selection of the scanning planes. The examples presented illustrate the planning of oral surgery of the ascending ramus in the treatment of malocclusions. This special method permits a determination of the optimum position of the osteotomy lines for each individual patient. (orig.).

  15. Computational manufacturing

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper presents a general framework for computational manufacturing. The methodology of computational manufacturing aims at integrating computational geometry, machining principle, sensor information fusion, optimization, computational intelligence and virtual prototyping to solve problems of the modeling, reasoning, control, planning and scheduling of manufacturing processes and systems. There are three typical problems in computational manufacturing, i.e., scheduling (time-domain), geometric reasoning (space-domain) and decision- making (interaction between time-domain and space-domain). Some theoretical fundamentals of computational manufacturing are also discussed.

  16. Contextual Computing

    CERN Document Server

    Porzel, Robert

    2011-01-01

    This book uses the latest in knowledge representation and human-computer interaction to address the problem of contextual computing in artificial intelligence. It uses high-level context to solve some challenging problems in natural language understanding.

  17. Computer Algebra.

    Science.gov (United States)

    Pavelle, Richard; And Others

    1981-01-01

    Describes the nature and use of computer algebra and its applications to various physical sciences. Includes diagrams illustrating, among others, a computer algebra system and flow chart of operation of the Euclidean algorithm. (SK)

  18. Computational dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Siebert, B.R.L.; Thomas, R.H.

    1996-01-01

    The paper presents a definition of the term ``Computational Dosimetry`` that is interpreted as the sub-discipline of computational physics which is devoted to radiation metrology. It is shown that computational dosimetry is more than a mere collection of computational methods. Computational simulations directed at basic understanding and modelling are important tools provided by computational dosimetry, while another very important application is the support that it can give to the design, optimization and analysis of experiments. However, the primary task of computational dosimetry is to reduce the variance in the determination of absorbed dose (and its related quantities), for example in the disciplines of radiological protection and radiation therapy. In this paper emphasis is given to the discussion of potential pitfalls in the applications of computational dosimetry and recommendations are given for their avoidance. The need for comparison of calculated and experimental data whenever possible is strongly stressed.

  19. Computational Medicine

    DEFF Research Database (Denmark)

    Nygaard, Jens Vinge

    2017-01-01

    The Health Technology Program at Aarhus University applies computational biology to investigate the heterogeneity of tumours......The Health Technology Program at Aarhus University applies computational biology to investigate the heterogeneity of tumours...

  20. Quantum computing

    OpenAIRE

    Li, Shu-Shen; Long, Gui-lu; Bai, Feng-Shan; Feng, Song-Lin; Zheng, Hou-Zhi

    2001-01-01

    Quantum computing is a quickly growing research field. This article introduces the basic concepts of quantum computing, recent developments in quantum searching, and decoherence in a possible quantum dot realization.

  1. Green Computing

    Directory of Open Access Journals (Sweden)

    K. Shalini

    2013-01-01

    Full Text Available Green computing is all about using computers in a smarter and eco-friendly way. It is the environmentally responsible use of computers and related resources which includes the implementation of energy-efficient central processing units, servers and peripherals as well as reduced resource consumption and proper disposal of electronic waste .Computers certainly make up a large part of many people lives and traditionally are extremely damaging to the environment. Manufacturers of computer and its parts have been espousing the green cause to help protect environment from computers and electronic waste in any way.Research continues into key areas such as making the use of computers as energy-efficient as Possible, and designing algorithms and systems for efficiency-related computer technologies.

  2. Computable models

    CERN Document Server

    Turner, Raymond

    2009-01-01

    Computational models can be found everywhere in present day science and engineering. In providing a logical framework and foundation for the specification and design of specification languages, Raymond Turner uses this framework to introduce and study computable models. In doing so he presents the first systematic attempt to provide computational models with a logical foundation. Computable models have wide-ranging applications from programming language semantics and specification languages, through to knowledge representation languages and formalism for natural language semantics. They are al

  3. Phenomenological Computation?

    DEFF Research Database (Denmark)

    Brier, Søren

    2014-01-01

    Open peer commentary on the article “Info-computational Constructivism and Cognition” by Gordana Dodig-Crnkovic. Upshot: The main problems with info-computationalism are: (1) Its basic concept of natural computing has neither been defined theoretically or implemented practically. (2. It cannot en...... cybernetics and Maturana and Varela’s theory of autopoiesis, which are both erroneously taken to support info-computationalism....

  4. Introduction to computer networking

    CERN Document Server

    Robertazzi, Thomas G

    2017-01-01

    This book gives a broad look at both fundamental networking technology and new areas that support it and use it. It is a concise introduction to the most prominent, recent technological topics in computer networking. Topics include network technology such as wired and wireless networks, enabling technologies such as data centers, software defined networking, cloud and grid computing and applications such as networks on chips, space networking and network security. The accessible writing style and non-mathematical treatment makes this a useful book for the student, network and communications engineer, computer scientist and IT professional. • Features a concise, accessible treatment of computer networking, focusing on new technological topics; • Provides non-mathematical introduction to networks in their most common forms today;< • Includes new developments in switching, optical networks, WiFi, Bluetooth, LTE, 5G, and quantum cryptography.

  5. Computing fundamentals introduction to computers

    CERN Document Server

    Wempen, Faithe

    2014-01-01

    The absolute beginner's guide to learning basic computer skills Computing Fundamentals, Introduction to Computers gets you up to speed on basic computing skills, showing you everything you need to know to conquer entry-level computing courses. Written by a Microsoft Office Master Instructor, this useful guide walks you step-by-step through the most important concepts and skills you need to be proficient on the computer, using nontechnical, easy-to-understand language. You'll start at the very beginning, getting acquainted with the actual, physical machine, then progress through the most common

  6. Quantum Computing for Computer Architects

    CERN Document Server

    Metodi, Tzvetan

    2011-01-01

    Quantum computers can (in theory) solve certain problems far faster than a classical computer running any known classical algorithm. While existing technologies for building quantum computers are in their infancy, it is not too early to consider their scalability and reliability in the context of the design of large-scale quantum computers. To architect such systems, one must understand what it takes to design and model a balanced, fault-tolerant quantum computer architecture. The goal of this lecture is to provide architectural abstractions for the design of a quantum computer and to explore

  7. Computational Complexity

    Directory of Open Access Journals (Sweden)

    J. A. Tenreiro Machado

    2017-02-01

    Full Text Available Complex systems (CS involve many elements that interact at different scales in time and space. The challenges in modeling CS led to the development of novel computational tools with applications in a wide range of scientific areas. The computational problems posed by CS exhibit intrinsic difficulties that are a major concern in Computational Complexity Theory. [...

  8. Computational Composites

    DEFF Research Database (Denmark)

    Vallgårda, Anna K. A.

    of the new microprocessors and network technologies. However, the understanding of the computer represented within this program poses a challenge for the intentions of the program. The computer is understood as a multitude of invisible intelligent information devices which confines the computer as a tool...

  9. Distributed Computing.

    Science.gov (United States)

    Ryland, Jane N.

    1988-01-01

    The microcomputer revolution, in which small and large computers have gained tremendously in capability, has created a distributed computing environment. This circumstance presents administrators with the opportunities and the dilemmas of choosing appropriate computing resources for each situation. (Author/MSE)

  10. Computational vision

    CERN Document Server

    Wechsler, Harry

    1990-01-01

    The book is suitable for advanced courses in computer vision and image processing. In addition to providing an overall view of computational vision, it contains extensive material on topics that are not usually covered in computer vision texts (including parallel distributed processing and neural networks) and considers many real applications.

  11. Phenomenological Computation?

    DEFF Research Database (Denmark)

    Brier, Søren

    2014-01-01

    Open peer commentary on the article “Info-computational Constructivism and Cognition” by Gordana Dodig-Crnkovic. Upshot: The main problems with info-computationalism are: (1) Its basic concept of natural computing has neither been defined theoretically or implemented practically. (2. It cannot en...

  12. Computer Ease.

    Science.gov (United States)

    Drenning, Susan; Getz, Lou

    1992-01-01

    Computer Ease is an intergenerational program designed to put an Ohio elementary school's computer lab, software library, staff, and students at the disposal of older adults desiring to become computer literate. Three 90-minute instructional sessions allow seniors to experience 1-to-1 high-tech instruction by enthusiastic, nonthreatening…

  13. Accuracy of Routine Treatment Planning 4-Dimensional and Deep-Inspiration Breath-Hold Computed Tomography Delineation of the Left Anterior Descending Artery in Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    White, Benjamin M., E-mail: benjamin.white@uphs.upenn.edu [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Vennarini, Sabina [L' Unità Operativa di Protonterapia, Azienda Provinciale per i Servizi Sanitari, Trento (Italy); Lin, Lilie; Freedman, Gary [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Santhanam, Anand; Low, Daniel A. [Department of Radiation Oncology, University of California, Los Angeles, California (United States); Both, Stefan [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States)

    2015-03-15

    Purpose: To assess the feasibility of radiation therapy treatment planning 4-dimensional computed tomography (4DCT) and deep-inspiration breath-hold (DIBH) CT to accurately contour the left anterior descending artery (LAD), a primary indicator of radiation-induced cardiac toxicity for patients undergoing radiation therapy. Methods and Materials: Ten subjects were prospectively imaged with a cardiac-gated MRI protocol to determine cardiac motion effects, including the displacement of a region of interest comprising the LAD. A series of planar views were obtained and resampled to create a 3-dimensional (3D) volume. A 3D optical flow deformable image registration algorithm determined tissue displacement during the cardiac cycle. The measured motion was then used as a spatial boundary to characterize motion blurring of the radiologist-delineated LAD structure for a cohort of 10 consecutive patients enrolled prospectively on a breast study including 4DCT and DIBH scans. Coronary motion–induced blurring artifacts were quantified by applying an unsharp filter to accentuate the LAD structure despite the presence of motion blurring. The 4DCT maximum inhalation and exhalation respiratory phases were coregistered to determine the LAD displacement during tidal respiration, as visualized in 4DCT. Results: The average 90th percentile heart motion for the region of interest was 0.7 ± 0.1 mm (left–right [LR]), 1.3 ± 0.6 mm (superior–inferior [SI]), and 0.6 ± 0.2 mm (anterior–posterior [AP]) in the cardiac-gated MRI cohort. The average relative increase in the number of voxels comprising the LAD contour was 69.4% ± 4.5% for the DIBH. The LAD volume overestimation had the dosimetric impact of decreasing the reported mean LAD dose by 23% ± 9% on average in the DIBH. During tidal respiration the average relative LAD contour increase was 69.3% ± 5.9% and 67.9% ± 4.6% for inhalation and exhalation respiratory phases, respectively. The average 90th

  14. Human Computation

    CERN Document Server

    CERN. Geneva

    2008-01-01

    What if people could play computer games and accomplish work without even realizing it? What if billions of people collaborated to solve important problems for humanity or generate training data for computers? My work aims at a general paradigm for doing exactly that: utilizing human processing power to solve computational problems in a distributed manner. In particular, I focus on harnessing human time and energy for addressing problems that computers cannot yet solve. Although computers have advanced dramatically in many respects over the last 50 years, they still do not possess the basic conceptual intelligence or perceptual capabilities...

  15. Computer science

    CERN Document Server

    Blum, Edward K

    2011-01-01

    Computer Science: The Hardware, Software and Heart of It focuses on the deeper aspects of the two recognized subdivisions of Computer Science, Software and Hardware. These subdivisions are shown to be closely interrelated as a result of the stored-program concept. Computer Science: The Hardware, Software and Heart of It includes certain classical theoretical computer science topics such as Unsolvability (e.g. the halting problem) and Undecidability (e.g. Godel's incompleteness theorem) that treat problems that exist under the Church-Turing thesis of computation. These problem topics explain in

  16. Computer Science Research: Computation Directorate

    Energy Technology Data Exchange (ETDEWEB)

    Durst, M.J. (ed.); Grupe, K.F. (ed.)

    1988-01-01

    This report contains short papers in the following areas: large-scale scientific computation; parallel computing; general-purpose numerical algorithms; distributed operating systems and networks; knowledge-based systems; and technology information systems.

  17. Network Tomography Based on Additive Metrics

    CERN Document Server

    Ni, Jian

    2008-01-01

    Inference of the network structure (e.g., routing topology) and dynamics (e.g., link performance) is an essential component in many network design and management tasks. In this paper we propose a new, general framework for analyzing and designing routing topology and link performance inference algorithms using ideas and tools from phylogenetic inference in evolutionary biology. The framework is applicable to a variety of measurement techniques. Based on the framework we introduce and develop several polynomial-time distance-based inference algorithms with provable performance. We provide sufficient conditions for the correctness of the algorithms. We show that the algorithms are consistent (return correct topology and link performance with an increasing sample size) and robust (can tolerate a certain level of measurement errors). In addition, we establish certain optimality properties of the algorithms (i.e., they achieve the optimal $l_\\infty$-radius) and demonstrate their effectiveness via model simulation.

  18. Computerized ionospheric tomography based on geosynchronous SAR

    Science.gov (United States)

    Hu, Cheng; Tian, Ye; Dong, Xichao; Wang, Rui; Long, Teng

    2017-02-01

    Computerized ionospheric tomography (CIT) based on spaceborne synthetic aperture radar (SAR) is an emerging technique to construct the three-dimensional (3-D) image of ionosphere. The current studies are all based on the Low Earth Orbit synthetic aperture radar (LEO SAR) which is limited by long repeat period and small coverage. In this paper, a novel ionospheric 3-D CIT technique based on geosynchronous SAR (GEO SAR) is put forward. First, several influences of complex atmospheric environment on GEO SAR focusing are detailedly analyzed, including background ionosphere and multiple scattering effects (induced by turbulent ionosphere), tropospheric effects, and random noises. Then the corresponding GEO SAR signal model is constructed with consideration of the temporal-variant background ionosphere within the GEO SAR long integration time (typically 100 s to 1000 s level). Concurrently, an accurate total electron content (TEC) retrieval method based on GEO SAR data is put forward through subband division in range and subaperture division in azimuth, obtaining variant TEC value with respect to the azimuth time. The processing steps of GEO SAR CIT are given and discussed. Owing to the short repeat period and large coverage area, GEO SAR CIT has potentials of covering the specific space continuously and completely and resultantly has excellent real-time performance. Finally, the TEC retrieval and GEO SAR CIT construction are performed by employing a numerical study based on the meteorological data. The feasibility and correctness of the proposed methods are verified.

  19. Computer software.

    Science.gov (United States)

    Rosenthal, L E

    1986-10-01

    Software is the component in a computer system that permits the hardware to perform the various functions that a computer system is capable of doing. The history of software and its development can be traced to the early nineteenth century. All computer systems are designed to utilize the "stored program concept" as first developed by Charles Babbage in the 1850s. The concept was lost until the mid-1940s, when modern computers made their appearance. Today, because of the complex and myriad tasks that a computer system can perform, there has been a differentiation of types of software. There is software designed to perform specific business applications. There is software that controls the overall operation of a computer system. And there is software that is designed to carry out specialized tasks. Regardless of types, software is the most critical component of any computer system. Without it, all one has is a collection of circuits, transistors, and silicone chips.

  20. Computer sciences

    Science.gov (United States)

    Smith, Paul H.

