WorldWideScience

Sample records for patient specific geometry

  1. Site-Specific Difference of Bone Geometry Indices in Hypoparathyroid Patients

    Directory of Open Access Journals (Sweden)

    Hye-Sun Park

    2017-02-01

    Full Text Available BackgroundHypoparathyroid patients often have a higher bone mineral density (BMD than the general population. However, an increase in BMD does not necessarily correlate with a solid bone microstructure. This study aimed to evaluate the bone microstructure of hypoparathyroid patients by using hip structure analysis (HSA.MethodsNinety-five hypoparathyroid patients >20 years old were enrolled and 31 of them had eligible data for analyzing bone geometry parameters using HSA. And among the control data, we extracted sex-, age-, and body mass index-matched three control subjects to each patient. The BMD data were reviewed retrospectively and the bone geometry parameters of the patients were analyzed by HSA.ResultsThe mean Z-scores of hypoparathyroid patients at the lumbar spine, femoral neck, and total hip were above zero (0.63±1.17, 0.48±1.13, and 0.62±1.10, respectively. The differences in bone geometric parameters were site specific. At the femoral neck and intertrochanter, the cross-sectional area (CSA and cortical thickness (C.th were higher, whereas the buckling ratio (BR was lower than in controls. However, those trends were opposite at the femoral shaft; that is, the CSA and C.th were low and the BR was high.ConclusionOur study shows the site-specific effects of hypoparathyroidism on the bone. Differences in bone components, marrow composition, or modeling based bone formation may explain these findings. However, further studies are warranted to investigate the mechanism, and its relation to fracture risk.

  2. Image-based reconstruction of three-dimensional myocardial infarct geometry for patient-specific modeling of cardiac electrophysiology

    Energy Technology Data Exchange (ETDEWEB)

    Ukwatta, Eranga, E-mail: eukwatt1@jhu.edu; Arevalo, Hermenegild; Pashakhanloo, Farhad; Prakosa, Adityo; Vadakkumpadan, Fijoy [Institute for Computational Medicine, Johns Hopkins University, Baltimore, Maryland 21205 and Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Rajchl, Martin [Department of Computing, Imperial College London, London SW7 2AZ (United Kingdom); White, James [Stephenson Cardiovascular MR Centre, University of Calgary, Calgary, Alberta T2N 2T9 (Canada); Herzka, Daniel A.; McVeigh, Elliot [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Lardo, Albert C. [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 and Division of Cardiology, Johns Hopkins Institute of Medicine, Baltimore, Maryland 21224 (United States); Trayanova, Natalia A. [Institute for Computational Medicine, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Department of Biomedical Engineering, Johns Hopkins Institute of Medicine, Baltimore, Maryland 21205 (United States)

    2015-08-15

    Purpose: Accurate three-dimensional (3D) reconstruction of myocardial infarct geometry is crucial to patient-specific modeling of the heart aimed at providing therapeutic guidance in ischemic cardiomyopathy. However, myocardial infarct imaging is clinically performed using two-dimensional (2D) late-gadolinium enhanced cardiac magnetic resonance (LGE-CMR) techniques, and a method to build accurate 3D infarct reconstructions from the 2D LGE-CMR images has been lacking. The purpose of this study was to address this need. Methods: The authors developed a novel methodology to reconstruct 3D infarct geometry from segmented low-resolution (Lo-res) clinical LGE-CMR images. Their methodology employed the so-called logarithm of odds (LogOdds) function to implicitly represent the shape of the infarct in segmented image slices as LogOdds maps. These 2D maps were then interpolated into a 3D image, and the result transformed via the inverse of LogOdds to a binary image representing the 3D infarct geometry. To assess the efficacy of this method, the authors utilized 39 high-resolution (Hi-res) LGE-CMR images, including 36 in vivo acquisitions of human subjects with prior myocardial infarction and 3 ex vivo scans of canine hearts following coronary ligation to induce infarction. The infarct was manually segmented by trained experts in each slice of the Hi-res images, and the segmented data were downsampled to typical clinical resolution. The proposed method was then used to reconstruct 3D infarct geometry from the downsampled images, and the resulting reconstructions were compared with the manually segmented data. The method was extensively evaluated using metrics based on geometry as well as results of electrophysiological simulations of cardiac sinus rhythm and ventricular tachycardia in individual hearts. Several alternative reconstruction techniques were also implemented and compared with the proposed method. Results: The accuracy of the LogOdds method in reconstructing 3D

  3. Real-time surgery simulation of intracranial aneurysm clipping with patient-specific geometries and haptic feedback

    Science.gov (United States)

    Fenz, Wolfgang; Dirnberger, Johannes

    2015-03-01

    Providing suitable training for aspiring neurosurgeons is becoming more and more problematic. The increasing popularity of the endovascular treatment of intracranial aneurysms leads to a lack of simple surgical situations for clipping operations, leaving mainly the complex cases, which present even experienced surgeons with a challenge. To alleviate this situation, we have developed a training simulator with haptic interaction allowing trainees to practice virtual clipping surgeries on real patient-specific vessel geometries. By using specialized finite element (FEM) algorithms (fast finite element method, matrix condensation) combined with GPU acceleration, we can achieve the necessary frame rate for smooth real-time interaction with the detailed models needed for a realistic simulation of the vessel wall deformation caused by the clamping with surgical clips. Vessel wall geometries for typical training scenarios were obtained from 3D-reconstructed medical image data, while for the instruments (clipping forceps, various types of clips, suction tubes) we use models provided by manufacturer Aesculap AG. Collisions between vessel and instruments have to be continuously detected and transformed into corresponding boundary conditions and feedback forces, calculated using a contact plane method. After a training, the achieved result can be assessed based on various criteria, including a simulation of the residual blood flow into the aneurysm. Rigid models of the surgical access and surrounding brain tissue, plus coupling a real forceps to the haptic input device further increase the realism of the simulation.

  4. Computational study to investigate effect of tonometer geometry and patient-specific variability on radial artery tonometry.

    Science.gov (United States)

    Singh, Pranjal; Choudhury, Mohammed Ikbal; Roy, Sitikantha; Prasad, Anamika

    2017-06-14

    Tonometry-based devices are valuable method for vascular function assessment and for measurement of blood pressure. However current design and calibration methods rely on simple models, neglecting key geometrical features, and anthropometric and property variability among patients. Understanding impact of these influences on tonometer measurement is thus essential for improving outcomes of current devices, and for proposing improved design. Towards this goal, we present a realistic computational model for tissue-device interaction using complete wrist section with hyperelastic material and frictional contact. Three different tonometry geometries were considered including a new design, and patient-specific influences incorporated via anthropometric and age-dependent tissue stiffness variations. The results indicated that the new design showed stable surface contact stress with minimum influence of the parameters analyzed. The computational predictions were validated with experimental data from a prototype based on the new design. Finally, we showed that the underlying mechanics of vascular unloading in tonometry to be fundamentally different from that of oscillatory method. Due to directional loading in tonometry, pulse amplitude maxima was observed to occur at a significantly lower compression level (around 31%) than previously reported, which can impact blood pressure calibration approaches based on maximum pulse pressure recordings. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Geometry reconstruction method for patient-specific finite element models for the assessment of tibia fracture risk in osteogenesis imperfecta.

    Science.gov (United States)

    Caouette, Christiane; Ikin, Nicole; Villemure, Isabelle; Arnoux, Pierre-Jean; Rauch, Frank; Aubin, Carl-Éric

    2017-04-01

    Lower limb deformation in children with osteogenesis imperfecta (OI) impairs ambulation and may lead to fracture. Corrective surgery is based on empirical assessment criteria. The objective was to develop a reconstruction method of the tibia for OI patients that could be used as input of a comprehensive finite element model to assess fracture risks. Data were obtained from three children with OI and tibia deformities. Four pQCT scans were registered to biplanar radiographs, and a template mesh was deformed to fit the bone outline. Cortical bone thickness was computed. Sensitivity of the model to missing slices of pQCT was assessed by calculating maximal von Mises stress for a vertical hopping load case. Sensitivity of the model to ±5 % of cortical thickness measurements was assessed by calculating loads at fracture. Difference between the mesh contour and bone outline on the radiographs was below 1 mm. Removal of one pQCT slice increased maximal von Mises stress by up to 10 %. Simulated ±5 % variation of cortical bone thickness leads to variations of up to 4.1 % on predicted fracture loads. Using clinically available tibia imaging from children with OI, the developed reconstruction method allowed the building of patient-specific finite element models.

  6. Recommendations by NACP for accurate treatment geometry specification

    International Nuclear Information System (INIS)

    Aaltonen, P.

    1995-01-01

    An investigation among the Nordic radiotherapy centres in 1991 confirmed that inconsistent use of dose and volume concepts is jeopardizing the high standard of radiation therapy. A Nordic working group was set up by NACP to standardize the concepts and quantities used throughout the whole radiation process. Now the draft report 'Specification of Dose Delivery in Radiation Therapy' is discussed with the radiotherapy community. The recent ICRU 50 report is the first step towards a uniform terminology and procedure at all radiotherapy centres. The new NACP report will be an important and more detailed addition for level 2-3 radiotherapy clinics and it will be specially adopted to the situation at the Nordic centres as well as other well equipped centres. The aim has been to recommend the use of concepts based on recent scientific development in the field of radiation therapy which are needed for the development of daily clinical practice. The terms and concepts for treatment geometry have been chosen by separating the concepts of tissues and volumes inside a patient. The tissues can be fixed in the coordinate system of the patient by adding a margin around them. This margin accounts for the movements of the tissues of interest inside the patient. The outer boundary of this margin is then encompassing the Strict Target Volume or Organ at Risk Volume which are fixed in the patient coordinate system. The set-up uncertainties of the patient in relation to the beams are considered during treatment planning by adding set-up margins to the beams

  7. On the optimization of low-cost FDM 3D printers for accurate replication of patient-specific abdominal aortic aneurysm geometry.

    Science.gov (United States)

    Chung, Michael; Radacsi, Norbert; Robert, Colin; McCarthy, Edward D; Callanan, Anthony; Conlisk, Noel; Hoskins, Peter R; Koutsos, Vasileios

    2018-01-01

    There is a potential for direct model manufacturing of abdominal aortic aneurysm (AAA) using 3D printing technique for generating flexible semi-transparent prototypes. A patient-specific AAA model was manufactured using fused deposition modelling (FDM) 3D printing technology. A flexible, semi-transparent thermoplastic polyurethane (TPU), called Cheetah Water (produced by Ninjatek, USA), was used as the flexible, transparent material for model manufacture with a hydrophilic support structure 3D printed with polyvinyl alcohol (PVA). Printing parameters were investigated to evaluate their effect on 3D-printing precision and transparency of the final model. ISO standard tear resistance tests were carried out on Ninjatek Cheetah specimens for a comparison of tear strength with silicone rubbers. It was found that an increase in printing speed decreased printing accuracy, whilst using an infill percentage of 100% and printing nozzle temperature of 255 °C produced the most transparent results. The model had fair transparency, allowing external inspection of model inserts such as stent grafts, and good flexibility with an overall discrepancy between CAD and physical model average wall thicknesses of 0.05 mm (2.5% thicker than the CAD model). The tear resistance test found Ninjatek Cheetah TPU to have an average tear resistance of 83 kN/m, higher than any of the silicone rubbers used in previous AAA model manufacture. The model had lower cost (4.50 GBP per model), shorter manufacturing time (25 h 3 min) and an acceptable level of accuracy (2.61% error) compared to other methods. It was concluded that the model would be of use in endovascular aneurysm repair planning and education, particularly for practicing placement of hooked or barbed stents, due to the model's balance of flexibility, transparency, robustness and cost-effectiveness.

  8. Geometries

    CERN Document Server

    Sossinsky, A B

    2012-01-01

    The book is an innovative modern exposition of geometry, or rather, of geometries; it is the first textbook in which Felix Klein's Erlangen Program (the action of transformation groups) is systematically used as the basis for defining various geometries. The course of study presented is dedicated to the proposition that all geometries are created equal--although some, of course, remain more equal than others. The author concentrates on several of the more distinguished and beautiful ones, which include what he terms "toy geometries", the geometries of Platonic bodies, discrete geometries, and classical continuous geometries. The text is based on first-year semester course lectures delivered at the Independent University of Moscow in 2003 and 2006. It is by no means a formal algebraic or analytic treatment of geometric topics, but rather, a highly visual exposition containing upwards of 200 illustrations. The reader is expected to possess a familiarity with elementary Euclidean geometry, albeit those lacking t...

  9. Geometry

    Indian Academy of Sciences (India)

    . In the previous article we looked at the origins of synthetic and analytic geometry. More practical minded people, the builders and navigators, were studying two other aspects of geometry- trigonometry and integral calculus. These are actually ...

  10. Geometry

    CERN Document Server

    Prasolov, V V

    2015-01-01

    This book provides a systematic introduction to various geometries, including Euclidean, affine, projective, spherical, and hyperbolic geometries. Also included is a chapter on infinite-dimensional generalizations of Euclidean and affine geometries. A uniform approach to different geometries, based on Klein's Erlangen Program is suggested, and similarities of various phenomena in all geometries are traced. An important notion of duality of geometric objects is highlighted throughout the book. The authors also include a detailed presentation of the theory of conics and quadrics, including the theory of conics for non-Euclidean geometries. The book contains many beautiful geometric facts and has plenty of problems, most of them with solutions, which nicely supplement the main text. With more than 150 figures illustrating the arguments, the book can be recommended as a textbook for undergraduate and graduate-level courses in geometry.

  11. Patient-Specific MRI-Based Right Ventricle Models Using Different Zero-Load Diastole and Systole Geometries for Better Cardiac Stress and Strain Calculations and Pulmonary Valve Replacement Surgical Outcome Predictions.

    Directory of Open Access Journals (Sweden)

    Dalin Tang

    Full Text Available Accurate calculation of ventricular stress and strain is critical for cardiovascular investigations. Sarcomere shortening in active contraction leads to change of ventricular zero-stress configurations during the cardiac cycle. A new model using different zero-load diastole and systole geometries was introduced to provide more accurate cardiac stress/strain calculations with potential to predict post pulmonary valve replacement (PVR surgical outcome.Cardiac magnetic resonance (CMR data were obtained from 16 patients with repaired tetralogy of Fallot prior to and 6 months after pulmonary valve replacement (8 male, 8 female, mean age 34.5 years. Patients were divided into Group 1 (n = 8 with better post PVR outcome and Group 2 (n = 8 with worse post PVR outcome based on their change in RV ejection fraction (EF. CMR-based patient-specific computational RV/LV models using one zero-load geometry (1G model and two zero-load geometries (diastole and systole, 2G model were constructed and RV wall thickness, volume, circumferential and longitudinal curvatures, mechanical stress and strain were obtained for analysis. Pairwise T-test and Linear Mixed Effect (LME model were used to determine if the differences from the 1G and 2G models were statistically significant, with the dependence of the pair-wise observations and the patient-slice clustering effects being taken into consideration. For group comparisons, continuous variables (RV volumes, WT, C- and L- curvatures, and stress and strain values were summarized as mean ± SD and compared between the outcome groups by using an unpaired Student t-test. Logistic regression analysis was used to identify potential morphological and mechanical predictors for post PVR surgical outcome.Based on results from the 16 patients, mean begin-ejection stress and strain from the 2G model were 28% and 40% higher than that from the 1G model, respectively. Using the 2G model results, RV EF changes correlated negatively with

  12. Geometry

    CERN Document Server

    Pedoe, Dan

    1988-01-01

    ""A lucid and masterly survey."" - Mathematics Gazette Professor Pedoe is widely known as a fine teacher and a fine geometer. His abilities in both areas are clearly evident in this self-contained, well-written, and lucid introduction to the scope and methods of elementary geometry. It covers the geometry usually included in undergraduate courses in mathematics, except for the theory of convex sets. Based on a course given by the author for several years at the University of Minnesota, the main purpose of the book is to increase geometrical, and therefore mathematical, understanding and to he

  13. Patient-specific models of cardiac biomechanics

    Science.gov (United States)

    Krishnamurthy, Adarsh; Villongco, Christopher T.; Chuang, Joyce; Frank, Lawrence R.; Nigam, Vishal; Belezzuoli, Ernest; Stark, Paul; Krummen, David E.; Narayan, Sanjiv; Omens, Jeffrey H.; McCulloch, Andrew D.; Kerckhoffs, Roy C. P.

    2013-07-01

    Patient-specific models of cardiac function have the potential to improve diagnosis and management of heart disease by integrating medical images with heterogeneous clinical measurements subject to constraints imposed by physical first principles and prior experimental knowledge. We describe new methods for creating three-dimensional patient-specific models of ventricular biomechanics in the failing heart. Three-dimensional bi-ventricular geometry is segmented from cardiac CT images at end-diastole from patients with heart failure. Human myofiber and sheet architecture is modeled using eigenvectors computed from diffusion tensor MR images from an isolated, fixed human organ-donor heart and transformed to the patient-specific geometric model using large deformation diffeomorphic mapping. Semi-automated methods were developed for optimizing the passive material properties while simultaneously computing the unloaded reference geometry of the ventricles for stress analysis. Material properties of active cardiac muscle contraction were optimized to match ventricular pressures measured by cardiac catheterization, and parameters of a lumped-parameter closed-loop model of the circulation were estimated with a circulatory adaptation algorithm making use of information derived from echocardiography. These components were then integrated to create a multi-scale model of the patient-specific heart. These methods were tested in five heart failure patients from the San Diego Veteran's Affairs Medical Center who gave informed consent. The simulation results showed good agreement with measured echocardiographic and global functional parameters such as ejection fraction and peak cavity pressures.

  14. Patient-specific surgical simulation.

    Science.gov (United States)

    Soler, Luc; Marescaux, Jacques

    2008-02-01

    Technological innovations of the twentieth century have provided medicine and surgery with new tools for education and therapy definition. Thus, by combining Medical Imaging and Virtual Reality, patient-specific applications providing preoperative surgical simulation have become possible.

  15. Patient-Specific Computational Modeling

    CERN Document Server

    Peña, Estefanía

    2012-01-01

    This book addresses patient-specific modeling. It integrates computational modeling, experimental procedures, imagine clinical segmentation and mesh generation with the finite element method (FEM) to solve problems in computational biomedicine and bioengineering. Specific areas of interest include cardiovascular problems, ocular and muscular systems and soft tissue modeling. Patient-specific modeling has been the subject of serious research over the last seven years and interest in the area is continually growing and this area is expected to further develop in the near future.

  16. Complexities of three dimensional part geometry. [Ambiguities in specification of pieces for manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Stark, R.H.

    1977-05-01

    This report is a non-technical exposition on the ambiguities in conventional specification of the shape of a part to be manufactured and on various alternatives for representing its geometry for computer processing. It touches lightly on wire-frame and bounded surface representations and on the concept of design by volumes. It concludes that no existing computer-aided design system has yet shown its long-range superiority over he spectrum of parts and of uses to which its information base should be applicable. 9 figures.

  17. Morphing methods to parameterize specimen-specific finite element model geometries.

    Science.gov (United States)

    Sigal, Ian A; Yang, Hongli; Roberts, Michael D; Downs, J Crawford

    2010-01-19

    Shape plays an important role in determining the biomechanical response of a structure. Specimen-specific finite element (FE) models have been developed to capture the details of the shape of biological structures and predict their biomechanics. Shape, however, can vary considerably across individuals or change due to aging or disease, and analysis of the sensitivity of specimen-specific models to these variations has proven challenging. An alternative to specimen-specific representation has been to develop generic models with simplified geometries whose shape is relatively easy to parameterize, and can therefore be readily used in sensitivity studies. Despite many successful applications, generic models are limited in that they cannot make predictions for individual specimens. We propose that it is possible to harness the detail available in specimen-specific models while leveraging the power of the parameterization techniques common in generic models. In this work we show that this can be accomplished by using morphing techniques to parameterize the geometry of specimen-specific FE models such that the model shape can be varied in a controlled and systematic way suitable for sensitivity analysis. We demonstrate three morphing techniques by using them on a model of the load-bearing tissues of the posterior pole of the eye. We show that using relatively straightforward procedures these morphing techniques can be combined, which allows the study of factor interactions. Finally, we illustrate that the techniques can be used in other systems by applying them to morph a femur. Morphing techniques provide an exciting new possibility for the analysis of the biomechanical role of shape, independently or in interaction with loading and material properties. Copyright 2009 Elsevier Ltd. All rights reserved.

  18. Subject-specific knee joint geometry improves predictions of medial tibiofemoral contact forces

    Science.gov (United States)

    Gerus, Pauline; Sartori, Massimo; Besier, Thor F.; Fregly, Benjamin J.; Delp, Scott L.; Banks, Scott A.; Pandy, Marcus G.; D’Lima, Darryl D.; Lloyd, David G.

    2013-01-01

    Estimating tibiofemoral joint contact forces is important for understanding the initiation and progression of knee osteoarthritis. However, tibiofemoral contact force predictions are influenced by many factors including muscle forces and anatomical representations of the knee joint. This study aimed to investigate the influence of subject-specific geometry and knee joint kinematics on the prediction of tibiofemoral contact forces using a calibrated EMG-driven neuromusculoskeletal model of the knee. One participant fitted with an instrumented total knee replacement walked at a self-selected speed while medial and lateral tibiofemoral contact forces, ground reaction forces, whole-body kinematics, and lower-limb muscle activity were simultaneously measured. The combination of generic and subject-specific knee joint geometry and kinematics resulted in four different OpenSim models used to estimate muscle-tendon lengths and moment arms. The subject-specific geometric model was created from CT scans and the subject-specific knee joint kinematics representing the translation of the tibia relative to the femur was obtained from fluoroscopy. The EMG-driven model was calibrated using one walking trial, but with three different cost functions that tracked the knee flexion/extension moments with and without constraint over the estimated joint contact forces. The calibrated models then predicted the medial and lateral tibiofemoral contact forces for five other different walking trials. The use of subject-specific models with minimization of the peak tibiofemoral contact forces improved the accuracy of medial contact forces by 47% and lateral contact forces by 7%, respectively compared with the use of generic musculoskeletal model. PMID:24074941

  19. Automatic selective feature retention in patient specific elastic surface registration

    CSIR Research Space (South Africa)

    Jansen van Rensburg, GJ

    2011-01-01

    Full Text Available The accuracy with which a recent elastic surface registration algorithm deforms the complex geometry of a skull is examined. This algorithm is then coupled to a line based algorithm as is frequently used in patient specific feature registration...

  20. Aortic root geometry in aortic stenosis patients (a SEAS substudy)

    DEFF Research Database (Denmark)

    Bahlmann, Edda; Nienaber, Christoph A; Cramariuc, Dana

    2011-01-01

    -specified requirements for the aortic root geometry for current available prostheses, CoreValve and Edwards-Sapien. The ratio of sinus of Valsalva height to sinus width was 1:2. In multivariate linear regression analysis, larger sinus of Valsalva height was associated with older age, larger sinus of Valsalva diameter......, lower ejection fraction and smaller supracoronary diameter (multiple R(2) = 0.19, PSapien prosthesis in 66.9%. Overall, annular dimension feasible for TAVI using any available prosthesis was found...

  1. Software development for specific geometry and safe design of isotropic material multicell beams

    International Nuclear Information System (INIS)

    Tariq, M.M.; Ahmed, M.A.

    2011-01-01

    Comparison of analytical results with finite element results for analysis of isotropic material multicell beams subjected to free torsion case is the main idea of this paper. Progress in the fundamentals and applications of advanced materials and their processing technologies involves costly experiments and prototype testing for reliability. The software development for design analysis of structures with advanced materials is a low cost but challenging research. Multicell beams have important industrial applications in the aerospace and automotive sectors. This paper explains software development to test different materials in design of a multicell beam. Objective of this paper is to compute the torsional loading of multicell beams of isotropic materials for safe design in both symmetrical and asymmetrical geometries. Software has been developed in Microsoft Visual Basic. Distribution of Saint Venant shear flows, shear stresses, factors of safety, volume, mass, weight, twist, polar moment of inertia and aspect ratio for free torsion in multicell beam have been calculated using this software. The software works on four algorithms, these are, Specific geometry algorithm, material selection algorithm, factor of safety algorithm and global algorithm. User can specify new materials analytically, or choose a pre-defined material from the list, which includes, plain carbon steels, low alloy steels, stainless steels, cast irons, aluminum alloys, copper alloys, magnesium alloys, titanium alloys, precious metals and refractory metals. Although this software is restricted to multicell beam comprising of three cells, however future versions can have ability to address more complicated shapes and cases of multicell beams. Software also describes nomenclature and mathematical formulas applied to help user understand the theoretical background. User can specify geometry of multicell beam for three rectangular cells. Software computes shear flows, shear stresses, safety factors

  2. Sensitivity of subject-specific models to errors in musculo-skeletal geometry.

    Science.gov (United States)

    Carbone, V; van der Krogt, M M; Koopman, H F J M; Verdonschot, N

    2012-09-21

    Subject-specific musculo-skeletal models of the lower extremity are an important tool for investigating various biomechanical problems, for instance the results of surgery such as joint replacements and tendon transfers. The aim of this study was to assess the potential effects of errors in musculo-skeletal geometry on subject-specific model results. We performed an extensive sensitivity analysis to quantify the effect of the perturbation of origin, insertion and via points of each of the 56 musculo-tendon parts contained in the model. We used two metrics, namely a Local Sensitivity Index (LSI) and an Overall Sensitivity Index (OSI), to distinguish the effect of the perturbation on the predicted force produced by only the perturbed musculo-tendon parts and by all the remaining musculo-tendon parts, respectively, during a simulated gait cycle. Results indicated that, for each musculo-tendon part, only two points show a significant sensitivity: its origin, or pseudo-origin, point and its insertion, or pseudo-insertion, point. The most sensitive points belong to those musculo-tendon parts that act as prime movers in the walking movement (insertion point of the Achilles Tendon: LSI=15.56%, OSI=7.17%; origin points of the Rectus Femoris: LSI=13.89%, OSI=2.44%) and as hip stabilizers (insertion points of the Gluteus Medius Anterior: LSI=17.92%, OSI=2.79%; insertion point of the Gluteus Minimus: LSI=21.71%, OSI=2.41%). The proposed priority list provides quantitative information to improve the predictive accuracy of subject-specific musculo-skeletal models. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Evaluation of blood flow distribution asymmetry and vascular geometry in patients with Fontan circulation using 4-D flow MRI

    International Nuclear Information System (INIS)

    Jarvis, Kelly; Markl, Michael; Schnell, Susanne; Barker, Alex J.; Garcia, Julio; Chowdhary, Varun; Carr, James; Lorenz, Ramona; Rose, Michael; Robinson, Joshua D.; Rigsby, Cynthia K.

    2016-01-01

    Asymmetrical caval to pulmonary blood flow is suspected to cause complications in patients with Fontan circulation. The aim of this study was to test the feasibility of 4-D flow MRI for characterizing the relationship between 3-D blood flow distribution and vascular geometry. We hypothesized that both flow distribution and geometry can be calculated with low interobserver variability and will detect a direct relationship between flow distribution and Fontan geometry. Four-dimensional flow MRI was acquired in 10 Fontan patients (age: 16 ± 4 years [mean ± standard deviation], range: 9-21 years). The Fontan connection was isolated by 3-D segmentation to evaluate flow distribution from the inferior vena cava (IVC) and superior vena cava (SVC) to the left and right pulmonary arteries (LPA, RPA) and to characterize geometry (cross-sectional area, caval offset, vessel angle). Flow distribution results indicated SVC flow tended toward the RPA while IVC flow was more evenly distributed (SVC to RPA: 78% ± 28 [9-100], IVC to LPA: 54% ± 28 [4-98]). There was a significant relationship between pulmonary artery cross-sectional area and flow distribution (IVC to RPA: R"2=0.50, P=0.02; SVC to LPA: R"2=0.81, P=0.0004). Good agreement was found between observers and for flow distribution when compared to net flow values. Four-dimensional flow MRI was able to detect relationships between flow distribution and vessel geometry. Future studies are warranted to investigate the potential of patient specific hemodynamic analysis to improve diagnostic capability. (orig.)

  4. Evaluation of blood flow distribution asymmetry and vascular geometry in patients with Fontan circulation using 4-D flow MRI

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, Kelly; Markl, Michael [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Chicago, IL (United States); Schnell, Susanne; Barker, Alex J.; Garcia, Julio; Chowdhary, Varun; Carr, James [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Lorenz, Ramona [University Medical Center Freiburg, Department of Radiology, Freiburg (Germany); Rose, Michael [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States); Robinson, Joshua D. [Northwestern University, Department of Pediatrics, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert H. Lurie Children' s Hospital of Chicago, Division of Cardiology, Chicago, IL (United States); Rigsby, Cynthia K. [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States)

    2016-10-15

    Asymmetrical caval to pulmonary blood flow is suspected to cause complications in patients with Fontan circulation. The aim of this study was to test the feasibility of 4-D flow MRI for characterizing the relationship between 3-D blood flow distribution and vascular geometry. We hypothesized that both flow distribution and geometry can be calculated with low interobserver variability and will detect a direct relationship between flow distribution and Fontan geometry. Four-dimensional flow MRI was acquired in 10 Fontan patients (age: 16 ± 4 years [mean ± standard deviation], range: 9-21 years). The Fontan connection was isolated by 3-D segmentation to evaluate flow distribution from the inferior vena cava (IVC) and superior vena cava (SVC) to the left and right pulmonary arteries (LPA, RPA) and to characterize geometry (cross-sectional area, caval offset, vessel angle). Flow distribution results indicated SVC flow tended toward the RPA while IVC flow was more evenly distributed (SVC to RPA: 78% ± 28 [9-100], IVC to LPA: 54% ± 28 [4-98]). There was a significant relationship between pulmonary artery cross-sectional area and flow distribution (IVC to RPA: R{sup 2}=0.50, P=0.02; SVC to LPA: R{sup 2}=0.81, P=0.0004). Good agreement was found between observers and for flow distribution when compared to net flow values. Four-dimensional flow MRI was able to detect relationships between flow distribution and vessel geometry. Future studies are warranted to investigate the potential of patient specific hemodynamic analysis to improve diagnostic capability. (orig.)

  5. Specific features of time-dependent Psub(N) approximations in spherical geometry

    International Nuclear Information System (INIS)

    Peltzer, P.; Pucker, N.

    1979-01-01

    Approximations to the time-dependent linear transport equation can result in more serious distortions in the description of the actual physical situation than in the stationary problem. This is demonstrated in detail for the case of a neutron pulse in spherical geometry, treated within a P 1 approximation. One has to pay special attention to the singularity at r = 0 and to the effect of the boundary conditions. Effects similar to those shown here are also to be expected in connection with Psub(N) approximations of higher order. (Auth.)

  6. The Effect of Inlet Waveforms on Computational Hemodynamics of Patient-Specific Intracranial Aneurysms

    OpenAIRE

    Xiang, J.; Siddiqui, A.H.; Meng, H.

    2014-01-01

    Due to the lack of patient-specific inlet flow waveform measurements, most computational fluid dynamics (CFD) simulations of intracranial aneurysms usually employ waveforms that are not patient-specific as inlet boundary conditions for the computational model. The current study examined how this assumption affects the predicted hemodynamics in patient-specific aneurysm geometries. We examined wall shear stress (WSS) and oscillatory shear index (OSI), the two most widely studied hemodynamic qu...

  7. Calculation of coincidence summing corrections for a specific small soil sample geometry

    Energy Technology Data Exchange (ETDEWEB)

    Helmer, R.G.; Gehrke, R.J.

    1996-10-01

    Previously, a system was developed at the INEL for measuring the {gamma}-ray emitting nuclides in small soil samples for the purpose of environmental monitoring. These samples were counted close to a {approx}20% Ge detector and, therefore, it was necessary to take into account the coincidence summing that occurs for some nuclides. In order to improve the technical basis for the coincidence summing corrections, the authors have carried out a study of the variation in the coincidence summing probability with position within the sample volume. A Monte Carlo electron and photon transport code (CYLTRAN) was used to compute peak and total efficiencies for various photon energies from 30 to 2,000 keV at 30 points throughout the sample volume. The geometry for these calculations included the various components of the detector and source along with the shielding. The associated coincidence summing corrections were computed at these 30 positions in the sample volume and then averaged for the whole source. The influence of the soil and the detector shielding on the efficiencies was investigated.

  8. Left Ventricular Diastolic Function in Essential Hypertensive Patients: Influence of Age and Left Ventricular Geometry

    Directory of Open Access Journals (Sweden)

    Rosa Eduardo Cantoni

    2002-01-01

    Full Text Available PURPOSE - To evaluate diastolic dysfunction (DD in essential hypertension and the influence of age and cardiac geometry on this parameter. METHODS - Four hundred sixty essential hypertensive patients (HT underwent Doppler echocardiography to obtain E/A wave ratio (E/A, atrial deceleration time (ADT, and isovolumetric relaxation time (IRT. All patients were grouped according to cardiac geometric patterns (NG - normal geometry; CR - concentric remodeling; CH- concentric hypertrophy; EH - eccentric hypertrophy and to age (60 years. One hundred six normotensives (NT persons were also evaluated. RESULTS - A worsening of diastolic function in the HT compared with the NT, including HT with NG (E/A: NT - 1.38±0.03 vs HT - 1.27±0.02, p<0.01, was observed. A higher prevalence of DD occurred parallel to age and cardiac geometry also in the prehypertrophic groups (CR. Multiple regression analysis identified age as the most important predictor of DD (r²=0.30, p<0.01. CONCLUSION - DD was prevalent in this hypertensive population, being highly affected by age and less by heart structural parameters. DD is observed in incipient stages of hypertensive heart disease, and thus its early detection may help in the risk stratification of hypertensive patients.

  9. Patient specific 3D printed phantom for IMRT quality assurance

    International Nuclear Information System (INIS)

    Ehler, Eric D; Higgins, Patrick D; Dusenbery, Kathryn E; Barney, Brett M

    2014-01-01

    The purpose of this study was to test the feasibility of a patient specific phantom for patient specific dosimetric verification. Using the head and neck region of an anthropomorphic phantom as a substitute for an actual patient, a soft-tissue equivalent model was constructed with the use of a 3D printer. Calculated and measured dose in the anthropomorphic phantom and the 3D printed phantom was compared for a parallel-opposed head and neck field geometry to establish tissue equivalence. A nine-field IMRT plan was constructed and dose verification measurements were performed for the 3D printed phantom as well as traditional standard phantoms. The maximum difference in calculated dose was 1.8% for the parallel-opposed configuration. Passing rates of various dosimetric parameters were compared for the IMRT plan measurements; the 3D printed phantom results showed greater disagreement at superficial depths than other methods. A custom phantom was created using a 3D printer. It was determined that the use of patient specific phantoms to perform dosimetric verification and estimate the dose in the patient is feasible. In addition, end-to-end testing on a per-patient basis was possible with the 3D printed phantom. Further refinement of the phantom construction process is needed for routine use. (paper)

  10. Patient-Specific Modeling in Tomorrow's Medicine

    CERN Document Server

    2012-01-01

    This book reviews the frontier of research and clinical applications of Patient Specific Modeling, and provides a state-of-the-art update as well as perspectives on future directions in this exciting field. The book is useful for medical physicists, biomedical engineers and other engineers who are interested in the science and technology aspects of Patient Specific Modeling, as well as for radiologists and other medical specialists who wish to be updated about the state of implementation.

  11. Sensitivity of subject-specific models to errors in musculo-skeletal geometry

    NARCIS (Netherlands)

    Carbone, V.; van der Krogt, M.M.; Koopman, H.F.J.M.; Verdonschot, N.

    2012-01-01

    Subject-specific musculo-skeletal models of the lower extremity are an important tool for investigating various biomechanical problems, for instance the results of surgery such as joint replacements and tendon transfers. The aim of this study was to assess the potential effects of errors in

  12. Spinning geometry = Twisted geometry

    International Nuclear Information System (INIS)

    Freidel, Laurent; Ziprick, Jonathan

    2014-01-01

    It is well known that the SU(2)-gauge invariant phase space of loop gravity can be represented in terms of twisted geometries. These are piecewise-linear-flat geometries obtained by gluing together polyhedra, but the resulting geometries are not continuous across the faces. Here we show that this phase space can also be represented by continuous, piecewise-flat three-geometries called spinning geometries. These are composed of metric-flat three-cells glued together consistently. The geometry of each cell and the manner in which they are glued is compatible with the choice of fluxes and holonomies. We first remark that the fluxes provide each edge with an angular momentum. By studying the piecewise-flat geometries which minimize edge lengths, we show that these angular momenta can be literally interpreted as the spin of the edges: the geometries of all edges are necessarily helices. We also show that the compatibility of the gluing maps with the holonomy data results in the same conclusion. This shows that a spinning geometry represents a way to glue together the three-cells of a twisted geometry to form a continuous geometry which represents a point in the loop gravity phase space. (paper)

  13. Retinal vascular geometry and its association to microvascular complications in patients with type 1 diabetes

    DEFF Research Database (Denmark)

    Rasmussen, M L; Broe, Rebecca; Frydkjaer-Olsen, Ulrik

    2017-01-01

    PURPOSE: To examine associations between retinal vascular geometry (tortuosity, branching coefficient [BC] and length-diameter ratio [LDR]) and diabetic proliferative retinopathy (PDR), nephropathy, and peripheral neuropathy in patients with type 1 diabetes mellitus (T1DM). METHODS: A cohort...... of patients with T1DM participated in a clinical examination in 2011. Blood and urine analyses were done and retinal images taken. PDR was defined as Early Treatment Diabetic Retinopathy Study level 61 or above, nephropathy as albumin-creatinin ratio ≥300 mg/g, and neuropathy as vibration perception threshold.......8% were male. Prevalence of PDR, nephropathy, and neuropathy were 26.5%, 6.8%, and 10.1% , respectively. Patients with increased arteriolar BC had a higher risk of nephropathy (OR: 3.10, 95% CI: [1.01-9.54]). Patients with increased venular BC had a higher risk of neuropathy (OR: 2.11, 95% CI: [1...

  14. Patient-specific workup of adrenal incidentalomas

    Directory of Open Access Journals (Sweden)

    Romy R. de Haan

    Full Text Available Purpose: : To develop a clinical prediction model to predict a clinically relevant adrenal disorder for patients with adrenal incidentaloma. Materials and methods: : This retrospective study is approved by the institutional review board, with waiver of informed consent. Natural language processing is used for filtering of adrenal incidentaloma cases in all thoracic and abdominal CT reports from 2010 till 2012. A total of 635 patients are identified. Stepwise logistic regression is used to construct the prediction model. The model predicts if a patient is at risk for malignancy or hormonal hyperfunction of the adrenal gland at the moment of initial presentation, thus generates a predicted probability for every individual patient. The prediction model is evaluated on its usefulness in clinical practice using decision curve analysis (DCA based on different threshold probabilities. For patients whose predicted probability is lower than the predetermined threshold probability, further workup could be omitted. Results: : A prediction model is successfully developed, with an area under the curve (AUC of 0.78. Results of the DCA indicate that up to 11% of patients with an adrenal incidentaloma can be avoided from unnecessary workup, with a sensitivity of 100% and specificity of 11%. Conclusion: : A prediction model can accurately predict if an adrenal incidentaloma patient is at risk for malignancy or hormonal hyperfunction of the adrenal gland based on initial imaging features and patient demographics. However, with most adrenal incidentalomas labeled as nonfunctional adrenocortical adenomas requiring no further treatment, it is likely that more patients could be omitting from unnecessary diagnostics. Keywords: Adrenal incidentaloma, Patient-specific workup, Prediction model

  15. Internal emitter dosimetry: are patient-specific calculations necessary?

    International Nuclear Information System (INIS)

    Sgouros, G.

    1996-01-01

    Full text: The question of whether patient-specific calculations are needed in internal emitter dosimetry arises when radionuclides are used for therapy. In diagnostic procedures the absorbed dose delivered to normal tissue is far below hazardous levels. In internal emitter therapy, the need for patient-specific dosimetry may arise if a large variability in biodistribution, normal tissue toxicity or efficacy is anticipated. Patient-specificity may be accomplished at the level of pharmacokinetics, anatomy/tumor-geometry or both. At the first level, information regarding the biodistribution of a particular radiolabeled agent is obtained and used to determine the maximum activity that may be administered for treatment. The classical example of this is radioiodine therapy for thyroid cancer. In radioiodine therapy, the therapy dose is preceded by a tracer dose of I-131-iodide which is used to measure patient kinetics by imaging and whole-body counting. Absorbed dose estimates obtained from these data are used to constrain the therapy dose to meet safety criteria established in a previously performed dose-response study. The most ambitious approach to patient-specific dosimetry, requires a three-dimensional set of images representing radionuclide distribution (SPECT or PET) and a corresponding set of registered images representing anatomy (CT or MRI). The spatial distribution of absorbed dose or dose-rate may then be obtained by convolution of a point-kernel with the radioactivity distribution or by Monte Carlo calculation. The spatial absorbed dose or dose-rate distribution may be represented as a set of images, as isodose contours, or as dose-volume histograms. The 3-D Monte Carlo approach is, in principle, the most patient-specific; it accounts for patient anatomy and tumor geometry as well as for the spatial distribution of radioactivity. It is also, however, the most logistically and technically demanding. Patients are required to undergo CT or MRI and at least one

  16. 3D-printed patient-specific applications in orthopedics

    Directory of Open Access Journals (Sweden)

    Wong KC

    2016-10-01

    Full Text Available Kwok Chuen Wong Department of Orthopedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong Abstract: With advances in both medical imaging and computer programming, two-dimensional axial images can be processed into other reformatted views (sagittal and coronal and three-dimensional (3D virtual models that represent a patients’ own anatomy. This processed digital information can be analyzed in detail by orthopedic surgeons to perform patient-specific orthopedic procedures. The use of 3D printing is rising and has become more prevalent in medical applications over the last decade as surgeons and researchers are increasingly utilizing the technology’s flexibility in manufacturing objects. 3D printing is a type of manufacturing process in which materials such as plastic or metal are deposited in layers to create a 3D object from a digital model. This additive manufacturing method has the advantage of fabricating objects with complex freeform geometry, which is impossible using traditional subtractive manufacturing methods. Specifically in surgical applications, the 3D printing techniques can not only generate models that give a better understanding of the complex anatomy and pathology of the patients and aid in education and surgical training, but can also produce patient-specific surgical guides or even custom implants that are tailor-made to the surgical requirements. As the clinical workflow of the 3D printing technology continues to evolve, orthopedic surgeons should embrace the latest knowledge of the technology and incorporate it into their clinical practice for patient-specific orthopedic applications. This paper is written to help orthopedic surgeons stay up-to-date on the emerging 3D technology, starting from the acquisition of clinical imaging to 3D printing for patient-specific applications in orthopedics. It 1 presents the necessary steps to prepare the medical images that are

  17. SU-E-J-128: 3D Surface Reconstruction of a Patient Using Epipolar Geometry

    Energy Technology Data Exchange (ETDEWEB)

    Kotoku, J; Nakabayashi, S; Kumagai, S; Ishibashi, T; Kobayashi, T [Teikyo University, Itabashi-ku, Tokyo (Japan); Haga, A; Saotome, N [University of Tokyo Hospital, Bunkyo-ku, Tokyo (Japan); Arai, N [Teikyo University Hospital, Itabashi-ku, Tokyo (Japan)

    2014-06-01

    Purpose: To obtain a 3D surface data of a patient in a non-invasive way can substantially reduce the effort for the registration of patient in radiation therapy. To achieve this goal, we introduced the multiple view stereo technique, which is known to be used in a 'photo tourism' on the internet. Methods: 70 Images were taken with a digital single-lens reflex camera from different angles and positions. The camera positions and angles were inferred later in the reconstruction step. A sparse 3D reconstruction model was locating by SIFT features, which is robust for rotation and shift variance, in each image. We then found a set of correspondences between pairs of images by computing the fundamental matrix using the eight-point algorithm with RANSAC. After the pair matching, we optimized the parameter including camera positions to minimize the reprojection error by use of bundle adjustment technique (non-linear optimization). As a final step, we performed dense reconstruction and associate a color with each point using the library of PMVS. Results: Surface data were reconstructed well by visual inspection. The human skin is reconstructed well, althogh the reconstruction was time-consuming for direct use in daily clinical practice. Conclusion: 3D reconstruction using multi view stereo geometry is a promising tool for reducing the effort of patient setup. This work was supported by JSPS KAKENHI(25861128)

  18. Femoral Geometry in Male Patients with Atraumatic Hip Fracture - Original Investigation

    Directory of Open Access Journals (Sweden)

    Gülten Tan

    2007-03-01

    Full Text Available Aims: Hip fracture is the most serious complication of osteoporosis and the most disabling type of fracture. In this study, we aimed to compare femoral geometry in hip fractured male patients aged more than 65 years old with age matched controls. Patients and Methods: 20 male patients with a history of nontraumatic hip fracture and 19 age-matched healthy controls were included in this study. Bone mineral density of neck and trochanter of hip were measured by DEXA. In addition to BMD, an experienced radiologist measured proximal femur geometric parameters potentially involved in bone strength. Results: Mean BMDs of trochanteric region were not significantly different between groups, but mean BMDs of neck region were statistically significantly lower in the hip fractured group. Neck shaft angle and femur shaft width were the geometric parameters found to be significantly higher in the hip fractured group. The correlation between femur geometric and the anthropometric measurements was present only in the kontrol group. Conclusion: We concluded that besides femur geometric measurements, correlation between these measurements might be an important factors for the fracture risk. (From the World of Osteoporosis 2007;13:15-8

  19. SU-E-J-128: 3D Surface Reconstruction of a Patient Using Epipolar Geometry

    International Nuclear Information System (INIS)

    Kotoku, J; Nakabayashi, S; Kumagai, S; Ishibashi, T; Kobayashi, T; Haga, A; Saotome, N; Arai, N

    2014-01-01

    Purpose: To obtain a 3D surface data of a patient in a non-invasive way can substantially reduce the effort for the registration of patient in radiation therapy. To achieve this goal, we introduced the multiple view stereo technique, which is known to be used in a 'photo tourism' on the internet. Methods: 70 Images were taken with a digital single-lens reflex camera from different angles and positions. The camera positions and angles were inferred later in the reconstruction step. A sparse 3D reconstruction model was locating by SIFT features, which is robust for rotation and shift variance, in each image. We then found a set of correspondences between pairs of images by computing the fundamental matrix using the eight-point algorithm with RANSAC. After the pair matching, we optimized the parameter including camera positions to minimize the reprojection error by use of bundle adjustment technique (non-linear optimization). As a final step, we performed dense reconstruction and associate a color with each point using the library of PMVS. Results: Surface data were reconstructed well by visual inspection. The human skin is reconstructed well, althogh the reconstruction was time-consuming for direct use in daily clinical practice. Conclusion: 3D reconstruction using multi view stereo geometry is a promising tool for reducing the effort of patient setup. This work was supported by JSPS KAKENHI(25861128)

  20. Morphing patient-specific musculoskeletal models

    DEFF Research Database (Denmark)

    Rasmussen, John; Galibarov, Pavel E.; Al-Munajjed, Amir

    the resulting models do indeed represent the patients’ biomechanics. As a particularly challenging case, foot deformities based only on point sets recovered from surface scans are considered as shown in the figure. The preliminary results are promising for the cases of severe flat foot and metatarsalgia while...... other conditions may require CT or MRI data. The method and its theoretical assumptions, advantages and limitations are presented, and several examples will illustrate morphing to patient-specific models. [1] Carbes S; Tørholm S; Rasmussen, J. A Detailed Twenty-six Segments Kinematic Foot model...

  1. SU-G-TeP3-02: Determination of Geometry-Specific Backscatter Factors for Radiobiology Studies

    Energy Technology Data Exchange (ETDEWEB)

    Viscariello, N; Culberson, W; Lawless, M; Kunugi, K; DeWerd, L [School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI (United States)

    2016-06-15

    Purpose: Radiation biology research relies on an accurate radiation dose delivered to the biological target. Large field irradiations in a cabinet irradiator may use the AAPM TG-61 protocol. This relies on an air-kerma measurement and conversion to absorbed dose to water (Dw) on the surface of a water phantom using provided backscatter factors. Cell or small animal studies differ significantly from this reference geometry. This study aims to determine the impact of the lack of full scatter conditions in four representative geometries that may be used in radiobiology studies. Methods: MCNP6 was used to model the Dw on the surface of a full scatter phantom in a validated orthovoltage x-ray reference beam. Dw in a cylindrical mouse, 100 mm Petri dish, 6-well and 96-well cell culture dishes was simulated and compared to this full scatter geometry. A reference dose rate was measured using the TG-61 protocol in a cabinet irradiator. This nominal dose rate was used to irradiate TLDs in each phantom to a given dose. Doses were obtained based on TLDs calibrated in a NIST-traceable beam. Results: Compared to the full scattering conditions, the simulated dose to water in the representative geometries were found to be underestimated by 12-26%. The discrepancy was smallest with the cylindrical mouse geometry, which most closely approximates adequate lateral- and backscatter. TLDs irradiated in the mouse and petri dish phantoms using the TG-61 determined dose rate showed similarly lower values of Dw. When corrected for this discrepancy, they agreed with the predicted Dw within 5%. Conclusion: Using the TG-61 in-air protocol and given backscatter factors to determine a reference dose rate in a biological irradiator may not be appropriate given the difference in scattering conditions between irradiation and calibration. Without accounting for this, the dose rate is overestimated and is dependent on irradiation geometry.

  2. Patient-specific dosimetric endpoints based treatment plan quality control in radiotherapy

    International Nuclear Information System (INIS)

    Song, Ting; Zhou, Linghong; Staub, David; Chen, Mingli; Lu, Weiguo; Tian, Zhen; Jia, Xun; Li, Yongbao; Jiang, Steve B; Gu, Xuejun

    2015-01-01

    In intensity modulated radiotherapy (IMRT), the optimal plan for each patient is specific due to unique patient anatomy. To achieve such a plan, patient-specific dosimetric goals reflecting each patient’s unique anatomy should be defined and adopted in the treatment planning procedure for plan quality control. This study is to develop such a personalized treatment plan quality control tool by predicting patient-specific dosimetric endpoints (DEs). The incorporation of patient specific DEs is realized by a multi-OAR geometry-dosimetry model, capable of predicting optimal DEs based on the individual patient’s geometry. The overall quality of a treatment plan is then judged with a numerical treatment plan quality indicator and characterized as optimal or suboptimal. Taking advantage of clinically available prostate volumetric modulated arc therapy (VMAT) treatment plans, we built and evaluated our proposed plan quality control tool. Using our developed tool, six of twenty evaluated plans were identified as sub-optimal plans. After plan re-optimization, these suboptimal plans achieved better OAR dose sparing without sacrificing the PTV coverage, and the dosimetric endpoints of the re-optimized plans agreed well with the model predicted values, which validate the predictability of the proposed tool. In conclusion, the developed tool is able to accurately predict optimally achievable DEs of multiple OARs, identify suboptimal plans, and guide plan optimization. It is a useful tool for achieving patient-specific treatment plan quality control. (paper)

  3. Patient-Specific Modeling of Intraventricular Hemodynamics

    Science.gov (United States)

    Vedula, Vijay; Marsden, Alison

    2017-11-01

    Heart disease is the one of the leading causes of death in the world. Apart from malfunctions in electrophysiology and myocardial mechanics, abnormal hemodynamics is a major factor attributed to heart disease across all ages. Computer simulations offer an efficient means to accurately reproduce in vivo flow conditions and also make predictions of post-operative outcomes and disease progression. We present an experimentally validated computational framework for performing patient-specific modeling of intraventricular hemodynamics. Our modeling framework employs the SimVascular open source software to build an anatomic model and employs robust image registration methods to extract ventricular motion from the image data. We then employ a stabilized finite element solver to simulate blood flow in the ventricles, solving the Navier-Stokes equations in arbitrary Lagrangian-Eulerian (ALE) coordinates by prescribing the wall motion extracted during registration. We model the fluid-structure interaction effects of the cardiac valves using an immersed boundary method and discuss the potential application of this methodology in single ventricle physiology and trans-catheter aortic valve replacement (TAVR). This research is supported in part by the Stanford Child Health Research Institute and the Stanford NIH-NCATS-CTSA through Grant UL1 TR001085 and partly through NIH NHLBI R01 Grant 5R01HL129727-02.

  4. Update of patient-specific maxillofacial implant.

    Science.gov (United States)

    Owusu, James A; Boahene, Kofi

    2015-08-01

    Patient-specific implant (PSI) is a personalized approach to reconstructive and esthetic surgery. This is particularly useful in maxillofacial surgery in which restoring the complex three-dimensional (3D) contour can be quite challenging. In certain situations, the best results can only be achieved with implants custom-made to fit a particular need. Significant progress has been made over the past decade in the design and manufacture of maxillofacial PSIs. Computer-aided design (CAD)/computer-aided manufacturing (CAM) technology is rapidly advancing and has provided new options for fabrication of PSIs with better precision. Maxillofacial PSIs can now be designed using preoperative imaging data as input into CAD software. The designed implant is then fabricated using a CAM technique such as 3D printing. This approach increases precision and decreases or completely eliminates the need for intraoperative modification of implants. The use of CAD/CAM-produced PSIs for maxillofacial reconstruction and augmentation can significantly improve contour outcomes and decrease operating time. CAD/CAM technology allows timely and precise fabrication of maxillofacial PSIs. This approach is gaining increasing popularity in maxillofacial reconstructive surgery. Continued advances in CAD technology and 3D printing are bound to improve the cost-effectiveness and decrease the production time of maxillofacial PSIs.

  5. Patient geometry-driven information retrieval for IMRT treatment plan quality control

    International Nuclear Information System (INIS)

    Wu Binbin; Ricchetti, Francesco; Sanguineti, Giuseppe; Kazhdan, Misha; Simari, Patricio; Chuang Ming; Taylor, Russell; Jacques, Robert; McNutt, Todd

    2009-01-01

    Purpose: Intensity modulated radiation therapy (IMRT) treatment plan quality depends on the planner's level of experience and the amount of time the planner invests in developing the plan. Planners often unwittingly accept plans when further sparing of the organs at risk (OARs) is possible. The authors propose a method of IMRT treatment plan quality control that helps planners to evaluate the doses of the OARs upon completion of a new plan. Methods: It is achieved by comparing the geometric configurations of the OARs and targets of a new patient with those of prior patients, whose plans are maintained in a database. They introduce the concept of a shape relationship descriptor and, specifically, the overlap volume histogram (OVH) to describe the spatial configuration of an OAR with respect to a target. The OVH provides a way to infer the likely DVHs of the OARs by comparing the relative spatial configurations between patients. A database of prior patients is built to serve as an external reference. At the conclusion of a new plan, planners search through the database and identify related patients by comparing the OAR-target geometric relationships of the new patient with those of prior patients. The treatment plans of these related patients are retrieved from the database and guide planners in determining whether lower doses delivered to the OARs in the new plan are feasible. Results: Preliminary evaluation is promising. In this evaluation, they applied the analysis to the parotid DVHs of 32 prior head-and-neck patients, whose plans are maintained in a database. Each parotid was queried against the other 63 parotids to determine whether a lower dose was possible. The 17 parotids that promised the greatest reduction in D 50 (DVH dose at 50% volume) were flagged. These 17 parotids came from 13 patients. The method also indicated that the doses of the other nine parotids of the 13 patients could not be reduced, so they were included in the replanning process as

  6. Hyperbolic geometry

    CERN Document Server

    Iversen, Birger

    1992-01-01

    Although it arose from purely theoretical considerations of the underlying axioms of geometry, the work of Einstein and Dirac has demonstrated that hyperbolic geometry is a fundamental aspect of modern physics

  7. Twistor geometry

    NARCIS (Netherlands)

    van den Broek, P.M.

    1984-01-01

    The aim of this paper is to give a detailed exposition of the relation between the geometry of twistor space and the geometry of Minkowski space. The paper has a didactical purpose; no use has been made of differential geometry and cohomology.

  8. Impact of left ventricular geometry on prognosis in hypertensive patients with left ventricular hypertrophy (the LIFE study)

    DEFF Research Database (Denmark)

    Gerdts, E.; Cramariuc, D.; Simone, G. de

    2008-01-01

    , and myocardial infarction) in 937 hypertensive patients with LV hypertrophy during 4.8 years losartan- or atenolol-based treatment in the Losartan Intervention for Endpoint reduction in hypertension (LIFE) echocardiography substudy. METHODS AND RESULTS: LV geometry was determined from LV mass/body surface area......AIMS: Less is known about the relation between in-treatment left ventricular (LV) geometry and risk of cardiovascular events. We assessed LV geometric patterns on baseline and annual echocardiograms as time-varying predictors of the primary composite endpoint (cardiovascular death, stroke...... including LV geometric patterns as time-varying variables and adjusting for treatment, Framingham risk score, race, and time-varying systolic blood pressure, the patterns independently predicted higher risk of primary composite endpoints [HR 2.99 (1.16-7.71) for concentric remodelling, HR 1.79 (1...

  9. The association of metabolic syndrome with left ventricular mass and geometry in community-based hypertensive patients among Han Chinese

    Directory of Open Access Journals (Sweden)

    Shuxia Wang

    2015-01-01

    Full Text Available Background: The association of metabolic syndrome (MS with left ventricular (LV hypertrophy is controversial. The objective of our study was to investigate the influence of MS on LV mass and geometry in community-based hypertensive patients among Han Chinese. Materials and Methods: This study included 1733 metabolic syndrome patients according to the International Diabetes Federation (IDF definition and 2373 non-MS hypertension patients. LV hypertrophy was diagnosed by the criteria of LV mass ≥49.2 g/m 2.7 for men and 46.7 g/m 2.7 for women. LV geometric patterns (normal, concentric remodeling, concentric or eccentric hypertrophy were calculated according to LV hypertrophy and relative wall thickness. Logistic regression analysis was used to determine odds ratio (OR and 95% confidence interval (CI of MS for LV hypertrophy and LV geometry abnormality. Results: The LV mass and LV mass index were higher in the MS group than in the non-MS group. In multiple adjusted models. LV mass index, LV mass, interventricular septum, and post wall were raised with the increased number of MS disorders. MS was associated with increased LV hypertrophy risk (unadjusted OR 1.38; 95% CI 1.21-1.57; age, sex, and blood pressure (BP; adjusted OR 1.39; 95% CI 1.22-1.59. MS was also associated with increased risk of eccentric hypertrophy in male and female patients. MS was only associated with increased risk of concentric hypertrophy in female patients; and MS was not associated with concentric remodeling. Conclusion: LV mass and LV mass index were associated with the increased number of MS disorders in the Chinese community-based hypertensive population. MS was not only associated with increased LV hypertrophy risk, but also associated with concentric and eccentric LV geometry abnormality, especially in females.

  10. Specifics of geriatric patients in oncology

    International Nuclear Information System (INIS)

    Jonas, P.; Krizanova, M.

    2012-01-01

    Prolonging human life by the growing number of seniors in the population is accompanied by an increased incidence of cancer in this population. The incidence of cancer in the elderly accounts for 50% of all cancers and is a steeper increase in the male population than female. In Slovakia, the incidence and spread of cancer identical to that in most EU countries. Early cancer detection rate among the elderly is limited poly morbidity and reluctance of patients to undergo preventative as well as diagnostic action. Early diagnosis of cancer allows selection of the appropriate treatment modality that takes into account performance status and co morbidities. Some of these patients require intensive training and so on and aftercare in the treatment of cancer. Failure when treatment when sick or getting into health care already at an advanced stage of the disease is suitable for palliative care. Palliative care is a complex of measures to improve the quality of life of patients and their families in the face of life-threatening disease so that timely identify and promptly diagnose and treat pain and other physical, psychosocial and spiritual problems, reducing suffering. (author)

  11. Influence of microalbuminuria on left ventricular geometry and function in hypertensive patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Picca, Maurizio; Agozzino, Francesco; Pelosi, Giancarlo

    2003-01-01

    An increased urinary albumin excretion (UAE) is associated with an augmented risk of cardiovascular disease in diabetic patients and in non-diabetic subjects. Left ventricular hypertrophy has been demonstrated to be a powerful predictor of cardiovascular morbidity and mortality in arterial hypertension and when the ventricular geometry is concentric the relation is even stronger. This echocardiographic and Doppler study was designed to evaluate the influence of microalbuminuria on the left ventricular geometry and function in hypertensive patients with type 2 diabetes melitus. Forty-two patients (16 males, 26 females, mean age 59.6 +/- 6.7 years) with mild-to-moderate essential hypertension and type 2 diabetes mellitus were enrolled in the study. Twenty-one patients had an elevated UAE (group 1) and 21 a normal UAE (group 2). M-mode (under two-dimensional control) and Doppler echocardiography were performed after a 4-week washout period off antihypertensive therapy. The left ventricular mass index was found to be greater than the partition value of 51 g/m2.7 in both groups but was significantly higher (p diabetes mellitus, an elevated UAE is associated with an increased left ventricular mass index, a higher prevalence of a concentric left ventricular hypertrophy pattern, a depressed midwall systolic performance and a markedly impaired diastolic function...

  12. Molecular geometry

    CERN Document Server

    Rodger, Alison

    1995-01-01

    Molecular Geometry discusses topics relevant to the arrangement of atoms. The book is comprised of seven chapters that tackle several areas of molecular geometry. Chapter 1 reviews the definition and determination of molecular geometry, while Chapter 2 discusses the unified view of stereochemistry and stereochemical changes. Chapter 3 covers the geometry of molecules of second row atoms, and Chapter 4 deals with the main group elements beyond the second row. The book also talks about the complexes of transition metals and f-block elements, and then covers the organometallic compounds and trans

  13. Disproportional geometry of the proximal femur in patients with Turner syndrome - a cross-sectional study

    DEFF Research Database (Denmark)

    Nissen, N.; Gravholt, Claus Højbjerg; Abrahamsen, Bo

    2007-01-01

    OBJECTIVE: Patients with Turner syndrome (TS) have altered growth and increased risk of osteoporosis due to oestrogen deficiency and possibly a host of other factors. Thus, TS patients have a 4.9-fold increased risk of femoral neck fractures. Most patients are treated with oestrogen during puberty...

  14. Creating Shape Templates for Patient Specific Biventricular Modeling in Congenital Heart Disease

    Science.gov (United States)

    Gilbert, Kathleen; Farrar, Genevieve; Cowan, Brett R.; Suinesiaputra, Avan; Occleshaw, Christopher; Pontré, Beau; Perry, James; Hegde, Sanjeet; Marsden, Alison; Omens, Jeff; McCulloch, Andrew; Young, Alistair A.

    2018-01-01

    Survival rates for infants with congenital heart disease (CHD) are improving, resulting in a growing population of adults with CHD. However, the analysis of left and right ventricular function is very time-consuming owing to the variety of congenital morphologies. Efficient customization of patient geometry and function depends on high quality shape templates specifically designed for the application. In this paper, we combine a method for creating finite element shape templates with an interactive template customization to patient MRI examinations. This enables different templates to be chosen depending on patient morphology. To demonstrate this pipeline, a new biventricular template with 162 elements was created and tested in place of an existing 82-element template. The method was able to provide fast interactive biventricular analysis with 0.31 sec per edit response time. The new template was customized to 13 CHD patients with similar biventricular topology, showing improved performance over the previous template and good agreement with clinical indices. PMID:26736353

  15. Optical geometry

    International Nuclear Information System (INIS)

    Robinson, I.; Trautman, A.

    1988-01-01

    The geometry of classical physics is Lorentzian; but weaker geometries are often more appropriate: null geodesics and electromagnetic fields, for example, are well known to be objects of conformal geometry. To deal with a single null congruence, or with the radiative electromagnetic fields associated with it, even less is needed: flag geometry for the first, optical geometry, with which this paper is chiefly concerned, for the second. The authors establish a natural one-to-one correspondence between optical geometries, considered locally, and three-dimensional Cauchy-Riemann structures. A number of Lorentzian geometries are shown to be equivalent from the optical point of view. For example the Goedel universe, the Taub-NUT metric and Hauser's twisting null solution have an optical geometry isomorphic to the one underlying the Robinson congruence in Minkowski space. The authors present general results on the problem of lifting a CR structure to a Lorentz manifold and, in particular, to Minkowski space; and exhibit the relevance of the deviation form to this problem

  16. Adaptive grid generation in a patient-specific cerebral aneurysm

    Science.gov (United States)

    Hodis, Simona; Kallmes, David F.; Dragomir-Daescu, Dan

    2013-11-01

    computational time for patient-specific hemodynamics simulations, which are used to help assess the likelihood of aneurysm rupture using CFD calculated flow patterns.

  17. MMCTP: a radiotherapy research environment for Monte Carlo and patient-specific treatment planning

    International Nuclear Information System (INIS)

    Alexander, A; DeBlois, F; Stroian, G; Al-Yahya, K; Heath, E; Seuntjens, J

    2007-01-01

    Radiotherapy research lacks a flexible computational research environment for Monte Carlo (MC) and patient-specific treatment planning. The purpose of this study was to develop a flexible software package on low-cost hardware with the aim of integrating new patient-specific treatment planning with MC dose calculations suitable for large-scale prospective and retrospective treatment planning studies. We designed the software package 'McGill Monte Carlo treatment planning' (MMCTP) for the research development of MC and patient-specific treatment planning. The MMCTP design consists of a graphical user interface (GUI), which runs on a simple workstation connected through standard secure-shell protocol to a cluster for lengthy MC calculations. Treatment planning information (e.g., images, structures, beam geometry properties and dose distributions) is converted into a convenient MMCTP local file storage format designated, the McGill RT format. MMCTP features include (a) DICOM R T, RTOG and CADPlan CART format imports; (b) 2D and 3D visualization views for images, structure contours, and dose distributions; (c) contouring tools; (d) DVH analysis, and dose matrix comparison tools; (e) external beam editing; (f) MC transport calculation from beam source to patient geometry for photon and electron beams. The MC input files, which are prepared from the beam geometry properties and patient information (e.g., images and structure contours), are uploaded and run on a cluster using shell commands controlled from the MMCTP GUI. The visualization, dose matrix operation and DVH tools offer extensive options for plan analysis and comparison between MC plans and plans imported from commercial treatment planning systems. The MMCTP GUI provides a flexible research platform for the development of patient-specific MC treatment planning for photon and electron external beam radiation therapy. The impact of this tool lies in the fact that it allows for systematic, platform

  18. Development of a patient-specific anatomical foot model from structured light scan data.

    Science.gov (United States)

    Lochner, Samuel J; Huissoon, Jan P; Bedi, Sanjeev S

    2014-01-01

    The use of anatomically accurate finite element (FE) models of the human foot in research studies has increased rapidly in recent years. Uses for FE foot models include advancing knowledge of orthotic design, shoe design, ankle-foot orthoses, pathomechanics, locomotion, plantar pressure, tissue mechanics, plantar fasciitis, joint stress and surgical interventions. Similar applications but for clinical use on a per-patient basis would also be on the rise if it were not for the high costs associated with developing patient-specific anatomical foot models. High costs arise primarily from the expense and challenges of acquiring anatomical data via magnetic resonance imaging (MRI) or computed tomography (CT) and reconstructing the three-dimensional models. The proposed solution morphs detailed anatomy from skin surface geometry and anatomical landmarks of a generic foot model (developed from CT or MRI) to surface geometry and anatomical landmarks acquired from an inexpensive structured light scan of a foot. The method yields a patient-specific anatomical foot model at a fraction of the cost of standard methods. Average error for bone surfaces was 2.53 mm for the six experiments completed. Highest accuracy occurred in the mid-foot and lowest in the forefoot due to the small, irregular bones of the toes. The method must be validated in the intended application to determine if the resulting errors are acceptable.

  19. Coupling of EIT with computational lung modeling for predicting patient-specific ventilatory responses.

    Science.gov (United States)

    Roth, Christian J; Becher, Tobias; Frerichs, Inéz; Weiler, Norbert; Wall, Wolfgang A

    2017-04-01

    Providing optimal personalized mechanical ventilation for patients with acute or chronic respiratory failure is still a challenge within a clinical setting for each case anew. In this article, we integrate electrical impedance tomography (EIT) monitoring into a powerful patient-specific computational lung model to create an approach for personalizing protective ventilatory treatment. The underlying computational lung model is based on a single computed tomography scan and able to predict global airflow quantities, as well as local tissue aeration and strains for any ventilation maneuver. For validation, a novel "virtual EIT" module is added to our computational lung model, allowing to simulate EIT images based on the patient's thorax geometry and the results of our numerically predicted tissue aeration. Clinically measured EIT images are not used to calibrate the computational model. Thus they provide an independent method to validate the computational predictions at high temporal resolution. The performance of this coupling approach has been tested in an example patient with acute respiratory distress syndrome. The method shows good agreement between computationally predicted and clinically measured airflow data and EIT images. These results imply that the proposed framework can be used for numerical prediction of patient-specific responses to certain therapeutic measures before applying them to an actual patient. In the long run, definition of patient-specific optimal ventilation protocols might be assisted by computational modeling. NEW & NOTEWORTHY In this work, we present a patient-specific computational lung model that is able to predict global and local ventilatory quantities for a given patient and any selected ventilation protocol. For the first time, such a predictive lung model is equipped with a virtual electrical impedance tomography module allowing real-time validation of the computed results with the patient measurements. First promising results

  20. Architectural geometry

    KAUST Repository

    Pottmann, Helmut; Eigensatz, Michael; Vaxman, Amir; Wallner, Johannes

    2014-01-01

    Around 2005 it became apparent in the geometry processing community that freeform architecture contains many problems of a geometric nature to be solved, and many opportunities for optimization which however require geometric understanding. This area of research, which has been called architectural geometry, meanwhile contains a great wealth of individual contributions which are relevant in various fields. For mathematicians, the relation to discrete differential geometry is significant, in particular the integrable system viewpoint. Besides, new application contexts have become available for quite some old-established concepts. Regarding graphics and geometry processing, architectural geometry yields interesting new questions but also new objects, e.g. replacing meshes by other combinatorial arrangements. Numerical optimization plays a major role but in itself would be powerless without geometric understanding. Summing up, architectural geometry has become a rewarding field of study. We here survey the main directions which have been pursued, we show real projects where geometric considerations have played a role, and we outline open problems which we think are significant for the future development of both theory and practice of architectural geometry.

  1. Architectural geometry

    KAUST Repository

    Pottmann, Helmut

    2014-11-26

    Around 2005 it became apparent in the geometry processing community that freeform architecture contains many problems of a geometric nature to be solved, and many opportunities for optimization which however require geometric understanding. This area of research, which has been called architectural geometry, meanwhile contains a great wealth of individual contributions which are relevant in various fields. For mathematicians, the relation to discrete differential geometry is significant, in particular the integrable system viewpoint. Besides, new application contexts have become available for quite some old-established concepts. Regarding graphics and geometry processing, architectural geometry yields interesting new questions but also new objects, e.g. replacing meshes by other combinatorial arrangements. Numerical optimization plays a major role but in itself would be powerless without geometric understanding. Summing up, architectural geometry has become a rewarding field of study. We here survey the main directions which have been pursued, we show real projects where geometric considerations have played a role, and we outline open problems which we think are significant for the future development of both theory and practice of architectural geometry.

  2. Beautiful geometry

    CERN Document Server

    Maor, Eli

    2014-01-01

    If you've ever thought that mathematics and art don't mix, this stunning visual history of geometry will change your mind. As much a work of art as a book about mathematics, Beautiful Geometry presents more than sixty exquisite color plates illustrating a wide range of geometric patterns and theorems, accompanied by brief accounts of the fascinating history and people behind each. With artwork by Swiss artist Eugen Jost and text by acclaimed math historian Eli Maor, this unique celebration of geometry covers numerous subjects, from straightedge-and-compass constructions to intriguing configur

  3. Specifics of nursing care for a patient with nutritional stoma.

    OpenAIRE

    MUSILOVÁ, Klára

    2017-01-01

    Main goal of the thesis was to map out the specifics of nursing care for a patient with a nutritious stoma. Three research questions have been identified in connection to this goal. First research question was focused on mapping out the nursing care for a patient prior applying the nutritious stoma. Second research question was focusing on nursing care for a patient while the nutritious stoma is being applied, and the last third question researches the nursing care for a patient after applyin...