    1988-01-01

    The Computer Science Program provides advanced concepts, techniques, system architectures, algorithms, and software for both space and aeronautics information sciences and computer systems. The overall goal is to provide the technical foundation within NASA for the advancement of computing technology in aerospace applications. The research program is improving the state of knowledge of fundamental aerospace computing principles and advancing computing technology in space applications such as software engineering and information extraction from data collected by scientific instruments in space. The program includes the development of special algorithms and techniques to exploit the computing power provided by high performance parallel processors and special purpose architectures. Research is being conducted in the fundamentals of data base logic and improvement techniques for producing reliable computing systems.

  1. 26 CFR 1.832-7T - Treatment of salvage and reinsurance in computing “losses incurred” deduction, taxable years...

    Science.gov (United States)

    2010-04-01

    ...). (a) In computing “losses incurred” the determination of unpaid losses at the close of each year must... includes all property (other than cash), real or personal, tangible or intangible, except that which may.... Such salvage in course of liquidation shall be taken into account to the extent of the value thereof at...

  2. Clinical applications of cone beam computed tomography in endodontics: a comprehensive review. Part 1: applications associated with endodontic treatment and diagnosis

    NARCIS (Netherlands)

    Cohenca, N.; Shemesh, H.

    2015-01-01

    Cone beam computed tomography (CBCT) is a new technology that produces three-dimensional (3D) digital imaging at reduced cost and less radiation for the patient than traditional CT scans. It also delivers faster and easier image acquisition. By providing a 3D representation of the maxillofacial

  3. Computer Literacy: Teaching Computer Ethics.

    Science.gov (United States)

    Troutner, Joanne

    1986-01-01

    Suggests learning activities for teaching computer ethics in three areas: (1) equal access; (2) computer crime; and (3) privacy. Topics include computer time, advertising, class enrollments, copyright law, sabotage ("worms"), the Privacy Act of 1974 and the Freedom of Information Act of 1966. (JM)

  4. Computer programming and computer systems

    CERN Document Server

    Hassitt, Anthony

    1966-01-01

    Computer Programming and Computer Systems imparts a "reading knowledge? of computer systems.This book describes the aspects of machine-language programming, monitor systems, computer hardware, and advanced programming that every thorough programmer should be acquainted with. This text discusses the automatic electronic digital computers, symbolic language, Reverse Polish Notation, and Fortran into assembly language. The routine for reading blocked tapes, dimension statements in subroutines, general-purpose input routine, and efficient use of memory are also elaborated.This publication is inten

  5. Organic Computing

    CERN Document Server

    Würtz, Rolf P

    2008-01-01

    Organic Computing is a research field emerging around the conviction that problems of organization in complex systems in computer science, telecommunications, neurobiology, molecular biology, ethology, and possibly even sociology can be tackled scientifically in a unified way. From the computer science point of view, the apparent ease in which living systems solve computationally difficult problems makes it inevitable to adopt strategies observed in nature for creating information processing machinery. In this book, the major ideas behind Organic Computing are delineated, together with a sparse sample of computational projects undertaken in this new field. Biological metaphors include evolution, neural networks, gene-regulatory networks, networks of brain modules, hormone system, insect swarms, and ant colonies. Applications are as diverse as system design, optimization, artificial growth, task allocation, clustering, routing, face recognition, and sign language understanding.

  6. Quantum Computing

    CERN Document Server

    Steane, A M

    1998-01-01

    The subject of quantum computing brings together ideas from classical information theory, computer science, and quantum physics. This review aims to summarise not just quantum computing, but the whole subject of quantum information theory. It turns out that information theory and quantum mechanics fit together very well. In order to explain their relationship, the review begins with an introduction to classical information theory and computer science, including Shannon's theorem, error correcting codes, Turing machines and computational complexity. The principles of quantum mechanics are then outlined, and the EPR experiment described. The EPR-Bell correlations, and quantum entanglement in general, form the essential new ingredient which distinguishes quantum from classical information theory, and, arguably, quantum from classical physics. Basic quantum information ideas are described, including key distribution, teleportation, data compression, quantum error correction, the universal quantum computer and qua...

  7. Impacted Lower Third Molar Fused with a Supernumerary Tooth —Diagnosis and Treatment Planning Using Cone-Beam Computed Tomography

    Science.gov (United States)

    Ferreira-Junior, Osny; de Ávila, Luciana Dorigatti; da Silva Sampieri, Marcelo Bonifácio; Dias-Ribeiro, Eduardo; Chen, Wei-liang; Fan, Song

    2009-01-01

    This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radiography was complemented by the Donovan's radiographic technique; but because of the proximity of the dental element to the mandibular ramus, it was not possible to have a final fusion diagnosis. Hence, the Cone-Beam Computed Tomography—which provides precise three-dimensional information—was used to determinate the fusion diagnosis and also to help in the surgical planning. In this case report we observed that the periapical, occlusal and panoramic were not able to show details which could only be examined through the cone-beam computed tomography. PMID:20690426

  8. Positive and negative features of a computer assisted drug treatment program delivered by mentors to homeless drug users living in hostels.

    Science.gov (United States)

    Neale, Joanne; Stevenson, Caral

    2014-10-01

    This paper explores positive and negative features of computer assisted therapy (CAT) delivered by mentors to homeless drug users (HDUs) living in hostels. Qualitative interviews were conducted with 30 HDUs and 15 mentors (all hostel staff) at the beginning and end of a 12-week CAT program. Findings indicate that successful delivery of the CAT relates to: 'program features' (e.g. its accessibility, flexibility, user-friendly interface); 'delivery context' (e.g. privacy, having appropriate computing equipment), 'client characteristics' (HDUs being recovery-focused and committed to using the program), and 'mentor support' (clients having personalized attention from an encouraging and sympathetic other). It is concluded that CATs can be used with HDUs but are unlikely to replace addiction therapists. Rather, they are more likely to be effective when combined with a strong therapeutic relationship. Services using CATs with HDUs need to provide staff training, support, and time to maximize the potential benefits.

  9. Computer Virus

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Computer viruses are small software programs that are designed to spread from one computerto another and to interfere with computer operation.A virus might delete data on your computer,use your e-mail program to spread itself to othercomputers,or even erase everything on your hard disk.Viruses are most easily spread by attach-ments in e-mail messages or instant messaging messages.That is why it is essential that you never

  10. Fog computing

    OpenAIRE

    Poplštein, Karel

    2016-01-01

    The purpose of this bachelor's thesis is to address fog computing technology, that emerged as a possible solution for the internet of things requirements and aims to lower latency and network bandwidth by moving a substantial part of computing operation to the network edge. The thesis identifies advantages as well as potential threats and analyses the possible solutions to these problems, proceeding to comparison of cloud and fog computing and specifying areas of use for both of them. Finally...

  11. Evaluation of Condylar Position after Orthognathic Surgery for Treatment of Class II Vertical Maxillary Excess and Mandibular Deficiency by Using Cone-Beam Computed Tomography

    OpenAIRE

    Reza Tabrizi; Shoaleh Shahidi; Dept. of Oral and Maxillofacial Radiology, Biomaterials Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.; Hamidreza Arabion

    2016-01-01

    Statement of the Problem: In orthognathic surgeries, proper condylar position is one of the most important factors in postoperative stability. Knowing the condylar movement after orthognathic surgery can help preventing postoperative instabilities. Purpose: The aim of this study was to evaluate the condylar positional changes after Le Fort I maxillary superior repositioning along with mandibular advancement by using cone beam computed tomography (CBCT). Materials and Method: This cross...

  12. The study of multi- functional instrument based on micro- computer for treatment of disabled body%微机控制智能型多功能肢体残疾治疗仪研制

    Institute of Scientific and Technical Information of China (English)

    鲁雯; 韩丰谈; 鲁玉来

    2005-01-01

    本文主要介绍微机控制的智能型多功能肢体残疾康复治疗装置,它主要应用于肢体残疾的治疗和康复.病人训练速度、角度以及时间,均可自动控制和监视.该仪器性能优良,操作简便,是一种新型的治疗和康复装置.%Intelligentized muti-functional limb treatment and rehabilitation based on micro-computer is introduced in this paper. It is mainly used for rehabilitation in the disablement of limb. The range speed and training time can be automatically controlled. Training parameter and result can be monitored on computer. The apparatus has the advantages of high reliability, easy operation and compact design. It is a new kind of intelligent limb rehabilitation.

  13. 网络病毒防治技术在计算机管理中的应用%Applying web virus prevention and treatment technology into computer management

    Institute of Scientific and Technical Information of China (English)

    杨国文

    2011-01-01

    From the perspective of computer laboratory management,this article discusses how web virus affects and harms computer lab teaching,open experiment teaching and innovate experiment teaching.It also puts forward means and methods of prevention and treatment of web virus transmission.%本文从计算机实验室管理的角度,探讨了计算机网络病毒对计算机实验教学、开放性实验、以及创新型实验造成的影响与危害,提出了防治网络病毒传播的技术与方法。

  14. Biological computation

    CERN Document Server

    Lamm, Ehud

    2011-01-01

    Introduction and Biological BackgroundBiological ComputationThe Influence of Biology on Mathematics-Historical ExamplesBiological IntroductionModels and Simulations Cellular Automata Biological BackgroundThe Game of Life General Definition of Cellular Automata One-Dimensional AutomataExamples of Cellular AutomataComparison with a Continuous Mathematical Model Computational UniversalitySelf-Replication Pseudo Code Evolutionary ComputationEvolutionary Biology and Evolutionary ComputationGenetic AlgorithmsExample ApplicationsAnalysis of the Behavior of Genetic AlgorithmsLamarckian Evolution Genet

  15. Cloud Computing

    CERN Document Server

    Mirashe, Shivaji P

    2010-01-01

    Computing as you know it is about to change, your applications and documents are going to move from the desktop into the cloud. I'm talking about cloud computing, where applications and files are hosted on a "cloud" consisting of thousands of computers and servers, all linked together and accessible via the Internet. With cloud computing, everything you do is now web based instead of being desktop based. You can access all your programs and documents from any computer that's connected to the Internet. How will cloud computing change the way you work? For one thing, you're no longer tied to a single computer. You can take your work anywhere because it's always accessible via the web. In addition, cloud computing facilitates group collaboration, as all group members can access the same programs and documents from wherever they happen to be located. Cloud computing might sound far-fetched, but chances are you're already using some cloud applications. If you're using a web-based email program, such as Gmail or Ho...

  16. GPGPU COMPUTING

    Directory of Open Access Journals (Sweden)

    BOGDAN OANCEA

    2012-05-01

    Full Text Available Since the first idea of using GPU to general purpose computing, things have evolved over the years and now there are several approaches to GPU programming. GPU computing practically began with the introduction of CUDA (Compute Unified Device Architecture by NVIDIA and Stream by AMD. These are APIs designed by the GPU vendors to be used together with the hardware that they provide. A new emerging standard, OpenCL (Open Computing Language tries to unify different GPU general computing API implementations and provides a framework for writing programs executed across heterogeneous platforms consisting of both CPUs and GPUs. OpenCL provides parallel computing using task-based and data-based parallelism. In this paper we will focus on the CUDA parallel computing architecture and programming model introduced by NVIDIA. We will present the benefits of the CUDA programming model. We will also compare the two main approaches, CUDA and AMD APP (STREAM and the new framwork, OpenCL that tries to unify the GPGPU computing models.

  17. Computational Sustainability

    OpenAIRE

    Eaton, Eric; University of Pennsylvania; Gomes, Carla P.; Cornell University; Williams, Brian; Massachusetts Institute of Technology

    2014-01-01

    Computational sustainability problems, which exist in dynamic environments with high amounts of uncertainty, provide a variety of unique challenges to artificial intelligence research and the opportunity for significant impact upon our collective future. This editorial provides an overview of artificial intelligence for computational sustainability, and introduces this special issue of AI Magazine.

  18. Platform computing

    CERN Multimedia

    2002-01-01

    "Platform Computing releases first grid-enabled workload management solution for IBM eServer Intel and UNIX high performance computing clusters. This Out-of-the-box solution maximizes the performance and capability of applications on IBM HPC clusters" (1/2 page) .

  19. Grid Computing

    Science.gov (United States)

    Foster, Ian

    2001-08-01

    The term "Grid Computing" refers to the use, for computational purposes, of emerging distributed Grid infrastructures: that is, network and middleware services designed to provide on-demand and high-performance access to all important computational resources within an organization or community. Grid computing promises to enable both evolutionary and revolutionary changes in the practice of computational science and engineering based on new application modalities such as high-speed distributed analysis of large datasets, collaborative engineering and visualization, desktop access to computation via "science portals," rapid parameter studies and Monte Carlo simulations that use all available resources within an organization, and online analysis of data from scientific instruments. In this article, I examine the status of Grid computing circa 2000, briefly reviewing some relevant history, outlining major current Grid research and development activities, and pointing out likely directions for future work. I also present a number of case studies, selected to illustrate the potential of Grid computing in various areas of science.

  20. Computational Deception

    NARCIS (Netherlands)

    Nijholt, Antinus; Acosta, P.S.; Cravo, P.

    2010-01-01

    In the future our daily life interactions with other people, with computers, robots and smart environments will be recorded and interpreted by computers or embedded intelligence in environments, furniture, robots, displays, and wearables. These sensors record our activities, our behaviour, and our

  1. Computational Science

    Institute of Scientific and Technical Information of China (English)

    K. Li

    2007-01-01

    @@ Computer science is the discipline that anchors the computer industry which has been improving processor performance, communication bandwidth and storage capacity on the so called "Moore's law" curve or at the rate of doubling every 18 to 24 months during the past decades.

  2. Granular Computing

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The basic ideas and principles of granular computing (GrC) have been studied explicitly or implicitly in many fields in isolation. With the recent renewed and fast growing interest, it is time to extract the commonality from a diversity of fields and to study systematically and formally the domain independent principles of granular computing in a unified model. A framework of granular computing can be established by applying its own principles. We examine such a framework from two perspectives,granular computing as structured thinking and structured problem solving. From the philosophical perspective or the conceptual level,granular computing focuses on structured thinking based on multiple levels of granularity. The implementation of such a philosophy in the application level deals with structured problem solving.

  3. Multiparty Computations

    DEFF Research Database (Denmark)

    Dziembowski, Stefan

    on Theory of Computing, pages 25-334, May 2000. [3]Tal Rabin and Michael Ben-Or. Verifiable secret sharing and multiparty protocols with honest majority (extended abstract). In Proceedings of the Twenty First Annual ACM Symposium on Theory of Computing, pages 73-85, Seattle, Washington, 15-17 May 1989.......In this thesis we study a problem of doing Verifiable Secret Sharing (VSS) and Multiparty Computations in a model where private channels between the players and a broadcast channel is available. The adversary is active, adaptive and has an unbounded computing power. The thesis is based on two...... an impossibility result indicating that a similar equivalence does not hold for Multiparty Computation (MPC): we show that even if protocols are given black-box access for free to an idealized secret sharing scheme secure for the access structure in question, it is not possible to handle all relevant access...

  4. Fault treatment of Feilaixia power plant’s computer monitoring LCU%飞来峡电厂计算机监控LCU故障处理

    Institute of Scientific and Technical Information of China (English)

    邱斌

    2014-01-01

    飞来峡电厂承担四台4×35MW机组的运行、维护工作,本文介绍飞来峡电厂计算机监控LCU报警故障并进行分析处理。%Feilaixia power plant is charged with the operation and maintenance of 4 piece 4*35MW machine,introduce the alarm malfunction of Feilaixia power plant’s computer monitoring LCU,And also carries on the analysis and processing.

  5. Time-Resolved C-Arm Computed Tomographic Angiography Derived From Computed Tomographic Perfusion Acquisition: New Capability for One-Stop-Shop Acute Ischemic Stroke Treatment in the Angiosuite.

    Science.gov (United States)

    Yang, Pengfei; Niu, Kai; Wu, Yijing; Struffert, Tobias; Dorfler, Arnd; Schafer, Sebastian; Royalty, Kevin; Strother, Charles; Chen, Guang-Hong

    2015-12-01

    Multimodal imaging using cone beam C-arm computed tomography (CT) may shorten the delay from ictus to revascularization for acute ischemic stroke patients with a large vessel occlusion. Largely because of limited temporal resolution, reconstruction of time-resolved CT angiography (CTA) from these systems has not yielded satisfactory results. We evaluated the image quality and diagnostic value of time-resolved C-arm CTA reconstructed using novel image processing algorithms. Studies were done under an Institutional Review Board approved protocol. Postprocessing of data from 21 C-arm CT dynamic perfusion acquisitions from 17 patients with acute ischemic stroke were done to derive time-resolved C-arm CTA images. Two observers independently evaluated image quality and diagnostic content for each case. ICC and receiver-operating characteristic analysis were performed to evaluate interobserver agreement and diagnostic value of this novel imaging modality. Time-resolved C-arm CTA images were successfully generated from 20 data sets (95.2%, 20/21). Two observers agreed well that the image quality for large cerebral arteries was good but was more limited for small cerebral arteries (distal to M1, A1, and P1). receiver-operating characteristic curves demonstrated excellent diagnostic value for detecting large vessel occlusions (area under the curve=0.987-1). Time-resolved CTAs derived from C-arm CT perfusion acquisitions provide high quality images that allowed accurate diagnosis of large vessel occlusions. Although image quality of smaller arteries in this study was not optimal ongoing modifications of the postprocessing algorithm will likely remove this limitation. Adding time-resolved C-arm CTAs to the capabilities of the angiography suite further enhances its suitability as a one-stop shop for care for patients with acute ischemic stroke. © 2015 American Heart Association, Inc.

  6. Resilient computer system design

    CERN Document Server

    Castano, Victor

    2015-01-01

    This book presents a paradigm for designing new generation resilient and evolving computer systems, including their key concepts, elements of supportive theory, methods of analysis and synthesis of ICT with new properties of evolving functioning, as well as implementation schemes and their prototyping. The book explains why new ICT applications require a complete redesign of computer systems to address challenges of extreme reliability, high performance, and power efficiency. The authors present a comprehensive treatment for designing the next generation of computers, especially addressing safety-critical, autonomous, real time, military, banking, and wearable health care systems.   §  Describes design solutions for new computer system - evolving reconfigurable architecture (ERA) that is free from drawbacks inherent in current ICT and related engineering models §  Pursues simplicity, reliability, scalability principles of design implemented through redundancy and re-configurability; targeted for energy-,...

  7. COMPUTATIONAL THINKING

    Directory of Open Access Journals (Sweden)

    Evgeniy K. Khenner

    2016-01-01

    Full Text Available Abstract. The aim of the research is to draw attention of the educational community to the phenomenon of computational thinking which actively discussed in the last decade in the foreign scientific and educational literature, to substantiate of its importance, practical utility and the right on affirmation in Russian education.Methods. The research is based on the analysis of foreign studies of the phenomenon of computational thinking and the ways of its formation in the process of education; on comparing the notion of «computational thinking» with related concepts used in the Russian scientific and pedagogical literature.Results. The concept «computational thinking» is analyzed from the point of view of intuitive understanding and scientific and applied aspects. It is shown as computational thinking has evolved in the process of development of computers hardware and software. The practice-oriented interpretation of computational thinking which dominant among educators is described along with some ways of its formation. It is shown that computational thinking is a metasubject result of general education as well as its tool. From the point of view of the author, purposeful development of computational thinking should be one of the tasks of the Russian education.Scientific novelty. The author gives a theoretical justification of the role of computational thinking schemes as metasubject results of learning. The dynamics of the development of this concept is described. This process is connected with the evolution of computer and information technologies as well as increase of number of the tasks for effective solutions of which computational thinking is required. Author substantiated the affirmation that including «computational thinking » in the set of pedagogical concepts which are used in the national education system fills an existing gap.Practical significance. New metasubject result of education associated with

  8. Routine Bone Marrow Biopsy Has Little or No Therapeutic Consequence for Positron Emission Tomography/Computed Tomography-Staged Treatment-Naive Patients With Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    El-Galaly, Tarec Christoffer; d'Amore, Francesco; Mylam, Karen Juul

    2012-01-01

    disease by PET/CT staging. BMB upstaged five patients, assessed as being stage III before BMB; none of the 454 patients would have been allocated to another treatment on the basis of BMB results. Focal skeletal PET/CT lesions identified positive and negative BMBs with a sensitivity and specificity of 85...

  9. The treatment of computer middle frequency on periarthritis of shoulder%电脑中频电治疗肩关节周围炎

    Institute of Scientific and Technical Information of China (English)

    赵丽; 夏军; 范剑非

    2003-01-01

    @@ BACKGROUND:Periarthritis of shoulder is thought as a common disease of middle aged in motor system,which chief clinical manifestations are shoulder pain,dysfunction of joint and muscular atrophy.The main treatments of periarthritis of shoulder are kinesitherapy,physiotherapy,massage and pharmacotherapy.

  10. Real-time respiration monitoring using the radiotherapy treatment beam and four-dimensional computed tomography (4DCT)--a conceptual study.

    Science.gov (United States)

    Lu, Weiguo; Ruchala, Kenneth J; Chen, Ming-Li; Chen, Quan; Olivera, Gustavo H

    2006-09-21

    Real-time knowledge of intra-fraction motion, such as respiration, is essential for four-dimensional (4D) radiotherapy. Surrogate-based and internal-fiducial-based methods may suffer from one or many drawbacks such as false correlation, being invasive, delivering extra patient radiation, and requiring complicated hardware and software development and implementation. In this paper we develop a simple non-surrogate, non-invasive method to monitor respiratory motion during radiotherapy treatments in real time. This method directly utilizes the treatment beam and thus imposes no additional radiation to the patient. The method requires a pre-treatment 4DCT and a real-time detector system. The method combines off-line processes with on-line processes. The off-line processes include 4DCT imaging and pre-calculating detector signals at each phase of the 4DCT based on the planned fluence map and the detector response function. The on-line processes include measuring detector signal from the treatment beam, and correlating the measured detector signal with the pre-calculated signals. The respiration phase is determined as the position of peak correlation. We tested our method with extensive simulations based on a TomoTherapy machine and a 4DCT of a lung cancer patient. Three types of simulations were implemented to mimic the clinical situations. Each type of simulation used three different TomoTherapy delivery sinograms, each with 800 to 1000 projections, as input fluences. Three arbitrary breathing patterns were simulated and two dose levels, 2 Gy/fraction and 2 cGy/fraction, were used for simulations to study the robustness of this method against detector quantum noise. The algorithm was used to determine the breathing phases and this result was compared with the simulated breathing patterns. For the 2 Gy/fraction simulations, the respiration phases were accurately determined within one phase error in real time for most projections of the treatment, except for a few

  11. Treatment Effects

    DEFF Research Database (Denmark)

    Heckman, James J.; Lopes, Hedibert F.; Piatek, Rémi

    2014-01-01

    This paper contributes to the emerging Bayesian literature on treatment effects. It derives treatment parameters in the framework of a potential outcomes model with a treatment choice equation, where the correlation between the unobservable components of the model is driven by a low...... to observe the same person in both the treated and untreated states, but it also turns out to be straightforward to implement. Formulae are provided to compute mean treatment effects as well as their distributional versions. A Monte Carlo simulation study is carried out to illustrate how the methodology can...

  12. Treatment Effects

    DEFF Research Database (Denmark)

    Heckman, James J.; Lopes, Hedibert F.; Piatek, Rémi

    2014-01-01

    This paper contributes to the emerging Bayesian literature on treatment effects. It derives treatment parameters in the framework of a potential outcomes model with a treatment choice equation, where the correlation between the unobservable components of the model is driven by a low...... to observe the same person in both the treated and untreated states, but it also turns out to be straightforward to implement. Formulae are provided to compute mean treatment effects as well as their distributional versions. A Monte Carlo simulation study is carried out to illustrate how the methodology can...

  13. Chromatin computation.

    Directory of Open Access Journals (Sweden)

    Barbara Bryant

    Full Text Available In living cells, DNA is packaged along with protein and RNA into chromatin. Chemical modifications to nucleotides and histone proteins are added, removed and recognized by multi-functional molecular complexes. Here I define a new computational model, in which chromatin modifications are information units that can be written onto a one-dimensional string of nucleosomes, analogous to the symbols written onto cells of a Turing machine tape, and chromatin-modifying complexes are modeled as read-write rules that operate on a finite set of adjacent nucleosomes. I illustrate the use of this "chromatin computer" to solve an instance of the Hamiltonian path problem. I prove that chromatin computers are computationally universal--and therefore more powerful than the logic circuits often used to model transcription factor control of gene expression. Features of biological chromatin provide a rich instruction set for efficient computation of nontrivial algorithms in biological time scales. Modeling chromatin as a computer shifts how we think about chromatin function, suggests new approaches to medical intervention, and lays the groundwork for the engineering of a new class of biological computing machines.

  14. Computing methods

    CERN Document Server

    Berezin, I S

    1965-01-01

    Computing Methods, Volume 2 is a five-chapter text that presents the numerical methods of solving sets of several mathematical equations. This volume includes computation sets of linear algebraic equations, high degree equations and transcendental equations, numerical methods of finding eigenvalues, and approximate methods of solving ordinary differential equations, partial differential equations and integral equations.The book is intended as a text-book for students in mechanical mathematical and physics-mathematical faculties specializing in computer mathematics and persons interested in the

  15. Cloud Computing

    CERN Document Server

    Baun, Christian; Nimis, Jens; Tai, Stefan

    2011-01-01

    Cloud computing is a buzz-word in today's information technology (IT) that nobody can escape. But what is really behind it? There are many interpretations of this term, but no standardized or even uniform definition. Instead, as a result of the multi-faceted viewpoints and the diverse interests expressed by the various stakeholders, cloud computing is perceived as a rather fuzzy concept. With this book, the authors deliver an overview of cloud computing architecture, services, and applications. Their aim is to bring readers up to date on this technology and thus to provide a common basis for d

  16. Computer interfacing

    CERN Document Server

    Dixey, Graham

    1994-01-01

    This book explains how computers interact with the world around them and therefore how to make them a useful tool. Topics covered include descriptions of all the components that make up a computer, principles of data exchange, interaction with peripherals, serial communication, input devices, recording methods, computer-controlled motors, and printers.In an informative and straightforward manner, Graham Dixey describes how to turn what might seem an incomprehensible 'black box' PC into a powerful and enjoyable tool that can help you in all areas of your work and leisure. With plenty of handy

  17. Computational physics

    CERN Document Server

    Newman, Mark

    2013-01-01

    A complete introduction to the field of computational physics, with examples and exercises in the Python programming language. Computers play a central role in virtually every major physics discovery today, from astrophysics and particle physics to biophysics and condensed matter. This book explains the fundamentals of computational physics and describes in simple terms the techniques that every physicist should know, such as finite difference methods, numerical quadrature, and the fast Fourier transform. The book offers a complete introduction to the topic at the undergraduate level, and is also suitable for the advanced student or researcher who wants to learn the foundational elements of this important field.

  18. Computer treatment of the contents of some elements in the normal and pathologically altered human colon mucosa tissues obtained by INAA

    Energy Technology Data Exchange (ETDEWEB)

    Draskovic, R.J.; Bozanic, M.; Bozanic, V.; Bohus, T. (Institut za Nuklearne Nauke Boris Kidric, Belgrade (Yugoslavia))

    1984-11-01

    Distribution of some elements (Cr, Fe, Co, Sb, Sc and Zn) in normal and pathologically altered human colon mucosa tissues were investigated by INAA. The following tissues were analyzed: normal colon mucosa, colitis chronica, colitis ulcerosa, adenoma tubulare and adenocarcinoma (diagnoses were previously confirmed clinically and histopathologically). The values of contents of the elements in these tissues (Csub(x) in nkg/g) are treated by specific computer functional programs. Regression functions of these parameters were found for the altered tissues in comparison to the normal, as well as specific functional correlations of the Csub(x)/Csub(y) relations for pairs of investigated elements. The functions which characterize these relations for the investigated colon mucosa tissue were also determined.

  19. Computational modelling flow and transport

    NARCIS (Netherlands)

    Stelling, G.S.; Booij, N.

    1999-01-01

    Lecture notes CT wa4340. Derivation of equations using balance principles; numerical treatment of ordinary differential equations; time dependent partial differential equations; the strucure of a computer model:DUFLO; usage of numerical models.

  20. Computing Religion

    DEFF Research Database (Denmark)

    Nielbo, Kristoffer Laigaard; Braxton, Donald M.; Upal, Afzal

    2012-01-01

    The computational approach has become an invaluable tool in many fields that are directly relevant to research in religious phenomena. Yet the use of computational tools is almost absent in the study of religion. Given that religion is a cluster of interrelated phenomena and that research...... concerning these phenomena should strive for multilevel analysis, this article argues that the computational approach offers new methodological and theoretical opportunities to the study of religion. We argue that the computational approach offers 1.) an intermediary step between any theoretical construct...... and its targeted empirical space and 2.) a new kind of data which allows the researcher to observe abstract constructs, estimate likely outcomes, and optimize empirical designs. Because sophisticated mulitilevel research is a collaborative project we also seek to introduce to scholars of religion some...

  1. APPLICATION OF SINGLE PHOTON EMMISSION COMPUTED TOMOGRAPHY TO CLINICAL STUDY ON THE THERAPEUTIC EFFECT OF ACUPUNCTURE IN TREATMENT OF CHILD CEREBRAL PARALYSIS

    Institute of Scientific and Technical Information of China (English)

    于海波; 鞠琰莉; 贾少微

    2001-01-01

    Subjective: To identify the practicability and clinical values of acupuncture in the treatment of child cerebral paralysis, try to provide visualized evidence and mechanisms for acupuncture treatment of this disease. Methods: 13 cerebral palsy children including 9 cases of spasmodic type, 2 cases of ataxia type and 2 cases of mixed type, 9 males and 4 females were subjected into this study. Acupoints used were Hegu (LI 4), Quchi (LI 11 ), Zusanli (ST 36) and Sanyinjiao (SP 6) that were punctured and stimulated electrically with parameters of frequency 2/15 Hz, electric current 5 mA, and duration of stimulation 30 min. Under monitoring of Siemens ECAM/ICON SPECT System, blood flow volumes of different brain regions were observed before, during and after elctroacupuncture (EA) stimulation of the above-mentioned acupoints. Results: SPECT revealed that in these 13 infantile patients, 18 regions of the brain in-cluding 12 in the frontal lobe and 6 in the temporal lobe presented insufficiency of blood perfusion and hypofunction; during EA, these cerebral regions and parietal lobe, visual cortex, thalamus, basal ganglion and cerebellum showed improvement in blood perfusion and function in different degrees. Results of the quantitative analysis on blood flow function changing rate (BFCR)% showed a significant increase in 83.3 % of the focal regions during EA. Conclusion: Acupuncture therapy can effectively improve cerebral blood perfusion of the focus and is of clinical value in treatment of infantile cerebral paralysis.