  4. Mucorales-Specific T Cells in Patients with Hematologic Malignancies.

    Science.gov (United States)

    Potenza, Leonardo; Vallerini, Daniela; Barozzi, Patrizia; Riva, Giovanni; Gilioli, Andrea; Forghieri, Fabio; Candoni, Anna; Cesaro, Simone; Quadrelli, Chiara; Maertens, Johan; Rossi, Giulio; Morselli, Monica; Codeluppi, Mauro; Mussini, Cristina; Colaci, Elisabetta; Messerotti, Andrea; Paolini, Ambra; Maccaferri, Monica; Fantuzzi, Valeria; Del Giovane, Cinzia; Stefani, Alessandro; Morandi, Uliano; Maffei, Rossana; Marasca, Roberto; Narni, Franco; Fanin, Renato; Comoli, Patrizia; Romani, Luigina; Beauvais, Anne; Viale, Pier Luigi; Latgè, Jean Paul; Lewis, Russell E; Luppi, Mario

    2016-01-01

    Invasive mucormycosis (IM) is an emerging life-threatening fungal infection. It is difficult to obtain a definite diagnosis and to initiate timely intervention. Mucorales-specific T cells occur during the course of IM and are involved in the clearance of the infection. We have evaluated the feasibility of detecting Mucorales-specific T cells in hematological patients at risk for IM, and have correlated the detection of such cells with the clinical conditions of the patients. By using an enzyme linked immunospot assay, the presence of Mucorales-specific T cells in peripheral blood (PB) samples has been investigated at three time points during high-dose chemotherapy for hematologic malignancies. Mucorales-specific T cells producing interferon-γ, interleukin-10 and interleukin-4 were analysed in order to detect a correlation between the immune response and the clinical picture. Twenty-one (10.3%) of 204 patients, accounting for 32 (5.3%) of 598 PB samples, tested positive for Mucorales-specific T cells. Two groups could be identified. Group 1, including 15 patients without signs or symptoms of invasive fungal diseases (IFD), showed a predominance of Mucorales-specific T cells producing interferon-gamma. Group 2 included 6 patients with a clinical picture consistent with invasive fungal disease (IFD): 2 cases of proven IM and 4 cases of possible IFD. The proven patients had significantly higher number of Mucorales-specific T cells producing interleukin-10 and interleukin-4 and higher rates of positive samples by using derived diagnostic cut-offs when compared with the 15 patients without IFD. Mucorales-specific T cells can be detected and monitored in patients with hematologic malignancies at risk for IM. Mucorales-specific T cells polarized to the production of T helper type 2 cytokines are associated with proven IM and may be evaluated as a surrogate diagnostic marker for IM.

  5. Mucorales-Specific T Cells in Patients with Hematologic Malignancies.

    Directory of Open Access Journals (Sweden)

    Leonardo Potenza

    Full Text Available Invasive mucormycosis (IM is an emerging life-threatening fungal infection. It is difficult to obtain a definite diagnosis and to initiate timely intervention. Mucorales-specific T cells occur during the course of IM and are involved in the clearance of the infection. We have evaluated the feasibility of detecting Mucorales-specific T cells in hematological patients at risk for IM, and have correlated the detection of such cells with the clinical conditions of the patients.By using an enzyme linked immunospot assay, the presence of Mucorales-specific T cells in peripheral blood (PB samples has been investigated at three time points during high-dose chemotherapy for hematologic malignancies. Mucorales-specific T cells producing interferon-γ, interleukin-10 and interleukin-4 were analysed in order to detect a correlation between the immune response and the clinical picture. Twenty-one (10.3% of 204 patients, accounting for 32 (5.3% of 598 PB samples, tested positive for Mucorales-specific T cells. Two groups could be identified. Group 1, including 15 patients without signs or symptoms of invasive fungal diseases (IFD, showed a predominance of Mucorales-specific T cells producing interferon-gamma. Group 2 included 6 patients with a clinical picture consistent with invasive fungal disease (IFD: 2 cases of proven IM and 4 cases of possible IFD. The proven patients had significantly higher number of Mucorales-specific T cells producing interleukin-10 and interleukin-4 and higher rates of positive samples by using derived diagnostic cut-offs when compared with the 15 patients without IFD.Mucorales-specific T cells can be detected and monitored in patients with hematologic malignancies at risk for IM. Mucorales-specific T cells polarized to the production of T helper type 2 cytokines are associated with proven IM and may be evaluated as a surrogate diagnostic marker for IM.

  6. Analytische Geometrie

    Science.gov (United States)

    Kemnitz, Arnfried

    Der Grundgedanke der Analytischen Geometrie besteht darin, dass geometrische Untersuchungen mit rechnerischen Mitteln geführt werden. Geometrische Objekte werden dabei durch Gleichungen beschrieben und mit algebraischen Methoden untersucht.

  7. Algebraic geometry

    CERN Document Server

    Lefschetz, Solomon

    2005-01-01

    An introduction to algebraic geometry and a bridge between its analytical-topological and algebraical aspects, this text for advanced undergraduate students is particularly relevant to those more familiar with analysis than algebra. 1953 edition.

  8. Information geometry

    CERN Document Server

    Ay, Nihat; Lê, Hông Vân; Schwachhöfer, Lorenz

    2017-01-01

    The book provides a comprehensive introduction and a novel mathematical foundation of the field of information geometry with complete proofs and detailed background material on measure theory, Riemannian geometry and Banach space theory. Parametrised measure models are defined as fundamental geometric objects, which can be both finite or infinite dimensional. Based on these models, canonical tensor fields are introduced and further studied, including the Fisher metric and the Amari-Chentsov tensor, and embeddings of statistical manifolds are investigated. This novel foundation then leads to application highlights, such as generalizations and extensions of the classical uniqueness result of Chentsov or the Cramér-Rao inequality. Additionally, several new application fields of information geometry are highlighted, for instance hierarchical and graphical models, complexity theory, population genetics, or Markov Chain Monte Carlo. The book will be of interest to mathematicians who are interested in geometry, inf...

  9. Impact of obesity on left ventricular geometry and function in pediatric patients after successful aortic coarctation repair.

    Science.gov (United States)

    Di Salvo, Giovanni; Gala, Simona; Castaldi, Biagio; Baldini, Luca; Limongelli, Giuseppe; D'Andrea, Antonello; Scognamiglio, Giancarlo; Sarubbi, Berardo; Caso, Pio; Pacileo, Giuseppe; Giovanna Russo, Maria; Calabrò, Raffaele

    2011-09-01

    To evaluate if obesity has an additional negative impact on left ventricular (LV) geometry and function in normotensive pediatric patients >12 months after successful treatment of aortic coarctation (CoA). We studied 40 CoA patients (mean age 14 ± 3 years, and male sex 70%), of them 10 were obese and 30 lean. Both groups were age and sex comparable. The entire studied sample underwent 24-ambulatory blood pressure (BP) monitoring, standard echocardiographic evaluation, and speckle tracking study. Both office and 24-hour diastolic BP were significantly increased in obese patients. Obese CoA patients showed increased LV mass (52 ± 13 g/m(2.7) vs. 43 ± 9 g/m(2.7) , P = 0.02), and significant reduction in E/A compared with lean CoA patients. Myocardial deformation properties were significantly reduced in obese CoA patients in all the three studied planes (longitudinal, radial, and circumferential) compared with CoA lean patients. LV twist values showed a significant reduction in the obese CoA group (9.9° ± 2.2° vs. 14.5° ± 2.3°, P < 0.0001). Our study shows that obesity in successfully treated CoA children, has an additional negative effect on BP, LV mass, and cardiac function. These findings are of particular concern, since life expectancy in CoA patients is limited mainly by atherosclerosis, and all the obesity-associated abnormalities found are harbingers of higher cardiovascular risk. © 2011, Wiley Periodicals, Inc.

  10. Fluid Structure Interaction simulation of heart prosthesis in patient-specific left-ventricle/aorta anatomies

    Science.gov (United States)

    Le, Trung; Borazjani, Iman; Sotiropoulos, Fotis

    2009-11-01

    In order to test and optimize heart valve prosthesis and enable virtual implantation of other biomedical devices it is essential to develop and validate high-resolution FSI-CFD codes for carrying out simulations in patient-specific geometries. We have developed a powerful numerical methodology for carrying out FSI simulations of cardiovascular flows based on the CURVIB approach (Borazjani, L. Ge, and F. Sotiropoulos, Journal of Computational physics, vol. 227, pp. 7587-7620 2008). We have extended our FSI method to overset grids to handle efficiently more complicated geometries e.g. simulating an MHV implanted in an anatomically realistic aorta and left-ventricle. A compliant, anatomic left-ventricle is modeled using prescribed motion in one domain. The mechanical heart valve is placed inside the second domain i.e. the body-fitted curvilinear mesh of the anatomic aorta. The simulations of an MHV with a left-ventricle model underscore the importance of inflow conditions and ventricular compliance for such simulations and demonstrate the potential of our method as a powerful tool for patient-specific simulations.

  11. Mucorales-Specific T Cells in Patients with Hematologic Malignancies

    OpenAIRE

    Potenza, L; Vallerini, D; Barozzi, P; Riva, G; Gilioli, A; Forghieri, F; Candoni, A; Cesaro, S; Quadrelli, C; Maertens, J; Rossi, G; Morselli, M; Codeluppi, M; Mussini, C; Colaci, E

    2016-01-01

    Background Invasive mucormycosis (IM) is an emerging life-threatening fungal infection. It is difficult to obtain a definite diagnosis and to initiate timely intervention. Mucorales-specific T cells occur during the course of IM and are involved in the clearance of the infection. We have evaluated the feasibility of detecting Mucorales-specific T cells in hematological patients at risk for IM, and have correlated the detection of such cells with the clinical conditions of the patients. Method...

  12. Design and manufacturing of patient-specific orthodontic appliances by computer-aided engineering techniques.

    Science.gov (United States)

    Barone, Sandro; Neri, Paolo; Paoli, Alessandro; Razionale, Armando Viviano

    2018-01-01

    Orthodontic treatments are usually performed using fixed brackets or removable oral appliances, which are traditionally made from alginate impressions and wax registrations. Among removable devices, eruption guidance appliances are used for early orthodontic treatments in order to intercept and prevent malocclusion problems. Commercially available eruption guidance appliances, however, are symmetric devices produced using a few standard sizes. For this reason, they are not able to meet all the specific patient's needs since the actual dental anatomies present various geometries and asymmetric conditions. In this article, a computer-aided design-based methodology for the design and manufacturing of a patient-specific eruption guidance appliances is presented. The proposed approach is based on the digitalization of several steps of the overall process: from the digital reconstruction of patients' anatomies to the manufacturing of customized appliances. A finite element model has been developed to evaluate the temporomandibular joint disks stress level caused by using symmetric eruption guidance appliances with different teeth misalignment conditions. The developed model can then be used to guide the design of a patient-specific appliance with the aim at reducing the patient discomfort. At this purpose, two different customization levels are proposed in order to face both arches and single tooth misalignment issues. A low-cost manufacturing process, based on an additive manufacturing technique, is finally presented and discussed.

  13. Disproportional geometry of the proximal femur in patients with Turner syndrome: a cross-sectional study

    DEFF Research Database (Denmark)

    Nissen, N; Gravholt, C H; Abrahamsen, B

    2007-01-01

    with healthy controls. PATIENTS: The study population comprised 58 patients with TS (aged 22-67 years) and 60 age-matched healthy women (aged 21-65 years). MEASUREMENTS: Hip axis length (HAL), neck width (NW), neck shaft angle (NSA), and femoral head-radius (HR) on dual-energy X-ray absorptiometry (DXA) screen...... for differences in height, HAL was not significantly different (9.4 +/- 0.5 vs. 9.5 +/- 0.5 cm; NS) in TS compared with controls while NW was significantly increased (3.5 +/- 0.4 cm vs. 3.3 +/- 0.2 cm, P NSA was similar (129 +/- 4 degrees vs. 130 +/- 4 degrees , NS), and HR was significantly decreased...

  14. Gender-specific contribution of cardiometabolic index and lipid accumulation product to left ventricular geometry change in general population of rural China.

    Science.gov (United States)

    Wang, Haoyu; Sun, Yingxian; Li, Zhao; Guo, Xiaofan; Chen, Shuang; Ye, Ning; Tian, Yichen; Zhang, Lijun

    2018-04-10

    Despite current interest in the unfavorable impact of cardiometabolic index (CMI) and lipid accumulation product (LAP) on diabetes and cardiovascular risk, information regarding the relation of CMI and LAP to left ventricular (LV) geometry has not been specifically addressed. We aimed to examine the hypothesis: (1) CMI and LAP represent an independent determinant of LV remodeling in general population of rural China; (2) there are gender differences in obesity-related alterations in terms of LV morphology. The sample for this cross-sectional analysis included 11,258 participants (mean age 53.9 years; 54.0% females) who underwent assessment of basic metabolic and anthropometric parameters in rural areas of northeast China. Comprehensive echocardiography-defined LV geometric pattern was determined according to left ventricular mass index and relative wall thickness. The prevalence rate of eccentric and concentric LV hypertrophy (LVH) presented a proportional increase with elevated quartiles of CMI and LAP in a dose-response manner (all P factor of 3.552 and 1.768 in females and males, respectively. In contrast to females, where LAP fourth quartile and concentric LVH were positively associated (OR:2.544, 95%CI:1.537-4.209), higher LAP did not correlate with concentric LVH in males (OR:1.234, 95%CI:0.824-1.849). CMI and LAP give rise to a new paradigm of accounting for gender difference in obesity-related abnormal LV geometry, an effect that was substantially greater in females. These two indices, acting in concert, may also be advantageous prognostically for refining cardiovascular risk stratification in individuals with LV remodeling.

  15. Mechanical Loading during Growth Is Associated with Plane-specific Differences in Vertebral Geometry: A Cross-sectional Analysis Comparing Artistic Gymnasts vs. Non-gymnasts

    Science.gov (United States)

    Dowthwaite, Jodi N.; Rosenbaum, Paula F.; Scerpella, Tamara A.

    2011-01-01

    Lumbar spine geometry, density and indices of bone strength were assessed relative to menarche status, using artistic gymnastics exposure during growth as a model of mechanical loading. Paired posteroanterior (PA) and supine lateral (LAT) DXA scans of L3 for 114 females (60 ex/gymnasts and 54 non-gymnasts) yielded output for comparison of paired (PALAT) versus standard PA and LAT outcomes. BMC, areal BMD, vertebral body dimensions, bone mineral apparent density (BMAD), axial compressive strength (IBS) and a fracture risk index were evaluated, modeling vertebral body geometry as an ellipsoid cylinder. Two-factor ANCOVA tested statistical effects of gymnastic exposure, menarche status and their interaction, adjusting for age and height as appropriate. Compared to non-gymnasts, ex/gymnasts exhibited greater PABMD, PABMC, PAWIDTH, PA CROSS-SECTIONAL AREA (CSA), PAVOLUME, LATBMD, LATBMAD, PALATCSA and PALATIBS (p<0.05). Non-gymnasts exhibited greater LATDEPTH/PAWIDTH, LATBMC/PABMC, LATVHEIGHT, LATAREA and Fracture Risk Index. Using ellipsoid vertebral geometric models, no significant differences were detected for PA or PALAT BMAD. In contrast, cuboid model results (Carter 1992) suggested erroneous ex/gymnast PABMAD advantages, resulting from invalid assumptions of proportional variation in linear skeletal dimensions. Gymnastic exposure was associated with shorter, wider vertebral bodies, yielding greater axial compressive strength and lower fracture risk, despite no BMAD advantage. Our results suggest the importance of plane-specific vertebral geometric adaptation to mechanical loading during growth. Paired scan output provides a more accurate assessment of this adaptation than PA or LAT plane scans alone. PMID:21839871

  16. Surgeon Design Interface for Patient-Specific Concentric Tube Robots.

    Science.gov (United States)

    Morimoto, Tania K; Greer, Joseph D; Hsieh, Michael H; Okamura, Allison M

    2016-06-01

    Concentric tube robots have potential for use in a wide variety of surgical procedures due to their small size, dexterity, and ability to move in highly curved paths. Unlike most existing clinical robots, the design of these robots can be developed and manufactured on a patient- and procedure-specific basis. The design of concentric tube robots typically requires significant computation and optimization, and it remains unclear how the surgeon should be involved. We propose to use a virtual reality-based design environment for surgeons to easily and intuitively visualize and design a set of concentric tube robots for a specific patient and procedure. In this paper, we describe a novel patient-specific design process in the context of the virtual reality interface. We also show a resulting concentric tube robot design, created by a pediatric urologist to access a kidney stone in a pediatric patient.

  17. Cerebral Aneurysm Clipping Surgery Simulation Using Patient-Specific 3D Printing and Silicone Casting.

    Science.gov (United States)

    Ryan, Justin R; Almefty, Kaith K; Nakaji, Peter; Frakes, David H

    2016-04-01

    Neurosurgery simulator development is growing as practitioners recognize the need for improved instructional and rehearsal platforms to improve procedural skills and patient care. In addition, changes in practice patterns have decreased the volume of specific cases, such as aneurysm clippings, which reduces the opportunity for operating room experience. The authors developed a hands-on, dimensionally accurate model for aneurysm clipping using patient-derived anatomic data and three-dimensional (3D) printing. Design of the model focused on reproducibility as well as adaptability to new patient geometry. A modular, reproducible, and patient-derived medical simulacrum was developed for medical learners to practice aneurysmal clipping procedures. Various forms of 3D printing were used to develop a geometrically accurate cranium and vascular tree featuring 9 patient-derived aneurysms. 3D printing in conjunction with elastomeric casting was leveraged to achieve a patient-derived brain model with tactile properties not yet available from commercial 3D printing technology. An educational pilot study was performed to gauge simulation efficacy. Through the novel manufacturing process, a patient-derived simulacrum was developed for neurovascular surgical simulation. A follow-up qualitative study suggests potential to enhance current educational programs; assessments support the efficacy of the simulacrum. The proposed aneurysm clipping simulator has the potential to improve learning experiences in surgical environment. 3D printing and elastomeric casting can produce patient-derived models for a dynamic learning environment that add value to surgical training and preparation. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Analytic geometry

    CERN Document Server

    Burdette, A C

    1971-01-01

    Analytic Geometry covers several fundamental aspects of analytic geometry needed for advanced subjects, including calculus.This book is composed of 12 chapters that review the principles, concepts, and analytic proofs of geometric theorems, families of lines, the normal equation of the line, and related matters. Other chapters highlight the application of graphing, foci, directrices, eccentricity, and conic-related topics. The remaining chapters deal with the concept polar and rectangular coordinates, surfaces and curves, and planes.This book will prove useful to undergraduate trigonometric st

  19. Geometry Revealed

    CERN Document Server

    Berger, Marcel

    2010-01-01

    Both classical geometry and modern differential geometry have been active subjects of research throughout the 20th century and lie at the heart of many recent advances in mathematics and physics. The underlying motivating concept for the present book is that it offers readers the elements of a modern geometric culture by means of a whole series of visually appealing unsolved (or recently solved) problems that require the creation of concepts and tools of varying abstraction. Starting with such natural, classical objects as lines, planes, circles, spheres, polygons, polyhedra, curves, surfaces,

  20. Vector geometry

    CERN Document Server

    Robinson, Gilbert de B

    2011-01-01

    This brief undergraduate-level text by a prominent Cambridge-educated mathematician explores the relationship between algebra and geometry. An elementary course in plane geometry is the sole requirement for Gilbert de B. Robinson's text, which is the result of several years of teaching and learning the most effective methods from discussions with students. Topics include lines and planes, determinants and linear equations, matrices, groups and linear transformations, and vectors and vector spaces. Additional subjects range from conics and quadrics to homogeneous coordinates and projective geom

  1. Noncommutative geometry

    CERN Document Server

    Connes, Alain

    1994-01-01

    This English version of the path-breaking French book on this subject gives the definitive treatment of the revolutionary approach to measure theory, geometry, and mathematical physics developed by Alain Connes. Profusely illustrated and invitingly written, this book is ideal for anyone who wants to know what noncommutative geometry is, what it can do, or how it can be used in various areas of mathematics, quantization, and elementary particles and fields.Key Features* First full treatment of the subject and its applications* Written by the pioneer of this field* Broad applications in mathemat

  2. Patient-related factors determining geometry of intracavitary applicators and pelvic dose distribution during cervical cancer brachytherapy

    International Nuclear Information System (INIS)

    Senkus-Konefka, Elzbieta; Kobierska, Anna; Jassem, Jacek; Badzio, Andrezej

    1997-01-01

    Purpose: The aim of this study was to assess retrospectively the influence of the size of cervical cancer brachytherapy applicators (ovoids and uterine tandems) on pelvic dose distribution and to analyze the impact of various patient-and disease-related factors on applicators' geometry and on dose distribution in particular applications. Methods and Materials: The subject of this study were 356 cervical cancer patients treated with Selectron LDR as a part of their radical radiotherapy. Analyzed factors included patient age, weight, number of vaginal deliveries, and disease stage. Results: The use of larger vaginal applicators resulted in lower bladder and rectum doses and in higher point B doses (all p < 0.0001); longer uterine tandems produced lower rectum doses and higher point B doses (both p < 0.0001). Increasing patient age and disease stage resulted in a decreased frequency of use of large ovoids (both p < 0.0001) and of long tandems (age: p = 0.0069, stage: p = 0.004). As a result, higher doses to bladder (age: p < 0.0001, stage: p = 0.017) and rectum (age: p = 0.037, stage: p = 0.011) were observed. Increasing age also resulted in lower point B doses (p < 0.0001). Increasing patient weight correlated with less frequent use of long tandems (p = 0.0015) and with higher bladder doses (p = 0.04). Higher number of vaginal deliveries was related to the increase in the use of long tandems (p = 0.002); in patients who had had at least one vaginal delivery, point B doses were significantly higher (p = 0.0059). In multivariate analysis ovoid size and uterine tandem length were dependent on patient age (respectively: p < 0.001 and p = 0.001), disease stage (respectively: p = 0.003 and p = 0.008) and on the number of vaginal deliveries (respectively: p = 0.07 and p 0.008). Doses to critical organs and to points B were dependent on patient age (respectively: p < 0.001, p = 0.011, and p < 0.001) and on disease stage (respectively: p < 0.001, p = 0.004, and p = 0

  3. Bone Geometry, Volumetric Density, Microarchitecture and Estimated Bone Strength Assessed by HR-pQCT in Adult Patients with Hypophosphatemic Rickets

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram Vinod; Hansen, Stinus; Folkestad, Lars

    2015-01-01

    Hypophosphatemic rickets (HR) is characterized by a generalized mineralization defect. Although densitometric studies have found the patients to have an elevated bone mineral density (BMD), data on bone geometry and microstructure are scarce. The aim of this cross-sectional in vivo study was to a......Hypophosphatemic rickets (HR) is characterized by a generalized mineralization defect. Although densitometric studies have found the patients to have an elevated bone mineral density (BMD), data on bone geometry and microstructure are scarce. The aim of this cross-sectional in vivo study...

  4. Projective Geometry

    Indian Academy of Sciences (India)

    mathematicians are trained to use very precise language, and so find it hard to simplify and state .... thing. If you take a plane on which there are two such triangles which enjoy the above ... within this geometry to simplify things if needed.

  5. Geometry -----------~--------------RESONANCE

    Indian Academy of Sciences (India)

    Parallel: A pair of lines in a plane is said to be parallel if they do not meet. Mathematicians were at war ... Subsequently, Poincare, Klein, Beltrami and others refined non-. Euclidean geometry. ... plane divides the plane into two half planes and.

  6. A novel patient-specific model to compute coronary fractional flow reserve.

    Science.gov (United States)

    Kwon, Soon-Sung; Chung, Eui-Chul; Park, Jin-Seo; Kim, Gook-Tae; Kim, Jun-Woo; Kim, Keun-Hong; Shin, Eun-Seok; Shim, Eun Bo

    2014-09-01

    The fractional flow reserve (FFR) is a widely used clinical index to evaluate the functional severity of coronary stenosis. A computer simulation method based on patients' computed tomography (CT) data is a plausible non-invasive approach for computing the FFR. This method can provide a detailed solution for the stenosed coronary hemodynamics by coupling computational fluid dynamics (CFD) with the lumped parameter model (LPM) of the cardiovascular system. In this work, we have implemented a simple computational method to compute the FFR. As this method uses only coronary arteries for the CFD model and includes only the LPM of the coronary vascular system, it provides simpler boundary conditions for the coronary geometry and is computationally more efficient than existing approaches. To test the efficacy of this method, we simulated a three-dimensional straight vessel using CFD coupled with the LPM. The computed results were compared with those of the LPM. To validate this method in terms of clinically realistic geometry, a patient-specific model of stenosed coronary arteries was constructed from CT images, and the computed FFR was compared with clinically measured results. We evaluated the effect of a model aorta on the computed FFR and compared this with a model without the aorta. Computationally, the model without the aorta was more efficient than that with the aorta, reducing the CPU time required for computing a cardiac cycle to 43.4%. Copyright © 2014. Published by Elsevier Ltd.

  7. Patient-specific hip prostheses designed by surgeons

    Directory of Open Access Journals (Sweden)

    Coigny Florian

    2016-09-01

    Full Text Available Patient-specific bone and joint replacement implants lead to better functional and aesthetic results than conventional methods [1], [2], [3]. But extracting 3D shape information from CT Data and designing individual implants is demanding and requires multiple surgeon-to-engineer interactions. For manufacturing purposes, Additive Manufacturing offers various advantages, especially for low volume manufacturing parts, such as patient specific implants. To ease these new approaches and to avoid surgeon-to-engineer interactions a new design software approach is needed which offers highly automated and user friendly planning steps.

  8. Riemannian geometry

    CERN Document Server

    Petersen, Peter

    2016-01-01

    Intended for a one year course, this text serves as a single source, introducing readers to the important techniques and theorems, while also containing enough background on advanced topics to appeal to those students wishing to specialize in Riemannian geometry. This is one of the few Works to combine both the geometric parts of Riemannian geometry and the analytic aspects of the theory. The book will appeal to a readership that have a basic knowledge of standard manifold theory, including tensors, forms, and Lie groups. Important revisions to the third edition include: a substantial addition of unique and enriching exercises scattered throughout the text; inclusion of an increased number of coordinate calculations of connection and curvature; addition of general formulas for curvature on Lie Groups and submersions; integration of variational calculus into the text allowing for an early treatment of the Sphere theorem using a proof by Berger; incorporation of several recent results about manifolds with posit...

  9. Special geometry

    International Nuclear Information System (INIS)

    Strominger, A.

    1990-01-01

    A special manifold is an allowed target manifold for the vector multiplets of D=4, N=2 supergravity. These manifolds are of interest for string theory because the moduli spaces of Calabi-Yau threefolds and c=9, (2,2) conformal field theories are special. Previous work has given a local, coordinate-dependent characterization of special geometry. A global description of special geometries is given herein, and their properties are studied. A special manifold M of complex dimension n is characterized by the existence of a holomorphic Sp(2n+2,R)xGL(1,C) vector bundle over M with a nowhere-vanishing holomorphic section Ω. The Kaehler potential on M is the logarithm of the Sp(2n+2,R) invariant norm of Ω. (orig.)

  10. Patient Specific Modeling of Head-Up Tilt

    DEFF Research Database (Denmark)

    Williams, Nakeya; Wright, Andrew; Mehlsen, Jesper

    2014-01-01

    Short term cardiovascular responses to head-up tilt (HUT) experiments involve complex cardiovascular regulation in order to maintain blood pressure at homeostatic levels. This manuscript presents a patient specific compartmental model developed to predict dynamic changes in heart rate and arterial...

  11. Patient specific 3D visualisation of human brain | Baichoo ...

    African Journals Online (AJOL)

    University of Mauritius Research Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 15, No 1 (2009) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Patient specific 3D visualisation of human brain.

  12. Patient specific 3D visualisation of human brain

    African Journals Online (AJOL)

    Nafiisah

    development of powerful new 3D image analysis and visualization algorithms that ... The tool is aimed to provide facility to reconstruct patient-specific 3D ... In this paper we present a review of the ... medical diagnosis, procedures training, pre-operative planning, ..... Body: Handbook of Numerical Analysis, Elsevier, 2004.

  13. Language-specific dysgraphia in Korean stroke patients.

    Science.gov (United States)

    Yoon, Ji Hye; Suh, Mee Kyung; Kim, HyangHee

    2010-12-01

    We investigated how changes in the writing of 14 Korean stroke patients reflect the unique features of the Korean writing system. The Korean writing system, Han-geul, has both linguistic and visuospatial/constructive characteristics. In the visuospatial construction of a syllable, the component consonant(s) and vowel(s) must be arranged from top-to-bottom and/or left-to-right within the form of a square. This syllabic organization, unique to Korean writing, may distinguish dysgraphia in Korean patients from the disorder in other languages, and reveal the effects of stroke on visuospatial/constructive abilities. We compared 2 groups of patients affected by stroke, 1 group with left hemisphere (LH) lesions and the other with right hemisphere (RH) lesions. We instructed them to write from a dictation of 90 monosyllabic stimuli, each presented with a real word cue. Patients had to repeat a target syllable and a word cue, and then to write the target syllable only. Patients with LH and RH lesions produced qualitatively different error patterns. While the LH lesion group produced primarily linguistic errors, visuospatial/constructive errors predominated in the group with RH lesions. With regard to language-specific features, these Korean patients with RH lesions produced diverse visuospatial/constructive errors not commonly observed in dysgraphia of the English language. Language-specific writing errors by Korean stroke patients reflect the unique characteristics of Korean writing, which include the arrangement of strokes and graphemes within a square syllabic form by dimensional and spatial rules. These findings support the notion that the Korean writing system possesses a language-specific nature with both linguistic and visuospatial/constructive processes. Distinctive patterns of dysgraphia in the Korean language also suggest interactivity between linguistic and visuospatial/constructive levels of processing. This study is noteworthy for its systematic description of

  14. Magnetic resonance imaging of the ear for patient-specific reconstructive surgery.

    Directory of Open Access Journals (Sweden)

    Luc Nimeskern

    Full Text Available INTRODUCTION: Like a fingerprint, ear shape is a unique personal feature that should be reconstructed with a high fidelity during reconstructive surgery. Ear cartilage tissue engineering (TE advantageously offers the possibility to use novel 3D manufacturing techniques to reconstruct the ear, thus allowing for a detailed auricular shape. However it also requires detailed patient-specific images of the 3D cartilage structures of the patient's intact contralateral ear (if available. Therefore the aim of this study was to develop and evaluate an imaging strategy for acquiring patient-specific ear cartilage shape, with sufficient precision and accuracy for use in a clinical setting. METHODS AND MATERIALS: Magnetic resonance imaging (MRI was performed on 14 volunteer and six cadaveric auricles and manually segmented. Reproducibility of cartilage volume (Cg.V, surface (Cg.S and thickness (Cg.Th was assessed, to determine whether raters could repeatedly define the same volume of interest. Additionally, six cadaveric auricles were harvested, scanned and segmented using the same procedure, then dissected and scanned using high resolution micro-CT. Correlation between MR and micro-CT measurements was assessed to determine accuracy. RESULTS: Good inter- and intra-rater reproducibility was observed (precision errors 0.82, but low for Cg.Th (0.95 demonstrated high accuracy. DISCUSSION AND CONCLUSION: This study demonstrated that precision and accuracy of the proposed method was high enough to detect patient-specific variation in ear cartilage geometry. The present study provides a clinical strategy to access the necessary information required for the production of 3D ear scaffolds for TE purposes, including detailed patient-specific shape. Furthermore, the protocol is applicable in daily clinical practice with existing infrastructure.

  15. CMS geometry through 2020

    International Nuclear Information System (INIS)

    Osborne, I; Brownson, E; Eulisse, G; Jones, C D; Sexton-Kennedy, E; Lange, D J

    2014-01-01

    CMS faces real challenges with upgrade of the CMS detector through 2020 and beyond. One of the challenges, from the software point of view, is managing upgrade simulations with the same software release as the 2013 scenario. We present the CMS geometry description software model, its integration with the CMS event setup and core software. The CMS geometry configuration and selection is implemented in Python. The tools collect the Python configuration fragments into a script used in CMS workflow. This flexible and automated geometry configuration allows choosing either transient or persistent version of the same scenario and specific version of the same scenario. We describe how the geometries are integrated and validated, and how we define and handle different geometry scenarios in simulation and reconstruction. We discuss how to transparently manage multiple incompatible geometries in the same software release. Several examples are shown based on current implementation assuring consistent choice of scenario conditions. The consequences and implications for multiple/different code algorithms are discussed.

  16. Patient specific ankle-foot orthoses using rapid prototyping.

    Science.gov (United States)

    Mavroidis, Constantinos; Ranky, Richard G; Sivak, Mark L; Patritti, Benjamin L; DiPisa, Joseph; Caddle, Alyssa; Gilhooly, Kara; Govoni, Lauren; Sivak, Seth; Lancia, Michael; Drillio, Robert; Bonato, Paolo

    2011-01-12

    Prefabricated orthotic devices are currently designed to fit a range of patients and therefore they do not provide individualized comfort and function. Custom-fit orthoses are superior to prefabricated orthotic devices from both of the above-mentioned standpoints. However, creating a custom-fit orthosis is a laborious and time-intensive manual process performed by skilled orthotists. Besides, adjustments made to both prefabricated and custom-fit orthoses are carried out in a qualitative manner. So both comfort and function can potentially suffer considerably. A computerized technique for fabricating patient-specific orthotic devices has the potential to provide excellent comfort and allow for changes in the standard design to meet the specific needs of each patient. In this paper, 3D laser scanning is combined with rapid prototyping to create patient-specific orthoses. A novel process was engineered to utilize patient-specific surface data of the patient anatomy as a digital input, manipulate the surface data to an optimal form using Computer Aided Design (CAD) software, and then download the digital output from the CAD software to a rapid prototyping machine for fabrication. Two AFOs were rapidly prototyped to demonstrate the proposed process. Gait analysis data of a subject wearing the AFOs indicated that the rapid prototyped AFOs performed comparably to the prefabricated polypropylene design. The rapidly prototyped orthoses fabricated in this study provided good fit of the subject's anatomy compared to a prefabricated AFO while delivering comparable function (i.e. mechanical effect on the biomechanics of gait). The rapid fabrication capability is of interest because it has potential for decreasing fabrication time and cost especially when a replacement of the orthosis is required.

  17. Patient specific ankle-foot orthoses using rapid prototyping

    Directory of Open Access Journals (Sweden)

    Sivak Seth

    2011-01-01

    Full Text Available Abstract Background Prefabricated orthotic devices are currently designed to fit a range of patients and therefore they do not provide individualized comfort and function. Custom-fit orthoses are superior to prefabricated orthotic devices from both of the above-mentioned standpoints. However, creating a custom-fit orthosis is a laborious and time-intensive manual process performed by skilled orthotists. Besides, adjustments made to both prefabricated and custom-fit orthoses are carried out in a qualitative manner. So both comfort and function can potentially suffer considerably. A computerized technique for fabricating patient-specific orthotic devices has the potential to provide excellent comfort and allow for changes in the standard design to meet the specific needs of each patient. Methods In this paper, 3D laser scanning is combined with rapid prototyping to create patient-specific orthoses. A novel process was engineered to utilize patient-specific surface data of the patient anatomy as a digital input, manipulate the surface data to an optimal form using Computer Aided Design (CAD software, and then download the digital output from the CAD software to a rapid prototyping machine for fabrication. Results Two AFOs were rapidly prototyped to demonstrate the proposed process. Gait analysis data of a subject wearing the AFOs indicated that the rapid prototyped AFOs performed comparably to the prefabricated polypropylene design. Conclusions The rapidly prototyped orthoses fabricated in this study provided good fit of the subject's anatomy compared to a prefabricated AFO while delivering comparable function (i.e. mechanical effect on the biomechanics of gait. The rapid fabrication capability is of interest because it has potential for decreasing fabrication time and cost especially when a replacement of the orthosis is required.

  18. General Geometry and Geometry of Electromagnetism

    OpenAIRE

    Shahverdiyev, Shervgi S.

    2002-01-01

    It is shown that Electromagnetism creates geometry different from Riemannian geometry. General geometry including Riemannian geometry as a special case is constructed. It is proven that the most simplest special case of General Geometry is geometry underlying Electromagnetism. Action for electromagnetic field and Maxwell equations are derived from curvature function of geometry underlying Electromagnetism. And it is shown that equation of motion for a particle interacting with electromagnetic...

  19. Patient-specific dose estimation for pediatric chest CT

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Frush, Donald P. [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Physics, Duke University, Durham, North Carolina 27710 (United States); and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Global Applied Science Laboratory, GE Healthcare, Waukesha, Wisconsin 53188 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham North Carolina 27710 (United States)

    2008-12-15

    Current methods for organ and effective dose estimations in pediatric CT are largely patient generic. Physical phantoms and computer models have only been developed for standard/limited patient sizes at discrete ages (e.g., 0, 1, 5, 10, 15 years old) and do not reflect the variability of patient anatomy and body habitus within the same size/age group. In this investigation, full-body computer models of seven pediatric patients in the same size/protocol group (weight: 11.9-18.2 kg) were created based on the patients' actual multi-detector array CT (MDCT) data. Organs and structures in the scan coverage were individually segmented. Other organs and structures were created by morphing existing adult models (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. Organ and effective dose of these patients from a chest MDCT scan protocol (64 slice LightSpeed VCT scanner, 120 kVp, 70 or 75 mA, 0.4 s gantry rotation period, pitch of 1.375, 20 mm beam collimation, and small body scan field-of-view) was calculated using a Monte Carlo program previously developed and validated to simulate radiation transport in the same CT system. The seven patients had normalized effective dose of 3.7-5.3 mSv/100 mAs (coefficient of variation: 10.8%). Normalized lung dose and heart dose were 10.4-12.6 mGy/100 mAs and 11.2-13.3 mGy/100 mAs, respectively. Organ dose variations across the patients were generally small for large organs in the scan coverage (<7%), but large for small organs in the scan coverage (9%-18%) and for partially or indirectly exposed organs (11%-77%). Normalized effective dose correlated weakly with body weight (correlation coefficient: r=-0.80). Normalized lung dose and heart dose correlated strongly with mid-chest equivalent diameter (lung: r=-0.99, heart: r=-0.93); these strong correlation relationships can be used to estimate patient-specific organ

  20. Modeling Patient-Specific Magnetic Drug Targeting Within the Intracranial Vasculature.

    Science.gov (United States)

    Patronis, Alexander; Richardson, Robin A; Schmieschek, Sebastian; Wylie, Brian J N; Nash, Rupert W; Coveney, Peter V

    2018-01-01

    Drug targeting promises to substantially enhance future therapies, for example through the focussing of chemotherapeutic drugs at the site of a tumor, thus reducing the exposure of healthy tissue to unwanted damage. Promising work on the steering of medication in the human body employs magnetic fields acting on nanoparticles made of paramagnetic materials. We develop a computational tool to aid in the optimization of the physical parameters of these particles and the magnetic configuration, estimating the fraction of particles reaching a given target site in a large patient-specific vascular system for different physiological states (heart rate, cardiac output, etc.). We demonstrate the excellent computational performance of our model by its application to the simulation of paramagnetic-nanoparticle-laden flows in a circle of Willis geometry obtained from an MRI scan. The results suggest a strong dependence of the particle density at the target site on the strength of the magnetic forcing and the velocity of the background fluid flow.

  1. Differential geometry

    CERN Document Server

    Ciarlet, Philippe G

    2007-01-01

    This book gives the basic notions of differential geometry, such as the metric tensor, the Riemann curvature tensor, the fundamental forms of a surface, covariant derivatives, and the fundamental theorem of surface theory in a selfcontained and accessible manner. Although the field is often considered a classical one, it has recently been rejuvenated, thanks to the manifold applications where it plays an essential role. The book presents some important applications to shells, such as the theory of linearly and nonlinearly elastic shells, the implementation of numerical methods for shells, and

  2. Disease-specific self-efficacy in spasmodic dysphonia patients.

    Science.gov (United States)

    Hu, Amanda; Isetti, Derek; Hillel, Allen D; Waugh, Patricia; Comstock, Bryan; Meyer, Tanya K

    2013-03-01

    Self-efficacy (SE) is an optimistic self-belief that one can perform a novel task. This concept involves empowerment, self-esteem, and adaptation to a stressful situation. SE is a strong predictor of health behaviors. Our objectives were to study SE in spasmodic dysphonia (SD) and to develop a disease-specific SE-SD scale. Prospective study. Academic hospital. Disease-specific SE-SD items were developed with laryngologists, speech pathologists, and SD patients. These items, General SE Scale, Voice Handicap Index-10 (VHI-10), Consensus Auditory Perceptual Evaluation of Voice (CAPE-V), and Hospital Anxiety and Depression Scale (HADS), were administered to SD patients who presented for botulinum toxin injections. One hundred forty-five SD patients (mean age 59.5 ± 13.6 years) had a general SE score (Cronbach's α = 0.894) of 33.4 ± 5.2 out of 40. This was negatively correlated with HADS-A (r = -0.42, P < 0.001) and HADS-D (r = -0.42, P < .001), but not correlated with VHI-10 (r = -0.098, P = .243) and CAPE-V (r = -0.047, P = .57). Factor analysis selected 8 items from the general SE scale and 5 disease-specific SE-SD items to generate a 13-item disease-specific SE-SD scale (Cronbach's α = 0.907). Disease-specific SE-SD score was 42.1 ± 6.9 out of 52 and was negatively correlated with VHI-10 (r = -0.19, P = .005), HADS-A (r = -0.43, P < .001), and HADS-D (r = -0.57, P < .001), but not correlated with CAPE-V (r = -0.024, P = .60). SD patients established on botulinum toxin injections have high degrees of general and disease-specific SE. Patients with higher SE-SD demonstrate lower vocal handicap and lower levels of anxiety and depression. A 13-item disease-specific SE-SD scale has been developed.

  3. Towards a Nano Geometry?

    DEFF Research Database (Denmark)

    Booss-Bavnbek, Bernhelm

    2011-01-01

    This paper applies I.M. Gelfand's distinction between adequate and non-adequate use of mathematical language in different contexts to the newly opened window of model-based measurements of intracellular dynamics. The specifics of geometry and dynamics on the mesoscale of cell physiology are elabo...

  4. SPECIFIC FEATURES OF ANESTHESIA IN PATIENTS WITH MYASTHENIA GRAVIS.

    Science.gov (United States)

    Spasojevic, Ivana; Hajdukovic, Danica; Komarcevic, Milena; Petrovic, Stanislava; Jovanovic, Jelena; Ciric, Aleksandra

    2016-09-01

    Myasthenia gravis is an autoimmune disease caused by antibodies leading to the destruction of nicotinic acetylcholine receptors on the neuromuscular junction. It is characterized by muscle weakness that gets aggravated with physical activity and improves at rest. Myasthenia Gravis Foundation of America made the clinical classification of Myasthenia gravis which is still in use today. "Tensilon test" is still the gold standard for the diagnosis of Myasthenia gravis. In addition to this test repeated muscular stimulation can be used as well as the analysis of specific autoantibodies. Treatment of Myasthenia Gravis. In conservative treatment of Mysthenia gravis anticholinesterases, immunosuppressants and plasmapheresis can be used. If conservative treatment does not lead to the desired remission, surgical treatment is indicated. The most accepted indication for thymectomy is the presence of thymoma with generalized form of Myasthenia gravis in adults. How to Distinguish Myasthenic From Cholinergic Crisis.'The following is important to make a difference between these two crises: knowledge of the events that preceded the crisis, the size of pupils as well as the presence of muscarinic signs and tensilon test. Specific Features of Anesthesia in Patients with Myasthienia Gravis. Mechanism of the disease development is the reason'for the increased sensitivity or resistance of these patients to certain types of drugs used in anesthesia. Protocol of Perioperative Anesthesia in Patients with Myasthenia Gravis. Based on 35 years of experience in the surgical treatment of patients with Myasthenia gravis anesthesiologists at the Department of Thoracic Surgery, Institute for Pulmonary Diseases of Vojvodina. made the protocol of anesthesia and perioperative treatment for these patients. Anesthesiologists may have to deal with a patient with myasthenia gravis in different types of surgical interventions. The protocol for anesthesia and perioperative management of these patients

  5. A Centerline Based Model Morphing Algorithm for Patient-Specific Finite Element Modelling of the Left Ventricle.

    Science.gov (United States)

    Behdadfar, S; Navarro, L; Sundnes, J; Maleckar, M; Ross, S; Odland, H H; Avril, S

    2017-09-20

    Hexahedral automatic model generation is a recurrent problem in computer vision and computational biomechanics. It may even become a challenging problem when one wants to develop a patient-specific finite-element (FE) model of the left ventricle (LV), particularly when only low resolution images are available. In the present study, a fast and efficient algorithm is presented and tested to address such a situation. A template FE hexahedral model was created for a LV geometry using a General Electric (GE) ultrasound (US) system. A system of centerline was considered for this LV mesh. Then, the nodes located over the endocardial and epicardial surfaces are respectively projected from this centerline onto the actual endocardial and epicardial surfaces reconstructed from a patient's US data. Finally, the position of the internal nodes is derived by finding the deformations with minimal elastic energy. This approach was applied to eight patients suffering from congestive heart disease. A FE analysis was performed to derive the stress induced in the LV tissue by diastolic blood pressure on each of them. Our model morphing algorithm was applied successfully and the obtained meshes showed only marginal mismatches when compared to the corresponding US geometries. The diastolic FE analyses were successfully performed in seven patients to derive the distribution of principal stresses. The original model morphing algorithm is fast and robust with low computational cost. This low cost model morphing algorithm may be highly beneficial for future patient-specific reduced-order modelling of the LV with potential application to other crucial organs.

  6. Specific efficacy expectations mediate exercise compliance in patients with COPD.

    Science.gov (United States)

    Kaplan, R M; Atkins, C J; Reinsch, S

    1984-01-01

    Social learning theory has generated two different approaches for the assessment of expectancies. Bandura argues that expectancies are specific and do not generalize. Therefore, he prefers measures of specific efficacy expectations. Others endorse the role of generalized expectancies measured by locus of control scales. The present study examines specific versus generalized expectancies as mediators of changes in exercise behavior among 60 older adult patients with Chronic Obstructive Pulmonary Disease. The patients were given a prescription to increase exercise and randomly assigned to experimental groups or control groups. All groups received attention but only experimental groups received training to increase their exercise. After 3 months, groups given specific training for compliance with walking significantly increased their activity in comparison to the control group receiving only attention. These changes were mediated by changes in perceived efficacy for walking, with efficacy expectations for other behaviors changing as a function of their similarity to walking. A generalized health locus of control expectancy measure was less clearly associated with behavior change. The results are interpreted as supporting Bandura's version of social theory.

  7. Association between patellar cartilage defects and patellofemoral geometry: a matched-pair MRI comparison of patients with and without isolated patellar cartilage defects.

    Science.gov (United States)

    Mehl, Julian; Feucht, Matthias J; Bode, Gerrit; Dovi-Akue, David; Südkamp, Norbert P; Niemeyer, Philipp

    2016-03-01

    To compare the geometry of the patellofemoral joint on magnetic resonance images (MRI) between patients with isolated cartilage defects of the patella and a gender- and age-matched control group of patients without patellar cartilage defects. A total of 43 patients (17 female, 26 male) with arthroscopically verified grade III and IV patellar cartilage defects (defect group) were compared with a matched-pair control group of patients with isolated traumatic rupture of the anterior cruciate ligament without cartilage defects of the patellofemoral joint. Preoperative MRI images were analysed retrospectively with regard to patellar geometry (width, thickness, facet angle), trochlear geometry (dysplasia according to Dejour, sulcus angle, sulcus depth, lateral condyle index, trochlea facet asymmetry, lateral trochlea inclination) and patellofemoral alignment (tibial tuberosity-trochlear groove distance, patella height, lateral patella displacement, lateral patellofemoral angle, patella tilt, congruence angle). In addition to the comparison of group values, the measured values were compared to normal values reported in the literature, and the frequency of patients with pathologic findings was compared between both groups. The defect group demonstrated a significantly higher proximal chondral sulcus angle (p patellofemoral joint. In particular, a flat and shallow trochlea, trochlea dysplasia and patella alta seem to contribute to the development of patellar cartilage defects, which must be taken into consideration when planning to do surgical cartilage repair at the patella. III.

  8. Quantitative analysis of patient-specific dosimetric IMRT verification

    International Nuclear Information System (INIS)

    Budgell, G J; Perrin, B A; Mott, J H L; Fairfoul, J; Mackay, R I

    2005-01-01

    Patient-specific dosimetric verification methods for IMRT treatments are variable, time-consuming and frequently qualitative, preventing evidence-based reduction in the amount of verification performed. This paper addresses some of these issues by applying a quantitative analysis parameter to the dosimetric verification procedure. Film measurements in different planes were acquired for a series of ten IMRT prostate patients, analysed using the quantitative parameter, and compared to determine the most suitable verification plane. Film and ion chamber verification results for 61 patients were analysed to determine long-term accuracy, reproducibility and stability of the planning and delivery system. The reproducibility of the measurement and analysis system was also studied. The results show that verification results are strongly dependent on the plane chosen, with the coronal plane particularly insensitive to delivery error. Unexpectedly, no correlation could be found between the levels of error in different verification planes. Longer term verification results showed consistent patterns which suggest that the amount of patient-specific verification can be safely reduced, provided proper caution is exercised: an evidence-based model for such reduction is proposed. It is concluded that dose/distance to agreement (e.g., 3%/3 mm) should be used as a criterion of acceptability. Quantitative parameters calculated for a given criterion of acceptability should be adopted in conjunction with displays that show where discrepancies occur. Planning and delivery systems which cannot meet the required standards of accuracy, reproducibility and stability to reduce verification will not be accepted by the radiotherapy community

  9. Applications of patient-specific 3D printing in medicine.

    Science.gov (United States)

    Heller, Martin; Bauer, Heide-Katharina; Goetze, Elisabeth; Gielisch, Matthias; Roth, Klaus E; Drees, Philipp; Maier, Gerrit S; Dorweiler, Bernhard; Ghazy, Ahmed; Neufurth, Meik; Müller, Werner E G; Schröder, Heinz C; Wang, Xiaohong; Vahl, Christian-Friedrich; Al-Nawas, Bilal

    Already three decades ago, the potential of medical 3D printing (3DP) or rapid prototyping for improved patient treatment began to be recognized. Since then, more and more medical indications in different surgical disciplines have been improved by using this new technique. Numerous examples have demonstrated the enormous benefit of 3DP in the medical care of patients by, for example, planning complex surgical interventions preoperatively, reducing implantation steps and anesthesia times, and helping with intraoperative orientation. At the beginning of every individual 3D model, patient-specific data on the basis of computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound data is generated, which is then digitalized and processed using computer-aided design/computer-aided manufacturing (CAD/CAM) software. Finally, the resulting data sets are used to generate 3D-printed models or even implants. There are a variety of different application areas in the various medical fields, eg, drill or positioning templates, or surgical guides in maxillofacial surgery, or patient-specific implants in orthopedics. Furthermore, in vascular surgery it is possible to visualize pathologies such as aortic aneurysms so as to improve the planning of surgical treatment. Although rapid prototyping of individual models and implants is already applied very successfully in regenerative medicine, most of the materials used for 3DP are not yet suitable for implantation in the body. Therefore, it will be necessary in future to develop novel therapy approaches and design new materials in order to completely reconstruct natural tissue.

  10. Patient-specific prediction of functional recovery after stroke.

    Science.gov (United States)

    Douiri, Abdel; Grace, Justin; Sarker, Shah-Jalal; Tilling, Kate; McKevitt, Christopher; Wolfe, Charles DA; Rudd, Anthony G

    2017-07-01

    Background and aims Clinical predictive models for stroke recovery could offer the opportunity of targeted early intervention and more specific information for patients and carers. In this study, we developed and validated a patient-specific prognostic model for monitoring recovery after stroke and assessed its clinical utility. Methods Four hundred and ninety-five patients from the population-based South London Stroke Register were included in a substudy between 2002 and 2004. Activities of daily living were assessed using Barthel Index) at one, two, three, four, six, eight, 12, 26, and 52 weeks after stroke. Penalized linear mixed models were developed to predict patients' functional recovery trajectories. An external validation cohort included 1049 newly registered stroke patients between 2005 and 2011. Prediction errors on discrimination and calibration were assessed. The potential clinical utility was evaluated using prognostic accuracy measurements and decision curve analysis. Results Predictive recovery curves showed good accuracy, with root mean squared deviation of 3 Barthel Index points and a R 2 of 83% up to one year after stroke in the external cohort. The negative predictive values of the risk of poor recovery (Barthel Index <8) at three and 12 months were also excellent, 96% (95% CI [93.6-97.4]) and 93% [90.8-95.3], respectively, with a potential clinical utility measured by likelihood ratios (LR+:17 [10.8-26.8] at three months and LR+:11 [6.5-17.2] at 12 months). Decision curve analysis showed an increased clinical benefit, particularly at threshold probabilities of above 5% for predictive risk of poor outcomes. Conclusions A recovery curves tool seems to accurately predict progression of functional recovery in poststroke patients.

  11. Just-in-time Design and Additive Manufacture of Patient-specific Medical Implants

    Science.gov (United States)

    Shidid, Darpan; Leary, Martin; Choong, Peter; Brandt, Milan

    Recent advances in medical imaging and manufacturing science have enabled the design and production of complex, patient-specific orthopaedic implants. Additive Manufacture (AM) generates three-dimensional structures layer by layer, and is not subject to the constraints associated with traditional manufacturing methods. AM provides significant opportunities for the design of novel geometries and complex lattice structures with enhanced functional performance. However, the design and manufacture of patient-specific AM implant structures requires unique expertise in handling various optimization platforms. Furthermore, the design process for complex structures is computationally intensive. The primary aim of this research is to enable the just-in-time customisation of AM prosthesis; whereby AM implant design and manufacture be completed within the time constraints of a single surgical procedure, while minimising prosthesis mass and optimising the lattice structure to match the stiffness of the surrounding bone tissue. In this research, a design approach using raw CT scan data is applied to the AM manufacture of femoral prosthesis. Using the proposed just-in-time concept, the mass of the prosthesis was rapidly designed and manufactured while satisfying the associated structural requirements. Compressive testing of lattice structures manufactured using proposed method shows that the load carrying capacity of the resected composite bone can be recovered by up to 85% and the compressive stiffness of the AM prosthesis is statistically indistinguishable from the stiffness of the initial bone.

  12. Using an EPID for patient-specific VMAT quality assurance

    International Nuclear Information System (INIS)

    Bakhtiari, M.; Kumaraswamy, L.; Bailey, D. W.; Boer, S. de; Malhotra, H. K.; Podgorsak, M. B.

    2011-01-01

    Purpose: A patient-specific quality assurance (QA) method was developed to verify gantry-specific individual multileaf collimator (MLC) apertures (control points) in volumetric modulated arc therapy (VMAT) plans using an electronic portal imaging device (EPID). Methods: VMAT treatment plans were generated in an Eclipse treatment planning system (TPS). DICOM images from a Varian EPID (aS1000) acquired in continuous acquisition mode were used for pretreatment QA. Each cine image file contains the grayscale image of the MLC aperture related to its specific control point and the corresponding gantry angle information. The TPS MLC file of this RapidArc plan contains the leaf positions for all 177 control points (gantry angles). In-house software was developed that interpolates the measured images based on the gantry angle and overlays them with the MLC pattern for all control points. The 38% isointensity line was used to define the edge of the MLC leaves on the portal images. The software generates graphs and tables that provide analysis for the number of mismatched leaf positions for a chosen distance to agreement at each control point and the frequency in which each particular leaf mismatches for the entire arc. Results: Seven patients plans were analyzed using this method. The leaves with the highest mismatched rate were found to be treatment plan dependent. Conclusions: This in-house software can be used to automatically verify the MLC leaf positions for all control points of VMAT plans using cine images acquired by an EPID.

  13. Towards patient specific thermal modelling of the prostate

    International Nuclear Information System (INIS)

    Berg, Cornelis A T van den; Kamer, Jeroen B van de; Leeuw, Astrid A C ee; Jeukens, Cecile R L P N; Raaymakers, Bas W; Vulpen, Marco van; Lagendijk, Jan J W

    2006-01-01

    The application of thermal modelling for hyperthermia and thermal ablation is severely hampered by lack of information about perfusion and vasculature. However, recently, with the advent of sophisticated angiography and dynamic contrast enhanced (DCE) imaging techniques, it has become possible to image small vessels and blood perfusion bringing the ultimate goal of patient specific thermal modelling closer within reach. In this study dynamic contrast enhanced multi-slice CT imaging techniques are employed to investigate the feasibility of this concept for regional hyperthermia treatment of the prostate. The results are retrospectively compared with clinical thermometry data of a patient group from an earlier trial. Furthermore, the role of the prostate vasculature in the establishment of the prostate temperature distribution is studied. Quantitative 3D perfusion maps of the prostate were constructed for five patients using a distributed-parameter tracer kinetics model to analyse dynamic CT data. CT angiography was applied to construct a discrete vessel model of the pelvis. Additionally, a discrete vessel model of the prostate vasculature was constructed of a prostate taken from a human corpse. Three thermal modelling schemes with increasing inclusion of the patient specific physiological information were used to simulate the temperature distribution of the prostate during regional hyperthermia. Prostate perfusion was found to be heterogeneous and T3 prostate carcinomas are often characterized by a strongly elevated tumour perfusion (up to 70-80 ml 100 g -1 min -1 ). This elevated tumour perfusion leads to 1-2 deg. C lower tumour temperatures than thermal simulations based on a homogeneous prostate perfusion. Furthermore, the comparison has shown that the simulations with the measured perfusion maps result in consistently lower prostate temperatures than clinically achieved. The simulations with the discrete vessel model indicate that significant pre-heating takes

  14. Novel approach for identification of left ventricle geometry in patients with chronic heart failure, AH and IHD in combination with COPD

    Directory of Open Access Journals (Sweden)

    Potabashniy V.A.

    2016-05-01

    Full Text Available The aim of this study was to examine the direction of change of left ventricle (LV geometry in patients with chronic heart failure (CHF, arterial hypertension (AH and ischemic heart disease (IHD in combination with chronic obstructive pulmonary disease (COPD in dependence on severity of clinical signs of CHF and COPD based on recommendation of American Society of Echocardiography and European Association of Cardiovascular Images (2015. We examined 67 patients with CHF, associated with AH and stable IHD and stable COPD. By the results of this study there were determined different types of left ventricle geometry: concentric LV hypertrophy (LVH, eccentric LVH, mixed LVH, dilated LVH, dependent on blood pressure level, fibrosic and ischemic myocardial changes,, primary predominant disease – AH, IHD or COPD.

  15. [Specific iatrogenic risks to patients with HIV infection].

    Science.gov (United States)

    De Tournemire, R; Yeni, P

    1994-01-01

    Human immunodeficiency virus-infected patients are exposed to more or less specific iatrogenic diseases. The main characteristics of the risks encountered in this field are described: drug intolerance, mostly to sulfamethoxazole-trimethoprim, is extremely frequent; nucleoside analogue antiviral toxicity is reminiscent of that of chemotherapy; nosocomial infections, in general, are more prominent than in HIV-non infected patients. Intravenous line infections are particularly frequent, but these devices are necessary for prolonged intravenous therapies such as anti-CMV treatment of parenteral nutrition. An improved understanding of different etiopathogenic mechanisms and a better approach of the toxicity/efficacy ratio for each treatment would allow to reduce the excessive morbidity due to iatrogenicity.

  16. Tract specific analysis in patients with sickle cell disease

    Science.gov (United States)

    Chai, Yaqiong; Coloigner, Julie; Qu, Xiaoping; Choi, Soyoung; Bush, Adam; Borzage, Matt; Vu, Chau; Lepore, Natasha; Wood, John

    2015-12-01

    Sickle cell disease (SCD) is a hereditary blood disorder in which the oxygen-carrying hemoglobin molecule in red blood cells is abnormal. It affects numerous people in the world and leads to a shorter life span, pain, anemia, serious infections and neurocognitive decline. Tract-Specific Analysis (TSA) is a statistical method to evaluate white matter alterations due to neurocognitive diseases, using diffusion tensor magnetic resonance images. Here, for the first time, TSA is used to compare 11 major brain white matter (WM) tracts between SCD patients and age-matched healthy subjects. Alterations are found in the corpus callosum (CC), the cortico-spinal tract (CST), inferior fronto-occipital fasciculus (IFO), inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus (SLF), and uncinated fasciculus (UNC). Based on previous studies on the neurocognitive functions of these tracts, the significant areas found in this paper might be related to several cognitive impairments and depression, both of which are observed in SCD patients.

  17. Reliability of patient specific instrumentation in total knee arthroplasty.

    Science.gov (United States)

    Jennart, Harold; Ngo Yamben, Marie-Ange; Kyriakidis, Theofylaktos; Zorman, David

    2015-12-01

    The aim of this study was to compare the precision between Patient Specific Instrumentation (PSI) and Conventional Instrumentation (CI) as determined intra-operatively by a pinless navigation system. Eighty patients were included in this prospective comparative study and they were divided into two homogeneous groups. We defined an original score from 6 to 30 points to evaluate the accuracy of the position of the cutting guides. This score is based on 6 objective criteria. The analysis indicated that PSI was not superior to conventional instrumentation in the overall score (p = 0.949). Moreover, no statistically significant difference was observed for any individual criteria of our score. Level of evidence II.

  18. Quality control of specific patient in radiotherapy with modulated intensity

    International Nuclear Information System (INIS)

    Aberbuj, P D; Tapia Coca, R C

    2012-01-01

    In this work we comment the details of the patient specific quality controls of the first Intensity Modulated Radiotherapy treatment done at Roffo Institute. These controls consisted in two sets of measurements: absolute dose with ionization chamber and relative dose with two dosimetric systems (Gafchromic EBT2 radiochromic films and the PTW 729 ionization chambers array). Two of the filters did not pass the dosimetrical tests, and they were manufactured again. The new filters passed the tests. For the relative two-dimensional measurements the radiochromic films had a better performance than the array due to their higher spatial resolution (author)

  19. Virus-Specific T Cells for the Immunocompromised Patient

    Directory of Open Access Journals (Sweden)

    Amy Houghtelin

    2017-10-01

    Full Text Available While progress has been made in the treatment of both hematologic cancers and solid tumors, chemorefractory or relapsed disease often portends a dismal prognosis, and salvage chemotherapy or radiation expose patients to intolerable toxicities and may not be effective. Hematopoietic stem cell transplant offers the promise of cure for many patients, and while mismatched, unrelated or haploidentical donors are increasingly available, the recipients are at higher risk of severe immunosuppression and immune dysregulation due to graft versus host disease. Viral infections remain a primary cause of severe morbidity and mortality in this patient population. Again, many therapeutic options for viral disease are toxic, may be ineffective or generate resistance, or fail to convey long-term protection. Adoptive cell therapy with virus-specific T cells (VSTs is a targeted therapy that is efficacious and has minimal toxicity in immunocompromised patients with CMV and EBV infections in particular. Products have since been generated specific for multiple viral antigens (multi-VST, which are not only effective but also confer protection in 70–90% of recipients when used as prophylaxis. Notably, these products can be generated from either virus-naive or virus-experienced autologous or allogeneic sources, including partially matched HLA-matched third-party donors. Obstacles to effective VST treatment are donor availability and product generation time. Banking of third-party VST is an attractive way to overcome these constraints and provide products on an as-needed basis. Other developments include epitope discovery to broaden the number of viral antigens targets in a single product, the optimization of VST generation from naive donor sources, and the modification of VSTs to enhance persistence and efficacy in vivo.

  20. Virus-Specific T Cells for the Immunocompromised Patient.

    Science.gov (United States)

    Houghtelin, Amy; Bollard, Catherine M

    2017-01-01

    While progress has been made in the treatment of both hematologic cancers and solid tumors, chemorefractory or relapsed disease often portends a dismal prognosis, and salvage chemotherapy or radiation expose patients to intolerable toxicities and may not be effective. Hematopoietic stem cell transplant offers the promise of cure for many patients, and while mismatched, unrelated or haploidentical donors are increasingly available, the recipients are at higher risk of severe immunosuppression and immune dysregulation due to graft versus host disease. Viral infections remain a primary cause of severe morbidity and mortality in this patient population. Again, many therapeutic options for viral disease are toxic, may be ineffective or generate resistance, or fail to convey long-term protection. Adoptive cell therapy with virus-specific T cells (VSTs) is a targeted therapy that is efficacious and has minimal toxicity in immunocompromised patients with CMV and EBV infections in particular. Products have since been generated specific for multiple viral antigens (multi-VST), which are not only effective but also confer protection in 70-90% of recipients when used as prophylaxis. Notably, these products can be generated from either virus-naive or virus-experienced autologous or allogeneic sources, including partially matched HLA-matched third-party donors. Obstacles to effective VST treatment are donor availability and product generation time. Banking of third-party VST is an attractive way to overcome these constraints and provide products on an as-needed basis. Other developments include epitope discovery to broaden the number of viral antigens targets in a single product, the optimization of VST generation from naive donor sources, and the modification of VSTs to enhance persistence and efficacy in vivo .

  1. The effect of inlet waveforms on computational hemodynamics of patient-specific intracranial aneurysms.

    Science.gov (United States)

    Xiang, J; Siddiqui, A H; Meng, H

    2014-12-18

    Due to the lack of patient-specific inlet flow waveform measurements, most computational fluid dynamics (CFD) simulations of intracranial aneurysms usually employ waveforms that are not patient-specific as inlet boundary conditions for the computational model. The current study examined how this assumption affects the predicted hemodynamics in patient-specific aneurysm geometries. We examined wall shear stress (WSS) and oscillatory shear index (OSI), the two most widely studied hemodynamic quantities that have been shown to predict aneurysm rupture, as well as maximal WSS (MWSS), energy loss (EL) and pressure loss coefficient (PLc). Sixteen pulsatile CFD simulations were carried out on four typical saccular aneurysms using 4 different waveforms and an identical inflow rate as inlet boundary conditions. Our results demonstrated that under the same mean inflow rate, different waveforms produced almost identical WSS distributions and WSS magnitudes, similar OSI distributions but drastically different OSI magnitudes. The OSI magnitude is correlated with the pulsatility index of the waveform. Furthermore, there is a linear relationship between aneurysm-averaged OSI values calculated from one waveform and those calculated from another waveform. In addition, different waveforms produced similar MWSS, EL and PLc in each aneurysm. In conclusion, inlet waveform has minimal effects on WSS, OSI distribution, MWSS, EL and PLc and a strong effect on OSI magnitude, but aneurysm-averaged OSI from different waveforms has a strong linear correlation with each other across different aneurysms, indicating that for the same aneurysm cohort, different waveforms can consistently stratify (rank) OSI of aneurysms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Challenges and limitations of patient-specific vascular phantom fabrication using 3D Polyjet printing

    Science.gov (United States)

    Ionita, Ciprian N.; Mokin, Maxim; Varble, Nicole; Bednarek, Daniel R.; Xiang, Jianping; Snyder, Kenneth V.; Siddiqui, Adnan H.; Levy, Elad I.; Meng, Hui; Rudin, Stephen

    2014-03-01

    Additive manufacturing (3D printing) technology offers a great opportunity towards development of patient-specific vascular anatomic models, for medical device testing and physiological condition evaluation. However, the development process is not yet well established and there are various limitations depending on the printing materials, the technology and the printer resolution. Patient-specific neuro-vascular anatomy was acquired from computed tomography angiography and rotational digital subtraction angiography (DSA). The volumes were imported into a Vitrea 3D workstation (Vital Images Inc.) and the vascular lumen of various vessels and pathologies were segmented using a "marching cubes" algorithm. The results were exported as Stereo Lithographic (STL) files and were further processed by smoothing, trimming, and wall extrusion (to add a custom wall to the model). The models were printed using a Polyjet printer, Eden 260V (Objet-Stratasys). To verify the phantom geometry accuracy, the phantom was reimaged using rotational DSA, and the new data was compared with the initial patient data. The most challenging part of the phantom manufacturing was removal of support material. This aspect could be a serious hurdle in building very tortuous phantoms or small vessels. The accuracy of the printed models was very good: distance analysis showed average differences of 120 μm between the patient and the phantom reconstructed volume dimensions. Most errors were due to residual support material left in the lumen of the phantom. Despite the post-printing challenges experienced during the support cleaning, this technology could be a tremendous benefit to medical research such as in device development and testing.

  3. Patient-Specific Variations in Biomarkers across Gingivitis and Periodontitis

    Science.gov (United States)

    Nagarajan, Radhakrishnan; Miller, Craig S.; Dawson, Dolph; Al-Sabbagh, Mohanad; Ebersole, Jeffrey L.

    2015-01-01

    This study investigates the use of saliva, as an emerging diagnostic fluid in conjunction with classification techniques to discern biological heterogeneity in clinically labelled gingivitis and periodontitis subjects (80 subjects; 40/group) A battery of classification techniques were investigated as traditional single classifier systems as well as within a novel selective voting ensemble classification approach (SVA) framework. Unlike traditional single classifiers, SVA is shown to reveal patient-specific variations within disease groups, which may be important for identifying proclivity to disease progression or disease stability. Salivary expression profiles of IL-1ß, IL-6, MMP-8, and MIP-1α from 80 patients were analyzed using four classification algorithms (LDA: Linear Discriminant Analysis [LDA], Quadratic Discriminant Analysis [QDA], Naïve Bayes Classifier [NBC] and Support Vector Machines [SVM]) as traditional single classifiers and within the SVA framework (SVA-LDA, SVA-QDA, SVA-NB and SVA-SVM). Our findings demonstrate that performance measures (sensitivity, specificity and accuracy) of traditional classification as single classifier were comparable to that of the SVA counterparts using clinical labels of the samples as ground truth. However, unlike traditional single classifier approaches, the normalized ensemble vote-counts from SVA revealed varying proclivity of the subjects for each of the disease groups. More importantly, the SVA identified a subset of gingivitis and periodontitis samples that demonstrated a biological proclivity commensurate with the other clinical group. This subset was confirmed across SVA-LDA, SVA-QDA, SVA-NB and SVA-SVM. Heatmap visualization of their ensemble sets revealed lack of consensus between these subsets and the rest of the samples within the respective disease groups indicating the unique nature of the patients in these subsets. While the source of variation is not known, the results presented clearly elucidate the

  4. Course of training in Specific internal dosimetry for the patient

    International Nuclear Information System (INIS)

    Rojo, A.M.; Michelin, S.C.; Gomez P, I.M.

    2006-01-01

    In this work the experience obtained in a course organized in Argentina to qualify professionals in the radiopharmaceutical dosimetry using the methodology MIRD and the patient's images is presented. The motivation to carry out it was based on the continuous development of new radiopharmaceuticals with therapeutic purposes that makes necessary the knowledge of the distribution of the absorbed dose to be able to establish the dose-response relationship. The main objective was the study of the biokinetic model and those techniques available that starting from images can contribute information of specific parameters of the patient to calculate with more accuracy the doses in the tumor and in different organs. In the design of the program of this course it was considered to approach the different focuses for the calculation of specific dose of the patient and includes the following topics: the patient's radiological protection, new concepts in damages by radiations (bystander effect), methodology for the internal dosimetry by radiopharmaceuticals, dosimetric systems (MIRD/ICRP), revision of the physical phantoms, design of kinetic studies, compartmental models, calculation tools and the demonstration of the programs SAAM and OLINDA; calculation of activity starting from the patient's images (planar and SPECT). Principles of the gamma camera: the dispersed radiation, calculation of the activity with planar images, the attenuation, correction of the dispersed radiation, collimation problems. SPECT: the common method of reconstruction, basic principles, method of filtered over head projection and iterative methods (MLEM/OSEM), measurement of the attenuation maps, problems of the penetration in the collimator (I-131, I-123), effects of partial volume, incorporation of corrections in an iterative reconstruction. Dosimetry in bone marrow, discussion of study cases of new radiopharmaceuticals. Internal dosimetry in small scale for electrons and photons. Perspectives of the

  5. Definition of treatment geometry in radiation therapy

    International Nuclear Information System (INIS)

    Aaltonen, P.

    1996-01-01

    When accurate systems for quality assurance and treatment optimization are employed, a precise system for fixation and dosimetric and portal verification are as important as a continued and standardized code of practice for dosimetry and patient follow-up, including registration of tumour responses and acute and late normal tissue reactions. To improve the accuracy of existing dose response relations in order to improve future therapy the treatment geometry and dose delivery concepts have to be accurately defined and uniformly employed. A Nordic working group was set up in 1991 (by Nordic Association of Clinica Physics) to standardize the concepts and quantities used during the whole radiotherapy process in the Nordic countries. Now the group is finalizing its report ''Specification of Dose Delivery in Radiation Therapy''. The report emphasizes that the treatment geometry shall be consistent with the geometry used during the diagnostic work up. The patient fixation is of importance early in the diagnostic phase to ensure that the same reference points and patients position will be used both during the diagnostic work up, simulation and treatment execution. Reference Coordinate System of the patient is a concept based on defined anatomic reference points. This Patient Reference System is a local system which has validity for the tissues, organs and volumes defined during radiotherapy. The reference points of the Patient Reference System should in turn be used for beam set-up. The treatment geometry is then defined by using different concepts describing tissues which are mobile in the Patient Reference System, and finally, volumes which are fixed in this coordinate system. A Set-up Margin has to be considered for movements of the volumes defined in the Reference Coordinate System of the Patient in relation to the radiation beam. The Set-up Margin is dependent on the treatment technique and it is needed in the treatment planning procedure to ensure that the prescribed

  6. Definition of treatment geometry in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, P [Finnish Centre for Radiation and Nuclear Safety (STUK), Helsinki (Finland)

    1996-08-01

    When accurate systems for quality assurance and treatment optimization are employed, a precise system for fixation and dosimetric and portal verification are as important as a continued and standardized code of practice for dosimetry and patient follow-up, including registration of tumour responses and acute and late normal tissue reactions. To improve the accuracy of existing dose response relations in order to improve future therapy the treatment geometry and dose delivery concepts have to be accurately defined and uniformly employed. A Nordic working group was set up in 1991 to standardize the concepts and quantities used during the whole radiotherapy process in the Nordic countries. Now the group is finalizing its report ``Specification of Dose Delivery in Radiation Therapy``. The report emphasizes that the treatment geometry shall be consistent with the geometry used during the diagnostic work up. The patient fixation is of importance early in the diagnostic phase to ensure that the same reference points and patients position will be used both during the diagnostic work up, simulation and treatment execution. Reference Coordinate System of the patient is a concept based on defined anatomic reference points. This Patient Reference System is a local system which has validity for the tissues, organs and volumes defined during radiotherapy. The reference points of the Patient Reference System should in turn be used for beam set-up. The treatment geometry is then defined by using different concepts describing tissues which are mobile in the Patient Reference System, and finally, volumes which are fixed in this coordinate system. A Set-up Margin has to be considered for movements of the volumes defined in the Reference Coordinate System of the Patient in relation to the radiation beam. The Set-up Margin is dependent on the treatment technique and it is needed in the treatment planning procedure to ensure that the prescribed dose to the Target Volume is delivered.

  7. Patient-specific radiation dose and cancer risk estimation in CT: Part II. Application to patients

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Toncheva, Greta; Yoshizumi, Terry T.; Frush, Donald P. [Medical Physics Graduate Program, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Medical Physics Graduate Program, Department of Physics, and Department of Biomedical Engineering, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Department of Biomedical Engineering, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Duke Radiation Dosimetry Laboratory, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Duke Radiation Dosimetry Laboratory, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Division of Pediatric Radiology, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2011-01-15

    Purpose: Current methods for estimating and reporting radiation dose from CT examinations are largely patient-generic; the body size and hence dose variation from patient to patient is not reflected. Furthermore, the current protocol designs rely on dose as a surrogate for the risk of cancer incidence, neglecting the strong dependence of risk on age and gender. The purpose of this study was to develop a method for estimating patient-specific radiation dose and cancer risk from CT examinations. Methods: The study included two patients (a 5-week-old female patient and a 12-year-old male patient), who underwent 64-slice CT examinations (LightSpeed VCT, GE Healthcare) of the chest, abdomen, and pelvis at our institution in 2006. For each patient, a nonuniform rational B-spine (NURBS) based full-body computer model was created based on the patient's clinical CT data. Large organs and structures inside the image volume were individually segmented and modeled. Other organs were created by transforming an existing adult male or female full-body computer model (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. A Monte Carlo program previously developed and validated for dose simulation on the LightSpeed VCT scanner was used to estimate patient-specific organ dose, from which effective dose and risks of cancer incidence were derived. Patient-specific organ dose and effective dose were compared with patient-generic CT dose quantities in current clinical use: the volume-weighted CT dose index (CTDI{sub vol}) and the effective dose derived from the dose-length product (DLP). Results: The effective dose for the CT examination of the newborn patient (5.7 mSv) was higher but comparable to that for the CT examination of the teenager patient (4.9 mSv) due to the size-based clinical CT protocols at our institution, which employ lower scan techniques for smaller

  8. Respiratory gated radiotherapy-pretreatment patient specific quality assurance

    Directory of Open Access Journals (Sweden)

    Rajesh Thiyagarajan

    2016-01-01

    Full Text Available Organ motions during inter-fraction and intra-fraction radiotherapy introduce errors in dose delivery, irradiating excess of normal tissue, and missing target volume. Lung and heart involuntary motions cause above inaccuracies and gated dose delivery try to overcome above effects. Present work attempts a novel method to verify dynamic dose delivery using a four-dimensional (4D phantom. Three patients with mobile target are coached to maintain regular and reproducible breathing pattern. Appropriate intensity projection image set generated from 4D-computed tomography (4D-CT is used for target delineation. Intensity modulated radiotherapy plans were generated on selected phase using CT simulator (Siemens AG, Germany in conjunction with "Real-time position management" (Varian, USA to acquire 4D-CT images. Verification plans were generated for both ion chamber and Gafchromic (EBT film image sets. Gated verification plans were delivered on the phantom moving with patient respiratory pattern. We developed a MATLAB-based software to generate maximum intensity projection, minimum intensity projections, and average intensity projections, also a program to convert patient breathing pattern to phantom compatible format. Dynamic thorax quality assurance (QA phantom (Computerized Imaging Reference Systems type is used to perform the patient specific QA, which holds an ion chamber and film to measure delivered radiation intensity. Exposed EBT films are analyzed and compared with treatment planning system calculated dose. The ion chamber measured dose shows good agreement with planned dose within ± 0.5% (0.203 ± 0.57%. Gamma value evaluated from EBT film shows passing rates 92–99% (96.63 ± 3.84% for 3% dose and 3 mm distance criteria. Respiratory gated treatment delivery accuracy is found to be within clinically acceptable level.

  9. Induced radioactivity in a patient-specific collimator used in proton therapy

    CERN Document Server

    Silari, M; Mauro, Egidio; Silari, Marco

    2010-01-01

    This paper discusses the activation of a patient-specific collimator, calculating dose rates, total activities and activities per unit mass of the mixture of radionuclides generated by proton irradiation in the energy range 100-250 MeV. Monte Carlo simulations were first performed for a generic case, using an approximate geometry and on the basis of assumptions on beam intensity and irradiation profile. A collimator used for a prostate cancer treatment was obtained from the MD Anderson Cancer Center (MDACC), Houston, USA, from which a number of samples were cut and analyzed by gamma spectrometry. The results of the gamma spectrometry are compared with the results of Monte Carlo simulations performed using geometrical and irradiation data specific to the unit. The assumptions made for the simulations and their impact on the results are discussed. Dose rate measurements performed in a low-background area at CERN and routine radiation protection measurements at the MDACC are also reported. It is shown that it sh...

  10. Numerical simulation of magnetic nano drug targeting in patient-specific lower respiratory tract

    Science.gov (United States)

    Russo, Flavia; Boghi, Andrea; Gori, Fabio

    2018-04-01

    Magnetic nano drug targeting, with an external magnetic field, can potentially improve the drug absorption in specific locations of the body. However, the effectiveness of the procedure can be reduced due to the limitations of the magnetic field intensity. This work investigates this technique with the Computational Fluid Dynamics (CFD) approach. A single rectangular coil generates the external magnetic field. A patient-specific geometry of the Trachea, with its primary and secondary bronchi, is reconstructed from Digital Imaging and Communications in Medicine (DICOM) formatted images, throughout the Vascular Modelling Tool Kit (VMTK) software. A solver, coupling the Lagrangian dynamics of the magnetic nanoparticles with the Eulerian dynamics of the air, is used to perform the simulations. The resistive pressure, the pulsatile inlet velocity and the rectangular coil magnetic field are the boundary conditions. The dynamics of the injected particles is investigated without and with the magnetic probe. The flow field promotes particles adhesion to the tracheal wall. The particles volumetric flow rate in both cases has been calculated. The magnetic probe is shown to increase the particles flow in the target region, but at a limited extent. This behavior has been attributed to the small particle size and the probe configuration.

  11. A Patient-Specific Airway Branching Model for Mechanically Ventilated Patients

    Directory of Open Access Journals (Sweden)

    Nor Salwa Damanhuri

    2014-01-01

    Full Text Available Background. Respiratory mechanics models have the potential to guide mechanical ventilation. Airway branching models (ABMs were developed from classical fluid mechanics models but do not provide accurate models of in vivo behaviour. Hence, the ABM was improved to include patient-specific parameters and better model observed behaviour (ABMps. Methods. The airway pressure drop of the ABMps was compared with the well-accepted dynostatic algorithm (DSA in patients diagnosed with acute respiratory distress syndrome (ARDS. A scaling factor (α was used to equate the area under the pressure curve (AUC from the ABMps to the AUC of the DSA and was linked to patient state. Results. The ABMps recorded a median α value of 0.58 (IQR: 0.54–0.63; range: 0.45–0.66 for these ARDS patients. Significantly lower α values were found for individuals with chronic obstructive pulmonary disease (P<0.001. Conclusion. The ABMps model allows the estimation of airway pressure drop at each bronchial generation with patient-specific physiological measurements and can be generated from data measured at the bedside. The distribution of patient-specific α values indicates that the overall ABM can be readily improved to better match observed data and capture patient condition.

  12. Patient-specific surgical planning and hemodynamic computational fluid dynamics optimization through free-form haptic anatomy editing tool (SURGEM).

    Science.gov (United States)

    Pekkan, Kerem; Whited, Brian; Kanter, Kirk; Sharma, Shiva; de Zelicourt, Diane; Sundareswaran, Kartik; Frakes, David; Rossignac, Jarek; Yoganathan, Ajit P

    2008-11-01

    The first version of an anatomy editing/surgical planning tool (SURGEM) targeting anatomical complexity and patient-specific computational fluid dynamics (CFD) analysis is presented. Novel three-dimensional (3D) shape editing concepts and human-shape interaction technologies have been integrated to facilitate interactive surgical morphology alterations, grid generation and CFD analysis. In order to implement "manual hemodynamic optimization" at the surgery planning phase for patients with congenital heart defects, these tools are applied to design and evaluate possible modifications of patient-specific anatomies. In this context, anatomies involve complex geometric topologies and tortuous 3D blood flow pathways with multiple inlets and outlets. These tools make it possible to freely deform the lumen surface and to bend and position baffles through real-time, direct manipulation of the 3D models with both hands, thus eliminating the tedious and time-consuming phase of entering the desired geometry using traditional computer-aided design (CAD) systems. The 3D models of the modified anatomies are seamlessly exported and meshed for patient-specific CFD analysis. Free-formed anatomical modifications are quantified using an in-house skeletization based cross-sectional geometry analysis tool. Hemodynamic performance of the systematically modified anatomies is compared with the original anatomy using CFD. CFD results showed the relative importance of the various surgically created features such as pouch size, vena cave to pulmonary artery (PA) flare and PA stenosis. An interactive surgical-patch size estimator is also introduced. The combined design/analysis cycle time is used for comparing and optimizing surgical plans and improvements are tabulated. The reduced cost of patient-specific shape design and analysis process, made it possible to envision large clinical studies to assess the validity of predictive patient-specific CFD simulations. In this paper, model

  13. Patterns of patient specific dosimetry in total body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Akino, Yuichi [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States); Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); McMullen, Kevin P.; Das, Indra J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States)

    2013-04-15

    Purpose: Total body irradiation (TBI) has been used for bone marrow transplant for hematologic and immune deficiency conditions. The goal of TBI is to deliver a homogeneous dose to the entire body, with a generally accepted range of dose uniformity being within {+-}10% of the prescribed dose. The moving table technique for TBI could make dose uniform in whole body by adjusting couch speed. However, it is difficult to accurately estimate the actual dose by calculation and hence in vivo dosimetry (IVD) is routinely performed. Here, the authors present patterns of patient-specific IVD in 161 TBI patients treated at our institution. Methods: Cobalt-60 teletherapy unit (Model C9 Cobalt-60 teletherapy unit, Picker X-ray Corporation) with customized moving bed (SITI Industrial Products, Inc., Fishers, IN) were used for TBI treatment. During treatment, OneDose{sup TM} (Sicel Technology, NC) Metal Oxide-silicon Semiconductor Field Effect Transistor detectors were placed at patient body surface; both entrance and exit side of the beam at patient head, neck, mediastinum, umbilicus, and knee to estimate midplane dose. When large differences (>10%) between the prescribed and measured dose were observed, dose delivery was corrected for subsequent fractions by the adjustment of couch speed and/or bolus placement. Under IRB exempt status, the authors retrospectively analyzed the treatment records of 161 patients who received TBI treatment between 2006 and 2011. Results: Across the entire cohort, the median {+-} SD (range) percent variance between calculated and measured dose for head, neck, mediastinum, umbilicus, and knee was -2.3 {+-} 10.2% (-66.2 to +35.3), 1.1 {+-} 11.5% (-62.2 to +40.3), -1.9 {+-} 9.5% (-66.4 to +46.6), -1.1 {+-} 7.2% (-35.2 to +42.9), and 3.4 {+-} 12.2% (-47.9 to +108.5), respectively. More than half of treatments were within {+-}10% of the prescribed dose for all anatomical regions. For 80% of treatments (10%-90%), dose at the umbilicus was within {+-}10

  14. Analysis of ion beam teletherapy patient-specific quality assurance.

    Science.gov (United States)

    Liu, Xiaoli; Deng, Yu; Schlegel, Nicki; Huang, Zhijie; Moyers, Michael F

    2018-02-27

    The objective of this study was to evaluate the procedures for patient-specific quality assurance measurements using modulated scanned and energy stacked beams for proton and carbon ion teletherapy. Delivery records from 1734 portal measurements were analyzed using a 3-point pass criteria: more than 22 of 24 chambers in a water phantom (WP) had to have a measured dose difference from the planned portal doses less than or equal to 3%, or the distance from the measurement point location to a point location in the plan having the same dose had to be less than or equal to 3 mm (distance to agreement [DTA]), and the mean dose deviation of all chambers had to be less than 3%. Stratification of results showed some associations between measurement parameters and pass rates. For proton portals, pass rates were high at all measurement depths, but for carbon ion portals, pass rates decreased as a function of increasing measurement depth. Pass rates of both proton and carbon ion portals with 1 WP were slightly lower than those with a second WP. The total pass rates were 97.7% and 91.9% for proton and carbon ion patient portals, respectively. In general, the measured doses exhibited good agreement with the treatment planning system (TPS) calculated doses. When the chamber position was deeper than 150 mm in carbon ion beams, a lower pass rate was observed, which may have been caused by ion chamber array setup uncertainty (lateral and depth) in highly modulated portals or incorrect modeling of scatter by the TPS. These deviations need further investigation. Copyright © 2018 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  15. Complex analysis and geometry

    CERN Document Server

    Silva, Alessandro

    1993-01-01

    The papers in this wide-ranging collection report on the results of investigations from a number of linked disciplines, including complex algebraic geometry, complex analytic geometry of manifolds and spaces, and complex differential geometry.

  16. Non-Riemannian geometry

    CERN Document Server

    Eisenhart, Luther Pfahler

    2005-01-01

    This concise text by a prominent mathematician deals chiefly with manifolds dominated by the geometry of paths. Topics include asymmetric and symmetric connections, the projective geometry of paths, and the geometry of sub-spaces. 1927 edition.

  17. Geometry of the Universe

    International Nuclear Information System (INIS)

    Gurevich, L.Eh.; Gliner, Eh.B.

    1978-01-01

    Problems of investigating the Universe space-time geometry are described on a popular level. Immediate space-time geometries, corresponding to three cosmologic models are considered. Space-time geometry of a closed model is the spherical Riemann geonetry, of an open model - is the Lobachevskij geometry; and of a plane model - is the Euclidean geometry. The Universe real geometry in the contemporary epoch of development is based on the data testifying to the fact that the Universe is infinitely expanding

  18. Additive manufacturing of patient-specific tubular continuum manipulators

    Science.gov (United States)

    Amanov, Ernar; Nguyen, Thien-Dang; Burgner-Kahrs, Jessica

    2015-03-01

    Tubular continuum robots, which are composed of multiple concentric, precurved, elastic tubes, provide more dexterity than traditional surgical instruments at the same diameter. The tubes can be precurved such that the resulting manipulator fulfills surgical task requirements. Up to now the only material used for the component tubes of those manipulators is NiTi, a super-elastic shape-memory alloy of nickel and titan. NiTi is a cost-intensive material and fabrication processes are complex, requiring (proprietary) technology, e.g. for shape setting. In this paper, we evaluate component tubes made of 3 different thermoplastic materials (PLA, PCL and nylon) using fused filament fabrication technology (3D printing). This enables quick and cost-effective production of custom, patient-specific continuum manipulators, produced on site on demand. Stress-strain and deformation characteristics are evaluated experimentally for 16 fabricated tubes of each thermoplastic with diameters and shapes equivalent to those of NiTi tubes. Tubes made of PCL and nylon exhibit properties comparable to those made of NiTi. We further demonstrate a tubular continuum manipulator composed of 3 nylon tubes in a transnasal, transsphenoidal skull base surgery scenario in vitro.

  19. Violence and Personality in Forensic Patients: Is There a Forensic Patient-Specific Personality Profile?

    Science.gov (United States)

    Stupperich, Alexandra; Ihm, Helga; Strack, Micha

    2009-01-01

    Concerning the discussion about the connection of personality traits, personality disorders, and mental illness, this study focused on the personality profiles of male forensic patients, prison inmates, and young men without criminal reports. The main topic centered on group-specific personality profiles and identifying personality facets…

  20. Fluid-Structure Simulations of a Ruptured Intracranial Aneurysm: Constant versus Patient-Specific Wall Thickness

    Directory of Open Access Journals (Sweden)

    S. Voß

    2016-01-01

    Full Text Available Computational Fluid Dynamics is intensively used to deepen the understanding of aneurysm growth and rupture in order to support physicians during therapy planning. However, numerous studies considering only the hemodynamics within the vessel lumen found no satisfactory criteria for rupture risk assessment. To improve available simulation models, the rigid vessel wall assumption has been discarded in this work and patient-specific wall thickness is considered within the simulation. For this purpose, a ruptured intracranial aneurysm was prepared ex vivo, followed by the acquisition of local wall thickness using μCT. The segmented inner and outer vessel surfaces served as solid domain for the fluid-structure interaction (FSI simulation. To compare wall stress distributions within the aneurysm wall and at the rupture site, FSI computations are repeated in a virtual model using a constant wall thickness approach. Although the wall stresses obtained by the two approaches—when averaged over the complete aneurysm sac—are in very good agreement, strong differences occur in their distribution. Accounting for the real wall thickness distribution, the rupture site exhibits much higher stress values compared to the configuration with constant wall thickness. The study reveals the importance of geometry reconstruction and accurate description of wall thickness in FSI simulations.

  1. Modeling Patient-Specific Magnetic Drug Targeting Within the Intracranial Vasculature

    Directory of Open Access Journals (Sweden)

    Alexander Patronis

    2018-04-01

    Full Text Available Drug targeting promises to substantially enhance future therapies, for example through the focussing of chemotherapeutic drugs at the site of a tumor, thus reducing the exposure of healthy tissue to unwanted damage. Promising work on the steering of medication in the human body employs magnetic fields acting on nanoparticles made of paramagnetic materials. We develop a computational tool to aid in the optimization of the physical parameters of these particles and the magnetic configuration, estimating the fraction of particles reaching a given target site in a large patient-specific vascular system for different physiological states (heart rate, cardiac output, etc.. We demonstrate the excellent computational performance of our model by its application to the simulation of paramagnetic-nanoparticle-laden flows in a circle of Willis geometry obtained from an MRI scan. The results suggest a strong dependence of the particle density at the target site on the strength of the magnetic forcing and the velocity of the background fluid flow.

  2. Numerical simulation of magnetic nano drug targeting in a patient-specific coeliac trunk

    Science.gov (United States)

    Boghi, Andrea; Russo, Flavia; Gori, Fabio

    2017-09-01

    Magnetic nano drug targeting, through the use of an external magnetic field, is a new technique for the treatment of several diseases, which can potentially avoid the dispersion of drugs in undesired locations of the body. Nevertheless, due to the limitations on the intensity of the magnetic field applied, the hydrodynamic forces can reduce the effectiveness of the procedure. This technique is studied in this paper with the Computational Fluid Dynamics (CFD), focusing on the influence of the magnetic probe position, and the direction of the circulating electric current. A single rectangular coil is used to generate the external magnetic field. A patient-specific geometry of the coeliac trunk is reconstructed from DICOM images, with the use of VMTK. A new solver, coupling the Lagrangian dynamics of the nanoparticles with the Eulerian dynamics of the blood, is implemented in OpenFOAM to perform the simulations. The resistive pressure, the Womersley's profile for the inlet velocity and the magnetic field of a rectangular coil are implemented in the software as boundary conditions. The results show the influence of the position of the probe, as well as the limitations associated with the rectangular coil configuration.

  3. Comparison of computed tomography based parametric and patient-specific finite element models of the healthy and metastatic spine using a mesh-morphing algorithm.

    Science.gov (United States)

    O'Reilly, Meaghan Anne; Whyne, Cari Marisa

    2008-08-01

    A comparative analysis of parametric and patient-specific finite element (FE) modeling of spinal motion segments. To develop patient-specific FE models of spinal motion segments using mesh-morphing methods applied to a parametric FE model. To compare strain and displacement patterns in parametric and morphed models for both healthy and metastatically involved vertebrae. Parametric FE models may be limited in their ability to fully represent patient-specific geometries and material property distributions. Generation of multiple patient-specific FE models has been limited because of computational expense. Morphing methods have been successfully used to generate multiple specimen-specific FE models of caudal rat vertebrae. FE models of a healthy and a metastatic T6-T8 spinal motion segment were analyzed with and without patient-specific material properties. Parametric and morphed models were compared using a landmark-based morphing algorithm. Morphing of the parametric FE model and including patient-specific material properties both had a strong impact on magnitudes and patterns of vertebral strain and displacement. Small but important geometric differences can be represented through morphing of parametric FE models. The mesh-morphing algorithm developed provides a rapid method for generating patient-specific FE models of spinal motion segments.

  4. Patient specific actual size 3D printed models for patient education in glioma treatment: first experiences.

    Science.gov (United States)

    van de Belt, Tom H; Nijmeijer, Hugo; Grim, David; Engelen, Lucien Jlpg; Vreeken, Rinaldo; van Gelder, Marleen Mmj; Laan, Mark Ter

    2018-06-02

    Cancer patients need high quality information about the disease stage, treatment options and side effects. High quality information can also improve health literacy, shared decision-making and satisfaction. We created patient-specific 3D models of tumours including surrounding functional areas, and assessed what patients with glioma actually value (or fear) about these models when they are used to educate them about the relation between their tumour and specific brain parts, the surgical procedure, and risks. We carried out an explorative study with adult glioma patients, who underwent functional MRI and DTi as part of the pre-operative work-up. All participants received an actual size 3D model, printed based on fMRI and DTi imaging. Semi-structured interviews were held to identify facilitators and barriers for using the model, and perceived effects. A model was successfully created for all 11 participants. A total of 18 facilitators and 8 barriers were identified. The model improved patients' understanding about their situation, that it was easier to ask questions to their neurosurgeon based on their model and that it supported their decision about the preferred treatment. A perceived barrier for using the 3D model was that it could be emotionally confronting, particularly in an early phase of the disease process. Positive effects were related to psychological domains including coping, learning effects and communication. Patient-specific 3D models are promising and simple tools that could help patients with glioma to better understand their situation, treatment options and risks. They have the potential to improve shared decision-making. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  5. SU-F-T-432: Magnetic Field Dose Effects for Various Radiation Beam Geometries for Patients Treated with Hypofractionated Partial Breast Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lim-Reinders, S [Sunnybrook Odette Cancer Centre, Toronto (Canada); University of Toronto, Department of Physics (Canada); Keller, B; McCann, C; Sahgal, A; Lee, J; Kim, A [Sunnybrook Odette Cancer Centre, Toronto (Canada); University of Toronto, Department of Radiation Oncology (Canada)

    2016-06-15

    Purpose: Hypofractionated partial breast irradiation (HPBI) is being used at our clinic to treat inoperable breast cancer patients who have advanced disease. We are investigating how these patients could benefit from being treated in an MRI-linac, where real-time daily MRI tumor imaging and plan adaptation would be possible. As a first step, this study evaluates the dosimetric impact of the magnetic field for different radiation beam geometries on relevant OARs. Methods: Five patients previously treated using HPBI were selected. Six treatment plans were generated for each patient, evaluating three beam geometries (VMAT, IMRT, 3DCRT) with and without B{sub 0}=1.5 T. The Monaco TPS was used with the Elekta MRI-Linac beam model, where the magnetic field is orthogonal to the radiation beam. All plans were re-scaled to the same isocoverage with a prescription of 40Gy/5 to the PTV. Plans were evaluated for the effect of the magnetic field and beam modality on skin V{sub 3} {sub 0}, lung V{sub 2} {sub 0} and mean heart dose. Results: Averaged over all patients, skin V{sub 3} {sub 0}for 3DCRT was higher than VMAT and IMRT (by +22% and +21%, with B{sub 0}-ON). The magnetic field caused larger increases in skin V{sub 3} {sub 0}for 3DCRT (+8%) than VMAT (+3%) and IMRT (+4%) compared with B{sub 0}-OFF. With B{sub 0}-ON, 3DCRT had a markedly lower mean heart dose than VMAT (by 538cGy) and IMRT (by 562cGy); for lung V{sub 2} {sub 0}, 3DCRT had a marginally lower dose than VMAT (by −2.2%) and IMRT (also −2.2%). The magnetic field had minimal effect on the mean heart dose and lung V{sub 2} {sub 0} for all geometries. Conclusion: The decreased skin dose in VMAT and IMRT can potentially mitigate the effects of skin reactions for HPBI in an MRI-linac. This study illustrated that more beam angles may result in lower skin toxicity and better tumor conformality, with the trade-off of elevated heart and lung doses. We are receiving funding support from Elekta.

  6. Geometry of Quantum States

    International Nuclear Information System (INIS)

    Hook, D W

    2008-01-01

    A geometric framework for quantum mechanics arose during the mid 1970s when authors such as Cantoni explored the notion of generalized transition probabilities, and Kibble promoted the idea that the space of pure quantum states provides a natural quantum mechanical analogue for classical phase space. This central idea can be seen easily since the projection of Schroedinger's equation from a Hilbert space into the space of pure spaces is a set of Hamilton's equations. Over the intervening years considerable work has been carried out by a variety of authors and a mature description of quantum mechanics in geometric terms has emerged with many applications. This current offering would seem ideally placed to review the last thirty years of progress and relate this to the most recent work in quantum entanglement. Bengtsson and Zyczkowski's beautifully illustrated volume, Geometry of Quantum States (referred to as GQS from now on) attempts to cover considerable ground in its 466 pages. Its topics range from colour theory in Chapter 1 to quantum entanglement in Chapter 15-to say that this is a whirlwind tour is, perhaps, no understatement. The use of the work 'introduction' in the subtitle of GQS, might suggest to the reader that this work be viewed as a textbook and I think that this interpretation would be incorrect. The authors have chosen to present a survey of different topics with the specific aim to introduce entanglement in geometric terms-the book is not intended as a pedagogical introduction to the geometric approach to quantum mechanics. Each of the fifteen chapters is a short, and mostly self-contained, essay on a particular aspect or application of geometry in the context of quantum mechanics with entanglement being addressed specifically in the final chapter. The chapters fall into three classifications: those concerned with the mathematical background, those which discuss quantum theory and the foundational aspects of the geometric framework, and

  7. Improved patient specific seizure detection during pre-surgical evaluation.

    LENUS (Irish Health Repository)

    Chua, Eric C-P

    2011-04-01

    There is considerable interest in improved off-line automated seizure detection methods that will decrease the workload of EEG monitoring units. Subject-specific approaches have been demonstrated to perform better than subject-independent ones. However, for pre-surgical diagnostics, the traditional method of obtaining a priori data to train subject-specific classifiers is not practical. We present an alternative method that works by adapting the threshold of a subject-independent to a specific subject based on feedback from the user.

  8. Akurasi Kriteria Voltase Elektrokardiografi Hipertrofi Ventrikel Kiri untuk Membedakan Jenis Geometri Hipertrofi Ventrikel Kiri

    Directory of Open Access Journals (Sweden)

    Octo Tumbur

    2017-08-01

    The different types of left ventricular hypertrophy geometry is associated with different risk of cardiovascular disease. Echocardiography is the gold standard for diagnosis of left ventricular hypertrophy. Electrocardiographic (ECGleft ventricular hypertrophy voltage criteria can distinguish the type of geometry of left ventricular hypertrophy. The purpose of this study to find out the role of various voltage ECG criteria to distinguish the type of geometry of left ventricle hypertrophy. A cross-sectional study doing from June to November 2015 on 100 patients in cardiology clinic and inpatient at Adam Malik Hospital, Medan, through anamnesis, body mass index  measurement, ECG and echocardiography examinations. If the Sokolow-Lyon ECG criteria for left ventricular hypertrophy did not met, normal left ventricular geometry was diagnosed with 60% sensitivity, 72.22% specificity and 71% accuracy. The eccentric left ventricular hypertrophy geometry was diagnosed if Cornel voltage was not fulfilled, with 25% sensitivity, 71.88% specificity and 55% accuracy. The concentric hypertrophy geometry was diagnosed if the RV6/V5 ratio >1, with 55.56% sensitivity, 56.36% specificity and 56% accuracy. If the RV6/V5 ratio >1 are not met, concentric hypertrophic remodeling geometry was diagnosed with a sensitivity of 55.56%, a specificity of 49.45% and an accuracy of 50%. This study also found the sensitivity and specificity for left ventricular hypertrophy in echocardiography of Sokolow-Lyon criteria were 72.22% and 60.00%, the Cornel voltage criteria with a sensitivity of 77.78% and a specificity of 70.00%, and RV6/V5 ratio criteria with a sensitivity of 51.11% and a specificity of 70.00%. The overall sensitivity and specificity was low. In conclusion, various criteria of  ECG left ventricular geometry voltage can differentiate left ventricular hypertrophy geometry types. Sokolow-Lyon and Cornell voltage criteria are more sensitive and specific than the RV6/V5 ratio.

  9. Patient-specific rhytidectomy: finding the angle of maximal rejuvenation.

    Science.gov (United States)

    Jacono, Andrew A; Ransom, Evan R

    2012-09-01

    Rhytidectomy is fundamentally an operation of tissue release and resuspension, although the manner and direction of suspension are subject to perpetual debate. The authors describe a method for identifying the angle of maximal rejuvenation during rhytidectomy and quantify the resulting angle and its relationship to patient age. Patients were prospectively enrolled; demographic data, history, and operative details were recorded. Rhytidectomies were performed by the senior author (AAJ). After complete elevation, the face-lift flap was rotated in a medially-based arc (0-90°) while attention was given to the submental area, jawline, and midface. The angle of maximal rejuvenation for each hemiface was identified as described, and the flap was resuspended. During redraping, measurements of vertical and horizontal skin excess were recorded in situ. The resulting angle of lift was then calculated for each hemiface using trigonometry. Symmetry between sides was determined, and the effect of patient age on this angle was assessed. Three hundred hemifaces were operated (147 women; 3 men). Mean age was 60 years (range, 37-80 years). Mean resulting angle for the cohort was 60° from horizontal (range, 46-77°). This was inversely correlated with patient age (r = -.3). Younger patients (<50 years, 64°) had a significantly more vertical angle than older patients (≥70 years, 56°; P < .0002). No significant intersubject difference was found between hemifaces (P = .53). The authors present a method for identifying the angle of maximal rejuvenation during rhytidectomy. This angle was more superior than posterior in all cases and is intimately related to patient age. Lasting results demand a detailed anatomical understanding and strict attention to the direction and degree of laxity.

  10. Comparison of serum prostate specific antigen levels and bone scintigraphy in patients with prostate carcinoma

    International Nuclear Information System (INIS)

    Bielickaite, J.; Zadeikaite, R.; Jurkiene, N. and others

    2003-01-01

    The aim of this study was to analyze the levels of serum prostate specific antigen in patients with and without bone metastases detected by means of bone scintigraphy and to determine the highest prostate specific antigen level in patients without bone metastases. The 50 patients consecutively diagnosed of prostate cancer between 1999 and 2001 in our institution made up the study population. Prostate specific antigen plasmatic levels were determined and bone scintigraphy was performed (whole body study after 99mTc-methyl-diphosphonate administration) in all the patients. In patients with positive bone scans (n=23), the mean prostate specific antigen level was 71.4±35.2 ng/ml and was significantly (p<0.00005) higher than in 14 patients with negative bone scans (mean prostate specific antigen level was 10.1±10.5 ng/ml). Suspicious lesions were found in 13 patients and their mean prostate specific antigen level was 8.5±7.7 ng/ml. Regarding prostate specific antigen levels, no statistically significant differences were found between patients with suspicious lessons and normal bone scans. The highest determined prostate specific antigen level in patients without bone metastases was 18 ng/ml. The bone scintigraphy should be performed in all patients with prostate specific antigen level above 18 ng/ml, but it is of limited value in patients with prostate specific antigen level below 18 ng/ml. (author)

  11. Patient-Specific Surgical Implants Made of 3D Printed PEEK: Material, Technology, and Scope of Surgical Application

    Directory of Open Access Journals (Sweden)

    Philipp Honigmann

    2018-01-01

    Full Text Available Additive manufacturing (AM is rapidly gaining acceptance in the healthcare sector. Three-dimensional (3D virtual surgical planning, fabrication of anatomical models, and patient-specific implants (PSI are well-established processes in the surgical fields. Polyetheretherketone (PEEK has been used, mainly in the reconstructive surgeries as a reliable alternative to other alloplastic materials for the fabrication of PSI. Recently, it has become possible to fabricate PEEK PSI with Fused Filament Fabrication (FFF technology. 3D printing of PEEK using FFF allows construction of almost any complex design geometry, which cannot be manufactured using other technologies. In this study, we fabricated various PEEK PSI by FFF 3D printer in an effort to check the feasibility of manufacturing PEEK with 3D printing. Based on these preliminary results, PEEK can be successfully used as an appropriate biomaterial to reconstruct the surgical defects in a “biomimetic” design.

  12. Patient-Specific Surgical Implants Made of 3D Printed PEEK: Material, Technology, and Scope of Surgical Application.

    Science.gov (United States)

    Honigmann, Philipp; Sharma, Neha; Okolo, Brando; Popp, Uwe; Msallem, Bilal; Thieringer, Florian M

    2018-01-01

    Additive manufacturing (AM) is rapidly gaining acceptance in the healthcare sector. Three-dimensional (3D) virtual surgical planning, fabrication of anatomical models, and patient-specific implants (PSI) are well-established processes in the surgical fields. Polyetheretherketone (PEEK) has been used, mainly in the reconstructive surgeries as a reliable alternative to other alloplastic materials for the fabrication of PSI. Recently, it has become possible to fabricate PEEK PSI with Fused Filament Fabrication (FFF) technology. 3D printing of PEEK using FFF allows construction of almost any complex design geometry, which cannot be manufactured using other technologies. In this study, we fabricated various PEEK PSI by FFF 3D printer in an effort to check the feasibility of manufacturing PEEK with 3D printing. Based on these preliminary results, PEEK can be successfully used as an appropriate biomaterial to reconstruct the surgical defects in a "biomimetic" design.

  13. Specifics of mental disorders of patients with metabolic syndrome

    Directory of Open Access Journals (Sweden)

    K. I. Kleban

    2017-09-01

    Full Text Available In the general-somatic network there is a steady increase in the number of patients with psychosomatic disorders. Problems of providing adequate psychiatric and psychotherapeutic assistance to this category of patients are related to the motivation of patients to participate in psychological measures and the readiness of the medical system to provide comprehensive care on the basis of the biopsychosocial approach. Mental factors are involved both in the occurrence and course of a metabolic syndrome in the form of a patient's lifestyle and behavior patterns of healthy functioning, and is a consequence of somatic pathology. Mental factors are involved both in the occurrence and course of a metabolic syndrome in the form of a patient's lifestyle and behavior patterns of healthy functioning, and is a consequence of somatic pathology. So mental disorders of metabolic syndrome are manifested in the form of psychosocial maladaptation, neurotic, affective, personality, and organic disorders. Desynchronosis which is a factor of the development of a metabolic syndrome and characterizes the complex chronobiological component of the regulation of psychophysiological functions in norm and under the influence of stress, deserves special attention. Addressing the diagnosis of mental disorders associated with metabolic syndrome is precisely aimed at determining chronobiological disorders of psychosomatic integrated areas and is supposed to improve diagnostic and treatment process and to shorten the treatment of these disorders.

  14. Numerical simulation of magnetic nano drug targeting in a patient-specific coeliac trunk

    Energy Technology Data Exchange (ETDEWEB)

    Boghi, Andrea, E-mail: a.boghi@cranfield.ac.uk [School of Water, Energy and Environment, Cranfield University, Cranfield, Bedfordshire MK43 0AL (United Kingdom); Russo, Flavia; Gori, Fabio [Department of Mechanical Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy)

    2017-09-01

    Highlights: • A mathematical model, describing magnetic nanoparticles in blood flow is proposed. • The model has been validated against MHD channel flow analytical solutions. • Four simulations have been carried out to study the parameters sensitivity. • The results show the limits of magnetic drug delivery applied to hepatic tumor. • Three parameters are deemed responsible for the low performances of the technique. - Abstract: Magnetic nano drug targeting, through the use of an external magnetic field, is a new technique for the treatment of several diseases, which can potentially avoid the dispersion of drugs in undesired locations of the body. Nevertheless, due to the limitations on the intensity of the magnetic field applied, the hydrodynamic forces can reduce the effectiveness of the procedure. This technique is studied in this paper with the Computational Fluid Dynamics (CFD), focusing on the influence of the magnetic probe position, and the direction of the circulating electric current. A single rectangular coil is used to generate the external magnetic field. A patient-specific geometry of the coeliac trunk is reconstructed from DICOM images, with the use of VMTK. A new solver, coupling the Lagrangian dynamics of the nanoparticles with the Eulerian dynamics of the blood, is implemented in OpenFOAM to perform the simulations. The resistive pressure, the Womersley’s profile for the inlet velocity and the magnetic field of a rectangular coil are implemented in the software as boundary conditions. The results show the influence of the position of the probe, as well as the limitations associated with the rectangular coil configuration.

  15. Numerical simulation of magnetic nano drug targeting in a patient-specific coeliac trunk

    International Nuclear Information System (INIS)

    Boghi, Andrea; Russo, Flavia; Gori, Fabio

    2017-01-01

    Highlights: • A mathematical model, describing magnetic nanoparticles in blood flow is proposed. • The model has been validated against MHD channel flow analytical solutions. • Four simulations have been carried out to study the parameters sensitivity. • The results show the limits of magnetic drug delivery applied to hepatic tumor. • Three parameters are deemed responsible for the low performances of the technique. - Abstract: Magnetic nano drug targeting, through the use of an external magnetic field, is a new technique for the treatment of several diseases, which can potentially avoid the dispersion of drugs in undesired locations of the body. Nevertheless, due to the limitations on the intensity of the magnetic field applied, the hydrodynamic forces can reduce the effectiveness of the procedure. This technique is studied in this paper with the Computational Fluid Dynamics (CFD), focusing on the influence of the magnetic probe position, and the direction of the circulating electric current. A single rectangular coil is used to generate the external magnetic field. A patient-specific geometry of the coeliac trunk is reconstructed from DICOM images, with the use of VMTK. A new solver, coupling the Lagrangian dynamics of the nanoparticles with the Eulerian dynamics of the blood, is implemented in OpenFOAM to perform the simulations. The resistive pressure, the Womersley’s profile for the inlet velocity and the magnetic field of a rectangular coil are implemented in the software as boundary conditions. The results show the influence of the position of the probe, as well as the limitations associated with the rectangular coil configuration.

  16. A Patient Specific Biomechanical Analysis of Custom Root Analogue Implant Designs on Alveolar Bone Stress: A Finite Element Study

    Directory of Open Access Journals (Sweden)

    David Anssari Moin

    2016-01-01

    Full Text Available Objectives. The aim of this study was to analyse by means of FEA the influence of 5 custom RAI designs on stress distribution of peri-implant bone and to evaluate the impact on microdisplacement for a specific patient case. Materials and Methods. A 3D surface model of a RAI for the upper right canine was constructed from the cone beam computed tomography data of one patient. Subsequently, five (targeted press-fit design modification FE models with five congruent bone models were designed: “Standard,” “Prism,” “Fins,” “Plug,” and “Bulbs,” respectively. Preprocessor software was applied to mesh the models. Two loads were applied: an oblique force (300 N and a vertical force (150 N. Analysis was performed to evaluate stress distributions and deformed contact separation at the peri-implant region. Results. The lowest von Mises stress levels were numerically observed for the Plug design. The lowest levels of contact separation were measured in the Fins model followed by the Bulbs design. Conclusions. Within the limitations of the applied methodology, adding targeted press-fit geometry to the RAI standard design will have a positive effect on stress distribution, lower concentration of bone stress, and will provide a better primary stability for this patient specific case.

  17. Geometry and its applications

    CERN Document Server

    Meyer, Walter J

    2006-01-01

    Meyer''s Geometry and Its Applications, Second Edition, combines traditional geometry with current ideas to present a modern approach that is grounded in real-world applications. It balances the deductive approach with discovery learning, and introduces axiomatic, Euclidean geometry, non-Euclidean geometry, and transformational geometry. The text integrates applications and examples throughout and includes historical notes in many chapters. The Second Edition of Geometry and Its Applications is a significant text for any college or university that focuses on geometry''s usefulness in other disciplines. It is especially appropriate for engineering and science majors, as well as future mathematics teachers.* Realistic applications integrated throughout the text, including (but not limited to): - Symmetries of artistic patterns- Physics- Robotics- Computer vision- Computer graphics- Stability of architectural structures- Molecular biology- Medicine- Pattern recognition* Historical notes included in many chapters...

  18. Algebraic geometry in India

    Indian Academy of Sciences (India)

    algebraic geometry but also in related fields like number theory. ... every vector bundle on the affine space is trivial. (equivalently ... les on a compact Riemann surface to unitary rep- ... tial geometry and topology and was generalised in.

  19. Spinorial Geometry and Branes

    International Nuclear Information System (INIS)

    Sloane, Peter

    2007-01-01

    We adapt the spinorial geometry method introduced in [J. Gillard, U. Gran and G. Papadopoulos, 'The spinorial geometry of supersymmetric backgrounds,' Class. Quant. Grav. 22 (2005) 1033 [ (arXiv:hep-th/0410155)

  20. Spinorial Geometry and Branes

    Energy Technology Data Exchange (ETDEWEB)

    Sloane, Peter [Department of Mathematics, King' s College, University of London, Strand, London WC2R 2LS (United Kingdom)

    2007-09-15

    We adapt the spinorial geometry method introduced in [J. Gillard, U. Gran and G. Papadopoulos, 'The spinorial geometry of supersymmetric backgrounds,' Class. Quant. Grav. 22 (2005) 1033 [ (arXiv:hep-th/0410155)

  1. Cause-Specific Mortality Among Spouses of Parkinson Disease Patients

    DEFF Research Database (Denmark)

    Nielsen, Malene; Hansen, Jonni; Ritz, Beate

    2014-01-01

    BACKGROUND: Caring for a chronically ill spouse is stressful, but the health effects of caregiving are not fully understood. We studied the effect on mortality of being married to a person with Parkinson disease. METHODS: All patients in Denmark with a first-time hospitalization for Parkinson...... disease between 1986 and 2009 were identified, and each case was matched to five population controls. We further identified all spouses of those with Parkinson disease (n = 8,515) and also the spouses of controls (n = 43,432). All spouses were followed in nationwide registries until 2011. RESULTS: Among...... men, being married to a Parkinson disease patient was associated with a slightly higher risk of all-cause mortality (hazard ratio = 1.06 [95% confidence interval = 1.00-1.11]). Mortality was particularly high for death due to external causes (1.42 [1.09-1.84]) including suicide (1.89 [1...

  2. Patient Specific Dosimetry based in excreted urine measurements

    Energy Technology Data Exchange (ETDEWEB)

    Barquero, R.; Nunez, C.; Ruiz, A.; Valverde, J.; Basurto, F.

    2006-07-01

    One of the limiting factors in utilising therapeutic radiopharmaceuticals in the I-131 thyroid therapy is the potential hazard to the bone marrow, kidneys, and other internal organs. In this work, by means of daily dose rate measurements at a point in contact of the can with the urine excreted by the patient undergoing radio-iodine therapy, activities and associated absorbed doses in total body are calculated. The urine can is characterised by a geometric and materials model for MC simulation with MCNP. Knowing the conversion factor from activity in urine to dose rate in the measurement point of the can for each filling volume, the urine and patient activity can be obtained at each measurement time. From the fitting of these activities, the time evolution, the effective half life in the patient and the cumulative whole body activity are calculated. The emission characteristics of I-131 are using after to estimate the maximum whole body absorbed dose. The results for 2 hyperthyroidism and 4 carcinoma treatments are presented. The maximum total body absorbed dose are 673 and 149 Gy for the carcinoma and hyperthyroidism. The corresponding range of T1/2 eff is o.2 to 2.5 days (carcinoma) and 5.4 to 6.6 days (hyperthyroidism). (Author)

  3. Exploring Bundling Theory with Geometry

    Science.gov (United States)

    Eckalbar, John C.

    2006-01-01

    The author shows how instructors might successfully introduce students in principles and intermediate microeconomic theory classes to the topic of bundling (i.e., the selling of two or more goods as a package, rather than separately). It is surprising how much students can learn using only the tools of high school geometry. To be specific, one can…

  4. Prostate Cancer–Specific Mortality After Radical Prostatectomy for Patients Treated in the Prostate-Specific Antigen Era

    Science.gov (United States)

    Stephenson, Andrew J.; Kattan, Michael W.; Eastham, James A.; Bianco, Fernando J.; Yossepowitch, Ofer; Vickers, Andrew J.; Klein, Eric A.; Wood, David P.; Scardino, Peter T.

    2009-01-01

    Purpose The long-term risk of prostate cancer–specific mortality (PCSM) after radical prostatectomy is poorly defined for patients treated in the era of widespread prostate-specific antigen (PSA) screening. Models that predict the risk of PCSM are needed for patient counseling and clinical trial design. Methods A multi-institutional cohort of 12,677 patients treated with radical prostatectomy between 1987 and 2005 was analyzed for the risk of PCSM. Patient clinical information and treatment outcome was modeled using Fine and Gray competing risk regression analysis to predict PCSM. Results Fifteen-year PCSM and all-cause mortality were 12% and 38%, respectively. The estimated PCSM ranged from 5% to 38% for patients in the lowest and highest quartiles of predicted risk of PSA-defined recurrence, based on a popular nomogram. Biopsy Gleason grade, PSA, and year of surgery were associated with PCSM. A nomogram predicting the 15-year risk of PCSM was developed, and the externally validated concordance index was 0.82. Neither preoperative PSA velocity nor body mass index improved the model's accuracy. Only 4% of contemporary patients had a predicted 15-year PCSM of greater than 5%. Conclusion Few patients will die from prostate cancer within 15 years of radical prostatectomy, despite the presence of adverse clinical features. This favorable prognosis may be related to the effectiveness of radical prostatectomy (with or without secondary therapy) or the low lethality of screen-detected cancers. Given the limited ability to identify contemporary patients at substantially elevated risk of PCSM on the basis of clinical features alone, the need for novel markers specifically associated with the biology of lethal prostate cancer is evident. PMID:19636023

  5. Comparison of left ventricular outflow geometry and aortic valve area in patients with aortic stenosis by 2-dimensional versus 3-dimensional echocardiography.

    Science.gov (United States)

    Saitoh, Takeji; Shiota, Maiko; Izumo, Masaki; Gurudevan, Swaminatha V; Tolstrup, Kirsten; Siegel, Robert J; Shiota, Takahiro

    2012-06-01

    The present study sought to elucidate the geometry of the left ventricular outflow tract (LVOT) in patients with aortic stenosis and its effect on the accuracy of the continuity equation-based aortic valve area (AVA) estimation. Real-time 3-dimensional transesophageal echocardiography (RT3D-TEE) provides high-resolution images of LVOT in patients with aortic stenosis. Thus, AVA is derived reliably with the continuity equation. Forty patients with aortic stenosis who underwent 2-dimensional transthoracic echocardiography (2D-TTE), 2-dimensional transesophageal echocardiography (2D-TEE), and RT3D-TEE were studied. In 2D-TTE and 2D-TEE, the LVOT areas were calculated as π × (LVOT dimension/2)(2). In RT3D-TEE, the LVOT areas and ellipticity ([diameter of the anteroposterior axis]/[diameter of the medial-lateral axis]) were evaluated by planimetry. The AVA is then determined using planimetry and the continuity equation method. LVOT shape was found to be elliptical (ellipticity of 0.80 ± 0.08). Accordingly, the LVOT areas measured by 2D-TTE (median 3.7 cm(2), interquartile range 3.1 to 4.1) and 2D-TEE (median 3.7 cm(2), interquartile range 3.1 to 4.0) were smaller than those by 3D-TEE (median 4.6 cm(2), interquartile range 3.9 to 5.3; p interquartile range 0.79 to 1.3, p interquartile range 0.64 to 0.94) and 2D-TEE (median 0.76 cm(2), interquartile range 0.62 to 0.95). Additionally, the continuity equation-based AVA by RT3D-TEE was consistent with the planimetry method. In conclusion, RT3D-TEE might allow more accurate evaluation of the elliptical LVOT geometry and continuity equation-based AVA in patients with aortic stenosis than 2D-TTE and 2D-TEE. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. New frontier in regenerative medicine: site-specific gene correction in patient-specific induced pluripotent stem cells.

    Science.gov (United States)

    Garate, Zita; Davis, Brian R; Quintana-Bustamante, Oscar; Segovia, Jose C

    2013-06-01

    Advances in cell and gene therapy are opening up new avenues for regenerative medicine. Because of their acquired pluripotency, human induced pluripotent stem cells (hiPSCs) are a promising source of autologous cells for regenerative medicine. They show unlimited self-renewal while retaining the ability, in principle, to differentiate into any cell type of the human body. Since Yamanaka and colleagues first reported the generation of hiPSCs in 2007, significant efforts have been made to understand the reprogramming process and to generate hiPSCs with potential for clinical use. On the other hand, the development of gene-editing platforms to increase homologous recombination efficiency, namely DNA nucleases (zinc finger nucleases, TAL effector nucleases, and meganucleases), is making the application of locus-specific gene therapy in human cells an achievable goal. The generation of patient-specific hiPSC, together with gene correction by homologous recombination, will potentially allow for their clinical application in the near future. In fact, reports have shown targeted gene correction through DNA-Nucleases in patient-specific hiPSCs. Various technologies have been described to reprogram patient cells and to correct these patient hiPSCs. However, no approach has been clearly more efficient and safer than the others. In addition, there are still significant challenges for the clinical application of these technologies, such as inefficient differentiation protocols, genetic instability resulting from the reprogramming process and hiPSC culture itself, the efficacy and specificity of the engineered DNA nucleases, and the overall homologous recombination efficiency. To summarize advances in the generation of gene corrected patient-specific hiPSCs, this review focuses on the available technological platforms, including their strengths and limitations regarding future therapeutic use of gene-corrected hiPSCs.

  7. SU-F-BRE-08: Feasibility of 3D Printed Patient Specific Phantoms for IMRT/IGRT QA

    International Nuclear Information System (INIS)

    Ehler, E; Higgins, P; Dusenbery, K

    2014-01-01

    Purpose: Test the feasibility of 3D printed, per-patient phantoms for IMRT QA to analyze the treatment delivery quality within the patient geometry. Methods: Using the head and neck region of an anthropomorphic phantom as a substitute for an actual patient, a soft-tissue equivalent model was constructed with the use of a 3D printer. A nine-field IMRT plan was constructed and dose verification measurements were performed for the 3D printed phantom. During the delivery of the IMRT QA on to the 3D printed phantom, the same patient positioning indexing system was used on the phantom and image guidance (cone beam CT) was used to localize the phantom, serving as a test of the IGRT system as well. The 3D printed phantom was designed to accommodate four radiochromic film planes (two axial, one coronal and one sagittal) and an ionization chamber measurement. As a frame of comparison, the IMRT QA was also performed on traditional phantoms. Dosimetric tolerance levels such as 3mm / 3% Gamma Index as well as 3% and 5% dose difference were considered. All detector systems were calibrated against a NIST traceable ionization chamber. Results: Comparison of results 3D printed patient phantom with the standard IMRT QA systems showed similar passing rates for the 3D printed phantom and the standard phantoms. However, the locations of the failing regions did not necessarily correlate. The 3D printed phantom was localized within 1 mm and 1° using on-board cone beam CT. Conclusion: A custom phantom was created using a 3D printer. It was determined that the use of patient specific phantoms to perform dosimetric verification and estimate the dose in the patient is feasible. In addition, end-to-end testing on a per-patient basis was possible with the 3D printed phantom. Further refinement of the phantom construction process is needed for routine clinical use

  8. SU-F-BRE-08: Feasibility of 3D Printed Patient Specific Phantoms for IMRT/IGRT QA

    Energy Technology Data Exchange (ETDEWEB)

    Ehler, E; Higgins, P; Dusenbery, K [University of Minnesota, Minneapolis, MN (United States)

    2014-06-15

    Purpose: Test the feasibility of 3D printed, per-patient phantoms for IMRT QA to analyze the treatment delivery quality within the patient geometry. Methods: Using the head and neck region of an anthropomorphic phantom as a substitute for an actual patient, a soft-tissue equivalent model was constructed with the use of a 3D printer. A nine-field IMRT plan was constructed and dose verification measurements were performed for the 3D printed phantom. During the delivery of the IMRT QA on to the 3D printed phantom, the same patient positioning indexing system was used on the phantom and image guidance (cone beam CT) was used to localize the phantom, serving as a test of the IGRT system as well. The 3D printed phantom was designed to accommodate four radiochromic film planes (two axial, one coronal and one sagittal) and an ionization chamber measurement. As a frame of comparison, the IMRT QA was also performed on traditional phantoms. Dosimetric tolerance levels such as 3mm / 3% Gamma Index as well as 3% and 5% dose difference were considered. All detector systems were calibrated against a NIST traceable ionization chamber. Results: Comparison of results 3D printed patient phantom with the standard IMRT QA systems showed similar passing rates for the 3D printed phantom and the standard phantoms. However, the locations of the failing regions did not necessarily correlate. The 3D printed phantom was localized within 1 mm and 1° using on-board cone beam CT. Conclusion: A custom phantom was created using a 3D printer. It was determined that the use of patient specific phantoms to perform dosimetric verification and estimate the dose in the patient is feasible. In addition, end-to-end testing on a per-patient basis was possible with the 3D printed phantom. Further refinement of the phantom construction process is needed for routine clinical use.

  9. Geometry essentials for dummies

    CERN Document Server

    Ryan, Mark

    2011-01-01

    Just the critical concepts you need to score high in geometry This practical, friendly guide focuses on critical concepts taught in a typical geometry course, from the properties of triangles, parallelograms, circles, and cylinders, to the skills and strategies you need to write geometry proofs. Geometry Essentials For Dummies is perfect for cramming or doing homework, or as a reference for parents helping kids study for exams. Get down to the basics - get a handle on the basics of geometry, from lines, segments, and angles, to vertices, altitudes, and diagonals Conque

  10. Combinatorial geometry in the plane

    CERN Document Server

    Hadwiger, Hugo; Klee, Victor

    2014-01-01

    Geared toward advanced undergraduates familiar with analysis and college geometry, this concise book discusses theorems on topics restricted to the plane such as convexity, coverings, and graphs. In addition to helping students cultivate rigorous thought, the text encourages the development of mathematical intuition and clarifies the nature of mathematical research.The two-part treatment begins with specific topics including integral distances, covering problems, point set geometry and convexity, simple paradoxes involving point sets, and pure combinatorics, among other subjects. The second pa

  11. Are patient specific meshes required for EIT head imaging?

    Science.gov (United States)

    Jehl, Markus; Aristovich, Kirill; Faulkner, Mayo; Holder, David

    2016-06-01

    Head imaging with electrical impedance tomography (EIT) is usually done with time-differential measurements, to reduce time-invariant modelling errors. Previous research suggested that more accurate head models improved image quality, but no thorough analysis has been done on the required accuracy. We propose a novel pipeline for creation of precise head meshes from magnetic resonance imaging and computed tomography scans, which was applied to four different heads. Voltages were simulated on all four heads for perturbations of different magnitude, haemorrhage and ischaemia, in five different positions and for three levels of instrumentation noise. Statistical analysis showed that reconstructions on the correct mesh were on average 25% better than on the other meshes. However, the stroke detection rates were not improved. We conclude that a generic head mesh is sufficient for monitoring patients for secondary strokes following head trauma.

  12. Age-specific mortality among TB patients in Denmark 1998-2010

    DEFF Research Database (Denmark)

    Fløe, Andreas; Løkke, Anders; Ibsen, Rikke

    Objective: To evaluate the age-specific mortality in a national TB cohort, and to estimate relative age-specific mortality compared with matched controls, in a retrospective case-control study. Methods: Using Danish National Patient Registry, we retrospectively identified TB-patients between 1998...... to matched controls. While the difference in survival is substantial among elderly patients, a high relative risk of dying is particularly of concern among young and middle-aged adult TB patients....

  13. Risks of all-cause and site-specific fractures among hospitalized patients with COPD

    OpenAIRE

    Liao, Kuang-Ming; Liang, Fu-Wen; Li, Chung-Yi

    2016-01-01

    Abstract Patients with chronic obstructive pulmonary disease (COPD) have a high prevalence of osteoporosis. The clinical sequel of osteoporosis is fracture. Patients with COPD who experience a fracture also have increased morbidity and mortality. Currently, the types of all-cause and site-specific fracture among patients with COPD are unknown. Thus, we elucidated the all-cause and site-specific fractures among patients with COPD. A retrospective, population-based, cohort study was conducted u...

  14. Arithmetic noncommutative geometry

    CERN Document Server

    Marcolli, Matilde

    2005-01-01

    Arithmetic noncommutative geometry denotes the use of ideas and tools from the field of noncommutative geometry, to address questions and reinterpret in a new perspective results and constructions from number theory and arithmetic algebraic geometry. This general philosophy is applied to the geometry and arithmetic of modular curves and to the fibers at archimedean places of arithmetic surfaces and varieties. The main reason why noncommutative geometry can be expected to say something about topics of arithmetic interest lies in the fact that it provides the right framework in which the tools of geometry continue to make sense on spaces that are very singular and apparently very far from the world of algebraic varieties. This provides a way of refining the boundary structure of certain classes of spaces that arise in the context of arithmetic geometry, such as moduli spaces (of which modular curves are the simplest case) or arithmetic varieties (completed by suitable "fibers at infinity"), by adding boundaries...

  15. Results of patient specific quality assurance for patients undergoing stereotactic ablative radiotherapy for lung lesions

    International Nuclear Information System (INIS)

    Hardcastle, Nicholas; Clements, Natalie; Cramb, Jim; Wanigaratne, Derrick M.; Chesson, Brent; Aarons, Yolanda; Siva, Shankar; Ball, David; Kron, Tomas

    2014-01-01

    Hypofractionated image guided radiotherapy of extracranial targets has become increasingly popular as a treatment modality for inoperable patients with one or more small lesions, often referred to as stereotactic ablative body radiotherapy (SABR). This report details the results of the physical quality assurance (QA) program used for the first 33 lung cancer SABR radiotherapy 3D conformal treatment plans in our centre. SABR involves one or few fractions of high radiation dose delivered in many small fields or arcs with tight margins to mobile targets often delivered through heterogeneous media with non-coplanar beams. We have conducted patient-specific QA similar to the more common intensity modulated radiotherapy QA with particular reference to motion management. Individual patient QA was performed in a Perspex phantom using point dose verification with an ionisation chamber and radiochromic film for verification of the dose distribution both with static and moving detectors to verify motion management strategies. While individual beams could vary by up to 7 %, the total dose in the target was found to be within ±2 % of the prescribed dose for all 33 plans. Film measurements showed qualitative and quantitative agreement between planned and measured isodose line shapes and dimensions. The QA process highlighted the need to account for couch transmission and demonstrated that the ITV construction was appropriate for the treatment technique used. QA is essential for complex radiotherapy deliveries such as SABR. We found individual patient QA helpful in setting up the technique and understanding potential weaknesses in SABR workflow, thus providing confidence in SABR delivery.

  16. Electrodynamics and Spacetime Geometry: Foundations

    Science.gov (United States)

    Cabral, Francisco; Lobo, Francisco S. N.

    2017-02-01

    We explore the intimate connection between spacetime geometry and electrodynamics. This link is already implicit in the constitutive relations between the field strengths and excitations, which are an essential part of the axiomatic structure of electromagnetism, clearly formulated via integration theory and differential forms. We review the foundations of classical electromagnetism based on charge and magnetic flux conservation, the Lorentz force and the constitutive relations. These relations introduce the conformal part of the metric and allow the study of electrodynamics for specific spacetime geometries. At the foundational level, we discuss the possibility of generalizing the vacuum constitutive relations, by relaxing the fixed conditions of homogeneity and isotropy, and by assuming that the symmetry properties of the electro-vacuum follow the spacetime isometries. The implications of this extension are briefly discussed in the context of the intimate connection between electromagnetism and the geometry (and causal structure) of spacetime.

  17. Patient-specific fibre-based models of muscle wrapping

    Science.gov (United States)

    Kohout, J.; Clapworthy, G. J.; Zhao, Y.; Tao, Y.; Gonzalez-Garcia, G.; Dong, F.; Wei, H.; Kohoutová, E.

    2013-01-01

    In many biomechanical problems, the availability of a suitable model for the wrapping of muscles when undergoing movement is essential for the estimation of forces produced on and by the body during motion. This is an important factor in the Osteoporotic Virtual Physiological Human project which is investigating the likelihood of fracture for osteoporotic patients undertaking a variety of movements. The weakening of their skeletons makes them particularly vulnerable to bone fracture caused by excessive loading being placed on the bones, even in simple everyday tasks. This paper provides an overview of a novel volumetric model that describes muscle wrapping around bones and other muscles during movement, and which includes a consideration of how the orientations of the muscle fibres change during the motion. The method can calculate the form of wrapping of a muscle of medium size and visualize the outcome within tenths of seconds on commodity hardware, while conserving muscle volume. This makes the method suitable not only for educational biomedical software, but also for clinical applications used to identify weak muscles that should be strengthened during rehabilitation or to identify bone stresses in order to estimate the risk of fractures. PMID:24427519

  18. 3D printing of patient-specific anatomy: A tool to improve patient consent and enhance imaging interpretation by trainees.

    Science.gov (United States)

    Liew, Yaoren; Beveridge, Erin; Demetriades, Andreas K; Hughes, Mark A

    2015-01-01

    We report the use of three-dimensional or 3D printed, patient-specific anatomy as a tool to improve informed patient consent and patient understanding in a case of posterior lumbar fixation. Next, we discuss its utility as an educational tool to enhance imaging interpretation by neurosurgery trainees.

  19. The Geometry Conference

    CERN Document Server

    Bárány, Imre; Vilcu, Costin

    2016-01-01

    This volume presents easy-to-understand yet surprising properties obtained using topological, geometric and graph theoretic tools in the areas covered by the Geometry Conference that took place in Mulhouse, France from September 7–11, 2014 in honour of Tudor Zamfirescu on the occasion of his 70th anniversary. The contributions address subjects in convexity and discrete geometry, in distance geometry or with geometrical flavor in combinatorics, graph theory or non-linear analysis. Written by top experts, these papers highlight the close connections between these fields, as well as ties to other domains of geometry and their reciprocal influence. They offer an overview on recent developments in geometry and its border with discrete mathematics, and provide answers to several open questions. The volume addresses a large audience in mathematics, including researchers and graduate students interested in geometry and geometrical problems.

  20. Planetary Image Geometry Library

    Science.gov (United States)

    Deen, Robert C.; Pariser, Oleg

    2010-01-01

    The Planetary Image Geometry (PIG) library is a multi-mission library used for projecting images (EDRs, or Experiment Data Records) and managing their geometry for in-situ missions. A collection of models describes cameras and their articulation, allowing application programs such as mosaickers, terrain generators, and pointing correction tools to be written in a multi-mission manner, without any knowledge of parameters specific to the supported missions. Camera model objects allow transformation of image coordinates to and from view vectors in XYZ space. Pointing models, specific to each mission, describe how to orient the camera models based on telemetry or other information. Surface models describe the surface in general terms. Coordinate system objects manage the various coordinate systems involved in most missions. File objects manage access to metadata (labels, including telemetry information) in the input EDRs and RDRs (Reduced Data Records). Label models manage metadata information in output files. Site objects keep track of different locations where the spacecraft might be at a given time. Radiometry models allow correction of radiometry for an image. Mission objects contain basic mission parameters. Pointing adjustment ("nav") files allow pointing to be corrected. The object-oriented structure (C++) makes it easy to subclass just the pieces of the library that are truly mission-specific. Typically, this involves just the pointing model and coordinate systems, and parts of the file model. Once the library was developed (initially for Mars Polar Lander, MPL), adding new missions ranged from two days to a few months, resulting in significant cost savings as compared to rewriting all the application programs for each mission. Currently supported missions include Mars Pathfinder (MPF), MPL, Mars Exploration Rover (MER), Phoenix, and Mars Science Lab (MSL). Applications based on this library create the majority of operational image RDRs for those missions. A

  1. Algorithms in Algebraic Geometry

    CERN Document Server

    Dickenstein, Alicia; Sommese, Andrew J

    2008-01-01

    In the last decade, there has been a burgeoning of activity in the design and implementation of algorithms for algebraic geometric computation. Some of these algorithms were originally designed for abstract algebraic geometry, but now are of interest for use in applications and some of these algorithms were originally designed for applications, but now are of interest for use in abstract algebraic geometry. The workshop on Algorithms in Algebraic Geometry that was held in the framework of the IMA Annual Program Year in Applications of Algebraic Geometry by the Institute for Mathematics and Its

  2. Revolutions of Geometry

    CERN Document Server

    O'Leary, Michael

    2010-01-01

    Guides readers through the development of geometry and basic proof writing using a historical approach to the topic. In an effort to fully appreciate the logic and structure of geometric proofs, Revolutions of Geometry places proofs into the context of geometry's history, helping readers to understand that proof writing is crucial to the job of a mathematician. Written for students and educators of mathematics alike, the book guides readers through the rich history and influential works, from ancient times to the present, behind the development of geometry. As a result, readers are successfull

  3. Fundamental concepts of geometry

    CERN Document Server

    Meserve, Bruce E

    1983-01-01

    Demonstrates relationships between different types of geometry. Provides excellent overview of the foundations and historical evolution of geometrical concepts. Exercises (no solutions). Includes 98 illustrations.

  4. Developments in special geometry

    International Nuclear Information System (INIS)

    Mohaupt, Thomas; Vaughan, Owen

    2012-01-01

    We review the special geometry of N = 2 supersymmetric vector and hypermultiplets with emphasis on recent developments and applications. A new formulation of the local c-map based on the Hesse potential and special real coordinates is presented. Other recent developments include the Euclidean version of special geometry, and generalizations of special geometry to non-supersymmetric theories. As applications we discuss the proof that the local r-map and c-map preserve geodesic completeness, and the construction of four- and five-dimensional static solutions through dimensional reduction over time. The shared features of the real, complex and quaternionic version of special geometry are stressed throughout.

  5. Prediagnostic prostate-specific antigen kinetics and the risk of biopsy progression in active surveillance patients.

    Science.gov (United States)

    Iremashvili, Viacheslav; Barney, Shane L; Manoharan, Murugesan; Kava, Bruce R; Parekh, Dipen J; Punnen, Sanoj

    2016-04-01

    To analyze the association between prediagnostic prostate-specific antigen kinetics and the risk of biopsy progression in prostate cancer patients on active surveillance, and to study the effect of prediagnostic prostate-specific antigen values on the predictive performance of prostate-specific antigen velocity and prostate-specific antigen doubling time. The study included 137 active surveillance patients with two or more prediagnostic prostate-specific antigen levels measured over a period of at least 3 months. Two sets of analyses were carried out. First, the association between prostate-specific antigen kinetics calculated using only the prediagnostic prostate-specific antigen values and the risk of biopsy progression was studied. Second, using the same cohort of patients, the predictive value of prostate-specific antigen kinetics calculated using only post-diagnostic prostate-specific antigens and compared with that of prostate-specific antigen kinetics based on both pre- and post-diagnostic prostate-specific antigen levels was analyzed. Of 137 patients included in the analysis, 37 (27%) had biopsy progression over a median follow-up period of 3.2 years. Prediagnostic prostate-specific antigen velocity of more than 2 ng/mL/year and 3 ng/mL/year was statistically significantly associated with the risk of future biopsy progression. However, after adjustment for baseline prostate-specific antigen density, these associations were no longer significant. None of the tested prostate-specific antigen kinetics based on combined pre- and post-diagnostic prostate-specific antigen values were statistically significantly associated with the risk of biopsy progression. Historical prediagnostic prostate-specific antigens seems to be not clinically useful in patients diagnosed with low-risk prostate cancer on active surveillance. © 2016 The Japanese Urological Association.

  6. Are There Gender-Specific Risk Factors for Suicidal Activity among Patients with Schizophrenia and Depression?

    Science.gov (United States)

    Kaplan, Kalman J.; Harrow, Martin; Faull, Robert N.

    2012-01-01

    Are there gender-specific risk factors for suicidal activity among patients with schizophrenia and depression? A total of 74 schizophrenia patients (51 men, 23 women) and 77 unipolar nonpsychotic depressed patients (26 men, 51 women) from the Chicago Follow-up Study were studied prospectively at 2 years posthospitalization and again at 7.5 years.…

  7. Geometric Transformations in Engineering Geometry

    Directory of Open Access Journals (Sweden)

    I. F. Borovikov

    2015-01-01

    Full Text Available Recently, for business purposes, in view of current trends and world experience in training engineers, research and faculty staff there has been a need to transform traditional courses of descriptive geometry into the course of engineering geometry in which the geometrical transformations have to become its main section. On the basis of critical analysis the paper gives suggestions to improve a presentation technique of this section both in the classroom and in academic literature, extend an application scope of geometrical transformations to solve the position and metric tasks and simulation of surfaces, as well as to design complex engineering configurations, which meet a number of pre-specified conditions.The article offers to make a number of considerable amendments to the terms and definitions used in the existing courses of descriptive geometry. It draws some conclusions and makes the appropriate proposals on feasibility of coordination in teaching the movement transformation in the courses of analytical and descriptive geometry. This will provide interdisciplinary team teaching and allow students to be convinced that a combination of analytical and graphic ways to solve geometric tasks is useful and reasonable.The traditional sections of learning courses need to be added with a theory of projective and bi-rational transformations. In terms of application simplicity and convenience it is enough to consider the central transformations when solving the applied tasks. These transformations contain a beam of sub-invariant (low-invariant straight lines on which the invariant curve induces non-involution and involution projectivities. The expediency of nonlinear transformations application is shown in the article by a specific example of geometric modeling of the interfacing surface "spar-blade".Implementation of these suggestions will contribute to a real transformation of a traditional course of descriptive geometry to the engineering geometry

  8. Primary stability of a cementless acetabular cup in a cohort of patient-specific finite element models.

    Science.gov (United States)

    O'Rourke, Dermot; Al-Dirini, Rami Ma; Taylor, Mark

    2018-03-01

    The primary stability achieved during total hip arthroplasty determines the long-term success of cementless acetabular cups. Pre-clinical finite element testing of cups typically use a model of a single patient and assume the results can be extrapolated to the general population. This study explored the variability in predicted primary stability of a Pinnacle ® cementless acetabular cup in 103 patient-specific finite element models of the hemipelvis and examined the association between patient-related factors and the observed variability. Cups were inserted by displacement-control into the FE models and then a loading configuration simulating a complete level gait cycle was applied. The cohort showed a range of polar gap of 284-1112 μm and 95th percentile composite peak micromotion (CPM) of 18-624 μm. Regression analysis was not conclusive on the relationship between patient-related factors and primary stability. No relationship was found between polar gap and micromotion. However, when the patient-related factors were categorised into quartile groups, trends suggested higher polar gaps occurred in subjects with small and shallow acetabular geometries and cup motion during gait was affected most by low elastic modulus and high bodyweight. The variation in primary stability in the cohort for an acetabular cup with a proven clinical track record may provide benchmark data when evaluating new cup designs. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1012-1023, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  9. Geometry of multihadron production

    Energy Technology Data Exchange (ETDEWEB)

    Bjorken, J.D.