  2. COMPUTERS HAZARDS

    Directory of Open Access Journals (Sweden)

    Andrzej Augustynek

    2007-01-01

    Full Text Available In June 2006, over 12.6 million Polish users of the Web registered. On the average, each of them spent 21 hours and 37 minutes monthly browsing the Web. That is why the problems of the psychological aspects of computer utilization have become an urgent research subject. The results of research into the development of Polish information society carried out in AGH University of Science and Technology, under the leadership of Leslaw H. Haber, in the period from 2000 until present time, indicate the emergence dynamic changes in the ways of computer utilization and their circumstances. One of the interesting regularities has been the inverse proportional relation between the level of computer skills and the frequency of the Web utilization.It has been found that in 2005, compared to 2000, the following changes occurred:- A significant drop in the number of students who never used computers and the Web;- Remarkable increase in computer knowledge and skills (particularly pronounced in the case of first years student- Decreasing gap in computer skills between students of the first and the third year; between male and female students;- Declining popularity of computer games.It has been demonstrated also that the hazard of computer screen addiction was the highest in he case of unemployed youth outside school system. As much as 12% of this group of young people were addicted to computer. A lot of leisure time that these youths enjoyed inducted them to excessive utilization of the Web. Polish housewives are another population group in risk of addiction to the Web. The duration of long Web charts carried out by younger and younger youths has been another matter of concern. Since the phenomenon of computer addiction is relatively new, no specific therapy methods has been developed. In general, the applied therapy in relation to computer addition syndrome is similar to the techniques applied in the cases of alcohol or gambling addiction. Individual and group

  3. Value of multislice computed tomography angiography of the thorax in preparation for catheter ablation for the treatment of atrial fibrillation: The impact of unexpected cardiac and extracardiac findings on patient care

    Energy Technology Data Exchange (ETDEWEB)

    Wissner, Erik; Wellnitz, Clinton V.; Srivathsan, Komandoor; Scott, Luis R. [Mayo Clinic Arizona - Mayo Clinic Hospital, Cardiovascular Diseases, 5777 East Mayo Boulevard, Phoenix, AZ 85054 (United States); Altemose, Gregory T. [Mayo Clinic Arizona - Mayo Clinic Hospital, Cardiovascular Diseases, 5777 East Mayo Boulevard, Phoenix, AZ 85054 (United States)], E-mail: altemose.gregory@mayo.edu

    2009-11-15

    Objective: In patients referred for catheter ablation for the treatment of atrial fibrillation, multislice computed tomography angiography of the thorax is routinely performed to assess pulmonary vein anatomy. We sought to investigate the incidence of unexpected cardiac and extracardiac findings in this select patient population and to establish how these findings influence subsequent patient care. Methods: Ninety-five patients (mean age 62 {+-} 10 years, 35% female) referred to our institution for ablation therapy for atrial fibrillation between July 2003 and October 2007 underwent multislice computed tomography angiography of the thorax. Radiologists interpreted all images. Need for additional testing, consultation and eventual diagnosis were assessed by electronic record review. Results: A total of 83 (5 cardiac, 78 extracardiac) unexpected findings were observed in 50/95 (53%) of patients. The findings prompted 23 additional tests (5 cardiac, 18 noncardiac) in 15/95 (16%) of patients and 8 subsequent referrals in 7/95 (7%) patients. In 6 patients the findings significantly altered future patient care and resulted in postponement of ablation therapy in 4 patients. In 2 patients, extracardiac findings (pulmonary emboli and adenocarcinoma of the lung) were of potentially life-saving consequence. Conclusions: In patients undergoing multislice computed tomography angiography of the thorax in anticipation of planned catheter ablation therapy for the treatment of atrial fibrillation, unexpected findings are common and of potentially significant value. In comparison, there is a higher prevalence of unexpected extracardiac, rather than cardiac findings. Further investigation of these findings may lead to postponement of ablation therapy, but may also be of potentially lifesaving consequence.

  4. Quantum Computers

    Science.gov (United States)

    2010-03-04

    efficient or less costly than their classical counterparts. A large-scale quantum computer is certainly an extremely ambi- tious goal, appearing to us...outperform the largest classical supercomputers in solving some specific problems important for data encryption. In the long term, another application...which the quantum computer depends, causing the quantum mechanically destructive process known as decoherence . Decoherence comes in several forms

  5. Computational sustainability

    CERN Document Server

    Kersting, Kristian; Morik, Katharina

    2016-01-01

    The book at hand gives an overview of the state of the art research in Computational Sustainability as well as case studies of different application scenarios. This covers topics such as renewable energy supply, energy storage and e-mobility, efficiency in data centers and networks, sustainable food and water supply, sustainable health, industrial production and quality, etc. The book describes computational methods and possible application scenarios.

  6. Computational chemistry

    Science.gov (United States)

    Arnold, J. O.

    1987-01-01

    With the advent of supercomputers, modern computational chemistry algorithms and codes, a powerful tool was created to help fill NASA's continuing need for information on the properties of matter in hostile or unusual environments. Computational resources provided under the National Aerodynamics Simulator (NAS) program were a cornerstone for recent advancements in this field. Properties of gases, materials, and their interactions can be determined from solutions of the governing equations. In the case of gases, for example, radiative transition probabilites per particle, bond-dissociation energies, and rates of simple chemical reactions can be determined computationally as reliably as from experiment. The data are proving to be quite valuable in providing inputs to real-gas flow simulation codes used to compute aerothermodynamic loads on NASA's aeroassist orbital transfer vehicles and a host of problems related to the National Aerospace Plane Program. Although more approximate, similar solutions can be obtained for ensembles of atoms simulating small particles of materials with and without the presence of gases. Computational chemistry has application in studying catalysis, properties of polymers, all of interest to various NASA missions, including those previously mentioned. In addition to discussing these applications of computational chemistry within NASA, the governing equations and the need for supercomputers for their solution is outlined.

  7. Computer Navigation-aided Resection of Sacral Chordomas

    Directory of Open Access Journals (Sweden)

    Yong-Kun Yang

    2016-01-01

    Full Text Available Background: Resection of sacral chordomas is challenging. The anatomy is complex, and there are often no bony landmarks to guide the resection. Achieving adequate surgical margins is, therefore, difficult, and the recurrence rate is high. Use of computer navigation may allow optimal preoperative planning and improve precision in tumor resection. The purpose of this study was to evaluate the safety and feasibility of computer navigation-aided resection of sacral chordomas. Methods: Between 2007 and 2013, a total of 26 patients with sacral chordoma underwent computer navigation-aided surgery were included and followed for a minimum of 18 months. There were 21 primary cases and 5 recurrent cases, with a mean age of 55.8 years old (range: 35-84 years old. Tumors were located above the level of the S3 neural foramen in 23 patients and below the level of the S3 neural foramen in 3 patients. Three-dimensional images were reconstructed with a computed tomography-based navigation system combined with the magnetic resonance images using the navigation software. Tumors were resected via a posterior approach assisted by the computer navigation. Mean follow-up was 38.6 months (range: 18-84 months. Results: Mean operative time was 307 min. Mean intraoperative blood loss was 3065 ml. For computer navigation, the mean registration deviation during surgery was 1.7 mm. There were 18 wide resections, 4 marginal resections, and 4 intralesional resections. All patients were alive at the final follow-up, with 2 (7.7% exhibiting tumor recurrence. The other 24 patients were tumor-free. The mean Musculoskeletal Tumor Society Score was 27.3 (range: 19-30. Conclusions: Computer-assisted navigation can be safely applied to the resection of the sacral chordomas, allowing execution of preoperative plans, and achieving good oncological outcomes. Nevertheless, this needs to be accomplished by surgeons with adequate experience and skill.

  8. Understanding Computational Bayesian Statistics

    CERN Document Server

    Bolstad, William M

    2011-01-01

    A hands-on introduction to computational statistics from a Bayesian point of view Providing a solid grounding in statistics while uniquely covering the topics from a Bayesian perspective, Understanding Computational Bayesian Statistics successfully guides readers through this new, cutting-edge approach. With its hands-on treatment of the topic, the book shows how samples can be drawn from the posterior distribution when the formula giving its shape is all that is known, and how Bayesian inferences can be based on these samples from the posterior. These ideas are illustrated on common statistic

  9. Computational creativity

    Directory of Open Access Journals (Sweden)

    López de Mántaras Badia, Ramon

    2013-12-01

    Full Text Available New technologies, and in particular artificial intelligence, are drastically changing the nature of creative processes. Computers are playing very significant roles in creative activities such as music, architecture, fine arts, and science. Indeed, the computer is already a canvas, a brush, a musical instrument, and so on. However, we believe that we must aim at more ambitious relations between computers and creativity. Rather than just seeing the computer as a tool to help human creators, we could see it as a creative entity in its own right. This view has triggered a new subfield of Artificial Intelligence called Computational Creativity. This article addresses the question of the possibility of achieving computational creativity through some examples of computer programs capable of replicating some aspects of creative behavior in the fields of music and science.Las nuevas tecnologías y en particular la Inteligencia Artificial están cambiando de forma importante la naturaleza del proceso creativo. Los ordenadores están jugando un papel muy significativo en actividades artísticas tales como la música, la arquitectura, las bellas artes y la ciencia. Efectivamente, el ordenador ya es el lienzo, el pincel, el instrumento musical, etc. Sin embargo creemos que debemos aspirar a relaciones más ambiciosas entre los ordenadores y la creatividad. En lugar de verlos solamente como herramientas de ayuda a la creación, los ordenadores podrían ser considerados agentes creativos. Este punto de vista ha dado lugar a un nuevo subcampo de la Inteligencia Artificial denominado Creatividad Computacional. En este artículo abordamos la cuestión de la posibilidad de alcanzar dicha creatividad computacional mediante algunos ejemplos de programas de ordenador capaces de replicar algunos aspectos relacionados con el comportamiento creativo en los ámbitos de la música y la ciencia.

  10. Optimization of the moving-bed biofilm sequencing batch reactor (MBSBR) to control aeration time by kinetic computational modeling: Simulated sugar-industry wastewater treatment.

    Science.gov (United States)

    Faridnasr, Maryam; Ghanbari, Bastam; Sassani, Ardavan

    2016-05-01

    A novel approach was applied for optimization of a moving-bed biofilm sequencing batch reactor (MBSBR) to treat sugar-industry wastewater (BOD5=500-2500 and COD=750-3750 mg/L) at 2-4 h of cycle time (CT). Although the experimental data showed that MBSBR reached high BOD5 and COD removal performances, it failed to achieve the standard limits at the mentioned CTs. Thus, optimization of the reactor was rendered by kinetic computational modeling and using statistical error indicator normalized root mean square error (NRMSE). The results of NRMSE revealed that Stover-Kincannon (error=6.40%) and Grau (error=6.15%) models provide better fits to the experimental data and may be used for CT optimization in the reactor. The models predicted required CTs of 4.5, 6.5, 7 and 7.5 h for effluent standardization of 500, 1000, 1500 and 2500 mg/L influent BOD5 concentrations, respectively. Similar pattern of the experimental data also confirmed these findings.

  11. Treatment of radiation-induced cystitis and vulvodynia via a ganglion impar block using a lateral approach under computed tomography guidance: a case report

    Science.gov (United States)

    Lee, Jeong-Eun; Kwak, Kyung-Hwa; Hong, Seong Wook; Jung, Hoon; Chung, Seung-Yeon

    2017-01-01

    Adjuvant radiation therapy (RT) after colorectal cancer surgery can prevent local recurrence, but has several side effects. Precise injection of drugs into the affected areas is complicated by radiation-induced fibrosis of soft or connective tissue. A 48-year-old woman experienced severe intractable perineal pain, dysuria, urinary urgency, and frequent urination after rectal cancer surgery and adjuvant RT, and was diagnosed with radiation-induced cystitis and vulvodynia. Her symptoms persisted despite two fluoroscopy-guided ganglion impar blocks. Fluoroscopy revealed atypical needle tip positioning and radiolucent dye distribution, presumably due to radiation-induced fibrosis in the target region. We performed two computed tomography (CT)-guided ganglion impar blocks by using a lateral approach, which allowed more accurate po-sitioning of the needle tip. Her pain visual analog score decreased from 9 to 3, and she recently resumed sexual intimacy. CT guidance is a viable alternative to fluoroscopy guidance when performing ganglion impar blocks in fibrotic areas. PMID:28184272

  12. Evaluation of angiographic computed tomography in the follow-up after endovascular treatment of cerebral aneurysms - a comparative study with DSA and TOF-MRA

    Energy Technology Data Exchange (ETDEWEB)

    Buhk, Jan-Hendrik; Kallenberg, Kai [University of Goettingen, Department of Neuroradiology, Goettingen (Germany)]|[University of Goettingen, MR-Research in Neurology and Psychiatry, Goettingen (Germany); Mohr, Alexander; Knauth, Michael [University of Goettingen, Department of Neuroradiology, Goettingen (Germany); Dechent, Peter [University of Goettingen, MR-Research in Neurology and Psychiatry, Goettingen (Germany)

    2009-02-15

    Following coil embolization of intracranial aneurysms, many centers perform at least one digital subtraction angiography (DSA) continuing with time-of-flight magnetic resonance angiography (TOF-MRA). Angiographic computed tomography (ACT) provides high-resolution data from a rotational acquisition of a c-arm-mounted flat panel detector. This study evaluates possible advantages of applying ACT in aneurysm follow-up. In 22 patients DSA examinations with a rotational acquisition were performed. Rotational data were processed into an isotropic high-resolution volume. TOF-MRA was performed the day before DSA. Three experienced neuroradiologists performed a rating of the occlusion rate and a subjective method comparison. Weighted {kappa} statistics were calculated to assess the level of interobserver agreement. Compared to DSA, the diagnostic value of ACT as well as of TOF-MRA was rated to be inferior, although the sensitivity of detecting residual necks was higher with both techniques. Compared to TOF-MRA, ACT achieves favorable ratings only in aneurysms after stent-remodeling. Interobserver agreement was high for all techniques. Ratings of the occlusion rate correlated highly between all observers (r > 0.85, p < 0.001, respectively). In selected patients ACT can add valuable diagnostic information to DSA. TOF-MRA remains a highly sensitive method for aneurysm follow-up. (orig.)