    1994-10-01

    This summary talk only reviews a small sample of topics featured at this symposium: Introduction; The Geometry and Geography of Phase space; Space-Time Geometry and HBT; Multiplicities, Intermittency, Correlations; Disoriented Chiral Condensate; Deep Inelastic Scattering at HERA; and Other Contributions.

  10. Designs and finite geometries

    CERN Document Server

    1996-01-01

    Designs and Finite Geometries brings together in one place important contributions and up-to-date research results in this important area of mathematics. Designs and Finite Geometries serves as an excellent reference, providing insight into some of the most important research issues in the field.

  11. Geometry of multihadron production

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1994-10-01

    This summary talk only reviews a small sample of topics featured at this symposium: Introduction; The Geometry and Geography of Phase space; Space-Time Geometry and HBT; Multiplicities, Intermittency, Correlations; Disoriented Chiral Condensate; Deep Inelastic Scattering at HERA; and Other Contributions

  12. The Beauty of Geometry

    Science.gov (United States)

    Morris, Barbara H.

    2004-01-01

    This article describes a geometry project that used the beauty of stained-glass-window designs to teach middle school students about geometric figures and concepts. Three honors prealgebra teachers and a middle school mathematics gifted intervention specialist created a geometry project that covered the curriculum and also assessed students'…

  13. WE-A-17A-08: Evaluation of the OncentraBrachy Collapsed Cone Convolution Algorithm for Ir-192 Source Using Phantom and Real-Patient Heterogeneous Geometries

    International Nuclear Information System (INIS)

    Ma, Y; Lacroix, F; Lavallee, M; Beaulieu, L

    2014-01-01

    Purpose: To evaluate the commercially released Collapsed Cone convolution-based(CCC) dose calculation module of the Elekta OncentraBrachy(OcB) treatment planning system(TPS). Methods: An allwater phantom was used to perform TG43 benchmarks with single source and seventeen sources, separately. Furthermore, four real-patient heterogeneous geometries (chestwall, lung, breast and prostate) were used. They were selected based on their clinical representativity of a class of clinical anatomies that pose clear challenges. The plans were used as is(no modification). For each case, TG43 and CCC calculations were performed in the OcB TPS, with TG186-recommended materials properly assigned to ROIs. For comparison, Monte Carlo simulation was run for each case with the same material scheme and grid mesh as TPS calculations. Both modes of CCC (standard and high quality) were tested. Results: For the benchmark case, the CCC dose, when divided by that of TG43, yields hot-n-cold spots in a radial pattern. The pattern of the high mode is denser than that of the standard mode and is representative of angular dicretization. The total deviation ((hot-cold)/TG43) is 18% for standard mode and 11% for high mode. Seventeen dwell positions help to reduce “ray-effect”, with the total deviation to 6% (standard) and 5% (high), respectively. For the four patient cases, CCC produces, as expected, more realistic dose distributions than TG43. A close agreement was observed between CCC and MC for all isodose lines, from 20% and up; the 10% isodose line of CCC appears shifted compared to that of MC. The DVH plots show dose deviations of CCC from MC in small volume, high dose regions (>100% isodose). For patient cases, the difference between standard and high modes is almost undiscernable. Conclusion: OncentraBrachy CCC algorithm marks a significant dosimetry improvement relative to TG43 in real-patient cases. Further researches are recommended regarding the clinical implications of the above

  14. WE-A-17A-08: Evaluation of the OncentraBrachy Collapsed Cone Convolution Algorithm for Ir-192 Source Using Phantom and Real-Patient Heterogeneous Geometries

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Y; Lacroix, F; Lavallee, M [CHUQ Hotel-Dieu De Quebec, Quebec, QC (Canada); Beaulieu, L [CHUQ Hotel-Dieu De Quebec, Quebec, QC (Canada); Centre Hospitalier University de Quebec, Quebec, QC (Canada)

    2014-06-15

    Purpose: To evaluate the commercially released Collapsed Cone convolution-based(CCC) dose calculation module of the Elekta OncentraBrachy(OcB) treatment planning system(TPS). Methods: An allwater phantom was used to perform TG43 benchmarks with single source and seventeen sources, separately. Furthermore, four real-patient heterogeneous geometries (chestwall, lung, breast and prostate) were used. They were selected based on their clinical representativity of a class of clinical anatomies that pose clear challenges. The plans were used as is(no modification). For each case, TG43 and CCC calculations were performed in the OcB TPS, with TG186-recommended materials properly assigned to ROIs. For comparison, Monte Carlo simulation was run for each case with the same material scheme and grid mesh as TPS calculations. Both modes of CCC (standard and high quality) were tested. Results: For the benchmark case, the CCC dose, when divided by that of TG43, yields hot-n-cold spots in a radial pattern. The pattern of the high mode is denser than that of the standard mode and is representative of angular dicretization. The total deviation ((hot-cold)/TG43) is 18% for standard mode and 11% for high mode. Seventeen dwell positions help to reduce “ray-effect”, with the total deviation to 6% (standard) and 5% (high), respectively. For the four patient cases, CCC produces, as expected, more realistic dose distributions than TG43. A close agreement was observed between CCC and MC for all isodose lines, from 20% and up; the 10% isodose line of CCC appears shifted compared to that of MC. The DVH plots show dose deviations of CCC from MC in small volume, high dose regions (>100% isodose). For patient cases, the difference between standard and high modes is almost undiscernable. Conclusion: OncentraBrachy CCC algorithm marks a significant dosimetry improvement relative to TG43 in real-patient cases. Further researches are recommended regarding the clinical implications of the above

  15. A Lorentzian quantum geometry

    Energy Technology Data Exchange (ETDEWEB)

    Grotz, Andreas

    2011-10-07

    In this thesis, a formulation of a Lorentzian quantum geometry based on the framework of causal fermion systems is proposed. After giving the general definition of causal fermion systems, we deduce space-time as a topological space with an underlying causal structure. Restricting attention to systems of spin dimension two, we derive the objects of our quantum geometry: the spin space, the tangent space endowed with a Lorentzian metric, connection and curvature. In order to get the correspondence to classical differential geometry, we construct examples of causal fermion systems by regularizing Dirac sea configurations in Minkowski space and on a globally hyperbolic Lorentzian manifold. When removing the regularization, the objects of our quantum geometry reduce to the common objects of spin geometry on Lorentzian manifolds, up to higher order curvature corrections.

  16. Methods of information geometry

    CERN Document Server

    Amari, Shun-Ichi

    2000-01-01

    Information geometry provides the mathematical sciences with a new framework of analysis. It has emerged from the investigation of the natural differential geometric structure on manifolds of probability distributions, which consists of a Riemannian metric defined by the Fisher information and a one-parameter family of affine connections called the \\alpha-connections. The duality between the \\alpha-connection and the (-\\alpha)-connection together with the metric play an essential role in this geometry. This kind of duality, having emerged from manifolds of probability distributions, is ubiquitous, appearing in a variety of problems which might have no explicit relation to probability theory. Through the duality, it is possible to analyze various fundamental problems in a unified perspective. The first half of this book is devoted to a comprehensive introduction to the mathematical foundation of information geometry, including preliminaries from differential geometry, the geometry of manifolds or probability d...

  17. A Lorentzian quantum geometry

    International Nuclear Information System (INIS)

    Grotz, Andreas

    2011-01-01

    In this thesis, a formulation of a Lorentzian quantum geometry based on the framework of causal fermion systems is proposed. After giving the general definition of causal fermion systems, we deduce space-time as a topological space with an underlying causal structure. Restricting attention to systems of spin dimension two, we derive the objects of our quantum geometry: the spin space, the tangent space endowed with a Lorentzian metric, connection and curvature. In order to get the correspondence to classical differential geometry, we construct examples of causal fermion systems by regularizing Dirac sea configurations in Minkowski space and on a globally hyperbolic Lorentzian manifold. When removing the regularization, the objects of our quantum geometry reduce to the common objects of spin geometry on Lorentzian manifolds, up to higher order curvature corrections.

  18. Cancer Patient T Cells Genetically Targeted to Prostate-Specific Membrane Antigen Specifically Lyse Prostate Cancer Cells and Release Cytokines in Response to Prostate-Specific Membrane Antigen

    Directory of Open Access Journals (Sweden)

    Michael C. Gong

    1999-06-01

    Full Text Available The expression of immunoglobulin-based artificial receptors in normal T lymphocytes provides a means to target lymphocytes to cell surface antigens independently of major histocompatibility complex restriction. Such artificial receptors have been previously shown to confer antigen-specific tumoricidal properties in murine T cells. We constructed a novel ζ chain fusion receptor specific for prostate-specific membrane antigen (PSMA termed Pz-1. PSMA is a cell-surface glycoprotein expressed on prostate cancer cells and the neovascular endothelium of multiple carcinomas. We show that primary T cells harvested from five of five patients with different stages of prostate cancer and transduced with the Pz-1 receptor readily lyse prostate cancer cells. Having established a culture system using fibroblasts that express PSMA, we next show that T cells expressing the Pz-1 receptor release cytokines in response to cell-bound PSMA. Furthermore, we show that the cytokine release is greatly augmented by B7.1-mediated costimulation. Thus, our findings support the feasibility of adoptive cell therapy by using genetically engineered T cells in prostate cancer patients and suggest that both CD4+ and CD8+ T lymphocyte functions can be synergistically targeted against tumor cells.

  19. Geometry on the space of geometries

    International Nuclear Information System (INIS)

    Christodoulakis, T.; Zanelli, J.

    1988-06-01

    We discuss the geometric structure of the configuration space of pure gravity. This is an infinite dimensional manifold, M, where each point represents one spatial geometry g ij (x). The metric on M is dictated by geometrodynamics, and from it, the Christoffel symbols and Riemann tensor can be found. A ''free geometry'' tracing a geodesic on the manifold describes the time evolution of space in the strong gravity limit. In a regularization previously introduced by the authors, it is found that M does not have the same dimensionality, D, everywhere, and that D is not a scalar, although it is covariantly constant. In this regularization, it is seen that the path integral measure can be absorbed in a renormalization of the cosmological constant. (author). 19 refs

  20. Association between PSA kinetics and cancer-specific mortality in patients with localised prostate cancer

    DEFF Research Database (Denmark)

    Thomsen, Frederik Birkebæk; Brasso, Klaus; Berg, Kasper Drimer

    2016-01-01

    BACKGROUND: The prognostic value of prostate-specific antigen (PSA) kinetics in untreated prostate cancer (PCa) patients is debatable. We investigated the association between PSA doubling time (PSAdt), PSA velocity (PSAvel) and PSAvel risk count (PSAvRC) and PCa mortality in a cohort of patients...... with localised PCa managed on watchful waiting. PATIENTS AND METHODS: Patients with clinically localised PCa managed observationally, who were randomised to and remained on placebo for minimum 18 months in the SPCG-6 study, were included. All patients survived at least 2 years and had a minimum of three PSA...... determinations available. The prognostic value of PSA kinetics was analysed and patients were stratified according to their PSA at consent: ≤10, 10.1-25, and >25 ng/ml. Cumulative incidences of PCa-specific mortality were estimated with the Aalen-Johansen method. RESULTS: Two hundred and sixty-three patients...

  1. Superficial dose distribution in breast for tangential radiation treatment, Monte Carlo evaluation of Eclipse algorithms in case of phantom and patient geometries

    International Nuclear Information System (INIS)

    Chakarova, Roumiana; Gustafsson, Magnus; Bäck, Anna; Drugge, Ninni; Palm, Åsa; Lindberg, Andreas; Berglund, Mattias

    2012-01-01

    Purpose: The aim of this study is to examine experimentally and by the Monte Carlo method the accuracy of the Eclipse Pencil Beam Convolution (PBC) and Analytical Anisotropic Algorithm (AAA) algorithms in the superficial region (0–2 cm) of the breast for tangential photon beams in a phantom case as well as in a number of patient geometries. The aim is also to identify differences in how the patient computer tomography data are handled by the treatment planning system and in the Monte Carlo simulations in order to reduce influences of these effects on the evaluation. Materials and methods: Measurements by thermoluminescent dosimeters and gafchromic film are performed for six MV tangential irradiation of the cylindrical solid water phantom. Tangential treatment of seven patients is investigated considering open beams. Dose distributions are obtained by the Eclipse PBC and AAA algorithms. Monte Carlo calculations are carried out by BEAMnrc/DOSXYZnrc code package. Calculations are performed with a calculation grid of 1.25 × 1.25 × 5 mm 3 for PBC and 2 × 2 × 5 mm 3 for AAA and Monte Carlo, respectively. Dose comparison is performed in both dose and spatial domains by the normalized dose difference method. Results: Experimental profiles from the surface toward the geometrical center of the cylindrical phantom are obtained at the beam entrance and exit as well as laterally. Full dose is received beyond 2 mm in the lateral superficial region and beyond 7 mm at the beam entrance. Good agreement between experimental, Monte Carlo and AAA data is obtained, whereas PBC is seen to underestimate the entrance dose the first 3–4 mm and the lateral dose by more than 5% up to 8 mm depth. In the patient cases considered, AAA and Monte Carlo show agreement within 3% dose and 4 mm spatial tolerance. PBC systematically underestimates the dose at the breast apex. The dimensions of region out of tolerance vary with the local breast shape. Different interpretations of patient

  2. Nurses' Perceptions of Implementing Fall Prevention Interventions to Mitigate Patient-Specific Fall Risk Factors.

    Science.gov (United States)

    Wilson, Deleise S; Montie, Mary; Conlon, Paul; Reynolds, Margaret; Ripley, Robert; Titler, Marita G

    2016-08-01

    Evidence-based (EB) fall prevention interventions to mitigate patient-specific fall risk factors are readily available but not routinely used in practice. Few studies have examined nurses' perceptions about both the use of these EB interventions and implementation strategies designed to promote their adoption. This article reports qualitative findings of nurses' perceptions about use of EB fall prevention interventions to mitigate patient-specific fall risks, and implementation strategies to promote use of these interventions. The findings revealed five major themes: before-study fall prevention practices, use of EB fall prevention interventions tailored to patient-specific fall risk factors, beneficial implementation strategies, overall impact on approach to fall prevention, and challenges These findings are useful to guide nurses' engagement and use of EB fall prevention practices tailored to patient-specific fall risk factors. © The Author(s) 2016.

  3. Patient- and cohort-specific dose and risk estimation for abdominopelvic CT: a study based on 100 patients

    Science.gov (United States)

    Tian, Xiaoyu; Li, Xiang; Segars, W. Paul; Frush, Donald P.; Samei, Ehsan

    2012-03-01

    The purpose of this work was twofold: (a) to estimate patient- and cohort-specific radiation dose and cancer risk index for abdominopelvic computer tomography (CT) scans; (b) to evaluate the effects of patient anatomical characteristics (size, age, and gender) and CT scanner model on dose and risk conversion coefficients. The study included 100 patient models (42 pediatric models, 58 adult models) and multi-detector array CT scanners from two commercial manufacturers (LightSpeed VCT, GE Healthcare; SOMATOM Definition Flash, Siemens Healthcare). A previously-validated Monte Carlo program was used to simulate organ dose for each patient model and each scanner, from which DLP-normalized-effective dose (k factor) and DLP-normalized-risk index values (q factor) were derived. The k factor showed exponential decrease with increasing patient size. For a given gender, q factor showed exponential decrease with both increasing patient size and patient age. The discrepancies in k and q factors across scanners were on average 8% and 15%, respectively. This study demonstrates the feasibility of estimating patient-specific organ dose and cohort-specific effective dose and risk index in abdominopelvic CT requiring only the knowledge of patient size, gender, and age.

  4. Disease-Specific Mortality of Differentiated Thyroid Cancer Patients in Korea: A Multicenter Cohort Study

    Directory of Open Access Journals (Sweden)

    Min Ji Jeon

    2017-11-01

    Full Text Available BackgroundLittle is known regarding disease-specific mortality of differentiated thyroid cancer (DTC patients and its risk factors in Korea.MethodsWe retrospectively reviewed a large multi-center cohort of thyroid cancer from six Korean hospitals and included 8,058 DTC patients who underwent initial surgery between 1996 and 2005.ResultsMean age of patients at diagnosis was 46.2±12.3 years; 87% were females. Most patients had papillary thyroid cancer (PTC; 97% and underwent total thyroidectomy (85%. Mean size of the primary tumor was 1.6±1.0 cm. Approximately 40% of patients had cervical lymph node (LN metastases and 1.3% had synchronous distant metastases. During 11.3 years of follow-up, 150 disease-specific mortalities (1.9% occurred; the 10-year disease-specific survival (DSS rate was 98%. According to the year of diagnosis, the number of disease-specific mortality was not different. However, the rate of disease-specific mortality decreased during the study period (from 7.7% to 0.7%. Older age (≥45 years at diagnosis, male, follicular thyroid cancer (FTC versus PTC, larger tumor size (>2 cm, presence of extrathyroidal extension (ETE, lateral cervical LN metastasis, distant metastasis and tumor node metastasis (TNM stage were independent risk factors of disease-specific mortality of DTC patients.ConclusionThe rate of disease-specific mortality of Korean DTC patients was 1.9%; the 10-year DSS rate was 98% during 1996 to 2005. Older age at diagnosis, male, FTC, larger tumor size, presence of ETE, lateral cervical LN metastasis, distant metastasis, and TNM stages were significant risk factors of disease-specific mortality of Korean DTC patients.

  5. From Patient-Specific Mathematical Neuro-Oncology to Precision Medicine

    Directory of Open Access Journals (Sweden)

    Anne eBaldock

    2013-04-01

    Full Text Available Gliomas are notoriously aggressive, malignant brain tumors that have variable response to treatment. These patients often have poor prognosis, informed primarily by histopathology. Mathematical neuro-oncology (MNO is a young and burgeoning field that leverages mathematical models to predict and quantify response to therapies. These mathematical models can form the basis of modern precision medicine approaches to tailor therapy in a patient-specific manner. Patient specific models (PSMs can be used to overcome imaging limitations, improve prognostic predictions, stratify patients and assess treatment response in silico. The information gleaned from such models can aid in the construction and efficacy of clinical trials and treatment protocols, accelerating the pace of clinical research in the war on cancer. This review focuses on the growing translation of PSM to clinical neuro-oncology. It will also provide a forward-looking view on a new era of patient-specific mathematical neuro-oncology.

  6. Complex and symplectic geometry

    CERN Document Server

    Medori, Costantino; Tomassini, Adriano

    2017-01-01

    This book arises from the INdAM Meeting "Complex and Symplectic Geometry", which was held in Cortona in June 2016. Several leading specialists, including young researchers, in the field of complex and symplectic geometry, present the state of the art of their research on topics such as the cohomology of complex manifolds; analytic techniques in Kähler and non-Kähler geometry; almost-complex and symplectic structures; special structures on complex manifolds; and deformations of complex objects. The work is intended for researchers in these areas.

  7. Non-Euclidean geometry

    CERN Document Server

    Kulczycki, Stefan

    2008-01-01

    This accessible approach features two varieties of proofs: stereometric and planimetric, as well as elementary proofs that employ only the simplest properties of the plane. A short history of geometry precedes a systematic exposition of the principles of non-Euclidean geometry.Starting with fundamental assumptions, the author examines the theorems of Hjelmslev, mapping a plane into a circle, the angle of parallelism and area of a polygon, regular polygons, straight lines and planes in space, and the horosphere. Further development of the theory covers hyperbolic functions, the geometry of suff

  8. A 4D digital phantom for patient-specific simulation of brain CT perfusion protocols.

    Science.gov (United States)

    van den Boom, Rieneke; Manniesing, Rashindra; Oei, Marcel T H; van der Woude, Willem-Jan; Smit, Ewoud J; Laue, Hendrik O A; van Ginneken, Bram; Prokop, Mathias

    2014-07-01

    Optimizing CT brain perfusion protocols is a challenge because of the complex interaction between image acquisition, calculation of perfusion data, and patient hemodynamics. Several digital phantoms have been developed to avoid unnecessary patient exposure or suboptimum choice of parameters. The authors expand this idea by using realistic noise patterns and measured tissue attenuation curves representing patient-specific hemodynamics. The purpose of this work is to validate that this approach can realistically simulate mean perfusion values and noise on perfusion data for individual patients. The proposed 4D digital phantom consists of three major components: (1) a definition of the spatial structure of various brain tissues within the phantom, (2) measured tissue attenuation curves, and (3) measured noise patterns. Tissue attenuation curves were measured in patient data using regions of interest in gray matter and white matter. By assigning the tissue attenuation curves to the corresponding tissue curves within the phantom, patient-specific CTP acquisitions were retrospectively simulated. Noise patterns were acquired by repeatedly scanning an anthropomorphic skull phantom at various exposure settings. The authors selected 20 consecutive patients that were scanned for suspected ischemic stroke and constructed patient-specific 4D digital phantoms using the individual patients' hemodynamics. The perfusion maps of the patient data were compared with the digital phantom data. Agreement between phantom- and patient-derived data was determined for mean perfusion values and for standard deviation in de perfusion data using intraclass correlation coefficients (ICCs) and a linear fit. ICCs ranged between 0.92 and 0.99 for mean perfusion values. ICCs for the standard deviation in perfusion maps were between 0.86 and 0.93. Linear fitting yielded slope values between 0.90 and 1.06. A patient-specific 4D digital phantom allows for realistic simulation of mean values and

  9. Characterization of cat dander-specific T lymphocytes from atopic patients

    NARCIS (Netherlands)

    van Neerven, R. J.; van de Pol, M. M.; van Milligen, F. J.; Jansen, H. M.; Aalberse, R. C.; Kapsenberg, M. L.

    1994-01-01

    Fel d I, the major cat dander allergen, is recognized by serum IgE of more than 80% of all cat-allergic patients. Because IgE synthesis by B lymphocytes is under the control of T lymphocytes, we studied the specificity and lymphokine production profiles of cat dander-specific T lymphocytes.

  10. Specificities of anti-neutrophil autoantibodies in patients with rheumatoid arthritis (RA)

    DEFF Research Database (Denmark)

    Brimnes, J; Halberg, P; Jacobsen, Søren

    1997-01-01

    The objective of this study was to characterize antigens recognized by neutrophil-specific autoantibodies from patients with RA. Sera from 62 RA patients were screened by indirect immunofluorescence (IIF). Positive sera were further tested by ELISAs for antibodies against various granule proteins...

  11. Muller cell-specific autoantibodies in a patient with progressive loss of vision

    NARCIS (Netherlands)

    Peek, R.; Verbraak, F.; Coevoet, H. M.; Kijlstra, A.

    1998-01-01

    PURPOSE. To study the specificity of circulating retinal autoantibodies in a patient with progressive loss of vision resembling cancer-associated retinopathy in the absence of systemic malignancy. METHODS. Patient's serum was tested for the presence of antiretinal antibodies by Western blot

  12. Psychiatric in-patients' experience of being secluded in a specific ...

    African Journals Online (AJOL)

    This qualitative, explorative, descriptive and contextual study was undertaken to explore and describe the experiences of psychiatric in-patients who are secluded in a specific hospital in Lesotho. Evidence about the rationale and appropriate use of seclusion as well as promotion of mental health in secluded patients has ...

  13. Lectures on coarse geometry

    CERN Document Server

    Roe, John

    2003-01-01

    Coarse geometry is the study of spaces (particularly metric spaces) from a 'large scale' point of view, so that two spaces that look the same from a great distance are actually equivalent. This point of view is effective because it is often true that the relevant geometric properties of metric spaces are determined by their coarse geometry. Two examples of important uses of coarse geometry are Gromov's beautiful notion of a hyperbolic group and Mostow's proof of his famous rigidity theorem. The first few chapters of the book provide a general perspective on coarse structures. Even when only metric coarse structures are in view, the abstract framework brings the same simplification as does the passage from epsilons and deltas to open sets when speaking of continuity. The middle section reviews notions of negative curvature and rigidity. Modern interest in large scale geometry derives in large part from Mostow's rigidity theorem and from Gromov's subsequent 'large scale' rendition of the crucial properties of n...

  14. Lectures on Symplectic Geometry

    CERN Document Server

    Silva, Ana Cannas

    2001-01-01

    The goal of these notes is to provide a fast introduction to symplectic geometry for graduate students with some knowledge of differential geometry, de Rham theory and classical Lie groups. This text addresses symplectomorphisms, local forms, contact manifolds, compatible almost complex structures, Kaehler manifolds, hamiltonian mechanics, moment maps, symplectic reduction and symplectic toric manifolds. It contains guided problems, called homework, designed to complement the exposition or extend the reader's understanding. There are by now excellent references on symplectic geometry, a subset of which is in the bibliography of this book. However, the most efficient introduction to a subject is often a short elementary treatment, and these notes attempt to serve that purpose. This text provides a taste of areas of current research and will prepare the reader to explore recent papers and extensive books on symplectic geometry where the pace is much faster. For this reprint numerous corrections and cl...

  15. Complex algebraic geometry

    CERN Document Server

    Kollár, János

    1997-01-01

    This volume contains the lectures presented at the third Regional Geometry Institute at Park City in 1993. The lectures provide an introduction to the subject, complex algebraic geometry, making the book suitable as a text for second- and third-year graduate students. The book deals with topics in algebraic geometry where one can reach the level of current research while starting with the basics. Topics covered include the theory of surfaces from the viewpoint of recent higher-dimensional developments, providing an excellent introduction to more advanced topics such as the minimal model program. Also included is an introduction to Hodge theory and intersection homology based on the simple topological ideas of Lefschetz and an overview of the recent interactions between algebraic geometry and theoretical physics, which involve mirror symmetry and string theory.

  16. Geometry and Combinatorics

    DEFF Research Database (Denmark)

    Kokkendorff, Simon Lyngby

    2002-01-01

    The subject of this Ph.D.-thesis is somewhere in between continuous and discrete geometry. Chapter 2 treats the geometry of finite point sets in semi-Riemannian hyperquadrics,using a matrix whose entries are a trigonometric function of relative distances in a given point set. The distance...... to the geometry of a simplex in a semi-Riemannian hyperquadric. In chapter 3 we study which finite metric spaces that are realizable in a hyperbolic space in the limit where curvature goes to -∞. We show that such spaces are the so called leaf spaces, the set of degree 1 vertices of weighted trees. We also...... establish results on the limiting geometry of such an isometrically realized leaf space simplex in hyperbolic space, when curvature goes to -∞. Chapter 4 discusses negative type of metric spaces. We give a measure theoretic treatment of this concept and related invariants. The theory developed...

  17. The geometry of geodesics

    CERN Document Server

    Busemann, Herbert

    2005-01-01

    A comprehensive approach to qualitative problems in intrinsic differential geometry, this text examines Desarguesian spaces, perpendiculars and parallels, covering spaces, the influence of the sign of the curvature on geodesics, more. 1955 edition. Includes 66 figures.

  18. Geometry and billiards

    CERN Document Server

    Tabachnikov, Serge

    2005-01-01

    Mathematical billiards describe the motion of a mass point in a domain with elastic reflections off the boundary or, equivalently, the behavior of rays of light in a domain with ideally reflecting boundary. From the point of view of differential geometry, the billiard flow is the geodesic flow on a manifold with boundary. This book is devoted to billiards in their relation with differential geometry, classical mechanics, and geometrical optics. The topics covered include variational principles of billiard motion, symplectic geometry of rays of light and integral geometry, existence and nonexistence of caustics, optical properties of conics and quadrics and completely integrable billiards, periodic billiard trajectories, polygonal billiards, mechanisms of chaos in billiard dynamics, and the lesser-known subject of dual (or outer) billiards. The book is based on an advanced undergraduate topics course (but contains more material than can be realistically taught in one semester). Although the minimum prerequisit...

  19. Introduction to tropical geometry

    CERN Document Server

    Maclagan, Diane

    2015-01-01

    Tropical geometry is a combinatorial shadow of algebraic geometry, offering new polyhedral tools to compute invariants of algebraic varieties. It is based on tropical algebra, where the sum of two numbers is their minimum and the product is their sum. This turns polynomials into piecewise-linear functions, and their zero sets into polyhedral complexes. These tropical varieties retain a surprising amount of information about their classical counterparts. Tropical geometry is a young subject that has undergone a rapid development since the beginning of the 21st century. While establishing itself as an area in its own right, deep connections have been made to many branches of pure and applied mathematics. This book offers a self-contained introduction to tropical geometry, suitable as a course text for beginning graduate students. Proofs are provided for the main results, such as the Fundamental Theorem and the Structure Theorem. Numerous examples and explicit computations illustrate the main concepts. Each of t...

  20. Rudiments of algebraic geometry

    CERN Document Server

    Jenner, WE

    2017-01-01

    Aimed at advanced undergraduate students of mathematics, this concise text covers the basics of algebraic geometry. Topics include affine spaces, projective spaces, rational curves, algebraic sets with group structure, more. 1963 edition.

  1. Tolerance design of patient-specific range QA using the DMAIC framework in proton therapy.

    Science.gov (United States)

    Rah, Jeong-Eun; Shin, Dongho; Manger, Ryan P; Kim, Tae Hyun; Oh, Do Hoon; Kim, Dae Yong; Kim, Gwe-Ya

    2018-02-01

    To implement the DMAIC (Define-Measure-Analyze-Improve-Control) can be used for customizing the patient-specific QA by designing site-specific range tolerances. The DMAIC framework (process flow diagram, cause and effect, Pareto chart, control chart, and capability analysis) were utilized to determine the steps that need focus for improving the patient-specific QA. The patient-specific range QA plans were selected according to seven treatment site groups, a total of 1437 cases. The process capability index, C pm was used to guide the tolerance design of patient site-specific range. For prostate field, our results suggested that the patient range measurements were capable at the current tolerance level of ±1 mm in clinical proton plans. For other site-specific ranges, we analyzed that the tolerance tends to be overdesigned to insufficient process capability calculated by the patient-specific QA data. The customized tolerances were calculated for treatment sites. Control charts were constructed to simulate the patient QA time before and after the new tolerances were implemented. It is found that the total simulation QA time was decreased on average of approximately 20% after establishing new site-specific range tolerances. We simulated the financial impact of this project. The QA failure for whole process in proton therapy would lead up to approximately 30% increase in total cost. DMAIC framework can be used to provide an effective QA by setting customized tolerances. When tolerance design is customized, the quality is reasonably balanced with time and cost demands. © 2017 American Association of Physicists in Medicine.

  2. Implosions and hypertoric geometry

    DEFF Research Database (Denmark)

    Dancer, A.; Kirwan, F.; Swann, A.

    2013-01-01

    The geometry of the universal hyperkahler implosion for SU (n) is explored. In particular, we show that the universal hyperkahler implosion naturally contains a hypertoric variety described in terms of quivers. Furthermore, we discuss a gauge theoretic approach to hyperkahler implosion.......The geometry of the universal hyperkahler implosion for SU (n) is explored. In particular, we show that the universal hyperkahler implosion naturally contains a hypertoric variety described in terms of quivers. Furthermore, we discuss a gauge theoretic approach to hyperkahler implosion....

  3. Intermediate algebra & analytic geometry

    CERN Document Server

    Gondin, William R

    1967-01-01

    Intermediate Algebra & Analytic Geometry Made Simple focuses on the principles, processes, calculations, and methodologies involved in intermediate algebra and analytic geometry. The publication first offers information on linear equations in two unknowns and variables, functions, and graphs. Discussions focus on graphic interpretations, explicit and implicit functions, first quadrant graphs, variables and functions, determinate and indeterminate systems, independent and dependent equations, and defective and redundant systems. The text then examines quadratic equations in one variable, system

  4. d-geometries revisited

    CERN Document Server

    Ceresole, Anna; Gnecchi, Alessandra; Marrani, Alessio

    2013-01-01

    We analyze some properties of the four dimensional supergravity theories which originate from five dimensions upon reduction. They generalize to N>2 extended supersymmetries the d-geometries with cubic prepotentials, familiar from N=2 special K\\"ahler geometry. We emphasize the role of a suitable parametrization of the scalar fields and the corresponding triangular symplectic basis. We also consider applications to the first order flow equations for non-BPS extremal black holes.

  5. Nutrition impact symptoms in advanced cancer patients: frequency and specific interventions, a case?control study

    OpenAIRE

    Omlin, Aurelius; Blum, David; Wierecky, Jan; Haile, Sarah R.; Ottery, Faith D.; Strasser, Florian

    2013-01-01

    Background Involuntary weight loss (IWL) is frequent in advanced cancer patients causing compromised anticancer treatment outcomes and function. Cancer cachexia is influenced by nutrition impact symptoms (NIS). The aim of this study was to explore the frequency of NIS in advanced patients and to assess specific interventions guided by a 12-item NIS checklist. Methods Consecutive patients from an outpatient nutrition-fatigue clinic completed the NIS checklist. The NIS checklist was developed b...

  6. Correlative study between neuron-specific enolase and blood sugar level in ischemic stroke patients

    OpenAIRE

    Pandey, Aparna; Saxena, Kiran; Verma, Meena; Bharosay, Anuradha

    2011-01-01

    Background: A study to investigate the level of the neurobiochemical marker, Neuron-Specific Enolase (NSE), at the time of admission and its correlation with the blood sugar level in ischemic stroke patients. Patients and Methods: We investigated 90 patients with complete stroke who were admitted to the Stroke Unit of the Department of Neurology at Sri Aurobindo Institute of Medical Sciences. NSE was measured with commercially available quantitative ′sandwich′ enzyme-linked immunosorbent assa...

  7. The situation-specific theory of pain experience for Asian American cancer patients.

    Science.gov (United States)

    Im, Eun-Ok

    2008-01-01

    Studies have indicated the need for theories that explain and target ethnic-specific cancer pain experiences, including those of Asian Americans. In this article, I present a situation-specific theory that explains the unique cancer pain experience of Asian Americans. Unlike other existing theories, this situation-specific theory was developed on the basis of evidence, including a systematic literature review and research findings, making it comprehensive and highly applicable to research and practice with Asian American patients with cancer. Thus, this theory would strengthen the interconnections among theory, evidence, and practice in pain management for Asian American cancer patients.

  8. Code subspaces for LLM geometries

    Science.gov (United States)

    Berenstein, David; Miller, Alexandra

    2018-03-01

    We consider effective field theory around classical background geometries with a gauge theory dual, specifically those in the class of LLM geometries. These are dual to half-BPS states of N= 4 SYM. We find that the language of code subspaces is natural for discussing the set of nearby states, which are built by acting with effective fields on these backgrounds. This work extends our previous work by going beyond the strict infinite N limit. We further discuss how one can extract the topology of the state beyond N→∞ and find that, as before, uncertainty and entanglement entropy calculations provide a useful tool to do so. Finally, we discuss obstructions to writing down a globally defined metric operator. We find that the answer depends on the choice of reference state that one starts with. Therefore, within this setup, there is ambiguity in trying to write an operator that describes the metric globally.

  9. Software Geometry in Simulations

    Science.gov (United States)

    Alion, Tyler; Viren, Brett; Junk, Tom

    2015-04-01

    The Long Baseline Neutrino Experiment (LBNE) involves many detectors. The experiment's near detector (ND) facility, may ultimately involve several detectors. The far detector (FD) will be significantly larger than any other Liquid Argon (LAr) detector yet constructed; many prototype detectors are being constructed and studied to motivate a plethora of proposed FD designs. Whether it be a constructed prototype or a proposed ND/FD design, every design must be simulated and analyzed. This presents a considerable challenge to LBNE software experts; each detector geometry must be described to the simulation software in an efficient way which allows for multiple authors to easily collaborate. Furthermore, different geometry versions must be tracked throughout their use. We present a framework called General Geometry Description (GGD), written and developed by LBNE software collaborators for managing software to generate geometries. Though GGD is flexible enough to be used by any experiment working with detectors, we present it's first use in generating Geometry Description Markup Language (GDML) files to interface with LArSoft, a framework of detector simulations, event reconstruction, and data analyses written for all LAr technology users at Fermilab. Brett is the other of the framework discussed here, the General Geometry Description (GGD).

  10. Introduction to combinatorial geometry

    International Nuclear Information System (INIS)

    Gabriel, T.A.; Emmett, M.B.

    1985-01-01

    The combinatorial geometry package as used in many three-dimensional multimedia Monte Carlo radiation transport codes, such as HETC, MORSE, and EGS, is becoming the preferred way to describe simple and complicated systems. Just about any system can be modeled using the package with relatively few input statements. This can be contrasted against the older style geometry packages in which the required input statements could be large even for relatively simple systems. However, with advancements come some difficulties. The users of combinatorial geometry must be able to visualize more, and, in some instances, all of the system at a time. Errors can be introduced into the modeling which, though slight, and at times hard to detect, can have devastating effects on the calculated results. As with all modeling packages, the best way to learn the combinatorial geometry is to use it, first on a simple system then on more complicated systems. The basic technique for the description of the geometry consists of defining the location and shape of the various zones in terms of the intersections and unions of geometric bodies. The geometric bodies which are generally included in most combinatorial geometry packages are: (1) box, (2) right parallelepiped, (3) sphere, (4) right circular cylinder, (5) right elliptic cylinder, (6) ellipsoid, (7) truncated right cone, (8) right angle wedge, and (9) arbitrary polyhedron. The data necessary to describe each of these bodies are given. As can be easily noted, there are some subsets included for simplicity

  11. Assessment of CT dose to the fetus and pregnant female patient using patient-specific computational models

    DEFF Research Database (Denmark)

    Xie, Tianwu; Poletti, Pierre-Alexandre; Platon, Alexandra

    2018-01-01

    of pregnant patients and the embedded foetus, we developed a methodology for construction of patient-specific voxel-based computational phantoms based on existing standardised hybrid computational pregnant female phantoms. We estimated the maternal absorbed dose and foetal organ dose for 30 pregnant patients...... for assessment of the radiation risks to pregnant patients and the foetus from various CT scanning protocols, thus guiding the decision-making process. KEY POINTS: • In CT examinations, the absorbed dose is non-uniformly distributed within foetal organs. • This work reports, for the first time, estimates...

  12. Patient-specific estimation of detailed cochlear shape from clinical CT images

    DEFF Research Database (Denmark)

    Kjer, H Martin; Fagertun, Jens; Wimmer, Wilhelm

    2018-01-01

    of the detailed patient-specific cochlear shape from CT images. From a collection of temporal bone [Formula: see text]CT images, we build a cochlear statistical deformation model (SDM), which is a description of how a human cochlea deforms to represent the observed anatomical variability. The model is used...... for regularization of a non-rigid image registration procedure between a patient CT scan and a [Formula: see text]CT image, allowing us to estimate the detailed patient-specific cochlear shape. We test the accuracy and precision of the predicted cochlear shape using both [Formula: see text]CT and CT images...

  13. Patient specific root-analogue dental implants – additive manufacturing and finite element analysis

    Directory of Open Access Journals (Sweden)

    Gattinger Johannes

    2016-09-01

    Full Text Available Aim of this study was to prove the possibility of manufacturing patient specific root analogue two-part (implant and abutment implants by direct metal laser sintering. The two-part implant design enables covered healing of the implant. Therefore, CT-scans of three patients are used for reverse engineering of the implants, abutments and crowns. Patient specific implants are manufactured and measured concerning dimensional accuracy and surface roughness. Impacts of occlusal forces are simulated via FEA and compared to those of standard implants.

  14. Patient-Specific Tailored Intervention Improves INR Time in Therapeutic Range and INR Variability in Heart Failure Patients.

    Science.gov (United States)

    Gotsman, Israel; Ezra, Orly; Hirsh Raccah, Bruria; Admon, Dan; Lotan, Chaim; Dekeyser Ganz, Freda

    2017-08-01

    Many patients with heart failure need anticoagulants, including warfarin. Good control is particularly challenging in heart failure patients, with range, thereby increasing the risk of complications. This study aimed to evaluate the effect of a patient-specific tailored intervention on anticoagulation control in patients with heart failure. Patients with heart failure taking warfarin therapy (n = 145) were randomized to either standard care or a 1-time intervention assessing potential risk factors for lability of INR, in which they received patient-specific instructions. Time in therapeutic range (TTR) using Rosendaal's linear model was assessed 3 months before and after the intervention. The patient-tailored intervention significantly increased anticoagulation control. The median TTR levels before intervention were suboptimal in the interventional and control groups (53% vs 45%, P = .14). After intervention the median TTR increased significantly in the interventional group compared with the control group (80% [interquartile range, 62%-93%] vs 44% [29%-61%], P <.0001). The intervention resulted in a significant improvement in the interventional group before versus after intervention (53% vs 80%, P <.0001) but not in the control group (45% vs 44%, P = .95). The percentage of patients with a TTR ≥60%, considered therapeutic, was substantially higher in the interventional group: 79% versus 25% (P <.0001). The INR variability (standard deviation of each patient's INR measurements) decreased significantly in the interventional group, from 0.53 to 0.32 (P <.0001) after intervention but not in the control group. Patient-specific tailored intervention significantly improves anticoagulation therapy in patients with heart failure. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Observations of pretreatment prostate-specific antigen doubling time in 107 patients referred for definitive radiotherapy

    International Nuclear Information System (INIS)

    Lee, W. Robert; Hanks, Gerald E.; Corn, Benjamin W.; Schultheiss, Timothy E.

    1995-01-01

    Purpose: To determine pretreatment prostate-specific antigen doubling times (PSADT) in patients referred for definitive radiotherapy. Methods and Materials: One hundred and seven patients with histologically proven nonmetastatic prostate cancer and an elevated prostate-specific antigen (PSA) who were referred for radiation therapy had three serum PSA values obtained prior to the start of definitive therapy. Prostate-specific antigen doubling times were calculated by linear regression. Results: Prostate-specific antigen values increased during the period of observation in 78 patients (73%). Forty-three patients (40%) had calculated PSADT of less than 2 years and of those patients with pretreatment serum PSA values of greater than 10 ng/mL more than 50% has calculated PSADT of less than 2 years. Conclusions: A significant minority of patients referred for radiotherapy have calculated PSADT of less than 2 years. The significance of this relatively fast growth rate is as yet undetermined, but suggests that patients referred for radiotherapy may have aggressive disease prior to treatment

  16. The effect of patient-specific factors on radiation-induced regional lung injury

    International Nuclear Information System (INIS)

    Garipagaoglu, Melahat; Munley, Michael T.; Hollis, Donna; Poulson, Jean M.; Bentel, Gunilla C.; Sibley, Gregory; Anscher, Mitchell S.; Fan Ming; Jaszczak, Ronald J.; Coleman, R. Edward; Marks, Lawrence B.

    1999-01-01

    Purpose: To assess the impact of patient-specific factors on radiation (RT)-induced reductions in regional lung perfusion. Methods: Fifty patients (32 lung carcinoma, 7 Hodgkin's disease, 9 breast carcinoma and 2 other thoracic tumors) had pre-RT and ≥24-week post-RT single photon emission computed tomography (SPECT) perfusion images to assess the dose dependence of RT-induced reductions in regional lung perfusion. The SPECT data were analyzed using a normalized and non-normalized approach. Furthermore, two different mathematical methods were used to assess the impact of patient-specific factors on the dose-response curve (DRC). First, DRCs for different patient subgroups were generated and compared. Second, in a more formal statistical approach, individual DRCs for regional lung injury for each patient were fit to a linear-quadratic model (reduction = coefficient 1 x dose + coefficient 2 x dose 2 ). Multiple patient-specific factors including tobacco history, pre-RT diffusion capacity to carbon monoxide (DLCO), transforming growth factor-beta (TGF-β), chemotherapy exposure, disease type, and mean lung dose were explored in a multivariate analysis to assess their impact on the coefficients. Results: None of the variables tested had a consistent impact on the radiation sensitivity of regional lung (i.e., the slope of the DRC). In the formal statistical analysis, there was a suggestion of a slight increase in radiation sensitivity in the dose range >40 Gy for nonsmokers (vs. smokers) and in those receiving chemotherapy (vs. no chemotherapy). However, this finding was very dependent on the specific statistical and normalization method used. Conclusion: Patient-specific factors do not have a dramatic effect on RT-induced reduction in regional lung perfusion. Additional studies are underway to better clarify this issue. We continue to postulate that patient-specific factors will impact on how the summation of regional injury translates into whole organ injury

  17. Global aspects of complex geometry

    CERN Document Server

    Catanese, Fabrizio; Huckleberry, Alan T

    2006-01-01

    Present an overview of developments in Complex Geometry. This book covers topics that range from curve and surface theory through special varieties in higher dimensions, moduli theory, Kahler geometry, and group actions to Hodge theory and characteristic p-geometry.

  18. Ventriculostomy Simulation Using Patient-Specific Ventricular Anatomy, 3D Printing, and Hydrogel Casting.

    Science.gov (United States)

    Ryan, Justin R; Chen, Tsinsue; Nakaji, Peter; Frakes, David H; Gonzalez, L Fernando

    2015-11-01

    Educational simulators provide a means for students and experts to learn and refine surgical skills. Educators can leverage the strengths of medical simulators to effectively teach complex and high-risk surgical procedures, such as placement of an external ventricular drain. Our objective was to develop a cost-effective, patient-derived medical simulacrum for cerebral lateral ventriculostomy. A cost-effective, patient-derived medical simulacrum was developed for placement of an external lateral ventriculostomy. Elastomeric and gel casting techniques were used to achieve realistic brain geometry and material properties. 3D printing technology was leveraged to develop accurate cranial properties and dimensions. An economical, gravity-driven pump was developed to provide normal and abnormal ventricular pressures. A small pilot study was performed to gauge simulation efficacy using a technology acceptance model. An accurate geometric representation of the brain was developed with independent lateral cerebral ventricular chambers. A gravity-driven pump pressurized the ventricular cavities to physiologic values. A qualitative study illustrated that the simulation has potential as an educational tool to train medical professionals in the ventriculostomy procedure. The ventricular simulacrum can improve learning in a medical education environment. Rapid prototyping and multi-material casting techniques can produce patient-derived models for cost-effective and realistic surgical training scenarios. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Cause-specific mortality in HPV+ and HPV- oropharyngeal cancer patients

    DEFF Research Database (Denmark)

    Nørregaard, Cecilie; Grønhøj, Christian; Jensen, David

    2018-01-01

    Identifying the causes of death in head and neck cancer patients can optimize follow-up and therapeutic strategies, but studies in oropharyngeal squamous cell carcinoma (OPSCC) patients stratified by HPV status are lacking. We report cause-specific mortality in a population-based cohort of patients...... with OPSCC. Patients who had been diagnosed with OPSCC (n = 1541) between 2000 and 2014 in eastern Denmark were included in the study. Causes of death were collected through medical files and the Danish National Cause of Death registry. Deaths were grouped as (1) primary oropharyngeal cancer, (2) secondary...... malignancies, (3) cardiovascular and pulmonary disease, or (4) other/unspecified. The cumulative incidence of death and specific causes of death were determined using risk analysis. At follow-up, 723 (47.5%) patients had died. The median time to and cause of death were determined: oropharyngeal cancer (n = 432...

  20. Managing patients with acute and chronic non-specific neck pain

    DEFF Research Database (Denmark)

    Brockhusen, Simon Sidenius; Bussières, André; French, Simon David

    2017-01-01

    was mainly reserved for chronic patients. Danish chiropractors' compliance with guidelines for neck-pain patients was low, but is neither worse nor better than what is seen for other complaints or health disciplines. Our findings suggest a need for active knowledge translation strategies and robust......Background: Non-specific neck pain represents a quarter of all chiropractic patient visits in Denmark. Evidence informed practice can help ensure providers use best available treatment, speed up patient recovery rate and reduce healthcare utilization. It is generally believed that Danish...... chiropractors treat according to best practice, but we do not know if this is true for management of neck-pain. The objective of this study was to investigate how Danish chiropractors treat patients with acute and chronic non-specific neck pain and determine if management is compliant with recent Canadian...

  1. COPE-ICD: Patient experience of participation in an ICD specific rehabilitation programme

    DEFF Research Database (Denmark)

    Berg, Selina Kikkenborg; Pedersen, Birthe Dagmar; Svendsen, Jesper Hastrup

    2012-01-01

    individualized care. Four themes emerged: Knowledge: patients gained much needed understanding; Physical attention: patients interpreted body signals and adjusted their exercise behaviour; Trust: patients regained trust, felt secure and dared to live again; Strategies of living: patients' coping was supported...... through reflection and professional dialogue, and they dealt with the risk of shock or death. CONCLUSION: Participating in an ICD-specific rehabilitation programme can make patients feel inspired and secure through individualized care. They discover that they have to rethink some of their strategies......PURPOSE: Evaluating rehabilitation programmes from the patient's perspective is much needed, as the patients are the most important stakeholders in the health care system. A comprehensive rehabilitation programme, COPE-ICD programme, consists of exercise training and nursing consultations during...

  2. Risks of all-cause and site-specific fractures among hospitalized patients with COPD

    Science.gov (United States)

    Liao, Kuang-Ming; Liang, Fu-Wen; Li, Chung-Yi

    2016-01-01

    Abstract Patients with chronic obstructive pulmonary disease (COPD) have a high prevalence of osteoporosis. The clinical sequel of osteoporosis is fracture. Patients with COPD who experience a fracture also have increased morbidity and mortality. Currently, the types of all-cause and site-specific fracture among patients with COPD are unknown. Thus, we elucidated the all-cause and site-specific fractures among patients with COPD. A retrospective, population-based, cohort study was conducted utilizing the Taiwan Longitudinal Health Insurance Database. Patients with COPD were defined as those who were hospitalized with an International Classification of Diseases, Ninth Revision, Clinical Modification code of 490 to 492 or 496 between 2001 and 2011. The index date was set as the date of discharge. The study patients were followed from the index date to the date when they sought care for any type of fracture, date of death, date of health insurance policy termination, or the last day of 2013. The types of fracture analyzed in this study included vertebral, rib, humeral, radial and ulnar/wrist, pelvic, femoral, and tibial and fibular fractures. The cohort consisted of 11,312 patients with COPD. Among these patients, 1944 experienced fractures. The most common site-specific fractures were vertebral, femoral, rib, and forearm fractures (radius, ulna, and wrist) at 32.4%, 31%, 12%, and 11.8%, respectively. The adjusted hazard ratios of fracture were 1.71 [95% confidence interval (95% CI) = 1.56–1.87] for female patient with COPD and 1.50 (95% CI = 1.39–1.52) for patients with osteoporosis after covariate adjustment. Vertebral and hip fractures are common among patients with COPD, especially among males with COPD. Many comorbidities contribute to the high risk of fracture among patients with COPD. PMID:27749576

  3. A Patient-Specific Foot Model for the Estimate of Ankle Joint Forces in Patients with Juvenile Idiopathic Arthritis.

    Science.gov (United States)

    Prinold, Joe A I; Mazzà, Claudia; Di Marco, Roberto; Hannah, Iain; Malattia, Clara; Magni-Manzoni, Silvia; Petrarca, Maurizio; Ronchetti, Anna B; Tanturri de Horatio, Laura; van Dijkhuizen, E H Pieter; Wesarg, Stefan; Viceconti, Marco

    2016-01-01

    Juvenile idiopathic arthritis (JIA) is the leading cause of childhood disability from a musculoskeletal disorder. It generally affects large joints such as the knee and the ankle, often causing structural damage. Different factors contribute to the damage onset, including altered joint loading and other mechanical factors, associated with pain and inflammation. The prediction of patients' joint loading can hence be a valuable tool in understanding the disease mechanisms involved in structural damage progression. A number of lower-limb musculoskeletal models have been proposed to analyse the hip and knee joints, but juvenile models of the foot are still lacking. This paper presents a modelling pipeline that allows the creation of juvenile patient-specific models starting from lower limb kinematics and foot and ankle MRI data. This pipeline has been applied to data from three children with JIA and the importance of patient-specific parameters and modelling assumptions has been tested in a sensitivity analysis focused on the variation of the joint reaction forces. This analysis highlighted the criticality of patient-specific definition of the ankle joint axes and location of the Achilles tendon insertions. Patient-specific detection of the Tibialis Anterior, Tibialis Posterior, and Peroneus Longus origins and insertions were also shown to be important.

  4. Calculating patient specific doses in X-ray diagnostics and from radiopharmaceuticals

    International Nuclear Information System (INIS)

    Lampinen, J.

    2000-01-01

    The risk associated with exposure to ionising radiation is dependent on the characteristics of the exposed individual. The size and structure of the individual influences the absorbed dose distribution in the organs. Traditional methods used to calculate the patient organ doses are based on standardised calculation phantoms, which neglect the variance of the patient size or even sex. When estimating the radiation dose of an individual patient, patient specific calculation methods must be used. Methods for patient specific dosimetry in the fields of X-ray diagnostics and diagnostic and therapeutic use of radiopharmaceuticals were proposed in this thesis. A computer program, ODS-60, for calculating organ doses from diagnostic X-ray exposures was presented. The calculation is done in a patient specific phantom with depth dose and profile algorithms fitted to Monte Carlo simulation data from a previous study. Improvements to the version reported earlier were introduced, e.g. bone attenuation was implemented. The applicability of the program to determine patient doses from complex X-ray examinations (barium enema examination) was studied. The conversion equations derived for female and male patients as a function of patient weight gave the smallest deviation from the actual patient doses when compared to previous studies. Another computer program, Intdose, was presented for calculation of the dose distribution from radiopharmaceuticals. The calculation is based on convolution of an isotope specific point dose kernel with activity distribution, obtained from single photon emission computed tomography (SPECT) images. Anatomical information is taken from magnetic resonance (MR) or computed tomography (CT) images. According to a phantom study, Intdose agreed within 3 % with measurements. For volunteers administered diagnostic radiopharmaceuticals, the results given by Intdose were found to agree with traditional methods in cases of medium sized patients. For patients

  5. The Specificity of Health-Related Autobiographical Memories in Patients With Somatic Symptom Disorder.

    Science.gov (United States)

    Walentynowicz, Marta; Raes, Filip; Van Diest, Ilse; Van den Bergh, Omer

    2017-01-01

    Patients with somatic symptom disorder (SSD) have persistent distressing somatic symptoms that are associated with excessive thoughts, feelings, and behaviors. Reduced autobiographical memory specificity (rAMS) is related to a range of emotional disorders and is considered a vulnerability factor for an unfavorable course of pathology. The present study investigated whether the specificity of health-related autobiographical memories is reduced in patients with SSD with medically unexplained dyspnea complaints, compared with healthy controls. Female patients with SSD (n = 30) and matched healthy controls (n = 24) completed a health-related Autobiographical Memory Test, the Beck Depression Inventory, the Ruminative Response Scale, and rumination scales concerning bodily reactions. Depressive symptoms and rumination were assessed because both variables previously showed associations with rAMS. Patients with SSD recalled fewer specific (F(1,52) = 13.63, p = .001) and more categoric (F(1,52) = 7.62, p = .008) autobiographical memories to health-related cue words than healthy controls. Patients also reported higher levels of depressive symptoms and rumination (all t > 3.00, p < .01). Importantly, the differences in memory specificity were independent of depressive symptoms and trait rumination. The present study extends findings on rAMS to a previously unstudied sample of patients with SSD. Importantly, the presence of rAMS could not be explained by increased levels of depressive symptoms and rumination. We submit that rAMS in this group reflects how health-related episodes and associated symptoms are encoded in memory.

  6. T helper cell subsets specific for Pseudomonas aeruginosa in healthy individuals and patients with cystic fibrosis.

    Directory of Open Access Journals (Sweden)

    Hannah K Bayes

    Full Text Available We set out to determine the magnitude of antigen-specific memory T helper cell responses to Pseudomonas aeruginosa in healthy humans and patients with cystic fibrosis.Peripheral blood human memory CD4(+ T cells were co-cultured with dendritic cells that had been infected with different strains of Pseudomonas aeruginosa. The T helper response was determined by measuring proliferation, immunoassay of cytokine output, and immunostaining of intracellular cytokines.Healthy individuals and patients with cystic fibrosis had robust antigen-specific memory CD4(+ T cell responses to Pseudomonas aeruginosa that not only contained a Th1 and Th17 component but also Th22 cells. In contrast to previous descriptions of human Th22 cells, these Pseudomonal-specific Th22 cells lacked the skin homing markers CCR4 or CCR10, although were CCR6(+. Healthy individuals and patients with cystic fibrosis had similar levels of Th22 cells, but the patient group had significantly fewer Th17 cells in peripheral blood.Th22 cells specific to Pseudomonas aeruginosa are induced in both healthy individuals and patients with cystic fibrosis. Along with Th17 cells, they may play an important role in the pulmonary response to this microbe in patients with cystic fibrosis and other conditions.

  7. Patient-specific cardiac phantom for clinical training and preprocedure surgical planning.

    Science.gov (United States)

    Laing, Justin; Moore, John; Vassallo, Reid; Bainbridge, Daniel; Drangova, Maria; Peters, Terry

    2018-04-01

    Minimally invasive mitral valve repair procedures including MitraClip ® are becoming increasingly common. For cases of complex or diseased anatomy, clinicians may benefit from using a patient-specific cardiac phantom for training, surgical planning, and the validation of devices or techniques. An imaging compatible cardiac phantom was developed to simulate a MitraClip ® procedure. The phantom contained a patient-specific cardiac model manufactured using tissue mimicking materials. To evaluate accuracy, the patient-specific model was imaged using computed tomography (CT), segmented, and the resulting point cloud dataset was compared using absolute distance to the original patient data. The result, when comparing the molded model point cloud to the original dataset, resulted in a maximum Euclidean distance error of 7.7 mm, an average error of 0.98 mm, and a standard deviation of 0.91 mm. The phantom was validated using a MitraClip ® device to ensure anatomical features and tools are identifiable under image guidance. Patient-specific cardiac phantoms may allow for surgical complications to be accounted for preoperative planning. The information gained by clinicians involved in planning and performing the procedure should lead to shorter procedural times and better outcomes for patients.

  8. NOTE: Patient-specific planning for prevention of mechanical collisions during radiotherapy

    Science.gov (United States)

    Nioutsikou, Elena; Bedford, James L.; Webb, Steve

    2003-11-01

    A common unwanted difficulty in treatment planning, especially in non-coplanar radiotherapy set-ups, is the potential collision of the rotating gantry with the couch and/or the patient's body. A technique and computer program that detects these and signals avoidance of such beam directions is presented. The problem was approached using analytical geometry. The separate components within the treatment room have either been measured and modelled for an Elekta linear accelerator, or read out from a Pinnacle3 treatment planning system and are represented as an integer grid of points in three-dimensional (3D) space. The module is attached to the treatment planning system and can provide rejection or acceptance of unwanted beam directions in a plan. In contrast to previous work that has only used patient models, each individual patient's outlines are considered here in their actual treatment position inclusive of any immobilization device. The extremities of the patient superiorly and inferiorly to the scanned region are simulated by an expanded version of the RANDO phantom. In this way, 'potential' collisions can be detected in addition to the certain ones. Patient position is not a limiting factor for the accuracy of the collision detection anymore, as each set-up is always created around the isocentre. Maps of allowed and forbidden zones within the treatment suite have been created by running the code for all possible gantry and couch angles for three commonly arising cases: a head and neck plan utilizing a small stereotactic collimator, a prostate plan with multileaf collimators and an abdominal plan with the lead tray attached. In the last case, the 3D map permitted significantly fewer set-up combinations. Good agreement between prediction and experiment confirmed the capability of the program and introduces a promising add-on for treatment planning.

  9. Sources of hyperbolic geometry

    CERN Document Server

    Stillwell, John

    1996-01-01

    This book presents, for the first time in English, the papers of Beltrami, Klein, and Poincaré that brought hyperbolic geometry into the mainstream of mathematics. A recognition of Beltrami comparable to that given the pioneering works of Bolyai and Lobachevsky seems long overdue-not only because Beltrami rescued hyperbolic geometry from oblivion by proving it to be logically consistent, but because he gave it a concrete meaning (a model) that made hyperbolic geometry part of ordinary mathematics. The models subsequently discovered by Klein and Poincaré brought hyperbolic geometry even further down to earth and paved the way for the current explosion of activity in low-dimensional geometry and topology. By placing the works of these three mathematicians side by side and providing commentaries, this book gives the student, historian, or professional geometer a bird's-eye view of one of the great episodes in mathematics. The unified setting and historical context reveal the insights of Beltrami, Klein, and Po...

  10. Generalizing optical geometry

    International Nuclear Information System (INIS)

    Jonsson, Rickard; Westman, Hans

    2006-01-01

    We show that by employing the standard projected curvature as a measure of spatial curvature, we can make a certain generalization of optical geometry (Abramowicz M A and Lasota J-P 1997 Class. Quantum Grav. A 14 23-30). This generalization applies to any spacetime that admits a hypersurface orthogonal shearfree congruence of worldlines. This is a somewhat larger class of spacetimes than the conformally static spacetimes assumed in standard optical geometry. In the generalized optical geometry, which in the generic case is time dependent, photons move with unit speed along spatial geodesics and the sideways force experienced by a particle following a spatially straight line is independent of the velocity. Also gyroscopes moving along spatial geodesics do not precess (relative to the forward direction). Gyroscopes that follow a curved spatial trajectory precess according to a very simple law of three-rotation. We also present an inertial force formalism in coordinate representation for this generalization. Furthermore, we show that by employing a new sense of spatial curvature (Jonsson R 2006 Class. Quantum Grav. 23 1)) closely connected to Fermat's principle, we can make a more extensive generalization of optical geometry that applies to arbitrary spacetimes. In general this optical geometry will be time dependent, but still geodesic photons move with unit speed and follow lines that are spatially straight in the new sense. Also, the sideways experienced (comoving) force on a test particle following a line that is straight in the new sense will be independent of the velocity

  11. Modeling retinal degeneration using patient-specific induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Zi-Bing Jin

    Full Text Available Retinitis pigmentosa (RP is the most common inherited human eye disease resulting in night blindness and visual defects. It is well known that the disease is caused by rod photoreceptor degeneration; however, it remains incurable, due to the unavailability of disease-specific human photoreceptor cells for use in mechanistic studies and drug screening. We obtained fibroblast cells from five RP patients with distinct mutations in the RP1, RP9, PRPH2 or RHO gene, and generated patient-specific induced pluripotent stem (iPS cells by ectopic expression of four key reprogramming factors. We differentiated the iPS cells into rod photoreceptor cells, which had been lost in the patients, and found that they exhibited suitable immunocytochemical features and electrophysiological properties. Interestingly, the number of the patient-derived rod cells with distinct mutations decreased in vitro; cells derived from patients with a specific mutation expressed markers for oxidation or endoplasmic reticulum stress, and exhibited different responses to vitamin E than had been observed in clinical trials. Overall, patient-derived rod cells recapitulated the disease phenotype and expressed markers of cellular stresses. Our results demonstrate that the use of patient-derived iPS cells will help to elucidate the pathogenic mechanisms caused by genetic mutations in RP.

  12. Development and fabrication of patient-specific knee implant using additive manufacturing techniques

    Science.gov (United States)

    Zammit, Robert; Rochman, Arif

    2017-10-01

    Total knee replacement is the most effective treatment to relief pain and restore normal function in a diseased knee joint. The aim of this research was to develop a patient-specific knee implant which can be fabricated using additive manufacturing techniques and has reduced wear rates using a highly wear resistant materials. The proposed design was chosen based on implant requirements, such as reduction in wear rates as well as strong fixation. The patient-specific knee implant improves on conventional knee implants by modifying the articulating surfaces and bone-implant interfaces. Moreover, tribological tests of different polymeric wear couples were carried out to determine the optimal materials to use for the articulating surfaces. Finite element analysis was utilized to evaluate the stresses sustained by the proposed design. Finally, the patient-specific knee implant was successfully built using additive manufacturing techniques.

  13. Computational synthetic geometry

    CERN Document Server

    Bokowski, Jürgen

    1989-01-01

    Computational synthetic geometry deals with methods for realizing abstract geometric objects in concrete vector spaces. This research monograph considers a large class of problems from convexity and discrete geometry including constructing convex polytopes from simplicial complexes, vector geometries from incidence structures and hyperplane arrangements from oriented matroids. It turns out that algorithms for these constructions exist if and only if arbitrary polynomial equations are decidable with respect to the underlying field. Besides such complexity theorems a variety of symbolic algorithms are discussed, and the methods are applied to obtain new mathematical results on convex polytopes, projective configurations and the combinatorics of Grassmann varieties. Finally algebraic varieties characterizing matroids and oriented matroids are introduced providing a new basis for applying computer algebra methods in this field. The necessary background knowledge is reviewed briefly. The text is accessible to stud...

  14. Discrete and computational geometry

    CERN Document Server

    Devadoss, Satyan L

    2011-01-01

    Discrete geometry is a relatively new development in pure mathematics, while computational geometry is an emerging area in applications-driven computer science. Their intermingling has yielded exciting advances in recent years, yet what has been lacking until now is an undergraduate textbook that bridges the gap between the two. Discrete and Computational Geometry offers a comprehensive yet accessible introduction to this cutting-edge frontier of mathematics and computer science. This book covers traditional topics such as convex hulls, triangulations, and Voronoi diagrams, as well as more recent subjects like pseudotriangulations, curve reconstruction, and locked chains. It also touches on more advanced material, including Dehn invariants, associahedra, quasigeodesics, Morse theory, and the recent resolution of the Poincaré conjecture. Connections to real-world applications are made throughout, and algorithms are presented independently of any programming language. This richly illustrated textbook also fe...

  15. Geometry and Cloaking Devices

    Science.gov (United States)

    Ochiai, T.; Nacher, J. C.

    2011-09-01

    Recently, the application of geometry and conformal mappings to artificial materials (metamaterials) has attracted the attention in various research communities. These materials, characterized by a unique man-made structure, have unusual optical properties, which materials found in nature do not exhibit. By applying the geometry and conformal mappings theory to metamaterial science, it may be possible to realize so-called "Harry Potter cloaking device". Although such a device is still in the science fiction realm, several works have shown that by using such metamaterials it may be possible to control the direction of the electromagnetic field at will. We could then make an object hidden inside of a cloaking device. Here, we will explain how to design invisibility device using differential geometry and conformal mappings.

  16. Lectures on discrete geometry

    CERN Document Server

    2002-01-01

    Discrete geometry investigates combinatorial properties of configurations of geometric objects. To a working mathematician or computer scientist, it offers sophisticated results and techniques of great diversity and it is a foundation for fields such as computational geometry or combinatorial optimization. This book is primarily a textbook introduction to various areas of discrete geometry. In each area, it explains several key results and methods, in an accessible and concrete manner. It also contains more advanced material in separate sections and thus it can serve as a collection of surveys in several narrower subfields. The main topics include: basics on convex sets, convex polytopes, and hyperplane arrangements; combinatorial complexity of geometric configurations; intersection patterns and transversals of convex sets; geometric Ramsey-type results; polyhedral combinatorics and high-dimensional convexity; and lastly, embeddings of finite metric spaces into normed spaces. Jiri Matousek is Professor of Com...

  17. Complex differential geometry

    CERN Document Server

    Zheng, Fangyang

    2002-01-01

    The theory of complex manifolds overlaps with several branches of mathematics, including differential geometry, algebraic geometry, several complex variables, global analysis, topology, algebraic number theory, and mathematical physics. Complex manifolds provide a rich class of geometric objects, for example the (common) zero locus of any generic set of complex polynomials is always a complex manifold. Yet complex manifolds behave differently than generic smooth manifolds; they are more coherent and fragile. The rich yet restrictive character of complex manifolds makes them a special and interesting object of study. This book is a self-contained graduate textbook that discusses the differential geometric aspects of complex manifolds. The first part contains standard materials from general topology, differentiable manifolds, and basic Riemannian geometry. The second part discusses complex manifolds and analytic varieties, sheaves and holomorphic vector bundles, and gives a brief account of the surface classifi...

  18. Microbial profile comparisons of saliva, pooled and site-specific subgingival samples in periodontitis patients.

    Directory of Open Access Journals (Sweden)

    Daniel Belstrøm

    Full Text Available The purpose of this study was to compare microbial profiles of saliva, pooled and site-specific subgingival samples in patients with periodontitis. We tested the hypotheses that saliva can be an alternative to pooled subgingival samples, when screening for presence of periopathogens.Site specific subgingival plaque samples (n = 54, pooled subgingival plaque samples (n = 18 and stimulated saliva samples (n = 18 were collected from 18 patients with generalized chronic periodontitis. Subgingival and salivary microbiotas were characterized by means of HOMINGS (Human Oral Microbe Identification using Next Generation Sequencing and microbial community profiles were compared using Spearman rank correlation coefficient.Pronounced intraindividual differences were recorded in site-specific microbial profiles, and site-specific information was in general not reflected by pooled subgingival samples. Presence of Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia, Filifactor alocis, Tannerella forsythia and Parvimona micra in site-specific subgingival samples were detected in saliva with an AUC of 0.79 (sensitivity: 0.61, specificity: 0.94, compared to an AUC of 0.76 (sensitivity: 0.56, specificity: 0.94 in pooled subgingival samples.Site-specific presence of periodontal pathogens was detected with comparable accuracy in stimulated saliva samples and pooled subgingival plaque samples. Consequently, saliva may be a reasonable surrogate for pooled subgingival samples when screening for presence of periopathogens. Future large-scale studies are needed to confirm findings from this study.

  19. Geometry and symmetry

    CERN Document Server

    Yale, Paul B

    2012-01-01

    This book is an introduction to the geometry of Euclidean, affine, and projective spaces with special emphasis on the important groups of symmetries of these spaces. The two major objectives of the text are to introduce the main ideas of affine and projective spaces and to develop facility in handling transformations and groups of transformations. Since there are many good texts on affine and projective planes, the author has concentrated on the n-dimensional cases.Designed to be used in advanced undergraduate mathematics or physics courses, the book focuses on ""practical geometry,"" emphasi

  20. Conventional patient specific IMRT QA and 3DVH verification of dose distribution for helical tomotherapy

    International Nuclear Information System (INIS)

    Sharma, Prabhat Krishna; Joshi, Kishore; Epili, D.; Gavake, Umesh; Paul, Siji; Reena, Ph.; Jamema, S.V.

    2016-01-01

    In recent years, patient-specific IMRT QA has transitioned from point dose measurements by ion chambers to films to 2D array measurements. 3DVH software has taken this transition a step further by estimating the 3D dose delivered to the patient volume from 2D diode measurements using a planned dose perturbation (PDP) algorithm. This algorithm was developed to determine, if the conventional IMRT QA though sensitive at detecting errors, has any predictive power in detecting dose errors of clinical significance related to dose to the target volume and organs at risk (OAR). The aim of this study is to compare the conventional IMRT patient specific QA and 3DVH dose distribution for patients treated with helical tomotherapy (HT)

  1. Development of patient specific cardiovascular models predicting dynamics in response to orthostatic stress challenges

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.

    2013-01-01

    Physiological realistic models of the controlled cardiovascular system are constructed and validated against clinical data. Special attention is paid to the control of blood pressure, cerebral blood flow velocity, and heart rate during postural challenges, including sit-to-stand and head-up tilt....... This study describes development of patient specific models, and how sensitivity analysis and nonlinear optimization methods can be used to predict patient specific characteristics when analyzed using experimental data. Finally, we discuss how a given model can be used to understand physiological changes...

  2. Computational biomechanics for medicine fundamental science and patient-specific applications

    CERN Document Server

    Miller, Karol; Wittek, Adam; Nielsen, Poul

    2014-01-01

    One of the greatest challenges facing the computational engineering community is to extend the success of computational mechanics to fields outside traditional engineering, in particular to biology, the biomedical sciences, and medicine. The Computational Biomechanics for Medicine titles provide an opportunity for specialists in computational biomechanics to present their latest methodologies and advancements. This latest installment comprises nine of the latest developments in both fundamental science and patient-specific applications, from researchers in Australia, New Zealand, USA, UK, France, Ireland, and China. Some of the interesting topics discussed are: cellular mechanics; tumor growth and modeling; medical image analysis; and both patient-specific fluid dynamics and solid mechanics simulations.