  13. Cross-Hole Radar Travel-Time Tomography Based on Digital Image Segmentation%基于数字图像分割法的跨孔雷达走时层析成像

    Institute of Scientific and Technical Information of China (English)

    曲昕馨; 李桐林; 王飞

    2014-01-01

    The effectiveness of cross-hole radar tomography depends mainly on the quality of the extracted first arrival-time.Digital image segmentation method,based on the projection onto convex sets (POCS)technique,is used to extract the first arrival-time by segmenting the color image of the energy ratio,and had previously been applied in refracted seismic first arrival-time extraction.We first applied digital image segmentation method into cross-hole radar travel-time tomography to reconstruct the velocity field using an iteratively linearized inversion approach.During the inversion,LSQR algorithm was employed to solve the system of linear equations,Jacobian matrix was constructed by the curved ray tracing technique, and the travel-time was calculated using Multistencils Fast Marching Method (MSFM).We employed a synthetic data set and a field data set to test the effectiveness of the digital image segmentation method in travel-time tomography.For comparison,a traditional energy ratio method is also used for first arrival-time extraction.The result reflected that the tomography based on digital image segmentation method is more accurate with smaller residuals,and can provide more effective judgment for the underground velocity field.%跨孔雷达走时层析成像主要利用雷达波的走时进行反演,走时提取的正确与否将直接影响到层析成像的效果。数字图像分割法基于凸集投影(POCS)方法,使用能量比彩色图像分割技术准确提取走时。数字图像分割法提取走时首先应用在折射地震波的数据处理中。笔者首次将数字图像分割法提取走时的方法应用到跨孔雷达走时层析成像中,使用迭代线性反演算法重建了雷达波速度场。反演过程中,使用最小二乘 QR 分解法(LSQR)求解线性方程组,利用弯曲射线追踪技术构建雅可比矩阵,走时的计算值则由多模板快速推进算法(MSFM)得到。为了验证数字图像分割法

  14. Cloud Computing

    DEFF Research Database (Denmark)

    Krogh, Simon

    2013-01-01

    The second half of the 20th century has been characterized by an explosive development in information technology (Maney, Hamm, & O'Brien, 2011). Processing power, storage capacity and network bandwidth have increased exponentially, resulting in new possibilities and shifting IT paradigms. In step...... with technological changes, the paradigmatic pendulum has swung between increased centralization on one side and a focus on distributed computing that pushes IT power out to end users on the other. With the introduction of outsourcing and cloud computing, centralization in large data centers is again dominating...... the IT scene. In line with the views presented by Nicolas Carr in 2003 (Carr, 2003), it is a popular assumption that cloud computing will be the next utility (like water, electricity and gas) (Buyya, Yeo, Venugopal, Broberg, & Brandic, 2009). However, this assumption disregards the fact that most IT production...

  15. Quantum computers.

    Science.gov (United States)

    Ladd, T D; Jelezko, F; Laflamme, R; Nakamura, Y; Monroe, C; O'Brien, J L

    2010-03-04

    Over the past several decades, quantum information science has emerged to seek answers to the question: can we gain some advantage by storing, transmitting and processing information encoded in systems that exhibit unique quantum properties? Today it is understood that the answer is yes, and many research groups around the world are working towards the highly ambitious technological goal of building a quantum computer, which would dramatically improve computational power for particular tasks. A number of physical systems, spanning much of modern physics, are being developed for quantum computation. However, it remains unclear which technology, if any, will ultimately prove successful. Here we describe the latest developments for each of the leading approaches and explain the major challenges for the future.

  16. I am your smartphone, and I know you are about to smoke: the application of mobile sensing and computing approaches to smoking research and treatment.

    Science.gov (United States)

    McClernon, F Joseph; Roy Choudhury, Romit

    2013-10-01

    Much is known about the immediate and predictive antecedents of smoking lapse, which include situations (e.g., presence of other smokers), activities (e.g., alcohol consumption), and contexts (e.g., outside). This commentary suggests smartphone-based systems could be used to infer these predictive antecedents in real time and provide the smoker with just-in-time intervention. The smartphone of today is equipped with an array of sensors, including GPS, cameras, light sensors, barometers, accelerometers, and so forth, that provide information regarding physical location, human movement, ambient sounds, and visual imagery. We propose that libraries of algorithms to infer these antecedents can be developed and then incorporated into diverse mobile research and personalized treatment applications. While a number of challenges to the development and implementation of such applications are recognized, our field benefits from a database of known antecedents to a problem behavior, and further research and development in this exciting area are warranted.

  17. Computational mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Raboin, P J

    1998-01-01

    The Computational Mechanics thrust area is a vital and growing facet of the Mechanical Engineering Department at Lawrence Livermore National Laboratory (LLNL). This work supports the development of computational analysis tools in the areas of structural mechanics and heat transfer. Over 75 analysts depend on thrust area-supported software running on a variety of computing platforms to meet the demands of LLNL programs. Interactions with the Department of Defense (DOD) High Performance Computing and Modernization Program and the Defense Special Weapons Agency are of special importance as they support our ParaDyn project in its development of new parallel capabilities for DYNA3D. Working with DOD customers has been invaluable to driving this technology in directions mutually beneficial to the Department of Energy. Other projects associated with the Computational Mechanics thrust area include work with the Partnership for a New Generation Vehicle (PNGV) for ''Springback Predictability'' and with the Federal Aviation Administration (FAA) for the ''Development of Methodologies for Evaluating Containment and Mitigation of Uncontained Engine Debris.'' In this report for FY-97, there are five articles detailing three code development activities and two projects that synthesized new code capabilities with new analytic research in damage/failure and biomechanics. The article this year are: (1) Energy- and Momentum-Conserving Rigid-Body Contact for NIKE3D and DYNA3D; (2) Computational Modeling of Prosthetics: A New Approach to Implant Design; (3) Characterization of Laser-Induced Mechanical Failure Damage of Optical Components; (4) Parallel Algorithm Research for Solid Mechanics Applications Using Finite Element Analysis; and (5) An Accurate One-Step Elasto-Plasticity Algorithm for Shell Elements in DYNA3D.

  18. Evaluation of Condylar Position after Orthognathic Surgery for Treatment of Class II Vertical Maxillary Excess and Mandibular Deficiency by Using Cone-Beam Computed Tomography

    Directory of Open Access Journals (Sweden)

    Reza Tabrizi

    2016-12-01

    Full Text Available Statement of the Problem: In orthognathic surgeries, proper condylar position is one of the most important factors in postoperative stability. Knowing the condylar movement after orthognathic surgery can help preventing postoperative instabilities. Purpose: The aim of this study was to evaluate the condylar positional changes after Le Fort I maxillary superior repositioning along with mandibular advancement by using cone beam computed tomography (CBCT. Materials and Method: This cross-sectional study was conducted on 22 subjects who had class II skeletal malocclusion along with vertical maxillary excess. Subjects underwent maxillary superior repositioning (Le Fort I osteotomy along with mandibular advancement. The CBCT images were taken a couple of days before the surgery (T0, and one month (T1 and 9 months (T2 after the surgery. The condyles positions were determined from the most superior point of the condyle to three distances including the deepest point of the glenoid fossa, the most anterior-inferior point of the articular eminence, and the most superior point of the external auditory meatus in the sagittal plane. Results: The mean mandibular advancement was 4.33±2.1 mm and the mean maxillary superior repositioning was 4.66±0.3 mm. The condyles displaced inferiorly, anteriorly, and laterally between T0 and T1. They were repositioned approximately in the initial position in T2. No correlation was observed between the mandibular and maxillary movement and the condylar positions. Conclusion: The condyles displaced in the inferior-anterior-lateral position one month after the bilateral sagittal split osteotomy for mandibular advancement in combination with the maxillary Le Fort I superior repositioning. It seems that the condyles adapted approximately in their initial position nine months after the surgeries. Keywords ● Mandible ● Condyle ● CBCT ● Sagittal Osteotomy ● Vertical Maxillary Excess

  19. Evaluation of Condylar Position after Orthognathic Surgery for Treatment of Class II Vertical Maxillary Excess and Mandibular Deficiency by Using Cone-Beam Computed Tomography

    Science.gov (United States)

    Tabrizi, Reza; Shahidi, Shoaleh; Bahramnejad, Emad; Arabion, Hamidreza

    2016-01-01

    Statement of the Problem: In orthognathic surgeries, proper condylar position is one of the most important factors in postoperative stability. Knowing the condylar movement after orthognathic surgery can help preventing postoperative instabilities. Purpose: The aim of this study was to evaluate the condylar positional changes after Le Fort I maxillary superior repositioning along with mandibular advancement by using cone beam computed tomography (CBCT). Materials and Method: This cross-sectional study was conducted on 22 subjects who had class II skeletal malocclusion along with vertical maxillary excess. Subjects underwent maxillary superior repositioning (Le Fort I osteotomy) along with mandibular advancement. The CBCT images were taken a couple of days before the surgery (T0), and one month (T1) and 9 months (T2) after the surgery. The condyles positions were determined from the most superior point of the condyle to three distances including the deepest point of the glenoid fossa, the most anterior-inferior point of the articular eminence, and the most superior point of the external auditory meatus in the sagittal plane. Results: The mean mandibular advancement was 4.33±2.1 mm and the mean maxillary superior repositioning was 4.66±0.3 mm. The condyles displaced inferiorly, anteriorly, and laterally between T0 and T1. They were repositioned approximately in the initial position in T2. No correlation was observed between the mandibular and maxillary movement and the condylar positions. Conclusion: The condyles displaced in the inferior-anterior-lateral position one month after the bilateral sagittal split osteotomy for mandibular advancement in combination with the maxillary Le Fort I superior repositioning. It seems that the condyles adapted approximately in their initial position nine months after the surgeries. PMID:27942547

  20. Characteristics and dimensions of the sinus membrane in patients referred for single-implant treatment in the posterior maxilla: a cone beam computed tomographic analysis.

    Science.gov (United States)

    Schneider, Adrienne C; Bragger, Urs; Sendi, Pedram; Caversaccio, Marco D; Buser, Daniel; Bornstein, Michael M

    2013-01-01

    The purpose of the present study was to evaluate the thickness and anatomic characteristics of the sinus membrane using cone beam computed tomography (CBCT) in patients evaluated for implant surgery in the posterior maxilla. The study included 131 consecutive patients referred for dental implant placement in the posterior maxilla. A total of 138 CBCT images was obtained using fields of view of 4 × 4 cm, 6 × 6 cm, or 8 × 8 cm. Reformatted sagittal CBCT slices were analyzed with regard to the thickness and characteristics of the sinus membrane at single-tooth gaps in the posterior maxilla. Factors that might influence the dimensions of the sinus membrane, such as age, sex, endodontic status, and the season, were analyzed. The mean thickness of the maxillary sinus mucosa varied between 2.1 and 2.69 mm in the three locations analyzed. Fewer than half of the evaluated sinuses exhibited a healthy mucosa (49 of 138, or 35.51%). Most of the pathologic findings were flat, shallow thickenings (63 of 138, or 45.65%). Sex did not influence the thickness of the sinus membrane at the root tips of the premolars or at single-tooth gaps, but there was a statistically significant correlation in the region of the maxillary molars. No other evaluated factors had a statistically significant effect on the dimensions of the antral mucosa. In the present study, sex was the only factor influencing the dimension of the sinus membrane, whereas patient age, season, and the endodontic status of neighboring teeth had no significant effect on the thickness of the antral mucosa. Future studies should address which types of mucosal thickening require interdisciplinary therapy.

  1. Computed tomography (CT perfusion as an early predictive marker for treatment response to neoadjuvant chemotherapy in gastroesophageal junction cancer and gastric cancer--a prospective study.

    Directory of Open Access Journals (Sweden)

    Martin Lundsgaard Hansen

    Full Text Available OBJECTIVES: To evaluate whether early reductions in CT perfusion parameters predict response to pre-operative chemotherapy prior to surgery for gastroesophageal junction (GEJ and gastric cancer. MATERIALS AND METHODS: Twenty-eight patients with adenocarcinoma of the gastro-esophageal junction (GEJ and stomach were included. Patients received three series of chemotherapy before surgery, each consisting of a 3-week cycle of intravenous epirubicin, cisplatin or oxaliplatin, concomitant with capecitabine peroral. The patients were evaluated with a CT perfusion scan prior to, after the first series of, and after three series of chemotherapy. The CT perfusion scans were performed using a 320-detector row scanner. Tumour volume and perfusion parameters (arterial flow, blood volume and permeability were computed on a dedicated workstation with a consensus between two radiologists. Response to chemotherapy was evaluated by two measures. Clinical response was defined as a tumour size reduction of more than 50%. Histological response was evaluated based on residual tumour cells in the surgical specimen using the standardized Mandard Score 1 to 5, in which values of 1 and 2 were classified as responders, and 3 to 5 were classified as nonresponders. RESULTS: A decrease in tumour permeability after one series of chemotherapy was positively correlated with clinical response after three series of chemotherapy. Significant changes in permeability and tumour volume were apparent after three series of chemotherapy in both clinical and histological responders. A cut-off value of more than 25% reduction in tumour permeability yielded a sensitivity of 69% and a specificity of 58% for predicting clinical response. CONCLUSION: Early decrease in permeability is correlated with the likelihood of clinical response to pre-operative chemotherapy in GEJ and gastric cancer. As a single diagnostic test, CT Perfusion only has moderate sensitivity and specificity in response

  2. Clinical application of dual-source computed tomography in diagnosis and treatment of tumor in the oral and maxillofacial region%双源CT在颌面部肿瘤诊疗中的临床应用

    Institute of Scientific and Technical Information of China (English)

    郭照中; 刘学; 张恒; 李焱; 王杨; 孙辉

    2012-01-01

    目的:探讨双源CT(Dual-source computed tomography,DSCT)在颌面部肿瘤诊疗中的应用价值.方法:7例颌面部肿瘤病人通过双源CT检查,将数据发送至工作站进行多平面重建、容积重建.结果,7例患者均经手术治疗,术中所见肿瘤部位与周围神经、血管、软组织及硬组织关系均与双源CT检查结果一致.结论:双源CT具有扫描速度快,图像清晰的特点,在工作站上三维影像可以任意旋转和切割,从不同角度观察肿瘤与周边血管、神经、软组织及硬组织的关系,为诊断和治疗提供了大量准确信息.%Objective: To evaluate the clinical values of the Dual-source computed tomography for diagnosis and treatment in maxillofacial tumors. Method: 7 cases of maxillofacial tumors were examined with Dual-source computed tomography and then the images were taken with multi-planar reformats and volume rendering technique on work-station. Result: All the patients have been operated. Conclusion: Dual-source CT can be provided with characteristic of ultrafast speed scan and clear images. Three-dimensional CT images were obtained from circumgyration and incision at will on work-station.Pathological changes could be observed from many projection in 3D images. Dual-source CT can offer a lot of information for constitution plan of treatment. Dual-source CT is a valuable method in diagnosis and treatment of facial fractures, and the combination of 2D-CT and 3D-CT would be the best demonstration.

  3. Computational Artifacts

    DEFF Research Database (Denmark)

    Schmidt, Kjeld; Bansler, Jørgen P.

    2016-01-01

    The key concern of CSCW research is that of understanding computing technologies in the social context of their use, that is, as integral features of our practices and our lives, and to think of their design and implementation under that perspective. However, the question of the nature of that wh...... of that which is actually integrated in our practices is often discussed in confusing ways, if at all. The article aims to try to clarify the issue and in doing so revisits and reconsiders the notion of ‘computational artifact’....

  4. Distributed computing

    CERN Document Server

    Van Renesse, R

    1991-01-01

    This series will start with an introduction to distributed computing systems. Distributed computing paradigms will be presented followed by a discussion on how several important contemporary distributed operating systems use these paradigms. Topics will include processing paradigms, storage paradigms, scalability and robustness. Throughout the course everything will be illustrated by modern distributed systems notably the Amoeba distributed operating system of the Free University in Amsterdam and the Plan 9 operating system of AT&T Bell Laboratories. Plan 9 is partly designed and implemented by Ken Thompson, the main person behind the successful UNIX operating system.

  5. Computer busses

    CERN Document Server

    Buchanan, William

    2000-01-01

    As more and more equipment is interface or'bus' driven, either by the use of controllers or directly from PCs, the question of which bus to use is becoming increasingly important both in industry and in the office. 'Computer Busses' has been designed to help choose the best type of bus for the particular application.There are several books which cover individual busses, but none which provide a complete guide to computer busses. The author provides a basic theory of busses and draws examples and applications from real bus case studies. Busses are analysed using from a top-down approach, helpin

  6. Cloud Computing

    CERN Document Server

    Antonopoulos, Nick

    2010-01-01

    Cloud computing has recently emerged as a subject of substantial industrial and academic interest, though its meaning and scope is hotly debated. For some researchers, clouds are a natural evolution towards the full commercialisation of grid systems, while others dismiss the term as a mere re-branding of existing pay-per-use technologies. From either perspective, 'cloud' is now the label of choice for accountable pay-per-use access to third party applications and computational resources on a massive scale. Clouds support patterns of less predictable resource use for applications and services a

  7. Computational artifacts

    DEFF Research Database (Denmark)

    Schmidt, Kjeld; Bansler, Jørgen P.

    2016-01-01

    The key concern of CSCW research is that of understanding computing technologies in the social context of their use, that is, as integral features of our practices and our lives, and to think of their design and implementation under that perspective. However, the question of the nature...... of that which is actually integrated in our practices is often discussed in confusing ways, if at all. The article aims to try to clarify the issue and in doing so revisits and reconsiders the notion of ‘computational artifact’....

  8. Reconfigurable Computing

    CERN Document Server

    Cardoso, Joao MP

    2011-01-01

    As the complexity of modern embedded systems increases, it becomes less practical to design monolithic processing platforms. As a result, reconfigurable computing is being adopted widely for more flexible design. Reconfigurable Computers offer the spatial parallelism and fine-grained customizability of application-specific circuits with the postfabrication programmability of software. To make the most of this unique combination of performance and flexibility, designers need to be aware of both hardware and software issues. FPGA users must think not only about the gates needed to perform a comp

  9. COMPUTATIONAL THINKING

    OpenAIRE

    Evgeniy K. Khenner

    2016-01-01

    Abstract. The aim of the research is to draw attention of the educational community to the phenomenon of computational thinking which actively discussed in the last decade in the foreign scientific and educational literature, to substantiate of its importance, practical utility and the right on affirmation in Russian education.Methods. The research is based on the analysis of foreign studies of the phenomenon of computational thinking and the ways of its formation in the process of education;...

  10. Computational engineering

    CERN Document Server

    2014-01-01

    The book presents state-of-the-art works in computational engineering. Focus is on mathematical modeling, numerical simulation, experimental validation and visualization in engineering sciences. In particular, the following topics are presented: constitutive models and their implementation into finite element codes, numerical models in nonlinear elasto-dynamics including seismic excitations, multiphase models in structural engineering and multiscale models of materials systems, sensitivity and reliability analysis of engineering structures, the application of scientific computing in urban water management and hydraulic engineering, and the application of genetic algorithms for the registration of laser scanner point clouds.

  11. Computer immunology.

    Science.gov (United States)

    Forrest, Stephanie; Beauchemin, Catherine

    2007-04-01

    This review describes a body of work on computational immune systems that behave analogously to the natural immune system. These artificial immune systems (AIS) simulate the behavior of the natural immune system and in some cases have been used to solve practical engineering problems such as computer security. AIS have several strengths that can complement wet lab immunology. It is easier to conduct simulation experiments and to vary experimental conditions, for example, to rule out hypotheses; it is easier to isolate a single mechanism to test hypotheses about how it functions; agent-based models of the immune system can integrate data from several different experiments into a single in silico experimental system.

  12. Computer systems

    Science.gov (United States)

    Olsen, Lola

    1992-01-01

    In addition to the discussions, Ocean Climate Data Workshop hosts gave participants an opportunity to hear about, see, and test for themselves some of the latest computer tools now available for those studying climate change and the oceans. Six speakers described computer systems and their functions. The introductory talks were followed by demonstrations to small groups of participants and some opportunities for participants to get hands-on experience. After this familiarization period, attendees were invited to return during the course of the Workshop and have one-on-one discussions and further hands-on experience with these systems. Brief summaries or abstracts of introductory presentations are addressed.

  13. Computer viruses

    Science.gov (United States)

    Denning, Peter J.

    1988-01-01

    The worm, Trojan horse, bacterium, and virus are destructive programs that attack information stored in a computer's memory. Virus programs, which propagate by incorporating copies of themselves into other programs, are a growing menace in the late-1980s world of unprotected, networked workstations and personal computers. Limited immunity is offered by memory protection hardware, digitally authenticated object programs,and antibody programs that kill specific viruses. Additional immunity can be gained from the practice of digital hygiene, primarily the refusal to use software from untrusted sources. Full immunity requires attention in a social dimension, the accountability of programmers.

  14. Computer security

    CERN Document Server

    Gollmann, Dieter

    2011-01-01

    A completely up-to-date resource on computer security Assuming no previous experience in the field of computer security, this must-have book walks you through the many essential aspects of this vast topic, from the newest advances in software and technology to the most recent information on Web applications security. This new edition includes sections on Windows NT, CORBA, and Java and discusses cross-site scripting and JavaScript hacking as well as SQL injection. Serving as a helpful introduction, this self-study guide is a wonderful starting point for examining the variety of competing sec

  15. Computational Literacy

    DEFF Research Database (Denmark)

    Chongtay, Rocio; Robering, Klaus

    2016-01-01

    for the acquisition of Computational Literacy at basic educational levels, focus on higher levels of education has been much less prominent. The present paper considers the case of courses for higher education programs within the Humanities. A model is proposed which conceives of Computational Literacy as a layered...... set of skills rather than one single skill. Skills acquisition at these layers can be tailored to the specific needs of students. The work presented here builds upon experience from courses for such students from the Humanities in which programming is taught as a tool for other purposes. Results...

  16. Computer vision syndrome: a review.

    Science.gov (United States)

    Blehm, Clayton; Vishnu, Seema; Khattak, Ashbala; Mitra, Shrabanee; Yee, Richard W

    2005-01-01

    As computers become part of our everyday life, more and more people are experiencing a variety of ocular symptoms related to computer use. These include eyestrain, tired eyes, irritation, redness, blurred vision, and double vision, collectively referred to as computer vision syndrome. This article describes both the characteristics and treatment modalities that are available at this time. Computer vision syndrome symptoms may be the cause of ocular (ocular-surface abnormalities or accommodative spasms) and/or extraocular (ergonomic) etiologies. However, the major contributor to computer vision syndrome symptoms by far appears to be dry eye. The visual effects of various display characteristics such as lighting, glare, display quality, refresh rates, and radiation are also discussed. Treatment requires a multidirectional approach combining ocular therapy with adjustment of the workstation. Proper lighting, anti-glare filters, ergonomic positioning of computer monitor and regular work breaks may help improve visual comfort. Lubricating eye drops and special computer glasses help relieve ocular surface-related symptoms. More work needs to be done to specifically define the processes that cause computer vision syndrome and to develop and improve effective treatments that successfully address these causes.

  17. Riemannian computing in computer vision

    CERN Document Server

    Srivastava, Anuj

    2016-01-01

    This book presents a comprehensive treatise on Riemannian geometric computations and related statistical inferences in several computer vision problems. This edited volume includes chapter contributions from leading figures in the field of computer vision who are applying Riemannian geometric approaches in problems such as face recognition, activity recognition, object detection, biomedical image analysis, and structure-from-motion. Some of the mathematical entities that necessitate a geometric analysis include rotation matrices (e.g. in modeling camera motion), stick figures (e.g. for activity recognition), subspace comparisons (e.g. in face recognition), symmetric positive-definite matrices (e.g. in diffusion tensor imaging), and function-spaces (e.g. in studying shapes of closed contours).   ·         Illustrates Riemannian computing theory on applications in computer vision, machine learning, and robotics ·         Emphasis on algorithmic advances that will allow re-application in other...

  18. Computational biology

    DEFF Research Database (Denmark)

    Hartmann, Lars Røeboe; Jones, Neil; Simonsen, Jakob Grue

    2011-01-01

    Computation via biological devices has been the subject of close scrutiny since von Neumann’s early work some 60 years ago. In spite of the many relevant works in this field, the notion of programming biological devices seems to be, at best, ill-defined. While many devices are claimed or proved t...

  19. Computational Physics.

    Science.gov (United States)

    Borcherds, P. H.

    1986-01-01

    Describes an optional course in "computational physics" offered at the University of Birmingham. Includes an introduction to numerical methods and presents exercises involving fast-Fourier transforms, non-linear least-squares, Monte Carlo methods, and the three-body problem. Recommends adding laboratory work into the course in the…

  20. Computational Finance

    DEFF Research Database (Denmark)

    Rasmussen, Lykke

    One of the major challenges in todays post-crisis finance environment is calculating the sensitivities of complex products for hedging and risk management. Historically, these derivatives have been determined using bump-and-revalue, but due to the increasing magnitude of these computations does...

  1. Computational Finance

    DEFF Research Database (Denmark)

    Rasmussen, Lykke

    One of the major challenges in todays post-crisis finance environment is calculating the sensitivities of complex products for hedging and risk management. Historically, these derivatives have been determined using bump-and-revalue, but due to the increasing magnitude of these computations does...

  2. Computational Logistics

    DEFF Research Database (Denmark)

    Pacino, Dario; Voss, Stefan; Jensen, Rune Møller

    2013-01-01

    This book constitutes the refereed proceedings of the 4th International Conference on Computational Logistics, ICCL 2013, held in Copenhagen, Denmark, in September 2013. The 19 papers presented in this volume were carefully reviewed and selected for inclusion in the book. They are organized...... in topical sections named: maritime shipping, road transport, vehicle routing problems, aviation applications, and logistics and supply chain management....

  3. Computational Logistics

    DEFF Research Database (Denmark)

    This book constitutes the refereed proceedings of the 4th International Conference on Computational Logistics, ICCL 2013, held in Copenhagen, Denmark, in September 2013. The 19 papers presented in this volume were carefully reviewed and selected for inclusion in the book. They are organized...... in topical sections named: maritime shipping, road transport, vehicle routing problems, aviation applications, and logistics and supply chain management....

  4. Computing News

    CERN Multimedia

    McCubbin, N

    2001-01-01

    We are still five years from the first LHC data, so we have plenty of time to get the computing into shape, don't we? Well, yes and no: there is time, but there's an awful lot to do! The recently-completed CERN Review of LHC Computing gives the flavour of the LHC computing challenge. The hardware scale for each of the LHC experiments is millions of 'SpecInt95' (SI95) units of cpu power and tens of PetaBytes of data storage. PCs today are about 20-30SI95, and expected to be about 100 SI95 by 2005, so it's a lot of PCs. This hardware will be distributed across several 'Regional Centres' of various sizes, connected by high-speed networks. How to realise this in an orderly and timely fashion is now being discussed in earnest by CERN, Funding Agencies, and the LHC experiments. Mixed in with this is, of course, the GRID concept...but that's a topic for another day! Of course hardware, networks and the GRID constitute just one part of the computing. Most of the ATLAS effort is spent on software development. What we ...

  5. Computational trigonometry

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, K. [Univ. of Colorado, Boulder, CO (United States)

    1994-12-31

    By means of the author`s earlier theory of antieigenvalues and antieigenvectors, a new computational approach to iterative methods is presented. This enables an explicit trigonometric understanding of iterative convergence and provides new insights into the sharpness of error bounds. Direct applications to Gradient descent, Conjugate gradient, GCR(k), Orthomin, CGN, GMRES, CGS, and other matrix iterative schemes will be given.

  6. [Grid computing

    CERN Multimedia

    Wolinsky, H

    2003-01-01

    "Turn on a water spigot, and it's like tapping a bottomless barrel of water. Ditto for electricity: Flip the switch, and the supply is endless. But computing is another matter. Even with the Internet revolution enabling us to connect in new ways, we are still limited to self-contained systems running locally stored software, limited by corporate, institutional and geographic boundaries" (1 page).

  7. Incoercible multiparty computation

    Energy Technology Data Exchange (ETDEWEB)

    Canetti, R.; Gennaro, R. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1996-12-31

    Current secure multiparty protocols have the following deficiency. The public transcript of the communication can be used as an involuntary commitment of the parties to their inputs and outputs. Thus parties can be later coerced by some authority to reveal their private data. Previous work that has pointed this interesting problem out contained only partial treatment. In this work we present the first general treatment of the coercion problem in secure computation. First we present a general definition of protocols that provide resilience to coercion. Our definition constitutes a natural extension of the general paradigm used for defining secure multiparty protocols. Next we show that if trapdoor permutations exist then any function can be incoercibly computed (i.e., computed by a protocol that provides resilience to coercion) in the presence of computationally bounded adversaries and only public communication channels. This holds as long as less than half the parties are coerced (or corrupted). In particular, ours are the first incoercible protocols without physical security assumptions. Also, our protocols constitute an alternative solution to the recently solved adaptive security problem. Our techniques are quite surprising and include non-standard use of deniable encryptions.

  8. Attenuation properties and percentage depth dose of tannin-based Rhizophora spp. particleboard phantoms using computed tomography (CT) and treatment planning system (TPS) at high energy x-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Yusof, M. F. Mohd, E-mail: mfahmi@usm.my [School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); School of Health Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan (Malaysia); Abdullah, R. [School of Health Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan (Malaysia); Tajuddin, A. A. [School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200 Kepala Batas, Penang (Malaysia); Hashim, R. [School of Industrial Technologies, Universiti Sains Malaysia, 11800 Penang (Malaysia); Bauk, S. [Physics Section, School of Distance Education, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2016-01-22

    A set of tannin-based Rhizophora spp. particleboard phantoms with dimension of 30 cm x 30 cm was fabricated at target density of 1.0 g/cm{sup 3}. The mass attenuation coefficient of the phantom was measured using {sup 60}Co gamma source. The phantoms were scanned using Computed Tomography (CT) scanner and the percentage depth dose (PDD) of the phantom was calculated using treatment planning system (TPS) at 6 MV and 10 MV x-ray and compared to that in solid water phantoms. The result showed that the mass attenuation coefficient of tannin-based Rhizohora spp. phantoms was near to the value of water with χ{sup 2} value of 1.2. The measured PDD also showed good agreement with solid water phantom at both 6 MV and 10 MV x-ray with percentage deviation below 8% at depth beyond the maximum dose, Z{sub max}.

  9. Dual-energy computed tomography for the assessment of early treatment effects of regorafenib in a preclinical tumor model: comparison with dynamic contrast-enhanced CT and conventional contrast-enhanced single-energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Knobloch, Gesine; Hamm, Bernd [Charite - Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany); Jost, Gregor; Pietsch, Hubertus [Bayer Healthcare, MR and CT Contrast Media Research, Berlin (Germany); Huppertz, Alexander [Imaging Science Institute Charite - Siemens, Berlin (Germany)

    2014-08-15

    The potential diagnostic value of dual-energy computed tomography (DE-CT) compared to dynamic contrast-enhanced CT (DCE-CT) and conventional contrast-enhanced CT (CE-CT) in the assessment of early regorafenib treatment effects was evaluated in a preclinical setting. A rat GS9L glioma model was examined with contrast-enhanced dynamic DE-CT measurements (80 kV/140 kV) for 4 min before and on days 1 and 4 after the start of daily regorafenib or placebo treatment. Tumour time-density curves (0-240 s, 80 kV), DE-CT (60 s) derived iodine maps and the DCE-CT (0-30 s, 80 kV) based parameters blood flow (BF), blood volume (BV) and permeability (PMB) were calculated and compared to conventional CE-CT (60 s, 80 kV). The regorafenib group showed a marked decrease in the tumour time-density curve, a significantly lower iodine concentration and a significantly lower PMB on day 1 and 4 compared to baseline, which was not observed for the placebo group. CE-CT showed a significant decrease in tumour density on day 4 but not on day 1. The DE-CT-derived iodine concentrations correlated with PMB and BV but not with BF. DE-CT allows early treatment monitoring, which correlates with DCE-CT. Superior performance was observed compared to single-energy CE-CT. circle Regorafenib treatment response was evaluated by CT in a rat tumour model. (orig.)