  3. Patients with Multiple Myeloma Develop SOX2-Specific Autoantibodies after Allogeneic Stem Cell Transplantation

    Directory of Open Access Journals (Sweden)

    Sebastian Kobold

    2011-01-01

    Full Text Available The occurrence of SOX2-specific autoantibodies seems to be associated with an improved prognosis in patients with monoclonal gammopathy of undetermined significance (MGUS. However, it is unclear if SOX2-specific antibodies also develop in established multiple myeloma (MM. Screening 1094 peripheral blood (PB sera from 196 MM patients and 100 PB sera from healthy donors, we detected SOX2-specific autoantibodies in 7.7% and 2.0% of patients and donors, respectively. We identified SOX2211–230 as an immunodominant antibody-epitope within the full protein sequence. SOX2 antigen was expressed in most healthy tissues and its expression did not correlate with the number of BM-resident plasma cells. Accordingly, anti-SOX2 immunity was not related to SOX2 expression levels or tumor burden in the patients’ BM. The only clinical factor predicting the development of anti-SOX2 immunity was application of allogeneic stem cell transplantation (alloSCT. Anti-SOX2 antibodies occurred more frequently in patients who had received alloSCT (n=74. Moreover, most SOX2-seropositive patients had only developed antibodies after alloSCT. This finding indicates that alloSCT is able to break tolerance towards this commonly expressed antigen. The questions whether SOX2-specific autoantibodies merely represent an epiphenomenon, are related to graft-versus-host effects or participate in the immune control of myeloma needs to be answered in prospective studies.

  4. Dose distribution in organs: patient-specific phantoms versus reference phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, I.V.B., E-mail: isabelle.lacerda@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife (Brazil); Vieira, J.W. [Instituto Federal de Pernambuco (IFPE), Recife (Brazil); Oliveira, M.L.; Lima, F.R.A. [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PB), Recife (Brazil)

    2017-07-01

    Discrepancies between ICRP phantoms and real patients lead to disparities on patient-dose estimations. This paper aims to compare distribution of dose in organs of male/female specific-phantoms and ICRP reference phantoms. The absorbed dose estimation was performed using the EGSnrc Monte Carlo code and a parallel source algorithm. In this work were used a patient-specific phantom for a man (1.73m/70.3kg) and another for a woman (1.63m/60.3kg) and the male and female ICRP reference phantoms. The comparison of the absorbed dose from each phantom gender was performed using the relative error. The results were expressed in terms of conversion coefficients to brain, lungs, liver and kidneys. The greatest absolute relative error between the organs of the patient-specific phantom and the reference phantom was 22.92% in the liver and 62.84% in the kidneys, respectively for man and woman. There are errors that cannot be disregarded. This paper shows the need for a specific study for each patient or for the population of each country, since there are different body types, which affects the distribution of the organ doses. (author)

  5. Dose distribution in organs: patient-specific phantoms versus reference phantoms

    International Nuclear Information System (INIS)

    Lacerda, I.V.B.; Vieira, J.W.; Oliveira, M.L.; Lima, F.R.A.

    2017-01-01

    Discrepancies between ICRP phantoms and real patients lead to disparities on patient-dose estimations. This paper aims to compare distribution of dose in organs of male/female specific-phantoms and ICRP reference phantoms. The absorbed dose estimation was performed using the EGSnrc Monte Carlo code and a parallel source algorithm. In this work were used a patient-specific phantom for a man (1.73m/70.3kg) and another for a woman (1.63m/60.3kg) and the male and female ICRP reference phantoms. The comparison of the absorbed dose from each phantom gender was performed using the relative error. The results were expressed in terms of conversion coefficients to brain, lungs, liver and kidneys. The greatest absolute relative error between the organs of the patient-specific phantom and the reference phantom was 22.92% in the liver and 62.84% in the kidneys, respectively for man and woman. There are errors that cannot be disregarded. This paper shows the need for a specific study for each patient or for the population of each country, since there are different body types, which affects the distribution of the organ doses. (author)

  6. Comparison of Detailed and Simplified Models of Human Atrial Myocytes to Recapitulate Patient Specific Properties.

    Directory of Open Access Journals (Sweden)

    Daniel M Lombardo

    2016-08-01

    Full Text Available Computer studies are often used to study mechanisms of cardiac arrhythmias, including atrial fibrillation (AF. A crucial component in these studies is the electrophysiological model that describes the membrane potential of myocytes. The models vary from detailed, describing numerous ion channels, to simplified, grouping ionic channels into a minimal set of variables. The parameters of these models, however, are determined across different experiments in varied species. Furthermore, a single set of parameters may not describe variations across patients, and models have rarely been shown to recapitulate critical features of AF in a given patient. In this study we develop physiologically accurate computational human atrial models by fitting parameters of a detailed and of a simplified model to clinical data for five patients undergoing ablation therapy. Parameters were simultaneously fitted to action potential (AP morphology, action potential duration (APD restitution and conduction velocity (CV restitution curves in these patients. For both models, our fitting procedure generated parameter sets that accurately reproduced clinical data, but differed markedly from published sets and between patients, emphasizing the need for patient-specific adjustment. Both models produced two-dimensional spiral wave dynamics for that were similar for each patient. These results show that simplified, computationally efficient models are an attractive choice for simulations of human atrial electrophysiology in spatially extended domains. This study motivates the development and validation of patient-specific model-based mechanistic studies to target therapy.

  7. Programming system for analytic geometry

    International Nuclear Information System (INIS)

    Raymond, Jacques

    1970-01-01

    After having outlined the characteristics of computing centres which do not comply with engineering tasks, notably the time required by all different tasks to be performed when developing a software (assembly, compilation, link edition, loading, run), and identified constraints specific to engineering, the author identifies the characteristics a programming system should have to suit engineering tasks. He discussed existing conversational systems and their programming language, and their main drawbacks. Then, he presents a system which aims at facilitating programming and addressing problems of analytic geometry and trigonometry

  8. Moduli spaces in algebraic geometry

    International Nuclear Information System (INIS)

    Goettsche, L.

    2000-01-01

    This volume of the new series of lecture notes of the Abdus Salam International Centre for Theoretical Physics contains the lecture notes of the School on Algebraic Geometry which took place at the Abdus Salam International Centre for Theoretical Physics from 26 July to 13 August 1999. The school consisted of 2 weeks of lecture courses and one week of conference. The topic of the school was moduli spaces. More specifically the lectures were divided into three subtopics: principal bundles on Riemann surfaces, moduli spaces of vector bundles and sheaves on projective varieties, and moduli spaces of curves

  9. Tropical geometry of statistical models.

    Science.gov (United States)

    Pachter, Lior; Sturmfels, Bernd

    2004-11-16

    This article presents a unified mathematical framework for inference in graphical models, building on the observation that graphical models are algebraic varieties. From this geometric viewpoint, observations generated from a model are coordinates of a point in the variety, and the sum-product algorithm is an efficient tool for evaluating specific coordinates. Here, we address the question of how the solutions to various inference problems depend on the model parameters. The proposed answer is expressed in terms of tropical algebraic geometry. The Newton polytope of a statistical model plays a key role. Our results are applied to the hidden Markov model and the general Markov model on a binary tree.

  10. Guidelines for patient-specific jawline definition with titanium implants in esthetic, deformity, and malformation surgery

    OpenAIRE

    Mommaerts, Maurice Yves

    2016-01-01

    Context: Asymmetry and unfavorable esthetics of the jawline have become possible to correct in three dimensions using computer aided design and computer aided manufacturing. Aims: The aim of this study was to provide esthetic, technical, and operative guidelines for mandibular angle and border augmentation using patient-specific titanium implants made by selective laser melting. Settings and Design: University hospital - prospective registry. Subjects and Methods: Twelve patients and 17 impla...

  11. Decrease in specific micronutrient intake in colorectal cancer patients with tumors presenting Ki-ras mutation

    OpenAIRE

    JORDI SALAS; NURIA LASO; SERGI MAS; M. JOSE LAFUENTE; XAVIER CASTERAD; MANUEL TRIAS; ANTONIO BALLESTA; RAFAEL MOLINA; CARLOS ASCASO; SHICHUN ZHENG; JOHN K. WIENCKE; AMALIA LAFUENTE

    2004-01-01

    Decrease in specific micronutrient intake in colorectal cancer patients with tumors presenting Ki-ras mutation BACKGROUND: The diversity of the Mediterranean diet and the heterogeneity of acquired genetic alterations in colorectal cancer (CRC) led us to examine the possible association between dietary factors and mutations, such as Ki-ras mutations, in genes implicated in the pathogenesis of these neoplasms. PATIENTS AND METHODS: The study was based on 246 cases and 296 controls. For th...

  12. Evaluation of Functional Correlation of Task-Specific Muscle Synergies with Motor Performance in Patients Poststroke

    Directory of Open Access Journals (Sweden)

    Si Li

    2017-07-01

    Full Text Available The central nervous system produces movements by activating specifically programmed muscle synergies that are also altered with injuries in the brain, such as stroke. In this study, we hypothesize that there exists a positive correlation between task-specific muscle synergy and motor functions at joint and task levels in patients following stroke. The purpose here is to define and evaluate neurophysiological metrics based on task-specific muscle synergy for assessing motor functions in patients. A patient group of 10 subjects suffering from stroke and a control group of nine age-matched healthy subjects were recruited to participate in this study. Electromyography (EMG signals and movement kinematics were recorded in patients and control subjects while performing arm reaching tasks. Muscle synergies of individual patients were extracted off-line from EMG records of each patient, and a baseline pattern of muscle synergy was obtained from the pooled EMG data of all nine control subjects. Peak velocities and movement durations of each reaching movement were computed from measured kinematics. Similarity indices of matching components to those of the baseline synergy were defined by synergy vectors and time profiles, respectively, as well as by a combined similarity of vector and time profile. Results showed that pathological synergies of patients were altered from the characteristics of baseline synergy with missing components, or varied vector patterns and time profiles. The kinematic performance measured by peak velocities and movement durations was significantly poorer for the patient group than the control group. In patients, all three similarity indices were found to correlate significantly to the kinematics of movements for the reaching tasks. The correlation to the Fugl-Meyer score of arm was the highest with the vector index, the lowest with the time profile index, and in between with the combined index. These findings illustrate that the

  13. Total knee arthroplasty using patient-specific blocks after prior femoral fracture without hardware removal

    Directory of Open Access Journals (Sweden)

    Raju Vaishya

    2018-01-01

    Full Text Available Background: The options to perform total knee arthroplasty (TKA with retained hardware in femur are mainly – removal of hardware, use of extramedullary guide, or computer-assisted surgery. Patient-specific blocks (PSBs have been introduced with many potential advantages, but their use in retained hardware has not been adequately explored. The purpose of the present study was to outline and assess the usefulness of the PSBs in performing TKA in patients with retained femoral hardware. Materials and Materials and Methods: Nine patients with retained femoral hardware underwent TKA using PSBs. All the surgeries were performed by the same surgeon using same implants. Nine cases (7 males and 2 females out of total of 120 primary TKA had retained hardware. The average age of the patients was 60.55 years. The retained hardware were 6 patients with nails, 2 with plates and one patient had screws. Out of the nine cases, only one patient needed removal of a screw which was hindering placement of pin for the PSB. Results: All the patients had significant improvement in their Knee Society Score (KSS which improved from 47.0 to postoperative KSS of 86.77 (P < 0.00. The mechanical axis was significantly improved (P < 0.03 after surgery. No patient required blood transfusion and the average tourniquet time was 41 min. Conclusion: TKA using PSBs is useful and can be used in patients with retained hardware with good functional and radiological outcome.

  14. Disease specific knowledge about cystic fibrosis, patient education and counselling in Poland

    Directory of Open Access Journals (Sweden)

    Sławomir Chomik

    2014-06-01

    Full Text Available introduction and objective. The presented study assesses levels of specific knowledge of the disease among cystic fibrosis (CF patients and their families, and evaluates the effectiveness of a targeted, disease specific education programme. materials and methods. A cross-sectional survey among 462 families with a CF child evaluated their knowledge of the disease. A one year follow up survey among 200 families assessed the effectiveness of an educational programme developed to correct gaps, errors and misconceptions identified in the previously administered survey. Self-administered, comprehensive, 5-domains, 45-item multiple-choice CF Disease Knowledge Questionnaire (CFDKQ was anonymously completed by 462 subjects. results. 228 respondents were male (49%, 234 female (51%. The level of disease-specific knowledge in the age groups 0–6 and 7–10 years, was significantly higher than in 11–14 and 15–18 years of age groups (p<0.005. General medical and Genetics/Reproduction knowledge was low in all patients. Significant predictors of patient and parental knowledge were age and domicile. Patients and parents rely heavily on doctors for information about CF (77%. The follow-up survey (CFDKQ emphasized that special education programmes significantly improved levels of disease specific knowledge (p<0.0001. conclusions. If left uncorrected, the misconceptions, gaps and errors in CF knowledge identified in the presented study could result in inadvertent non-adherence to treatment, and impact on the progression and outcome of the disease. Secondly, the results demonstrate the effectiveness of targeted, disease specific information in improving disease knowledge of CF patients and their families, and highlights the value and need for the development of educational programmes for chronically ill patients and their families.

  15. Assessment of CT dose to the fetus and pregnant female patient using patient-specific computational models

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Tianwu; Poletti, Pierre-Alexandre; Platon, Alexandra; Becker, Christoph D. [Geneva University Hospital, Department of Medical Imaging and Information Sciences, Geneva (Switzerland); Zaidi, Habib [Geneva University Hospital, Department of Medical Imaging and Information Sciences, Geneva (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland); University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, Groningen (Netherlands); University of Southern Denmark, Department of Nuclear Medicine, Odense (Denmark); Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva (Switzerland)

    2018-03-15

    This work provides detailed estimates of the foetal dose from diagnostic CT imaging of pregnant patients to enable the assessment of the diagnostic benefits considering the associated radiation risks. To produce realistic biological and physical representations of pregnant patients and the embedded foetus, we developed a methodology for construction of patient-specific voxel-based computational phantoms based on existing standardised hybrid computational pregnant female phantoms. We estimated the maternal absorbed dose and foetal organ dose for 30 pregnant patients referred to the emergency unit of Geneva University Hospital for abdominal CT scans. The effective dose to the mother varied from 1.1 mSv to 2.0 mSv with an average of 1.6 mSv, while commercial dose-tracking software reported an average effective dose of 1.9 mSv (range 1.7-2.3 mSv). The foetal dose normalised to CTDI{sub vol} varies between 0.85 and 1.63 with an average of 1.17. The methodology for construction of personalised computational models can be exploited to estimate the patient-specific radiation dose from CT imaging procedures. Likewise, the dosimetric data can be used for assessment of the radiation risks to pregnant patients and the foetus from various CT scanning protocols, thus guiding the decision-making process. (orig.)

  16. Rare myositis-specific autoantibody associations among Hungarian patients with idiopathic inflammatory myopathy.

    Science.gov (United States)

    Bodoki, L; Nagy-Vincze, M; Griger, Z; Betteridge, Z; Szöllősi, L; Jobanputra, R; Dankó, K

    2015-01-01

    Idiopathic inflammatory myopathies are systemic, chronic autoimmune diseases characterized by symmetrical, proximal muscle weakness. Homogeneous groups present with similar symptoms. The response to therapy and prognosis could be facilitated by myositis-specific autoantibodies, and in this way, give rise to immunoserological classification. The myositis-specific autoantibodies are directed against specific proteins found in the cytoplasm or in the nucleus of the cells. To date, literature suggests the rarity of the co-existence of two myositis-specific autoantibodies. In this study the authors highlight rare associations of myositis-specific autoantibodies. Three hundred and thirty-seven Hungarian patients with polymyositis or dermatomyositis were studied. Their clinical findings were noted retrospectively. Specific blood tests identified six patients with the rare co-existence of myositis-specific autoantibodies, anti-Jo-1 and anti-SRP, anti-Jo-1 and anti-Mi-2, anti-Mi-2 and anti-PL-12, anti-Mi-2 and anti-SRP, and anti-SRP and anti-PL-7, respectively. This case review aims to identify the clinical importance of these rare associations and their place within the immunoserological classification.

  17. Towards relativistic quantum geometry

    Energy Technology Data Exchange (ETDEWEB)

    Ridao, Luis Santiago [Instituto de Investigaciones Físicas de Mar del Plata (IFIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata (Argentina); Bellini, Mauricio, E-mail: mbellini@mdp.edu.ar [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, C.P. 7600, Mar del Plata (Argentina); Instituto de Investigaciones Físicas de Mar del Plata (IFIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata (Argentina)

    2015-12-17

    We obtain a gauge-invariant relativistic quantum geometry by using a Weylian-like manifold with a geometric scalar field which provides a gauge-invariant relativistic quantum theory in which the algebra of the Weylian-like field depends on observers. An example for a Reissner–Nordström black-hole is studied.

  18. Multiplicity in difference geometry

    OpenAIRE

    Tomasic, Ivan

    2011-01-01

    We prove a first principle of preservation of multiplicity in difference geometry, paving the way for the development of a more general intersection theory. In particular, the fibres of a \\sigma-finite morphism between difference curves are all of the same size, when counted with correct multiplicities.

  19. Spacetime and Euclidean geometry

    Science.gov (United States)

    Brill, Dieter; Jacobson, Ted

    2006-04-01

    Using only the principle of relativity and Euclidean geometry we show in this pedagogical article that the square of proper time or length in a two-dimensional spacetime diagram is proportional to the Euclidean area of the corresponding causal domain. We use this relation to derive the Minkowski line element by two geometric proofs of the spacetime Pythagoras theorem.

  20. Physics and geometry

    International Nuclear Information System (INIS)

    Konopleva, N.P.

    2009-01-01

    The basic ideas of description methods of physical fields and elementary particle interactions are discussed. One of such ideas is the conception of space-time geometry. In this connection experimental measurement methods are analyzed. It is shown that measure procedures are the origin of geometrical axioms. The connection between space symmetry properties and the conservation laws is considered

  1. Origami, Geometry and Art

    Science.gov (United States)

    Wares, Arsalan; Elstak, Iwan

    2017-01-01

    The purpose of this paper is to describe the mathematics that emanates from the construction of an origami box. We first construct a simple origami box from a rectangular sheet and then discuss some of the mathematical questions that arise in the context of geometry and algebra. The activity can be used as a context for illustrating how algebra…

  2. Gravity is Geometry.

    Science.gov (United States)

    MacKeown, P. K.

    1984-01-01

    Clarifies two concepts of gravity--those of a fictitious force and those of how space and time may have geometry. Reviews the position of Newton's theory of gravity in the context of special relativity and considers why gravity (as distinct from electromagnetics) lends itself to Einstein's revolutionary interpretation. (JN)

  3. Diophantine geometry an introduction

    CERN Document Server

    Hindry, Marc

    2000-01-01

    This is an introduction to diophantine geometry at the advanced graduate level. The book contains a proof of the Mordell conjecture which will make it quite attractive to graduate students and professional mathematicians. In each part of the book, the reader will find numerous exercises.

  4. Sliding vane geometry turbines

    Science.gov (United States)

    Sun, Harold Huimin; Zhang, Jizhong; Hu, Liangjun; Hanna, Dave R

    2014-12-30

    Various systems and methods are described for a variable geometry turbine. In one example, a turbine nozzle comprises a central axis and a nozzle vane. The nozzle vane includes a stationary vane and a sliding vane. The sliding vane is positioned to slide in a direction substantially tangent to an inner circumference of the turbine nozzle and in contact with the stationary vane.

  5. History of analytic geometry

    CERN Document Server

    Boyer, Carl B

    2012-01-01

    Designed as an integrated survey of the development of analytic geometry, this study presents the concepts and contributions from before the Alexandrian Age through the eras of the great French mathematicians Fermat and Descartes, and on through Newton and Euler to the "Golden Age," from 1789 to 1850.

  6. Non-euclidean geometry

    CERN Document Server

    Coxeter, HSM

    1965-01-01

    This textbook introduces non-Euclidean geometry, and the third edition adds a new chapter, including a description of the two families of 'mid-lines' between two given lines and an elementary derivation of the basic formulae of spherical trigonometry and hyperbolic trigonometry, and other new material.

  7. Topics in Riemannian geometry

    International Nuclear Information System (INIS)

    Ezin, J.P.

    1988-08-01

    The lectures given at the ''5th Symposium of Mathematics in Abidjan: Differential Geometry and Mechanics'' are presented. They are divided into four chapters: Riemannian metric on a differential manifold, curvature tensor fields on a Riemannian manifold, some classical functionals on Riemannian manifolds and questions. 11 refs

  8. Geometry Euclid and beyond

    CERN Document Server

    Hartshorne, Robin

    2000-01-01

    In recent years, I have been teaching a junior-senior-level course on the classi­ cal geometries. This book has grown out of that teaching experience. I assume only high-school geometry and some abstract algebra. The course begins in Chapter 1 with a critical examination of Euclid's Elements. Students are expected to read concurrently Books I-IV of Euclid's text, which must be obtained sepa­ rately. The remainder of the book is an exploration of questions that arise natu­ rally from this reading, together with their modern answers. To shore up the foundations we use Hilbert's axioms. The Cartesian plane over a field provides an analytic model of the theory, and conversely, we see that one can introduce coordinates into an abstract geometry. The theory of area is analyzed by cutting figures into triangles. The algebra of field extensions provides a method for deciding which geometrical constructions are possible. The investigation of the parallel postulate leads to the various non-Euclidean geometries. And ...

  9. Predictive value of specific radiographic findings of disability in patients with rheumatoid arthritis

    International Nuclear Information System (INIS)

    Kaye, J.J.; Nance, E.P. Jr.; Callahan, L.F.; Pincus, T.

    1986-01-01

    This study was carried out to determine whether and to what extend radiographic erosion, joint space narrowing, and malalignment are predictive of clinical disability in patients with rheumatoid arthristis (RA). Radiographs of the hands and wrists of 224 patients with RA were scored for these radiographic parameters. To determine which of these findings best explained variation in clinical measures of disability, a series of regression analyses was performed. Malalignment scores were the best predictor of joint deformity and limitation of motion. Erosion scores were most predictive of variation in functional tests. The author concludes that specific radiographic findings of malalignment and erosion are significantly predictive of disability in patients with RA

  10. HPV specific testing: a requirement for oropharyngeal squamous cell carcinoma patients.

    Science.gov (United States)

    Robinson, Max; Schache, Andrew; Sloan, Philip; Thavaraj, Selvam

    2012-07-01

    Human papillomavirus (HPV) testing is now recommended as part of the work up for patients with oropharyngeal squamous cell carcinoma (OPSCC) and those patients with cervical lymph node metastasis of unknown origin. The laboratory testing strategy should accurately assess the presence or absence of oncogenic HPV infection in routinely collected tumour samples that are subject to standard fixation protocols, alcohol-fixed cytological preparations and formalin-fixed tissue samples. The HPV status should correlate with biologically relevant outcome measures such as overall, disease-specific and disease-free survival. Whilst increased expression of p16 by immunohistochemistry is considered to be a surrogate marker of oncogenic HPV infection and is a validated independent prognostic biomarker, only HPV specific tests provide definitive evidence of the aetiological agent. We provide an overview of HPV testing in OPSCC, justifying the use of HPV specific tests. We examine the analytical accuracy of HPV specific tests against the 'reference' test--high risk HPV mRNA in fresh tissue--and contrast this with the performance of p16 immunohistochemistry as a stand alone test. We highlight the added value of HPV specific tests in prognostication, clinical trial design, and population-based disease surveillance. We consider that HPV specific testing is the starting point for developing increasingly informative biomarker panels in the context of 'stratified medicine'. We briefly frame test information in the context of disclosure of HPV status to patients. We conclude that only a testing strategy that includes HPV specific tests can deliver more effective care for patients with OPSCC. The international head and neck oncology community should work together to clearly define the minimum requirements for assigning a diagnosis of HPV-related OPSCC in order to ensure consistent reporting of this emerging and increasingly prevalent disease.

  11. [Partial replacement of the knee joint with patient-specific instruments and implants (ConforMIS iUni, iDuo)].

    Science.gov (United States)

    Beckmann, J; Steinert, A; Zilkens, C; Zeh, A; Schnurr, C; Schmitt-Sody, M; Gebauer, M

    2016-04-01

    Knee arthroplasty is a successful standard procedure in orthopedic surgery; however, approximately 20 % of patients are dissatisfied with the clinical results as they suffer pain and can no longer achieve the presurgery level of activity. According to the literature the reasons are inexact fitting of the prosthesis or too few anatomically formed implants resulting in less physiological kinematics of the knee joint. Reducing the number of dissatisfied patients and the corresponding number of revisions is an important goal considering the increasing need for artificial joints. In this context, patient-specific knee implants are an obvious alternative to conventional implants. For the first time implants are now matched to the individual bone and not vice versa to achieve the best possible individual situation and geometry and more structures (e.g. ligaments and bone) are preserved or only those structures are replaced which were actually destroyed by arthrosis. According to the authors view, this represents an optimal and pioneering addition to conventional implants. Patient-specific implants and the instruments needed for correct alignment and fitting can be manufactured by virtual 3D reconstruction and 3D printing based on computed tomography (CT) scans. The portfolio covers medial as well as lateral unicondylar implants, medial as well as lateral bicompartmental implants (femorotibial and patellofemoral compartments) and cruciate ligament-preserving as well as cruciate ligament-substituting total knee replacements; however, it must be explicitly emphasized that the literature is sparse and no long-term data are available.

  12. Initial stress and nonlinear material behavior in patient-specific AAA wall stress analysis

    NARCIS (Netherlands)

    Speelman, L.; Bosboom, E.M.H.; Schurink, G.W.H.; Buth, J.; Breeuwer, M.; Jacobs, M.J.; Vosse, van de F.N.

    2009-01-01

    Rupture risk estimation of abdominal aortic aneurysms (AAA) is currently based on the maximum diameter of the AAA. A more critical approach is based on AAA wall stress analysis. For that, in most cases, the AAA geometry is obtained from CT-data and treated as a stress free geometry. However, during

  13. Correlative study between neuron-specific enolase and blood sugar level in ischemic stroke patients

    Directory of Open Access Journals (Sweden)

    Aparna Pandey

    2011-01-01

    Full Text Available Background: A study to investigate the level of the neurobiochemical marker, Neuron-Specific Enolase (NSE, at the time of admission and its correlation with the blood sugar level in ischemic stroke patients. Patients and Methods: We investigated 90 patients with complete stroke who were admitted to the Stroke Unit of the Department of Neurology at Sri Aurobindo Institute of Medical Sciences. NSE was measured with commercially available quantitative ′sandwich′ enzyme-linked immunosorbent assay kits obtained from R and D Systems. Hyperglycemia was defined as blood glucose concentration ≥ 7 mmol / L, and measured using the glucose oxidase method immediately. Results: Significantly increased NSE and lipid profile levels were found in ischemic stroke patients as compared to the control. Hyperglycemic ischemic stroke patients had increased levels of NSE, lipid profile, and National Institute of Health stroke scale scores (NIHSS score compared to normoglycemic ischemic stroke patients. In addition the serum NSE level of hyperglycemic stroke patients was also positively correlated with the blood sugar level (r = 0.734 P < 0.001. Conclusions: Hyperglycemia predicts an increased risk of poor outcome after ischemic stroke and it is reflected by a significantly increased level of Neuron-Specific Enolase.

  14. How specific are emotional deficits? A comparison of empathic abilities in schizophrenia, bipolar and depressed patients

    Science.gov (United States)

    Derntl, Birgit; Seidel, Eva-Maria; Schneider, Frank; Habel, Ute

    2012-01-01

    Empathy is a rather elaborated human ability and several recent studies highlight significant impairments in patients suffering from psychiatric disorders, such as schizophrenia, bipolar disorder or major depression. Therefore, the present study aimed at comparing behavioral empathy performance in schizophrenia, bipolar and depressed patients with healthy controls. All subjects performed three tasks tapping the core components of empathy: emotion recognition, emotional perspective taking and affective responsiveness. Groups were matched for age, gender, and verbal intelligence. Data analysis revealed three main findings: First, schizophrenia patients showed the strongest impairment in empathic performance followed by bipolar patients while depressed patients performed similar to controls in most tasks, except for affective responsiveness. Second, a significant association between clinical characteristics and empathy performance was only apparent in depression, indicating worse affective responsiveness with stronger symptom severity and longer duration of illness. Third, self-report data indicate that particularly bipolar patients describe themselves as less empathic, reporting less empathic concern and less perspective taking. Taken together, this study constitutes the first approach to directly compare specificity of empathic deficits in severe psychiatric disorders. Our results suggest disorder-specific impairments in emotional competencies that enable better characterization of the patient groups investigated and indicate different psychotherapeutic interventions. PMID:23116884

  15. [Subjective illness beliefs of Turkish migrants with mental disorders--specific characteristics compared to german patients].

    Science.gov (United States)

    Franz, Michael; Lujić, Claudia; Koch, Eckhardt; Wüsten, Bernd; Yürük, Nergüz; Gallhofer, Bernd

    2007-10-01

    Knowledge about culture- and migration-specific characteristics of subjective illness beliefs in Turkish patients is necessary for adequate treatment. Analysis of subjective illness beliefs in Turkish patients (F3; F4; n = 79) in comparison to matched Germans (n = 79) using a modified version of the Illness Perception Questionnaire IPQ-R. Differences were explored by t-tests and chi(2)-tests. Turkish patients believed significantly stronger in a chronical timeline of illness and in negative illness consequences, while German patients believed significantly stronger in treatment control and personal control. Turkish patients more often mentioned external causes of their disease compared to Germans. The results provide explanations of the deficient health care situation for Turkish migrants in Germany.

  16. Wildtype p53-specific Antibody and T-Cell Responses in Cancer Patients

    DEFF Research Database (Denmark)

    Pedersen, Anders Elm; Stryhn, Anette; Justesen, Sune

    2011-01-01

    patients. Detection of antibodies against wt p53 protein has been used as a diagnostic and prognostic marker and discovery of new T-cell epitopes has enabled design of cancer vaccination protocols with promising results. Here, we identified wt p53-specific antibodies in various cancer patients......(264-272) in breast cancer patients and against HLA-A*01:01 binding peptide wt p53(226-234) and HLA-B*07:02 binding peptide wt p53(74-82) in renal cell cancer and breast cancer patients, respectively. Finally, we analyzed antibody and T-cell responses against wt p53 15-mer peptides in patients with metastatic renal...

  17. Comment on “Drug Screening for ALS Using Patient-Specific Induced Pluripotent Stem Cells”

    Science.gov (United States)

    Bilican, Bilada; Serio, Andrea; Barmada, Sami J.; Nishimura, Agnes Lumi; Sullivan, Gareth J.; Carrasco, Monica; Phatnani, Hemali P.; Puddifoot, Clare A.; Story, David; Fletcher, Judy; Park, In-Hyun; Friedman, Brad A.; Daley, George Q.; Wyllie, David J. A.; Hardingham, Giles E.; Wilmut, Ian; Finkbeiner, Steven; Maniatis, Tom; Shaw, Christopher E.; Chandran, Siddharthan

    2014-01-01

    Egawa et al. recently showed the value of patient-specific induced pluripotent stem cells (iPSCs) for modeling amyotrophic lateral sclerosis in vitro. Their study and our work highlight the need for complementary assays to detect small, but potentially important, phenotypic differences between control iPSC lines and those carrying disease mutations. PMID:23740897

  18. Increased serum neuron specific enolase concentrations in patients with hyperglycemic cortical ischemic stroke

    NARCIS (Netherlands)

    Elting, JW; De Keyser, J; Sulter, G.

    1998-01-01

    A detrimental effect of hyperglycemia in ischemic brain has been demonstrated in laboratory experiments and it has been found that hyperglycemia in ischemic stroke is a predictor of poor outcome. We determined serum neuron specific enolase (NSE) concentrations in 41 consecutive patients with a

  19. Patient-specific model of a scoliotic torso for surgical planning

    Science.gov (United States)

    Harmouche, Rola; Cheriet, Farida; Labelle, Hubert; Dansereau, Jean

    2013-03-01

    A method for the construction of a patient-specific model of a scoliotic torso for surgical planning via inter-patient registration is presented. Magnetic Resonance Images (MRI) of a generic model are registered to surface topography (TP) and X-ray data of a test patient. A partial model is first obtained via thin-plate spline registration between TP and X-ray data of the test patient. The MRIs from the generic model are then fit into the test patient using articulated model registration between the vertebrae of the generic model's MRIs in prone position and the test patient's X-rays in standing position. A non-rigid deformation of the soft tissues is performed using a modified thin-plate spline constrained to maintain bone rigidity and to fit in the space between the vertebrae and the surface of the torso. Results show average Dice values of 0:975 +/- 0:012 between the MRIs following inter-patient registration and the surface topography of the test patient, which is comparable to the average value of 0:976 +/- 0:009 previously obtained following intra-patient registration. The results also show a significant improvement compared to rigid inter-patient registration. Future work includes validating the method on a larger cohort of patients and incorporating soft tissue stiffness constraints. The method developed can be used to obtain a geometric model of a patient including bone structures, soft tissues and the surface of the torso which can be incorporated in a surgical simulator in order to better predict the outcome of scoliosis surgery, even if MRI data cannot be acquired for the patient.

  20. Disease specific stress of tumor patients at the beginning of radiotherapy. Effect on psychosocial support requirement

    International Nuclear Information System (INIS)

    Sehlen, S.; Hollenhorst, H.; Schymura, B.; Firsching, M.; Duehmke, E.; Herschbach, P.

    2001-01-01

    Purpose: Radiotherapy brings a tumor patient into a special life situation in which different variables play a role of often unknown importance. The goal of this study was to investigate disease specific stress of tumor patients at the beginning of radiotherapy with established psychodiagnostic questionnaires and to evaluate the effect on psychosocial support requirement in order to reduce stress and to improve quality of life and compliance during radiotherapeutical treatment. Patients and Methods: 732 patients were screened, of whom 446 (60.9%) fulfilled the criteria for inclusion (refusals 21.0%, low Karnofsky performance status 6.6%, management problems 3.4%, language barriers 3.0%, cognitive restrictions 2.6%, death 2.5%). Disease specific aspects of stress in the questionnaire (Fragebogen zur Belastung von Krebspatienten, FBK), life situation (LS) and self-defined care requirements (BB) were self-rated by patients with different tumor types before radiotherapy. Medical and sociodemographic data were also documented. We investigated 446 patients (262 male, 184 female; median age 60.0 years) with different diagnoses. Results: Stress was observed mainly due to reduction of efficiency, anxiety and pain on the subscales. Women had a significant higher stress on subscales of pain (p=0.016) and anxiety (p=0.009), patients younger than 45 years in the subscale information (p=0.002) and patients older than 45 and younger than 60 years in the subscale anxiety (p=0.002) and the total score (p=0.003). Patients with mamma carcinoma had the highest stress. The maximum percentages of patients under high stress were found for the subscales of efficiency (43%) and anxiety (40%). The support requirement was characterized by the need of more medical information and dialogue with the doctor. We saw a significant correlation of high stress and high care requirement. Conclusions: Psychosocial support should be founded on psychosocial stress diagnostic and self-defined care

  1. Analysis and description of disease-specific quality of life in patients with anal fistula.

    Science.gov (United States)

    Ferrer-Márquez, Manuel; Espínola-Cortés, Natalia; Reina-Duarte, Ángel; Granero-Molina, José; Fernández-Sola, Cayetano; Hernández-Padilla, José Manuel

    2018-04-01

    In patients diagnosed with anal fistula, knowing the quality of life specifically related to the disease can help coloproctology specialists to choose the most appropriate therapeutic strategy for each case. The aim of our study is to analyzse and describe the factors related to the specific quality of life in a consecutive series of patients diagnosed with anal fistula. Observational, cross-sectional study carried out from March 2015 to February 2017. All patients were assessed in the colorectal surgery unit of a hospital in southeast of Spain. After performing an initial anamnesis and a physical examination, patients diagnosed with anal fistula completed the Quality of Life in Ppatients with Anal Fistula Questionnaire (QoLAF-Q). This questionnaire specifically measures quality of life in people with anal fistula and its score range is the following: zero impact = 14 points, limited impact = 15 to 28 points, moderate impact = 29 to 42 points, high impact = 43 to 56 points, and very high impact = 57 to 70 points. A total of 80 patients were included. The median score obtained in the questionnaire for the sample studied was 34.00 (range=14-68). Statistically significant differences between patients with "primary anal fistula" (n=65) and "recurrent anal fistula" (n=15) were observed (mean rank=42.96 vs. mean rank=29.83, p=0.048). Furthermore, an inverse proportion (P=.016) between "time with clinical symptoms" and "impact on quality of life" was found (5 years: mean rank = 19.00). There were no statistically significant differences (P=.149) between quality of life amongst patients diagnosed with complex (mean rank = 36.13) and simple fistulae (mean rank = 43.59). Anal fistulae exert moderate-high impact on patients' quality of life. "Shorter time experiencing clinical symptoms" and the "presence of primary fistula" are factors that can be associated with worse quality of life. Copyright © 2018 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Erythroid-specific transcriptional changes in PBMCs from pulmonary hypertension patients.

    Directory of Open Access Journals (Sweden)

    Chris Cheadle

    Full Text Available Gene expression profiling of peripheral blood mononuclear cells (PBMCs is a powerful tool for the identification of surrogate markers involved in disease processes. The hypothesis tested in this study was that chronic exposure of PBMCs to a hypertensive environment in remodeled pulmonary vessels would be reflected by specific transcriptional changes in these cells.The transcript profiles of PBMCs from 30 idiopathic pulmonary arterial hypertension patients (IPAH, 19 patients with systemic sclerosis without pulmonary hypertension (SSc, 42 scleroderma-associated pulmonary arterial hypertensio patients (SSc-PAH, and 8 patients with SSc complicated by interstitial lung disease and pulmonary hypertension (SSc-PH-ILD were compared to the gene expression profiles of PBMCs from 41 healthy individuals. Multiple gene expression signatures were identified which could distinguish various disease groups from controls. One of these signatures, specific for erythrocyte maturation, is enriched specifically in patients with PH. This association was validated in multiple published datasets. The erythropoiesis signature was strongly correlated with hemodynamic measures of increasing disease severity in IPAH patients. No significant correlation of the same type was noted for SSc-PAH patients, this despite a clear signature enrichment within this group overall. These findings suggest an association of the erythropoiesis signature in PBMCs from patients with PH with a variable presentation among different subtypes of disease.In PH, the expansion of immature red blood cell precursors may constitute a response to the increasingly hypoxic conditions prevalent in this syndrome. A correlation of this erythrocyte signature with more severe hypertension cases may provide an important biomarker of disease progression.

  3. Fast patient-specific Monte Carlo brachytherapy dose calculations via the correlated sampling variance reduction technique

    Energy Technology Data Exchange (ETDEWEB)

    Sampson, Andrew; Le Yi; Williamson, Jeffrey F. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)

    2012-02-15

    Purpose: To demonstrate potential of correlated sampling Monte Carlo (CMC) simulation to improve the calculation efficiency for permanent seed brachytherapy (PSB) implants without loss of accuracy. Methods: CMC was implemented within an in-house MC code family (PTRAN) and used to compute 3D dose distributions for two patient cases: a clinical PSB postimplant prostate CT imaging study and a simulated post lumpectomy breast PSB implant planned on a screening dedicated breast cone-beam CT patient exam. CMC tallies the dose difference, {Delta}D, between highly correlated histories in homogeneous and heterogeneous geometries. The heterogeneous geometry histories were derived from photon collisions sampled in a geometrically identical but purely homogeneous medium geometry, by altering their particle weights to correct for bias. The prostate case consisted of 78 Model-6711 {sup 125}I seeds. The breast case consisted of 87 Model-200 {sup 103}Pd seeds embedded around a simulated lumpectomy cavity. Systematic and random errors in CMC were unfolded using low-uncertainty uncorrelated MC (UMC) as the benchmark. CMC efficiency gains, relative to UMC, were computed for all voxels, and the mean was classified in regions that received minimum doses greater than 20%, 50%, and 90% of D{sub 90}, as well as for various anatomical regions. Results: Systematic errors in CMC relative to UMC were less than 0.6% for 99% of the voxels and 0.04% for 100% of the voxels for the prostate and breast cases, respectively. For a 1 x 1 x 1 mm{sup 3} dose grid, efficiency gains were realized in all structures with 38.1- and 59.8-fold average gains within the prostate and breast clinical target volumes (CTVs), respectively. Greater than 99% of the voxels within the prostate and breast CTVs experienced an efficiency gain. Additionally, it was shown that efficiency losses were confined to low dose regions while the largest gains were located where little difference exists between the homogeneous and

  4. Screening for prostate cancer with the prostate-specific antigen test: are patients making informed decisions?

    Science.gov (United States)

    O'Dell, K J; Volk, R J; Cass, A R; Spann, S J

    1999-09-01

    The benefits of early detection of prostate cancer are uncertain, and the American College of Physicians and the American Academy of Family Physicians recommend individual decision making in prostate cancer screening. This study reports the knowledge of male primary care patients about prostate cancer and prostate-specific antigen (PSA) testing and examines how that knowledge is related to PSA testing, preferences for testing in the future, and desire for involvement in physician-patient decision making. The sample included 160 men aged 45 to 70 years with no history of prostate cancer who presented for care at a university-based family medicine clinic. Before scheduled office visits, patients completed a questionnaire developed for this study that included a 10-question measure of prostate cancer knowledge, the Deber-Kraestchmer Problem-Solving Decision-Making Scale, sociodemographic indicators, and questions on PSA testing. In general, patients who were college graduates were more knowledgeable about prostate cancer and early detection than those with a high school education or less. Aside from college graduates, most patients could not identify the principle advantages and disadvantages of PSA testing. Patients indicating previous or future plans for PSA testing demonstrated greater knowledge than other patients. Desire for involvement in decision making varied by patient education but was not related to past PSA testing. Patients lack knowledge about prostate cancer and early detection. This knowledge deficit may impede the early detection of prostate cancer and is a barrier to making an informed decision about undergoing PSA testing.

  5. Frequency and specificity of red blood cell alloimmunization in chilean transfused patients.

    Science.gov (United States)

    Caamaño, José; Musante, Evangelina; Contreras, Margarita; Ulloa, Hernán; Reyes, Carolina; Inaipil, Verónica; Saavedra, Nicolás; Guzmán, Neftalí

    2015-01-01

    Alloimmunization is an adverse effect of blood transfusions. In Chile, alloimmunization frequency is not established, and for this reason the aim of this study was to investigate the prevalence and specificity of red blood cell (RBC) alloantibodies in Chilean transfused subjects. Records from 4,716 multi-transfused patients were analyzed. In these patients, antibody screening was carried out prior to cross-matching with a commercially available two-cell panel by the microcolum gel test, and samples with a positive screen were analyzed for the specificity of the alloantibody with a 16-cell identification panel. The incidence of RBC alloimmunization in transfused patients was 1.02% (48/4,716) with a higher prevalence in women (40/48). We detected 52 antibodies, the most frequent specificities identified were anti-E (30.8%), anti-K (26.9%), anti-D (7.7%), and anti-Fy(a) (5.8%). The highest incidence of alloantibodies was observed in cancer and gastroenterology patients. The data demonstrated a low alloimmunization frequency in Chilean transfused patients, principally associated with antibodies anti-E, anti-K, anti-D, and anti-Fy(a).

  6. Prostate-specific antigen density values among patients with symptomatic prostatic enlargement in Nigeria.

    Science.gov (United States)

    Udeh, Emeka I; Nnabugwu, Ikenna I; Ozoemena, Francis O; Ugwumba, Fred O; Aderibigbe, Adesina S O; Ohayi, Samuel R; Echetabu, Kevin N

    2016-06-29

    This study aims to estimate the prostate-specific antigen density (PSAD) cutoff level for detecting prostate cancer (CAP) in Nigerian men with "grey zone PSA" (4-10 ng/ml) and normal digital rectal examination findings. We addressed this research question: Is the international PSAD cutoff of 0.15 ideal for detecting CAP in our symptomatic patients with "grey zone PSA?" To estimate the prostate-specific antigen density (PSAD) cutoff level for detecting CAP in Nigerian men with "grey zone PSA" (4-10 ng/ml) and normal digital rectal examination findings. Prospective. A tertiary medical center in Enugu, Nigeria. Two hundred and fifty-four men with either benign prostatic hyperplasia (BPH) or CAP were recruited. Patients with PSA above 4 ng/ml or abnormal digital rectal examination or hypoechoic lesion in the prostate were biopsied. PSAD and histology report of BPH or CAP. Ninety-seven patients had CAP while 157 had benign prostatic hyperplasia (BPH). Seventy-two patients had their serum PSA value within the range of 4.0 and 10 ng/ml. PSAD cutoff level to detect CAP was 0.04 (sensitivity 95.88 %; specificity 28.7 %). The PSAD cutoff level generated for Nigerian men in this study is 0.04 which is relatively different from international consensus. This PSAD cutoff level has a positive correlation with histology and could detect patients with CAP who have "grey zone PSA."

  7. 3D-Printed Patient-Specific ACL Femoral Tunnel Guide from MRI.

    Science.gov (United States)

    Rankin, Iain; Rehman, Haroon; Frame, Mark

    2018-01-01

    Traditional ACL reconstruction with non-anatomic techniques can demonstrate unsatisfactory long-term outcomes with regards instability and the degenerative knee changes observed with these results. Anatomic ACL reconstruction attempts to closely reproduce the patient's individual anatomic characteristics with the aim of restoring knee kinematics, in order to improve patient short and long-term outcomes. We designed an arthroscopic, patient-specific, ACL femoral tunnel guide to aid anatomical placement of the ACL graft within the femoral tunnel. The guide design was based on MRI scan of the subject's uninjured contralateral knee, identifying the femoral footprint and its anatomical position relative to the borders of the femoral articular cartilage. Image processing software was used to create a 3D computer aided design which was subsequently exported to a 3D-printing service. Transparent acrylic based photopolymer, PA220 plastic and 316L stainless steel patient-specific ACL femoral tunnel guides were created; the models produced were accurate with no statistical difference in size and positioning of the center of the ACL femoral footprint guide to MRI ( p =0.344, p =0.189, p =0.233 respectively). The guides aim to provide accurate marking of the starting point of the femoral tunnel in arthroscopic ACL reconstruction. This study serves as a proof of concept for the accurate creation of 3D-printed patient-specific guides for the anatomical placement of the femoral tunnel during ACL reconstruction.

  8. Are specific antiretrovirals associated with an increased risk of discontinuation due to toxicities or patient/physician choice in patients with hepatitis C virus coinfection?

    DEFF Research Database (Denmark)

    Mocroft, A; Rockstroh, J; Soriano, V

    2005-01-01

    clinical trials as patients with HCV are often excluded. AIMS: To compare incidence rates of discontinuation due to TOXPC associated with specific antiretrovial drugs in patients with or without HCV. PATIENTS/METHODS: A total of 4929 patients from EuroSIDA under follow-up from January 1999 on a specific...

  9. Disease-specific health status as a predictor of mortality in patients with heart failure

    DEFF Research Database (Denmark)

    Mastenbroek, Mirjam H; Versteeg, Henneke; Zijlstra, Wobbe P

    2014-01-01

    AIMS: Some, but not all, studies have shown that patient-reported health status, including symptoms, functioning, and health-related quality of life, provides additional information to traditional clinical factors in predicting prognosis in heart failure patients. To evaluate the overall evidence......, the association of disease-specific health status on mortality in heart failure was examined through a systematic review and meta-analysis. METHODS AND RESULTS: Prospective cohort studies that assessed the independent association of disease-specific health status with mortality in heart failure were selected....... Searching PubMed (until March 2013) resulted in 17 articles in the systematic review and 17 studies in the meta-analysis. About half of the studies reported a significant relationship between disease-specific health status and mortality in heart failure, while the remainder found no association. A larger...

  10. Myositis-specific autoantibodies and their association with malignancy in Italian patients with polymyositis and dermatomyositis.

    Science.gov (United States)

    Ceribelli, Angela; Isailovic, Natasa; De Santis, Maria; Generali, Elena; Fredi, Micaela; Cavazzana, Ilaria; Franceschini, Franco; Cantarini, Luca; Satoh, Minoru; Selmi, Carlo

    2017-02-01

    This study aims to characterize myositis-specific antibodies in a well-defined cohort of patients with idiopathic inflammatory myopathy and to determine their association with cancer. Sera from 40 patients with polymyositis, dermatomyositis, and controls were tested by protein and RNA immunoprecipitation to detect autoantibodies, and immunoprecipitation-Western blot was used for anti-MJ/NXP-2, anti-MDA5, and anti-TIF1γ/α identification. Medical records were re-evaluated with specific focus on cancer. Anti-MJ/NXP-2 and anti-TIF1γ/α were the most common antibodies in dermatomyositis. In six dermatomyositis cases, we found five solid forms of cancer and one Hodgkin's lymphoma in long-term remission. Among patients with cancer-associated dermatomyositis, three were positive for anti-TIF1γ/α, two for anti-Mi-2, and one for anti-MJ/NXP-2. The strongest positivity of anti-TIF1γ was seen in two active forms of cancer, and this antibody was either negative or positive at low titers in the absence of cancer or in the 7-year remission Hodgkin's lymphoma. Four out of twenty (20 %) patients with polymyositis had solid cancer, but no specific association with autoantibodies was identified; further, none of the four cases of antisynthetase syndrome had a history of cancer. No serum myositis-associated autoantibody was observed in control sera, resulting in positive predictive value 75 %, negative predictive value 78.5 %, sensitivity 50 %, specificity 92 %, and area under the ROC curve 0.7083 for the risk of paraneoplastic DM in anti-TIF1γ/α (+) patients. Myositis-specific autoantibodies can be identified thanks to the use of immunoprecipitation, and their association with cancer is particularly clear for anti-TIF1γ/α in dermatomyositis. This association should be evaluated in a prospective study by immunoprecipitation in clinical practice.

  11. Systematic Review of Patient-Specific Surgical Simulation: Toward Advancing Medical Education.

    Science.gov (United States)

    Ryu, Won Hyung A; Dharampal, Navjit; Mostafa, Ahmed E; Sharlin, Ehud; Kopp, Gail; Jacobs, William Bradley; Hurlbert, Robin John; Chan, Sonny; Sutherland, Garnette R

    Simulation-based education has been shown to be an effective tool to teach foundational technical skills in various surgical specialties. However, most of the current simulations are limited to generic scenarios and do not allow continuation of the learning curve beyond basic technical skills to prepare for more advanced expertise, such as patient-specific surgical planning. The objective of this study was to evaluate the current medical literature with respect to the utilization and educational value of patient-specific simulations for surgical training. We performed a systematic review of the literature using Pubmed, Embase, and Scopus focusing on themes of simulation, patient-specific, surgical procedure, and education. The study included randomized controlled trials, cohort studies, and case-control studies published between 2005 and 2016. Two independent reviewers (W.H.R. and N.D) conducted the study appraisal, data abstraction, and quality assessment of the studies. The search identified 13 studies that met the inclusion criteria; 7 studies employed computer simulations and 6 studies used 3-dimensional (3D) synthetic models. A number of surgical specialties evaluated patient-specific simulation, including neurosurgery, vascular surgery, orthopedic surgery, and interventional radiology. However, most studies were small in size and primarily aimed at feasibility assessments and early validation. Early evidence has shown feasibility and utility of patient-specific simulation for surgical education. With further development of this technology, simulation-based education may be able to support training of higher-level competencies outside the clinical settingto aid learners in their development of surgical skills. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  12. Reduced autobiographical memory specificity is associated with impaired discrimination learning in anxiety disorder patients

    Science.gov (United States)

    Lenaert, Bert; Boddez, Yannick; Vervliet, Bram; Schruers, Koen; Hermans, Dirk

    2015-01-01

    Associative learning plays an important role in the development of anxiety disorders, but a thorough understanding of the variables that impact such learning is still lacking. We investigated whether individual differences in autobiographical memory specificity are related to discrimination learning and generalization. In an associative learning task, participants learned the association between two pictures of female faces and a non-aversive outcome. Subsequently, six morphed pictures functioning as generalization stimuli (GSs) were introduced. In a sample of healthy participants (Study 1), we did not find evidence for differences in discrimination learning as a function of memory specificity. In a sample of anxiety disorder patients (Study 2), individuals who were characterized by low memory specificity showed deficient discrimination learning relative to high specific individuals. In contrast to previous findings, results revealed no effect of memory specificity on generalization. These results indicate that impaired discrimination learning, previously shown in patients suffering from an anxiety disorder, may be—in part—due to limited memory specificity. Together, these studies emphasize the importance of incorporating cognitive variables in associative learning theories and their implications for the development of anxiety disorders. In addition, re-analyses of the data (Study 3) showed that patients suffering from panic disorder showed higher outcome expectancies in the presence of the stimulus that was never followed by an outcome during discrimination training, relative to patients suffering from other anxiety disorders and healthy participants. Because we used a neutral, non-aversive outcome (i.e., drawing of a lightning bolt), these data suggest that learning abnormalities in panic disorder may not be restricted to fear learning, but rather reflect a more general associative learning deficit that also manifests in fear irrelevant contexts. PMID

  13. SU-F-I-38: Patient Organ Specific Dose Assessment in Coronary CT Angiograph Using Voxellaized Volume Dose Index in Monte Carlo Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Fallal, Mohammadi Gh.; Riyahi, Alam N.; Graily, Gh. [Tehran University of Medical Scienced(TUMS), School of Medicine, Department of Nedical Physics and Biomedical Engineering, Tehran (Iran, Islamic Republic of); Paydar, R. [Iran University of Medical Sciences(IUMS), Allied Medicine Faculty, Department of radiation Sciences, Tehran (Iran, Islamic Republic of)

    2016-06-15

    Purpose: Clinical use of multi detector computed tomography(MDCT) in diagnosis of diseases due to high speed in data acquisition and high spatial resolution is significantly increased. Regarding to the high radiation dose in CT and necessity of patient specific radiation risk assessment, the adoption of new method in the calculation of organ dose is completely required and necessary. In this study by introducing a conversion factor, patient organ dose in thorax region based on CT image data using MC system was calculated. Methods: The geometry of x-ray tube, inherent filter, bow tie filter and collimator were designed using EGSnrc/BEAMnrc MC-system component modules according to GE-Light-speed 64-slices CT-scanner geometry. CT-scan image of patient thorax as a specific phantom was voxellised with 6.25mm3 in voxel and 64×64×20 matrix size. Dose to thorax organ include esophagus, lung, heart, breast, ribs, muscle, spine, spinal cord with imaging technical condition of prospectively-gated-coronary CT-Angiography(PGT) as a step and shoot method, were calculated. Irradiation of patient specific phantom was performed using a dedicated MC-code as DOSXYZnrc with PGT-irradiation model. The ratio of organ dose value calculated in MC-method to the volume CT dose index(CTDIvol) reported by CT-scanner machine according to PGT radiation technique has been introduced as conversion factor. Results: In PGT method, CTDIvol was 10.6mGy and Organ Dose/CTDIvol conversion factor for esophagus, lung, heart, breast, ribs, muscle, spine and spinal cord were obtained as; 0.96, 1.46, 1.2, 3.28. 6.68. 1.35, 3.41 and 0.93 respectively. Conclusion: The results showed while, underestimation of patient dose was found in dose calculation based on CTDIvol, also dose to breast is higher than the other studies. Therefore, the method in this study can be used to provide the actual patient organ dose in CT imaging based on CTDIvol in order to calculation of real effective dose(ED) based on organ dose

  14. Language-specific dysgraphia in Korean patients with right brain stroke: influence of unilateral spatial neglect.

    Science.gov (United States)

    Jang, Dae-Hyun; Kim, Min-Wook; Park, Kyoung Ha; Lee, Jae Woo

    2015-03-01

    The purpose of the present study was to investigate the relationship between Korean language-specific dysgraphia and unilateral spatial neglect in 31 right brain stroke patients. All patients were tested for writing errors in spontaneous writing, dictation, and copying tests. The dysgraphia was classified into visuospatial omission, visuospatial destruction, syllabic tilting, stroke omission, stroke addition, and stroke tilting. Twenty-three (77.4%) of the 31 patients made dysgraphia and 18 (58.1%) demonstrated unilateral spatial neglect. The visuospatial omission was the most common dysgraphia followed by stroke addition and omission errors. The highest number of errors was made in the copying and the least was in the spontaneous writing test. Patients with unilateral spatial neglect made a significantly higher number of dysgraphia in the copying test than those without. We identified specific dysgraphia features such as a right side space omission and a vertical stroke addition in Korean right brain stroke patients. In conclusion, unilateral spatial neglect influences copy writing system of Korean language in patients with right brain stroke.

  15. Maintenance plasma exchange treatment for muscle specific kinase antibody positive myasthenia gravis patients.

    Science.gov (United States)

    Yamada, Chisa; Teener, James W; Davenport, Robertson D; Cooling, Laura

    2015-10-01

    Anti-muscle specific kinase antibody positive myasthenia gravis (MuSK MG) is often characterized by a relatively severe and progressive course, refractoriness to standard myasthenia gravis (MG) medications, and an increased risk of myasthenic crisis. We report here successful management of three MuSK MG patients using maintenance therapeutic plasma exchange (TPE) treatment for up to 4.5 years. The study was a 5-year retrospective review of all MG patients treated with TPE between 2008 and 2013 at University of Michigan. Inclusion criteria of MuSK MG were positive for anti-MuSK antibodies and a diagnosis of MuSK MG by staff neurologists. Patient data included age, gender, diagnostic testing results, medications, and the dates and response to TPE treatments. A total of 153 MG patients underwent at least one course of TPE between 2008 and 2013. A total of 12 patients (7.8%) were positive for anti-MuSK antibodies. Patients were predominantly female (83.3%) and a median age of onset was 46-years old. Three MuSK MG patients were successfully managed with maintenance TPE. Maintenance TPE may be an effective option for MuSK MG patients. The key of successful maintenance treatment at our institution has been to tailor the TPE frequency for each individual, and to modify the treatment interval in conjunction with medical management. © 2014 Wiley Periodicals, Inc.

  16. Spontaneous presence of FOXO3-specific T cells in cancer patients

    DEFF Research Database (Denmark)

    Larsen, Stine Kiaer; Ahmad, Shamaila Munir; Idorn, Manja

    2014-01-01

    In the present study, we describe forkhead box O3 (FOXO3)-specific, cytotoxic CD8(+) T cells existent among peripheral-blood mononuclear cells (PBMCs) of cancer patients. FOXO3 immunogenicity appears specific, as we did not detect reactivity toward FOXO3 among T cells in healthy individuals. FOXO3...... may naturally serve as a target antigen for tumor-reactive T cells as it is frequently over-expressed in cancer cells. In addition, expression of FOXO3 plays a critical role in immunosuppression mediated by tumor-associated dendritic cells (TADCs). Indeed, FOXO3-specific cytotoxic T lymphocytes (CTLs......) were able to specifically recognize and kill both FOXO3-expressing cancer cells as well as dendritic cells. Thus, FOXO3 was processed and presented by HLA-A2 on the cell surface of both immune cells and cancer cells. As FOXO3 programs TADCs to become tolerogenic, FOXO3 signaling thereby comprises...

  17. A fluid-structure interaction study using patient-specific ruptured and unruptured aneurysm: the effect of aneurysm morphology, hypertension and elasticity.

    Science.gov (United States)

    Lee, C J; Zhang, Y; Takao, H; Murayama, Y; Qian, Y

    2013-09-27

    Fluid-structure interaction (FSI) simulations using five patient-specific aneurysm geometries are carried out to investigate the difference between ruptured and unruptured aneurysms. Two different blood pressure conditions (normal and hypertension, for all cases), and two different values of elastic modulus (1 and 2MPa, for two cases) are tested. Ruptured aneurysms (RA) generally displayed larger displacement at the dome, lower area-average WSS and higher von Mises stress than unruptured aneurysms (URA) regardless of elasticity or blood pressure condition. RAs had a longitudinal expansion whereas URAs had a radial expansion, which was the key difference between the two types. The difference in expansion pattern may be one of the keys to explaining aneurysm rupture, and further analysis is required in the future to confirm this theory. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Multivariate calculus and geometry

    CERN Document Server

    Dineen, Seán

    2014-01-01

    Multivariate calculus can be understood best by combining geometric insight, intuitive arguments, detailed explanations and mathematical reasoning. This textbook has successfully followed this programme. It additionally provides a solid description of the basic concepts, via familiar examples, which are then tested in technically demanding situations. In this new edition the introductory chapter and two of the chapters on the geometry of surfaces have been revised. Some exercises have been replaced and others provided with expanded solutions. Familiarity with partial derivatives and a course in linear algebra are essential prerequisites for readers of this book. Multivariate Calculus and Geometry is aimed primarily at higher level undergraduates in the mathematical sciences. The inclusion of many practical examples involving problems of several variables will appeal to mathematics, science and engineering students.

  19. Transformational plane geometry

    CERN Document Server

    Umble, Ronald N

    2014-01-01

    Axioms of Euclidean Plane Geometry The Existence and Incidence Postulates The Distance and Ruler Postulates The Plane Separation Postulate The Protractor Postulate The Side-Angle-Side Postulate and the Euclidean Parallel Postulate Theorems of Euclidean Plane Geometry The Exterior Angle Theorem Triangle Congruence Theorems The Alternate Interior Angles Theorem and the Angle Sum Theorem Similar Triangles Introduction to Transformations, Isometries, and Similarities Transformations Isometries and SimilaritiesAppendix: Proof of Surjectivity Translations, Rotations, and Reflections Translations Rotations Reflections Appendix: Geometer's Sketchpad Commands Required by Exploratory Activities Compositions of Translations, Rotations, and Reflections The Three Points Theorem Rotations as Compositions of Two Reflections Translations as Compositions of Two Halfturns or Two Reflections The Angle Addition Theorem Glide Reflections Classification of Isometries The Fundamental Theorem and Congruence Classification of Isometr...

  20. Multilevel geometry optimization

    Science.gov (United States)

    Rodgers, Jocelyn M.; Fast, Patton L.; Truhlar, Donald G.

    2000-02-01

    Geometry optimization has been carried out for three test molecules using six multilevel electronic structure methods, in particular Gaussian-2, Gaussian-3, multicoefficient G2, multicoefficient G3, and two multicoefficient correlation methods based on correlation-consistent basis sets. In the Gaussian-2 and Gaussian-3 methods, various levels are added and subtracted with unit coefficients, whereas the multicoefficient Gaussian-x methods involve noninteger parameters as coefficients. The multilevel optimizations drop the average error in the geometry (averaged over the 18 cases) by a factor of about two when compared to the single most expensive component of a given multilevel calculation, and in all 18 cases the accuracy of the atomization energy for the three test molecules improves; with an average improvement of 16.7 kcal/mol.

  1. Multilevel geometry optimization

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, Jocelyn M. [Department of Chemistry and Supercomputer Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431 (United States); Fast, Patton L. [Department of Chemistry and Supercomputer Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431 (United States); Truhlar, Donald G. [Department of Chemistry and Supercomputer Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431 (United States)

    2000-02-15

    Geometry optimization has been carried out for three test molecules using six multilevel electronic structure methods, in particular Gaussian-2, Gaussian-3, multicoefficient G2, multicoefficient G3, and two multicoefficient correlation methods based on correlation-consistent basis sets. In the Gaussian-2 and Gaussian-3 methods, various levels are added and subtracted with unit coefficients, whereas the multicoefficient Gaussian-x methods involve noninteger parameters as coefficients. The multilevel optimizations drop the average error in the geometry (averaged over the 18 cases) by a factor of about two when compared to the single most expensive component of a given multilevel calculation, and in all 18 cases the accuracy of the atomization energy for the three test molecules improves; with an average improvement of 16.7 kcal/mol. (c) 2000 American Institute of Physics.

  2. Memory deficit in patients with schizophrenia and posttraumatic stress disorder: relational vs item-specific memory

    Directory of Open Access Journals (Sweden)

    Jung W

    2016-05-01

    Full Text Available Wookyoung Jung,1 Seung-Hwan Lee1,2 1Clinical Emotions and Cognition Research Laboratory, Department of Psychiatry, Inje University, Ilsan-Paik Hospital, 2Department of Psychiatry, Inje University, Ilsan-Paik Hospital, Goyang, Korea Abstract: It has been well established that patients with schizophrenia have impairments in cognitive functioning and also that patients who experienced traumatic events suffer from cognitive deficits. Of the cognitive deficits revealed in schizophrenia or posttraumatic stress disorder (PTSD patients, the current article provides a brief review of deficit in episodic memory, which is highly predictive of patients’ quality of life and global functioning. In particular, we have focused on studies that compared relational and item-specific memory performance in schizophrenia and PTSD, because measures of relational and item-specific memory are considered the most promising constructs for immediate tangible development of clinical trial paradigm. The behavioral findings of schizophrenia are based on the tasks developed by the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS initiative and the Cognitive Neuroscience Test Reliability and Clinical Applications for Schizophrenia (CNTRACS Consortium. The findings we reviewed consistently showed that schizophrenia and PTSD are closely associated with more severe impairments in relational memory compared to item-specific memory. Candidate brain regions involved in relational memory impairment in schizophrenia and PTSD are also discussed. Keywords: schizophrenia, posttraumatic stress disorder, episodic memory deficit, relational memory, item-specific memory, prefrontal cortex, hippocampus

  3. Patient-specific system for prognosis of surgical treatment outcomes of human cardiovascular system

    Science.gov (United States)

    Golyadkina, Anastasiya A.; Kalinin, Aleksey A.; Kirillova, Irina V.; Kossovich, Elena L.; Kossovich, Leonid Y.; Menishova, Liyana R.; Polienko, Asel V.

    2015-03-01

    Object of study: Improvement of life quality of patients with high stroke risk ia the main goal for development of system for patient-specific modeling of cardiovascular system. This work is dedicated at increase of safety outcomes for surgical treatment of brain blood supply alterations. The objects of study are common carotid artery, internal and external carotid arteries and bulb. Methods: We estimated mechanical properties of carotid arteries tissues and patching materials utilized at angioplasty. We studied angioarchitecture features of arteries. We developed and clinically adapted computer biomechanical models, which are characterized by geometrical, physical and mechanical similarity with carotid artery in norm and with pathology (atherosclerosis, pathological tortuosity, and their combination). Results: Collaboration of practicing cardiovascular surgeons and specialists in the area of Mathematics and Mechanics allowed to successfully conduct finite-element modeling of surgical treatment taking into account various features of operation techniques and patching materials for a specific patient. Numerical experiment allowed to reveal factors leading to brain blood supply decrease and atherosclerosis development. Modeling of carotid artery reconstruction surgery for a specific patient on the basis of the constructed biomechanical model demonstrated the possibility of its application in clinical practice at approximation of numerical experiment to the real conditions.

  4. Estimating patient-specific soft-tissue properties in a TKA knee.

    Science.gov (United States)

    Ewing, Joseph A; Kaufman, Michelle K; Hutter, Erin E; Granger, Jeffrey F; Beal, Matthew D; Piazza, Stephen J; Siston, Robert A

    2016-03-01

    Surgical technique is one factor that has been identified as critical to success of total knee arthroplasty. Researchers have shown that computer simulations can aid in determining how decisions in the operating room generally affect post-operative outcomes. However, to use simulations to make clinically relevant predictions about knee forces and motions for a specific total knee patient, patient-specific models are needed. This study introduces a methodology for estimating knee soft-tissue properties of an individual total knee patient. A custom surgical navigation system and stability device were used to measure the force-displacement relationship of the knee. Soft-tissue properties were estimated using a parameter optimization that matched simulated tibiofemoral kinematics with experimental tibiofemoral kinematics. Simulations using optimized ligament properties had an average root mean square error of 3.5° across all tests while simulations using generic ligament properties taken from literature had an average root mean square error of 8.4°. Specimens showed large variability among ligament properties regardless of similarities in prosthetic component alignment and measured knee laxity. These results demonstrate the importance of soft-tissue properties in determining knee stability, and suggest that to make clinically relevant predictions of post-operative knee motions and forces using computer simulations, patient-specific soft-tissue properties are needed. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  5. Pediatric Crohn disease patients exhibit specific ileal transcriptome and microbiome signature.

    Science.gov (United States)

    Haberman, Yael; Tickle, Timothy L; Dexheimer, Phillip J; Kim, Mi-Ok; Tang, Dora; Karns, Rebekah; Baldassano, Robert N; Noe, Joshua D; Rosh, Joel; Markowitz, James; Heyman, Melvin B; Griffiths, Anne M; Crandall, Wallace V; Mack, David R; Baker, Susan S; Huttenhower, Curtis; Keljo, David J; Hyams, Jeffrey S; Kugathasan, Subra; Walters, Thomas D; Aronow, Bruce; Xavier, Ramnik J; Gevers, Dirk; Denson, Lee A

    2014-08-01

    Interactions between the host and gut microbial community likely contribute to Crohn disease (CD) pathogenesis; however, direct evidence for these interactions at the onset of disease is lacking. Here, we characterized the global pattern of ileal gene expression and the ileal microbial community in 359 treatment-naive pediatric patients with CD, patients with ulcerative colitis (UC), and control individuals. We identified core gene expression profiles and microbial communities in the affected CD ilea that are preserved in the unaffected ilea of patients with colon-only CD but not present in those with UC or control individuals; therefore, this signature is specific to CD and independent of clinical inflammation. An abnormal increase of antimicrobial dual oxidase (DUOX2) expression was detected in association with an expansion of Proteobacteria in both UC and CD, while expression of lipoprotein APOA1 gene was downregulated and associated with CD-specific alterations in Firmicutes. The increased DUOX2 and decreased APOA1 gene expression signature favored oxidative stress and Th1 polarization and was maximally altered in patients with more severe mucosal injury. A regression model that included APOA1 gene expression and microbial abundance more accurately predicted month 6 steroid-free remission than a model using clinical factors alone. These CD-specific host and microbe profiles identify the ileum as the primary inductive site for all forms of CD and may direct prognostic and therapeutic approaches.

  6. Tumor-specific binding of radiolabeled G-22 monoclonal antibody in glioma patients

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Jun; Wakabayashi, Toshihiko; Mizuno, Masaaki; Sugita, Kenichiro; Oshima, Motoo; Tadokoro, Masanori; Sakuma, Sadayuki [Nagoya Univ. (Japan). Faculty of Medicine; Seo, Hisao

    1992-03-01

    Iodine-131-labeled G-22 monoclonal antibody F(ab'){sub 2} fragment reacting specifically with a glioma-associated surface glycoprotein was administered to 12 glioma patients to investigate its use in radioimaging of intracranial gliomas. No immediate or delayed side effects were attributable to antibody injection. Nine patients received the radiolabeled complex intravenously. The images of low-grade gliomas were generally poor and disappeared within 4 days. High-contrast images were obtained beyond the 7th day in high-grade gliomas except one case in the pineal region. Three patients received intraventricular or intratumoral administration. Clear images of all tumors were demonstrated from the 2nd until later than the 7th day. One patient with cerebrospinal fluid (CSF) dissemination of brainstem glioma demonstrated negative CSF cytology after intraventricular administration. (author).

  7. Diffusion tensor tract-specific analysis of the uncinate fasciculus in patients with amyotrophic lateral sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Kanako; Masutani, Yoshitaka; Watadani, Takeyuki; Nakata, Yasuhiro; Yoshida, Mariko; Abe, Osamu; Ohtomo, Kuni [University of Tokyo, Department of Radiology, Graduate School of Medicine, Bunkyo, Tokyo (Japan); Aoki, Shigeki [Juntendo University, Department of Radiology, Bunkyo, Tokyo (Japan); Iwata, Nobue K.; Terao, Yasuo; Tsuji, Shoji [University of Tokyo, Department of Neurology, Graduate School of Medicine, Bunkyo, Tokyo (Japan)

    2010-08-15

    The uncinate fasciculus (UF) consists of core fibers connecting the frontal and temporal lobes and is considered to be related to cognitive/behavioral function. Using diffusion tensor tractography, we quantitatively evaluated changes in fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) of the UF by tract-specific analysis to evaluate the damage of the UF in patients with amyotrophic lateral sclerosis (ALS). We obtained diffusion tensor images of 15 patients with ALS and 9 age-matched volunteers. Patients with ALS showed significantly lower mean FA (P = 0.029) compared with controls. No significant difference was seen in mean ADC. The results suggest that damage of the UF in patients with ALS can be quantitatively evaluated with FA. (orig.)

  8. Geometry and Destiny

    OpenAIRE

    Krauss, Lawrence M.; Turner, Michael S.