  10. The effect of rib and lung heterogeneities on the computed dose to lung in Ir-192 high-dose-rate breast brachytherapy: Monte Carlo versus a treatment planning system.

    Science.gov (United States)

    Yazdi, Hossein Salehi; Shamsaei, Mojtaba; Jaberi, Ramin; Shabani, Hamid Reza; Allahverdi, Mahmoud; Vaezzadeh, Seyed Ali

    2012-01-01

    This study investigates to what extent the dose received by lungs from a commercially available treatment planning system, Ir-192 high-dose-rate (HDR), in breast brachytherapy, is accurate, with the emphasis on tissue heterogeneities, and taking into account the presence of ribs, in dose delivery to the lung. A computed tomography (CT) scan of a breast was acquired and transferred to the 3-D treatment planning system and was also used to construct a patient-equivalent phantom. An implant involving 13 plastic catheters and 383 programmed source dwell positions were simulated, using the Monte Carlo N-Particle eXtended (MCNPX) code. The Monte Carlo calculations were compared with the corresponding commercial treatment planning system (TPS) in the form of percentage isodose and cumulative dose-volume histogram (DVH) in the breast, lungs, and ribs. The comparison of the Monte Carlo results and the TPS calculations showed that a percentage of isodose greater than 75% in the breast, which was located rather close to the implant or away from the breast curvature surface and lung boundary, were in good agreement. TPS calculations overestimated the dose to the lung for lower isodose contours that were lying near the breast surface and the boundary of breast and lung and were relatively away from the implant. Taking into account the ribs and entering the actual data for breasts, ribs, and lungs, revealed an average overestimation of the dose by a factor of 8% in the lung for TPS calculations. Therefore, the accuracy of the TPS results may be limited to regions near the implants where the treatment is planned, and is a more conservative approach for regions at boundaries with curvatures or tissues with a different material than that in the breast.

  11. Computed tomography-guided percutaneous microwave ablation combined with osteoplasty for palliative treatment of painful extraspinal bone metastases from lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Zhigang; Ye, Xin; Yang, Xia; Zheng, Aimin; Huang, Guanghui; Wang, Jiao [Shandong Provincial Hospital Affiliated to Shandong University, Department of Oncology, Jinan, Shandong Province (China); Zhang, Kaixian [Teng Zhou Central People' s Hospital Affiliated to Jining Medical College, Department of Oncology, Tengzhou, Shandong Province (China)

    2015-10-15

    To retrospectively evaluate the efficacy and safety of microwave ablation (MWA) combined with osteoplasty in lung cancer patients with painful extraspinal bone metastases. From January 2011 to July 2014, 26 lung cancer patients with 33 painful extraspinal bone metastases underwent percutaneous MWA combined with osteoplasty. Effectiveness was evaluated by visual analog scale (VAS) and daily morphine dose with a follow-up of 6-months. Complications were also recorded. Mean VAS score and morphine dose pre-procedure were 7.4 ± 1.6 (range, 5-10) and 47.7 ± 30.1 mg (range, 20-120 mg), respectively. Technical success and pain relief were achieved in all patients. Mean VAS scores and daily morphine doses post-procedure were as follows: 48 h, 1.7 ± 1.2 (p < 0.001) and 29.6 ± 16.1 mg (p = 0.003); 7 days, 1.9 ± 1.7 (p < 0.001) and 16.1 ± 12.0 mg (p < 0.001); 1 month, 1.5 ± 0.9 (p < 0.001) and 10.8 ± 10.9 (p < 0.001); 3 months, 0.9 ± 0.7 (p < 0.001) and 8.4 ± 9.2 mg (p < 0.001); and 6 months, 1.2 ± 0.8 (p < 0.001) and 9.2 ± 12.3 mg (p < 0.001). Complications were observed in eight patients (28 %); among these, major complications were reported in two (7.7 %) patients, one with local infection and the other with a bone fracture. The minor complication rate was 23.1 % (6/26). MWA combination with osteoplasty appeared to be an effective and safe treatment for lung cancer patients with painful extraspinal bone metastases. (orig.)

  12. Computable Frames in Computable Banach Spaces

    Directory of Open Access Journals (Sweden)

    S.K. Kaushik

    2016-06-01

    Full Text Available We develop some parts of the frame theory in Banach spaces from the point of view of Computable Analysis. We define computable M-basis and use it to construct a computable Banach space of scalar valued sequences. Computable Xd frames and computable Banach frames are also defined and computable versions of sufficient conditions for their existence are obtained.

  13. Computational Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, C K; Mizobuchi, Y; Poinsot, T J; Smith, P J; Warnatz, J

    2004-08-26

    Progress in the field of computational combustion over the past 50 years is reviewed. Particular attention is given to those classes of models that are common to most system modeling efforts, including fluid dynamics, chemical kinetics, liquid sprays, and turbulent flame models. The developments in combustion modeling are placed into the time-dependent context of the accompanying exponential growth in computer capabilities and Moore's Law. Superimposed on this steady growth, the occasional sudden advances in modeling capabilities are identified and their impacts are discussed. Integration of submodels into system models for spark ignition, diesel and homogeneous charge, compression ignition engines, surface and catalytic combustion, pulse combustion, and detonations are described. Finally, the current state of combustion modeling is illustrated by descriptions of a very large jet lifted 3D turbulent hydrogen flame with direct numerical simulation and 3D large eddy simulations of practical gas burner combustion devices.

  14. Computational Electromagnetics

    CERN Document Server

    Rylander, Thomas; Bondeson, Anders

    2013-01-01

    Computational Electromagnetics is a young and growing discipline, expanding as a result of the steadily increasing demand for software for the design and analysis of electrical devices. This book introduces three of the most popular numerical methods for simulating electromagnetic fields: the finite difference method, the finite element method and the method of moments. In particular it focuses on how these methods are used to obtain valid approximations to the solutions of Maxwell's equations, using, for example, "staggered grids" and "edge elements." The main goal of the book is to make the reader aware of different sources of errors in numerical computations, and also to provide the tools for assessing the accuracy of numerical methods and their solutions. To reach this goal, convergence analysis, extrapolation, von Neumann stability analysis, and dispersion analysis are introduced and used frequently throughout the book. Another major goal of the book is to provide students with enough practical understan...

  15. Computational Physics

    Science.gov (United States)

    Thijssen, Jos

    2013-10-01

    1. Introduction; 2. Quantum scattering with a spherically symmetric potential; 3. The variational method for the Schrödinger equation; 4. The Hartree-Fock method; 5. Density functional theory; 6. Solving the Schrödinger equation in periodic solids; 7. Classical equilibrium statistical mechanics; 8. Molecular dynamics simulations; 9. Quantum molecular dynamics; 10. The Monte Carlo method; 11. Transfer matrix and diagonalisation of spin chains; 12. Quantum Monte Carlo methods; 13. The infinite element method for partial differential equations; 14. The lattice Boltzmann method for fluid dynamics; 15. Computational methods for lattice field theories; 16. High performance computing and parallelism; Appendix A. Numerical methods; Appendix B. Random number generators; References; Index.

  16. Computational Electromagnetics

    Science.gov (United States)

    2011-02-20

    a collaboration between Caltech’s postdoctoral associate N. Albin and OB) have shown that, for a variety of reasons, the first-order...KZK approximation", Nathan Albin , Oscar P. Bruno, Theresa Y. Cheung and Robin O. Cleveland, preprint, (2011) "A Spectral FC Solver for the Compressible...Navier-Stokes Equations in General Domains I: Explicit time-stepping" Nathan Albin and Oscar P. Bruno, To appear in Journal of Computational Physics

  17. Computer files.

    Science.gov (United States)

    Malik, M

    1995-02-01

    From what has been said, several recommendations can be made for users of small personal computers regardless of which operating system they use. If your computer has a large hard disk not specially required by any single application, organize the disk into a small number of volumes. You will then be using the computer as if it had several smaller disks, which will help you to create a logical file structure. The size of individual volumes has to be selected carefully with respect to the files kept in each volume. Otherwise, it may be that you will have too much space in one volume and not enough in another. In each volume, organize the structure of directories and subdirectories logically so that they correspond to the logic of your file content. Be aware of the fact that the directories suggested as default when installing new software are often not the optimum. For instance, it is better to put different graphics packages under a common subdirectory rather than to install them at the same level as all other packages including statistics, text processors, etc. Create a special directory for each task you use the computer. Note that it is a bad practice to keep many different and logically unsorted files in the root directory of any of your volumes. Only system and important service files should be kept there. Although any file may be written all over the disk, access to it will be faster if it is written over the minimum number of cylinders. From time to time, use special programs that reorganize your files in this way.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Everything Computes

    Institute of Scientific and Technical Information of China (English)

    Bill; Hofmann

    1999-01-01

    Dear American Professor, I am a student in Beijing. At the beginning of last semester, we fourroommates gathered some 10,000 yuan (a big sum here. approximately 1150USD ) and bought a computer, which is our joint-property. Since the computercame into our room, it was used round the clock except the time we were havingc1asses. So even at midnight, when I woke up from the dream, I could still see

  19. 小型医用机器人和计算机辅助定位治疗胫骨骨折%Mini-sized medical robot and computer-assisted localization for treatment of tibial fracture

    Institute of Scientific and Technical Information of China (English)

    王剑飞; 郭龙; 王军强; 武作鹏; 苏永刚; 胡磊; 王豫; 王满宜; 叶军

    2008-01-01

    设计一种在胫骨骨折闭合复位带锁髓内钉内固定手术中应刖的医疗机器人.该系统主要由立体定位框架和计算机系统两大部分组成,利用由C型臂采集到的一幅含有各标记点和髓内钉锁孔两端中心的X射线图像,根据空间映射关系,计算出锁孔在定位框体坐标系中的实际坐标位置,并根据计算结果定位参考坐标面卜的导向孔.电动牵引复位系统可以实现精确复位,通过Internet 网络传输手术数据,可以实现远程遥控操作.在17例胫骨骨折闭合复位带锁髓内钉内固定手术中应用医用机器人复位骨折和计算机辅助定位远端锁孔,其中4例采用远程遥控操作.均按照机器人及导航系统的预定程序,规划完成,所有远端锁钉均一次成功置入.提示医用机器人和计算机辅助定位导航系统可以满足胫骨骨折闭合复位带锁髓内钉内固定在临床应用中骨折复位和远端锁钉置入,减少了术中X射线透视时间,远程遥控操作可靠方便,系统结构简单,易于掌握.%A medical robot that is used for closed reduction and the internal fixation of intramedullary locking nailing in treatment of tibial fracture is designed.The system is primarily composed of stereotaxic frame and computer system.Using C-shaped arm-taken X-ray images containing various marked points and keyhole-two-end-center of intramedullary nail,the system calculates the actual position of keyhole in the coordinate system of stereotaxic frame according to space mapping relation and locates the pilot hole on the reference coordinate according to computation.Electric-traction system can realize the precise reduction and remote control operation by network transmission of operation data.In the closed reduction and the internal fixation of intramedullary nail for treatment of tibial fracture in 17 patients,robot reducing fracture and computer-assisted localization of distal keyhole were used.Remote control

  20. Cone beam-computed topographic evaluation of a central incisor with an open apex and a failed root canal treatment using one-step apexification with Biodentine™: A case report.

    Science.gov (United States)

    Sinha, Nidhi; Singh, Bijay; Patil, Santosh

    2014-05-01

    A symptomatic endodontically treated immature tooth with periapical pathology presents multiple challenges to the clinician. Owing to incomplete root formation, gutta percha removal has to be done carefully without further damaging the periapical tissue or pushing the obturating material beyond the apex. Nonsurgical approach toward treating such a tooth would necessitate the creation of an apical barrier followed by conventional root canal treatment. Current literature suggests one-step apexification with mineral trioxide aggregate (MTA), with an apical matrix as the treatment of choice. A new calcium silicate-based cement also called as dentine substitute by the manufacturers with good handling properties has been introduced recently by the trade name Biodentine™ (Septodont, St. Maurdes Fossés, France). This case report presents management of a secondary endodontic case with an open apex treated with the concept of 'lesion sterilization and tissue repair (LSTR)' using triantibiotic paste and Biodentine™ for apical barrier formation. A 12-month follow up with cone beam-computed topography (CBCT) exhibited progressive involution of periapical radiolucency with indications of good healing of the periapical tissues and absence of clinical symptoms.

  1. Computer Spectrometers

    Science.gov (United States)

    Dattani, Nikesh S.

    2017-06-01

    Ideally, the cataloguing of spectroscopic linelists would not demand laborious and expensive experiments. Whatever an experiment might achieve, the same information would be attainable by running a calculation on a computer. Kolos and Wolniewicz were the first to demonstrate that calculations on a computer can outperform even the most sophisticated molecular spectroscopic experiments of the time, when their 1964 calculations of the dissociation energies of H_2 and D_{2} were found to be more than 1 cm^{-1} larger than the best experiments by Gerhard Herzberg, suggesting the experiment violated a strict variational principle. As explained in his Nobel Lecture, it took 5 more years for Herzberg to perform an experiment which caught up to the accuracy of the 1964 calculations. Today, numerical solutions to the Schrödinger equation, supplemented with relativistic and higher-order quantum electrodynamics (QED) corrections can provide ro-vibrational spectra for molecules that we strongly believe to be correct, even in the absence of experimental data. Why do we believe these calculated spectra are correct if we do not have experiments against which to test them? All evidence seen so far suggests that corrections due to gravity or other forces are not needed for a computer simulated QED spectrum of ro-vibrational energy transitions to be correct at the precision of typical spectrometers. Therefore a computer-generated spectrum can be considered to be as good as one coming from a more conventional spectrometer, and this has been shown to be true not just for the H_2 energies back in 1964, but now also for several other molecules. So are we at the stage where we can launch an array of calculations, each with just the atomic number changed in the input file, to reproduce the NIST energy level databases? Not quite. But I will show that for the 6e^- molecule Li_2, we have reproduced the vibrational spacings to within 0.001 cm^{-1} of the experimental spectrum, and I will

  2. Data on analysis of coronary atherosclerosis on computed tomography and 18F-sodium fluoride positron emission tomography

    Directory of Open Access Journals (Sweden)

    Toshiro Kitagawa

    2017-08-01

    Full Text Available This article contains the data showing illustrative examples of plaque classification on coronary computed tomography angiography (CCTA and measurement of 18F-sodium fluoride (18F-NaF uptake in coronary atherosclerotic lesions on positron emission tomography (PET. We divided the lesions into one of three plaque types on CCTA (calcified plaque, non-calcified plaque, partially calcified plaque. Focal 18F-NaF uptake of each lesion was quantified using maximum tissue-to-background ratio. This article also provides a representative case with a non-calcified coronary plaque detected on CCTA and identified on 18F-NaF PET/non-contrast computed tomography based on a location of a vessel branch as a landmark. These complement the data reported by Kitagawa et al. (2017 [1].

  3. Customizable computing

    CERN Document Server

    Chen, Yu-Ting; Gill, Michael; Reinman, Glenn; Xiao, Bingjun

    2015-01-01

    Since the end of Dennard scaling in the early 2000s, improving the energy efficiency of computation has been the main concern of the research community and industry. The large energy efficiency gap between general-purpose processors and application-specific integrated circuits (ASICs) motivates the exploration of customizable architectures, where one can adapt the architecture to the workload. In this Synthesis lecture, we present an overview and introduction of the recent developments on energy-efficient customizable architectures, including customizable cores and accelerators, on-chip memory

  4. Computer vision

    Science.gov (United States)

    Gennery, D.; Cunningham, R.; Saund, E.; High, J.; Ruoff, C.

    1981-01-01

    The field of computer vision is surveyed and assessed, key research issues are identified, and possibilities for a future vision system are discussed. The problems of descriptions of two and three dimensional worlds are discussed. The representation of such features as texture, edges, curves, and corners are detailed. Recognition methods are described in which cross correlation coefficients are maximized or numerical values for a set of features are measured. Object tracking is discussed in terms of the robust matching algorithms that must be devised. Stereo vision, camera control and calibration, and the hardware and systems architecture are discussed.

  5. Computational radiology for orthopaedic interventions

    CERN Document Server

    Li, Shuo

    2016-01-01

    This book provides a cohesive overview of the current technological advances in computational radiology, and their applications in orthopaedic interventions. Contributed by the leading researchers in the field, this volume covers not only basic computational radiology techniques such as statistical shape modeling, CT/MRI segmentation, augmented reality and micro-CT image processing, but also the applications of these techniques to various orthopaedic interventional tasks. Details about following important state-of-the-art development are featured: 3D preoperative planning and patient-specific instrumentation for surgical treatment of long-bone deformities, computer assisted diagnosis and planning of periacetabular osteotomy and femoroacetabular impingement, 2D-3D reconstruction-based planning of total hip arthroplasty, image fusion for  computer-assisted bone tumor surgery, intra-operative three-dimensional imaging in fracture treatment, augmented reality based orthopaedic interventions and education, medica...

  6. Tensor computations in computer algebra systems

    CERN Document Server

    Korolkova, A V; Sevastyanov, L A

    2014-01-01

    This paper considers three types of tensor computations. On their basis, we attempt to formulate criteria that must be satisfied by a computer algebra system dealing with tensors. We briefly overview the current state of tensor computations in different computer algebra systems. The tensor computations are illustrated with appropriate examples implemented in specific systems: Cadabra and Maxima.

  7. Treatment of Palmar Hyperhidrosis by Computer-assisted Thoracic Sympathetic Nerve Block%计算机辅助下胸交感神经阻滞治疗手汗症

    Institute of Scientific and Technical Information of China (English)

    武肖娜; 彭凯润; 杨红军; 罗高权

    2012-01-01

    目的:观察利用计算机辅助下胸交感神经阻滞治疗手汗症的效果.方法:对6例原发性手多汗症患者,术前行CT扫描,应用Mimics软件对患者进行三维重建,设计手术路径,根据设计方案完成手术.结果:术前的模拟手术使手术时间明显缩短,减少了术中气胸和出血概率.6例患者均获得了良好效果.结论:计算机辅助下胸交感神经阻滞治疗手汗症可以在临床中推广应用,并发症减少,手术时间缩短,手术的精确度提高.%Objective: Clinical application of the patients with essential hyperhidrosis using computer-aided technology. Methods: 6 patients with essential hyperhidrosis were selected, preoperative CT was performed, design bone and soft tissues using mimics software, according to design result to guide surgery. Results: According to pre-operation design, operating repair and post-operation effective was evaluated, 6 patients suffering from facial asymmetry obtained good results. Conclusions: To design individual models with computer aided design technology is a useful method for treatment of essential hyperhidrosis, which short operation time and complication, improve accurately.

  8. Computer Tree

    Directory of Open Access Journals (Sweden)

    Onur AĞAOĞLU

    2014-12-01

    Full Text Available It is crucial that gifted and talented students should be supported by different educational methods for their interests and skills. The science and arts centres (gifted centres provide the Supportive Education Program for these students with an interdisciplinary perspective. In line with the program, an ICT lesson entitled “Computer Tree” serves for identifying learner readiness levels, and defining the basic conceptual framework. A language teacher also contributes to the process, since it caters for the creative function of the basic linguistic skills. The teaching technique is applied for 9-11 aged student level. The lesson introduces an evaluation process including basic information, skills, and interests of the target group. Furthermore, it includes an observation process by way of peer assessment. The lesson is considered to be a good sample of planning for any subject, for the unpredicted convergence of visual and technical abilities with linguistic abilities.

  9. computer networks

    Directory of Open Access Journals (Sweden)

    N. U. Ahmed

    2002-01-01

    Full Text Available In this paper, we construct a new dynamic model for the Token Bucket (TB algorithm used in computer networks and use systems approach for its analysis. This model is then augmented by adding a dynamic model for a multiplexor at an access node where the TB exercises a policing function. In the model, traffic policing, multiplexing and network utilization are formally defined. Based on the model, we study such issues as (quality of service QoS, traffic sizing and network dimensioning. Also we propose an algorithm using feedback control to improve QoS and network utilization. Applying MPEG video traces as the input traffic to the model, we verify the usefulness and effectiveness of our model.

  10. Social Computing

    CERN Document Server

    CERN. Geneva

    2011-01-01

    The past decade has witnessed a momentous transformation in the way people interact with each other. Content is now co-produced, shared, classified, and rated by millions of people, while attention has become the ephemeral and valuable resource that everyone seeks to acquire. This talk will describe how social attention determines the production and consumption of content within both the scientific community and social media, how its dynamics can be used to predict the future and the role that social media plays in setting the public agenda. About the speaker Bernardo Huberman is a Senior HP Fellow and Director of the Social Computing Lab at Hewlett Packard Laboratories. He received his Ph.D. in Physics from the University of Pennsylvania, and is currently a Consulting Professor in the Department of Applied Physics at Stanford University. He originally worked in condensed matter physics, ranging from superionic conductors to two-dimensional superfluids, and made contributions to the theory of critical p...

  11. Computational neuroscience

    CERN Document Server

    Blackwell, Kim L

    2014-01-01

    Progress in Molecular Biology and Translational Science provides a forum for discussion of new discoveries, approaches, and ideas in molecular biology. It contains contributions from leaders in their fields and abundant references. This volume brings together different aspects of, and approaches to, molecular and multi-scale modeling, with applications to a diverse range of neurological diseases. Mathematical and computational modeling offers a powerful approach for examining the interaction between molecular pathways and ionic channels in producing neuron electrical activity. It is well accepted that non-linear interactions among diverse ionic channels can produce unexpected neuron behavior and hinder a deep understanding of how ion channel mutations bring about abnormal behavior and disease. Interactions with the diverse signaling pathways activated by G protein coupled receptors or calcium influx adds an additional level of complexity. Modeling is an approach to integrate myriad data sources into a cohesiv...

  12. Brain computer

    Directory of Open Access Journals (Sweden)

    Sarah N. Abdulkader

    2015-07-01

    Full Text Available Brain computer interface technology represents a highly growing field of research with application systems. Its contributions in medical fields range from prevention to neuronal rehabilitation for serious injuries. Mind reading and remote communication have their unique fingerprint in numerous fields such as educational, self-regulation, production, marketing, security as well as games and entertainment. It creates a mutual understanding between users and the surrounding systems. This paper shows the application areas that could benefit from brain waves in facilitating or achieving their goals. We also discuss major usability and technical challenges that face brain signals utilization in various components of BCI system. Different solutions that aim to limit and decrease their effects have also been reviewed.

  13. Computational micromechanics

    Science.gov (United States)

    Ortiz, M.

    1996-09-01

    Selected issues in computational micromechanics are reviewed, with particular emphasis on multiple-scale problems and micromechanical models of material behavior. Examples considered include: the bridging of atomistic and continuum scales, with application to nanoindentation and the brittle-to-ductile transition; the development of dislocation-based constitutive relations for pure metallic crystals and intermetallic compounds, with applications to fracture of single crystals and bicrystals; the simulation of non-planar three-dimensional crack growth at the microscale, with application to mixed mode I III effective behavior and crack trapping and bridging in fiber-reinforced composites; and the direct micromechanical simulation of fragmentation of brittle solids and subsequent flow of the comminuted phase.

  14. Efficacy of Stent-Retriever Thrombectomy in Magnetic Resonance Imaging Versus Computed Tomographic Perfusion-Selected Patients in SWIFT PRIME Trial (Solitaire FR With the Intention for Thrombectomy as Primary Endovascular Treatment for Acute Ischemic Stroke).

    Science.gov (United States)

    Menjot de Champfleur, Nicolas; Saver, Jeffrey L; Goyal, Mayank; Jahan, Reza; Diener, Hans-Christoph; Bonafe, Alain; Levy, Elad I; Pereira, Vitor M; Cognard, Christophe; Yavagal, Dileep R; Albers, Gregory W

    2017-06-01

    The majority of patients enrolled in SWIFT PRIME trial (Solitaire FR With the Intention for Thrombectomy as Primary Endovascular Treatment for Acute Ischemic Stroke) had computed tomographic perfusion (CTP) imaging before randomization; 34 patients were randomized after magnetic resonance imaging (MRI). Patients with middle cerebral artery and distal carotid occlusions were randomized to treatment with tPA (tissue-type plasminogen activator) alone or tPA+stentriever thrombectomy. The primary outcome was the distribution of the modified Rankin Scale score at 90 days. Patients with the target mismatch profile for enrollment were identified on MRI and CTP. MRI selection was performed in 34 patients; CTP in 139 patients. Baseline National Institutes of Health Stroke Scale score was 17 in both groups. Target mismatch profile was present in 95% (MRI) versus 83% (CTP). A higher percentage of the MRI group was transferred from an outside hospital (P=0.02), and therefore, the time from stroke onset to randomization was longer in the MRI group (P=0.003). Time from emergency room arrival to randomization did not differ in CTP versus MRI-selected patients. Baseline ischemic core volumes were similar in both groups. Reperfusion rates (>90%/TICI [Thrombolysis in Cerebral Infarction] score 3) did not differ in the stentriever-treated patients in the MRI versus CTP groups. The primary efficacy analysis (90-day mRS score) demonstrated a statistically significant benefit in both subgroups (MRI, P=0.02; CTP, P=0.01). Infarct growth was reduced in the stentriever-treated group in both MRI and CTP groups. Time to randomization was significantly longer in MRI-selected patients; however, site arrival to randomization times were not prolonged, and the benefits of endovascular therapy were similar. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01657461. © 2017 American Heart Association, Inc.

  15. Application of computer-assisted navigation system in education of complex zygomatic fractures treatment%计算机辅助导航在复杂颧骨颧弓骨折治疗中的教学应用

    Institute of Scientific and Technical Information of China (English)

    杨荣涛; 李祖兵; 李智; 杨学文

    2016-01-01

    Complex zygomatic fracture is a difficult part in teaching maxillofacial fractures. We applied computer-assisted navigation system for the education of complex zygomatic fractures treatment , making it a bridge between theory and practice. This method greatly motivated students′participation,and promoted their learning efficiency. The application of this technique in teaching practice is improvement and innovation of traditional teaching methods,and is worth to be popularized in oral and maxillofacial surgery teaching.%复杂颧骨颧弓骨折是颌面部骨折的教学难点,将计算机辅助导航应用于复杂颧骨颧弓骨折的教学过程,使其成为理论与实践相互转化的桥梁,极大提高学生主动参与的积极性,提升学习效率.该技术在教学实践中的应用,是对传统教学模式的完善及革新,值得在口腔颌面外科教学过程中推广.

  16. Computational analysis to predict functional role of hsa-miR-3065-3p as an antiviral therapeutic agent for treatment of triple infections: HCV, HIV-1, and HBV

    Directory of Open Access Journals (Sweden)

    Ambreen Khokhar

    2012-12-01

    Full Text Available Background: Triple infection (TI with HIV-1, HCV, and HBV (TI is highly prevalent in intravenous drug users (IDUs. These TI patients have a faster progression to AIDS, and even after antiretroviral therapy (ART the prognosis of their disease is poor. The use of microRNA (miRNA to silence genes holds potential applications for anti-HCV therapy. Methods: We analyzed the role of human miRNAs (hsa-miRs in TI by computational analyses for HCV, HIV-1, and HBV showing identity to these three viral genomes. Results: We identified one unique miRNA, hsa-miR-3065-3p, that shares significant mutual identity to these three viral genomes (∼61–83%. In addition, hsa-miR-99, hsa-miR-548, and hsa-miR-122 also showed mutual identity with these three viral genomes, albeit at a lower degree (∼52–88%. Conclusion: Here, we present evidence using essential components of bioinformatics tools, and hypothesize that utility of hsa-miR-3065-3p and perhaps miR-548 would be potential antiviral therapeutic agents in the treatment of TI patients because it shows near perfect alignment in the seed region for all three viruses. We also make an argument that current proposed therapy with hsa-miR-122 may not be the optimal choice for HCV patients since it lacks essential gene alignment and may be harmful for the patients.

  17. Effect of long-term cholesterol-lowering treatment with HMG-CoA reductase inhibitor (Simvastatin) of myocardial perfusion evaluated by thallium-201 single photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hosokawa, Ryohei; Nohara, Ryuji; Linxue, Li; Sasayama, Shigetake [Kyoto Univ. (Japan). Graduate School of Medicine; Tamaki, Shunichi; Hashimoto, Tetsuo; Tanaka, Masahiro; Miki, Shinji

    2000-03-01

    Fifteen patients with either angina pectoris or old myocardial infarction, who had positive {sup 201}Tl single photon emission computed tomography (SPECT) imaging and coronary sclerosis of more than 50%, were treated with an HMG-CoA reductase inhibitor (simvastatin) for more than 1 year. They were compared with an untreated control group (n=25). Total cholesterol decreased 22% and high-density lipoprotein (HDL) increased 9% with simvastatin; both changes were significantly different from those in controls. Long-term simvastatin induced improvement of myocardial perfusion on {sup 201}Tl SPECT images both during exercise and at rest, which was also significantly different from controls. In addition, the improvement of myocardial perfusion on {sup 201}Tl SPECT images was clearly related to the improvements in cholesterol values, especially nonHDL cholesterol. Thus, the greater the decrease in nonHDL cholesterol, the greater the improvement in myocardial perfusion at rest or during exercise with long-term treatment using an HMG-CoA reductase inhibitor. These findings indicate that the improvements in cholesterol values caused by HMG-CoA reductase inhibitor therapy are related to improvements of myocardial perfusion seen on {sup 201}Tl SPECT images. (author)

  18. Chest computed tomography

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  19. Experimental DNA computing

    NARCIS (Netherlands)

    Henkel, Christiaan

    2005-01-01

    Because of their information storing and processing capabilities, nucleic acids are interesting building blocks for molecular scale computers. Potential applications of such DNA computers range from massively parallel computation to computational gene therapy. In this thesis, several implementations

  20. Analog and hybrid computing

    CERN Document Server

    Hyndman, D E

    2013-01-01

    Analog and Hybrid Computing focuses on the operations of analog and hybrid computers. The book first outlines the history of computing devices that influenced the creation of analog and digital computers. The types of problems to be solved on computers, computing systems, and digital computers are discussed. The text looks at the theory and operation of electronic analog computers, including linear and non-linear computing units and use of analog computers as operational amplifiers. The monograph examines the preparation of problems to be deciphered on computers. Flow diagrams, methods of ampl