    1999-01-01

    The recognition that the cosmological constant may be non-zero forces us to re-evaluate standard notions about the connection between geometry and the fate of our Universe. An open Universe can recollapse, and a closed Universe can expand forever. As a corollary, we point out that there is no set of cosmological observations we can perform that will unambiguously allow us to determine what the ultimate destiny of the Universe will be.

  9. Complex geometries in wood

    DEFF Research Database (Denmark)

    Tamke, Martin; Ramsgaard Thomsen, Mette; Riiber Nielsen, Jacob

    2009-01-01

    The versatility of wood constructions and traditional wood joints for the production of non standard elements was in focus of a design based research. Herein we established a seamless process from digital design to fabrication. A first research phase centered on the development of a robust...... parametric model and a generic design language a later explored the possibilities to construct complex shaped geometries with self registering joints on modern wood crafting machines. The research was carried out as collaboration with industrial partners....

  10. Electroweak vacuum geometry

    International Nuclear Information System (INIS)

    Lepora, N.; Kibble, T.

    1999-01-01

    We analyse symmetry breaking in the Weinberg-Salam model paying particular attention to the underlying geometry of the theory. In this context we find two natural metrics upon the vacuum manifold: an isotropic metric associated with the scalar sector, and a squashed metric associated with the gauge sector. Physically, the interplay between these metrics gives rise to many of the non-perturbative features of Weinberg-Salam theory. (author)

  11. W-geometry

    International Nuclear Information System (INIS)

    Hull, C.M.

    1993-01-01

    The geometric structure of theories with gauge fields of spins two and higher should involve a higher spin generalisation of Riemannian geometry. Such geometries are discussed and the case of W ∝ -gravity is analysed in detail. While the gauge group for gravity in d dimensions is the diffeomorphism group of the space-time, the gauge group for a certain W-gravity theory (which is W ∝ -gravity in the case d=2) is the group of symplectic diffeomorphisms of the cotangent bundle of the space-time. Gauge transformations for W-gravity gauge fields are given by requiring the invariance of a generalised line element. Densities exist and can be constructed from the line element (generalising √detg μν ) only if d=1 or d=2, so that only for d=1,2 can actions be constructed. These two cases and the corresponding W-gravity actions are considered in detail. In d=2, the gauge group is effectively only a subgroup of the symplectic diffeomorphisms group. Some of the constraints that arise for d=2 are similar to equations arising in the study of self-dual four-dimensional geometries and can be analysed using twistor methods, allowing contact to be made with other formulations of W-gravity. While the twistor transform for self-dual spaces with one Killing vector reduces to a Legendre transform, that for two Killing vectors gives a generalisation of the Legendre transform. (orig.)

  12. Integral geometry and valuations

    CERN Document Server

    Solanes, Gil

    2014-01-01

    Valuations are finitely additive functionals on the space of convex bodies. Their study has become a central subject in convexity theory, with fundamental applications to integral geometry. In the last years there has been significant progress in the theory of valuations, which in turn has led to important achievements in integral geometry. This book originated from two courses delivered by the authors at the CRM and provides a self-contained introduction to these topics, covering most of the recent advances. The first part, by Semyon Alesker, is devoted to the theory of convex valuations, with emphasis on the latest developments. A special focus is put on the new fundamental structures of the space of valuations discovered after Alesker's irreducibility theorem. Moreover, the author describes the newly developed theory of valuations on manifolds. In the second part, Joseph H. G. Fu gives a modern introduction to integral geometry in the sense of Blaschke and Santaló, based on the notions and tools presented...

  13. CBM RICH geometry optimization

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoud, Tariq; Hoehne, Claudia [II. Physikalisches Institut, Giessen Univ. (Germany); Collaboration: CBM-Collaboration

    2016-07-01

    The Compressed Baryonic Matter (CBM) experiment at the future FAIR complex will investigate the phase diagram of strongly interacting matter at high baryon density and moderate temperatures in A+A collisions from 2-11 AGeV (SIS100) beam energy. The main electron identification detector in the CBM experiment will be a RICH detector with a CO{sub 2} gaseous-radiator, focusing spherical glass mirrors, and MAPMT photo-detectors being placed on a PMT-plane. The RICH detector is located directly behind the CBM dipole magnet. As the final magnet geometry is now available, some changes in the RICH geometry become necessary. In order to guarantee a magnetic field of 1 mT at maximum in the PMT plane for effective operation of the MAPMTs, two measures have to be taken: The PMT plane is moved outwards of the stray field by tilting the mirrors by 10 degrees and shielding boxes have been designed. In this contribution the results of the geometry optimization procedure are presented.

  14. Elevated Cancer-Specific Mortality Among HIV-Infected Patients in the United States.

    Science.gov (United States)

    Coghill, Anna E; Shiels, Meredith S; Suneja, Gita; Engels, Eric A

    2015-07-20

    Despite advances in the treatment of HIV, HIV-infected people remain at increased risk for many cancers, and the number of non-AIDS-defining cancers is increasing with the aging of the HIV-infected population. No prior study has comprehensively evaluated the effect of HIV on cancer-specific mortality. We identified cases of 14 common cancers occurring from 1996 to 2010 in six US states participating in a linkage of cancer and HIV/AIDS registries. We used Cox regression to examine the association between patient HIV status and death resulting from the presenting cancer (ascertained from death certificates), adjusting for age, sex, race/ethnicity, year of cancer diagnosis, and cancer stage. We included 1,816,461 patients with cancer, 6,459 (0.36%) of whom were HIV infected. Cancer-specific mortality was significantly elevated in HIV-infected compared with HIV-uninfected patients for many cancers: colorectum (adjusted hazard ratio [HR], 1.49; 95% CI, 1.21 to 1.84), pancreas (HR, 1.71; 95% CI, 1.35 to 2.18), larynx (HR, 1.62; 95% CI, 1.06 to 2.47), lung (HR, 1.28; 95% CI, 1.17 to 1.39), melanoma (HR, 1.72; 95% CI, 1.09 to 2.70), breast (HR, 2.61; 95% CI, 2.06 to 3.31), and prostate (HR, 1.57; 95% CI, 1.02 to 2.41). HIV was not associated with increased cancer-specific mortality for anal cancer, Hodgkin lymphoma, or diffuse large B-cell lymphoma. After further adjustment for cancer treatment, HIV remained associated with elevated cancer-specific mortality for common non-AIDS-defining cancers: colorectum (HR, 1.40; 95% CI, 1.09 to 1.80), lung (HR, 1.28; 95% CI, 1.14 to 1.44), melanoma (HR, 1.93; 95% CI, 1.14 to 3.27), and breast (HR, 2.64; 95% CI, 1.86 to 3.73). HIV-infected patients with cancer experienced higher cancer-specific mortality than HIV-uninfected patients, independent of cancer stage or receipt of cancer treatment. The elevation in cancer-specific mortality among HIV-infected patients may be attributable to unmeasured stage or treatment differences as well

  15. Advanced 3D Mesh Manipulation in Stereolithographic Files and Post-Print Processing for the Manufacturing of Patient-Specific Vascular Flow Phantoms.

    Science.gov (United States)

    O'Hara, Ryan P; Chand, Arpita; Vidiyala, Sowmya; Arechavala, Stacie M; Mitsouras, Dimitrios; Rudin, Stephen; Ionita, Ciprian N

    2016-02-27

    Complex vascular anatomies can cause the failure of image-guided endovascular procedures. 3D printed patient-specific vascular phantoms provide clinicians and medical device companies the ability to preemptively plan surgical treatments, test the likelihood of device success, and determine potential operative setbacks. This research aims to present advanced mesh manipulation techniques of stereolithographic (STL) files segmented from medical imaging and post-print surface optimization to match physiological vascular flow resistance. For phantom design, we developed three mesh manipulation techniques. The first method allows outlet 3D mesh manipulations to merge superfluous vessels into a single junction, decreasing the number of flow outlets and making it feasible to include smaller vessels. Next we introduced Boolean operations to eliminate the need to manually merge mesh layers and eliminate errors of mesh self-intersections that previously occurred. Finally we optimize support addition to preserve the patient anatomical geometry. For post-print surface optimization, we investigated various solutions and methods to remove support material and smooth the inner vessel surface. Solutions of chloroform, alcohol and sodium hydroxide were used to process various phantoms and hydraulic resistance was measured and compared with values reported in literature. The newly mesh manipulation methods decrease the phantom design time by 30 - 80% and allow for rapid development of accurate vascular models. We have created 3D printed vascular models with vessel diameters less than 0.5 mm. The methods presented in this work could lead to shorter design time for patient specific phantoms and better physiological simulations.

  16. Introducing geometry concept based on history of Islamic geometry

    Science.gov (United States)

    Maarif, S.; Wahyudin; Raditya, A.; Perbowo, K. S.

    2018-01-01

    Geometry is one of the areas of mathematics interesting to discuss. Geometry also has a long history in mathematical developments. Therefore, it is important integrated historical development of geometry in the classroom to increase’ knowledge of how mathematicians earlier finding and constructing a geometric concept. Introduction geometrical concept can be started by introducing the Muslim mathematician who invented these concepts so that students can understand in detail how a concept of geometry can be found. However, the history of mathematics development, especially history of Islamic geometry today is less popular in the world of education in Indonesia. There are several concepts discovered by Muslim mathematicians that should be appreciated by the students in learning geometry. Great ideas of mathematicians Muslim can be used as study materials to supplement religious character values taught by Muslim mathematicians. Additionally, by integrating the history of geometry in teaching geometry are expected to improve motivation and geometrical understanding concept.

  17. Patient-Specific Dosimetry of Pretargeted Radioimmunotherapy Using CC49 Fusion Protein in Patients with Gastrointestinal Malignancies

    International Nuclear Information System (INIS)

    Shen, Shang; Forero, Andres; LoBuglio, Albert F.; Breitz, H.; Khazaeli, M. B.; Fisher, Darrell R.; Wang, W. Q.; Meredith, Ruby F.

    2005-01-01

    Patient-Specific Dosimetry of Pretargeted Radioimmunotherapy Using CC49 Fusion Protein in Patients with Gastrointestinal Malignancies. Shen S, Forero A, Lobuglio AF, Breitz H, Khazaeli MB, Fisher DR, Wang W, Meredith RF. Department of Radiation Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, and Radioisotopes Program at Pacific Northwest National Laboratory, Richland, Washington. Pretargeted radioimmunotherapy (RIT) using CC49 fusion protein, comprised of CC49-(scFv)(4) and streptavidin, in conjunction with (90)Y/(111)In-DOTA-biotin (DOTA = dodecanetetraacetic acid) provides a new opportunity to improve efficacy by increasing the tumor-to-normal tissue dose ratio. To our knowledge, the patient-specific dosimetry of pretargeted (90)Y/(111)In-DOTA-biotin after CC49 fusion protein in patients has not been reported previously. METHODS: Nine patients received 3-step pretargeted RIT: (a) 160 mg/m(2) of CC49 fusion protein, (b) synthetic clearing agent (sCA) at 48 or 72 h later, and (c) (90)Y/(111)In-DOTA-biotin 24 h after the sCA administration. Sequential whole-body (111)In images were acquired immediately and at 2-144 h after injection of (90)Y/(111)In-DOTA-biotin. Geometric-mean quantification with background and attenuation correction was used for liver and lung dosimetry. Effective point source quantification was used for spleen, kidneys, and tumors. Organ and tumor (90)Y doses were calculated based on (111)In imaging data and the MIRD formalism using patient-specific organ masses determined from CT images. Patient-specific marrow doses were determined based on radioactivity concentration in the blood. RESULTS: The (90)Y/(111)In-DOTA-biotin had a rapid plasma clearance, which was biphasic with <10% residual at 8 h. Organ masses ranged from 1,263 to 3,855 g for liver, 95 to 1,009 g for spleen, and 309 to 578 g for kidneys. The patient-specific mean (90)Y dose (cGy/37 MBq, or rad/mCi) was 0.53 (0.32-0.78) to whole body

  18. Destructive arthritis in a patient with chikungunya virus infection with persistent specific IgM antibodies

    Directory of Open Access Journals (Sweden)

    Receveur Marie-Catherine

    2009-12-01

    Full Text Available Abstract Background Chikungunya fever is an emerging arboviral disease characterized by an algo-eruptive syndrome, inflammatory polyarthralgias, or tenosynovitis that can last for months to years. Up to now, the pathophysiology of the chronic stage is poorly understood. Case presentation We report the first case of CHIKV infection with chronic associated rheumatism in a patient who developed progressive erosive arthritis with expression of inflammatory mediators and persistence of specific IgM antibodies over 24 months following infection. Conclusions Understanding the specific features of chikungunya virus as well as how the virus interacts with its host are essential for the prevention, treatment or cure of chikungunya disease.

  19. Guidelines for patient-specific jawline definition with titanium implants in esthetic, deformity, and malformation surgery.

    Science.gov (United States)

    Mommaerts, Maurice Yves

    2016-01-01

    Asymmetry and unfavorable esthetics of the jawline have become possible to correct in three dimensions using computer aided design and computer aided manufacturing. The aim of this study was to provide esthetic, technical, and operative guidelines for mandibular angle and border augmentation using patient-specific titanium implants made by selective laser melting. University hospital - prospective registry. Twelve patients and 17 implantation sites were documented and prospectively registered. Malformational, deformational, and purely esthetic indications were encountered. Descriptive. Patient satisfaction was high, probably because the patients had input into the planned dimensions and shape. A serious infection with implant removal occurred in one patient who had six previous surgeries at the same sites. Technical and surgical guidelines were developed including splitting implants into two segments when the mental nerve was at risk, using a three-dimensional (3D) puzzle connection, providing at least two screw holes per segment, using scaffolds at the bony contact side, using a "satin" finish at the periosteal side, referring to anatomical structures where possible, making provisions for transbuccal and transoral fixation, using a high vestibular incision, and using a double-layer closure. Esthetic guidelines are discussed but could not be upgraded. Mirroring techniques and 3D print accuracy up to 0.1 mm allow precise planning of jaw angle implants. Patients are pleased when given preoperative renderings for their consideration. Infections can be managed using technical and operative recommendations and careful patient selection.

  20. Distinct trajectories of disease-specific health status in heart failure patients undergoing cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Mastenbroek, Mirjam H.; Pedersen, Susanne S.; Meine, Mathias

    2016-01-01

    of beta-blockers, use of psychotropic medication, anxiety, depression, and type D personality were found to be associated with poorer health status in unadjusted analyses. Interestingly, subgroups of patients (12-20 %) who experienced poor health status at baseline improved to stable good health status....... The timely identification of CRT-D patients who present with poor disease-specific health status (i.e., KCCQ score anxiety, depression, and/or type D personality) is paramount, as they may benefit from cardiac rehabilitation in combination...

  1. Creating Patient-Specific Neural Cells for the In Vitro Study of Brain Disorders

    Directory of Open Access Journals (Sweden)

    Kristen J. Brennand

    2015-12-01

    Full Text Available As a group, we met to discuss the current challenges for creating meaningful patient-specific in vitro models to study brain disorders. Although the convergence of findings between laboratories and patient cohorts provided us confidence and optimism that hiPSC-based platforms will inform future drug discovery efforts, a number of critical technical challenges remain. This opinion piece outlines our collective views on the current state of hiPSC-based disease modeling and discusses what we see to be the critical objectives that must be addressed collectively as a field.

  2. Generation of Transplantable Beta Cells for Patient-Specific Cell Therapy

    Directory of Open Access Journals (Sweden)

    Xiaojie Wang

    2012-01-01

    Full Text Available Islet cell transplantation offers a potential cure for type 1 diabetes, but it is challenged by insufficient donor tissue and side effects of current immunosuppressive drugs. Therefore, alternative sources of insulin-producing cells and isletfriendly immunosuppression are required to increase the efficiency and safety of this procedure. Beta cells can be transdifferentiated from precursors or another heterologous (non-beta-cell source. Recent advances in beta cell regeneration from somatic cells such as fibroblasts could circumvent the usage of immunosuppressive drugs. Therefore, generation of patient-specific beta cells provides the potential of an evolutionary treatment for patients with diabetes.

  3. Automated classification of eligibility criteria in clinical trials to facilitate patient-trial matching for specific patient populations.

    Science.gov (United States)

    Zhang, Kevin; Demner-Fushman, Dina

    2017-07-01

    To develop automated classification methods for eligibility criteria in ClinicalTrials.gov to facilitate patient-trial matching for specific populations such as persons living with HIV or pregnant women. We annotated 891 interventional cancer trials from ClinicalTrials.gov based on their eligibility for human immunodeficiency virus (HIV)-positive patients using their eligibility criteria. These annotations were used to develop classifiers based on regular expressions and machine learning (ML). After evaluating classification of cancer trials for eligibility of HIV-positive patients, we sought to evaluate the generalizability of our approach to more general diseases and conditions. We annotated the eligibility criteria for 1570 of the most recent interventional trials from ClinicalTrials.gov for HIV-positive and pregnancy eligibility, and the classifiers were retrained and reevaluated using these data. On the cancer-HIV dataset, the baseline regex model, the bag-of-words ML classifier, and the ML classifier with named entity recognition (NER) achieved macro-averaged F2 scores of 0.77, 0.87, and 0.87, respectively; the addition of NER did not result in a significant performance improvement. On the general dataset, ML + NER achieved macro-averaged F2 scores of 0.91 and 0.85 for HIV and pregnancy, respectively. The eligibility status of specific patient populations, such as persons living with HIV and pregnant women, for clinical trials is of interest to both patients and clinicians. We show that it is feasible to develop a high-performing, automated trial classification system for eligibility status that can be integrated into consumer-facing search engines as well as patient-trial matching systems. Published by Oxford University Press on behalf of the American Medical Informatics Association 2017. This work is written by US Government employees and is in the public domain in the US.

  4. Are Hip-Specific Items Useful in a Quality of Life Questionnaire for Patients with Hip Fractures?

    Science.gov (United States)

    Yao, Kai-Ping Grace; Lee, Hsin-Yi; Tsauo, Jau-Yih

    2009-01-01

    Researchers measure the significance of hip fracture by the patient's impairment. The patient's quality of life (QOL) is usually also substantially affected. However, there is no specific quality of life (QOL) questionnaire for patients with hip fractures. This study was designed to determine whether adding a new set of specific questions about…

  5. THE COMMON EVOLUTION OF GEOMETRY AND ARCHITECTURE FROM A GEODETIC POINT OF VIEW

    Directory of Open Access Journals (Sweden)

    T. Bellone

    2017-05-01

    Full Text Available Throughout history the link between geometry and architecture has been strong and while architects have used mathematics to construct their buildings, geometry has always been the essential tool allowing them to choose spatial shapes which are aesthetically appropriate. Sometimes it is geometry which drives architectural choices, but at other times it is architectural innovation which facilitates the emergence of new ideas in geometry. Among the best known types of geometry (Euclidean, projective, analytical, Topology, descriptive, fractal,… those most frequently employed in architectural design are: – Euclidean Geometry – Projective Geometry – The non-Euclidean geometries. Entire architectural periods are linked to specific types of geometry. Euclidean geometry, for example, was the basis for architectural styles from Antiquity through to the Romanesque period. Perspective and Projective geometry, for their part, were important from the Gothic period through the Renaissance and into the Baroque and Neo-classical eras, while non-Euclidean geometries characterize modern architecture.

  6. The Common Evolution of Geometry and Architecture from a Geodetic Point of View

    Science.gov (United States)

    Bellone, T.; Fiermonte, F.; Mussio, L.

    2017-05-01

    Throughout history the link between geometry and architecture has been strong and while architects have used mathematics to construct their buildings, geometry has always been the essential tool allowing them to choose spatial shapes which are aesthetically appropriate. Sometimes it is geometry which drives architectural choices, but at other times it is architectural innovation which facilitates the emergence of new ideas in geometry. Among the best known types of geometry (Euclidean, projective, analytical, Topology, descriptive, fractal,…) those most frequently employed in architectural design are: - Euclidean Geometry - Projective Geometry - The non-Euclidean geometries. Entire architectural periods are linked to specific types of geometry. Euclidean geometry, for example, was the basis for architectural styles from Antiquity through to the Romanesque period. Perspective and Projective geometry, for their part, were important from the Gothic period through the Renaissance and into the Baroque and Neo-classical eras, while non-Euclidean geometries characterize modern architecture.

  7. Two lectures on D-geometry and noncommutative geometry

    International Nuclear Information System (INIS)

    Douglas, M.R.

    1999-01-01

    This is a write-up of lectures given at the 1998 Spring School at the Abdus Salam ICTP. We give a conceptual introduction to D-geometry, the study of geometry as seen by D-branes in string theory, and to noncommutative geometry as it has appeared in D-brane and Matrix theory physics. (author)

  8. Evaluation of a patient specific femoral alignment guide for hip resurfacing.

    Science.gov (United States)

    Olsen, Michael; Naudie, Douglas D; Edwards, Max R; Sellan, Michael E; McCalden, Richard W; Schemitsch, Emil H

    2014-03-01

    A novel alternative to conventional instrumentation for femoral component insertion in hip resurfacing is a patient specific, computed tomography based femoral alignment guide. A benchside study using cadaveric femora was performed comparing a custom alignment guide to conventional instrumentation and computer navigation. A clinical series of twenty-five hip resurfacings utilizing a custom alignment guide was conducted by three surgeons experienced in hip resurfacing. Using cadaveric femora, the custom guide was comparable to conventional instrumentation with computer navigation proving superior to both. Clinical femoral component alignment accuracy was 3.7° and measured within ± 5° of plan in 20 of 24 cases. Patient specific femoral alignment guides provide a satisfactory level of accuracy and may be a better alternative to conventional instrumentation for initial femoral guidewire placement in hip resurfacing. Crown Copyright © 2014. All rights reserved.

  9. Direct Lineage Reprogramming Reveals Disease-Specific Phenotypes of Motor Neurons from Human ALS Patients

    Directory of Open Access Journals (Sweden)

    Meng-Lu Liu

    2016-01-01

    Full Text Available Subtype-specific neurons obtained from adult humans will be critical to modeling neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS. Here, we show that adult human skin fibroblasts can be directly and efficiently converted into highly pure motor neurons without passing through an induced pluripotent stem cell stage. These adult human induced motor neurons (hiMNs exhibit the cytological and electrophysiological features of spinal motor neurons and form functional neuromuscular junctions (NMJs with skeletal muscles. Importantly, hiMNs converted from ALS patient fibroblasts show disease-specific degeneration manifested through poor survival, soma shrinkage, hypoactivity, and an inability to form NMJs. A chemical screen revealed that the degenerative features of ALS hiMNs can be remarkably rescued by the small molecule kenpaullone. Taken together, our results define a direct and efficient strategy to obtain disease-relevant neuronal subtypes from adult human patients and reveal their promising value in disease modeling and drug identification.

  10. miR-30c is specifically repressed in patients with active pulmonary tuberculosis.

    Science.gov (United States)

    Spinelli, Silvana V; Fernández, Rocío Del V; Zoff, Luciana; Bongiovanni, Bettina; Díaz, Ariana; D'Attilio, Luciano; Santucci, Natalia; Alvarez, Tomás; Marchesini, Marcela M; Bogue, Cristina; Bay, Maria L; Bottasso, Oscar A

    2017-07-01

    Tuberculous pleurisy (PLTB) is a common form of extrapulmonary tuberculosis. It often resolves without chemotherapy being hence considered a rather benign manifestation of the disease. Patients with PLTB mount an effective anti-mycobacterial response, unlike those with active pulmonary TB (pTB) that were shown to present an imbalance in plasma immune and endocrine mediators. In this work, we explored whether expression of the active isoform of the glucocorticoid receptor (hGRα) in the context of the inflammatory-anti-inflammatory responses of TB patients may be associated to microRNA levels. As expected, the inflammatory response triggered in patients coexists with increased circulating cortisol and altered hGRα levels in the peripheral blood mononuclear cells. However, while hGRα expression is significantly downregulated in PLTB, its levels in pTB patients are higher within the control values. These results point out to the existence of an additional mechanism tending to preserve hGRα levels probably to deal with the chronic inflammation observed in pTB. In this regard, we found that miR-30c is strongly downregulated in mononuclear cells of pTB patients compared to PLTB cases, showing an expression profile opposite to that seen with hGRα. Interestingly, low levels of miR-30c are specific for this active form of TB, as its expression is not altered in mononuclear cells from either healthy controls or patients with tuberculous or non-tuberculous pleurisy. Moreover, miR-30c and hGRα also showed an inverse expression pattern in M. tuberculosis-stimulated THP-1 macrophage cultures. In sum, our studies identify miR-30c as a specific correlate of pulmonary manifestations of TB, potentially involved in the altered glucocorticoid sensitivity observed in these patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. SPECIFICITIES OF THE SUBSET PROFILE OF PERIPHERAL BLOOD IN PATIENTS WITH GLIOBLASTOMA: PATHOGENETIC AND CLINICAL ASSESSMENTS

    Directory of Open Access Journals (Sweden)

    V. A. Chumakov

    2006-01-01

    Full Text Available Abstract. In glioblastoma (GB, it is necessary to take into consideration GB-associated secondary immunodeficiency (SID, so-called syndrome of tumor-associated SID (STASID. Cell subsets having effector and regulatory functions, play an important role in developing STASID, and their proportions in patients with different forms of GB can be of pathogenetic importance and have clinical value for treatment and rehabilitation scheduling as well. The most pathogenically and clinically important features of cell subsets profile of peripheral blood were analyzed in patients with different clinical and morphological types of GB. The patients were divided into three groups, i.e., groups I and II were formed by patients with STASID (marked and slightly marked SID, accordingly; group III – patients with SIDTAS (tumor-associated autoimmune syndrome, associated with SID. Marked suppression of cell immunity is typical of group I - imbalance in T-lymphocytes, in a number of specific subsets, and in subsets clusters, as well as disproportions in the immunoregulatory indexes. In group II, the subset profiles of blood were slightly different from the norm. In patients with SIDTAS, activation of cell immunity was evident, forming SID with signs of autoimmune syndrome, affecting effector and regulatory chains of immunity, and influencing the severity and forecast of the disease. Specific features of the immune status in patients with GB identified can be resulted from different clinicalmorphological types of the tumor; the latter are to be considered in differential diagnostics of clinical course of GB and in scheduling of clinical-immunological efficient anti-tumor pharmacotherapy in pre- and postoperative periods.

  12. Specificity of antibodies directed against the cytolethal distending toxin of Haemophilus ducreyi in patients with chancroid.

    Science.gov (United States)

    Mbwana, Judica; Ahmed, Hinda J; Ahlman, Karin; Sundaeus, Vivian; Dahlén, Gunnar; Lyamuya, Eligius; Lagergård, Teresa

    2003-09-01

    Antibodies specific for the cytolethal-distending toxin of Haemophilus ducreyi (HdCDT) complex and for the CdtA, CdtB, and CdtC components were measured by ELISA in the sera of 50 patients with culture and/or PCR proven chancroid, 42 patients with periodontitis, 50 blood donors from Tanzania, 50 blood donors from Sweden. In addition, the biological activity e.g. neutralization capacity of the sera were tested. Our results demonstrate that majority of chancroid patients and healthy individuals had detectable levels of serum antibodies to HdCDT complex and to separate toxin components. However, high levels (> or =100 units) of antibodies to HdCDT complex were significantly more prevalent in the sera of patients with both chancroid and periodontitis than in the sera of the corresponding controls (P=0.001 and P=0.04, respectively). In the sera of the 50 patients with chancroid, antibodies to CdtA, CdtB, and CdtC were detected in 50, 35, and 34 individuals, respectively. Antibodies to CdtC, being less frequently detected than the antibodies to other components, show a good correlation with the neutralizing capacity of sera. High levels of neutralizing antibodies (> or =160) were detected in only 22 and 2% of the patients with chancroid and periodontitis, respectively. The data suggest that the low levels of anti-HdCDT antibodies, which include neutralizing antibodies, may contribute to limited protection in chancroid and since anti-HdCDT antibodies, may be detected in healthy individuals and in patients with certain disease conditions (e.g. periodontitis), they may not be specific markers for chancroid infection.

  13. Age-Specific Patient Navigation Preferences Among Adolescents and Young Adults with Cancer.

    Science.gov (United States)

    Pannier, Samantha T; Warner, Echo L; Fowler, Brynn; Fair, Douglas; Salmon, Sara K; Kirchhoff, Anne C

    2017-11-23

    Patient navigation is increasingly being directed at adolescent and young adult (AYA) patients. This study provides a novel description of differences in AYA cancer patients' preferences for navigation services by developmental age at diagnosis. Eligible patients were diagnosed with cancer between ages 15 and 39 and had completed at least 1 month of treatment. Between October 2015 and January 2016, patients completed semi-structured interviews about navigation preferences. Summary statistics of demographic and cancer characteristics were generated. Differences in patient navigation preferences were examined through qualitative analyses by developmental age at diagnosis. AYAs were interviewed (adolescents 15-18 years N = 8; emerging adults 19-25 years N = 8; young adults 26-39 years N = 23). On average, participants were 4.5 years from diagnosis. All age groups were interested in face-to-face connection with a navigator and using multiple communication platforms (phone, text, email) to follow-up. Three of the most frequently cited needs were insurance, finances, and information. AYAs differed in support, healthcare, and resource preferences by developmental age; only adolescents preferred educational support. While all groups preferred financial and family support, the specific type of assistance (medical versus living expenses, partner/spouse, child, or parental assistance) varied by age group. AYAs with cancer have different preferences for patient navigation by developmental age at diagnosis. AYAs are not a one-size-fits-all population, and navigation programs can better assist AYAs when services are targeted to appropriate developmental ages. Future research should examine fertility and navigation preferences by time since diagnosis. While some navigation needs to span the AYA age range, other needs are specific to developmental age.

  14. [Comparative study of immunoglobulins and specific antibodies in the sera of chronic brucellosis patients].

    Science.gov (United States)

    Kichieva, B N; Chernysheva, M I; Zheludkov, M M; Musaeva, N B

    1982-04-01

    The data on the IgA, IgM and IgG levels in the sera of 89 patients with chronic brucellosis lasting for 1-10 years and longer are presented. The chronic form of brucellosis is characterized by the normal or low level of immunoglobulins. No correlation between the levels of IgG, IgM and the titer of specific antibodies has been established.

  15. Comparative study of specific IgE for cockroach between asthma and allergic rhinitis patients

    International Nuclear Information System (INIS)

    Guo Yinshi; Xu Yiping; Zhu Lijun; Wang Limin; Cao Lingxian; Yao Suhang

    2005-01-01

    To compare the degrees of allergic reaction and the cross-reactive allergens for three strains of cockroach (Periplanceta fuliginosa , Periplaneta americana and Blattella germanica) between patients with asthma and allergic rhinitis, the specific IgE(sIgE) in asthma and allergic rhinitis for these three strains of cockroach were determined with ELISA. The results showed that the sIgE positive rates for Periplaneta americana, Periplaneta fuliginosa and Blattella germanica in patients with asthma were 23.5%, 16.0% and 14.8%, respectively. The reactive coincidence rate between Periplaneta americana and Periplaneta fuliginoas was 74.0%, between Periplaneta americana and Blattella germanica was 73.5%, and between Periplaneta fuliginosa and Blattella germanica was 85.0% in asthma patients. The IgE positive rates for Periplaneta americana, Periplaneta fuliginosa and Blattella gerraanica in allergic rhinitis patients were 24.8%, 17.6% and 15.8%, respectively. The reactive coincidence rate between Periplaneta americana and Periplaneta fuliginosa was 73.9%, between Periplaneta americana and Blattella germanica was 75.2%, and between Periplaneta fuliginosa and Blattella germanica was 86.1% in allergic rhinitis patients. There was no significant difference between asthma and allergic rhinitis patients although the sIgE positive rates of allergic rhinitis patients were higher than those of asthma patients for these three strains of cock- roach. All these results indicated that the degrees of allergic reaction are similar between asthma and allergic rhinitis patients and there are some cross-reactive allergic components among these three strains of cockroach. (authors)

  16. [Obstetrical prognosis improvement in patients exposed in utero to diethylstilbestrol with specific care management].

    Science.gov (United States)

    Amour, M-C; Mokdad, A; Mayenga, J-M; Belaisch-Allart, J

    2004-11-01

    To define the interest of a specific care management of pregnancies in patients exposed in utero to diethylstilbestrol, with the intention of reducing the number of spontaneous miscarriage and prematurity. One hundred and three pregnancies in 49 patients exposed in utero to diethylstilbestrol were followed during a 4-year study, while establishing a specific care management of pregnancies in those women. Spontaneous miscarriage rate was 18.5%, among which 16.5% before 15 weeks of pregnancy and 2% after 15 weeks of pregnancy. Premature birth rate was 41.9%, among which 10.8% of great premature birth (before 32 weeks of pregnancy), 13.5% of moderate premature birth (between 32 and 36 weeks of pregnancy), and 17.6% of minor prematurity (after 36 weeks of pregnancy). The patients' average delivery term was 36 +/-3.6 weeks. As compared with the literature data, our miscarriage and prematurity rates are found to be lower. Our specific care management seems thus to be effective.

  17. Lung fibrosis quantified by HRCT in scleroderma patients with different disease forms and ANA specificities

    Directory of Open Access Journals (Sweden)

    S. Mancin

    2011-09-01

    Full Text Available Objective: to define the prevalence of interstitial lung fibrosis in systemic sclerosis (SSc and its relationship with the different clinical forms of disease and ANA specificities. Methods: fifty patients with SSc were submitted to pulmonary high resolution computed tomography (HRCT. Lung abnormalities were evaluated according to Warrick’s score that considers both the severity and the extent of fibrotic lesions. Results: pulmonary HRCT abnormalities were observed in 84% of SSc patients. Ground glass aspects (60%, irregular pleural margins (56% and septal/subpleural lines (68% were the most common lesions. The distribution of these abnormalities favoured the posterior basilar segments of both lungs. HRCT findings were significantly more frequent in males and in patients with the cutaneous diffuse form of SSc and with the specific antibody anti-Scl70. Conclusions: HRCT is a very useful method for the diagnosis of interstitial lung fibrosis in SSc. Warrick’s score permits to quantify the HRCT findings and to evaluate their relationship with the disease clinical forms and ANA specificities.

  18. Residual symptoms and specific functional impairments in euthymic patients with bipolar disorder.

    Science.gov (United States)

    Samalin, Ludovic; de Chazeron, Ingrid; Vieta, Eduard; Bellivier, Frank; Llorca, Pierre-Michel

    2016-03-01

    The aims of the present study were to confirm the impact of residual symptoms on overall functioning in a large sample of euthymic patients with bipolar disorder in real-life conditions and to explore the relationship between residual symptoms and specific areas of functional impairment. This was a multicenter, cross-sectional, non-interventional study of euthymic outpatients with bipolar disorder. The Functioning Assessment Short Test was used to assess overall and specific domains of functioning (autonomy, occupational functioning, cognitive functioning, financial issues, interpersonal relationships, and leisure time). Various residual symptoms were assessed (residual mood symptoms, emotional dysregulation, sleep and sexual disorders, stigma, and perceived cognitive impairment). Logistic regression was used to determine the best model of association between functional domains and residual symptoms. Almost half of the 468 patients included (42%) had poor overall functioning. Residual depressive symptoms appeared to have an impact on overall functioning and in nearly all areas of functioning. In addition, specific residual symptoms had significantly more negative effects on some domains of functioning in euthymic patients with bipolar disorder (residual manic symptoms and occupational stigma on autonomy, emotional inhibition on occupational functioning, residual manic symptoms on financial issues, family stigma on interpersonal relationships, and sexual function and occupational stigma on leisure time). Our findings highlight the importance of evaluating overall functioning in clinical practice as well as functional domains. They also indicate that some residuals symptoms in patients with bipolar disorder should be targeted in personalized treatment plans, in order to improve functioning in the domains in which the patient is most impaired. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Bilateral Malar Reconstruction Using Patient-Specific Polyether Ether Ketone Implants in Treacher-Collins Syndrome Patients With Absent Zygomas.

    Science.gov (United States)

    Sainsbury, David C G; George, Alan; Forrest, Christopher R; Phillips, John H

    2017-03-01

    The authors performed bilateral malar reconstruction using polyether ether ketone implants in 3 patients with Treacher-Collins syndrome with absent, as opposed to hypoplastic, zygomata. These patient-specific implants were fabricated using computed-aided design software reformatted from three-dimensional bony preoperative computed tomography images. The first time the authors performed this procedure the implant compressed the globe resulting in temporary anisocoria that was quickly recognized intraoperatively. The implant was immediately removed and the patient made a full-recovery with no ocular disturbance. The computer-aided design and manufacturing process was adjusted to include periorbital soft-tissue boundaries to aid in contouring the new implants. The same patient, and 2 further patients, subsequently underwent malar reconstruction using this soft tissue periorbital boundary fabrication process with an additional 2 mm relief removed from the implant's orbital surface. These subsequent procedures were performed without complication and with pleasing aesthetic results. The authors describe their experience and the salutary lessons learnt.

  20. Surface mesh to voxel data registration for patient-specific anatomical modeling

    Science.gov (United States)

    de Oliveira, Júlia E. E.; Giessler, Paul; Keszei, András.; Herrler, Andreas; Deserno, Thomas M.

    2016-03-01

    Virtual Physiological Human (VPH) models are frequently used for training, planning, and performing medical procedures. The Regional Anaesthesia Simulator and Assistant (RASimAs) project has the goal of increasing the application and effectiveness of regional anesthesia (RA) by combining a simulator of ultrasound-guided and electrical nerve-stimulated RA procedures and a subject-specific assistance system through an integration of image processing, physiological models, subject-specific data, and virtual reality. Individualized models enrich the virtual training tools for learning and improving regional anaesthesia (RA) skills. Therefore, we suggest patient-specific VPH models that are composed by registering the general mesh-based models with patient voxel data-based recordings. Specifically, the pelvis region has been focused for the support of the femoral nerve block. The processing pipeline is composed of different freely available toolboxes such as MatLab, the open Simulation framework (SOFA), and MeshLab. The approach of Gilles is applied for mesh-to-voxel registration. Personalized VPH models include anatomical as well as mechanical properties of the tissues. Two commercial VPH models (Zygote and Anatomium) were used together with 34 MRI data sets. Results are presented for the skin surface and pelvic bones. Future work will extend the registration procedure to cope with all model tissue (i.e., skin, muscle, bone, vessel, nerve, fascia) in a one-step procedure and extrapolating the personalized models to body regions actually being out of the captured field of view.

  1. The research of Proactive Coping Behavior of Patients with Chronic Non-Specific Lung Disease

    Directory of Open Access Journals (Sweden)

    Marija A. Yaroslavskaya

    2011-01-01

    Full Text Available The purpose of the research was to study the patterns of using proactive coping and adherences to it's different types in patients with chronic non-specifi c lung diseases. Participants of the study (N=180 were 30 to 60 years old. The Proactive Coping Inventory was used to assess the patients' psychological status. According to the results of the study patients with chronic non-specifi c lung diseases use dif-ferent types of proactive coping behavior while solving problematic and stressful situations. The research revealed that patients with bronchial asthma don't have the skills of independent decision making, definition of objectives, considering of options in solving conflicts or other inconvenient situations sufficiently developed. Patients with chronic obstructive pulmonary disease are less satisfied with the emotional support that they receive from their relatives and closest people, it's harder for them to reveal their feelings and emotions than for those who suffer from bronchial asthma and healthy ones. The results of the study may be useful in developing educational systems of proactive coping behavior skills for patients with chronic non-specific lung diseases for their health and well-being support.

  2. Nutrition impact symptoms in advanced cancer patients: frequency and specific interventions, a case-control study.

    Science.gov (United States)

    Omlin, Aurelius; Blum, David; Wierecky, Jan; Haile, Sarah R; Ottery, Faith D; Strasser, Florian

    2013-03-01

    Involuntary weight loss (IWL) is frequent in advanced cancer patients causing compromised anticancer treatment outcomes and function. Cancer cachexia is influenced by nutrition impact symptoms (NIS). The aim of this study was to explore the frequency of NIS in advanced patients and to assess specific interventions guided by a 12-item NIS checklist. Consecutive patients from an outpatient nutrition-fatigue clinic completed the NIS checklist. The NIS checklist was developed based on literature review and multiprofessional clinical expert consensus. Chart review was performed to detect defined NIS typical interventions. Oncology outpatients not seen in the nutrition-fatigue clinic were matched for age, sex, and tumor to serve as controls. In 52 nutrition-fatigue clinic patients, a mixed cancer population [IWL in 2 months 5.96 % (mean)], the five most frequent NIS were taste and smell alterations 27 %, constipation 19 %, abdominal pain 14 %, dysphagia 12 %, and epigastric pain 10 %. A statistically significant difference for NIS typical interventions in patients with taste and smell alterations (p = 0.04), constipation (p = 0.01), pain (p = 0.0001), and fatigue (p = 0.0004) were found compared to the control population [mixed cancer, 3.53 % IWL in 2 months (mean)]. NIS are common in advanced cancer patients. The NIS checklist can guide therapeutic nutrition-targeted interventions. The awareness for NIS will likely evoke more research in assessment, impact, and treatment.

  3. Neuron- specific enolase level in patients with metabolic syndrome and its value forecasting acute stroke

    Directory of Open Access Journals (Sweden)

    Oral Ospanov

    2018-03-01

    Full Text Available Background Patients with metabolic syndrome are at a greater risk of experiencing a cerebrovascular event. Several studies show that patients with metabolic syndrome have asymptomatic ischemic brain injury. In this case, there is a need for rapid determination of asymptomatic brain lesions and prediction of acute stroke. Aims The aim of the study was to determine the neuron-specific enolase (NSE serum level in patients with metabolic syndrome and the value of this level for forecasting acute stroke. Methods The study used the following information to determine metabolic syndrome: waist circumference, total cholesterol, triglycerides, high-density lipoprotein cholesterol, blood pressure, and blood glucose. Doppler sonography mapping of the brachiocephalic trunk was held to determine the percentage of the carotid artery stenosis. To determine asymptomatic ischemic brain injury, the NSE serum marker was measured. Statistical processing of the measurements was performed using the H test and the Mann–Whitney test. The possible link between MS and NSE were determined by logistic regression analysis. Mathematical modeling was performed using logistic regression. Results There are statistically significant differences in NSE concentrations in groups with metabolic syndrome and ischemic stroke patients. This assertion is confirmed by logistic regression analysis, which revealed the existence of a relationship between metabolic syndrome and increased concentration of NSE. Conclusion Patients with metabolic syndrome have an increased concentration of NSE. This indicates the presence of asymptomatic ischemic neuronal damage. A prognostic model for determining the probability that patients with metabolic syndrome will have an acute stroke was developed.

  4. Pathway index models for construction of patient-specific risk profiles.

    Science.gov (United States)

    Eng, Kevin H; Wang, Sijian; Bradley, William H; Rader, Janet S; Kendziorski, Christina

    2013-04-30

    Statistical methods for variable selection, prediction, and classification have proven extremely useful in moving personalized genomics medicine forward, in particular, leading to a number of genomic-based assays now in clinical use for predicting cancer recurrence. Although invaluable in individual cases, the information provided by these assays is limited. Most often, a patient is classified into one of very few groups (e.g., recur or not), limiting the potential for truly personalized treatment. Furthermore, although these assays provide information on which individuals are at most risk (e.g., those for which recurrence is predicted), they provide no information on the aberrant biological pathways that give rise to the increased risk. We have developed an approach to address these limitations. The approach models a time-to-event outcome as a function of known biological pathways, identifies important genomic aberrations, and provides pathway-based patient-specific assessments of risk. As we demonstrate in a study of ovarian cancer from The Cancer Genome Atlas project, the patient-specific risk profiles are powerful and efficient characterizations useful in addressing a number of questions related to identifying informative patient subtypes and predicting survival. Copyright © 2012 John Wiley & Sons, Ltd.

  5. Sensitivity and Specificity of a Five-Minute Cognitive Screening Test in Patients With Heart Failure.

    Science.gov (United States)

    Cameron, Janette D; Gallagher, Robyn; Pressler, Susan J; McLennan, Skye N; Ski, Chantal F; Tofler, Geoffrey; Thompson, David R

    2016-02-01

    Cognitive impairment occurs in up to 80% of patients with heart failure (HF). The National Institute for Neurological Disorders and Stroke (NINDS) and the Canadian Stroke Network (CSN) recommend a 5-minute cognitive screening protocol that has yet to be psychometrically evaluated in HF populations. The aim of this study was to conduct a secondary analysis of the sensitivity and specificity of the NINDS-CSN brief cognitive screening protocol in HF patients. The Montreal Cognitive Assessment (MoCA) was administered to 221 HF patients. The NINDS-CSN screen comprises 3 MoCA items, with lower scores indicating poorer cognitive function. Receiver operator characteristic (ROC) curves were constructed, determining the sensitivity, specificity and appropriate cutoff scores of the NINDS-CSN screen. In an HF population aged 76 ± 12 years, 136 (62%) were characterized with cognitive impairment (MoCA area under the receiver operating characteristic curve indicated good accuracy in screening for cognitive impairment (0.88; P cognitive impairment in patients with HF. Future studies should include a neuropsychologic battery to more comprehensively examine the diagnostic accuracy of brief cognitive screening protocols. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Effect of circuit class versus individual task specific training on balance in post-stroke patients

    International Nuclear Information System (INIS)

    Basri, R.; Ali, A.; Ullah, S.; Naseem, M.; Haq, Z.U.

    2017-01-01

    Objective: To compare the efficacy of circuit class versus individual, task specific training on balance, in post stroke patients. Methods: From a total of 64 participants, 32 participants were treated in circuit based workstations, while 32 participants were treated individually for 4 weeks. Importantly, both groups were treated with standard balance physiotherapy protocols. The treatment was delivered for 5 days per week with 1.5 hours daily. The patients were evaluated for three outcome measures i.e. berg balance scale, time up and go test and for motor assessment scale at baseline and after treatment. Results: Patients in both groups reported significant improvement after 4 weeks of training program compared to baseline on all outcome measures, except time up and go test that did not significantly improve in individual group. Compared to individual group, circuit group reported more improvement on berg balance scale scores (31.33 versus 37.80), time up and go test (23.13sec versus 16.67sec) and on motor assessment scale scores (18.77 versus 20.63) respectively. Conclusion: Circuit class training is more efficacious in improving balance in stroke patients as compared to individual task specific training. (author)

  7. Automated segmentation and reconstruction of patient-specific cardiac anatomy and pathology from in vivo MRI

    International Nuclear Information System (INIS)

    Ringenberg, Jordan; Deo, Makarand; Devabhaktuni, Vijay; Filgueiras-Rama, David; Pizarro, Gonzalo; Ibañez, Borja; Berenfeld, Omer; Boyers, Pamela; Gold, Jeffrey

    2012-01-01

    This paper presents an automated method to segment left ventricle (LV) tissues from functional and delayed-enhancement (DE) cardiac magnetic resonance imaging (MRI) scans using a sequential multi-step approach. First, a region of interest (ROI) is computed to create a subvolume around the LV using morphological operations and image arithmetic. From the subvolume, the myocardial contours are automatically delineated using difference of Gaussians (DoG) filters and GSV snakes. These contours are used as a mask to identify pathological tissues, such as fibrosis or scar, within the DE-MRI. The presented automated technique is able to accurately delineate the myocardium and identify the pathological tissue in patient sets. The results were validated by two expert cardiologists, and in one set the automated results are quantitatively and qualitatively compared with expert manual delineation. Furthermore, the method is patient-specific, performed on an entire patient MRI series. Thus, in addition to providing a quick analysis of individual MRI scans, the fully automated segmentation method is used for effectively tagging regions in order to reconstruct computerized patient-specific 3D cardiac models. These models can then be used in electrophysiological studies and surgical strategy planning. (paper)

  8. Patient Specific Multiscale Simulations of Blood Flow in Coronary Artery Bypass Surgery

    Science.gov (United States)

    Bangalore Ramachandra, Abhay; Sankaran, Sethuraman; Kahn, Andrew M.; Marsden, Alison L.

    2013-11-01

    Coronary artery bypass surgery is performed to revascularize blocked coronary arteries in roughly 400,000 patients per year in the US.While arterial grafts offer superior patency, vein grafts are used in more than 70% of procedures, as most patients require multiple grafts. Vein graft failure (approx. 50% within 10 years) remains a major clinical issue. Mounting evidence suggests that hemodynamics plays a key role as a mechano-biological stimulus contributing to graft failure. However, quantifying relevant hemodynamic quantities (e.g. wall shear stress) invivo is not possible directly using clinical imaging techniques. We numerically compute graft hemodynamics in a cohort of 3-D patient specific models using a stabilized finite element method. The 3D flow domain is coupled to a 0D lumped parameter circulatory model. Boundary conditions are tuned to match patient specific blood pressures, stroke volumes & heart rates. Results reproduce clinically observed coronary flow waveforms. We quantify differences in multiple hemodynamic quantities between arterial & venous grafts & discuss possible correlations between graft hemodynamics & clinically observed graft failure.Such correlations will provide further insight into mechanisms of graft failure and may lead to improved clinical outcomes.

  9. Specific insomnia symptoms and self-efficacy explain CPAP compliance in a sample of OSAS patients.

    Science.gov (United States)

    Philip, Pierre; Bioulac, Stéphanie; Altena, Elemarije; Morin, Charles M; Ghorayeb, Imad; Coste, Olivier; Monteyrol, Pierre-Jean; Micoulaud-Franchi, Jean-Arthur

    2018-01-01

    This study explores the association between specific insomnia symptoms (sleep onset, sleep maintenance and early morning awakenings symptoms) and self-efficacy (perceived self-confidence in the ability to use CPAP) with CPAP compliance in French patients with obstructive sleep apnea syndrome (OSAS). We performed a retrospective, cross-sectional analysis of CPAP compliance in a cohort of 404 patients diagnosed with OSAS. Patients completed mailed questionnaires on sleepiness (ESS), insomnia (ISI) and self-efficacy in sleep apnea (SEMSA). Linear regression modeling analyses were performed to explore the impact of measured variables on the number of hours of CPAP use. Of the initial pool of 404 patients, 288 returned the questionnaires (71% response rate). Their mean age was 63.16±12.73 yrs, 31% were females, mean BMI was 30.39±6.31 kg/m2, mean daily CPAP use was 6.19±2.03 h, mean number of years of use was 6.58±6.03 yrs, and mean initial AHI before CPAP use was 34.61±20.71 /h. Age (pCPAP use. We found that specific insomnia symptoms and self-efficacy were associated with CPAP compliance. Our findings underline the need to demonstrate that interventions that reduce insomnia symptoms and improve self-efficacy will increase CPAP compliance.

  10. Non-organ-specific autoantibodies in chronic hepatitis C patients: association with histological activity and fibrosis.

    Science.gov (United States)

    Chrétien, P; Chousterman, M; Abd Alsamad, I; Ozenne, V; Rosa, I; Barrault, C; Lons, T; Hagège, H

    2009-01-01

    Non-organ-specific autoantibodies (NOSAs) are frequently found in the sera of patients with Hepatitis C Virus (HCV) infection. However, no conclusive answers have been produced concerning the clinical relevance of these antibodies. To determine whether a relationship might exist between the presence of NOSA and the severity of liver disease in chronic hepatitis C. 186 treatment-naïve chronic hepatitis C patients were studied consecutively for autoantibodies. Liver biopsies were analyzed according to the Metavir score. NOSAs were present in 75 patients (40%). Anti-nuclear antibodies were found in 32% of patients (speckled pattern), anti-smooth muscle in 15% without F-actin specificity, anti-mitochondria in 0.5%, and anti-LKM1 in 0.5%, respectively. No liver-cytosol1 or soluble liver antigen antibodies were detected. There was a highly significant correlation between the positivity of NOSA and the degree of inflammation and hepatocellular injury (p = 0.001) and also with the degree of fibrosis (p < 0.0001). The presence of NOSA was associated with higher aspartate aminotransferase, gamma-glutamyl-transpeptidase, gamma-globulin and immunoglobulin G levels. By contrast, no differences were observed regarding age, gender, route of infection, duration of disease, HCV genotypes or viral load. NOSAs were associated with the most severe forms of chronic HCV infections.

  11. Functional integration over geometries

    International Nuclear Information System (INIS)

    Mottola, E.

    1995-01-01

    The geometric construction of the functional integral over coset spaces M/G is reviewed. The inner product on the cotangent space of infinitesimal deformations of M defines an invariant distance and volume form, or functional integration measure on the full configuration space. Then, by a simple change of coordinates parameterizing the gauge fiber G, the functional measure on the coset space M/G is deduced. This change of integration variables leads to a Jacobian which is entirely equivalent to the Faddeev--Popov determinant of the more traditional gauge fixed approach in non-abelian gauge theory. If the general construction is applied to the case where G is the group of coordinate reparameterizations of spacetime, the continuum functional integral over geometries, i.e. metrics modulo coordinate reparameterizations may be defined. The invariant functional integration measure is used to derive the trace anomaly and effective action for the conformal part of the metric in two and four dimensional spacetime. In two dimensions this approach generates the Polyakov--Liouville action of closed bosonic non-critical string theory. In four dimensions the corresponding effective action leads to novel conclusions on the importance of quantum effects in gravity in the far infrared, and in particular, a dramatic modification of the classical Einstein theory at cosmological distance scales, signaled first by the quantum instability of classical de Sitter spacetime. Finite volume scaling relations for the functional integral of quantum gravity in two and four dimensions are derived, and comparison with the discretized dynamical triangulation approach to the integration over geometries are discussed. Outstanding unsolved problems in both the continuum definition and the simplicial approach to the functional integral over geometries are highlighted

  12. Dynamics of plasma levels of specific IgE in chlorhexidine allergic patients with and without accidental re-exposure

    DEFF Research Database (Denmark)

    Opstrup, Morten Schjørring; Poulsen, Lars K.; Malling, Hans Jørgen

    2016-01-01

    longer time periods is lacking and it is unknown whether levels fall below influences levels of specific IgE. OBJECTIVE: To investigate the dynamics of specific IgE in chlorhexidine allergic patients...

  13. WE-D-BRA-05: Pseudo In Vivo Patient Dosimetry Using a 3D-Printed Patient-Specific Phantom

    International Nuclear Information System (INIS)

    Ger, R; Craft, DF; Burgett, EA; Price, RR; Kry, SF; Howell, RM

    2015-01-01

    Purpose: To test the feasibility of using 3D-printed patient-specific phantoms for intensity-modulated radiation therapy (IMRT) quality assurance (QA). Methods: We created a patient-specific whole-head phantom using a 3D printer. The printer data file was created from high-resolution DICOM computed tomography (CT) images of 3-year old child treated at our institution for medulloblastoma. A custom-modified extruder system was used to create tissue-equivalent materials. For the printing process, the Hounsfield Units from the CT images were converted to proportional volumetric densities. A 5-field IMRT plan was created from the patient CT and delivered to the 3D- phantom. Dose was measured by an ion chamber placed through the eye. The ion chamber was placed at the posterior edge of the planning target volume in a high dose gradient region. CT scans of the patient and 3D-phantom were fused by using commercial treatment planning software (TPS). The patient’s plan was calculated on the phantom CT images. The ion chamber’s active volume was delineated in the TPS; dose per field and total dose were obtained. Measured and calculated doses were compared. Results: The 3D-phantom dimensions and tissue densities were in good agreement with the patient. However, because of a printing error, there was a large discrepancy in the density in the frontal cortex. The calculated and measured treatment plan doses were 1.74 Gy and 1.72 Gy, respectively. For individual fields, the absolute dose difference between measured and calculated values was on average 3.50%. Conclusion: This study demonstrated the feasibility of using 3D-printed patient-specific phantoms for IMRT QA. Such phantoms would be particularly advantageous for complex IMRT treatment plans featuring high dose gradients and/or for anatomical sites with high variation in tissue densities. Our preliminary findings are promising. We anticipate that, once the printing process is further refined, the agreement between

  14. WE-D-BRA-05: Pseudo In Vivo Patient Dosimetry Using a 3D-Printed Patient-Specific Phantom

    Energy Technology Data Exchange (ETDEWEB)

    Ger, R; Craft, DF [The University of Texas Graduate School of Biomedical Sciences (United States); Burgett, EA [Idaho State University, Pocatello, idaho (United States); Price, RR [RANDJ Consulting, Frederick, MD (United States); Kry, SF; Howell, RM [The University of Texas Graduate School of Biomedical Sciences (United States); The University of Texas MD Anderson Cancer Ctr., Houston, TX (United States)

    2015-06-15

    Purpose: To test the feasibility of using 3D-printed patient-specific phantoms for intensity-modulated radiation therapy (IMRT) quality assurance (QA). Methods: We created a patient-specific whole-head phantom using a 3D printer. The printer data file was created from high-resolution DICOM computed tomography (CT) images of 3-year old child treated at our institution for medulloblastoma. A custom-modified extruder system was used to create tissue-equivalent materials. For the printing process, the Hounsfield Units from the CT images were converted to proportional volumetric densities. A 5-field IMRT plan was created from the patient CT and delivered to the 3D- phantom. Dose was measured by an ion chamber placed through the eye. The ion chamber was placed at the posterior edge of the planning target volume in a high dose gradient region. CT scans of the patient and 3D-phantom were fused by using commercial treatment planning software (TPS). The patient’s plan was calculated on the phantom CT images. The ion chamber’s active volume was delineated in the TPS; dose per field and total dose were obtained. Measured and calculated doses were compared. Results: The 3D-phantom dimensions and tissue densities were in good agreement with the patient. However, because of a printing error, there was a large discrepancy in the density in the frontal cortex. The calculated and measured treatment plan doses were 1.74 Gy and 1.72 Gy, respectively. For individual fields, the absolute dose difference between measured and calculated values was on average 3.50%. Conclusion: This study demonstrated the feasibility of using 3D-printed patient-specific phantoms for IMRT QA. Such phantoms would be particularly advantageous for complex IMRT treatment plans featuring high dose gradients and/or for anatomical sites with high variation in tissue densities. Our preliminary findings are promising. We anticipate that, once the printing process is further refined, the agreement between

  15. Kinematic geometry of gearing

    CERN Document Server

    Dooner, David B

    2012-01-01

    Building on the first edition published in 1995 this new edition of Kinematic Geometry of Gearing has been extensively revised and updated with new and original material. This includes the methodology for general tooth forms, radius of torsure', cylinder of osculation, and cylindroid of torsure; the author has also completely reworked the '3 laws of gearing', the first law re-written to better parallel the existing 'Law of Gearing" as pioneered by Leonard Euler, expanded from Euler's original law to encompass non-circular gears and hypoid gears, the 2nd law of gearing describing a unique relat

  16. From geometry to topology

    CERN Document Server

    Flegg, H Graham

    2001-01-01

    This excellent introduction to topology eases first-year math students and general readers into the subject by surveying its concepts in a descriptive and intuitive way, attempting to build a bridge from the familiar concepts of geometry to the formalized study of topology. The first three chapters focus on congruence classes defined by transformations in real Euclidean space. As the number of permitted transformations increases, these classes become larger, and their common topological properties become intuitively clear. Chapters 4-12 give a largely intuitive presentation of selected topics.

  17. Torsional heterotic geometries

    International Nuclear Information System (INIS)

    Becker, Katrin; Sethi, Savdeep

    2009-01-01

    We construct new examples of torsional heterotic backgrounds using duality with orientifold flux compactifications. We explain how duality provides a perturbative solution to the type I/heterotic string Bianchi identity. The choice of connection used in the Bianchi identity plays an important role in the construction. We propose the existence of a much larger landscape of compact torsional geometries using string duality. Finally, we present some quantum exact metrics that correspond to NS5-branes placed on an elliptic space. These metrics describe how torus isometries are broken by NS flux.

  18. Geometrie verstehen: statisch - kinematisch

    Science.gov (United States)

    Kroll, Ekkehard

    Dem Allgemeinen steht begrifflich das Besondere gegenüber. In diesem Sinne sind allgemeine Überlegungen zum Verstehen von Mathematik zu ergänzen durch Untersuchungen hinsichtlich des Verstehens der einzelnen mathematischen Disziplinen, insbesondere der Geometrie. Hier haben viele Schülerinnen und Schüler Probleme. Diese rühren hauptsächlich daher, dass eine fertige geometrische Konstruktion in ihrer statischen Präsentation auf Papier nicht mehr die einzelnen Konstruktionsschritte erkennen lässt; zum Nachvollzug müssen sie daher ergänzend in einer Konstruktionsbeschreibung festgehalten werden.

  19. Elementary algebraic geometry

    CERN Document Server

    Kendig, Keith

    2015-01-01

    Designed to make learning introductory algebraic geometry as easy as possible, this text is intended for advanced undergraduates and graduate students who have taken a one-year course in algebra and are familiar with complex analysis. This newly updated second edition enhances the original treatment's extensive use of concrete examples and exercises with numerous figures that have been specially redrawn in Adobe Illustrator. An introductory chapter that focuses on examples of curves is followed by a more rigorous and careful look at plane curves. Subsequent chapters explore commutative ring th

  20. Local analytic geometry

    CERN Document Server

    Abhyankar, Shreeram Shankar

    1964-01-01

    This book provides, for use in a graduate course or for self-study by graduate students, a well-motivated treatment of several topics, especially the following: (1) algebraic treatment of several complex variables; (2) geometric approach to algebraic geometry via analytic sets; (3) survey of local algebra; (4) survey of sheaf theory. The book has been written in the spirit of Weierstrass. Power series play the dominant role. The treatment, being algebraic, is not restricted to complex numbers, but remains valid over any complete-valued field. This makes it applicable to situations arising from

  1. Geometry of conics

    CERN Document Server

    Akopyan, A V

    2007-01-01

    The book is devoted to the properties of conics (plane curves of second degree) that can be formulated and proved using only elementary geometry. Starting with the well-known optical properties of conics, the authors move to less trivial results, both classical and contemporary. In particular, the chapter on projective properties of conics contains a detailed analysis of the polar correspondence, pencils of conics, and the Poncelet theorem. In the chapter on metric properties of conics the authors discuss, in particular, inscribed conics, normals to conics, and the Poncelet theorem for confoca

  2. Geometry and trigonometry

    CERN Document Server

    2015-01-01

    This stimulating volume offers a broad collection of the principles of geometry and trigonometry and contains colorful diagrams to bring mathematical principles to life. Subjects are enriched by references to famous mathematicians and their ideas, and the stories are presented in a very comprehensible way. Readers investigate the relationships of points, lines, surfaces, and solids. They study construction methods for drawing figures, a wealth of facts about these figures, and above all, methods to prove the facts. They learn about triangle measure for circular motion, sine and cosine, tangent

  3. Geometry I essentials

    CERN Document Server

    REA, The Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Geometry I includes methods of proof, points, lines, planes, angles, congruent angles and line segments, triangles, parallelism, quadrilaterals, geometric inequalities, and geometric

  4. Graded geometry and Poisson reduction

    OpenAIRE

    Cattaneo, A S; Zambon, M

    2009-01-01

    The main result of [2] extends the Marsden-Ratiu reduction theorem [4] in Poisson geometry, and is proven by means of graded geometry. In this note we provide the background material about graded geometry necessary for the proof in [2]. Further, we provide an alternative algebraic proof for the main result. ©2009 American Institute of Physics

  5. Evaluative Measurement Properties of the Patient-Specific Functional Scale for Primary Shoulder Complaints in Physical Therapy Practice

    NARCIS (Netherlands)

    Koehorst, Marije L. S.; van Trijffel, Emiel; Lindeboom, Robert

    2014-01-01

    STUDY DESIGN: Clinical measurement, longitudinal. OBJECTIVES: To assess the test-retest reliability, construct validity, and responsiveness of the Patient-Specific Functional Scale (PSFS) in patients with a primary shoulder complaint. BACKGROUND: Health measurement outcomes have become increasingly

  6. Geometry and the Design of Product Packaging

    Science.gov (United States)

    Cherico, Cindy M.

    2011-01-01

    The most common question the author's students ask is, "When will I ever use this in real life?" To address this question in her geometry classes, the author sought to create a project that would incorporate a real-world business situation with their lesson series on the surface area and volume of three-dimensional objects--specifically, prisms,…

  7. Patient-Specific Circulating Tumor DNA Detection during Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer.

    Science.gov (United States)

    Riva, Francesca; Bidard, Francois-Clement; Houy, Alexandre; Saliou, Adrien; Madic, Jordan; Rampanou, Aurore; Hego, Caroline; Milder, Maud; Cottu, Paul; Sablin, Marie-Paule; Vincent-Salomon, Anne; Lantz, Olivier; Stern, Marc-Henri; Proudhon, Charlotte; Pierga, Jean-Yves

    2017-03-01

    In nonmetastatic triple-negative breast cancer (TNBC) patients, we investigated whether circulating tumor DNA (ctDNA) detection can reflect the tumor response to neoadjuvant chemotherapy (NCT) and detect minimal residual disease after surgery. Ten milliliters of plasma were collected at 4 time points: before NCT; after 1 cycle; before surgery; after surgery. Customized droplet digital PCR (ddPCR) assays were used to track tumor protein p53 ( TP53 ) mutations previously characterized in tumor tissue by massively parallel sequencing (MPS). Forty-six patients with nonmetastatic TNBC were enrolled. TP53 mutations were identified in 40 of them. Customized ddPCR probes were validated for 38 patients, with excellent correlation with MPS ( r = 0.99), specificity (≥2 droplets/assay), and sensitivity (at least 0.1%). At baseline, ctDNA was detected in 27/36 patients (75%). Its detection was associated with mitotic index ( P = 0.003), tumor grade ( P = 0.003), and stage ( P = 0.03). During treatment, we observed a drop of ctDNA levels in all patients but 1. No patient had detectable ctDNA after surgery. The patient with rising ctDNA levels experienced tumor progression during NCT. Pathological complete response (16/38 patients) was not correlated with ctDNA detection at any time point. ctDNA positivity after 1 cycle of NCT was correlated with shorter disease-free ( P < 0.001) and overall ( P = 0.006) survival. Customized ctDNA detection by ddPCR achieved a 75% detection rate at baseline. During NCT, ctDNA levels decreased quickly and minimal residual disease was not detected after surgery. However, a slow decrease of ctDNA level during NCT was strongly associated with shorter survival. © 2016 American Association for Clinical Chemistry.

  8. Chemotherapy and radiation therapy elicits tumor specific T cell responses in a breast cancer patient

    International Nuclear Information System (INIS)

    Bernal-Estévez, David; Sánchez, Ramiro; Tejada, Rafael E.; Parra-López, Carlos

    2016-01-01

    Experimental evidence and clinical studies in breast cancer suggest that some anti-tumor therapy regimens generate stimulation of the immune system that accounts for tumor clinical responses, however, demonstration of the immunostimulatory power of these therapies on cancer patients continues to be a formidable challenge. Here we present experimental evidence from a breast cancer patient with complete clinical response after 7 years, associated with responsiveness of tumor specific T cells. T cells were obtained before and after anti-tumor therapy from peripheral blood of a 63-years old woman diagnosed with ductal breast cancer (HER2/neu+++, ER-, PR-, HLA-A*02:01) treated with surgery, followed by paclitaxel, trastuzumab (suspended due to cardiac toxicity), and radiotherapy. We obtained a leukapheresis before surgery and after 8 months of treatment. Using in vitro cell cultures stimulated with autologous monocyte-derived dendritic cells (DCs) that produce high levels of IL-12, we characterize by flow cytometry the phenotype of tumor associated antigens (TAAs) HER2/neu and NY-ESO 1 specific T cells. The ex vivo analysis of the TCR-Vβ repertoire of TAA specific T cells in blood and Tumor Infiltrating Lymphocytes (TILs) were performed in order to correlate both repertoires prior and after therapy. We evidence a functional recovery of T cell responsiveness to polyclonal stimuli and expansion of TAAs specific CD8+ T cells using peptide pulsed DCs, with an increase of CTLA-4 and memory effector phenotype after anti-tumor therapy. The ex vivo analysis of the TCR-Vβ repertoire of TAA specific T cells in blood and TILs showed that whereas the TCR-Vβ04-02 clonotype is highly expressed in TILs the HER2/neu specific T cells are expressed mainly in blood after therapy, suggesting that this particular TCR was selectively enriched in blood after anti-tumor therapy. Our results show the benefits of anti-tumor therapy in a breast cancer patient with clinical complete response in

  9. Sensitivity and Specificity of the Comfort Scale to Assess Pain in Ventilated Critically Ill Adult Patients in Intensive Care Unit

    OpenAIRE

    Wahyuningsih, Indah Sri; Prasetyo, Awal; Utami, Reni Sulung

    2017-01-01

    Background: Pain is a common phenomenon experienced by ventilated and critically ill adult patients. It is urgent to measure the pain among these patients since they are unable to report their pain verbally. Comfort Scale is one of the instruments used to measure pain in adult patients. The scale is used to measure pain among children patients with fairly high sensitivity and specificity.Purpose: This study aimed to examine the sensitivity and specificity of the Comfort Scale to measure pain ...

  10. 3D patient-specific models for left atrium characterization to support ablation in atrial fibrillation patients.

    Science.gov (United States)

    Valinoti, Maddalena; Fabbri, Claudio; Turco, Dario; Mantovan, Roberto; Pasini, Antonio; Corsi, Cristiana

    2018-01-01

    Radiofrequency ablation (RFA) is an important and promising therapy for atrial fibrillation (AF) patients. Optimization of patient selection and the availability of an accurate anatomical guide could improve RFA success rate. In this study we propose a unified, fully automated approach to build a 3D patient-specific left atrium (LA) model including pulmonary veins (PVs) in order to provide an accurate anatomical guide during RFA and without PVs in order to characterize LA volumetry and support patient selection for AF ablation. Magnetic resonance data from twenty-six patients referred for AF RFA were processed applying an edge-based level set approach guided by a phase-based edge detector to obtain the 3D LA model with PVs. An automated technique based on the shape diameter function was designed and applied to remove PVs and compute LA volume. 3D LA models were qualitatively compared with 3D LA surfaces acquired during the ablation procedure. An expert radiologist manually traced the LA on MR images twice. LA surfaces from the automatic approach and manual tracing were compared by mean surface-to-surface distance. In addition, LA volumes were compared with volumes from manual segmentation by linear and Bland-Altman analyses. Qualitative comparison of 3D LA models showed several inaccuracies, in particular PVs reconstruction was not accurate and left atrial appendage was missing in the model obtained during RFA procedure. LA surfaces were very similar (mean surface-to-surface distance: 2.3±0.7mm). LA volumes were in excellent agreement (y=1.03x-1.4, r=0.99, bias=-1.37ml (-1.43%) SD=2.16ml (2.3%), mean percentage difference=1.3%±2.1%). Results showed the proposed 3D patient-specific LA model with PVs is able to better describe LA anatomy compared to models derived from the navigation system, thus potentially improving electrograms and voltage information location and reducing fluoroscopic time during RFA. Quantitative assessment of LA volume derived from our 3D LA

  11. Patient-specific quality assurance for intracranial cases in robotic radiosurgery system.

    Science.gov (United States)

    Koksal, Canan; Akbas, Ugur; Donmez Kesen, Nazmiye; Okutan, Murat; Bilge, Hatice; Kemikler, Gonul

    2018-01-01

    The purpose of this study was to perform pretreatment patient-specific quality assurance (QA) for intracranial irradiation using CyberKnife with an ion chamber. Twenty-five intracranial plans created using the ray-tracing algorithm were used for this study. Computed tomography (CT) images of the water-equivalent RW3 slab phantom with PinPoint ionization chamber were acquired with 1-mm slice thickness and transferred to the MultiPlan treatment planning system (TPS). Four gold fiducial markers embedded into two different plates were used to tracking during the irradiation. Intracranial plans were transferred to CT images of the RW3 phantom. The isodose curves and sensitive volume of ion chamber were overlapped. Point dose measurements were performed three times and the mean point doses were calculated for each plan. The mean doses measured by the PinPoint ion chamber were compared with those of the calculated by MultiPlan TPS in the sensitive volume of PinPoint. The mean percentage difference (MPD) in point dose measurements was -2.44±1.97 for 25 plans. The maximum and minimum percentage differences between the measured and calculated absolute point doses were -7.14 and 0.23, respectively. The MPD was -1.70±1.90 for 12 plans using a fixed collimator and -3.11±1.86 for 13 plans using an IRIS cone. Point dose measurement is a reliable and functional method for pre-treatment patient-specific QA in intracranial CyberKnife plans. Point dose verification should be performed to correct any possible errors prior to patient treatment. It is recommended for use in patient-specific QA process in the CyberKnife plans.

  12. Efficient generation of lens progenitor cells from cataract patient-specific induced pluripotent stem cells.

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    Xiaodi Qiu

    Full Text Available The development of a technique to induce the transformation of somatic cells to a pluripotent state via the ectopic expression of defined transcription factors was a transformational event in the field of regenerative medicine. The development of this technique also impacted ophthalmology, as patient-specific induced pluripotent stemcells (iPSCs may be useful resources for some ophthalmological diseases. The lens is a key refractive element in the eye that focuses images of the visual world onto the retina. To establish a new model for drug screening to treat lens diseases and investigating lens aging and development, we examined whether human lens epithelial cells (HLECs could be induced into iPSCs and if lens-specific differentiation of these cells could be achieved under defined chemical conditions. We first efficiently reprogrammed HLECs from age-related cataract patients to iPSCs with OCT-4, SOX-2, and KLF-4. The resulting HLEC-derived iPS (HLE-iPS colonies were indistinguishable from human ES cells with respect to morphology, gene expression, pluripotent marker expression and their ability to generate all embryonic germ-cell layers. Next, we performed a 3-step induction procedure: HLE-iPS cells were differentiated into large numbers of lens progenitor-like cells with defined factors (Noggin, BMP and FGF2, and we determined that these cells expressed lens-specific markers (PAX6, SOX2, SIX3, CRYAB, CRYAA, BFSP1, and MIP. In addition, HLE-iPS-derived lens cells exhibited reduced expression of epithelial mesenchymal transition (EMT markers compared with human embryonic stem cells (hESCs and fibroblast-derived iPSCs. Our study describes a highly efficient procedure for generating lens progenitor cells from cataract patient HLEC-derived iPSCs. These patient-derived pluripotent cells provide a valuable model for studying the developmental and molecular biological mechanisms that underlie cell determination in lens development and cataract

  13. 3D Modelling and Printing Technology to Produce Patient-Specific 3D Models.

    Science.gov (United States)

    Birbara, Nicolette S; Otton, James M; Pather, Nalini

    2017-11-10

    A comprehensive knowledge of mitral valve (MV) anatomy is crucial in the assessment of MV disease. While the use of three-dimensional (3D) modelling and printing in MV assessment has undergone early clinical evaluation, the precision and usefulness of this technology requires further investigation. This study aimed to assess and validate 3D modelling and printing technology to produce patient-specific 3D MV models. A prototype method for MV 3D modelling and printing was developed from computed tomography (CT) scans of a plastinated human heart. Mitral valve models were printed using four 3D printing methods and validated to assess precision. Cardiac CT and 3D echocardiography imaging data of four MV disease patients was used to produce patient-specific 3D printed models, and 40 cardiac health professionals (CHPs) were surveyed on the perceived value and potential uses of 3D models in a clinical setting. The prototype method demonstrated submillimetre precision for all four 3D printing methods used, and statistical analysis showed a significant difference (p3D printed models, particularly using multiple print materials, were considered useful by CHPs for preoperative planning, as well as other applications such as teaching and training. This study suggests that, with further advances in 3D modelling and printing technology, patient-specific 3D MV models could serve as a useful clinical tool. The findings also highlight the potential of this technology to be applied in a variety of medical areas within both clinical and educational settings. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  14. The technique for 3D printing patient-specific models for auricular reconstruction.

    Science.gov (United States)

    Flores, Roberto L; Liss, Hannah; Raffaelli, Samuel; Humayun, Aiza; Khouri, Kimberly S; Coelho, Paulo G; Witek, Lukasz

    2017-06-01

    Currently, surgeons approach autogenous microtia repair by creating a two-dimensional (2D) tracing of the unaffected ear to approximate a three-dimensional (3D) construct, a difficult process. To address these shortcomings, this study introduces the fabrication of patient-specific, sterilizable 3D printed auricular model for autogenous auricular reconstruction. A high-resolution 3D digital photograph was captured of the patient's unaffected ear and surrounding anatomic structures. The photographs were exported and uploaded into Amira, for transformation into a digital (.stl) model, which was imported into Blender, an open source software platform for digital modification of data. The unaffected auricle as digitally isolated and inverted to render a model for the contralateral side. The depths of the scapha, triangular fossa, and cymba were deepened to accentuate their contours. Extra relief was added to the helical root to further distinguish this structure. The ear was then digitally deconstructed and separated into its individual auricular components for reconstruction. The completed ear and its individual components were 3D printed using polylactic acid filament and sterilized following manufacturer specifications. The sterilized models were brought to the operating room to be utilized by the surgeon. The models allowed for more accurate anatomic measurements compared to 2D tracings, which reduced the degree of estimation required by surgeons. Approximately 20 g of the PLA filament were utilized for the construction of these models, yielding a total material cost of approximately $1. Using the methodology detailed in this report, as well as departmentally available resources (3D digital photography and 3D printing), a sterilizable, patient-specific, and inexpensive 3D auricular model was fabricated to be used intraoperatively. This technique of printing customized-to-patient models for surgeons to use as 'guides' shows great promise. Copyright © 2017 European

  15. Seizure outcomes of temporal lobe epilepsy surgery in patients with normal MRI and without specific histopathology.

    Science.gov (United States)

    Ivanovic, Jugoslav; Larsson, Pål G; Østby, Ylva; Hald, John; Krossnes, Bård K; Fjeld, Jan G; Pripp, Are H; Alfstad, Kristin Å; Egge, Arild; Stanisic, Milo

    2017-05-01

    Seizure outcome following surgery in pharmacoresistant temporal lobe epilepsy patients with normal magnetic resonance imaging and normal or non-specific histopathology is not sufficiently presented in the literature. In a retrospective design, we reviewed data of 263 patients who had undergone temporal lobe epilepsy surgery and identified 26 (9.9%) who met the inclusion criteria. Seizure outcomes were determined at 2-year follow-up. Potential predictors of Engel class I (satisfactory outcome) were identified by logistic regression analyses. Engel class I outcome was achieved in 61.5% of patients, 50% being completely seizure free (Engel class IA outcome). The strongest predictors of satisfactory outcome were typical ictal seizure semiology (p = 0.048) and localised ictal discharges on scalp EEG (p = 0.036). Surgery might be an effective treatment choice for the majority of these patients, although outcomes are less favourable than in patients with magnetic resonance imaging-defined lesional temporal lobe epilepsy. Typical ictal seizure semiology and localised ictal discharges on scalp EEG were predictors of Engel class I outcome.

  16. Patient-Specific Modeling of Interventricular Hemodynamics in Single Ventricle Physiology

    Science.gov (United States)

    Vedula, Vijay; Feinstein, Jeffrey; Marsden, Alison

    2016-11-01

    Single ventricle (SV) congenital heart defects, in which babies are born with only functional ventricle, lead to significant morbidity and mortality with over 30% of patients developing heart failure prior to adulthood. Newborns with SV physiology typically undergo three palliative surgeries, in which the SV becomes the systemic pumping chamber. Depending on which ventricle performs the systemic function, patients are classified as having either a single left ventricle (SLV) or a single right ventricle (SRV), with SRV patients at higher risk of failure. As the native right ventricles are not designed to meet systemic demands, they undergo remodeling leading to abnormal hemodynamics. The hemodynamic characteristics of SLVs compared with SRVs is not well established. We present a validated computational framework for performing patient-specific modeling of ventricular flows, and apply it across 6 SV patients (3SLV + 3SRV), comparing hemodynamic conditions between the two subgroups. Simulations are performed with a stabilized finite element method coupled with an immersed boundary method for modeling heart valves. We discuss identification of hemodynamic biomarkers of ventricular remodeling for early risk assessment of failure. This research is supported in part by the Stanford Child Health Research Institute and the Stanford NIH-NCATS-CTSA through Grant UL1 TR001085 and due to U.S. National Institute of Health through NIH NHLBI R01 Grants 5R01HL129727-02 and 5R01HL121754-03.

  17. Patient-specific scatter correction in clinical cone beam computed tomography imaging made possible by the combination of Monte Carlo simulations and a ray tracing algorithm

    International Nuclear Information System (INIS)

    Thing, Rune S.; Bernchou, Uffe; Brink, Carsten; Mainegra-Hing, Ernesto

    2013-01-01

    Purpose: Cone beam computed tomography (CBCT) image quality is limited by scattered photons. Monte Carlo (MC) simulations provide the ability of predicting the patient-specific scatter contamination in clinical CBCT imaging. Lengthy simulations prevent MC-based scatter correction from being fully implemented in a clinical setting. This study investigates the combination of using fast MC simulations to predict scatter distributions with a ray tracing algorithm to allow calibration between simulated and clinical CBCT images. Material and methods: An EGSnrc-based user code (egs c bct), was used to perform MC simulations of an Elekta XVI CBCT imaging system. A 60keV x-ray source was used, and air kerma scored at the detector plane. Several variance reduction techniques (VRTs) were used to increase the scatter calculation efficiency. Three patient phantoms based on CT scans were simulated, namely a brain, a thorax and a pelvis scan. A ray tracing algorithm was used to calculate the detector signal due to primary photons. A total of 288 projections were simulated, one for each thread on the computer cluster used for the investigation. Results: Scatter distributions for the brain, thorax and pelvis scan were simulated within 2 % statistical uncertainty in two hours per scan. Within the same time, the ray tracing algorithm provided the primary signal for each of the projections. Thus, all the data needed for MC-based scatter correction in clinical CBCT imaging was obtained within two hours per patient, using a full simulation of the clinical CBCT geometry. Conclusions: This study shows that use of MC-based scatter corrections in CBCT imaging has a great potential to improve CBCT image quality. By use of powerful VRTs to predict scatter distributions and a ray tracing algorithm to calculate the primary signal, it is possible to obtain the necessary data for patient specific MC scatter correction within two hours per patient

  18. Diagnostic value of tissue polypeptide specific antigen in serum for patients with pancreatic carcinoma

    International Nuclear Information System (INIS)

    Lu Yun; Liu Xingdang; Li Ding; Dei Shouzhen

    2009-01-01

    Objective: To compare the diagnostic value of tissue polypeptide specific antigen (TPS) in serum, with the carbohydrate antigens (CA) 19-9, CA50, CA125 and CA242 in pancreatic carcinoma. Methods: Serum TPS was measured with enzyme linked immunosorbent assay (ELISA). CA19-9 and CA125 were measured with chemiluminescent immunoassay. CAS0 and CA242 were measured with immunoradiometric assay in 33 patients with pancreatitis, 34 patients with pathologically proven pancreatic carcinoma, and 35 patients with non-pancreatic malignancies. Statistic analysis was carried out with SPSS 9.0 software. Results: Patients with pancreatic carcinoma had relatively higher levels of TPS [(386.5 ± 315. 1) U/L] and CA19-9 [(10 820.9 ± 389.7) kU/L] when compared with patients with pancreatitis [(86. 2 ± 28.1) U/L and (61.5 ± 24.7) kU/L, respectively; F = 936. 42, P < 0. 001 ; F = 2217. 09, P < 0. 001], with a sensitivity and a specificity of 70.6% (48/68) and 57.4% (39/68), respectively, for TPS, and 82.4% (28/34) and 77.9% (53/68), respectively, for CA19-9. Diagnostic performance was further improved when TPS was assayed in combination with CA19-9, CA50, CA125 and CA242. Conclusion: Serum TPS has an incremental value in complementing CA19-9 in the diagnosis of pancreatic carcinoma. (authors)

  19. The relationship between neuron-specific enolase and prognosis of patients with acute traumatic brain injury

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    Yun-yang LIU

    2015-03-01

    Full Text Available Objective To investigate the relationship between neuron-specific enolase (NSE levels in serum and cerebrospinal fluid (CSF of patients with acute traumatic brain injury (TBI and the prognosis of TBI patients.  Methods A total of 89 patients with acute TBI were divided into light, medium, heavy and severe TBI groups based on admission Glasgow Coma Scale (GCS score. Serum NSE expression levels were detected in all cases and NSE levels in CSF were detected in 18 cases within 12 h after TBI. The expression levels of serum NSE in 20 normal people, except cases of lung disease and nervous system damage, were detected as a control group. Results Compared with the control group, serum NSE expression levels of patients in each TBI group were elevated (P < 0.05, for all, and the NSE levels in severe and heavy TBI groups were higher than that in medium and light groups (P < 0.05, for all. The serum NSE expression levels of patients with cerebral contusion were higher than that of patients with diffuse axonal injury (DAI, P = 0.025, subdural hematoma (P = 0.031 and epidural hematoma (P = 0.021. Serum NSE expression levels were negatively correlated with GCS score (rs = - 0.327, P = 0.024 and Glasgow Outcome Scale (GOS score (rs = - 0.252, P = 0.049. The NSE expression levels of CSF in severe and heavy TBI patients were higher than that of serum (P = 0.039, 0.031.  Conclusions NSE expression changes can be evaluated as an auxiliary indicator in reflecting the degree of acute TBI, typing diagnosis and prognostic evaluation, and NSE levels of CSF is more sensitive than that of serum. DOI: 10.3969/j.issn.1672-6731.2015.03.013

  20. Specificity and sensibility of 9-Itens Wearing-off Questionnaire in Brazilian Parkinson disease patient sample

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    Jasper Guimarães Santos

    2014-11-01

    Full Text Available Objective (1 To evaluate whether the Nine Items Questionnaire (WOQ-9 for the detection of wearing-off (WO in Parkinson Disease (PD, by means of its screening ability, is a helpful tool to assist neurologists in diagnosing WO; (2 To determine the sensitivity and the specificity of a free Brazilian Portuguese translation of WOQ-9. Method A sample obtained by convenience included 60 patients. The WOQ-9 was answered by the patients themselves before their routine consultations. The detection of the WO by the WOQ-9 was compared with the neurologist assessment. Statistical significance was 5%. Results The WOQ-9 showed sensitivity of 100%, specificity of 10.3%, positive and negative predictive values of 54.4% and 100% respectively. The identification of WO by the WOQ-9 was congruent in 54.5% of cases with neurological evaluation. Conclusion The WOQ-9 is a convenient screening tool to aid physicians to detect WO in PD patients, and it is a quick and easy self-administered questionnaire.

  1. Validation of Patient-Specific Cerebral Blood Flow Simulation Using Transcranial Doppler Measurements

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    Derek Groen

    2018-06-01

    Full Text Available We present a validation study comparing results from a patient-specific lattice-Boltzmann simulation to transcranial Doppler (TCD velocity measurements in four different planes of the middle cerebral artery (MCA. As part of the study, we compared simulations using a Newtonian and a Carreau-Yasuda rheology model. We also investigated the viability of using downscaled velocities to reduce the required resolution. Simulations with unscaled velocities predict the maximum flow velocity with an error of less than 9%, independent of the rheology model chosen. The accuracy of the simulation predictions worsens considerably when simulations are run at reduced velocity, as is for example the case when inflow velocities from healthy individuals are used on a vascular model of a stroke patient. Our results demonstrate the importance of using directly measured and patient-specific inflow velocities when simulating blood flow in MCAs. We conclude that localized TCD measurements together with predictive simulations can be used to obtain flow estimates with high fidelity over a larger region, and reduce the need for more invasive flow measurement procedures.

  2. [Copy number alterations in adult patients with mature B acute lymphoblastic leukemia treated with specific immunochemotherapy].

    Science.gov (United States)

    Ribera, Jordi; Zamora, Lurdes; García, Olga; Hernández-Rivas, Jesús-María; Genescà, Eulàlia; Ribera, Josep-Maria

    2016-12-02

    Unlike Burkitt lymphoma, molecular abnormalities other than C-MYC rearrangements have scarcely been studied in patients with mature B acute lymphoblastic leukemia (B-ALL). The aim of this study was to analyze the frequency and prognostic significance of copy number alterations (CNA) in genes involved in lymphoid differentiation, cell cycle and tumor suppression in adult patients with B-ALL. We have analyzed by multiplex ligation-dependent probe amplification the genetic material from bone marrow at diagnosis from 25 adult B-ALL patients treated with rituximab and specific chemotherapy. The most frequent CNA were alterations in the 14q32.33 region (11 cases, 44%) followed by alterations in the cell cycle regulator genes CDKN2A/B and RB1 (16%). No correlation between the presence of specific CNA and the clinical-biologic features or the response to therapy was found. The high frequency of CNA in the 14q32.33 region, CDKN2A/B and RB1 found in our study could contribute to the aggressiveness and invasiveness of mature B-ALL. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  3. Physically consistent data assimilation method based on feedback control for patient-specific blood flow analysis.

    Science.gov (United States)

    Ii, Satoshi; Adib, Mohd Azrul Hisham Mohd; Watanabe, Yoshiyuki; Wada, Shigeo

    2018-01-01

    This paper presents a novel data assimilation method for patient-specific blood flow analysis based on feedback control theory called the physically consistent feedback control-based data assimilation (PFC-DA) method. In the PFC-DA method, the signal, which is the residual error term of the velocity when comparing the numerical and reference measurement data, is cast as a source term in a Poisson equation for the scalar potential field that induces flow in a closed system. The pressure values at the inlet and outlet boundaries are recursively calculated by this scalar potential field. Hence, the flow field is physically consistent because it is driven by the calculated inlet and outlet pressures, without any artificial body forces. As compared with existing variational approaches, although this PFC-DA method does not guarantee the optimal solution, only one additional Poisson equation for the scalar potential field is required, providing a remarkable improvement for such a small additional computational cost at every iteration. Through numerical examples for 2D and 3D exact flow fields, with both noise-free and noisy reference data as well as a blood flow analysis on a cerebral aneurysm using actual patient data, the robustness and accuracy of this approach is shown. Moreover, the feasibility of a patient-specific practical blood flow analysis is demonstrated. Copyright © 2017 John Wiley & Sons, Ltd.

  4. Compliant Buckled Foam Actuators and Application in Patient-Specific Direct Cardiac Compression.

    Science.gov (United States)

    Mac Murray, Benjamin C; Futran, Chaim C; Lee, Jeanne; O'Brien, Kevin W; Amiri Moghadam, Amir A; Mosadegh, Bobak; Silberstein, Meredith N; Min, James K; Shepherd, Robert F

    2018-02-01

    We introduce the use of buckled foam for soft pneumatic actuators. A moderate amount of residual compressive strain within elastomer foam increases the applied force ∼1.4 × or stroke ∼2 × compared with actuators without residual strain. The origin of these improved characteristics is explained analytically. These actuators are applied in a direct cardiac compression (DCC) device design, a type of implanted mechanical circulatory support that avoids direct blood contact, mitigating risks of clot formation and stroke. This article describes a first step toward a pneumatically powered, patient-specific DCC design by employing elastomer foam as the mechanism for cardiac compression. To form the device, a mold of a patient's heart was obtained by 3D printing a digitized X-ray computed tomography or magnetic resonance imaging scan into a solid model. From this model, a soft, robotic foam DCC device was molded. The DCC device is compliant and uses compressed air to inflate foam chambers that in turn apply compression to the exterior of a heart. The device is demonstrated on a porcine heart and is capable of assisting heart pumping at physiologically relevant durations (∼200 ms for systole and ∼400 ms for diastole) and stroke volumes (∼70 mL). Although further development is necessary to produce a fully implantable device, the material and processing insights presented here are essential to the implementation of a foam-based, patient-specific DCC design.

  5. THE USE OF SPECIFIC AND NON-SPECIFIC QUESTIONNAIRES TO ASSESS QUALITY OF LIFE IN PATIENTS WITH FUNCTIONAL DISORDERS OF INTESTINE

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    A. E. Shklyaev

    2016-01-01

    Full Text Available Objective: comparative assessment of the quality of life of IBS patients in the treatment process with the use of specific and non-specific questionnaires.Materials and methods: a dynamic study of quality of life in 40 patients of IBS with the use of questionnaires GSRS and SF-36.Results: marked decrease in the severity of syndromes on all 6 scales of the questionnaire GSRS, and after 1 to 3 weeks of treatment dynamics was gained statistically significant, and total score improved significantly already after 1 week of therapy. Positive dynamics was obtained on the two scales of the questionnaire SF-36 (social functioning, and emotional functioning, as well as physical and psychological components of health.Conclusions: the high sensitivity of specific questionnaire GSRS and diagnostic significance of nonspecific SF-36 questionnaire in patients with IBS, the necessity to combine them.

  6. Myositis-specific and myositis-associated autoantibodies in Indian patients with inflammatory myositis.

    Science.gov (United States)

    Srivastava, Puja; Dwivedi, Sanjay; Misra, Ramnath

    2016-07-01

    We aimed to study the prevalence and clinical associations of myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs) in a large cohort of Indian patients with idiopathic inflammatory myositis (IIM). Clinical details and serum samples were collected from patients with IIM (satisfying Bohan and Peter Criteria, 1975) and CTD-associated myositis. Sera were analysed for antibodies against SRP, Mi2, Jo1, PL7, PL12, EJ, OJ, Ro52, Ku, Pm-Scl 75 and PM-Scl 100, using immunoblot assay. The cohort comprised 124 patients with IIM (M:F = 1:3.6). Fifty-five of them had dermatomyositis (DM), 22 had juvenile dermatomyositis (JDM), 25 had polymyositis (PM) and 22 had connective tissue disease-associated myositis (CTD myositis). Mean disease duration was 10.9 months. ANA was positive in 84 (68.9 %), and MSAs in 61 (49.2 %) patients. Among MSAs, autoantibodies to Mi2, synthetase (Jo1, PL7, PL12, EJ) and SRP were present in 26 (20.9 %), 29 (23.4 %) and 6 (4.8 %) patients, respectively. Prevalence of MAAs was as follows: antibodies to Ro52 in 45 (36.3 %), Ku and PM-Scl 75 in 13 (10.5 %) and PM-Scl 100 in 5 (4 %) patients. Anti-Mi2 antibodies were positively associated with DM (21/55, 38.2 %; p < 0.0001) and pharyngeal weakness (13/34, 38.2 %; p = 0.004) and negatively associated with ILD (0/28; p = 0.001). ILD and mechanics' hands were significantly more in patients with anti-synthetase antibodies (16/28, 57 % and 14/22, 63.6 %; p < 0.0001). Four of six patients with anti-SRP antibody showed poor response to multiple drugs. Higher prevalence of anti-Mi2 is probably related to higher proportion of patients with DM. Absence of ILD in patients with anti-Mi2 antibody suggests that it may protect against ILD. In Indian population also, anti-synthetase antibodies are associated with ILD, and anti-SRP antibodies with poor response to treatment.

  7. The value of urine specific gravity in detecting diabetes insipidus in a patient with uncontrolled diabetes mellitus: urine specific gravity in differential diagnosis.

    Science.gov (United States)

    Akarsu, Ersin; Buyukhatipoglu, Hakan; Aktaran, Sebnem; Geyik, Ramazan

    2006-11-01

    When a patient with diabetes mellitus presents with worsening polyuria and polydipsia, what is a sensible, cost-effective approach? We report the unique coincidence of type 2 diabetes mellitus and diabetes insipidus. A 46-year-old woman with poorly controlled type 2 diabetes complained of polyuria with a daily output of 5 L. Although urinalysis demonstrated significant glucosuria, diabetes insipidus was suspected owing to a low urine specific gravity (1.008). The low specific gravity persisted during a water deprivation test. Ultimately, diabetes insipidus was confirmed when urine specific gravity and urine osmolality normalized following desmopressin administration. This case emphasizes the importance of accurately interpreting the urine specific gravity in patients with polyuria and diabetes mellitus to detect diabetes insipidus.

  8. Physical properties corresponding to vortical flow geometry

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, K, E-mail: nakayama@aitech.ac.jp [Department of Mechanical Engineering, Aichi Institute of Technology, Toyota, Aichi 470-0392 (Japan)

    2014-10-01

    We examine a vortical flow geometry specified by the velocity gradient tensor ∇v, and derive properties representing the symmetry (axisymmetry or skewness) of the vortical flow in the swirl plane and a property specifying inflowing (outflowing) motion in all directions around the point. We focus on the radial and azimuthal velocities in a plane nonparallel to the eigenvector corresponding to the real eigenvalue of ∇v and show that these components are expressed as specific quadratic forms. The real and imaginary parts of the complex eigenvalues of ∇v represent averages of these eigenvalues of the quadratic forms, and are inadequate to specify the detailed flow geometry uniquely. The new properties complement specifying the precise flow geometry of the vortical flow.

  9. The Value of Urine Specific Gravity in Detecting Diabetes Insipidus in a Patient with Uncontrolled Diabetes Mellitus: Urine Specific Gravity in Differential Diagnosis

    OpenAIRE

    Akarsu, Ersin; Buyukhatipoglu, Hakan; Aktaran, Sebnem; Geyik, Ramazan

    2006-01-01

    When a patient with diabetes mellitus presents with worsening polyuria and polydipsia, what is a sensible, cost-effective approach? We report the unique coincidence of type 2 diabetes mellitus and diabetes insipidus. A 46-year-old woman with poorly controlled type 2 diabetes complained of polyuria with a daily output of 5 L. Although urinalysis demonstrated significant glucosuria, diabetes insipidus was suspected owing to a low urine specific gravity (1.008). The low specific gravity persiste...

  10. Validity of three asthma-specific quality of life questionnaires: the patients' perspective

    Science.gov (United States)

    Jones, Christina J; Frew, Anthony; Smith, Helen

    2016-01-01

    Objectives It is not known which of the many asthma-specific quality of life (QoL) questionnaires best capture the lived experience of people with asthma. The objective of this study was to explore patients' views of three commonly used asthma-specific QoL questionnaires. Design Qualitative study using semistructured interviews. Setting Primary and secondary care in Brighton and Hove, UK. Participants 30 adult people with a physician-diagnosis of asthma who were asked to complete the Juniper Asthma Quality of Life Questionnaire (AQLQ-J), the Sydney Asthma Quality of Life Questionnaire (AQLQ-S) and the Living with Asthma Questionnaire (LWAQ) to elicit their views on the content validity of these. Results Thematic content analysis revealed a lack of congruence between the concerns of people with asthma and the questionnaire content in terms of missing (eg, allergies) and irrelevant (eg, smoky restaurants) content. The AQLQ-J was perceived as a ‘narrow’, ‘medical’ questionnaire focused on symptoms, the environment and functional ability. In contrast, the LWAQ and the AQLQ-S were perceived to be ‘non-medical’. The LWAQ was described as a ‘test’ and as a wide-ranging, embracing and holistic questionnaire. Its strong emotional focus was irritating to some. The AQLQ-S was described as a simple, quick and easy questionnaire, although there was a perception that it was lacking in depth. Conclusions Patient interviews highlighted strengths and shortcomings in the content validity of these three asthma-specific questionnaires. For patients, the AQLQ-S content seemed to be the most pertinent in its adequacy of coverage of medical, social and emotional aspects of health-related QoL in asthma. PMID:28007706

  11. Search for specific biomarkers of IFNβ bioactivity in patients with multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Sunny Malhotra

    Full Text Available Myxovirus A (MxA, a protein encoded by the MX1 gene with antiviral activity, has proven to be a sensitive measure of IFNβ bioactivity in multiple sclerosis (MS. However, the use of MxA as a biomarker of IFNβ bioactivity has been criticized for the lack of evidence of its role on disease pathogenesis and the clinical response to IFNβ. Here, we aimed to identify specific biomarkers of IFNβ bioactivity in order to compare their gene expression induction by type I IFNs with the MxA, and to investigate their potential role in MS pathogenesis. Gene expression microarrays were performed in PBMC from MS patients who developed neutralizing antibodies (NAB to IFNβ at 12 and/or 24 months of treatment and patients who remained NAB negative. Nine genes followed patterns in gene expression over time similar to the MX1, which was considered the gold standard gene, and were selected for further experiments: IFI6, IFI27, IFI44L, IFIT1, HERC5, LY6E, RSAD2, SIGLEC1, and USP18. In vitro experiments in PBMC from healthy controls revealed specific induction of selected biomarkers by IFNβ but not IFNγ, and several markers, in particular USP18 and HERC5, were shown to be significantly induced at lower IFNβ concentrations and more selective than the MX1 as biomarkers of IFNβ bioactivity. In addition, USP18 expression was deficient in MS patients compared with healthy controls (p = 0.0004. We propose specific biomarkers that may be considered in addition to the MxA to evaluate IFNβ bioactivity, and to further explore their implication in MS pathogenesis.

  12. Patient-specific coronary blood supply territories for quantitative perfusion analysis

    Science.gov (United States)

    Zakkaroff, Constantine; Biglands, John D.; Greenwood, John P.; Plein, Sven; Boyle, Roger D.; Radjenovic, Aleksandra; Magee, Derek R.

    2018-01-01

    Abstract Myocardial perfusion imaging, coupled with quantitative perfusion analysis, provides an important diagnostic tool for the identification of ischaemic heart disease caused by coronary stenoses. The accurate mapping between coronary anatomy and under-perfused areas of the myocardium is important for diagnosis and treatment. However, in the absence of the actual coronary anatomy during the reporting of perfusion images, areas of ischaemia are allocated to a coronary territory based on a population-derived 17-segment (American Heart Association) AHA model of coronary blood supply. This work presents a solution for the fusion of 2D Magnetic Resonance (MR) myocardial perfusion images and 3D MR angiography data with the aim to improve the detection of ischaemic heart disease. The key contribution of this work is a novel method for the mediated spatiotemporal registration of perfusion and angiography data and a novel method for the calculation of patient-specific coronary supply territories. The registration method uses 4D cardiac MR cine series spanning the complete cardiac cycle in order to overcome the under-constrained nature of non-rigid slice-to-volume perfusion-to-angiography registration. This is achieved by separating out the deformable registration problem and solving it through phase-to-phase registration of the cine series. The use of patient-specific blood supply territories in quantitative perfusion analysis (instead of the population-based model of coronary blood supply) has the potential of increasing the accuracy of perfusion analysis. Quantitative perfusion analysis diagnostic accuracy evaluation with patient-specific territories against the AHA model demonstrates the value of the mediated spatiotemporal registration in the context of ischaemic heart disease diagnosis. PMID:29392098

  13. The sensitivity of patient specific IMRT QC to systematic MLC leaf bank offset errors

    International Nuclear Information System (INIS)

    Rangel, Alejandra; Palte, Gesa; Dunscombe, Peter

    2010-01-01

    Purpose: Patient specific IMRT QC is performed routinely in many clinics as a safeguard against errors and inaccuracies which may be introduced during the complex planning, data transfer, and delivery phases of this type of treatment. The purpose of this work is to evaluate the feasibility of detecting systematic errors in MLC leaf bank position with patient specific checks. Methods: 9 head and neck (H and N) and 14 prostate IMRT beams were delivered using MLC files containing systematic offsets (±1 mm in two banks, ±0.5 mm in two banks, and 1 mm in one bank of leaves). The beams were measured using both MAPCHECK (Sun Nuclear Corp., Melbourne, FL) and the aS1000 electronic portal imaging device (Varian Medical Systems, Palo Alto, CA). Comparisons with calculated fields, without offsets, were made using commonly adopted criteria including absolute dose (AD) difference, relative dose difference, distance to agreement (DTA), and the gamma index. Results: The criteria most sensitive to systematic leaf bank offsets were the 3% AD, 3 mm DTA for MAPCHECK and the gamma index with 2% AD and 2 mm DTA for the EPID. The criterion based on the relative dose measurements was the least sensitive to MLC offsets. More highly modulated fields, i.e., H and N, showed greater changes in the percentage of passing points due to systematic MLC inaccuracy than prostate fields. Conclusions: None of the techniques or criteria tested is sufficiently sensitive, with the population of IMRT fields, to detect a systematic MLC offset at a clinically significant level on an individual field. Patient specific QC cannot, therefore, substitute for routine QC of the MLC itself.

  14. The sensitivity of patient specific IMRT QC to systematic MLC leaf bank offset errors

    Energy Technology Data Exchange (ETDEWEB)

    Rangel, Alejandra; Palte, Gesa; Dunscombe, Peter [Department of Medical Physics, Tom Baker Cancer Centre, 1331-29 Street NW, Calgary, Alberta T2N 4N2, Canada and Department of Physics and Astronomy, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4 (Canada); Department of Medical Physics, Tom Baker Cancer Centre, 1331-29 Street NW, Calgary, Alberta T2N 4N2 (Canada); Department of Medical Physics, Tom Baker Cancer Centre, 1331-29 Street NW, Calgary, Alberta T2N 4N2 (Canada); Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4 (Canada) and Department of Oncology, Tom Baker Cancer Centre, 1331-29 Street NW, Calgary, Alberta T2N 4N2 (Canada)

    2010-07-15

    Purpose: Patient specific IMRT QC is performed routinely in many clinics as a safeguard against errors and inaccuracies which may be introduced during the complex planning, data transfer, and delivery phases of this type of treatment. The purpose of this work is to evaluate the feasibility of detecting systematic errors in MLC leaf bank position with patient specific checks. Methods: 9 head and neck (H and N) and 14 prostate IMRT beams were delivered using MLC files containing systematic offsets ({+-}1 mm in two banks, {+-}0.5 mm in two banks, and 1 mm in one bank of leaves). The beams were measured using both MAPCHECK (Sun Nuclear Corp., Melbourne, FL) and the aS1000 electronic portal imaging device (Varian Medical Systems, Palo Alto, CA). Comparisons with calculated fields, without offsets, were made using commonly adopted criteria including absolute dose (AD) difference, relative dose difference, distance to agreement (DTA), and the gamma index. Results: The criteria most sensitive to systematic leaf bank offsets were the 3% AD, 3 mm DTA for MAPCHECK and the gamma index with 2% AD and 2 mm DTA for the EPID. The criterion based on the relative dose measurements was the least sensitive to MLC offsets. More highly modulated fields, i.e., H and N, showed greater changes in the percentage of passing points due to systematic MLC inaccuracy than prostate fields. Conclusions: None of the techniques or criteria tested is sufficiently sensitive, with the population of IMRT fields, to detect a systematic MLC offset at a clinically significant level on an individual field. Patient specific QC cannot, therefore, substitute for routine QC of the MLC itself.

  15. Institutional Patient-specific IMRT QA Does Not Predict Unacceptable Plan Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Kry, Stephen F., E-mail: sfkry@mdanderson.org [Imaging and Radiation Oncology Core at Houston, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Molineu, Andrea [Imaging and Radiation Oncology Core at Houston, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kerns, James R.; Faught, Austin M.; Huang, Jessie Y.; Pulliam, Kiley B.; Tonigan, Jackie [Imaging and Radiation Oncology Core at Houston, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); The University of Texas Health Science Center Houston, Graduate School of Biomedical Sciences, Houston, Texas (United States); Alvarez, Paola [Imaging and Radiation Oncology Core at Houston, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Stingo, Francesco [The University of Texas Health Science Center Houston, Graduate School of Biomedical Sciences, Houston, Texas (United States); Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Followill, David S. [Imaging and Radiation Oncology Core at Houston, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); The University of Texas Health Science Center Houston, Graduate School of Biomedical Sciences, Houston, Texas (United States)

    2014-12-01

    Purpose: To determine whether in-house patient-specific intensity modulated radiation therapy quality assurance (IMRT QA) results predict Imaging and Radiation Oncology Core (IROC)-Houston phantom results. Methods and Materials: IROC Houston's IMRT head and neck phantoms have been irradiated by numerous institutions as part of clinical trial credentialing. We retrospectively compared these phantom results with those of in-house IMRT QA (following the institution's clinical process) for 855 irradiations performed between 2003 and 2013. The sensitivity and specificity of IMRT QA to detect unacceptable or acceptable plans were determined relative to the IROC Houston phantom results. Additional analyses evaluated specific IMRT QA dosimeters and analysis methods. Results: IMRT QA universally showed poor sensitivity relative to the head and neck phantom, that is, poor ability to predict a failing IROC Houston phantom result. Depending on how the IMRT QA results were interpreted, overall sensitivity ranged from 2% to 18%. For different IMRT QA methods, sensitivity ranged from 3% to 54%. Although the observed sensitivity was particularly poor at clinical thresholds (eg 3% dose difference or 90% of pixels passing gamma), receiver operator characteristic analysis indicated that no threshold showed good sensitivity and specificity for the devices evaluated. Conclusions: IMRT QA is not a reasonable replacement for a credentialing phantom. Moreover, the particularly poor agreement between IMRT QA and the IROC Houston phantoms highlights surprising inconsistency in the QA process.

  16. Measurement properties of disease-specific questionnaires in patients with neck pain: a systematic review.

    Science.gov (United States)

    Schellingerhout, Jasper M; Verhagen, Arianne P; Heymans, Martijn W; Koes, Bart W; de Vet, Henrica C; Terwee, Caroline B

    2012-05-01

    To critically appraise and compare the measurement properties of the original versions of neck-specific questionnaires. Bibliographic databases were searched for articles concerning the development or evaluation of the measurement properties of an original version of a self-reported questionnaire, evaluating pain and/or disability, which was specifically developed or adapted for patients with neck pain. The methodological quality of the selected studies and the results of the measurement properties were critically appraised and rated using a checklist, specifically designed for evaluating studies on measurement properties. The search strategy resulted in a total of 3,641 unique hits, of which 25 articles, evaluating 8 different questionnaires, were included in our study. The Neck Disability Index is the most frequently evaluated questionnaire and shows positive results for internal consistency, content validity, structural validity, hypothesis testing, and responsiveness, but a negative result for reliability. The other questionnaires show positive results, but the evidence for each measurement property is mostly limited, and at least 50% of the information on measurement properties per questionnaire is lacking. Our findings imply that studies of high methodological quality are needed to properly assess the measurement properties of the currently available questionnaires. Until high quality studies are available, we recommend using these questionnaires with caution. There is no need for the development of new neck-specific questionnaires until the current questionnaires have been adequately assessed.

  17. Institutional Patient-specific IMRT QA Does Not Predict Unacceptable Plan Delivery

    International Nuclear Information System (INIS)

    Kry, Stephen F.; Molineu, Andrea; Kerns, James R.; Faught, Austin M.; Huang, Jessie Y.; Pulliam, Kiley B.; Tonigan, Jackie; Alvarez, Paola; Stingo, Francesco; Followill, David S.

    2014-01-01

    Purpose: To determine whether in-house patient-specific intensity modulated radiation therapy quality assurance (IMRT QA) results predict Imaging and Radiation Oncology Core (IROC)-Houston phantom results. Methods and Materials: IROC Houston's IMRT head and neck phantoms have been irradiated by numerous institutions as part of clinical trial credentialing. We retrospectively compared these phantom results with those of in-house IMRT QA (following the institution's clinical process) for 855 irradiations performed between 2003 and 2013. The sensitivity and specificity of IMRT QA to detect unacceptable or acceptable plans were determined relative to the IROC Houston phantom results. Additional analyses evaluated specific IMRT QA dosimeters and analysis methods. Results: IMRT QA universally showed poor sensitivity relative to the head and neck phantom, that is, poor ability to predict a failing IROC Houston phantom result. Depending on how the IMRT QA results were interpreted, overall sensitivity ranged from 2% to 18%. For different IMRT QA methods, sensitivity ranged from 3% to 54%. Although the observed sensitivity was particularly poor at clinical thresholds (eg 3% dose difference or 90% of pixels passing gamma), receiver operator characteristic analysis indicated that no threshold showed good sensitivity and specificity for the devices evaluated. Conclusions: IMRT QA is not a reasonable replacement for a credentialing phantom. Moreover, the particularly poor agreement between IMRT QA and the IROC Houston phantoms highlights surprising inconsistency in the QA process

  18. Generation of patient-specific induced pluripotent stem cells from Leber's hereditary optic neuropathy

    Directory of Open Access Journals (Sweden)

    Huai-En Lu

    2018-04-01

    Full Text Available Leber's hereditary optic neuropathy (LHON is a maternally inherited mitochondrial disease caused by homoplasmic point mutations in complex I subunit genes of mitochondrial DNA. In this report, we generated an induced pluripotent stem cell (iPSCs line, TVGH-iPSC-010-09, from the peripheral blood mononuclear cells of a female patient with Leber's hereditary optic neuropathy (LHON by using the Sendai-virus delivery system. The resulting iPSCs retained the disease-causing mitochondrial DNA mutation, expressed pluripotent markers and could differentiate into the three germ layers. We believe LHON patient-specific iPSCs provide a powerful in vitro model for evaluating the pathological phenotypes of the disease.

  19. Type-specific proactive interference in patients with semantic and phonological STM deficits.

    Science.gov (United States)

    Harris, Lara; Olson, Andrew; Humphreys, Glyn

    2014-01-01

    Prior neuropsychological evidence suggests that semantic and phonological components of short-term memory (STM) are functionally and neurologically distinct. The current paper examines proactive interference (PI) from semantic and phonological information in two STM-impaired patients, DS (semantic STM deficit) and AK (phonological STM deficit). In Experiment 1 probe recognition tasks with open and closed sets of stimuli were used. Phonological PI was assessed using nonword items, and semantic and phonological PI was assessed using words. In Experiment 2 phonological and semantic PI was elicited by an item recognition probe test with stimuli that bore phonological and semantic relations to the probes. The data suggested heightened phonological PI for the semantic STM patient, and exaggerated effects of semantic PI in the phonological STM case. The findings are consistent with an account of extremely rapid decay of activated type-specific representations in cases of severely impaired phonological and semantic STM.

  20. Real algebraic geometry

    CERN Document Server

    Bochnak, Jacek; Roy, Marie-Françoise

    1998-01-01

    This book is a systematic treatment of real algebraic geometry, a subject that has strong interrelation with other areas of mathematics: singularity theory, differential topology, quadratic forms, commutative algebra, model theory, complexity theory etc. The careful and clearly written account covers both basic concepts and up-to-date research topics. It may be used as text for a graduate course. The present edition is a substantially revised and expanded English version of the book "Géometrie algébrique réelle" originally published in French, in 1987, as Volume 12 of ERGEBNISSE. Since the publication of the French version the theory has made advances in several directions. Many of these are included in this English version. Thus the English book may be regarded as a completely new treatment of the subject.

  1. Critique of information geometry

    International Nuclear Information System (INIS)

    Skilling, John

    2014-01-01

    As applied to probability, information geometry fails because probability distributions do not form a metric space. Probability theory rests on a compelling foundation of elementary symmetries, which also support information (aka minus entropy, Kullback-Leibler) H(p;q) as the unique measure of divergence from source probability distribution q to destination p. Because the only compatible connective H is from≠to asymmetric, H(p;q)≠H(q;p), there can be no compatible geometrical distance (which would necessarily be from=to symmetric). Hence there is no distance relationship compatible with the structure of probability theory. Metrics g and densities sqrt(det(g)) interpreted as prior probabilities follow from the definition of distance, and must fail likewise. Various metrics and corresponding priors have been proposed, Fisher's being the most popular, but all must behave unacceptably. This is illustrated with simple counter-examples

  2. Geometry from Gauge Theory

    International Nuclear Information System (INIS)

    Correa, Diego H.; Silva, Guillermo A.

    2008-01-01

    We discuss how geometrical and topological aspects of certain (1/2)-BPS type IIB geometries are captured by their dual operators in N = 4 Super Yang-Mills theory. The type IIB solutions are characterized by arbitrary droplet pictures in a plane and we consider, in particular, axially symmetric droplets. The 1-loop anomalous dimension of the dual gauge theory operators probed with single traces is described by some bosonic lattice Hamiltonians. These Hamiltonians are shown to encode the topology of the droplets. In appropriate BMN limits, the Hamiltonians spectrum reproduces the spectrum of near-BPS string excitations propagating along each of the individual edges of the droplet. We also study semiclassical regimes for the Hamiltonians. For droplets having disconnected constituents, the Hamiltonian admits different complimentary semiclassical descriptions, each one replicating the semiclassical description for closed strings extending in each of the constituents

  3. Emergent geometry of membranes

    Energy Technology Data Exchange (ETDEWEB)

    Badyn, Mathias Hudoba de; Karczmarek, Joanna L.; Sabella-Garnier, Philippe; Yeh, Ken Huai-Che [Department of Physics and Astronomy, University of British Columbia,6224 Agricultural Road, Vancouver (Canada)

    2015-11-13

    In work http://dx.doi.org/10.1103/PhysRevD.86.086001, a surface embedded in flat ℝ{sup 3} is associated to any three hermitian matrices. We study this emergent surface when the matrices are large, by constructing coherent states corresponding to points in the emergent geometry. We find the original matrices determine not only shape of the emergent surface, but also a unique Poisson structure. We prove that commutators of matrix operators correspond to Poisson brackets. Through our construction, we can realize arbitrary noncommutative membranes: for example, we examine a round sphere with a non-spherically symmetric Poisson structure. We also give a natural construction for a noncommutative torus embedded in ℝ{sup 3}. Finally, we make remarks about area and find matrix equations for minimal area surfaces.

  4. A magic bullet to specifically eliminate mutated mitochondrial genomes from patients' cells

    Science.gov (United States)

    Moraes, Carlos T

    2014-01-01

    When mitochondrial diseases result from mutations found in the mitochondrial DNA, engineered mitochondrial-targeted nucleases such as mitochondrial-targeted zinc finger nucleases are shown to specifically eliminate the mutated molecules, leaving the wild-type mitochondrial DNA intact to replicate and restore normal copy number. In this issue, Gammage and colleagues successfully apply this improved technology on patients' cells with two types of genetic alterations responsible for neuropathy ataxia and retinitis pigmentosa (NARP) syndrome and Kearns Sayre syndrome and progressive external ophthalmoplegia (PEO). PMID:24623377

  5. Patient-specific three-dimensional printing for pre-surgical planning in hepatocellular carcinoma treatment.

    Science.gov (United States)

    Perica, Elizabeth; Sun, Zhonghua

    2017-12-01

    Recently, three-dimensional (3D) printing has shown great interest in medicine, and 3D printed models may be rendered as part of the pre-surgical planning process in order to better understand the complexities of an individual's anatomy. The aim of this study is to investigate the feasibility of utilising 3D printed liver models as clinical tools in pre-operative planning for resectable hepatocellular carcinoma (HCC) lesions. High-resolution contrast-enhanced computed tomography (CT) images were acquired and utilized to generate a patient-specific 3D printed liver model. Hepatic structures were segmented and edited to produce a printable model delineating intrahepatic anatomy and a resectable HCC lesion. Quantitative assessment of 3D model accuracy compared measurements of critical anatomical landmarks acquired from the original CT images, standard tessellation language (STL) files, and the 3D printed liver model. Comparative analysis of surveys completed by two radiologists investigated the clinical value of 3D printed liver models in radiology. The application of utilizing 3D printed liver models as tools in surgical planning for resectable HCC lesions was evaluated through kappa analysis of questionnaires completed by two abdominal surgeons. A scaled down multi-material 3D liver model delineating patient-specific hepatic anatomy and pathology was produced, requiring a total production time of 25.25 hours and costing a total of AUD $1,250. A discrepancy was found in the total mean of measurements at each stage of production, with a total mean of 18.28±9.31 mm for measurements acquired from the original CT data, 15.63±8.06 mm for the STL files, and 14.47±7.71 mm for the 3D printed liver model. The 3D liver model did not enhance the radiologists' perception of patient-specific anatomy or pathology. Kappa analysis of the surgeon's responses to survey questions yielded a percentage agreement of 80%, and a κ value of 0.38 (P=0.24) indicating fair agreement. Study

  6. SPECIFIC CHARACTERISTICS OF BRAIN METASTASIZING IN PATIENTS WITH LUMINAL SUBTYPE OF BREAST CANCER

    Directory of Open Access Journals (Sweden)

    A. S. Balkanov

    2016-01-01

    Full Text Available Background: More than half of female patients with breast cancer are diagnosed with a  luminal subtype of the disease; however, specific characteristics of its metastases to the brain have been not well studied, unlike those of HER2 positive and triple negative subtypes. Aim: A  comparative analysis of characteristics of metastatic brain lesions in patients with luminal breast cancer. Materials and methods: The time from surgery for breast cancer to the first recurrence and to metastatic brain lesions (assessed by contrast-enhanced MRI imaging was measured in 41 patients with luminal subtype of breast cancer (median age, 49.5±9.6  years, depending on a  diameter of the primary tumor and numbers of involved axillary lymph nodes. Results: The time interval to occurrence of brain metastases in luminal subtype of breast cancer is not associated with the size of the tumor. If≥4  axillary lymph nodes are involved (N2–3, brain metastases are identified much earlier (p<0.05 than in patients with N0–1 (34.5±23.9 months and 62.7±50 months, respectively. Neither the size nor the involvement of axillary lymph nodes has any impact on the rates of metastatic lesion to the brain during the first recurrence. Conclusion: Brain metastases occur at a much shorter time in those patients of luminal subtype of breast cancer who have metastases in≥4  axillary lymph nodes. Brain metastases develop in 50% of patients with the first recurrence of the luminal subtype of breast cancer.

  7. Disease-specific quality of life in young patients with tourette syndrome.

    Science.gov (United States)

    Cavanna, Andrea E; Luoni, Chiara; Selvini, Claudia; Blangiardo, Rosanna; Eddy, Clare M; Silvestri, Paola R; Calì, Paola V; Gagliardi, Emanuela; Balottin, Umberto; Cardona, Francesco; Rizzo, Renata; Termine, Cristiano

    2013-02-01

    Tourette syndrome is a neurodevelopmental disorder characterized by multiple tics and is often associated with comorbid behavioral problems. Research with generic instruments in child populations showed that comorbid disorders can have a greater impact on health-related quality of life than tic severity. This study investigated the usefulness of a newly developed disease-specific instrument, the Gilles de la Tourette Syndrome-Quality of Life Scale for Children and Adolescents (GTS-QOL-C&A), in assessing health-related quality of life in young patients with Tourette syndrome with and without behavioral comorbidity. We recruited 75 patients with Tourette syndrome (60 males; age 12.4 ± 3.2 years). All participants were evaluated by a neuropsychiatrist and completed a standardized psychometric battery, including the GTS-QOL-C&A, Child Depression Inventory, and Multidimensional Anxiety Scale for Children. Forty-two patients (56%) fulfilled diagnostic criteria for at least one comorbidity: obsessive-compulsive disorder (n = 25 patients [33.3%]); attention deficit/hyperactivity disorder (n = 6 patients [8%]); both (n = 11 patients [14.7%]). The GTS-QOL-C&A demonstrated usefulness in differentiating "pure" Tourette syndrome from Tourette syndrome "plus" behavioral problems with regard to health-related quality of life scores for the obsessive-compulsive subscale. In addition to focusing on core tic symptoms, the GTS-QOL-C&A showed sensitivity to the impact of behavioral comorbidities on health-related quality of life and can usefully complement existing nonspecific instruments. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Craniofacial reconstruction using patient-specific implants polyether ether ketone with computer-assisted planning.

    Science.gov (United States)

    Manrique, Oscar J; Lalezarzadeh, Frank; Dayan, Erez; Shin, Joseph; Buchbinder, Daniel; Smith, Mark

    2015-05-01

    Reconstruction of bony craniofacial defects requires precise understanding of the anatomic relationships. The ideal reconstructive technique should be fast as well as economical, with minimal donor-site morbidity, and provide a lasting and aesthetically pleasing result. There are some circumstances in which a patient's own tissue is not sufficient to reconstruct defects. The development of sophisticated software has facilitated the manufacturing of patient-specific implants (PSIs). The aim of this study was to analyze the utility of polyether ether ketone (PEEK) PSIs for craniofacial reconstruction. We performed a retrospective chart review from July 2009 to July 2013 in patients who underwent craniofacial reconstruction using PEEK-PSIs using a virtual process based on computer-aided design and computer-aided manufacturing. A total of 6 patients were identified. The mean age was 46 years (16-68 y). Operative indications included cancer (n = 4), congenital deformities (n = 1), and infection (n = 1). The mean surgical time was 3.7 hours and the mean hospital stay was 1.5 days. The mean surface area of the defect was 93.4 ± 43.26 cm(2), the mean implant cost was $8493 ± $837.95, and the mean time required to manufacture the implants was 2 weeks. No major or minor complications were seen during the 4-year follow-up. We found PEEK implants to be useful in the reconstruction of complex calvarial defects, demonstrating a low complication rate, good outcomes, and high patient satisfaction in this small series of patients. Polyether ether ketone implants show promising potential and warrant further study to better establish the role of this technology in cranial reconstruction.

  9. Health-related quality of life of food allergic patients measured with generic and disease-specific questionnaires

    NARCIS (Netherlands)

    Flokstra-de Blok, B. M. J.; van der Velde, J. L.; Vlieg-Boerstra, B. J.; Oude Elberink, J. N. G.; DunnGalvin, A.; Hourihane, J. O.'B.; Duiverman, E. J.; Dubois, A. E. J.

    2010-01-01

    Health-related quality of life (HRQL) has never been measured with both generic and disease-specific questionnaires in the same group of food allergic patients. The aim of this study was to compare HRQL of food allergic patients as measured with generic and disease-specific questionnaires. Generic

  10. Health-related quality of life of food allergic patients measured with generic and disease-specific questionnaires

    NARCIS (Netherlands)

    Flokstra-de Blok, B. M. J.; van der Velde, J. L.; Vlieg-Boerstra, B. J.; Oude Elberink, J. N. G.; DunnGalvin, A.; Hourihane, J. O'B.; Duiverman, E. J.; Dubois, A. E. J.

    P>Background: Health-related quality of life (HRQL) has never been measured with both generic and disease-specific questionnaires in the same group of food allergic patients. The aim of this study was to compare HRQL of food allergic patients as measured with generic and disease-specific

  11. On the relationship between pain intensity and postural sway in patients with non-specific neck pain

    DEFF Research Database (Denmark)

    Ruhe, Alexander; Fejer, René; Walker, Bruce

    2013-01-01

    Increased center of pressure excursions are well documented in patients with non-specific neck pain. While a linear relationship between pain intensity and postural sway has been described in low back pain patients, no such investigation has been conducted in adults with non-specific neck pain....

  12. Circulating interleukin-18: A specific biomarker for atherosclerosis-prone patients with metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Nemoto Shinji

    2011-01-01

    Full Text Available Abstract Background Metabolic syndrome (MetS is associated with an increased risk of the development of atherosclerotic cardiovascular disease (CVD. Interleukin-18 (IL-18, which is a pleiotropic proinflammatory cytokine with important regulatory functions in the innate immune response system, plays a crucial role in vascular pathologies. IL-18 is also a predictor of cardiovascular death in patients with CVD and is involved in atherosclerotic plaque destabilization. Results In order to determine if circulating levels of IL-18 can serve as a specific biomarker for distinguishing MetS patients from pre-MetS subjects, we studied 78 patients with visceral fat deposition and 14 age-matched control subjects. Increased levels of IL-18 were observed more frequently in patients with MetS than in pre-MetS subjects and were positively associated with waist circumference. Serum levels of IL-18 were significantly reduced by a change in weight caused by lifestyle modifications. There was a significant interaction between waist circumference and serum IL-18 concentration. Weight loss of at least 5% of the body weight caused by lifestyle modification decreased IL-18 circulating levels relative to the reduction in waist circumference and blood pressure, suggesting that this degree of weight loss benefits the cardiovascular system. Conclusion IL-18 may be a useful biomarker of the clinical manifestations of MetS and for the management of the risk factors of CVD.

  13. Patient specific quality assurance of IMRT: quantitative approach using film dosimetry and optimization

    International Nuclear Information System (INIS)

    Shin, Kyung Hwan; Park, Sung Yong; Park, Dong Hyun

    2005-01-01

    Film dosimetry an a part of patient specific intensity modulated radiation therapy quality assurance (IMRT QA) was performed to develop a new optimization method of film isocenter offset and to then suggest new quantitative criteria for film dosimetry. Film dosimetry was performed on 14 IMRT patients with head and neck cancers. An optimization method for obtaining the local minimum was developed to adjust for the error in the film isocenter offset, which is the largest part of the systemic errors. The adjust value of the film isocenter offset under optimization was 1 mm in 12 patients, while only two patients showed 2 mm translation. The means of absolute average dose difference before and after optimization were 2.36 and 1.56%, respectively, and the mean radios over a 5% tolerance were 9.67 and 2.88%. After optimization, the differences in the dose decreased dramatically. A low dose range cutoff (L-Cutoff) had been suggested for clinical application. New quantitative criteria of a ratio of over a 5%, but less than 10% tolerance, and for an absolute average dose difference less than 3% have been suggested for the verification of film dosimetry. The new optimization method was effective in adjusting for the film dosimetry error, and the newly quantitative criteria suggested in this research are believed to be sufficiently accurate and clinically useful

  14. The Effect of Femoral Cutting Guide Design Improvements for Patient-Specific Instruments

    Directory of Open Access Journals (Sweden)

    Oh-Ryong Kwon

    2015-01-01

    Full Text Available Although the application of patient-specific instruments (PSI for total knee arthroplasty (TKA increases the cost of the surgical procedure, PSI may reduce operative time and improve implant alignment, which could reduce the number of revision surgeries. We report our experience with TKA using PSI techniques in 120 patients from March to December 2014. PSI for TKA were created from data provided by computed tomography (CT scans or magnetic resonance imaging (MRI; which imaging technology is more reliable for the PSI technique remains unclear. In the first 20 patients, the accuracy of bone resection and PSI stability were compared between CT and MRI scans with presurgical results as a reference; MRI produced better results. In the second and third groups, each with 50 patients, the results of bone resection and stability were compared in MRI scans with respect to the quality of scanning due to motion artifacts and experienced know-how in PSI design, respectively. The optimized femoral cutting guide design for PSI showed the closest outcomes in bone resection and PSI stability with presurgical data. It is expected that this design could be a reasonable guideline in PSI.

  15. Cost-effectiveness of specific subcutaneous immunotherapy in patients with allergic rhinitis and allergic asthma.

    Science.gov (United States)

    Brüggenjürgen, Bernd; Reinhold, Thomas; Brehler, Randolf; Laake, Eckard; Wiese, Günther; Machate, Ulrich; Willich, Stefan N

    2008-09-01

    Specific immunotherapy is the only potentially curative treatment in patients with allergic rhinitis and allergic asthma. Health economic evaluations on this treatment, particularly in a German context, are sparse. To evaluate the cost-effectiveness of specific subcutaneous immunotherapy (SCIT) in addition to symptomatic treatment (ST) compared with ST alone in a German health care setting. The analysis was performed as a health economic model calculation based on Markov models. In addition, we performed a concomitant expert board composed of allergy experts in pediatrics, dermatology, pneumology, and otolaryngology. The primary perspective of the study was societal. Additional sensitivity analyses were performed to prove our results for robustness. The SCIT and ST combination was associated with annual cost savings of Euro140 per patient. After 10 years of disease duration, SCIT and ST reach the breakeven point. The overall incremental cost-effectiveness ratio (ICER) was Euro-19,787 per quality-adjusted life-year (QALY), with a range that depended on patient age (adults, Euro-22,196; adolescents, Euro-14,747; children, Euro-12,750). From a third-party payer's perspective, SCIT was associated with slightly additional costs. Thus, the resulting ICER was Euro8,308 per QALY for all patients. Additional SCIT was associated with improved medical outcomes and cost savings compared with symptomatic treatment alone according to a societal perspective. Taking a European accepted ICER threshold of up to Euro50,000 per QALY into account, additional SCIT is considered clearly cost-effective compared with routine care in Germany. The degree of cost-effectiveness is strongly affected by costs related to SCIT and the target population receiving such treatment.

  16. Patient-specific pediatric silicone heart valve models based on 3D ultrasound

    Science.gov (United States)

    Ilina, Anna; Lasso, Andras; Jolley, Matthew A.; Wohler, Brittany; Nguyen, Alex; Scanlan, Adam; Baum, Zachary; McGowan, Frank; Fichtinger, Gabor

    2017-03-01

    PURPOSE: Patient-specific heart and valve models have shown promise as training and planning tools for heart surgery, but physically realistic valve models remain elusive. Available proprietary, simulation-focused heart valve models are generic adult mitral valves and do not allow for patient-specific modeling as may be needed for rare diseases such as congenitally abnormal valves. We propose creating silicone valve models from a 3D-printed plastic mold as a solution that can be adapted to any individual patient and heart valve at a fraction of the cost of direct 3D-printing using soft materials. METHODS: Leaflets of a pediatric mitral valve, a tricuspid valve in a patient with hypoplastic left heart syndrome, and a complete atrioventricular canal valve were segmented from ultrasound images. A custom software was developed to automatically generate molds for each valve based on the segmentation. These molds were 3D-printed and used to make silicone valve models. The models were designed with cylindrical rims of different sizes surrounding the leaflets, to show the outline of the valve and add rigidity. Pediatric cardiac surgeons practiced suturing on the models and evaluated them for use as surgical planning and training tools. RESULTS: Five out of six surgeons reported that the valve models would be very useful as training tools for cardiac surgery. In this first iteration of valve models, leaflets were felt to be unrealistically thick or stiff compared to real pediatric leaflets. A thin tube rim was preferred for valve flexibility. CONCLUSION: The valve models were well received and considered to be valuable and accessible tools for heart valve surgery training. Further improvements will be made based on surgeons' feedback.

  17. Geometry through history Euclidean, hyperbolic, and projective geometries

    CERN Document Server

    Dillon, Meighan I

    2018-01-01

    Presented as an engaging discourse, this textbook invites readers to delve into the historical origins and uses of geometry. The narrative traces the influence of Euclid’s system of geometry, as developed in his classic text The Elements, through the Arabic period, the modern era in the West, and up to twentieth century mathematics. Axioms and proof methods used by mathematicians from those periods are explored alongside the problems in Euclidean geometry that lead to their work. Students cultivate skills applicable to much of modern mathematics through sections that integrate concepts like projective and hyperbolic geometry with representative proof-based exercises. For its sophisticated account of ancient to modern geometries, this text assumes only a year of college mathematics as it builds towards its conclusion with algebraic curves and quaternions. Euclid’s work has affected geometry for thousands of years, so this text has something to offer to anyone who wants to broaden their appreciation for the...

  18. Patient-specific dosimetry of 99mTc-HYNIC-Tyr3-Octreotide in patients with neuroendocrine tumors

    International Nuclear Information System (INIS)

    Chalkia, M.T.; Stefanoyiannis, A.P.; Prentakis, A.; Chatziioannou, S.N.; Armeniakos, I.; Geronikola-Trapali, X.; Liotsou, T.; Efstathopoulos, E.P.

    2015-01-01

    : 0.005 - 0.021 mGy/MBq; -) Urinary bladder: 0.007 - 0.042 mGy/MBq; -) NETs: 0.005 - 0.028 mGy/MBq. Conclusion: the dosimetric results of this study are in agreement with other published data, demonstrating that even a simple patient-specific 2-dimensional dosimetric protocol, relatively easily adopted in clinical routine, can be proved efficient. Despite the fact that spleen receives the highest absorbed dose, kidneys are considered to be the dose-limiting organs in case of subsequent PRRT, due to their higher radiosensitivity. Significant interpatient dose and volume variations in organs and tumors necessitate the application of patient-specific dosimetry. (authors)

  19. On organizing principles of discrete differential geometry. Geometry of spheres

    International Nuclear Information System (INIS)

    Bobenko, Alexander I; Suris, Yury B

    2007-01-01

    Discrete differential geometry aims to develop discrete equivalents of the geometric notions and methods of classical differential geometry. This survey contains a discussion of the following two fundamental discretization principles: the transformation group principle (smooth geometric objects and their discretizations are invariant with respect to the same transformation group) and the consistency principle (discretizations of smooth parametrized geometries can be extended to multidimensional consistent nets). The main concrete geometric problem treated here is discretization of curvature-line parametrized surfaces in Lie geometry. Systematic use of the discretization principles leads to a discretization of curvature-line parametrization which unifies circular and conical nets.

  20. Higher geometry an introduction to advanced methods in analytic geometry

    CERN Document Server

    Woods, Frederick S

    2005-01-01

    For students of mathematics with a sound background in analytic geometry and some knowledge of determinants, this volume has long been among the best available expositions of advanced work on projective and algebraic geometry. Developed from Professor Woods' lectures at the Massachusetts Institute of Technology, it bridges the gap between intermediate studies in the field and highly specialized works.With exceptional thoroughness, it presents the most important general concepts and methods of advanced algebraic geometry (as distinguished from differential geometry). It offers a thorough study

  1. Segmenting CT prostate images using population and patient-specific statistics for radiotherapy

    International Nuclear Information System (INIS)

    Feng, Qianjin; Foskey, Mark; Chen Wufan; Shen Dinggang

    2010-01-01

    Purpose: In the segmentation of sequential treatment-time CT prostate images acquired in image-guided radiotherapy, accurately capturing the intrapatient variation of the patient under therapy is more important than capturing interpatient variation. However, using the traditional deformable-model-based segmentation methods, it is difficult to capture intrapatient variation when the number of samples from the same patient is limited. This article presents a new deformable model, designed specifically for segmenting sequential CT images of the prostate, which leverages both population and patient-specific statistics to accurately capture the intrapatient variation of the patient under therapy. Methods: The novelty of the proposed method is twofold: First, a weighted combination of gradient and probability distribution function (PDF) features is used to build the appearance model to guide model deformation. The strengths of each feature type are emphasized by dynamically adjusting the weight between the profile-based gradient features and the local-region-based PDF features during the optimization process. An additional novel aspect of the gradient-based features is that, to alleviate the effect of feature inconsistency in the regions of gas and bone adjacent to the prostate, the optimal profile length at each landmark is calculated by statistically investigating the intensity profile in the training set. The resulting gradient-PDF combined feature produces more accurate and robust segmentations than general gradient features. Second, an online learning mechanism is used to build shape and appearance statistics for accurately capturing intrapatient variation. Results: The performance of the proposed method was evaluated on 306 images of the 24 patients. Compared to traditional gradient features, the proposed gradient-PDF combination features brought 5.2% increment in the success ratio of segmentation (from 94.1% to 99.3%). To evaluate the effectiveness of online

  2. Aberrant allele-specific replication, independent of parental origin, in blood cells of cancer patients

    International Nuclear Information System (INIS)

    Dotan, Zohar A; Dotan, Aviva; Ramon, Jacob; Avivi, Lydia

    2008-01-01

    Allelic counterparts of biallelically expressed genes display an epigenetic symmetry normally manifested by synchronous replication, different from genes subjected to monoallelic expression, which normally are characterized by an asynchronous mode of replication (well exemplified by the SNRPN imprinted locus). Malignancy was documented to be associated with gross modifications in the inherent replication-timing coordination between allelic counterparts of imprinted genes as well as of biallelically expressed loci. The cancer-related allelic replication timing aberrations are non-disease specific and appear in peripheral blood cells of cancer patients, including those with solid tumors. As such they offer potential blood markers for non-invasive cancer test. The present study was aimed to gain some insight into the mechanism leading to the replication timing alterations of genes in blood lymphocytes of cancer patients. Peripheral blood samples derived from patients with prostate cancer were chosen to represent the cancerous status, and samples taken from patients with no cancer but with benign prostate hyperplasia were used to portray the normal status. Fluorescence In Situ Hybridization (FISH) replication assay, applied to phytohemagglutinin (PHA)-stimulated blood lymphocytes, was used to evaluate the temporal order (either synchronous or asynchronous) of genes in the patients' cells. We demonstrated that: (i) the aberrant epigenetic profile, as delineated by the cancer status, is a reversible modification, evidenced by our ability to restore the normal patterns of replication in three unrelated loci (CEN15, SNRPN and RB1) by introducing an archetypical demethylating agent, 5-azacytidine; (ii) following the rehabilitating effect of demethylation, an imprinted gene (SNRPN) retains its original parental imprint; and (iii) the choice of an allele between early or late replication in the aberrant asynchronous replication, delineated by the cancer status, is not

  3. Segmenting CT prostate images using population and patient-specific statistics for radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Qianjin; Foskey, Mark; Chen Wufan; Shen Dinggang [Biomedical Engineering College, South Medical University, Guangzhou (China) and Department of Radiology, University of North Carolina, Chapel Hill, North Carolina 27510 (United States); Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Biomedical Engineering College, South Medical University, Guangzhou 510510 (China); Department of Radiology, University of North Carolina, Chapel Hill, North Carolina 27510 (United States)

    2010-08-15

    Purpose: In the segmentation of sequential treatment-time CT prostate images acquired in image-guided radiotherapy, accurately capturing the intrapatient variation of the patient under therapy is more important than capturing interpatient variation. However, using the traditional deformable-model-based segmentation methods, it is difficult to capture intrapatient variation when the number of samples from the same patient is limited. This article presents a new deformable model, designed specifically for segmenting sequential CT images of the prostate, which leverages both population and patient-specific statistics to accurately capture the intrapatient variation of the patient under therapy. Methods: The novelty of the proposed method is twofold: First, a weighted combination of gradient and probability distribution function (PDF) features is used to build the appearance model to guide model deformation. The strengths of each feature type are emphasized by dynamically adjusting the weight between the profile-based gradient features and the local-region-based PDF features during the optimization process. An additional novel aspect of the gradient-based features is that, to alleviate the effect of feature inconsistency in the regions of gas and bone adjacent to the prostate, the optimal profile length at each landmark is calculated by statistically investigating the intensity profile in the training set. The resulting gradient-PDF combined feature produces more accurate and robust segmentations than general gradient features. Second, an online learning mechanism is used to build shape and appearance statistics for accurately capturing intrapatient variation. Results: The performance of the proposed method was evaluated on 306 images of the 24 patients. Compared to traditional gradient features, the proposed gradient-PDF combination features brought 5.2% increment in the success ratio of segmentation (from 94.1% to 99.3%). To evaluate the effectiveness of online

  4. SPANDY: a Monte Carlo program for gas target scattering geometry

    International Nuclear Information System (INIS)

    Jarmie, N.; Jett, J.H.; Niethammer, A.C.

    1977-02-01

    A Monte Carlo computer program is presented that simulates a two-slit gas target scattering geometry. The program is useful in estimating effects due to finite geometry and multiple scattering in the target foil. Details of the program are presented and experience with a specific example is discussed

  5. Torsional Newton-Cartan Geometry and Lifshitz Holography

    NARCIS (Netherlands)

    Christensen, M.H.; Hartong, J.; Obers, N.A.; Rollier, B.

    2014-01-01

    We obtain the Lifshitz UV completion in a specific model for z=2 Lifshitz geometries. We use a vielbein formalism which enables identification of all the sources as leading components of well-chosen bulk fields. We show that the geometry induced from the bulk onto the boundary is a novel extension

  6. Specific vulnerability of face perception to noise: a similar effect in schizophrenia patients and healthy individuals.

    Science.gov (United States)

    Chen, Yue; McBain, Ryan; Norton, Daniel

    2015-02-28

    Face perception plays a foundational role in the social world. This perceptual ability is deficient in schizophrenia. A noise-filtering mechanism is essential for perceptual processing. It remains unclear as to whether a specific noise-filtering mechanism is implicated in the face perception problem or a general noise-filtering mechanism is involved which also mediates non-face visual perception problems associated with this psychiatric disorder. This study examined and compared the effects of external noise on the performance of face discrimination and car discrimination in schizophrenia patients (n=25) and healthy controls (n=27). Superimposing the external visual noise on face or car stimuli elevated perceptual thresholds (i.e. degraded performance levels) for both face and car discrimination. However, the effect of noise was significantly larger on face than on car discrimination, both in patients and controls. This pattern of results suggests specific vulnerability of face processing to noise in healthy individuals and those with schizophrenia. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. Microwave beamforming for non-invasive patient-specific hyperthermia treatment of pediatric brain cancer

    International Nuclear Information System (INIS)

    Burfeindt, Matthew J; Zastrow, Earl; Hagness, Susan C; Van Veen, Barry D; Medow, Joshua E

    2011-01-01

    We present a numerical study of an array-based microwave beamforming approach for non-invasive hyperthermia treatment of pediatric brain tumors. The transmit beamformer is designed to achieve localized heating-that is, to achieve constructive interference and selective absorption of the transmitted electromagnetic waves at the desired focus location in the brain while achieving destructive interference elsewhere. The design process takes into account patient-specific and target-specific propagation characteristics at 1 GHz. We evaluate the effectiveness of the beamforming approach using finite-difference time-domain simulations of two MRI-derived child head models from the Virtual Family (IT'IS Foundation). Microwave power deposition and the resulting steady-state thermal distribution are calculated for each of several randomly chosen focus locations. We also explore the robustness of the design to mismatch between the assumed and actual dielectric properties of the patient. Lastly, we demonstrate the ability of the beamformer to suppress hot spots caused by pockets of cerebrospinal fluid (CSF) in the brain. Our results show that microwave beamforming has the potential to create localized heating zones in the head models for focus locations that are not surrounded by large amounts of CSF. These promising results suggest that the technique warrants further investigation and development.

  8. Precision Oncology Medicine: The Clinical Relevance of Patient-Specific Biomarkers Used to Optimize Cancer Treatment.

    Science.gov (United States)

    Schmidt, Keith T; Chau, Cindy H; Price, Douglas K; Figg, William D

    2016-12-01

    Precision medicine in oncology is the result of an increasing awareness of patient-specific clinical features coupled with the development of genomic-based diagnostics and targeted therapeutics. Companion diagnostics designed for specific drug-target pairs were the first to widely utilize clinically applicable tumor biomarkers (eg, HER2, EGFR), directing treatment for patients whose tumors exhibit a mutation susceptible to an FDA-approved targeted therapy (eg, trastuzumab, erlotinib). Clinically relevant germline mutations in drug-metabolizing enzymes and transporters (eg, TPMT, DPYD) have been shown to impact drug response, providing a rationale for individualized dosing to optimize treatment. The use of multigene expression-based assays to analyze an array of prognostic biomarkers has been shown to help direct treatment decisions, especially in breast cancer (eg, Oncotype DX). More recently, the use of next-generation sequencing to detect many potential "actionable" cancer molecular alterations is further shifting the 1 gene-1 drug paradigm toward a more comprehensive, multigene approach. Currently, many clinical trials (eg, NCI-MATCH, NCI-MPACT) are assessing novel diagnostic tools with a combination of different targeted therapeutics while also examining tumor biomarkers that were previously unexplored in a variety of cancer histologies. Results from ongoing trials such as the NCI-MATCH will help determine the clinical utility and future development of the precision-medicine approach. © 2016, The American College of Clinical Pharmacology.

  9. Interplay of Proximal Flow Confluence and Distal Flow Divergence in Patient-Specific Vertebrobasilar System.

    Directory of Open Access Journals (Sweden)

    Xiaoping Yin

    Full Text Available Approximately one-quarter of ischemic strokes involve the vertebrobasilar arterial system that includes the upstream flow confluence and downstream flow divergence. A patient-specific hemodynamic analysis is needed to understand the posterior circulation. The objective of this study is to determine the distribution of hemodynamic parameters in the vertebrobasilar system, based on computer tomography angiography images. Here, the interplay of upstream flow confluence and downstream flow divergence was hypothesized to be a determinant factor for the hemodynamic distribution in the vertebrobasilar system. A computational fluid dynamics model was used to compute the flow fields in patient-specific vertebrobasilar models (n = 6. The inlet and outlet boundary conditions were the aortic pressure waveform and flow resistances, respectively. A 50% reduction of total outlet area was found to induce a ten-fold increase in surface area ratio of low time-averaged wall shear stress (i.e., TAWSS ≤ 4 dynes/cm2. This study enhances our understanding of the posterior circulation associated with the incidence of atherosclerotic plaques.

  10. Dosimetric characterization of an a-based EPID for quality control if patient-specific IMRT

    International Nuclear Information System (INIS)

    Larrinaga Cortina, Eduardo Francisco; Alfonso Laguardia, Rodolfo; Silvestre Patallo, Ileana; Garcia Yip, Fernando

    2009-01-01

    The Electronic portal imaging devices, EPID for its acronym in English is a technology widely used for verification of patient positioning on linear accelerators routinely. Its use as a dosimetry device is not as widespread, although many researches in this field. It assessed the availability and versatility of the use EPID based on an amorphous silicon (a-Si) as a means of quality control specific patient for a methodology of Radiation Intensity Modulated IMRT. Dosimetric parameters were determined for the linearity of dose versus response, dispersion and sensitivity factors off-axis radiation. For absolute measurements the linearity of the dose-response relationship EPID was better than 1.1 and 1.5% for photon beams of 6 and 15mV respectively, in the range from 2 to 500 UM. The dose dependence with field size was studied and compared with the factors of dispersion in water at different depths, in agreement with those measured at 5 cm depth, Scp (z = 5cm). Off-axis sensitivity of the EPID was determined by comparing the measured profiles versus the same profiles at different depths in water. The best correspondence was observed at 5 cm depth, where the EPID response underestimates the dose to 4% for all sizes of fields in the plateau area. The EPID can be used for the evaluation of dosimetric parameters of the beam at a specific depth in water of 5 cm and a discrepancy in an acceptable maximum rate of 4%. (author)

  11. An efficient parallel simulation of unsteady blood flows in patient-specific pulmonary artery.

    Science.gov (United States)

    Kong, Fande; Kheyfets, Vitaly; Finol, Ender; Cai, Xiao-Chuan

    2018-04-01

    Simulation of blood flows in the pulmonary artery provides some insight into certain diseases by examining the relationship between some continuum metrics, eg, the wall shear stress acting on the vascular endothelium, which responds to flow-induced mechanical forces by releasing vasodilators/constrictors. V. Kheyfets, in his previous work, studies numerically a patient-specific pulmonary circulation to show that decreasing wall shear stress is correlated with increasing pulmonary vascular impedance. In this paper, we develop a scalable parallel algorithm based on domain decomposition methods to investigate an unsteady model with patient-specific pulsatile waveforms as the inlet boundary condition. The unsteady model offers tremendously more information about the dynamic behavior of the flow field, but computationally speaking, the simulation is a lot more expensive since a problem which is similar to the steady-state problem has to be solved many times, and therefore, the traditional sequential approach is not suitable anymore. We show computationally that simulations using the proposed parallel approach with up to 10 000 processor cores can be obtained with much reduced compute time. This makes the technology potentially usable for the routine study of the dynamic behavior of blood flows in the pulmonary artery, in particular, the changes of the blood flows and the wall shear stress in the spatial and temporal dimensions. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Motor recovery in post-stroke patients with aphasia: the role of specific linguistic abilities.

    Science.gov (United States)

    Ginex, Valeria; Veronelli, Laura; Vanacore, Nicola; Lacorte, Eleonora; Monti, Alessia; Corbo, Massimo

    2017-09-01

    Aphasia is a serious consequence of stroke but aphasics patients have been routinely excluded from participation in some areas of stroke research. To assess the role of specific linguistic and non-verbal cognitive abilities on the short-term motor recovery of patients with aphasia due to first-ever stroke to the left hemisphere after an intensive rehabilitation treatment. 48 post-acute aphasic patients, who underwent physiotherapy and speech language therapy, were enrolled for this retrospective cohort-study. Four types of possible predictive factors were taken into account: clinical variables, functional status, language and non-verbal cognitive abilities. The motor FIM at discharge was used as the main dependent variable. Patients were classified as follows: 6 amnestic, 9 Broca's, 7 Wernicke's, and 26 global aphasics. Motor FIM at admission (p = 0.003) and at discharge (p = 0.042), all linguistic subtests of Aachener AphasieTest (p = 0.001), and non-verbal reasoning abilities (Raven's CPM, p = 0.006) resulted significantly different across different types of aphasia. Post-hoc analyses showed differences only between global aphasia and the other groups. A Multiple Linear Regression shows that admission motor FIM (p = 0.001) and Token test (p = 0.040), adjusted for clinical, language, and non-verbal reasoning variables, resulted as independent predictors of motor FIM scores at discharge, while Raven's CPM resulted close to statistical significance. Motor function at admission resulted as the variable that most affects the motor recovery of post-stroke patients with aphasia after rehabilitation. A linguistic test requiring also non-linguistic abilities, including attention and working memory (i.e. Token test) is an independent predictor as well.

  13. Profound tumor-specific Th2 bias in patients with malignant glioma

    International Nuclear Information System (INIS)

    Shimato, Shinji; Maier, Lisa M; Maier, Richard; Bruce, Jeffrey N; Anderson, Richard CE; Anderson, David E

    2012-01-01

    Vaccination against tumor-associated antigens is one promising approach to immunotherapy against malignant gliomas. While previous vaccine efforts have focused exclusively on HLA class I-restricted peptides, class II-restricted peptides are necessary to induce CD4 + helper T cells and sustain effective anti-tumor immunity. In this report we investigated the ability of five candidate peptide epitopes derived from glioma-associated antigens MAGE and IL-13 receptor α2 to detect and characterize CD4 + helper T cell responses in the peripheral blood of patients with malignant gliomas. Primary T cell responses were determined by stimulating freshly isolated PBMCs from patients with primary glioblastoma (GBM) (n = 8), recurrent GBM (n = 5), meningioma (n = 7), and healthy controls (n = 6) with each candidate peptide, as well as anti-CD3 monoclonal antibody (mAb) and an immunodominant peptide epitope derived from myelin basic protein (MBP) serving as positive and negative controls, respectively. ELISA was used to measure IFN-γ and IL-5 levels, and the ratio of IFN-γ/IL-5 was used to determine whether the response had a predominant Th1 or Th2 bias. We demonstrate that novel HLA Class-II restricted MAGE-A3 and IL-13Rα2 peptides can detect T cell responses in patients with GBMs as well as in healthy subjects. Stimulation with a variety of peptide antigens over-expressed by gliomas is associated with a profound reduction in the IFN-γ/IL-5 ratio in GBM patients relative to healthy subjects. This bias is more pronounced in patients with recurrent GBMs. Therapeutic vaccine strategies to shift tumor antigen-specific T cell response to a more immunostimulatory Th1 bias may be needed for immunotherapeutic trials to be more successful clinically

  14. Patient-specific radiation dose and cancer risk for pediatric chest CT.

    Science.gov (United States)

    Li, Xiang; Samei, Ehsan; Segars, W Paul; Sturgeon, Gregory M; Colsher, James G; Frush, Donald P

    2011-06-01

    To estimate patient-specific radiation dose and cancer risk for pediatric chest computed tomography (CT) and to evaluate factors affecting dose and risk, including patient size, patient age, and scanning parameters. The institutional review board approved this study and waived informed consent. This study was HIPAA compliant. The study included 30 patients (0-16 years old), for whom full-body computer models were recently created from clinical CT data. A validated Monte Carlo program was used to estimate organ dose from eight chest protocols, representing clinically relevant combinations of bow tie filter, collimation, pitch, and tube potential. Organ dose was used to calculate effective dose and risk index (an index of total cancer incidence risk). The dose and risk estimates before and after normalization by volume-weighted CT dose index (CTDI(vol)) or dose-length product (DLP) were correlated with patient size and age. The effect of each scanning parameter was studied. Organ dose normalized by tube current-time product or CTDI(vol) decreased exponentially with increasing average chest diameter. Effective dose normalized by tube current-time product or DLP decreased exponentially with increasing chest diameter. Chest diameter was a stronger predictor of dose than weight and total scan length. Risk index normalized by tube current-time product or DLP decreased exponentially with both chest diameter and age. When normalized by DLP, effective dose and risk index were independent of collimation, pitch, and tube potential (chest CT protocols. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101900/-/DC1. RSNA, 2011

  15. The prevalence and specific characteristics of hospitalised pressure ulcer patients: A multicentre cross-sectional study.

    Science.gov (United States)

    Zhou, Qing; Yu, Ting; Liu, Yuan; Shi, Ruifen; Tian, Suping; Yang, Chaoxia; Gan, Huaxiu; Zhu, Yanying; Liang, Xia; Wang, Ling; Wu, Zhenhua; Huang, Jinping; Hu, Ailing

    2018-02-01

    To ascertain the pressure ulcer prevalence in secondary and tertiary general hospitals in different areas of Guangdong Province in China and explore the possible risk factors that are related to pressure ulcers. Few multicentre studies have been conducted on pressure ulcer prevalence in Chinese hospitals. A cross-sectional study design was used. Data from a total of 25,264 patients were included in the analysis at 25 hospitals in China. The investigators were divided into two groups. The investigators in group 1 examined the patients' skin. When a pressure ulcer was found, a pressure ulcer assessment form was completed. The investigators in group 2 provided guidance to the nurses, who assessed all patients and completed another questionnaire. A multivariate logistic regression analysis was used to analyse the relationship between the possible risk factors and pressure ulcer. The overall prevalence rate of pressure ulcers in the 25 hospitals ranged from 0%-3.49%, with a mean of 1.26%. The most common stage of the pressure ulcers was stage II (41.4%); most common anatomical locations were sacrum (39.5%) and the feet (16.4%). Braden score (p pressure ulcers from the multivariate logistic regression analysis. The overall prevalence rate of pressure ulcers in Chinese hospitals was lower than that reported in previous investigations. Specific characteristics of pressure ulcer patients were as follows: low Braden score, longer expected length of stay, double incontinence, an ICU and a medical ward, hospital location in the Pearl River Delta, a university hospital and an older patient. The survey could make managers know their prevalence level of pressure ulcers and provide priorities for clinical nurses. © 2017 John Wiley & Sons Ltd.

  16. 3D fluoroscopic image estimation using patient-specific 4DCBCT-based motion models

    International Nuclear Information System (INIS)

    Dhou, S; Hurwitz, M; Cai, W; Rottmann, J; Williams, C; Wagar, M; Berbeco, R; Lewis, J H; Mishra, P; Li, R; Ionascu, D

    2015-01-01

    3D fluoroscopic images represent volumetric patient anatomy during treatment with high spatial and temporal resolution. 3D fluoroscopic images estimated using motion models built using 4DCT images, taken days or weeks prior to treatment, do not reliably represent patient anatomy during treatment. In this study we developed and performed initial evaluation of techniques to develop patient-specific motion models from 4D cone-beam CT (4DCBCT) images, taken immediately before treatment, and used these models to estimate 3D fluoroscopic images based on 2D kV projections captured during treatment. We evaluate the accuracy of 3D fluoroscopic images by comparison to ground truth digital and physical phantom images. The performance of 4DCBCT-based and 4DCT-based motion models are compared in simulated clinical situations representing tumor baseline shift or initial patient positioning errors. The results of this study demonstrate the ability for 4DCBCT imaging to generate motion models that can account for changes that cannot be accounted for with 4DCT-based motion models. When simulating tumor baseline shift and patient positioning errors of up to 5 mm, the average tumor localization error and the 95th percentile error in six datasets were 1.20 and 2.2 mm, respectively, for 4DCBCT-based motion models. 4DCT-based motion models applied to the same six datasets resulted in average tumor localization error and the 95th percentile error of 4.18 and 5.4 mm, respectively. Analysis of voxel-wise intensity differences was also conducted for all experiments. In summary, this study demonstrates the feasibility of 4DCBCT-based 3D fluoroscopic image generation in digital and physical phantoms and shows the potential advantage of 4DCBCT-based 3D fluoroscopic image estimation when there are changes in anatomy between the time of 4DCT imaging and the time of treatment delivery. (paper)

  17. Relationship of specific MRI findings to treatment outcomes in patients receiving transforaminal epidural steroid injections

    Energy Technology Data Exchange (ETDEWEB)

    Lechmann, Marco; Rosskopf, Andrea; Ehrmann, Christine; Sutter, Reto; Pfirrmann, Christian W.A.; Peterson, Cynthia K. [University of Zuerich, Department of Radiology, Orthopaedic University Hospital Balgrist, Zuerich (Switzerland)

    2016-12-15

    To determine whether specific MRI findings are related to outcomes after lumbar transforaminal epidural steroid injections (TFESI) and to assess the inter-rater reliability of imaging diagnosis. A prospective outcomes study on 156 consecutive patients with 1-month follow-up outcomes data and MRI within 3 months of TFESI was conducted. Pain levels (numerical rating scale) (NRS) were recorded prior to injection. Overall 'improvement' was determined using the Patients Global Impression of Change (PGIC) scale and NRS data were collected at three time points post injection. Two radiologists independently evaluated all images blinded to treatment outcome for reliability of diagnosis. The Chi-square test compared MRI findings for the senior radiologist to 'improvement'. NRS change scores were compared to MRI findings with the unpaired t-test or ANOVA. Kappa and percent agreement assessed inter-rater agreement of diagnosis. The only abnormality linked to 'improvement' (p = 0.03) and higher NRS change scores (p = 0.0001) at 1 month was the disc herniation morphology 'protrusion + sequestration'. Patients with degeneration by osteophytes (p = 0.034), grade 3 foraminal nerve root compression (p = 0.01) and foraminal/extraforaminal location of herniation (p = 0.014) also had higher 1 month NRS change scores. Reliability of diagnosis was 'fair' to 'substantial' depending on MRI findings. Patients with disc protrusion plus sequestration were significantly more likely to report overall improvement and more pain reduction at 1 month. Higher pain reduction was noted in patients with degeneration by osteophytes, grade 3 foraminal nerve root compression, or foraminal/extraforaminal disc herniation location. (orig.)

  18. Influence of model boundary conditions on blood flow patterns in a patient specific stenotic right coronary artery.

    Science.gov (United States)

    Liu, Biyue; Zheng, Jie; Bach, Richard; Tang, Dalin

    2015-01-01

    In literature, the effect of the inflow boundary condition was investigated by examining the impact of the waveform and the shape of the spatial profile of the inlet velocity on the cardiac hemodynamics. However, not much work has been reported on comparing the effect of the different combinations of the inlet/outlet boundary conditions on the quantification of the pressure field and flow distribution patterns in stenotic right coronary arteries. Non-Newtonian models were used to simulate blood flow in a patient-specific stenotic right coronary artery and investigate the influence of different boundary conditions on the phasic variation and the spatial distribution patterns of blood flow. The 3D geometry of a diseased artery segment was reconstructed from a series of IVUS slices. Five different combinations of the inlet and the outlet boundary conditions were tested and compared. The temporal distribution patterns and the magnitudes of the velocity, the wall shear stress (WSS), the pressure, the pressure drop (PD), and the spatial gradient of wall pressure (WPG) were different when boundary conditions were imposed using different pressure/velocity combinations at inlet/outlet. The maximum velocity magnitude in a cardiac cycle at the center of the inlet from models with imposed inlet pressure conditions was about 29% lower than that from models using fully developed inlet velocity data. Due to the fact that models with imposed pressure conditions led to blunt velocity profile, the maximum wall shear stress at inlet in a cardiac cycle from models with imposed inlet pressure conditions was about 29% higher than that from models with imposed inlet velocity boundary conditions. When the inlet boundary was imposed by a velocity waveform, the models with different outlet boundary conditions resulted in different temporal distribution patterns and magnitudes of the phasic variation of pressure. On the other hand, the type of different boundary conditions imposed at the

  19. Development and application of CATIA-GDML geometry builder

    International Nuclear Information System (INIS)

    Belogurov, S; Chernogorov, A; Ovcharenko, E; Schetinin, V; Berchun, Yu; Malzacher, P

    2014-01-01

    Due to conceptual difference between geometry descriptions in Computer-Aided Design (CAD) systems and particle transport Monte Carlo (MC) codes direct conversion of detector geometry in either direction is not feasible. The paper presents an update on functionality and application practice of the CATIA-GDML geometry builder first introduced at CHEP2010. This set of CATIAv5 tools has been developed for building a MC optimized GEANT4/ROOT compatible geometry based on the existing CAD model. The model can be exported via Geometry Description Markup Language (GDML). The builder allows also import and visualization of GEANT4/ROOT geometries in CATIA. The structure of a GDML file, including replicated volumes, volume assemblies and variables, is mapped into a part specification tree. A dedicated file template, a wide range of primitives, tools for measurement and implicit calculation of parameters, different types of multiple volume instantiation, mirroring, positioning and quality check have been implemented. Several use cases are discussed.

  20. An introduction to incidence geometry

    CERN Document Server

    De Bruyn, Bart

    2016-01-01

    This book gives an introduction to the field of Incidence Geometry by discussing the basic families of point-line geometries and introducing some of the mathematical techniques that are essential for their study. The families of geometries covered in this book include among others the generalized polygons, near polygons, polar spaces, dual polar spaces and designs. Also the various relationships between these geometries are investigated. Ovals and ovoids of projective spaces are studied and some applications to particular geometries will be given. A separate chapter introduces the necessary mathematical tools and techniques from graph theory. This chapter itself can be regarded as a self-contained introduction to strongly regular and distance-regular graphs. This book is essentially self-contained, only assuming the knowledge of basic notions from (linear) algebra and projective and affine geometry. Almost all theorems are accompanied with proofs and a list of exercises with full solutions is given at the end...

  1. Treatment planning for image-guided neuro-vascular interventions using patient-specific 3D printed phantoms

    Science.gov (United States)

    Russ, M.; O'Hara, R.; Setlur Nagesh, S. V.; Mokin, M.; Jimenez, C.; Siddiqui, A.; Bednarek, D.; Rudin, S.; Ionita, C.

    2015-03-01

    Minimally invasive endovascular image-guided interventions (EIGIs) are the preferred procedures for treatment of a wide range of vascular disorders. Despite benefits including reduced trauma and recovery time, EIGIs have their own challenges. Remote catheter actuation and challenging anatomical morphology may lead to erroneous endovascular device selections, delays or even complications such as vessel injury. EIGI planning using 3D phantoms would allow interventionists to become familiarized with the patient vessel anatomy by first performing the planned treatment on a phantom under standard operating protocols. In this study the optimal workflow to obtain such phantoms from 3D data for interventionist to practice on prior to an actual procedure was investigated. Patientspecific phantoms and phantoms presenting a wide range of challenging geometries were created. Computed Tomographic Angiography (CTA) data was uploaded into a Vitrea 3D station which allows segmentation and resulting stereo-lithographic files to be exported. The files were uploaded using processing software where preloaded vessel structures were included to create a closed-flow vasculature having structural support. The final file was printed, cleaned, connected to a flow loop and placed in an angiographic room for EIGI practice. Various Circle of Willis and cardiac arterial geometries were used. The phantoms were tested for ischemic stroke treatment, distal catheter navigation, aneurysm stenting and cardiac imaging under angiographic guidance. This method should allow for adjustments to treatment plans to be made before the patient is actually in the procedure room and enabling reduced risk of peri-operative complications or delays.

  2. Patient-specific distal radius locking plate for fixation and accurate 3D positioning in corrective osteotomy.

    Science.gov (United States)

    Dobbe, J G G; Vroemen, J C; Strackee, S D; Streekstra, G J

    2014-11-01

    Preoperative three-dimensional planning methods have been described extensively. However, transferring the virtual plan to the patient is often challenging. In this report, we describe the management of a severely malunited distal radius fracture using a patient-specific plate for accurate spatial positioning and fixation. Twenty months postoperatively the patient shows almost painless reconstruction and a nearly normal range of motion.

  3. Sensitivity and specificity of the amer dizziness diagnostic scale (adds) for patients with vestibular disorders.

    Science.gov (United States)

    Al Saif, Amer; Alsenany, Samira

    2015-01-01

    [Purpose] To investigate the sensitivity and specificity of a newly developed diagnostic tool, the Amer Dizziness Diagnostic Scale (ADDS), to evaluate and differentially diagnose vestibular disorder and to identify the strengths and weaknesses of the scale and its usefulness in clinical practice. [Subjects and Methods] Two hundred subjects of both genders (72 males, 128 females) aged between 18 to 60 (49.5±7.8) who had a history of vertigo and/or dizziness symptoms for this previous two weeks or less were recruited for the study. All subjects were referred by otolaryngologists, neurologists or family physicians in and around Jeddah, Kingdom of Saudi Arabia. On the first clinic visit, all the patients were evaluated once using the ADDS, following which they underwent routine testing of clinical signs and symptoms, audiometry, and a neurological examination, coupled with tests of Vestibulo-Ocular Reflex function, which often serves as the "gold standard" for determining the probability of a vestibular deficit. [Results] The results show that the ADDS strongly correlated with "true-positive" and "true-negative" responses for determining the probability of a vestibular disorder (r =0.95). A stepwise linear regression was conducted and the results indicate that the ADDS was a significant predictor of "true-positive" and "true-negative" responses in vestibular disorders (R(2) =0.90). Approximately 90% of the variability in the vestibular gold standard test was explained by its relationship to the ADDS. Moreover, the ADDS was found to have a sensitivity of 96% and a specificity of 96%. [Conclusion] This study showed that the Amer Dizziness Diagnostic Scale has high sensitivity and specificity and that it can be used as a method of differential diagnosis for patients with vestibular disorders.

  4. Evolution of design considerations in complex craniofacial reconstruction using patient-specific implants.

    Science.gov (United States)

    Peel, Sean; Bhatia, Satyajeet; Eggbeer, Dominic; Morris, Daniel S; Hayhurst, Caroline

    2017-06-01

    Previously published evidence has established major clinical benefits from using computer-aided design, computer-aided manufacturing, and additive manufacturing to produce patient-specific devices. These include cutting guides, drilling guides, positioning guides, and implants. However, custom devices produced using these methods are still not in routine use, particularly by the UK National Health Service. Oft-cited reasons for this slow uptake include the following: a higher up-front cost than conventionally fabricated devices, material-choice uncertainty, and a lack of long-term follow-up due to their relatively recent introduction. This article identifies a further gap in current knowledge - that of design rules, or key specification considerations for complex computer-aided design/computer-aided manufacturing/additive manufacturing devices. This research begins to address the gap by combining a detailed review of the literature with first-hand experience of interdisciplinary collaboration on five craniofacial patient case studies. In each patient case, bony lesions in the orbito-temporal region were segmented, excised, and reconstructed in the virtual environment. Three cases translated these digital plans into theatre via polymer surgical guides. Four cases utilised additive manufacturing to fabricate titanium implants. One implant was machined from polyether ether ketone. From the literature, articles with relevant abstracts were analysed to extract design considerations. In all, 19 frequently recurring design considerations were extracted from previous publications. Nine new design considerations were extracted from the case studies - on the basis of subjective clinical evaluation. These were synthesised to produce a design considerations framework to assist clinicians with prescribing and design engineers with modelling. Promising avenues for further research are proposed.

  5. Towards Effective and Efficient Patient-Specific Quality Assurance for Spot Scanning Proton Therapy

    Directory of Open Access Journals (Sweden)

    X. Ronald. Zhu

    2015-04-01

    Full Text Available An intensity-modulated proton therapy (IMPT patient-specific quality assurance (PSQA program based on measurement alone can be very time consuming due to the highly modulated dose distributions of IMPT fields. Incorporating independent dose calculation and treatment log file analysis could reduce the time required for measurements. In this article, we summarize our effort to develop an efficient and effective PSQA program that consists of three components: measurements, independent dose calculation, and analysis of patient-specific treatment delivery log files. Measurements included two-dimensional (2D measurements using an ionization chamber array detector for each field delivered at the planned gantry angles with the electronic medical record (EMR system in the QA mode and the accelerator control system (ACS in the treatment mode, and additional measurements at depths for each field with the ACS in physics mode and without the EMR system. Dose distributions for each field in a water phantom were calculated independently using a recently developed in-house pencil beam algorithm and compared with those obtained using the treatment planning system (TPS. The treatment log file for each field was analyzed in terms of deviations in delivered spot positions from their planned positions using various statistical methods. Using this improved PSQA program, we were able to verify the integrity of the data transfer from the TPS to the EMR to the ACS, the dose calculation of the TPS, and the treatment delivery, including the dose delivered and spot positions. On the basis of this experience, we estimate that the in-room measurement time required for each complex IMPT case (e.g., a patient receiving bilateral IMPT for head and neck cancer is less than 1 h using the improved PSQA program. Our experience demonstrates that it is possible to develop an efficient and effective PSQA program for IMPT with the equipment and resources available in the clinic.

  6. Patient-specific in silico models can quantify primary implant stability in elderly human bone.

    Science.gov (United States)

    Steiner, Juri A; Hofmann, Urs A T; Christen, Patrik; Favre, Jean M; Ferguson, Stephen J; van Lenthe, G Harry

    2018-03-01

    Secure implant fixation is challenging in osteoporotic bone. Due to the high variability in inter- and intra-patient bone quality, ex vivo mechanical testing of implants in bone is very material- and time-consuming. Alternatively, in silico models could substantially reduce costs and speed up the design of novel implants if they had the capability to capture the intricate bone microstructure. Therefore, the aim of this study was to validate a micro-finite element model of a multi-screw fracture fixation system. Eight human cadaveric humerii were scanned using micro-CT and mechanically tested to quantify bone stiffness. Osteotomy and fracture fixation were performed, followed by mechanical testing to quantify displacements at 12 different locations on the instrumented bone. For each experimental case, a micro-finite element model was created. From the micro-finite element analyses of the intact model, the patient-specific bone tissue modulus was determined such that the simulated apparent stiffness matched the measured stiffness of the intact bone. Similarly, the tissue modulus of a small damage region around each screw was determined for the instrumented bone. For validation, all in silico models were rerun using averaged material properties, resulting in an average coefficient of determination of 0.89 ± 0.04 with a slope of 0.93 ± 0.19 and a mean absolute error of 43 ± 10 μm when correlating in silico marker displacements with the ex vivo test. In conclusion, we validated a patient-specific computer model of an entire organ bone-implant system at the tissue-level at high resolution with excellent overall accuracy. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:954-962, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  7. Machine learning-based patient specific prompt-gamma dose monitoring in proton therapy

    Science.gov (United States)

    Gueth, P.; Dauvergne, D.; Freud, N.; Létang, J. M.; Ray, C.; Testa, E.; Sarrut, D.

    2013-07-01

    Online dose monitoring in proton therapy is currently being investigated with prompt-gamma (PG) devices. PG emission was shown to be correlated with dose deposition. This relationship is mostly unknown under real conditions. We propose a machine learning approach based on simulations to create optimized treatment-specific classifiers that detect discrepancies between planned and delivered dose. Simulations were performed with the Monte-Carlo platform Gate/Geant4 for a spot-scanning proton therapy treatment and a PG camera prototype currently under investigation. The method first builds a learning set of perturbed situations corresponding to a range of patient translation. This set is then used to train a combined classifier using distal falloff and registered correlation measures. Classifier performances were evaluated using receiver operating characteristic curves and maximum associated specificity and sensitivity. A leave-one-out study showed that it is possible to detect discrepancies of 5 mm with specificity and sensitivity of 85% whereas using only distal falloff decreases the sensitivity down to 77% on the same data set. The proposed method could help to evaluate performance and to optimize the design of PG monitoring devices. It is generic: other learning sets of deviations, other measures and other types of classifiers could be studied to potentially reach better performance. At the moment, the main limitation lies in the computation time needed to perform the simulations.

  8. Machine learning-based patient specific prompt-gamma dose monitoring in proton therapy

    International Nuclear Information System (INIS)

    Gueth, P; Freud, N; Létang, J M; Sarrut, D; Dauvergne, D; Ray, C; Testa, E

    2013-01-01

    Online dose monitoring in proton therapy is currently being investigated with prompt-gamma (PG) devices. PG emission was shown to be correlated with dose deposition. This relationship is mostly unknown under real conditions. We propose a machine learning approach based on simulations to create optimized treatment-specific classifiers that detect discrepancies between planned and delivered dose. Simulations were performed with the Monte-Carlo platform Gate/Geant4 for a spot-scanning proton therapy treatment and a PG camera prototype currently under investigation. The method first builds a learning set of perturbed situations corresponding to a range of patient translation. This set is then used to train a combined classifier using distal falloff and registered correlation measures. Classifier performances were evaluated using receiver operating characteristic curves and maximum associated specificity and sensitivity. A leave-one-out study showed that it is possible to detect discrepancies of 5 mm with specificity and sensitivity of 85% whereas using only distal falloff decreases the sensitivity down to 77% on the same data set. The proposed method could help to evaluate performance and to optimize the design of PG monitoring devices. It is generic: other learning sets of deviations, other measures and other types of classifiers could be studied to potentially reach better performance. At the moment, the main limitation lies in the computation time needed to perform the simulations. (paper)

  9. Patient-specific quality assurance for the delivery of 60Co intensity modulated radiation therapy subject to a 0.35 T lateral magnetic field

    Science.gov (United States)

    Li, H. Harold; Rodriguez, Vivian L.; Green, Olga L.; Hu, Yanle; Kashani, Rojano; Wooten, H. Omar; Yang, Deshan; Mutic, Sasa

    2014-01-01

    Purpose This work describes a patient-specific dosimetry quality assurance (QA) program for intensity modulated radiation therapy (IMRT) using ViewRay, the first commercial magnetic resonance imaging guided radiation therapy device. Methods and materials The program consisted of the following components: 1) one-dimensional multipoint ionization chamber measurement using a customized 15 cm3 cubic phantom, 2) two-dimensional (2D) radiographic film measurement using a 30×30×20 cm3 phantom with multiple inserted ionization chambers, 3) quasi- three-dimensional (3D) diode array (ArcCHECK) measurement with a centrally inserted ionization chamber, 4) 2D fluence verification using machine delivery log files, and 5) 3D Monte-Carlo (MC) dose reconstruction with machine delivery files and phantom CT. Results The ionization chamber measurements agreed well with treatment planning system (TPS) computed doses in all phantom geometries where the mean difference (mean ± SD) was 0.0% ± 1.3% (n=102, range, −3.0 % to 2.9%). The film measurements also showed excellent agreement with the TPS computed 2D dose distributions where the mean passing rate using 3% relative/3 mm gamma criteria was 94.6% ± 3.4% (n=30, range, 87.4% to 100%). For ArcCHECK measurements, the mean passing rate using 3% relative/3 mm gamma criteria was 98.9% ± 1.1% (n=34, range, 95.8% to 100%). 2D fluence maps with a resolution of 1×1 mm2 showed 100% passing rates for all plan deliveries (n=34). The MC reconstructed doses to the phantom agreed well with planned 3D doses where the mean passing rate using 3% absolute/3 mm gamma criteria was 99.0% ± 1.0% (n=18, range, 97.0% to100%), demonstrating the feasibility of evaluating the QA results in the patient geometry. Conclusions We have developed a dosimetry program for ViewRay’s patient-specific IMRT QA. The methodology will be useful for other ViewRay users. The QA results presented here can assist the RT community to establish appropriate tolerance and

  10. Patient-specific quality assurance for the delivery of (60)Co intensity modulated radiation therapy subject to a 0.35-T lateral magnetic field.

    Science.gov (United States)

    Li, H Harold; Rodriguez, Vivian L; Green, Olga L; Hu, Yanle; Kashani, Rojano; Wooten, H Omar; Yang, Deshan; Mutic, Sasa

    2015-01-01

    This work describes a patient-specific dosimetry quality assurance (QA) program for intensity modulated radiation therapy (IMRT) using ViewRay, the first commercial magnetic resonance imaging-guided RT device. The program consisted of: (1) a 1-dimensional multipoint ionization chamber measurement using a customized 15-cm(3) cube-shaped phantom; (2) 2-dimensional (2D) radiographic film measurement using a 30- × 30- × 20-cm(3) phantom with multiple inserted ionization chambers; (3) quasi-3D diode array (ArcCHECK) measurement with a centrally inserted ionization chamber; (4) 2D fluence verification using machine delivery log files; and (5) 3D Monte Carlo (MC) dose reconstruction with machine delivery files and phantom CT. Ionization chamber measurements agreed well with treatment planning system (TPS)-computed doses in all phantom geometries where the mean ± SD difference was 0.0% ± 1.3% (n=102; range, -3.0%-2.9%). Film measurements also showed excellent agreement with the TPS-computed 2D dose distributions where the mean passing rate using 3% relative/3 mm gamma criteria was 94.6% ± 3.4% (n=30; range, 87.4%-100%). For ArcCHECK measurements, the mean ± SD passing rate using 3% relative/3 mm gamma criteria was 98.9% ± 1.1% (n=34; range, 95.8%-100%). 2D fluence maps with a resolution of 1 × 1 mm(2) showed 100% passing rates for all plan deliveries (n=34). The MC reconstructed doses to the phantom agreed well with planned 3D doses where the mean passing rate using 3% absolute/3 mm gamma criteria was 99.0% ± 1.0% (n=18; range, 97.0%-100%), demonstrating the feasibility of evaluating the QA results in the patient geometry. We developed a dosimetry program for ViewRay's patient-specific IMRT QA. The methodology will be useful for other ViewRay users. The QA results presented here can assist the RT community to establish appropriate tolerance and action limits for ViewRay's IMRT QA. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Patient-Specific Quality Assurance for the Delivery of 60Co Intensity Modulated Radiation Therapy Subject to a 0.35-T Lateral Magnetic Field

    International Nuclear Information System (INIS)

    Li, H. Harold; Rodriguez, Vivian L.; Green, Olga L.; Hu, Yanle; Kashani, Rojano; Wooten, H. Omar; Yang, Deshan; Mutic, Sasa

    2015-01-01

    Purpose: This work describes a patient-specific dosimetry quality assurance (QA) program for intensity modulated radiation therapy (IMRT) using ViewRay, the first commercial magnetic resonance imaging-guided RT device. Methods and Materials: The program consisted of: (1) a 1-dimensional multipoint ionization chamber measurement using a customized 15-cm 3 cube-shaped phantom; (2) 2-dimensional (2D) radiographic film measurement using a 30- × 30- × 20-cm 3 phantom with multiple inserted ionization chambers; (3) quasi-3D diode array (ArcCHECK) measurement with a centrally inserted ionization chamber; (4) 2D fluence verification using machine delivery log files; and (5) 3D Monte Carlo (MC) dose reconstruction with machine delivery files and phantom CT. Results: Ionization chamber measurements agreed well with treatment planning system (TPS)-computed doses in all phantom geometries where the mean ± SD difference was 0.0% ± 1.3% (n=102; range, −3.0%-2.9%). Film measurements also showed excellent agreement with the TPS-computed 2D dose distributions where the mean passing rate using 3% relative/3 mm gamma criteria was 94.6% ± 3.4% (n=30; range, 87.4%-100%). For ArcCHECK measurements, the mean ± SD passing rate using 3% relative/3 mm gamma criteria was 98.9% ± 1.1% (n=34; range, 95.8%-100%). 2D fluence maps with a resolution of 1 × 1 mm 2 showed 100% passing rates for all plan deliveries (n=34). The MC reconstructed doses to the phantom agreed well with planned 3D doses where the mean passing rate using 3% absolute/3 mm gamma criteria was 99.0% ± 1.0% (n=18; range, 97.0%-100%), demonstrating the feasibility of evaluating the QA results in the patient geometry. Conclusions: We developed a dosimetry program for ViewRay's patient-specific IMRT QA. The methodology will be useful for other ViewRay users. The QA results presented here can assist the RT community to establish appropriate tolerance and action limits for ViewRay's IMRT

  12. Casimir forces and geometry

    International Nuclear Information System (INIS)

    Buescher, R.

    2005-01-01

    Casimir interactions are interactions induced by quantum vacuum fluctuations and thermal fluctuations of the electromagnetic field. Using a path integral quantization for the gauge field, an effective Gaussian action will be derived which is the starting point to compute Casimir forces between macroscopic objects analytically and numerically. No assumptions about the independence of the material and shape dependent contributions to the interaction are made. We study the limit of flat surfaces in further detail and obtain a concise derivation of Lifshitz' theory of molecular forces. For the case of ideally conducting boundaries, the Gaussian action will be calculated explicitly. Both limiting cases are also discussed within the framework of a scalar field quantization approach, which is applicable for translationally invariant geometries. We develop a non-perturbative approach to calculate the Casimir interaction from the Gaussian action for periodically deformed and ideally conducting objects numerically. The obtained results reveal two different scaling regimes for the Casimir force as a function of the distance between the objects, their deformation wavelength and -amplitude. The results confirm that the interaction is non-additive, especially in the presence of strong geometric deformations. Furthermore, the numerical approach is extended to calculate lateral Casimir forces. The results are consistent with the results of the proximity-force approximation for large deformation wavelengths. A qualitatively different behaviour between the normal and lateral force is revealed. We also establish a relation between the boundary induced change of the of the density of states for the scalar Helmholtz equation and the Casimir interaction using the path integral method. For statically deformed boundaries, this relation can be expressed as a novel trace formula, which is formally similar to the so-called Krein-Friedel-Lloyd formula. While the latter formula describes the

  13. Patient-Specific Dosimetry and Radiobiological Modeling of Targeted Radionuclide Therapy Grant - final report

    Energy Technology Data Exchange (ETDEWEB)

    George Sgouros, Ph.D.

    2007-03-20

    The broad, long-term objectives of this application are to 1. develop easily implementable tools for radionuclide dosimetry that can be used to predict normal organ toxicity and tumor response in targeted radionuclide therapy; and 2. to apply these tools to the analysis of clinical trial data in order to demonstrate dose-response relationships for radionuclide therapy treatment planning. The work is founded on the hypothesis that robust dose-response relationships have not been observed in targeted radionuclide therapy studies because currently available internal dosimetry methodologies are inadequate, failing to adequately account for individual variations in patient anatomy, radionuclide activity distribution/kinetics, absorbed dose-distribution, and absorbed dose-rate. To reduce development time the previously available software package, 3D-ID, one of the first dosimetry software packages to incorporate 3-D radionuclide distribution with individual patient anatomy; and the first to be applied for the comprehensive analysis of patient data, will be used as a platform to build the functionality listed above. The following specific aims are proposed to satisfy the long-term objectives stated above: 1. develop a comprehensive and validated methodology for converting one or more SPECT images of the radionuclide distribution to a 3-D representation of the cumulated activity distribution; 2. account for differences in tissue density and atomic number by incorporating an easily implementable Monte Carlo methodology for the 3-D dosimetry calculations; 3. incorporate the biologically equivalent dose (BED) and equivalent uniform dose (EUD) models to convert the spatial distribution of absorbed dose and dose-rate into equivalent single values that account for differences in dose uniformity and rate and that may be correlated with tumor response and normal organ toxicity; 4. test the hypothesis stated above by applying the resulting package to patient trials of targeted

  14. Development of a patient-specific two-compartment anthropomorphic breast phantom

    International Nuclear Information System (INIS)

    Prionas, Nicolas D; Burkett, George W; McKenney, Sarah E; Chen, Lin; Boone, John M; Stern, Robin L

    2012-01-01

    The purpose of this paper is to develop a technique for the construction of a two-compartment anthropomorphic breast phantom specific to an individual patient's pendant breast anatomy. Three-dimensional breast images were acquired on a prototype dedicated breast computed tomography (bCT) scanner as part of an ongoing IRB-approved clinical trial of bCT. The images from the breast of a patient were segmented into adipose and glandular tissue regions and divided into 1.59 mm thick breast sections to correspond to the thickness of polyethylene stock. A computer-controlled water-jet cutting machine was used to cut the outer breast edge and the internal regions corresponding to glandular tissue from the polyethylene. The stack of polyethylene breast segments was encased in a thermoplastic ‘skin’ and filled with water. Water-filled spaces modeled glandular tissue structures and the surrounding polyethylene modeled the adipose tissue compartment. Utility of the phantom was demonstrated by inserting 200 µm microcalcifications as well as by measuring point dose deposition during bCT scanning. Affine registration of the original patient images with bCT images of the phantom showed similar tissue distribution. Linear profiles through the registered images demonstrated a mean coefficient of determination (r 2 ) between grayscale profiles of 0.881. The exponent of the power law describing the anatomical noise power spectrum was identical in the coronal images of the patient's breast and the phantom. Microcalcifications were visualized in the phantom at bCT scanning. The real-time air kerma rate was measured during bCT scanning and fluctuated with breast anatomy. On average, point dose deposition was 7.1% greater than the mean glandular dose. A technique to generate a two-compartment anthropomorphic breast phantom from bCT images has been demonstrated. The phantom is the first, to our knowledge, to accurately model the uncompressed pendant breast and the glandular tissue

  15. [Specific features of Becker Muscular Dystrophy patients and female carriers of Duchenne Muscular Dystrophy].

    Science.gov (United States)

    Magot, A; Mercier, S; Péréon, Y

    2015-12-01

    Becker muscular dystrophy (BMD) was first described in 1955 and linked to the DMD gene in 1987. Compared to Duchenne muscular dystrophy (DMD), clinical onset of BMD usually occurs after the age of 12 and wheelchair is required after the age of 16. BMD is characterized by generalized weakness first affecting limb girdle muscles, hypertrophy of the calves and cardiomyopathy in males. Some patients have only mild symptoms such as cramps or elevated serum creatine kinases (SCK) throughout all their lives. SCK levels are usually elevated. Muscle biopsy (immunohistochemistry or immunoblotting) shows a dystrophic pattern with abnormal dystrophin staining. Diagnosis is confirmed by DMD gene sequencing. Deletions or duplications of one or several exons are identified in the majority of cases. A multidisciplinary approach is recommended for the care management of these patients with a particular attention to the cardiomyopathy, which is typically responsible for death but can be prevented by specific treatment. X-linked dilated cardiomyopathies linked to DMD gene are a phenotypic continuum of BMD. Some female carriers of DMD mutations exhibit clinical symptoms of variable severity, often milder and beginning later than in males. The cardiomyopathy is the most frequent feature that should be especially monitored in these patients. Genetic counselling should be systematically proposed. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  16. Effects of radiotherapy on non-specific immunological parameters in patients with malignant brain tumors

    International Nuclear Information System (INIS)

    Yamashita, Junkoh; Iwaki, Kazuo; Ohtsuka, Shin-ichi; Yamasaki, Toshiki; Gi, Hidefuku

    1983-01-01

    The non-specific immunological parameters of 37 patients with malignant brain tumors were analysed by means of 1) purified protein derivative (PPD) skin test, 2) lymphocyte counts, and 3) phytohemagglutinin (PHA) blastogenesis. The PPD skin reaction and PHA blastogenesis were already depressed preoperatively in patients with malignant brain tumors as compared to those in normal controls. When radiotherapy was confined to the head, lymphocyte counts and PHA blastogenesis were further depressed, but gradually recovered to preoperative levels within 6 months after the completion of radiotherapy. In the cases with medulloblastoma and germinoma who received whole cerebrospinal axis irradiation, lymphocyte counts and PHA blastogenesis were more markedly depressed and took more than 6 months after completion of the radiotherapy to recover to their preoperative levels. The result of the PPD skin test, on the other hand, was not affected and was rather enhanced by radiotherapy, showing a marked dissociation from the changes in lymphocyte counts and PHA blastogenesis. The results of PPD skin test on discharge from hospital were relatively well correlated with the prognosis of the patients. The profound immunosuppressive influence of radiotherapy and the natural course of recovery should be taken into consideration if any immunological treatments are to be undertaken with or after the course of radiotherapy. (author)

  17. Quantification of hepatic flow distribution using particle tracking for patient specific virtual Fontan surgery

    Science.gov (United States)

    Yang, Weiguang; Vignon-Clementel, Irene; Troianowski, Guillaume; Shadden, Shawn; Mohhan Reddy, V.; Feinstein, Jeffrey; Marsden, Alison

    2010-11-01

    The Fontan surgery is the third and final stage in a palliative series to treat children with single ventricle heart defects. In the extracardiac Fontan procedure, the inferior vena cava (IVC) is connected to the pulmonary arteries via a tube-shaped Gore-tex graft. Clinical observations have shown that the absence of a hepatic factor, carried in the IVC flow, can cause pulmonary arteriovenous malformations. Although it is clear that hepatic flow distribution is an important determinant of Fontan performance, few studies have quantified its relation to Fontan design. In this study, we virtually implanted three types of grafts (T-junction, offset and Y-graft) into 5 patient specific models of the Glenn (stage 2) anatomy. We then performed 3D time-dependent simulations and systematically compared the IVC flow distribution, energy loss, and pressure levels in different surgical designs. A robustness test is performed to evaluate the sensitivity of hepatic distribution to pulmonary flow split. Results show that the Y-graft design effectively improves the IVC flow distribution, compared to traditional designs and that surgical designs could be customized on a patient-by-patient basis.

  18. SPECIFIC COURSE OF PREGNANCY, PERINATAL OUTCOMES AND TREATMENT RESULTS IN HIV NEGATIVE FEMALE PATIENTS

    Directory of Open Access Journals (Sweden)

    A. V. Nesterenko

    2017-01-01

    Full Text Available The objective of the study is to investigate the specific course of pregnancy, perinatal outcomes and treatment results in HIV negative female patients.Subjects and Methods. Medical files of 109 pregnant tuberculosis patients were analyzed who were followed up in Krasnoyarsk Regional TB Dispensary no. 1 from 2010 to 2014.Results. The part of children prematurely born by mothers ill with tuberculosis was practically compatible with the overall national cohort of live-born children (6.8% in the analyzed group versus 5.7% in the national cohort for 2014. The part of children with congenital abnormalities born by mothers suffering from tuberculosis turned out to be twice lower versus the overall national cohort of live-born children (1.4% versus 3.0% in 2010 and 2.9% in 2014.The efficiency of the main treatment course in pregnant women without multiple drug resistant tuberculosis, of which 3.8 ± 0.3 months of tuberculosis treatment coincided with pregnancy was practically the same as treatment efficiency for the overall cohort of patients in Krasnoyarsky Kray (66.2% in the analyzed cohort versus 60.3-72.7% in the regional cohort for 2010-2014. In the pregnant with multiple drug resistant forms of tuberculosis, treatment efficiency was lower versus the regional cohort (30.4% in the analyzed cohort versus 41.1-60.2% in the regional cohort for 2010-2014. 

  19. Recent advancements in medical simulation: patient-specific virtual reality simulation.

    Science.gov (United States)

    Willaert, Willem I M; Aggarwal, Rajesh; Van Herzeele, Isabelle; Cheshire, Nicholas J; Vermassen, Frank E

    2012-07-01

    Patient-specific virtual reality simulation (PSVR) is a new technological advancement that allows practice of upcoming real operations and complements the established role of VR simulation as a generic training tool. This review describes current developments in PSVR and draws parallels with other high-stake industries, such as aviation, military, and sports. A review of the literature was performed using PubMed and Internet search engines to retrieve data relevant to PSVR in medicine. All reports pertaining to PSVR were included. Reports on simulators that did not incorporate a haptic interface device were excluded from the review. Fifteen reports described 12 simulators that enabled PSVR. Medical procedures in the field of laparoscopy, vascular surgery, orthopedics, neurosurgery, and plastic surgery were included. In all cases, source data was two-dimensional CT or MRI data. Face validity was most commonly reported. Only one (vascular) simulator had undergone face, content, and construct validity. Of the 12 simulators, 1 is commercialized and 11 are prototypes. Five simulators have been used in conjunction with real patient procedures. PSVR is a promising technological advance within medicine. The majority of simulators are still in the prototype phase. As further developments unfold, the validity of PSVR will have to be examined much like generic VR simulation for training purposes. Nonetheless, similar to the aviation, military, and sport industries, operative performance and patient safety may be enhanced by the application of this novel technology.

  20. Evaluation of Dosimetry Check software for IMRT patient-specific quality assurance.

    Science.gov (United States)

    Narayanasamy, Ganesh; Zalman, Travis; Ha, Chul S; Papanikolaou, Niko; Stathakis, Sotirios

    2015-05-08

    The purpose of this study is to evaluate the use of the Dosimetry Check system for patient-specific IMRT QA. Typical QA methods measure the dose in an array dosimeter surrounded by homogenous medium for which the treatment plan has been recomputed. With the Dosimetry Check system, fluence measurements acquired on a portal dosimeter is applied to the patient's CT scans. Instead of making dose comparisons in a plane, Dosimetry Check system produces isodose lines and dose-volume histograms based on the planning CT images. By exporting the dose distribution from the treatment planning system into the Dosimetry Check system, one is able to make a direct comparison between the calculated dose and the planned dose. The versatility of the software is evaluated with respect to the two IMRT techniques - step and shoot and volumetric arc therapy. The system analyzed measurements made using EPID, PTW seven29, and IBA MatriXX, and an intercomparison study was performed. Plans from patients previously treated at our institution with treated anatomical site on brain, head & neck, liver, lung, and prostate were analyzed using Dosimetry Check system for any anatomical site dependence. We have recommendations and possible precautions that may be necessary to ensure proper QA with the Dosimetry Check system.

  1. Initiation to global Finslerian geometry

    CERN Document Server

    Akbar-Zadeh, Hassan

    2006-01-01

    After a brief description of the evolution of thinking on Finslerian geometry starting from Riemann, Finsler, Berwald and Elie Cartan, the book gives a clear and precise treatment of this geometry. The first three chapters develop the basic notions and methods, introduced by the author, to reach the global problems in Finslerian Geometry. The next five chapters are independent of each other, and deal with among others the geometry of generalized Einstein manifolds, the classification of Finslerian manifolds of constant sectional curvatures. They also give a treatment of isometric, affine, p

  2. Bone Geometry, Volumetric Density, Microarchitecture, and Estimated Bone Strength Assessed by HR-pQCT in Adult Patients With Type 1 Diabetes Mellitus

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram V; Hansen, Stinus; Frost, Morten

    2015-01-01

    The primary goal of this cross-sectional in vivo study was to assess peripheral bone microarchitecture, bone strength, and bone remodeling in adult type 1 diabetes (T1D) patients with and without diabetic microvascular disease (MVD+ and MVD-, respectively) and to compare them with age-, gender......-, and height-matched healthy control subjects (CoMVD+ and CoMVD-, respectively). The secondary goal was to assess differences in MVD- and MVD+ patients. Fifty-five patients with T1DM (MVD+ group: n = 29) were recruited from the Funen Diabetes Database. Dual-energy X-ray absorptiometry (DXA), high...... in MVD+ and MVD- groups in comparison to controls, they were similar between the MVD+ and MVD- groups. The results of our study suggest that the presence of MVD was associated with deficits in cortical and trabecular bone vBMD and microarchitecture that could partly explain the excess skeletal fragility...

  3. Evaluation of left ventricular volumes in patients with congenital heart disease and abnormal left ventricular geometry. Comparison of MRI and transthoracic 3-dimensional echocardiography

    International Nuclear Information System (INIS)

    Gutberlet, M.; Grothoff, M.; Roettgen, R.; Lange, P.; Felix, R.; Abdul-Khaliq, H.; Schroeter, J.; Schmitt, B.; Vogel, M.

    2003-01-01

    Purpose: To assess the new method of 3-dimensional echocardiography in comparison to the 'gold standard' MRI as to its ability to calculate left ventricular volumes in patients with congenital heart disease. Materials and methods: Eighteen patients between the ages of 3.9 to 37.3 years (mean: 12.8±9.7) with a geometrically abnormal left ventricle were examined using a 1.5 T scanner with a fast gradient-echo sequence (TR=14 ms, TE=2.6-2.9 ms, FOV=300-400 mm, flip angle=20 , matrix=128:256, slice thickness=5 mm, retrospective gating) in multislice-multiphase technique. Transthoracic 3D-echocardiography was performed with a 3.5 MHz transducer and a Tomtec trademark (Munich, Germany) system for 3D reconstruction. Results: Volume calculation was possible in all patients with 3D-echocardiography, but the muscle mass calculation only succeeded in 11 to 18 patients (61%) due to inadequate visualization of the entire myocardium. Comparing MRI and 3D-echocardiography, the correlation was r=0.97 for the end-systolic volumes, r=0.98 for the end-diastolic volumes, r=0.79 for the end-systolic muscle mass and r=0.77 for the end-diastolic muscle mass. The agreement between both methods was considered good for the calculated end-diastolic volumes and sufficient for the calculated end-systolic volumes. The muscle mass calculations showed larger differences especially for the end-systolic mass. Mean intraobserver variability was 18.6% for end-systolic and 8.3% for end-diastolic volumes. Conclusion: In patients with an abnormal left ventricular configuration due to congenital heart disease, the new method of 3D-echocardiography is sufficient for volume calculations in preselected patients. The high intraobserver variability is still a limitation of transthoracic 3D-echocardiography in comparison to MRI. (orig.) [de

  4. Ostrich eggs geometry

    Directory of Open Access Journals (Sweden)

    Šárka Nedomová

    2013-01-01

    Full Text Available Precise quantification of the profile of egg can provide a powerful tool for the analysis of egg shape for various biological problems. A new approach to the geometry of a Ostrich’s egg profile is presented here using an analysing the egg’s digital photo by edge detection techniques. The obtained points on the eggshell counter are fitted by the Fourier series. The obtained equations describing an egg profile have been used to calculate radii of curvature. The radii of the curvature at the important point of the egg profile (sharp end, blunt end and maximum thickness are independent on the egg shape index. The exact values of the egg surface and the egg volume have been obtained. These quantities are also independent on the egg shape index. These quantities can be successively estimated on the basis of simplified equations which are expressed in terms of the egg length, L¸ and its width, B. The surface area of the eggshells also exhibits good correlation with the egg long circumference length. Some limitations of the most used procedures have been also shown.

  5. Nonperturbative quantum geometries

    International Nuclear Information System (INIS)

    Jacobson, T.; California Univ., Santa Barbara; Smolin, L.; California Univ., Santa Barbara

    1988-01-01

    Using the self-dual representation of quantum general relativity, based on Ashtekar's new phase space variables, we present an infinite dimensional family of quantum states of the gravitational field which are exactly annihilated by the hamiltonian constraint. These states are constructed from Wilson loops for Ashtekar's connection (which is the spatial part of the left handed spin connection). We propose a new regularization procedure which allows us to evaluate the action of the hamiltonian constraint on these states. Infinite linear combinations of these states which are formally annihilated by the diffeomorphism constraints as well are also described. These are explicit examples of physical states of the gravitational field - and for the compact case are exact zero eigenstates of the hamiltonian of quantum general relativity. Several different approaches to constructing diffeomorphism invariant states in the self dual representation are also described. The physical interpretation of the states described here is discussed. However, as we do not yet know the physical inner product, any interpretation is at this stage speculative. Nevertheless, this work suggests that quantum geometry at Planck scales might be much simpler when explored in terms of the parallel transport of left-handed spinors than when explored in terms of the three metric. (orig.)

  6. Matrix Information Geometry

    CERN Document Server

    Bhatia, Rajendra

    2013-01-01

    This book is an outcome of the Indo-French Workshop on Matrix Information Geometries (MIG): Applications in Sensor and Cognitive Systems Engineering, which was held in Ecole Polytechnique and Thales Research and Technology Center, Palaiseau, France, in February 23-25, 2011. The workshop was generously funded by the Indo-French Centre for the Promotion of Advanced Research (IFCPAR).  During the event, 22 renowned invited french or indian speakers gave lectures on their areas of expertise within the field of matrix analysis or processing. From these talks, a total of 17 original contribution or state-of-the-art chapters have been assembled in this volume. All articles were thoroughly peer-reviewed and improved, according to the suggestions of the international referees. The 17 contributions presented  are organized in three parts: (1) State-of-the-art surveys & original matrix theory work, (2) Advanced matrix theory for radar processing, and (3) Matrix-based signal processing applications.  

  7. Patient-specific parameter estimation in single-ventricle lumped circulation models under uncertainty

    Science.gov (United States)

    Schiavazzi, Daniele E.; Baretta, Alessia; Pennati, Giancarlo; Hsia, Tain-Yen; Marsden, Alison L.

    2017-01-01

    Summary Computational models of cardiovascular physiology can inform clinical decision-making, providing a physically consistent framework to assess vascular pressures and flow distributions, and aiding in treatment planning. In particular, lumped parameter network (LPN) models that make an analogy to electrical circuits offer a fast and surprisingly realistic method to reproduce the circulatory physiology. The complexity of LPN models can vary significantly to account, for example, for cardiac and valve function, respiration, autoregulation, and time-dependent hemodynamics. More complex models provide insight into detailed physiological mechanisms, but their utility is maximized if one can quickly identify patient specific parameters. The clinical utility of LPN models with many parameters will be greatly enhanced by automated parameter identification, particularly if parameter tuning can match non-invasively obtained clinical data. We present a framework for automated tuning of 0D lumped model parameters to match clinical data. We demonstrate the utility of this framework through application to single ventricle pediatric patients with Norwood physiology. Through a combination of local identifiability, Bayesian estimation and maximum a posteriori simplex optimization, we show the ability to automatically determine physiologically consistent point estimates of the parameters and to quantify uncertainty induced by errors and assumptions in the collected clinical data. We show that multi-level estimation, that is, updating the parameter prior information through sub-model analysis, can lead to a significant reduction in the parameter marginal posterior variance. We first consider virtual patient conditions, with clinical targets generated through model solutions, and second application to a cohort of four single-ventricle patients with Norwood physiology. PMID:27155892

  8. Quality of Life of Head and Neck Cancer Patients Receiving Cancer Specific Treatments

    Directory of Open Access Journals (Sweden)

    James Gonsalves

    2013-01-01

    Full Text Available Background: Head and neck cancer (HNC remains a considerable challenge to both patient and health care provider as the disease can have profound effect on Quality of life (QOL. Aims and Objectives: To assess the QOL and performance status of HNC patients, to find relation between domains of QOL and to find association between QOL and demographic and disease variables. Settings and Design: The study was conducted at Manipal group of hospitals, Manipal and Mangalore, using descriptive survey design. Material and Methods: The study comprised of 89 samples with all stages of HNC. Patients primarily diagnosed with HNC and undergoing disease specific treatment were included in the study. Tool on demographic, disease variables and quality of life were developed and content validity was established. Reliability of the tool was established. Karnofsky Performance Status (KPS scale was used to assess performance status. Corelational analysis was done to find relation between the domains of QOL. Association was found between the quality of life and demographic and disease variables. Results: Majority (83% of the participants were males, 39% had cancer arising from oral cavity, and 35% each were in cancer stage III and IV. Quality of life was poor among 30% of the subjects and 65% had KPS scores<80 %. There was moderate positive relation between the domains of QOL and a positive correlation between the QOL and performance status. No statistically significant association was found between QOL and disease and demographic variables. Conclusion: Physical, psychological, social and spiritual domains of QOL and functional status are affected in patients with HNC. The impact on one domain area of well being, significantly affects the other domain of QOL and there is relationship between the performance status and QOL

  9. Improvement in Neuropathy Specific Quality of Life in Patients with Diabetes after Vitamin D Supplementation

    Directory of Open Access Journals (Sweden)

    Uazman Alam

    2017-01-01

    Full Text Available Objective. To assess the effect of vitamin D supplementation on neuropathy specific quality of life (NeuroQoL in patients with painful diabetic neuropathy. Methods. This prospective, open label study was conducted between June 2012 and April 2013. Patients with symptomatic diabetic neuropathy were given a single dose of 600,000 IU intramuscular vitamin D, and NeuroQol was assessed at baseline and at five follow-up visits every 4 weeks. Results. Of 143 participants, 41.3% were vitamin D deficient (vitamin D < 20 ng/ml. Treatment with vitamin D resulted in a significant increase in 25(OHD (P<0.0001 and a significant improvement in the NeuroQoL subscale score for emotional distress (P=0.04, with no significant change in the other NeuroQoL domains of painful symptoms and paresthesia, loss of temperature and touch sensation, unsteadiness, limitation in daily activities, and interpersonal problems. There was a significant reduction in patient perception about foot problems on QoL of “quite a lot” (P<0.05 and “very much” (P<0.0001 with a significant reduction in the baseline response of having a “poor” QoL from 5.2% to 0.7% (P<0.0001 and an increase in the response of an “excellent QoL” from 1.5% to 7.4% (P<0.0001. Conclusion. Vitamin D is effective in improving quality of life in patients with painful diabetic neuropathy.

  10. Toward optimizing patient-specific IMRT QA techniques in the accurate detection of dosimetrically acceptable and unacceptable patient plans.

    Science.gov (United States)

    McKenzie, Elizabeth M; Balter, Peter A; Stingo, Francesco C; Jones, Jimmy; Followill, David S; Kry, Stephen F

    2014-12-01

    The authors investigated the performance of several patient-specific intensity-modulated radiation therapy (IMRT) quality assurance (QA) dosimeters in terms of their ability to correctly identify dosimetrically acceptable and unacceptable IMRT patient plans, as determined by an in-house-designed multiple ion chamber phantom used as the gold standard. A further goal was to examine optimal threshold criteria that were consistent and based on the same criteria among the various dosimeters. The authors used receiver operating characteristic (ROC) curves to determine the sensitivity and specificity of (1) a 2D diode array undergoing anterior irradiation with field-by-field evaluation, (2) a 2D diode array undergoing anterior irradiation with composite evaluation, (3) a 2D diode array using planned irradiation angles with composite evaluation, (4) a helical diode array, (5) radiographic film, and (6) an ion chamber. This was done with a variety of evaluation criteria for a set of 15 dosimetrically unacceptable and 9 acceptable clinical IMRT patient plans, where acceptability was defined on the basis of multiple ion chamber measurements using independent ion chambers and a phantom. The area under the curve (AUC) on the ROC curves was used to compare dosimeter performance across all thresholds. Optimal threshold values were obtained from the ROC curves while incorporating considerations for cost and prevalence of unacceptable plans. Using common clinical acceptance thresholds, most devices performed very poorly in terms of identifying unacceptable plans. Grouping the detector performance based on AUC showed two significantly different groups. The ion chamber, radiographic film, helical diode array, and anterior-delivered composite 2D diode array were in the better-performing group, whereas the anterior-delivered field-by-field and planned gantry angle delivery using the 2D diode array performed less well. Additionally, based on the AUCs, there was no significant difference

  11. Nonorgan-specific autoantibodies in HIV-infected patients in the HAART era.

    Science.gov (United States)

    Iordache, Laura; Bengoufa, Djaouida; Taulera, Olivier; Rami, Agathe; Lascoux-Combe, Caroline; Day, Nesrine; Parrinello, Maguy; Sellier, Pierre-Olivier; Molina, Jean-Michel; Mahr, Alfred

    2017-03-01

    Nonorgan-specific autoantibodies (AAbs) are used for diagnosing autoimmune diseases but can also be detected in other conditions. We carried out a cross-sectional study with the aim to screen HIV1-infected patients in the era of highly active antiretroviral therapy (HAART) for AAbs and to analyze the association of their presence with hypergammaglobulinemia and immunovirological status.Blood samples from HIV1-infected patients without major concomitant illnesses followed in 2 hospitals in Paris, France were tested for immunovirological status, serum immunoglobulin G (IgG) level, antinuclear antibodies (ANAs), anti-double-stranded DNA (anti-dsDNA), anti-extractable nuclear antigens (anti-ENAs), anticardiolipin (aCL), anti-β2glycoprotein1 (anti-β2GP1), and antineutrophil cytoplasmic antibodies (ANCAs). Clinically relevant AAbs were defined as ANAs with titers ≥1:160, anti-dsDNA or anti-ENA antibodies; aCL or anti-β2GP1 antibodies with a level ≥40 U/ml; and ANCAs reacting with proteinase 3 or myeloperoxidase.We included 92 patients (mean age 47 years, men 55%, sub-Saharan African background 55%, HAART 85%, mean CD4 lymphocyte count 611/mm, viral load < 40 copies/mL 74%). At least 1 AAb was detected in 45% of patients, mostly ANAs (33%) and ANCAs (13%); 12% had ≥1 clinically relevant AAb. Above-normal IgG levels were found in 71% of patients. We found an inverse association between the presence of ≥1 AAb and CD4 lymphocyte count (P = 0.03) and between above-normal IgG levels and duration of virological control (P = 0.02) and non-sub-Saharan African background (P = 0.001).In sum, in HIV1-infected patients without any major concomitant illness in the HAART era, the prevalence of AAbs remains high but AAb patterns leading to high suspicion of autoimmune diseases are rather uncommon. AAb presence is associated with reduced CD4 lymphocyte count but not hypergammaglobulinemia.

  12. Clinical and Phenomenological Characteristics of Patients with Task-Specific Lingual Dystonia: Possible Association with Occupation

    Directory of Open Access Journals (Sweden)

    Kazuya Yoshida

    2017-12-01

    Full Text Available BackgroundLingual dystonia is a subtype of oromandibular dystonia, which is a movement disorder characterized by involuntary sustained or intermittent contraction of the masticatory and/or tongue muscles. Lingual dystonia interferes with important daily activities, such as speaking, chewing, and swallowing, resulting in vocational and social disability.ObjectiveThe aim of this study was to investigate a possible relationship between occupation and the development of lingual dystonia.MethodsPhenomenological and clinical characteristics of 95 patients [53 females (55.8% and 42 males (44.2%, mean age 48.0 years] with task-specific, speech-induced lingual dystonia were analyzed. Structured interviews were carried out to obtain information regarding primary occupation, including overtime work and stress during work. The factors that might have influenced the development of lingual dystonia were estimated using multivariate logistic regression analysis of the 95 patients with lingual dystonia and 95 controls [68 females (71.6% and 27 males (28.4%, mean age 47.2 years] with temporomandibular disorders.ResultsOverall, 84.2% of the patients had regular occupations; 73.8% of the patients with regular occupations reported working overtime more than twice a week, and 63.8% of them experienced stress at the workplace. Furthermore, 82.1% of the patients had engaged in occupations that required them to talk to customers or other people under stressful situations over prolonged periods of time for many years (mean: 15.6 years. The most common occupation was sales representative (17.9%, followed by telephone operator (13.7%, customer service representative (10.5%, health care worker (9.5%, waiter or waitress (5.3%, receptionist (5.3%, and cashier (5.3%. Twenty-nine patients (30.5% had tardive lingual dystonia. Logistic regression analyses revealed that frequent requirements for professional speaking (p = 0.011, odds ratio: 5.66, high stress during work

  13. Effects of Intraluminal Thrombus on Patient-Specific Abdominal Aortic Aneurysm Hemodynamics via Stereoscopic Particle Image Velocity and Computational Fluid Dynamics Modeling

    Science.gov (United States)

    Chen, Chia-Yuan; Antón, Raúl; Hung, Ming-yang; Menon, Prahlad; Finol, Ender A.; Pekkan, Kerem

    2014-01-01

    The pathology of the human abdominal aortic aneurysm (AAA) and its relationship to the later complication of intraluminal thrombus (ILT) formation remains unclear. The hemodynamics in the diseased abdominal aorta are hypothesized to be a key contributor to the formation and growth of ILT. The objective of this investigation is to establish a reliable 3D flow visualization method with corresponding validation tests with high confidence in order to provide insight into the basic hemodynamic features for a better understanding of hemodynamics in AAA pathology and seek potential treatment for AAA diseases. A stereoscopic particle image velocity (PIV) experiment was conducted using transparent patient-specific experimental AAA models (with and without ILT) at three axial planes. Results show that before ILT formation, a 3D vortex was generated in the AAA phantom. This geometry-related vortex was not observed after the formation of ILT, indicating its possible role in the subsequent appearance of ILT in this patient. It may indicate that a longer residence time of recirculated blood flow in the aortic lumen due to this vortex caused sufficient shear-induced platelet activation to develop ILT and maintain uniform flow conditions. Additionally, two computational fluid dynamics (CFD) modeling codes (Fluent and an in-house cardiovascular CFD code) were compared with the two-dimensional, three-component velocity stereoscopic PIV data. Results showed that correlation coefficients of the out-of-plane velocity data between PIV and both CFD methods are greater than 0.85, demonstrating good quantitative agreement. The stereoscopic PIV study can be utilized as test case templates for ongoing efforts in cardiovascular CFD solver development. Likewise, it is envisaged that the patient-specific data may provide a benchmark for further studying hemodynamics of actual AAA, ILT, and their convolution effects under physiological conditions for clinical applications. PMID:24316984

  14. Dose-Specific Adverse Drug Reaction Identification in Electronic Patient Records: Temporal Data Mining in an Inpatient Psychiatric Population

    DEFF Research Database (Denmark)

    Eriksson, Robert; Werge, Thomas; Jensen, Lars Juhl

    2014-01-01

    patient-specific adverse events (AEs) and links these to specific drugs and dosages in a temporal manner, based on integration of text mining results and structured data. The structured data contained precise information on drug identity, dosage and strength.When applying the method to the 3,394 patients...... all indication areas.The aim of this study was to take advantage of techniques for temporal data mining of EPRs in order to detect ADRs in a patient- and dose-specific manner.We used a psychiatric hospital’s EPR system to investigate undesired drug effects. Within one workflow the method identified...

  15. SU-F-207-09: Evaluating the Dosimetric Accuracy of Extended Field-Of-View CT Reconstructions Using Clinical Data with Real Patient Geometries

    Energy Technology Data Exchange (ETDEWEB)

    Shugard, E; Cheung, J; Pouliot, J; Chen, J [University of California San Francisco, San Francisco (United States); Mistry, N [Siemens Healthcare USA, Malvern, PA (United States)

    2015-06-15

    Purpose: To determine the accuracy of dose calculations performed with CT images reconstructed using extended field of view (FOV) algorithms. Methods: In this study we selected 6 radiotherapy patients (3 head and neck & 3 chest/pelvis) whose body circumferences extended past the 50 cm scan FOV in the treatment planning CT. Images acquired on a Siemens Sensation Open scanner, were reconstructed using the standard FOV (sFOV) and two different extended FOV algorithms, eFOV and HDFOV. A physician and dosimetrist identified the radiation target, critical organs, and external patient contour. A benchmark CT was created for each patient, consisting of an average of the 3 CT reconstructions with a density override applied to regions containing truncation artifacts, and was used to create an optimal radiation treatment plan. The plan was copied onto each reconstruction without density override and dose was recalculated. Results: Th